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社会信用与企业韧性——基于社会信用体系改革试点的准自然实验

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科学决策 2024年第3期 45-56页

作者：阳立高王智志李玉双长沙理工大学经济与管理学院长沙理工大学产业高质量发展研究院嘉兴大学经济学院

在当前全球经济环境不稳定的背景下,如何增强企业韧性是所有企业都要面临的重要问题。文章基于2007—2021年我国A股上市公司的平衡面板数据,测度了企业韧性水平,并以城市社会信用体系改革试点作为一项准自然实验,运用多时点DID模型实证... 详细信息

在当前全球经济环境不稳定的背景下,如何增强企业韧性是所有企业都要面临的重要问题。文章基于2007—2021年我国A股上市公司的平衡面板数据,测度了企业韧性水平,并以城市社会信用体系改革试点作为一项准自然实验,运用多时点DID模型实证检验了社会信用对企业韧性的影响。结果表明:社会信用提升能够显著增强企业韧性;社会信用主要通过提高城市人力资本水平、降低企业交易成本和提升企业劳动生产率三个机制来增强企业韧性。异质性分析发现:社会信用对企业韧性的增强作用在内部治理水平较低企业、非国有企业、市场化程度较低地区中的效果更大。文章为研究企业韧性的影响因素提供了新的视角,对如何增强企业韧性、实现企业高质量发展具有一定的启示。

关键词：社会信用企业韧性城市人力资本企业交易成本企业劳动生产率

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数字经济对环境污染的影响及作用机制研究

技术经济与管理研究 2024年第8期 52-58页

作者：李高扬刘明广华南农业大学广东广州510642 华南师范大学广东广州510006

环境污染是人类面临的重要威胁之一,数字经济有望成为抑制环境污染的新抓手。基于大数据试验区准自然实验,选取中国278个地级市2012—2021年面板数据,采用双重差分模型分析数字经济对环境污染的影响及作用机制。研究发现,数字经济能够... 详细信息

环境污染是人类面临的重要威胁之一,数字经济有望成为抑制环境污染的新抓手。基于大数据试验区准自然实验,选取中国278个地级市2012—2021年面板数据,采用双重差分模型分析数字经济对环境污染的影响及作用机制。研究发现,数字经济能够显著抑制城市环境污染。该结论经过平行趋势检验、PSM-DID检验、安慰剂检验及排除同期相关政策影响后依然成立。作用机制检验发现,数字经济可通过加强环境规制和提升实质性技术创新两条传导路径抑制环境污染,而策略性技术创新传导路径未获数据支持。异质性分析表明,与基础设施统筹发展试验区相比,跨区域试验区和区域示范试验区所体现的数字经济环境污染抑制效应更强;沿海城市以及数字普惠金融水平较高的城市数字经济对环境污染的抑制效应更强。

关键词：大数据试验区数字经济环境污染环境规制技术创新

Parameter Optimization of a Stability-Training Platform's 4-PSS/PS Parallel Mechanism Based on Training Ability Evaluation Index and PSO Algorithm

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Chinese Journal of Mechanical Engineering 2018年第3期31卷 37-47页

作者： Wei-Guo Wu li-yang gao School of Mechatronics Engineering Harbin Institute of Technology

The existing mechanism parameter optimization(MPO) method of parallel mechanisms only considers the workspace size and ignores contribution of each configuration's performance. So a novel MPO method is proposed for our serial?parallel mechanism platform,which is used in stability training of legged robots. Regarding the platform's parallel mechanism part,a 4?PSS/PS parallel mechanism,two object functions and three constraint conditions are defined to establish the MPO model. The first object function uses critical motion indexes of the moving platform. The second one uses derivative function of the defined disturbance Lagrange function. After analyzing stability?training require?ments of five existing legged robots,requirements of the platform's motion capability are given out. Regarding each proposed object function separately,the MPO model is solved by the particle swarm optimization(PSO) algorithm. Valid workspace boundaries corresponding to the optimization results are solved by a numerical method. The overall optimal solution is determined based on volume of the valid workspace. It is revealed that the two object functions result in similar optimization solutions,which shows that the proposed object functions can reflect the stability?training ability consistently. This paper proposes and verifies the established MPO model,which considers both the workspace size and configurations' performance evaluation.

