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:      
  示例: 沙坡头地区,人工植被区,变化  检索词用空格隔开表示必须包含全部检索词,用“,”隔开表示只需满足任一检索词即可!
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   10810篇
  免费   4篇
管理学   1532篇
民族学   104篇
人口学   2441篇
丛书文集   1篇
理论方法论   536篇
综合类   288篇
社会学   4707篇
统计学   1205篇
  2024年   7篇
  2023年   8篇
  2022年   1篇
  2021年   7篇
  2020年   26篇
  2019年   25篇
  2018年   1678篇
  2017年   1679篇
  2016年   1100篇
  2015年   55篇
  2014年   58篇
  2013年   116篇
  2012年   336篇
  2011年   1172篇
  2010年   1057篇
  2009年   786篇
  2008年   826篇
  2007年   1001篇
  2006年   8篇
  2005年   230篇
  2004年   252篇
  2003年   212篇
  2002年   82篇
  2001年   7篇
  2000年   11篇
  1999年   6篇
  1998年   3篇
  1997年   4篇
  1996年   32篇
  1992年   1篇
  1991年   1篇
  1990年   2篇
  1989年   1篇
  1988年   10篇
  1985年   2篇
  1982年   2篇
  1981年   1篇
  1979年   1篇
  1978年   1篇
  1976年   1篇
  1974年   1篇
  1971年   1篇
  1970年   2篇
  1967年   1篇
  1962年   1篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
Strategic human resource management has avoided to evaluate its efforts in relation to employees’ careers. Recent research has investigated a selection of individual human resource management (HRM) practices (e.?g., training and development, mentoring, career development, talent management, performance appraisal) in relation to objective and subjective career success, but failed to study HRM systems or bundles. This paper argues that HRM systems and career success can be connected via human capital theory because human capital is understood as an organizational resource and as an individual antecedent to careers. Based on extant research that relates individual HRM practices to objective or subjective career success, this paper reviews and discusses the relationship between bundles of HRM practices and the individual practices contained therein and career success. The final conclusion suggests that evaluations of HRM systems should take careers into account because organizations rely on employees’ human capital. Future research should focus more intensely on the role of HRM for the development of careers also across organizations.  相似文献   
92.
For the ?news‘ section of the journal ?Gruppe, Interaktion, Organisation (GIO)‘, Janine Klemmt inducts into the functioning of US conference formats, which have long-since spread to European conference landscape. Among them there are formats like BarCamp or the predecessor Open-Space-Technology. These formats increasingly rely on the active participation and involvement of their attendees. Occasionally, the conference content is completely locally determined by the attendees. These participatory conferences have a decentralized structure, which is similar to the way social media works, but cannot be explained by an imitation of contemporary social media formats. Rather by means of decentralization online and conference platforms have a common organizational component, a common denominator, which, especially with cybernetics, has moved into the field of science, has been taken up in societal areas such as technology and business, and thus increasingly found its way into the everyday world.  相似文献   
93.
In 1952, von Neumann introduced the rejection method for random variate generation. We revisit this algorithm when we have a source of perfect bits at our disposal. In this random bit model, there are universal lower bounds for generating a random variate with a given density to within an accuracy \(\epsilon \) derived by Knuth and Yao, and refined by the authors. In general, von Neumann’s method fails in this model. We propose a modification that insures proper behavior for all Riemann-integrable densities on compact sets, and show that the expected number of random bits needed behaves optimally with respect to universal lower bounds. In particular, we introduce the notion of an oracle that evaluates the supremum and infimum of a function on any rectangle of \({\mathbb {R}}^{d}\), and develop a quadtree-style extension of the classical rejection method.  相似文献   
94.
Decisions about how to share resources with others often need to be taken under uncertainty regarding its allocational consequences. Although risk preferences are likely important, existing research is silent about how social and risk preferences interact in such situations. In this paper we provide experimental evidence on this question. In a first experiment givers are not exposed to risk while beneficiaries’ final earnings may be larger or smaller than the allocation itself, depending on the realized state of the world. In a second experiment, risk affects the earnings of givers but not of beneficiaries. We find that individuals’ risk preferences are predictive for giving in both experiments. Increased risk exposure of beneficiaries tends to decrease giving whereas increased risk exposure of givers has no effect. We propose a simple non-linear generalization of a model allowing for other-regarding preferences, ex-post and ex-ante fairness, and risk aversion. We find some support for it in our data when risk is on the beneficiaries’ side but less so when risk is on the givers’ side. Our results point to the importance of the further development of models of social preferences that also incorporate risk preferences.  相似文献   
95.
96.
The objective of this study was to evaluate the relative effects of watershed land-use on streambed substrate composition in eight low-order tropical streams. Data were collected at 24 sampling sites for eight wadeable streams in the Pirapó River Basin, southern Brazil. According to the percentage of impervious surfaces in the watershed, we defined the streams as either urban or rural. We estimate the percentages of the different streambed substrates, hydrological variables, and the rainfall intensity. The results showed that silt, sand and coarse particulate organic matter (CPOM) contributed to significant differences in streambed substrate composition between urban and rural streams. Silt, sand and CPOM were found in a higher mean proportion in the rural streams. Probably the urban streams have a greater bed load, promoted by precipitation and discharge, than rural streams, especially fine sediment. Rural streams have soft hydrographs, with stream flow slowly increasing during a rainstorm and subsequently decreasing over a long period after the rain event is over. These characteristics can provide the lixiviation of fine sediments into the stream channels due to land-surface clearance for agricultural activities and their accumulation in the streambed due to the moderate discharge regime.  相似文献   
97.
98.

