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Microwave-assisted rapid synthesis of multi-heterostructured chalcogenides with greatly enhanced photocatalytic hydrogen evolution

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Microwave-assisted rapid synthesis of multi-heterostructured...

Inverted Modelling:An Effective Way to Support Motion Planning of Legged Mobile Robots

中国化学会第三届中国能源材料化学研讨会

作者： Aili Binshu Sun Rui huo Pengsheng Ling Shun Wang weizhong Jiang College of Materials Science and Engineering Donghua University College of Chemistry and Materials Engineering Wenzhou University

＜正＞Nanostructured multi-heterostructured chalcogenides have garnered considerable attention because of their wide range of application in various areas including photoelectrocatalysis,energy storage and conversion.This research focus on the perparation of multi-heterostructured chalcogenides and their application in photocatalytic hydrogen evolution.

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Chinese Journal of Mechanical Engineering 2023年第1期36卷 268-279页

作者： Chenyao Zhao weizhong Guo State Key Laboratory of Mechanical Systems and Vibration School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai200240China

This paper presents an effective way to support motion planning of legged mobile robots—Inverted Modelling,based on the equivalent metamorphic mechanism concept.The difference from the previous research is that we herein invert the equivalent parallel mechanism.Assuming the leg mechanisms are hybrid links,the body of robot being considered as fixed platform,and ground as moving platform.The motion performance is transformed and measured in the body frame.Terrain and joint limits are used as input parameters to the model,resulting in the representation which is independent of terrains and particular poses in Inverted Modelling.Hence,it can universally be applied to any kind of legged robots as global motion performance framework.Several performance measurements using Inverted Modelling are presented and used in motion performance evaluation.According to the requirements of actual work like motion continuity and stability,motion planning of legged robot can be achieved using different measurements on different terrains.Two cases studies present the simulations of quadruped and hexapod robots walking on rugged roads.The results verify the correctness and effectiveness of the proposed method.

关键词： Gait planning Inverted Modelling Legged mobile robot Motion planning Workspace

Numerical Algorithm with Fourth-Order Spatial Accuracy for Solving the Time-Fractional Dual-Phase-Lagging Nanoscale Heat Conduction Equation

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Numerical Mathematics(Theory,Methods and Applications) 2023年第2期16卷 511-540页

作者： Cui-Cui Ji weizhong Dai School of Mathematics and Statistics Qingdao UniversityQingdao 266071China Mathematics and Statistics Louisiana Tech UniversityRustonLA 71272USA

Nanoscale heat transfer cannot be described by the classical Fourier law due to the very small dimension,and therefore,analyzing heat transfer in nanoscale is of crucial importance for the design and operation of nano-devices and the optimization of thermal processing of nano-materials.Recently,time-fractional dualphase-lagging(DPL)equations with temperature jump boundary conditions have showed promising for analyzing the heat conduction in nanoscale.This article proposes a numerical algorithm with high spatial accuracy for solving the timefractional dual-phase-lagging nano-heat conduction equation with temperature jump boundary conditions.To this end,we first develop a fourth-order accurate and unconditionally stable compact finite difference scheme for solving this time-fractional DPL model.We then present a fast numerical solver based on the divide-and-conquer strategy for the obtained finite difference scheme in order to reduce the huge computational work and storage.Finally,the algorithm is tested by two examples to verify the accuracy of the scheme and computational speed.And we apply the numerical algorithm for predicting the temperature rise in a nano-scale silicon thin film.Numerical results confirm that the present difference scheme provides min{2−α,2−β}order accuracy in time and fourth-order accuracy in space,which coincides with the theoretical analysis.Results indicate that the mentioned time-fractional DPL model could be a tool for investigating the thermal analysis in a simple nanoscale semiconductor silicon device by choosing the suitable fractional order of Caputo derivative and the parameters in the model.

