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   586篇
  免费   5篇
电工技术   6篇
化学工业   57篇
金属工艺   11篇
机械仪表   5篇
建筑科学   22篇
矿业工程   9篇
能源动力   25篇
轻工业   40篇
水利工程   5篇
石油天然气   3篇
无线电   26篇
一般工业技术   38篇
冶金工业   256篇
原子能技术   9篇
自动化技术   79篇
  2021年   4篇
  2019年   3篇
  2018年   5篇
  2017年   4篇
  2016年   5篇
  2015年   8篇
  2014年   10篇
  2013年   37篇
  2012年   14篇
  2011年   23篇
  2010年   12篇
  2009年   11篇
  2008年   23篇
  2007年   23篇
  2006年   32篇
  2005年   19篇
  2004年   23篇
  2003年   7篇
  2002年   13篇
  2001年   13篇
  2000年   15篇
  1999年   19篇
  1998年   16篇
  1997年   14篇
  1996年   14篇
  1995年   22篇
  1994年   17篇
  1993年   18篇
  1992年   18篇
  1991年   3篇
  1990年   18篇
  1989年   11篇
  1988年   6篇
  1987年   7篇
  1986年   11篇
  1985年   11篇
  1984年   10篇
  1983年   5篇
  1982年   11篇
  1981年   8篇
  1980年   9篇
  1977年   6篇
  1976年   3篇
  1975年   5篇
  1974年   5篇
  1973年   3篇
  1971年   2篇
  1969年   2篇
  1967年   2篇
  1966年   2篇
排序方式: 共有591条查询结果,搜索用时 31 毫秒
81.
Expert panels and governmental guidelines now recommend that obese persons seek modest (i.e., "reasonable") reductions in body weight rather than striving for "ideal" weights. Little is known, however, about patients' views of what is a "reasonable" weight loss. This study assessed patients' goals, expectations, and evaluations of various outcomes before, during, and after 48 weeks of treatment. Before treatment, 60 obese women (99.1?±?12.3 kg; body mass index of 36.3?±?4.3 kg/m–2) defined their goal weight and 4 other weights: "dream weight"; "happy weight"; "acceptable weight"; and "disappointed weight." Goal weight averaged a 32% reduction in body weight. A 17-kg weight loss was defined as disappointed; a 25-kg loss, was acceptable. After 48 weeks of treatment and a 16-kg weight loss, 47% of patients did not achieve even a disappointed weight. These data illustrate the dramatic disparity between patients' expectations and professional recommendations and the need to help patients accept more modest weight loss outcomes. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
82.
Reviews the literature that discusses the treatment of sexual problems experienced by spinal-cord-injured (SCI) persons. The effects of SCIs on sexual response and performance are described. Sex therapy interventions including support, education, behavioral and couple modifications, and intrapsychic changes are outlined. Suggestions for helping SCI clients express their sexuality are offered. (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
83.
An investigation was conducted into the feasibility of applying a nearest neighbor algorithm to the problem of recognizing electromyographic (EMG) signal patterns for prosthesis control. A nearest neighbor algorithm correctly identified arm motions as belonging to one of six pattern classes from 72 to 100 percent of the time. A condensed nearest neighbor classifier was constructed to determine what minimum number of vectors was necessary in the look-up table.  相似文献   
84.
Yeast flora present in minced beef before and after radurisation were examined. No reduction in the number of yeast cells was observed after the meat was radurised at a dose of 2.5 kGy. A definite increase in the number of psychrotrophic yeast was observed in radurised meat after 14 days of storage at 4°C. The recovered yeast flora comprised representatives of the following species: Candida famata (9 isolates); C. lipolytica (4 isolates); C. parapsilosis (20 isolates); C. sake (27 isolates); C. zeylanoides (28 isolates); Cryptococcus albidus var. albidus (6 isolates); Cr. infirmo-miniatus (1 isolate); Cr. laurentii var. laurentii (31 isolates); Trichosporon cutaneum (1 isolate); Tr. pullulans (2 isolates); Rhodotorula minuta var. texensis (1 isolate); Rh. rubra (1 isolate).  相似文献   
85.
Data from a cohort of relatively high functioning, older men and women were used to test the hypothesis that stronger self-efficacy beliefs predict better maintenance of cognitive performance. Structural equation modeling revealed that stronger baseline instrumental efficacy beliefs predicted better verbal memory performance at follow-up among men but not among women, controlling for baseline verbal memory score and sociodemographic and health status characteristics. For both men and women there were no significant associations between either type of self-efficacy beliefs and measures of nonverbal memory, abstraction, or spatial ability. Consistent with previous research showing relationships between baseline cognitive performance and change in self-efficacy beliefs, better abstraction ability was also predictive of increases in instrumental efficacy beliefs among the men. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
86.