关键词： Stability training 4?PSS/PS parallel mechanism Mechanism parameter optimization Singularity analysis Particle swarm optimization

First record of Thalassiosira curviseriata Takano (Bacillariophyta) and its bloom in the East China Sea

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Acta Oceanologica Sinica 2008年第6期27卷 124-132页

作者： XIE Wenling li yang gao Yahui Key laboratory for Subtropical Wetland Ecosystem Research of Ministry of Education School of Life Sciences Xiamen University Xiamen 361005 China

A bloom caused by a diatom, Thalassiosira curviseriata Takano （Bacillariophyta） , is recorded in the East China Sea for the first time in China during a red tide investigation cruise （MC2005 -2） from 27 March to 12 April 2005. This bloom was developed with the competition of Chaetoceros debilis and Skeletonema spp. The highest cell density of T. curviseriata, which has reached 1.27 × 10^6 cells/dm3, was found in the surface and middle water layers of Stas ZD, ZB in the East China Sea （27. 22°-29.48°N, 121.53° - 122. 98°E）in early spring in 2005. During the blooming period of T. curviseriata, the population with high cell density was found in the water area with temperature of 10 -15 ℃ and salinity of 29.0 - 33.5. The percentage of the predominant species, T. curviseriata, has reached 95.8% of total diatom cells at one time in the middle water layer. The morphological characteristics of T. curviseriata, were observed with light microscope （LM） and transmission electronic microscope （TEM）. The cells are 5.0 - 12. 6 μm in diameter, connecting each other by mucilaginous thread to form spiral and curved chains. Description and LM and TEM images of T. curviseriata are presented. T. curviseriata is ecologically characterized by eurythermy and euryhalinity, and its population variation is affected mainly by silicate, the ratios of phosphorus to silicon and nitrogen to silicon.

关键词： bloom Thalassiosira curviseriata East China Sea

Characterization of a Novel Mesophilic Bacterial Amylase Secreted by ZW2531-1, a Strain Newly Isolated from Soil

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Chemical Research in Chinese Universities 2009年第2期25卷 198-202页

作者： WANG yang li Fan gao Chao-hui ZHANG Ying-Jiu Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education Jilin University Changchun 130021 P. R. China

A novel mesophilic bacterial amylase, named oligosaccharide-producing multifunctional amylase（OPMA）, was discovered and characterized. OPMA is an extracellular enzyme secreted by ZW253 1-1, a strain newly isolated from Chinese soil. It could be purified to homogeneity from the culture supernatant of ZW2531-1 by 30%-60% saturated ammonium sulfate precipitation, followed by twice Sephadex gel filtration chromatography. OPMA is a 66 kDa protein based on SDS-PAGE and has an isoelectric point（p/） at pH=5.3 by Isoelectric focusing electrophoresis（WE）. It only catalyzes the degradation of starch, rather than other alpha-l,4- and/or 1,6-glucan polysaccbarides such as fl-cyclomaltodextrin and pullulan. OPMA degraded starch to produce several oligosccharides including maltose, maltotriose, and isomaltotriose as the major end-products, and perhaps other oligosaccharides such as isomalto- tetraose, rather than glucose. OPMA exhibited optimal catalytic activity at a reaction temperature of 50 ℃ and pH=6.0, as determined by orthogonal test. Under the optimal reaction conditions, purified OPMA bad a specific activity of 13.75 U/rag. These findings suggest that OPMA could be used for the production of some oligosaccharides beneficial to the food industry and medicine.

关键词： Amylase Bacterium Oligosaccharide Purification Starch

Electrical stimulation upregulates angiopoietin-1/Tie-2 mRNA expression in a rat model of focal cerebral ischemia

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Neural Regeneration Research 2010年第19期5卷 1470-1474页

作者： Shasha li Yonghong yang Qiang gao Jing He Chengqi He Department of Rehabifitation Medicine Key Laboratory of Rehabilitation Medicine of Sichuan Province West China Hospital SichuanUniversity Chengdu 610041 Sichuan Province China

Angiopoietin-1/tyrosine kinase with immunoglobulin and epidermal growth factor homology domains 2 （Tie-2） is a newly discovered signaling pathway of angiogenesis. Angiogenesis benefits recovery of neurological functions such as swallowing. In the present study, a rat model of dysphagia following stroke was induced by middle cerebral artery occlusion to investigate the influence of low frequency electrical stimulus with bidirectional square waves and triangular waves on angiopoietin-1/-13e-2 mRNA expression. Reverse transcription-polymerase chain reaction results showed that low frequency electrical stimulus significantly improved the neurological scores of the model rats, and increased angiopoietin-1/＇13e-2 mRNA expression. This demonstrates that low frequency electrical stimulation can ameliorate neurological function in rats with focal brain ischemia, potentially through regulation of angiopoietin-1/-13e-2 expression in the angiogenesis pathway.

