全文获取类型
收费全文 | 17876篇 |
免费 | 306篇 |
专业分类
管理学 | 2433篇 |
民族学 | 82篇 |
人才学 | 3篇 |
人口学 | 1583篇 |
丛书文集 | 104篇 |
教育普及 | 2篇 |
理论方法论 | 1831篇 |
综合类 | 385篇 |
社会学 | 8892篇 |
统计学 | 2867篇 |
出版年
2021年 | 85篇 |
2020年 | 266篇 |
2019年 | 323篇 |
2018年 | 331篇 |
2017年 | 495篇 |
2016年 | 417篇 |
2015年 | 322篇 |
2014年 | 382篇 |
2013年 | 2919篇 |
2012年 | 541篇 |
2011年 | 462篇 |
2010年 | 336篇 |
2009年 | 367篇 |
2008年 | 410篇 |
2007年 | 434篇 |
2006年 | 363篇 |
2005年 | 494篇 |
2004年 | 449篇 |
2003年 | 417篇 |
2002年 | 441篇 |
2001年 | 449篇 |
2000年 | 405篇 |
1999年 | 422篇 |
1998年 | 304篇 |
1997年 | 292篇 |
1996年 | 293篇 |
1995年 | 270篇 |
1994年 | 284篇 |
1993年 | 268篇 |
1992年 | 298篇 |
1991年 | 309篇 |
1990年 | 269篇 |
1989年 | 271篇 |
1988年 | 258篇 |
1987年 | 232篇 |
1986年 | 234篇 |
1985年 | 231篇 |
1984年 | 262篇 |
1983年 | 249篇 |
1982年 | 218篇 |
1981年 | 183篇 |
1980年 | 178篇 |
1979年 | 209篇 |
1978年 | 176篇 |
1977年 | 161篇 |
1976年 | 143篇 |
1975年 | 140篇 |
1974年 | 125篇 |
1973年 | 120篇 |
1971年 | 83篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
John DeFrain 《Journal of marital and family therapy》1991,17(3):215-232
Family therapists can learn a great deal that would be of utility to them in their clinical work from normal families grieving over the death of an infant. When a baby dies, families begin a long and difficult journey, a search for security and meaning in a world that for them has gone insane. The researcher discusses 10 probing, extremely difficult questions family members commonly pose in the aftermath of an infant death and offers guidelines that could be helpful to family therapists hoping to be of service to families in the process of healing and growing through this tragedy. 相似文献
82.
John A. Eccleston Deborah J. Street 《Australian & New Zealand Journal of Statistics》1994,36(3):371-378
This paper presents an algorithm for the construction of optimal or near optimal change-over designs for arbitrary numbers of treatments, periods and units. Previous research on optimality has been either theoretical or has resulted in limited tabulations of small optimal designs. The algorithm consists of a number of steps:first find an optimal direct treatment effects design, ignoring residual effects, and then optimise this class of designs with respect to residual effects. Poor designs are avoided by judicious application of the (M, S)-optimality criterion, and modifications of it, to appropriate matrices. The performance of the algorithm is illustrated by examples. 相似文献
83.
Michael I. Miller Sarang Joshi David R. Maffitt James G. Mcnally Ulf Grenander 《Journal of applied statistics》1994,21(1):141-163
Most real-world shapes and images are characterized by high variability- they are not rigid, like crystals, for example—but they are strongly structured. Therefore, a fundamental task in the understanding and analysis of such image ensembles is the construction of models that incorporate both variability and structure in a mathematically precise way. The global shape models introduced in Grenander's general pattern theory are intended to do this. In this paper, we describe the representation of two-dimensional mitochondria and membranes in electron microscope photographs, and three-dimensional amoebae in optical sectioning microscopy. There are three kinds of variability to all of these patterns, which these representations accommodate. The first is the variability in shape and viewing orientation. For this, the typical structure is represented via linear, circular and spherical templates, with the variability accomodated via the application of transformations applied to the templates. The transformations form groups: scale, rotation and translation. They are locally applied throughout the continuum and of high dimension. The second is the textural variability; the inside and outside of these basic shapes are subject to random variation, as well as sensor noise. For this, statistical sensor models and Markov random field texture models are used to connect the constituent structures of the shapes to the measured data. The third variability type is associated with the fact that each scene is made up of a variable number of shapes; this number is not assumed to be known a priori. Each scene has a variable number of parameters encoding the transformations of the templates appropriate for that scene. For this, a single posterior distribution is defined over the countable union of spaces representing models of varying numbers of shapes. Bayesian inference is performed via computation of the conditional expectation of the parametrically defined shapes under the posterior. These conditional mean estimates are generated using jump-diffusion processes. Results for membranes, mitochondria and amoebae are shown. 相似文献
84.
