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   202篇
  免费   3篇
  国内免费   1篇
电工技术   3篇
化学工业   9篇
能源动力   4篇
轻工业   8篇
水利工程   1篇
无线电   24篇
一般工业技术   9篇
冶金工业   91篇
原子能技术   3篇
自动化技术   54篇
  2023年   1篇
  2021年   1篇
  2018年   2篇
  2017年   2篇
  2016年   3篇
  2014年   3篇
  2013年   4篇
  2012年   6篇
  2011年   1篇
  2010年   7篇
  2009年   5篇
  2008年   12篇
  2007年   3篇
  2006年   10篇
  2005年   3篇
  2004年   9篇
  2003年   6篇
  2002年   3篇
  2001年   5篇
  2000年   4篇
  1999年   6篇
  1998年   14篇
  1997年   9篇
  1996年   7篇
  1995年   4篇
  1994年   10篇
  1993年   2篇
  1991年   4篇
  1990年   2篇
  1989年   7篇
  1988年   3篇
  1987年   2篇
  1986年   1篇
  1985年   4篇
  1984年   2篇
  1983年   4篇
  1982年   3篇
  1981年   3篇
  1980年   4篇
  1979年   7篇
  1978年   4篇
  1977年   3篇
  1976年   1篇
  1975年   2篇
  1974年   1篇
  1973年   2篇
  1971年   1篇
  1970年   2篇
  1968年   2篇
排序方式: 共有206条查询结果,搜索用时 15 毫秒
71.
Automated telephone messaging systems have dramatically expanded communication about health service appointments, but few studies have directly investigated these messages. The present study investigated whether message repetition (1, 2, or 3 presentations) and listener age (mean age = 71 or 19 years) improved memory for automated appointment messages. Repetition improved older and younger adult memory for appointment information. Moreover, 2 presentations reduced age differences in accuracy of answering questions about the messages. This was not the case for free recall, suggesting that older adults differentially benefited from repetition only when provided with additional retrieval support. These findings show that older as well as younger adults benefit from at least 1 repetition of appointment messages. Actual or potential applications of this research include the use of repetition to improve comprehension of automated telephone messages.  相似文献   
72.
73.
Previous research has shown that dispositional optimism is a prospective predictor of successful adaptation to stressful encounters. In this research we attempted to identify possible mechanisms underlying these effects by examining how optimists differ from pessimists in the kinds of coping strategies that they use. The results of two separate studies revealed modest but reliable positive correlations between optimism and problem-focused coping, seeking of social support, and emphasizing positive aspects of the stressful situation. Pessimism was associated with denial and distancing (Study 1), with focusing on stressful feelings, and with disengagement from the goal with which the stressor was interfering (Study 2). Study 1 also found a positive association between optimism and acceptance/resignation, but only when the event was construed as uncontrollable. Discussion centers on the implications of these findings for understanding the meaning of people's coping efforts in stressful circumstances. (42 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
74.
The authors tested whether dispositional pessimism would predict withdrawal from social activities among women treated for breast cancer. In a cross-sectional sample 3-12 months postsurgery, disruption of social and recreational activities (measured by the Sickness Impact Profile) correlated with concurrently assessed pessimism. This association appeared mediated by emotional distress and fatigue. A longitudinal sample was studied shortly postsurgery and over the next year. Initial pessimism predicted disruption of social activities concurrently and prospectively (3, 6, and 12 months later) but predicted change in disruption from one time to the next only at final follow-up. These associations appeared partially mediated by distress. The authors conclude that pessimism places patients at risk for adverse outcomes in several respects rather than solely with regard to emotional distress. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
75.
ASSERT-4 is a subchannel code based on the non-equilibrium equations of two-fluid flow. The paper briefly describes the equations and constitutive models used in the code, and reviews a number of validation exercises in which code results were compared to measurements in vertical and horizontal two-phase flows.  相似文献   
76.
Research has shown that resource allocation in a dyad sometimes follows the principle of equity (proportional reward) and sometimes that of parity (equal reward). However, existing evidence does not clarify the conditions under which each of these rules is invoked. A number of theorists have suggested that salience of the other as a person should lead to parity-based allocation, whereas salience of the other as a functionary filling a role should lead to equity-based allocation. The present study with 60 male and 60 female undergraduates tested these possibilities. Ss were led to perceive their own inputs to group performance as being either substantially lower or substantially higher than a partner's inputs. The partner had been portrayed to the S in terms that made salient the partner's personal characteristics, the partner's role assignment, or neither of these. Among females, subsequent reward allocation followed the predicted pattern in both high- and low-input conditions. Among males, contrary to expectation, person salience led to heightened feelings of competitiveness and to increased allocations to the self. (22 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
77.
78.
The first prestressed segmental concrete bridge in the United States opened to traffic was a small bridge in Madison County, Tennessee. The bridge was constructed using prestressed concrete segments and was opened to traffic in October 1950. Prestressed concrete beams were placed side by side to form the superstructure of the bridge. The construction of this bridge and several other similar prestressed concrete bridges are described herein. The existing condition of eleven prestressed concrete bridges remaining in Tennessee is given. Only minor spalling, leaching, and horizontal cracking are present in the superstructure after fifty years of service. Many of the design features introduced in this design can be found in today’s modern precast segmental concrete bridges.  相似文献   
79.
An aircraft experiment was conducted in early summer of 1981 to determine the feasibility of optical and microwave remote sensing techniques for the detection of fully developed and incipient saline seeps in South Dakota and Montana. The NASA C-130 earth resources aircraft was used to acquire L-band and C-band scatterometer data (backscattering coefficient profiles), radiometer data (brightness temperature profiles), and color-infrared photography; additional passive microwave data and thermal images were acquired by the L- band radiometer on the Beechcraft D-18 aircraft operated by South Dakota State University. Intensive soil moisture and salinity data were collected on a uniform 20-m grid spacing and at several depths for the 600 × 600 m South Dakota site. The two Montana sites were over-flown with flight lines several kilometers in length, and ground truth information was obtained by identifying known geological and geohydrological units with varying soil salinities on a regional basis. The C-130 radiometers (both L- and C-bands) were effective in detecting wet soil areas including fully developed seeps; however, incipient seeps were not accurately detected by the radiometers. The D-18 L-band radiometer data did not appear to be sensitive to soil wetness. The C-130 scatterometer data profiles, although showing some sensitivity to soil moisture, were greatly influenced by surface roughness and appear to be ineffective in accurately delineating either fully developed or incipient seeps. Thermal-IR scanner data acquired by the D-18 aircraft did not appear to provide a reliable means for identifying potential seeps.  相似文献   
80.
This paper tutorially describes mixed digital-analog serial multiplexers (scanners) that we use to visualize the activity of one- and two-dimensional arrays of analog VLSI elements. These scanners range from simple one-dimensional devices designed to scan a one-dimensional array onto an oscilloscope, to complete video scanners with integrated sync and blank computation and on-chip video amplifiers. We discuss practical details of design and performance, and we give a source for example scanner layout.  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