全文获取类型
收费全文 | 3610篇 |
免费 | 211篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 29篇 |
综合类 | 2篇 |
化学工业 | 926篇 |
金属工艺 | 78篇 |
机械仪表 | 85篇 |
建筑科学 | 137篇 |
矿业工程 | 12篇 |
能源动力 | 131篇 |
轻工业 | 269篇 |
水利工程 | 30篇 |
石油天然气 | 8篇 |
无线电 | 272篇 |
一般工业技术 | 747篇 |
冶金工业 | 484篇 |
原子能技术 | 17篇 |
自动化技术 | 597篇 |
出版年
2024年 | 10篇 |
2023年 | 53篇 |
2022年 | 122篇 |
2021年 | 172篇 |
2020年 | 89篇 |
2019年 | 84篇 |
2018年 | 125篇 |
2017年 | 114篇 |
2016年 | 122篇 |
2015年 | 103篇 |
2014年 | 164篇 |
2013年 | 255篇 |
2012年 | 225篇 |
2011年 | 285篇 |
2010年 | 206篇 |
2009年 | 167篇 |
2008年 | 172篇 |
2007年 | 182篇 |
2006年 | 120篇 |
2005年 | 103篇 |
2004年 | 101篇 |
2003年 | 88篇 |
2002年 | 79篇 |
2001年 | 43篇 |
2000年 | 39篇 |
1999年 | 37篇 |
1998年 | 72篇 |
1997年 | 70篇 |
1996年 | 36篇 |
1995年 | 36篇 |
1994年 | 27篇 |
1993年 | 25篇 |
1992年 | 24篇 |
1991年 | 16篇 |
1990年 | 28篇 |
1989年 | 18篇 |
1988年 | 11篇 |
1987年 | 9篇 |
1986年 | 11篇 |
1985年 | 17篇 |
1984年 | 9篇 |
1983年 | 13篇 |
1982年 | 9篇 |
1981年 | 13篇 |
1980年 | 11篇 |
1979年 | 10篇 |
1977年 | 9篇 |
1976年 | 21篇 |
1975年 | 8篇 |
1974年 | 9篇 |
排序方式: 共有3824条查询结果,搜索用时 15 毫秒
101.
Hoshino-Browne Etsuko; Zanna Adam S.; Spencer Steven J.; Zanna Mark P.; Kitayama Shinobu; Lackenbauer Sandra 《Canadian Metallurgical Quarterly》2005,89(3):294
Cognitive dissonance and effects of self-affirmation on dissonance arousal were examined cross-culturally. In Studies 1 and 2, European Canadians justified their choices more when they made them for themselves, whereas Asian Canadians (Study 1) or Japanese (Study 2) justified their choices more when they made them for a friend. In Study 3, an interdependent self-affirmation reduced dissonance for Asian Canadians but not for European Canadians. In Study 4, when Asian Canadians made choices for a friend, an independent self-affirmation reduced dissonance for bicultural Asian Canadians but not for monocultural Asian Canadians. These studies demonstrate that both Easterners and Westerners can experience dissonance, but culture shapes the situations in which dissonance is aroused and reduced. Implications of these cultural differences for theories of cognitive dissonance and self-affirmation are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
102.
In this paper the conjugate fluid flow and energy transport problem (involving conduction-convection-radiation heat transfer) resulting from the Czochralski crystal growth process is analysed. The solidifying material is treated as a pure and semitransparent substance with material properties depending neither on temperature nor on the wavelength. The solution of the problem is obtained iteratively using two computer codes: FLUENT, a commercial CFD package, and BEM-based in-house code capable of analysing the radiative heat transfer in the entire computational domain.Obtained results not only show velocity field and temperature distribution within the bodies under consideration but also demonstrate the influence of thermal radiation on these quantities. 相似文献
103.
This paper presents results of investigation of the stress sensitivity of the fluxgate sensor with amorphous alloy (CoFe)89(MnMoSiB)11 (Vitrovac 6150F) ring core. Stress was applied in two directions: perpendicularly to the flux density in the ring core or in the direction of diameter of the ring. The influence of mechanical stress from the external forces on magnetic properties of this ring core was measured. Then results of this testing were used in computer simulation of the influence of the stress on the output signal of the fluxgate sensor. 相似文献
104.
