检索结果-南通市图书馆

A Study of Multi-Scale Relationship Between Investor Sentiment and Stock Index Fluctuation Based on the Analysis of BEMD Spillover Index

在线全文

学校读者我要写书评

暂无评论

Journal of Systems Science and Information 2021年第4期9卷 399-420页

作者： Weiguo CHEN shufen zhou Yin ZHANG Yi SUN College of Economics and Management Beijing University of TechnologyBeijing 100124China China Post Group Corporation Limited Training Center Shijiazhuang 050021China School of Finance Anhui University of Finance and EconomicsBengbu 233000China

According to behavioral finance theory, investor sentiment generally exists in investors’ trading activities and influences financial market. In order to investigate the interaction between investor sentiment and stock market as well as financial industry, this study decomposed investor sentiment, stock price index and SWS index of financial industry into IMF components at different scales by using BEMD algorithm. Moreover, the fluctuation characteristics of time series at different time scales were extracted, and the IMF components were reconstructed into short-term high-frequency components, medium-term important event low-frequency components and long-term trend components. The short-term interaction between investor sentiment and Shanghai Composite Index, Shenzhen Component Index and financial industries represented by SWS index was investigated based on the spillover index. The time difference correlation coefficient was employed to determine the medium-term and long-term correlation among variables. Results demonstrate that investor sentiment has a strong correlation with Shanghai Composite Index, Shenzhen Component Index and different financial industries represented by SWS index at the original scale, and the change of investor sentiment is mainly influenced by external market information. The interaction between most markets at the short-term scale is weaker than that at the original scale. Investor sentiment is more significantly correlated with SWS Bond, SWS Diversified Finance and Shanghai Composite Index at the long-term scale than that at the medium-term scale.

关键词： investor sentiment spillover index BEMD algorithm

热氧老化对马来酸酐接枝聚丙烯的结构与性能的影响

在线全文

学校读者我要写书评

暂无评论

塑料工业 2024年第2期52卷 135-140页

作者：谢海生周淑芬兰修才李谦曹艳肖冉国文李涛袁弋惠中蓝晨光化工研究设计院有限公司四川成都610041

以自制的马来酸酐接枝聚丙烯(PP-g-MAH)为研究对象,研究了PP-g-MAH对玻璃纤维增强聚丙烯材料性能的影响以及热氧老化对PP-g-MAH分子结构和性能的影响。结果表明,自制的PP-g-MAH大幅度提高了30%玻纤增强聚丙烯材料的力学性能;随着热氧老... 详细信息

以自制的马来酸酐接枝聚丙烯(PP-g-MAH)为研究对象,研究了PP-g-MAH对玻璃纤维增强聚丙烯材料性能的影响以及热氧老化对PP-g-MAH分子结构和性能的影响。结果表明,自制的PP-g-MAH大幅度提高了30%玻纤增强聚丙烯材料的力学性能;随着热氧老化时间的延长,PP-g-MAH的MFR不断增加,对玻璃纤维增强聚丙烯材料的力学性能的提升作用不断降低;通过凝胶色谱仪(GPC)、红外光谱(IR)和马来酸酐(MAH)接枝率测定结果的分析,热氧老化过程没有对PP分子链接枝的马来酸酐产生明显的影响,而是引起了聚丙烯分子链的断裂,造成PP-g-MAH分子量下降,导致自身力学性能下降,使得PP与玻璃纤维之间的界面强度下降,使得PP-g-MAH对玻璃纤维增强聚丙烯材料的力学性能提升作用下降。

关键词：热氧老化马来酸酐接枝聚丙烯分子结构力学性能相容性玻璃纤维增强聚丙烯

Recent advances in multifunctional shape memory photonic crystals and practical applications

在线全文

学校读者我要写书评

暂无评论

Nano Research 2024年第1期17卷 79-96页

作者： Yong Qi shufen Zhang State Key Laboratory of Fine Chemicals Frontier Science Center for Smart MaterialsDalian University of TechnologyDalian 116024China

