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1.
有害藻华是近海常见的灾害性生态异常现象,不仅包括微藻形成的"赤潮"和"褐潮",也包括大型藻类形成的"绿潮"。在许多海域,有害藻华问题一旦出现,就会持续很长一段时间,对海水养殖、生态安全和人类健康构成威胁。在我国,有害藻华已成为一类突出的海洋生态灾害问题。渤海海域、长江口及其邻近海域和南海近岸海域是3个典型的赤潮高发区,大规模暴发的赤潮对海水养殖业造成了严重破坏,也威胁到海域生态安全和人类健康。近期在南黄海和渤海海域还出现了绿潮和褐潮等灾害性有害藻华现象,受到高度关注。综合分析我国近海的有害藻华问题可以看出,我国近海藻华原因种呈现出多样化、有害化和小型化的演变趋势,这给藻华的监测和管理带来了许多困难。为有效防控有害藻华,有必要加强针对有害藻华的基础研究,阐明藻华原因种的多样性状况、藻华发生与生态系统健康的关系、藻华的演变趋势及其驱动因子、藻华演变可能造成的生态效应等基础问题,同时,应进一步加强对藻华的观测预警和控制防范能力。 相似文献
2.
中国科学院胶州湾海洋生态系统定位研究站基于长期观测与系统研究，揭示了中国近海关键种——中华哲水蚤的度夏机制；在国际上，率先提出浮游动物功能群概念；阐明了全球变化影响下胶州湾生态系统的长期演变过程与机制；揭示了中国近海水母灾害暴发的关键过程、机理及生态环境效应；揭示了黄海绿潮成因，提出了黄海绿潮规模的预测思路和方法，形成系统化的防控应对策略；揭示了我国近海海水与关键海洋生物体内微塑料特征；研发了近海生态系统健康与承载力评估系统。相关研究在国内外产生了重要影响，为我国近海生态系统健康、生态环境保护、生物资源可持续发展提供了坚实的理论基础和科技支撑。 相似文献
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蒙古高原生态服务消费空间差异的实证研究 总被引：3，自引：2，他引：1
本文结合一手问卷调查资料和相关统计资料,从生态系统服务消费者的角度,对蒙古高原典型牧区生态系统服务中食物和燃料的消费进行实证分析,分析消费的空间差异及其影响因素,并将结果与我国内蒙古牧区的消费情况进行对比.结果表明:蒙古国粮食消费中以小麦为主,其他副食品以肉类和奶制品的消费为主,而家畜干粪和木柴则是蒙古国最主要的燃料来源;我国内蒙古牧区基本无马肉消费,蔬菜和秸秆人均消费量高于蒙古国.社会经济因素、生态系统服务的可获得性或可达性以及消费行为如消费偏好等,均影响人类对生态系统服务的消费模式和意愿,也影响研究区生态系统服务消费的空间差异.本文是对生态系统服务消费理论的实证研究,可以为整个蒙古高原牧区生态-环境-经济可持续发展提供科学依据. 相似文献
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This editorial examines the question of whether plagiarism may be on the increase in the social sciences and, if so, what needs to be done to keep the problem in check. It was prompted by the discovery of an alert reader in June 2007 that a 1993 paper in Research Policy appeared to have plagiarised a 1980 article in the Journal of Business. The allegation was investigated, and it was agreed by the Editors that the 1993 paper constituted a clear and serious case of plagiarism. However, the author concerned has published over 100 articles and books. Already, two other publications have been judged by the editors of the journals concerned to have plagiarised previous publications. Two more are under investigation, but the great majority of the remainder still remain to be checked. The fact that academic misconduct on this scale has gone unchecked over such a prolonged period raises serious issues about the efficacy of the processes used to police the conduct of researchers. Furthermore, the unexpected discovery that a paper by the author under investigation appears itself to have been plagiarised poses a fundamental question as to whether plagiarism may be far more common than previously assumed. The editorial concludes that a measured degree of vigilance and a greater willingness to pursue any well-founded suspicions of research misconduct are required by editors, referees, publishers and the wider academic community if the scourge of plagiarism is to be kept at bay. 相似文献
5.
