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   51354篇
  免费   601篇
  国内免费   4篇
  51959篇
  2019年   393篇
  2018年   3861篇
  2017年   3224篇
  2016年   2766篇
  2015年   653篇
  2014年   580篇
  2013年   2738篇
  2012年   1479篇
  2011年   3255篇
  2010年   3008篇
  2009年   2023篇
  2008年   2445篇
  2007年   2940篇
  2006年   822篇
  2005年   945篇
  2004年   865篇
  2003年   843篇
  2002年   782篇
  2001年   917篇
  2000年   903篇
  1999年   703篇
  1998年   377篇
  1997年   344篇
  1996年   362篇
  1995年   338篇
  1992年   569篇
  1991年   583篇
  1990年   536篇
  1989年   505篇
  1988年   525篇
  1987年   503篇
  1986年   489篇
  1985年   502篇
  1984年   438篇
  1983年   413篇
  1982年   338篇
  1981年   347篇
  1979年   482篇
  1978年   390篇
  1977年   341篇
  1976年   338篇
  1975年   393篇
  1974年   469篇
  1973年   475篇
  1972年   364篇
  1971年   351篇
  1970年   339篇
  1968年   410篇
  1967年   359篇
  1966年   323篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
991.
This study assesses the impact of accountability, the status quo, and anticipated costs and benefits on judgement of the acceptability of a drug in the US pharmaceuticals market. Several effects are documented: (1) subjects were more accepting of a drug, the lower the anticipated risks of side effects and the greater the anticipated benefits; (2) subjects were especially unwilling to accept risk when the drug was not yet on the market and when they felt accountable for their decisions; (3) accountable subjects confronted by an off-the-market drug that posed moderate or high risk were also especially likely to procrastinate, to buckpass, and to think in integratively complex ways about the problem, notwithstanding the fact that many more lives would be saved than lost. We explain these results by positing that perceptual-cognitive processes (loss aversion) and political processes (blame avoidance) mutually reinforce each other when decision makers are accountable for choices that raise the possibility of changing the status quo in ways that impose losses on identifiable constituencies. We conclude by commenting on the complex normative issues that arise in labelling response tendencies as biases. Choices that look irrational within one ethical or political framework sometimes appear quite reasonable with another.  相似文献   
992.
993.
Doress-Worters  Paula B. 《Sex roles》1994,31(9-10):597-616
Sex Roles - Research on the effect of multiple roles on women's well-being has focused almost exclusively on the employment and child rearing roles of younger women, and has overlooked the...  相似文献   
994.
The objective of this study was to use qualitative methodology to tailor and refine an existing smoking cessation intervention for the population of people who use cigarettes and are diagnosed with schizophrenia, schizoaffective, or psychotic disorder. Successive cohort design methodology was used to iteratively modify the treatment in response to qualitative participant, therapist, and consultant feedback on the intervention. Qualitative methodology for participant feedback included analysis of semistructured interviews with participants, visualization of app utilization data, and stakeholder feedback from study therapists and consultants. Using the successive cohort design, a tailored multicomponent mobile health smoking cessation intervention was developed. The intervention included mobile contingency management (i.e., financial compensation for confirmed abstinence from smoking), pharmacotherapy for smoking cessation, cognitive-behavioral counseling sessions, and the Stay Quit app for relapse prevention. Two cohorts (N = 13) were completed in the study; after each cohort, the treatment protocol was revised. The intervention is described, as well as the qualitative findings from each cohort and subsequent changes made to the intervention based upon patient and provider feedback. Metrics of patient engagement included treatment adherence (40% in Cohort 1 and 63% in Cohort 2). Both participants and therapists reported that the intervention was helpful. Over one third of participants self-reported abstinence at posttreatment. Since qualitative methodology is often underutilized in mental health treatment development, this study demonstrates the utility of the successive cohort design for treatment development of behavior change interventions for at-risk, vulnerable populations.  相似文献   
995.

