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Special precovering classes in comma categories

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Science China Mathematics 2022年第5期65卷 933-950页

作者： Jiangsheng Hu haiyan zhu School of Mathematics and Physics Jiangsu University of TechnologyChangzhou 213001China College of Science Zhejiang University of TechnologyHangzhou 310023China

Let T be a right exact functor from an abelian category B into another abelian category A.Then there exists a functor p from the product category A×B to the comma category(T↓A).In this paper,we study the property of the extension closure of some classes of objects in(T↓A),the exactness of the functor p and the detailed description of orthogonal classes of a given class p(X,Y)in(T↓A).Moreover,we characterize when special precovering classes in abelian categories A and B can induce special precovering classes in(T↓A).As an application,we prove that under suitable conditions,the class of Gorenstein projective leftΛ-modules over a triangular matrix ringΛ=(R M 0 S)is special precovering if and only if both the classes of Gorenstein projective left R-modules and left S-modules are special precovering.Consequently,we produce a large variety of examples of rings such that the class of Gorenstein projective modules is special precovering over them.

关键词： abelian category comma category special precovering class cotorsion pair Gorenstein projective object

Selective C-C bonds formation,N-alkylation and benzo[d]imidazoles synthesis by a recyclable zinc composite

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Chinese Chemical Letters 2022年第1期33卷 266-270页

作者： Guanxin zhu Zheng-Chao Duan haiyan zhu Dongdong Ye Dawei Wang The Key Laboratory of Synthetic and Biological Colloids Ministry of EducationSchool of Chemical and Material EngineeringJiangnan UniversityWuxi 214122China State Key Laboratory of Pulp and Paper Engineering South China University of TechnologyGuangzhou 510640China School of Chemical and Environmental Engineering Hubei Minzu UniversityEnshi 445000China

Earth abundant metals are much less expensive,promising,valuable metals and could be served as catalysts for the borrowing hydrogen reaction,dehydrogenation and heterocycles synthesis,instead of noble metals.The uniformly dispersed zinc composites were designed,synthesized and carefully characterized by means of XPS,EDS,TEM and XRD.The resulting zinc composite showed good catalytic activity for the N-alkylation of amines with amines,ketones with alcohols in water under base-free conditions,while unsaturated carbonyl compounds could also be synthesized by tuning the reaction conditions.Importantly,it was the first time to realize the synthesis of 2-aryl-1H-benzo[d]imidazole derivatives by using this zinc composite under green conditions.Meanwhile,this zinc catalyst could be easily recovered and reused for at least five times.

关键词： Unsymmetrical Zinc Borrowing hydrogen Recyclability Selective

Balanced Pairs on Triangulated Categories

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代数集刊:英文版 2023年第3期30卷 385-394页

作者： Xianhui Fu Jiangsheng Hu Dongdong Zhang haiyan zhu School of Mathematics and Statistics Northeast Normal UniversityChangchun 130024China School of Mathematics Hangzhou Normal UniversityHangzhou 311121China Department of Mathematics Zhejiang Normal UniversityJinhuaZhejiang 321004China College of Science Zhejiang University of TechnologyHangzhou 310023China

Let C be a triangulated category.We first introduce the notion of balanced pairs in C,and then establish the bijective correspondence between balanced pairs and proper classesξwith enoughξ-projectives andξ-injectives.Assume thatξ:=ξX=ξ^(Y) is the proper class induced by a balanced pair(X,Y).We prove that(C,Eξ,sξ)is an extriangulated category.Moreover,it is proved that(C,Eξ,sξ)is a triangulated category if and only if X=Y=0,and that(C,Eξ,sξ)is an exact category if and only if X=Y=C.As an application,we produce a large variety of examples of extriangulated categories which are neither exact nor triangulated.

关键词： triangulated category proper class balanced pair extriangulated category

Constructing cotorsion pairs over generalized path algebras

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Frontiers of Mathematics in China 2016年第4期11卷 1079-1096页

作者： haiyan zhu College of Science Zhejiang University of Technology Hangzhou 310023 China

我们介绍二伴随对(e i ，() i ) 并且(() i , e i ) 并且给一个新方法构造 cotorsion 对。作为应用，我们描绘射影的所有和概括路径代数学和射影的展览和是 monomorphisms 范畴的归纳的范畴 M p 的 injective 目标的 injective 代表。

关键词：路代数广义伴随对对象类内射投射

Coupled heat-fluid-solid numerical study on heat extraction potential of hot dry rocks based on discrete fracture network model

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能源地球科学(英文)

