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Brain-derived neurotrophic factor signaling in the neuromuscular junction during developmental axonal competition and synapse elimination
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作者 Josep Tomàs Víctor Cilleros-Mañé +7 位作者 Laia Just-Borràs Marta Balanyà-Segura Aleksandra Polishchuk Laura Nadal Marta Tomàs Carolina Silvera-Simón Manel M.Santafé Maria A.Lanuza 《Neural Regeneration Research》 SCIE CAS 2025年第2期394-401,共8页
During the development of the nervous system,there is an overproduction of neurons and synapses.Hebbian competition between neighboring nerve endings and synapses performing different activity levels leads to their el... During the development of the nervous system,there is an overproduction of neurons and synapses.Hebbian competition between neighboring nerve endings and synapses performing different activity levels leads to their elimination or strengthening.We have extensively studied the involvement of the brain-derived neurotrophic factor-Tropomyosin-related kinase B receptor neurotrophic retrograde pathway,at the neuromuscular junction,in the axonal development and synapse elimination process versus the synapse consolidation.The purpose of this review is to describe the neurotrophic influence on developmental synapse elimination,in relation to other molecular pathways that we and others have found to regulate this process.In particular,we summarize our published results based on transmitter release analysis and axonal counts to show the different involvement of the presynaptic acetylcholine muscarinic autoreceptors,coupled to downstream serine-threonine protein kinases A and C(PKA and PKC)and voltage-gated calcium channels,at different nerve endings in developmental competition.The dynamic changes that occur simultaneously in several nerve terminals and synapses converge across a postsynaptic site,influence each other,and require careful studies to individualize the mechanisms of specific endings.We describe an activity-dependent balance(related to the extent of transmitter release)between the presynaptic muscarinic subtypes and the neurotrophin-mediated TrkB/p75NTR pathways that can influence the timing and fate of the competitive interactions between the different axon terminals.The downstream displacement of the PKA/PKC activity ratio to lower values,both in competing nerve terminals and at postsynaptic sites,plays a relevant role in controlling the elimination of supernumerary synapses.Finally,calcium entry through L-and P/Q-subtypes of voltage-gated calcium channels(both channels are present,together with the N-type channel in developing nerve terminals)contributes to reduce transmitter release and promote withdrawal of the most unfavorable nerve terminals during elimination(the weakest in acetylcholine release and those that have already become silent).The main findings contribute to a better understanding of punishment-rewarding interactions between nerve endings during development.Identifying the molecular targets and signaling pathways that allow synapse consolidation or withdrawal of synapses in different situations is important for potential therapies in neurodegenerative diseases. 展开更多
关键词 acetylcholine release adenosine receptors axonal competition brain-derived neurotrophic factor calcium channels motor end-plate muscarinic acetylcholine receptors postnatal synapse elimination serine kinases tropomyosin-related kinase receptorB
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Mixed Market Competition in a Quality Differentiated Duopoly Model An Approach to Banking Sector
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作者 Ram Kumar Phuyal 《Chinese Business Review》 2014年第1期19-27,共9页
