The poor corrosion and wear resistances of Mg alloys seriously limit their potential applications in various industries.The conventional epoxy coating easily forms many intrinsic defects during the solidification proc...The poor corrosion and wear resistances of Mg alloys seriously limit their potential applications in various industries.The conventional epoxy coating easily forms many intrinsic defects during the solidification process,which cannot provide sufficient protection.In the current study,we design a double-layer epoxy composite coating on Mg alloy with enhanced anti-corrosion/wear properties,via the spin-assisted assembly technique.The outer layer is functionalized graphene(FG)in waterborne epoxy resin(WEP)and the inner layer is Ce-based conversion(Ce)film.The FG sheets can be homogeneously dispersed within the epoxy matrix to fill the intrinsic defects and improve the barrier capability.The Ce film connects the outer layer with the substrate,showing the transition effect.The corrosion rate of Ce/WEP/FG composite coating is 2131 times lower than that of bare Mg alloy,and the wear rate is decreased by~90%.The improved corrosion resistance is attributed to the labyrinth effect(hindering the penetration of corrosive medium)and the obstruction of galvanic coupling behavior.The synergistic effect derived from the FG sheet and blocking layer exhibits great potential in realizing the improvement of multi-functional integration,which will open up a new avenue for the development of novel composite protection coatings of Mg alloys.展开更多
Pseudorabies(PR)is an acute infectious disease of pigs caused by the PR virus(PRV)and results in great economic losses to the pig industry worldwide.PRV glycoprotein E(gE)-based enzyme-linked immunosorbent assay(ELISA...Pseudorabies(PR)is an acute infectious disease of pigs caused by the PR virus(PRV)and results in great economic losses to the pig industry worldwide.PRV glycoprotein E(gE)-based enzyme-linked immunosorbent assay(ELISA)has been used to distinguish gE-deleted vaccine-immunized pigs from wild-type virus-infected pigs to eradicate PR in some countries.Nanobody has the advantages of small size and easy genetic engineering and has been a promising diagnostic reagent.However,there were few reports about developing nanobody-based ELISA for detecting anti-PRV-gE antibodies.In the present study,the recombinant PRV-gE was expressed with a bacterial system and used to immunize the Bactrian camel.Then,two nanobodies against PRV-gE were screened from the immunized camel by phage display technique.Subsequently,two nanobody-HRP fusion proteins were expressed with HEK293T cells.The PRV-gE-Nb36-HRP fusion protein was selected as the probe for developing the blocking ELISA(bELISA)to detect anti-PRV-gE antibodies.Through optimizing the conditions of bELISA,the amount of coated antigen was 200 ng per well,and dilutions of the fusion protein and tested pig sera were separately 1:320 and 1:5.The cut-off value of bELISA was 24.20%,and the sensitivity and specificity were 96.43 and 92.63%,respectively.By detecting 233 clinical pig sera with the developed bELISA and a commercial kit,the results showed that the coincidence rate of two assays was 93.99%.Additionallly,epitope mapping showed that PRV-gE-Nb36 recognized a conserved conformational epitope in different reference PRV strains.Simple,great stability and low-cost nanobody-based bELISA for detecting anti-PRV-gE antibodies were developed.The bELISA could be used for monitoring and eradicating PR.展开更多
As drilling wells continue to move into deep ultra-deep layers,the requirements for temperature resistance of drilling fluid treatments are getting higher and higher.Among them,blocking agent,as one of the key treatme...As drilling wells continue to move into deep ultra-deep layers,the requirements for temperature resistance of drilling fluid treatments are getting higher and higher.Among them,blocking agent,as one of the key treatment agents,has also become a hot spot of research.In this study,a high temperature resistant strong adsorption rigid blocking agent(QW-1)was prepared using KH570 modified silica,acrylamide(AM)and allyltrimethylammonium chloride(TMAAC).QW-1 has good thermal stability,average particle size of 1.46μm,water contact angle of 10.5.,has a strong hydrophilicity,can be well dispersed in water.The experimental results showed that when 2 wt%QW-1 was added to