全文获取类型
收费全文 | 22248篇 |
免费 | 360篇 |
国内免费 | 2篇 |
专业分类
管理学 | 3088篇 |
民族学 | 151篇 |
人口学 | 3469篇 |
丛书文集 | 49篇 |
理论方法论 | 1533篇 |
综合类 | 455篇 |
社会学 | 9702篇 |
统计学 | 4163篇 |
出版年
2023年 | 86篇 |
2021年 | 80篇 |
2020年 | 233篇 |
2019年 | 308篇 |
2018年 | 2000篇 |
2017年 | 2088篇 |
2016年 | 1379篇 |
2015年 | 309篇 |
2014年 | 378篇 |
2013年 | 2354篇 |
2012年 | 778篇 |
2011年 | 1450篇 |
2010年 | 1306篇 |
2009年 | 1022篇 |
2008年 | 1128篇 |
2007年 | 1304篇 |
2006年 | 256篇 |
2005年 | 436篇 |
2004年 | 444篇 |
2003年 | 373篇 |
2002年 | 286篇 |
2001年 | 249篇 |
2000年 | 229篇 |
1999年 | 203篇 |
1998年 | 167篇 |
1997年 | 170篇 |
1996年 | 190篇 |
1995年 | 143篇 |
1994年 | 125篇 |
1993年 | 162篇 |
1992年 | 187篇 |
1991年 | 167篇 |
1990年 | 162篇 |
1989年 | 139篇 |
1988年 | 157篇 |
1987年 | 128篇 |
1986年 | 123篇 |
1985年 | 121篇 |
1984年 | 144篇 |
1983年 | 137篇 |
1982年 | 118篇 |
1981年 | 85篇 |
1980年 | 115篇 |
1979年 | 127篇 |
1978年 | 111篇 |
1977年 | 98篇 |
1976年 | 93篇 |
1975年 | 106篇 |
1974年 | 79篇 |
1972年 | 74篇 |
排序方式: 共有10000条查询结果,搜索用时 500 毫秒
291.
292.
Melamine contamination of food has become a major food safety issue because of incidents of infant disease caused by exposure to this chemical. This study was aimed at establishing a safety limit in Taiwan for the degree of melamine migration from food containers. Health risk assessment was performed for three exposure groups (preschool children, individuals who dine out, and elderly residents of nursing homes). Selected values of tolerable daily intake (TDI) for melamine were used to calculate the reference migration concentration limit (RMCL) or reference specific migration limit (RSML) for melamine food containers. The only existing values of these limits for international standards today are 1.2 mg/L (0.2 mg/dm2) in China and 30 mg/L (5 mg/dm2) in the European Union. The factors used in the calculations included the specific surface area of food containers, daily food consumption rate, body weight, TDI, and the percentile of the population protected at a given migration concentration limit (MCL). The results indicate that children are indeed at higher risk of melamine exposure at toxic levels than are other groups and that the 95th percentile of MCL (specific surface area = 5) for children aged 1–6 years should be the RMCL (0.07 mg/dm2) for protecting the sensitive and general population. 相似文献
293.
To compare two modes of administration (self-administered; by interviewer) and two response options format (using words; images
of “facial-expressions”) of the first question of SF-36 (Q1SF-36), and to test its validity. We included 825 participants
(20–90 years). Q1SF-36, using words or images, was included in a global questionnaire interview and at the end participants
filled the SF-36. The agreement was tested by weighted kappa coefficients (WKappa). Classification Trees were used in the
calibration of Q1SF-36 responses, with the physical (PDSF36) and mental dimensions of SF-36. Polyserial correlation coefficients
and areas under the ROC curves (AUC) were used for validation. After categorization, using PDSF36 classification trees, the
WKappa were 0.770 (self-administered vs. interviewer), 0.569 (self-administered vs. facial-expressions) and 0.566 (interviewer
vs. facial-expressions). The WKappa between the PDSF36 and the modes (self-administered, interviewer and facial-expressions)
were 0.784, 0.713 and 0.579 and the corresponding polyserial correlation coefficients were 0.784, 0.713 and 0.579. A good
discriminatory power was found comparing the modes with the PDSF36 (AUC = 0.907, 0.923 and 0.827), but not with mental dimension
(AUC = 0.538, 0.501 and 0.629). The Q1SF-36, by self-administration or interviewer, may be a valid alternative for assessment
of subjective physical health, but not mental health. 相似文献
294.
295.
Julia L. Carboni 《Voluntas: International Journal of Voluntary and Nonprofit Organizations》2016,27(4):1781-1808
Social service contracting to nongovernmental organizations is popular form of privatization across the world. Although nonprofits are preferable social service providers for legal and normative reasons, governments in the United States increasingly rely on for-profit organizations to deliver social services. This trend warrants further exploration about whether nonprofits or for-profits perform according to theoretical expectations when they exist in the same market. This study employs qualitative comparative analysis (QCA) to examine how sector-public, nonprofit, and for-profit-combines with structural variables to produce acceptable contract performance in juvenile justice programs. QCA is a discovery-oriented research tool that determines whether combinations of variables within cases produce a specific outcome and whether those combinations are consistent across cases. I find sector is not a necessary or sufficient predictor of acceptable performance on its own. Rather it combines with market factors to lead to acceptable contract performance. Combinations vary by sector, indicating that sectors behave differently in similar circumstances. The primary theoretical contribution of this paper is to provide a nuanced account of contract performance in mixed sector markets. 相似文献
296.
