全文获取类型
收费全文 | 791篇 |
免费 | 24篇 |
专业分类
电工技术 | 6篇 |
化学工业 | 113篇 |
金属工艺 | 4篇 |
机械仪表 | 8篇 |
建筑科学 | 23篇 |
矿业工程 | 1篇 |
能源动力 | 11篇 |
轻工业 | 71篇 |
水利工程 | 14篇 |
石油天然气 | 1篇 |
无线电 | 92篇 |
一般工业技术 | 97篇 |
冶金工业 | 316篇 |
原子能技术 | 4篇 |
自动化技术 | 54篇 |
出版年
2023年 | 4篇 |
2022年 | 9篇 |
2021年 | 8篇 |
2020年 | 7篇 |
2019年 | 12篇 |
2018年 | 11篇 |
2017年 | 12篇 |
2016年 | 5篇 |
2015年 | 13篇 |
2014年 | 22篇 |
2013年 | 25篇 |
2012年 | 29篇 |
2011年 | 42篇 |
2010年 | 23篇 |
2009年 | 21篇 |
2008年 | 20篇 |
2007年 | 21篇 |
2006年 | 21篇 |
2005年 | 20篇 |
2004年 | 17篇 |
2003年 | 25篇 |
2002年 | 16篇 |
2001年 | 14篇 |
2000年 | 12篇 |
1999年 | 21篇 |
1998年 | 78篇 |
1997年 | 36篇 |
1996年 | 40篇 |
1995年 | 21篇 |
1994年 | 24篇 |
1993年 | 17篇 |
1992年 | 13篇 |
1991年 | 8篇 |
1990年 | 16篇 |
1989年 | 10篇 |
1988年 | 13篇 |
1987年 | 8篇 |
1986年 | 5篇 |
1985年 | 6篇 |
1984年 | 6篇 |
1983年 | 5篇 |
1982年 | 5篇 |
1980年 | 7篇 |
1979年 | 8篇 |
1977年 | 7篇 |
1976年 | 18篇 |
1974年 | 3篇 |
1973年 | 3篇 |
1972年 | 4篇 |
1971年 | 3篇 |
排序方式: 共有815条查询结果,搜索用时 0 毫秒
1.
Camacho Christopher J.; Higgins E. Tory; Luger Lindsay 《Canadian Metallurgical Quarterly》2003,84(3):498
People experience regulatory fit (E. T. Higgins, 2000) when the strategic manner of their goal pursuit suits their regulatory orientation, and this regulatory fit feels right. Fit violation feels wrong. Four studies tested the proposal that experiences of fit can transfer to moral evaluations. The authors examined transfer of feeling wrong from fit violation by having participants in a promotion or prevention focus recall transgressions of commission or omission (Studies 1 and 2). Both studies found that when the type of transgression was a fit violation, participants expressed more guilt. Studies 3 and 4 examined transfer of feeling right from regulatory fit. Participants evaluated conflict resolutions (Study 3) and public policies (Study 4) as more right when the means pursued had fit. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
2.
In 1895 Trendelenburg described his sign to determine the integrity of hip function. We found the sign to be positive in a patient whose hip was clinically and radiologically normal, and therefore investigated this in other patients. We confirmed that a medial shift of the mechanical axis of the leg below the hip may cause a positive Trendelenburg sign. This has not been previously described. 相似文献
3.
Youngwoo Kwon Sovero E.A. Deakin D.S. Higgins J.A. 《Microwave Theory and Techniques》1998,46(9):1237-1241
A 44-GHz monolithic waveguide plane-wave amplifier (PWA) with improved unit cell design is presented in this paper. The unit cell is a two-stage direct-coupled design and satisfies size, bistability, and stability requirements of the waveguide PWA. The ultra-compact unit cell had a cell size of 0.8 mm2, and showed a small-signal gain of 8 dB and an output power of 15 dBm at 44 GHz with a corresponding dc-to-RF efficiency of 10%. A monolithic waveguide PWA using these unit cells showed a “flange-to-flange” gain of 5 dB, an output power of 0.3 W, and an efficiency of 2% at 44 GHz 相似文献
4.
Hodgins D. Bertsch A. Post N. Frischholz M. Volckaerts B. Spensley J. Wasikiewicz J.M. Higgins H. von Stetten F. Kenney L. 《Pervasive Computing, IEEE》2008,7(1):14-21
Healthy Aims is a 23- million, four-year project, funded under the EU's information society technology sixth framework program to develop intelligent medical implants and diagnostic systems (www.healthyaims.org). The project has 25 partners from 10 countries, including commercial, clinical, and research groups. This consortium represents a combination of disciplines to design and fabricate new medical devices and components as well as to test them in laboratories and subsequent clinical trials. The project focuses on medical implants for nerve stimulation and diagnostic equipment based on strain-gauge technology. 相似文献
5.
