全文获取类型
收费全文 | 1778篇 |
免费 | 16篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 10篇 |
化学工业 | 256篇 |
金属工艺 | 22篇 |
机械仪表 | 38篇 |
建筑科学 | 115篇 |
矿业工程 | 10篇 |
能源动力 | 28篇 |
轻工业 | 278篇 |
水利工程 | 12篇 |
石油天然气 | 5篇 |
无线电 | 91篇 |
一般工业技术 | 199篇 |
冶金工业 | 501篇 |
原子能技术 | 2篇 |
自动化技术 | 228篇 |
出版年
2024年 | 12篇 |
2023年 | 8篇 |
2022年 | 33篇 |
2021年 | 39篇 |
2020年 | 23篇 |
2019年 | 28篇 |
2018年 | 30篇 |
2017年 | 30篇 |
2016年 | 39篇 |
2015年 | 31篇 |
2014年 | 45篇 |
2013年 | 113篇 |
2012年 | 66篇 |
2011年 | 91篇 |
2010年 | 85篇 |
2009年 | 69篇 |
2008年 | 86篇 |
2007年 | 80篇 |
2006年 | 90篇 |
2005年 | 77篇 |
2004年 | 49篇 |
2003年 | 45篇 |
2002年 | 44篇 |
2001年 | 30篇 |
2000年 | 25篇 |
1999年 | 31篇 |
1998年 | 35篇 |
1997年 | 28篇 |
1996年 | 33篇 |
1995年 | 31篇 |
1994年 | 34篇 |
1993年 | 20篇 |
1992年 | 16篇 |
1991年 | 12篇 |
1990年 | 14篇 |
1989年 | 18篇 |
1988年 | 20篇 |
1987年 | 22篇 |
1986年 | 18篇 |
1985年 | 29篇 |
1984年 | 20篇 |
1983年 | 19篇 |
1982年 | 10篇 |
1981年 | 17篇 |
1980年 | 9篇 |
1979年 | 12篇 |
1978年 | 7篇 |
1976年 | 6篇 |
1975年 | 7篇 |
1974年 | 8篇 |
排序方式: 共有1795条查询结果,搜索用时 15 毫秒
991.
Msetfi Rachel M.; Murphy Robin A.; Simpson Jane; Kornbrot Diana E. 《Canadian Metallurgical Quarterly》2005,134(1):10
The perception of the effectiveness of instrumental actions is influenced by depressed mood. Depressive realism (DR) is the claim that depressed people are particularly accurate in evaluating instrumentality. In two experiments, the authors tested the DR hypothesis using an action-outcome contingency judgment task. DR effects were a function of intertrial interval length and outcome density, suggesting that depressed mood is accompanied by reduced contextual processing rather than increased judgment accuracy. The DR effect was observed only when participants were exposed to extended periods in which no actions or outcomes occurred. This implies that DR may result from an impairment in contextual processing rather than accurate but negative expectations. Therefore, DR is consistent with a cognitive distortion view of depression. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
992.
In this study, the authors investigated the relationship between autobiographical memory and the onset and maintenance of distressing memories following cancer. In Study 1, participants recently diagnosed with head, neck, or lung cancer were assessed for acute stress disorder (ASD). Participants with ASD reported fewer specific memories than did participants without ASD. In Study 2, the same participants were assessed 6 months later for autobiographical memory and cancer-related posttraumatic stress disorder (PTSD). Deficits in the retrieval of specific memories in Study 1 were not predictive of subsequent PTSD. Increased hopelessness during the 6 months was associated with a decline in the retrieval of positive memories and an increase in the retrieval of negative memories. These findings accord with propositions that retrieval of distressing memories is guided by current self-image and attitude toward one's future. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
993.
This study investigated the predictors of posttraumatic stress disorder (PTSD) following a diagnosis of cancer. Individuals who were recently diagnosed with 1st onset head and neck or lung malignancy (N = 82) were assessed within 1 month of diagnosis for acute stress disorder (ASD) and other psychological responses including depression; individuals were reassessed (N = 63) for PTSD 6 months following their cancer diagnosis. At the initial assessment ASD was diagnosed in 28% of participants, and 22% met criteria for PTSD at 6-months follow-up. Peritraumatic dissociative symptoms at the time of receiving one's cancer diagnosis was the sole predictor of PTSD severity at 6-months follow-up. Elevated dissociative symptoms and greater distress at the initial assessment were the best predictors of PTSD caseness at 6-months follow-up. This study provides evidence for identifying recently diagnosed cancer patients who may benefit from psychological assistance in order to prevent chronic psychopathology. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
994.
Netz Yael; Wu Meng-Jia; Becker Betsy Jane; Tenenbaum Gershon 《Canadian Metallurgical Quarterly》2005,20(2):272
A meta-analysis examined data from 36 studies linking physical activity to well-being in older adults without clinical disorders. The weighted mean-change effect size for treatment groups (dC. = 0.24) was almost 3 times the mean for control groups (dC. = 0.09). Aerobic training was most beneficial (dC. = 0.29), and moderate intensity activity was the most beneficial activity level (dC. = 0.34). Longer exercise duration was less beneficial for several types of well-being, though findings are inconclusive. Physical activity had the strongest effects on self-efficacy (dC.= 0.38), and improvements in cardiovascular status, strength, and functional capacity were linked to well-being improvement overall. Social-cognitive theory is used to explain the effect of physical activity on well-being. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
995.