recipe A(4 wt%bentonite slurry+0.5 wt%DSP-1(filtration loss depressant)),the API filtration loss decreased from 7.8to 6.4 m L.After aging at 240.C,the API loss of filtration was reduced from 21 to 14 m L,which has certain performance of high temperature loss of filtration.At the same time,it is effective in sealing 80-100mesh and 100-120 mesh sand beds as well as 3 and 5μm ceramic sand discs.Under the same conditions,the blocking performance was superior to silica(5μm)and calcium carbonate(2.6μm).In addition,the mechanism of action of QW-1 was further investigated.The results show that QW-1 with amide and quaternary ammonium groups on the molecular chain can be adsorbed onto the surface of clay particles through hydrogen bonding and electrostatic interaction to form a dense blocking layer,thus preventing further intrusion of drilling fluid into the formation.展开更多
The virtuality and openness of online social platforms make networks a hotbed for the rapid propagation of various rumors.In order to block the outbreak of rumor,one of the most effective containment measures is sprea...The virtuality and openness of online social platforms make networks a hotbed for the rapid propagation of various rumors.In order to block the outbreak of rumor,one of the most effective containment measures is spreading positive information to counterbalance the diffusion of rumor.The spreading mechanism of rumors and effective suppression strategies are significant and challenging research issues.Firstly,in order to simulate the dissemination of multiple types of information,we propose a competitive linear threshold model with state transition(CLTST)to describe the spreading process of rumor and anti-rumor in the same network.Subsequently,we put forward a community-based rumor blocking(CRB)algorithm based on influence maximization theory in social networks.Its crucial step is to identify a set of influential seeds that propagate anti-rumor information to other nodes,which includes community detection,selection of candidate anti-rumor seeds and generation of anti-rumor seed set.Under the CLTST model,the CRB algorithm has been compared with six state-of-the-art algorithms on nine online social networks to verify the performance.Experimental results show that the proposed model can better reflect the process of rumor propagation,and review the propagation mechanism of rumor and anti-rumor in online social networks.Moreover,the proposed CRB algorithm has better performance in weakening the rumor dissemination ability,which can select anti-rumor seeds in networks more accurately and achieve better performance in influence spread,sensitivity analysis,seeds distribution and running time.展开更多
BACKGROUND Abdominal aortic aneurysm(AAA)repair often involves significant postoperative pain,traditionally managed with systemic opioids,which can cause undesirable side effects.This case report explores the novel us...BACKGROUND Abdominal aortic aneurysm(AAA)repair often involves significant postoperative pain,traditionally managed with systemic opioids,which can cause undesirable side effects.This case report explores the novel use of a surgically-initiated rectus sheath block with a catheter-over-needle assembly for pain management in AAA repair.CASE SUMMARY A 67-year-old female with hypertension and previous aortic dissection underwent elective open repair of an infrarenal AAA,which had grown from 3.4 cm to 4.3 cm over 14 months.A rectus sheath block was initiated surgically for postoperative pain control.The patient reported low pain scores and did not require systemic intravenous opioids,enabling early ambulation and discharge on postoperative day seven without complications.By preventing complications of systemic opi-oids,the method indicating a promising direction for postoperative pain management in major vascular surgeries.CONCLUSION Surgically-initiated rectus sheath block as a valuable tool for managing postoperative pain in AAA repair.展开更多