This paper attempts to develop a theoretical framework to investigate the competitive implications of quality choices of financial institutions whereby they charge prices to consumers based on their willingness to pay... This paper attempts to develop a theoretical framework to investigate the competitive implications of quality choices of financial institutions whereby they charge prices to consumers based on their willingness to pay for the service qualities in the mixed market scenario under vertical product differentiation model. Initially, it analyzes benchmark equilibrium solutions of monopoly and duopoly to establish the degree of quality differentiation between two private banks in an uncover market configuration. Further, it estimates the quality differentiation between private and public banks, and examines the interaction between two market structures keeping public bank as both leader and follower, and then measures the social welfare from different prospectives. The explicit operation of two stages Nash equilibrium game forecasted that public banks' monopoly seems to be still better than a private banking, and it is socially optimal. The outcome demonstrates a significant importance of vertical quality differentiation for policy implication in banking industry and provides an insight on the reasons of particular co-existence of public and private banking services in the specified location. In this context, it is concluded that the presence of public banks in banking industries is a crucial condition for obtaining the higher range of social welfare. 展开更多
关键词 banking industry Bertrand price competition mixed duopoly vertical quality differentiation
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Impacts of COVID-19 Lockdown on the Banking Activities in Conakry
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作者 Yansane Alhousseine Souare Sekou +4 位作者 Sêna Paumelie Immaculée N’Diaye Marie Angele Mamadou Mouctar Diallo F.B.A. Diallo Conde Namoudou 《Occupational Diseases and Environmental Medicine》 2024年第4期363-368,共6页
Introduction: The COVID-19 pandemic has affected all professional sectors to varying degrees. It has forced companies to restructure, initiate and promote telework. The aim was to study the impacts of COVID-19 lockdow... Introduction: The COVID-19 pandemic has affected all professional sectors to varying degrees. It has forced companies to restructure, initiate and promote telework. The aim was to study the impacts of COVID-19 lockdown on banking activities in Conakry. Materials and Methods: This was a descriptive cross-sectional study over seven months (from November 25, 2020 to June 27, 2021) and multicentric. It included thirteen of the eighteen banks of the main city of the capital Conakry (Kaloum). We analysed socio-demographic data and occupational characteristics. We paid particular attention to banking activities and medical datas. Results: During our study period, 875 workers met to our criteria, one third of whom were men. The average age was 37.93 ± 9.39 years [22 - 71]. Financial accounters were the most represented and average seniority at the job was 5.35 years. The work schedule was reduced during lockdown but an telework increased (29.8%). On the medical datas, the prevalence of COVID-19 was 20.7%;the lethality rate was 0.6% and the absentee rate 15.6%. The COVID-19 lockdown has deeply impacted the banking activities in Conakry particularly the productivity by a significant decrease in net banking income. Conclusion: Despite the continuity of activities during this pandemic, banks have experienced a reduction in their productivity resulting in a significant decrease in net banking income. These impacts of COVID-19 on the banking sector reflect its impact on the national economy. 展开更多
关键词 banking Sector COVID-19 Lockdown
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Research on Early Warning of Banking Crises from the Perspective of Credit Structures
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作者 Zhou Yuqin Luo Zixuan Wu Shan 《Contemporary Social Sciences》 2024年第3期45-63,共19页
The relationship between credit expansion and banking crises is complex and cannot be fully explained by total credit alone.A systematic analysis of the relationship between the amount and structure of total credit an... The relationship between credit expansion and banking crises is complex and cannot be fully explained by total credit alone.A systematic analysis of the relationship between the amount and structure of total credit and banking crises is important for an objective prediction of the influence of potential financial risks.This paper,drawing on data from 15 selected countries,delves into the power of credit indicators in the early warning of banking crises from the perspectives of industrial structure,sector structure,and term structure of credit.Various machine