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不同结构SAPO-34催化剂上1-己烯催化裂解制丙烯(英文)

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催化学报 2009年第10期30卷 1049-1057页

作者： zeeshan nawaz 汤效平朱杰魏飞 Shahid NAVEED 清华大学化工系北京市绿色反应工程与工艺实验室北京100084 拉合尔大学化学工程系巴基斯坦拉合尔54890

制备了100%SAPO-34,30%SAPO-34和介孔-SAPO-34三种不同类型的SAPO-34分子筛催化剂,并采用氮吸附、扫描电镜、X射线衍射和红外光谱等方法对催化剂进行了表征.三种催化剂的微孔结构、比表面积和总酸量近似,但具有不同的催化剂组成和次级结... 详细信息

制备了100%SAPO-34,30%SAPO-34和介孔-SAPO-34三种不同类型的SAPO-34分子筛催化剂,并采用氮吸附、扫描电镜、X射线衍射和红外光谱等方法对催化剂进行了表征.三种催化剂的微孔结构、比表面积和总酸量近似,但具有不同的催化剂组成和次级结构.以1-己烯裂解为模型反应考察了三种催化剂的催化活性.对于30%SAPO-34催化剂,由于添加了粘结剂,其外表面酸性和扩散性能下降,导致催化活性降低;100% SAPO-34催化剂则具有较好的催化性能;介孔SAPO-34催化剂次级结构的存在使其失活较慢,从而提高了原料的转化率.详细讨论了1-己烯催化裂解制丙烯的活性和选择性曲线,以进一步说明催化剂组成和结构的影响.

关键词： 1-己烯催化裂解丙烯扩散 SAPO-34

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增产丙烯技术研究进展

石油化工 2008年第10期37卷 979-986页

作者：魏飞汤效平周华群 zeeshan nawaz 清华大学化工系绿色反应工程与工艺北京市重点实验室北京100084

对由石油路线和非石油路线增产丙烯技术所涉及到的工艺过程进行了综述,指出近期丙烯生产仍将以石油路线为主,非石油路线为辅。从反应机理、热力学分析可知,采用择形分子筛催化剂在较低反应温度(400～600℃)下的烃类裂解制丙烯工艺可得... 详细信息

对由石油路线和非石油路线增产丙烯技术所涉及到的工艺过程进行了综述,指出近期丙烯生产仍将以石油路线为主,非石油路线为辅。从反应机理、热力学分析可知,采用择形分子筛催化剂在较低反应温度(400～600℃)下的烃类裂解制丙烯工艺可得到高的丙烯收率,是目前由石油路线增产丙烯的主要发展方向,特别是采用择形分子筛催化剂的多产丙烯流化催化裂化技术和低碳烯烃转化技术相耦合的工艺;而非石油路线中的甲醇/二甲醚转化制丙烯技术与低碳烯烃转化技术相耦合的工艺将是我国增产丙烯的另一重要途径。

关键词：增产丙烯石油路线非石油路线催化裂化低碳烯烃转化甲醇转化制丙烯

In situ Synthesis of SAPO-34 Zeolites in Kaolin Microspheres for a Fluidized Methanol or Dimethyl Ether to Olefins Process

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Chinese Journal of Chemical Engineering 2010年第6期18卷 979-987页

作者： ZHU Jie CUI Yu nawaz zeeshan WANG Yao WEI Fei Beijing Key Laboratory of Green Chemical Reaction Engineering and Technology Department of Chemical Engineering Tsinghua University Beijing 100084 China

SAPO-34 zeolite is considered to be an effective catalyst for methanol or dimethyl ether conversion to olefins. In this study,we developed the in situ synthesis technology to prepare SAPO-34 zeolite in kaolin micro-spheres as a catalyst for fluidized methanol or dimethyl ether to olefins process. The silicoaluminophosphate zeolite was first time reported to be synthesized in kaolin microspheres. The SAPO-34 content of synthesized catalyst was about 22% as measured by three different quantitative methods(micropore area,X-ray fluorescence and energy dispersive spectroscopy element analysis) . Most of the SAPO-34 zeolites were in nanoscale size and distributed uniformly inside the spheres. The catalytic performance was evaluated in fixed bed and fluidized bed reactors. Compared with the conventional spray-dry catalyst,SAPO/kaolin catalyst showed superior catalytic activities,bet-ter olefin selectivities(up to 94%,exclusive coke) ,and very good hydrothermal stability. The in situ synthesis of SAPO-34 in kaolin microspheres is a facile and economically feasible way to prepare more effective catalyst for fluidized MTO/DTO(methanol to olefins/dimethyl ether to olefins) process.

