全文获取类型
收费全文 | 167篇 |
免费 | 6篇 |
国内免费 | 2篇 |
专业分类
综合类 | 14篇 |
化学工业 | 75篇 |
金属工艺 | 3篇 |
建筑科学 | 9篇 |
矿业工程 | 37篇 |
能源动力 | 2篇 |
轻工业 | 2篇 |
石油天然气 | 11篇 |
一般工业技术 | 19篇 |
冶金工业 | 2篇 |
自动化技术 | 1篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 5篇 |
2020年 | 3篇 |
2019年 | 5篇 |
2018年 | 4篇 |
2017年 | 1篇 |
2016年 | 3篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 8篇 |
2012年 | 5篇 |
2011年 | 11篇 |
2010年 | 5篇 |
2009年 | 14篇 |
2008年 | 8篇 |
2007年 | 8篇 |
2006年 | 9篇 |
2005年 | 10篇 |
2004年 | 12篇 |
2003年 | 9篇 |
2002年 | 3篇 |
2001年 | 3篇 |
2000年 | 3篇 |
1999年 | 4篇 |
1998年 | 3篇 |
1997年 | 8篇 |
1996年 | 3篇 |
1995年 | 1篇 |
1994年 | 3篇 |
1993年 | 3篇 |
1992年 | 1篇 |
1991年 | 1篇 |
1990年 | 3篇 |
排序方式: 共有175条查询结果,搜索用时 187 毫秒
31.
Hojin Ryu Eiki Kasai Kazumasa Sugiyama Fumio Saito Yoshio Waseda Hiromichi Ohta 《Particulate Science and Technology》1993,11(3):157-164
The present paper describes the effect of grinding a kaolinite/aiuminum-trihydroxide mixture using a planetary ball mill on the structure of the ground product and the mean thermal expansion coefficients of samples sintered from the unground and ground mixtures. The size reduction of the mixture predominates in the early stage of grinding and the obtained fine particles aggregate subsequently with an increase in grinding time. The crystal structure of the mixture is collapsed easily into a disordered one, of which amount increases with an increase in grinding time. Only mullite phase was detected in the sintered body of the ground products at relatively lower temperature 1523K except for anatase as an inherent impurity, whereas corundum, cristobalite and Al-Si spinel phases besides mullite were formed in the sintered body of the unground mixture. The thermal expansion coefficients of sintered bodies of the 120 minutes-ground mixture are considerably lower than those of the unground mixture by about 10%. Consequently, the planetary milling enables us to improve the uniform mixing state at the atomic scale resulting in direct formation of mullite with high purity at relatively low temperature with a lower thermal expansion coefficient of the sintered body. 相似文献
32.
Petr Ptá?ek František Šoukal Tomáš Opravil Jaromír Havlica Ji?í Brandštetr 《Powder Technology》2011,208(1):20-25
The thermal decomposition of kaolinite was studied by differential thermogravimetry (DTG) technique under non-isothermal conditions. Samples of industrially treated (washed) kaolin with high content of the medium ordered kaolinite were calcined using a heating rate from 1 to 40 K min− 1. The apparent activation energy and frequency factor for the dehydroxylation of kaolinite was evaluated by Kissinger method as 195 ± 2 kJ × mol− 1 and (8.58 ± 0.33) × 1014 s− 1, respectively. Avrami exponent of the process was estimated using Kissinger empirical kinetic models and Carne equation. 相似文献
33.
应用Menke条件,在改性高岭土固体酸催化下,甲苯能被浓硝酸对位选择性硝化,表现在对邻硝化产物比例达到1.5。 相似文献
34.
Since there are hydrogen bonds and no exchangeable ions between the layers of kaolinite, the intercalation reaction of organics is difficult. We induct microwave techniques into the preparation of kaolinite/organics intercalation compound. We studied the microwave effect for the inserted piece (dimethylsulfoxide), intercalation rate and intercalation speed and discussed intercalation compound by Fourier-transformed infrared spectroscopy, X-ray diffraction (powder method), thermal analysis (TG/DTA) and transmission electron microscopy. The result shows that microwave radiation can greatly shorten reaction time. XRD shows the intercalation rate can reach above 80% after 40 min reaction. FTIR proves the hydrogen bonds are formed between DMSO molecules and the inner surface hydroxyls of kaolinite and a TEM micrograph shows that microwave radiation can accelerate an exfoliation effect, which makes stacking layers of kaolinite delaminated as well as a reduction of the particle size dimensions. 相似文献
35.
