The coal-measure source rock in the Chinese sea area plays a significant role as a hydrocarbon source rock,with its genetic environment,development and distribution,and hydrocarbon generation potential serving as esse...The coal-measure source rock in the Chinese sea area plays a significant role as a hydrocarbon source rock,with its genetic environment,development and distribution,and hydrocarbon generation potential serving as essential factors for the exploration of coal-type oil and gas fields.This study focuses on the coal-measure source rock of the Paleogene Enping Formation in the ZhuⅠDepression,located in the northern South China Sea.The main geological insights obtained are as follows.The coal measures of the Enping Formation are developed in a warm and wet tropical-subtropical climate.The development environment of the coal-measure source rock in the Enping Formation includes the braided river delta upper plain peat swamp,characterized by dry forest swamp coal facies with relatively thick coal seams and a small number of layers.The braided river delta lower plain swamp-interdistributary bay of braided river delta front represents a forest edge-wetland herbaceous swamp coal facies with numerous layers of thin coal seams and poor stability.The shore swamp corresponds to an open water swamp coal facies with multiple layers of thin coal seams and poor stability.The organic matter abundance in the braided river delta upper plain is the highest,followed by the braided river delta lower plain-braided river delta front,and the shore-shallow lake.The organic matter type is predominantly typeⅡ1.Thermal evolution analysis suggests that the organic matter has progressed into a substantial oil generation stage.The hydrocarbon generation potential of the coal-measure source rock in the Enping Formation is the highest in the braided river delta upper plain,followed by the braided river delta lower plain-braided river delta front and the shore-shallow lake.Overall,this study proposes three organic facies in the coal-measure source rock of the Enping Formation:upper-plain swamp-dry forest swamp facies,lower plain-interdistributary bay-forest-herbaceous swamp facies,and lake swamp-herbaceous swamp facies.展开更多
The growing demand for electronic devices, smart devices, and the Internet of Things constitutes the primary driving force for marching down the path of decreased critical dimension and increased circuit intricacy of ...The growing demand for electronic devices, smart devices, and the Internet of Things constitutes the primary driving force for marching down the path of decreased critical dimension and increased circuit intricacy of integrated circuits. However, as sub-10 nm high-volume manufacturing is becoming the mainstream, there is greater awareness that defects introduced by original equipment manufacturer components impact yield and manufacturing costs. The identification, positioning, and classification of these defects, including random particles and systematic defects, are becoming more and more challenging at the 10 nm node and beyond.Very recently, the combination of conventional optical defect inspection with emerging techniques such as nanophotonics, optical vortices, computational imaging, quantitative phase imaging, and deep learning is giving the field a new possibility. Hence, it is extremely necessary to make a thorough review for disclosing new perspectives and exciting trends, on the foundation of former great reviews in the field of defect inspection methods. In this article, we give a comprehensive review of the emerging topics in the past decade with a focus on three specific areas:(a) the defect detectability evaluation,(b) the diverse optical inspection systems,and(c) the post-processing algorithms. We hope, this work can be of importance to both new entrants in the field and people who are seeking to use it in interdisciplinary work.展开更多
The study of sulfur hexafluoride(SF6) discharge is vital for its application in gas-insulated equipment. Direct current partial discharge(PD) may cause SF6 decomposition, and the decomposed products of SF6, such as F ...The study of sulfur hexafluoride(SF6) discharge is vital for its application in gas-insulated equipment. Direct current partial discharge(PD) may cause SF6 decomposition, and the decomposed products of SF6, such as F atoms, play a dominant role in the breakdown of insulation systems. In this study, the PD caused by metal protrusion defects is simulated by a needle-plate electrode using pulsed high voltage in SF6/Ar mixtures. The spatial and temporal characteristics of SF6/Ar plasma are analyzed by measuring the emission spectra of F and Ar atoms, which are important for understanding the characteristics of PD. The spatial resolved results show that both F and Ar atom spectral intensities increase first from the plate anode to the needle and then decrease under the conditions of a background pressure of400 Pa, peak voltage of-1000 V, frequency of 2 kHz, pulse width of 60 μs, and electrode gap of 5-9 mm. However, the distribution characteristics of F and Ar are significantly different. The temporal distribution results show that the spectral intensity of Ar decreasesfirst and then increases slowly, while the spectral intensity of F increases slowly for the duration of the pulsed discharge at the electrode gap of 5 mm and the pulse width of40-80 μs.展开更多
An experimental setup has been designed and realized in order to optimize the characteristics of laser-induced breakdown spectroscopy system working in various pressure environments. An approach combined the normaliza...An experimental setup has been designed and realized in order to optimize the characteristics of laser-induced breakdown spectroscopy system working in various pressure environments. An approach combined the normalization methods with the partial least squares(PLS) method are developed for quantitative analysis of molybdenum(Mo) element in the multi-component alloy,which is the first wall material in the Experimental Advanced Superconducting Tokamak. In this study, the different spectral normalization methods(total spectral area normalization,background normalization, and reference line normalization) are investigated for reducing the uncertainty and improving the accuracy of spectral measurement. The results indicates that the approach of PLS based on inter-element interference is significantly better than the conventional PLS methods as well as the univariate linear methods in the various pressure for molybdenum element analysis.展开更多
