全文获取类型
收费全文 | 20839篇 |
免费 | 422篇 |
国内免费 | 1篇 |
专业分类
管理学 | 2708篇 |
民族学 | 120篇 |
人才学 | 1篇 |
人口学 | 1845篇 |
丛书文集 | 83篇 |
教育普及 | 1篇 |
理论方法论 | 1873篇 |
综合类 | 199篇 |
社会学 | 10568篇 |
统计学 | 3864篇 |
出版年
2023年 | 142篇 |
2022年 | 93篇 |
2021年 | 146篇 |
2020年 | 376篇 |
2019年 | 552篇 |
2018年 | 652篇 |
2017年 | 845篇 |
2016年 | 653篇 |
2015年 | 438篇 |
2014年 | 606篇 |
2013年 | 3716篇 |
2012年 | 776篇 |
2011年 | 732篇 |
2010年 | 530篇 |
2009年 | 435篇 |
2008年 | 568篇 |
2007年 | 519篇 |
2006年 | 551篇 |
2005年 | 455篇 |
2004年 | 442篇 |
2003年 | 378篇 |
2002年 | 397篇 |
2001年 | 487篇 |
2000年 | 437篇 |
1999年 | 423篇 |
1998年 | 323篇 |
1997年 | 275篇 |
1996年 | 291篇 |
1995年 | 293篇 |
1994年 | 260篇 |
1993年 | 271篇 |
1992年 | 306篇 |
1991年 | 303篇 |
1990年 | 296篇 |
1989年 | 258篇 |
1988年 | 241篇 |
1987年 | 208篇 |
1986年 | 232篇 |
1985年 | 259篇 |
1984年 | 228篇 |
1983年 | 198篇 |
1982年 | 165篇 |
1981年 | 134篇 |
1980年 | 162篇 |
1979年 | 175篇 |
1978年 | 140篇 |
1977年 | 116篇 |
1976年 | 94篇 |
1975年 | 92篇 |
1974年 | 95篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
In this paper we develop a study on several types of parallel genetic algorithms (PGAs). Our motivation is to bring some uniformity to the proposal, comparison, and knowledge exchange among the traditionally opposite kinds of serial and parallel GAs. We comparatively analyze the properties of steady-state, generational, and cellular genetic algorithms. Afterwards, this study is extended to consider a distributed model consisting in a ring of GA islands. The analyzed features are the time complexity, selection pressure, schema processing rates, efficacy in finding an optimum, efficiency, speedup, and resistance to scalability. Besides that, we briefly discuss how the migration policy affects the search. Also, some of the search properties of cellular GAs are investigated. The selected benchmark is a representative subset of problems containing real world difficulties. We often conclude that parallel GAs are numerically better and faster than equivalent sequential GAs. Our aim is to shed some light on the advantages and drawbacks of various sequential and parallel GAs to help researchers using them in the very diverse application fields of the evolutionary computation. 相似文献
92.
Christine Hunt Ian Shochet Robert King 《Australian and New Zealand Journal of Family Therapy》2005,26(1):10-20
The therapeutic letter has a long history, with roots in psychoanalytic work and continuing application in family therapy. The advent of e‐mail has allowed another form for therapeutic written communication which, while incorporating the benefits of therapeutic letters, adds to these. It has also opened up some potential risks. This article incorporates a brief review of the literature covering therapeutic written communication and offers a case example where e‐mail was used as an adjunct in face‐to‐face therapy with a client who experienced attachment difficulties. This therapy was informed by systemic and psychoanalytic traditions. The authors explore a variety of technical matters including the timing and crafting of e‐mail responses, the integration of written communication with face‐to‐face therapy, impact on the therapeutic relationship and management of crisis. Ethical issues such as confidentiality and duty of care are also considered. 相似文献
93.
A. Baddeley R. Turner J. Møller M. Hazelton 《Journal of the Royal Statistical Society. Series B, Statistical methodology》2005,67(5):617-666
Summary. We define residuals for point process models fitted to spatial point pattern data, and we propose diagnostic plots based on them. The residuals apply to any point process model that has a conditional intensity; the model may exhibit spatial heterogeneity, interpoint interaction and dependence on spatial covariates. Some existing ad hoc methods for model checking (quadrat counts, scan statistic, kernel smoothed intensity and Berman's diagnostic) are recovered as special cases. Diagnostic tools are developed systematically, by using an analogy between our spatial residuals and the usual residuals for (non-spatial) generalized linear models. The conditional intensity λ plays the role of the mean response. This makes it possible to adapt existing knowledge about model validation for generalized linear models to the spatial point process context, giving recommendations for diagnostic plots. A plot of smoothed residuals against spatial location, or against a spatial covariate, is effective in diagnosing spatial trend or co-variate effects. Q – Q -plots of the residuals are effective in diagnosing interpoint interaction. 相似文献
94.
The extent to which 4‐month attentional regulation during an infant‐mother still‐face situation and 12‐month attachment security during the Strange Situation predicted rates of compliance and noncompliance during a cleanup task at 36 months was examined longitudinally in 70 infant‐mother dyads. Hierarchical multiple regression analyses indicated that infants who showed more attentional regulation during the still‐face situation with mothers later showed a higher rate of committed compliance and a lower rate of situational compliance during cleanup with mothers. Furthermore, lower levels of attentional regulation were later associated with higher rates of assertive behavior, but only for infants in an insecure attachment relationship. 相似文献
95.
