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Stability of a Variable Coefficient Star-Shaped Network with Distributed Delay

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Journal of Systems Science & Complexity 2022年第6期35卷 2077-2106页

作者： ZHANG hai-E XU Gen-Qi chen Hao LI Min School of Mathematics Tianjin UniversityTianjin 300350China Department of Basic Science Tangshan UniversityTangshan 063000China School of Mechatronical Engineering Beijing Institute of TechnologyBeijing 100081China

The paper deals with the exponential stability problem of a variable coefficient star-shaped network,whose strings are coupled at a common end in a star-shaped configuration and the common connection of all strings can be moved.Two kinds of media materials with a component of viscous and another simply elastic are distributed on each string.Under suitable hypothesis on the coefficient functionsμj(x)of damping terms and the kernelsηj(s)of distributed delay terms,the well-posedness of the system is obtained by means of resolvent family theory.In addition,the allocation proportion of the two parts and the property of the material character functions are discussed when the starshaped network is exponentially stable.Meanwhile,the sufficient condition of exponential stability is established.Numerical simulations are also included to verify the main results.

关键词： Allocation proportion elastic and viscous exponential stability resolvent family starshaped network

Chemical inhomogeneity inhibits grain boundary fracture:A comparative study in CrCoNi medium entropy alloy

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Journal of Materials Science & Technology 2023年第22期153卷 228-241页

作者： Fuhua Cao Yan chen hai-Ying Wang Lan-Hong Dai State Key Laboratory of Nonlinear Mechanics Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 101408China School of Future Technology University of Chinese Academy of SciencesBeijing 100049China

Grain boundary(GB)fracture is arguably one of the most important reasons for the catastrophic failure of ductile polycrystalline materials.It is of interest to explore the role of chemical distribution on GB defor-mation and fracture,as GB segregation becomes a key strategy for tailoring GB properties.Here we report that the inhomogeneous chemical distribution effectively inhibits GB fracture in a model CoCrNi medium entropy alloy compared to a so-called‘average-atom’sample.Atomic deformation kinematics combined with electronic behavior analysis reveals that the strong charge redistribution ability in chemical disor-dered CrCoNi GBs enhances shear deformation and thus prevents GB crack formation and propagation.Inspects on the GBs with different chemical components and chemical distributions suggest that not only disordered chemical distribution but also sufficient“harmonic elements”with large electronic flexibility contribute to improving the GB fracture resistance.This study provides new insight into the influence mechanism of GB chemistry on fracture behavior,and yields a systematic strategy and criterion,from the atoms and electrons level,forward in the design of high-performance materials with enhanced GB fracture resistance.

关键词： Fracture Chemical inhomogeneity Grain boundary Medium entropy alloy

Vacancy healing for stable perovskite solar cells via bifunctional potassium tartrate

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Journal of Energy Chemistry 2024年第1期88卷 64-70,I0002页

作者： Jing Dou Yue Ma Xiuxiu Niu Wentao Zhou Xueyuan Wei Jie Dou Zhenhua Cui Qizhen Song Tinglu Song Huanping Zhou cheng Zhu Yang Bai Qi chen Experimental Centre for Advanced Materials School of Materials Science and EngineeringBeijing Institute of TechnologyBeijing 100081China Beijing Key Laboratory for Theory and Technology of Advanced Battery Materials Key Laboratory of Polymer Chemistry and Physics of Ministry of EducationBIC-ESATSchool of Materials Science and EngineeringPeking UniversityBeijing 100871China

Perovskite solar cell has gained widespread attention as a promising technology for renewable energy.However, their commercial viability has been hampered by their long-term stability and potential Pb leakage. Herein, we demonstrate a bifunctional passivator of the potassium tartrate(PT) to address both challenges. PT minimizes the Pb leakage in perovskites and also heals cationic vacancy defects, resulting in improved device performance and stability. Benefiting from PT modification, the power conversion efficiency(PCE) is improved to 23.26% and the Pb leakage in unencapsulated films is significantly reduced to 9.79 ppm. Furthermore, the corresponding device exhibits no significant decay in PCE after tracking at the maximum power point(MPP) for 2000 h under illumination(LED source, 100 mW cm^(-2)).

