Purpose:The quantitative rankings of over 55,000 institutions and their institutional programs are based on the individual rankings of approximately 30 million scholars determined by their productivity,impact,and qual...Purpose:The quantitative rankings of over 55,000 institutions and their institutional programs are based on the individual rankings of approximately 30 million scholars determined by their productivity,impact,and quality.Design/methodology/approach:The institutional ranking process developed here considers all institutions in all countries and regions,thereby including those that are established,as well as those that are emerging in scholarly prowess.Rankings of individual scholars worldwide are first generated using the recently introduced,fully indexed ScholarGPS database.The rankings of individual scholars are extended here to determine the lifetime and last-five-year Top 20 rankings of academic institutions over all Fields of scholarly endeavor,in 14 individual Fields,in 177 Disciplines,and in approximately 350,000 unique Specialties.Rankings associated with five specific Fields(Medicine,Engineering&Computer Science,Life Sciences,Physical Sciences&Mathematics,and Social Sciences),and in two Disciplines(Chemistry,and Electrical&Computer Engineering)are presented as examples,and changes in the rankings over time are discussed.Findings:For the Fields considered here,the Top 20 institutional rankings in Medicine have undergone the least change(lifetime versus last five years),while the rankings in Engineering&Computer Science have exhibited significant change.The evolution of institutional rankings over time is largely attributed to the recent emergence of Chinese academic institutions,although this emergence is shown to be highly Field-and Discipline-dependent.Practical implementations:Existing rankings of academic institutions have:(i)often been restricted to pre-selected institutions,clouding the potential discovery of scholarly activity in emerging institutions and countries;(ii)considered only broad areas of research,limiting the ability of university leadership to act on the assessments in a concrete manner,or in contrast;(iii)have considered only a narrow area of research for comparison,diminishing the broader applicability and impact of the assessment.In general,existing institutional rankings depend on which institutions are included in the ranking process,which areas of research are considered,the breadth(or granularity)of the research areas of interest,and the methodologies used to define and quantify research performance.In contrast,the methods presented here can provide important data over a broad range of granularity to allow responsible individuals to gauge the performance of any institution from the Overall(all Fields)level,to the level of the Specialty.The methods may also assist identification of the root causes of shifts in institution rankings,and how these shifts vary across hundreds of thousands of Fields,Disciplines,and Specialties of scholarly endeavor.Originality/value:This study provides the first ranking of all academic institutions worldwide over Fields,Disciplines,and Specialties based on a unique methodology that quantifies the productivity,impact,and quality of individual scholars.展开更多
The reuse of waste recycled concrete from harsh environments has become a research hotspot in the field of construction.This study investigated the repair effect of carbonation treatment on second-generation recycled ...The reuse of waste recycled concrete from harsh environments has become a research hotspot in the field of construction.This study investigated the repair effect of carbonation treatment on second-generation recycled fine aggregate(SRFA)obtained from recycled fine aggregate concrete(RFAC)subjected to freeze-thaw(FT)cycles.Before and after carbonation,the properties of SRFA were evaluated.Carbonated second-generation recycled fine aggregate(CSRFA)at five substitution rates(0%,25%,50%,75%,100%)to replace SRFA was used to prepare carbonated second-generation recycled fine aggregate concrete(CSRFAC).The water absorption,porosity and mechanical properties of CSRFAC were tested,and its frost-resisting durability was evaluated.The results showed after carbonation treatment,the physical properties of SRFA was improved and met the requirements of II aggregate.The micro-hardness of the interfacial transition zone and attached mortar in CSRFA was 50.5%and 31.2%higher than that in SRFA,respectively.With the increase of CSRFA replacement rate,the water absorption and porosity of CSRFAC gradually decreased,and the mechanical properties and frost resistance of CSRFAC were gradually improved.Carbonation treatment effectively repairs the damage of SRFA caused by FT cycles and improves its application potential.展开更多