This paper presents the results of a study on the electrokinetic treatment of kaolinite and humic acid kaolinite complexes spiked with 2,6-dichlorophenol or 3-(3,4-dichlorophenyl)-1,1-dimethylurea (diuron). In particular, the attention was paid to the interaction between solid surface and dissolved organics: the effects of contaminant sorption as well as the physicochemical reactions on the efficiency of electrokinetic remediation were investigated. Using a 3V/cm voltage gradient, approximately 90% of diuron was removed from kaolinite after one water pore volume was collected in the cathode reservoir, but much lower efficiency was obtained in the electrokinetic removal of this compound from humic acid-coated kaolinite. The results also showed that partial degradation of the contaminant occurred during electrokinetic treatment of kaolinite clay spiked with 2,6-dichlorophenol: the contamination in the clay could be remediated by the combination of electrokinetic extraction and electrochemical reactions. 相似文献
36.
A.J. McFarlane 《Powder Technology》2005,160(1):27-34
The effect of shear on dewatering behaviour and particle interactions of Na-exchanged smectite and kaolinite clay dispersions has been investigated at pH 7.5, using hydrolysable Ca(II) and Mn(II) ions as coagulants and high molecular weight anionic and non-ionic polyacrylamide (PAM A and PAM N, respectively) and polyethylene oxide (PEO) flocculants. Metal ion addition enhanced the flocculation performance by dramatically reducing the magnitude of the particle zeta potential and, in the case of smectite pulp, suppressing osmotic swelling. Under optimum orthokinetic flocculation conditions of controlled agitation rate and duration, PAM A and PEO-based flocs settled faster than those of PAM N whilst kaolinite pulps produced higher sedimentation rates than smectite pulps. The settling rates are nearly an order of magnitude greater than those observed under standard flocculant-pulp mixing/flocculation methods of inversion and plunging. The difference in the flocculant behaviour is attributed to the more expanded conformation of PAM A and PEO polymer chains in contrast to PAM N, whilst the lower yield stresses, reflecting inter-particle bridging and floc network structure strength that are conducive to faster clarification, were displayed by kaolinite pulps. Following shear, similar consolidation enhancement of ≈ 5-7 wt.% solid for both pulps was achieved at an optimum agitation range of 100-200 rpm. This was accompanied by decreased yield stress in the case of PAM A-based pulps, indicating non-reversible disruption of polymer mediated particle and floc network structure. In contrast, the yield stresses of PAM N and PEO flocculated dispersions indicated similar and stronger particle interactions, respectively, upon consolidation following shear. The findings show clear links between effect of shear, interfacial chemistry and polymer structure on pulp particle interactions and dewaterability. 相似文献
37.
改性高岭土上甲苯的选择性硝化 总被引:1,自引:0,他引:1
在 Menke条件下 ,应用改性高岭土固体酸催化剂 ,甲苯能被浓硝酸对位选择性硝化 ,对、邻硝化产物比例为 1 .3 ,较硝硫混酸的 0 .6显著提高。 相似文献
38.
H. A. Essawy A. M. Youssef A. A. Abd El-Hakim A. M. Rabie 《Polymer-Plastics Technology and Engineering》2013,52(2):177-184
Injection molding is one of the most widely employed methods for the fabri- cating of polymer articles, being characterized by high production rates and accurately dimensioned products. The process includes the flow of polymer melt through a runner system and gates followed by injection into a cold mold, packing under high pressure, and subsequent cooling to solidification. Accordingly, during the injection-molding process the polymer undergoes simultaneous mechanical and therma! influences while in fluid, rubbery, and glassy states. Such effects introduce residual stresses and strains into the final product [1,2], resulting in highly anisotropic mechanical behavior [3–9] and warpage and shrinkage [10–13]. Thus, understanding the factors governing the residual-stress development during molding is of great importance. 相似文献
39.
Hisham A. Essawy Ahmed S. Badran Abu El-Fetoh A. Abd El-Hakim Ahmed M. Youssef 《Polymer-Plastics Technology and Engineering》2013,52(1):66-71
Kaolinite was intercalated with N-methylformamide (NMF) and dimethylsulphoxide (DMSO), separately. The intercalation of these species expanded the basal space of kaolinite from 0.72 to 1.08 and 1.13 nm, respectively as shown by the X-ray diffraction (XRD). Emulsion polymerization of vinylacetate (VAc) was carried out at different temperatures (60–80°C) using acetone sodium bisulfite as initiator in the absence and presence of untreated as well as the modified forrms of kaolinite (K-NMF, K-DMSO). The results revealed that the presence of kaolinite decreased the rate of polymerization (Rp) by factor of 4 at 60 and 70°C and 7 at 80°C and also the activation energy of polymerization (E a ) was decreased from 43.35 × 104 to 10.32 × 104 J mole?1 if compared with the polymerization of VAc in absence of kaolinite. Using the modified forms of kaolinite (K-NMF, K-DMSO) enhanced the Rp and reduced effectively the E a to ? 27.92 and ? 55.78, respectively. Conversely to untreated kaolinite, the Rp was declining with increasing the temperature in these cases. In all cases, Rp was the highest in the absence of any kaolinite form but in the same time the E a was also the highest. These results were discussed and explained on the basis of the catalytic activity of the different forms, radical scavenging nature of the kaolinite, and chain transfer. 相似文献
40.