learning methods were used,including Logistic Regression,Random Forest,Decision Tree,Support Vector Machine(SVM),Bagging,and Boosting models.The empirical findings indicate that credit expansion plays a crucial role in triggering banking crises.However,total credit is better suited for the early warning of short-term banking crises,whereas credit structure is more useful for the early warning of long-term banking crises.Moreover,in an early warning system,identifying key early warning indicators is more meaningful than merely increasing the number of indicators.Machine learning can somewhat enhance the early warning power,but it may not always be robust.Therefore,more attention should be paid to potential systemic banking crises resulting from an imbalance in credit structure while regulating the total credit threshold. 展开更多
关键词 banking crises credit expansion transnational empirical evidence structural perspective
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Anion competition for Li^(+)solvated coordination environments in poly(1,3 dioxolane)electrolyte to enable high-voltage lithium metal solid-state batteries
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作者 Qiujun Wang Yanqiang Ma +6 位作者 Xiaomeng Jia Di Zhang Zhaojin Li Huilan Sun Qujiang Sun Bo Wang Li-Zhen Fan 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第9期633-641,共9页
Gel-based polymer electrolytes are limited by the polarity of the residual solvent,which restricts the coupling-breaking behaviour during Li^(+)conduction,resulting in the Li^(+)transport kinetics being greatly affect... Gel-based polymer electrolytes are limited by the polarity of the residual solvent,which restricts the coupling-breaking behaviour during Li^(+)conduction,resulting in the Li^(+)transport kinetics being greatly affected.Here,we designed anion competitive gel polymer electrolyte(ACPE)by introducing lithium difluoro(oxalato)borate(LiDFOB)anion into the 1,3-dioxolane(DOL)in situ polymerisation system.ACPE enhances the ionic dipole interaction between Li^(+)and the solvent molecules and synergizes with Li^(+)across the solvation site of the polymer ethylene oxide(EO)unit,combination that greatly improves the Li^(+)transport efficiency.As a result,ACPE exhibits 1.12 mS cm^(−1)ionic conductivity and 0.75 Li^(+)transfer number at room temperature.Additionally,this intra-polymer solvation sheath allows preferential desolvation of DFOB−,which contributes to the formation of kinetically stable anion-derived interphase and effectively mitigates side reactions.Our results demonstrate that the assembled Li||NCM622 solid-state battery exhibits lifespan of over 300 cycles with average Coulombic efficiency of 98.8%and capacity retention of 80.3%.This study introduces a novel approach for ion migration and interface design,paving the way for high-safety and high-energy-density batteries. 展开更多
关键词 Li-metal batteries Poly(1 3-dioxolane) In situ polymerization Solid-state polymer electrolytes Anion competition
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Tree allometry responses to competition and complementarity in mixed-species plantations of Betula alnoides
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作者 Boyao Chen Kaili Liu +5 位作者 Chunsheng Wang Junjie Guo Junkun Lu Lin Chen Zhigang Zhao Jie Zeng 《Forest Ecosystems》 SCIE CSCD 2024年第4期469-479,共11页
Tree allometry plays a crucial role in tree survival,stability,and timber quantity and quality of mixed-species plantations.However,the responses of tree allometry to resource utilisation within the framework of inter... Tree allometry plays a crucial role in tree survival,stability,and timber quantity and quality of mixed-species plantations.However,the responses of tree allometry to resource utilisation within the framework of interspecific competition and complementarity remain poorly understood.Taking into consideration strong-and weakspace competition(SC and WC),as well as N_(2)-fixing and non-N_(2)-fixing tree species(FN and nFN),a mixedspecies planting trial was conducted for Betula alnoides,a pioneer tree species,which was separately mixed with Acacia melanoxylon(SC+FN),Erythrophleum fordii(WC+FN),Eucalyptus cloeziana(SC+nFN)and Pinus kesiya var.langbianensis(WC+nFN)in southern China.Six years after planting,tree growth,total nitrogen(N)and