With the emphasis on environmental issues,the recycling of waste concrete,even recycled concrete,has become a hot spot in the field of architecture.But the repeated recycling of waste concrete used in harsh environmen...With the emphasis on environmental issues,the recycling of waste concrete,even recycled concrete,has become a hot spot in the field of architecture.But the repeated recycling of waste concrete used in harsh environments is still a complex problem.This paper discusses the durability and recyclability of recycled aggregate concrete(RAC)as a prefabricated material in the harsh environment,the effect of high-temperature curing(60℃,80℃,and 100℃)on the frost resistance of RAC and physical properties of the second generation recycled coarse aggregate(RCA_(2))of RAC after 300 freeze-thaw cycles were studied.The frost resistance of RAC was characterized by compressive strength,relative dynamic elastic modulus,and mass loss.As the physical properties of RCA_(2),the apparent density,water absorption,and crushing value were measured.And the SEM images of RAC after 300 freeze-thaw cycles were shown.The results indicated that the frost resistance of RAC cured at 80℃ for 7 days was comparable to that cured in the standard condition(cured for 28 days at 20℃±2℃ and 95%humidity),and the RAC cured at 100℃ was slightly worse.However,the frost resistance of RAC cured at 60℃ deteriorated seriously.The RAC cured at 80℃ for 7 days is the best.Whether after the freeze-thaw cycle or not,the RCA that curd at 60℃,80℃,and 100℃ for 7 days can also meet the requirements of Grade III RCA and be used as the aggregate of non-bearing part of prefabricated concrete components.RCA_(2) which is cured at 80℃ for 7 days had the best physical properties.展开更多
From November 7 to 10,the China Institute of International Studies(CIIS)held the 20th China-US Yong Scholars’Dialogue,with the theme of“Finding the Right Way for China and the US to Get Along in the New Era:Opportun...From November 7 to 10,the China Institute of International Studies(CIIS)held the 20th China-US Yong Scholars’Dialogue,with the theme of“Finding the Right Way for China and the US to Get Along in the New Era:Opportunities and Challenges.”CIIS President Chen Bo delivered the opening remarks,and Vice President Liu Qing delivered the closing speech.展开更多
The fables of Pre-Qin scholars occupied an important position in the history of the development of Chinese culture,thoughts,and literature,hence had profound and extensive influence on later generations.As a kind of c...The fables of Pre-Qin scholars occupied an important position in the history of the development of Chinese culture,thoughts,and literature,hence had profound and extensive influence on later generations.As a kind of carrier of thoughts,the fables of the Pre-Qin scholars were not immutable and frozen,for they have been influenced by various aspects in the process of transmitting and recognizing.This article attempts to study the evolution of the function,expression,and connotation of the fables of the Pre-Qin scholars.展开更多
It was a shock and disbelief to learn of Peter's death last December.To me,he was so fit in his figure,so healthy in his lifestyle,so mild and mindful in his social behavior,and so devout in his religious belief,....It was a shock and disbelief to learn of Peter's death last December.To me,he was so fit in his figure,so healthy in his lifestyle,so mild and mindful in his social behavior,and so devout in his religious belief,......,I had expected a long and happy life for him,and planned to join his 80th or even 100th birthday celebration.展开更多
This paper discusses the principle and procedures of the second-generation wavelet transform and its application to the denoising of seismic data. Based on lifting steps, it is a flexible wavelet construction method u...This paper discusses the principle and procedures of the second-generation wavelet transform and its application to the denoising of seismic data. Based on lifting steps, it is a flexible wavelet construction method using linear and nonlinear spatial prediction and operators to implement the wavelet transform and to make it reversible. The lifting scheme transform -includes three steps: split, predict, and update. Deslauriers-Dubuc (4, 2) wavelet transforms are used to process both synthetic and real data in our second-generation wavelet transform. The processing results show that random noise is effectively suppressed and the signal to noise ratio improves remarkably. The lifting wavelet transform is an efficient algorithm.展开更多
Google Scholar的推出吸引了越来越多的学术研究人员。本文详细介绍了图书馆链接计划的运作模式和SFX技术的原理。重点介绍了免费链接解析服务器ScholarSFX的配置方法,以及它在浙江大学图书馆的应用,最后对Google Scholar图书馆链接的...Google Scholar的推出吸引了越来越多的学术研究人员。本文详细介绍了图书馆链接计划的运作模式和SFX技术的原理。重点介绍了免费链接解析服务器ScholarSFX的配置方法,以及它在浙江大学图书馆的应用,最后对Google Scholar图书馆链接的应用情况进行了总结。展开更多
