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Computer Modeling in Engineering & Sciences 2023年第2期134卷 981-1003页

作者： Jintao Liu Juan Zhao xiaowei shen College of Architecture and Civil Engineering Xinyang Normal UniversityXinyang464000China College of Mechanics and Materials Hohai UniversityNanjing211100China

In this work,an acoustic topology optimizationmethod for structural surface design covered by porous materials is proposed.The analysis of acoustic problems is performed using the isogeometric boundary elementmethod.Taking the element density of porousmaterials as the design variable,the volume of porousmaterials as the constraint,and the minimum sound pressure or maximum scattered sound power as the design goal,the topology optimization is carried out by solid isotropic material with penalization(SIMP)method.To get a limpid 0–1 distribution,a smoothing Heaviside-like function is proposed.To obtain the gradient value of the objective function,a sensitivity analysis method based on the adjoint variable method(AVM)is proposed.To find the optimal solution,the optimization problems are solved by the method of moving asymptotes(MMA)based on gradient information.Numerical examples verify the effectiveness of the proposed topology optimization method in the optimization process of two-dimensional acoustic problems.Furthermore,the optimal distribution of sound-absorbingmaterials is highly frequency-dependent and usually needs to be performed within a frequency band.

关键词： Boundary element method isogeometric analysis two-dimensional acoustic analysis sound-absorbing materials topology optimization adjoint variable method

A review on the rational design and fabrication of nanosized highentropy materials

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Nano Research 2023年第5期16卷 7874-7905页

作者： Yuanbo Zhou xiaowei shen Tao Qian Chenglin Yan Jianmei Lu Collaborative Innovation Center of Suzhou Nano Science and Technology College of Chemistry Chemical Engineering and Materials Science Soochow University199 Ren’ai RoadSuzhou 215123China Key Laboratory of Core Technology of High Specific Energy Battery and Key Materials for Petroleum and Chemical Industry College of EnergySoochow UniversitySuzhou 215006China School of Chemistry and Chemical Engineering Nantong UniversityNantong 226019China School of Electrical Engineering Nantong UniversityNantong 226019China Light Industry Institute of Electrochemical Power Sources Suzhou 215600China

High-entropy materials are mainly composed of high-entropy alloys(HEAs)and their derivates.Among them,HEAs account for a big part.As a new kind of alloy,they are now arousing great interests because of their high mechanical strength,extraordinary fracture toughness,corrosion resistance compared with traditional alloys.These characteristics allow the use of HEAs in various fields,including mechanical manufacturing,heat-resistant,radiation-resistant,corrosion-resistant,wear-resistant coatings,energy storage,heterocatalysis,etc.In order to promote the extensive application of HEAs,it is of significance to realize their rational design and preparation.In this paper,a systematic review focusing on the rational design and fabrication of nanosized HEAs is given.The design principles of how to match different elements in HEAs and the premise for the formation of single-phase solid solution HEAs are first illustrated.Computation methods for the prediction of formation conditions and properties of HEAs are also in discussion.Then,a detailed description and comparison of the synthesis methods of HEAs and their derivate,as well as their growing mechanism under various synthetic environments is provided.The commonly used characterization methods for the detection of HEAs,along with the typical cases of the application of HEAs in industrial materials,energy storage materials and catalytic materials are also included.Finally,the challenges and perspectives in the design and synthesis of HEAs would be proposed.We hope this review will give guidance for the future development of HEAs materials.

