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Selecting the Technology of Sodium Silicate Modified Poplar with the Highest Performance by Fuzzy Orthogonal Method

Journal of Renewable Materials 2023年第5期11卷 2399-2415页

作者： Xiaoqian Bi Pengfei Guan Ping Li Yuan Zhang Xingong Li Yingfeng Zuo college of Materials Science and engineering Central South University of Forestry and TechnologyChangsha410004China college of Furniture and Art design Central South University of Forestry and TechnologyChangsha410004China

Sodium silicate modification can improve the overall performance of wood.The modification process has a great influence on the properties of modified wood.In this study,a new method was introduced to analyze the wood modification process,and the properties of modified wood were studied.Poplar wood was modified with sodium silicate by vacuum-pressure impregnation.After screening using single-factor experiments,an orthogonal experiment was carried out with solution concentration,impregnation time,impregnation pressure,and the cycle times as experimental factors.The modified poplar with the best properties was selected by fuzzy mathematics and characterized by SEM,FT-IR,XRD and TG.The results showed that some lignin and hemicellulose were removed from the wood due to the alkaline action of sodium silicate,and the orderly crystal area of poplar became disorderly,resulting in the reduction of crystallinity of the modified poplar wood.FT-IR analysis showed that sodium silicate was hydrolyzed to form polysilicic acid in wood,and structural analysis revealed the formation of Si-O-Si and Si-O-C,indicating that sodium silicate reacted with fibers on the wood cell wall.TG-DTG curves showed that the final residual mass of modified poplar wood increased from 25%to 67%,and the temperature of the maximum loss rate decreased from 343℃ to 276℃.The heat release and smoke release of modified poplar wood decreased obviously.This kind of material with high strength and fire resistance can be used in the outdoor building and indoor furniture.

关键词： Poplar wood sodium silicate impregnation modification fuzzy orthogonal method process optimization flame retardant

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The convexity about ultimate bearing hypersurfaces o structures

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Frontiers of Structural and Civil engineering 2016年第4期10卷 456-461页

作者： Chengxi GUO Tingting GUO college of Civil engineering Institution of Architecture Design Xi'an University of Architecture and Technology Xi'an 710055China

The relationship between the convexity on the ultimate bearing surface of a structure and the second- order effects of loads is discussed. All of generalized non-overload forces acted on a structure forms a convex set when ignoring the second-order effects （coupling effects between the generalized forces）. It is true also when the Hessian matrix composed of the second-order partial derivatives on the hypersurface about the ultimate bearing of the structure is negative definite. The outward convexity is kept when the surface is expressed by certain dimensionless parameters. A series of properties based on the convexity are pointed out. Some applications in the analysis of bearing capacity of structures were illustrated with examples. The study shows that an evaluation about the bearing capacity state of a complex structure can be made on the basis of several points on the surface of the ultimate bearing of the structure.

关键词： service limit load ultimate bearing surface convexity generalized force generalized displacement frame structure

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由旋错引起的弹性声子板的拓扑束缚态

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Acta Mechanica Sinica 2022年第2期38卷 154-164,I0005页

作者：夏百战姜子涵童亮郑圣洁满先锋 State Key Laboratory of Advanced design and Manufacturing for Vehicle Body Hunan UniversityChangsha 410082China college of Mechanical and Vehicle engineering Hunan UniversityChangsha 410082China college of Mechanical and Electrical engineering Changsha UniversityChangsha 410022China

拓扑缺陷(包括旋错和位错)存在于各种材料中,具有优异的机械和物理性能,显示出惊人的潜力.本文在拓扑弹性声子板中探讨了旋错机理.旋错产生晶格变形,进而产生具有五重对称性的五边形核.拓扑束缚态能够在五边形核边界附近实现弹性波良好... 详细信息

拓扑缺陷(包括旋错和位错)存在于各种材料中,具有优异的机械和物理性能,显示出惊人的潜力.本文在拓扑弹性声子板中探讨了旋错机理.旋错产生晶格变形,进而产生具有五重对称性的五边形核.拓扑束缚态能够在五边形核边界附近实现弹性波良好的局域.拓扑束缚态能够在有限尺寸的弹性板中实现,能够免疫一定程度的缺陷,本质上不同于普通缺陷态.拓扑束缚态的发现开辟了拓扑力学和物理学的新领域,为实现具有拓扑保护共振特性的大型弹性器件提供了新的思路与方法.

