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11.
E. Rivera-Muñoz D. Lardizabal G. Alonso A. Aguilar M.H. Siadati R.R. Chianelli 《Catalysis Letters》2003,85(3-4):147-151
MCM-41- and silica gel-supported MoS2 catalysts were prepared. MCM-41 was synthesized and impregnated with precursor, then activated to obtain the active phase. The sol–gel method was used for providing the SiO2 support as well as for including the catalyst precursors in one single step of preparation. Such catalysts have applications particularly in hydrodesulfurization (HDS) and hydrodenitrogenation (HDN) processes. A comparison of the activities of the catalysts was made. The catalytic activity results showed the method of preparation used in this study was successful in producing very efficient catalysts for the HDS of dibenzothiophene (DBT).A higher selectivity for direct C–S bond cleavage was observed for the MoS2 catalyst supported on SiO2 by the sol–gel method. X-ray diffraction studies showed that the catalysts were poorly crystallized with a very weak intensity of the (002) line of 2H-MoS2. 相似文献
12.
选用具有高比表面积的介孔分子筛SBA-15作为载体,采用等体积浸渍法制备Mo/SBA-15和KMo/SBA-15催化剂并用于一步法合成甲硫醇,并采用氮气吸脱附(BET)、X射线衍射分析(XRD)、拉曼光谱(Raman)、X射线光电子能谱分析(XPS)等进行表征,研究钾离子的添加对催化合成甲硫醇的影响。结果表明,K的添加大幅提升了Mo/SBA-15的甲硫醇选择性和CO的转化率;在高浓度H2S环境下,KMo/SBA-15催化剂上甲硫醇选择性达到了62%,高于目前文献报道的催化剂。Raman、XPS表征结果表明,添加K的催化剂上硫化后加氢脱硫活性相MoS2含量增多。 相似文献
13.
Zenon Sarbak 《Catalysis Today》2001,65(2-4):293-299
In the search for the active catalysts of hydrodesulfurization reaction, an attempt was made to use zeolites as supports. A series of NaLaX, Mo/NaLaX and NiMo/NaLaX as well as NaLaY, Mo/NaLaY and NiMo/NaLaY catalysts was prepared and their performance in this reaction was studied. It was shown that crystalline structure of the lanthana forms of the above zeolites only little collapsed after ion-exchange and impregnation with active Mo and NiMo components. The NiMo catalysts supported on the zeolites studied were found active in thiophene hydrodesulfurization. The catalysts with lanthana after the first step of ion exchange were the most active. 相似文献
14.
Ajoy P. Raje Shuh-Jeng Liaw Ram Srinivasan Burtron H. Davis 《Applied Catalysis A: General》1997,150(2):3404-318
Naphtha derived from an Illinois No. 6 coal contains appreciable quantities of sulfur-, nitrogen- and oxygen-containing compounds. The hydrotreatment of this naphtha has been evaluated over unsupported transition metal sulfide catalysts of the second row in the Periodic Table. The catalysts were prepared by a room temperature precipitation reaction. Surface areas, crystalline phase and particle size distributions were determined by Brunauer-Emmet-Teller (BET), X-ray diffraction (XRD) and transmission electron microscopy (TEM), respectively. A comparison of average particle sizes calculated from these three techniques has enabled the understanding of the morphology of the transition metal sulfides. The catalysts exhibit a so-called volcano plot for the HDS of dibenzothiophene. Similar so-called volcano plots are also exhibited for the simultaneous hydrodesulfurization (HDS), hydrodenitrogenation (HDN) and the hydrodeoxygenation (HDO) of the coal-derived naphtha containing a mixture of heteroatoms. The order of reactivity of the transition metal catalysts is the same for all three of the processes. Ruthenium sulfide (RuS2) is the most active catalyst for HDS, HDN and HDO of the coal-derived naphtha. 相似文献
15.
