全文获取类型
收费全文 | 312篇 |
免费 | 10篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 6篇 |
化学工业 | 91篇 |
金属工艺 | 10篇 |
机械仪表 | 7篇 |
建筑科学 | 4篇 |
矿业工程 | 3篇 |
能源动力 | 2篇 |
轻工业 | 6篇 |
水利工程 | 1篇 |
石油天然气 | 4篇 |
无线电 | 37篇 |
一般工业技术 | 84篇 |
冶金工业 | 17篇 |
原子能技术 | 5篇 |
自动化技术 | 46篇 |
出版年
2023年 | 3篇 |
2022年 | 12篇 |
2021年 | 8篇 |
2020年 | 15篇 |
2019年 | 17篇 |
2018年 | 10篇 |
2017年 | 14篇 |
2016年 | 15篇 |
2015年 | 8篇 |
2014年 | 11篇 |
2013年 | 18篇 |
2012年 | 21篇 |
2011年 | 17篇 |
2010年 | 8篇 |
2009年 | 10篇 |
2008年 | 6篇 |
2007年 | 11篇 |
2006年 | 2篇 |
2005年 | 5篇 |
2004年 | 7篇 |
2003年 | 5篇 |
2002年 | 5篇 |
2001年 | 6篇 |
2000年 | 6篇 |
1999年 | 2篇 |
1998年 | 4篇 |
1997年 | 3篇 |
1996年 | 5篇 |
1995年 | 5篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 2篇 |
1991年 | 3篇 |
1989年 | 4篇 |
1988年 | 3篇 |
1987年 | 2篇 |
1986年 | 3篇 |
1984年 | 7篇 |
1982年 | 2篇 |
1980年 | 2篇 |
1979年 | 2篇 |
1978年 | 2篇 |
1977年 | 3篇 |
1973年 | 2篇 |
1970年 | 2篇 |
1969年 | 6篇 |
1968年 | 2篇 |
1966年 | 1篇 |
1965年 | 2篇 |
1962年 | 2篇 |
排序方式: 共有323条查询结果,搜索用时 15 毫秒
11.
A. V. Bogachev E. A. Vorob’eva N. E. Zubov E. A. Mikrin M. Sh. Misrikhanov V. N. Ryabchenko S. N. Timakov 《Journal of Computer and Systems Sciences International》2011,50(3):483-490
The problem of gravitational unloading of the angular momentum of inertial actuators of a spacecraft in the pitch channel
for circular and elliptic orbits is considered using the band theory of modal control. Control laws for gravitational unloading
and stabilization of a given spacecraft position unambiguously determined by the object parameters and given coefficients
of characteristic equation are obtained. 相似文献
12.
Attempts to carry out the hydroformylation of allyldiethylamine homogeneously catalyzed by rhodium complexes led to unexpected formation of N,N,N,N-tetraethyl-1,4-diaminobutane and 4-(diethylamino)-1-butanole as final products. The role of the catalyst on the product formation and the reaction mechanism are briefly discussed. 相似文献
13.
We propose a method for the recalculation of dynamic stresses from a photoelastic model to a real solid in plane problems of the mechanics of orthotropic bodies. To estimate the accuracy of the method, we recalculate stresses for a problem with known theoretical solution. 相似文献
14.
Test results for different high-strength steel specimens in static and impact tension and compression over a wide range of strain rates were summarized. These data were used to calculate the generalized deformation curve. The calculations based on this curve were compared with the experimental data on impact indentation with the conical indenter to evaluate the applicability of this method for studying the behavior of metals at high strain rates. 相似文献
15.
16.
N. E. Zubov E. A. Mikrin M. Sh. Misrikhanov V. N. Ryabchenko 《Journal of Computer and Systems Sciences International》2016,55(6):856-864
Based on band matrices, a new formula for finding polynomial coefficients of the numerator of the transfer function for a linear single-input single-output system is derived. Its properties are studied for analyzing and synthesizing linear systems with many outputs, as a result of which a method is developed for the synthesis of the specified polynomial of zero dynamics (specified output) for a linear system with many outputs. 相似文献
17.