Objective:To investigate the clinical nursing intervention effect of moxibustion on abdominal distension symptoms in heart failure(heart and kidney yang deficiency and blood stasis blocking collaterals syndrome).Metho...Objective:To investigate the clinical nursing intervention effect of moxibustion on abdominal distension symptoms in heart failure(heart and kidney yang deficiency and blood stasis blocking collaterals syndrome).Methods:62 patients with heart failure(heart and kidney yang deficiency and blood stasis blocking collaterals syndrome)admitted to our hospital from February 2023 to February 2024 were selected and divided into the observation group(n=31)and the control group(n=31)by using the random numerical table method.The control group adopted conventional nursing interventions,and the observation group received the nursing program of the control group with the addition of moxibustion nursing interventions.The nursing effectiveness,quality of life scores,and nursing satisfaction were compared between the two groups.Results:The nursing effectiveness of the observation group was significantly higher than the control group(P<0.05);the quality of life score of the observation group was significantly higher than the control group(P<0.05);the nursing satisfaction of the observation group was significantly higher than that of the control group(P<0.05).Conclusion:The use of moxibustion nursing intervention in patients with heart failure(heart and kidney yang deficiency and blood stasis blocking collaterals syndrome)can effectively relieve the symptoms of abdominal distension,improve patients'quality of life,and increase nursing satisfaction,which has promotion and application values.展开更多
The Bijigou intrusion is one of the largest and most well-differentiated Fe–Ti oxide-bearing layered intrusions in the Hannan massif located in the northwestern margin of the Yangtze Block,South China.Besides the min...The Bijigou intrusion is one of the largest and most well-differentiated Fe–Ti oxide-bearing layered intrusions in the Hannan massif located in the northwestern margin of the Yangtze Block,South China.Besides the mineralization-related mafic-ultramafic rocks,the intermediate-acid intrusive rocks are also exposed in the mining area,which is of great significance for the understanding the Neoproterozoic tectonic evolution of the Yangtze Block,but studies on these intermediate-acid rocks are scarce.The Bijigou mafic-ultramafic layered intrusion is surrounded by granite and cut by syenite veins.Here,we report new zircon U-Pb ages,Lu-Hf isotope composition and bulk rock geochemical data of the Bijigou syenite vein and wall-rock granite in the northwestern margin of the Yangtze Block.Laser ablation inductively coupled plasma mass spectrometry(LAICP-MS)zircon U-Pb dating results show that the Bijigou syenite vein and wall-rock granite formed at 770±3.5 Ma(MSWD=0.17,n=28)and 810±4 Ma(MSWD=0.84,n=26),respectively.The zirconεHf(t)values of the syenite veins range from+1.52 to+5.33(average of+3.05),combined with its high potassium contents,negative Nb–Ta anomalies and positive Pb anomalies,suggesting that they may have originated from mantle-derived basaltic magma,which was modified by materials from subducting oceanic slab.The zirconεHf(t)and T_(DM2)ages of the wall-rock granite range from+0.71 to+5.71(average+3.06)and 1344 to 1659 Ma(average 1519 Ma),respectively,indicating that the granite was produced by partial melting of juvenile crust.The geochemical characteristics of the Bijigou syenite and granite indicate that they were formed in a continental margin arc setting.Thus,combined with previous studies,it suggests that there was a major subduction system along the northwestern margin of the Yangtze Block during 824-720 Ma,and the magmatism in the Hannan massif was divided into two episodes:(1)early magmatism(824-790 Ma),such as the Bijigou,Hongmiaozhen and Huangguanzhen granitoids,was derived from partial melting of the juvenile or pre-existing crust in a continental arc setting;(2)later magmatism(789-718 Ma),including Bijigou syenite,Wudumen,Erliba and Zushidian granitoids,formed in a subduction-related back-arc extensional environment.The long-term subduction system along the northwestern margin of the Yangtze Block during 824-720 Ma suggests that the Yangtze Block was previously located at the periphery of the Rodinia supercontinent.展开更多
