全文获取类型
收费全文 | 23996篇 |
免费 | 1032篇 |
国内免费 | 18篇 |
出版年
2020年 | 280篇 |
2019年 | 304篇 |
2018年 | 485篇 |
2017年 | 487篇 |
2016年 | 473篇 |
2015年 | 371篇 |
2014年 | 403篇 |
2013年 | 1971篇 |
2012年 | 769篇 |
2011年 | 846篇 |
2010年 | 480篇 |
2009年 | 472篇 |
2008年 | 645篇 |
2007年 | 649篇 |
2006年 | 574篇 |
2005年 | 499篇 |
2004年 | 487篇 |
2003年 | 460篇 |
2002年 | 487篇 |
2001年 | 896篇 |
2000年 | 895篇 |
1999年 | 606篇 |
1998年 | 252篇 |
1997年 | 236篇 |
1996年 | 216篇 |
1993年 | 207篇 |
1992年 | 492篇 |
1991年 | 464篇 |
1990年 | 463篇 |
1989年 | 439篇 |
1988年 | 408篇 |
1987年 | 393篇 |
1986年 | 431篇 |
1985年 | 421篇 |
1984年 | 348篇 |
1983年 | 302篇 |
1979年 | 301篇 |
1978年 | 253篇 |
1977年 | 212篇 |
1976年 | 198篇 |
1975年 | 272篇 |
1974年 | 355篇 |
1973年 | 312篇 |
1972年 | 283篇 |
1971年 | 246篇 |
1970年 | 237篇 |
1969年 | 276篇 |
1968年 | 314篇 |
1967年 | 245篇 |
1966年 | 278篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
951.
952.
953.
954.
Marjorie K. Bradley 《Journal of counseling and development : JCD》1978,57(1):42-45
Major criticisms directed at counseling are identified and prominent suggestions for their elimination are described through an analysis of the counseling literature of the past 10 years. A brief outline of the history of counseling offers a historical perspective to the discussion. One suggestion to improve counseling, that counselors become change agents in their institutions, is examined and described with steps for its implementation. The implementation of the change-agent role for counselors would address much of the substantive criticism directed at counseling, and would remold the profession to more effectively meet today's needs. 相似文献
955.
956.
Conditioned fear and startle magnitude: effects of different footshock or backshock intensities used in training 总被引:4,自引:0,他引:4
M Davis D I Astrachan 《Journal of experimental psychology. Animal behavior processes》1978,4(2):95-103
In Experiment 1 four groups of rats received 30 light-shock pairings using footshock intensities of either .2, .4, .8, or 1.6 mA. One day later all rats were tested for startle by presenting tones in the presence or absence of the light CS. Potentiated startle (the difference between startle on light-tone vs tone-alone trials) was nonmonotonically related to the shock intensity used in training, with the greatest potentiation at intermediate shock levels. Experiment 3 demonstrated a similar relationship when backshocks instead of footshocks were used. In Experiment 2 rats were trained with either a moderate or high shock and then given an extended extinction-test session 1 day later. The moderate-shock group showed a gradual decline in potentiated startle over extinction. The high-shock group showed a nonmonotonic extinction curve where potentiation progressively increased toward the middle of extinction and dissipated thereafter. The results suggest that acoustic startle bears an inverted U-shaped relationship to fear and are discussed in relation to other studies concerned with this issue. 相似文献
957.
The difficulties in measuring the idiosyncratic collateral behavior emitted by rats on a DRL schedule are overcome by providing woodblocks attached to a sensor. Wood gnawing is recorded by stylus transducer signals. An audio amplifier raises these signals to a suitable level for the operation of a threshold control unit. A pulse former operates the final relay amplifier for 150 msec from the onset of disturbance to the transducer. 相似文献
958.
Howard L. Kaplan Neil A. Macmillan C. Douglas Creelman 《Behavior research methods》1978,10(6):796-813
Signal detection theory (SDT) allows a bias-free measure of sensitivity, d′, to be simply estimated from discrimination data when certain conditions are met. The computation is not straightforward, however, in several popular discrimination designs, such as two- and four-interval same-different designs and the ABX design. The present tables, derived from the SDT models of Macmillan, Kaplan, and Creelman (1977), make possible the estimation of d’ from these complex discrimination designs. 相似文献
959.
Alliston K. Reid 《Behavior research methods》1978,10(6):854-855
960.
Switching transients or “glitches” are frequently encountered in signal processing applications involving digital-to-analog (D/A) conversion. A low-cost “deglitching” circuit is described and implemented for the Digital Equipment Corporation AA50 D/A converter option on the PDP-8/e minicomputer. Switching transients were eliminated using a noninverting, unity-gain sample-and-hold circuit (employing Datei System’s SHM-IC-1). Switching transients were reduced to below-noise levels across a wide range of output levels and sampling rates. 相似文献