Stephan Klasen Tatyana Krivobokova Friederike Greb Rahul Lahoti Syamsul Hidayat Pasaribu Manuel Wiesenfarth 《Journal of Economic Inequality》2016,14(2):199-225
We critically review conceptual and empirical issues surrounding the derivation of the international poverty line, expressed in PPP-adjusted dollars and linked to various rounds of the International Comparison Program (ICP). We find that there are some limitations in the current estimation of these lines, but show that statistically superior methods lead to lines that are relatively robust and confirm the $1.25 using 2005 PPPs and suggest $1.67–1.71 using 2011 PPPs (or close to the $1.90 proposed by the World Bank if we follow the World Bank’s approach of adjusting inflation rates in some countries); they also roughly confirm the current shape of the proposed ‘weakly relative’ poverty line. Using the new absolute line based on 2011 PPPs would lead to substantially lower poverty in our estimation. The extent of the decline depends on whether and how one treats China, India, and Indonesia differently from other countries in the 2005 and 2011 PPPs. More seriously, we note that the dependence on successive ICP rounds creates conceptual and empirical problems that have become worse over time so that we suggest that it would be best to consider alternatives to the current reliance on ICP rounds and the resulting PPPs. As a short-term solution we propose to fix the international poverty line in national currencies using either the 2005 or 2011 level; in the medium term, we argue for global poverty measurement based on internationally coordinated national poverty measurement. 相似文献
297.
Xiaohui Hou 《Journal of Family and Economic Issues》2016,37(1):115-131
Understanding the effects of power distribution, particularly women’s decision making, on human development is important. This study used a set of direct measures of decision-making power from the Pakistan Social and Living Standard Measurement Survey and examined the relationship between women’s decision-making power and the food budget share, nutrition and child schooling. It found that in Pakistan, the relationship between women’s decision-making power and nutrition was not linear and varied depending on rural or urban residence. There was no clear evidence that higher women’s decision-making power would lead to better nutrition availability in Pakistan, but overall households were more likely to consume less grain and more vegetables. When women had higher decision-making power, children, particularly rural girls, were more likely to be enrolled in school. 相似文献
298.
ECONOMIC DETERMINANTS OF THE TIMING OF PREFERENTIAL TRADE AGREEMENT FORMATIONS AND ENLARGEMENTS
下载免费PDF全文
![点击此处可从《Economic inquiry》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Preferential trade agreements (PTAs) have proliferated over the past 60 years. While a small number of recent studies have examined empirically the economic determinants of the likelihood of a pair of countries having a PTA, this study explains empirically the timing of all PTA formations and enlargements from 1950 through 2006 using duration analysis. Our main and novel goal is to predict (in‐ and out‐of‐sample) a substantive share of these 1,560 PTA events using a parsimonious model with mainly economic variables, taking selection dynamics into account. Our analysis reveals that we can predict correctly in‐sample the actual year of entry into force for 26% of the 1,560 bilateral PTA formations/enlargements in the period 1950–2006 among 10,518 pairings of 146 countries using only a few economic and political variables. Moreover, we can predict correctly in‐sample 57% of these PTA events within a 10‐year window leading up to the event using this model. The model also performs well out‐of‐sample for the near term (82%), but not if the out‐of‐sample period is very long. We conclude with an evaluation of the model's ability to predict the timing of the North American Free Trade Agreement, the European Union's formation and enlargements, and the model's ten most likely post‐2006 PTA events. (JEL F14, F15) 相似文献
299.
You Hyun Kim Seok Eun Kim 《Voluntas: International Journal of Voluntary and Nonprofit Organizations》2016,27(6):2937-2961
This study draws an economic model of the growth of nonprofit organizations by analyzing the behaviors of three major actors—nonprofit organizations, private donors, and governments—in making decisions on the allocation of limited resources for nonprofit services. Since decisions made by each actor affect resource allocation, it is important to understand what drives these decisions. The model was tested using an unbalanced, 463 panel dataset collected from 28 OECD countries over a 23-year period. The results indicated that macro- and micro-economic trends and government policies framed the decision premises of the three major actors, which led them to leverage the supply and demand for goods and services and, in turn, determined how they allocated limited resources for nonprofit services. This result implies that understanding the interdependencies of all sectors of the economy is critical to comprehending the size and development of the nonprofit sector. Effective management of micro-economic policies and macro-economic stability is necessary. More important, however, is understanding how a decision in one part of the economy will have intended and unintended effects on the nonprofit sector. 相似文献
300.
María Isabel Ayala 《Sociological Forum》2012,27(4):1037-1045
In this essay, I present an interdisciplinary examination of the state of research in Latino education, addressing not only the cultural forces influencing Latinos’ educational attainment, but also the structural conditions faced by them—as a racialized minority group—throughout their schooling and that have a cumulative effect on their academic attainment. Overall, I suggest that by engaging in a critical review of the literature on Latinos’ educational attainment, the reader will acknowledge that the racially driven hierarchical structural arrangements are highly responsible for the patterns observed. 相似文献