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   868篇
  免费   79篇
  国内免费   23篇
  2024年   3篇
  2023年   5篇
  2022年   11篇
  2021年   28篇
  2020年   34篇
  2019年   47篇
  2018年   39篇
  2017年   49篇
  2016年   36篇
  2015年   37篇
  2014年   27篇
  2013年   139篇
  2012年   32篇
  2011年   24篇
  2010年   20篇
  2009年   35篇
  2008年   43篇
  2007年   40篇
  2006年   40篇
  2005年   31篇
  2004年   36篇
  2003年   24篇
  2002年   28篇
  2001年   22篇
  2000年   20篇
  1999年   18篇
  1998年   20篇
  1997年   10篇
  1996年   12篇
  1995年   14篇
  1994年   5篇
  1993年   5篇
  1992年   6篇
  1991年   2篇
  1990年   1篇
  1989年   4篇
  1988年   3篇
  1987年   2篇
  1986年   1篇
  1985年   2篇
  1984年   1篇
  1982年   2篇
  1981年   3篇
  1980年   2篇
  1979年   2篇
  1978年   1篇
  1977年   1篇
  1976年   3篇
排序方式: 共有970条查询结果,搜索用时 15 毫秒
181.
After reviewing portions of the 21st Century Nanotechnology Research and Development Act that call for examination of societal and ethical issues, this essay seeks to understand how nanoethics can play a role in nanotechnology development. What can and should nanoethics aim to achieve? The focus of the essay is on the challenges of examining ethical issues with regard to a technology that is still emerging, still ‘in the making.’ The literature of science and technology studies (STS) is used to understand the nanotechnology endeavor in a way that makes room for influence by nanoethics. The analysis emphasizes: the contingency of technology and the many actors involved in its development; a conception of technology as sociotechnical systems; and, the values infused (in a variety of ways) in technology. Nanoethicists can be among the many actors who shape the meaning and materiality of an emerging technology. Nevertheless, there are dangers that nanoethicists should try to avoid. The possibility of being co-opted from working along side nanotechnology engineers and scientists is one danger that is inseparable from trying to influence. Related but somewhat different is the danger of not asking about the worthiness of the nanotechnology enterprise as a social investment in the future.  相似文献   
182.
Two classes of π are studied whose properties are similar to those of the protoalgebraic deductive systems of Blok and Pigozzi. The first is the class of N-protoalgebraic π-institutions and the second is the wider class of N-prealgebraic π-institutions. Several characterizations are provided. For instance, N-prealgebraic π-institutions are exactly those π-institutions that satisfy monotonicity of the N-Leibniz operator on theory systems and N-protoalgebraic π-institutions those that satisfy monotonicity of the N-Leibniz operator on theory families. Analogs of the correspondence property of Blok and Pigozzi for π-institutions are also introduced and their connections with preand protoalgebraicity are explored. Finally, relations of these two classes with the (, N)-algebraic systems, introduced previously by the author as an analog of the -algebras of Font and Jansana, and with an analog of the Suszko operator of Czelakowski for π-institutions are also investigated. Presented by Josep Maria Font  相似文献   
183.
We give complete sequent-like tableau systems for the modal logics KB, KDB, K5, and KD5. Analytic cut rules are used to obtain the completeness. Our systems have the analytic superformula property and can thus give a decision procedure. Using the systems, we prove the Craig interpolation lemma for the mentioned logics.  相似文献   
184.
This article examines strategic framing efforts within the president's inner circle of foreign policy advisors. The comparative case study method is used to describe and explain the framing process involved in President Jimmy Carter's arms control decisions with respect to the Soviet Union. Carter's two central foreign policy advisors, National Security Advisor Zbigniew Brzezinski and Secretary of State Cyrus Vance, portrayed the Soviets in very different terms. The premise underlying this study is that advisors attempt to frame their policy preferences favorably in order to influence the group process and the president's policy choice. Advisors do so by playing up the positive aspects of an option and downplaying any negative aspects. Three components of the framing process are explored: historical/cultural symbolism, personal beliefs and values, and political cost assessments.  相似文献   
185.