关键词：束缚态五重对称弹性板缺陷态弹性波拓扑缺陷共振特性人的潜力

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Non-random vibration analysis for general viscous damping systems

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Chinese Journal of Aeronautics 2019年第12期32卷 2655-2666页

作者： Chao JIANG Long LIU Jinwu LI Bingyu NI State Key Laboratory of Advanced design and Manufacturing for Vehicle Body College of Mechanical and Vehicle Engineering Hunan University

The authors recently developed a kind of non-probabilistic analysis method, named as‘non-random vibration analysis’, to deal with the important random vibration problems, in which the excitation and response are both given in the form of interval process rather than stochastic process. Since it has some attractive advantages such as easy to understand, convenient to use and small dependence on samples, the non-random vibration analysis method is expected to be an effective supplement of the traditional random vibration theory. In this paper, we further extend the nonrandom vibration analysis into the general viscous damping system, and formulate a method to calculate the dynamic response bounds of a viscous damping vibration system under uncertain excitations. Firstly, the unit impulse response matrix of the system is obtained by using a complex mode superposition method. Secondly, an analytic formulation of the system dynamic response middle point and radius under uncertain excitations is derived based on the Duhamel’s integral, and thus the upper and lower response bounds of the system can be obtained. Finally, two numerical examples are investigated to demonstrate the effectiveness of the proposed method.

关键词： Complex mode Dynamic response bounds Interval process Random vibration Viscous damping system

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Tuning Polymer Molecular Weight Distribution in Cationic RAFT Polymerization by Mixing Chain Transfer Agents

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中国化学:英文版 2023年第14期41卷 1684-1690页

作者： Miao Chen Jiajia Li Dong Xing Xiangqiang Pan Jian Zhu State and Local Joint engineering Laboratory for Novel Functional Polymeric Materials Jiangsu Key Laboratory of Advanced Functional Polymer Design and ApplicationSuzhou Key Laboratory of Macromolecular Design and Precision SynthesisDepartment of Polymer Science and EngineeringCollege of ChemistryChemical Engineering and Materials ScienceSoochow UniversitySuzhouJiangsu215123 China

Polymer dispersity (Đ) or molecular weight distribution (MWD) is a basic but vital parameter for the properties of polymeric materials. Developing new methodologies for controlling polymer MWD is emerging as a research hotspot. However, the methods to tune polymer MWD in cationic polymerization are still not well explored. Herein, we present a simple method to control the dispersity of poly(isobutyl vinyl ether) (PIBVE) by mixing two different chain transfer agents in batch visible light induced cationic RAFT polymerization. A broad dispersity range (Đ ≈ 1.16—1.80) was successfully achieved while maintaining monomodal MWD. Moreover, chain extension of PIBVE through both cationic polymerization and radical polymerization has been studied, which also provides a method to tune polymer MWD in mechanism transformation polymerization.

关键词： RAFT Photopolymerization Copolymers lonic polymerization Molecular weight distribution Dispersity

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An efficient path delay variability model for wide-voltage-range digital circuits

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Science China(Information Sciences) 2023年第2期66卷 285-286页

作者： Weiwei SHAN Yuqiang CUI Wentao DAI Xinning LIU Jingjing GUO Peng CAO Jun YANG National ASIC System engineering Research Center Southeast University Cadence design Systems Inc. college of Integrated Circuit Science and engineering Nanjing University of Posts and Telecommunications

Dear editor,As process technology advances, the parasitic effects of integrated circuits become increasingly prominent, posing serious challenges for integrated circuit design [1, 2]. Variations in the process corner, voltage, and temperature(PVT) have a more significant impact on path delay in digital circuits in advanced processes, especially at the near-threshold voltage(NTV) [3, 4]. The delay variability of the critical path needs to be evaluated to minimize the timing margin while ensuring reliability. Because NTV circuits have more severe variability than the super-threshold voltage(STV) circuits,

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What May Future Electricity Markets Look Like?

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Journal of Modern Power Systems and Clean Energy 2023年第3期11卷 705-713页

作者： Pierre Pinson Dyson School of design engineering Imperial College LondonLondonU.K Department of Technology Management and EconomicsTechnical University of DenmarkKongens Lyngby IEEE

Should the organization,design and functioning of electricity markets be taken for granted?Definitely not.While decades of evolution of electricity markets in countries that committed early to restructure their electric power sector made us believe that we may have found the right and future-proof model,the substantially and rapidly evolving context of our power and energy systems is challenging this idea in many ways.Actually,that situation brings both challenges and opportunities.Challenges include accommodation of renewable energy generation,decentralization and support to investment,while opportunities are mainly that advances in technical and social sciences provide us with many more options in terms of future market design.We here take a holistic point of view,by trying to understand where we are coming from with electricity markets and where we may be going.Future electricity markets should be made fit for purpose by considering them as a way to organize and operate a socio-techno-economic system.

