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Some problerns in adsorption and calorimetric studies of the steps of catalytic processes

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Journal of Natural Gas Chemistry 2004年第3期13卷 123-147页

作者： Victor e.Ostrovskii Karpov Institute of Physical Chemistry ul. Vorontsovo Pole 10 Moscow 105064 Russiarincipal side factors as well as technical and procedural peculiarities capable of distorting the results of measurements of adsorbed and desorbed amounts of falsifying the nature of the processes proceeding in the systems under study and of promoting artifacts in calorimetric and other studies of gas chemisorption on powders are considered. Modified techniques and procedures allowing the elimination of sources of side phenomena and artifacts and freeing traditional glass static adsorption apparatuses and experimental procedures from undesirable factors and peculiarities are proposed. Some available chemisorption and calorimetric data representing artifacts and also some data that are not artifacts but due to imperfections of chemisorption techniques show up as artifacts are presented and discussed. Several applications of the improved techniques and procedures to calorimetric and adsorption studies of the steps of catalytic processes proceeding on the basis of natural gas and of products of its processing are presented and discussed.

Principal side factors as well as technical and procedural peculiarities capable of distorting the results of measurements of adsorbed and desorbed amounts, of falsifying the nature of the processes proceeding in the systems under study, and of promoting artifacts in calorimetric and other studies of gas chemisorption on powders are considered. Modified techniques and procedures allowing the elimination of sources of side phenomena and artifacts and freeing traditional glass static adsorption apparatuses and experimental procedures from undesirable factors and peculiarities are proposed. Some available chemisorption and calorimetric data representing artifacts and also some data that are not artifacts but, due to imperfections of chemisorption techniques, show up as artifacts are presented and discussed. Several applications of the improved techniques and procedures to calorimetric and adsorption studies of the steps of catalytic processes proceeding on the basis of natural gas and of products of its processing are presented and discussed.

关键词： adsorption techniques and procedures adsorption and calorimetric artifacts calorimetric and chemisorption techniques chemisorption heats catalytic mechanisms chemisorption mechanisms heats of adsorption.

Characterization of coal water slurry prepared for PRB coal

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燃料化学学报 2014年第10期42卷 1167-1171页

作者： Fei Yi Akshay Gopan Richard l.Axelbaum Department of energy Environmental & Chemical Engineering Consortium for Clean Coal UtilizationWashington University in St. Louis

Powder River Basin(PRB)coal,which accounts for over 40%of the coal consumed for power generation in the United States,was investigated for preparation of coal water slurry(CWS).The static stability and rheology of the CWS were characterized as a function of *** coal loading was varied from 30%to 50%and both ionic(sodium polystyrene sulphonate(PSS))and nonionic(Triton X-100)surfactants were employed as *** addition of PSS to PRB slurries was found to yield poor static *** the other hand,Triton X-100 was found to be an effective surfactant,reducing the sedimentation by more than 50%compared to the one without surfactant in 45%*** Triton X-100 reduces the viscosity of the CWS for coal loadings of30%and 40%.Although the viscosities for coal loading of 42.5%and 45%are higher when Triton X-100 is added,the static stability is significantly better than for samples without *** highest coal loading for PRB slurry with acceptable viscosity for pumping is 42.5%.

关键词：煤水泥浆 PRB 煤描述

lu–Hf constraints on pre-,syn,and post-collision associations of the Gurupi Belt,Brazil:Insights on the Rhyacian crustal evolution

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Geoscience Frontiers 2022年第5期13卷 336-349页

作者： evandro l.Klein Joseneusa B.Rodrigues Geological Survey of Brazil SBNQuadra 02Bloco HEd.Central Brasília1andarAsa NorteBrasília-DF CEP:70040-904Brazil GPGe–Grupo de Pesquisa em Geologia econômica(economic Geology Research Group) PPGG–Programa de Pós-Graduação em Geologia e GeoquímicaUniversidade Federal do ParáBelém-PABrazil