关键词： Nanoscale heat transfer fractional dual-phase-lagging model finite difference scheme stability convergence

Measuring the past 20 years of urban-rural land growth in flood-prone areas in the developed Taihu Lake watershed, China

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Frontiers of Earth Science 2017年第2期11卷 361-371页

作者： weizhong SU Key Laboratory of Watershed Geographic Sciences Nanjing Institute of Geography & Limnology Chinese Academy of Sciences Nanjing 210008 China

There is growing interest in using the urban landscape for stormwater management studies, where land patterns and processes can be important controls for the sustainability of urban development and planning. This paper proposes an original index of Major Hazard Oriented Level （MHOL） and investigates the structure distribution, driving factors, and controlling suggestions of urban-rural land growth in flood-prone areas in the Taihu Lake watershed, China. The MHOL of incremental urban-rural land increased from M 31.51 during the years 1985-1995 to M 38.37 during the years 1995-2010 （M for medium structure distribution, and the number for high-hazard value）. The index shows that urban-rnraI land was distributed uniformly in flood hazard levels and tended to move rapidly to high-hazard areas, where 72.68% of incremental urban-rural land was aggregated maximally in new urban districts along the Huning traffic line and the Yangtze River. Thus, the current accelerating growth of new urban districts could account for the ampliative exposure to high-hazard areas. New districts are driven by the powerful link between land financial benefits and political achievements for local governments and the past unsustainable process of ＂single objective＂ oriented planning. The correlation categorical analysis of the current development intensity and carrying capacity of hydrological ecosystems for sub-basins was used to determine four types of development areas and provide decision makers with indications on the future watershed- scale subdivision of Major Function Oriented Zoning implemented by the Chinese government.

关键词： urban-rural land growth flood-prone areas major hazard oriented level major function oriented zoning,Taihu Lake Watershed

Design of A Novel Wheel-Legged Robot with Rim Shape Changeable Wheels

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Chinese Journal of Mechanical Engineering 2023年第6期36卷 62-72页

作者： Ze Fu Hao Xu Yinghui Li weizhong Guo State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China

The wheel-legged hybrid structure has been utilized by ground mobile platforms in recent years to achieve good mobility on both flat surfaces and rough terrain.However,most of the wheel-legged robots only have one-directional obstacle-crossing ability.During the motion,most of the wheel-legged robots’centroid fluctuates violently,which damages the stability of the load.What’s more,many designs of the obstacle-crossing part and transformation-driving part of this structure are highly coupled,which limits its optimal performance in both aspects.This paper presents a novel wheel-legged robot with a rim-shaped changeable wheel,which has a bi-directional and smooth obstacle-crossing ability.Based on the kinematic model,the geometric parameters of the wheel structure and the design variables of the driving four-bar mechanism are optimized separately.The kinetostatics model of the mobile platform when climbing stairs is established to determine the body length and angular velocity of the driving wheels.A pro-totype is made according to the optimal parameters.Experiments show that the prototype installed with the novel transformable wheels can overcome steps with a height of 1.52 times of its wheel radius with less fluctuation of its centroid and performs good locomotion capabilities in different environments.

关键词： Mobile platform Transformable wheel-legged robot Kinematics analysis Mechanical design Obstacle

Lateral compression and energy absorption of foamed concrete-filled polyethylene circular pipe as yielding layer for high geo-stress soft rock tunnels

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International Journal of Mining Science and Technology 2022年第5期32卷 1087-1096页

作者： Chaoxuan Zhang Xianjun Tan Hongming Tian weizhong Chen State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China University of Chinese Academy of Sciences Beijing 100049China

Foamed concrete as energy absorption material for high geo-stress soft rock tunnels has been proven to be feasible due to its high compressibility and lightweight.However,the lengthy curing and defoaming problems caused by the cast-in-place method of large-volume foamed concrete remain unsolved.In this study,we propose a novel energy absorber composed of foamed concrete-filled polyethylene(FC-PE)pipe and analyze its deformation and energy absorption capacity via quasi-static lateral compression experiments.Results show that FC-PE pipes exhibit typical three-stage deformation characteristics,comprising the elastic stage,the plastic plateau,and the densification stage.Furthermore,the plateau stress,energy absorption,and specific energy absorption of the specimens are 0.81–1.91 MPa,164–533 J,and 1.4–3.6 J/g,respectively.As the density of the foamed concrete increases,the plateau stress and energy absorption increase significantly.Conversely,the length of the plastic plateau and energy absorption efficiency decrease.Moreover,based on the vertical slice method,progressive compression of core material,and the 6 plastic hinges deformation mechanism of the pipe wall,a theoretical calculation method for effective energy absorption is established and achieves good agreement with experimental results,which is beneficial to the optimization of the composite structure.