能源地球科学(英文) 2023年第4期4卷 81-94页

作者： Daobing Wang haiyan zhu Marembo Micheal Xuanhe Tang Qin Li Xiangyi Yi Dongliang Sun Bo Yu Qiang Liu School of Mechanical Engineering Beijing Institute of Petrochemical TechnologyBeijing102617China School of Energy Chengdu University of TechnologyChengduSichuan610059China Department of Modern Mechanics University of Science and Technology of ChinaHeifeiAnhui230027China Academy of Artificial Intelligence Beijing Institute of Petrochemical TechnologyBeijing102617China

Fracture networks within hot dry rock(HDR)geothermal reservoirs are complex,and heat extraction via water injection is thus a coupled process of heat-fluid-solid multifield.In this paper,utilizing the theory of normally distributed random functions,we develop a corresponding pre-processing subprogram to establish a discrete network model of complex fracture distribution in HDR reservoirs;then construct a heat-fluid-solid finite element model for heat extraction via water injection and compare the numerical solution with the analytical solution of the one-dimensional non-isothermal consolidation problem for verification.The numerical simulation results show that the main factors affecting the heat extraction efficiency of HDR reservoirs include fracture width,fracture density,fracture permeability,and matrix permeability.When a HDR reservoir is injected with water for heat extraction,there is a certain threshold value of these influential parameters,beyond which the outlet temperature drops significantly,resulting in an obvious thermal breakthrough.When injecting water for heat extraction,the values of these parameters should be controlled and kept at a reasonable level,otherwise,the HDR reservoir may enter a thermal breakthrough stage in advance,which is not conducive for long-period heat extraction.Influenced by the random distribution of complex fractures,the leading edge of the cold front may present an irregular distribution.During the process of heat extraction,the stress gradually changes from a compressional state to a tensile state,which induces further damage to the HDR reservoir.

关键词： Enhanced geothermal system Seepage and heat transfer Complex fractures Heat extraction efficiency Multifield coupling

Ordered mesoporous carbon spheres assisted Ru nanoclusters/RuO_(2) with redistribution of charge density for efficient CO_(2) methanation in a novel H2/CO_(2)fuel cell

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Journal of Energy Chemistry 2022年第9期31卷 116-124,I0004页

作者： Yan Liu Tao Zhang Chao Deng Shixiu Cao Xin Dai Shengwu Guo Yuanzhen Chen Qiang Tan haiyan zhu Sheng Zhang Yongning Liu State Key Laboratory for Mechanical Behavior of Materials Xi’an Jiaotong UniversityXi’an 710049ShaanxiChina Department of Chemical and Biochemical Engineering RutgersThe State University of New JerseyPiscataway 08854New JerseyUnited States Chongqing University Key Laboratory of Micro/Nano Materials Engineering and Technology Chongqing University of Arts and SciencesChongqing 402160China Institute of Modern Physics Northwest UniversityShaanxi Key Laboratory for Theoretical Physics FrontiersXi’an 710069ShaanxiChina Key Laboratory for Green Chemical Technology of Ministry of Education School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China

Efficiently reducing carbon dioxide(CO_(2))into carbon chemicals and fuels is highly desirable due to the rapid growth of atmospheric CO_(2)ncentration.In prior work,we described a unique H/CO_(2)fuel cell driven by low-valued waste heat,which not only CO_(2)nverts CO_(2)to methane(CH_(4))but also outputs electrical energy,yet the CO_(2)reduction rate needs to be urgently improved.Here,a novel Ru-RuOcatalyst with heterostructure was grafted on mesoporous carbon spheres by in situ partially reducing RuOinto ultrasmall Ru clusters(~1 nm),in which heteroatom-doped carbon spheres as a matrix with excellent CO_(2)nductivity and abundant pores can not only easily CO_(2)nfine the formation of Ru nanocluster but also are beneficial to the exposed active sites of Ru CO_(2)mplex and the mass transport.CO_(2)mpared to pure RuOnanoparticles supported on carbon spheres,our CO_(2)mposite catalyst boosts the CO_(2) nversion rate by more than 5-fold,reaching a value of 382.7μmol gcat.h-1at 170℃.Moreover,a decent output power density of 2.92 W mwas obtained from this H2/CO_(2)fuel cell using Ru-RuOembedded carbon spheres as a cathode catalyst.The Ru-RuOheterostructure can modify the adsorption energy of CO_(2)and induce the redistribution of charge density,thus boosting CO_(2)reduction significantly.This work not only offers an efficient catalyst for this novel H_(2)/CO_(2)fuel cell but also presents a facile method to prepare Ru nanoclusters.

