全文获取类型
收费全文 | 241410篇 |
免费 | 2632篇 |
国内免费 | 427篇 |
专业分类
电工技术 | 4292篇 |
综合类 | 257篇 |
化学工业 | 39412篇 |
金属工艺 | 9383篇 |
机械仪表 | 7398篇 |
建筑科学 | 5463篇 |
矿业工程 | 1391篇 |
能源动力 | 5162篇 |
轻工业 | 24826篇 |
水利工程 | 2477篇 |
石油天然气 | 5092篇 |
武器工业 | 32篇 |
无线电 | 25048篇 |
一般工业技术 | 44793篇 |
冶金工业 | 45389篇 |
原子能技术 | 5950篇 |
自动化技术 | 18104篇 |
出版年
2021年 | 2108篇 |
2019年 | 2017篇 |
2018年 | 3490篇 |
2017年 | 3426篇 |
2016年 | 3689篇 |
2015年 | 2236篇 |
2014年 | 3901篇 |
2013年 | 10189篇 |
2012年 | 6152篇 |
2011年 | 8316篇 |
2010年 | 6560篇 |
2009年 | 7239篇 |
2008年 | 7589篇 |
2007年 | 7721篇 |
2006年 | 6891篇 |
2005年 | 6051篇 |
2004年 | 5820篇 |
2003年 | 5600篇 |
2002年 | 5676篇 |
2001年 | 5563篇 |
2000年 | 5385篇 |
1999年 | 5303篇 |
1998年 | 12593篇 |
1997年 | 8912篇 |
1996年 | 6860篇 |
1995年 | 5336篇 |
1994年 | 4739篇 |
1993年 | 4626篇 |
1992年 | 3669篇 |
1991年 | 3389篇 |
1990年 | 3594篇 |
1989年 | 3473篇 |
1988年 | 3303篇 |
1987年 | 2895篇 |
1986年 | 2932篇 |
1985年 | 3373篇 |
1984年 | 3219篇 |
1983年 | 2892篇 |
1982年 | 2738篇 |
1981年 | 2822篇 |
1980年 | 2721篇 |
1979年 | 2625篇 |
1978年 | 2684篇 |
1977年 | 2948篇 |
1976年 | 3808篇 |
1975年 | 2368篇 |
1974年 | 2242篇 |
1973年 | 2376篇 |
1972年 | 1970篇 |
1971年 | 1858篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
871.
872.
873.
874.
T Rodriguez E Baumgarten R Fengler D Soumpasis G Henze 《Canadian Metallurgical Quarterly》1995,207(4):207-210
Nine children of the ALL-REZ BFM 87 and 90 trial received L-Asparginase (L-ASP) as a continuous infusion for 48-72 hs (i.e. 25 therapy cycles). Seven patients had had an allergic reaction towards an i.m. application (i.m., 29 therapy cycles). Two further patients got L-ASP initially as continuous infusion. The i.m. applications were carried out 19 times with Erwinia and 10 times with E. coli-Asparaginase, the continuous infusions 15 times with Erwinia and 10 times with E. coli-Asparaginase. In case of four patients continuous infusions of the same L-ASP type (E. coli or Erwinia) was well tolerated, after there had been an allergic reaction after i.m. application. Allergic reactions after i.m. application occurred during 10 courses as local painful erythema, during five courses as urticaria, during four courses as a general exanthema during one course as difficult breathing and during a further course as drop in blood pressure. After continuous infusion of L-ASP urticaria and difficult breathing occurred once and a transient exanthema two times. There was no anaphylactic reaction in any case. These data show that i.m. application of L-ASP causes no life-threatening side effects but allergic reactions (local pain and swelling) which clearly impaired general condition. Continuous infusion is a pharmacologically equivalent alternative with less impairment of the patients' general condition. 相似文献
875.
Chun Hu Ji Zhao Li G.P. Liu P. Worley E. White J. Kjar R. 《Electron Device Letters, IEEE》1995,16(2):61-63
The effects of the plasma etching process induced gate oxide damages on device's low frequency noise behavior are investigated on MOSFET's fabricated with different field plate perimeter to gate area ratio antennas. Abnormal 1/f noise spectrum with a shoulder centered in the frequency range of 100 and to 1 kHz was frequently observed in small geometry devices, and it is attributable to a nonuniform distribution of oxide traps induced by plasma etching process 相似文献
876.
C Oddoux E Reich F Axelrod A Blumenfeld C Maayan S Slaugenhaupt J Gusella H Ostrer 《Canadian Metallurgical Quarterly》1995,15(9):817-826
Familial dysautonomia (FD), a recessively inherited disease, has been mapped to chromosome 9q31. Highly polymorphic dinucleotide repeat markers flanking the genetic locus and at the same genetic location have been identified. We describe the prenatal diagnosis of FD using linkage and linkage disequilibrium analyses with these markers. Twelve families were analysed for informativeness and of these, seven went on to have prenatal testing (a total of eight fetuses tested). All of these fetuses were predicted to be heterozygous unaffected (FD carriers). Seven fetuses have come to term and are normal. In the absence of a recombinant proband, a panel of three proximal and three distal markers is sufficient to provide informative flanking markers and an 87-96 per cent likelihood of a highly predictive test. In an additional family at 1:4 risk for FD, no DNA was available from the propositus. This family was analysed using linkage disequilibrium to the #18 allele of the tightly linked marker D9S58 in conjunction with linkage analysis using data from two unaffected children. Prenatal diagnosis in this family indicated an affected fetus. 相似文献
877.
E Schweikert 《Canadian Metallurgical Quarterly》1995,14(4):80, 82, 84-80, 82, 85
878.
879.
880.
Cerebral lateralization in visual perception was investigated in 9 severe stuttering, 11 mild stuttering and 48 fluent speakers. The subjects were asked to identify words presented in the left or right visual field for 20 ms. Children responded by pointing to the exposed test word on a response card which contained four different words. Errors committed in the left and right visual fields were analyzed. The data showed a left hemisphere superiority in the processing of words in both the mild stutterers and the fluent speakers, but a right hemisphere advantage in the severe stutterers. The results suggest a close relationship between the severity of stuttering and functional brain organization. 相似文献