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   42351篇
  免费   969篇
  国内免费   13篇
  2020年   274篇
  2019年   268篇
  2018年   3805篇
  2017年   3100篇
  2016年   2611篇
  2015年   472篇
  2014年   472篇
  2013年   1751篇
  2012年   1222篇
  2011年   3024篇
  2010年   2834篇
  2009年   1883篇
  2008年   2275篇
  2007年   2710篇
  2006年   598篇
  2005年   717篇
  2004年   655篇
  2003年   593篇
  2002年   491篇
  2001年   844篇
  2000年   868篇
  1999年   608篇
  1998年   268篇
  1997年   242篇
  1996年   212篇
  1992年   495篇
  1991年   431篇
  1990年   507篇
  1989年   418篇
  1988年   397篇
  1987年   376篇
  1986年   399篇
  1985年   451篇
  1984年   348篇
  1983年   293篇
  1982年   223篇
  1979年   327篇
  1978年   259篇
  1977年   206篇
  1976年   201篇
  1975年   300篇
  1974年   348篇
  1973年   350篇
  1972年   276篇
  1971年   242篇
  1970年   210篇
  1969年   230篇
  1968年   290篇
  1967年   253篇
  1966年   273篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
921.
A Bayesian approach for simultaneous optimization of test-based decisions is presented using the example of a selection decision for a treatment followed by a mastery decision. A distinction is made between weak and strong rules where, as opposed to strong rules, weak rules use prior test scores as collateral data. Conditions for monotonicity of optimal weak and strong rules are presented. It is shown that under mild conditions on the test score distributions and utility functions, weak rules are always compensatory by nature. The authors are indebted to Wilbert Kallenberg for his valuable comments and to Jan Gulmans for providing the data for the empirical example. The names of the authors are alphabetical; they are equally responsible for the contents of this paper.  相似文献   
922.
923.
We present three experiments designed to investigate the role of prosody during sentence processing. The first investigated the question of whether an utterance's prosodic contour influences its comprehension on-line. We spliced the beginning and end portions of direct object and embedded clause sentences and observed the consequent effects on comprehension using a dual-task procedure to measure processing load. Our second experiment sought to determine-whether the constituent structure of these sentences could be reliably predicted using prosodic information. We found that the duration and F0 contour associated with the main-clause verb and the following NP reliably distinguished between the direct object and embedded clause constructions. In the final experiment, we manipulated the duration of the main-clause verb and found that subjects used this information to guide their initial parse during on-line sentence comprehension. The need for a model of sentence processing that addresses the use of prosodic information is discussed.The work reported in this paper was supported in part by NTH grant DC00494.  相似文献   
924.
The importance of using culturally sensitive educational materials in HIV-related interventions with racial and ethnic minority groups is widely recognized. However, little empirical research has been conducted to assess the relative effectiveness of different techniques for creating culturally sensitive AIDS educational videos. Two field experiments with three samples of African American adults (N = 174, 173, and 143) were conducted to assess how source characteristics (race of communicator), message characteristics (multicultural message vs. culturally specific message), and audience characteristics (racial distrust and AIDS-related distrust) influence proximate (perceptions of the message's credibility and attractiveness) and distal (AIDS-related attitudes, beliefs, and behavioral intentions) output variables for AIDS educational videos. In Study 1, an AIDS video with a culturally specific message was rated as more credible, more attractive, and of higher quality than was a video with a multicultural message. The multicultural message was rated less favorably when delivered by a White announcer than when the announcer was Black. In Study 2, the same pattern was replicated with a second community sample and a campus-based sample. Study 2 also indicated that a multicultural message might be more effective if delivered in a culturally specific context, namely, after audience members watch a culturally specific video. Minimal changes were observed in distal outcome variables. It is argued that influencing proximate output variables is necessary, though not sufficient, for effecting long-term change in AIDS-related attitudes, beliefs, and behaviors.  相似文献   
925.
Although few guidelines exist, many therapists use prayer as a part of psychotherapy. The immense variance inherent in prayer behaviors and the paucity of literature on its use beckons the profession to develop a model for its use in therapy, examine the ethical implications for such use, and prepare guidelines for practice. A tripartite model for the conceptualization and localization of prayer in therapy is presented, ethical issues of therapist bias and competence and clients' right to autonomous decision making are considered, and guidelines for employing prayer in psychotherapy are developed.  相似文献   
926.