The behavior of single-phase flow and conjugate heat transfer in micro-channel heat sinks(MCHS)subjected to auniform heat flux is investigated by means of numerical simulations.Various geometrical configurations areex...The behavior of single-phase flow and conjugate heat transfer in micro-channel heat sinks(MCHS)subjected to auniform heat flux is investigated by means of numerical simulations.Various geometrical configurations areexamined,particularly,the combinations of rectangular solid and perforated blocks,used to create a disturbancein the flow.The analysis focuses on several key aspects and related metrics,including the temperature distribution,the mean Fanning friction factor,the pressure drop,the Nusselt number,and the overall heat transfer coefficientacross a range of Reynolds numbers(80–870).It is shown that the introduction of such blocks significantlyenhances the heat transfer performances of the MCHS compared to the straight-through flow channel.Specifically,a case is found where the Nusselt number increases by 2.3 times relative to the reference case.The integrationof perforated blocks facilitates the generation of vorticity within the channel,promoting the mixing of coldand hot fluids.Notably,MCHS incorporating perforated rectangular blocks exhibit more pronounced heat transferbenefits at Reynolds numbers smaller than 400.展开更多
Although the late Quaternary slip rate of the Northern Margin Fault of the Huaizhuo Basin(NFHB)was studied approximately 30 years ago using thermoluminescence and geomorphic methods,the underlying uncertainty cannot b...Although the late Quaternary slip rate of the Northern Margin Fault of the Huaizhuo Basin(NFHB)was studied approximately 30 years ago using thermoluminescence and geomorphic methods,the underlying uncertainty cannot be neglected,considering the limitations resulting from age and displacement measurements.Accordingly,we attempted to re-estimate the late Quaternary slip rate of the NFHB using high-precision remote sensing image interpretation,large-scale geological and geomorphic mapping,paleoseismic analysis,and Quaternary geochronology testing.The results,based on stratigraphic dislocation and age constraint in the trenches,show that the present deformation of the NFHB has been dominated by the extension,with a vertical slip rate~0.04-0.11 mm/a.We estimate a vertical slip rate of~0.06 mm/a,with an R^(2) value of~0.91,which is much lower than the~0.5 mm/a result estimated previously.There are three possible reasons for this discrepancy.The fi rst is the limitation resulting from dating and displacement measurements in earlier studies;the second is the slip decomposition caused by multiple branches of the NFHB,which leads to the low slip rate observed at a single fault;and third possible explanation is that the fault may be locked at present with a low slip rate,which means that the earthquake hazard of the NFHB cannot be ignored,and more in-depth research,such as geodetic and intensive observations of earthquake precursors,is urgently needed.This discovery poses a new challenge for the active study of the NFHB and the northeast corner of the Ordos Plateau in the North China Block.展开更多
[Objective] This study aimed to increase the sensitivity and specificity of enzyme-linked immunosorbent assay （ELISA） through analyzing the effects of different blocking buffers and sample diluents and their differe...[Objective] This study aimed to increase the sensitivity and specificity of enzyme-linked immunosorbent assay （ELISA） through analyzing the effects of different blocking buffers and sample diluents and their different concentrations on the result of ELISA. [Method] Different types of blocking buffer [casein, gelatin, BSA, goat serum （GS）, horse serum （HS） and rabbit serum （RS）]and sample diluent （PBST, casein, gelatin, BSA, GS, HS and RS） as well as their different concentrations were tested in ELISA to screen the optimal combination of blocking buffer and sample diluent. [Result] The results showed that 2% BSA had better effect on blocking than 1% and 3% BSA, and both 2% and 1% casein had better blocking effect than 3% casein; 8% and 10% RS showed better blocking effects than 6%RS and 7%RS; compared to BSA and casein, RS had the best effect on blocking, and 8% RS performed best as the blocking buffer and sample diluent. [Conclusion] A good combination of blocking buffer and diluent can effectively reduce the non-specific reaction and improve the sensitivity and specificity of ELISA. This study provides an important reference for the development of a perfect ELISA method.展开更多
