全文获取类型
收费全文 | 307篇 |
免费 | 1篇 |
国内免费 | 5篇 |
专业分类
化学 | 55篇 |
力学 | 2篇 |
综合类 | 4篇 |
数学 | 1篇 |
物理学 | 9篇 |
综合类 | 242篇 |
出版年
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 4篇 |
2019年 | 3篇 |
2018年 | 2篇 |
2017年 | 4篇 |
2016年 | 2篇 |
2015年 | 3篇 |
2014年 | 8篇 |
2013年 | 6篇 |
2012年 | 7篇 |
2011年 | 8篇 |
2010年 | 5篇 |
2009年 | 12篇 |
2008年 | 11篇 |
2007年 | 18篇 |
2006年 | 19篇 |
2005年 | 11篇 |
2004年 | 24篇 |
2003年 | 16篇 |
2002年 | 24篇 |
2001年 | 14篇 |
2000年 | 9篇 |
1999年 | 17篇 |
1998年 | 12篇 |
1997年 | 10篇 |
1996年 | 4篇 |
1995年 | 11篇 |
1994年 | 14篇 |
1993年 | 11篇 |
1992年 | 6篇 |
1991年 | 3篇 |
1990年 | 3篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1981年 | 1篇 |
排序方式: 共有313条查询结果,搜索用时 140 毫秒
1.
The shrink proofing on wool with treatment of protease named Argaenzyme STL was studied. The various pretreating auxiliaries, different parameters for protease treating process and the effect of stabilizer were discussed in detail. The varieties of some properties before and after protease treatment were also investigated. 相似文献
2.
298K毛吸附溴化烷基三甲铵的性质及自由能 总被引:1,自引:0,他引:1
用液 /固吸附计量置换模型 ( SDM- A) ,研究了 2 98K羊毛纤维吸附溴化烷基三甲铵阳离子表面活性剂 CTAB和 DTAB的吸附等温线 ,结果表明它们均遵从 SDM- A的线性作图关系 .用 SDM-A的线性参数βα 和 q/z很好地描述了碳氢链长及加盐效应对于吸附性质的影响规律 ,特别是能定量地描述加盐效应对于吸附同时具有的促进和抵消两种相反作用的程度 ,并用 SDM- A的热力学 ,由线性参数计算得到了不同体系的吸附亲和能 ΔGA,解吸能 ΔGD 及总过程的自由能 ΔGP.一个吸附体系中 ,ΔGA 为常数且为较大的负值 ;ΔGD 为随溶液体相浓度 c增大而增大的正值 ;ΔGP为与 lgc呈线性关系的较小的负值 .计算所得结果能很好地解释实验事实 ,并可从更深层次上揭示吸附机理 . 相似文献
3.
通过前臂试验对26种轻薄型羊毛机织精纺面料和7种其他纤维的轻薄型机织面料的刺痒感进行了比较研究,并用显微镜对部分轻薄型羊毛机织面料的表面纤维分布进行了研究。结果表明多数毛织物在温度为(24±1)℃、相对湿度为(65±5)%的条件下存在刺痒感,并且毛织物的刺痒感与其表面纤维的平面直径及直径大于26μm的表面纤维根数密切相关。 相似文献
4.
应赛丹 《西安工程科技学院学报》1994,(1)
根据国产原毛表面各种污染物的特点、分布状态及其去除过程,提出了原毛表面污染物去除过程的四个阶段:润湿阶段、溶胀阶段、快速去污阶段和慢速去污阶段;原毛表面污染物可分为附着层、混凝层和结合层。各层污染物在纤维表面附着状态不同、结合形式不同,因而各污染物洗涤难易程度和去除机理各不相同.结合层污染物较难去除,洗涤时针对结合层污染物特点需采用特殊工艺。 相似文献
5.
