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The complete principal divisor lattices

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Science China Mathematics 2010年第8期53卷 2159-2172页

作者： wang xueping & QU XiaoBing College of Mathematics and Software Science,Sichuan Normal University,Chengdu 610066,China College of Mathematics and Software Science Sichuan Normal University Chengdu China

In this paper,we introduce a concept of principal divisor lattice and describe the structure of its *** first give a necessary and sufficient condition for the existence of irredundant join irreducible decompositions in complete principal divisor distributive lattices,and prove that the complete lower continuous,principal divisor lattices have irredundant join irreducible *** the end,we show the descriptions of lattices that have unique(***) irredundant join irreducible decompositions in complete lower continuous principal divisor lattices.

关键词： complete lattice principal divisor lattice distributive lattice irredundant join irreducible decomposition

Ontogenetic resource use and trophic dynamics of endangered juvenile Tachypleus tridentatus among diversified nursery habitats in the northern Beibu Gulf,China

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Integrative Zoology 2021年第6期16卷 908-928页

作者： Kit Yue KWAN Justin BOPP Shuyan HUANG Qiao CHEN Chun-Chieh wang xueping wang Wenquan ZHEN Junhua ZHU Xing HUANG College of Marine Sciences Beibu Gulf UniversityQinzhouChina Guangxi Key Laboratory of Beibu Gulf Marine Biodiversity Conservation QinzhouChina School of Marine and Atmospheric Sciences Stony Brook UniversityStony BrookNew YorkUSA Futian-CityU Mangrove R&D Center City University of Hong Kong Shenzhen Research InstituteShenzhenChina Guangxi Key Laboratory of Marine Environmental Science Guangxi Beibu Gulf Marine Research CenterGuangxi Academy of SciencesNanningChina Guangxi Key Laboratory of Marine Disaster in the Beibu Gulf QinzhouChina

Horseshoe crabs,the most well-known example of“living fossils”,are iconic and ecologically important macroinvertebrates in coastal and estuarine *** blood is a crucial resource for manufacturing Limulus or Tachypleus amebocyte lysate to detect bacterial endotoxins or fungal contamination in drug and medical *** enhanced understanding of their ecological roles and trophic interactions in the food webs is fundamental to facilitate resource management for the declining populations in *** information of the Asian species,however,is mainly derived from preliminary,scattered reports from a limited number of study *** this study,resource utilization,trophic niche dynamics,and trophic interaction of the juvenile tri-spine horseshoe crab,Tachypleus tridentatus(instars 1–12,approximately 0.5–8 years old)across ontogeny was assessed in diversified nursery habitats along the northern Beibu Gulf,China,using carbon and nitrogen stable *** results suggest that:(i)*** are ecological generalists given the vast range of carbon isotopic values and trophic niche width estimates exhibited between multiple instar groups;(ii)juvenile *** across most habitat types predominantly assimilated energy from a variety of basal production sources in the food web,but primarily depended on sedimentary organic matter and seagrass resource pools;(iii)ontogenetic shifts in juvenile dietary proportions were evident,with decreased reliance on sedimentary organic matter,coupled with increased reliance on benthic macroinvertebrate grazers,detritivores,and omnivores with age;and(iv)nearly all juvenile instars occupied similar trophic positions in the food web with slight shifts in trophic position present with increasing *** findings indicate that resource availability and ontogenetic diet shifts strongly influence horseshoe crab trophic dynamics,and age should be accounted when formulating habitat conservation measures based on resour

关键词： intertidal food webs ontogenetic shift stable isotopes Tachypleus tridentatus trophic niche width

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近水楼台先得月:地理距离对政府采购的影响

财经论丛 2023年第11期 15-24页

作者：王小平王雪平宜春学院经济与管理学院江西宜春336000 江西财经大学会计学院江西南昌330013

政府采购作为财政支出管理的重要措施,是国家对经济实施宏观调控的有效手段。本文以2015—2021年A股上市公司为样本,探讨了地理距离对政府采购的影响。实证检验表明,企业注册地与地方政府的地理距离越近,企业获得的政府采购订单越多。... 详细信息

政府采购作为财政支出管理的重要措施,是国家对经济实施宏观调控的有效手段。本文以2015—2021年A股上市公司为样本,探讨了地理距离对政府采购的影响。实证检验表明,企业注册地与地方政府的地理距离越近,企业获得的政府采购订单越多。内生性检验与其他一系列稳健性检验均支持上述结论。机制检验发现,地理距离对政府采购的影响机制在于政府采购增加了寻租行为、提升了政治关联水平。受政商关系、政府依赖异质性的影响,地理距离对政府采购的影响有显著差异。位于政商关系差地区和对政府依赖高的企业,其与政府的地理距离对政府采购的影响更为显著。经济后果检验表明,政府采购能够为企业带来经济效益,体现在企业创新水平的提升。本文研究丰富了政府采购的经济后果的文献,对于当前深化财税体制改革、大力推进政府采购改革具有一定借鉴意义。

