全文获取类型
收费全文 | 859篇 |
免费 | 23篇 |
专业分类
电工技术 | 16篇 |
综合类 | 9篇 |
化学工业 | 317篇 |
金属工艺 | 37篇 |
机械仪表 | 18篇 |
建筑科学 | 26篇 |
矿业工程 | 1篇 |
能源动力 | 54篇 |
轻工业 | 41篇 |
水利工程 | 10篇 |
石油天然气 | 2篇 |
无线电 | 70篇 |
一般工业技术 | 123篇 |
冶金工业 | 55篇 |
原子能技术 | 2篇 |
自动化技术 | 101篇 |
出版年
2023年 | 6篇 |
2022年 | 31篇 |
2021年 | 47篇 |
2020年 | 13篇 |
2019年 | 12篇 |
2018年 | 15篇 |
2017年 | 18篇 |
2016年 | 20篇 |
2015年 | 12篇 |
2014年 | 41篇 |
2013年 | 68篇 |
2012年 | 42篇 |
2011年 | 57篇 |
2010年 | 34篇 |
2009年 | 39篇 |
2008年 | 42篇 |
2007年 | 31篇 |
2006年 | 30篇 |
2005年 | 31篇 |
2004年 | 19篇 |
2003年 | 28篇 |
2002年 | 22篇 |
2001年 | 16篇 |
2000年 | 15篇 |
1999年 | 12篇 |
1998年 | 17篇 |
1997年 | 16篇 |
1996年 | 11篇 |
1995年 | 10篇 |
1994年 | 10篇 |
1993年 | 10篇 |
1992年 | 6篇 |
1991年 | 5篇 |
1990年 | 11篇 |
1989年 | 6篇 |
1988年 | 6篇 |
1987年 | 5篇 |
1986年 | 6篇 |
1985年 | 11篇 |
1984年 | 7篇 |
1983年 | 6篇 |
1981年 | 4篇 |
1980年 | 5篇 |
1979年 | 4篇 |
1977年 | 5篇 |
1976年 | 4篇 |
1975年 | 2篇 |
1971年 | 2篇 |
1965年 | 2篇 |
1956年 | 2篇 |
排序方式: 共有882条查询结果,搜索用时 16 毫秒
1.
Grzyb Janusz Pfeiffer Ullrich 《Journal of Infrared, Millimeter and Terahertz Waves》2015,36(10):998-1032
Journal of Infrared, Millimeter, and Terahertz Waves - The main scope of this paper is to address various implementation aspects of THz detector arrays in the nanoscale silicon technologies... 相似文献
2.
Wireless Personal Communications - For robust monitoring, control and proper energy management of renewable energy sources (RES), wireless sensing networks (WSNs) are proved to be a vital solution.... 相似文献
3.
Victor Chabanenko Roman Puźniak Adam Nabiałek Sergei Vasiliev Vladimir Rusakov Loh Huanqian Ritta Szymczak Henryk Szymczak Jan Jun Janusz Karpiński Vitaly Finkel 《Journal of Low Temperature Physics》2003,130(3-4):175-191
We present a study of magneto-thermal instabilities in polycrystalline MgB2 superconductor, by magnetic hysteresis loop measurements and by investigations of magnetic flux dynamics with a miniature Hall probe. Temperature and magnetic field ranges where the flux jumps may be observed have been determined. On the basis of measurements of the magnetic flux dynamics, an average magnetic diffusivity describing the process of the flux jump is estimated. This parameter is compared with the thermal and magnetic diffusivities calculated on the basis of available data for thermal conductivity, heat capacity and resistivity. It is shown that the estimated value of the field of the first flux jump is influenced significantly by the field dependence of specific heat. In order to explain the observed phenomenon, the temperature reached by the sample during the flux jump at different magnetic fields is calculated. 相似文献
4.
5.
Marek Markowski Ireneusz Bialobrzewski Janusz Bowszys Stanislaw Suchecki 《Drying Technology》2007,25(9):1527-1536
A neural-deterministic simulation model applied for calculating distributions of temperatures and moisture content in a bed of wheat stored in a steel silo without aeration is presented in the article. The model consists of differential equations of heat and moisture transfer, initial and boundary conditions, and three artificial neural networks used during simulated ambient air conditions. Experiments and computer simulations were carried out in order to determine temperature fields in wheat grain stored in a steel silo for two months. The computer simulations were carried using MATLAB and FEMLAB software. The difference between measured and simulated temperature in grain near the silo wall at a height of 2.5 m from the bottom was less than 3.0°C. On the basis of the analysis performed it was concluded that the temperature distributions obtained with the model were consistent with the measured results obtained for grain stored in a steel silo without aeration. 相似文献
6.