Fuel retention measurement on plasma-facing components is an active field of study in magnetic confinement nuclear fusion devices.The laser-induced breakdown spectroscopy(LIBS)diagnostic method has been well demonstra...Fuel retention measurement on plasma-facing components is an active field of study in magnetic confinement nuclear fusion devices.The laser-induced breakdown spectroscopy(LIBS)diagnostic method has been well demonstrated to detect the elemental distribution in PFCs.In this work,an upgraded co-axis LIBS system based on a linear fiber bundle collection system has been developed to measure the hydrogen(H) retention on a tantalum(Ta) sample under a vacuum condition.The spatial resolution measurement of the different positions of the LIBS plasma can be achieved simultaneously with varying delay times.The temporal and spatial evolution results of LIBS plasma emission show that the H plasma observably expands from the delay times of 0-200 ns.The diameter of Ta plasma is about 6 mm which is much less than the size of H plasma after 200 ns.The difference in the temporal and spatial evolution behaviors between H plasma and Ta plasma is due to the great difference in the atomic mass of H and Ta.The depth profile result shows that H retention mainly exists on the surface of the sample.The temporal and spatial evolution behaviors of the electron excited temperature are consistent with that of the Ta emission.The result will further improve the understanding of the evolution of the dynamics of LIBS plasma and optimize the current collection system of in situ LIBS in fusion devices.展开更多
The treatment of gastrointestinal cancer has always been a crucial research area,and targeted therapy has been receiving increasing attention.At present,the effect of targeted therapy is unsatisfactory for gastric can...The treatment of gastrointestinal cancer has always been a crucial research area,and targeted therapy has been receiving increasing attention.At present,the effect of targeted therapy is unsatisfactory for gastric cancer.Thus,the discovery of new targets is crucial.Claudin 18.2(CLDN18.2),a member of the claudin family,belongs to the tight junction protein family that controls the flow of molecules between cell layers.CLDN18.2 expression has been discussed in many studies.In recent years,there have been many studies on targeted therapy with CLDN18.2-ideal monoclonal antibody 362.Furthermore,CLDN18.2-specific chimeric antigen receptor T therapy has been used for CLDN18.2-positive tumors,such as gastric and pancreatic cancers.Considerable research has been focused on CLDN18.2.CLDN18.2,a newly discovered marker for precise targeted therapy of gastric cancer,could offer new hope for the treatment of gastric cancer.展开更多
Lithium metal batteries(LMBs)based on metallic Li exhibit high energy density to be competent for advanced energy storage applications.However,the unstable solid electrolyte interphase(SEI)layer due to continuous deco...Lithium metal batteries(LMBs)based on metallic Li exhibit high energy density to be competent for advanced energy storage applications.However,the unstable solid electrolyte interphase(SEI)layer due to continuous decomposition of electrolytes,and the attendant problem of Li dendrite growth frustrate their commercialization process.Herein,a hybrid SEI comprising abundant LiF,lithiophilic Li-Ge alloy,and Ge nanoparticles is constructed via a simple brush coating method.This fluorinated interface layer with embedded Ge-containing components isolates the Li anode from the corrosive electrolyte and facilitates homogenous Li nucleation as well as uniform growth.Consequently,the modified Li anode exhibits remarkable stability without notorious Li dendrites,delivering stable cycling lives of more than 1000 h for symmetric Li||Li cells and over 600 cycles for Li||Cu cells at 1 mA·cm^(−2).Moreover,the reinforced Li anodes endow multiple full-cell architectures with dramatically improved cyclability under different test conditions.This work provides rational guidance to design an artificial hybrid SEI layer and would stimulate more ideas to solve the dendrite issue and promote the further development of advanced LMBs.展开更多
After explorations in a diversity of single-atom nanozymes(SAzymes),developing dual-centered SAzymes becomes a promising approach for superior catalytic performance.But confusing mechanisms including atomic coordinati...After explorations in a diversity of single-atom nanozymes(SAzymes),developing dual-centered SAzymes becomes a promising approach for superior catalytic performance.But confusing mechanisms including atomic coordination,spatial configuration,and metal–metal atom interaction hinder the development and design of SAzymes.Herein,a dual-centered Fe-Cu-N_(x)SAzyme exhibits excellent peroxidase(POD)-and catalase(CAT)-like activities with d-band center(ε_(d))coordination of Fe and Cu in multiple reaction stages,which plays a critical role in the adsorption of H_(2)O_(2)molecule and H_(2)O and O_(2)release.Therefore,the dband center coordination,which can be represented byε_(d)(Fe)–ε_(d)(Cu)shifts,leads to the competition between one-side and bilateral adsorption,which determines the favorable reaction path with lower energy barriers.Based on experimental statistics,simulated formation energies,and reaction barriers,3 configurations,Fe-Cu-N6-I,Fe-Cu-N_(8)-II,and Fe-Cu-N_(8)-III,are modeled and validated.Impressively,configuration-dependent catalytic selectivity and the competition between one-side and bilateral adsorption can be unveiled by d-band center coordination paradigm analysis.Theoretical simulations suggest that the unsymmetrical charge distribution over the three Fe-Cu configurations could tune the adsorption strength compared with the counterparts FeN_(4)and CuN_(4).The present work provides a potential route for optimizing enzyme-like catalysis by designing the dual-or even triple-metal SAzymes,which demonstrates the large space to modulate the metal atomic configuration and interaction.展开更多
With the continued shrinking of the critical dimensions(CDs)of wafer patterning,the requirements for modeling precision in optical proximity correction(OPC)increase accordingly.This requirement extends beyond CD contr...With the continued shrinking of the critical dimensions(CDs)of wafer patterning,the requirements for modeling precision in optical proximity correction(OPC)increase accordingly.This requirement extends beyond CD controlling accuracy to include pattern alignment accuracy because misalignment can lead to considerable overlay and metal-via coverage issues at advanced nodes,affecting process window and yield.This paper proposes an efficient OPC modeling approach that prioritizes pattern-shift-related elements to tackle the issue accurately.Our method integrates careful measurement selection,the implementation of pattern-shift-aware structures in design,and the manipulation of the cost function during model tuning to establish a robust model.Confirmatory experiments are performed on a via layer fabricated using a negative tone development.Results demonstrate that pattern shifts can be constrained within a range of+1 nm,remarkably better than the original range of±3 nm.Furthermore,simulations reveal notable differences between post OPC and original masks when considering pattern shifts at locations sensitive to this phenomenon.Experimental validation confirms the accuracy of the proposed modeling approach,and a firm consistency is observed between the simulation results and experimental data obtained from actual design structures.展开更多