carbon(C)contents,and the natural abundances of^(15)N and^(13)C in the leaves were measured for each species,and the mycorrhizal colonisation rates of B.alnoides were investigated under each treatment.Allometric variations and their relationships with space competition and nutrient-related factors were analyzed.The results showed a consistent effect of space competition on the height-diameter relationship of B.alnoides in mixtures with FN or nFN.The tree height growth of B.alnoides was significantly promoted under high space competition,and growth in diameter at breast height(DBH),tree height and crown size were all expedited in mixtures with FN.The symbiotic relationship between ectomycorrhizal fungi and B.alnoides was significantly influenced by both space competition and N_(2) fixation by the accompanying tree species,whereas such significant effects were absent for arbuscular mycorrhizal fungi.Furthermore,high space competition significantly decreased the water use efficiency(WUE)of B.alnoides,and its N use efficiency(NUE)was much lower in the FN mixtures.Structural equation modeling further demonstrated that the stem allometry of B.alnoides was affected by its NUE and WUE via changes in its height growth,and crown allometry was influenced by the mycorrhizal symbiotic relationship.Our findings provide new insights into the mechanisms driving tree allometric responses to above-and belowground resource competition and complementarity in mixed-species plantations,which are instructive for the establishment of mixed-species plantations. 展开更多
关键词 Allometric relationship Resources competition and complementarity Mixed-species forest Tree-fungal symbiotic relationship N_2-fixing tree species Resource utilisation strategies
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The Impact of the Monetary Policy During the COVID-19 in the Brazilian Banking Sector
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作者 Karina Robial Michele Nascimento Jucá 《Chinese Business Review》 2024年第2期60-75,共16页
The COVID-19 pandemic caused an outbreak on the global productive chains,transforming companies and society in general.Governments adopted anticyclical policies such as basic interest rates reduction as response.Brazi... The COVID-19 pandemic caused an outbreak on the global productive chains,transforming companies and society in general.Governments adopted anticyclical policies such as basic interest rates reduction as response.Brazil basic interest rate is denominated Selic.The application of these policies requires the protagonist of bank’s financial intermediation.This study aims to verify two events-under the perspective of the efficient markets’theory.The first is the communication of the first death by COVID-19-and the subsequent,Selic rate reduction to 2%p.a.-and its effects on bank’s shares prices.The hypotheses presented are:H1-The announcement of the first death by COVID-19 negatively impacts the banks’shares returns and H2-The announcement of the Selic interest rate-during the COVID-19-positively impacts the return of the banks’shares.We adopt event study methodology in a final sample of nine and 15 banks to Events 1 and 2 respectively.The results confirm H1 as well as the semi-strong informational efficiency market.H2 is not confirmed.Results confirm the non-effectiveness of the anticyclical policy of basic interest rate reduction.This contributes to the discussion about the impacts of COVID-19 and the efficacy of anticyclical policies. 展开更多
关键词 monetary policy COVID-19 BANKS Brazil event study
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Dilemmas and Optimization of Third-Party Assessment System in Chinese Fair Competition Review
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作者 Cui Xu Mingyu Hu 《Open Journal of Applied Sciences》 2024年第8期2039-2049,共11页