Examined the effect of imagery on implicit and explicit tests of memory in young and old adults. 48 undergraduates (mean age 21 yrs) and 64 adults (mean age 72.48 yrs) in Canada were presented with 2 separate word lists in a random order and were assigned to imagery or no-imagery instruction conditions. Ss in the imagery instruction condition read the words to themselves, formed a mental image of it, and rated their ability to do so. Ss in the no-imagery instruction condition simply read the words. All Ss were tested on explicit or implicit memory tests and asked to describe the mnemonic strategies used. Results show that imaging the referent of a visually-presented word improved the performance of the young Ss on the explicit memory test, but reduced their performance on the implicit test. Results of the elderly Ss showed a similar trend but did not reach the level of significance observed for young adults. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
87.
This study tested the effects of a 10-week group cognitive–behavioral stress management (CBSM) intervention on mood and immunologic parameters in HIV-seropositive gay men whose disease had progressed to a symptomatic stage. Men were randomized to either CBSM or a modified waiting-list control group. The CBSM intervention significantly decreased self-reported dysphoria, anxiety, and total distress. Individuals who practiced relaxation more consistently had significantly greater drops in dysphoria. The intervention also decreased herpes simplex virus-Type 2 (HSV-2) immunoglobulin G antibody titers. The control group showed no significant changes in either mood or antibody titers. Individual difference analyses revealed that decreases in dysphoria significantly predicted lower HSV-2 antibody titers by the end of the 10-week period. Neither group displayed changes in HSV-Type I antibody titers or in CD4+ or CD8+ cell numbers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
88.
Separate and combined effects of nicotine (NIC) and the nicotinic antagonist mecamylamine (MEC) were studied. 12 smokers rated test cigarettes after administration of MEC vs placebo capsules and NIC vs non-NIC preload. Smoking withdrawal symptoms, task performance, and cardiovascular activity were also measured. MEC attenuated smoking satisfaction, liking, and airway sensations. The NIC preload similarly reduced the enjoyable aspects of subsequent test cigarettes, and this action of the preload was not prevented by MEC. In contrast, MEC blocked NIC-related increases in heart rate and systolic blood pressure. Conversely, NIC counteracted MEC's effects on tapping speed and orthostatic blood pressure response. Although each drug offset potential side effects of the other, they acted in unison to attenuate smoking satisfaction and should be evaluated in combination for smoking cessation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
89.
This article describes an algorithm for incremental parsing of expressions in the context of syntax-directed editors for programming languages. Since a syntax-directed editor represents programs as trees and statements and expressions as nodes in trees, making minor modifications in an expression can be difficult. Consider, for example, changing a “ + ” operator to a “1” operator or adding a short subexpression at a syntactically but not structurally correct position, such as inserting “) 1 (d“ at the # mark in” (a + b # + c)”. To make these changes in a typical syntax-directed editor, the user must understand the tree structure and type a number of tree-oriented construction and manipulation commands. This article describes an algorithm that allows the user to think in terms of the syntax of the expression as it is displayed on the screen (in infix notation) rather than in terms of its internal representation (which is effectively prefix), while maintaining the benefits of syntax-directed editing. This algorithm is significantly different from other incremental parsing algorithms in that it does not involve modifications to a traditional parsing algorithm or the overhead of maintaining a parser stack or any data structure other than the syntax tree. Instead, the algorithm applies tree transformations, in real-time as each token is inserted or deleted, to maintain a correct syntax tree.  相似文献   
90.
Examined (a) differences in physiological response of Type A and Type B individuals to conditions that varied in both controllability and consistency of controllability over an aversive stimulus and (b) whether Type A relative to Type B individuals use more denial and/or projection in cognitively coping with arousing situations as well as whether they differ in being preoccupied in such situations. 96 male undergraduates were randomly assigned to 1 of 4 conditions: no control over shock, consistent control over shock, intermittent control over shock, and low stress. Type A and B behaviors were assessed with the Activity scale of the Thurstone Temperament Schedule. Results indicated that relative to Type B Ss, Type A's manifested (a) greater pulse rates and systolic and diastolic blood pressure in the consistent control condition, (b) greater systolic blood pressure in the no-control condition, and (c) greater diastolic blood pressure in the intermittent control condition. Type A's also used more denial and projection across the 3 high-stress conditions but did not differ in how preoccupied they were as compared to Type B's. (39 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  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