Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the structure.Therefore,it is particularly significant to identify the structural modal parameters accordi...Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the structure.Therefore,it is particularly significant to identify the structural modal parameters according to the monitoring data information in the structural health monitoring(SHM)system,so as to provide a scientific basis for structural damage identification and dynamic model modification.In view of this,this paper reviews methods for identifying structural modal parameters under environmental excitation and briefly describes how to identify structural damages based on the derived modal parameters.The paper primarily introduces data-driven modal parameter recognition methods(e.g.,time-domain,frequency-domain,and time-frequency-domain methods,etc.),briefly describes damage identification methods based on the variations of modal parameters(e.g.,natural frequency,modal shapes,and curvature modal shapes,etc.)and modal validation methods(e.g.,Stability Diagram and Modal Assurance Criterion,etc.).The current status of the application of artificial intelligence(AI)methods in the direction of modal parameter recognition and damage identification is further discussed.Based on the pre-vious analysis,the main development trends of structural modal parameter recognition and damage identification methods are given to provide scientific references for the optimized design and functional upgrading of SHM systems.展开更多
BACKGROUND Malignant obstructive jaundice(MOJ)is characterized by the presence of malignant tumors infiltrating or compressing the bile duct,causing poor bile drainage,generalized yellowing,pain,itching,and malaise.MO...BACKGROUND Malignant obstructive jaundice(MOJ)is characterized by the presence of malignant tumors infiltrating or compressing the bile duct,causing poor bile drainage,generalized yellowing,pain,itching,and malaise.MOJ is burdensome for both the society and the families of affected patients and should be taken seriously.AIM To evaluate the clinical effect of stent placement during endoscopic retrograde cholangiopancreatography for relieving MOJ and the efficacy of percutaneous transhepatic biliary drainage in terms of liver function improvement,complication rates,and long-term patient outcomes.METHODS The clinical data of 59 patients with MOJ who were admitted to our hospital between March 2018 and August 2019 were retrospectively analyzed.According to the treatment method,the patients were divided into an observation group(29 patients)and a control group(30 patients).General data,liver function indices,complications,adverse effects,and 3-year survival rates after different surgical treatments were recorded for the two groups.RESULTS There were no significant differences in baseline information(sex,age,tumor type,or tumor diameter)between the two groups(P>0.05).Alanine aminotransferase,aspartate aminotransferase,and total bilirubin levels were significantly better in both groups after surgery than before surgery(P<0.05).The overall incidence of biliary bleeding,gastrointestinal bleeding,pancreatitis,and cholangitis was 6.9%in the observation group and 30%in the control group(P<0.05).No significant differences in the rates of blood transfusion,intensive care unit admission,or death within 3 years were observed between the two groups at the 1-month follow-up(P>0.05).The 3-year survival rates were 46.06%and 39.71%in the observation and control groups,respectively.CONCLUSION Endoscopic biliary stenting effectively relieves MOJ and significantly improves liver function,with minimal complications.This technique is a promising palliative approach for patients ineligible for radical surgery.However,further research is needed to optimize current treatment strategies and to explore their potential in treating nonmalignant cases of obstructive jaundice.展开更多
BACKGROUND Postpancreatectomy hemorrhage is one of the most severe and life-threatening complications after pancreaticoduodenectomy.We present four cases of gastrointestinal bleeding patients to clarify its appropriat...BACKGROUND Postpancreatectomy hemorrhage is one of the most severe and life-threatening complications after pancreaticoduodenectomy.We present four cases of gastrointestinal bleeding patients to clarify its appropriate treatment and prevention.CASE SUMMARY The main symptoms included black stool,hematochezia,haematemesis,blood in the nasogastric tube,and hemorrhagic shock.The mean age was 66.25 years old and the median onset time was 340 d after the surgery.The bleeding location comprised gastrointestinal anastomosis,bile duct-jejunum anastomosis,and extraluminal bleeding.The possible causes included marginal ulcer,jejunal varix,and abdominal infection.Endoscopic hemostatic clips,as well as a covered stent using angiography,were utilized to stop the bleeding and three patients survived.Only one patient died of gastrointestinal bleeding,abdominal bleeding,abdominal infection,hypovolemic shock,and disseminated intravascular coagulation.CONCLUSION Early and effective endoscopic intervention is the key to successful hemostasis in patients with gastrointestinal bleeding after pancreatoduodenectomy.展开更多
We report a novel double-shelled nanoboxes photocatalyst architecture with tailored interfaces that accelerate quantum efficiency for photocatalytic CO_(2) reduction reaction(CO_(2)RR)via Mo–S bridging bonds sites in...We report a novel double-shelled nanoboxes photocatalyst architecture with tailored interfaces that accelerate quantum efficiency for photocatalytic CO_(2) reduction reaction(CO_(2)RR)via Mo–S bridging bonds sites in S_(v)–In_(2)S_(3)@2H–MoTe_(2).The X-ray absorption near-edge structure shows that the formation of S_(v)–In_(2)S_(3)@2H–MoTe_(2) adjusts the coordination environment via interface engineering and forms Mo–S polarized sites at the interface.The interfacial dynamics and catalytic behavior are clearly revealed by ultrafast femtosecond transient absorption,time-resolved,and in situ diffuse reflectance–Infrared Fourier transform spectroscopy.A tunable electronic structure through steric interaction of Mo–S bridging bonds induces a 1.7-fold enhancement in S_(v)–In_(2)S_(3)@2H–MoTe_(2)(5)photogenerated carrier concentration relative to pristine S_(v)–In_(2)S_(3).Benefiting from lower carrier transport activation energy,an internal quantum efficiency of 94.01%at 380 nm was used for photocatalytic CO_(2)RR.This study proposes a new strategy to design photocatalyst through bridging sites to adjust the selectivity of photocatalytic CO_(2)RR.展开更多
Dear Editor,Three dimensional(3D)bioprinted extracellular matrix(ECM)can be used to provide both biochemical and biophysical cues to direct mesenchymal stem cells(MSCs)differentiation,and then differentiated cells wer...Dear Editor,Three dimensional(3D)bioprinted extracellular matrix(ECM)can be used to provide both biochemical and biophysical cues to direct mesenchymal stem cells(MSCs)differentiation,and then differentiated cells were isolated for implantation in vivo using surgical procedures.However,the reduced cell activity after cell isolation from 3D constructs and low cell retention in injured sites limit its application[1].Methacrylated gelatin(GelMA)hydrogel has the advantage of fast crosslinking,which could resemble complex architectures of tissue construct in vivo[2].Here,we adopted a noninvasive bioprinting procedure to imitate the regenerative microenvironment that could simultaneously direct the sweat gland(SG)and vascular differentiation from MSCs and ultimately promote the replacement of glandular tissue in situ(Fig.1a).展开更多