The Kyoto Protocol's clean development mechanism (CDM) was established in 1997 with the dual purposes of assisting non-Annex I Parties in achieving sustainable development and assisting Annex I Parties in achieving compliance with their quantified greenhouse gas (GHG) emission commitments. This paper looks at the development of the CDM portfolio as well as achievements of the CDM to date in the context of wider private and public flows of investment into developing countries. These achievements include the development of 325 (by May 2005) proposed CDM projects which are together expected to generate more than 79 Mt CO2-eq credits/year during 2008–2012, increasing awareness of climate change mitigation options among possible investors and others that may facilitate transactions (i.e. governments), and the strengthening of climate-relevant institutions within countries. The paper also draws lessons from this experience to date, and outlines what changes may be needed to transform the CDM concept to a broader scale after the end of the first commitment period in 2012. 相似文献
996.
Jane 《国外纺织技术(纺织针织服装化纤染整)》2008,(6)
任馨侧记二三事:第一次接触任馨,是在某论坛的筹备会上,她娇小地窝在角落的一张椅子里,低调而随意的黑色穿着,在她说话之前,我一直以为她是任馨的助理。第二天,她坐在论坛的主席台上,一身典型的LIZZY活动装,高贵而不失亲和,简约而充满张力,很像个董事长兼设计总监,我有瞬间的恍惚。真正激起我的新闻敏感的是一通电话。我跟LIZZY公司要一些资料,半个小时后一个手机号码打过来,您好,我是任馨,我刚刚在开车,现在才回复您,不好意思。……我的大脑有两秒的当机,我没想到回复我的会是一个老总,而且还用她的手机,而且刚刚过了半个小时还不好意思,那时我对于她的概念应该还仅仅是一个对不上名字和人的陌生小记者。 相似文献
997.
In this work we introduce Bio-PEPA, a process algebra for the modelling and the analysis of biochemical networks. It is a modification of PEPA to deal with some features of biological models, such as stoichiometry and the use of generic kinetic laws. Bio-PEPA may be seen as an intermediate, formal, compositional representation of biological systems, on which different kinds of analysis can be carried out. Finally, we show a representation of a model, concerning a simple genetic network, in the new language. 相似文献
998.
The effector dependence of automatic imitation was investigated using a stimulus–response compatibility (SRC) procedure during which participants were required to make an open or closed response with their hand or their mouth. The correct response for each trial was indicated by a pair of letters in Experiments 1 and 2 and by a colored square in Experiment 3. Each of these imperative stimuli was accompanied by task-irrelevant action images depicting a hand or mouth opening or closing. In relation to the response, the irrelevant stimulus was movement compatible or movement incompatible, and effector compatible or effector incompatible. A movement compatibility effect was observed for both hand and mouth responses. These movement compatibility effects were present when the irrelevant stimulus was effector compatible and when it was effector incompatible, but were smaller when the irrelevant stimulus and response effectors were incompatible. Consistent with the associative sequence learning (ASL) model of imitation, these findings indicate that automatic imitation is partially effector dependent and therefore that the effector dependence of intentional imitation reflects, at least in part, the nature of the mechanisms that mediate visuomotor translation for imitation. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
999.
Steinberg and Monahan's (2011) reanalysis of the Teen Media longitudinal survey of adolescents does not meet prevailing standards for propensity score analysis and therefore does not undermine the original conclusions of the Brown, L'Engle, Pardun, Guo, Kenneavy, and Jackson (2006) analysis. The media do matter in the sexual socialization of adolescents. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
1000.
Objective: We examined the direct and indirect impact of minority stress on mental health and substance use among sexual minority women. Method: A combination of snowball and targeted sampling strategies was used to recruit lesbian and bisexual women (N = 1,381) for a cross-sectional, online survey. Participants (M age = 33.54 years; 74% White) completed a questionnaire assessing gender expression, minority stressors (i.e., victimization, internalized homophobia, and concealment), social–psychological resources (i.e., social support, spirituality), and health-related outcomes. We used structural equation modeling to test associations among these factors, with gender expression as an antecedent and social–psychological resources as a mediator between minority stress and health. Results: The final model demonstrated acceptable fit, χ2(79) = 414.00, p confirmatory fit index = .93, Tucker–Lewis index = .91, standardized root-mean-square residual = .05, root-mean-square error of approximation = .06, accounting for significant portions of the variance in mental health problems (56%) and substance use (14%), as well as the mediator social–psychological resources (24%). Beyond indirect effects of minority stress on health outcomes, direct links emerged between victimization and substance use and between internalized homophobia and substance use. Conclusions: Findings indicate a significant impact of minority stressors and social–psychological resources on mental health and substance use among sexual minority women. The results improve understanding of the distinct role of various minority stressors and their mechanisms on health outcomes. Health care professionals should assess for minority stress and coping resources and refer for evidence-based psychosocial treatments. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献