全文获取类型
收费全文 | 1800篇 |
免费 | 28篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 106篇 |
化学工业 | 333篇 |
金属工艺 | 27篇 |
机械仪表 | 28篇 |
建筑科学 | 76篇 |
矿业工程 | 7篇 |
能源动力 | 49篇 |
轻工业 | 114篇 |
水利工程 | 22篇 |
石油天然气 | 4篇 |
无线电 | 116篇 |
一般工业技术 | 238篇 |
冶金工业 | 433篇 |
原子能技术 | 16篇 |
自动化技术 | 261篇 |
出版年
2021年 | 20篇 |
2020年 | 17篇 |
2019年 | 25篇 |
2018年 | 30篇 |
2017年 | 22篇 |
2016年 | 25篇 |
2015年 | 20篇 |
2014年 | 36篇 |
2013年 | 94篇 |
2012年 | 49篇 |
2011年 | 78篇 |
2010年 | 70篇 |
2009年 | 53篇 |
2008年 | 59篇 |
2007年 | 78篇 |
2006年 | 53篇 |
2005年 | 51篇 |
2004年 | 46篇 |
2003年 | 53篇 |
2002年 | 46篇 |
2001年 | 31篇 |
2000年 | 32篇 |
1999年 | 28篇 |
1998年 | 78篇 |
1997年 | 59篇 |
1996年 | 47篇 |
1995年 | 48篇 |
1994年 | 45篇 |
1993年 | 26篇 |
1992年 | 18篇 |
1991年 | 15篇 |
1990年 | 24篇 |
1989年 | 18篇 |
1988年 | 25篇 |
1987年 | 30篇 |
1986年 | 21篇 |
1985年 | 31篇 |
1984年 | 18篇 |
1983年 | 22篇 |
1982年 | 22篇 |
1981年 | 21篇 |
1980年 | 14篇 |
1979年 | 26篇 |
1978年 | 19篇 |
1977年 | 21篇 |
1976年 | 20篇 |
1975年 | 25篇 |
1974年 | 13篇 |
1973年 | 15篇 |
1971年 | 13篇 |
排序方式: 共有1830条查询结果,搜索用时 15 毫秒
1.
Rodrigo Montoya Allan G. Ruiz-García Alma Ortiz-Ozuna Blanca Ramírez-Barat Juan Genesca 《工业材料与腐蚀》2021,72(7):1259-1269
The electrochemical interactions between aluminum alloy 7075 and low-carbon steels under gelled electrolytes were studied. Such electrolytes provided the opportunity to investigate both thick and thin electrolyte systems. The electrolyte was chemically modified to visually track the acidic fronts during the anodic reaction and the subsequent hydrolysis process. Two mathematical models were validated for both thick and ultrathin electrolytes. The acidification of thick electrolytes was extended some millimeters beyond the aluminum alloy surface, whereas the acidic front was localized next to the metallic joint using ultrathin electrolytes. The combination of both numerical and experimental results allows proving (and explaining why) that the acidification process is more aggressive under dilute than under concentrated electrolytes. 相似文献
2.
Jie Hong Chiang Allan K. Hardacre Michael E. Parker 《International Journal of Food Science & Technology》2020,55(2):649-659
This study investigated the effects of moisture content (MC) on the physicochemical properties of extruded meat alternatives made from Maillard-reacted beef bone hydrolysate and plant proteins. Samples were extruded at 170 °C (maximum barrel temperature), at 3.6 kg h−1 (liquid feed rate) and at 1.8, 2.2, 2.6 and 3.0 kg h−1 (dry feed rates) to obtain MC of 60%MC, 56%MC, 52%MC and 49%MC, respectively. Meat alternatives at 52%MC showed the greatest degree of texturisation. However, meat alternatives at 49%MC were the closest in terms of both textural and microstructural properties to reference sample, boiled chicken breast. Results from protein solubility suggested that a large amount of aggregated proteins were associated with hydrogen bonds, while disulphide bonds were the main contributor in the formation of fibrous structure in meat alternatives. Results showed that the change in MC as process parameter played an important role in the formation of fibrous structure in extruded meat alternatives. 相似文献
3.
4.
5.
Fermented Nut‐Based Vegan Food: Characterization of a Home made Product and Scale‐Up to an Industrial Pilot‐Scale Production 下载免费PDF全文
6.
A diffusion-based kinetic model for resin-based ion exchange is proposed that simultaneously describes extra- and intraparticle diffusion for the purpose of predicting batch transient adsorption rates during resin operation. The extraparticle diffusion is simulated through Newton's-law-of-cooling assuming a stagnant laminar layer, while the intraparticle simulation assumes a homogeneous internal pore environment and uses the Nernst–Planck equation to describe multi-ion diffusion. The key parameters of the model are the mass transfer coefficient, the intrinsic diffusivities of the adsorbing and desorbing ions and the equilibrium coefficient associated with the Mass-Action-Law, which is assumed to be applicable at the liquid/resin interface. A novel method is described to determine the critically important ion concentration at the interface from experiment. Kinetic tests are undertaken in a closed circuit system, adsorbing Na, Mg, and Ba ions separately onto gel type acid resin, and the simulation is fitted to the measured raw data using the Hook–Jeeves search algorithm. The intraparticle diffusivities of the three ions are hence measured and reported. 相似文献
7.
Behaviormetrika - In the original publication of the article, Appendix A was published incorrectly. 相似文献
8.
安利路位于阿德莱德大城市地区南部近郊,它是澳大利亚大城市中相当常见的“中心大街”的一个缩影。本文通过南澳大利亚大学规划专业学生在社区调查基础上进行的项目研究,反映了安利路作为中心大街商业区的主要特征、对安利路形成竞争的因素、对安利路产生影响的问题,并探讨了从社区愿望出发对安利路进行改善的方法和管理战略。 相似文献
9.
A power-supply unit for pulsed lasers that are pumped by low- and medium-power flashlamps with long pump pulses that does not require a capacitive storage unit is described. The pump-pulse duration is limited by the radiation and thermal stability of the active elements and pump lamps. A functional diagram of the power-supply unit and a circuit diagram of its power system are presented. The basic parameters and elements of this unit, as well as the results of using a laser with the described power supply in experiments, are presented. 相似文献
10.
White James F. Holladay Johnathan E. Zacher Allan A. Frye John G. Werpy Todd A. 《Topics in Catalysis》2014,57(17):1325-1334
Fermentation derived succinic acid ammonium salt is an ideal precursor for manufacture of renewable N-methyl pyrrolidinone (NMP) or 2-pyrrolidinone (2P) via heterogeneous catalysis. However, there are many challenges to making this a practical reality. Chief among the challenges is avoiding catalyst poisoning by fermentation by- and co-products. Battelle/Pacific Northwest National Laboratory have developed an effective technology strategy for this purpose. The technology is a combination of purely thermal processing, followed by simple catalytic hydrogenation that together avoids catalyst poisoning from fermentation impurities and provides high selectivity and yields of NMP or 2P.
相似文献