To study the dynamic mechanical properties and failure characteristics of intersecting jointed rock masses with different joint distributions under confining pressure,considering the cross angleαand joint persistence...To study the dynamic mechanical properties and failure characteristics of intersecting jointed rock masses with different joint distributions under confining pressure,considering the cross angleαand joint persistence ratioη,a numerical model of the biaxial Hopkinson bar test system was established using the finite element method–discrete-element model coupling method.The validity of the model was verified by comparing and analyzing it in conjunction with laboratory test results.Dynamics-static combined impact tests were conducted on specimens under various conditions to investigate the strength characteristics and patterns of crack initiation and expansion.The study revealed the predominant factors influencing intersecting joints with different angles and penetrations under impact loading.The results show that the peak stress of the specimens decreases first and then increases with the increase of the cross angle.Whenα<60°,regardless of the value ofη,the dynamic stress of the specimens is controlled by the main joint.Whenα≥60°,the peak stress borne by the specimens decreases with increasingη.Whenα<60°,the initiation and propagation of cracks in the cross-jointed specimens are mainly controlled by the main joint,and the final failure surface of the specimens is composed of the main joint and wing cracks.Whenα≥60°orη≥0.67,the secondary joint guides the expansion of the wing cracks,and multiple failure surfaces composed of main and secondary joints,wing cracks,and co-planar cracks are formed.Increasing lateral confinement significantly increases the dynamic peak stress able to be borne by the specimens.Under triaxial conditions,the degree of failure of the intersecting jointed specimens is much lower than that under uniaxial and biaxial conditions.展开更多
The demand for highly porous yet transparent aerogels with mechanical flexibility and solar-thermal dual-regulation for energy-saving windows is significant but challenging.Herein,a delaminated aerogel film(DAF)is fab...The demand for highly porous yet transparent aerogels with mechanical flexibility and solar-thermal dual-regulation for energy-saving windows is significant but challenging.Herein,a delaminated aerogel film(DAF)is fabricated through filtration-induced delaminated gelation and ambient drying.The delaminated gelation process involves the assembly of fluorinated cellulose nanofiber(FCNF)at the solid-liquid interface between the filter and the filtrate during filtration,resulting in the formation of lamellar FCNF hydrogels with strong intra-plane and weak interlayer hydrogen bonding.By exchanging the solvents from water to hexane,the hydrogen bonding in the FCNF hydrogel is further enhanced,enabling the formation of the DAF with intra-layer mesopores upon ambient drying.The resulting aerogel film is lightweight and ultra-flexible,which pos-sesses desirable properties of high visible-light transmittance(91.0%),low thermal conductivity(33 mW m^(-1) K^(-1)),and high atmospheric-window emissivity(90.1%).Furthermore,the DAF exhibits reduced surface energy and exceptional hydrophobicity due to the presence of fluorine-containing groups,enhancing its durability and UV resistance.Consequently,the DAF has demonstrated its potential as solar-thermal regulatory cooling window materials capable of simultaneously providing indoor lighting,thermal insulation,and daytime radiative cooling under direct sunlight.Significantly,the enclosed space protected by the DAF exhibits a temperature reduction of 2.6℃ compared to that shielded by conventional architectural glass.展开更多
Aqueous organic redox flow batteries(AORFBs),which exploit the reversible electrochemical reactions of water-soluble organic electrolytes to store electricity,have emerged as an efficient electrochemical energy storag...Aqueous organic redox flow batteries(AORFBs),which exploit the reversible electrochemical reactions of water-soluble organic electrolytes to store electricity,have emerged as an efficient electrochemical energy storage technology for the grid-scale integration of renewable electricity.pH-neutral AORFBs that feature high safety,low corrosivity,and environmental benignity are particularly promising,and their battery performance is significantly impacted by redox-active molecules and ion-exchange membranes(IEMs).Here,representative anolytes and catholytes engineered for use in pH-neutral AORFBs are outlined and summarized,as well as their side reactions that cause irreversible battery capacity fading.In addition,the recent achievements of IEMs for pH-neutral AORFBs are discussed,with a focus on the construction and tuning of ion transport channels.Finally,the critical challenges and potential research opportunities for developing practically relevant pH-neutral AORFBs are presented.展开更多
Corrosion-resistant and biocompatible films were fabricated on AZ91D Mg alloy substrates by varying their roughness levels using met-allographic preparation and subsequent hydrothermal procedures.The coated films comp...Corrosion-resistant and biocompatible films were fabricated on AZ91D Mg alloy substrates by varying their roughness levels using met-allographic preparation and subsequent hydrothermal procedures.The coated films comprised a mixed structure of Mg(OH)_(2)and Mg-Al layered double hydroxides(LDH)and exhibited excellent compactness.Coating film thickness increased with decreasing surface roughness.Corrosion resistance was evaluated using potentiodynamic polarization and electrochemical impedance spectroscopy.Metallographic pretreat-ment influenced the chemical activity of the Mg alloy surface and helped modulate the dissolution rate of the Mg_(17)Al_(12)phase during the hydrothermal procedure.With decreasing roughness of the Mg substrate,the Al^(3+)concentration gradually increased,accelerating the in-situ formation of the Mg(OH)_(2)/LDH composite coating and improving its crystallinity.A thick and dense Mg(OH)_(2)/LDH coating was synthesized on the Mg substrate with the least roughness,substantially improving the corrosion resistance of the AZ91D alloy.The lowest corrosion current density((5.73±2.75)×10^(−8)A·cm^(−2))was achieved,which was approximately three orders of magnitude less than that of bare AZ91D.Moreover,the coating demonstrated biocompatibility with no evident cytotoxicity,cellular damage,and hemolytic phenomena.This study provides an effective method for preparing coatings on Mg alloy surfaces with excellent corrosion resistance and biocompatibility.展开更多
