全文获取类型
收费全文 | 1326篇 |
免费 | 2篇 |
专业分类
化学工业 | 13篇 |
机械仪表 | 2篇 |
建筑科学 | 2篇 |
能源动力 | 3篇 |
轻工业 | 1篇 |
水利工程 | 1篇 |
无线电 | 2篇 |
一般工业技术 | 1篇 |
冶金工业 | 1298篇 |
自动化技术 | 5篇 |
出版年
2023年 | 1篇 |
2022年 | 1篇 |
2021年 | 1篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2015年 | 1篇 |
2013年 | 2篇 |
2011年 | 4篇 |
2009年 | 4篇 |
2008年 | 2篇 |
2007年 | 1篇 |
2006年 | 1篇 |
2005年 | 1篇 |
2003年 | 5篇 |
2001年 | 1篇 |
1999年 | 36篇 |
1998年 | 395篇 |
1997年 | 239篇 |
1996年 | 129篇 |
1995年 | 86篇 |
1994年 | 65篇 |
1993年 | 87篇 |
1992年 | 6篇 |
1991年 | 25篇 |
1990年 | 18篇 |
1989年 | 14篇 |
1988年 | 15篇 |
1987年 | 21篇 |
1986年 | 11篇 |
1985年 | 10篇 |
1983年 | 4篇 |
1982年 | 4篇 |
1981年 | 7篇 |
1980年 | 8篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 32篇 |
1976年 | 80篇 |
1975年 | 2篇 |
1955年 | 3篇 |
排序方式: 共有1328条查询结果,搜索用时 804 毫秒
991.
KP Lesch J Gross E Franzek BL Wolozin P Riederer DL Murphy 《Canadian Metallurgical Quarterly》1995,37(4):215-223
Genetic factors have been implicated in the etiology of affective disorders but due to the complex inheritance patterns of these disorders, identification of the responsible gene(s) has so far been unsuccessful. Decreased platelet serotonin (5-HT) transport and reduced binding of imipramine or paroxetine to brain and platelet 5-HT uptake sites/transporters in patients with depression and suicide victims define the 5-HT transporter (5-HTT) as a candidate gene. The primary structure of the 5-HTT was analyzed in 17 patients meeting DSM-III-R diagnostic criteria for major depressive or bipolar disorder and in 4 healthy controls using polymerase chain reaction (PCR-) amplification and sequencing of complementary deoxyribose nucleic acid (cDNA) synthesized from platelet 5-HTT messenger ribose nucleic acid (mRNA). Direct PCR sequencing of the protein coding region failed to reveal changes in the deduced amino acid sequence of the platelet/brain 5-HTT (40,000 base pairs sequence screened), although a conservative single-base substitution representing a silent polymorphism was found. The results provide preliminary evidence that alterations in the primary structure of 5-HTT are not generally involved in the pathogenesis of unipolar depression and manic-depressive illness. 相似文献
992.
PR Ortiz de Montellano BL Mangold C Wheeler KL Kunze NO Reich 《Canadian Metallurgical Quarterly》1983,258(7):4208-4213
Oxidation of 1-octene by cytochrome P-450 results concurrently in formation of 1,2-oxidooctane and in N-alkylation by the catalytically activated olefin of the prosthetic heme group. The stereochemistry of trans-1-[1-2H]octene is retained during both transformations. This alkylation stereochemistry requires addition of the pyrrole nitrogen and the activated oxygen to the same side of the double bond, a reaction geometry opposite to that expected if the heme were alkylated by the epoxide metabolite. Stereochemical analysis shows that the S enantiomer of the epoxide is formed in slight excess over the R enantiomer by oxidation of the re and si faces, respectively, of the olefin, but that heme alkylation only occurs during oxidation of the re face. The stereochemical specificity of epoxidation and heme alkylation requires that (a) the two processes proceed by independent (probably concerted) mechanisms, or (b) the two processes diverge from a common acyclic intermediate. 相似文献
993.
R Sithiprasasna D Strickman BL Innis KJ Linthicum 《Canadian Metallurgical Quarterly》1994,88(4):397-404
An indirect ELISA has been developed for detecting two viruses in triturated, experimentally infected mosquitoes: dengue (DEN) in Aedes aegypti (L.) and Ae. albopictus (Skuse) and Japanese encephalitis (JE) viral antigen in Culex tritaeniorhynchus Giles. DEN antigen from four strains of the virus, representing each of the four serotypes, and JE antigen were captured with a polyclonal anti-flavivirus IgG and detected with a monoclonal antibody (4G2) that reacts with all flaviviruses. Minimum viral titres detectable by the flavivirus antigen-capture ELISA, measured as multiples of the dose infecting 50% of mosquitoes (MID50), were 10(6.4), 10(4.5), 10(6.3), 10(6.9) and < or = 10(6.9) MID50/ml for DEN 1, DEN 2, DEN 3, DEN 4 and JE, respectively. Pools of up to 100 larvae or adults of Ae. aegypti and Ae. albopictus did not reduce the sensitivity of the ELISA to DEN 1, 2, 3 or 4. The results indicate that the antigen-capture ELISA could readily screen for DEN antigen in individual and pooled mosquitoes. 相似文献
994.
995.
Susceptibility genes for breast cancer 总被引:1,自引:0,他引:1
BL Weber 《Canadian Metallurgical Quarterly》1994,331(22):1523-1524
996.
997.
998.
999.
1000.