关键词： high-entropy alloys high-entropy alloy(HEA)derivate rational design synthesis strategies characterization application

Low-temperature Li-S batteries enabled by all amorphous con version process of organosulfur cathode

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Journal of Energy Chemistry 2022年第1期31卷 496-502,I0013页

作者： Zhenkang Wang xiaowei shen Sijie Li Yuxuan Wu Tingzhou Yang Jie Liu Tao Qian Chenglin Yan College of Energy Key Laboratory of Advanced Carb on Materials and Wearable Energy Technologies of Jiangsu ProvinceSoochow UniversitySuzhou 215006JiangsuChina College of Chemistry and Chemical Engineering.Nantong University Seyuan 9Nantong 226000JiangsuChina

The high degree of crystallinity of discharging in termediates of Li-S batteries(Li_(2)S_(2)/Li_(2)S)causes a severe capacity attenuation at low temperatures.Herein,a sulfur-rich polymer is fabricated,which enables all the discharging in termediates to exist in an amorphous state without long-range order,promoti ng the substantial conversion of discharging intermediates and enhancing Li-S batteries'performance at low temperatures greatly.This cathode material exhibits excellent performance both at room and low temperatures.Even under an extremely low temperature(-40℃),the discharge capacity can remain 67% of that at room temperature.Besides,in-situ UV/Vis spectroscopy and density functional theory calculations reveal that this organosulfur cathode undergoes a new mechanism during discharge.Li_(2)S_(6) and Li_(2)S_(3) are the primary discharging intermediates that are quite different from conventional Li-S batteries.These results provide a new directi on for a broader range of applications of Li-S batteries.

关键词： Low temperature Organosulfur polymers Li-S battery Crystallinity

Altering the rate-determining step over cobalt single clusters leading to highly efficient ammonia synthesis

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National Science Review 2021年第5期8卷 110-118页

作者： Sisi Liu Mengfan Wang Haoqing Ji xiaowei shen Chenglin Yan Tao Qian College of Energy Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu ProvinceSoochow University

Activation of high-energy triple-bonds of Nis the most significant bottleneck of ammonia synthesis under ambient conditions. Here, by importing cobalt single clusters as strong electron-donating promoter into the catalyst, the rate-determining step of ammonia synthesis is altered to the subsequent proton addition so that the barrier of Ndissociation can be successfully overcome. As revealed by density functional theory calculations, the Ndissociation becomes exothermic over the cobalt single cluster upon the strong electron backdonation from metal to the Nantibonding orbitals. The energy barrier of the positively shifted rate-determining step is also greatly reduced. At the same time, advanced sampling molecular dynamics simulations indicate a barrier-less process of the Napproaching the active sites that greatly facilitates the mass transfer. With suitable thermodynamic and dynamic property, a high ammonia yield rate of 76.2 μg hmg.and superior Faradaic efficiency of 52.9% were simultaneously achieved.

关键词： nitrogen reduction reaction rate-determining step cobalt single cluster mass transfer molecular dynamics simulations

Single lithium-ion channel polymer binder for stabilizing sulfur cathodes

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National Science Review 2020年第2期7卷 315-323页

作者： Chaoqun Niu Jie Liu Tao Qian xiaowei shen Jinqiu Zhou Chenglin Yan College of Energy Collaborative Innovation Center of Suzhou Nano Science and Technology Key Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu ProvinceSoochow University

Lithium–sulfur batteries have great potential for high-performance energy-storage devices, yet the severe diffusion of soluble polysulfide to electrolyte greatly limits their practical applications. To address the above issues, herein we design and synthesize a novel polymer binder with single lithium-ion channels allowing fast lithium-ion transport while blocking the shuttle of unnecessary polysulfide anions. In situ UV–vis spectroscopy measurements reveal that the prepared polymer binder has effective immobilization to polysulfide intermediates. As expected, the resultant sulfur cathode achieves an excellent specific capacity of 1310 mAh g-1at 0.2 C, high Coulombic efficiency of 99.5% at 0.5 C after 100 cycles and stable cycling performance for 300 cycles at 1 C(1 C = 1675 mA g-1). This study reports a new avenue to assemble a polymer binder with a single lithium-ion channel for solving the serious problem of energy attenuation of lithium–sulfur batteries.