Some novel techniques of computational fluid dynamics are used to establish a mathematical model for the open diversion channel with two embankments in river blocking.The technique of boundary fitted coordinate syste...Some novel techniques of computational fluid dynamics are used to establish a mathematical model for the open diversion channel with two embankments in river blocking.The technique of boundary fitted coordinate system is used to overcome the difficulties resulting from the complicated shapes of natural river boundaries;the method of alternating direction implicit finite difference scheme is used to solve the partial differential equations in the transformed plane;and the technique of moving boundary is used to deal with the river bed exposed to water surface.This model has been used to predict the flow characteristics in the blocking of the Yangtz river in the Three Gorge Project (TGP).Comparison between the computed and experimental data shows a satisfactory agreement.展开更多
基金the National Natural Science Foundation of China(Grant number 51771178)Shaanxi Outstanding Youth Fund project(Grant number 2021JC-45)+2 种基金Key international cooperation projects in Shaanxi Province(Grant number 2020KWZ-007)the Major Program of Science and Technology in Shaanxi Province(Grant number20191102006)Open Fund of State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body(Grant number 32115019)。
文摘The poor corrosion and wear resistances of Mg alloys seriously limit their potential applications in various industries.The conventional epoxy coating easily forms many intrinsic defects during the solidification process,which cannot provide sufficient protection.In the current study,we design a double-layer epoxy composite coating on Mg alloy with enhanced anti-corrosion/wear properties,via the spin-assisted assembly technique.The outer layer is functionalized graphene(FG)in waterborne epoxy resin(WEP)and the inner layer is Ce-based conversion(Ce)film.The FG sheets can be homogeneously dispersed within the epoxy matrix to fill the intrinsic defects and improve the barrier capability.The Ce film connects the outer layer with the substrate,showing the transition effect.The corrosion rate of Ce/WEP/FG composite coating is 2131 times lower than that of bare Mg alloy,and the wear rate is decreased by~90%.The improved corrosion resistance is attributed to the labyrinth effect(hindering the penetration of corrosive medium)and the obstruction of galvanic coupling behavior.The synergistic effect derived from the FG sheet and blocking layer exhibits great potential in realizing the improvement of multi-functional integration,which will open up a new avenue for the development of novel composite protection coatings of Mg alloys.
基金supported by the National Natural Science Foundation of China(32273041)the Key R&D Program of Shaanxi Province,China(2022NY-104)the Natural Science Foundation of Shaanxi Province,China(2022JC-12)。
文摘Pseudorabies(PR)is an acute infectious disease of pigs caused by the PR virus(PRV)and results in great economic losses to the pig industry worldwide.PRV glycoprotein E(gE)-based enzyme-linked immunosorbent assay(ELISA)has been used to distinguish gE-deleted vaccine-immunized pigs from wild-type virus-infected pigs to eradicate PR in some countries.Nanobody has the advantages of small size and easy genetic engineering and has been a promising diagnostic reagent.However,there were few reports about developing nanobody-based ELISA for detecting anti-PRV-gE antibodies.In the present study,the recombinant PRV-gE was expressed with a bacterial system and used to immunize the Bactrian camel.Then,two nanobodies against PRV-gE were screened from the immunized camel by phage display technique.Subsequently,two nanobody-HRP fusion proteins were expressed with HEK293T cells.The PRV-gE-Nb36-HRP fusion protein was selected as the probe for developing the blocking ELISA(bELISA)to detect anti-PRV-gE antibodies.Through optimizing the conditions of bELISA,the amount of coated antigen was 200 ng per well,and dilutions of the fusion protein and tested pig sera were separately 1:320 and 1:5.The cut-off value of bELISA was 24.20%,and the sensitivity and specificity were 96.43 and 92.63%,respectively.By detecting 233 clinical pig sera with the developed bELISA and a commercial kit,the results showed that the coincidence rate of two assays was 93.99%.Additionallly,epitope mapping showed that PRV-gE-Nb36 recognized a conserved conformational epitope in different reference PRV strains.Simple,great stability and low-cost nanobody-based bELISA for detecting anti-PRV-gE antibodies were developed.The bELISA could be used for monitoring and eradicating PR.