Objective:Home blood pressure monitoring(HBPM)is viewed as a facilitating factor in the initial diagnosis and long-term management of treated hypertension.However,evidence remains scarce about the effectiveness of HBP...Objective:Home blood pressure monitoring(HBPM)is viewed as a facilitating factor in the initial diagnosis and long-term management of treated hypertension.However,evidence remains scarce about the effectiveness of HBPM use in the real world.This study aimed to examine the associations of HBPM use with blood pressure(BP)control and medication adherence.Methods:This prospective cohort study included hypertensive patients with high cardiovascular risk who were aged≥50 years.At baseline,information about types of BP monitor,frequency of HBPM,perception of anti-hypertensive treatment,and measured office BP were collected.During the 1-year follow-up(visits at 1,2,3,6,and 12 months),information on medication adherence was collected at each visit.The 2 major outcomes were BP control at baseline and medication adherence during the 1-year follow-up.A log-binomial regression model was used to examine the association between frequency of HBPM and outcomes,stratified by the perceptions of anti-hypertensive treatment.Results:A total of 5,363 hypertensive patients were included in the analysis.The age was(64.6±7.2)years,and 41.2%(2,208)were female.Of the total patients,85.9%(4,606)had a home BP monitor and 47.8%(2,564)had an incorrect perception of anti-hypertensive treatment.Overall,24.2%(1,299)of patients monitored their BP daily,37.6%(2,015)weekly,17.3%(926)monthly,and 20.9%(1,123)less than monthly.At baseline,the systolic BP and diastolic BP were(146.6±10.8)mmHg and(81.9±10.6)mmHg,respectively,and 28.5%(1,527)of patients had their BP controlled.Regardless of whether the patients had correct or incorrect perceptions of anti-hypertensive treatment,there is no significant association between HBPM frequency and BP control at baseline.During the 1-year follow-up,23.9%(1,280)of patients had non-adherence to medications at least once.In patients with an incorrect perception of anti-hypertensive treatment,those monitoring BP most frequently(daily)had the highest non-adherence rate(29.9%,175/585).Compared with those monitoring their BP less than monthly,patients who monitored their BP daily were more likely not to adhere to anti-hypertensive medications(adjusted relative risk=1.38,95%confidence interval:1.11–1.72,P=0.004).Conclusions:HBPM performance among hypertensive patients in China is,in general,sub-optimal.No association was observed between using HBPM alone and hypertension control,indicating that the effects of HBPM could be conditional.Patients’misconceptions about anti-hypertensive treatment may impair the role of BP monitoring in achieving medication adherence.Fully incorporating the correct perception of hypertension into the management of hypertensive patients is needed.展开更多
In integrated circuit(IC)manufacturing,fast,nondestructive,and precise detection of defects in patterned wafers,realized by bright-field microscopy,is one of the critical factors for ensuring the final performance and...In integrated circuit(IC)manufacturing,fast,nondestructive,and precise detection of defects in patterned wafers,realized by bright-field microscopy,is one of the critical factors for ensuring the final performance and yields of chips.With the critical dimensions of IC nanostructures continuing to shrink,directly imaging or classifying deep-subwavelength defects by bright-field microscopy is challenging due to the well-known diffraction barrier,the weak scattering effect,and the faint correlation between the scattering cross-section and the defect morphology.Herein,we propose an optical far-field inspection method based on the form-birefringence scattering imaging of the defective nanostructure,which can identify and classify various defects without requiring optical super-resolution.The technique is built upon the principle of breaking the optical form birefringence of the original periodic nanostructures by the defect perturbation under the anisotropic illumination modes,such as the orthogonally polarized plane waves,then combined with the high-order difference of far-field images.We validated the feasibility and effectiveness of the proposed method in detecting deep subwavelength defects through rigid vector imaging modeling and optical detection experiments of various defective nanostructures based on polarization microscopy.On this basis,an intelligent classification algorithm for typical patterned defects based on a dual-channel AlexNet neural network has been proposed,stabilizing the classification accuracy ofλ/16-sized defects with highly similar features at more than 90%.The strong classification capability of the two-channel network on typical patterned defects can be attributed to the high-order difference image and its transverse gradient being used as the network’s input,which highlights the polarization modulation difference between different patterned defects more significantly than conventional bright-field microscopy results.This work will provide a new but easy-to-operate method for detecting and classifying deep-subwavelength defects in patterned wafers or photomasks,which thus endows current online inspection equipment with more missions in advanced IC manufacturing.展开更多
Understanding the ultrafast carrier dynamics and the mechanism of two-dimensional(2D)transition metal dichalcogenides(TMDs)is key to their applications in the field of optoelectronic devices.In this work,a single puls...Understanding the ultrafast carrier dynamics and the mechanism of two-dimensional(2D)transition metal dichalcogenides(TMDs)is key to their applications in the field of optoelectronic devices.In this work,a single pulse pump probe method is introduced to detect the layer-dependent ultrafast carrier dynamics of monolayer and few-layer WS_(2) excited by a femtosecond pulse.Results show that the ultrafast carrier dynamics of the layered WS_(2) films can be divided into three stages:the fast photoexcitation phase with the characteristic time of 2–4 ps,the fast decay phase with the characteristic time of 4–20 ps,and the slow decay phase lasting several hundred picoseconds.Moreover,the layer dependency of the characteristic time of each stage has been observed,and the corresponding mechanism of free carrier dynamics has been discussed.It has been observed as well that the monolayer WS_(2) exhibits a unique rising time of carriers after photoexcitation.The proposed method can be expected to be an effective approach for studying the dynamics of the photoexcited carriers in 2D TMDs.Our results provide a comprehensive understanding of the photoexcited carrier dynamics of layered WS_(2),which is essential for its application in optoelectronics and photovoltaic devices.展开更多