After three rounds of rigorous evaluation of registered scholars conducted by the Reference Citation Analysis(RCA)editorial team of Baishideng Publishing Group(Baishideng),the RCA database of Baishideng officially rel...After three rounds of rigorous evaluation of registered scholars conducted by the Reference Citation Analysis(RCA)editorial team of Baishideng Publishing Group(Baishideng),the RCA database of Baishideng officially released the 2022 Article Influence Index(2022 AII)of 632 scholars from 74 countries/territories in 98 research categories,for the first time.The list of 632 scholars can be found at:https://www.referencecitationanalysis.com/searchscholar.Among them,the highest 2022 AII is 348.211,the highest number of total citations is 42830,and the highest number of total articles is 901.The category with the largest number of RCA scholars is Gastroenterology&Hepatology,with a total of 100(15.8%),and the second is Surgery,with a total of 46(7.3%).This article summarizes the RCA scholars and describes the mission of RCA,the openness and transparency of RCA evaluation,the calculation method for the 2022 AII,and the evaluation process of RCA scholars.The RCA scholar list will effectively serve as a useful Find-a-Scholar tool.Any interested scholar is welcome to register and join this RCA scholar list.展开更多
Ground-penetrating radar(GPR)is a highly efficient,fast and non-destructive exploration method for shallow surfaces.High-precision numerical simulation method is employed to improve the interpretation precision of det...Ground-penetrating radar(GPR)is a highly efficient,fast and non-destructive exploration method for shallow surfaces.High-precision numerical simulation method is employed to improve the interpretation precision of detection.Second-generation wavelet finite element is introduced into the forward modeling of the GPR.As the finite element basis function,the second-generation wavelet scaling function constructed by the scheme is characterized as having multiple scales and resolutions.The function can change the analytical scale arbitrarily according to actual needs.We can adopt a small analysis scale at a large gradient to improve the precision of analysis while adopting a large analytical scale at a small gradient to improve the efficiency of analysis.This approach is beneficial to capture the local mutation characteristics of the solution and improve the resolution without changing mesh subdivision to realize the efficient solution of the forward GPR problem.The algorithm is applied to the numerical simulation of line current radiation source and tunnel non-dense lining model with analytical solutions.Result show that the solution results of the secondgeneration wavelet finite element are in agreement with the analytical solutions and the conventional finite element solutions,thereby verifying the accuracy of the second-generation wavelet finite element algorithm.Furthermore,the second-generation wavelet finite element algorithm can change the analysis scale arbitrarily according to the actual problem without subdividing grids again.The adaptive algorithm is superior to traditional scheme in grid refinement and basis function order increase,which makes this algorithm suitable for solving complex GPR forward-modeling problems with large gradient and singularity.展开更多
Alternating-current losses in a two-layer superconducting cable, each layer being composed of 15 closely-spaced rectangular wires made up of second-generation superconductors when the ends of wires are coated by eithe...Alternating-current losses in a two-layer superconducting cable, each layer being composed of 15 closely-spaced rectangular wires made up of second-generation superconductors when the ends of wires are coated by either a non-magnetic or strong ferromagnetic material having a U profile is numerically investigated. Computations are carried out through the finite-element method. The alternating-current losses do not increase significantly if the relative permeability of the coating is increased three orders of magnitude, provided that the current amplitude is less than half of the critical current in a superconducting wire. However, the losses are much higher for ferromagnetic coating if the amplitude of the applied current oscillating at 50 Hz is close to the critical current. The ferromagnetic coating is seen to accumulate the magnetic field lines normally on its surfaces, while the field lines are parallel to the long axes of the wires, leading to more significant flux penetration in the coated regions. This facilitates a uniform low-loss current flow in the uncoated regions of the wires. In contrast, coating with a non-magnetic material gives rise to a considerably smaller current flow in the uncoated regions, whereas the low-loss flow is maintained in the coated regions. Moreover, the current flows in opposite directions in the coated and uncoated regions, where the direction in each region is converse for the two materials.展开更多