关键词： polymer binders single lithium-ion channels polysulfide intermediates lithium–sulfur batteries

Insight into the reaction mechanism of sulfur chains adjustable polymer cathode for high-loading lithium-organosulfur batteries

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Journal of Energy Chemistry 2021年第5期30卷 238-244页

作者： Jinqiu Zhou Xi Zhou Yawen Sun xiaowei shen Tao Qian Chenglin Yan Soochow Institute for Energy and Materials Innovations College of EnergyKey Laboratory of Advanced Carbon Materials and Wearable Energy Technologies of Jiangsu ProvinceSoochow UniversitySuzhou 215006JiangsuChina Institute of Chemical Industry of Forestry Products Chinese Academy of ForestryNanjing 210042JiangsuChina

Small molecules with adjustable sulfur atoms in the confined structure were acted as precursor for the synthesis of polymer cathodes for lithium-organosulfur batteries.Among them,poly(diallyl tetrasulfide)(PDATtS)delivered a high capacity of 700 mAh g^(-1),stable capacity retention of 85%after 300 cycles,high areal capacity~4 m Ah cm^(-2) for electrode with up to 10.3 mg cm^(-2) loading.New insight into the reaction mechanism of PDATtS electrode that radicals arisen from the homolytic cleavage of S-S bond in PDATtS reacted with Li+to generate thiolates(RSLi)and insoluble lithium sulfides(Li_(2)S)or lithium disulfide(Li_(2)S_(2))was clearly verified by in-situ UV/Vis spectroscopy,nuclear magnetic resonance(NMR)studies and density-functional theory(DFT)calculations.Therefore,based on the unique reaction mechanism,problems of rapid capacity fading due to the formation of soluble polysulfide intermediates and their serious shuttle effect in conventional lithium-sulfur(Li-S)batteries was totally avoided,realizing the dendrite-free lithium sulfur batteries.This study sets new trends for avenues of further research to advance Li-S battery technologies.

关键词： Lithium-sulfur battery Organosulfur polymer Adjustable sulfur chains Cathode material

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排水箱涵上跨地铁区间的影响分析及应对措施

江苏建筑 2024年第1期 46-48,57页

作者：张杰沈晓伟华设设计集团股份有限公司江苏南京210014 南京地铁集团有限公司江苏南京210008

在既有运营地铁区间上方进行基坑开挖,将会改变地铁区间原有受力状态,产生附加应力和变形。文章基于南京某上跨地铁区间的市政排水箱涵工程,采用MADIS有限元软件对基坑开挖、回填过程进行模拟分析,研究了土方分区分块和整体开挖两种方... 详细信息

在既有运营地铁区间上方进行基坑开挖,将会改变地铁区间原有受力状态,产生附加应力和变形。文章基于南京某上跨地铁区间的市政排水箱涵工程,采用MADIS有限元软件对基坑开挖、回填过程进行模拟分析,研究了土方分区分块和整体开挖两种方式下对下方区间结构的变形影响情况。研究表明,通过合理分区分块方案,可有效控制下方区间的变形,保证地铁的运营及结构安全,并结合实际监测数据得以验证,为类似工程建设提供一定借鉴。

关键词：不同的开挖方式分区分块区间变形

软弱土地区基坑工程对邻近地铁结构的影响分析

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国防交通工程与技术 2024年第1期22卷 56-60页

作者：张杰沈晓伟管珊珊华设设计集团股份有限公司江苏南京210014 南京地铁集团有限公司江苏南京210008

软弱土地层抗扰动能力较弱,基坑施工极易对邻近既有地铁结构产生影响,如何有效控制基坑施工产生不利影响成为保护地铁结构安全的研究重点。以南京长江漫滩地区临近地铁结构的基坑工程为例,采用MIDAS-GTS软件分析基坑各工况对相邻地铁结... 详细信息

