全文获取类型
收费全文 | 1241篇 |
免费 | 90篇 |
专业分类
电工技术 | 6篇 |
综合类 | 4篇 |
化学工业 | 423篇 |
金属工艺 | 12篇 |
机械仪表 | 22篇 |
建筑科学 | 53篇 |
能源动力 | 17篇 |
轻工业 | 162篇 |
水利工程 | 11篇 |
石油天然气 | 1篇 |
无线电 | 61篇 |
一般工业技术 | 208篇 |
冶金工业 | 213篇 |
自动化技术 | 138篇 |
出版年
2024年 | 1篇 |
2023年 | 20篇 |
2022年 | 54篇 |
2021年 | 92篇 |
2020年 | 45篇 |
2019年 | 45篇 |
2018年 | 35篇 |
2017年 | 42篇 |
2016年 | 36篇 |
2015年 | 51篇 |
2014年 | 38篇 |
2013年 | 70篇 |
2012年 | 80篇 |
2011年 | 100篇 |
2010年 | 75篇 |
2009年 | 67篇 |
2008年 | 82篇 |
2007年 | 69篇 |
2006年 | 55篇 |
2005年 | 34篇 |
2004年 | 39篇 |
2003年 | 35篇 |
2002年 | 26篇 |
2001年 | 23篇 |
2000年 | 16篇 |
1999年 | 11篇 |
1998年 | 18篇 |
1997年 | 13篇 |
1996年 | 9篇 |
1995年 | 5篇 |
1994年 | 1篇 |
1993年 | 5篇 |
1992年 | 1篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1989年 | 3篇 |
1988年 | 7篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1985年 | 6篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 2篇 |
1979年 | 1篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1973年 | 1篇 |
排序方式: 共有1331条查询结果,搜索用时 781 毫秒
81.
Four studies present the validation of a self-report scale capturing academic entitlement, which is defined as the tendency to possess an expectation of academic success without a sense of personal responsibility for achieving that success. The Academic Entitlement scale possesses a 2-factor structure (Study 1); 10 items measure students’ Externalized Responsibility for their academic success, and 5 items measure students’ self-serving Entitled Expectations about professors and course policies. In Study 2, the Externalized Responsibility subscale correlated positively with related measures of entitlement, grandiosity, and narcissism, and it was negatively related to self-esteem, personal control, need for cognition, agreeableness, and conscientiousness. In Study 3, participants rated various responses to academic situations selected by university instructors as highly inappropriate or highly appropriate. The Academic Entitlement scale predicted students’ ratings of the appropriateness of these student behaviors as well as the likelihood that they themselves would engage in these behaviors. In a laboratory setting, individuals with high Academic Entitlement scores evaluated the researcher more negatively than those with low Academic Entitlement scores (Study 4). Practical applications are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
82.
83.
Rafael Salles Kurusu Nicole Raymonde Demarquette Catherine Gauthier Jean‐Marc Chenal 《Polymer International》2014,63(6):1085-1093
Poly(3‐hydroxybutyrate) (PHB) undergoes an ageing process that contributes to its remarkable fragility. Blending it with an elastomer is a possibility to increase toughness. In this work, the mechanical properties of a 70/30 wt% blend of PHB and poly(ethylene‐co‐methyl‐acrylate‐co‐glycidyl‐methacrylate) were studied over time. The phenomenon of ageing affected the blend, which lost its ductility and became fragile days after its processing. Differential scanning calorimetry and small angle X‐ray scattering analyses showed that this drop in mechanical properties was due to changes in the crystalline structure of the matrix. Annealing reduced fragility, increased toughness and prevented a re‐ageing of the blend. Biodegradation in soil was also more intense for annealed samples. © 2013 Society of Chemical Industry 相似文献
84.
Nicole Robinson 《建设机械技术与管理》2009,(12):I0043-I0044
一种新型超重吨位轮式起重机的伸缩臂如此大。以至于要分成两部分来运输才行.且其中的一段需要特种运输车来运输。 相似文献
85.
Phospholipid bilayer coatings for the separation of proteins in capillary electrophoresis 总被引:1,自引:0,他引:1
The double-chained, zwitterionic phospholipid 1,2-dilauroyl-sn-phosphatidylcholine (DLPC, C12) was investigated for its use as a wall coating for the prevention of protein adsorption in capillary electrophoresis. DLPC forms a semipermanent coating at the capillary wall, which allows excess phospholipid to be removed from the capillary prior to electrophoretic separation. A DLPC-coated capillary allowed for the separation of both cationic and anionic proteins with efficiencies as high as 1.4 million plates/m. Migration time reproducibility was less than 1.3% RSD from run to run and less than 4.0% RSD from day to day. Protein recovery was as high as 93%. Cationic and anionic proteins could be separated over a pH range of 3-10, all yielding good efficiencies (N up to 1 million plates/m). The chain length of the phospholipid affected the performance of the wall coating. The C10 analogue of DLPC (DDPC) did not form a coating on the capillary wall while the C14 analogue of DLPC (DMPC) formed a stable coating that prevented protein adsorption to the same extent as its C12 counterpart. 相似文献
86.
Dànielle Nicole DeVoss Author Vitae James E. Porter Author Vitae 《Computers and Composition》2006,23(2):178-210
This article discusses the Napster phenomenon and its cultural significance, traces some of the threads of the current “copyright crisis,” and connects these cultural and legal dynamics to show how the current filesharing context of digital environments pertains to issues affecting writing teachers. The article (1) urges writing teachers to view the Napster moment—and the writing practice at the center of it, filesharing—in terms of the rhetorical and economic dynamics of digital publishing and in the context of public battles about copyright and intellectual property and (2) argues that digital filesharing forms the basis for an emergent ethic of digital delivery, an ethic that should lead composition teachers to rethink pedagogical approaches and to revise plagiarism policies to recognize the value of filesharing and to acknowledge Fair Use as an ethic for digital composition. 相似文献
87.
We present a model that integrates the discrete working time choice of heterogenous households into a general equilibrium
setting where wages are determined by sectoral bargaining between firms and trade unions. The model is calibrated to German
micro and macro data. We then use it to analyse a stylised policy reform designed to stimulate labour supply.
JEL Code: D58, J22, J51
An erratum to this article can be found at 相似文献
88.
89.
90.
Need for recovery from work: evaluating short-term effects of working hours,patterns and schedules 总被引:1,自引:0,他引:1
In this paper working hours, patterns and work schedules of employees were evaluated in terms of need for recovery from work. Self-administered questionnaire data from employees of the Maastricht Cohort Study on Fatigue at Work (n = 12,095) were used. Poisson regression analyses and multivariate logistic regression analyses revealed that higher working hours a day and working hours a week generally went together with more need for recovery from work. Overtime work was particularly associated with higher need for recovery from work in both genders. Both male and female three-shift or irregular shift workers had higher odds of elevated need for recovery compared to day workers. When additionally controlling for work-related factors, need for recovery levels among shift workers substantially lowered. This study clearly showed that working hours and schedules are associated with need for recovery from work, with different associations for men and women. Especially the associations between work schedules and need for recovery from work were very interrelated with other work-related factors. Future studies could further investigate the possibility that shift work might function as a proxy of other work-related factors that explain the different levels in need for recovery from work, or that job demands are perceived higher among shift workers and may therefore lead to more need for recovery from work. 相似文献