基金supported by the National Natural Science Foundation of China (No.52074330,No.52288101)。
文摘As drilling wells continue to move into deep ultra-deep layers,the requirements for temperature resistance of drilling fluid treatments are getting higher and higher.Among them,blocking agent,as one of the key treatment agents,has also become a hot spot of research.In this study,a high temperature resistant strong adsorption rigid blocking agent(QW-1)was prepared using KH570 modified silica,acrylamide(AM)and allyltrimethylammonium chloride(TMAAC).QW-1 has good thermal stability,average particle size of 1.46μm,water contact angle of 10.5.,has a strong hydrophilicity,can be well dispersed in water.The experimental results showed that when 2 wt%QW-1 was added to recipe A(4 wt%bentonite slurry+0.5 wt%DSP-1(filtration loss depressant)),the API filtration loss decreased from 7.8to 6.4 m L.After aging at 240.C,the API loss of filtration was reduced from 21 to 14 m L,which has certain performance of high temperature loss of filtration.At the same time,it is effective in sealing 80-100mesh and 100-120 mesh sand beds as well as 3 and 5μm ceramic sand discs.Under the same conditions,the blocking performance was superior to silica(5μm)and calcium carbonate(2.6μm).In addition,the mechanism of action of QW-1 was further investigated.The results show that QW-1 with amide and quaternary ammonium groups on the molecular chain can be adsorbed onto the surface of clay particles through hydrogen bonding and electrostatic interaction to form a dense blocking layer,thus preventing further intrusion of drilling fluid into the formation.
基金supported by the National Social Science Fund of China (Grant No.23BGL270)。
文摘The virtuality and openness of online social platforms make networks a hotbed for the rapid propagation of various rumors.In order to block the outbreak of rumor,one of the most effective containment measures is spreading positive information to counterbalance the diffusion of rumor.The spreading mechanism of rumors and effective suppression strategies are significant and challenging research issues.Firstly,in order to simulate the dissemination of multiple types of information,we propose a competitive linear threshold model with state transition(CLTST)to describe the spreading process of rumor and anti-rumor in the same network.Subsequently,we put forward a community-based rumor blocking(CRB)algorithm based on influence maximization theory in social networks.Its crucial step is to identify a set of influential seeds that propagate anti-rumor information to other nodes,which includes community detection,selection of candidate anti-rumor seeds and generation of anti-rumor seed set.Under the CLTST model,the CRB algorithm has been compared with six state-of-the-art algorithms on nine online social networks to verify the performance.Experimental results show that the proposed model can better reflect the process of rumor propagation,and review the propagation mechanism of rumor and anti-rumor in online social networks.Moreover,the proposed CRB algorithm has better performance in weakening the rumor dissemination ability,which can select anti-rumor seeds in networks more accurately and achieve better performance in influence spread,sensitivity analysis,seeds distribution and running time.
基金Supported by the Taichung Veterans General Hospital,No.TCVGH-1125401B.
文摘BACKGROUND Abdominal aortic aneurysm(AAA)repair often involves significant postoperative pain,traditionally managed with systemic opioids,which can cause undesirable side effects.This case report explores the novel use of a surgically-initiated rectus sheath block with a catheter-over-needle assembly for pain management in AAA repair.CASE SUMMARY A 67-year-old female with hypertension and previous aortic dissection underwent elective open repair of an infrarenal AAA,which had grown from 3.4 cm to 4.3 cm over 14 months.A rectus sheath block was initiated surgically for postoperative pain control.The patient reported low pain scores and did not require systemic intravenous opioids,enabling early ambulation and discharge on postoperative day seven without complications.By preventing complications of systemic opi-oids,the method indicating a promising direction for postoperative pain management in major vascular surgeries.CONCLUSION Surgically-initiated rectus sheath block as a valuable tool for managing postoperative pain in AAA repair.
文摘Objective:To investigate the clinical nursing intervention effect of moxibustion on abdominal distension symptoms in heart failure(heart and kidney yang deficiency and blood stasis blocking collaterals syndrome).Methods:62 patients with heart failure(heart and kidney yang deficiency and blood stasis blocking collaterals syndrome)admitted to our hospital from February 2023 to February 2024 were selected and divided into the observation group(n=31)and the control group(n=31)by using the random numerical table method.The control group adopted conventional nursing interventions,and the observation group received the nursing program of the control group with the addition of moxibustion nursing interventions.The nursing effectiveness,quality of life scores,and nursing satisfaction were compared between the two groups.Results:The nursing effectiveness of the observation group was significantly higher than the control group(P<0.05);the quality of life score of the observation group was significantly higher than the control group(P<0.05);the nursing satisfaction of the observation group was significantly higher than that of the control group(P<0.05).Conclusion:The use of moxibustion nursing intervention in patients with heart failure(heart and kidney yang deficiency and blood stasis blocking collaterals syndrome)can effectively relieve the symptoms of abdominal distension,improve patients'quality of life,and increase nursing satisfaction,which has promotion and application values.
