全文获取类型
收费全文 | 21035篇 |
免费 | 568篇 |
国内免费 | 2篇 |
专业分类
管理学 | 2744篇 |
民族学 | 109篇 |
人才学 | 3篇 |
人口学 | 1806篇 |
丛书文集 | 127篇 |
教育普及 | 3篇 |
理论方法论 | 1981篇 |
综合类 | 324篇 |
社会学 | 11105篇 |
统计学 | 3403篇 |
出版年
2021年 | 109篇 |
2020年 | 277篇 |
2019年 | 439篇 |
2018年 | 468篇 |
2017年 | 674篇 |
2016年 | 474篇 |
2015年 | 366篇 |
2014年 | 483篇 |
2013年 | 3906篇 |
2012年 | 619篇 |
2011年 | 618篇 |
2010年 | 470篇 |
2009年 | 446篇 |
2008年 | 453篇 |
2007年 | 500篇 |
2006年 | 487篇 |
2005年 | 468篇 |
2004年 | 414篇 |
2003年 | 331篇 |
2002年 | 387篇 |
2001年 | 518篇 |
2000年 | 457篇 |
1999年 | 458篇 |
1998年 | 320篇 |
1997年 | 296篇 |
1996年 | 346篇 |
1995年 | 340篇 |
1994年 | 351篇 |
1993年 | 358篇 |
1992年 | 367篇 |
1991年 | 353篇 |
1990年 | 379篇 |
1989年 | 333篇 |
1988年 | 313篇 |
1987年 | 305篇 |
1986年 | 260篇 |
1985年 | 295篇 |
1984年 | 306篇 |
1983年 | 251篇 |
1982年 | 231篇 |
1981年 | 181篇 |
1980年 | 209篇 |
1979年 | 216篇 |
1978年 | 190篇 |
1977年 | 158篇 |
1976年 | 158篇 |
1975年 | 177篇 |
1974年 | 147篇 |
1973年 | 118篇 |
1972年 | 106篇 |
排序方式: 共有10000条查询结果,搜索用时 546 毫秒
481.
Aided by the Internet, microfinance institutions have found new ways to expand the reach of financing entrepreneurial projects on a small scale. Using a unique data set of individual loans posted to Kiva.org, we explore the determinants of lenders’ nonprofit lending choices in the growing microfinance industry. We find that lenders make choices in purposive ways even in the absence of market interest rates, especially with respect to the demographic characteristics of borrowers and the uses of proposed funds. Hence, the results provide valuable new information about consumer choice in charitable giving and investment. 相似文献
482.
Using In Vitro High‐Throughput Screening Data for Predicting Benzo[k]Fluoranthene Human Health Hazards
下载免费PDF全文
![点击此处可从《Risk analysis》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Today there are more than 80,000 chemicals in commerce and the environment. The potential human health risks are unknown for the vast majority of these chemicals as they lack human health risk assessments, toxicity reference values, and risk screening values. We aim to use computational toxicology and quantitative high‐throughput screening (qHTS) technologies to fill these data gaps, and begin to prioritize these chemicals for additional assessment. In this pilot, we demonstrate how we were able to identify that benzo[k]fluoranthene may induce DNA damage and steatosis using qHTS data and two separate adverse outcome pathways (AOPs). We also demonstrate how bootstrap natural spline‐based meta‐regression can be used to integrate data across multiple assay replicates to generate a concentration–response curve. We used this analysis to calculate an in vitro point of departure of 0.751 μM and risk‐specific in vitro concentrations of 0.29 μM and 0.28 μM for 1:1,000 and 1:10,000 risk, respectively, for DNA damage. Based on the available evidence, and considering that only a single HSD17B4 assay is available, we have low overall confidence in the steatosis hazard identification. This case study suggests that coupling qHTS assays with AOPs and ontologies will facilitate hazard identification. Combining this with quantitative evidence integration methods, such as bootstrap meta‐regression, may allow risk assessors to identify points of departure and risk‐specific internal/in vitro concentrations. These results are sufficient to prioritize the chemicals; however, in the longer term we will need to estimate external doses for risk screening purposes, such as through margin of exposure methods. 相似文献
483.
As rural communities undergo substantial demographic and economic changes, understanding the migration intentions and their antecedents of rural elderly persons becomes increasingly important. Using data drawn from a survey of adults from 24 rural Utah communities conducted in 2008, we examine whether rural residents 60 years of age or older plan to remain in their present communities (N= 621). We use structural equation models (SEM) to estimate the relationships between a variety of individual and community-level background measures, including perceptions of local service quality, leaving one's community for health care, Internet use, attachment to and satisfaction with community, and plans to age in place. Results suggest that even as the rural context of economic decline, population loss, and distance to medical services may reduce the viability of staying in a community, a desire to remain in the community is primarily a function of perceptions of the quality of local services and community satisfaction. This research highlights the need to better understand the interplay between the availability of medical services and perceptions of distance as well as to understand the complex relationship between individual and community level characteristics for migration intentions. 相似文献
484.
E. J. Vanderperre 《统计学通讯:理论与方法》2017,46(16):7872-7886
We analyze the survival time of a general duplex system sustained by a cold standby unit subjected to a priority rule. The analysis is based on advanced complex function theory (sectionally holomorphic functions). As an example, we consider Weibull–Gnedenko and Erlang distributions for failure and repair. Several graphs are displaying the survival function. 相似文献
485.
