全文获取类型
收费全文 | 3497篇 |
免费 | 119篇 |
国内免费 | 26篇 |
专业分类
管理学 | 410篇 |
劳动科学 | 5篇 |
民族学 | 79篇 |
人才学 | 1篇 |
人口学 | 264篇 |
丛书文集 | 383篇 |
理论方法论 | 196篇 |
综合类 | 1024篇 |
社会学 | 648篇 |
统计学 | 632篇 |
出版年
2023年 | 30篇 |
2022年 | 56篇 |
2021年 | 57篇 |
2020年 | 60篇 |
2019年 | 66篇 |
2018年 | 80篇 |
2017年 | 142篇 |
2016年 | 85篇 |
2015年 | 105篇 |
2014年 | 130篇 |
2013年 | 418篇 |
2012年 | 153篇 |
2011年 | 184篇 |
2010年 | 165篇 |
2009年 | 175篇 |
2008年 | 153篇 |
2007年 | 165篇 |
2006年 | 146篇 |
2005年 | 127篇 |
2004年 | 104篇 |
2003年 | 104篇 |
2002年 | 118篇 |
2001年 | 121篇 |
2000年 | 76篇 |
1999年 | 65篇 |
1998年 | 43篇 |
1997年 | 41篇 |
1996年 | 36篇 |
1995年 | 32篇 |
1994年 | 32篇 |
1993年 | 22篇 |
1992年 | 24篇 |
1991年 | 10篇 |
1990年 | 16篇 |
1989年 | 29篇 |
1988年 | 28篇 |
1987年 | 24篇 |
1986年 | 26篇 |
1985年 | 26篇 |
1984年 | 28篇 |
1983年 | 29篇 |
1982年 | 21篇 |
1981年 | 25篇 |
1980年 | 16篇 |
1979年 | 4篇 |
1978年 | 4篇 |
1977年 | 4篇 |
1976年 | 7篇 |
1973年 | 6篇 |
1972年 | 4篇 |
排序方式: 共有3642条查询结果,搜索用时 751 毫秒
51.
In this paper, a new multivariate zero-inflated binomial (MZIB) distribution is proposed to analyse the correlated proportional data with excessive zeros. The distributional properties of purposed model are studied. The Fisher scoring algorithm and EM algorithm are given for the computation of estimates of parameters in the proposed MZIB model with/without covariates. The score tests and the likelihood ratio tests are derived for assessing both the zero-inflation and the equality of multiple binomial probabilities in correlated proportional data. A limited simulation study is performed to evaluate the performance of derived EM algorithms for the estimation of parameters in the model with/without covariates and to compare the nominal levels and powers of both score tests and likelihood ratio tests. The whitefly data is used to illustrate the proposed methodologies. 相似文献
52.
金工实习是工科专业理论联系实际重要的一门基础实训课程,是农林院校农业工程机械类专业和非农业工程工学类专业学生的必修课程。该文以安徽农业大学工学院金工实训中心实践教学现状为例,分析了当前金工实习中存在的不足,从教学安全、教学模式、考核方式、师资队伍和教学硬件5个方面提出了改革措施,为推动省属农林院校金工实习改革提供参考。 相似文献
53.
Risk Analysis, Systems Analysis, and Covey's Seven Habits 总被引:2,自引:0,他引:2
Yacov Y. Haimes 《Risk analysis》2001,21(2):217-224
This article relates problem solving to the common approaches of the gestalt-holistic philosophies of systems analysis, risk analysis, and Stephen Covey's Seven Habits of Highly Effective People. Guiding principles developed on the basis of these philosophies provide the foundations for methodological frameworks that build on a plethora of theory, methods, tools, and techniques. Although systems analysis and risk analysis differ in their historical evolution and technical maturity, both study and solve problems using methodological frameworks that share a holistic vision. 相似文献
54.
In the production planning and control of discrete-parts manufacture, aggregation of parts into families, on the basis of similarity, is carried out to ease both long-horizon planning and short-horizon scheduling. Additional advantages are related to those of group technology (GT), such as simplifying the flow of parts and tools and reducing both set-up and production costs. The problem of formally forming part families is presented and discussed. Previous work is reviewed and assessed. Two solution approaches, one based on a location model, the other on simulated annealing, are presented and compared along with test results. The location formulation, which results in an integer programming model solved by Lagrangian relaxation, proved capable of producing solutions of excellent quality, but only for relatively small problem instances. In contrast, simulated annealing, which is a general heuristic approach to combinatorial optimization, produced solutions of comparable quality and could handle realistically large problem instances. However, careful design of the simulated annealing algorithm is crucially important. An effective design is presented. 相似文献
55.
