检索结果-南通市图书馆

ELUCIDATION OF HYDRODESULFURIZATION AND HYDROGENATION MECHANISMS USING RADIOISOTOPE TRACER METHODS

在线全文

学校读者我要写书评

暂无评论

石油学报（石油加工） 2001年第1期17卷 18-24页

作者： Atsushi ISHIHARA, Wei hua QIAN, Toshiaki KABE (department of chemical engineering Faculty of Technology, Tokey university of Agriculture and Technology, 2 24 1 Nakacho, Koganei, Tokyo 184 8588, Japan) Tokey university of Agriculture and Technology 日本 184 8588

To meet the specification of sulfur and aromatic contents in diesel fuel, it is necessary for refiners to develop a new catalyst with high activity of hydrodesulfurization and hydrogenation. In the present study, the properties of noble metal catalysts for hydrodesulfurization and hydrogenation in the presence of sulfur compounds have been investigated. The hydrogenation activity of phenanthrene (PHE) on single noble metal and double noble metal catalysts—Pt/Al 2O 3, Pd/Al 2O 3 and Pd Pt/Al 2O 3 in the presence of dibenzothiophene (DBT) was perforrned in a fixed bed flow reactor. The Pt based catalysts revealed the similar HDS activities and higher HYD activity compared with convertional Mo based ca talysts . The maximum activity was obtained around 320 ℃ for both catalyst types. The Pt based catalysts produced perhydrophenanthrene as a major product at the maximum activity in the hydrogenation of PHE while the Mo based catalysts produced octahydrophenanthrene. A 35 S radioisotope pulse tracer method ( 35 S RPTM) was used to estimate the behavior of sulfur on the working catalysts and to clarity the differences between Pt and Mo based catalysts. Very little amount of labile sulfur was accumulated on the Pt and Pd catalysts in the HDS of [ 35 S]DBT (PtS 0.25 or PdS 0.25 ). This indicates that the mechanism of DBT HDS on noble metal catalysts is significantly different from that on conventional Mo based catalysts where Mo is present as MoS 2 less than 60% of which can be labile in the case of Co Mo/Al 2O 3. Another Ru Cs/Al 2O 3 catalysts were also prepared and the behavior of sulfur on the working catalyst was compared with those of Mo based catalysts and Pt and Pd catalysts. The values of labile sulfur in the HDS reaction for Ru Cs catalysts approximately correspond to RuS 0.5-0.74 . These amounts of labile sulfur are much higher than those for Pt and Pd catalysts. The result suggests that the oxidation state of Ru species is present between the oxidation states of

关键词：加氢脱硫氢化作用柴油机催化转化

Preparation of Cyclodextrin-Based Carbonaceous Catalyst and Its Application in the Esterification

在线全文

学校读者我要写书评

暂无评论

Journal of Wuhan university of Technology(Materials Science) 2011年第3期26卷 455-458页

作者：单纯 department of Environmental and chemical engineering Shanghai University department of Automation Science Guangdong Polytechnic Normal University

A new carbonaceous catalyst with sulfonic acid group （-SO3H） was prepared by incomplete carbonization of β-cyclodextrin followed by *** sulfonated amorphous carbon was characterized by IR,elemental analysis,DSC-TGA and PXRD,and the catalytic activity was investigated to be an efficient catalyst for the esterification reactions with maximum yield of 87%.The sulfonated carbonaceous catalyst was readily separated from the reaction solution and keeps approximately equal catalytic *** results confirm that the active centre is the hydrophilic sulfonic acid functional group in the esterification reactions.