《Research Policy》2022,51(9):104065
This paper develops and applies a new evaluative approach to local entrepreneuriale cosystems, as configural narratives. We examine how configurations of local entrepreneurial ecosystem attributes, as evaluated by local experts, support or hinder the emergence of new and innovative firms. Drawing on sociology of place, we present a novel configurational comparative analysis of local experts' evaluation of their ecosystems in Chile. Our proposed approach to entrepreneurial ecosystems helps us uncover two counterintuitive findings and so elaborateon interferences that have not yet been addressed through conventional concepts, methods and data. First, we reveal three distinct ecosystem types explaining different local levels of new firm activity: Active self-propelled, Indulged and Passive self-absorbed. The internal composition of these types change when only innovative and high growth firms are taken into consideration. Second, we show why, when seen as configural narratives, ecosystem attributes that have been assumed necessary play only a peripheral role. Our study demonstrates a split picture against seemingly similar outcomes and homogenous local contexts, contributing to the advancement of entrepreneurial ecosystem theory, observation and assessment. 相似文献
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长江经济带是中国重要的水资源聚集区、水生态功能区,其水资源绿色效率问题直接影响了生态系统质量和稳定性.本文从高质量发展视角,构建了长江经济带110个城市水资源绿色效率评价指标体系,采用定基极差熵权法、超效率EBM模型和GML生产率指数以及空间面板分位数回归等计量方法,对水资源绿色效率的时空演变特征及其影响因素等问题进行... 相似文献
7.
D.J. Mullan 《Journal of The Franklin Institute》1974,298(4):341-362
The observed properties of solar magnetic fields are reviewed, with particular reference to the complexities imposed on the field by motions of the highly conducting gas. Turbulent interactions between gas and field lead to heating or cooling of the gas according as the field energy density is less or greater than the maximum kinetic energy density in the convection zone. The field strength above which cooling sets in is 700 G.A weak solar dipole field may be primeval, but dynamo action is also important in generating new flux. The dynamo is probably not confined to the convection zone, but extends throughout most of the volume of the sun. Planetary tides appear to play a role in driving the dynamo. 相似文献
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全球生态系统服务价值评估研究进展 总被引：167，自引：8，他引：167
随着人类对生态系统功能不可替代性的认识愈来愈深刻，生态系统服务功能研究愈来愈受到人们的重视。近年来，这一领域的研究已经取得了令人注目的进展。研究的重点主要集中在采用各种方法对自然资本的边际服务价值进行估计。评估的方法大都直接或间接地基于对生态系统服务的个人偿付意愿进行计量。对全球生态系统服务价值评估的代表是基于全球静态总平衡输入输出模型的评估和基于全球静态部分平衡的评估，中国对区域生态系统服务价值也进行了初步估算。生态系统功能与服务的复杂性、价值的多重认识、市场失效及价格空缺、实证的困难与自然资本总价值得无限至今还制约着生态系统服务价值研究的发展，今后需要研究的领域及发展趋势是：1、不同生态类型的各种服务价值研究；2、生态系统服务空间异质性研究；3、包含非线性及阈值的动态地区模型和全球模型；4、改变账户系统和制定相应政策；5、考虑生态系统服务损失的项目评估；6、大规模的小幅度变化和小规模的大幅度变化边际研究. 相似文献
9.