关键词：地理距离政府采购寻租行为政治关联

Primary frequency control considering communication delay for grid-connected offshore wind power systems

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Global Energy Interconnection 2024年第3期7卷 241-253页

作者： xueping Pan Qijie Xu Tao Xu Jinpeng Guo Xiaorong Sun Yuquan Chen Qiang Li Wei Liang School of Electrical and Power Engineering Hohai UniversityNanjing 211100P.R.China Electric Power Research Institute of State Grid Jiangsu Electric Power Co.Ltd Nanjing 211103P.R.China

Offshore wind farms are becoming increasingly distant from onshore centralized control centers,and the communication delays between them inevitably introduce time delays in the measurement signal of the primary frequency *** causes a deterioration in the performance of the primary frequency control and,in some cases,may even result in frequency instability within the power ***,a frequency response model that incorporates communication delays was established for power systems that integrate offshore wind *** Padéapproximation was used to model the time delays,and a linearized frequency response model of the power system was derived to investigate the frequency stability under different time *** influences of the wind power proportion and frequency control parameters on the system frequency stability were *** addition,a Smith delay compensation control strategy was devised to mitigate the effects of communication delays on the system frequency ***,a power system incorporating offshore wind power was constructed using the MATLAB/Simulink *** simulation results demonstrate the effectiveness and robustness of the proposed delay compensation control strategy.

关键词： Offshore wind power Primary frequency control Time delay Padéapproximation Time-delay compensation control

预算绩效管理改革能缓解地方政府财政压力吗?——基于准自然实验的经验证据

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经济与管理研究 2022年第10期43卷 20-37页

作者：王雪平王小平江西财经大学会计学院南昌330013 宜春学院经济与管理学院宜春336000

面对延宕反复的疫情形势和国内外经济形势的发展变化,地方财政收支平衡性受到了较大威胁。如何缓解地方政府的财政压力成了焦点话题。本文利用2001—2020年省级面板数据,采用双重差分模型,实证检验预算绩效管理改革对地方财政压力的影... 详细信息

面对延宕反复的疫情形势和国内外经济形势的发展变化,地方财政收支平衡性受到了较大威胁。如何缓解地方政府的财政压力成了焦点话题。本文利用2001—2020年省级面板数据,采用双重差分模型,实证检验预算绩效管理改革对地方财政压力的影响。研究发现:预算绩效管理改革显著降低了地方财政压力。平行趋势检验、熵平衡匹配回归与其他一系列稳健性检验均支持上述结论。异质性分析发现,预算绩效管理改革抑制财政压力的作用在制度环境较差、政府审计较弱、财政分权程度较高的地区更加明显。机制检验发现,这一抑制作用的影响机制在于预算绩效管理改革提升了财政支出效率、降低了政府行政成本以及增强了财政透明度。进一步分析发现,预算绩效管理的广度不足,尚未有效覆盖一般公共预算之外的其他预算,如政府性基金预算。经济后果检验表明,预算绩效管理改革缓解了财政压力之后,地方政府会放松对辖区企业的税收监管,提高对辖区企业的政府补助。本文的研究丰富了预算绩效管理改革的经济后果的文献,为地方政府运用预算绩效管理来缓解财政压力提供了实证证据。

关键词：财政收支平衡财政压力预算绩效管理改革财政支出效率财政透明度

Cayli所构造二元算子成一致模的一些条件

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西北大学学报(自然科学版) 2022年第4期52卷 528-538页

作者：王学平何鹏四川师范大学数学科学学院成都信息工程大学应用数学学院

2019年，Cayli在有界格上给出了两种用子区间[0,e]上三角模Te和[e,1]上三角余模Se构造以e为单位元的一致模的方法。该文将从格结构的角度给出Cayli所构造有界格上二元算子成一致模的一些条件。

关键词：有界格三角模三角余模一致模

Chloroplast immunity: A cornerstone of plant defense

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Molecular Plant 2024年第5期17卷 686-688页

作者： Jie Liu Pan Gong Ruobin Lu Rosa Lozano-Duran xueping Zhou Fangfang Li State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing 100081China State Key Laboratory of Rice Biology Institute of BiotechnologyZhejiang UniversityHangzhouZhejiang 310058China Department of Plant Biochemistry Centre for Plant Molecular Biology(ZMBP)Eberhard Karls UniversityTubingen 72076Germany

Increasing evidence supports the notion that pattern-recognition-receptor-mediated immunity goes beyond plasma membrane-to-nucleus *** the findings of the pathways linking plasma membrane and chloroplasts and the functions of stromules and perinuclear chloroplast clustering(PCC)in plant defense,chloroplast immunity has emerged as a cornerstone of plant defense and a target of plant pathogens.