Verticillium dahliae is an important fungal pathogen affecting cotton yield and quality.Therefore,the mining of V.dahlia-resistance genes is urgently needed.Proteases and protease inhibitors play crucial roles in plan...Verticillium dahliae is an important fungal pathogen affecting cotton yield and quality.Therefore,the mining of V.dahlia-resistance genes is urgently needed.Proteases and protease inhibitors play crucial roles in plant defense responses.However,the functions and regulatory mechanisms of the protease inhibitor PR6 gene family remain largely unknown.This study provides a comprehensive analysis of the PR6 gene family in the cotton genome.We performed genome-wide identification and functional characterization of the cotton GhPR6 gene family,which belongs to the potato protease inhibitor I family of inhibitors.Thirty-nine PR6s were identified in Gossypium arboreum,G.raimondii,G.barbadense,and G.hirsutum,and they were clustered into four groups.Based on the analysis of pathogen-induced and Ghlmm transcriptome data,Gh PR6-5b was identified as the key gene for V.dahliae resistance.Virus-induced gene silencing experiments revealed that cotton was more sensitive to V.dahliae V991after PR6-5b silencing.The present study established that GhWRKY75 plays an important role in resistance to Verticillium wilt in cotton by positively regulating GhPR6-5b expression by directly binding to the W-box TTGAC(T/C).Our findings established that GhWRKY75 is a potential candidate for improving cotton resistance to V.dahliae,and provide primary information for further investigations and the development of specific strategies to bolster the defense mechanisms of cotton against V.dahliae.展开更多
The reliable prediction of state of charge(SOC)is one of the vital functions of advanced battery management system(BMS),which has great significance towards safe operation of electric vehicles.By far,the empirical mod...The reliable prediction of state of charge(SOC)is one of the vital functions of advanced battery management system(BMS),which has great significance towards safe operation of electric vehicles.By far,the empirical model-based and data-driven-based SOC estimation methods of lithium-ion batteries have been comprehensively discussed and reviewed in various literatures.However,few reviews involving SOC estimation focused on electrochemical mechanism,which gives physical explanations to SOC and becomes most attractive candidate for advanced BMS.For this reason,this paper comprehensively surveys on physics-based SOC algorithms applied in advanced BMS.First,the research progresses of physical SOC estimation methods for lithium-ion batteries are thoroughly discussed and corresponding evaluation criteria are carefully elaborated.Second,future perspectives of the current researches on physics-based battery SOC estimation are presented.The insights stated in this paper are expected to catalyze the development and application of the physics-based advanced BMS algorithms.展开更多
Underground liquified natural gas(LNG)storage is essential in guaranteeing national energy strategic reserves,and its construction is being accelerated.The stability of surrounding rock of underground LNG storage cave...Underground liquified natural gas(LNG)storage is essential in guaranteeing national energy strategic reserves,and its construction is being accelerated.The stability of surrounding rock of underground LNG storage caverns under stress-low temperature coupling effect is the key factor determining the feasibility of LNG storage.First,a mathematical model used for controlling the stress-low temperature coupling and the processes of rock damage evolution is given,followed by a 2-D numerical execution process of the mathematical model mentioned above described based on Comsol Multiphysics and Matlab code.Finally,a series of 2-D simulations are performed to study the influence of LNG storage cavern layout,burial depth,temperature and internal pressure on the stability of surrounding rocks of these underground storage caverns.The results indicate that all the factors mentioned above affect the evolution of deformation and plastic zone of surrounding rocks.The research results contribute to the engineering design of underground LNG storage caverns.展开更多
During the operational process of natural gas gathering and transmission pipelines,the formation of hydrates is highly probable,leading to uncontrolled movement and aggregation of hydrates.The continuous migration and...During the operational process of natural gas gathering and transmission pipelines,the formation of hydrates is highly probable,leading to uncontrolled movement and aggregation of hydrates.The continuous migration and accumulation of hydrates further contribute to the obstruction of natural gas pipelines,resulting in production reduction,shutdowns,and pressure build-ups.Consequently,a cascade of risks is prone to occur.To address this issue,this study focuses on the operational process of natural gas gathering and transmission pipelines,where a comprehensive framework is established.This framework includes theoretical models for pipeline temperature distribution,pipeline pressure distribution,multiphase flow within the pipeline,hydrate blockage,and numerical solution methods.By analyzing the influence of inlet temperature,inlet pressure,and terminal pressure on hydrate formation within the pipeline,the sensitivity patterns of hydrate blockage risks are derived.The research indicates that reducing inlet pressure and terminal pressure could lead to a decreased maximum hydrate formation rate,potentially mitigating pipeline blockage during natural gas transportation.Furthermore,an increase in inlet temperature and terminal pressure,and a decrease in inlet pressure,results in a displacement of the most probable location for hydrate blockage towards the terminal station.However,it is crucial to note that operating under low-pressure conditions significantly elevates energy consumption within the gathering system,contradicting the operational goal of energy efficiency and reduction of energy consumption.Consequently,for high-pressure gathering pipelines,measures such as raising the inlet temperature or employing inhibitors,electrical heat tracing,and thermal insulation should be adopted to prevent hydrate formation during natural gas transportation.Moreover,considering abnormal conditions such as gas well production and pipeline network shutdowns,which could potentially trigger hydrate formation,the installation of methanol injection connectors remains necessary to ensure production safety.展开更多
It is difficult to effectively improve the low bonding strength of TA1/304 clad plates.This study proposes a new process for applying pulse current(1500 A,500 Hz,50%duty cycle)to TA1/304 clad plates during the rolling...It is difficult to effectively improve the low bonding strength of TA1/304 clad plates.This study proposes a new process for applying pulse current(1500 A,500 Hz,50%duty cycle)to TA1/304 clad plates during the rolling process,which changes the interface microstructure and effectively improves the bonding strength of the clad plates.The influence of the pulsed current on the interface microstructure and bonding strength was systematically studied.The results indicate that the clad plate is initially bonded at 750℃ and 35%reduction ratio under electrically-assisted rolling(EAR),and finally the higher bonding strength is obtained at 850℃ and 48%reduction ratio,reaching 395 MPa.The strengthening of the interface element diffusion and grain refinement under the action of the pulsed current are important reasons for the improvement in the bonding strength of the clad plate.This discovery provides new ideas for the preparation of clad plates with high bonding performance.展开更多