George Lekakos Pavlos Vlachos Christos Koritos 《Ethics and Information Technology》2014,16(2):103-117
There is an emerging consensus in the corporate social responsibility (CSR) literature suggesting that the quest for the so-called business case for CSR should be abandoned. In the same vein, several researchers have suggested that future research should start examining not whether, but rather when CSR is likely to have strengthened, weakened or even nullified effects on organizational outcomes (e.g. Margolis et al. in Does it pay to be good? A meta-analysis and redirection of research on corporate social and financial performance. Working Paper, Harvard Business School, 2007; Kiron et al. in MIT Sloan Manag Rev 53(2):69–74, 2012). Using perspectives from several theoretical frameworks (Needs Theory, Technology Acceptance Theory, and Psychological Distance Theory), we contribute to the literature by empirically examining the tension between functional and sustainability attributes in a novel context, namely that of green e-banking services. The findings indicate that the positive effect of CSR on users’ attitudes towards green e-banking services is moderated by two primarily utilitarian information systems factors—namely perceived ease of use and perceived usefulness—and an important utilitarian individual difference variable—namely perceived self-efficacy with technology. Our findings are also important if interpreted within the context of the ethical decision-making literature (e.g. O’Fallon and Butterfield in J Bus Ethics 59(4):375–413, 2005), as they indicate that the linkage between moral judgment and moral outcomes is unlikely to be that straightforward. 相似文献
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The living cells are arranged in a complex natural environment wherein they interact with extracellular matrix and other neighboring cells. Cell-cell interactions, especially those between distinct phenotypes, have attracted particular interest due to the significant physiological relevance they can reveal for both fundamental and applied biomedical research. To study cell-cell interactions, it is necessary to develop co-culture systems, where different cell types can be cultured within the same confined space. Although the current advancement in lab-on-a-chip technology has allowed the creation of in vitro models to mimic the complexity of in vivo environment, it is still rather challenging to create such co-culture systems for easy control of different colonies of cells. In this paper, we have demonstrated a straightforward method for the development of an on-chip co-culture system. It involves a series of steps to selectively change the surface property for discriminative cell seeding and to induce cellular interaction in a co-culture region. Bone marrow stromal cells (HS5) and a liver tumor cell line (HuH7) have been used to demonstrate this co-culture model. The cell migration and cellular interaction have been analyzed using microscopy and biochemical assays. This co-culture system could be used as a disease model to obtain biological insight of pathological progression, as well as a tool to evaluate the efficacy of different drugs for pharmaceutical studies. 相似文献
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《Research Policy》2022,51(2):104398
Scholarly literature on the concept of entrepreneurial ecosystems has increased sharply over the past five years. The surge in interest has also heightened the demand for robust empirical measures that capture the complexity of dynamic relationships among ecosystem constituents. We offer a framework for measurement that places collaborative relationships among entrepreneurs, firms, government agencies, and research institutions at the center of the ecosystem concept. We further emphasize the four roles of the federal government as a catalyst, coordinator, certifier, and customer in shaping these relationships. Despite the central importance of these firm-government interactions, there is surprisingly little research on suitable methodologies and appropriate data for systematically and reliably incorporating them into measures of ecosystem health. Our study aims to address this gap in the literature by first developing a conceptual framework for measuring entrepreneurial ecosystems and then describing an array of accompanying databases that provide rich and detailed information on firms and their relationships with government organizations, accelerators, and research institutions. A major advantage of our approach is that all the underlying databases are drawn from non-confidential, publicly available sources that are transparently disclosed and regularly updated. This greatly expands the potential community of scholars, managers, and policymakers that may independently use these databases to test theories, make decisions, and formulate policies related to innovation and entrepreneurship. 相似文献
15.
University-industry linkages in the UK: What are the factors underlying the variety of interactions with industry? 总被引：7，自引：0，他引：7
This paper examines the different channels through which academic researchers interact with industry and the factors that influence the researchers’ engagement in a variety of interactions. This study is based on a large scale survey of UK academic researchers. The results show that university researchers interact with industry using a wide variety of channels, and engage more frequently in the majority of the channels examined - such as consultancy & contract research, joint research, or training - as compared to patenting or spin-out activities. In explaining the variety and frequency of interactions, we find that individual characteristics of researchers have a stronger impact than the characteristics of their departments or universities. Finally, we argue that by paying greater attention to the broad range of knowledge transfer mechanisms (in addition to patenting and spin-outs), policy initiatives could contribute to building the researchers’ skills necessary to integrate the worlds of scientific research and application. 相似文献
16.
《Research Policy》2022,51(9):104579
Scholarly literature on the concept of entrepreneurial ecosystems has increased sharply over the past five years. The surge in interest has also heightened the demand for robust empirical measures that capture the complexity of dynamic relationships among ecosystem constituents. We offer a framework for measurement that places collaborative relationships among entrepreneurs, firms, government agencies, and research institutions at the center of the ecosystem concept. We further emphasize the four roles of the federal government as a catalyst, coordinator, certifier, and customer in shaping these relationships. Despite the central importance of these firm-government interactions, there is surprisingly little research on suitable methodologies and appropriate data for systematically and reliably incorporating them into measures of ecosystem health. Our study aims to address this gap in the literature by first developing a conceptual framework for measuring entrepreneurial ecosystems and then describing an array of accompanying databases that provide rich and detailed information on firms and their relationships with government organizations, accelerators, and research institutions. A major advantage of our approach is that all the underlying databases are drawn from non-confidential, publicly available sources that are transparently disclosed and regularly updated. This greatly expands the potential community of scholars, managers, and policymakers that may independently use these databases to test theories, make decisions, and formulate policies related to innovation and entrepreneurship. 相似文献
17.