基金jointly supported financially by the National Natural Science Foundation of China(No.41603040)the Natural Science Basic Research Plan in Shaanxi Province of China(No.2023-JC-YB-239)Fundamental Research Funds for the Central Universities(S202310710204)。
文摘The Bijigou intrusion is one of the largest and most well-differentiated Fe–Ti oxide-bearing layered intrusions in the Hannan massif located in the northwestern margin of the Yangtze Block,South China.Besides the mineralization-related mafic-ultramafic rocks,the intermediate-acid intrusive rocks are also exposed in the mining area,which is of great significance for the understanding the Neoproterozoic tectonic evolution of the Yangtze Block,but studies on these intermediate-acid rocks are scarce.The Bijigou mafic-ultramafic layered intrusion is surrounded by granite and cut by syenite veins.Here,we report new zircon U-Pb ages,Lu-Hf isotope composition and bulk rock geochemical data of the Bijigou syenite vein and wall-rock granite in the northwestern margin of the Yangtze Block.Laser ablation inductively coupled plasma mass spectrometry(LAICP-MS)zircon U-Pb dating results show that the Bijigou syenite vein and wall-rock granite formed at 770±3.5 Ma(MSWD=0.17,n=28)and 810±4 Ma(MSWD=0.84,n=26),respectively.The zirconεHf(t)values of the syenite veins range from+1.52 to+5.33(average of+3.05),combined with its high potassium contents,negative Nb–Ta anomalies and positive Pb anomalies,suggesting that they may have originated from mantle-derived basaltic magma,which was modified by materials from subducting oceanic slab.The zirconεHf(t)and T_(DM2)ages of the wall-rock granite range from+0.71 to+5.71(average+3.06)and 1344 to 1659 Ma(average 1519 Ma),respectively,indicating that the granite was produced by partial melting of juvenile crust.The geochemical characteristics of the Bijigou syenite and granite indicate that they were formed in a continental margin arc setting.Thus,combined with previous studies,it suggests that there was a major subduction system along the northwestern margin of the Yangtze Block during 824-720 Ma,and the magmatism in the Hannan massif was divided into two episodes:(1)early magmatism(824-790 Ma),such as the Bijigou,Hongmiaozhen and Huangguanzhen granitoids,was derived from partial melting of the juvenile or pre-existing crust in a continental arc setting;(2)later magmatism(789-718 Ma),including Bijigou syenite,Wudumen,Erliba and Zushidian granitoids,formed in a subduction-related back-arc extensional environment.The long-term subduction system along the northwestern margin of the Yangtze Block during 824-720 Ma suggests that the Yangtze Block was previously located at the periphery of the Rodinia supercontinent.
基金funded by the Project of the Hubei Provincial Department of Science and Technology(Grant No.2022CFB957)the Project of Hubei Engineering University of Teaching Research(Grant No.JY2024032)+1 种基金Ministry of Education University-Industry Cooperation Collaborative Education Project(Grant No.220903584161245)College Students’Innovation and Entrepreneurship Training Program(Grant Nos.DC2024031,DC2024032).