The IgE-mediated allergic response involves a series of physiological pathways that result in the array of symptoms commonly associated with allergy. This article describes the mediators that prompt specific clinical responses and identifies those at risk for latex hypersensitivity. 相似文献
6.
7.
Ho W.J. Chang M.F. Sailer A. Zampardi P. Deakin D. McDermott B. Pierson R. Higgins J.A. Waldrop J. 《Electron Device Letters, IEEE》1993,14(12):572-574
The use of GaInP/GaAs heterojunction bipolar transistors (HBTs) for integrated circuit applications is demonstrated. The discrete devices fabricated showed excellent DC characteristics with low Vce offset voltage and very low temperature sensitivity of the current gain. For a non-self-aligned device with a 3-μm×1.4-μm emitter area, fT was extrapolated to 45 GHz and fmax was extrapolated to 70 GHz. The measured 1/f noise level was 20 dB better than that of AlGaAs HBTs and comparable to that of low-noise silicon bipolar junction transistors, and the noise bump (Lorentzian component) was not observed. The fabricated gain block circuits showed 8.5 dB gain with a 3-dB bandwidth of 12 GHz, and static frequency dividers (divide by 4) were operable up to 8 GHz 相似文献
8.
Skeleton weed, centaurea juncea, is a declared weed in Western Australia because it competes with grain crops for nutrients and moisture. When it is found during harvesting, mechanised teams search and eradicate it. In an earlier report of field trials (Hartley et al, 1989) it was reported that search teams' detection rate was poor and since search teams had usually never seen skeleton weeds, visual discrimination learning was to be expected and observed during searches. The present study investigated the nature of this discrimination learning in a laboratory by developing a training programme of colour photographic slides of weeds in stubble. Subjects receiving specific training with feedback on their performance compared with those receiving pseudo-training showed a significant improvement in detections. Subsequently the benefit of the programme was validated in a field trial. 相似文献
9.
Jafari F Higgins PD 《IEEE transactions on ultrasonics, ferroelectrics, and frequency control》1989,36(2):191-196
Predictive thermometry, utilizing minimally invasive sampling techniques, is an essential ingredient in the development of hyperthermia treatment planning capabilities. The authors demonstrate a powerful, but simple approach toward predicting temperature distributions in tissues, based on analytic solution, using in cylindrical symmetry, of the heat diffusion equation. Conduction and localized perfusion effects are combined as an effective conductivity term, readily measurable, and parametrized in a general exponential form. The proposed approach allows a first-order approximation to modeling three typical situations: hypoxic or necrotic tumor core with homogeneously perfused periphery; highly perfused periphery (in rapidly growing tumors); or perfused central cover with a less well-supplied periphery (such as for some invasive tumors). The utility and strength of this approach is that it provides a rapid, accurate model of directly observing the technical quality to be expected for different heating methods, making it possible to optimally configure source distributions in a treatment planning setting. 相似文献
10.
S. Arepalli H. Fireman C. Huffman P. Moloney P. Nikolaev L. Yowell K. Kim P. A. Kohl C. D. Higgins S. P. Turano W. J. Ready 《JOM Journal of the Minerals, Metals and Materials Society》2005,57(12):26-31
Electrochemical double-layer capacitors, or supercapacitors, have tremendous potential as high-power energy sources for use
in low-weight hybrid systems for space exploration. Electrodes based on single-wall carbon nanotubes (SWCNTs) offer exceptional
power and energy performance due to the high surface area, high conductivity, and the ability to functionalize the SWCNTs
to optimize capacitor properties. This paper will report on the preparation of electrochemical capacitors incorporating SWCNT
electrodes and their performance compared with existing commercial technology. Preliminary results indicate that substantial
increases in power and energy density are possible. The effects of nanotube growth and processing methods on electrochemical
capacitor performance is also presented. The compatibility of different SWCNTs and electrolytes was studied by varying the
type of electrolyte ions that accumulate on the high-surface-area electrodes.
For more information, contact W.J. Ready, Georgia Tech Research Institute, 925 Dalney St., Atlanta, GA 30332; (404) 385-4497;
fax (404) 894-0580; e-mail jud.ready@gtri.gatech.edu. 相似文献