关键词： β-Cyclodextrin carbonization carbonaceous catalyst esterification activity

Microstructure evolution of single crystal copper wires in cold drawing

在线全文

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2007年第6期50卷 736-748页

作者： CHEN Jian1,2, YAN Wen1,2, WANG XueYan2 & FAN XinHui2 1 department of Applied Physics, Northwestern Polytechnical university, Xi’an 710072, China 2 School of Material Science and chemical engineering, Xi’an Technological university, Xi’an 710032, China 1. department of Applied Physics Northwestern Polytechnical University Xi’an 710072 China 2. School of Material Science and chemical engineering Xi’an Technological University Xi’an 710032 China

The deformation microstructure evolution of single crystal copper wires produced by OCC method has been studied with the help of TEM, EBSD; OM. The results show that there are a small number of dendrites; twins in the undeformed single crystal copper wires. However, it is difficult to observe these dendrites in deformed single crystal copper wires. The structure evolution of deformed single crystal copper wires during drawing process can be divided into three stages. When the true strain is lower than 0.94, macroscopic subdivision of grains is not evident,; the microscopic evolution of deformed structure is that the cells are formed; elongated in drawn direction. When the true strain is between 0.94; 1.96, macroscopic subdivision of grains takes place,; the number of microbands located on {111}; cell blocks is much more than that with the true strain lower than 0.94. When the true strain is larger than 1.96, the macroscopic subdivision of grains becomes more evident than that with the true strain between 0.94; 1.96,; S-bands structure; lamellar boundaries will be formed. From EBSD analysis, it is found that part of 100 texture resulting from solidifying is transformed into 111; 112 due to shear deformation, but 100 texture component is still kept in majority. When the true strain is 0.94, the misorientation angle of dislocation boundaries resulting from deformation is lower than 14°. However, when the true strain arrives at 1.96, the misorientation angle of some boundaries will be greater than 50°,; the peak of misorientation angle distribution produced by texture evolution is located in the range between 25°; 30°.

关键词： single crystal copper wires, deformation structure, electron backscattering diffraction, transmission electron microscopy

在线全文

学校读者我要写书评

暂无评论

Atomic phase diagram

Progress in Natural Science:Materials International 2004年第2期14卷 17-22页

作者： LI Shichun*(Materials department, university of petroleum, Dongying 257061, China) Univ Petr Dept Mat Dongying 257061 Peoples R China

Based on the Thomas-Fermi-Dirac-Cheng model, atomic phase diagram or electron density versus atomic radius diagram describing the interaction properties of atoms of different kinds in equilibrium state is developed. Atomic phase diagram is established based on the two-atoms model. Besides atomic radius, electron density and continuity condition for electron density on interfaces between atoms, the lever law of atomic phase diagram involving other physical parameters is taken into account, such as the binding energy, for the sake of simplicity.

关键词： TFDC model atom phase diagram two-atoms model electron density atomic radius.

Preparation of PFSA/PSf hollow fiber composite membranes with recovered PFSA for the pervaporation separation of EtOH/H_2O

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2010年第1期53卷 273-280页

作者： LANG WanZhong1,2,TONG Wei2,XU ZhenLiang2 & GUO YaJun1 1department of Chemistry,Shanghai Normal university,Shanghai 200234,China 2chemical engineering Research Center,East China university of Science and Technology,Shanghai 200237,China 1. department of Chemistry Shanghai Normal University Shanghai 200234 China2. Chemical Engineering Research Center East China University of Science and Technology Shanghai 200237 China

Perfluorosulfonic acid/Polysulfone(PFSA/PSf) hollow fiber composite membranes have been prepared by dip-coating method using PSf ultrafiltration(UF) membrane as substrate with recovered *** composite membranes were applied to the pervaporation separation of 95% ethanol(EtOH)/H2O *** images show that the thickness of the PFSA skin layer of the composite membranes is about 2 μm,much thinner than those of other PFSA composite membranes revealed in the *** of annealing temperature,coating solution concentration and counter-ions of PFSA on the pervaporation performances of the composite membranes were *** total flux decreases and separation factor increases with the increase of annealing *** highest permeation flux of 3230 g m-2 h-1 and a separation factor of 5.4 is obtained for the composite membrane annealed at 80°*** lowest permeation flux of 396 g m-2 h-1 and a separation factor of 27.7 is obtained for the composite membrane annealed at 160°*** permeation performances of the PFSA/PSf composite membrane are evidently influenced by the counter-ions of *** flux sequence of the PFSA/PSf composite membranes with different counter-ions is H+>Li+>Ca2+>Mg2+>Na+>K+>Ba2+>Fe3+>Al3+,and the separation factor sequence is H+2+2+2+Na+>K+.There are very little variations of △Eapp values between the composite membranes with three divalent counterions(Mg2+,Ca2+ and Ba2+),and the △Eapp values of the composite membranes with two trivalent counterions(Fe3+ and Al3+) are relatively high.