Cam-lobe radial-piston hydraulic motors are widely used as rotation driving units for various marine machinery owing to their ultrahigh output torque(more than 100 kN m).A multi-row cam roller bearing(MCRB)is the key ...Cam-lobe radial-piston hydraulic motors are widely used as rotation driving units for various marine machinery owing to their ultrahigh output torque(more than 100 kN m).A multi-row cam roller bearing(MCRB)is the key component that directly determines the fatigue life of a cam-lobe radial-piston hydraulic motor.However,compact geometry and complex loads render MCRB susceptible to fatigue failure,highlighting the need for an optimized MCRB to achieve longer fatigue life and higher reliability.Therefore,this study proposes an innovative geometry optimization method for an MCRB to improve its fatigue life.In this method,a quasi-static model was developed to calculate the load distribution,with the fatigue life of the MCRB calculated using both basic dynamic loading and load distribution.Subsequently,a genetic algorithm was used to obtain the optimized geometry parameters,which significantly improved the fatigue life of the MCRB.Finally,a loading test was conducted on a hydraulic motor installed with both the initial and optimized MCRB to validate the effectiveness of the proposed optimization method.This study provides a theoretical guideline for optimizing the design of MCRB,thereby increasing the fatigue life of hydraulic motors.展开更多
Dear Editor,Timely and effective hemostasis is of great significance for reducing body damage and mortality of patients [1]. Alginate is generally considered to be an excellent hemostatic polymer-based biomaterial and...Dear Editor,Timely and effective hemostasis is of great significance for reducing body damage and mortality of patients [1]. Alginate is generally considered to be an excellent hemostatic polymer-based biomaterial and has been approved by the Food and Drug Administration as Generally Recognized as Safe [2]. However, the violent crosslinking reaction and unstable structure at the wound site limit its clinical applications. Hence, we report a biocompatible and injectable composite hydrogel methacrylate alginate (Alg-AEMA)-based Eosin Y/N-phenylglycine (NPG)-initiated composite hydrogel (AEC) composed of photocrosslinkable alginate, viscosity modifiers and novel white light photoinitiator, namely Eosin Y/NPG system, for instant hemorrhage control.展开更多
In this study,the fluid flow and mixing process in an impinging stream-rotating packed bed(IS-RPB)is simulated by using a new three-dimensional computational fluid dynamics model.Specifically,the gaseliquid flow is si...In this study,the fluid flow and mixing process in an impinging stream-rotating packed bed(IS-RPB)is simulated by using a new three-dimensional computational fluid dynamics model.Specifically,the gaseliquid flow is simulated by the Euler-Euler model,the hydrodynamics of the reactor is predicted by the RNG k-εmethod,and the high-gravity environment is simulated by the sliding mesh model.The turbulent mass transfer process is characterized by the concentration variance c^(2) and its dissipation rateεc formulations,and therefore the turbulent mass diffusivity can be directly obtained.The simulated segregation index Xs is in agreement with our previous experimental results.The simulated results reveal that the fringe effect of IS can be offset by the end effect at the inner radius of RPB,so the investigation of the coupling mechanism between IS and RPB is critical to intensify the mixing process in IS-RPB.展开更多
An analytical solution for the responses of composite laminates under oblique low-velocity impacts is presented for a cross-ply,orthotropic,and rectangular plate under oblique low-velocity impacts.The plate is under s...An analytical solution for the responses of composite laminates under oblique low-velocity impacts is presented for a cross-ply,orthotropic,and rectangular plate under oblique low-velocity impacts.The plate is under simply-supported edge conditions,and the dynamic displacement field is expressed in a mixed form by in-plane double Fourier series and cubic polynomials through the thickness as 12 variables for each layer.A system of modified Lagrange equations is derived with all interface constraints.The Hertz and Cattaneo-Mindlin theories are used to solve for the normal and tangential contact forces during the impacts.By further discretizing in the time domain,the oblique impact problem is solved iteratively.While the numerical results clearly show the influence of impact velocity,stacking sequence,mechanical parameters,and geometric parameters,the proposed analytical approach could serve as a theoretical basis for the laminate analysis and design when it is under low-velocity impacts.展开更多
Accurate cropland information is critical for agricultural planning and production,especially in foodstressed countries like China.Although widely used medium-to-high-resolution satellite-based cropland maps have been...Accurate cropland information is critical for agricultural planning and production,especially in foodstressed countries like China.Although widely used medium-to-high-resolution satellite-based cropland maps have been developed from various remotely sensed data sources over the past few decades,considerable discrepancies exist among these products both in total area and in spatial distribution of croplands,impeding further applications of these datasets.The factors influencing their inconsistency are also unknown.In this study,we evaluated the consistency and accuracy of six cropland maps widely used in China in circa 2020,including three state-of-the-art 10-m products(i.e.,Google Dynamic World,ESRI Land Cover,and ESA WorldCover)and three 30-m ones(i.e.,GLC_FCS30,GlobeLand 30,and CLCD).We also investigated the effects of landscape fragmentation,climate,and agricultural management.Validation using a ground-truth sample revealed that the 10-m-resolution WorldCover provided the highest accuracy(92.3%).These maps collectively overestimated Chinese cropland area by up to 56%.Up to 37%of the land showed spatial inconsistency among the maps,concentrated mainly in mountainous regions and attributed to the varying accuracy of cropland maps,cropland fragmentation and management practices such as irrigation.Our work shed light on the promotion of future cropland mapping efforts,especially in highly inconsistent regions.展开更多
基金supported by the Innovation Foundation of Provincial Education Department of Gansu(2024B-005)the Gansu Province National Science Foundation(22YF7GA182)the Fundamental Research Funds for the Central Universities(No.lzujbky2022-kb01)。
文摘Modal parameters can accurately characterize the structural dynamic properties and assess the physical state of the structure.Therefore,it is particularly significant to identify the structural modal parameters according to the monitoring data information in the structural health monitoring(SHM)system,so as to provide a scientific basis for structural damage identification and dynamic model modification.In view of this,this paper reviews methods for identifying structural modal parameters under environmental excitation and briefly describes how to identify structural damages based on the derived modal parameters.The paper primarily introduces data-driven modal parameter recognition methods(e.g.,time-domain,frequency-domain,and time-frequency-domain methods,etc.),briefly describes damage identification methods based on the variations of modal parameters(e.g.,natural frequency,modal shapes,and curvature modal shapes,etc.)and modal validation methods(e.g.,Stability Diagram and Modal Assurance Criterion,etc.).The current status of the application of artificial intelligence(AI)methods in the direction of modal parameter recognition and damage identification is further discussed.Based on the pre-vious analysis,the main development trends of structural modal parameter recognition and damage identification methods are given to provide scientific references for the optimized design and functional upgrading of SHM systems.