Saussure and his linguistic theories have great influences for the study of linguistics and second language acquisition of the world over.Chinese linguistics more or less is influenced by Saussure's theories.This ...Saussure and his linguistic theories have great influences for the study of linguistics and second language acquisition of the world over.Chinese linguistics more or less is influenced by Saussure's theories.This paper is aiming to review all papers written by Chinese scholars on the records by CNKI(Chinese National Knowledge Infrastructure) from 1979 to September 28(2012),meanwhile,and trying to analysis on studies of topics and contents in different periods about Saussure and his theories in China.展开更多
[ Objective] To explore the effects of spaceflight on the second-generation seeds of alfalfa and provide a theoretical basis for mutation breeding. [Method] The seeds of Medicago stavia L. lines no. 1, no. 2 and no. 4...[ Objective] To explore the effects of spaceflight on the second-generation seeds of alfalfa and provide a theoretical basis for mutation breeding. [Method] The seeds of Medicago stavia L. lines no. 1, no. 2 and no. 4 were carried into space by the Shijian-8 seed breeding satellite for a 15-d spaceflight treatment. After returning to the ground, seedlings were transplanted to field. Traits of the second-generation seeds of alfalfa were evaluated. [Result] The 1 000-grain weight of the second-generation seeds were 5% -9% significantly higher than that the control (P 〈 0.05). The germination rate, seedling weight, shoot length and root length were significantly increased (P 〈 0.05). The hard seed rate and the rate of moldy seeds were significantly decreased ( P 〈 0.05). However, the rate of dead seeds was increased. [ Conclusion] Spaceflight treatment has positive mutagenic effects on the second-generation seeds of alfalfa.展开更多
Background:The safety and efficacy of coronary artery bypass grafting(CABG)and second-generation drug-eluting stents(DESs)in patients with coronary artery disease(CAD)remain controversial.Therefore we aimed to compare...Background:The safety and efficacy of coronary artery bypass grafting(CABG)and second-generation drug-eluting stents(DESs)in patients with coronary artery disease(CAD)remain controversial.Therefore we aimed to compare the outcomes of CAD patients treated with CABG and second-generation DESs.Methods:We systematically searched the PubMed,Cochrane Library,Ovid,and Elsevier databases.Studies comparing second-generation DESs with CABG in CAD patients were included.RevMan 5.3 was used to extract and pool the data from the applicable studies.Results:Six trials(N=6604 participants)were included in this meta-analysis.Among all of the CAD patients,second-generation DESs were associated with no differences in the risks of all-cause death[risk ratio(RR)1.18,95% confi dence interval(CI)0.98–1.43,P=0.09],cardiovascular death(RR 1.14,95% CI 0.81–1.59,P=0.45),myocardial infarction(RR 1.22,95% CI 0.98–1.54,P=0.08),and stroke(RR 0.83,95% CI 0.59–1.17,P=0.29),but increased the risks of revascularization(RR 1.95,95% CI 1.66–2.30,P<0.001)and major adverse cardiac and cerebrovascular events(RR 1.72,95% CI:1.31–2.26,P<0.001)when compared with CABG.Conclusions:In the treatment of CAD patients,second-generation DESs was not associated with increased risks of all-cause death,cardiovascular death,myocardial infarction,and stroke,but increased the risks of revascularization and major adverse cardiac and cerebrovascular events when compared with CABG.展开更多
Anatomical dissectionis an important part of human anatomy course and relies much on cadavers.Body donation is the primary source of cadavers used in ana tomical dissection course in China.This study aimed to systemat...Anatomical dissectionis an important part of human anatomy course and relies much on cadavers.Body donation is the primary source of cadavers used in ana tomical dissection course in China.This study aimed to systematically review the contributions of Chinese scholars to body donation research in international journals,in the 100^(th) anniversary of the foundation of Chinese Society for Anatomical Sciences.The search was conducted on May 12,2020.The searching strategy was(body or anatomy or anatomical or cadaver or cadaveric)and(donate or donation or bequest or gift or gifting)and(China or Hong Kong or Macao or Taiwan).Only English articles focusing on body donation research were included.A total of 578 articles were retrieved.展开更多
The study is to explore the test anxiety of three university English teachers in their collaborative learning community when they do their visiting scholar program.The research questions are about the representations ...The study is to explore the test anxiety of three university English teachers in their collaborative learning community when they do their visiting scholar program.The research questions are about the representations of test anxiety of the college English teacher collaborative learning community as visiting scholars,and the interaction between anxiety and their collaborative learning.The main data collection includes deep interview,field observation,online chatting,etc.The research finds that at the three stages of their learning,the participant shows various representations of test anxiety from cognitive,affective and behavioral perspectives,and collaborative learning community facilitates the participant have better execution in learning,more pressure released and much cognitive enhancement achieved.In contrast,lack of collaborative learning environment in her working university and the specific anxiety for marriage in female participant are two additional findings in the study,which may prove the positive effect of collaborative learning on anxiety from another point of view.展开更多