The governance effects of directors’and officers’liability insurance(D&O insurance),an important tool for risk diversification,are of strong concern in the capital market.Using a sample of Chinese A-share listed...The governance effects of directors’and officers’liability insurance(D&O insurance),an important tool for risk diversification,are of strong concern in the capital market.Using a sample of Chinese A-share listed firms from2009 to 2018,we examine the impact of D&O insurance on excess corporate leverage.We find that D&O insurance is negatively associated with excess corporate leverage and that this result is consistent with a series of robustness tests.Further analyses show that D&O insurance impedes excess corporate leverage mainly because of its effect on external monitoring.The effect is more pronounced for firms that are state-owned,have political connections and are located in provinces with low marketization than for other firms.展开更多
We study a model for the long-term behavior of a single-species population with some degree of pollution tolerance in a polluted environment. The model consists of three ordinary differential equations： one for the p...We study a model for the long-term behavior of a single-species population with some degree of pollution tolerance in a polluted environment. The model consists of three ordinary differential equations： one for the population density, one for the amount of toxicant inside the living organisms, and one for the amount of toxicant in the environment. We derive sufficient conditions for the persistence and the extinction of the population depending on the exogenous input rate of the toxicant into the environment and the level of pollution tolerance of the organisms. Numerical simulations are carried out to illustrate our main results.展开更多
The purpose of this study was to gain insight into the mechanism of iron dextran(DexFe)absorption in the intestines.A total of 72 piglets(average BW=7.12±0.75 kg,male to female ratio=1:1)weaned at 28 d of age wer...The purpose of this study was to gain insight into the mechanism of iron dextran(DexFe)absorption in the intestines.A total of 72 piglets(average BW=7.12±0.75 kg,male to female ratio=1:1)weaned at 28 d of age were randomly divided into two treatment groups with six replicates for each group.The experimental diets included the basal diet supplemented with 100 mg/kg iron dextran(DexFe group)and the basal diet supplemented with 100 mg/kg FeSO_(4)$H_(2)O(CON group).The experiment lasted for 28 d.The piglets'intestinal iron transport was measured in vitro using an Ussing chamber.Porcine intestinal epithelial cell line(IPEC-J2)cells were used to develop a monolayer cell model that explored the molecular mechanism of DexFe absorption.Results showed that compared to the CON group,the ADG of pigs in the DexFe group was improved(P=0.022),while the F/G was decreased(P=0.015).The serum iron concentration,apparent iron digestibility,and iron deposition in the duodenum,jejunum,and ileum were increased(P<0.05)by dietary DexFe supplementation.Piglets in the DexFe group had higher serum red blood count,hemoglobin,serum iron content,serum ferritin and transferrin levels and lower total iron binding capacity(P<0.05).In the Ussing chamber test,the iron absorption rate of the DexFe group was greater(P<0.001)than the CON group,and there was no significant difference between the DexFe group and the glucose group(P>0.05).Furthermore,when compared to the CON group,DexFe administration improved(P<0.05)SLC2A5 gene and glucose transporter 5(GLUT5)protein expression but had no effect(P>0.05)on SLC11A2 gene or divalent metal transporter 1(DMT1)protein expression.Once the GLUT5 protein was suppressed,the iron transport rate and apparent permeability coefficient were decreased(P<0.05)in IPEC-J2 monolayer cell models.The findings suggest the effectiveness of DexFe application in weaned piglets and revealed for the first time that DexFe absorption in the intestine is closely related to the glucose transporter GLUT5 protein channel.展开更多
基金The Scientific research project under contract under contract No.CCL2021RCPS172KQNFormation mechanism and distribution prediction of Cenozoic marine source rocks in Qiongdongnan and Pearl River Mouth Basin under contract No.2021KT-YXKY-01+2 种基金the resource potential,accumulation mechanism and breakthrough direction of potential oil-rich sags in offshore basins of China under contract No.2021-KT-YXKY-03the Open Foundation of Hebei Provincial Key Laboratory of Resource Survey and Researchthe National Natural Science Foundation of China(NSFC)under contract Nos 42072188,42272205。
文摘The coal-measure source rock in the Chinese sea area plays a significant role as a hydrocarbon source rock,with its genetic environment,development and distribution,and hydrocarbon generation potential serving as essential factors for the exploration of coal-type oil and gas fields.This study focuses on the coal-measure source rock of the Paleogene Enping Formation in the ZhuⅠDepression,located in the northern South China Sea.The main geological insights obtained are as follows.The coal measures of the Enping Formation are developed in a warm and wet tropical-subtropical climate.The development environment of the coal-measure source rock in the Enping Formation includes the braided river delta upper plain peat swamp,characterized by dry forest swamp coal facies with relatively thick coal seams and a small number of layers.The braided river delta lower plain swamp-interdistributary bay of braided river delta front represents a forest edge-wetland herbaceous swamp coal facies with numerous layers of thin coal seams and poor stability.The shore swamp corresponds to an open water swamp coal facies with multiple layers of thin coal seams and poor stability.The organic matter abundance in the braided river delta upper plain is the highest,followed by the braided river delta lower plain-braided river delta front,and the shore-shallow lake.The organic matter type is predominantly typeⅡ1.Thermal evolution analysis suggests that the organic matter has progressed into a substantial oil generation stage.The hydrocarbon generation potential of the coal-measure source rock in the Enping Formation is the highest in the braided river delta upper plain,followed by the braided river delta lower plain-braided river delta front and the shore-shallow lake.Overall,this study proposes three organic facies in the coal-measure source rock of the Enping Formation:upper-plain swamp-dry forest swamp facies,lower plain-interdistributary bay-forest-herbaceous swamp facies,and lake swamp-herbaceous swamp facies.
