首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   242篇
  免费   28篇
  国内免费   4篇
综合类   16篇
化学工业   122篇
金属工艺   4篇
机械仪表   2篇
建筑科学   11篇
矿业工程   49篇
能源动力   1篇
轻工业   28篇
水利工程   1篇
石油天然气   3篇
无线电   2篇
一般工业技术   29篇
冶金工业   6篇
  2024年   2篇
  2023年   5篇
  2022年   6篇
  2021年   6篇
  2020年   8篇
  2019年   8篇
  2018年   5篇
  2017年   8篇
  2016年   11篇
  2015年   9篇
  2014年   9篇
  2013年   14篇
  2012年   17篇
  2011年   10篇
  2010年   25篇
  2009年   8篇
  2008年   13篇
  2007年   15篇
  2006年   16篇
  2005年   12篇
  2004年   12篇
  2003年   10篇
  2002年   3篇
  2001年   11篇
  2000年   5篇
  1999年   2篇
  1998年   5篇
  1997年   1篇
  1996年   1篇
  1995年   3篇
  1994年   3篇
  1993年   1篇
  1992年   6篇
  1991年   1篇
  1989年   1篇
  1988年   1篇
  1979年   1篇
排序方式: 共有274条查询结果,搜索用时 46 毫秒
51.
金川矿石中脉石矿物易浮原因的探讨   总被引:1,自引:0,他引:1  
通过对金川原矿矿石性质研究和精矿及尾矿中硫化矿物的XPS表面测试、扫描电镜统计及能谱测试,探索了金川矿石中脉石矿物易浮的原因。结果表明,金川硫化物表面易与镁结合,蛇纹石表面常有墨铜矿及羟镁硫铁矿,这两个矿物在蛇纹石表面形成使蛇纹石向滑石转变,蛇纹石表面已滑石化或为蛇纹石与滑石的过渡相,这是造成金川脉石矿物易浮且难以抑制的原因。  相似文献   
52.
This research work aims to fabricate industrial refractory bricks using cheap and abundant kaolin DD3 constituted of Halloysite. The fabrication process consists on mixing the crushed raw materials (Kaolin/Clay, Fireclay, Talc) with the respective proportions and an optimized granulometry, shaped by a uniaxial hydrostatic pressure of 250 bars, followed by drying at 100°C and sintering at 1300°C. The addition of Talc - at first with water, Fireclay and AP/DD3- as a source of MgO promotes the increase of Cordierite formation in order to obtain high heat resistance shock and reduced thermal expansion. Three assays are studied with AP Clay and DD3 Kaolin weight ratios (100/0, 50/50 and 0/100) % corresponding to (ER0, ER1 and ER2) respectively. Mineralogical analysis results of the new refractory bricks, indicate the presence of Mullite and Cordierite as major phases besides Corundum and Quartz as minor phases. All products (ER0, ER1 and ER2) are found to be argillaceous refractory with Alumina concentration (40 < Al2O3 < 45%, FC 40 group) and a melting point higher than 1600°C. The mechanical resistance of the samples is of the same order of magnitude; reaching 51 MPa.  相似文献   
53.
将自制含有双键和酰胺键的新型可聚合硼酸酯作为偶联剂用于改性滑石粉,填充于高密度聚乙烯树脂中制备成滑石粉/HDPE复合体系.结果表明:经自制硼酸酯偶联剂改性过的滑石粉可均匀分散在聚乙烯中,且与基体界面结合良好.改性滑石粉/HDPE复合体系的力学性能较未改性滑石粉/HDPE复合体系、KH-550改性滑石粉/HDPE复合体系的力学性能均有所提高,在改性滑石粉添加量为40份,偶联剂添加量为滑石粉质量的2%时,综合力学性能最佳,拉伸强度达到33.52 MPa,弯曲强度为32.99 MPa,断裂伸长率为73.22%,冲击强度为7.06 kJ·m-2.复合体系流动性能测试结果表明,添加硼酸酯偶联剂改性的复合体系熔融指数明显提高,达到0.146 g/min.  相似文献   
54.
本文介绍用普通级滑石粉制造人造块滑石的方法。将滑石粉、无机粘结剂等调成半干粉状,经机械压制成的人造块滑石,具有与天然块滑石相近的物理性质和机械加工性能。人造块滑石可以替代天然块滑石加工成机械、造船工业使用的滑石粉笔。  相似文献   
55.
高流动性高韧性PP/POE共混体系材料研究   总被引:1,自引:0,他引:1  
用聚烯烃弹性体(POE)代替传统的弹性体,对聚丙烯(PP)增韧改性。探讨了基体树脂、POE、高密度聚乙烯(HDPE)、滑石粉、纳米CaCO3以及润滑剂乙撑双硬脂酸酰胺(EBS)的用量对共混体系力学性能和流动性的影响。并通过扫描电镜观察冲击断面,研究共混物的形态结构。结果表明,POE能大幅度地改善材料的冲击韧性,HDPE与POE具有协同增韧效应,加工助剂EBS能改善PP共混材料的流动性,所制得的改性材料可用于制造汽车装饰件。  相似文献   
56.