文摘Purpose:The quantitative rankings of over 55,000 institutions and their institutional programs are based on the individual rankings of approximately 30 million scholars determined by their productivity,impact,and quality.Design/methodology/approach:The institutional ranking process developed here considers all institutions in all countries and regions,thereby including those that are established,as well as those that are emerging in scholarly prowess.Rankings of individual scholars worldwide are first generated using the recently introduced,fully indexed ScholarGPS database.The rankings of individual scholars are extended here to determine the lifetime and last-five-year Top 20 rankings of academic institutions over all Fields of scholarly endeavor,in 14 individual Fields,in 177 Disciplines,and in approximately 350,000 unique Specialties.Rankings associated with five specific Fields(Medicine,Engineering&Computer Science,Life Sciences,Physical Sciences&Mathematics,and Social Sciences),and in two Disciplines(Chemistry,and Electrical&Computer Engineering)are presented as examples,and changes in the rankings over time are discussed.Findings:For the Fields considered here,the Top 20 institutional rankings in Medicine have undergone the least change(lifetime versus last five years),while the rankings in Engineering&Computer Science have exhibited significant change.The evolution of institutional rankings over time is largely attributed to the recent emergence of Chinese academic institutions,although this emergence is shown to be highly Field-and Discipline-dependent.Practical implementations:Existing rankings of academic institutions have:(i)often been restricted to pre-selected institutions,clouding the potential discovery of scholarly activity in emerging institutions and countries;(ii)considered only broad areas of research,limiting the ability of university leadership to act on the assessments in a concrete manner,or in contrast;(iii)have considered only a narrow area of research for comparison,diminishing the broader applicability and impact of the assessment.In general,existing institutional rankings depend on which institutions are included in the ranking process,which areas of research are considered,the breadth(or granularity)of the research areas of interest,and the methodologies used to define and quantify research performance.In contrast,the methods presented here can provide important data over a broad range of granularity to allow responsible individuals to gauge the performance of any institution from the Overall(all Fields)level,to the level of the Specialty.The methods may also assist identification of the root causes of shifts in institution rankings,and how these shifts vary across hundreds of thousands of Fields,Disciplines,and Specialties of scholarly endeavor.Originality/value:This study provides the first ranking of all academic institutions worldwide over Fields,Disciplines,and Specialties based on a unique methodology that quantifies the productivity,impact,and quality of individual scholars.
基金financially sponsored by Qing Lan Project in Jiangsu Province of China(2023)Scientific Research Project of Taizhou Polytechnic College(TZYKY-22-4).
文摘The reuse of waste recycled concrete from harsh environments has become a research hotspot in the field of construction.This study investigated the repair effect of carbonation treatment on second-generation recycled fine aggregate(SRFA)obtained from recycled fine aggregate concrete(RFAC)subjected to freeze-thaw(FT)cycles.Before and after carbonation,the properties of SRFA were evaluated.Carbonated second-generation recycled fine aggregate(CSRFA)at five substitution rates(0%,25%,50%,75%,100%)to replace SRFA was used to prepare carbonated second-generation recycled fine aggregate concrete(CSRFAC).The water absorption,porosity and mechanical properties of CSRFAC were tested,and its frost-resisting durability was evaluated.The results showed after carbonation treatment,the physical properties of SRFA was improved and met the requirements of II aggregate.The micro-hardness of the interfacial transition zone and attached mortar in CSRFA was 50.5%and 31.2%higher than that in SRFA,respectively.With the increase of CSRFA replacement rate,the water absorption and porosity of CSRFAC gradually decreased,and the mechanical properties and frost resistance of CSRFAC were gradually improved.Carbonation treatment effectively repairs the damage of SRFA caused by FT cycles and improves its application potential.
