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Assessment of composite failure and ultimate strength without experiment on composite

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Acta Mechanica Sinica 2014年第4期30卷 569-588页

作者： zheng-Ming huang Ling Liu School of Aerospace Engineering & Applied Mechanics Tongji University Micromechanics of Materials Zernike Institute for Advanced MaterialsUniversity of Groningen

This paper attempts to estimate the ultimate strength of a laminated composite only based on its con- stituent properties measured independently. Three important issues involved have been systematically addressed, i.e., stress calculation for the constituent fiber and matrix materials, failure detection for the lamina and laminate upon the internal stresses in their constituents, and input data determination of the constituents from monolithic measurements. There are three important factors to influence the accuracy of the strength prediction. One is the stress concentration factor （SCF） in the matrix. Another is matrix plasticity. The third is thermal residual stresses in the constituents. It is these three factors, however, that have not been sufficiently well realized in the composite community. One can easily find out the elastic and strength parameters of a great many laminae and laminates in the current literature. Unfortunately, necessary information to determine the SCF, the matrix plasticity, and the thermal residual stresses of the composites is rare or incomplete. A useful design methodology is demonstrated in the paper.

关键词： Composite · Strength · Stress concentrations ·Plasticity · Residual stress · Bridging model

Fast flow simulation study of pulsating ventilation performance on air contaminant removal

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Building Simulation 2024年第8期17卷 1309-1322页

作者： Pengzhi Zhou Haidong Wang Yuwei dai Chen huang School of Environment and Architecture University of Shanghai for Science and Technology516 Jungong RoadShanghai200093China

Fast flow simulation is imperative in the design of pulsating ventilation,which is potentially efficient in indoor air contaminant *** execution of the conventional CFD method requires considerable amount of computational *** this study,five different numerical schemes were proposed based on fast fluid dynamics(FFD)and fractional step(FS)methods,and were evaluated to achieve quick simulation of airflow/contaminant *** of these numerical schemes was identified with the best overall computing efficiency for investigating the performance of pulsating *** this numerical scheme at hand,the air contaminant removal effectiveness of different ventilation types was *** kinds of pulsating ventilation and one kind of steady ventilation were tested upon a benchmark isothermal mixing *** effect of adjusting supply velocity parameters on the ventilation performance was also ***_(2)concentration,airflow pattern,and vortex structure of different ventilation types were illustrated and *** results reveal that the FS method is more suitable for transient simulation of wall-bounded indoor airflow than the FFD method,and 34%–51%of computing time could be saved compared to the conventional CFD *** the choice of ventilation type,steady ventilation might result in short-circuit airflow and stagnant zones;alternatively,pulsating ventilation has greater potential in air contaminant removal due to its ever-changing vortex structure.

关键词： pulsating ventilation fast fluid dynamics fractional step method contaminant removal efficiency time-periodic supply vortex structure

Design of a Transverse-flux Permanent-magnet Linear Generator and Controller for Use with a Free-piston Stirling Engine

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Chinese Journal of Mechanical Engineering 2016年第4期29卷 832-842页

作者： zheng Jigui huang Yuping WU Hongxing zheng Ping Electrical Engineering & Automation Department Harbin Institute of Technology Harbin 150001 China Beijing Research Institute of Precise Mechatronic Controls Beijing 100076 China

Transverse-flux with high efficiency has been applied in Stirling engine and permanent magnet synchronous linear generator system,however it is restricted for large application because of low and complex process.A novel type of cylindrical,non-overlapping,transverse-flux,and permanent-magnet linear motor（TFPLM） is investigated,furthermore,a high power factor and less process complexity structure research is *** impact of magnetic leakage factor on power factor is discussed,by using the Finite Element Analysis（FEA） model of stirling engine and TFPLM,an optimization method for electro-magnetic design of TFPLM is proposed based on magnetic leakage *** relation between power factor and structure parameter is investigated,and a structure parameter optimization method is proposed taking power factor maximum as a *** last,the test bench is founded,starting experimental and generating experimental are performed,and a good agreement of simulation and experimental is *** power factor is improved and the process complexity is *** research provides the instruction to design high-power factor permanent-magnet linear generator.

关键词： permanent-magnet linear motor(TFPLM) stirling engine magnetic leakage factor power factor

Two-dimensional material separation membranes for renewable energy purification, storage, and conversion

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Green Energy & Environment 2021年第2期6卷 193-211页

作者： Liheng dai Kang huang Yongsheng Xia Zhi Xu State Key Laborutory of Chemical Engineering Schood of Chemical Engineering East China University of Science and Technology 130 Meilong RoadShanghai200237China State Key Laboratory of Materials-Oriented Chemical Engineering College of Chemical EngineeringNanjing Tech Universiy30 Puzhu Road(S)Nanjing211816China

