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炼油火炬系统水封罐设计压力研究

中国安全科学学报 2010年第9期20卷 75-80页

作者：党文义于安峰化学品安全控制国家重点实验室青岛266071 中国石油化工股份有限公司青岛安全工程研究院安全评价研究室青岛266071

水封罐作为炼油火炬系统防止回火爆炸的重要安全设施,其设计应能保证在发生回火爆炸事故时不被破坏。采用数值模拟技术,利用FLACS工具,建立水封罐三维模型,模拟计算水封罐内的典型气体爆炸,据此提出水封罐的设计压力。结果表明：烃类气... 详细信息

水封罐作为炼油火炬系统防止回火爆炸的重要安全设施,其设计应能保证在发生回火爆炸事故时不被破坏。采用数值模拟技术,利用FLACS工具,建立水封罐三维模型,模拟计算水封罐内的典型气体爆炸,据此提出水封罐的设计压力。结果表明：烃类气体（如甲烷、丙烷）在水封罐密闭空间内发生爆炸产生的压力为气体初始压力（绝压）的7~8倍,氢气爆炸产生的压力为气体初始压力（绝压）的10~12倍。对于炼油火炬系统,建议富氢气体排放系统的水封罐设计压力不低于1.0MPa（绝压）,一般烃类火炬气排放系统的水封罐设计压力不低于0.7MPa（绝压）。

关键词：火炬系统水封罐设计压力气体爆炸数值模拟

局部麻醉支气管软镜下氩气刀治疗中心气道阻塞性病变的困难

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中国内镜杂志 2007年第6期13卷 598-601页

作者：党斌温张杰首都医科大学附属北京天坛医院呼吸科北京100050

目的观察评价局部麻醉支气管软镜下氩等离子体凝固(argon plasma coagulation,APC简称氩气刀)治疗中心气道阻塞性病变的困难。方法局部麻醉支气管软镜下应用ERBE的APC300型氩气刀治疗中心气道阻塞性病变,观察治疗中的困难。结果2003年1... 详细信息

目的观察评价局部麻醉支气管软镜下氩等离子体凝固(argon plasma coagulation,APC简称氩气刀)治疗中心气道阻塞性病变的困难。方法局部麻醉支气管软镜下应用ERBE的APC300型氩气刀治疗中心气道阻塞性病变,观察治疗中的困难。结果2003年11月～2006年1月,28例中心气道阻塞的患者,共接受APC治疗71例次。术中遇到的主要困难如下。3例气管严重堵塞的患者,1例在APC治疗中少量出血,患者不愿承担手术风险而放弃继续手术,另2例术中窒息,其中1例改用全身麻醉完成手术,另外1例双侧主支气管严重堵塞未完成手术;肿物完全堵塞气道超过4cm以上的7例患者,每例患者短期内都进行了多次长时间APC治疗,患者难以耐受,其中3例被迫改用全身麻醉;8例患者在15例次的治疗中,靶组织结构不清,通过优先凝切、剥离管腔中心病变和分次治疗完成治疗;12例病变广泛的患者,在24例次的治疗中,清创费时,使用冷冻探头清创缩短了时间。3例因伴有软骨环损害气道塌陷和管壁外压,联合使用气道支架方才缓解了气道阻塞。结论局部麻醉软镜下氩气刀治疗气道阻塞性病变有一些困难,应该选择风险小、短时间能完成的手术。靶组织结构不清需要采取分次治疗。清创费时,冷冻探头能缩短清创时间。其局限性决定了软骨环损害致管壁塌陷和管壁外压者需联用支架。

关键词：氩等离子体凝固支气管镜下治疗介入治疗中心气道阻塞

Asymmetric radical allylation of β-keto esters with vinyl cyclopropanes by dual photoredox/nickel catalysis

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Science China Chemistry 2024年第11期67卷 3807-3816页

作者： wen-Yuan Qu Xue-Song Zhou wen-Jing Xiao Jia-Rong Chen Engineering Research Center of Photoenergy Utilization for Pollution Control and Carbon Reduction Ministry of EducationCollege of Chemistry Central China Normal University Wuhan Institute of Photochemistry and Technology Key Laboratory of Organo-Pharmaceutical Chemistry of Jiangxi Province Gannan Normal University

Radical-involved allylation reactions have emerged as a powerful platform for construction of carbon-carbon and carbonheteroatom bonds, facilitating the strategic incorporation of diverse allyl moieties. Nevertheless, this burgeoning field still faces ongoing challenges, including limitations of radical precursors and coupling partners, and difficulties in achieving enantiocontrol. Herein, we report for the first time a highly enantioselective radical allylation involving β-keto esters with vinyl cyclopropanes utilizing a synergistic dual photoredox/nickel catalysis under visible light irradiation. The mild and redox-neutral catalytic protocol demonstrates an extensive substrate compatibility and good functional tolerance, providing access to enantioenriched β-keto esters featuring quaternary α-stereocenter with good yields and high enantioselectivities. Preliminary mechanistic studies have uncovered that the success of the reaction hinges on the dual roles of nickel catalyst, including in situ formation of photoredox sensitive substrate/Ni complex and the ensuing asymmetric radical addition step.