基金This research was funded by the National Natural Science Foundation of China(52078068)Practice Innovation Program of Jiangsu Province(KYCX22_3082).
文摘With the emphasis on environmental issues,the recycling of waste concrete,even recycled concrete,has become a hot spot in the field of architecture.But the repeated recycling of waste concrete used in harsh environments is still a complex problem.This paper discusses the durability and recyclability of recycled aggregate concrete(RAC)as a prefabricated material in the harsh environment,the effect of high-temperature curing(60℃,80℃,and 100℃)on the frost resistance of RAC and physical properties of the second generation recycled coarse aggregate(RCA_(2))of RAC after 300 freeze-thaw cycles were studied.The frost resistance of RAC was characterized by compressive strength,relative dynamic elastic modulus,and mass loss.As the physical properties of RCA_(2),the apparent density,water absorption,and crushing value were measured.And the SEM images of RAC after 300 freeze-thaw cycles were shown.The results indicated that the frost resistance of RAC cured at 80℃ for 7 days was comparable to that cured in the standard condition(cured for 28 days at 20℃±2℃ and 95%humidity),and the RAC cured at 100℃ was slightly worse.However,the frost resistance of RAC cured at 60℃ deteriorated seriously.The RAC cured at 80℃ for 7 days is the best.Whether after the freeze-thaw cycle or not,the RCA that curd at 60℃,80℃,and 100℃ for 7 days can also meet the requirements of Grade III RCA and be used as the aggregate of non-bearing part of prefabricated concrete components.RCA_(2) which is cured at 80℃ for 7 days had the best physical properties.
文摘From November 7 to 10,the China Institute of International Studies(CIIS)held the 20th China-US Yong Scholars’Dialogue,with the theme of“Finding the Right Way for China and the US to Get Along in the New Era:Opportunities and Challenges.”CIIS President Chen Bo delivered the opening remarks,and Vice President Liu Qing delivered the closing speech.
基金北京市大学生创新训练项目-先秦子部“寓言”文本生成与传播路径研究,Serial Number S202210015036北京印刷学院校级教改创新重点项目-国家级一流专业--编辑出版学专业建设研究,Serial Number22150223075.
文摘The fables of Pre-Qin scholars occupied an important position in the history of the development of Chinese culture,thoughts,and literature,hence had profound and extensive influence on later generations.As a kind of carrier of thoughts,the fables of the Pre-Qin scholars were not immutable and frozen,for they have been influenced by various aspects in the process of transmitting and recognizing.This article attempts to study the evolution of the function,expression,and connotation of the fables of the Pre-Qin scholars.
文摘It was a shock and disbelief to learn of Peter's death last December.To me,he was so fit in his figure,so healthy in his lifestyle,so mild and mindful in his social behavior,and so devout in his religious belief,......,I had expected a long and happy life for him,and planned to join his 80th or even 100th birthday celebration.
文摘This paper discusses the principle and procedures of the second-generation wavelet transform and its application to the denoising of seismic data. Based on lifting steps, it is a flexible wavelet construction method using linear and nonlinear spatial prediction and operators to implement the wavelet transform and to make it reversible. The lifting scheme transform -includes three steps: split, predict, and update. Deslauriers-Dubuc (4, 2) wavelet transforms are used to process both synthetic and real data in our second-generation wavelet transform. The processing results show that random noise is effectively suppressed and the signal to noise ratio improves remarkably. The lifting wavelet transform is an efficient algorithm.
