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   516篇
  免费   7篇
化学工业   98篇
金属工艺   5篇
机械仪表   9篇
建筑科学   16篇
矿业工程   11篇
能源动力   10篇
轻工业   28篇
水利工程   9篇
无线电   22篇
一般工业技术   65篇
冶金工业   184篇
自动化技术   66篇
  2024年   3篇
  2023年   2篇
  2022年   4篇
  2021年   6篇
  2020年   3篇
  2019年   4篇
  2018年   12篇
  2017年   2篇
  2016年   6篇
  2015年   2篇
  2014年   11篇
  2013年   28篇
  2012年   17篇
  2011年   31篇
  2010年   18篇
  2009年   29篇
  2008年   30篇
  2007年   29篇
  2006年   23篇
  2005年   19篇
  2004年   15篇
  2003年   15篇
  2002年   17篇
  2001年   14篇
  2000年   12篇
  1999年   17篇
  1998年   21篇
  1997年   14篇
  1996年   13篇
  1995年   10篇
  1994年   11篇
  1993年   15篇
  1992年   6篇
  1991年   5篇
  1990年   10篇
  1989年   4篇
  1988年   7篇
  1987年   6篇
  1986年   4篇
  1985年   6篇
  1984年   4篇
  1983年   2篇
  1982年   2篇
  1980年   1篇
  1979年   3篇
  1978年   2篇
  1976年   3篇
  1974年   1篇
  1971年   2篇
  1967年   1篇
排序方式: 共有523条查询结果,搜索用时 234 毫秒
51.
Holographic reprocessing (HR) facilitates holistic reappraisal of attributions regarding interpersonal violence and maltreatment. The authors tested the feasibility to train therapists to run a protocol using HR to reduce negative thoughts associated with posttraumatic stress disorder (PTSD) in women veterans who have had sexual trauma or abuse. The study assessed pre- and postscores on the Posttraumatic Cognitions Inventory (PTCI) in a naturalistic clinical setting with 5 therapists. The protocol consisted of screening for PTSD, followed by an average of 9 HR treatment sessions. Twenty-two women were referred to the study; 17 enrolled and completed treatment (0% dropout rate). Significant decreases were found on all scales of the PTCI, with large effect sizes: total negative thoughts, t(16) = 4.42, p  相似文献   
52.
Applying optimal stimulation theory, the present study explored the development of sustained attention as a dynamic process. It examined the interaction of modality and temperament over time in children and adults. Second-grade children and college-aged adults performed auditory and visual vigilance tasks. Using the Carey temperament questionnaires (S. C. McDevitt & W. B. Carey, 1995), the authors classified participants according to temperament composites of reactivity and task orientation. In a preliminary study, tasks were equated across age and modality using d= matching procedures. In the main experiment, 48 children and 48 adults performed these calibrated tasks. The auditory task proved more difficult for both children and adults. Intermodal relations changed with age: Performance across modality was significantly correlated for children but not for adults. Although temperament did not significantly predict performance in adults, it did for children. The temperament effects observed in children-specifically in those with the composite of reactivity-occurred in connection with the auditory task and in a manner consistent with theoretical predictions derived from optimal stimulation theory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
53.
The tetragonal tungsten bronze (TTB) type of Sr x Ba1− x m Nb2O6 (SBN) (0.5 ≤ x ≤ 0.75) was synthesized by a mixed-oxide route. Using the two-step densification process of pressureless sintering followed by oxygen HIPing, transparent ceramics were successfully fabricated. Microstructural, dielectric, optical, and electrooptic properties were investigated. All single-phase TTB-type SBN showed the characteristics of relaxor ferroelectrics. The extinction coefficients of the sample with the highest transparency were calculated from transmission spectra to be 30.4, 5.8, and 2.4 cm−1 at 600, 1450, and 2000 nm, respectively. The linear electrooptic coefficients for SBN55, r 33 and r 13, were 46 × 10−12 and 21 × 10−12 m/V at 633 nm, respectively.  相似文献   
54.
This article develops and tests a structurally based, integrated theory of person-team fit. The theory developed is an extension of structural contingency theory and considers issues of external fit simultaneously with its examination of internal fit at the team level. Results from 80 teams working on an interdependent team task indicate that divisional structures demand high levels of cognitive ability on the part of teammembers. However, the advantages of high cognitive ability in divisional structures are neutralized when there is poor external fit between the structure and the environment. Instead, emotional stability becomes a critical factor among teammembers when a divisional structure is out of alignment with its environment. Individual differences seem to play little or no role in functional structures, regardless of the degree of external fit. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
55.
This article addresses concerns raised about F. D. Fincham, P. C. Garnier, S. Gano-Phillips, and L. N. Osborne's (1995) study by placing it in the context of current marital research. Studies of marriage-related cognitions have centered on the content of cognitions and have ignored the cognitive processes that give rise to them. Therefore, little is known about spousal cognitions that are unavailable for self-report or about the role of cognitive processes in initiating, maintaining, or alleviating marital distress. Reaction time has the potential to be one of several variables that can be used to investigate such processes. The challenge faced by marital researchers is to incorporate the information-processing paradigm into their work, thereby integrating it with broader literatures in cognitive psychology and social cognition. Failure to do so will leave marital researchers with an incomplete picture of marriage. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
56.
