全文获取类型
收费全文 | 3939篇 |
免费 | 196篇 |
国内免费 | 43篇 |
专业分类
电工技术 | 4篇 |
综合类 | 224篇 |
化学工业 | 1460篇 |
金属工艺 | 46篇 |
机械仪表 | 25篇 |
建筑科学 | 34篇 |
矿业工程 | 27篇 |
能源动力 | 13篇 |
轻工业 | 2023篇 |
水利工程 | 2篇 |
石油天然气 | 17篇 |
武器工业 | 3篇 |
无线电 | 41篇 |
一般工业技术 | 131篇 |
冶金工业 | 86篇 |
原子能技术 | 11篇 |
自动化技术 | 31篇 |
出版年
2024年 | 8篇 |
2023年 | 30篇 |
2022年 | 78篇 |
2021年 | 115篇 |
2020年 | 73篇 |
2019年 | 68篇 |
2018年 | 55篇 |
2017年 | 83篇 |
2016年 | 69篇 |
2015年 | 93篇 |
2014年 | 145篇 |
2013年 | 172篇 |
2012年 | 288篇 |
2011年 | 324篇 |
2010年 | 202篇 |
2009年 | 178篇 |
2008年 | 178篇 |
2007年 | 312篇 |
2006年 | 287篇 |
2005年 | 269篇 |
2004年 | 211篇 |
2003年 | 160篇 |
2002年 | 129篇 |
2001年 | 104篇 |
2000年 | 117篇 |
1999年 | 88篇 |
1998年 | 87篇 |
1997年 | 65篇 |
1996年 | 38篇 |
1995年 | 39篇 |
1994年 | 27篇 |
1993年 | 24篇 |
1992年 | 15篇 |
1991年 | 10篇 |
1990年 | 12篇 |
1989年 | 2篇 |
1988年 | 6篇 |
1987年 | 4篇 |
1986年 | 2篇 |
1985年 | 3篇 |
1984年 | 4篇 |
1982年 | 3篇 |
1981年 | 1篇 |
排序方式: 共有4178条查询结果,搜索用时 15 毫秒
1.
Cryogels based on poly(vinyl alcohol) [PVA] and three types of bioinsertions such as scleroglucan, cellulose microfibers, and zein, respectively, have been prepared using capacity of PVA to crosslink by repeated freezing–thawing cycles. The effect of the incorporation of biopolymers on the properties of PVA cryogel has been studied by using several techniques such as: scanning electron microscopy, differential scanning calorimetry, and Fourier transform infrared studies. The obtained biobased cryogel membranes were subjected to sorption and to diffusion experiments using Crystal Violet (CV), a dye commonly used in the textile industry and in medicine. Image analysis with CIELAB system was used both to monitor the cryogels loading with CV and to gain insight in the dye state into the gel, in correlation with the bioinsertion type and gels morphology. Dye diffusion but also sorption capacity of the cryogels was found to be closely related to the type of biopolymer. In this article the equilibrium (sorption isotherms) and transport properties (diffusion and permeability coefficients) of CV, in/through physical cross‐linked PVA hydrogel membranes with bioinsertions has been reported. The highest efficiency for the CV removal from aqueous solutions was obtained for the PVA/Scl cryogels. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 41838. 相似文献
2.
3.
Heat resistant coatings are required primarily for stacks, exhaust pipes, reactors, space crafts and similar equipments that are permanently or occasionally exposed to elevated temperatures. High-temperature coatings are generally based on silicone resin with ceramic and metallic pigments. In this study, iron oxide, cobalt oxide (thermo chromic compound) and aluminum oxide are used for the preparation of four new types of coloured pigments. The thermal resistant characteristics of these ceramic pigments were studied by differential thermal analysis, thermo gravimetric analysis and differential scanning calorimetric analysis. These ceramic pigments are found to be thermally stable up to 400 °C. 相似文献
4.
The work focuses on the synthesis of a red ceramic pigment by inclusion of hematite in a fumed silica matrix with different specific surface areas. Iron(II) sulfate was used as hematite precursor. Mixtures of iron(II) sulfate and fumed silica with different mole ratios were heated at different temperatures from 1000 to 1300 °C for 4 h. 相似文献
5.
6.
7.
着色型珠光颜料涂布纸的研制 总被引:1,自引:1,他引:0
本文论述了着色型珠光颜料涂布纸的研制工作,并对影响珠光涂料制备的几个因素进行探讨.优化结果表明,瓷土0~30%,珠光颜料70%~100%,胶粘剂25%~30%,固含量23%~25%,涂布量10~15g/m2时,其纸面呈现强烈的珠光光泽,适用于胶印. 相似文献
8.
9.
新疆茶藨中紫红色素的萃取工艺及稳定性研究 总被引:4,自引:1,他引:3
本文介绍了新疆野生植物茶子果实中,紫红色素提取及定性检验和色素的提取工艺。 相似文献
10.