The Gurupi Belt(together with the São luís cratonic fragment),in north-northeastern Brazil,has been described in previous studies that used extensive field geology,structural analysis,airborne geophysics,zircon U–Pb dating,and whole-rock Sm–Nd isotope and geochemical data as a polyphase orogenic belt,with the Rhyacian being the main period of crust *** was related to a 2240 Ma to 2140 Ma accretionary processes that produced juvenile crust,which has subsequently been reworked during a collisional event at 2100±20 Ma,with little evidence of Archean *** this study,we use lu–Hf isotopic data in zircon from granitoids(including gneiss)of variable magmatic series,and amphibolite to improve the knowledge of this scenario,and investigate additional evidence of recycling of Archean ***-collisional high Ba-Sr and ferroan granitoids and amphibolite formed in island arc(2180–2145 Ma),show only zircons with suprachondriticεHf values(ca.+1 to+8)indicating the large predominance of juvenile *** 10%of the data show slightly negativeεHf values(0 to-4),which have been observed in granodiorite-gneiss formed in continental arc(2170–2140 Ma),and in strongly peraluminous collisional granites(2125–2070 Ma),indicating the rework of older Paleoproterozoic to Archean components(Hf_(TDM)=2.11–3.69 Ga).A two-component mixing model using both Hf and published Nd isotope data are in line with this interpretation and indicate more than 90%of juvenile material,and less influence of Archean *** with other Rhyacian terranes that are interpreted to have been close to Gurupi in a pre-Columbia configuration(ca.2.0 Ga),our results differ from those of SeGuiana Shield,which show strong influence of Archean protoliths,and are very similar to those of the central-eastern portion of the Baoulé-Mossi Domain of the West African Craton,which has also been formed largely by juvenile magmas in an accretionary-collisional orogen.

关键词： Paleoproterozoic Accretion Collision Isotope geology lu–Hf isotopes Rhyacian

Uniform surface polished method of complex holes in abrasive flow machining

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中国有色金属学会会刊：英文版 2009年第B09期19卷 250-257页

作者： lung TSAI Kuo-Zoo l IANG Chun-Ho lIU Department of Mechanical engineering Ching Yun University

Abrasive flow machining(AFM) is an effective method that can remove the recasting layer produced by wire electrical discharge machining(WeDM). However, the surface roughness will not be easily uniform when a complex hole is polished by this method. CFD numerical method is aided to design good passageways to find the smooth roughness on the complex hole in AFM. Through the present method, it reveals that the shear forces in the polishing process and the flow properties of the medium in AFM play the roles in controlling the roughness on the entire surface. A power law model was firstly set up by utilizing the effect of shear rates on the medium viscosities, and the coefficients of the power law would be found by solving the algebraic equation from the relations between the shear rates and viscosities. Then the velocities, strain rates and shear forces of the medium acting on the surface would be obtained in the constant pressure by CFD software. Finally, the optimal mold core put into the complex hole could be designed after these simulations. The results show that the shear forces and strain rates change sharply on the entire surface if no mold core is inserted into the complex hole, whereas they hardly make any difference when the core shape is similar to the complex hole. Three experimental types of mold core were used. The results demonstrate that the similar shape of the mold core inserted into the hole could find the uniform roughness on the surface.

关键词：表面抛光磨料流加工表面粗糙度原子力显微镜计算机辅助设计 CFD软件介质粘度电火花加工

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基于相变蓄冷的核电厂主控室非能动冷却系统

暖通空调 2024年第1期54卷 1-4,30页

作者：赵丹林宇清吕胡人上海核工程研究设计院股份有限公司上海

为提高现有核电厂主控室紧急可居留系统的蓄冷能力及热舒适性水平,提出了基于定形相变蓄冷材料的核电厂主控室非能动冷却系统。基于主控室热负荷分布情况,该冷却系统在主控室顶板与吊顶之间、内墙面、地板底面及循环风道内,针对性地布... 详细信息

为提高现有核电厂主控室紧急可居留系统的蓄冷能力及热舒适性水平,提出了基于定形相变蓄冷材料的核电厂主控室非能动冷却系统。基于主控室热负荷分布情况,该冷却系统在主控室顶板与吊顶之间、内墙面、地板底面及循环风道内,针对性地布置相应的含有定形相变材料的非能动冷却装置,进而实现事故工况下对主控室温度的精确控制。该非能动冷却系统无需引入额外冷源和管道,可靠性强,同时不破坏主体结构,且可灵活布置,解决了现有主控室非能动热阱时间余量小、热舒适性差的问题。

关键词：核电厂相变蓄冷非能动冷却系统主控室应急可居留系统定形相变材料

MRI诊断马德龙病并颈部脂肪瘤1例并文献复习

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黑龙江医学 2024年第8期48卷 956-958页

作者：刘高峰孙源吕浩安徽省濉溪县医院影像科安徽淮北235100 安徽省濉溪县医院耳鼻喉科安徽淮北235100 安徽省濉溪县医院病理科安徽淮北235100

回顾性地分析1例MRI诊断马德龙病并颈部脂肪瘤的临床相关资料,并进行相关文献的分析。马德龙病具有特征性的影像学表现,虽然影像表现不能作为诊断的金标准,但通过影像检查可在客观上为临床提供一种极佳的手术依据,对临床的诊疗活动有一... 详细信息

回顾性地分析1例MRI诊断马德龙病并颈部脂肪瘤的临床相关资料,并进行相关文献的分析。马德龙病具有特征性的影像学表现,虽然影像表现不能作为诊断的金标准,但通过影像检查可在客观上为临床提供一种极佳的手术依据,对临床的诊疗活动有一定指导作用。

