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Dynamic characteristics of multi-span spinning beams with elastic constraints under an axial compressive force

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Applied Mathematics and Mechanics(English Edition) 2024年第2期45卷 295-310页

作者： Xiaodong GUO Zhu SU lifeng wang State Key Laboratory of Mechanics and Control for Aerospace Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China

A theoretical model for the multi-span spinning beams with elastic constraints under an axial compressive force is *** displacement and bending angle functions are represented through an improved Fourier series,which ensures the continuity of the derivative at the boundary and enhances the *** exact characteristic equations of the multi-span spinning beams with elastic constraints under an axial compressive force are derived by the Lagrange *** efficiency and accuracy of the present method are validated in comparison with the finite element method(FEM)and other *** effects of the boundary spring stiffness,the number of spans,the spinning velocity,and the axial compressive force on the dynamic characteristics of the multi-span spinning beams are *** results show that the present method can freely simulate any boundary constraints without modifying the solution *** elastic range of linear springs is larger than that of torsion springs,and it is not affected by the number of *** an increase in the axial compressive force,the attenuation rate of the natural frequency of a spinning beam with a large number of spans becomes larger,while the attenuation rate with an elastic boundary is lower than that under a classic simply supported boundary.

关键词： multi-span spinning beam elastic constraint improved Fourier series free vibration semi-analytical solution

Mass-spring model for elastic wave propagation in multilayered van der Waals metamaterials

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Applied Mathematics and Mechanics(English Edition) 2024年第7期45卷 1107-1118页

作者： Yabin JING lifeng wang Yuqiang GAO State Key Laboratory of Mechanics and Control for Aerospace Structures Nanjing University of Aeronautics and AstronauticsNanjing210016China

Multilayered van der Waals(vdW)materials have attracted increasing interest because of the manipulability of their superior optical,electrical,thermal,and mechanical properties.A mass-spring model(MSM)for elastic wave propagation in multilayered vdW metamaterials is reported in this *** dynamics(MD)simulations are adopted to simulate the propagation of elastic waves in multilayered vdW *** results show that the graphene/MoS_(2)metamaterials have an elastic wave bandgap in the terahertz *** MSM for the multilayered vdW metamaterials is proposed,and the numerical simulation results show that this model can well describe the dispersion and transmission characteristics of the multilayered vdW *** MSM can predict elastic wave transmission characteristics in multilayered vdW metamaterials stacked with different two-dimensional(2D)*** results presented in this paper offer theoretical help for the vibration reduction of multilayered vdW semiconductors.

关键词： multilayered van der Waals(vd W)metamaterial molecular dynamics(MD) mass-spring model(MSM) dispersion relation transmission characteristic

Flexible Load Participation in Peaking Shaving and Valley Filling Based on Dynamic Price Incentives

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Energy Engineering 2024年第2期121卷 523-540页

作者： lifeng wang Jing Yu Wenlu Ji Nanjing Power Supply Company Nanjing210019China State Grid Jiangsu Electric Power Co. Ltd.Nanjing211103China

Considering the widening of the peak-valley difference in the power grid and the difficulty of the existing fixed time-of-use electricity price mechanism in meeting the energy demand of heterogeneous users at various moments or motivating users,the design of a reasonable dynamic pricing mechanism to actively engage users in demand response becomes imperative for power grid *** this purpose,a power grid-flexible load bilevel model is constructed based on dynamic pricing,where the leader is the dispatching center and the lower-level flexible load acts as the ***,an upper-level day-ahead dispatching model for the power grid is established,considering the lowest power grid dispatching cost as the objective function and incorporating the power grid-side ***,the lower level comprehensively considers the load characteristics of industrial load,energy storage,and data centers,and then establishes a lower-level flexible load operation model with the lowest user power-consuming cost as the objective ***,the proposed method is validated using the IEEE-118 system,and the findings indicate that the dynamic pricing mechanism for peaking shaving and valley filling can effectively guide users to respond actively,thereby reducing the peak-valley difference and decreasing users’purchasing costs.