The current predominant self-review mechanism by policy-making bodies suffers from deficiencies such as insufficient motivations, limited review capabilities, and weak external supervision. Third-party assessment, cha... The current predominant self-review mechanism by policy-making bodies suffers from deficiencies such as insufficient motivations, limited review capabilities, and weak external supervision. Third-party assessment, characterized by independence and specialization, is designed to mitigate these shortcomings. However, the implementation of third-party assessment faces challenges too. This paper intends to improve the third-party assessment system and to realize the legislative purpose of the system. Based on social research, discussions and exchanges with relevant parties, and the existing research results, this paper analyzes the challenges and possible optimization measures for the third-party assessment. The challenges include repulsion from policy-making bodies, insufficient independence of assessment bodies, disparity of assessment quality, and limited application of assessment outcomes. Possible optimization measures include promoting fair competition culture, increasing the acceptance of third-party assessment from policy-making bodies, enhancing the quality of third-party assessment, clarifying the relationship between policy-making bodies and assessment bodies, ensuring the independence of third-party assessments, and promoting the application of assessment results. 展开更多
关键词 Fair competition Review Self-Review Third-Party Assessment DILEMMA Optimization
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Discussion on the Application of Technical and Tactical Skills in Mixed Martial Arts Competitions
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作者 Yu Huang 《Journal of Contemporary Educational Research》 2024年第2期8-13,共6页
This article mainly analyzes the application of technical and tactical skills in mixed martial arts competitions,including mixed martial arts and its competition characteristics,the main application significance of te... This article mainly analyzes the application of technical and tactical skills in mixed martial arts competitions,including mixed martial arts and its competition characteristics,the main application significance of technical and tactical skills in mixed martial arts competitions,and its primary application strategies.It is hoped that this analysis can provide some guidelines for the appropriate application of mixed martial arts athletes’technical and tactical skills to improve their winning rate in mixed martial arts competitions. 展开更多
关键词 Mixed martial arts competition Technical and tactical skills Fighting awareness Fighting movements competition rhythm
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ISO Certification and Technical Efficiency in the Banking Sector:An Evidence from WAEMU’s Countries Using the DEA Method
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作者 Gnoleba Martin Zahore 《Economics World》 2024年第2期55-68,共14页
In the view of the international organization of standardization,the introduction of ISO standards is typical of quality management systems oriented towards strengthening the efficiency of enterprises.Business banks a... In the view of the international organization of standardization,the introduction of ISO standards is typical of quality management systems oriented towards strengthening the efficiency of enterprises.Business banks are not excluded from this requirement.The current study aims to evaluate the effect of ISO certification on the technical performance of WAEMU banks.Using BCEAO data(2020),the DEA model and Tobit estimates show that ISO certification has no effect on the efficiency scores of the banks in the sample.It is therefore appropriate for these banks to work on improving their business climate. 展开更多
关键词 business banks DEA technical efficiency ISO WAEMU TOBIT
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Investigating customer churn in banking:a machine learning approach and visualization app for data science and management
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作者 Pahul Preet Singh Fahim Islam Anik +3 位作者 Rahul Senapati Arnav Sinha Nazmus Sakib Eklas Hossain 《Data Science and Management》 2024年第1期7-16,共10页