文摘The behavior of single-phase flow and conjugate heat transfer in micro-channel heat sinks(MCHS)subjected to auniform heat flux is investigated by means of numerical simulations.Various geometrical configurations areexamined,particularly,the combinations of rectangular solid and perforated blocks,used to create a disturbancein the flow.The analysis focuses on several key aspects and related metrics,including the temperature distribution,the mean Fanning friction factor,the pressure drop,the Nusselt number,and the overall heat transfer coefficientacross a range of Reynolds numbers(80–870).It is shown that the introduction of such blocks significantlyenhances the heat transfer performances of the MCHS compared to the straight-through flow channel.Specifically,a case is found where the Nusselt number increases by 2.3 times relative to the reference case.The integrationof perforated blocks facilitates the generation of vorticity within the channel,promoting the mixing of coldand hot fluids.Notably,MCHS incorporating perforated rectangular blocks exhibit more pronounced heat transferbenefits at Reynolds numbers smaller than 400.
基金The research and development project of Beijing Disaster Prevention Technology Co.,Ltd.(FZKJYF202201)funded this work.
文摘Although the late Quaternary slip rate of the Northern Margin Fault of the Huaizhuo Basin(NFHB)was studied approximately 30 years ago using thermoluminescence and geomorphic methods,the underlying uncertainty cannot be neglected,considering the limitations resulting from age and displacement measurements.Accordingly,we attempted to re-estimate the late Quaternary slip rate of the NFHB using high-precision remote sensing image interpretation,large-scale geological and geomorphic mapping,paleoseismic analysis,and Quaternary geochronology testing.The results,based on stratigraphic dislocation and age constraint in the trenches,show that the present deformation of the NFHB has been dominated by the extension,with a vertical slip rate~0.04-0.11 mm/a.We estimate a vertical slip rate of~0.06 mm/a,with an R^(2) value of~0.91,which is much lower than the~0.5 mm/a result estimated previously.There are three possible reasons for this discrepancy.The fi rst is the limitation resulting from dating and displacement measurements in earlier studies;the second is the slip decomposition caused by multiple branches of the NFHB,which leads to the low slip rate observed at a single fault;and third possible explanation is that the fault may be locked at present with a low slip rate,which means that the earthquake hazard of the NFHB cannot be ignored,and more in-depth research,such as geodetic and intensive observations of earthquake precursors,is urgently needed.This discovery poses a new challenge for the active study of the NFHB and the northeast corner of the Ordos Plateau in the North China Block.
基金Supported by the Jiangsu Agriculture Sience and Technology Innovation Fund(JASTIF)[CX(13)3076]Jiangsu Provincial Postdoctoral Sustentation Fund(6511201,1202055C)~~
文摘[Objective] This study aimed to increase the sensitivity and specificity of enzyme-linked immunosorbent assay （ELISA） through analyzing the effects of different blocking buffers and sample diluents and their different concentrations on the result of ELISA. [Method] Different types of blocking buffer [casein, gelatin, BSA, goat serum （GS）, horse serum （HS） and rabbit serum （RS）]and sample diluent （PBST, casein, gelatin, BSA, GS, HS and RS） as well as their different concentrations were tested in ELISA to screen the optimal combination of blocking buffer and sample diluent. [Result] The results showed that 2% BSA had better effect on blocking than 1% and 3% BSA, and both 2% and 1% casein had better blocking effect than 3% casein; 8% and 10% RS showed better blocking effects than 6%RS and 7%RS; compared to BSA and casein, RS had the best effect on blocking, and 8% RS performed best as the blocking buffer and sample diluent. [Conclusion] A good combination of blocking buffer and diluent can effectively reduce the non-specific reaction and improve the sensitivity and specificity of ELISA. This study provides an important reference for the development of a perfect ELISA method.
文摘Some novel techniques of computational fluid dynamics are used to establish a mathematical model for the open diversion channel with two embankments in river blocking.The technique of boundary fitted coordinate system is used to overcome the difficulties resulting from the complicated shapes of natural river boundaries;the method of alternating direction implicit finite difference scheme is used to solve the partial differential equations in the transformed plane;and the technique of moving boundary is used to deal with the river bed exposed to water surface.This model has been used to predict the flow characteristics in the blocking of the Yangtz river in the Three Gorge Project (TGP).Comparison between the computed and experimental data shows a satisfactory agreement.
