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金属／分子筛催化剂的卤化氢处理对环己烯加氢转化的影响Ⅱ．Re／H-ZSM-5催化剂

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催化学报 2008年第2期29卷 113-122页

作者： ahmed k.aboul-gheit Noha A.k.aboul-gheit ahmed E.AWADALLAH 埃及石油研究所过程研发部纳赛尔城9540信箱开罗11787埃及

用HCl或HF对Re/H-ZSM-5催化剂进行了后处理,并在50～400℃用连续流动反应器研究了催化剂对环己烯加氢转化反应的影响.与HCl处理相比,HF处理显著提高了催化剂上环己烯加氢生成环己烷以及甲基环戊烯加氢生成甲基环戊烷的催化活性,这主要... 详细信息

用HCl或HF对Re/H-ZSM-5催化剂进行了后处理,并在50～400℃用连续流动反应器研究了催化剂对环己烯加氢转化反应的影响.与HCl处理相比,HF处理显著提高了催化剂上环己烯加氢生成环己烷以及甲基环戊烯加氢生成甲基环戊烷的催化活性,这主要是因为HF处理催化剂具有较高的铼分散度、酸中心数及酸强度.Re/H-ZSM-5(HF)催化剂上最高的酸中心强度使其具有最高的加氢裂化活性及最低的环己烯脱氢生成环己二烯活性.在未处理的Re/H-ZSM-5催化剂上,沉积在分子筛载体孔道和空穴中非骨架Al和Si的量最少,因而对生成芳烃的脱氢反应具有最高活性.卤化氢处理催化剂上二甲苯异构体的相对产量表明:HF处理催化剂上,对二甲苯产量高于间二甲苯;HCl处理催化剂上,间二甲苯和对二甲苯产量基本相当;在未处理的催化剂上,间二甲苯量产量比对二甲苯高.此外,上述所有催化剂上的邻二甲苯产量均约等于对二甲苯与间二甲苯之和.

关键词：铼 ZSM-5分子筛氯化氢处理氟化氢处理环己烯加氢转化

Effect of Pd or Ir on the catalytic performance of Mo/H-ZSM-5 during the non-oxidative conversion of natural gas to petrochemicals

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Journal of Natural Gas Chemistry 2008年第4期17卷 337-343页

作者： ahmed k.aboul-gheit ahmed E.Awadallah Salah M.El-k.ssy Abdel-Lateef H.Mahmoud Process Development Division Egyptian Petroleum Research Institute Faculty of Science Department of ChemistryMNF University Ageeba Petroleum Co.

Natural gas conversion to petrochemicals, principally, benzene, naphthalene, toluene, as well as ethylene under non-oxidative conditions was examined in a fixed bed flow reactor at 700 ℃ and gaseous hourly space velocity （GHSV） of 1500 ml·g ^-1·h^-1 at time-on-stream ranging from 5 rain to 4 h using catalysts containing 6.0%Mo/H-ZSM-5 promoted with Pd or Ir metal. The catalysts were characterized by XRD, TPD, and TGA. The addition of Pd or Ir to 6%Mo/H-ZSM-5 catalyst promoted ethylene production but inhibited the cyclization reaction to aromatics owing to the strong interaction between these noble metals and the framework.Al species, which were attached to the acid sites during the impregnation process. Cok. deposition on the catalysts was found to decrease upon addition of 0.5wt% of Pd or Ir to 6%Mo/H-ZSM-5 catalyst owing to the hydrogenating activity of these metals.

关键词： natural gas methane benzene ethylene molybdenum Pd Ir H-ZSM-5

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沸石催化甘蔗渣裂解制备多壁碳纳米管

燃料化学学报 2021年第10期49卷 1421-1434页

作者： aboul-ENEIN Ateyya A AWADALLAH ahmed E EL-DESOUk. Doaa S aboul-gheit Noha Ak Process Development Division Egyptian Petroleum Research InstituteCairo 11727Egypt EPRI-Nanotechnology Center Egyptian Petroleum Research InstituteCairo 11727Egypt

通过催化热解农业废弃物甘蔗渣(SCB),采用两步工艺生产具有显著应用价值的碳纳米管(CNTs)。主要研究沸石催化剂(HZSM-5、HMOR和HY)、热解温度(450−700℃)和SCB/ZSM-5的比例(3−12)对SCB催化热解的影响,确定最佳工艺参数。随后,将第一步... 详细信息