Background

A low urine pH is a characteristic metabolic feature of metabolic syndrome and type 2 diabetes. The purpose of the current study was to investigate the effects of a 12-week home-based bench step exercise on the urine pH status of elderly female subjects.

Methods

The current study is a secondary analysis of a randomized controlled trial (RCT) in which 59 postmenopausal female subjects were randomized to either the exercise group (n?=?29) or the control group (n?=?30). The subjects in the exercise group were instructed to perform home-based exercises using a bench step at the anaerobic threshold (AT), with a goal of performing ≥140 min/week at home for 12 weeks. The subjects in the control group were instructed to not change their normal lifestyle. Urine was collected after overnight fasting, and the urine pH was measured using a urinary test strip. The inter-group-differences at baseline and the pre-post changes within groups were assessed using the Mann-Whitney U test and Wilcoxon’s signed-rank test, respectively. Additionally, the difference in the post-intervention urine pH levels of the two groups, adjusted for the pre-intervention values (the estimated effect size) and the precision (95% confidence intervals) were investigated using an analysis of covariance.

Results

The pre-post comparison of the urine pH data using Wilcoxon’s signed-rank test showed a significant increase in the urine pH levels of the exercise group (p?<?0.05); there was no significant change in the urine pH levels of the control group. However, the estimated effect size (0.15) was small and the confidence interval straddled 0 (?0.25–0.55).

Conclusions

Based on the results of the current secondary analysis of an RCT, we could not clearly conclude that exercise has a beneficial effect on the urine pH. Further well-designed RCTs should be conducted to determine whether aerobic exercise is truly able to ameliorate urine acidification.

Trial registration

The study was retrospectively registered in the University Hospital Medical Information Network (UMIN) as “Effect of step exercise on aerobic fitness and progression of atherosclerosis in the elderly” under the registration number UMIN 000026743 (the date of registration: March 28, 2017).
  相似文献   
99.
Research has examined various elements of Twitter; however, no scholarship has explored how sociologists currently use the platform. This empirically driven paper explores how individuals that self-identify as sociologists on Twitter use the popular micro-blogging social media site. A total of 152,977 tweets from Twitter profiles of 130 sociologists were collected and examined using qualitative media analysis. The potential use of Twitter allows the sociologist to become both the generator and interlocutor of dialogue with publics. We frame our data analysis and discussion around the core theme of expertise - namely, the role that expertise plays in the use of Twitter by sociologists. Our findings indicate that when sociologists used Twitter as sociologists (i.e., drawing upon their stated research expertise) little direct engagement with publics occurred. Thus, while sociologists appear to be using Twitter as a space for public sociology, the use of this interactive platform is mostly limited to the generation of content, a finding consistent with Burawoy’s traditional form of public sociology. Suggestions for future research are noted.  相似文献   
100.
Quantifizierung     
The challenge in data analysis often lies in taking account of the multi-dimensionality and complexity of the data and at the same time discovering patterns, which requires reduction and simplification. Quantitizing qualitative data can serve as an additional step during data analysis to broaden the perspective and collect complementary views. Examples from research illustrate how information gathered during one data collection can generate different types of data or how qualitative data can be transformed to be analysed statistically. Practicalities of integrating qualitative and quantitative analyses are illustrated to offer good-practice examples for transformation designs (QUAL → QUAN). With the methodological reflection of research practice I evaluate consequences for the field of mixed methods research, in which the statistical analysis of codes created during an interpretive phase plays a minor role.  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