The current energy crisis has prompted the development of new energy sources and energy storage/conversion devices. Membranes, as the key component, not only provide enormous separation potential for energy purification but also guarantee stable and high-efficiency operation for rechargeable batteries and fuel cells. Remarkably, two-dimensional(2D) material separation membranes have attracted intense attention on their excellent performance in energy field applications, owing to high mechanical/chemical stability, low mass transport resistance, strict sizeexclusion, and abundant modifiable functional groups. In this review, we concentrate on the recent progress of 2D membrane and introduce 2D membranes based on graphene oxide(GO), MXenes, 2D MOFs, 2D COFs, and 2D zeolite nanosheets, which are applied in membrane separation(H2 collection and biofuel purification) and battery separators(vanadium flow battery, Li–S battery, and fuel cell). The mass transport mechanism, selectivity mechanism, and modification methods of these 2D membranes are stated in brief, mainly focusing on interlayer dominant membranes(GO and MXenes) and pore dominant membranes(MOFs, COFs, and zeolite nanosheets). In conclusion, we highlight the challenges and outlooks of applying 2D membranes in energy fields.

关键词： Two-dimensional materials Membranes Separation New energy

A Comprehensive Experimental Study on Immiscible Displacements in Porous Media:Effects of Capillary Forces,Viscous Forces,Wettability and Pore Geometries

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Journal of Thermal Science 2021年第6期30卷 2137-2149页

作者： huang Chao dai Xiaoye SHI Changxing SHI Lin Department of Energy and Power Engineering Tsinghua UniversityBeijing 100084China Key Laboratory of Thermal Science and Power Engineering of Ministry of Education of China Beijing 100084China Key Laboratory for C02 Utilization and Reduction Technology of Beijing Beijing 100084China Department of Mechanical and Industrial Engineering University of Illinois at ChicagoChicago 60607United States

Immiscible displacements in porous media are fundamentally significant for many natural processes and industrial *** extensive work has been done in this field,some limitations still exist due to the difficulty to cover the large number of influencing *** this paper,we present a systematic study involving the coupled influence of capillary forces,viscous forces,wetting properties and pore *** microfluidic experiments with high resolutions,both residual fluid distributions and dynamical invasion processes were clearly captured and quantitatively characterized.A void-filling behavior was identified for drainage as the capillary number Ca *** anomalous void-leaving behavior was found for the case of imbibition with an unfavorable viscosity ratio M,representing many ribbon-like regions invaded at intermediate Ca turned to be not accessible at high Ca.A pore geometry with a large typical pore-throat ratio seemed to enhance the void-leaving *** the dynamical invasion processes,an intermittency behavior was captured in the form of a fluctuation of the increasing rate of the invading saturation with *** intermittency dynamics were most evident for drainage with an unfavorable M.A pore geometry with high porosity acted to suppress the intermittency *** experimental results sketched out a full view of immiscible displacements in porous media under different conditions,and provided a complete dataset which could be used to test the rapid developing pore-scale models.

关键词： immiscible displacements porous media microfluidic experiments fluid distributions intermittency dynamics

Preparation of Aryloxy-aluminoxanes and Their Use as Activators in the Bis(imino)pyridyl Iron-catalyzed Oligomerization of Ethylene

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Chinese Journal of Polymer Science 2018年第11期36卷 1207-1207,1208-1216页

作者： Wei Zhang Bin-Bo Jiang Jian Ye Zu-Wei Liao zheng-Liang huang Jing-dai Wang Yong-Rong Yang Zhejiang Provincial Key Laboratory of Advanced Chemical Engineering Manufacture Technology State Key Laboratory of Chemical Engineering College of Chemical and Biological Engineering Zhejiang University

In this study, a series of aryloxy-aluminoxanes originated directly from the hydrolysis of reaction products of A1Me3 and phenols were synthesized, which could serve as effective polymer-retarding activators for the iron-catalyzed ethylene oligomerization. The molar ratios of [PhOH]/[AlMe3] and [H2O]/[Al] during the preparation were explored and their impacts on the oligomerization activity and product distribution were discussed. To obtain the effective activators with good polymer-retarding effect and relatively high activity, the optimized conditions were proposed to be [PhOH]/[AlMe3] = 0.5 and [H2O]/[Al] = 0.7. Various aluminoxanes with different [-OH] sources confirmed the importance of using phenols in preparing the effective polymer-retarding activators. By utilizing these aryloxy-aluminoxanes, the mass fraction of polymers in the total products could be reduced to lower than 1.0 wt%, which is much lower than that of the MAO-activated systems （〉 30 wt%）. This is a potential benefit for the industrial application of the iron-catalyzed oligomerization process.

关键词： Ethylene oligomerization Bis(imino)pyridyl iron catalysts Aryloxy-aluminoxanes Phenols Trimethylaluminum hydrolysis

Advertisement *** Subsidy:Which is Better for Remanufacturing?

