全文获取类型
收费全文 | 140篇 |
免费 | 4篇 |
国内免费 | 4篇 |
专业分类
综合类 | 10篇 |
化学工业 | 60篇 |
金属工艺 | 9篇 |
机械仪表 | 1篇 |
建筑科学 | 5篇 |
能源动力 | 3篇 |
轻工业 | 3篇 |
水利工程 | 2篇 |
无线电 | 11篇 |
一般工业技术 | 43篇 |
自动化技术 | 1篇 |
出版年
2023年 | 1篇 |
2021年 | 1篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2017年 | 5篇 |
2016年 | 1篇 |
2015年 | 7篇 |
2014年 | 6篇 |
2013年 | 10篇 |
2012年 | 17篇 |
2011年 | 13篇 |
2010年 | 10篇 |
2009年 | 14篇 |
2008年 | 8篇 |
2007年 | 9篇 |
2006年 | 12篇 |
2005年 | 5篇 |
2004年 | 1篇 |
2003年 | 8篇 |
2002年 | 2篇 |
2001年 | 5篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1998年 | 4篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1990年 | 1篇 |
排序方式: 共有148条查询结果,搜索用时 17 毫秒
131.
以正硅酸乙酯(TEOS)为无机前驱体、三乙烯四胺(TETA)为固化剂和γ-氨丙基三乙氧基硅烷(KH-550)为硅烷偶联剂,采用溶胶-凝胶一步法制备SiO2/EP(环氧树脂)杂化材料。研究了TEOS和丙酮含量对杂化材料的力学性能、热性能等影响,并对杂化材料的微观相态结构和性能进行了表征和分析。结果表明:当w(TEOS)=3%(相对于改性EP质量而言)时,不加丙酮的杂化材料具有相对最好的综合性能,其断面形貌呈韧性断裂,热变形温度和玻璃化转变温度均高于纯EP体系,生成的SiO2粒径为20 nm左右且分布较均匀;加入丙酮后的杂化材料透明性变好,但其力学强度和热性能均随丙酮含量增加而降低。 相似文献
132.
本文搭建了一套大气压等离子体薄膜沉积系统,其装置采用喷枪方式,结合运动机构控制喷枪按特定轨迹移动镀膜。四乙氧基硅烷(TEOS)作为硅的先驱体,氮气为先驱体载气和等离子体放电气体,基底温度50℃~300℃,进行了大气压等离子体化学气相沉积氧化硅薄膜的研究。运用红外光谱(FTIR)、光学椭偏仪,扫描电镜(SEM)和纳米压痕仪对沉积的薄膜进行了表征。研究表明,薄膜中富含Si—O—Si键且有少量S—OH键;较高基底温度有利于在硅基底上得到一层平整致密的薄膜;基底温度300℃时薄膜硬度达到4.8GPa,略低于采用PECVD方法沉积的氧化硅薄膜。 相似文献
133.
Novel organic–inorganic hybrid films were synthesised through the reaction of epoxidised castor oil (ECO) with γ-glycidoxypropyltrimethoxysilane (GPTMS) and tetraethoxysilane (TEOS). The amounts of GPTMS employed were sufficient to react with 25, 50 or 75% of the epoxy groups present in the ECO, whilst the mass proportions of ECO to TEOS varied from 90:10 to 70:30. Films were pre-cured at room temperature under an inert atmosphere, and subsequently submitted to thermal curing. Macro and microscopic properties of the films, including adhesion, hardness, swelling in toluene, microstructure (scanning electron microscopy) and thermal properties were determined as a function of the proportion of organic to inorganic precursor. Morphologic studies showed that the hybrid films were microscopically homogeneous when lower proportions of inorganic precursors were employed. Hardness and tensile strength increased, and swelling in toluene decreased, with the increase in the concentration of inorganic precursors. Good adhesion of the films to an aluminium surface was observed throughout the hybrid series. 相似文献
134.
《Materials Science & Technology》2013,29(8):1062-1064
AbstractNd:YAG ceramics with CaF2 and tetraethoxysilane (TEOS) as sintering additives were fabricated by vacuum sintering at 1750°C for 5 h and the microstructures were characterised using X-ray diffraction and scanning electron microscopy. Scanning electron microscopy result shows that the sintered bulk doped with TEOS contains many pores in the grains. The bulk doped with CaF2 displays uniform microstructure. The average size of the grains is 10 mm and few pores can be detected in this sintered bulk. The maximum transmittance of the sintered Nd:YAG ceramics were 44% doped with CaF2 and 14% doped with TEOS. 相似文献
135.
136.
137.
