全文获取类型
收费全文 | 7237篇 |
免费 | 12篇 |
专业分类
电工技术 | 15篇 |
综合类 | 3篇 |
化学工业 | 177篇 |
金属工艺 | 17篇 |
机械仪表 | 42篇 |
建筑科学 | 89篇 |
矿业工程 | 2篇 |
能源动力 | 29篇 |
轻工业 | 118篇 |
水利工程 | 20篇 |
石油天然气 | 1篇 |
无线电 | 107篇 |
一般工业技术 | 174篇 |
冶金工业 | 6293篇 |
原子能技术 | 12篇 |
自动化技术 | 150篇 |
出版年
2021年 | 15篇 |
2020年 | 18篇 |
2019年 | 13篇 |
2018年 | 17篇 |
2017年 | 14篇 |
2016年 | 17篇 |
2014年 | 22篇 |
2013年 | 74篇 |
2012年 | 44篇 |
2011年 | 40篇 |
2010年 | 45篇 |
2009年 | 37篇 |
2008年 | 40篇 |
2007年 | 39篇 |
2006年 | 34篇 |
2005年 | 38篇 |
2004年 | 29篇 |
2003年 | 36篇 |
2002年 | 26篇 |
2001年 | 27篇 |
2000年 | 28篇 |
1999年 | 211篇 |
1998年 | 2027篇 |
1997年 | 1160篇 |
1996年 | 748篇 |
1995年 | 418篇 |
1994年 | 305篇 |
1993年 | 392篇 |
1992年 | 57篇 |
1991年 | 59篇 |
1990年 | 77篇 |
1989年 | 66篇 |
1988年 | 70篇 |
1987年 | 53篇 |
1986年 | 47篇 |
1985年 | 59篇 |
1984年 | 17篇 |
1983年 | 37篇 |
1982年 | 34篇 |
1981年 | 50篇 |
1980年 | 65篇 |
1979年 | 25篇 |
1978年 | 25篇 |
1977年 | 152篇 |
1976年 | 323篇 |
1975年 | 24篇 |
1974年 | 12篇 |
1973年 | 10篇 |
1972年 | 10篇 |
1955年 | 8篇 |
排序方式: 共有7249条查询结果,搜索用时 0 毫秒
11.
AM al-Senaidy 《Canadian Metallurgical Quarterly》1996,66(3):210-216
"Holistic therapy" can be just a slogan, a catchword. Two examples--the combination of behaviour therapy and pharmacotherapy on one side, the use of biofeedback in psychiatry on the other--shall present the possible integration of different therapeutic strategies into a holistic concept. The quality of different therapeutic concepts may be influenced by their possible combination. No more any therapeutic method (except some eclectic ones) can see itself as the one and only cure for everything. Of course this view has a consequence on psychopathology and diagnosis, which have to be more exact under these premisses. A holistic treatment requires more knowledge about details in psychopathology and diagnosis as well as about therapeutic methods. 相似文献
12.
23 highly hypnotizable undergraduates (Harvard Group Scale of Hypnotic Susceptibility) underwent 2 specially constructed 7-item hypnotic inductions. Over the 14 items, the main finding was of a relationship between E. R. Hilgard's (1973, 1977, 1979) "hidden observer" effect and 2 aspects of hypnotic age regression. Ss reporting a hidden observer experienced duality during regression to age 5, in which they were aware of being both adult and child. When asked to write a complex sentence, most did so, usually without spelling errors. The Ss not reporting this effect experienced quasi-lateral age regression in which they had the exclusive feeling of being 5 yrs old, with no sense of an adult identity. Most of these Ss were unable to write the same complex sentence when requested to during age regression. The study replicated Hilgard's finding of the hidden observer phenomenon in terms of its incidence and obtained similar verbal reports from Ss experiencing it. At the same time, the results suggest that a neodissociation account of hypnosis may need some modifications to accommodate these additional findings. (27 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
13.