文摘BACKGROUND Malignant obstructive jaundice(MOJ)is characterized by the presence of malignant tumors infiltrating or compressing the bile duct,causing poor bile drainage,generalized yellowing,pain,itching,and malaise.MOJ is burdensome for both the society and the families of affected patients and should be taken seriously.AIM To evaluate the clinical effect of stent placement during endoscopic retrograde cholangiopancreatography for relieving MOJ and the efficacy of percutaneous transhepatic biliary drainage in terms of liver function improvement,complication rates,and long-term patient outcomes.METHODS The clinical data of 59 patients with MOJ who were admitted to our hospital between March 2018 and August 2019 were retrospectively analyzed.According to the treatment method,the patients were divided into an observation group(29 patients)and a control group(30 patients).General data,liver function indices,complications,adverse effects,and 3-year survival rates after different surgical treatments were recorded for the two groups.RESULTS There were no significant differences in baseline information(sex,age,tumor type,or tumor diameter)between the two groups(P>0.05).Alanine aminotransferase,aspartate aminotransferase,and total bilirubin levels were significantly better in both groups after surgery than before surgery(P<0.05).The overall incidence of biliary bleeding,gastrointestinal bleeding,pancreatitis,and cholangitis was 6.9%in the observation group and 30%in the control group(P<0.05).No significant differences in the rates of blood transfusion,intensive care unit admission,or death within 3 years were observed between the two groups at the 1-month follow-up(P>0.05).The 3-year survival rates were 46.06%and 39.71%in the observation and control groups,respectively.CONCLUSION Endoscopic biliary stenting effectively relieves MOJ and significantly improves liver function,with minimal complications.This technique is a promising palliative approach for patients ineligible for radical surgery.However,further research is needed to optimize current treatment strategies and to explore their potential in treating nonmalignant cases of obstructive jaundice.
文摘BACKGROUND Postpancreatectomy hemorrhage is one of the most severe and life-threatening complications after pancreaticoduodenectomy.We present four cases of gastrointestinal bleeding patients to clarify its appropriate treatment and prevention.CASE SUMMARY The main symptoms included black stool,hematochezia,haematemesis,blood in the nasogastric tube,and hemorrhagic shock.The mean age was 66.25 years old and the median onset time was 340 d after the surgery.The bleeding location comprised gastrointestinal anastomosis,bile duct-jejunum anastomosis,and extraluminal bleeding.The possible causes included marginal ulcer,jejunal varix,and abdominal infection.Endoscopic hemostatic clips,as well as a covered stent using angiography,were utilized to stop the bleeding and three patients survived.Only one patient died of gastrointestinal bleeding,abdominal bleeding,abdominal infection,hypovolemic shock,and disseminated intravascular coagulation.CONCLUSION Early and effective endoscopic intervention is the key to successful hemostasis in patients with gastrointestinal bleeding after pancreatoduodenectomy.
基金the Natural Science Foundation of China(11922415,12274471)Guangdong Basic and Applied Basic Research Foundation(2022A1515011168,2019A1515011718,2019A1515011337)the Key Research and Development Program of Guangdong Province,China(2019B110209003).
文摘We report a novel double-shelled nanoboxes photocatalyst architecture with tailored interfaces that accelerate quantum efficiency for photocatalytic CO_(2) reduction reaction(CO_(2)RR)via Mo–S bridging bonds sites in S_(v)–In_(2)S_(3)@2H–MoTe_(2).The X-ray absorption near-edge structure shows that the formation of S_(v)–In_(2)S_(3)@2H–MoTe_(2) adjusts the coordination environment via interface engineering and forms Mo–S polarized sites at the interface.The interfacial dynamics and catalytic behavior are clearly revealed by ultrafast femtosecond transient absorption,time-resolved,and in situ diffuse reflectance–Infrared Fourier transform spectroscopy.A tunable electronic structure through steric interaction of Mo–S bridging bonds induces a 1.7-fold enhancement in S_(v)–In_(2)S_(3)@2H–MoTe_(2)(5)photogenerated carrier concentration relative to pristine S_(v)–In_(2)S_(3).Benefiting from lower carrier transport activation energy,an internal quantum efficiency of 94.01%at 380 nm was used for photocatalytic CO_(2)RR.This study proposes a new strategy to design photocatalyst through bridging sites to adjust the selectivity of photocatalytic CO_(2)RR.
基金supported by the Science Fund for National Defense Distinguished Young Scholars(2022-JCJQ-ZQ-016)the Key Basic Research Projects of the Foundation Strengthening Plan(2022-JCJQZD-096-00)+2 种基金the National Key Research and Development Program of China(2022YFA1104604)the National Natural Science Foundation of China(32000969)the Key Support Program for Growth Factor Research(SZYZ-TR-03).
文摘Dear Editor,Three dimensional(3D)bioprinted extracellular matrix(ECM)can be used to provide both biochemical and biophysical cues to direct mesenchymal stem cells(MSCs)differentiation,and then differentiated cells were isolated for implantation in vivo using surgical procedures.However,the reduced cell activity after cell isolation from 3D constructs and low cell retention in injured sites limit its application[1].Methacrylated gelatin(GelMA)hydrogel has the advantage of fast crosslinking,which could resemble complex architectures of tissue construct in vivo[2].Here,we adopted a noninvasive bioprinting procedure to imitate the regenerative microenvironment that could simultaneously direct the sweat gland(SG)and vascular differentiation from MSCs and ultimately promote the replacement of glandular tissue in situ(Fig.1a).