关键词： asymmetric allylation photoredox catalysis radical addition nickel catalysis β-keto esters vinyl cyclopropanes

Effect of BaO and MgO on structure and properties of aluminate slag with various CaO/Al_(2)0_(3)ratios

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Journal of Iron and Steel Research International 2024年第1期31卷 204-214页

作者： Yu-qi Kong Ting Wu wen-zhi Xia wen Yang Hai-chuan Wang School of Metallurgical Engineering Anhui University of TechnologyMa’anshan243032AnhuiChina Key Laboratory of Metallurgical Emission Reduction and Resource Recycling(Ministry of Education) Anhui University of TechnologyMa’anshan243002AnhuiChina

To provide theoretical guidance for performance stability control of low-reactive mold fluxes,the effects of BaO and MgO on the structure and properties of aluminate slag with various CaO/Al_(2)0_(3)(C/A)ratios were investigated using the Fourier transform infrared spectrometer,Raman spectroscope,hemispherical melting point instrument,rotational viscometer and X-ray *** results indicated that with BaO and MgO addition,the structure polymerization was first weakened and then enhanced at C/A of 1.1,and the transition contents corresponded to 8 wt.%BaO and 2 wt.%MgO,respectively,while the structure polymerization decreased continuously at C/A of *** the viscosity change was well consistent with the structure evolution,the polymerization degree played a more prominent role in the slag viscosity than superheat degree when the melting temperature difference was within 40℃.The break temperature decreased initially and then increased with augment of BaO and MgO at C/A of 1.1,while it manifested a decrease trend with BaO addition,and it decreased obviously but then turned to increase with MgO increment at C/A of *** crystallization phase and crystallization ratio kept stable with BaO increment,while the crystallization ratio rose greatly with MgO promoting LiAlO_(2)precipitation at C/A of *** crystal types of all experimental slags were mainly Ca_(12)Al_(14)O_(33)and CaF_(2)at C/A of 1.3,and the precipitation of crystalline phase BaAl2O4 demonstrated a rising trend,while that of Ca_(12)Al_(14)O_(33)gradually declined with BaO augment.

关键词： Aluminate slag Structure MgO BaO Viscosity Property

Porous nanofibrous dressing enables mesenchymal stem cell spheroid formation and delivery to promote diabetic wound healing

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Chinese Journal of Chemical Engineering 2024年第4期68卷 156-164页

作者： Kexin Zhang wenmin Zhang Heng An Zhe Huang Yanzhen wen Xiangyu Jiao Yongqiang wen College of Chemical Engineering and Technology Taiyuan University of Science and TechnologyTaiyuan 030024China Beijing Key Laboratory for Bioengineering and Sensing Technology Daxing Research InstituteSchool of Chemistry&Biological EngineeringUniversity of Science&Technology BeijingBeijing 100083China

Delayed and nonhealing of diabetic wounds imposes substantial economic burdens and physical pain on *** stem cells(MSCs)promote diabetic wound *** when MSCs aggregate into multicellular spheroids,their therapeutic effect is ***,traditional culture platforms are inadequate for the efficient preparation and delivery of MSC spheroids,resulting in inefficiencies and inconveniences in MSC spheroid *** this study,a three-dimensional porous nanofibrous dressing(NFD)is prepared using a combination of electrospinning and homogeneous *** thermal crosslinking,the NFD not only achieves satisfactory elasticity but also maintains notable *** the design of its structure and chemical composition,the NFD allows MSCs to spontaneously form MSC spheroids with controllable sizes,serving as MSC spheroid delivery systems for diabetic wound *** importantly,MSC spheroids cultured on the NFD exhibit improved secretion of vascular endothelial growth factor,basic fibroblast growth factor,and hepatocyte growth factor,thereby accelerating diabetic wound *** NFD provides a competitive strategy for MSC spheroid formation and delivery to promote diabetic wound healing.