Shape memory photonic crystals(SMPCs)are smart composite materials with changeable structural color integrated by shape memory polymer and photonic *** can produce one or more temporary shapes through nanoscale deformation,memorizing current *** can be recovered to their original shapes or some intermediate states under external stimuli,accompanied by the variation of structural *** porous carriers with built-in sensing properties,SMPCs promoted the interdisciplinary development of nanophotonic technology in materials science,environmental engineering,biomedicine,chemical engineering,and ***,the recent progress on multifunctional SMPCs and practical applications,including traditional and cold programmable SMPCs,is summarized and *** primary concern is shape programming at the nanoscale that has demonstrated numerous attractive functions,including smart sensing,ink-free printing,solvent detection,reprogrammable gradient wetting,and controllable bubble transportation,under variations of the surface *** aims to figure out the nanoscale shape memory effects on structural color conversion and additional performance,inspiring the fabrication of the next generation of ***,perspectives on future research directions and applications are also *** is believed that multifunctional SMPCs are powerful nanophotonic tools for the interdisciplinary development of numerous disciplines in the future.

关键词： photonic crystal shape memory structural color cold programmable shape recovery

Blockchain-Based Certificateless Bidirectional Authenticated Searchable Encryption Scheme in Cloud Email System

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2024年第6期139卷 3287-3310页

作者： Yanzhong Sun Xiaoni Du shufen Niu Xiaodong Yang College of Mathematics and Statistics Northwest Normal UniversityLanzhou730070China College of Computer Science and Engineering Northwest Normal UniversityLanzhou730070China

Traditional email systems can only achieve one-way communication,which means only the receiver is allowed to search for emails on the email *** this paper,we propose a blockchain-based certificateless bidirectional authenticated searchable encryption model for a cloud email system named certificateless authenticated bidirectional searchable encryption(CL-BSE)by combining the storage function of cloud server with the communication function of email *** the new model,not only can the data receiver search for the relevant content by generating its own trapdoor,but the data owner also can retrieve the content in the same ***,there are dual authentication functions in our ***,during encryption,the data owner uses the private key to authenticate their identity,ensuring that only legal owner can generate the keyword ***,the blockchain verifies the data owner’s identity by the received ciphertext,allowing only authorized members to store their data in the server and avoiding unnecessary storage space *** obtain a formal definition of CL-BSE and formulate a specific scheme from the new system *** the security of the scheme is analyzed based on the formalized security *** results demonstrate that the scheme achieves multikeyword ciphertext indistinguishability andmulti-keyword trapdoor privacy against any adversary *** addition,performance evaluation shows that the new scheme has higher computational and communication efficiency by comparing it with some existing ones.

关键词： Cloud email system authenticated searchable encryption blockchain-based designated server test multi-trapdoor privacy multi-ciphertext indistinguishability

Melatonin delays leaf senescence in pak choi(Brassica rapa ***)by regulating biosynthesis of the second messenger cGMP

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Horticultural Plant Journal 2024年第1期10卷 145-155页

作者： Xuesong Liu Ronghui An Guofeng Li shufen Luo Huali Hu Pengxia Li Institute of Agricultural Facilities and Equipment Jiangsu Academy of Agricultural SciencesNanjingJiangsu 210014China School of Food and Biological Engineering Jiangsu UniversityZhenjiangJiangsu 212013China Jiangsu Key Laboratory for Horticultural Crop Genetic Improvement NanjingJiangsu 210014China Key Laboratory of Cold Chain Logistics Technology for Agro-Products Ministry of Agriculture and Rural AffairsNanjingJiangsu 210014China Jinan Fruit Research Institute All China Federation of Supply and Marketing CooperativesJinanShandong 250220China

Melatonin(MT)is a low molecular weight compound with multiple biological functions in *** is known to delay leaf senescence in various ***,no data are available on the MT signaling pathway in postharvest *** study demonstrates that MT increases cGMP concentration and the expression of the cGMP synthesis gene BcGC1 in pak *** c GMP inhibitor LY83583 destroys effect of MT delaying the leaf ***83583 also prevents MT treatment from reducing the expression of chlorophyll metabolism-related genes(BcNYC1,BcNOL,BcPPH1/2,BcSGR1/2,and BcPAO)and senescence genes(BcSAG12 and BcSAG21).It also inhibits MT from reducing the activity of the key chlorophyll catabolism enzymes Mg-dechelatase,pheophytinase,and pheide a ***,the ability of MT to maintain high levels of chlorophyll metabolites is also *** Arabidopsis c GMP synthetic gene mutant atgc1 was used to confirm that delayed leaf senescence caused by MT is mediated,at least in part,by the second messenger c GMP.