关键词： Perovskite Potassium tartrate Lead leakage Long-term stability

Copper Metabolism and Cuproptosis:Molecular Mechanisms and Therapeutic Perspectives in Neurodegenerative Diseases

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Current Medical Science 2024年第1期44卷 28-50页

作者： Xiao-xia BAN Hao WAN Xin-xing WAN Ya-ting TAN Xi-min HU Hong-xia BAN Xin-yu chen Kun HUANG Qi ZHANG Kun XIONG Department of Human Anatomy and Neurobiology School of Basic Medical ScienceCentral South UniversityChangsha 430013China Department of Endocrinology Third Xiangya HospitalCentral South UniversityChangsha 430013China Department of Dermatology Xiangya HospitalCentral South UniversityChangsha 430013China Affiliated Hospital Inner Mongolia Medical UniversityHohhot 010050China Key Laboratory of Emergency and Trauma of Ministry of Education Hainan Medical UniversityHaikou 571199China Hunan Key Laboratory of Ophthalmology Changsha 430013China

Copper is an essential trace element,and plays a vital role in numerous physiological processes within the human body.During normal metabolism,the human body maintains copper homeostasis.Copper deficiency or excess can adversely affect cellular function.Therefore,copper homeostasis is stringently regulated.Recent studies suggest that copper can trigger a specific form of cell death,namely,cuproptosis,which is triggered by excessive levels of intracellular copper.Cuproptosis induces the aggregation of mitochondrial lipoylated proteins,and the loss of iron-sulfur cluster proteins.In neurodegenerative diseases,the pathogenesis and progression of neurological disorders are linked to copper homeostasis.This review summarizes the advances in copper homeostasis and cuproptosis in the nervous system and neurodegenerative diseases.This offers research perspectives that provide new insights into the targeted treatment of neurodegenerative diseases based on cuproptosis.

关键词： cuproptosis copper metabolism copper homeostasis neurodegeneration neurodegenerativedisease

fast neutron absorption spectroscopy;laser plasma accelerator;photo-nuclear neutrons;single neutron count

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High Power Laser Science and Engineering 2024年第1期12卷 108-115页

作者： Wen-Zhao Wang Jie Feng Xiao-Peng Zhang Yao-Jun Li Wei-Jun Zhou Wen-Chao Yan Guo-Qiang Zhang Chang-Bo Fu Li-Ming chen Key Laboratory of Laser Plasma(MoE) School of Physics and AstronomyShanghai Jiao Tong UniversityShanghaiChina IFSA Collaborative Innovation Center Shanghai Jiao Tong UniversityShanghaiChina Institute of High Energy Physics Chinese Academy of SciencesBeijingChina Shanghai Advanced Research Institute Chinese Academy of SciencesShanghaiChina Key Laboratory of Nuclear Physics and Ion-beam Application(MoE) Institute of Modern PhysicsFudan UniversityShanghaiChina

Fast neutron absorption spectroscopy is widely used in the study of nuclear structure and element analysis. However,due to the traditional neutron source pulse duration being of the order of nanoseconds, it is difficult to obtain a high-resolution absorption spectrum. Thus, we present a method of ultrahigh energy-resolution absorption spectroscopy via a high repetition rate, picosecond duration pulsed neutron source driven by a terawatt laser. The technology of single neutron count is used, which results in easily distinguishing the width of approximately 20 keV at 2 MeV and an asymmetric shape of the neutron absorption peak. The absorption spectroscopy based on a laser neutron source has one order of magnitude higher energy-resolution power than the state-of-the-art traditional neutron sources, which could be of benefit for precisely measuring nuclear structure data.