A selenium depletion diet (.025 ppm selenium) was fed to two male Holstein calves for its effect on concentrations of selenium in serum. By 90 days, selenium in serum was depressed from .022 ppm to .013 ppm, and one of two calves had died of "possible white muscle disease." Repletion was rapid in that a diet containing .200 ppm selenium increased selenium in serum to .028 ppm within 2 wk. Dietary .280 ppm selenium increased it to .051 ppm in 1 wk. Eleven cows and eleven calves showed averages of .030 ppm in serum (range of .013 to .051 ppm) fed a diet of corn silage (.039 ppm) and supplement (.090 ppm). A sampling of feedstuffs showed a wide range of selenium among feedstuffs (.023 for corn cobs to 2.663 ppm for dried egg albumin) and a wide range within one type feedstuff (shelled corn, .017 to .219 ppm). 相似文献
14.
15.
Roger Perry 《Journal of Electronic Testing》1992,3(4):317-325
I
DDQ
testing with precision measurement unit (PMU) was used to eliminate early life failures caused by CMOS digital ASICs in our products. Failure analysis of the rejected parts found that bridging faults caused by particles were not detected in incoming tests created by automatic test generation (ATG) for stuck-at-faults (SAF). The nominal 99.6% SAF test coverage required to release a design for production was not enough! This article shows how I
DDQ
testing and supplier process improvements affected our early life failure rates over a three year period. A typical I
DDQ
measurement distribution, effects of multiple I
DDQ
testing, and examples of the defects found are presented. The effects of less than 99.6% fault coverage after the I
DDQ
testing was implemented are reviewed. The methods used to establish I
DDQ
test limits and implement the I
DDQ
test with existing ATG testing are included. This article is a revision of one given at International Test Conference [1]. 相似文献
16.
A sharp interface model has been developed to model intermediate-phase growth under the influence of electromigration in a binary system. Simulation results show that the phase growth rate depends on both the magnitude and the direction of the applied current. With the current density fixed, at early times, there is a parabolic growth behavior for the intermediate phase, while at longer times, there is a linear phase growth behavior when the electron flow aids diffusion of atoms; however, a limiting thickness is found when the electron flow hinders diffusion. Qualitative analysis shows that the longer time behavior also holds in a binary system with multiple intermediate phases present. 相似文献
17.
The performance of our Quality Oriented Adaptation Scheme (QOAS) for multimedia streaming in local networks is compared with other existing solutions (TFRCP, LDA+, and non-adaptive). This comparison is done in terms of bandwidth utilization, number of concurrent clients, loss rate, and end-user perceived quality. Simulation results show that for the same average end-user quality, our QOAS system can accommodate a significantly higher number of simultaneous clients while also having higher bandwidth utilization. For the same number of clients, the average end-user quality is always higher for QOAS than for the other solutions studied. 相似文献
18.
Childers Donald G. Fischler Ira S. Boaz Timothy L. Perry Nathan W. Arroyo A. Antonio 《IEEE transactions on bio-medical engineering》1986,(12):1069-1075
We report on the effect of electrode placement and number of electrodes on the classification of single trial event related potentials (ERP's). The subjects read propositions relating fictitious people and their occupations while ERP's were recorded. The subjects decided if the proposition was correct or incorrect and responded as per instructions. The single trial, multichannel ERP data were classified using various methods, e. g., hold-out, leave-one-out, resubstitution. Several other factors were examined to determine their effect on ERP classification, including taking a majority vote among channels, using the single best channel, and averaging the data across channels for a single ERP. The results from other experiments are compared to those presented here. 相似文献
19.
AM Malashenko 《Canadian Metallurgical Quarterly》1976,12(3):163-165
Diethylsulphate solution was injected intraperitoneally twice a week to male mice B10.C3H having the wild-type colour at a 5 mg/kg dose. The treatment lasted 10 weeks, so that the total dose administered was 5-20 = 100 mg/kg. In fifth week after the end of the treatment these males were crossed to YT females homozygous for seven recessive mutant genes. In the control group all the F1 descendants were of wild-type colour, while in the experimental group among 5042 F1 mice derived from DES-treated spermatogonia there was one mutant d and 4 mosaics (3 with respect to the locus c and 1 with respect to the locusa). These results are interpreted as the evidence of the mutagenic effect of DES. 相似文献
20.