首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   208411篇
  免费   7071篇
  国内免费   1931篇
管理学   6178篇
劳动科学   35篇
民族学   3179篇
人才学   37篇
人口学   2779篇
丛书文集   27260篇
理论方法论   8487篇
综合类   150083篇
社会学   8298篇
统计学   11077篇
  2024年   224篇
  2023年   1027篇
  2022年   1671篇
  2021年   1861篇
  2020年   2393篇
  2019年   2412篇
  2018年   2505篇
  2017年   3111篇
  2016年   3292篇
  2015年   4364篇
  2014年   10350篇
  2013年   13236篇
  2012年   12947篇
  2011年   14927篇
  2010年   12208篇
  2009年   12523篇
  2008年   13168篇
  2007年   16092篇
  2006年   16117篇
  2005年   14715篇
  2004年   13747篇
  2003年   13422篇
  2002年   10838篇
  2001年   9015篇
  2000年   5054篇
  1999年   1540篇
  1998年   804篇
  1997年   658篇
  1996年   543篇
  1995年   465篇
  1994年   343篇
  1993年   310篇
  1992年   237篇
  1991年   175篇
  1990年   106篇
  1989年   90篇
  1988年   92篇
  1987年   39篇
  1986年   37篇
  1985年   120篇
  1984年   132篇
  1983年   108篇
  1982年   95篇
  1981年   73篇
  1980年   61篇
  1979年   66篇
  1978年   57篇
  1977年   18篇
  1976年   13篇
  1975年   10篇
排序方式: 共有10000条查询结果,搜索用时 391 毫秒
71.
《Risk analysis》2018,38(1):84-98
The emergence of the complexity characterizing our systems of systems (SoS) requires a reevaluation of the way we model, assess, manage, communicate, and analyze the risk thereto. Current models for risk analysis of emergent complex SoS are insufficient because too often they rely on the same risk functions and models used for single systems. These models commonly fail to incorporate the complexity derived from the networks of interdependencies and interconnectedness (I–I) characterizing SoS. There is a need to reevaluate currently practiced risk analysis to respond to this reality by examining, and thus comprehending, what makes emergent SoS complex. The key to evaluating the risk to SoS lies in understanding the genesis of characterizing I–I of systems manifested through shared states and other essential entities within and among the systems that constitute SoS. The term “essential entities” includes shared decisions, resources, functions, policies, decisionmakers, stakeholders, organizational setups, and others. This undertaking can be accomplished by building on state‐space theory, which is fundamental to systems engineering and process control. This article presents a theoretical and analytical framework for modeling the risk to SoS with two case studies performed with the MITRE Corporation and demonstrates the pivotal contributions made by shared states and other essential entities to modeling and analysis of the risk to complex SoS. A third case study highlights the multifarious representations of SoS, which require harmonizing the risk analysis process currently applied to single systems when applied to complex SoS.  相似文献   
72.
Modern analytical models for anti-monopoly laws are a core element of the application of those laws. Since the Anti-Monopoly Law of the People’s Republic of China was promulgated in 2008, law enforcement and judicial authorities have applied different analytical models, leading to divergent legal and regulatory outcomes as similar cases receive different verdicts. To select a suitable analytical model for China’s Anti-Monopoly Law, we need to consider the possible contribution of both economic analysis and legal formalism and to learn from the mature systems and experience of foreign countries. It is also necessary to take into account such binding constraints as the current composition of China’s anti-monopoly legal system, the ability of implementing agencies and the supply of economic analysis, in order to ensure complementarity between the analytical model chosen and the complexity of economic analysis and between the professionalism of implementing agencies and the cost of compliance for participants in economic activities. In terms of institutional design, the models should provide a considered explanation of the legislative aims of the law’s provisions. It is necessary, therefore, to establish a processing model of behavioral classification that is based on China’s national conditions, applies analytical models using normative comprehensive analysis, makes use of the distribution rule of burden of proof, improves supporting systems related to analytical models and enhances the ability of public authorities to implement the law.  相似文献   
73.
潘澈 《东方论坛》2021,(2):113-122
对于舜之“怨慕”,朱熹作出了不同于孟子的解读。这是基于心学、理学内在逻辑的不同。孟子作为私学之儒,和孔子一样,是主张士君子的阳刚人格的,并且从性向善的人性论出发,协调义与利、公与私的关系,而以君臣父子关系都属对待关系;依此,将舜之“怨慕”解读为舜对父母的既怨又慕。朱熹则作为官学之儒,以所谓“气质之性”协调理学先驱荀子的性向恶论,以二歧化思维把天地之性、天理绝对化,以公去私,视君臣父子关系则为下对上的绝对服从关系;依此解读,舜之“怨”只能是自怨。  相似文献   
74.