Customer attrition in the banking industry occurs when consumers quit using the goods and services offered by the bank for some time and,after that,end their connection with the bank.Therefore,customer retention is es... Customer attrition in the banking industry occurs when consumers quit using the goods and services offered by the bank for some time and,after that,end their connection with the bank.Therefore,customer retention is essential in today’s extremely competitive banking market.Additionally,having a solid customer base helps attract new consumers by fostering confidence and a referral from a current clientele.These factors make reducing client attrition a crucial step that banks must pursue.In our research,we aim to examine bank data and forecast which users will most likely discontinue using the bank’s services and become paying customers.We use various machine learning algorithms to analyze the data and show comparative analysis on different evaluation metrics.In addition,we developed a Data Visualization RShiny app for data science and management regarding customer churn analysis.Analyzing this data will help the bank indicate the trend and then try to retain customers on the verge of attrition. 展开更多
关键词 Bank customer attrition Churn prediction Machine learning XGboost Random forest
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Research on the Role of Guiding Students to Participate in Skills Competitions on the Development of Young Teachers in Vocational Colleges
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作者 Jinru Ma Meiqin Liang 《Journal of Contemporary Educational Research》 2024年第5期212-217,共6页
This paper explores the role of guiding students to participate in skills competitions on the development of young teachers in vocational colleges.We investigate the impact of skills competitions on the consolidation ... This paper explores the role of guiding students to participate in skills competitions on the development of young teachers in vocational colleges.We investigate the impact of skills competitions on the consolidation of professional knowledge,development of innovation capabilities,improvement of hands-on abilities,and enhancement of communication skills with students.The results of this research demonstrate that skills competitions have a positive influence on the professional growth of young teachers.The consolidation of professional knowledge,development of innovation capabilities,improvement of hands-on abilities,and enhancement of communication skills collectively contribute to the effectiveness of young teachers in vocational colleges.It is recommended that vocational colleges prioritize and support the participation of young teachers in skills competitions to foster their professional development. 展开更多
关键词 Skills competitions Young teachers Vocational colleges Professional development Communication skills
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Teaching Design and Implementation of the Electrical and Electronic Technology Course Based on Teaching Ability Competition
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作者 Xiayida Maxue’er 《Journal of Electronic Research and Application》 2024年第3期66-71,共6页
The teaching ability competition is a vital method for stimulating teachers’enthusiasm and enhancing their teaching skills.This approach has gained increasing attention from colleges and universities in recent years.... The teaching ability competition is a vital method for stimulating teachers’enthusiasm and enhancing their teaching skills.This approach has gained increasing attention from colleges and universities in recent years.The competition focuses on evaluating teachers’capabilities in designing and implementing lessons,encouraging the exchange of new educational ideas and high-quality teaching methods.Reforming the teaching of Electrical and Electronic Technology courses based on insights from teaching competitions can significantly improve teaching quality.This paper explores the teaching design and implementation of the Electrical and Electronic Technology course,drawing on the principles of teaching ability competitions.First,it analyzes the existing problems in teaching this course.Then,it highlights the significant benefits that teaching competitions bring to the course.Based on these insights,the paper proposes practical strategies aimed at enhancing students’interest and practical skills,thereby promoting innovative developments in teaching Electrical and Electronic Technology. 展开更多
关键词 Teaching ability competition Electrical and Electronic Technology Course instructional design Colleges and universities
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Discussion on the Integration of“Post,Course,Competition,Certificate”:Taking the Internet of Things Application Technology Courses in Higher Vocational Colleges as an Example