关键词： Electrospinning Homogenization Biomedical engineering Nanomaterials Stem cell spheroids Diabetic wound healing

General formalism for dirty extreme-mass-ratio inspirals

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Science China(Physics,Mechanics & Astronomy) 2024年第7期67卷 22-29页

作者： Ye Jiang wen-Biao Han Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of SciencesHangzhou 310024China Shanghai Frontiers Science Center for Gravitational Wave Detection Shanghai 200240China

Detecting the environment around the supermassive black holes and tests of general relativity are important applications of extreme-mass-ratio inspirals(EMRIs).There is still a challenge to efficiently describe various“dirty”impacts on the inspirals,such as dark matter,gas,dipole radiation,and electromagnetic *** this study,we find the inherent linearity of the asymptotic solution of the inhomogeneous Teukolsky *** the basis of this property,we completely decouple the factors of the perturber and the background spacetime in the energy fluxes and *** the new decoupling form,the waveforms of EMRIs with non-geodesic motion in Kerr spacetime can be conveniently *** will help to resolve the environment(including gas,field,dark matter,electromagnetic interaction)around supermassive black holes and test general relativity.

关键词： gravitational wave Teukolsky equation extreme-mass-ratio inspirals

我国独立董事制度创新的“内卷化”问题实证研究

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当代经济科学 2006年第3期28卷 40-47页

作者：张宗益党文娟重庆大学经济与工商管理学院重庆400030

本文从宏观制度层面对独立董事制度进行制度经济效果分析。采用的方法是利用混合横截面数据做政策经济效果分析。通过对2000年与2004年的混合截面数据进行分析,证实独立董事制度并没有取得经济效果,制度创新的“内卷化”是独立董事制度... 详细信息

本文从宏观制度层面对独立董事制度进行制度经济效果分析。采用的方法是利用混合横截面数据做政策经济效果分析。通过对2000年与2004年的混合截面数据进行分析,证实独立董事制度并没有取得经济效果,制度创新的“内卷化”是独立董事制度没有效果的深层次的,也是最根本的原因。

关键词：独立董事经济效果实证研究内卷化

Impact of wastewater treatment plant effluent discharge on the antibiotic resistome in downstream aquatic environments:a mini review

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Frontiers of Environmental Science & Engineering 2024年第3期18卷 131-141页

作者： Zhiguo Su Lyujun Chen Donghui wen School of Environment Tsinghua UniversityBeijng 100084China 2 Zhejiang Provincial Key Laboratory of Water Science and Technology Department of Environmental Technology and EcologyYangtze Delta Region Institute of Tsinghua UniversityJiaxing 314050China College of Environmental Sciences and Engineering Peking UniversityBeijing 100871China

Antimicrobial resistance(AMR)has emerged as a significant challenge in human *** treatment plants(WWTPs),acting as a link between human activities and the environment,create ideal conditions for the selection and spread of antibiotic resistance genes(ARGs)and antibioticresistant bacteria(ARB).Unfortunately,current treatment processes are ineffective in removing ARGs,resulting in the release of large quantities of ARB and ARGs into the aquatic environment through WWTP ***,in turn,leads to their dispersion and potential transmission to human through water and the food *** safeguard human and environmental health,it is crucial to comprehend the mechanisms by which WWTP effluent discharge influences the distribution and diffusion of ARGs in downstream *** this study,we examine the latest researches on the antibiotic resistome in various waterbodies that have been exposed to WWTP effluent,highlighting the key influencing ***,recommendations for future research and management strategies to control the dissemination of ARGs from WWTPs to the environment are provided,with the aim to achieve the“One Health”objective.

关键词： Antibiotic resistance genes(ARGs) Wastewater treatment plants(WWTPs) Effluent-receiving waterbodies Environmental risk Influencing mechanism

Unconditionally stable Crank-Nicolson algorithm with enhanced absorption for rotationally symmetric multi-scale problems in anisotropic magnetized plasma

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Journal of Systems Engineering and Electronics 2024年第1期35卷 65-73页

作者： wen Yi WANG Junxiang XU Hongbing School of Automatic Engineering University of Electronic Science and Technology of ChinaChengdu 611731China Beijing Institute of Aerospace Systems Engineering Beijing 100076China

Large calculation error can be formed by directly employing the conventional Yee’s grid to curve *** order to alleviate such condition,unconditionally stable CrankNicolson Douglas-Gunn(CNDG)algorithm with is proposed for rotationally symmetric multi-scale problems in anisotropic magnetized *** the CNDG algorithm,an alternative scheme for the simulation of anisotropic plasma is proposed in body-of-revolution *** perfectly matched layer(CPML)formulation is proposed to efficiently solve the open region *** example is carried out for the illustration of effectiveness including the efficiency,resources,and *** the results,it can be concluded that the proposed scheme shows considerable performance during the simulation.

关键词： anisotropic magnetized plasma body-of-revolution(BOR) Crank-Nicolson Douglas-Gunn(CNDG) finite-difference time-domain(FDTD) perfectly matched layer(PML) rotationally symmetric multi-scale problems