检索结果-南通市图书馆

A Hybrid Level Set Optimization Design Method of Functionally Graded Cellular Structures Considering Connectivity

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2024年第4期79卷 1-18页

作者： Yan dong Kang Zhao liang Gao Hao li The State Key Lab of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan430074China Institute of Systems Engineering China Academy of Engineering PhysicsMianyang621900China

With the continuous advancement in topology optimization and additive manufacturing(AM)technology,the capability to fabricate functionally graded materials and intricate cellular structures with spatially varying microstructures has grown significantly.However,a critical challenge is encountered in the design of these structures–the absence of robust interface connections between adjacent microstructures,potentially resulting in diminished efficiency or macroscopic failure.A Hybrid Level Set Method(HLSM)is proposed,specifically designed to enhance connectivity among non-uniform microstructures,contributing to the design of functionally graded cellular structures.The HLSM introduces a pioneering algorithm for effectively blending heterogeneous microstructure interfaces.Initially,an interpolation algorithm is presented to construct transition microstructures seamlessly connected on both sides.Subsequently,the algorithm enables the morphing of non-uniform unit cells to seamlessly adapt to interconnected adjacent microstructures.The method,seamlessly integrated into a multi-scale topology optimization framework using the level set method,exhibits its efficacy through numerical examples,showcasing its prowess in optimizing 2D and 3D functionally graded materials(FGM)and multi-scale topology optimization.In essence,the pressing issue of interface connections in complex structure design is not only addressed but also a robust methodology is introduced,substantiated by numerical evidence,advancing optimization capabilities in the realm of functionally graded materials and cellular structures.

关键词： Hybrid level set method functionally graded cellular structure connectivity interpolated transition optimization design

Weighted Composition Operators That Preserve Frames on Weighted Hardy Spaces

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第7期40卷 1645-1654页

作者： Ya li dong Rui liU Guo Xiang LU School of Mathematical Sciences and LPMC Nankai University School of Statistics and Mathematics Zhongnan University of Economics and Law

In this paper, we characterize weighted composition operators that preserve frames on the weighted Hardy spaces in the unit disk. In particular, we obtain the symbol properties of the bounded invertible weighted composition operators. Moreover, we establish the equivalence between bounded invertible operators and frame-preserving operators. Furthermore, we show that weighted composition operator preserves frames if and only if it preserves the Riesz bases property. Additionally,we investigate the weighted composition operators that preserve tight or normalized tight frames on the Dirichlet space.

关键词： Weighted composition operators Weighted Hardy spaces frames invertible 46B15

Fully fluorinated hybrid zeolite imidazole/Prussian blue analogs with combined advantages for efficient oxygen evolution reaction

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第6期35卷 222-228页

作者： Jiayu Xu Meng li Baoxia dong ligang Feng School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225002China

Hybrid metal-organic framework(MOF)derivatives play a significant role in the novel catalyst development in energy conversion reactions.Here,we demonstrated the low-temperature fully fluorinated zeolitic imidazole framework(ZIF)coupled with a three-dimensional open framework Prussian blue analog(PBA)with combined advantages for electrocatalytic oxygen evolution reaction(OER)in water splitting reaction.The spectroscopic analysis and the electrochemical studies revealed the combined advantages of efficient electronic effect and active site synergism.Because of good conductivity improvement by Ndoped carbon derived from ZIF and the high electrochemical surface area and active site exposure from PBA derivatives,good catalytic performance was obtained on the optimal catalyst of Co Ni ZIF/Co Fe-PBAF-300,which required a low overpotential of 250 m V to reach 10 m A/cm^(2)loaded on the glassy carbon electrode,with Tafel slope of 47.4 m V/dec,and very high dynamic and steady stability.In addition,the multi-component with the mixed structure from highly polar metal fluorides promoted the easy formation of the active phase as revealed by the post-sample analysis.The current results showed a novel composite catalyst materials development from the hybrid MOF derivatives,which would be promising in the electrolysis of water oxidation reactions and energy-relevant catalysis reactions.

关键词： Metal-organic framework Zeolitic imidazole framework Prussian blue analog Fluoridation Multi-component Oxygen evolution reaction

Effect of Mn content on microstructure and properties of AlCrCuFeMnx high-entropy alloy

在线全文

学校读者我要写书评

暂无评论

China Foundry 2024年第2期21卷 147-158页

作者： Ning Wang Kai Ma Qiu-da li Yu-dong Yuan Yan-chun Zhao li Feng School of Materials Science and Engineering Lanzhou University of TechnologyLanzhou 730050China State Key Laboratory of Advanced Processing and Reuse of Nonferrous Metals Lanzhou 730050China CNNC Nuclear Power Operation and Management Co. Ltd.Haiyan 314300ZhejiangChina

