全文获取类型
收费全文 | 5864篇 |
免费 | 541篇 |
国内免费 | 213篇 |
专业分类
电工技术 | 538篇 |
综合类 | 379篇 |
化学工业 | 1775篇 |
金属工艺 | 227篇 |
机械仪表 | 170篇 |
建筑科学 | 366篇 |
矿业工程 | 269篇 |
能源动力 | 320篇 |
轻工业 | 752篇 |
水利工程 | 137篇 |
石油天然气 | 263篇 |
武器工业 | 15篇 |
无线电 | 263篇 |
一般工业技术 | 332篇 |
冶金工业 | 716篇 |
原子能技术 | 20篇 |
自动化技术 | 76篇 |
出版年
2024年 | 23篇 |
2023年 | 75篇 |
2022年 | 105篇 |
2021年 | 145篇 |
2020年 | 176篇 |
2019年 | 144篇 |
2018年 | 141篇 |
2017年 | 158篇 |
2016年 | 175篇 |
2015年 | 170篇 |
2014年 | 322篇 |
2013年 | 302篇 |
2012年 | 496篇 |
2011年 | 510篇 |
2010年 | 334篇 |
2009年 | 375篇 |
2008年 | 321篇 |
2007年 | 452篇 |
2006年 | 361篇 |
2005年 | 353篇 |
2004年 | 269篇 |
2003年 | 231篇 |
2002年 | 186篇 |
2001年 | 180篇 |
2000年 | 150篇 |
1999年 | 99篇 |
1998年 | 82篇 |
1997年 | 69篇 |
1996年 | 51篇 |
1995年 | 33篇 |
1994年 | 25篇 |
1993年 | 24篇 |
1992年 | 19篇 |
1991年 | 13篇 |
1990年 | 9篇 |
1989年 | 12篇 |
1988年 | 6篇 |
1987年 | 6篇 |
1986年 | 3篇 |
1985年 | 5篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 2篇 |
1951年 | 1篇 |
排序方式: 共有6618条查询结果,搜索用时 15 毫秒
1.
M. R. Thompson 《Drug development and industrial pharmacy》2015,41(8):1223-1231
Twin screw granulation (TSG) is a new process of interest to the pharmaceutical community that can continuously wet granulate powders, doing so at lower liquid concentrations and with better product consistency than found by a high shear batch mixer. A considerable body of research has evolved over the short time since this process was introduced but generally with little comparison of results. A certain degree of confidence has been developed through these studies related to how process variables and many attributes of machinery configuration will affect granulation but some major challenges still lay ahead related to scalability, variations in the processing regimes related to degree of channel fill and the impact of wetting and granulation of complex powder formulations. This review examines the current literature for wet granulation processes studied in twin screw extrusion machinery, summarizing the influences of operational and system parameters affecting granule properties as well as strives to provide some practical observations to newly interested users of the technique. 相似文献
2.
Muralidhar N. Ingale Vijaykumar V. Mahajani 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》1995,64(1):80-86
The effectiveness of the hybrid system sonication followed by wet oxidation (SONIWO) to treat otherwise refractory waste has been demonstrated. In such a hybrid system homogeneous CuSO4 catalyst was found to be very efficient. 相似文献
3.
济钢燃气厂针对济钢转炉煤气储存加压系统的设备现状,组织了一次设备大修,大修后煤气柜升降速度提高到了1.0m/min,并解决了加压机前负压等问题。 相似文献
4.
5.
介绍了湿法炉保护的作用原理,YZ—101防腐阻垢剂的使用方法、注意事项以及使用后所带来的经济效益。 相似文献
6.
本文重点讨论了硫氰酸钠湿纺腈纶设备因钝化膜缺陷和Cl-侵入而产生孔蚀的机理及环境因素对孔蚀的影响,并针对产生孔蚀的主要原因提出了防护措施。 相似文献
7.
8.
The objective of this study is to determine the chemical kinetics of desulphurization of Thai limestone in an atmospheric fluidized bed combustor (AFBC). The experiments, which employed the batch technique using the limestone samples from six major sources in Thailand, were performed in a laboratory‐scale AFBC. The results obtained were analysed and correlated in the form of apparent reaction rate and deactivation rate constants as a function of operating conditions of the furnace and their properties, respectively. The formulae derived from these correlations were kept as general as possible in order that they could be used as input parameters for the selected mathematical model of desulphurization in an AFBC that is suitable for practical use. The predicted results were in good agreement with the experimental data reported in the literature. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
9.
The present work is to study the possibility for controlled distribution of the impurities when they are decomposed by sulphuric acid to wet phosphoric acid and phosphogypsum, as well as generating technological conditions for production of clean wet phosphoric acid and its derivatives - phosphoric fertilizers, food phosphates and other phosphoric products.A coefficient of distribution DA is introduced as a general criterion for elements dispersion. The study includes relationships between the weight ratio sulphuric acid/natural phosphate and DA; the period of decomposition and DA; the particle's size content of the natural phosphate and DA. The obtained experimental data and relationships about the influence of the above discussed technological parameters on dispersion of more than 23 elements allow for control of that process in wet phosphoric acid and phosphogypsum by selecting specific technological conditions. Thus, depending on the requirements of acid's consumers and procedures for secondary processing of phosphogypsum to end-products, a selective decomposition of the natural phosphates to phosphoric acid and phosphogypsum can be carried out with content of the impurities in those products varying in narrow limits. 相似文献
10.
针对攀钢当前和未来几年重点治污项目——烧结合硫烟气治理的实际需要,在世界十几种主要成熟的烟气脱硫工艺中,重点选取六种工业化应用程度较高的进行述评,分析了攀钢烧结烟气特性,对攀钢烧结烟气脱硫工艺选择提出了看法。 相似文献