全文获取类型
收费全文 | 4136篇 |
免费 | 229篇 |
国内免费 | 2篇 |
专业分类
4367篇 |
出版年
2024年 | 10篇 |
2023年 | 62篇 |
2022年 | 64篇 |
2021年 | 97篇 |
2020年 | 130篇 |
2019年 | 142篇 |
2018年 | 208篇 |
2017年 | 221篇 |
2016年 | 182篇 |
2015年 | 116篇 |
2014年 | 134篇 |
2013年 | 536篇 |
2012年 | 318篇 |
2011年 | 322篇 |
2010年 | 196篇 |
2009年 | 101篇 |
2008年 | 280篇 |
2007年 | 208篇 |
2006年 | 216篇 |
2005年 | 131篇 |
2004年 | 102篇 |
2003年 | 87篇 |
2002年 | 75篇 |
2001年 | 34篇 |
2000年 | 53篇 |
1999年 | 35篇 |
1998年 | 24篇 |
1997年 | 22篇 |
1996年 | 15篇 |
1995年 | 13篇 |
1994年 | 12篇 |
1993年 | 10篇 |
1992年 | 18篇 |
1991年 | 15篇 |
1990年 | 23篇 |
1989年 | 16篇 |
1988年 | 11篇 |
1987年 | 14篇 |
1986年 | 9篇 |
1985年 | 12篇 |
1983年 | 6篇 |
1982年 | 7篇 |
1981年 | 10篇 |
1980年 | 5篇 |
1979年 | 6篇 |
1978年 | 5篇 |
1972年 | 5篇 |
1971年 | 5篇 |
1969年 | 4篇 |
1966年 | 4篇 |
排序方式: 共有4367条查询结果,搜索用时 0 毫秒
111.
The aim of this study is to analyze how the length of time a patient spends in an Intensive Care Unit (ICU) affects close relatives, with regard to specific clinical variables of personality, family relationships and fear of death. The study group consisted of 57 relatives of seriously ill patients admitted to the ICU of "Virgen del Rocío" Rehabilitation and Trauma Hospital (Seville, Spain). The instruments applied were: a psychosocial questionnaire, clinical analysis questionnaire, family environment scale and fear of death scale. The relatives of patients admitted to ICU obtained higher scores in hypochondria, suicidal depression, agitation, anxious depression, guilt-resentment, paranoia, psychasthenia, psychological maladjustment and self-expression, and less in fear of their own death, as when compared to interviews with the same relatives 4 years later. The length of time a patient spent in the ICU influenced relatives in some clinical variables of personality, family relationships and fear of death 相似文献
112.
In this paper, the distributional properties and power rates of the Lz, Eci2z, and Eci4z statistics when they are used as item fit statistics were explored. The results were compared to t-transformation of Outfit and Infit mean square. Four sample sizes were selected: 100, 250, 500, and 1000 examinees. The abilities were uniform and normal with mean 0 and standard deviation 1, and uniform and normal with mean -1 and standard deviation 1. The pseudo-guessing parameter was fixed at .25. Two ranges of difficulty parameters were selected: +/- 1 logits and +/- 2 logits. Two test lengths were selected: 15 and 30 items. The results showed important differences between the T-infit, T-outfit, Lz, Eci2z, and Eci4z statistics. The T-oufit, T-infit, and Lz statistics showed poor standardization with estimated parameters because their distributional properties were not close to the expected values. However, the Eci2z and Eci4z statistics showed satisfactory standardization on all conditions. Further, the power rates of Eci2z and Eci4z were 5% to 10% higher than the power rates of Lz, T-outfit, and T-infit to detect items that do not fit Rasch model. 相似文献
113.
Twenty-four detoxified opiate addicts were randomized to an experimental group and a control group to evaluate efficacy of a group cue-exposure treatment to reduce or extinguish classically conditioned responses to drug-related stimuli. Assessment included psychophysiological responses (skin temperature, skin conductance level--SCL--, and heart rate) to a videotape and subjective measures (subjective craving, positive and negative affect) before and after the videotape. The experimental group received a group cue-exposure program to drug-related stimuli that comprised twelve treatment sessions administered three times weekly. The treatment program significantly reduced conditioned responses to drug-related stimuli, as measured by SCL and positive affect. 相似文献
114.
Spatial learning in rats is impaired by microinfusions of protein kinase C-gamma antisense oligodeoxynucleotide within the nucleus accumbens 总被引:1,自引:0,他引:1
Alvarez-Jaimes L Betancourt E Centeno-González M Feliciano-Rivera MZ Rodríguez D Peña de Ortíz S Maldonado-Vlaar CS 《Neurobiology of learning and memory》2004,81(2):120-136
The nucleus accumbens (NAcc) has been shown to play a role in motor and spatial learning. Protein kinase C (PKC) has been implicated in the mechanisms of initiation and maintenance of long-term potentiation that is thought to be involved in the storage of long-term memory. In the present study, the importance of de novo synthesis of PKC-gamma within the NAcc in the acquisition and retention of spatial discrimination learning was assessed using an antisense knockdown approach. Separate groups of Long-Evans rats were exposed to acute microinfusions (6microg/microl) of PKC-gamma antisense oligodeoxynucleotide (AS-ODN), control oligodeoxynucleotide (C-ODN) or vehicle into the NAcc at 24 and 3h before each training session. Behavioral findings showed that the blockade of NAcc-PKC-gamma translation caused impairments in the early phase of learning and retention of spatial information. Biochemical experiments showed that PKC-gamma expression was reduced and Ca(2+)/phospholipid-dependent protein kinase C (PKC) activity was blocked significantly in the AS-ODN-treated rats in comparison with control rats. The present findings suggest that NAcc-PKC-gamma plays a role during the early acquisition of spatial learning. Also, retention test results suggest that NAcc-PKC-gamma may be working as an intermediate factor involved in the onset of molecular mechanisms necessary for spatial memory consolidation within the NAcc. 相似文献
115.