关键词： Digitalization electricity markets mechanism design optimization renewable energy

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Behavior of axially loaded tubular X-joints using bolted connection:mechanical model and validation

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Journal of Zhejiang University-Science A(Applied Physics & engineering) 2013年第12期14卷 880-889页

作者： Yong CHEN Ji-yang WANG Yong GUO Guo-hui SHEN Li-xian YANG Bin-nan SUN college of Civil engineering and Architecture Zhejiang University Zhejiang Electric Power design Institute

X-joints are one of the fundamental joint configurations used in a wide range of transmission tubular structures.Experimental investigation of four tubular X-joints with bolted connection was conducted in this study,and it was found that the annular plate was the main yielding control member of such X-joints.Moreover,the portion outside the effective width of the chord member still had a restriction effect on the annular plate,which led to reducing the yielding strength of the joint,while the gusset plate could help to improve the yield strength capacity.In the current design code of steel structures,the contribution to the strength capacity of the gusset plate has not been taken into account.Therefore,based on some mechanical assumptions,a general mechanical model was proposed.After the introduction of the gusset plate strength capacity factor,the yield capacity simplified calculation method of such X-joints was derived.Through the analyses of such X-joints with various diameters and thicknesses,it was concluded that a simple mechanical model could predict test results very well and that the contribution of the gusset plate was also taken into account.

关键词： Steel tubular X-joint Bolted connection Annular plate Gusset plate Strength capacity

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Ensemble deep transfer learning driven by multisensor signals for the fault diagnosis of bevel-gear cross-operation conditions

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Science China(Technological Sciences) 2021年第3期64卷 481-492页

作者： DI ZiYang SHAO HaiDong XIANG JiaWei State Key Laboratory of Advanced design and Manufacturing for Vehicle Body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha 410082China college of Mechanical and Electrical engineering Wenzhou UniversityWenzhou 325035China

The existing intelligent fault diagnosis techniques of bevel gear focus on single-sensor signal analysis under the steady operation condition.In this study,a new method is proposed based on ensemble deep transfer learning and multisensor signals to enhance the fault diagnosis adaptability and reliability of bevel gear under various operation conditions.First,a novel stacked autoencoder(NSAE)is constructed using a denoising autoencoder,batch normalization,and the Swish activation function.Second,a series of source-domain NSAEs with multisensor vibration signals is pretrained.Third,the good model parameters provided by the source-domain NSAEs are transferred to initialize the corresponding target-domain NSAEs.Finally,a modified voting fusion strategy is designed to obtain a comprehensive result.The multisensor signals collected under the different operation conditions of bevel gear are used to verify the proposed method.The comparison results show that the proposed method can diagnose different faults in an accurate and stable manner using only one target-domain sample,thereby outperforming the existing methods.

关键词： ensemble deep transfer learning bevel-gear fault diagnosis novel stacked autoencoder multisensor signals modified voting fusion strategy

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Advances in air pollution control for vessels in China

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Journal of Environmental Sciences 2023年第1期123卷 212-221页

作者： Yanping Yang Yue Gong Ying Wang Xuecheng Wu Zhiying Zhou Weiguo Weng Yongxin Zhang State Key Laboratory of Clean Energy Utilization College of Energy EngineeringZhejiang UniversityHangzhou 310027China Energy engineering design and Research Institute Co.Ltd. Zhejiang UniversityHangzhou 310027China

Vessel emissions have contributed a great deal to air quality deterioration in China.Hence,the Chinese government has promulgated a series of stringent emission regulations.It is in this context that vessel emission control technology research is in full swing.In particular,during the 13th Five-Year Plan,the air pollution control technology of vessels has greatly improved.Vessel emission control has followed two main governance routes:source emission reduction and aftertreatment technology.Source control focuses on alternative fuels,with two main directions,the development of new fuels and the modification of existing fuels.Moreover,after-treatment technologies have also been developed,including wet desulfurization technology using seawater or alkaline liquids as wet washing liquids and selective catalytic reduction(SCR)for the control of NOx emission.Due to China’s increasingly stringent emissions standards and regulations,work on the development of clean alternative fuels and further upgrading the collaborative application of after-treatment technologies to meet the near-zero-emissions requirements of vessels is still necessary.

关键词： Vessels Legislation Emission control Liquefied natural gas Desulfurization Selective catalytic reduction

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