Wenhao Xu Murong Wen Jingbo Yu Qihong Zhang Nikolay E. Polyakov Alexandr V. Dushkin 《Drug development and industrial pharmacy》2013,39(12):1924-1932
AbstractIn this study, complexes of kaempferol (KF) with polysaccharide arabinogalactan (AG) and disodium glycyrrhizinate (Na2GA) were prepared through mechanochemical technique to improve the solubility and bioavailability of KF. The physicochemical properties and the interactions of KF with AG/Na2GA were investigated through dissolution, SEM, XRD, and DSC studies. The reduction of particle sizes and destruction of crystal forms revealed the formation of solid dispersion which may have assisted the dissolution of the drug. The accelerated stability study showed higher stability for KF–Na2GA complex. In vivo pharmacokinetic study was performed to observe the plasma drug concentrations for KF complexes. Mechanochemical complexation of KF with AG/Na2GA improved the pharmacological activity as evident by the inhibitory potential of the complexes towards carbohydrate metabolic enzymes. In vivo studies were performed in STZ-induced diabetic mice, where the group treated with KF–AG complex showed better liver and kidney function and lower blood glucose levels than pure KF. Therefore, mechanochemical complexes of KF with polysaccharide or glycyrrhizate may serve as a promising formulation for the treatment of diabetes. 相似文献
18.
Alexandr Valentinovich Vinogradov Vladimir Valentinovich Vinogradov 《Journal of the American Ceramic Society》2014,97(1):290-294
Nowadays, it is a great challenge to synthesize crystalline TiO2 nanostructures using low‐temperature methods without annealing stage. Such an approach allows to perform functional and structural modification in the formed crystalline phase by thermally unstable compounds, such as biomaterials, MOFs, dye sets in situ, which was previously considered impossible. In this work, we have developed and analyzed the effect of acidic peptization on formation of highly photoactive titania crystallites in an aqueous solution using titanium tetraisopropylate as a precursor. Acids with different dissociation degrees in water were used as peptizing mediators to determine the effect of protonation on sol formation. The dip‐coating films were obtained with consequent drying of the sols via evaporation of the solvent. The as‐prepared catalysts were characterized by X‐ray diffraction, AFM microscopy, UV–V is spectroscopy, Brunauer–Emmett–Teller surface area. The aggregate size of TiO2 in the colloidal suspension solution was measured by dynamic light scattering. Photocatalytic activity of films was studied by decomposition of Rhodamine B dye. It is found that the size of colloids in an aqueous solution is proportional to the protonation degree of the surface of particles and does not depend on the [Ti4+]/[H+] ratio, and peptization under weakly acidic conditions leads to anisotropic rod‐like nanoparticles. The highest photocatalytic activity was exhibited by the TiO2–HCl‐based coatings, ~3.5 times higher than that of the Acet.‐prepared sample. 相似文献
19.
Y. A. Zubov S. N. Chvalun V. I. Selikhova M. B. Konstantinopolskaya N. Ph. Bakeev 《Polymer Engineering and Science》1992,32(17):1316-1324
A comparative study of the structure of uniaxially-oriented bulk samples of linear PE of various molecular weights over a wide range of draw ratios has been carried out by means of small and wide angle X-ray analysis, NMR-spectroscopy and DSC. The structure of oriented high molecular weight PE samples, prepared by drawing single crystal mats to draw ratios up to 200, have also been studied. A large number of unfolded tie-molecules have been found to exist in the trans-conformation in PE amorphous regions. These tie-molecules, which connect the adjacent crystallites along the axis of orientation, and are not large crystals, account for the high mechanical properties of these samples. It has been shown that in the course of the orientation process, chain unfolding in the amorphous regions is accompanied by the formation of continuous linear systems consisting of several coherent crystallites and tie-molecules. These are coherently aligned along the macromolecular axis. 相似文献
20.
Pavel P. Fedorov Vera Y. Proydakova Sergey V. Kuznetsov Valery V. Voronov Alexandr A. Pynenkov Konstantin N. Nishchev 《Journal of the American Ceramic Society》2020,103(5):3390-3400
The thermal analysis and X-ray powder diffraction studies of the Li2SO4–Na2SO4 system, including the high-temperature X-ray diffraction technique, have elucidated four phases of variable composition: three solid solutions based on the α-Li2SO4, α-Na2SO4, and α-LiNaSO4 high-temperature polymorphs, and a low-temperature β-LiNaSO4 phase. α-Na2SO4-Base solid solution disintegrates into two phases via a monotectoid phase transformation. It is quite probable that the monotectoid process is related to the conversion of the second-order phase transition to the first-order phase transition. 相似文献