The proliferation of the telephone answering machine raisesa number of questions about the continued efficiency of thetelephone as a data-gathering mechanism. The most critical ofthese is what effect the use of these machines might have onestablishing contact with potential respondents. If individualsroutinely use these machines to screen calls, then their accessibilityto telephone survey researchers will be restricted. A secondquestion is the degree to which respondents who own answeringmachines and are reachable are likely to participate in a survey.A third question is the extent to which the incidence of theanswering machine as a response disposition might vary by thetime of calling and the respondent's place of residence. Thefindings of this study, based on a nationwide survey, pointto a significant proportion of answering machine owners beingreachable and willing to participate. Furthermore, the answeringmachine appears to be in use more on weekends than on weekdayevenings and in more urbanized areas than in areas with fewerinhabitants. 相似文献
96.
Lester M. Salamon Helmut K. Anheier 《Voluntas: International Journal of Voluntary and Nonprofit Organizations》1994,4(4):530-554
As a result in part of the way non-profit institutions are defined and treated in the United Nations System of National Accounts (SNA), little is known about the size, scope, financial base and role of this set of institutions at the international level, even though their importance is increasingly being recognised throughout the world. To remedy this significant lack of systematic information on non-profit institutions cross-nationally, the Johns Hopkins Comparative Nonprofit Sector Project has undertaken a major analysis of the economic role of this sector in twelve countries throughout the world, utilising a more meaningful definition of the sector and an approach that is otherwise consistent with the overall thrust of the SNA system. This paper outlines the basis of the more inclusive definition of the non-profit sector embodied in this project, the classification system formulated to structure data-gathering on this more broadly-defined sector and the data assembly strategy developed to build up key estimates of the scale, structure and revenue sources of the non-profit sector in the project countries. The article concludes with a recommendation to incorporate a similar approach to the assembly of data on the non-profit sector into the ongoing SNA system on a regular basis.Professor Lester Salamon is Director of the Institute for Policy Studies and Director of the Comparative Nonprofit Sector Project at the Johns Hopkins University, Baltimore, Maryland, 21218.Helmut Anheier is Research Scientist at the Institute for Policy Studies at the Johns Hopkins University and Assistant Professor of Sociology at Rutgers University, New Brunswick, New Jersey, 08903. He is co-editor ofVoluntas. 相似文献
97.
I. M. Endresen B. Ellertsen C. Endresen A. M. Hjelmen R. Matre H. Ursin 《Work and stress》1991,5(3):217-227
This study concerned the immunological correlates of stress and work. Self reported stress, emotional state, ego-strength, and defensiveness were examined in relation to measures of cellular immunity (T-cell response to Con A and number of T4 and T8 cells) and humoral immunity (concentrations of immunoglobulins and complement components in plasma) in a group of 96 Norwegian female bank employees. The analyses showed that workload, the stress factor with the highest group mean, was associated with number of T-cells, while strain due to body posture during work was related to concentrations of IgM and C3. Further, depression was significantly correlated with IgM concentration and T-cell number, and anxiety with C3 concentration. T-cell activity was the immunological parameter most consistently associated with psychological well-being, showing positive correlations with defensiveness and ego-strength and negative correlations with anxiety and depression. In conclusion, T-cell number and concentrations of IgM and C3 were sensitive to both work-related stress experience and emotional distress. Coping abilities, indicated by the MMPI Ego-strength scale and emotional distress, were reflected in T-cell activity; insufficient coping was associated with low T-cell activity. 相似文献
98.
Natural and social order at Walt Disney World; the functions and contradictions of civilising nature
Chris Wright 《The Sociological review》2006,54(2):303-317
Elias’ theory of the civilising process is used to show how the Walt Disney World Theme Parks construct social control over visitors without calling into question the official presentation of these visitors as free, choice‐making, experience seeking individuals. Particular attention is drawn to the manipulation of images of nature as either ‘wild’ or ‘civilised’ to code, respectively, forbidden and legitimate places for visitors. In doing so, WDW is able to maintain civilised, non‐coercive, discourse with its ‘guests’ who are, thus presented to themselves as responsible and self‐regulating persons. Attention is drawn to the contradiction that this strategy creates between ‘authentic’ and ‘civilised’ spectacle particularly in the presentation of animals. It is noted how this creates an imperative to show only civilised animal behaviour but which, in turn, limits the means that the Disney Corporation can adopt in order to create a space that is free from the intrusion of uncivilised nature. 相似文献
99.
This study investigated factors affecting the adjustment of parentally bereaved children by reviewing existing literature and comparing it to observations made by professional social workers. Interviewees had between 1 1/2 and 22 years of experience in counseling bereaved children. The specific factors examined were age and sex of the bereaved child, circumstances of the death, and adjustment of remaining caregiver. Participants (n = 5) responded to an interview instrument specifically designed for this study which contained seven in-depth, open-ended questions. Participants’ replies were mostly in accordance with the literature, but also generated some new perspectives that had not been previously considered for this study and had not appeared in the literature. This study has implications for practice with parentally bereaved children and their surviving caregivers.Rebecca M. Hope, LCSW, Outpatient Clinician, New River Valley Community Services, 700 University City Boulevard, Blacksburg, VA 24060.Diane M. Hodge, Ph.D. is an Associate Professor of Social Work, Radford University, P.O. Box 6958, Radford, VA 24141; e-mail: dmhodge@radford.eduAddress correspondence to Rebecca M. Hope, LCSW, Outpatient Clinician, New River Valley Community Services, 700 University City Boulevard, Blacksburg, VA 24060; e-mail: rmhope@verizon.net 相似文献
100.