AlCrCuFeMnx(x=0,0.5,1,1.5,and 2)high-entropy alloys were prepared using the vacuum arc melting technology.The microstructure and mechanical properties of AlCrCuFeMnxwere analyzed and tested by XRD,SEM,TEM,nanoindentation,and electronic universal testing.The results indicate that the AlCrCuFeMnxhigh-entropy alloy exhibits a dendritic structure,consisting of dendrites with a BCC structure,interdendrite regions with an FCC structure,and precipitates with an ordered BCC structure that form within the dendrite.Manganese(Mn)has a strong affinity for dendritic,interdendritic,and precipitate structures,allowing it to easily enter these areas.With an increase in Mn content,the size of the precipitated nanoparticles in the dendritic region initially increases and then decreases.Similarly,the area fraction initially decreases and then increases.Additionally,the alloy’s strength and wear resistance decrease,while its plasticity increases.The Al Cr Cu Fe Mn1.5alloy boasts excellent mechanical properties,including a hardness of 360 HV and a wear rate of 2.4×10^(-5)mm^(3)·N^(-1)·mm^(-1).It also exhibits impressive yield strength,compressive strength,and deformation rates of 960 MPa,1,700 MPa,and 27.5%,respectively.

关键词： high-entropy alloys microstructure mechanical properties wear resistance strengthening mechanisms

Design strategies for rechargeable aqueous metal-ion batteries

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2024年第1期67卷 165-190页

作者： Yang li Xin Zhao Yifu Gao Yichen Ding Zhichun Si liubing dong dong Zhou Feiyu Kang Tsinghua Shenzhen International Graduate School Tsinghua UniversityShenzhen 518055China College of Chemistry and Materials Science Jinan UniversityGuangzhou 511443China

Rechargeable aqueous metal-ion batteries(AMBs)have attracted extensive scientific and commercial interest due to their potential for cost-effective,highly safe,and scalable stationary energy storage.However,their limited output voltage,inadequate energy density,and poor reversibility of ambiguous electrode reactions in aqueous electrolytes strongly limit their practical viability.This review aims to elucidate the challenges of existing AMBs from the material design to whole device applications.We summarize the emerging electrochemistry,fundamental properties,and key issues in interfacial behaviors of various classes of prevailing AMBs,including aqueous alkali metal-ion batteries and multivalent-ion batteries,and present an appraisal of recent advances for addressing the performance deficiency.Specifically,the progress of zinc-ion batteries is highlighted to provide a ubiquitous guideline for their commercialization in the grid-scale energy storage.Finally,we figure out the dominating general challenges for achieving high-performance AMBs,laying out a perspective for future breakthroughs.

关键词： aqueous metal-ion batteries aqueous alkali metal-ion batteries zinc-ion batteries interfacial behavior stationary energy storage

Three-dimensional stability calculation method for high and large composite slopes formed by mining stope and inner dump in adjacent open pits

在线全文

学校读者我要写书评

暂无评论

International Journal of Mining Science and Technology 2024年第4期34卷 507-520页

作者： Zuchao liang dong Wang Guanghe li Guangyu Sun Mingyu Yu dong Xia Chunjian Ding College of Mining Engineering Liaoning Technical UniversityFuxin 123000China Inner Mongolia Pingxi Baiyinhua Coal Industry Co. Ltd.Xilingol League 026000China Guoneng Baorixile Energy Co. Ltd.Hulunbuir 021008China

The 2D limit equilibrium method is widely used for slope stability analysis.However,with the advancement of dump engineering,composite slopes often exhibit significant 3D mechanical effects.Consequently,it is of significant importance to develop an effective 3D stability calculation method for composite slopes to enhance the design and stability control of open-pit slope engineering.Using the composite slope formed by the mining stope and inner dump in Baiyinhua No.1 and No.2 open-pit coal mine as a case study,this research investigates the failure mode of composite slopes and establishes spatial shape equations for the sliding mass.By integrating the shear resistance and sliding force of each row of microstrip columns onto the bottom surface of the strip corresponding to the main sliding surface,a novel 2D equivalent physical and mechanical parameters analysis method for the strips on the main sliding surface of 3D sliding masses is proposed.Subsequently,a comprehensive 3D stability calculation method for composite slopes is developed,and the quantitative relationship between the coordinated development distance and its 3D stability coefficients is examined.The analysis reveals that the failure mode of the composite slope is characterized by cutting-bedding sliding,with the arc serving as the side interface and the weak layer as the bottom interface,while the destabilization mechanism primarily involves shear failure.The spatial form equation of the sliding mass comprises an ellipsoid and weak plane equation.The analysis revealed that when the coordinated development distance is 1500 m,the error rate between the 3D stability calculation result and the 2D stability calculation result of the composite slope is less than 8%,thereby verifying the proposed analytical method of equivalent physical and mechanical parameters and the 3D stability calculation method for composite slopes.Furthermore,the3D stability coefficient of the composite slope exhibits an exponential correlation with the coordinated development dista