关键词：马德龙病颈部脂肪瘤鉴别诊断磁共振成像

Tensile behavior of Sn-0.7Cu with Zn addition at various deformation temperatures

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Acta Metallurgica Sinica(english letters) 2011年第2期24卷 155-160页

作者： Zhongbing l UO Jie ZHAO Junshan ZHANG lai WANG School of Materials Science and engineering Dalian University of Technology Dalian 116085 China

The tensile behavior of Sn-0.7Cu and Sn-0.7Cu-1Zn was compared at various deformation temperatures. Refined microstructure and γ-CuZn particles were discovered with Zn addition. The strengths of Zn-containing solder were higher than that of Sn-0.7Cu at room and subzero temperatures. With the elevation of deformation temperature, they both decreased and they were nearly the same at 80 ？ C. The works of fracture exhibited the similar evolution law. For Sn-0.7Cu solder, the elongation after fracture was smaller and the reduction of area was bigger than those of Sn-0.7Cu-1Zn. This shows that Zn addition improved the deformation stability, which is attributed to the modification of the microstructure. Dimples in fracture surface became smaller and shallower with the decreasing temperature. Ductile fracture was discovered in all the samples.

关键词： Sn-0.7Cu Zn Tensile Temperature Strength Ductility Fracture

紫外增强KMnO_(4)氧化电镀废水中铜-有机络合物

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环境科学学报 2024年第2期44卷 21-31页

作者：刘铭浩李达光张筱昱方政陈平吕文英刘国光广东工业大学环境科学与工程学院广州510000

高锰酸钾(KMnO_(4))是一种氧化性能很强且环境友好的氧化剂.本文探究了紫外(UV)增强KMnO_(4)处理氧化铜-乙二胺四乙酸有机络合物(Cu-eDTA)的动力学和机制,考察了KMnO_(4)浓度、初始溶液pH及水体中常见离子等影响因素对该体系的影响,确... 详细信息

高锰酸钾(KMnO_(4))是一种氧化性能很强且环境友好的氧化剂.本文探究了紫外(UV)增强KMnO_(4)处理氧化铜-乙二胺四乙酸有机络合物(Cu-eDTA)的动力学和机制,考察了KMnO_(4)浓度、初始溶液pH及水体中常见离子等影响因素对该体系的影响,确认了主要活性物种,并推导了Cu-eDTA的氧化路径和KMnO_(4)的作用机理.结果表明:相比单独UV或KMnO_(4)的作用,UV/KMnO_(4)能够显著增强Cu-eDTA的氧化效果.在初始pH=3.2、最佳氧化剂和污染物比例为1.2、反应时间为20 min的条件下,Cu的去除效率可以达到92%.随着KMnO_(4)浓度在0.09~0.9 mmol·l^(-1)范围内增加,Cu去除率随之增加.粹灭实验表明,与HO·相比,活性锰物种(RMnS)是UV/KMnO_(4)氧化Cu-eDTA的主要活性物种.采用超高效液相色谱-质谱联用技术分析Cu-eDTA的降解产物,表明其降解遵循脱羧反应.不同环境因子影响实验表明,强酸条件有利于反应,而随着溶液初始pH升高,Cu的去除率呈下降趋势;硝酸根离子、氯离子和硫酸根离子对Cu-eDTA降解的影响较小,天然有机物(NOM)对Cu-eDTA的降解起到明显抑制作用.另外,本文阐述了UV/KMnO_(4)的作用机制,为该技术应用于处理有机金属污染水体提供了理论支撑.

关键词：铜-有机络合物高锰酸钾紫外影响因素降解途径

A semi-analytical approach for calculating the equilibrium structure and radial breathing mode frequency of single-walled carbon nanotubes

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Acta Mechanica Sinica 2016年第6期32卷 1075-1087页

作者： J.Gong l.Thompson G.li Department of Mechanical engineering Clemson University

A semi-analytical model for determining the equilibrium configuration and the radial breathing mode (RBM) frequency of single-wall carbon nanotubes (CNTs) is presented. By taking advantage of the symmetry characteristics, a CNT structure is represented by five independent variables. A line search optimization procedure is employed to determine the equilibrium values of these variables by minimizing the potential energy. With the equilibrium configuration obtained, the semi-analytical model enables an efficient calculation of the RBM frequency of the CNTs. The radius and radial breathing mode frequency results obtained from the semi-analytical approach are compared with those from molecular dynamics (MD) and ab initio calculations. The results demonstrate that the semi-analytical approach offers an efficient and accurate way to determine the equilibrium structure and radial breathing mode frequency of CNTs.

关键词： Carbon nanotubes equilibrium structure Radial breathing mode frequency