关键词： Soft rock Yielding layer Foamed concrete Polyethylene pipe Lateral compression Energy absorption

Injectable self-healing polysaccharide hydrogel loading CuS and pH-responsive DOX@ZIF-8 nanoparticles for synergistic photothermal-photodynamic-chemo therapy of cancer

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Journal of Materials Science & Technology 2022年第32期127卷 245-255页

作者： Zhiyi Qian Nuoya Zhao Chunyao Wang weizhong Yuan School of Materials Science and Engineering Key Laboratory of Advanced Civil Materials of Ministry of EducationTongji UniversityShanghai 201804China Beijing Research Institute of Chemical Industry(BRICI) SinopecBeijing 100013China

The injectable self-healing polysaccharide hydrogel was prepared by the formation of Schiff base bonds between aldehyde-modified methylcellulose(MC–CHO)and carboxymethyl chitosan(CMC).The copper sulfide nanoparticles(CuS NPs)and pH-sensitive doxorubicin-loaded zeolitic imidazolate frameworks nanoparticles(DOX@ZIF-8 NPs)were prepared and could be well-dispersed into the hydrogel system.The presence of CuS NPs can achieve photothermal therapy(PTT)for tumors under the irradiation of the near-infrared(NIR)laser.Moreover,CuS NPs can generate photodynamic effects under NIR irradiation,converting oxygen into toxic reactive oxygen species(ROS)and presenting efficient photodynamic therapy(PDT).The DOX@ZIF-8 NPs can be decomposed under an intracellular acidic environment and realize the controlled release of DOX.The injectable self-healing hydrogel loading Cu S and DOX@ZIF-8 NPs can achieve synergistic photothermal-photodynamic-chemo therapy for tumors and will inspire the researchers to construct a platform from hydrogel combined with multifunctional nanomaterials to realize the effective multimodal therapy for tumor.

关键词： Injectable self-healing hydrogel Copper sulfide Zeolitic imidazolate frameworks Synergistic cancer therapy

Conceptual design and analysis of legged landers with orientation capability

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Chinese Journal of Aeronautics 2023年第3期36卷 171-183页

作者： Rongfu LIN weizhong GUO Changjie ZHAO Mingda HE State Key Laboratory of Mechanical System and Vibration School of Mechanical EngineeringShanghai Jiao Tong University200240China

The lander with orientation capability is of fundamental importance for the“Returning”mission because its body can be the base with a suitable launching angle for the ascender lifting off.This paper proposes the conceptual design and verification of Landers with Orientation Capability(LOCs).Firstly,the topological composition of the lander is analyzed and expressed in the form of Lie group,which provides the fundamental principle for the type synthesis of LOCs.Then,the type synthesis approach for designing LOCs is proposed,which includes designing the Equivalent Parallel Mechanism(EPM)and the auxiliary limbs.Numerous mechanisms of LOCs with twodimensional rotational motions are obtained based on the type synthesis approach by developing and combining the EPMs and auxiliary limbs.Afterward,kinematics and Jacobian matrix of a typical legged lander are developed,the workspace is analyzed,singularity configurations are analyzed based on the wrench graph method,and finally,the orientation capability is analyzed.The pitch and yaw angle reach 17.5°,considering the permissible range of joints.The proposed types of LOCs offer potential candidate for the“Returning”mission of the exploration mission.

关键词： Legged lander Orientation analysis Orientation capability Parallel mechanism Type synthesis

Editorial for the Special Issue on Public Health

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Engineering 2021年第7期7卷 889-890页

作者： Chen Wang weizhong Yang Chinese Academy of Medical Sciences&Peking Union Medical College Beijing 100730China

Microbes have a long history of spilling over from animals to humans,resulting in occasional surprise attacks on the global population.One of the most recent of these attacks,coronavirus disease 2019(COVID-19),led to the most harmful and widespread respiratory infectious disease pandemic during the last century.COVID-19 has not only taken a heavy toll on human life and health around the world,but also introduced formidable challenges to global economic development,technological innovation,social progress,and national and international politics.In addition,the pandemic has fostered new insights into how to understand and prepare for outbreaks of emerging infectious diseases,how to better utilize technological and social interventions to prevent or respond to these outbreaks,and how to implement science-based control and treatment to mitigate their effects.

关键词： utilize insight technological