This paper presents the results of a study aimed at validating psychological questionnaires evaluating temperamental and personality features. It discusses their usefulness in diagnosing drivers’ aptitude for safe driving and working as professional drivers. Three psychological questionnaires were validated: the Formal Characteristics of Behaviour – Temperament Inventory (FCB-TI), the Eysenck Personality Questionnaire – Revised and Short Scale (EPQ-R (S)) and the Impulsiveness Questionnaire (IVE). Three groups of drivers (n = 246) aged 19–75 participated in the study. Group I (professional drivers; n = 96) and Group II (nonprofessional drivers; n = 75) had never been involved in road crashes, whereas Group III (nonprofessional drivers; n = 75) were offenders involved in fatal injury road crashes. Criterion-related validity, Cronbach's alpha and Guttman split-half reliability coefficient were in assessing the psychometric properties of the questionnaires. There were some significant differences between Groups II and III for most traits. However, contrary to expectations, higher Emotional Reactivity, Perseveration and lower Endurance as well as higher Neuroticism, Impulsiveness and Venturesomeness were determined for Group II than for Group III. Additionally, the temperament and personality profile of Group II turned out to be less fitted to the profile of safe drivers than that of Group III, whose profile was actually similar to that of Group I. This seems to result from a high tendency for a positive self-presentation among Group I and Group III (a significantly higher result on the Lie scale in comparison with Group II). The results suggest that if psychological tests are to decide on whether a person may be a professional driver or may drive vehicles, the three questionnaires (FCB-TI, EPQ-R(S) and IVE) do not provide a valid diagnosis of professional drivers’ aptitude because of drivers’ high tendency for positive self-presentation. However, they can be used in job counselling and in screening high-risk drivers. 相似文献
105.
106.
107.
Recent advances in the production of γ‐valerolactone from biomass‐derived feedstocks via heterogeneous catalytic transfer hydrogenation
下载免费PDF全文
![点击此处可从《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Amin Osatiashtiani Adam F Lee Karen Wilson 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2017,92(6):1125-1135
γ‐valerolactone (GVL) is an important intermediate chemical with a wide range of applications as fuel, fuel additive and as a green solvent which has received a great deal of attentions from both academia and industry. This review aims to summarise the advances in conversion of renewable feedstocks into GVL through heterogeneous catalytic transfer hydrogenation (CTH) with a strong emphasis on discussing preparation, characterisation and performance of the catalysts in order to provide a better understanding of various catalytic systems and also to compare them in terms of catalytic performance. © 2017 Society of Chemical Industry 相似文献
108.
Amazon’s online service, Mechanical Turk (MTurk) has become a popular option for data collection among social scientists. Early work (Buhrmester, Kwang, & Gosling, 2011) indicated that data collection through MTurk was faster and less expensive than traditional collection methods (undergraduate human subject pool), as well as being reliable when administered at different dates. Building on their work, we sought to extend this investigation of reliability to a larger measure. For the current research we chose a 120-item measure of personality. After collecting data through MTurk, it was determined that our MTurk sample had strong test–retest reliability, indicating that they did not significantly change between administration dates. 相似文献
109.
110.
Martina Halasova Zdenek Chlup Adam Strachota Martin Cerny Ivo Dlouhy 《Journal of the European Ceramic Society》2012,32(16):4489-4495
The presented work describes mechanical properties of materials prepared by the pyrolysis of polysiloxane resins. The polymeric precursors have different chemical composition. Materials under investigation are predetermined for high temperature resistant applications usually in composite form, i.e. accompanied by some reinforcement. Instrumented hardness tests were employed for material characterisation. The Vickers hardness, Martens hardness and indentation elastic modulus were the key parameters, determined either from the standard optical technique or load–indentation depth curves. The influence of mechanical properties on the monomers ratio was established. The exposition to the temperature between 1200 °C and 1500 °C in air was applied to observe damage caused by these severe conditions. 相似文献