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作者 Dongmei He 《Journal of Contemporary Educational Research》 2024年第9期25-31,共7页
This article explores the development of the Internet of Things(IoT)application technology course in higher vocational colleges under the background of“post,course,competition,certificate.”It first emphasizes the im... This article explores the development of the Internet of Things(IoT)application technology course in higher vocational colleges under the background of“post,course,competition,certificate.”It first emphasizes the importance of IoT talent training and course construction in higher vocational colleges and deeply analyzes the core concept of“post,course,competition,certificate”integration.In view of the problems faced in the course construction of IoT application technology in higher vocational colleges and the practical experience of Tianjin Vocational College of Mechanics and Electricity,the implementation strategy of the course construction of IoT application technology in higher vocational colleges is elaborated in detail based on the integrated concept of“post,course,competition,certificate.” 展开更多
关键词 Post course competition certificate Course construction Integration of industry and education
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The Model of“Post,Course,Competition,Certificate”Integrated Education for Electronic Information Engineering Technology Major in Higher Vocational Colleges
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作者 Qinqin Jing Yun Liu Xinyu Zheng 《Journal of Contemporary Educational Research》 2024年第5期223-229,共7页
The core education function of higher vocational colleges is to train technical talents with high quality,so as to meet the needs of talents in the development stage of our society.Under the guidance of talent trainin... The core education function of higher vocational colleges is to train technical talents with high quality,so as to meet the needs of talents in the development stage of our society.Under the guidance of talent training,higher vocational colleges need to pay attention to establishing an all-round and three-dimensional education model,and promote innovation of higher vocational education on the basis of this.It is also a way to promote the innovation of higher vocational education to vigorously promote the construction of“post,course,competition,certificate”mode in the construction of education mode.Through the construction of“post,course,competition,certificate”mode,the education mode of higher vocational colleges is gradually improved,so as to strengthen the effectiveness of talent training in higher vocational colleges.Therefore,in this paper,the author puts forward some suggestions to promote the construction of the integrated education mode of the electronic information engineering technology major in higher vocational colleges,so as to help improve the talent training level of higher vocational colleges. 展开更多
关键词 Higher vocational education Electronic information engineering technology major “Post course competition certificate” Integrated education model
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库岸塔柱状危岩的压裂耦合损伤-突变失稳预测
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作者 唐红梅 宋刚 +2 位作者 杨健 毛柯洁 周福川 《三峡大学学报(自然科学版)》 CAS 北大核心 2025年第1期28-36,共9页
位于三峡库区巫峡段消落带的塔柱状危岩,其底部多损伤因素的耦合作用下常呈压裂诱发座溃整体失稳模式,危岩底部耦合损伤至突变机制是研究该类库岸危岩体失稳预警的关键科学问题.以三峡库区库岸巫峡段箭穿洞塔柱状危岩体为例,将危岩体简... 位于三峡库区巫峡段消落带的塔柱状危岩,其底部多损伤因素的耦合作用下常呈压裂诱发座溃整体失稳模式,危岩底部耦合损伤至突变机制是研究该类库岸危岩体失稳预警的关键科学问题.以三峡库区库岸巫峡段箭穿洞塔柱状危岩体为例,将危岩体简化为中上部非劣化区和下部劣化区的二元地质力学模型,基于应变等价原理获得其危岩体下部劣化区的荷载效应、溶蚀效应、干湿循环弱化效应的耦合损伤本构模型和总损伤度演化方程,根据地质力学模型概化为等效弹簧模型转化为力-位移的耦合损伤本构方程;基于能量平衡原理和突变理论建立了塔柱状危岩的耦合损伤-折叠突变模型,获取了其失稳判据和临界位移的表达式.通过案例分析结果表明:该危岩体突变失稳时的系统控制变量为-0.0073,预测模型计算理论的突变起点垂向位移为42.2mm,终止点位移为60.5mm,当监测数据危岩体最大垂向累积位移为26.2mm时,小于突变起始位移时就采用及时治理措施,与危岩未失稳的状态吻合.其研究成果可为三峡库区灰岩地区库岸塔柱状压溃型危岩的监测预警与防治提供重要的理论支撑. 展开更多
关键词 库岸塔柱状危岩 压溃失稳型 耦合损伤 突变模型
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Effects of Interspecific Competition on the Population Dynamics of Four Stored Grain Insect Pests 被引量:3
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作者 崔晋波 邓永学 +3 位作者 王进军 杨龙德 杨自力 蒋天科 《Zoological Research》 CAS CSCD 北大核心 2006年第3期275-280,共6页