文摘After three rounds of rigorous evaluation of registered scholars conducted by the Reference Citation Analysis(RCA)editorial team of Baishideng Publishing Group(Baishideng),the RCA database of Baishideng officially released the 2022 Article Influence Index(2022 AII)of 632 scholars from 74 countries/territories in 98 research categories,for the first time.The list of 632 scholars can be found at:https://www.referencecitationanalysis.com/searchscholar.Among them,the highest 2022 AII is 348.211,the highest number of total citations is 42830,and the highest number of total articles is 901.The category with the largest number of RCA scholars is Gastroenterology&Hepatology,with a total of 100(15.8%),and the second is Surgery,with a total of 46(7.3%).This article summarizes the RCA scholars and describes the mission of RCA,the openness and transparency of RCA evaluation,the calculation method for the 2022 AII,and the evaluation process of RCA scholars.The RCA scholar list will effectively serve as a useful Find-a-Scholar tool.Any interested scholar is welcome to register and join this RCA scholar list.
基金supported by the National Natural Science Foundation of China(Nos.41574116 and 41774132)Hunan Provincial Innovation Foundation for Postgraduate(Grant Nos.CX2017B052)the Fundamental Research Funds for the Central Universities of Central South University(Nos.2018zzts693)。
文摘Ground-penetrating radar(GPR)is a highly efficient,fast and non-destructive exploration method for shallow surfaces.High-precision numerical simulation method is employed to improve the interpretation precision of detection.Second-generation wavelet finite element is introduced into the forward modeling of the GPR.As the finite element basis function,the second-generation wavelet scaling function constructed by the scheme is characterized as having multiple scales and resolutions.The function can change the analytical scale arbitrarily according to actual needs.We can adopt a small analysis scale at a large gradient to improve the precision of analysis while adopting a large analytical scale at a small gradient to improve the efficiency of analysis.This approach is beneficial to capture the local mutation characteristics of the solution and improve the resolution without changing mesh subdivision to realize the efficient solution of the forward GPR problem.The algorithm is applied to the numerical simulation of line current radiation source and tunnel non-dense lining model with analytical solutions.Result show that the solution results of the secondgeneration wavelet finite element are in agreement with the analytical solutions and the conventional finite element solutions,thereby verifying the accuracy of the second-generation wavelet finite element algorithm.Furthermore,the second-generation wavelet finite element algorithm can change the analysis scale arbitrarily according to the actual problem without subdividing grids again.The adaptive algorithm is superior to traditional scheme in grid refinement and basis function order increase,which makes this algorithm suitable for solving complex GPR forward-modeling problems with large gradient and singularity.
基金Project supported by the Fund from the Scientific and Technological Research Council of Turkey(TüB˙ITAK)(Grant No.110T876)
文摘Alternating-current losses in a two-layer superconducting cable, each layer being composed of 15 closely-spaced rectangular wires made up of second-generation superconductors when the ends of wires are coated by either a non-magnetic or strong ferromagnetic material having a U profile is numerically investigated. Computations are carried out through the finite-element method. The alternating-current losses do not increase significantly if the relative permeability of the coating is increased three orders of magnitude, provided that the current amplitude is less than half of the critical current in a superconducting wire. However, the losses are much higher for ferromagnetic coating if the amplitude of the applied current oscillating at 50 Hz is close to the critical current. The ferromagnetic coating is seen to accumulate the magnetic field lines normally on its surfaces, while the field lines are parallel to the long axes of the wires, leading to more significant flux penetration in the coated regions. This facilitates a uniform low-loss current flow in the uncoated regions of the wires. In contrast, coating with a non-magnetic material gives rise to a considerably smaller current flow in the uncoated regions, whereas the low-loss flow is maintained in the coated regions. Moreover, the current flows in opposite directions in the coated and uncoated regions, where the direction in each region is converse for the two materials.
文摘Saussure and his linguistic theories have great influences for the study of linguistics and second language acquisition of the world over.Chinese linguistics more or less is influenced by Saussure's theories.This paper is aiming to review all papers written by Chinese scholars on the records by CNKI(Chinese National Knowledge Infrastructure) from 1979 to September 28(2012),meanwhile,and trying to analysis on studies of topics and contents in different periods about Saussure and his theories in China.