A point of view is suggested from which the Hierarchical Holographic Modeling (HHM) method can be seen as one more method within the Theory of Scenario Structuring (TSS), which is that part of Quantitative Risk Assessment having to do with the task of identifying the set of risk scenarios. Seen in this way, HHM brings strongly to our attention the fact that different methods within TSS can result in different sets of risk scenarios for the same underlying problem. Although this is not a problem practically, it is a bit awkward conceptually from the standpoint of the "set of triplets" definition of risk, in which the scenario set is part of the definition. Accordingly, the present article suggests a refinement to the set of triplets definition, which removes the specific set of scenarios, found by any of the TSS methods, from the definition of risk and casts it, instead, as an approximation to the "true" set of scenarios that is native to the problem at hand and not affected by the TSS method used. 相似文献
56.
57.
Flood Catastrophe Model for Designing Optimal Flood Insurance Program: Estimating Location‐Specific Premiums in the Netherlands 下载免费PDF全文
T. Ermolieva T. Filatova Y. Ermoliev M. Obersteiner K. M. de Bruijn A. Jeuken 《Risk analysis》2017,37(1):82-98
As flood risks grow worldwide, a well‐designed insurance program engaging various stakeholders becomes a vital instrument in flood risk management. The main challenge concerns the applicability of standard approaches for calculating insurance premiums of rare catastrophic losses. This article focuses on the design of a flood‐loss‐sharing program involving private insurance based on location‐specific exposures. The analysis is guided by a developed integrated catastrophe risk management (ICRM) model consisting of a GIS‐based flood model and a stochastic optimization procedure with respect to location‐specific risk exposures. To achieve the stability and robustness of the program towards floods with various recurrences, the ICRM uses stochastic optimization procedure, which relies on quantile‐related risk functions of a systemic insolvency involving overpayments and underpayments of the stakeholders. Two alternative ways of calculating insurance premiums are compared: the robust derived with the ICRM and the traditional average annual loss approach. The applicability of the proposed model is illustrated in a case study of a Rotterdam area outside the main flood protection system in the Netherlands. Our numerical experiments demonstrate essential advantages of the robust premiums, namely, that they: (1) guarantee the program's solvency under all relevant flood scenarios rather than one average event; (2) establish a tradeoff between the security of the program and the welfare of locations; and (3) decrease the need for other risk transfer and risk reduction measures. 相似文献
58.
Open innovation and absorptive capacity are two concepts based on the idea that companies can leverage the knowledge generated externally to improve their innovation performance. The aim of this paper is to analyse the joint effect of open innovation and absorptive capacity on a firm's radical innovation. Open innovation is expressed in terms of external search breadth and depth strategies and absorptive capacity is described by distinguishing between potential and realized absorptive capacity. In order to test our hypotheses, we carried out empirical research in firms operating in high-technology industries. The results indicate that internal routines and processes for absorbing external knowledge help explain radical innovation as they show a significant effect of potential and realized absorptive capacity. Also, there is a moderating effect of absorptive capacity on open innovation. Specifically, potential absorptive capacity exerts a positive effect on the relationship between external search breadth and depth and radical innovation. Realized absorptive capacity moderates the influence of external search breadth. These findings confirm the complementary nature of absorptive capacity and open innovation search strategies on radical innovation. 相似文献
59.
田晖 《山西高等学校社会科学学报》2012,24(9):91-94
大学阶段是一个人身心成长发育的关键时期,健康的心理是大学生接受科学文化知识的重要前提。然而,由于社会、家庭以及大学生个体等因素的影响,致使他们出现了各种不同程度的心理问题。其特点是:政治价值观复杂多元,信仰趋向自由化和多元化,人生价值趋向迷茫、功利思想严重,职业兴趣不明确,而在择偶问题上则较成熟。解决这些问题,要发挥思想政治理论课的主渠道作用进行教育引导,同时应在高校的马克思主义学院设立心理咨询中心,分阶段进行心理健康教育,以提高大学生的心理健康水平。 相似文献
60.
彭雨明 《湛江师范学院学报》2012,33(6)
洛必答法则是求解极限的一个非常重要的方法,一般教材的编写,只是着重例题类型的分类专门讨论,在技巧的讨论上着墨较少,文章则从洛必答法则使用技巧以及注意事项方面针对一些实例做出浅析. 相似文献