关键词： SAPO-34 in situ synthesis kaolin fluidized bed methanol to olefins

The Strategic Form of Quantum Prisoners' Dilemma

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Chinese Physics Letters 2013年第5期30卷 4-9页

作者： Ahmad nawaz National Centre for Physics Quaid-i-Azam University CampusIslamabad 45320Pakistan

In a normal form, prisoners' dilemma (PD) is represented by a payoff matrix showing players' strategies and payoffs. To obtain the distinguishing trait and strategic form of PD, certain constraints are imposed on the elements of its payoff matrix. We quantize PD by a generalized quantization scheme to analyze its strategic behavior in the quantum domain. The game starts with a general entangled state of the form |ψ>=cos(ξ/2)|00>+sin(ξ/2)|11> and the measurement for payoffs is performed in entangled and product bases. We show that for both measurements, there exist respective cutoff values of entanglement of the initial quantum state up to which the strategic form of the game remains intact. Beyond these cutoffs the quantized PD behaves like the chicken game (CG) up to another cutoff value. For the measurement in the entangled basis the dilemma is resolved for sinξ >1/7 with Q⊗Q as a Nash Equilibrium (NE). However, the quantized game behaves like PD when sinξ >1/3;whereas in the range 1/7

关键词： bases behave strategic

Quantum State Tomography and Quantum Games

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Chinese Physics Letters 2012年第3期29卷 37-40页

作者： Ahmad nawaz National Centre for Physics Quaid-i-Azam University CampusIslamabadPakistan

A technique is developed for single qubit quantum state tomography using the mathematical setup of generalized quantization scheme for *** this technique,Alice sends an unknown pure quantum state to Bob who appends it with|0><0|and then applies the unitary operators on the appended quantum state and finds the payoffs for Alice and *** is shown that for a particular set of unitary operators,these payoffs are equal to Stokes parameters for an unknown quantum *** this way an unknown quantum state can be measured and *** speaking,this technique is not a game as no strategic competitions are involved.

关键词： state quantum operators

Distributed Stochastic Security Constrained Unit Commitment for Coordinated Operation of Transmission and Distribution System

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CSEE Journal of Power and Energy Systems 2021年第4期7卷 708-718页

作者： Aamir nawaz Hongtao Wang Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education Shandong UniversityJinan 250000China

With the high penetration of renewable energies in modern power systems,deterministic coordination algorithms are facing two major problems:one is degradation in accuracy if fewer scenarios are utilized for uncertainty evaluation while second is the high computational time if a high number of scenarios are considered for better accuracy・In both cases,the efficiency of the algorithm is degraded・To solve these problems in coupled transmission system and distribution systems(TSDS),probabilistic coordination algorithms are adopted to solve with less *** this paper,a TSDS probabilistic coordination model is proposed to solve the coordinated security-constrained unit commitment problem.A mean and standard deviation matching based probabilistic analytical target cascading algorithm has been utilized for evaluation of TSDS coordination *** of solving each scenario as a separate problem,the proposed algorithm considers a single coordination problem with probabilistic characteristics as shared variables and hence,achieves fast convergence・Different case studies are performed to prove the efficacy of the proposed *** verify that the proposed algorithm reduces computational time and resources for large-scale systems.

关键词： Distribution system mean probabilistic analytical standard deviation target Cascading transmission system

Risk-aware Distributed Optimal Power Flow in Coordinated Transmission and Distribution System

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Journal of Modern Power Systems and Clean Energy 2021年第3期9卷 502-515页

作者： Aamir nawaz Hongtao Wang Key Laboratory of Power System Intelligent Dispatch and Control of Ministry of Education Shandong UniversityJinan 250000China

Active distribution grids cause bi-directional power flow between transmission system(TS)and distribution system(DS),which not only affects the optimal cost but also the secure operation of the power *** paper proposes a hybrid coordination method to solve the risk-aware distributed optimal power flow(RA-DOPF)problem in coordinated TS and *** operation risk evaluation,the weather-based contingencies are considered in both TS and DS.A hybrid coordination method is developed that entails analytical target cascading(ATC)and Benders decomposition(BD).Moreover,the risk-aware optimal power flow(RAOPF)in TS and risk-based security-constrained optimal power flow in DS have been performed using the BD method considering basic optimal power flow as a master problem,whereas N-1 and N-2 contingencies are considered as *** case studies are performed using the IEEE 30-bus system with generation reserves as a TS and a 13-bus system as a *** results demonstrate the efficacy of the proposed method.