基金funded by the National Natural Science Foundation of China(Grant Nos.52175509 and 52130504)the National Key Research and Development Program of China(2017YFF0204705)+1 种基金the Key Research and Development Plan of Hubei Province(2021BAA013)the National Science and Technology Major Project(2017ZX02101006-004)。
文摘The growing demand for electronic devices, smart devices, and the Internet of Things constitutes the primary driving force for marching down the path of decreased critical dimension and increased circuit intricacy of integrated circuits. However, as sub-10 nm high-volume manufacturing is becoming the mainstream, there is greater awareness that defects introduced by original equipment manufacturer components impact yield and manufacturing costs. The identification, positioning, and classification of these defects, including random particles and systematic defects, are becoming more and more challenging at the 10 nm node and beyond.Very recently, the combination of conventional optical defect inspection with emerging techniques such as nanophotonics, optical vortices, computational imaging, quantitative phase imaging, and deep learning is giving the field a new possibility. Hence, it is extremely necessary to make a thorough review for disclosing new perspectives and exciting trends, on the foundation of former great reviews in the field of defect inspection methods. In this article, we give a comprehensive review of the emerging topics in the past decade with a focus on three specific areas:(a) the defect detectability evaluation,(b) the diverse optical inspection systems,and(c) the post-processing algorithms. We hope, this work can be of importance to both new entrants in the field and people who are seeking to use it in interdisciplinary work.
基金supported by National Natural Science Foundation of China (Nos. 11605023, 11805028, and 11705020)the National Key R&D Program of China (No. 2017YFE0301300)+1 种基金the China Postdoctoral Science Foundation (Nos. 2017T100172 and 2016M591423)the Fundamental Research Funds for the Central Universities (Nos. DUT17RC(4)53 and DUT18LK38)
文摘The study of sulfur hexafluoride(SF6) discharge is vital for its application in gas-insulated equipment. Direct current partial discharge(PD) may cause SF6 decomposition, and the decomposed products of SF6, such as F atoms, play a dominant role in the breakdown of insulation systems. In this study, the PD caused by metal protrusion defects is simulated by a needle-plate electrode using pulsed high voltage in SF6/Ar mixtures. The spatial and temporal characteristics of SF6/Ar plasma are analyzed by measuring the emission spectra of F and Ar atoms, which are important for understanding the characteristics of PD. The spatial resolved results show that both F and Ar atom spectral intensities increase first from the plate anode to the needle and then decrease under the conditions of a background pressure of400 Pa, peak voltage of-1000 V, frequency of 2 kHz, pulse width of 60 μs, and electrode gap of 5-9 mm. However, the distribution characteristics of F and Ar are significantly different. The temporal distribution results show that the spectral intensity of Ar decreasesfirst and then increases slowly, while the spectral intensity of F increases slowly for the duration of the pulsed discharge at the electrode gap of 5 mm and the pulse width of40-80 μs.
基金supported by the National Magnetic Confinement Fusion Science Program of China (No. 2017YFE0301304)National Natural Science Foundation of China (Nos. 11 475 039, 11 605 023, 11 705 020)+2 种基金China Postdoctoral Science Foundation (Nos. 2016M591423, 2017T100172, 2018M630285)the Fundamental Research Funds for the Central Universities (Nos. DUT15RC(3)072, DUT17RC(4)53, DUT18LK38)Liaoning Provincial Natural Science Foundation of China (No. 20 170 540 153)
文摘An experimental setup has been designed and realized in order to optimize the characteristics of laser-induced breakdown spectroscopy system working in various pressure environments. An approach combined the normalization methods with the partial least squares(PLS) method are developed for quantitative analysis of molybdenum(Mo) element in the multi-component alloy,which is the first wall material in the Experimental Advanced Superconducting Tokamak. In this study, the different spectral normalization methods(total spectral area normalization,background normalization, and reference line normalization) are investigated for reducing the uncertainty and improving the accuracy of spectral measurement. The results indicates that the approach of PLS based on inter-element interference is significantly better than the conventional PLS methods as well as the univariate linear methods in the various pressure for molybdenum element analysis.
