全文获取类型
收费全文 | 7883篇 |
免费 | 309篇 |
国内免费 | 2篇 |
专业分类
8194篇 |
出版年
2021年 | 58篇 |
2020年 | 122篇 |
2019年 | 134篇 |
2018年 | 165篇 |
2017年 | 201篇 |
2016年 | 186篇 |
2015年 | 161篇 |
2014年 | 188篇 |
2013年 | 944篇 |
2012年 | 324篇 |
2011年 | 318篇 |
2010年 | 201篇 |
2009年 | 229篇 |
2008年 | 319篇 |
2007年 | 308篇 |
2006年 | 283篇 |
2005年 | 287篇 |
2004年 | 260篇 |
2003年 | 251篇 |
2002年 | 261篇 |
2001年 | 119篇 |
2000年 | 110篇 |
1999年 | 125篇 |
1998年 | 131篇 |
1997年 | 86篇 |
1996年 | 97篇 |
1995年 | 101篇 |
1994年 | 86篇 |
1993年 | 79篇 |
1992年 | 81篇 |
1991年 | 80篇 |
1990年 | 65篇 |
1989年 | 74篇 |
1988年 | 68篇 |
1987年 | 66篇 |
1986年 | 69篇 |
1985年 | 85篇 |
1984年 | 92篇 |
1983年 | 73篇 |
1982年 | 64篇 |
1981年 | 69篇 |
1980年 | 73篇 |
1979年 | 51篇 |
1978年 | 68篇 |
1977年 | 76篇 |
1976年 | 73篇 |
1975年 | 67篇 |
1974年 | 70篇 |
1973年 | 50篇 |
1972年 | 50篇 |
排序方式: 共有8194条查询结果,搜索用时 15 毫秒
141.
Formal systems are standardly envisaged in terms of a grammar specifying well-formed formulae together with a set of axioms and rules. Derivations are ordered lists of formulae each of which is either an axiom or is generated from earlier items on the list by means of the rules of the system; the theorems of a formal system are simply those formulae for which there are derivations. Here we outline a set of alternative and explicitly visual ways of envisaging and analyzing at least simple formal systems using fractal patterns of infinite depth. Progressively deeper dimensions of such a fractal can be used to map increasingly complex wffs or increasingly complex value spaces, with tautologies, contradictions, and various forms of contingency coded in terms of color. This and related approaches, it turns out, offer not only visually immediate and geometrically intriguing representations of formal systems as a whole but also promising formal links (1) between standard systems and classical patterns in fractal geometry, (2) between quite different kinds of value spaces in classical and infinite-valued logics, and (3) between cellular automata and logic. It is hoped that pattern analysis of this kind may open possibilities for a geometrical approach to further questions within logic and metalogic.\looseness=-1 相似文献
142.
143.
Paul L. Hewitt James Newton Gordon L. Flett Lois Callander 《Journal of abnormal child psychology》1997,25(2):95-101
This study was conducted to examine the relations between dimensions of perfectionism and suicide ideation in an adolescent psychiatric sample. A sample of 66 adolescents from an inpatient psychiatric facility completed the Child and Adolescent Perfectionism Scale, the Child's Hopelessness Scale, and the Suicide Ideation Questionnaire. Overall, the results indicated that socially prescribed perfectionism was associated with greater suicide ideation and that it, along with hopelessness, accounted for unique variance in suicide ideation scores. The findings are discussed in terms of their practical and theoretical significance as well as their consistency with similar research with adults. 相似文献
144.
Engel JD Kane G Jones DL Lynn-McHale D Swartz M Durbin P Klingen D 《The Journal of medical humanities》1997,18(3):193-208
This study describes the results of a retrospective review of patients' charts who had an advanced directive (AD) and who were hospitalized in a tertiary, acute care teaching hospital. The purpose of the review was to understand from clinical, sociological, ethical and legal perspectives the nature and utility of ADs. Findings and implications of the review are discussed in terms of: patient demographics; diagnoses; quality of ADs; influence of ADs on clinical decisions; and legal aspects of ADs. 相似文献
145.