关键词： Pak choi Melatonin cGMP Chlorophyll degradation Senescence

Searching for plant NLR immune receptors conferring resistance to potyviruses

在线全文

学校读者我要写书评

暂无评论

The Crop Journal 2024年第1期12卷 28-44页

作者： Xin Hong shufen Li Xiaofei Cheng Haijian Zhi Jinlong Yin Kai Xu Jiangsu Key Laboratory for Microbes and Functional Genomics Jiangsu Engineering and Technology Research Center for MicrobiologyCollege of Life SciencesNanjing Normal UniversityNanjing 210023JiangsuChina College of Plant Protection Northeast Agricultural UniversityHarbin 150030HeilongjiangChina National Center for Soybean Improvement National Key Laboratory for Crop Genetics and Germplasm EnhancementKey Laboratory of Biology and Genetic Improvement of Soybean-Ministry of AgricultureNanjing Agricultural UniversityNanjing 210095JiangsuChina

To fight against invasion by pathogens,plants have evolved an elaborate innate immune system,of which the nucleotide-binding domain leucine-rich repeat-containing receptor(NLR)acts as the sensor and immune ***,comprising one of the largest genera of plant viruses,cause severe crop yield losses *** crop resistance to potyviruses can be used in breeding and plant transgenesis to control disease *** review summarizes achievements in mapping and cloning NLR genes conferring dominant resistance against potyvirus in the families Fabaceae,Solanaceae,Brassicaceae,and *** compares mechanisms of potyviral protein recognition and downstream signaling employed by NLRs and discusses strategies for exploiting NLRs to better control diseases caused by potyviruses.

关键词： NLR Potyvirus resistance Genetic diversity Mapping Engineer

Phosphorus limitation on CO_(2)fertilization effect in tropical forests informed by a coupled biogeochemical model

在线全文

学校读者我要写书评

暂无评论

Forest Ecosystems 2024年第4期11卷 502-515页

作者： Zhuonan Wang Hanqin Tian shufen Pan Hao Shi Jia Yang Naishen Liang Latif Kalin Christopher Anderson Natural Resources Ecology Laboratory Colorado State UniversityFort CollinsCO80523USA Center for Earth System Science and Global Sustainability Schiller Institute for Integrated Science and SocietyBoston CollegeChestnut HillMAUSA Department of Earth and Environmental Sciences Boston CollegeChestnut HillMAUSA Department of Engineering Boston CollegeChestnut HillMAUSA Research Center for Eco-Environmental Sciences State Key Laboratory of Urban and Regional EcologyChinese Academy of SciencesBeijingChina Department of Natural Resource Ecology and Management Oklahoma State UniversityStillwaterOKUSA Center for Global Environmental Research(CGER) National Institute for Environmental Studies(NIES)TsukubaIbaraki305-8506Japan College of Forestry Wildlife and EnvironmentAuburn UniversityAuburnALUSA

Tropical forests store more than half of the world's terrestrial carbon(C)pool and account for one-third of global net primary productivity(NPP).Many terrestrial biosphere models(TBMs)estimate increased productivity in tropical forests throughout the 21st century due to CO_(2)***,phosphorus(P)liaitations on vegetation photosynthesis and productivity could significantly reduce the CO_(2)fertilization ***,we used a carbon-nitrogen-phosphorus coupled model(Dynamic Land Ecosystem Model;DLEM-CNP)with heterogeneous maximum carboxylation rates to examine how P limitation has affected C fluxes in tropical forests *** model results showed that the inclusion of the P processes enhanced model performance in simulating ecosystem *** further compared the simulations from DLEM-CNP,DLEM-CN,and DLEMC and the results showed that the inclusion of P processes reduced the CO_(2)fertilization effect on gross primary production(GPP)by 25%and 45%,and net ecosystem production(NEP)by 28%and 41%,respectively,relative to CN-only and C-on ly *** the 1860s to the 2010s,the DLEM-CNP estimated that in tropical forests GPP increased by 17%,plant respiration(Ra)increased by 18%,ecosystem respiration(Rh)increased by 13%,NEP increased by 121%per unit area,***,factorial experiments with DLEM-CNP showed that the enhanced NPP benefiting from the CO_(2) fertilization effect had been offset by 135%due to deforestation from the 1860s to the *** study highlights the importance of P limitation on the C cycle and the weakened CO_(2)fertilization effect resulting from P limitation in tropical forests.