Recent research on hunger and eating has shown that (a) among individuals with adlibitum access to food, hunger and eating are not regulated by deviations in the body's energy resources from set-points, and (b) it is healthier for people to consume their daily caloric intake as several small snacks than as 3 large meals. People's beliefs about hunger and eating were assessed in 2 questionnaire studies. In Study 1, a large sample of undergraduates was surveyed; in Study 2, dietetics students, nursing students, medical students, dietitians, nurses, and doctors were surveyed. Both studies revealed that people's personal theories of hunger and eating were inconsistent with research findings in ways that could promote overconsumption. These results suggest that educational programs designed to modify the beliefs about hunger and eating of people suffering from problems of overconsumption and of health professionals who treat problems of overconsumption may increase the effectiveness of current treatment regimens.  相似文献   
927.
The proposal of Friman, Hayes, and Wilson (1998) that the concept of emotion be incorporated into behavior analysis is questioned. Their proposal is undermined by the problem of the verification of private events by others. A focus on private events, as exemplified by the proposal of Friman et al., can lead to a reversion to notions of agency and the autonomous individual. Also, the anchoring of hypothetical constructs to the behavioral data language is ill advised.  相似文献   
928.
Multiple baseline designs were used to examine the effects of an instructional package on accuracy of performance in solving multiplication facts by 3 students with learning disabilities. The instructional package included the following components: (a) a modified instructional sequence in which multiplication facts were grouped into the zeros, ones, doubles, fives, and nines categories, and those remaining; (b) identification of the category in which each fact belonged; (c) mnemonic strategies associated with solving facts in each category; and (d) steps to be completed for solving facts in each category. Results indicated that the instructional package produced substantial and immediate effects. After receiving instruction, a participant's accuracy was often 100%, and this was maintained throughout the evaluation even as other strategies were introduced. Comparable results occurred across students, demonstrating replication of the effects of the instructional package.  相似文献   
929.
FEMALE PARTNERS OF BISEXUAL MEN What They Don't Know Might Hurt Them   总被引:2,自引:0,他引:2  
Individual interviews with 350 behaviorally bisexual men aged 18–30 revealed that 71% of their female sexual partners and 59% of their steady female sexual partners in the past 6 months had not been aware of their homosexual activity. Rates of nondisclosure were higher for African-American than White men. Compared to nondisclosers, men who disclosed to all their female partners were less self-homophobic and perceived their friends, families, and neighbors as more accepting of their homosexual behavior. Compared to men who had disclosed, the nondisclosers had more female partners and used condoms less consistently with women.  相似文献   
930.
The aim of this study is to provide further characterization of a subgroup of so-called “Grammatical specific language-impaired (SLI)” children. The Grammatical SLI children have a persistent and disproportionate impairment in grammatical comprehension and expression of language. Previous research has indicated that their language impairment may be characterized by a domain-specific and modular language deficit. This study provides an initial investigation as to whether there is a genetic basis underlying their disorder as has been found for other forms of SLI and for SLI in general. The incidence of familial aggregation of language impairment was investigated in 12 Grammatical SLI children (aged 9:3 to 12:10). A familial language impairment (LI) history was classified as positive if one or more of the probands' relatives had a history of a speech/language or reading/writing problem which required speech therapy or any other form of remedial help. Case history information provided an initial indication that the Grammatical SLI children had a significantly higher incidence of a positive familial LI history than could be expected by chance. A questionnaire provided evidence of a positive LI history in the first-degree relatives of the SLI probands and 49 normally developing control probands. The SLI probands had a clearly and significantly higher incidence of a positive familial LI history than the control probands (77.8 vs. 28.5%, respectively). The results are consistent with a genetic basis underlying Grammatical SLI. The pattern of impairment in the SLI probands' relatives is consistent with an autosomal dominant genetic inheritance. In contrast to the control probands, the SLI probands' impaired relatives did not show a male gender bias. Thus, the gene does not appear to be sex-linked. The data indicate that further research is warranted to investigate the nature of the LI in the relatives of the Grammatical SLI probands and the genetic characteristics of this subgroup. The implications for the biological, domain-specific, and modular bases to language 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