基金supported by National Key R&D Program of China(No.2017TFE0301300)the National Natural Science Foundation of China(Nos.11605023,11805028,11861131010)the China Postdoctoral Science Foundation(Nos.2017T100172,2016M591423)。
文摘Fuel retention measurement on plasma-facing components is an active field of study in magnetic confinement nuclear fusion devices.The laser-induced breakdown spectroscopy(LIBS)diagnostic method has been well demonstrated to detect the elemental distribution in PFCs.In this work,an upgraded co-axis LIBS system based on a linear fiber bundle collection system has been developed to measure the hydrogen(H) retention on a tantalum(Ta) sample under a vacuum condition.The spatial resolution measurement of the different positions of the LIBS plasma can be achieved simultaneously with varying delay times.The temporal and spatial evolution results of LIBS plasma emission show that the H plasma observably expands from the delay times of 0-200 ns.The diameter of Ta plasma is about 6 mm which is much less than the size of H plasma after 200 ns.The difference in the temporal and spatial evolution behaviors between H plasma and Ta plasma is due to the great difference in the atomic mass of H and Ta.The depth profile result shows that H retention mainly exists on the surface of the sample.The temporal and spatial evolution behaviors of the electron excited temperature are consistent with that of the Ta emission.The result will further improve the understanding of the evolution of the dynamics of LIBS plasma and optimize the current collection system of in situ LIBS in fusion devices.
文摘The treatment of gastrointestinal cancer has always been a crucial research area,and targeted therapy has been receiving increasing attention.At present,the effect of targeted therapy is unsatisfactory for gastric cancer.Thus,the discovery of new targets is crucial.Claudin 18.2(CLDN18.2),a member of the claudin family,belongs to the tight junction protein family that controls the flow of molecules between cell layers.CLDN18.2 expression has been discussed in many studies.In recent years,there have been many studies on targeted therapy with CLDN18.2-ideal monoclonal antibody 362.Furthermore,CLDN18.2-specific chimeric antigen receptor T therapy has been used for CLDN18.2-positive tumors,such as gastric and pancreatic cancers.Considerable research has been focused on CLDN18.2.CLDN18.2,a newly discovered marker for precise targeted therapy of gastric cancer,could offer new hope for the treatment of gastric cancer.
基金the National Natural Science Foundation of China(Nos.51904344 and 52172264)the Natural Science Foundation of Hunan Province of China(Nos.2021JJ10060 and 2022GK2033).
文摘Lithium metal batteries(LMBs)based on metallic Li exhibit high energy density to be competent for advanced energy storage applications.However,the unstable solid electrolyte interphase(SEI)layer due to continuous decomposition of electrolytes,and the attendant problem of Li dendrite growth frustrate their commercialization process.Herein,a hybrid SEI comprising abundant LiF,lithiophilic Li-Ge alloy,and Ge nanoparticles is constructed via a simple brush coating method.This fluorinated interface layer with embedded Ge-containing components isolates the Li anode from the corrosive electrolyte and facilitates homogenous Li nucleation as well as uniform growth.Consequently,the modified Li anode exhibits remarkable stability without notorious Li dendrites,delivering stable cycling lives of more than 1000 h for symmetric Li||Li cells and over 600 cycles for Li||Cu cells at 1 mA·cm^(−2).Moreover,the reinforced Li anodes endow multiple full-cell architectures with dramatically improved cyclability under different test conditions.This work provides rational guidance to design an artificial hybrid SEI layer and would stimulate more ideas to solve the dendrite issue and promote the further development of advanced LMBs.
基金supported by the National Key Research and Development Program of China(Nos.2021YFF1200700 and 2021YFF1200701)the National Natural Science Foundation of China(Nos.91859101,81971744,U1932107,82001952,11804248,82302361,and 82302381)+5 种基金Outstanding Youth Funds of Tianjin(No.2021FJ-0009)STI 2030-Major Projects(No.2022ZD0210200)National Natural Science Foundation of Tianjin(Nos.19JCZDJC34000,20JCYBJC00940,21JCYBJC00550,21JCZDJC00620,and 21JCYBJC00490)the Key Projects of Tianjin Natural Fund(No.21JCZDJC00490)the Innovation Foundation of Tianjin University,China Postdoctoral Science Foundation(No.2023M732601)CAS Interdisciplinary Innovation Team(No.JCTD-2020-08).
文摘After explorations in a diversity of single-atom nanozymes(SAzymes),developing dual-centered SAzymes becomes a promising approach for superior catalytic performance.But confusing mechanisms including atomic coordination,spatial configuration,and metal–metal atom interaction hinder the development and design of SAzymes.Herein,a dual-centered Fe-Cu-N_(x)SAzyme exhibits excellent peroxidase(POD)-and catalase(CAT)-like activities with d-band center(ε_(d))coordination of Fe and Cu in multiple reaction stages,which plays a critical role in the adsorption of H_(2)O_(2)molecule and H_(2)O and O_(2)release.Therefore,the dband center coordination,which can be represented byε_(d)(Fe)–ε_(d)(Cu)shifts,leads to the competition between one-side and bilateral adsorption,which determines the favorable reaction path with lower energy barriers.Based on experimental statistics,simulated formation energies,and reaction barriers,3 configurations,Fe-Cu-N6-I,Fe-Cu-N_(8)-II,and Fe-Cu-N_(8)-III,are modeled and validated.Impressively,configuration-dependent catalytic selectivity and the competition between one-side and bilateral adsorption can be unveiled by d-band center coordination paradigm analysis.Theoretical simulations suggest that the unsymmetrical charge distribution over the three Fe-Cu configurations could tune the adsorption strength compared with the counterparts FeN_(4)and CuN_(4).The present work provides a potential route for optimizing enzyme-like catalysis by designing the dual-or even triple-metal SAzymes,which demonstrates the large space to modulate the metal atomic configuration and interaction.