Particulate reinforced thermoplastic composites are designed to improve the properties and to lower the overall cost of engineering plastics. In this study, the influence of adding talc and kaolin fillers on the mechanical properties of nylon 6 was investigated. Fillers, either singly or mixed by various weight ratios between 10 and 30 wt %, were added to nylon 6. Test samples of the composite material were prepared by the injection‐molding process. Uniaxial tensile and Izod impact tests were carried out. Tensile strength, elongation at break, modulus of elasticity, and impact energy were obtained. The results showed that the tensile strength and modulus of elasticity of nylon 6 composite increased with the increase in filler ratio, whereas the impact strength and maximum elongation decreased with the increase in filler ratio. The optimal nylon composite was determined with the addition of a 10 to 15 wt % filler ratio. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1694–1697, 2003  相似文献   
57.
The effect of the stearic acid coated fillers and their geometry on the shear/dynamic viscosity and complex viscosity has been investigated using polypropylene (PP) compounds filled with stearic acid uncoated and coated talc, calcite, and mixed talc/calcite particles. The viscosity was measured over a wide range of shear rates (10?8 to 103) using a capillary, cone‐plate and sandwich rheometer. Overall, the rheological properties of the compounds exhibited different behavior upon different filler systems, stearic acid involvement, shear stress or strain, and frequencies due to stearic acid involvement. This implies that the stearic acid lowers the interfacial force between the filler surface and the resin matrix, followed by a favorable processing. In addition, at very low shear stresses, the viscosity of talc(un) compounds was higher than calcite(un) ones; at very high shear stresses, on the other hand, talc compounds became lower than calcite(un) compounds. This is interpreted as due to the different geometry between talc and calcite. The yield value as a function of shear stress was observed for all filler systems and exhibited lower than that obtained from the extrapolation. Furthermore, the Cox–Merz relation between the complex and shear viscosity for both the stearic acid uncoated and coated compounds is found not valid. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2105–2113, 2004  相似文献   
58.
用高分子量聚丙烯(HWPP)分别与共聚PP、均聚PP、POE熔融共混制备出HWPP的无机填料复合物。结果表明,当HWPP含量为20%时,HWPP与均聚PP复合物的加工流动性最好,通过共混可得到优异的力学性能,而加入适量的滑石粉对该复合材料的加工性能有着明显的改善;HWPP与共聚PP复合物在HWPP含量为20%时,拉伸强度和断裂伸长率在实验用量范围内最大,而其悬臂梁冲击强度在HWPP含量为30%时达到最大;在POE含量由10%上升到20%时,HWPP与POE的滑石粉填料复合物的悬臂梁冲击强度提高了近1倍。  相似文献   
59.
利用马来酸酐(MAH)/苯乙烯(St)共单体固相接枝聚丙烯(MSP)作增容剂,采用熔融共混和注塑成型的方法制备了PP/滑石粉复合材料,研究了MSP对PP/滑石粉复合材料热行为、拉伸强度和动态力学性能的影响.结果显示MSP降低了PP/滑石粉复合材料中PP相的熔融温度(Tm),但随着增容剂MSP含量的增加,Tm呈上升趋势.MSP改善了PP/滑石粉间的相容性,促进了滑石粉的异相成核作用,提高了PP相的Tco随着MSP含量的提高,Tc呈下降趋势.MSP增容剂提高了PP/MSP/滑石粉复合材料的拉伸强度和动态贮能模量,并存在一最佳的增容剂添加量.  相似文献   
60.
The addition of mineral talc, Aquatal®(Toulouse, France), to activated sludge treating paper mill effluents and its effect on settlement characteristics has been investigated. One laboratory study and a full‐scale investigation on a large waste water treatment plant (WWTP) with a capacity of 500.000 population equivalent (p.e.) have been carried out using this mineral. The sludge in the full‐scale plant was filamentous and had specific sludge volume index (SSVI) values in excess of 250. The talc dosing which was adapted to sludge settleability reduced SSVI values by 38%, improved the total suspended solids' concentrations by 86% and reduced the specific sludge load by 34%. In the laboratory‐scale plant, the sludge had SSVI values of 200–260 before treatment and was hydrophilic. The use of Aquatal® at a dose of 0.7 g/g mixed liquor suspended solids (MLSS) took 2 weeks to reduce the SSVI to 78. It also increased the hydrophobicity to a balanced 50%. The use of mineral converted the somewhat diffuse flocs into a compact structure.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号