关键词： Composite slope Destabilization mechanism 3D mechanical effect Three-dimensional stability Coordinated development distance

Topological non-reciprocal robust waveguide transport

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第5期67卷 39-45页

作者： Ruizhi dong Yihuan Zhu dongxing Mao Xu Wang Yong li Institute of Acoustics Tongji UniversityShanghai 200092China

Devices that surpass the restriction of reciprocity of classical physical waves have brought intriguing possibilities for wave modulation.Non-reciprocal acoustic devices that rely on the viscosity of the medium or nonlinear effect have low efficiency and distortion problems respectively,and poor immunity to defects.The appearance of acoustic topological insulators achieves nonreciprocal transport with high robustness.However,the local nature of topological states means that their appearance depends on a system with a larger dimension.That is,most of the area of a topological device is occupied by useless lattices that do not directly contribute to non-reciprocal transport.The extra cost of topology protection severely limits the application scenarios of topology states,decreases the cost-effectiveness of topology devices,and is not conducive to device miniaturization and integration.In this work,we construct an acoustic three-layer heterojunction by introducing two types of domain walls into a conventional quantum Hall effect acoustic topological insulator,and successfully construct a non-reciprocal scattering network that forms topological modes spanning the interlayer domain.These extended states are still protected by bulk-band topology,making their non-reciprocity robust against disorder.This structure flawlessly realizes the path broadening in a two-dimensional topological system and can accomplish functions such as non-reciprocal acoustic splitting and multichannel transmission.Our work opens up opportunities for developing topological-insulator-based non-reciprocal devices in acoustics.

关键词： reciprocal topological topology

Fast strength-ductility synergistically adjusting of cold spray additive manufactured Cu deposits via electric pulse processing

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第5期37卷 558-569页

作者： dong WU Yaxin XU Wenya li Xiawei YANG Yu SU State Key Laboratory of Solidification Processing School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China Shaanxi Key Laboratory of Friction Welding Technologies School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi’an 710072China

Electric Pulse Processing(EPP)treatment was innovatively introduced to optimize the strength and ductility of the CSAMed Cu deposits.The results show that EPP is an efficient and fast post-treatment to improve the strength and ductility(within tens of seconds).The larger the pulse current and number of pulses,the better the mechanical properties.Interestingly,this research found that when the heat input determined by pulse current and number of pulses exceeds a certain threshold(pulse current intensity is 2000 A,number of pulses is 10),increasing the number of repeat time could also effectively improve the mechanical properties.A tensile strength of 210 MPa and a ductility of 14.0%could be obtained with reasonable EPP parameters(pulse current intensity is 2000 A,number of pulses is 10,and repeat number is 2),which is similar to those of conventional annealing(e.g.,tensile strength is 272 MPa,elongation is 28.3%).The microstructure evolution analysis shows that EPP can effectively improve the bonding quality between the deposited particles by recrystallization,promote grain growth and the formation of twins,which is the main reason for the improvement of mechanical properties.

关键词： Cold spray additive manufacturing Copper deposit Mechanical property Electric pulse processing Post treatment

Polysaccharides from Chinese herbal medicine:a review on the hepatoprotective and molecular mechanism

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Natural Medicines 2024年第1期22卷 4-14页

作者： li Jifeng GUO Haolin dong Ying YUAN Shuo WEI Xiaotong ZHANG Yuxin dong Lu WANG Fei BAI Ting YANG Yong Dalian Key Laboratory of Chronic Disease Research Center Dalian UniversityDalian 116622China Key Laboratory of Natural Medicines of the Changbai Mountain Ministry of EducationCollege of PharmacyYanbian UniversityYanji 133002China

Polysaccharides,predominantly extracted from traditional Chinese medicinal herbs such as Lycium barbarum,Angelica sinensis,Astragalus membranaceus,Dendrobium officinale,Ganoderma lucidum,and Poria cocos,represent principal bioactive constituents extensively utilized in Chinese medicine.These compounds have demonstrated significant anti-inflammatory capabilities,especially anti-liver injury activities,while exhibiting minimal adverse effects.This review summarized recent studies to elucidate the hepatoprotective efficacy and underlying molecular mechanisms of these herbal polysaccharides.It underscored the role of these polysaccharides in regulating hepatic function,enhancing immunological responses,and improving antioxidant capacities,thus contributing to the attenuation of hepatocyte apoptosis and liver protection.Analyses of molecular pathways in these studies revealed the intricate and indispensable functions of traditional Chinese herbal polysaccharides in liver injury management.Therefore,this review provides a thorough examination of the hepatoprotective attributes and molecular mechanisms of these medicinal polysaccharides,thereby offering valuable insights for the advancement of polysaccharide-based therapeutic research and their potential clinical applications in liver disease treatment.

关键词： Polysaccharides Hepatoprotective Chinese herbal medicine Mechanism