As most sample liquids tend to pass through an empty injector insert at a speed which is too high to enable complete evaporation, movement of the liquid must be arrested before it reaches the column entrance. Stopping the liquid means deposition on to a surface; this, however, is possible only after the temperature of the surface has been cooled to (or below) the boiling point of the liquid (solvent). The performance of different means of stopping the liquid has been tested visually (by the method described in Part 2). Baffles on the wall of the injector insert had hardly any effect on evaporation: the band of liquid leaving the syringe needle performed a perfect slalorn around them. The inverted cup proved more efficient, but the best performance was obtained from a light plug of glass wool: owing to its low thermal mass, the first fibers to be met by the liquid are immediately cooled to the solvent boiling point, allowing the liquid to wet it. The sample liquid is sucked up by the glass wool, from where the sample evaporates relatively slowly, often over a period of several seconds. 相似文献
6.
Zhenya Zhang Taisheng Quan Pomin Li Yansheng Zhang Norio Sugiura Takaaki Maekawa 《Applied biochemistry and biotechnology》2004,115(1-3):1033-1039
We studied biogas fermentation from alcohol waste fluid to evaluate the anaerobic digestion process and the production of
vitamin B12 as a byproduct. Anaerobic digestion using acclimated methanogens was performed using the continuously stirred tank reactor
(CSTR) and fixed-bed reactor packed with rock wool as carrier material at 55°C. We also studied the effects of metal ions
added to the culture broth on methane and vitamin B12 formation. Vitamin B12 production was 2.92 mg/L in the broth of the fixed-bed reactor, twice that of the CSTR. The optimum concentrations of trace
metal ions added to the culture liquid for methane and vitamin B12 production were 1.0 and 8 mL/L for the CSTR and fixed-bed reactor, respectively. Furthermore, an effective method for extracting
and purifying vitamin B12 from digested fluid was developed. 相似文献
7.
The way to measure quantitatively full dissolution and crystallization of polyamides in water up to 200 °C and above by DSC is described. Stainless-steel high-pressure pans enable research on fully dissolving polyamides in water under vapor pressure. The results show clearly that polyamide 6 (PA6) is soluble in water under vapor pressure in the whole concentration range and that water acts as a crystallization and melting point suppressor. The maximum temperature depression is approximately 60 °C. This depression of the transitions is independent of concentration over a large range (10-70 mass% PA6 in water). When PA6 dissolves in water during heating, the polymer often sets to the sides of the DSC sample pan. Because of this the contact between the sample and the bottom of the pan reduces during measurement and therefore DSC heating curves are frequently curved. Adding steel wool to these stainless-steel high-pressure pans improves the measurements by increasing the thermal conductivity between the sample and pan bottom, and as a result the DSC curves become less curved. The interpretation of the measurements improves and the possibility of reproducible peak area calculations also in heating comes in sight. 相似文献
8.
拉伸羊毛分子结构的显微红外光谱分析 总被引:1,自引:0,他引:1
应用显微镜偏振红外光谱法分析了拉伸羊毛纤维大分子结构的变化,通过对特征谱带的分析,得到了羊毛大分子链段结构和大分子构象随拉伸率的变化情况;由此可知,显微红外光谱具有很高的灵敏度,应用偏振显微红外光谱可以准确地对纤维大分子结构的变化进行分析和表征。 相似文献
9.
报道了高号数高比例粗纺针织牦牛绒衫产品开发的生产工艺。牦牛绒产品的开发前景良好,颇有潜力。但其分梳、纺纱、织衫及后整理等加工工艺有一定的特殊性。文未还对今后的研究方向提供了几点意见。 相似文献
10.
利用扫描电镜观测法,通过对产地采集的山羊原绒、牦牛绒和绵羊毛进行鳞片结构的观察和分析,对解决商贸中的羊绒含量纠纷可起到有效的鉴别作用。确立我国国际权威性的羊绒检测机构,提高羊绒制品品质,重视品牌和商贸诚信,将有利于我国羊绒制品国际贸易的顺利发展。 相似文献