关键词： fast neutron absorption spectroscopy laser plasma accelerator photo-nuclear neutrons single neutron count

Dynamic Spacer Installation of Multifunctionalities into Metal-Organic Frameworks for Spontaneous One-Step Ethylene Purification from a Ternary C_(2)-Hydrocarbons Mixture

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CCS Chemistry 2024年第1期6卷 241-254页

作者： Yang-Yang Xiong cheng-Xia chen Tony Pham Zhang-Wen Wei Katherine A.Forrest Mei Pan cheng-Yong Su MOE Laboratory of Bioinorganic and Synthetic Chemistry Lehn Institute of Functional MaterialsSchool of ChemistrySun Yat-sen UniversityGuangzhou 510275 Department of Chemistry University of South FloridaTampaFlorida 33620

Simultaneous ethane and acetylene removal from a C_(2)-gases mixture(C_(2)H_(6),C_(2)H_(4),and C_(2)H_(2))through a one-step separation process for ethylene purification is of great importance yet challenging in petrochemical industry,owing to their similar molecule sizes and physical properties.Herein,a series of multifunctionalized metal–organic frameworks(MOFs),LIFM-XYY-1∼8(LIFM stands for Lehn Institute of Functional Materials,and XYY are the initials of the first author),are constructed via a dynamic spacer installation(DSI)approach to optimize the pore-nanospaces for efficient C_(2)H_(4) isolation from the ternary C_(2)-gases mixture.Installation of variable organic-spacers into the prototypical MOFs,LIFM-28 or PCN-700,results in dramatically improved pore volume/surface area,contracted pore size,and functionalized pore surface,which in turn bring out high C_(2)-gases uptake capacities,enhanced C_(2)H_(6) and C_(2)H_(2) adsorption selectivities over C_(2)H_(4),and fast adsorption kinetics,providing an effective strategy to achieve delicate trade-off among these indexes for adequate separation performance.Specifically,optimized LIFM-XYY-7 presents four-times C_(2)H_(6) and C_(2)H_(2) adsorption capacities than proto-PCN-700.Dynamic breakthrough experiments reveal that poly-grade C_(2)H_(4)(>99.9%)can be obtained from binary or ternary C_(2)-hydrocarbon mixtures through a single separation process.Combined with themolecular simulations,this work demonstrates a promising protocol of porenanospace engineering via multi-functional optimization by the DSI approach to screen out MOFs for a formidable task.

关键词： metal-organic frameworks dynamic spacer installation C_(2)H_(6)/C_(2)H_(2)/C_(2)H_(4)gases separation pore nanospace engineering multi-functional optimization

Improvement for creep strength of a second-generation single crystal superalloy by design of heat treatments

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Rare Metals 2024年第1期43卷 342-350页

作者： Wan-Shun Xia Xin-Bao Zhao Jia-chen Xu Quan-Zhao Yue Qing-Qing Ding Huan-Chang Duan Yue-Feng Gu Hong-Bin Bei Ze Zhang Institute of Superalloys Science and Technology School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027China State Key Laboratory of Silicon and Advanced Materials School of Materials Science and EngineeringZhejiang UniversityHangzhou 310027China

Design of heat treatments is related to the key technology for development of nickel-based single crystal superalloys(Ni-SXs). Based on the full understanding of the solidification characteristics, this work applies optimization design of heat treatments for a second-generation Ni-SX. Microstructure evolution and creep properties are compared in the material under conventional/standard(Std.) and optimized(Opt.) treatments. For the Std. sample,strong dendritic segregations determine inconsistent microstructure evolution in the dendritic(D) and interdendritic region(ID), while the latter serves as weak area to have the prior microcrack initiation, damaging overall performance of the alloy. The Opt. treatment applies higher homogenization temperature, leading to overall reduced segregations, while not inducing incipient melting. A lower temperature of first-step ageing is used to lower the size ofγ'particles. These help to form the more uniform microstructure in dendritic and interdendritic region and relieve the inconsistent microstructure evolution. The balanced local strength makes ID no longer as the weak area,thus restricting microcrack initiation. Great improvement of high temperature and low stress property is obtained by this progress, leading to the pronounced increase of creep rupture life under 1100 °C/140 MPa.