基金supported by Open Research Fund of Hubei Key Laboratory of Blasting(Engineering HKL-BEF202006)the National Natural Science Foundation of China(52079102,52108368).
文摘To study the dynamic mechanical properties and failure characteristics of intersecting jointed rock masses with different joint distributions under confining pressure,considering the cross angleαand joint persistence ratioη,a numerical model of the biaxial Hopkinson bar test system was established using the finite element method–discrete-element model coupling method.The validity of the model was verified by comparing and analyzing it in conjunction with laboratory test results.Dynamics-static combined impact tests were conducted on specimens under various conditions to investigate the strength characteristics and patterns of crack initiation and expansion.The study revealed the predominant factors influencing intersecting joints with different angles and penetrations under impact loading.The results show that the peak stress of the specimens decreases first and then increases with the increase of the cross angle.Whenα<60°,regardless of the value ofη,the dynamic stress of the specimens is controlled by the main joint.Whenα≥60°,the peak stress borne by the specimens decreases with increasingη.Whenα<60°,the initiation and propagation of cracks in the cross-jointed specimens are mainly controlled by the main joint,and the final failure surface of the specimens is composed of the main joint and wing cracks.Whenα≥60°orη≥0.67,the secondary joint guides the expansion of the wing cracks,and multiple failure surfaces composed of main and secondary joints,wing cracks,and co-planar cracks are formed.Increasing lateral confinement significantly increases the dynamic peak stress able to be borne by the specimens.Under triaxial conditions,the degree of failure of the intersecting jointed specimens is much lower than that under uniaxial and biaxial conditions.
基金The authors are grateful for the financial support from the National Natural Science Foundation of China(Grant Nos.52273067,52122303,52233006)the Fundamental Research Funds for the Central Universities(Grant No.2232023A-03)the Shuguang Program of Shanghai Education Development Foundation and Shanghai Municipal Education Commission(23SG29).
文摘The demand for highly porous yet transparent aerogels with mechanical flexibility and solar-thermal dual-regulation for energy-saving windows is significant but challenging.Herein,a delaminated aerogel film(DAF)is fabricated through filtration-induced delaminated gelation and ambient drying.The delaminated gelation process involves the assembly of fluorinated cellulose nanofiber(FCNF)at the solid-liquid interface between the filter and the filtrate during filtration,resulting in the formation of lamellar FCNF hydrogels with strong intra-plane and weak interlayer hydrogen bonding.By exchanging the solvents from water to hexane,the hydrogen bonding in the FCNF hydrogel is further enhanced,enabling the formation of the DAF with intra-layer mesopores upon ambient drying.The resulting aerogel film is lightweight and ultra-flexible,which pos-sesses desirable properties of high visible-light transmittance(91.0%),low thermal conductivity(33 mW m^(-1) K^(-1)),and high atmospheric-window emissivity(90.1%).Furthermore,the DAF exhibits reduced surface energy and exceptional hydrophobicity due to the presence of fluorine-containing groups,enhancing its durability and UV resistance.Consequently,the DAF has demonstrated its potential as solar-thermal regulatory cooling window materials capable of simultaneously providing indoor lighting,thermal insulation,and daytime radiative cooling under direct sunlight.Significantly,the enclosed space protected by the DAF exhibits a temperature reduction of 2.6℃ compared to that shielded by conventional architectural glass.
基金funded by the National Key Research and Development Program of China(Nos.2022YFB3805303,2022YFB3805304)the National Natural Science Foundation of China(Grant/Award Numbers:22308345,U20A20127)+1 种基金the Anhui Provincial Natural Science Foundation(No.2308085QB68)the Fundamental Research Funds for the Central Universities(No.WK2060000059).
文摘Aqueous organic redox flow batteries(AORFBs),which exploit the reversible electrochemical reactions of water-soluble organic electrolytes to store electricity,have emerged as an efficient electrochemical energy storage technology for the grid-scale integration of renewable electricity.pH-neutral AORFBs that feature high safety,low corrosivity,and environmental benignity are particularly promising,and their battery performance is significantly impacted by redox-active molecules and ion-exchange membranes(IEMs).Here,representative anolytes and catholytes engineered for use in pH-neutral AORFBs are outlined and summarized,as well as their side reactions that cause irreversible battery capacity fading.In addition,the recent achievements of IEMs for pH-neutral AORFBs are discussed,with a focus on the construction and tuning of ion transport channels.Finally,the critical challenges and potential research opportunities for developing practically relevant pH-neutral AORFBs are presented.
基金the financial support by the Natural Science Foundation of Ningxia(Grant no.2022AAC03099)the Key R&D Project of Ningxia(Grant no.2020BDE03012)。
文摘Corrosion-resistant and biocompatible films were fabricated on AZ91D Mg alloy substrates by varying their roughness levels using met-allographic preparation and subsequent hydrothermal procedures.The coated films comprised a mixed structure of Mg(OH)_(2)and Mg-Al layered double hydroxides(LDH)and exhibited excellent compactness.Coating film thickness increased with decreasing surface roughness.Corrosion resistance was evaluated using potentiodynamic polarization and electrochemical impedance spectroscopy.Metallographic pretreat-ment influenced the chemical activity of the Mg alloy surface and helped modulate the dissolution rate of the Mg_(17)Al_(12)phase during the hydrothermal procedure.With decreasing roughness of the Mg substrate,the Al^(3+)concentration gradually increased,accelerating the in-situ formation of the Mg(OH)_(2)/LDH composite coating and improving its crystallinity.A thick and dense Mg(OH)_(2)/LDH coating was synthesized on the Mg substrate with the least roughness,substantially improving the corrosion resistance of the AZ91D alloy.The lowest corrosion current density((5.73±2.75)×10^(−8)A·cm^(−2))was achieved,which was approximately three orders of magnitude less than that of bare AZ91D.Moreover,the coating demonstrated biocompatibility with no evident cytotoxicity,cellular damage,and hemolytic phenomena.This study provides an effective method for preparing coatings on Mg alloy surfaces with excellent corrosion resistance and biocompatibility.