通过催化热解农业废弃物甘蔗渣(SCB),采用两步工艺生产具有显著应用价值的碳纳米管(CNTs)。主要研究沸石催化剂(HZSM-5、HMOR和HY)、热解温度(450−700℃)和SCB/ZSM-5的比例(3−12)对SCB催化热解的影响,确定最佳工艺参数。随后,将第一步产生富含碳的热解产物用于第二步由Co-Mo/MgO催化生长CNTs。通过简单的两步工艺催化热解SCB生产CNTs。SCB的催化热解在半间歇式反应器(外径=4 cm,长度=90 cm)中进行,CNTs的生长在水平反应器(外径=2.5 cm,长度=100 cm)中进行。两个反应器通过玻璃管(直径0.6 cm,长度12 cm)连接并将热解产物从反应器I转移到反应器II。在半间歇式反应器中放入经过预处理的SCB和沸石催化剂,并以20℃/min加热到反应所需温度。随后,将0.5 g Co-Mo/MgO加入到水平反应器中作为CNTs的生长催化剂。在一个典型的实验中,将2 g沸石催化剂、24 g SCB放入半间歇式反应器,研究了不同种类沸石催化剂在500℃温度条件下对SCB热解的影响。接着,使用HZSM-5研究了不同温度(450−700℃)对SCB热解的影响。最后,研究了不同SCB/ZSM-5投料比例(SCB/ZSM-5=3、6、9、12)对SCB热解的影响。此外,水平反应器中的CNTs生长温度恒定为700℃。通过XRD、TPR和TPD进行催化剂表征。XRD谱图证实了催化剂存在MgO和Co_(3)O_(4),以及以小尺寸颗粒形式存在的CoMoO4和MgMoO4。使用XRD数据根据Scherrer方程计算45%Co-5%Mo/MgO催化剂的平均晶粒尺寸为25.8 nm。TPR分析表明,Co-Mo/MgO催化剂是由未反应的Co_(3)O_(4)以及混合氧化物组成。使用XRD数据,计算得到HZSM-5、HMOR和HY的平均晶粒尺寸分别为43、41和51 nm。NH3-TPD分析表明沸石催化剂存在大量的酸性位点。催化热解SCB结果表明,由HY和HZSM-5催化剂在500℃得到的挥发性产品(生物油和气体)的总收率值分别为34.4%和32.8%,而使用HMOR产生的这些挥发性产品的收率值最低(28.8%)。用HZSM-5催化热解SCB获得了最高的炭产量(23.1%)。然而,使用HMOR和HY热解催化剂产生的炭产量值较低,分别为15.8%和9.8%。使用TEM表征通过两步法生产的碳纳米管,并且测量了CNTs的外径。数据显示,用HZSM-5进行SCB热解产生了直径分布范围较宽的CNTs(10−56 nm),而用HMOR和HY热解催化剂则分别获得了直径较窄的CNTs(13−44 nm,12−28 nm)。拉曼光谱分析表明,使用HZSM-5作为SCB热解的催化剂可以生产最优的CNTs。研究了不同热解温度对CNTs产量的影响。结果显示,将热解温度从450℃提高到500℃,炭产率值从6.7%达到最佳值23.1%,接着增加温度至700℃,炭产量下降至16.7%。随后对不同温度下催化热解形成的炭产品进行TEM表征,结果显示,随着温度的升高炭产品中CNTs的比例下降,CNTs的直径范围变窄。拉曼光谱分析结果表明,在500和700℃形成的CNMs具有最少的缺陷。研究了投料比例对炭产品产量的影响,结果表明,SCB/ZSM-5的比例从3提高到12,生物油和气体的总产量从36.4%下降到32.8%,而生物炭的产量分别从63.6%增加到67.2%。根据催化剂的质量计算得到炭产量的最佳值是使用SCB/ZSM-5比例为6。使用TEM表征不同投料比例生产的炭产品,分析表征结果可得SCB/ZSM-5的比例为6,是形成具有良好质量的致密CNTs的最佳选择。并且不同投料比例的拉曼光谱显示,SCB/ZSM-5比例为6可以生产最优的CNTs。沸石类型(HZSM-5、HMOR和HY)、热解温度(450−700℃)和SCB/ZSM-5比例(3−12)影响CNTs和热解产物(气体、生物油和生物炭)的产量。实验结果表明,获得最高CNTs产量的条件为:热解温度为500℃、SCB/ZSM-5比例为6;获得最高生物油和气体总产量(40%)的条件为:热解温度为700℃、SCB/ZSM-5比例为12。TEM分析表明,使用HZSM-5催化剂在热解温度450℃只生成竹节状碳纳米管(BCNTs),而CNTs和碳纳米洋葱(CNO)是在较高温度热解温度(500−700℃)下产生的。使用SCB/ZSM-5的比例为6时,生成CNTs的直径分布范围最大(7−76 nm)。拉曼光谱分析表明,使用SCB/ZSM-5的比例为6时,形成的CNTs最优。该研究显示,在半间歇式反应器中催化热解SCB是生产CNTs的有效技术,通过对工艺和反应器的优化可以达到更好的效果。