关键词： Analytical target cascading Benders decomposition distribution system preventive and corrective contingen-cies risk awareness transmission system

Enhanced catalytic complete oxidation of 1,2-dichloroethane over mesoporous transition metal-doped γ-Al_2O_3

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Journal of Environmental Sciences 2015年第3期27卷 199-209页

作者： Abbas Khaleel Muhammad nawaz Department of Chemistry United Arab Emirates University

High-surface-area mesoprous powders of γ-Al2O3 doped with Cu^2＋, Cr^3＋, and V^3＋ ions were prepared uia a modified sol-gel method and were investigated as catalysts for the oxidation of chlorinated organic compounds. The composites retained high surface areas and pore volumes comparable with those of undoped γ-Al2O3 and the presence of the transition metal ions enhanced their surface acidic properties. The catalytic activity of the prepared catalysts in the oxidation of 1,2-dichloroethane （DCE） was studied in the temperature range of 250-400℃. The catalytic activity and product selectivity were strongly dependent on the presence and the type of dopant ion. While Cu^2＋- and Cr^3＋-containing catalysts showed 100% conversion at 300℃ and 350℃, V3＋-containing catalyst showed considerably lower conversion. Furthermore, while the major products of the reactions over γ-alumina were vinyl chloride （C2H3Cl） and hydrogen chloride （HCl） at all temperatures, Cu- and Cr-doped catalysts showed siguiticantly stronger capability for deep oxidation to CO2.

关键词： Chlorinated organic compounds Catalytic oxidation Sol-gel method Mixed metal oxides

Gender disparities and woman-specific trends in Barrett’s esophagus in the United States:An 11-year nationwide populationbased study

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World Journal of Methodology 2025年第1期15卷 60-71页

作者： Karina Fatakhova Faisal Inayat Hassam Ali Pratik Patel Attiq Ur Rehman Arslan Afzal Muhammad Sarfraz Shiza Sarfraz Gul nawaz Ahtshamullah Chaudhry Rubaid Dhillon Arthur Dilibe Benjamin Glazebnik Lindsey Jones Emily Glazer Division of Gastroenterology and Hepatology Mather Hospital and Zucker School of Medicine at Hofstra UniversityPort JeffersonNY 11777United States Department of Internal Medicine Allama Iqbal Medical CollegeLahorePunjab 54550Pakistan Division of Gastroenterology and Hepatology East Carolina University Brody School of MedicineGreenvilleNC 27834United States Division of Gastroenterology and Hepatology Geisinger Wyoming Valley Medical CenterWilkes-BarrePA 18711United States Department of Internal Medicine East Carolina University Brody School of MedicineGreenvilleNC 27834United States Department of Internal Medicine St.Dominic's HospitalJacksonMS 39216United States Department of Gastroenterology Hepatologyand NutritionCleveland Clinic FoundationClevelandOH 44195United States Department of Internal Medicine Mather Hospital and Hofstra University ZuckerSchool of MedicinePort JeffersonNY 11777United States

BACKGROUND Barrett's esophagus(BE)is a known premalignant precursor to esophageal adenocarcinoma(EAC).The prevalence rates continue to rise in the United States,but many patients who are at risk of EAC are not *** practice guidelines include male gender as a predisposing factor for BE and *** population-based clinical evidence regarding female gender remains *** To study comparative trends of gender disparities in patients with BE in the United *** A nationwide retrospective study was conducted using the 2009-2019 National Inpatient Sample(NIS)*** with a primary or secondary diagnosis code of BE were *** major outcome of interest was determining the gender disparities in patients with *** analysis for respective outcomes for females was also reported to ascertain any time-based *** We identified 1204190 patients with BE for the study *** the included patients,717439(59.6%)were men and 486751(40.4%)were *** mean age was higher in women than in men(67.1±0.4 vs 66.6±0.3 years,P<0.001).The rate of BE per 100000 total NIS hospitalizations for males increased from 144.6 in 2009 to 213.4 in 2019(P<0.001).The rate for females increased from 96.8 in 2009 to 148.7 in 2019(P<0.001).There was a higher frequency of obesity among women compared to men(17.4%vs 12.6%,P<0.001).Obesity prevalence among females increased from 12.3%in 2009 to 21.9%in 2019(P<0.001).A lower prevalence of smoking was noted in women than in men(20.8%vs 35.7%,P<0.001).However,trend analysis showed an increasing prevalence of smoking among women,from 12.9%in 2009 to 30.7%in 2019(P<0.001).Additionally,there was a lower prevalence of alcohol abuse,Helicobacter pylori(***),and diabetes mellitus among females than males(P<0.001).Trend analysis showed an increasing prevalence of alcohol use disorder and a decreasing prevalence of *** and diabetes mellitus among women(P<0.001).CONCLUSION The prevalence of BE among

关键词： Barrett’s esophagus Gender disparity Epidemiological trends Esophageal adenocarcinoma Screening endoscopy Female gender Risk factors