W/O微乳体系酸催化水解硅酸乙酯合成单分散酸性超微二氧化硅 总被引:7,自引:0,他引:7
研究不同亲水亲油平衡值 (HLB)的Span80 Tween60表面活性剂复配体系对酸性水溶液微乳化增溶力的影响 ,最佳HLB值在 1 3左右 ,该体系用作超微或纳米粒子的微乳法合成体系。在水 (HNO3) /Span80 Tween60 /环己烷体系中水解硅酸乙酯(TEOS)合成了 1 1 0~ 550nm的单分散酸性超微二氧化硅粒子 ,研究了R(n水/n表)和H(n水/nTEOS)对粒径的影响 ,随着R的增大 ,粒径越小 ,达到最小值再增大 ;H越高 ,粒径越大。提出了W/O微乳体系酸催化水解TEOS合成二氧化硅粒子的过程模型 ,指出酸催化过程中缩聚凝结是晶核长大的重要方式 相似文献
138.
合成了一种硅钛柱撑蒙脱土微孔材料.用十六烷基三甲基溴化铵改性蒙脱土,制得有机蒙脱土,再以正硅酸乙酯为硅源,采用溶胶-凝胶法,在正硅酸乙酯-蒙脱土水溶液中加入四氯化钛,以四氯化钛作为硅柱前驱体进入粘土片层间反应的驱动力,在钛阳离子的驱动下,使正硅酸乙酯在蒙脱土的片层之间发生水解缩合反应,制备了硅钛柱撑蒙脱土微孔复合材料.用XRD、DTA以及N2吸附脱附测试,分别对材料进行了表征.XRD测试结果表明:复合材料的最大层间可达到17.7 A.;DTA测试结果表明:改性后蒙脱土复合材料的热稳定性明显提高了;N2吸附脱附曲线以及孔径分布曲线说明合成的多孔材料中多为微孔分布,平均单孔体积为0.14 cc/g,平均孔径达到17.5 A.,SBET表面积由30.2 m2/g增加到242.0 m2/g.这种材料以其柱撑多孔结构,作为环保材料如:吸收剂、催化剂应用,具有广阔的发展前景. 相似文献
139.
Muhammad Ali Zulfikar A. Wahab Mohammad Abdul Amir Kadhum Nidal Hilal 《应用聚合物科学杂志》2006,99(6):3163-3171
In this paper, hybrid organic–inorganic membranes were prepared using three different solvents and characterized. The hybrid membranes were fabricated using sol–gel technique, which had polymethyl‐methacrylate (PMMA) and tetraethyl orthosilicate (TEOS) as materials, with 80/20 ratio. The thin films were then characterized using FTIR, SEM, EDX, and mapping techniques. From the preliminary characterization, hybrid membranes were found to have nano and ultra scale tight‐pores ranges, which was influenced by the solvent used. The SEM images clearly show that hybrid membranes have homogenous and smooth surface. FTIR spectroscopy uncovered all the signature peaks characteristic of silicate structures in the near‐surface regions. Fingerprints of Si? O? Si groups in cyclic and linear molecular substructures were also present. From DSC analysis, the Tg value of the PMMA moieties in hybrids membranes was in the order H‐15‐Toluene < Pure PMMA < H‐15‐THF < H‐15‐DMF. Furthermore, from TGA analysis it was found that the hybrid membranes have higher thermal stability compared with that of pure PMMA. EDX and mapping analysis showed that the composition and distribution of particles in the membranes were different and dependent on the solvents used. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci, 2006 相似文献
140.
Biological application of sol–gel matrices has been extensively used through doping process. However the bioactivity of these materials is impaired mainly by uneven distribution of the biological molecules into the sol–gel matrix. The main objective of the present study was to apply electrophoretic field in order to concentrate biomolecules alongside sol–gel surface in order to increase the interaction capability with external molecules. Two potential applications of an electrophoretic field on sol–gel matrices were demonstrated. Silica gels in solid and liquid states were used as an electrophoretic matrix. In the first application, cylindrical rods made of solid silica gel and filled with tracking dye at one end, were subjected to applied electrical field. A well-defined movement of the tracking dye was attained from one edge to the other under applied electrophoretic current through the sol–gel rod pores. In the second application, accumulation of small biomolecules at one pole was obtained in a liquid pre-gelation sol–gel matrix during its polymerization. In order to optimize biologically active compounds movement in electrical field applied to sol–gel matrixes, parameters of both sol–gel and electrophoretic processes were studied. Under optimal conditions, it was feasible to increase the concentration of small biomolecules at sol–gel surface and consequently to enhance their availability towards external reactants. 相似文献