关键词： low frequency electrical stimulation angiopoietin-1 tyrosine kinase with immunoglobulin and epidermal growth factor homology domains middle cerebral artery occlusion model dysphagia

Effects on the local symptoms of subgenomic RNAs expressions and their translational products of Tobacco necrosis virus A Chinese isolate

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Chinese Science Bulletin 2008年第11期53卷 1682-1690页

作者： li Jiang li Min li Cui gao yang li DaWei HAN ChengGui YU Jialin State Key Laboratory of Agro-Biotechnology China Agricultural University Beijing 100094 China

Based on a full-length infectious cDNA clone, gene modifications of Tobacco necrosis virus A Chinese isolate (TNV-AC) were made by site-directed mutagenesis or nucleotide deletions for in vitro transcrip-tion of mutant viral RNAs. Mechanical inoculations of Chenopodium amaranticolor with in vitro tran-scripts, containing a single nucleic acid substitution at the presumed transcriptional start sites for the two subgenomic (sg) RNAs, showed that the sgRNA1 and sgRNA2 of TNV-AC were initiated at G2184 or G2460, respectively. Mutagenesis of the translational initiation-codons for the open-reading frame (ORF) P8 or P6 encoded by sgRNA1 indicated that each of the two genes was essential for formation of local lesions on C. amaranticolor leaves, perhaps by blocking virus cell-to-cell movement, but were not necessary for viral RNA replication in the protoplast of tobacco cell BY-2. Results of prokaryotic expression showed that the ORF coding for coat protein on TNV-AC sgRNA2 was initiatively translated by the first AUG codon at nucleotides 2612―2614. Site-directed mutation of translational start codons, and deletion of the entire coding region, showed that the intact TNV-AC coat protein was dispensable for establishment of TNV-AC infection in C. amaranticolor, otherwise the numbers of local lesions and the viral RNA accumulation level were reduced, or the time to symptom appearance significantly delayed. These results suggested that the nucleotide sequence around the translational start codon coding for TNV-AC coat protein gene may play an important role in the local symptoms. Aspects of the involve-ment of the coat protein in the TNV-AC life cycle were discussed.

关键词：烟草坏死病毒A RNAs 染色体基因表达

Spatiotemporal pattern of climate change in the China-Myanmar Economic Corridor from 1901 to 2018

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Journal of Mountain Science 2024年第1期21卷 131-145页

作者： yang Xiaoliu li Yungang gao Lu Institute of Geography Fujian Normal UniversityFuzhou 350117China School of Geographical Sciences Fujian Normal UniversityFuzhou 350117China Institute of International Rivers and Eco-Security Yunnan UniversityKunming 650500China Fujian Provincial Engineering Research Center for Monitoring and Accessing Terrestrial Disasters Fujian Normal UniversityFuzhou 350117China Key Laboratory for Humid Subtropical Eco-geographical Processes of the Ministry of Education Fujian Normal UniversityFuzhou 350117China

The China-Myanmar Economic Corridor(CMEC) is an important part of China's Belt and Road Initiative and an important area for global ecology and biodiversity. In this study, the annual and seasonal spatiotemporal patterns of temperature and precipitation in the CMEC over the past century were investigated using linear tendency estimation, the Mann-Kendall mutation test, the T-test, and wavelet analysis based on the monthly mean climatic data from 1901 to 2018 released by the Climatic Research Unit(CRU) of the University of East Anglia, UK. The results show that the CMEC demonstrated a trend of warming and drying over the past 100 years, and the rate of change in Myanmar was stronger than that in Yunnan Province of China. The warming rate was 0.039 ℃/10a. Precipitation decreased at a rate of -6.1 mm/10a. From the perspective of spatial distribution, temperature was high in the central and southern, low in the north of the CMEC, and the high-temperature centers were mainly distributed in the southern plain and river valley. Precipitation decreased from west to east and from south to north of the CMEC. From the perspective of the rate of change, warming was stronger in central and northern CMEC than in southern and northeastern CMEC. The rate of precipitation decline was stronger in the central and western regions than in the eastern region. This study provides a scientific reference for the CMEC to address climate change and ensure sustainable social and economic development and ecological security.

关键词： China-Myanmar Economic Corridor CRU Air temperature Precipitation Spatiotemporal pattern

Implications of mosquito metabolism on vector competence

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Insect Science 2024年第3期31卷 674-682页

作者： li gao Wenxu yang Jingwen Wang State Key Laboratory of Genetic Engineering School of Life SciencesFudan UniversityShanghaiChina Ministry of Education Key Laboratory of Contemporary Anthropology School of Life SciencesFudan UniversityShanghaiChina

Mosquito-borne diseases(MBDs)annually kill nearly half a million *** to the lack of effective vaccines and drugs on most MBDs,disease prevention relies primarily on controlling *** huge efforts having been put into mosquito control,eco-friendly and sustainable mosquito-control strategies are still lacking and urgently *** mosquito-transmitted pathogens have lost the capacity of de novo nutrition biosynthesis,and rely on their vertebrate and invertebrate hosts for sustenance during the long-term obligate parasitism ***,a better understanding of the metabolic interactions between mosquitoes and pathogens will contribute to the discovery of novel metabolic targets or regulators that lead to reduced mosquito populations or vector *** review summarizes the current knowledge about the effects of mosquito metabolism on the transmission of multiple *** also discuss that research in this area remains to be explored to develop multiple biological prevention and control strategies for MBDs.

关键词： flaviviruses mosquito metabolism Plasmodium vector competence