基金funded by the National Natural Science Foundation of China(Grant Nos.52130504,52305577,and 52205592)the Key Research and Development Plan of Hubei Province,China(Grant No.2022BAA013)+2 种基金the Major Program(JD)of Hubei Province,China(Grant No.2023BAA008-2)the Innovation Projection of Optics Valley Laboratory,China(Grant No.OVL2023PY003)the Postdoctoral Fellowship Program(Grade B)of the China Postdoctoral Science Foundation(Grant No.GZB20230244).
文摘With the continued shrinking of the critical dimensions(CDs)of wafer patterning,the requirements for modeling precision in optical proximity correction(OPC)increase accordingly.This requirement extends beyond CD controlling accuracy to include pattern alignment accuracy because misalignment can lead to considerable overlay and metal-via coverage issues at advanced nodes,affecting process window and yield.This paper proposes an efficient OPC modeling approach that prioritizes pattern-shift-related elements to tackle the issue accurately.Our method integrates careful measurement selection,the implementation of pattern-shift-aware structures in design,and the manipulation of the cost function during model tuning to establish a robust model.Confirmatory experiments are performed on a via layer fabricated using a negative tone development.Results demonstrate that pattern shifts can be constrained within a range of+1 nm,remarkably better than the original range of±3 nm.Furthermore,simulations reveal notable differences between post OPC and original masks when considering pattern shifts at locations sensitive to this phenomenon.Experimental validation confirms the accuracy of the proposed modeling approach,and a firm consistency is observed between the simulation results and experimental data obtained from actual design structures.
基金supported by the National Key Research and Development Program of China(2018YFC1312404,2018YFC1312400)by the National Clinical Research Center for Cardiovascular Diseases,Fuwai Hospital,Chinese Academy of Medical Sciences(NCRC2021001).
文摘Objective:Home blood pressure monitoring(HBPM)is viewed as a facilitating factor in the initial diagnosis and long-term management of treated hypertension.However,evidence remains scarce about the effectiveness of HBPM use in the real world.This study aimed to examine the associations of HBPM use with blood pressure(BP)control and medication adherence.Methods:This prospective cohort study included hypertensive patients with high cardiovascular risk who were aged≥50 years.At baseline,information about types of BP monitor,frequency of HBPM,perception of anti-hypertensive treatment,and measured office BP were collected.During the 1-year follow-up(visits at 1,2,3,6,and 12 months),information on medication adherence was collected at each visit.The 2 major outcomes were BP control at baseline and medication adherence during the 1-year follow-up.A log-binomial regression model was used to examine the association between frequency of HBPM and outcomes,stratified by the perceptions of anti-hypertensive treatment.Results:A total of 5,363 hypertensive patients were included in the analysis.The age was(64.6±7.2)years,and 41.2%(2,208)were female.Of the total patients,85.9%(4,606)had a home BP monitor and 47.8%(2,564)had an incorrect perception of anti-hypertensive treatment.Overall,24.2%(1,299)of patients monitored their BP daily,37.6%(2,015)weekly,17.3%(926)monthly,and 20.9%(1,123)less than monthly.At baseline,the systolic BP and diastolic BP were(146.6±10.8)mmHg and(81.9±10.6)mmHg,respectively,and 28.5%(1,527)of patients had their BP controlled.Regardless of whether the patients had correct or incorrect perceptions of anti-hypertensive treatment,there is no significant association between HBPM frequency and BP control at baseline.During the 1-year follow-up,23.9%(1,280)of patients had non-adherence to medications at least once.In patients with an incorrect perception of anti-hypertensive treatment,those monitoring BP most frequently(daily)had the highest non-adherence rate(29.9%,175/585).Compared with those monitoring their BP less than monthly,patients who monitored their BP daily were more likely not to adhere to anti-hypertensive medications(adjusted relative risk=1.38,95%confidence interval:1.11–1.72,P=0.004).Conclusions:HBPM performance among hypertensive patients in China is,in general,sub-optimal.No association was observed between using HBPM alone and hypertension control,indicating that the effects of HBPM could be conditional.Patients’misconceptions about anti-hypertensive treatment may impair the role of BP monitoring in achieving medication adherence.Fully incorporating the correct perception of hypertension into the management of hypertensive patients is needed.
基金funded by National Natural Science Foundation of China(Grant Nos.52130504,52305577,and 52175509)the Key Research and Development Plan of Hubei Province(Grant No.2022BAA013)+4 种基金the Major Program(JD)of Hubei Province(Grant No.2023BAA008-2)the Interdisciplinary Research Program of Huazhong University of Science and Technology(2023JCYJ047)the Innovation Project of Optics Valley Laboratory(Grant No.OVL2023PY003)the Postdoctoral Fellowship Program(Grade B)of China Postdoctoral Science Foundation(Grant No.GZB20230244)the fellowship from the China Postdoctoral Science Foundation(2024M750995)。
文摘In integrated circuit(IC)manufacturing,fast,nondestructive,and precise detection of defects in patterned wafers,realized by bright-field microscopy,is one of the critical factors for ensuring the final performance and yields of chips.With the critical dimensions of IC nanostructures continuing to shrink,directly imaging or classifying deep-subwavelength defects by bright-field microscopy is challenging due to the well-known diffraction barrier,the weak scattering effect,and the faint correlation between the scattering cross-section and the defect morphology.Herein,we propose an optical far-field inspection method based on the form-birefringence scattering imaging of the defective nanostructure,which can identify and classify various defects without requiring optical super-resolution.The technique is built upon the principle of breaking the optical form birefringence of the original periodic nanostructures by the defect perturbation under the anisotropic illumination modes,such as the orthogonally polarized plane waves,then combined with the high-order difference of far-field images.We validated the feasibility and effectiveness of the proposed method in detecting deep subwavelength defects through rigid vector imaging modeling and optical detection experiments of various defective nanostructures based on polarization microscopy.On this basis,an intelligent classification algorithm for typical patterned defects based on a dual-channel AlexNet neural network has been proposed,stabilizing the classification accuracy ofλ/16-sized defects with highly similar features at more than 90%.The strong classification capability of the two-channel network on typical patterned defects can be attributed to the high-order difference image and its transverse gradient being used as the network’s input,which highlights the polarization modulation difference between different patterned defects more significantly than conventional bright-field microscopy results.This work will provide a new but easy-to-operate method for detecting and classifying deep-subwavelength defects in patterned wafers or photomasks,which thus endows current online inspection equipment with more missions in advanced IC manufacturing.
