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   1330篇
  免费   39篇
  国内免费   6篇
管理学   62篇
民族学   23篇
人口学   29篇
丛书文集   122篇
理论方法论   67篇
综合类   950篇
社会学   65篇
统计学   57篇
  2024年   1篇
  2023年   2篇
  2022年   10篇
  2021年   13篇
  2020年   11篇
  2019年   17篇
  2018年   14篇
  2017年   14篇
  2016年   31篇
  2015年   22篇
  2014年   64篇
  2013年   77篇
  2012年   79篇
  2011年   76篇
  2010年   68篇
  2009年   72篇
  2008年   69篇
  2007年   75篇
  2006年   82篇
  2005年   80篇
  2004年   82篇
  2003年   82篇
  2002年   59篇
  2001年   58篇
  2000年   49篇
  1999年   29篇
  1998年   19篇
  1997年   19篇
  1996年   15篇
  1995年   25篇
  1994年   12篇
  1993年   11篇
  1992年   13篇
  1991年   5篇
  1990年   4篇
  1989年   4篇
  1988年   6篇
  1987年   4篇
  1985年   1篇
  1984年   1篇
排序方式: 共有1375条查询结果,搜索用时 156 毫秒
21.
为缓解融资困境,各地都在探索农村金融的新模式,吉林省开展的“土地收益权质押”就是其中之一。它是指在不改变现行土地承包经营制度和土地农业用途的前提下,以土地的未来收益作为担保财产,为农户贷款提供担保的模式,该模式有“利于融资”与“避免失地”的双重优势。然而,通过仔细分析可以发现,吉林模式中的“土地收益权质押”名不副实,其实质是土地承包经营权的让与担保,存在诸多的法律弊端。而由于土地与公路等公共基础设施在“自动产生收益”这一属性上存在区别,所以无法通过借鉴“公路收费权质押”的制度经验来构建土地收益权质押。此外,利用土地未来的经营收益质押贷款的思路也不可行,理由是:经营收益由土地价值与劳动价值共同构成,而劳动价值无法登记,从而不具有优先效力;而且这种方式使得清偿能力取决于债务人自身,不符合特别担保之属性。在尚未放活经营权之前,以土地承租权担保贷款的构想较为可行,但须建立配套的登记制度。  相似文献   
22.
井壁稳定性问题(即井壁坍塌破裂)会引起系列严重的井下卡钻井漏等事故。靖边气田在钻井过程中,钻遇的地层当中存在多煤层,井壁稳定性问题十分突出,在该地区水平井钻井设计当中进行井壁稳定性分析有着重要的意义。分析了井壁围岩应力分布规律并建立地层坍塌(破裂)压力计算模式,根据库仑-摩尔强度准则和最大拉应力破裂准则,计算井壁坍塌(破裂)压力与钻井液安全密度窗口。通过实验研究分析煤层坍塌压力和破裂压力随井斜角、方位角变化规律,提出合理的方位角优选方案,指导水平井钻井方案设计。  相似文献   
23.
侯芳 《中国管理科学》2019,27(12):185-196
依据复杂网络理论分析服务型制造网络Holon协同需求问题,给出一种考虑以直觉正态模糊数表示且多Holon协同的服务型制造网络协同需求评价方法。首先,在区分Holon复合协同和递归协同基础上构建服务型制造网络协同需求评价指标体系;其次,考虑基于网络结构特征的Holon相似稳定性,根据服务型制造网络节点相似性测度分析Holon协同需求特征,并测算不同相似性测度修正的Holon网络结构熵;再次,建立面向服务型制造网络和Holon的有专家信息双向触动反馈机制,反馈包括评价指标和网络协同状况,反馈Holon信息包括基于服务型制造网络演化方向的Holon间协同需求建议和基于服务型制造网络现有状态的网络连通性Holon协同需求建议;最后由INFCWAINFCWAR)算子或INFCWGINFCWGR)算子分别对复合协同和递归协同评价信息集结并得出评价结论。方法设计过程通过例证分析说明根据服务型制造网络目标控制的Holon协同需求评价改进了群组评价效率。  相似文献   
24.
Ethiopia has been lauded for its economic growth and progress in human development indicators. For some, that success is rooted in the developmental state approach advocated by the government. For others, the theory of the developmental state and the practice in Ethiopia were often at odds. Up until 2018, ideas that challenged the state and its approaches were not welcome, and politicians, academics and journalists were jailed for expressing alternative views. However, this appears to have changed, and in June 2018 the Deputy Prime Minister called for debate on the developmental state model. This article explores Ethiopia's developmental state model using the building stability framework, analysing its ability to establish fair power structures, foster inclusive economic growth, develop conflict‐resolution mechanisms, create effective and legitimate institutions, and enable a supportive regional environment. We find the developmental state was effective in a number of ways, but that this modality of governance appears to have passed its peak of securing advantage in Ethiopia. A shift from the developmental state to developmental democracy appears to be underway. Decision‐making and economic policies need to align with this change.  相似文献   
25.
利用12个发达国家和发展中国家的非平衡面板样本数据,对微观、宏观和其他因素对生产者货币计价(PCP)的影响进行实证研究,指出经济规模、市场份额、金融市场的发达程度、币值的对内稳定性和产品差异化程度是最主要的影响因素,而出口商的谈判能力、币值的对外稳定性等因素也对PCP的选择有一定影响。根据实证检验结果,对人民币作为贸易计价货币的条件进行评估,发现其优势在于我国的经济规模、出口商的市场份额及其谈判能力以及人民币汇率的相对稳定性; 劣势在于相对落后的金融市场、不可预期性较大的通货膨胀水平以及产品的差异化程度。  相似文献   
26.
Evidence suggests that problem gambling is an unstable state where gamblers move into and out of risk over time. This article looks at longitudinal changes in risky gambling and the factors associated with an increased risk (measured by the Problem Gambling Severity Index [PGSI]) in the current New Zealand context, which has experienced a doubling of the electronic gaming machine (EGM) market over the last two decades. Respondents from a nationally representative baseline sample (n = 2672) were recontacted two years later to assess changes in gambling behaviours. Among the 901 respondents reached at follow-up, average gambling risk increased over time, and the prevalence of those who had at least some level of gambling risk (i.e. low-risk or greater) more than doubled (from 4.7% to 12.4%). The majority (80.2%) of those who were at risk at follow-up had not been at risk at baseline. Multivariate linear regression analyses show that the predictors of low to moderate increased risk include Pacific ethnicity; high neighbourhood deprivation status; baseline frequent, continuous gambler type; baseline PGSI status; and playing EGMs. These findings highlight the need to develop theories of gambling addiction trajectories and to identify the earliest point along the trajectory where public health interventions should occur.  相似文献   
27.
“款词文化超稳定性”的成因直接受侗族家族制度、生态环境、社会政治环境、语言特殊性及其生产、生活方式等因素的共同影响.  相似文献   
28.