关键词： Single crystal superalloy Heat treatment Segregation Solidification Creep property

磺化聚苯砜/聚砜纳滤脱色膜的制备及其性能研究

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水处理技术 2024年第2期50卷 79-82,89页

作者：刘文超张晓萌陈可可陈涛潘巧明谭惠芬蓝星(杭州)膜工业有限公司杭州水处理技术研究开发中心有限公司浙江省特种设备科学研究院浙江杭州310012

本文中引用一种新的高分子聚合物-磺化聚苯砜(SPPSU)制备纳滤脱色膜的涂覆层,将其与其余药品混合后制备成纳滤膜的表层涂覆液,从而制备成可分离开染料/无机盐混合液的纳滤脱色膜。经过优化调整SPPSU的浓度,磺化度,以及后处理温度三个变... 详细信息

本文中引用一种新的高分子聚合物-磺化聚苯砜(SPPSU)制备纳滤脱色膜的涂覆层,将其与其余药品混合后制备成纳滤膜的表层涂覆液,从而制备成可分离开染料/无机盐混合液的纳滤脱色膜。经过优化调整SPPSU的浓度,磺化度,以及后处理温度三个变量,最终确定SPPSU浓度为1.5%,磺化度为35%,后处理温度为100℃时,其对刚果红的截留率最高可达99.6%,水通量最高可达142 L/(m^(2)·h),与此同时硫酸钠的截留率低于5%;在甲基蓝与硫酸钠的混合液处理过程中,甲基蓝的截留率为92.5%,水通量为75 L/(m^(2)·h),硫酸钠截留率在20%以下,实现了染料溶液与无机盐的有效分离,并在此基础上,将其与海德能的商业纳滤脱色膜进行对照,得出可以与HYDRACoRe10-LD的性能相似,而水通量却高出很多,说明此纳滤脱色膜有很好的应用前景。

关键词：磺化聚苯砜纳滤脱色膜染料废水截留率

Minimizing interfacial energy losses in inverted perovskite solar cells by a dipolar stereochemical 2D perovskite interface

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Journal of Energy Chemistry 2024年第3期90卷 496-503,I0011页

作者： Junjie Qian Jingjing He Qihang Zhang chenyue Zhu Shilin chen Zhanpeng Wei Xuesong Leng Ziren Zhou Benben Shen Yu Peng Qiang Niu Shuang Yang Yu Hou Key Laboratory for Ultrafine Materials of Ministry of Education Shanghai Engineering Research Center of Hierarchical NanomaterialsSchool of Materials Science and EngineeringEast China University of Science and TechnologyShanghai 200237China National Enterprise Technology Center Inner Mongolia Erdos Electric Power and Metallurgy Group Company LimitedOrdos 016064Inner MongoliaChina

Inverted perovskite solar cells(PSCs) have attracted broad research and industrial interest owing to their suppressed hysteresis,cost-effectiveness,and easy-fabrication.However,the issue of non-radiative recombination losses at the n-type interface between the perovskite and fullerene has impeded further improvement of photovoltaic performance.Here,we modify the n-type interface of FAPbI_(3) perovskite films by constructing a stereochemical two-dimensional(2D) perovskite interlayer,in which the organic cations comprise both pyridine and ammonium groups.The pyridine N donor can create stable bonding with the surface-uncoordinated Pb on the perovskite,thereby passivating the shallow-level defects and enhancing the air stability of the film.Furthermore,the pyridine N donor also offers a positive polar interface to decrease the surface work function of the perovskite film,enabling n-type modification.Ultimately,we employ a p-i-n photovoltaic(PV) device with the positive dipole interlayer at perovskite/fullerene contact and achieve remarkable photoelectric conversion efficiency(PCE) of 22.0%.

关键词： Perovskite solar cells Dipole interlayer Stereochemistry Non-radiative recombination