Characterizing perceived injustice as a form of stress, we examined the main and interactive relationships among interactional, procedural, and distributive injustice and psychological strain while controlling for job insecurity. Using moderated multiple regression analysis with a sample of 1,083 government employees, we show that interactional, procedural, and distributive injustice are all unique predictors of psychological strain that account for significant unique variance beyond that explained by job insecurity. Those individuals who perceive more interactional, procedural, or distributive injustice at work reported a higher degree of strain. However, there were no significant interactive effects, suggesting that these three categories of perceived injustice do not interact to predict symptoms of psychological strain. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
57.
The literature has identified housing as a fundamental unmet need for people living with HIV; yet there has been little qualitative evidence exploring housing and HIV, particularly from a Canadian context. This paper focuses on our qualitative analyses of the housing experiences of 48 HIV-positive people living in Ontario. Findings from our interviews illustrate healthy housing as a dynamic interconnection between health, housing and other social factors that are influential to the health and well-being of people with HIV. Four salient themes have emerged from our qualitative findings: the interplay between healthy housing and economic security; the relationship between HIV, health and housing precariousness; the interconnection between housing, HIV, safety, stigma, social isolation and social exclusion; and the meaning of healthy housing for people living with HIV. These findings re-emphasize the importance of housing policies that consider housing as more than just a roof over one’s head, but also as something that supports the physical, mental, emotional and social well-being of people living with HIV.  相似文献   
58.
Reactions of methylglyoxal with amino acids, methylamine, and ammonium sulfate can take place in aqueous aerosol and evaporating cloud droplets. These processes are simulated by drying droplets and bulk solutions of these compounds (at low millimolar and 1 M concentrations, respectively) and analyzing the residuals by scanning mobility particle sizing, nuclear magnetic resonance, aerosol mass spectrometry (AMS), and electrospray ionization MS. The results are consistent with imine (but not diimine) formation on a time scale of seconds, followed by the formation of nitrogen-containing oligomers, methylimidazole, and dimethylimidazole products on a time scale of minutes to hours. Measured elemental ratios are consistent with imidazoles and oligomers being major reaction products, while effective aerosol densities suggest extensive reactions take place within minutes. These reactions may be a source of the light-absorbing, nitrogen-containing oligomers observed in urban and biomass-burning aerosol particles.  相似文献   
59.
Bottlenose dolphins (Tursiops truncatus) are apex predators in coastal southeastern U.S. waters; as such they are indicators of persistent organic pollutants (POPs) in coastal ecosystems. POP concentrations measured in a dolphin's blubber are influenced by a number of factors, including the animal's sex and ranging pattern in relation to POP point sources. This study examined POP concentrations measured in bottlenose dolphin blubber samples (n = 102) from the Georgia, USA coast in relation to individual ranging patterns and specifically, distance of sightings from a polychlorinated biphenyl (PCB) point source near Brunswick, Georgia. Dolphin ranging patterns were determined based upon 5 years of photo-identification data from two field sites approximately 40 km apart: (1) the Brunswick field site, which included the Turtle/Brunswick River Estuary (TBRE), and (2) the Sapelo field site, which included the Sapelo Island National Estuarine Research Reserve (SINERR). Dolphins were categorized into one of three ranging patterns from photo-identification data. Individuals with sighting histories exclusively within one of the defined field sites were considered to have either Brunswick or Sapelo ranging patterns. Individuals sighted in both field sites were classified as having a Mixed ranging pattern. Brunswick males had the highest concentrations of PCBs reported for any marine mammal. The pattern of PCB congeners was consistent with Aroclor 1268, a highly chlorinated PCB mixture associated with a Superfund site in Brunswick. PCB levels in Sapelo males were lower than in Brunswick males, but comparable to the highest levels measured in other dolphin populations along the southeastern U.S. Female dolphins had higher Aroclor 1268 proportions than males, suggesting that the highly chlorinated congeners associated with Aroclor 1268 may not be offloaded through parturition and lactation, as easily as less halogenated POPs. Individuals sighted farther from the Superfund point source had lower Aroclor 1268 proportions.  相似文献   
60.
The effects of number of predictors, predictor intercorrelations, validity, and level of subgroup difference on composite validity, adverse impact ratios, and mean subgroup difference associated with various predictor composites, including and excluding a "high impact" ability measure, were assessed. The size of subgroup differences is substantially smaller when low-impact predictors are combined with a high-impact predictor, but hiring ratios for majority and minority groups still indicate a prima facie case of discrimination, using the fourth-fifths rule for most predictor-criterion combinations. However, the validity of a composite of alternate predictors and cognitive ability may exceed the validity of cognitive ability alone and reduce the size of subgroup differences. (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