全文获取类型
收费全文 | 3473篇 |
免费 | 129篇 |
国内免费 | 43篇 |
专业分类
电工技术 | 6篇 |
综合类 | 191篇 |
化学工业 | 1246篇 |
金属工艺 | 40篇 |
机械仪表 | 15篇 |
建筑科学 | 33篇 |
矿业工程 | 31篇 |
能源动力 | 11篇 |
轻工业 | 1839篇 |
水利工程 | 2篇 |
石油天然气 | 16篇 |
无线电 | 31篇 |
一般工业技术 | 94篇 |
冶金工业 | 48篇 |
原子能技术 | 12篇 |
自动化技术 | 30篇 |
出版年
2024年 | 9篇 |
2023年 | 17篇 |
2022年 | 63篇 |
2021年 | 92篇 |
2020年 | 61篇 |
2019年 | 59篇 |
2018年 | 54篇 |
2017年 | 67篇 |
2016年 | 49篇 |
2015年 | 77篇 |
2014年 | 138篇 |
2013年 | 163篇 |
2012年 | 239篇 |
2011年 | 292篇 |
2010年 | 179篇 |
2009年 | 147篇 |
2008年 | 147篇 |
2007年 | 279篇 |
2006年 | 260篇 |
2005年 | 241篇 |
2004年 | 189篇 |
2003年 | 150篇 |
2002年 | 106篇 |
2001年 | 99篇 |
2000年 | 109篇 |
1999年 | 81篇 |
1998年 | 81篇 |
1997年 | 56篇 |
1996年 | 33篇 |
1995年 | 29篇 |
1994年 | 22篇 |
1993年 | 19篇 |
1992年 | 12篇 |
1991年 | 6篇 |
1990年 | 5篇 |
1988年 | 5篇 |
1987年 | 1篇 |
1986年 | 4篇 |
1985年 | 4篇 |
1959年 | 1篇 |
排序方式: 共有3645条查询结果,搜索用时 15 毫秒
1.
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
2.
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
3.
4.
Basem Abdullah & Rula Al-Najdawi 《International Journal of Food Science & Technology》2005,40(5):537-543
Samples of chicken meat from spent laying hens were obtained by four different methods: (1) manual deboning of whole carcasses; (2) manual deboning of skinned carcasses; (3) mechanical deboning of whole carcasses; and (4) mechanical deboning of skinned carcasses. The meat was packaged, frozen and stored at ?18 °C for up to 3 months. Functional properties studied were pH, emulsifying capacity (EC) and water‐holding capacity (WHC) and, in addition, pigment concentration was investigated. Sensory properties included aroma, colour, texture and overall acceptability, as judged by a trained panel using a nine‐point hedonic scale. Removal of the skin prior to deboning by either method gave significantly higher values (P < 0.05) for EC, while WHC values were not significantly different among the experimental treatments, despite higher pH values for mechanically‐deboned meat, with and without skin. Pigment concentrations were highest in meat from Treatment 4 and lowest for Treatment 1, but values for both methods of deboning were affected by the presence of skin. There were no significant differences between treatments for any of the sensory properties studied. Changes occurring in the meat during frozen storage are described. 相似文献
5.
Colour extension properties of individual pigments and effects on shades of foundations in cake form
AKIRA TSUGITA TAKASHI FUKISHIMA TOHRU YONEYA YASUSH INISHIJIMA 《International journal of cosmetic science》1985,7(1):15-27
The mechanism of colour change during the pigment dispersion process and during powder application to the skin surface was studied by examining the colour extension properties of Yellow. Red , and Black iron oxides in white powder bases. A new measure for the evaluation of the degree of colour extension was devised. This measure corresponded well with human visual sensation, and was found to be useful for comparing the rates of colour extension of pigments. The rate of colour extension of pigments was found to vary in the order: Yellow acicular Red granular Red Black. This result explains colour darkening and the change towards reddish tones during the pigment dispersion process, because Yellow extends fully in the early stage of the process but Red , especially in granular form, and Black continue to extend even in the later stage. Acicular Red iron oxide is more favourably employed than the granular form to attain sufficient colour extension of foundations with lower energy expenditure, and to decrease the discrepancy between the cake colour and the colour of applied powder.
Le développement des oxydes de fer et effet sur les nuances des fonds de teint compacts 相似文献
Le développement des oxydes de fer et effet sur les nuances des fonds de teint compacts 相似文献
6.
7.
8.
9.
10.
用MOCVD法制备铁系云母珠光颜料 总被引:7,自引:0,他引:7
以Fe(CO) 5为物源 ,在常压喷动流化反应器中 ,以金属有机化学气相沉积 (MOCVD)法对云母粉进行包覆 ,制备铁系 -云母珠光颜料。实验结果表明 :在沉积温度 2 5 0℃ ,氧气流量 3mL·s-1,沉积时间 5min时能得到棕色色泽的珠光颜料 ;随着沉积温度的提高和反应时间的延长 ,可获得红棕、金红、橙红、深红等不同色泽的珠光颜料。用色差仪测定颜料的明度值L 、红度值a 、黄度值b ;X衍射仪表征颜料的表面成分 ;酸滴定计算氧化物的涂覆率。探讨了温度、时间、氧量对珠光颜料表面成分和珠光光泽的影响 相似文献