Ruben C. Gur J.Daniel Ragland Lyn Harper Mozley P.David Mozley Robin Smith Abass Alavi Warren Bilker Raquel E. Gur 《Brain and cognition》1997,33(3):388-414
Functional neuroimaging has been used to investigate neural substrates of mnemonic processes, and cerebral blood flow (CBF) measures have been sensitive to activation with memory tasks. Studies of memory with two-dimensional133Xenon clearance techniques found that word and face recognition tasks produced contralateral CBF changes in mid-temporal cortical regions. This study replicated the activation paradigm, expanding to the three-dimensional resolution of positron emission tomography (PET). Word and face recognition, and a control baseline task were administered to 19 healthy right-handed volunteers (11 men, 8 women) during successive 10 min PET15O-water measures of CBF. Quantitative CBF rates were calculated with the arterial input function and the equilibrium model. Redistributions of blood flow were compared across tasks using both absolute and relative (region/whole brain) CBF.Replicating the133Xenon clearance findings, CBF was “appropriately” lateralized during task performance (left–right for words > left–right for faces) in the mid-temporal region. Contrary to predictions, the recognition tasks did not activate expected mesolimbic or prefrontal areas. The task-induced CBF changes also correlated with performance. Bilateral CBF in mid-temporal and parahippocampal gyrus regions of interest correlated with the ability to correctly identify word targets (sensitivity). Left-lateralized CBF in the amygdala and hippocampus correlated with better word sensitivity as well as specificity (ability to correctly reject foils). Complementally, right-lateralized CBF in the parahippocampal gyrus correlated with better face specificity performance. In addition, left-lateralized CBF in the amygdala and right-lateralized CBF in the parahippocampal gyrus and hippocampus correlated with “mental effort” indices (task performance relative to basal ability) for word and face memory tasks, respectively. Thus, whereas this recognition task showed the expected lateralized increase in the mid-temporal region and not in frontal and limbic areas, lateralized activation in some of these areas was associated with better performance. Exploratory analyses on other regions showed lateralized changes in one additional temporal region, the occipital-temporal, and several limbic regions. 相似文献
146.
Paul M. Kohn Colleen O'Brien Donna I. Pickering 《Personality and individual differences》1997,22(6):895-899
Adaptiveness constitutes coping consistently with Stressors so to reduce distress or, at worst, not aggravate it. Accordingly, it should moderate the adverse impact of hassles. Undergraduate volunteers (N = 200) responded to measures of hassles, adaptiveness, and the criteria of subjective distress, psychiatric symptomatology and minor physical ailments. In all three regression analyses, hassles made a substantial positive contribution and adaptiveness a small negative contribution to adverse outcome. The interaction between hassles and adaptiveness was non-significant in all three cases. Alternative interpretations were identified to guide further research. 相似文献
147.
Paul M. Mastrangelo 《Journal of business and psychology》1997,11(3):325-337
Two experiments examined the effects of drug testing policies on undergraduates' behavioral intentions and attitudes toward the company. Study 1 (n=267) manipulated type of drug testing and consequences of detected use. Study 2 (n=267) manipulated the presence of applicant and employee drug testing. Subjects in both studies showed stronger intentions to apply to a company with random employee testing than one with no employee testing. Study 2 also found that an interaction between company policy and subjects' attitudes toward drug testing affected attitudes toward the company. Both studies suggest that employee drug testing may now foster recruitment.Study 1 was conducted while the author was at Ohio University and was presented in an earlier version at the Eastern Psychological Association's 64th Annual Meeting, Arlington, VA, April 16–April 18, 1993.I thank Candie Burbick and Jamie Winters for their work as student assistants. I also thank Jane Kestner, Kim Mastrangelo, James Rogers, and the JBP reviewers for their suggestions. 相似文献
148.
The authors summarise the findings of four recent experiments whichexamined childrens capacity to remember a particular occurrence of arecurring event. Issues discussed include the timing of the interview, thetype of errors, the questioning techniques, the age of the child, theconsistency of the childs account, and the impact of an interveninginterview. Implications for professionals who conduct investigatory orevidentiary interviews with child witnesses are discussed and suggestionsfor future research are also offered. 相似文献
149.
Paul Wink Beryl Gao Stephanie Jones Frances Chao 《International journal of psychology》1997,32(3):169-179
This study compared social values and relationships with parents among American college women of Chinese and European descent. Chinese-American women scored higher on a measure of practicality and pragmatism (mastery), hierarchy, and traditionality. The Euro-American women showed a greater interest in voluntary prosocial behaviour and philanthropy. Both groups of women reported having a sense of self, autonomous of their parents. Within the Chinese-American group, ethnic identification and religion, but not generation, moderated scores on a measure of traditionality of outlook regarding issues of law and order and social equality. We discuss the implications of our findings for recent debates in cross-cultural psychology, including the growing challenge to the individualism-collectivism dimension. 相似文献
150.