In this article, we attempt to extend and nuance the debate on intellectual property (IP) strategy, appropriation, and open innovation in dynamic and systemic innovation contexts. We present the case of four generations of mobile telecommunications systems (covering the period 1980–2015), and describe and analyze the co-evolution of strategic IP management and innovation ecosystems. Throughout this development, technologies and technological relationships were governed with different and shifting degrees of formality. Simultaneously, firms differentiated technology accessibility across actors and technologies to benefit from openness and appropriation of innovation. Our analysis shows that the discussion of competitiveness and appropriability needs to be expanded from the focal appropriability regime and complementary assets to the larger context of the innovation ecosystem and its cooperative and competitive actor relations, with dispersed complementary and substitute assets and technologies. Consequently, the shaping of complementary and substitute appropriability regimes is central when strategizing in dynamic and systemic innovation contexts. This holds important implications for the management of open innovation, innovation ecosystems, platforms, and coopetition.  相似文献   
75.
中国共产党的宪法治理经历了从根据地局部执政时期的革命宪法,新中国成立初期移植苏联宪制模式及本土化探索,到改革开放后逐步形成依宪治国与依宪执政的新局面。百年宪法治理历程曲折蹒跚,终坚定向前,经验值得弘扬。宪法治理模式的移植当慎重,宪法的权威应维护,加强党的领导和中国特色社会主义宪制创新,培育中国特色社会主义宪法文化任重道远。  相似文献   
76.
基于2004—2017年中国省级面板数据,运用面板向量自回归(PVAR)模型,使用系统GMM估计、脉冲响应函数、方差分解以及格兰杰因果关系检验等方法分析了影子银行、地方政府债务及金融发展之间的动态关系.结果表明:影子银行、地方政府债务与金融发展水平三者之间存在动态耦合关系.在地方政府融资能力受到约束的情况下,影子银行为地方政府提供了多元的融资方式,在增加政府融资能力的同时提升了政府债务水平;而地方政府债务需求显著推动了影子银行规模的快速发展.同时,影子银行过度扩张危害了金融市场的健康发展,降低金融发展水平,继而使地方政府的融资渠道受到约束.但金融发展并不能有效约束影子银行规模,原因在于,政府融资需求是影子银行的主要动力,若不能控制地方政府的借贷行为则无法从源头解决问题.监管机构在去杠杆的过程中,应该综合考虑影子银行与地方政府债务、金融发展之间的动态关系,如此才能够实现预期的政策效果.  相似文献   
77.
《Risk analysis》2018,38(9):1988-2009
Harbor seals in Iliamna Lake, Alaska, are a small, isolated population, and one of only two freshwater populations of harbor seals in the world, yet little is known about their abundance or risk for extinction. Bayesian hierarchical models were used to estimate abundance and trend of this population. Observational models were developed from aerial survey and harvest data, and they included effects for time of year and time of day on survey counts. Underlying models of abundance and trend were based on a Leslie matrix model that used prior information on vital rates from the literature. We developed three scenarios for variability in the priors and used them as part of a sensitivity analysis. The models were fitted using Markov chain Monte Carlo methods. The population production rate implied by the vital rate estimates was about 5% per year, very similar to the average annual harvest rate. After a period of growth in the 1980s, the population appears to be relatively stable at around 400 individuals. A population viability analysis assessing the risk of quasi‐extinction, defined as any reduction to 50 animals or below in the next 100 years, ranged from 1% to 3%, depending on the prior scenario. Although this is moderately low risk, it does not include genetic or catastrophic environmental events, which may have occurred to the population in the past, so our results should be applied cautiously.  相似文献   
78.
Abstract

This paper focuses on the inference of suitable generally non linear functions in stochastic volatility models. In this context, in order to estimate the variance of the proposed estimators, a moving block bootstrap (MBB) approach is suggested and discussed. Under mild assumptions, we show that the MBB procedure is weakly consistent. Moreover, a methodology to choose the optimal length block in the MBB is proposed. Some examples and simulations on the model are also made to show the performance of the proposed procedure.  相似文献   
79.
根据支撑基础、责任负担、保障水平以及民众需求等维度,可以把民生保障划分为托底型、基本型、改善型以及富裕型等四种类型。改善型民生是经济社会发展到一定阶段的产物,也是国家治理体系与治理能力现代化的客观要求。它是指通过各类民生项目的安排及民生待遇优化以促进民众生活得到持续改善、社会发展水平得到提升的一种制度类型,是民生项目更加齐全、内容更为完善、治理水平更高、使民众各按其分的民生模式,是人们的日常生活与服务消费支出总额持续增长以便能够提升生活水平的民生类型,是那种不断满足人的需要特别是较高层次需要的模式类型,也是更有助于形成社会结构稳定、国家长治久安的民生制度类型,因而具有综合性、完善性、激励性以及发展性等特点。这要求我们优化民生类型设计及民生投入结构,补齐改善型民生短板,营造良好社会秩序,扎实推进国家治理体系及治理能力现代化建设。  相似文献   
80.
考虑由新能源汽车租赁企业和政府组成的二级系统,在需求率为随机且与推广努力水平相关的市场环境下,建立了新能源汽车租赁企业和政府之间的博弈模型,探讨了分散决策、集中决策、收益共享与成本共担契约下的最优车队配置和推广努力水平,并对三种情形下的最优决策进行了比较和分析。研究结果表明:在分散决策情况下无法实现系统协调,通过引入成本共担与收益共享组合契约,当契约参数满足一定条件时,该组合契约模型不仅可以实现系统协调而且可以使系统成员达到帕累托改进。最后通过算例分析,验证了模型了可靠性和有效性。  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号