Sources of drug information among adolescent students 总被引:1,自引:0,他引:1
E Mirzaee P M Kingery B E Pruitt G Heuberger R S Hurley 《Journal of drug education》1991,21(2):95-106
A sample of 1023 eighth and tenth grade students in small to medium-sized central Texas school districts was assessed to determine the amount of information they receive from ten sources about six categories of drugs. The amount of information males reported receiving about each drug category was significantly greater than what females reported, and the amount of information that eighth graders reported receiving about each drug category was significantly greater than what tenth graders reported. Television was the primary source of drug information for all categories of drugs except inhalants, for which friends and television were equally important sources. Parents and printed media (magazines or newspapers) were of secondary importance, followed by friends and teachers. Adolescents were less likely to receive drug-related information from experience, siblings, church, doctors, and police. The reliance on the mass media for drug information in smaller school districts is a pattern which has been previously observed in larger urban districts. This consistency suggests that mass media approaches to drug education are likely to be as effective in rural areas and smaller towns as they are among urban adolescents. Implications for television programming are discussed. 相似文献
85.
86.
87.
88.
The importance of client beliefs in career counseling depends on their ability to add unique information about the client over and above that contributed by aptitudes and interests. The Career Beliefs Inventory was administered to 200 Australian students in grade 10 together with measures of Holland's RIASEC interest themes and scholastic aptitudes. The correlations between scales from the three domains showed clearly that beliefs made a contribution distinct from that provided by aptitudes and interests. Even though the results may reflect possible sampling or method variance, career beliefs in this sample added unique information to that traditionally used in career counseling. 相似文献
89.
Gallup macropartisanship varies more over time than aggregatemeasures of partisanship employing the standard Michigan SurveyResearch Center (SRC) party identification measure, but previousanalyses do not provide direct evidence about why Gallup macropartisanshipis more variable. Although these differences could result fromthe short-term focus of the Gallup party affiliation question,aggregate-level analyses cannot test the effects of questionwording directly. Between March and October 1992, we conducteda series of question-wording experiments, employing six statewidecomputer-assisted telephone interview (CATI) surveys of Michiganadults, including a four-wave panel study. Our analyses stronglysuggest that the Gallup measure responds more to short-termpolitical conditions and clearly demonstrate that the Gallupmeasure is less stable over time. These individual-level resultshelp explain why Gallup macropartisanship varies more over timethan aggregate measures of partisanship employing the standardSRC measure and raise questions about the degree to which onecan generalize from analyses using the Gallup data to the researchliterature on party identification. 相似文献
90.
John E. Roemer 《Social Choice and Welfare》1994,11(4):355-380
Voter preferences are characterized by a parameter s (say, income) distributed on a set S according to a probability measure F. There is a single issue (say, a tax rate) whose level, b, is to be politically decided. There are two parties, each of which is a perfect agent of some constituency of voters, voters with a given value of s. An equilibrium of the electoral game is a pair of policies, b 1 and b 2, proposed by the two parties, such that b i maximizes the expected utility of the voters whom party i represents, given the policy proposed by the opposition. Under reasonable assumptions, the unique electoral equilibrium consists in both parties proposing the favorite policy of the median voter. What theory can explain why, historically, we observe electoral equilibria where the ‘right’ and ‘left’ parties propose different policies? Uncertainty concerning the distribution of voters is introduced. Let {F(t)} t ε T be a class of probability measures on S; all voters and parties share a common prior that the distribution of t is described by a probability measure H on T. If H has finite support, there is in general no electoral equilibrium. However, if H is continuous, then electoral equilibrium generally exists, and in equilibrium the parties propose different policies. Convergence of equilibrium to median voter politics is proved as uncertainty about the distribution of voter traits becomes small. 相似文献