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:      
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   25925篇
  免费   858篇
  国内免费   12篇
  2019年   245篇
  2018年   297篇
  2017年   340篇
  2016年   383篇
  2015年   300篇
  2014年   332篇
  2013年   1836篇
  2012年   630篇
  2011年   645篇
  2010年   410篇
  2009年   426篇
  2008年   607篇
  2007年   545篇
  2006年   482篇
  2005年   481篇
  2004年   444篇
  2003年   451篇
  2002年   466篇
  2001年   687篇
  2000年   676篇
  1999年   477篇
  1998年   250篇
  1992年   474篇
  1991年   455篇
  1990年   463篇
  1989年   466篇
  1988年   415篇
  1987年   425篇
  1986年   452篇
  1985年   490篇
  1984年   416篇
  1983年   381篇
  1982年   276篇
  1981年   321篇
  1980年   249篇
  1979年   444篇
  1978年   323篇
  1977年   290篇
  1976年   279篇
  1975年   413篇
  1974年   461篇
  1973年   490篇
  1972年   413篇
  1971年   407篇
  1970年   381篇
  1969年   402篇
  1968年   493篇
  1967年   476篇
  1966年   453篇
  1958年   252篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
941.
With the end of the cold war, issues of environment and economic development are assuming greater international salience. By the 1970s, environmental degradation was becoming pervasive, with growing global effects. Increasingly, global and emergent globalized problems are forcing environmental interdependence on the world. Transboundary threats cannot be addressed unilaterally by any single country or group of countries. The global environmental agenda is reviving the North-South debate and rejuvenating the Third World coalition in international fora. The encouragement of environmentally sustainable forms of industrialization in the South requires expanded and improved international cooperation. However, the North’s greater resources and greater responsibility in causing global environmental degradation require its continuing involvement in the search for solutions, including ones applicable to newly industrializing countries. In June 1992, the largest intergovernmental conference ever held was convened in Rio de Janeiro to address these issues: the United Nations Conference on Environment and Development (UNCED, or the Earth Summit). It produced a consensus action plan of about 700 pages: Agenda 21. Agenda 21 presents massive challenges for international cooperation as well as for national and private actors and scientific and technical institutions. It reflects a complex configuration of demands for institutional arrangements that support environmentally sustainable technical and socioeconomic change. One of the most consistent of the Agenda 21 themes, and one of the most intractable issues, concerns “access to technology.” This can be as straightforward as diagnosing and improving the efficiency of a production process in a small manufacturing firm, or as complex as engineering a technological revolution in which production and consumption take place with virtually no material or energy loss to the environment. The selection of entry points for action is a critical strategic problem as well as an important operational issue. In this paper I identify and describe new initiatives intended to improve the environmental performance of industry in the South, and find that they largely aim to promote incremental industrial innovation through international technology transfer and diffusion. This strategy raises many questions about how to promote effective technology transfer and diffusion. This is a revised version of a paper prepared for the ORSTOM/UNESCO Conference “20th Century Science: Beyond the Metropolis,” Paris, 19–23 Sept. 1994.  相似文献   
942.
We conducted two experiments to investigate if college students would create false memories of childhood experiences in response to misleading information and repeated interviews. In both experiments we contacted parents to obtain information about events that happened to the students during childhood. In a series of interviews we asked the students to recall the parent-reported events and one experimenter-created false event. In the second experiment we varied the age at which we claimed the false event occurred. In both experiments we found that some individuals created false memories in these circumstances and in the second experiment we found no effect of age of attempted incorporation. In the second experiment we also found that those who discussed related background knowledge during the early interviews were more likely to create a false recall. Generalizations to therapy contexts are discussed.  相似文献   
943.
944.