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Journal of Systems Science and Systems Engineering 2020年第3期29卷 344-359页

作者： Yanting huang Benrong zheng Zongjun Wang College of Management Shenzhen UniversityShenzhen 518060China College of Economics&Management Huazhong Agricultural UniversityWuhan 430070China School of Management Huazhong University of Science and TechnologyWuhan 430074China

The government subsidy plays an important role in the recycling and remanufacturing process of a closed-loop supply *** paper focuses on the impacts of different patterns of government subsidy on the chain members'profits and the ***,we develop three models in a supply chain including a manufacturer,a retailer and a collector,namely(1)the government invests public service advertisement to stimulate the remanufacturing process(Model AS);(2)the government offers only monetary subsidy to the collector(Model MS);(3)the government allocates the subsidy into two parts,namely both advertisement and monetary subsidy(Model HS).We find that,no matter which subsidy pattern the government adopts,both the manufacturer and the collector are beneficiaries of the government subsidy,and that such subsidizing activity is definitely conducive to the environmental *** into account the chain members,profits and the environmental impact,the optimal hybrid subsidy scheme(Model HS)is more beneficial than that in both Model MS and Model AS,which can be attributed to the combination of the incentives provided by the public service advertisement and the price attraction by the monetary *** also find that,for single advertisement and monetary subsidy,the amount of government subsidy will decide their merits and *** direct monetary subsidy in Model MS will have a greater influence regarding to the supply quantity of used products than the mere advertisement subsidy in Model AS when the subsidy is relatively large.

关键词： Supply chain management remanufacturing government subsidy environmental impact

A new class of luminescent nanoprobes based on main-group Sb^(3+) emitters

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Nano Research 2022年第1期15卷 179-185页

作者： Chunguang Zhang Meiran Zhang Wei zheng Jiaojiao Wei Shiteng Wang Ping huang Xingwen Cheng Tao dai Zhuo Chen Xueyuan Chen CAS Key Laboratory of Design and Assembly of Functional Nanostructures Fujian Key Laboratory of Nanomaterialsand State Key Laboratory of Structural ChemistryFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China College of Chemistry and Materials Science Fujian Normal UniversityFuzhou 350007China Fujian Science Technology Innovation Laboratory for Optoelectronic Information of China Fuzhou 350108China

Inorganic luminescent nanocrystals(NCs)doped with main-group ns^(2)-metal ions have evoked tremendous interest in many technological fields owing to their superior optical ***,we report a new class of luminescent nanoprobes based on 5s2-metal Sb3+-doped CaS NCs that are excitable by using a near ultraviolet light-emitting *** optical properties and excited-state dynamics of Sb3+in CaS NCs are comprehensively surveyed through temperature-dependent steady-state and transient photoluminescence(PL)*** to the strong electron-phonon coupling of Sb^(3+)in CaS NCs,Sb3+ions experience a dynamic Jahn-Taller distortion on the excited state,which results in bright green PL of Sb3+with a broad emission band,a large Stokes shift,and a high PL quantum yield up to 17.3%.By taking advantage of the intense PL of Sb^(3+),we show in proof-of-concept experiments the application of biotinylated CaS:Sb^(3+)NCs as sensitive luminescent nanoprobes for biotin receptor-targeted cancer cell imaging and zebrafish imaging with a high imaging *** findings provide fundamental insights into the excited-state dynamics of Sb^(3+)in CaS NCs,thus laying a foundation for future design of novel and versatile luminescent nanoprobes via main-group ns2-metal doping.

关键词： CaS Sb^(3+) photoluminescence excited-state dynamics nanoprobe bioimaging

An Online Compensation Method of DC Drift for Three-Phase Current Reconstruction with DC-Link Resistance

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Chinese Journal of Electronics 2020年第5期29卷 982-990页

作者： huang Lili zheng Lianqing LI Pengwei Department of Electric Machine and Electric Apparatus School of Electrical Engineering Chongqing University State Key Laboratory of Power Transmission Equipment & System Security and New Technology Chongqing University

In a three-phase power convertor system,phase current reconstruction technique using a DC-link resistance can reduce the cost and weight of the diving system. The three-phase current without DC offset in normal condition is introduced in this paper *** on this premise, the DC-link current offset is considered and the logical relationship between threephase voltage, three-phase current, and DC offset are analyzed and depicted. The DC offset introduced during the sampling processes a distortion into phase current,which is composed of fundamental and harmonic frequency based on FFT analysis. The fundamental component of the distortion shares the same phase angle with counterpart voltage, which distorts power factor and amplitude of three-phase currents. The harmonic components of the distortion can be transformed into 6th harmonic components in synchronous dq axes and undermine the performance of the controlling system. After that, a practical method is proposed to solve this problem, namely sampling the DC offset signal during the period of the zero voltage vectors. An analogy sample circuit is designed and tested. This method can avoid the DC offset from the source. Finally, its effectiveness is verified via simulation and experiment.

关键词： Phase current reconstruction DC offset FFT analysis Current deviation