基金supported by the National Key R&D Program of China(2022YFD1200300)the National Nature Science Youth Science Fund Project,China(31801412)+2 种基金the Key R&D Program of Shandong Province,China(2021LZGC026)the Agricultural Science and Technology Innovation Project of Shandong Academy of Agricultural Sciences,China(CXGC2023G02)the Shandong Provincial Program,China(WST2020011)。
文摘Verticillium dahliae is an important fungal pathogen affecting cotton yield and quality.Therefore,the mining of V.dahlia-resistance genes is urgently needed.Proteases and protease inhibitors play crucial roles in plant defense responses.However,the functions and regulatory mechanisms of the protease inhibitor PR6 gene family remain largely unknown.This study provides a comprehensive analysis of the PR6 gene family in the cotton genome.We performed genome-wide identification and functional characterization of the cotton GhPR6 gene family,which belongs to the potato protease inhibitor I family of inhibitors.Thirty-nine PR6s were identified in Gossypium arboreum,G.raimondii,G.barbadense,and G.hirsutum,and they were clustered into four groups.Based on the analysis of pathogen-induced and Ghlmm transcriptome data,Gh PR6-5b was identified as the key gene for V.dahliae resistance.Virus-induced gene silencing experiments revealed that cotton was more sensitive to V.dahliae V991after PR6-5b silencing.The present study established that GhWRKY75 plays an important role in resistance to Verticillium wilt in cotton by positively regulating GhPR6-5b expression by directly binding to the W-box TTGAC(T/C).Our findings established that GhWRKY75 is a potential candidate for improving cotton resistance to V.dahliae,and provide primary information for further investigations and the development of specific strategies to bolster the defense mechanisms of cotton against V.dahliae.
基金supported by the Open Project of Hubei Key Laboratory of Power System Design and Test for Electrical Vehicle(No.ZDSYS202304)the National Natural Science Foundation of China(No.62303007)the Anhui Provincial Natural Science Foundation(No.2308085ME142)。
文摘The reliable prediction of state of charge(SOC)is one of the vital functions of advanced battery management system(BMS),which has great significance towards safe operation of electric vehicles.By far,the empirical model-based and data-driven-based SOC estimation methods of lithium-ion batteries have been comprehensively discussed and reviewed in various literatures.However,few reviews involving SOC estimation focused on electrochemical mechanism,which gives physical explanations to SOC and becomes most attractive candidate for advanced BMS.For this reason,this paper comprehensively surveys on physics-based SOC algorithms applied in advanced BMS.First,the research progresses of physical SOC estimation methods for lithium-ion batteries are thoroughly discussed and corresponding evaluation criteria are carefully elaborated.Second,future perspectives of the current researches on physics-based battery SOC estimation are presented.The insights stated in this paper are expected to catalyze the development and application of the physics-based advanced BMS algorithms.
基金funded by the Major science and technology project of CNOOC(KJZX-2022-12-XNY-0803).
文摘Underground liquified natural gas(LNG)storage is essential in guaranteeing national energy strategic reserves,and its construction is being accelerated.The stability of surrounding rock of underground LNG storage caverns under stress-low temperature coupling effect is the key factor determining the feasibility of LNG storage.First,a mathematical model used for controlling the stress-low temperature coupling and the processes of rock damage evolution is given,followed by a 2-D numerical execution process of the mathematical model mentioned above described based on Comsol Multiphysics and Matlab code.Finally,a series of 2-D simulations are performed to study the influence of LNG storage cavern layout,burial depth,temperature and internal pressure on the stability of surrounding rocks of these underground storage caverns.The results indicate that all the factors mentioned above affect the evolution of deformation and plastic zone of surrounding rocks.The research results contribute to the engineering design of underground LNG storage caverns.
基金supported by 111 Project (No.D21025)Open Fund Project of State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Nos.PLN2021-01,PLN2021-02,PLN2021-03)+2 种基金High-end Foreign Expert Introduction Program (No.G2021036005L)National Key Research and Development Program (No.2021YFC2800903)National Natural Science Foundation of China (No.U20B6005-05)。
文摘During the operational process of natural gas gathering and transmission pipelines,the formation of hydrates is highly probable,leading to uncontrolled movement and aggregation of hydrates.The continuous migration and accumulation of hydrates further contribute to the obstruction of natural gas pipelines,resulting in production reduction,shutdowns,and pressure build-ups.Consequently,a cascade of risks is prone to occur.To address this issue,this study focuses on the operational process of natural gas gathering and transmission pipelines,where a comprehensive framework is established.This framework includes theoretical models for pipeline temperature distribution,pipeline pressure distribution,multiphase flow within the pipeline,hydrate blockage,and numerical solution methods.By analyzing the influence of inlet temperature,inlet pressure,and terminal pressure on hydrate formation within the pipeline,the sensitivity patterns of hydrate blockage risks are derived.The research indicates that reducing inlet pressure and terminal pressure could lead to a decreased maximum hydrate formation rate,potentially mitigating pipeline blockage during natural gas transportation.Furthermore,an increase in inlet temperature and terminal pressure,and a decrease in inlet pressure,results in a displacement of the most probable location for hydrate blockage towards the terminal station.However,it is crucial to note that operating under low-pressure conditions significantly elevates energy consumption within the gathering system,contradicting the operational goal of energy efficiency and reduction of energy consumption.Consequently,for high-pressure gathering pipelines,measures such as raising the inlet temperature or employing inhibitors,electrical heat tracing,and thermal insulation should be adopted to prevent hydrate formation during natural gas transportation.Moreover,considering abnormal conditions such as gas well production and pipeline network shutdowns,which could potentially trigger hydrate formation,the installation of methanol injection connectors remains necessary to ensure production safety.
基金Supported by Shanxi Provincial Natural Science Foundation(Grant No.202303021224002)National Natural Science Foundation of China(Grant No.U23B2099)+2 种基金Shanxi Provincial Science and Technology Innovation Teams(Grant No.202304051001025)the Central Special Fund for Guiding Local Science and Technology Development(Grant No.YDZX20191400002149)the Xinjiang Institute of Intelligent Equipment(Grant No.XJYJY2024010).