基金supported by the National Natural Science Foundation of China (Nos. 51975232 and 51727809)the Experiment Center for Advanced Manufacturing and Technology in the School of Mechanical Science & Engineering of HUST for the technical support.
文摘Understanding the ultrafast carrier dynamics and the mechanism of two-dimensional(2D)transition metal dichalcogenides(TMDs)is key to their applications in the field of optoelectronic devices.In this work,a single pulse pump probe method is introduced to detect the layer-dependent ultrafast carrier dynamics of monolayer and few-layer WS_(2) excited by a femtosecond pulse.Results show that the ultrafast carrier dynamics of the layered WS_(2) films can be divided into three stages:the fast photoexcitation phase with the characteristic time of 2–4 ps,the fast decay phase with the characteristic time of 4–20 ps,and the slow decay phase lasting several hundred picoseconds.Moreover,the layer dependency of the characteristic time of each stage has been observed,and the corresponding mechanism of free carrier dynamics has been discussed.It has been observed as well that the monolayer WS_(2) exhibits a unique rising time of carriers after photoexcitation.The proposed method can be expected to be an effective approach for studying the dynamics of the photoexcited carriers in 2D TMDs.Our results provide a comprehensive understanding of the photoexcited carrier dynamics of layered WS_(2),which is essential for its application in optoelectronics and photovoltaic devices.
基金supported by the National Social Science Youth Foundation of China(Project No.20CGL014)the Social Science Planning Project in Chongqing,China(Project No.2021BS084)
文摘The governance effects of directors’and officers’liability insurance(D&O insurance),an important tool for risk diversification,are of strong concern in the capital market.Using a sample of Chinese A-share listed firms from2009 to 2018,we examine the impact of D&O insurance on excess corporate leverage.We find that D&O insurance is negatively associated with excess corporate leverage and that this result is consistent with a series of robustness tests.Further analyses show that D&O insurance impedes excess corporate leverage mainly because of its effect on external monitoring.The effect is more pronounced for firms that are state-owned,have political connections and are located in provinces with low marketization than for other firms.
基金Supported by National Natural Science Foundation of China(No.11201075)Natural Science Foundation of Fujian Province(No.2016J01015)Scholarship under Education Department of Fujian Province
文摘We study a model for the long-term behavior of a single-species population with some degree of pollution tolerance in a polluted environment. The model consists of three ordinary differential equations： one for the population density, one for the amount of toxicant inside the living organisms, and one for the amount of toxicant in the environment. We derive sufficient conditions for the persistence and the extinction of the population depending on the exogenous input rate of the toxicant into the environment and the level of pollution tolerance of the organisms. Numerical simulations are carried out to illustrate our main results.
基金financially supported by the Hunan Engineering Research Center of Intelligent Animal Husbandry(grant number:20211231GCZX)of ChinaEvaluation of the Effectiveness of Iron Dextran Supplementation in Pig Diets(grant number,2022xczx-214)of Hunan Agricultural University.
文摘The purpose of this study was to gain insight into the mechanism of iron dextran(DexFe)absorption in the intestines.A total of 72 piglets(average BW=7.12±0.75 kg,male to female ratio=1:1)weaned at 28 d of age were randomly divided into two treatment groups with six replicates for each group.The experimental diets included the basal diet supplemented with 100 mg/kg iron dextran(DexFe group)and the basal diet supplemented with 100 mg/kg FeSO_(4)$H_(2)O(CON group).The experiment lasted for 28 d.The piglets'intestinal iron transport was measured in vitro using an Ussing chamber.Porcine intestinal epithelial cell line(IPEC-J2)cells were used to develop a monolayer cell model that explored the molecular mechanism of DexFe absorption.Results showed that compared to the CON group,the ADG of pigs in the DexFe group was improved(P=0.022),while the F/G was decreased(P=0.015).The serum iron concentration,apparent iron digestibility,and iron deposition in the duodenum,jejunum,and ileum were increased(P<0.05)by dietary DexFe supplementation.Piglets in the DexFe group had higher serum red blood count,hemoglobin,serum iron content,serum ferritin and transferrin levels and lower total iron binding capacity(P<0.05).In the Ussing chamber test,the iron absorption rate of the DexFe group was greater(P<0.001)than the CON group,and there was no significant difference between the DexFe group and the glucose group(P>0.05).Furthermore,when compared to the CON group,DexFe administration improved(P<0.05)SLC2A5 gene and glucose transporter 5(GLUT5)protein expression but had no effect(P>0.05)on SLC11A2 gene or divalent metal transporter 1(DMT1)protein expression.Once the GLUT5 protein was suppressed,the iron transport rate and apparent permeability coefficient were decreased(P<0.05)in IPEC-J2 monolayer cell models.The findings suggest the effectiveness of DexFe application in weaned piglets and revealed for the first time that DexFe absorption in the intestine is closely related to the glucose transporter GLUT5 protein channel.