The objective of the present work is to further explore the problem of selection of the flow stress function which will give the best agreement with experiments for a wide range of the Zener‐Hollomon parameter. Analysis of various flow stress functions was performed, with particular emphasis on the Zerilli‐Armstrong model. Inverse analysis was successfully applied to identify the flow stress model for microalloyed steels deformed in ferrite, two‐phase and austenite regions. Inverse method is applied to interpret the results of the axisymmetrical compression tests performed for HSLA steel samples on a Gleeble 3800 and Split Hopkinson Pressure Bar. Sensitivity analysis is performed based on local and global methods. The objective of the sensitivity analysis in the present study is the evaluation to what extent the selected coefficients in the rheological model influence the result of simulations. In the considered tests this result is represented by two dependent variables, the load and the shape of the sample (barrelling). It is confirmed that the Zerilli‐Armstrong equations should be applied at very high strain rates. Physical meaning is an advantage of this model. Difficulties with identification are the main disadvantage. 相似文献
7.
The synthesis and characterization of a new series of hydrated uranium(III) complex chlorides of the general formula M1UCl4-3H2O (M1K, Rb or NH4) are reported. The compounds crystallize in the monoclinic system. Unit cell parameters were determined from X-ray powder diffraction data. The magnetic susceptibilities of the complex chlorides were measured by the Faraday method in the 4.2–300 K range. The compounds exhibit Curie-Weiss paramagnetism in the 100–300 K range, with the derived effective magnetic moments ranging from 3.57μB to 3.71μB. Solid state electronic and IR spectra were recorded in the 4000–30 000 and 80–4000 cm−1 ranges, respectively and discussed. Non-static high vacuum thermal dehydrations enabled us to obtain the anhydrous compounds KUCl4, RbUCl4 and UCl3. 相似文献
8.
Katarzyna Jasieniecka-Gazarkiewicz Kamil Demski Satinder K. Gidda Sylwia Kliska Janusz Niedojado Ida Lager Anders S. Carlsson Elena A. Minina Robert T. Mullen Peter V. Bozhkov Sten Stymne Antoni Bana 《International journal of molecular sciences》2021,22(6)
Arabidopsis thaliana possesses two acyl-CoA:lysophosphatidylethanolamine acyltransferases, LPEAT1 and LPEAT2, which are encoded by At1g80950 and At2g45670 genes, respectively. Both single lpeat2 mutant and double lpeat1 lpeat2 mutant plants exhibit a variety of conspicuous phenotypes, including dwarfed growth. Confocal microscopic analysis of tobacco suspension-cultured cells transiently transformed with green fluorescent protein-tagged versions of LPEAT1 or LPEAT2 revealed that LPEAT1 is localized to the endoplasmic reticulum (ER), whereas LPEAT2 is localized to both Golgi and late endosomes. Considering that the primary product of the reaction catalyzed by LPEATs is phosphatidylethanolamine, which is known to be covalently conjugated with autophagy-related protein ATG8 during a key step of the formation of autophagosomes, we investigated the requirements for LPEATs to engage in autophagic activity in Arabidopsis. Knocking out of either or both LPEAT genes led to enhanced accumulation of the autophagic adaptor protein NBR1 and decreased levels of both ATG8a mRNA and total ATG8 protein. Moreover, we detected significantly fewer membrane objects in the vacuoles of lpeat1 lpeat2 double mutant mesophyll cells than in vacuoles of control plants. However, contrary to what has been reported on autophagy deficient plants, the lpeat mutants displayed a prolonged life span compared to wild type, including delayed senescence. 相似文献
9.
The main objective of the paper is to establish an arrangement of sources of exergy losses (internal and external ones) and to estimate the value of the losses in an industrial ozone production installation. An exergetic model of industrial installation in a system approach corresponding to real conditions has been formulated. 相似文献
10.
An alternative solution to the reduction of a discharge of residual nitric oxide and nitrogen dioxide into atmosphere has been proposed. Instead of using methane or ammonia for SCR or gas absorption into alkali solutions, which are the most popular treatment methods of tail gases, now the use of powerful oxidant—ozone capable of transforming nitrous acid and nitric oxides into nitrogen of the highest oxidation level—could be employed for this purpose. As the intensive oxidation and ozonation of nitrous acid is the heterogeneous gas-liquid process, the solubility of oxygen and ozone in HNO2/HNO3 aqueous solution was necessary to be determined. Variations of reaction rates depending on temperature, ozone dose and nitrous and nitric acid concentrations were studied experimentally. The kinetic model of the reactions, 2HNO2+O2→2HNO3 and HNO2+O3→O2+HNO3, were proposed and the kinetic parameters (rate constants and activation energies) were estimated on the basis of experimental data in semi-batch laboratory gas-liquid contactor with the liquid phase drawn from an absorption column in the nitric acid plant. The determined kinetic parameters were then used in designing and modeling of the oxidation of nitrous acid using ozone-oxygen mixture in a continuous bubble column. The model consists of mass transfer kinetic equations and material balance equations for the gas and liquid phases. The co-current flow of gas and liquid phases and the complex kinetics of chemical reaction in the liquid phase were taken into account. The variation of the following process conditions, flow rate, compositions of the gas and liquid phases, temperature, and pressure in the bubble column of different diameters and heights, were studied in numerical solutions of the proposed model. 相似文献