关键词： Demand response fixed time-of-use electricity price mechanism dynamic price incentives mechanism bi-level model flexible load

Evaluation of the intracellular lipid-lowering effect of polyphenols extract from highland barley in HepG2 cells

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Food Science and Human Wellness 2024年第1期13卷 454-461页

作者： Yijun Yao Zhifang Li Bowen Qin Xingrong Ju lifeng wang College of Food Science and Engineering/Collaborative Innovation Centre for Modern Grain Circulation and Safety Nanjing University of Finance and EconomicsNanjing 210023China

Active ingredients from highland barley have received considerable attention as natural products for developing treatments and dietary supplements against *** practical application,the research of food combinations is more significant than a specific food *** study investigated the lipid-lowering effect of highland barley polyphenols via lipase assay in vitro and HepG2 cells induced by oleic acid(OA).Five indexes,triglyceride(TG),total cholesterol(T-CHO),low density lipoprotein-cholesterol(LDL-C),aspartate aminotransferase(AST),and alanine aminotransferase(ALT),were used to evaluate the lipidlowering effect of highland barley *** also preliminary studied the lipid-lowering mechanism by Realtime fluorescent quantitative polymerase chain reaction(q PCR).The results indicated that highland barley extract contains many components with lipid-lowering effects,such as hyperoside and *** vitro,the lipase assay showed an 18.4%lipase inhibition rate when the additive contents of highland barley extract were 100μg/m *** intracellular lipid-lowering effect of highland barley extract was examined using 0.25 mmol/L OA-induced HepG2 *** results showed that intracellular TG,LDL-C,and T-CHO content decreased by 34.4%,51.2%,and 18.4%,*** and AST decreased by 51.6%and 20.7%compared with the untreated hyperlipidemic HepG2 cells.q PCR results showed that highland barley polyphenols could up-regulation the expression of lipid metabolism-related genes such as PPARγand Fabp4.

关键词： Highland barley Polyphenols extract Lipid-lowering effect HepG2 cells

Preparation of single atom catalysts for high sensitive gas sensing

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International Journal of Extreme Manufacturing 2024年第3期6卷 216-248页

作者： Xinxin He Ping Guo Xuyang An Yuyang Li Jiatai Chen Xingyu Zhang lifeng wang Mingjin Dai Chaoliang Tan Jia Zhang Key Laboratory of Microsystems and Microstructure Manufacturing Ministry of EducationHarbin Institute of TechnologyHarbin 150080People’s Republic of China Institute for Frontier Materials Deakin UniversityWaurn Ponds CampusLocked Bag 20000Victoria 3220Australia School of Electrical and Electronic Engineering Nanyang Technological UniversitySingapore 639798Singapore Department of Electrical and Electronic Engineering The University of Hong KongPokfulam RoadHong Kong Special Administrative Region of China 999077People’s Republic of China Chongqing Research Institute Harbin Institute of TechnologyChongqing 401120People’s Republic of China

Single atom catalysts(SACs)have garnered significant attention in the field of catalysis over the past decade due to their exceptional atom utilization efficiency and distinct physical and chemical *** the semiconductor-based electrical gas sensor,the core is the catalysis process of target gas molecules on the sensitive *** this context,the SACs offer great potential for highly sensitive and selective gas sensing,however,only some of the bubbles come to the *** facilitate practical applications,we present a comprehensive review of the preparation strategies for SACs,with a focus on overcoming the challenges of aggregation and low *** research efforts have been devoted to investigating the gas sensing mechanism,exploring sensitive materials,optimizing device structures,and refining signal post-processing ***,the challenges and future perspectives on the SACs based gas sensing are presented.

关键词： single atom catalysts preparation sensing mechanism gas sensing

China's International Hunt for Corrupt Fugitives

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China News Release 2024年第4期 70-71页

作者： wang lifeng the School of Public Administration at Jinlin University the Inner-Party Regulations Research Institute of the Jilin Province Law Society

China has been ramping up efforts to hunt down international fugitives and take this as a supplement and extension of domestic Party conduct and clean government construction and anti-corruption *** January 2014,Chinese President Xi Jinping told the third plenary session of the 18 th Central Commission for Discipline Inspection of the Communist Party of China(CPC)that efforts should be made to hunt down international fugitives.