杉木人工林生态系统管理：思想与实践 总被引：7，自引：0，他引：7
杉木人工林是我国最重要的用材林之一,在国民经济中占有极为重要的地位。如何保持杉木人工林生产力的可持续性,长期以来一直是我国林学界和生产部门关注的一个重要议题。最近提出的生态系统管理的思想、理论与方法为解决杉木人工林的可持续经营提供了新思路。本文从生态系统管理的具体定义和内涵出发,结合所面临的问题,指出杉木人工林生态系统管理不应仅指对林木本身的管理,还应包括林分形成的前期阶段、系统内各组分对系统整体功能的影响、凋落物分解管理、土壤生态系统管理,以及在广大林区开展综合性的长期生态监测计划等方面。包括上述各个方面的综合管理方法,是实现杉木人工林生产力可持续性的根本途径。 相似文献
18.
A biological population can be viewed as a distributed parameter dynamical system. The dynamics of host-parasite systems are investigated by coupling populations via age specific interactions; analysis and simulation results are compared with experiments performed on a laboratory ecosystem. A number of novel dynamical effects emerge from the model which have some interesting ecological consequences. 相似文献
19.
绿色信贷政策对企业绿色创新的影响 《科学学研究》2022,40(2):345-356
在“绿水青山就是金山银山”的发展理念下,如何更好地发挥绿色信贷在引导企业绿色创新、推动经济绿色转型方面的作用,已成为一项亟待研究和解决的重要课题。本文以2012年《绿色信贷指引》的出台作为准自然实验,选取2009-2014年中国A股上市工业企业作为研究样本,运用双重差分法考察该项绿色信贷政策对重污染企业绿色创新的影响及作用机制。研究发现,绿色信贷政策对于重污染企业绿色创新具有显著的抑制作用,以上结论在进行控制配对偏差、更换代理变量、剔除干扰样本等一系列稳健性检验后依然成立。机制分析发现,由信贷规模缩减和信贷成本提高所引致的信贷约束加剧是其中的主要作用机制。异质性分析显示,绿色信贷政策对于重污染企业绿色创新的抑制效应在非国有企业、小规模企业样本以及绿色发明专利层面较为显著。区别已有文献,本文从企业绿色创新的视角揭示了绿色信贷政策的微观效果,不仅有助于理解绿色信贷政策的经济效应以及企业参与绿色创新的具体动机,而且为后续绿色信贷政策的推进以及中国绿色金融体系的构建提供了相应启示。 相似文献
20.
BackgroundLaccases are copper-containing enzymes which have been used as green biocatalysts for many industrial processes. Although bacterial laccases have high stabilities which facilitate their application under harsh conditions, their activities and production yields are usually very low. In this work, we attempt to use a combinatorial strategy, including site-directed mutagenesis, codon and cultivation optimization, for improving the productivity of a thermo-alkali stable bacterial laccase in Pichia pastoris.ResultsA D500G mutant of Bacillus licheniformis LS04 laccase, which was constructed by site-directed mutagenesis, demonstrated 2.1-fold higher activity when expressed in P. pastoris. The D500G variant retained similar catalytic characteristics to the wild-type laccase, and could efficiently decolorize synthetic dyes at alkaline conditions. Various cultivation factors such as medium components, pH and temperature were investigated for their effects on laccase expression. After cultivation optimization, a laccase activity of 347 ± 7 U/L was finally achieved for D500G after 3 d of induction, which was about 9.3 times higher than that of wild-type enzyme. The protein yield under the optimized conditions was about 59 mg/L for D500G.ConclusionsThe productivity of the thermo-alkali stable laccase from B. licheniformis expressed in P. pastoris was significantly improved through the combination of site-directed mutagenesis and optimization of the cultivation process. The mutant enzyme retains good stability under high temperature and alkaline conditions, and is a good candidate for industrial application in dye decolorization. 相似文献