关键词： pervaporation hollow fiber composite membrane perfluorslulfonic acid(PFSA) ethanol(EtOH)/H2O mixture

Effects of Nutrients on Biofouling Formation and Preponderant Bacteria Diversity in Recirculating Cooling Water System

在线全文

学校读者我要写书评

暂无评论

China petroleum Processing & Petrochemical Technology 2010年第4期12卷 57-62页

作者： Ma Tao Liu Fang Zhang Guizhi Zhao Chaocheng (College of Chemistry and chemical engineering,China university of petroleum,Qingdao 266555) China Univ Petr Coll Chem & Chem Engn Qingdao 266555 Peoples R China

A series of orthogonal array experiments were conducted using carbon source, ammonia nitrogen and total phosphorus （TP） as major influencing factors to investigate the effects of nutrients on biofouling formation and preponderant bacteria diversity in the recirculatiug cooling water system. Carbon source was demonstrated to be the most significant determinant affecting the biofouling formation. A minimum biofouling outcome was obtained when BOD2, NHa＋-N and TP were 25, 10, and 1 mg/L, respectively. Then the preponderant bacteria strains in biofouling mass under two typical culture conditions （negative and favorable） were identified applying both traditional biochemical methods and further molecular biology technology with phylogenetic affiliation analysis, which indicated that Enterobacteriaceae Enterobacter, Micrococcaceae Staphylococcus, Bacillaceae Bacillus, Enterobacteriaceae Proteus, Neisseriaceae Neisseria and Pseudomonadaceae Pseudomonas were dominant under negative condition, while Enterobacteriaceae Klebsiella, Enterobacteriaceae Enterobacter and Microbacterium - under favorable one.

关键词： recirculating cooling water biofouling numerical analysis polymerase chain reaction

Chemiluminescence behavior of sodium hydrogen carbonate in the potassium permanganate-hydrogen peroxide reaction

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2010年第8期53卷 1784-1792页

作者： CHEN Hui1,2,LU Chao1,LI RuiBo1,GUO GuangSheng1 & LIN Jin-Ming2 1State Key Laboratory of chemical Resource engineering Beijing university of chemical Technology,Beijing 100029,China 2department of Chemistry,Tsinghua university,Beijing 100084,China 1. State Key Laboratory of chemical Resource engineering Beijing University of Chemical Technology Beijing 100029 China2. Department of Chemistry Tsinghua University Beijing 100084 China

Chemiluminescence (CL) phenomenon of hydrogen peroxide with potassium permanganate in the presence of sodium hydrogen carbonate was *** of the surfactant on the CL system were *** surfactants could effectively increase the CL *** scavengers and organic reagents such as nitro blue tetrazolium chloride (NBT),cytochrome c,sodium azide,ascorbic acid,thiourea,tert-butanol and dimethyl sulphoxide were used to study the emitting *** emission spectrum was recorded and the results showed that the maximal emission wavelengths of NaHCO3-H2O2-KMnO4 system were 440 and 634 *** mechanism was discussed based on electron spin resonance (ESR) spectra,fluorescence spectra and UV-vis absorption *** addition of rhodamine B or uranine into this CL system enhanced the CL *** was due to part of the energy transfer from singlet oxygen and excited triplet dimers of two CO2 molecules to rhodamine B or *** CL could be induced by excited rhodamine B or uranine.