116.
The fact that early lexical and grammatical acquisition are strongly correlated has been cited as evidence against the view that the language faculty is composed of dissociable and autonomous modules (Bates & Goodman, 1997). However, previous studies have not yet eliminated the possibility that lexical-grammar associations may be attributable to language-general individual differences (e.g. children who are good at learning words are good at learning grammar). Parent report assessments of toddlers who are simultaneously learning English and Spanish (n = 113) allow an examination of the specificity of lexical-grammar relationships while holding child factors constant. Within-language vocabulary-grammar associations were stronger than cross-language relationships, even after controlling for age, proportion of language exposure, general language skill and reporter bias. Similar patterns were found based on naturalistic language samples (n = 22), ruling out a methodological artifact. These results are consistent with the view that grammar learning is specifically tied to lexical progress in a given language and provide further support for strong lexical-grammatical continuity early in acquisition. 相似文献
117.
Prey might assess that risk level estimated in the first encounter with a predator was fixed in subsequent responses, whereas prey using flexible behavior would track short-term changes in risk. The authors examined, in the field, refuge use of Iberian rock lizards (Lacerta monticola) after simulated predator attacks and tested (a) how risk was assessed when multiple sources of risk were present simultaneously, (b) how short-term changes in risk level of successive attacks affected refuge use, and (c) whether the interval between attacks was important, insofar as attacks were considered to be coming from the same or different predators. Results suggest that lizards have a flexible estimate of risk that is based on multiple sources and flexibly dependent on previous estimates. 相似文献
118.
Schmitt DP Alcalay L Allik J Angleitner A Ault L Austers I Bennett KL Bianchi G Boholst F Borg Cunen MA Braeckman J Brainerd EG Caral LG Caron G Casullo MM Cunningham M Daibo I De Backer C De Souza E Diaz-Loving R Diniz G Durkin K Echegaray M Eremsoy E Euler HA Falzon R Fisher ML Foley D Fry DP Fry S Ghayur MA Golden DL Grammer K Grimaldi L Halberstadt J Haque S Herrera D Hertel J Hoffmann H Hooper D Hradilekova Z Hudek-Kene-evi J Jaafar J Jankauskaite M Kabangu-Stahel H Kardum I Khoury B 《Journal of personality and social psychology》2004,86(4):560-584
119.
Quality of life assessment in Turkish patients with schizophrenia and their relatives 总被引:2,自引:0,他引:2
Alptekin K Akdede BB Akvardar Y Celikgün S Dilşen NS Durak G Türk A Fidaner H 《Psychological reports》2004,95(1):197-206
Quality of life of first-degree relatives living in the same household with patients having schizophrenia has not been sufficiently explored. 30 patients with schizophrenia (16 women, 14 men), diagnosed using DSM-IV criteria, 31 of their relatives (15 women, 16 men), and 34 control subjects (21 women, 13 men) were included in the study. The mean age of the patients, their relatives, and the control subects were 39.8 +/- 10.9, 58.1 +/- 12.5 and 37.3 +/- 17.0, respectively. The World Health Oranization Quality of Life-Brief Form was administered to all subjects. Quality of life was worse for the patient group than for their relatives and control subjects, but relatives of the patients and control subjects were not significantly different on Quality of life. Quality of life was negatively correlated with the severity of psychopathology and extrapyramidal side effects induced by antipsychotic drugs in the patients. 相似文献
120.
This study aims at verifying whether Portuguese gender-inflected nouns and adjectives are represented as full forms as suggested by Spanish data (Dominguez, Cuetos, & Segui, 1999). A series of lexical decision experiments is reported. Grammatical gender, frequency dominance, and grammatical category are manipulated and cumulative frequency is controlled. The results do not provide support for a full form representation of gender-inflected words. They suggest that grammatical category, or the nature of the inflectional process involved (lexical or syntactic), affects the way words are represented and accessed. Shorter recognition latencies were obtained for nouns drawn from Feminine dominant gender-inflected pairs than from Masculine dominant pairs whereas a tendency in the opposite direction was observed in adjectives. The effect of frequency dominance appears, nevertheless, to be restricted to feminine nouns. The data are compatible with the view that masculine nouns and adjectives are represented as gender-unmarked forms. These results are discussed in relation to current dual-access models of word recognition and to the notion of "interpretability" of lexico-syntactic features, as put forward in the Minimalist Program of Generative Linguistics. 相似文献