关键词： plant immunity corners

Plant virology in the 21st century in China:Recent advances and future directions

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Journal of Integrative Plant Biology 2024年第3期66卷 579-622页

作者： Jianguo Wu Yongliang Zhang Fangfang Li Xiaoming Zhang Jian Ye Taiyun Wei Zhenghe Li Xiaorong Tao Feng Cui Xianbing wang Lili Zhang Fei Yan Shifang Li Yule Liu Dawei Li xueping Zhou Yi Li State Key Laboratory for Ecological Pest Control of Fujian and Taiwan Crops Vector-borne Virus Research CenterCollege of Plant ProtectionFujian Agriculture and Forestry UniversityFuzhou 350002China State Key Laboratory of Plant Environmental Resilience and Ministry of Agriculture Key Laboratory of Soil Microbiology College of Biological SciencesChina Agricultural UniversityBeijing 100193China State Key Laboratory for Biology of Plant Diseases and Insect Pests Institute of Plant ProtectionChinese Academy of Agricultural SciencesBeijing 100193China State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of ZoologyChinese Academy of SciencesBeijing 100101China CAS Center for Excellence in Biotic Interactions University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory of Plant Genomics Institute of MicrobiologyChinese Academy of SciencesBeijing 100101China State Key Laboratory of Rice Biology Institute of BiotechnologyZhejiang UniversityHangzhou 310058China Department of Plant Pathology The Key Laboratory of Plant ImmunityNanjing Agricultural UniversityNanjing 210095China State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products Institute of Plant VirologyNingbo UniversityNingbo 315211China MOE Key Laboratory of Bioinformatics Center for Plant BiologySchool of Life SciencesTsinghua UniversityBeijing 100084China State Key Laboratory of Protein and Plant Gene Research School of Life SciencesPeking UniversityBeijing 100871China

Plant viruses are a group of intracellular pathogens that persistently threaten global food *** advances in plant virology have been achieved by Chinese scientists over the last 20 years,including basic research and technologies for preventing and controlling plant viral ***,we review these milestones and advances,including the identification of new crop-infecting viruses,dissection of pathogenic mechanisms of multiple viruses,examination of multilayered interactions among viruses,their host plants,and virus-transmitting arthropod vectors,and in-depth interrogation of plantencoded resistance and susceptibility ***,various plant virus-based vectors have also been successfully developed for gene function studies and target gene expression in *** also recommend future plant virology studies in China.

关键词： China emerging plant viruses plant virology plant resistance/susceptibility to viral infection plant-virus transmission vector interactions plant virus-based vectors viral pathogenesis

High-static-low-dynamic stiffness isolator based on an electromagnetic negative stiffness spring with long linear stroke

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Science China(Technological Sciences) 2024年第3期67卷 740-752页

作者： YUAN ShuJin WU YaJun SONG DaiPing PU HuaYan MOU LiSheng HOU Lei ZHAO JingLei LI xueping LUO Jun WU Jie HUANG XiaoXu State Key Laboratory of Mechanical Transmissions Chongqing UniversityChongqing 400044China China Aerodynamics Research and Development Center Mianyang 621000China College of Materials Science and Engineering Chongqing UniversityChongqing 400044China

Negative stiffness mechanisms can improve low-frequency vibration isolation performance and have been widely used in the vibration isolation of precision equipment. However, the negative stiffness mechanism usually introduces a nonlinear stiffness,resulting in a nonlinear response and worsening the vibration isolation performance, especially under large amplitude *** this paper, an electromagnetic spring with linear negative stiffness(ESLNS) is proposed, in which the antagonistic ampere forces of the energized coils are used to generate negative stiffness within a long linear stroke. The magnetic field distribution is improved through the design of the magnetic circuit, thereby increasing the stiffness generation efficiency. The stiffness can be adjusted bidirectionally by current within the range of positive and negative stiffness. An electromagnetic stiffness model was established based on the equivalent magnetic circuit method. Experimental measurements verified the accuracy of the model and proved the linearity of the electromagnetic spring. A vibration isolator with high static and low dynamic stiffness(HSLDS) based on the ESLNS is designed and tested. The experimental results prove that the introduction of the ESLNS can effectively expand the isolation frequency band without changing the equilibrium position. Moreover, the vibration isolator with ESLNS does not produce nonlinear response. The proposed electromagnetic spring with linear negative stiffness extends the application range of HSLDS isolators to a large amplitude vibration environment.

关键词： linear negative stiffness mechanism low-frequency vibration isolation electromagnetic spring vibration control