关键词： CO_(2)methanation Fuel cell Generating electricity Ru nanocluster/RuO_(2)hybrid Ordered mesoporous carbon spheres

Pancreatic Cancer Presents as Inguinal Mass: A Case Report and Literature Review

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Chinese Medical Sciences Journal 2020年第1期35卷 101-104页

作者： haiyan zhu Min Dai Department of Oncology Haian Hospital Affiliated to Nantong UniversityJiangsu 226600China Department of General Surgery Haian Hospital Affiliated to Nantong UniversityJiangsu 226600China

A 70-year-old male presenting with a mass in the right inguinal area was treated with surgery,and was diagnosed pathologically as spermatic cord metastasis of pancreatic cancer.He was given systemic chemotherapy.Unfor... 详细信息

关键词： pancreatic neoplasm spermatic cord metastasis

CO_(2)增强页岩气开采及地质埋存的三维数值模拟

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天然气工业 2024年第4期44卷 104-114页

作者：赵鹏朱海燕张丰收地质灾害防治与地质环境保护国家重点实验室·成都理工大学油气藏地质及开发工程全国重点实验室·成都理工大学成都理工大学能源学院同济大学土木工程学院

将CO_(2)注入页岩储层中,既可以提高气藏天然气采收率,又可以达到CO_(2)地质埋存的目的,是实现减少碳排放的有效途径之一。页岩储层非均质性强,将CO_(2)注入页岩储层后,储层纵向非均质性对于CO_(2)增强CH_(4)开采效果的影响机理研究还... 详细信息

将CO_(2)注入页岩储层中,既可以提高气藏天然气采收率,又可以达到CO_(2)地质埋存的目的,是实现减少碳排放的有效途径之一。页岩储层非均质性强,将CO_(2)注入页岩储层后,储层纵向非均质性对于CO_(2)增强CH_(4)开采效果的影响机理研究还存在不足。为此以四川盆地上奥陶统五峰组—下志留统龙马溪组页岩储层为对象,以考虑CO_(2)和CH_(4)竞争吸附的热—流—固多场耦合数值模拟方法为基础,建立了页岩非均质储层CO_(2)增强CH_(4)开采及地质埋存一体化三维数值模型,最后通过CO_(2)驱替CH_(4)室内实验结果验证该数值模拟方法的可靠性。研究结果表明:①当注入井所在层位保持不变时,随着开采井埋深增加,各小层内CH_(4)剩余量呈增加趋势,CO_(2)埋存量表现出逐渐减小的趋势;②当开采井所在层位保持不变时,各小层内CH_(4)的剩余量随注入井埋深的增加而减小,各小层内CO_(2)的埋存量随注采井纵向间距的增加而提高;③增加注采井纵向距离能够提高CH_(4)增产量和CO_(2)埋存量。结论认为,页岩对CO_(2)和CH_(4)有较强的竞争吸附特性,相关过程是一个复杂的热—流—固耦合过程,该基础理论模拟研究对注CO_(2)置换CH_(4)提高页岩气采收率并实现碳封存具有现实意义,且研究认识对今后相关技术的现场应用提供了理论支撑。

关键词： CO_(2)增强页岩气开采 CO_(2)地质埋存储层非均质性热—流—固多场耦合三维模型

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轮轨激励对高速列车轴装制动盘热-机耦合疲劳分析

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机械工程学报 2024年第4期60卷 409-419页

作者：朱海燕黎洁肖乾陈道云华东交通大学轨道交通基础设施性能监测与保障国家重点实验室南昌330013 华东交通大学机电与车辆工程学院南昌330013

为研究轮轨激励对高速列车轴装制动盘热-机耦合疲劳影响,建立高速列车制动盘动力学模型和三维瞬态热-机耦合有限元模型,对紧急制动工况下轴装制动盘振动特性和热-机耦合特性进行计算分析。结果表明,高速列车制动盘在垂向上的振动加速度... 详细信息

为研究轮轨激励对高速列车轴装制动盘热-机耦合疲劳影响,建立高速列车制动盘动力学模型和三维瞬态热-机耦合有限元模型,对紧急制动工况下轴装制动盘振动特性和热-机耦合特性进行计算分析。结果表明,高速列车制动盘在垂向上的振动加速度值最大,横向上最小,且振动形式以制动抖动为主,在0~100 Hz范围抖动最剧烈;与无轮轨激励工况相比,有轮轨激励的轴装制动盘表面温度升高得既快又高,在散热时,温度下降也更快;摩擦面总体呈现三个环状温度分布,在摩擦半径中心处制动盘表面温度比两侧温度高,在三个不同的摩擦半径上,温度呈现梯度分布;有、无轮轨激励工况下制动盘表面的疲劳损伤和疲劳寿命的分布云图与制动盘表面的温度场分布情况基本一致,且热应力越大制动盘表面的疲劳损伤越严重,疲劳寿命越短。

关键词：轮轨激励振动热机耦合制动盘热疲劳损伤