全文获取类型
收费全文 | 293篇 |
免费 | 9篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 77篇 |
金属工艺 | 1篇 |
机械仪表 | 5篇 |
建筑科学 | 12篇 |
矿业工程 | 4篇 |
能源动力 | 10篇 |
轻工业 | 22篇 |
水利工程 | 8篇 |
石油天然气 | 2篇 |
无线电 | 29篇 |
一般工业技术 | 34篇 |
冶金工业 | 47篇 |
原子能技术 | 1篇 |
自动化技术 | 49篇 |
出版年
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 10篇 |
2020年 | 7篇 |
2019年 | 6篇 |
2018年 | 7篇 |
2017年 | 6篇 |
2016年 | 8篇 |
2015年 | 3篇 |
2014年 | 11篇 |
2013年 | 17篇 |
2012年 | 9篇 |
2011年 | 19篇 |
2010年 | 10篇 |
2009年 | 12篇 |
2008年 | 13篇 |
2007年 | 9篇 |
2006年 | 5篇 |
2005年 | 6篇 |
2004年 | 10篇 |
2003年 | 10篇 |
2002年 | 5篇 |
2000年 | 6篇 |
1999年 | 3篇 |
1998年 | 7篇 |
1997年 | 5篇 |
1996年 | 2篇 |
1994年 | 4篇 |
1993年 | 3篇 |
1991年 | 6篇 |
1990年 | 2篇 |
1989年 | 4篇 |
1988年 | 5篇 |
1987年 | 2篇 |
1986年 | 2篇 |
1984年 | 5篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1980年 | 2篇 |
1979年 | 7篇 |
1978年 | 2篇 |
1977年 | 5篇 |
1976年 | 6篇 |
1972年 | 2篇 |
1965年 | 2篇 |
1959年 | 2篇 |
1955年 | 2篇 |
1946年 | 4篇 |
1942年 | 2篇 |
排序方式: 共有302条查询结果,搜索用时 15 毫秒
1.
2.
3.
Deffenbacher Jerry L.; Lynch Rebekah S.; Oetting Eugene R.; Kemper Calvin C. 《Canadian Metallurgical Quarterly》1996,43(2):149
High-anger 6–8th graders received cognitive-relaxation coping skills (CRCS), social skills training (SST), or no treatment. Compared to the control, CRCS and SST were equally effective in reducing trait, general, and personal–situational anger and outward negative anger expression, as well as increasing controlled anger expression. On other variables, however, CRCS showed some superiority. Although both interventions led to equivalent reductions on one measure of anxiety, CRCS lowered depression, shyness, general deviance, and another measure of anxiety, whereas SST did not and was not significantly different from other groups. CRCS lowered school deviance more than SST. No between-group differences were found on self-esteem, alcohol consumption, or intoxication. Possible explanations of these findings were discussed, along with methodological issues. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
4.
Michal Podhradský Calvin Coopmans Austin Jensen 《Journal of Intelligent and Robotic Systems》2014,74(1-2):193-207
Small unmanned aerial vehicles (UAV) are typically driven by Lithium polymer batteries. The batteries have their own dynamics, which changes during discharge. Classical approaches to altitude control assume a time-invariant system and therefore fail. Adaptive controllers require an identified system model which is often unavailable. Battery dynamics can be characterized and used for a battery model-based controller. This controller is useful in situations when no feedback from actuators (such as RPM or thrust) is available. After measuring the battery dynamics for two distinct types of batteries, a controller is designed and experimentally verified, showing a consistent performance during entire discharge test and a consequent flight verification. 相似文献
5.
With the proliferation of macroergonomic field research, it is time to carefully examine how such research should be managed and implemented. We argue that the importance of attending to high-quality implementation of field research is equal to that of methodological rigor. One way to systematically manage the implementation process is to adopt a change management framework, wherein the research project is conceptualized as an instance of organization-level change. Consequently, principles for successful organization-level change from the literature on change management can be used to guide successful field research implementation. This paper briefly reviews that literature, deriving 30 principles of successful change management, covering topics such as political awareness, assembling the change team, generating buy-in, and management support. For each principle, corresponding suggestions for macroergonomic field research practice are presented. We urge other researchers to further develop and adopt frameworks that guide the implementation of field research. 相似文献
6.
7.
8.
Qafoku NP Ainsworth CC Szecsody JE Qafoku OS Heald SM 《Environmental science & technology》2003,37(16):3640-3646
Aluminum-rich, hyperalkaline (pH > 13.5) and saline high-level nuclear waste (HLW) fluids at elevated temperatures (>50 degrees C), that possibly contained as much as 0.41 mol L(-1) Cr(VI), accidentally leaked to the sediments at the Hanford Site, WA. These extreme conditions promote base-induced dissolution of soil minerals which may affect Cr(VI)aq mobility. Our objective was to investigate Cr(VI)aq transport in sediments leached with HLW simulants at 50 degrees C, under CO2 and O2 free conditions. Results demonstrated that Cr(VI)aq fate was closely related to dissolution, and Cr(VI)aq mass loss was negligible in the first pore volumes but increased significantly thereafter. Similar to dissolution, Cr(VI)aq attenuation increased with increasing fluid residence time and NaOH concentration but decreased with Al concentrations in the leaching solutions. Aqueous Cr(VI) removal rate half-lives varied from 1.2 to 230 h with the fastest at the highest base concentration, lowest Al concentration, greatest reaction time, and lowest Cr(VI) concentration in the leaching solution. The rate of Cr(VI) removal (normalized to 1 kg of solution) varied from 0.83 x 10(-9) (+/-0.44 x 10(-9)) to 9.16 x 10(-9) (+/-1.10 x 10(-9)) mol s(-1). The predominant mechanism responsible for removing Cr(VI) from the aqueous phase appears to be homogeneous Cr(VI) reduction to Cr(III) by Fe(II) released during mineral dissolution. Cr(VI)aq removal was time-limited probably because it was controlled by the rate of Fe(II) release into the soil solution upon mineral dissolution, which was also a time-limited process, and other processes that may act to lower Fe(II)aq activity. 相似文献
9.
Calvin Golumbic A. I. Schepartz B. F. Daubert 《Journal of the American Oil Chemists' Society》1946,23(12):380-381
Summary A simulated soybean oil has been synthesized from purified fatty acids. The flavor characteristics of the oil after heat and
light treatment are described and compared to those of soybean and cottonseed oils.
The generous financial assistance of the National Association of Margarine Manufactures is gratefully acknowledged.
Contribution No. 613 from the Department of Chemistry, University of Pittsburgh. 相似文献
10.