全文获取类型
收费全文 | 995篇 |
免费 | 3篇 |
国内免费 | 4篇 |
专业分类
电工技术 | 7篇 |
综合类 | 3篇 |
化学工业 | 176篇 |
金属工艺 | 26篇 |
机械仪表 | 27篇 |
建筑科学 | 2篇 |
矿业工程 | 12篇 |
能源动力 | 5篇 |
轻工业 | 25篇 |
水利工程 | 17篇 |
石油天然气 | 53篇 |
无线电 | 50篇 |
一般工业技术 | 122篇 |
冶金工业 | 434篇 |
原子能技术 | 24篇 |
自动化技术 | 19篇 |
出版年
2022年 | 12篇 |
2021年 | 9篇 |
2020年 | 14篇 |
2019年 | 11篇 |
2018年 | 30篇 |
2017年 | 22篇 |
2016年 | 24篇 |
2015年 | 9篇 |
2014年 | 15篇 |
2013年 | 25篇 |
2012年 | 21篇 |
2011年 | 12篇 |
2010年 | 13篇 |
2009年 | 13篇 |
2008年 | 9篇 |
2007年 | 14篇 |
2006年 | 7篇 |
2004年 | 10篇 |
2003年 | 9篇 |
2002年 | 8篇 |
2000年 | 8篇 |
1999年 | 11篇 |
1998年 | 123篇 |
1997年 | 74篇 |
1996年 | 52篇 |
1995年 | 36篇 |
1994年 | 30篇 |
1993年 | 22篇 |
1992年 | 8篇 |
1991年 | 10篇 |
1990年 | 22篇 |
1989年 | 8篇 |
1988年 | 19篇 |
1987年 | 9篇 |
1986年 | 19篇 |
1985年 | 9篇 |
1984年 | 7篇 |
1983年 | 7篇 |
1982年 | 11篇 |
1981年 | 12篇 |
1980年 | 10篇 |
1979年 | 18篇 |
1978年 | 11篇 |
1977年 | 29篇 |
1976年 | 50篇 |
1975年 | 15篇 |
1973年 | 8篇 |
1972年 | 8篇 |
1971年 | 7篇 |
1965年 | 6篇 |
排序方式: 共有1002条查询结果,搜索用时 15 毫秒
71.
72.
73.
The steady-state kinetics of the ThTP hydrolysis by thiamine triphosphatase (EC 3.6.1.28) from bovine brain testified to the presence of two kinetically significant conformational states of the protein, their equilibrium being determined by the substrate concentration. The ThTPase isomeric forms had different activities, affinities for ThTP and activation energies. The form with high affinity for the substrate was characterized by the Km and Vmax values of 43 microM and 9.9 mumol.s-1.mg-1 whereas for the form with lower affinity these values were equal to 298 microM and 19.3 mumol.s-1.mg-1, respectively. The activation energies of the ThTP hydrolysis reactions were 85.3 and 47.1 kJ.mol-1. Several mechanisms of the enzyme activity regulation in the cell are suggested. One of the mechanisms is related to the allosteric ThTP effect inducing reversible transition of the protein to a more active conformational state, while the others include the inhibition activity by ATP and the activation of ThTP-ase by Mg2+ free ions. 相似文献
74.
75.
Methods used for the measurement of stresses in pipelines operating under conditions favorable to development of stress-induced
corrosion cracking are compared.
Comparative measurements of stresses due to internal pressure, residual stresses caused by pipe-production procedures, and
assembly-induced stresses that develop during the welding and laying of a gas line are performed.
__________
Translated from Khimicheskoe i Neftegazovoe Mashinostroenie, No. 3, pp. 42–43, March, 2007. 相似文献
76.
We describe a case of multicentric reticulohistiocytosis complicated by central retinal vein thrombosis and trigeminal neuropathy. A variety of treatment modalities were tried in this patient. Both skin disease and arthritis responded to low dose methotrexate over 8 years of followup. Graduated compression gloves produced an excellent cosmetic improvement in the disfiguring skin lesions. 相似文献
77.
IP Sokolova AM Arnautov NN Nikol'ski? ES Kornilova 《Canadian Metallurgical Quarterly》1998,40(10):862-868
A study was made of an association of small GTPase Rab7, commonly considered as a marker of late endosomes, with endosomal compartments of cells expressing EGF receptor with different ability to be sorted for degradative pathway. It was found that in cells HER14, expressing normal EGF receptor, Rab7 was associated with both early and late endosomes and the extent of association correlated with the number of EGF-receptor complexes in the specific endosomal fraction. Cels with a receptor, lacking major sites of autophosphorylation by deletion of 126 C-terminal residues (CD126), demonstrated a low efficiency of EGF-receptor sorting to late endosomes and decreased association dynamics with Rab7. Interaction of Rab7 with endosomes of cells expressing kinase negative receptors (K721) was found to be minimal. At the same time, in cells Cd126 and K721 with a low sorting efficiency Rab7 was mainly associated with early endosomes. These data favor Rab7 involvement in mediating early-to-late endosomal transition. 相似文献
78.
79.
Operative treatment of fractures of the femur neck is the method of choice. The authors prefer the A. Seppo construction out of great number of fixtures but it is difficult to introduce and remove this fixture due to its complexity. To make the procedure of such interventions easier the authors propose a marking device, a screwdriver and a device allowing the fixture's curvature to be regulated. The modification of the technique and using a specially developed extractor is explained by difficulties in removing the fixture by common methods. The variant of the improved instrumental tooling proposed by the authors makes the operation more handy and practicable. 相似文献
80.
Generalized angular coefficients are calculated with consideration of selectivity in absorption by the medium which consists of gaseous CO2 and H2O.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 50, No. 1, pp. 98–104, January, 1986. 相似文献