关键词： chemiluminescence potassium permanganate emitting species energy transfer

A whisker-like carbon composite for the immobilization of laccase and its bioelectrochemistry

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2010年第6期53卷 1332-1336页

作者： MA GuoXian1,2,ZHONG QingDong2 & LU TianHong3 1department of chemical engineering,Shanghai Institute of Technology,Shanghai 200233,China 2School of Materials Science and engineering,Shanghai university,Shanghai 200072,China 3department of Chemistry,Nanjing Normal university,Nanjing 210097,China 1. department of chemical engineering Shanghai Institute of Technology Shanghai 200233 China2. School of Materials Science and Engineering Shanghai University Shanghai 200072 China3. Department of Chemistry Nanjing Normal University Nanjing 210097 China

A novel mesoporous carbon/whisker-like carbon (MCWC) composite was used for the immobilization of laccase (Lac) and its bioelectrochemical behaviors were *** was confirmed by XPS that Lac was strongly adsorbed on the surface of the MCWC *** cyclic voltammetric results showed that the immobilized Lac underwent a direct quasi-reversible electrochemical *** value of the electron transfer rate constant ks was estimated to be 0.770 s-1,indicating a reasonably fast electron transfer between the immobilized Lac and the underlying *** surface concentration (I-) of Lac was estimated to be 2.730 × 10-12 mol/*** experimental results showed that the immobilized Lac displayed an appreciable electrocatalytic activity to the electrochemical reduction of *** properties could be attributed to the particular structure of loosely packed nanometer-scale carbon whiskers and the existence of a large amount of oxygen-containing *** immo- bilization method and the novel carrier (MCWC) may find new applications in fabricating the biocatalysts for biofuel cells.

关键词： laccase whisker-like carbon composite direct electrochemical reaction oxygen bioelectrochemistry

Controlled free radical polymerization of styrene initiated from the alkoxyamine-functionalized silicon surface

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2005年第5期48卷 449-458页

作者： CHEN Zhijun1, ZHOU Sikai1, LU Wenzhong1, FANG Shaoming1, JIANG Xiqun2 & YANG Changzheng2 1. College of Materials and chemical engineering, Zhengzhou university of Light Industry, Zhengzhou 450002, China 2. Laboratory of Mesoscopic Material Science and department of Polymer Science & engineering, College of Chemistry & chemical engineering, Nanjing university, Nanjing 210093, China 1. College of Materials and chemical engineering Zhengzhou University of Light Industry 450002 Zhengzhou China 2. Laboratory of Mesoscopic Material Science and department of Polymer Science & engineering College of Chemistry & Chemical Engineering Nanjing University 210093 Nanjing China

We describe a new method of fabricating a brush-like polystyrene layer anchored on the surface of the silicon substrate, which involves three steps, namely (i) the attachment of 3-methacryloxypropyltrimethoxysilane onto the silicon surface; (ii) the reaction of vinyl moiety at another extremity of the anchored 3-methacryloxypropyltrimethoxysilane to 4-Hydroxyl-2, 2, 6, 6-tetramethyl-1-piperidinyloxy (HTEMPO?) catalyzed by azobisisobutyronitrile (AIBN); (iii) living free radical grafting polymerization of styrene in the presence of HTEMPO?. The controllable living free radical polymerization permits accurate control of both the molecular weight and the polydispersity. X-photoelectron spectroscopy measurement proved that the alkoxyamine initiator layer forms on the silicon surface. XPS and Ellipsometry measurements showed that the poly-styrene chains were covalently anchored onto the silicon surface. The thickness of the grafted polymer layer can be accurately manipulated by altering the polymerization time. The new method allows synthesizing random copolymer and block copolymers by the sequential growth of monomers from the substrate surface.

关键词： polymer brush, controlled living free radical polymerization, thickness, atomic force microscopy, 3-methacryloxypropyltrimethoxysilane.