以十六烷基三甲基溴化铵作为模板剂,将ZSM-5用不同浓度氢氧化钠处理脱硅,并利用重结晶法成功合成了具有较强酸性的ZSM-5-MCM-41复合分子筛〔记为ZMC-M(x), M=1.5,2.0,2.5 mol/L NaOH, x=n(SiO2)/n(Al2O3) 〕。然后,采用浸渍法制备了MoS2/ZMC和Ni-MoS2/ZMC催化剂。考察了不同NaOH处理浓度对复合分子筛ZMC结构和性质的影响。同时以噻吩/十四烷为模型化合物,考察了ZMC的硅铝比、NiMo双金属硫化物对噻吩加氢脱硫的影响。结果表明,随着NaOH浓度的增加,复合分子筛ZMC会生成更多的介孔相,但是过高的NaOH处理浓度会破坏ZSM-5的结构。因此确定了最佳NaOH处理浓度为2.0 mol/L。随着ZMC的硅铝比增加,催化剂加氢脱硫活性增加提高,并且复合分子筛负载NiMo双金属硫化物的加氢脱硫性能优于复合分子筛负载MoS2。在H2压力3 MPa、温度280 ºC、40 ml(1000 ug/L)噻吩/十四烷的条件下,20%MoS2/ZMC-2.0(70)和20%Ni-MoS2/ZMC-2.0(70)催化剂对噻吩的转化率脱硫率分别达到84.1 %和95.2 %。 相似文献
16.
17.
Zeolite-supported highly dispersed Co sulfide clusters are synthesized using Co(CO)3 (NO) as a precursor. The amount of Co inCoSx/zeolite anchored by a CVD technique increases as the Al/Si ratio of the zeolite increases, whereas the activity per Co atomdecreases
for thiophene hydrodesulfurization (HDS). When an Na-exchanged USY zeolite is used, the Co sulfide catalyst shows a muchhigher
HDS activity than a conventional Co—Mo/Al2 O3 catalyst. It is considered from XAFS and NO adsorption techniques that thehigh HDS activity of CoSx/USY-Na is due to an extremely high dispersion of Co sulfide clusters.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
18.
The effect of phosphorus on physical properties of the catalyst and on activity of hydrotreating of Maya crude was studied in this work. Catalysts were prepared by the co-impregnation method. Alumina-titania binary oxide was used as a support material. The presence of phosphorus in the catalyst decreases the percentage of micropores, and it results in a decrease of specific surface area. Temperature program reduction (TPR) shows that phosphates reduce metal support interaction. It leads to the formation of polymolybdate phases in expense of strongly bonded tetrahedral molybdates. At higher P loading, polymolybdates may be present with quasi crystalline MoO3. However, the TPR experiment is not sufficiently sensitive to distinguish several phases present on the catalysts used by the authors. A slight increment of HDM activity is observed, but HDS activity is lower in the P containing catalyst compared with the P free catalyst. The changes of physical properties of the spent catalysts are mainly due to the coke formation on the catalyst. The presence of phosphorus on hydrotreating catalysts inhibits coke formation during the hydrotreating reaction. 相似文献
19.
Hydrotreating of Maya heavy crude oil over high specific surface area CoMo/TiO2–Al2O3 oxide supported catalysts was studied in an integral reactor close to industrial practice. Activity studies were carried out with Maya crude hydrodesulfurization (HDS), hydrodemetallization (HDM), hydrodenitrogenation (HDN), and hydrodeasphaltenization (HDAs) reactions. The effect of support composition, the method of TiO2 incorporation, and the catalyst deactivation are examined. Supported catalysts are characterized by BET specific surface area (SSA), pore volume (PV), pore size distribution (PSD), and atomic absorption. It has been found that sulfided catalysts showed a wide range of activity variation with TiO2 incorporation into the alumina, which confirmed that molybdenum sulfided active phases strongly depend on the nature of support. The pore diameter and nature of the active site for HDS, HDM, HDN, and HDAs account for the influence of the large reactant molecules restricted diffusion into the pore, and/or the decrease in the number of active sites due to the MoS2 phases buried with time-on-stream. The textural properties and hysteresis loop area of supported and spent catalysts indicated that catalysts were deactivated at the pore mouth due to the metal and carbon depositions. The atomic absorption results agreed well regarding the textural properties of spent catalysts. Thus, incorporation of TiO2 with γ-Al2O3 alters the nature of active metal interaction with support, which may facilitate the dispersion of active phases on the support surface. Therefore, the TiO2 counterpart plays a promoting role to HDS activity due to the favorable morphology of MoS2 phases and metal support interaction. 相似文献
20.