Age‐specific models of population renewal (with and without feedback) which imply convergence to a stable state for some levels of fertility or feedback may imply the presence of long‐term cycling around a constant or exponentially changing equilibrium for other levels of fertility or feedback. The switch from one regime to the other is a “bifurcation.”; The conditions for bifurcation involve the roots of an analogue of Lotka's Equation.

Typically bifurcation is induced by raising the strength of feedback or the level of fertility. It has been known since the early 1980s, however, that this is sometimes impossible. It is sometimes impossible even with the linear renewal equation itself and with the most basic of non‐linear models, Lee's cohort feedback model.

Here it is proved that this typical route to bifurcation does not fail for these basic models in the presence of a condition which always holds for realistic applications with higher organisms: the existence of a span of ages before the onset of fertility.

Specifically, a strictly positive lower bound on ages of procreation is proved to be sufficient to guarantee the existence of a rescaling of Lotka's Equation for which the real part of some complex root vanishes. This result holds for absolutely Lebesgue‐integrable (signed) net maternity functions on the positive real line and for absolutely summable (signed) net maternities on the positive integers.

It follows that Coale's rescaling device for the analysis of approach to stability in stable population theory can be implemented for all realistic human net maternity schedules. It also follows that the many special cases of the cohort feedback model throughout population biology will all generate persistent cycling instead of stability if feedback is sufficiently strong.  相似文献   
29.
In 2008, Industry Canada auctioned 105 MHz of spectrum to a group of bidders that included incumbents and potential new entrants into the Canadian mobile phone market, raising $4.25 billion. In an effort to promote new entry, 40 MHz of spectrum was set‐aside for new entrants. In order to estimate the implicit cost of the set‐aside provision, we estimate the parameters of the bidders' profit function via a maximum match estimator based on the notion of pairwise stability in matches. We find that all telecommunications firms valued both geographic complementarities across auction licenses as well as absolute spectrum. Under a reasonable alternative scenario, our results indicate that the set‐aside led to a total profit loss of approximately 10%.  相似文献   
30.
契约型农产品渠道中专有资产投入、人际信任与关系稳定   总被引:1,自引:0,他引:1  
文章探讨了收购商与农户构成的契约型农产品渠道关系中,收购商与农户双方的专有资产投入对农户信任的影响,以及农户信任对关系稳定性的影响作用.实证研究发现,收购商专有资产投入会促进农户信任,而农户专有资产投入会强化上述关系;同时,农户信任会提升其续约意愿,降低其违约倾向.此外,政府支持会强化农户信任对其续约意愿的正向影响,但会削弱农户信任对其违约倾向的负向影响.研究结论拓展了传统渠道中专有资产投入对信任影响的适用范围,指出了双方锁定的渠道关系对信任的重要作用,为农产品渠道中契约稳定性的研究提供了新视角.研究还发现,政府支持对提高契约型农产品渠道关系稳定性具有重要作用,这对制定契约型农产品渠道的管理政策具有一定的启发意义.  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