全文获取类型
收费全文 | 30780篇 |
免费 | 1433篇 |
国内免费 | 21篇 |
出版年
2021年 | 280篇 |
2020年 | 494篇 |
2019年 | 542篇 |
2018年 | 793篇 |
2017年 | 783篇 |
2016年 | 850篇 |
2015年 | 596篇 |
2014年 | 748篇 |
2013年 | 2945篇 |
2012年 | 1219篇 |
2011年 | 1299篇 |
2010年 | 832篇 |
2009年 | 830篇 |
2008年 | 1125篇 |
2007年 | 1109篇 |
2006年 | 962篇 |
2005年 | 799篇 |
2004年 | 846篇 |
2003年 | 793篇 |
2002年 | 766篇 |
2001年 | 905篇 |
2000年 | 948篇 |
1999年 | 666篇 |
1998年 | 380篇 |
1997年 | 341篇 |
1996年 | 257篇 |
1995年 | 284篇 |
1994年 | 272篇 |
1993年 | 282篇 |
1992年 | 490篇 |
1991年 | 442篇 |
1990年 | 458篇 |
1989年 | 444篇 |
1988年 | 432篇 |
1987年 | 400篇 |
1986年 | 397篇 |
1985年 | 393篇 |
1984年 | 353篇 |
1983年 | 304篇 |
1982年 | 242篇 |
1981年 | 246篇 |
1979年 | 301篇 |
1978年 | 273篇 |
1977年 | 225篇 |
1976年 | 220篇 |
1975年 | 259篇 |
1974年 | 322篇 |
1973年 | 256篇 |
1972年 | 244篇 |
1968年 | 223篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
971.
Dr. Neuro Transmitter, a psychotherapist in Paramus, New Jersey, provides services through an online, real-time consultation service known as CyberShrink, Inc., of Dallas, Texas. He is paid by the hour for his consultation services to subscribers who are billed by credit card through CyberShrink. One afternoon he logs on and is connected via private "chat channel" to a new subscriber to the service. She is Ann Hedonia of Simi Valley, California. Ten minutes into the session, Dr Transmitter recognizes that Ms. Hedonia is seriously depressed with suicidal ideation and is feeling on the edge of her ability to cope. He gently suggests that perhaps she ought to think about hospitalization near her home. Ms. Hedonia replies, "Even you don't care about me! That's it. I'm going to do it!" and disconnects. Discussion questions: Is offering psychotherapy services online ethical? What are Dr. Transmitter's obligations in general and at this particular moment to Ms. Hedonia? Suppose Ms. Hedonia has a complaint about Dr. Transmitter. From whom can she seek a remedy? Which state's laws apply regarding professional practice, confidentiality, or licensing qualifications? Must Dr. Transmitter be licensed in any state to offer this service? 相似文献
972.
In this article we explore ethical issues arising in a study of home Internet use by low-income families. We consider questions of our responsibility as educational researchers and discuss the ethical implications of some unanticipated consequences of our study. We illustrate ways in which the principles of research ethics for use of human subjects can be ambiguous and possibly inadequate for anticipating potential harm in educational research. In this exploratory research of personal communication technologies, participants experienced changes that were personal and relational. These unanticipated changes in their way of being complicated our research relationships, testing the boundaries of our committment to the principle of trustworthiness and forcing us to reevaluate our responsibilities. 相似文献
973.
W. Brian McPherson Peggy T. Ackerman D. Michael Oglesby Roscoe A. Dykman 《Integrative psychological & behavioral science》1996,31(1):3-17
Event-related brain potentials were recorded while disabled adolescent subjects read and judged whether two sequentially presented pictures had names that rhymed. Subjects with relatively good phonetic skills displayed an N400 priming effect, i.e., a significant reduction in the amplitude of the negative peak, occurring approximately 400 msec post-stimulus, for pictures with names that rhymed with preceding pictures as compared with pictures that had names that did not rhyme with the prime. No such effect was evident for subjects with relatively poor phonetic skills. This lack of an N400 priming effect provides evidence for a reduction in neural capacity and/or activation during phonological processing in the subjects with poor phonological skills. Demonstrating the N400 priming effect to be stronger in one group of reading disabled subjects, compared to another, supports the position that specific subtypes of reading disability exist. In addition to the stronger N400 priming effect, the phonetically stronger group also exhibited an enhanced negativity, from 700 to 1,000 msec after target stimulus onset, compared to phonetically inferior subjects. This finding replicates earlier work and possibly reflects a higher level of confidence in the group with better phonetic skills. 相似文献
974.