关键词： Communist struggle forts

Photoswitchable Molecular Recognition Enabled by Dithienylethene-Mediated Structural Changes of Dynamic Covalent Hydrazone Bonds

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CCS Chemistry 2024年第2期6卷 497-506页

作者： lifeng wang Hanxun Zou Hebo Ye Yu Hai Hanwei Lu Junmiao Deng Lei You State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002 College of Chemistry and Material Science Fujian Normal UniversityFuzhou 350007 University of Chinese Academy of Sciences Beijing 100049 Fujian Science&Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108

Light-induced recognition,assemblies,and materials are intensive areas of research due to their high spatiotemporal ***,we demonstrated photoswitchable molecular recognition via dithienylethene-triggeredreversible structural regulation of dynamic covalent hydrazone *** combining dithienylethenes and cyclic hemiacetals,the photochemical open-ring and closed-ring forms enabled turningoff and on the creation of awide range of hydrazones when ***-induced bidirectional switching between hydrazones and their cyclization structures promoted by a neighboring carboxyl group was further *** taking advantage of reversible structural changes totoggleon andoff the binding pocket,photoswitchable recognitionofmetal ionswas ***,the construction of an acylhydrazone polymer offered a facile way for light-mediated selective extraction/*** strategies and results reported here should find applications in many contexts,such asdynamicassemblies,molecular switches,and smart materials.

关键词： molecular recognition photoswitch dynamic covalent chemistry hydrazone selective extraction/release

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主动可调谐压电超材料梁的宽带振动抑制优化

Acta Mechanica Sinica 2024年第3期40卷 202-213页

作者：高玉强王立峰 State Key Laboratory of Mechanics and Control for Aerospace Structures Nanjing University of Aeronautics and AstronauticsNanjing 210016China

压电超材料在带隙调控方面已经得到了广泛的应用,然而,在工程应用中,宽带振动抑制是仍存在着挑战.在本文中,设计了一中包含多个压电单元的压电超胞结构,并提出一种压电超材料梁的优化方法用于拓宽超材料振动抑制的频率范围.采用遗传算... 详细信息

压电超材料在带隙调控方面已经得到了广泛的应用,然而,在工程应用中,宽带振动抑制是仍存在着挑战.在本文中,设计了一中包含多个压电单元的压电超胞结构,并提出一种压电超材料梁的优化方法用于拓宽超材料振动抑制的频率范围.采用遗传算法对压电单元中的LR分流电路进行优化.通过优化将多个局部共振带隙耦合到布拉格带隙中.同时可定制超材料的衰减常数,并优化得到最大带宽.为验证优化方法的正确性以及宽频振动抑制能力,利用合成电路模拟LR电路中的可调电感,通过调节电感,实验实现了可调节的振动抑振能力.实验结果还表明,优化后的超材料可拓宽振动抑制频率范围.实验验证了超材料宽频可调节的振动抑振能力.本文为宽带振动抑制提供了一种新的方法和途径.

关键词： Optimization Broadband vibration suppression Piezoelectric metamaterial Tunable bandgap

煤矿用反应型高分子材料安全管理现状及对策措施研究

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煤炭工程 2024年第7期56卷 187-192页

作者：王利峰安标国家矿用产品安全标志中心有限公司北京100013

为提高反应型高分子材料的安全性能,对煤矿井下反应型高分子材料使用现状进行了梳理,指出目前煤矿井下反应型高分子材料主要有以下几类:煤矿加固煤岩体用高分子材料,煤矿堵水用高分子材料,煤矿充填密闭用高分子材料,煤矿喷涂堵漏风用高... 详细信息

为提高反应型高分子材料的安全性能,对煤矿井下反应型高分子材料使用现状进行了梳理,指出目前煤矿井下反应型高分子材料主要有以下几类:煤矿加固煤岩体用高分子材料,煤矿堵水用高分子材料,煤矿充填密闭用高分子材料,煤矿喷涂堵漏风用高分子材料,并对各类材料进行了分析,研究分析了安全管理存在问题。通过调查与分析反应型高分子材料的生产特点、施工工艺及质量监控等关键环节,结合相关准则和规定,进而探索了一套新的反应型高分子材料的管理方法,并对如何提高此类材料的安全性能提供了研究建议,进一步提出改善煤矿反应型高分子材料安全保障水平的对策措施,为新技术、新材料的安全使用提供客观的理论支持和宝贵的安全经验,满足安全把关的需求。

关键词：反应型高分子材料煤矿化学属性安全管理