关键词：碳纳米管 Co-Mo/MgO 热解甘蔗渣 ZSM-5沸石

Effect of energy content of the nitraminic plastic bonded explosives on their performance and sensitivity characteristics

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Defence Technology（防务技术） 2019年第4期15卷 488-494页

作者： Svatopluk.Zeman ahmed k. Hussein Marcela Jungova ahmed Elbeih Institute of Enegetic Materials Faculty of Chemical Technology University of Pardubice CZ-532 10 Pardubice Czechia Military Technical College Kobry Elkobbah Cairo Egypt

Information about the forty nine nitraminic plastic bonded explosives(PBXs)and different nitramines were *** of these PBXs are nitramines 1,3,5-trinitro-1,3,5-triazinane(RDX)and β-1,3,5,7-tetranitro-1,3,5-tetrazocane(β-HMX),cis-1,3,4,6-tetranitro-octahydroimidazo-[4,5-d]imidazole(bicyclo-HMX,BCHMX)and e-2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane(e-HNIW,CL-20)which are bonded by polyfluoro-elastomers,polydimethyl-siloxane,poly-glycidyl azide,polyisobutylene,polystyrene-butadiene,poly-acrylonitrile-butadiene and hydroxyl-terminated polybutadiene in addition to a melt cast compositions based on 2,4,*** thirty two of these PBXs the relationships are specified and analyzed between heats of their combustion and relative explosive strengths;by means of these relationships it might be possible to estimate,which groupings in the macromolecule of binder could be liable to their primary fission in the PBXs ***,for forty two of these explosives,the relationships are described and analyzed between their enthalpies of formation and impact sensitivities;here is especially attention paid to PBXs filled by *** rate constants from Vacuum Stability Test(VST)of four nitramines and twenty PBXs are introduced into relationships with their enthalpies of *** to all the mentioned cases,increasing of energy content of the studied explosives leads to increase of the relative explosive strength or initiation reactivity,*** with the opposite trend,the outputs of VST are for BCHMX,where in PBXs are matrices with the esteric plasticizers or the energetic poly-glycidyl *** of RDX or HMX,respectively,into the BCHX PBXs gives ternary PBXs whose thermal stability,in the sense of applied VST,is higher comparing to the original binary explosives.

关键词： Enthalpy Explosive strength Combustion Nitramines PBX Thermal stability

Three-dimensional simulation for problem of penetrative convection near the maximum density

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Journal of Hydrodynamics 2015年第2期27卷 292-303页

作者： HARFASH Ak.l J. ALSHARA ahmed k. Department of Mathematics College of SciencesUniversity of Basrah Petroleum Department College of EngineeringUniversity of Misan

The problem of penetrative convection with the cubic and fifth-order equations of state proposed by Merk.r, Waas and Grigull is studied. Both linear instability and nonlinear stability analyses are performed to assess the suitability of linear theory to predict destabilisation of the convection. The validity of both the linear instability and global nonlinear energy stability thresholds are tested using three-dimensional simulation. The results show that the linear threshold accurately predicts the onset of instability in the basic steady state solution.

关键词： thermal convection linear instability nonlinear stability finite difference scheme

The role of crystal lattice free volume in nitramine detonation

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Defence Technology（防务技术） 2019年第4期15卷 519-525页

作者： Svatopluk.Zeman Ning Liu ahmed k. Hussein Institute of Energetic Materials Faculty of Chemical Technology University of Pardubice CZ-532 10 Pardubice Czech Republic Xi'an Modern Chemistry Research Institute Xi'an Shaanxi 710065 China Military Technical College Kobry Elkobbah Cairo Egypt

Crystal lattice free volumes,△V,of 22 nitramines introduced into relationships of maximal theoretical crystal densities(TMD),detonation velocities(D)and volume heats of explosives(ρ.Q).Values of all these characteristics increase with an increase in the AV ***,more realistic dependencies for the TMD and D values are obtained by using correlations with ratio of the intrinsic molecular volume,Vint,to△V(***/△V),whereby the dependence on the D values reflects their similar relationship to a sum of the positive(VS,max)and negative(VS,min)extremes of the molecular surface electrostatic potentials(VS,∑).Also,directly proportional linear relationships are specified between the VS,∑ values on the one hand,and the △V and Vint/△V values,on the *** is stated that the crystal lattice free volumes might have a similar role in detonation of nitramines as the intermolecular force effect in their molecular crystals(they are as if representative of such forces).