The relations between reactive aggression, situational cues, and emotion regulation were examined by means of the Pulkkinen Aggression Machine (PAM) task. In the PAM, provocation and response were systematically varied under two conditions: the impulsive aggression condition and the controlled aggression condition. In the impulsive condition, no information about the attacker was provided, while in the controlled condition the attackers were specified in terms of sex, age, and physical strength. The task was administered to 109 children aged 8 to 13 years. Boys (n = 61) and girls (n = 48), as well as subgroups of Adjusted (n = 67) and Maladjusted (n = 26) children were compared. The results confirmed earlier findings showing that there is a strong relationship between attack and response intensity. However, this relationship was consistently modified by the effects of situation and personality‐related variables. This meant that, while for the impulsive condition response intensity was closely tied to stimulus intensity, in the controlled condition this effect was modulated by the characteristics of the opponent: the more equal the opponent the stronger the retaliations displayed. The Maladjusted children reacted more intensively in the impulsive condition and to minor provocation in the controlled condition than the Adjusted children. This suggests that the intensity of the elicited aggression in the Maladjusted group was particularly dependent on contextual rather than internal control. Aggr. Behav. 27:430–445, 2001. © 2001 Wiley‐Liss, Inc.  相似文献   
186.
187.
The term “Cognitive Architectures” indicates both abstract models of cognition, in natural and artificial agents, and the software instantiations of such models which are then employed in the field of Artificial Intelligence (AI). The main role of Cognitive Architectures in AI is that one of enabling the realization of artificial systems able to exhibit intelligent behavior in a general setting through a detailed analogy with the constitutive and developmental functioning and mechanisms underlying human cognition. We provide a brief overview of the status quo and the potential role that Cognitive Architectures may serve in the fields of Computational Cognitive Science and Artificial Intelligence (AI) research.  相似文献   
188.
Applying linear systems analysis to dynamic behavior   总被引:1,自引:1,他引:0       下载免费PDF全文
In this paper we present an abbreviated discussion of the linear systems analysis in the time domain. We then consider the qualitative character of the behavioral dynamics predicted using the linear form of the analysis. The analysis is then extended to a second-order form. We illustrate some relevant new features introduced by the second-order form with a special case example.  相似文献   
189.
Empirical results are presented from school-based interventions in three California counties that are pioneering participants in a carefully evaluated effort to create an innovative system of care for youth with severe emotional disturbance. Data are presented about the educational attendance and achievement of youth enrolled in clinical and academic programs designed to provide collaborative mental health and education services. Attendance levels were uniformly high. The youth were below expected grade level as measured by standardized tests at program admission. Across programs, two counties demonstrated grade level increases of one year or more for one year in school on all subscales of established measures of educational achievement. The third county demonstrated increases of slightly less than one year on two of three subscales of the educational achievement measures. These results are the first from a multisite demonstration of integrated education and mental health programs embedded within a broader system of care for youth. The findings, combined with those from our prior studies, illustrate that is possible to reduce and control placements in restrictive levels of care while improving the academic performance of a vast majority of the youth enrolled in specialized programs within the care systems.  相似文献   
190.
Recent and dramatic changes in the demand for and reimbursement of psychological services and expertise in health care delivery systems have radical implications for the preparation of psychologists at the predoctoral, internship, and postdoctoral levels. In order to respond to these changes effectively and advance the profession, training programs must realize the expanded and potential role of psychological expertise in evolving health care delivery systems. In this paper, we review several limitations and unfortunate consequences of traditional training programs that have confined the scope of research and practice to the realm of mental health. We propose that future psychologists be recognized and trained from a broader perspective as behavioral scientists, prepared to operate at the highest levels of health care delivery systems. Specific recommendations for training and education are discussed.  相似文献   
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