全文获取类型
收费全文 | 2814篇 |
免费 | 2篇 |
专业分类
电工技术 | 2篇 |
化学工业 | 22篇 |
金属工艺 | 1篇 |
机械仪表 | 1篇 |
建筑科学 | 1篇 |
轻工业 | 2篇 |
石油天然气 | 3篇 |
无线电 | 3篇 |
一般工业技术 | 10篇 |
冶金工业 | 2749篇 |
自动化技术 | 22篇 |
出版年
2018年 | 1篇 |
2017年 | 2篇 |
2015年 | 1篇 |
2014年 | 2篇 |
2013年 | 3篇 |
2012年 | 3篇 |
2011年 | 1篇 |
2008年 | 1篇 |
2007年 | 2篇 |
2006年 | 4篇 |
2004年 | 2篇 |
2003年 | 5篇 |
2002年 | 1篇 |
2001年 | 1篇 |
2000年 | 4篇 |
1999年 | 80篇 |
1998年 | 803篇 |
1997年 | 437篇 |
1996年 | 308篇 |
1995年 | 166篇 |
1994年 | 152篇 |
1993年 | 168篇 |
1992年 | 17篇 |
1991年 | 37篇 |
1990年 | 35篇 |
1989年 | 37篇 |
1988年 | 44篇 |
1987年 | 44篇 |
1986年 | 28篇 |
1985年 | 32篇 |
1984年 | 1篇 |
1983年 | 4篇 |
1982年 | 15篇 |
1981年 | 14篇 |
1980年 | 31篇 |
1979年 | 1篇 |
1978年 | 8篇 |
1977年 | 94篇 |
1976年 | 212篇 |
1975年 | 5篇 |
1971年 | 1篇 |
1970年 | 1篇 |
1969年 | 1篇 |
1966年 | 2篇 |
1965年 | 1篇 |
1955年 | 4篇 |
排序方式: 共有2816条查询结果,搜索用时 15 毫秒
911.
The interaction of squalene with liposomes and monolayers of dipalmitoyl phosphatidylcholine (DPL) has been studied by differential scanning calorimetry, Raman spectroscopy, and surface potential measurements. Mole ratios of squalene to DPL up to 9 to 1 were studied. In contrast to small, nonpolar molecules, which profoundly influence the structure of lipid bilayers as detected by changes in both their thermodynamic phase transition parameters and membrane fluidity, this large, nonpolar, linear hydrocarbon is devoid of such influences. It is clear from our data that a large nonpolar molecule such as squalene, having no polar group that might anchor it to the aqueous interface, cannot intercalate between the acyl chains either below or above the phase transition of DPL. This behavior is not compatible with models that treat the bilayer interior as a bulk hydrocarbon, and suggests that great caution should be exercised in extrapolating partition coefficients based on bulk hydrocarbon measurements to lipid bilayers. 相似文献
912.
RC Zayan 《Canadian Metallurgical Quarterly》1976,41(2):142-190
Laboratory experiments on pairs of male male of the genus Xiphophorus were carried out to test the hypothesis that the duration of a pre-experimental isolation period would modify the effects of prior residence on aggressive behaviour and dominance. Resident and intruder were isolated either both for 3 or both for 22 h (Exp. 1), or one for 3 and other other for 22 h (Exp. 2). Prior residence effects were only evident when the resident had been isolated for 3 h. Other connections between isolation conditions, reciprocal aggression and final dominance were also analysed, as was the influence of size differences between the opponents. 相似文献
913.
Protein kinases play an important role in controlling synaptic strength at excitatory synapses on CA1 pyramidal cells. We examined the effects of activating cAMP-dependent protein kinase or protein kinase C (PKC) on the frequency and amplitude of miniature excitatory postsynaptic currents (mEPSCs) with perforated patch recording techniques. Both forskolin and phorbol-12,13-dibutryate (PDBu) caused a large increase in mEPSC frequency, but only PDBu increased mEPSC amplitude, an effect that was not observed when standard whole cell recording was performed. These results support biochemical observations indicating that PKC, similar to calcium/calmodulin-dependent protein kinase II, has an important role in controlling synaptic strength via modulation of AMPA receptor function, potentially through the direct phosphorylation of the GluR1 subunit. 相似文献
914.
The author, the fifth superintendent of Alabama's Bryce Hospital since the Wyatt v. Stickney order was issued in 1972, discusses the major problems faced by an administrator in complying with the court-set standards. They relate to qualified mental health professionals, staffing ratios, staff attitudes, individualized treatment plans, and the hospital's negative image. He also discusses the role of the human rights committee and the hospital's goal of providing treatment of sufficient quality that the court order will be lifted. 相似文献
915.
RC Rosen 《Canadian Metallurgical Quarterly》1998,351(9116):1599-1600
916.
SP Langdon AA Ritchie M Muir M Dodds AF Howie RC Leonard PK Stockman WR Miller 《Canadian Metallurgical Quarterly》1998,34(3):384-388
We have mapped the chromosomal locations of three human nuclear genes for putative components of the apparatus of mitochondrial gene expression, using a combination of in situ hybridization and interspecies hybrid mapping. The genes RPMS12 (mitoribosomal protein S12, a conserved protein component of the mitoribosomal accuracy center), TUFM (mitochondrial elongation factor EF-Tu), and AFG3L1 (similar to the yeast genes Afg3 and Rca1 involved in the turnover of mistranslated or misfolded mtDNA-encoded polypeptides) were initially characterized by a combination of database sequence analysis, PCR, cloning, and DNA sequencing. RPMS12 maps to chromosome 19q13.1, close to the previously mapped gene for autosomal dominant hearing loss DFNA4. The TUFM gene is located on chromosome 16p11.2, with a putative pseudogene or variant (TUFML) located very close to the centromere of chromosome 17. AFG3L1 is located on chromosome 16q24, very close to the telomere. By virtue of their inferred functions in mitochondria, these genes should be regarded as candidates of disorders sharing features with mitochondrial disease syndromes, such as sensorineural deafness, diabetes, and retinopathy. 相似文献
917.
918.
919.
920.
RC Drews 《Canadian Metallurgical Quarterly》1976,82(6):938-939
A mirror is the ideal fixation device for an ophthalmoscopic examination: it is the essense of simplicity, and there is nothing the patient would rather watch than himself. 相似文献