文摘It is difficult to effectively improve the low bonding strength of TA1/304 clad plates.This study proposes a new process for applying pulse current(1500 A,500 Hz,50%duty cycle)to TA1/304 clad plates during the rolling process,which changes the interface microstructure and effectively improves the bonding strength of the clad plates.The influence of the pulsed current on the interface microstructure and bonding strength was systematically studied.The results indicate that the clad plate is initially bonded at 750℃ and 35%reduction ratio under electrically-assisted rolling(EAR),and finally the higher bonding strength is obtained at 850℃ and 48%reduction ratio,reaching 395 MPa.The strengthening of the interface element diffusion and grain refinement under the action of the pulsed current are important reasons for the improvement in the bonding strength of the clad plate.This discovery provides new ideas for the preparation of clad plates with high bonding performance.
基金Supported by National Key R&D Program of China(Grant No.2021YFB3400501).
文摘Cam-lobe radial-piston hydraulic motors are widely used as rotation driving units for various marine machinery owing to their ultrahigh output torque(more than 100 kN m).A multi-row cam roller bearing(MCRB)is the key component that directly determines the fatigue life of a cam-lobe radial-piston hydraulic motor.However,compact geometry and complex loads render MCRB susceptible to fatigue failure,highlighting the need for an optimized MCRB to achieve longer fatigue life and higher reliability.Therefore,this study proposes an innovative geometry optimization method for an MCRB to improve its fatigue life.In this method,a quasi-static model was developed to calculate the load distribution,with the fatigue life of the MCRB calculated using both basic dynamic loading and load distribution.Subsequently,a genetic algorithm was used to obtain the optimized geometry parameters,which significantly improved the fatigue life of the MCRB.Finally,a loading test was conducted on a hydraulic motor installed with both the initial and optimized MCRB to validate the effectiveness of the proposed optimization method.This study provides a theoretical guideline for optimizing the design of MCRB,thereby increasing the fatigue life of hydraulic motors.
基金National Key Research and Development Program(2022YFA1104604,2017YFC1103303)Science Fund for National Defense Distinguished Young Scholars(2022-JCJQ-ZQ-016)+2 种基金National Nature Science Foundation of China(32000969,82002056,92268206)Military Medical Research Projects(145AKJ260015000X,2022-JCJQ-ZD-096-00)Key Support Program for Growth Factor Research(SZYZ-TR-03).
文摘Dear Editor,Timely and effective hemostasis is of great significance for reducing body damage and mortality of patients [1]. Alginate is generally considered to be an excellent hemostatic polymer-based biomaterial and has been approved by the Food and Drug Administration as Generally Recognized as Safe [2]. However, the violent crosslinking reaction and unstable structure at the wound site limit its clinical applications. Hence, we report a biocompatible and injectable composite hydrogel methacrylate alginate (Alg-AEMA)-based Eosin Y/N-phenylglycine (NPG)-initiated composite hydrogel (AEC) composed of photocrosslinkable alginate, viscosity modifiers and novel white light photoinitiator, namely Eosin Y/NPG system, for instant hemorrhage control.
基金supported by the National Natural Science Foundation of China (22208328, 22378370 and 22108261)Fundamental Research Program of Shanxi Province(20210302124618)
文摘In this study,the fluid flow and mixing process in an impinging stream-rotating packed bed(IS-RPB)is simulated by using a new three-dimensional computational fluid dynamics model.Specifically,the gaseliquid flow is simulated by the Euler-Euler model,the hydrodynamics of the reactor is predicted by the RNG k-εmethod,and the high-gravity environment is simulated by the sliding mesh model.The turbulent mass transfer process is characterized by the concentration variance c^(2) and its dissipation rateεc formulations,and therefore the turbulent mass diffusivity can be directly obtained.The simulated segregation index Xs is in agreement with our previous experimental results.The simulated results reveal that the fringe effect of IS can be offset by the end effect at the inner radius of RPB,so the investigation of the coupling mechanism between IS and RPB is critical to intensify the mixing process in IS-RPB.
基金Project supported by the National Natural Science Foundation of China(Nos.12172303 and12111530222)the Shaanxi Key Research and Development Program for International Cooperation and Exchanges of China(No.2022KWZ-23)+1 种基金the Fundamental Research Funds for the Central Universities of China(No.5000220118)the Science and Technology Council of Taiwan of China(No.NSTC 111-2811-E-A49-534)。
文摘An analytical solution for the responses of composite laminates under oblique low-velocity impacts is presented for a cross-ply,orthotropic,and rectangular plate under oblique low-velocity impacts.The plate is under simply-supported edge conditions,and the dynamic displacement field is expressed in a mixed form by in-plane double Fourier series and cubic polynomials through the thickness as 12 variables for each layer.A system of modified Lagrange equations is derived with all interface constraints.The Hertz and Cattaneo-Mindlin theories are used to solve for the normal and tangential contact forces during the impacts.By further discretizing in the time domain,the oblique impact problem is solved iteratively.While the numerical results clearly show the influence of impact velocity,stacking sequence,mechanical parameters,and geometric parameters,the proposed analytical approach could serve as a theoretical basis for the laminate analysis and design when it is under low-velocity impacts.
基金This work was supported by the National Natural Science Foundation of China(72221002,42271375)the Strategic Priority Research Program(XDA28060100)the Informatization Plan Project(CAS-WX2021PY-0109)of the Chinese Academy of Sciences.
文摘Accurate cropland information is critical for agricultural planning and production,especially in foodstressed countries like China.Although widely used medium-to-high-resolution satellite-based cropland maps have been developed from various remotely sensed data sources over the past few decades,considerable discrepancies exist among these products both in total area and in spatial distribution of croplands,impeding further applications of these datasets.The factors influencing their inconsistency are also unknown.In this study,we evaluated the consistency and accuracy of six cropland maps widely used in China in circa 2020,including three state-of-the-art 10-m products(i.e.,Google Dynamic World,ESRI Land Cover,and ESA WorldCover)and three 30-m ones(i.e.,GLC_FCS30,GlobeLand 30,and CLCD).We also investigated the effects of landscape fragmentation,climate,and agricultural management.Validation using a ground-truth sample revealed that the 10-m-resolution WorldCover provided the highest accuracy(92.3%).These maps collectively overestimated Chinese cropland area by up to 56%.Up to 37%of the land showed spatial inconsistency among the maps,concentrated mainly in mountainous regions and attributed to the varying accuracy of cropland maps,cropland fragmentation and management practices such as irrigation.Our work shed light on the promotion of future cropland mapping efforts,especially in highly inconsistent regions.