Patti Johnson M.S. John Schuster Ed.D. Jennifer K. Bell M.S. 《Journal of Behavioral Education》1996,6(4):437-458
This study compared the effectiveness and efficiency of simultaneous prompting with and without error correction during daily probe sessions in teaching science vocabulary words. The teacher presented the vocabulary word definitions as instructive feedback during training sessions. Five 16–17 year old students with disabilities participated in an adapted alternating treatments design that evaluated the simultaneous prompting strategy, error correction and instructive feedback. Instruction occurred in a group format using choral responding. The results indicate that (a) all students learned to read the vocabulary words, (b) simultaneous prompting with error correction was slightly more efficient for three of the five subjects in learning the targeted words, and four of the five students made fewer errors in this condition, (c) all students preferred simultaneous prompting with error correction over simultaneous prompting without error correction, (d) words mastered in both conditions generalized equally, (e) there were minimal differences between the two conditions in the collected maintenance data, and (e) students experienced only minimal improvement in their ability to define vocabulary words (instructive feedback). Discussion focuses on issues for further research and implications for instructional practice with simultaneous prompting, error correction and instructive feedback. 相似文献
975.
Rothenberg KH 《Kennedy Institute of Ethics journal》1996,6(1):69-84
Feminist legal theory provides a healthy skepticism toward legal doctrine and insists that we reexamine even formally gender-neutral rules to uncover problematic assumptions behind them. The article first outlines feminist legal theory from the perspectives of liberal, cultural, and radical feminism. Examples of how each theory influences legal practice, case law, and legislation are highlighted. Each perspective is then applied to a contemporary bioethical issue, egg donation. Following a brief discussion of the common themes shared by feminist jurisprudence, the article incorporates a narrative reflecting on the integration of the common feminist themes in the context of the passage of the Maryland Health Care Decisions Act. The article concludes that gender does matter and that an understanding of feminist legal theory and practice will enrich the analysis of contemporary bioethical issues. 相似文献
976.
Michael E. Nielsen 《Behavior research methods》1996,28(3):483-485
Scott’s (1969)H is a statistic that represents the number of independent dimensions in a set of binary (1,0) data.H has been used by personality and social psychologists to measure the complexity of thought people have about themselves (self-complexity) and about other people. This article describesH-Comp, a program that calculatesH. Using data input from either the keyboard or from an ASCII data file,H-Comp calculatesH and writes the resulting score and raw data to output files.H-Comp provides an accurate and efficient way to calculateH. 相似文献
977.
It is now relatively easy to implement pupillometry in social psychological research. We describe a system in which a Macintosh computer presents visual and auditory stimuli to subjects while monitoring an infrared pupillometer. The computer records information on subject, task, and pupil diameter into a data file for input into standard statistical analysis programs. Pupil diameter is measured continuously while subjects respond to stimuli that last for several seconds or minutes. A demonstration experiment verifies the usefulness of the system. The ability of the Macintosh computer to easily handle visual and auditory stimuli and to record responses lasting a considerable length of time makes the system well suited for studying pupil responses to complex social stimuli. This system is also well suited for the researcher initiating a research program using pupillometry. Ease of operation makes using a large number of subjects feasible. 相似文献
978.