Aksam Yassin Joanne E. Nettleship Raidh A. Talib Yousef Almehmadi Gheorge Doros 《The aging male》2016,19(1):64-69
Whether testosterone replacement therapy (TRT) is a lifelong treatment for men with hypogonadism remains unknown. We investigated long-term TRT and TRT withdrawal on obesity and prostate-related parameters. Two hundred and sixty-two hypogonadal patients (mean age 59.5) received testosterone undecanoate in 12-week intervals for a maximum of 11 years. One hundred and forty-seven men had TRT interrupted for a mean of 16.9 months and resumed thereafter (Group A). The remaining 115 patients were treated continuously (Group B). Prostate volume, prostate-specific antigen (PSA), residual voiding volume, bladder wall thickness, C-reactive protein (CRP), aging male symptoms (AMS), International Index of erectile function – erectile function (IIEF-EF) and International Prostate Symptoms Scores (IPSS) were measured over the study period with anthropometric parameters of obesity, including weight, body mass index (BMI) and waist circumference. Prior to interruption, TRT resulted in improvements in residual voiding volume, bladder wall thickness, CRP, AMS, IIEF-EF, IPSS and obesity parameters while PSA and prostate volume increased. TRT interruption reduced total testosterone to hypogonadal levels in Group A and resulted in worsening of obesity parameters, AMS, IPSS, residual voiding volume and bladder wall thickness, IIEF-EF and PSA while CRP and prostate volume were unchanged until treatment resumed whereby these effects were reversed. TRT interruption results in worsening of symptoms. Hypogonadism may require lifelong TRT. 相似文献
486.
David E. Bloom Mathew J. McKenna Klaus Prettner 《International social security review》2019,72(3):43-78
Globally, an estimated 734 million jobs will be required between 2010 and 2030 to accommodate recent and ongoing demographic shifts, account for plausible changes in labour force participation rates, and achieve target unemployment rates of at or below 4 per cent for adults and at or below 8 per cent for youth. The facts that most new jobs will be required in countries where “decent” jobs are less prevalent and workers in many occupations are increasingly subject to risks of automation further compound the challenge of job creation, which is already quite sizable in historical perspective. Failure to create the jobs that are needed through 2030 would put currently operative social security systems under pressure and undermine efforts to guarantee the national social protection floors enshrined in the Sustainable Development Goals (SDGs). 相似文献
487.
This study examined whether being in a romantic relationship is associated with undergraduates’ alcohol use and negative consequences of drinking. Alcohol use was operationalized to include amount and frequency of drinking, binge drinking, and drunkenness. Negative consequences included: having a hangover, missing a class, getting behind in school work, doing something that was later regretted, forgetting where the student was or what they did, having unplanned sex, and getting hurt or injured. Data came from an online survey distributed to Midwestern undergraduate students (N = 572), with analyses conducted separately for men and women. Results indicated that being in a committed relationship generally served as a protective factor against drunkenness, but did not reduce frequency of drinking or binge drinking. Whereas romantically committed men were only less likely to report doing something that was later regretted, women in romantic relationships were less likely to experience all negative consequences of drinking considered here. 相似文献
488.
489.
Global leaders and managers have been facing new challenges in the twenty-first century since globalization has created a much more integrated and borderless business environment. One of the key issues that they constantly deal with is business ethics. The global economy has made ethical issues become more complex and challenging. Businesses nowadays face urgent demands to act ethically and responsibly. In order for global leaders and managers to manage such a cultural diverse and complex workforce, they must have the ability to understand these complex issues and act ethically. They also need to possess adequate leadership skills to lead an ethical organization in a multinational environment. Thus, understanding and recognizing the cultural differences as well as the ethical standards of people in different countries are critical to the success of global leaders and managers. The purpose of this study is to investigate the perception of working professionals on business ethics in the two high-context cultures in South East Asia: Thailand and Vietnam. Using the Univariate Analysis of Variance method and adopting the widely-used Clark and Clark’s Personal Business Ethics Scores (PBES) measure, this study will compare the level of ethical maturity of the respondents based on a variety of variables including gender, business law course taken, code of conduct, ethics training, and government work experience. The authors will provide a thorough literature review on business ethics as well as the current ethical issues, i.e., bribery and corruption, in the two countries, together with practical suggestions and implications for educators, managers, and employees. 相似文献
490.
Introduction to the Special Section Value Development from Middle Childhood to Early Adulthood—New Insights from Longitudinal and Genetically Informed Research
下载免费PDF全文
![点击此处可从《Social Development》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Research into values at an early age has only started recently, although it has expanded quickly and dynamically in the past years. The purpose of this article is twofold: First, it provides an introduction to a special section that aims to help fill the gap in value development research. The special section brings together four new longitudinal and genetically informed studies of value development from the beginning of middle childhood through early adulthood. Second, this article reviews recent research from this special section and beyond, aiming to provide new directions to the field. With new methods for assessing children's values and an increased awareness of the role of values in children's and adolescents' development, the field now seems ripe for an in‐depth investigation. Our review of empirical evidence shows that, as is the case with adults, children's values are organized based on compatibilities and conflicts in their underlying motivations. Values show some consistency across situations, as well as stability across time. This longitudinal stability tends to increase with age, although mean changes are also observed. These patterns of change seem to be compatible with Schwartz's (1992) theory of values (e.g., if the importance of openness to change values increases, the importance of conservation values decreases). The contributions of culture, family, peers, significant life events, and individual characteristics to values are discussed, as well as the development of values as guides for behavior. 相似文献