PREVENTION OF DEPRESSIVE SYMPTOMS IN SCHOOLCHILDREN:   总被引:2,自引:0,他引:2  
Abstract— After teaching cognitive and social-problem-solving techniques designed to prevent depressive symptoms, we followed 69 fifth- and sixth-grade children at risk for depression for 2 years. We compared these children with 49 children in a matched no-treatment control group The prevention group re- ported fewer depressive symptoms through the 2-year follow-up, and moderate to severe symptoms were reduced by half. Surprisingly, the effects of the prevention program grew larger after the program was over. We suggest that psychological immunization against depression can occur by leaching cognitive and social skills to children as they enter puberty  相似文献   
945.
In the present study, a naturalistic functional analysis procedure was used to assess the effect of environmental stimulation on the stereotypic behavior (body rocking) of an adult whose stereotypy appeared to be induced by an acquired brain injury. Environmental stimulation, operationalized in terms of both physical and social characteristics, resulted in only minimal changes in the occurrence of body rocking. Body rocking occurred in excess of 50% of the observations in all environmental stimulation conditions and in a naturally occurring baseline condition. To our knowledge, this is the first published report of a functional analysis of stereotypy associated with acquired brain injury.  相似文献   
946.
This case study examines the relationship between self-initiations of an adult woman with severe disabilities and the directive behavior of staff persons in a community residential setting. Hypotheses generated from functional assessment procedures indicated that (a) Susan's low self-initiations were very likely related to high directive behavior of staff persons, and (b) infrequent problem behaviors during the morning routine were maintained by escape from repeated staff demands. An intervention was implemented to enable Susan to increase self-initiation in choice and sequence of activities and simultaneously decrease staff directives. Results and discussion focus on the need for a contextual approach for addressing problematic situations and an affirmation of the effectiveness of the positive behavioral support technology for increasing adaptive behaviors in individuals with severe disabilities.  相似文献   
947.
This paper examines those children receiving mental health services in Puerto Rico, their demographic and psychosocial characteristics, and describes service providers and nature of facilities. The survey was done on a probability sample of children ages 4 through 16 across the island of Puerto Rico (N=777). Need for services was clinically defined as presence of a DSM-III diagnosis and functional impairment. The overall rate of service utilization for Puerto Rican children was 6% (26.2% of definite cases and 5.1% of probable cases). In most cases services were provided by psychologists and/or social workers, and they were mainly provided in schools and general medical facilities. In over 60% of the children assessed as cases, who did not receive services, the reason, given by the parent was that they considered the problem not serious. Factors associated with service utilization were measures of psychopathology, teacher's perceived need, and parental rates of criticism and hostility. These findings suggest that there is a need for more research on the motivating factors for service use (impairment and parental criticism). Teachers could benefit from receiving special training to help them readily recognize behavioral problems in children, communicate them to parents and set up services alternatives.  相似文献   
948.
Discharge planning for vulnerable infants and children is a collaborative, interdisciplinary, decision-making activity that is grounded in the ethical complexities of clinical practice. Although it is a psychosocial intervention that frequently causes moral distress for professionals and has the potential to inflict harm on children and their families, the process has received little attention from ethicists. An ongoing study of the transition of technology-dependent children from hospital to home suggests that the ethical issues embedded in the discharge-planning process may be concealed by dominant cultural values, institutional policies, clinical standards, historical precedents, and legal regulations.  相似文献   
949.
Behavior analytic evaluation instruments should benefit teacher education programs in assessing: (a) teacher and student interactions in practice teaching settings, and (b) the immediate and long range effects of the teacher training received. Though empirical substantiation remains scarce, such instruments may be designed to foster teacher trainee sensitivity to, and better control of, complex stimulus and response mechanisms which either impede or facilitate learning. This study analyzed one technologically driven Behavior Analysis Strategy and Taxonomy (BEST) and related Temporal Analysis System (TAS) (Hawkins, Sharpe, & Ray, 1994) currently used within one preservice teacher education program. A multiple probe design with experimental and control groups demonstrated the instruments' effects when used as an instructional feedback tool with teachers in training. Findings supported the instruments' use in terms of teacher and student behavior changes demonstrated for the experimental group as compared to a control group not exposed to the instrument. Implications of this technology when applied to teacher education are last described.  相似文献   
950.
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