Although interest development is often conceptualized as a process that occurs within an individual, interest can be developed through various social mechanisms. Messages that suggest that one is or is not welcome within a context may serve to bolster or attenuate interest in those contexts. In a sample of first semester freshmen undergraduate science students, we tested whether or not talking with close others about one’s interests, and receiving social recognition during those conversations, was related to having a greater science career interest over time. Our findings suggest that the way in which students perceive others’ reactions to their scientific interests (social recognition) during these conversations may have the greatest impact on students that face greater external barriers to persisting. We found that positive social recognition appraisals that convey that a listener understands and encourages one’s interest in science predicted a greater science career interest over time for women, but not men. The impact of positive social recognition appraisals on interest in a science career was greatest among women with relatively low or average science identities, but not for women with a relatively high science identity. The implications for the development of students’ interest and for broadening participation in science are discussed.

  相似文献   
996.
997.
A general class of labeled sequent calculi is investigated, and necessary and sufficient conditions are given for when such a calculus is sound and complete for a finite-valued logic if the labels are interpreted as sets of truth values (sets-as-signs). Furthermore, it is shown that any finite-valued logic can be given an axiomatization by such a labeled calculus using arbitrary "systems of signs," i.e., of sets of truth values, as labels. The number of labels needed is logarithmic in the number of truth values, and it is shown that this bound is tight.  相似文献   
998.
Post RB  Welch RB  Caufield K 《Perception》1998,27(7):827-838
The shaft portions of Müller-Lyer (M-L) figures, one-ended M-L figures, Judd figures, and their respective control (tails-up) figures were divided by subjects into eight equal-appearing intervals by means of successive bisections. For most of the control stimuli the length of the left half of the shaft tended to be overestimated relative to the length of the right side. For the tails-out version of the M-L figure, there was relative overestimation of segments of the shaft adjacent to the tails, while for the tails-in version there was relative underestimation of these segments. These results indicate that the distortion of perceived length in the M-L illusion is not distributed evenly along the shaft. For the one-ended M-L figures the apparent overestimations and underestimations extended further along the shaft than for the standard figures. For the Judd figure perceived length varied systematically along the length of the shaft from underestimation near the tails-in end of the figure to overestimation near the tails-out end. These results are contradictory to the hypothesis that the M-L illusion results from inappropriate size scaling produced through the operation of size-constancy mechanisms, since this conjecture would predict uniform expansion or contraction. The results are compared with findings that localization responses are accurate for M-L figures but biased for one-ended M-L figures and Judd figures.  相似文献   
999.
Illusory tip-of-the-tongue states.   总被引:2,自引:0,他引:2  
The tip-of-the-tongue state (TOT) is the phenomenological experience that a target word is on the verge of being recalled. An illusory TOT occurs when a person experiences a TOT, but the actual target is either unavailable, forgotten, or never learned. Illusory TOTs were induced by asking participants to answer questions that did not have correct answers. In Experiment 1, an episodic-memory paradigm, participants were shown fictional animals, some of which were accompanied by the animal's name (identified targets) and some of which were not (unidentified targets). Some participants experienced TOTs for unidentified targets. In Experiment 2, a semantic-memory paradigm, participants were asked general-information questions, some of which were questions with no correct answer. Every one of the 31 participants experienced at least one illusory TOT. The characteristics of illusory TOTs are discussed in light of inferential and direct-access views of TOTS.  相似文献   
1000.
In both Pavlovian conditioning and human causal judgment, competition between cues is well known to occur when multiple cues are presented in compound and followed by an outcome. More questionable is the occurrence of competition between outcomes when a single cue is followed by multiple outcomes presented in compound. In the experiment reported here, we demonstrated blocking (a type of stimulus competition) between outcomes. When the cue predicted one outcome, its ability to predict a second outcome that was presented in compound with the first outcome was reduced. The procedure minimized the likelihood that the observed competition between outcomes arose from selective attention. The competition between outcomes that we observed is problematic for contemporary theories of learning.  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