The effects of interspecific competition on the population dynamics of four insect grain Insecp pests ( Sitophilus zeamais, Rhizopertha dominica, Tribolium castaneum and Cryptolestes ferrugineus ) was studied at 30... The effects of interspecific competition on the population dynamics of four insect grain Insecp pests ( Sitophilus zeamais, Rhizopertha dominica, Tribolium castaneum and Cryptolestes ferrugineus ) was studied at 30℃, 75% relative humidity. A regression analysis of the population dynamics was conducted. The results showed that population growth of S. zeamais , R. dominica, T. castaneum and C. ferrugineus was restrained under mixed rearing. Population growth of T. castaneum and C. ferrugineus was remarkably accelerated when they coexisted with S. zeamais or R. dominica, while that of S. zeamais and R. dominica was restrained to some extent. Regression analysis results showed that the population growth potential of S. zeamais was the largest and that of C. ferrugineus was the smallest, and the changing trends of population growth rates were not distinct. 展开更多
关键词 Interspecific competition Population dynamics Sitophilus zeamais Rhizopertha dominica Tribolium castaneum Cryptolestes ferrugineus
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Test of Resource Competition Theory Between Microalga and Macroalga Under Phosphate Limitation 被引量:8
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作者 南春容 董双林 金秋 《Acta Botanica Sinica》 CSCD 2003年第3期282-288,共7页
Short_term batch cultures were used to measure the phosphate_dependent growth kinetics for a marine microalga, Tetraselmis subcordiformis (Wille) Hazen, and a marine macroalga, Ulva pertusa Kjellm. Results wer... Short_term batch cultures were used to measure the phosphate_dependent growth kinetics for a marine microalga, Tetraselmis subcordiformis (Wille) Hazen, and a marine macroalga, Ulva pertusa Kjellm. Results were fitted to the Monod model. U. pertusa had a lower half_saturation constant and maximum growth rate, which were 0.016 μmol/L and 0.16 d -1 respectively, while the growth kinetics of T. subcordiformis were 0.021 μmol/L and 0.83 d -1 . Long_term semicontinuous nutrient competition experiments were performed between T. subcordiformis and U. pertusa under phosphate limitation in laboratory. Loss rates were manipulated to get the same or different resource requirement values ( R * ) of the two species. Comparison between the theoretical predictions derived from Monod kinetics and the outcome of competition experiments indicated that the Monod model could predict the results only when the R * values of the two species were significantly different, and T. subcordiformis displaced U. pertusa when they had the same resource requirements. The Monod model can only partly predict the competition results between microalga and macroalga. 展开更多
关键词 MACROALGA MICROALGA Monod model PHOSPHATE resource competition theory R * _rule
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企业网络地位对数据资产信息披露的影响研究
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作者 何地 赵唱 庞铭 《工业技术经济》 北大核心 2025年第1期75-84,共10页
随着数据资产作为重要战略资源的价值日益凸显,数据资产信息披露已经成为学术界和实业界共同关注的重要议题。本文基于2009~2023年A股上市公司数据,实证检验了企业网络地位对数据资产信息披露的影响及作用机制。研究结果发现,企业网络... 随着数据资产作为重要战略资源的价值日益凸显,数据资产信息披露已经成为学术界和实业界共同关注的重要议题。本文基于2009~2023年A股上市公司数据,实证检验了企业网络地位对数据资产信息披露的影响及作用机制。研究结果发现,企业网络地位对其数据资产信息披露水平具有正向影响。机制分析结果表明,客户集中度在企业网络地位对其数据资产信息披露水平的影响中发挥调节作用,即客户集中度越低,企业网络地位对其数据资产信息披露水平的影响越强。异质性分析结果发现,对于非国有企业、多阶(长链)结构和小规模企业而言,企业网络地位对数据资产信息披露的影响效果尤为明显。本文揭示了企业网络地位影响数据资产信息披露的微观机制,为我国完善数据要素市场制度以及促进数字经济高质量发展提供了政策启示。 展开更多
关键词 企业网络地位 数字资产信息披露 客户集中度 文本分析法 信号传递理论 数字经济 数字化转型 企业竞争力
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企业环保投资的治理效应——基于杠杆操纵视角
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作者 谭琳 刘江涛 贺康 《工业技术经济》 北大核心 2025年第1期140-149,共10页
企业为避免监管以及满足融资需求而进行的杠杆操纵行为屡见不鲜。在强调可持续发展理念的时代变局中,为环境绩效付诸的努力能否对企业杠杆操纵起到治理效应亟待讨论。本文以2012~2023年沪深A股上市公司为样本,探究企业环保投资对杠杆操... 企业为避免监管以及满足融资需求而进行的杠杆操纵行为屡见不鲜。在强调可持续发展理念的时代变局中,为环境绩效付诸的努力能否对企业杠杆操纵起到治理效应亟待讨论。本文以2012~2023年沪深A股上市公司为样本,探究企业环保投资对杠杆操纵行为的影响及其潜在的作用渠道。研究发现,环保投资能够显著降低企业的杠杆操纵程度,并且这一影响受到地区环境规制力度、重污染行业属性以及低市场竞争度的强化。渠道检验结果表明,环保投资能帮助企业获取债权融资、提升ESG表现,进而实现对企业杠杆操纵行为的治理效应。本文从杠杆操纵的视角揭示了环保投资在公司治理中的积极作用,凸显了践行可持续发展理念在提高上市公司会计信息质量中的重要地位,为政府部门监管企业行为提供了来自环保实践层面的启示。 展开更多
关键词 环保投资 杠杆操纵 可持续发展 债权融资 ESG 环境规制 重污染行业 市场竞争度
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