基金supported by the grants of the National Key Technology R&D Program (2008BADB3B04 )Basic Science and Research Special Fund for the State Level and Public Scientific Research Institute (Grassland Research Institute,Chinese Academy of Agricultural Sciences) (2007-1-02)
文摘[ Objective] To explore the effects of spaceflight on the second-generation seeds of alfalfa and provide a theoretical basis for mutation breeding. [Method] The seeds of Medicago stavia L. lines no. 1, no. 2 and no. 4 were carried into space by the Shijian-8 seed breeding satellite for a 15-d spaceflight treatment. After returning to the ground, seedlings were transplanted to field. Traits of the second-generation seeds of alfalfa were evaluated. [Result] The 1 000-grain weight of the second-generation seeds were 5% -9% significantly higher than that the control (P 〈 0.05). The germination rate, seedling weight, shoot length and root length were significantly increased (P 〈 0.05). The hard seed rate and the rate of moldy seeds were significantly decreased ( P 〈 0.05). However, the rate of dead seeds was increased. [ Conclusion] Spaceflight treatment has positive mutagenic effects on the second-generation seeds of alfalfa.
基金the National Natural Science Foundation of China (8153000545).
文摘Background:The safety and efficacy of coronary artery bypass grafting(CABG)and second-generation drug-eluting stents(DESs)in patients with coronary artery disease(CAD)remain controversial.Therefore we aimed to compare the outcomes of CAD patients treated with CABG and second-generation DESs.Methods:We systematically searched the PubMed,Cochrane Library,Ovid,and Elsevier databases.Studies comparing second-generation DESs with CABG in CAD patients were included.RevMan 5.3 was used to extract and pool the data from the applicable studies.Results:Six trials(N=6604 participants)were included in this meta-analysis.Among all of the CAD patients,second-generation DESs were associated with no differences in the risks of all-cause death[risk ratio(RR)1.18,95% confi dence interval(CI)0.98–1.43,P=0.09],cardiovascular death(RR 1.14,95% CI 0.81–1.59,P=0.45),myocardial infarction(RR 1.22,95% CI 0.98–1.54,P=0.08),and stroke(RR 0.83,95% CI 0.59–1.17,P=0.29),but increased the risks of revascularization(RR 1.95,95% CI 1.66–2.30,P<0.001)and major adverse cardiac and cerebrovascular events(RR 1.72,95% CI:1.31–2.26,P<0.001)when compared with CABG.Conclusions:In the treatment of CAD patients,second-generation DESs was not associated with increased risks of all-cause death,cardiovascular death,myocardial infarction,and stroke,but increased the risks of revascularization and major adverse cardiac and cerebrovascular events when compared with CABG.
文摘Anatomical dissectionis an important part of human anatomy course and relies much on cadavers.Body donation is the primary source of cadavers used in ana tomical dissection course in China.This study aimed to systematically review the contributions of Chinese scholars to body donation research in international journals,in the 100^(th) anniversary of the foundation of Chinese Society for Anatomical Sciences.The search was conducted on May 12,2020.The searching strategy was(body or anatomy or anatomical or cadaver or cadaveric)and(donate or donation or bequest or gift or gifting)and(China or Hong Kong or Macao or Taiwan).Only English articles focusing on body donation research were included.A total of 578 articles were retrieved.
基金The author wishes to acknowledge support from English Language and Literature,a Key Program in Gauangdong Province(GDTX170109),2017The Research Team in South China Buisiness College:The Association Project of Comparative Study of English and Chinese in the New Era(2017-298).
文摘The study is to explore the test anxiety of three university English teachers in their collaborative learning community when they do their visiting scholar program.The research questions are about the representations of test anxiety of the college English teacher collaborative learning community as visiting scholars,and the interaction between anxiety and their collaborative learning.The main data collection includes deep interview,field observation,online chatting,etc.The research finds that at the three stages of their learning,the participant shows various representations of test anxiety from cognitive,affective and behavioral perspectives,and collaborative learning community facilitates the participant have better execution in learning,more pressure released and much cognitive enhancement achieved.In contrast,lack of collaborative learning environment in her working university and the specific anxiety for marriage in female participant are two additional findings in the study,which may prove the positive effect of collaborative learning on anxiety from another point of view.