软弱土地层抗扰动能力较弱,基坑施工极易对邻近既有地铁结构产生影响,如何有效控制基坑施工产生不利影响成为保护地铁结构安全的研究重点。以南京长江漫滩地区临近地铁结构的基坑工程为例,采用MIDAS-GTS软件分析基坑各工况对相邻地铁结构变形影响发展趋势,并利用Modflow软件研究了基坑降水对坑外地下水作用,进一步了解止水帷幕随深度增加对周边环境影响趋势,继而确定最佳止水帷幕深度值,对类似的工程有借鉴意义。

关键词：基坑工程地铁结构长江漫滩数值模拟变形降水止水帷幕

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用于毫米波雷达频率源的四倍频器设计

杭州电子科技大学学报（自然科学版） 2024年第2期44卷 14-22,42页

作者：王梓任杨煜黄宇欣沈啸伟陈奇超高海军杭州电子科技大学射频电路与系统教育部重点实验室浙江杭州310018

基于SMIC 55 nm CMOS工艺,设计了一款面向毫米波FMCW雷达频率源的四倍频器。该四倍频器由相同拓扑结构的二倍频级联构成,二倍频核心采用Push-Push结构实现,采用磁耦合谐振器(MCR)实现输入阻抗匹配,同时实现单端转差分和抑制谐波的功能;... 详细信息

基于SMIC 55 nm CMOS工艺,设计了一款面向毫米波FMCW雷达频率源的四倍频器。该四倍频器由相同拓扑结构的二倍频级联构成,二倍频核心采用Push-Push结构实现,采用磁耦合谐振器(MCR)实现输入阻抗匹配,同时实现单端转差分和抑制谐波的功能;论文同时提出了一种谐波抑制结构,运用带通结构结合MCR完成级间匹配和输出功率匹配,满足抑制谐波和较高输出功率的要求。设计结果表明,在60~64 GHz输出频率内,四倍频器饱和输出功率为2.2 dBm,谐波抑制度大于35 dBc,直流功耗59 mW。该四倍频器在满足宽倍频器程的前提下,具有高谐波抑制度和高输出功率的特点,可用于毫米波雷达系统中的频率源产生电路。

关键词： MCR 四倍频器 CMOS工艺谐波抑制毫米波频率源

Numerical simulations of Atlantic meridional overturning circulation(AMOC)from OMIP experiments and its sensitivity to surface forcing

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Journal of Oceanology and Limnology 2024年第2期42卷 454-467页

作者： xiaowei WANG Yongqiang YU State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics(LASG) Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

Atlantic meridional overturning circulation(AMOC)plays an important role in transporting heat meridionally in the Earth’s climate system and is also a key metrical tool to verify oceanic general circulation models.Two OMIP(Ocean Model Intercomparison Project phase 1 and 2)simulations with LICOM3(version 3 of the LASG/IAP Climate System Ocean Model)developed at the State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics(LASG),Institute of Atmospheric Physics(IAP),are compared in this study.Both simulations well reproduce the fundamental characteristics of the AMOC,but the OMIP1 simulation shows a significantly stronger AMOC than the OMIP2 simulation.Because the LICOM3 configurations are identical between these two experiments,any differences between them must be attributed to the surface forcing data.Further analysis suggests that sea surface salinity(SSS)differences should be mainly responsible for the enhanced AMOC in the OMIP1 simulation,but sea surface temperature(SST)also play an unignorable role in modulating AMOC.In the North Atlantic,where deep convection occurs,the SSS in OMIP1 is more saline than that in OMIP1.We find that in the major region of deep convection,the change of SSS has more significant effect on density than the change of SST.As a result,the SSS was more saline than that in OMIP2,leading to stronger deep convection and subsequently intensify the AMOC.We conduct a series of numerical experiments with LICOM3,and the results confirmed that the changes in SSS have more significant effect on the strength of AMOC than the changes in SST.

关键词： oceanic general circulation model(OGCM) Atlantic meridional overturning(AMOC) surface forcing deep convection