关键词： Crystal lattice Detonation Initiation reactivity Nitramines

A STUDY OF A FULLY COUPLED TWO-PARAMETER SYSTEM OF SEQUENTIAL FRACTIONAL INTEGRO-DIFFERENTIAL EQUATIONS WITH NONLOCAL INTEGRO-MULTIPOINT BOUNDARY CONDITIONS

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Acta Mathematica Scientia 2019年第4期39卷 927-944页

作者： ahmed ALSAEDI Bashir AHMAD Shorog ALJOUDI Sotiris k. NTOUYAS Nonlinear Analysis and Applied Mathematics (NA AM)-Research Group Department of Mathematics Faculty of Science King Abdulaziz UniversityP.O. Box 80203 Jeddah 21589 Saudi Arabia Department of Mathematics University of Ioannina 451 10 Ioannina Greece Nonlinear Analysis and Applied Mathematics (NA AM)-Research Group Department of Mathematics Faculty of Science King Abdulaziz UniversityP. O. Box 80203 Jeddah 21589 Saudi Arabia

In this article, we discuss the existence and uniqueness of solutions for a coupled two-parameter system of sequential fractional integro-differential equations supplemented with nonlocal integro-multipoint boundary conditions. The standard tools of the fixed-point theory are employed to obtain the main results. We emphasize that our results are not only new in the given configuration, but also correspond to several new special cases for specific values of the parameters involved in the problem at hand.

关键词： Coupled system sequential fractional derivative multi-point integral boundary conditions existence

Preparation and Reactions of 2-Methyl-7-（3-methyl-5-oxo-1- phenyl-2-pyrazolin-4-yl）-5-arylthiazolo[3,2-a]- pyrimido[4,5-d]oxazin-4（5H）-one

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Chinese Journal of Chemistry 2011年第7期29卷 1473-1482页

作者： Youssef, Mohamed Salah k. Abbady, Mohamed S. ahmed, Ragaa A. Omar, ahmed A. Chemistry Department Faculty of Science Assiut University Assiut 71516 Egypt

Ethyl 7-amino-3-（3-methyl-5-oxo- 1-phenyl-2-pyrazolin-4-yl）-5-aryl-5H-thiazolo[3,2-a]pyrimidine-6-carboxy- late was hydrolyzed with an ethanolic sodium hydroxide and the sodium salt thus formed underwent cyclization with acetic anhydride to afford 2-methyl-7-（3-methyl-5-oxo-l-phenyl-2-pyrazolin-4-yl）-5-arylthiazolo[3,2-a]- pyrimido[4,5-d]oxazin-4（SH）-one. This compound was transformed to related heterocyclic systems via its reaction with various reagents. The biological activity of the prepared compounds was tested against Gram positive and Gram negative bacteria as well as yeast-lik. and filamentous fungi. They revealed in some cases excellent biocidal properties.

关键词： thiazolopyrimidooxazinone thiazolopyrimidopyrimidines antimicrobial activity

The Effect of Injection Angle on Mixing and Flame Holding in Supersonic Combustor

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Journal of Thermal Science 2002年第1期11卷 80-91页

作者： Shak.l ahmed Mohammad Ali A. k. M. Sadrul Islam Department of Mechanical Engineering Bangladesh University of Engineering and Technology (BUET) Dhaka Bangladesh

A numerical study on mixing of hydrogen injected into a supersonic air stream has been performed by solving two-dimensional full Navier-Stok.s equations. An explicit Harten-Yee Non-MUSCL Modified-flux-type TVD scheme has been used to solve the system of equations, and a zero-equation algebraic turbulence model to calculate the eddy viscosity coefficient. The main objectives of this study are to increase the mixing efficiency and flame holding capability of a supersonic combustor. The performance of combustor has been investigated by varying the hydrogen injection angle made with the direction of air stream considering anti-clock.ise direction as positive. The injector position from left boundary, back.ard-facing step height and the inlet width of air stream are k.pt constant. The results show that upstream of injector the mixing is dominated by recirculation and in downstream the mixing is dominated by mass concentration of hydrogen. Upstream recirculation is dominant for injecting angle 600 and 900 . Incorporating the various effects, perpendicular injection shows the maximum mixing efficiency and its large upstream recirculation region has a good flame holding capability.

关键词： scramjet engine TVD scheme back.ard-facing step supersonic mixing supersonic stream flame holding.