关键词： Tropical forests Carbon-nitrogen-phosphorus model Phosphorus limitation CO_(2)fertilization effect Terrestfial ecosy stem model

绿色金融视角下农业循环经济发展的政策支持研究——以河北省为例

在线全文

学校读者我要写书评

暂无评论

中国农业资源与区划 2017年第7期38卷 200-206页

作者：周淑芬李妍王康中国邮政集团公司培训中心石家庄邮电职业技术学院

[目的]循环经济模式已经成为当今农业经济增长的主要方式,在农业区域循环经济持续发展过程中充分发挥金融支持作用,优化制定农业循环经济协调发展的金融支持战略,有助于实现农业区域循环经济的可持续发展。[方法]采用问卷调查法对河北... 详细信息

[目的]循环经济模式已经成为当今农业经济增长的主要方式,在农业区域循环经济持续发展过程中充分发挥金融支持作用,优化制定农业循环经济协调发展的金融支持战略,有助于实现农业区域循环经济的可持续发展。[方法]采用问卷调查法对河北省农村地区的部分企业、农户和金融机构针对目前主要融资渠道、对绿色金融政策和产品的了解程度及绿色金融支持现状等方面进行分析研究。[结果]调查结果显示,被调查的农户和企业大部分均有融资需求,但目前河北省大部分农户和企业并不了解当地绿色金融相关政策和相关产品,其中37.5%农村企业目前主要的融资方式为银行贷款,而85%农户主要通过民间借贷和亲友间无偿借款的融资方式,农村地区金融机构提供的绿色金融产品以绿色信贷为主,绿色保险、绿色证券涉及较少,导致农村融资渠道受限。[结论]深化企业和农户对绿色金融政策和产品的认识和了解、完善绿色金融政策支持机制和法律法规体系,不断丰富绿色金融产品种类和融资渠道,能够为促进农村经济的可持续发展提供理论基础,对农业循环经济与生态环境的双赢、可持续发展起到重要作用。

关键词：农业循环经济绿色金融支持农业循环经济金融

The Relationships between Executive Function and Problem Behavior of Preschool Children:Contextual Specificity and Gender Differences

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Education in China 2024年第2期19卷 119-137页

作者： BAI Rong YAN Rong WANG Qian LI Ye XING shufen Beijing Key Laboratory of Learning and Cognition School of PsychologyCapital Normal UniversityBeijing 100048China Institute of Leadership and Education Advanced Development Xi’an Jiaotong-Liverpool UniversitySuzhou 215123China

This study utilized a longitudinal design to examine the relationships between the specific components of executive function(EF)and the internalizing and externalizing behavior across different genders and contexts in Chinese cultural ***,cognitive flexibility,and working memory of EF based on 101 preschool children’s(48 boys and 53 girls)(M_(T1)=4.25,SD=0.76)performances were measured when completing tasks in NIH *** months later,boys’and girls’internalizing and externalizing behavior in home-and school-settings was assessed through mother’s feedback on the Strengths and Difficulties Questionnaire and teachers’reports of the Child Behavior Rating *** results show that boys’inhibition,cognitive flexibility,and working memory negatively predict their externalizing behavior in the home context,while their cognitive flexibility negatively predicts externalizing behavior in the school ***,boys’inhibition positively predicts their internalizing behavior only in the school *** girls,their cognitive flexibility positively predicts externalizing behavior only in the school *** significant relationship is found among the girls between EF and problem behavior in the home *** findings suggest that gender differences and a shift in contexts could alternate the relationship between EF and children’s problem *** study sheds light on targeted preventions and interventions based on contexts and gender.

关键词： executive function(EF) problem behavior contextual specificity gender differences preschool children