René A. De Wijk Wim Vaessen Johannes Heidema E. P. Köster 《Behavior research methods》1996,28(3):383-391
An injection olfactometer for human psychophysical experiments is described. The olfactometer is capable of presenting, either mono- or birhinally, single odorants and binary mixtures. The pulse form of the olfactory stimulus at the exit of the olfactometer approaches a rectangular form, which makes the olfactometer well suited for olfactory reaction time measurements. Since stimulation periods are independent of the subject’s inhalation, time-intensity measurements over prolonged periods of time are possible as well. In the second part of this paper, a new technique is described for the measurement of the stimulus pulse form at the exit of the olfactometer. 相似文献
979.
Harald K. Taukulis 《Neurobiology of learning and memory》1996,65(3):223-232
On multiple occasions, rats were administered diazepam (2.0 mg/kg, ip) followed 30 min thereafter by yohimbine hydrochloride (2.5 or 5.0 mg/kg) or isotonic saline (forward conditioning groups). Three additional groups (backward conditioning controls) were given equivalent injections, but in reverse order. After eight such pairings, the effects of a single injection of diazepam on motor performance (balancing on a rotating drum) was assessed. Rats that had received either dose of yohimbine during forward conditioning trials maintained their balance longer than the saline controls. After four additional conditioning trials, the animals’ activity patterns in a plus-maze screening test for anxiolytics were examined. Placed into the maze after a single test injection of isotonic saline, the behavior of all groups was virtually identical: less than 16% of total entries into or time spent in the four arms of the maze was spent in the two “open” arms (unprotected by surrounding walls). When tested in the maze again, but 35 min after a single injection of diazepam, the groups that had received diazepam but not yohimbine during the conditioning phase exhibited the expected increase in open-arm activity, and equivalent increases were found in backward conditioning groups. However, the group previously conditioned with 2.5 mg/kg of yohimbine following diazepam also showed an increased open-arm activity when tested with diazepam alone, but it was significantly greater than that seen in the control group. In contrast, the group conditioned with 5.0 mg/kg yohimbine following diazepam exhibited no effect of diazepam upon their plus maze activity; consequently, these animals spent less time in the open arms than either of the other groups. Yohimbine alone normally decreases open-arm activity (a putative “anxiogenic” effect) in a linear dose-dependent fashion. The fact that it had a bidirectional conditional effect on the diazepam cue drug demonstrates that a conditional response in drug → drug conditioning cannot always be predicted on the basis of the behavioral response to the signaled drug. Consideration is given to possible reasons for these effects of diazepam → yohimbine pairings in terms of the known neuropharmacological properties of yohimbine. 相似文献
980.
Michael H. Mesches Marino Bianchin James L. McGaugh 《Neurobiology of learning and memory》1996,66(3):324-340
The aim of these experiments was to determine whether impaired retention performance in aversively motivated tasks, induced by blockade of amygdala AMPA receptors, is due to influences on mechanisms underlying memory retrieval or to other influences on performance. Rats received either footshock escape training (1 or 10 trials), or no foot shock, in a two-compartment straight alley and bilateral intra-amygdala infusions of the AMPA receptor antagonist CNQX (0.5 μg) were subsequently administered prior to inhibitory avoidance retention testing 8 days later. The CNQX impaired, but did not block, inhibitory avoidance retention performance as indicated by the initial latencies to enter the shock compartment. The animals were then retained in the alley until they remained in the starting compartment for 100 consecutive s and entries into the shock compartment were recorded as errors. In both the controls and CNQX-treated groups, increases in amount of original training resulted in fewer errors, indicating memory for the escape training. Furthermore, regardless of the amount of original training (i.e., 0, 1, or 10 trials), CNQX-treated groups made more errors. Other experiments examined intra-amygdala CNQX effects on reactivity to footshock, locomotor activity, and anxiety. CNQX decreased reactivity to footshock, blocked shock-induced decreases in locomotor activity, and had an anxiolytic effect in an elevated plus maze comparable to that induced by midazolam (0.5 μg). These findings suggest that intra-amygdala infusions of CNQX prior to retention testing affect inhibitory avoidance retention performance following aversive training by altering locomotor activity, reducing sensitivity to footshock, and reducing anxiety. The implications of these findings for hypotheses concerning amygdala function in aversively motivated learning and memory is discussed. 相似文献