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   1756篇
  免费   36篇
  国内免费   2篇
电工技术   9篇
综合类   1篇
化学工业   224篇
金属工艺   13篇
机械仪表   23篇
建筑科学   59篇
矿业工程   8篇
能源动力   59篇
轻工业   304篇
水利工程   6篇
石油天然气   9篇
无线电   82篇
一般工业技术   139篇
冶金工业   667篇
原子能技术   8篇
自动化技术   183篇
  2022年   11篇
  2021年   27篇
  2020年   19篇
  2019年   20篇
  2018年   21篇
  2017年   17篇
  2016年   20篇
  2015年   20篇
  2014年   28篇
  2013年   73篇
  2012年   50篇
  2011年   73篇
  2010年   63篇
  2009年   51篇
  2008年   67篇
  2007年   85篇
  2006年   73篇
  2005年   73篇
  2004年   56篇
  2003年   61篇
  2002年   48篇
  2001年   37篇
  2000年   34篇
  1999年   35篇
  1998年   62篇
  1997年   53篇
  1996年   53篇
  1995年   42篇
  1994年   39篇
  1993年   34篇
  1992年   28篇
  1991年   11篇
  1990年   34篇
  1989年   37篇
  1988年   29篇
  1987年   27篇
  1986年   39篇
  1985年   24篇
  1984年   20篇
  1983年   31篇
  1982年   23篇
  1981年   23篇
  1980年   14篇
  1979年   22篇
  1978年   20篇
  1977年   6篇
  1976年   12篇
  1975年   6篇
  1974年   6篇
  1964年   4篇
排序方式: 共有1794条查询结果,搜索用时 15 毫秒
101.
This bibliography compiles references from 1970 to 1982 on ethical and legal issues in various areas of therapeutic practice. The 162 references are intended to provide resources to the practitioner that are easily accessible in the published literature. Works deal with child therapy, marital and family therapy, group therapy, behavior therapy, community work, forensic work, and testing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
102.
Two studies with 57 college students investigated the factors that cause persons to emerge as organizing categories during the initial classification of social information about individuals in groups. Preintegration categorization processes were studied using a speeded classification procedure for 4 social-information ensembles (unfamiliar and familiar names with high and low association values). Results suggest that person discriminability and strength of the person–feature association are important determinants of the categorization process. These findings emerged for both generic knowledge structures and newly developed person categories. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
103.
A video database of moving faces and people   总被引:3,自引:0,他引:3  
We describe a database of static images and video clips of human faces and people that is useful for testing algorithms for face and person recognition, head/eye tracking, and computer graphics modeling of natural human motions. For each person there are nine static "facial mug shots" and a series of video streams. The videos include a "moving facial mug shot," a facial speech clip, one or more dynamic facial expression clips, two gait videos, and a conversation video taken at a moderate distance from the camera. Complete data sets are available for 284 subjects and duplicate data sets, taken subsequent to the original set, are available for 229 subjects.  相似文献   
104.
Wall RS  Ashmead DH  Bentzen BL  Barlow J 《Ergonomics》2004,47(12):1318-1338
Typical audible pedestrian signals indicate when the pedestrian walk interval is in effect but provide little, or even misleading information for directional alignment. In three experiments, blind and blindfolded sighted adults crossed a simulated crossing with recorded traffic noise to approximate street sounds. This was done to investigate how characteristics of signal presentation affected usefulness of the auditory signal for guiding crossing behaviour. Crossing was more accurate when signals came only from the far end of the crossing rather than the typical practice of presenting signals simultaneously from both ends. Alternating the signal between ends of the crossing was not helpful. Also, the customary practice of signalling two parallel crossings at the same time drew participants somewhat toward the opposite crossing. Providing a locator tone at the end of the crossing during the pedestrian clearance interval improved crossing accuracy. These findings provide a basis for designing audible pedestrian signals to enhance directional guidance. The principal findings were the same for blind and sighted participants and applied across a range of specific signals (e.g. chirps, clicks, voices).  相似文献   
105.
Abstract

A system methodology for modeling and optimizing social systems is presented. It allows constructing dynamical models formulated stochastically, i.e., their results are given by confidence intervals. The models provide optimal intervention ways to reach the stated objectives. Two optimization methods are used: (1) to test strategies and scenarios and (2) to optimize with a genetic algorithm. The application case presented is a small nonformal education Spanish business. First, the model is validated in the 2008–2012 period, and subsequently, the optimal way to obtain a maximum profit in the 2013–2025 period is obtained using the two methods.  相似文献   
106.
Distributed machining control and monitoring using smart sensors/actuators   总被引:1,自引:1,他引:1  
The study of smart sensors and actuators led, during the past few years, to the development of facilities which improve traditional sensors and actuators in a necessary way to automate production systems. In another context, many studies have been carried out aimed at defining a decisional structure for production activity control and the increasing need of reactivity leads to the autonomization of decisional levels close to the operational system. We study in this paper the natural convergence between these two approaches and we propose an integration architecture, dealing with machine tool and machining control, that enables the exploitation of distributed smart sensors and actuators in the decisional system.  相似文献   
107.
Abstract

The strongest tradition of classroom‐environment research has focused on empirically testing the relationship between the classroom environment and student outcomes. This paper reports a study conducted within this general framework. Specifically, this research investigated the relationship between the classroom environment and self‐handicapping by students in Canadian high school mathematics classes. Results showed that the classroom environment accounted for appreciable proportions of variance in self‐handicapping, beyond that attributable to academic efficacy. Enhanced affective dimensions of the classroom environment were associated with reduced levels of self‐handicapping.  相似文献   
108.
109.
Mother-infant dyads grouped according to whether the infants had been delivered vaginally (n?=?74) or by planned (n?=?37) or unplanned cesarean (n?=?56) were compared on psychosocial outcomes at 4 and 12 months postpartum. Hypotheses were that unplanned cesarean delivery would be related to less optimal outcomes and that this relationship would be mediated by mother's appraisal of the delivery and would attenuate over time. No delivery-related differences in mother–infant interactions were found at 4 or 12 months postpartum with one exception: Women low in neuroticism who delivered by unplanned cesarean showed less positive affect toward their infants at 4 months than did women high in neuroticism who delivered by unplanned cesarean or women in any other group. There was some evidence of the mediating role of maternal appraisal of the delivery on these effects. In general, the results indicate little cause for concern about the quality of mother–infant interactions following cesarean deliveries. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
110.
Satellite images, along with oceanographic, meteorological, and whale aerial survey data, are used to illustrate aspects of ocean circulation associated with a bowhead whale feeding ‘hotspot’ near Barrow, Alaska. In response to weak winds, a strong front forms near the shelf-break along the southern edge of Barrow Canyon when the Alaska Coastal Current flows adjacent to the southern flank of Barrow Canyon or intrudes onto the western Beaufort shelf. This front is of particular local interest because it is indicative of aggregation and retention of zooplankton on the western Beaufort shelf and, as a result, is a locus for bowhead whales pausing to feed during their westward fall migration. Groups (4 or more individuals) of bowhead whales are primarily seen on the western Beaufort shelf following wind conditions that promote the formation of this front.  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