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Influence of hot rolling on microstructure and mechanical characteristics of explosive-welded FSS/CS laminate

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Journal of Iron and Steel Research International 2018年第5期25卷 572-579页

作者： Xiao-rong Yang Li-feng ma guang-ming Liu guang-hui Zhao Zheng-yi Jiang Shanxi Provincial Key Laboratory of Metallurgical DeviceDesign Theory and Technology Taiyuan University ofScience and Technology Taiyuan 030024 Shanxi China School of Mechanical Materials and Mechatronic Engineering University of Wollongong Wollongong 2522Australia

The influence of hot rolling on the microstructure and subsequent mechanical characteristics of explosive-welded ferritic stainless steel （FSS）/carbon steel （CS） laminate was investigated. The results indicate that by hot rolling, decarburization layer disappears and a uniform structure is gained in CS side, but ferrite grains and carbides in constituent FSS form an uneven band microstructure which is denser at superficial zone than near the interface. The transmission electron microscopy results indicate that the layers adhering to the interface show typical deformed microstructure features, i.e., stream-like strips and elongated grains in FSS plates, carbide precipitates and bended cementite fragments in CS plates; and high-density dislocations in both plates, With hot rolling, various mechanical strengths and hardness are increased, while the elongation percentage is diminished. Examination of fractographs from tensile tests reveals predominately small dimples for explosive-welded specimens, whereas both big dimples and cleavage fracture for rolled specimens. Stereomicroscopic fractographs taken on shear samples indicate that the surfaces of explosive-welded specimens exhibit uniform deformation, but uneven deformation is displayed for that of rolled specimens. These results indicate that hot rolling is beneficial to improve the strength of explosive-welded FSS/CS laminate but not good for enhancing its plasticity.

关键词： Hot rolling · Composite steel plate · Interface ·Ferritic stainless steel ·Carbon steel

Molecular simulation study of the microstructures and properties of pyridinium ionic liquid[HPy][BF_(4)]mixed with acetonitrile

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原子与分子物理学报 2025年第4期42卷 27-32页

作者： XU Jian-Qiang ma Zhao-Peng CHENG Si LIU Zhi-Cong ZHU guang-Lai Department of Physics School of Physics and Electronic InformationAnhui Normal UniversityWuhu 241002China

The microstructures and thermodynamic properties of mixed systems comprising pyridinium ionic liquid[HPy][BF_(4)]and acetonitrile at different mole fractions were studied using molecular dynamics simulation in this *** following properties were determined:density,self-diffusion coefficient,excess molar volume,and radial distribution *** results show that with an increase in the mole fraction of[HPy][BF_(4)],the self-diffusion coefficient ***,the excess molar volume initially decreases,reaches a minimum,and then *** rules of radial distribution functions(RDFs)of characteristic atoms are *** increasing the mole fraction of[HPy][BF_(4)],the first peak of the RDFs of HA1-F decreases,while that of CT6-CT6 rises at first and then *** indicates that the solvent molecules affect the polar and non-polar regions of[HPy][BF_(4)]differently.

关键词： Pyridinium ionic liquids Thermodynamic properties Molecular dynamics simulation Radial distribution functions

Characterization and Properties of a New Amorphous Small-molecule material Containing Both Donor and Acceptor Moieties for Photovoltaic Application

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Chemical Research in Chinese Universities 2013年第6期29卷 1193-1198页

作者： ZHAO Yang ZHANG Feng-ling ZHANG ming ma Yu-guang State Key Laboratory of Supramolecular Structure and materials Jilin University Changchun 130012 P.R.China Biomolecular and Organic Electronics Department of Physics Chemistry and BiologyLink(o)ping University Link(o)ping Sweden

A new amorphous small-molecule material, in which the electron-donating carbazole units are connected to the backbone by flexible side chains, has been synthesized and utilised in the photovoltaic（PV） field. This material exhibits the amorphous feature, higher thermal stability and good film forming ability. The influence of the heat-treatment on the morphology and the performance of PV devices were studied. Eventually, a relatively high photovoltaic conversion efficiency was achieved. At the same time, the PV device displayed an ideal open-circuit voltage（over 1 V） which is very close to the upper limit of its theoretical value.

关键词： Amorphous material Donor-acceptor bonding Photovoltaic device

Constant Barrier Strategies in a Two-state markov-modulated Dual Risk Model

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Acta mathematicae Applicatae Sinica 2011年第4期27卷 679-690页

作者： Xue-min ma Kui LUO guang-ming WANG Yi-jun HU School of mathematics and Statistics Wuhan University Wuhan 430072 China

In this paper, we consider the dividend problem in a two-state markov-modulated dual risk model, in which the gain arrivals, gain sizes and expenses are influenced by a markov process. A system of integro-differential equations for the expected value of the discounted dividends until ruin is derived. In the case of exponential gain sizes, the equations are solved and the best barrier is obtained via numerical example. Finally, using numerical example, we compare the best barrier and the expected discounted dividends in the two-state markov-modulated dual risk model with those in an associated averaged compound Poisson risk model. Numerical results suggest that one could use the results of the associated averaged compound Poisson risk model to approximate those for the two-state markov-modulated dual risk model.

关键词： Dual risk model markov-modulated risk model barrier strategy

Driving force coordinated control of an 8x8 in-wheel motor drive vehicle with tire-road friction coefficient identification

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Defence Technology（防务技术） 2022年第1期18卷 119-132页

作者： Zheng Zhang Chun-guang Liu Xiao-jun ma Yun-yin Zhang Lu-ming Chen Department of Weapons and Control Engineering Army Academny of Armored Forces Beijing100072China

Because of the complexities of tire-road interaction,the wheels of a multi-wheel distributed electricdrive vehicle can easily slip under certain working *** wheel slip affects the dynamic per-formance and stability of the vehicle,it is crucial to control it and coordinate the driving *** this aim,this paper presents a driving force coordination control strategy with road identification for eight-wheeled electric vehicles equipped with an in-wheel motor for each *** the proposed control strategy,the road identification module estimates tire-road forces using an unscented Kalman filter al-gorithm and recognizes the road adhesion coefficient by employing the recursive least-square method According to road identification,the optimal sip ratio under the current driving condition is obtainedand a controller based on sliding mode control with a conditional integrator uses this value for accel-eration slip *** anti-slip controller obtains the adjusting torque,which is integrated with the driver-command-based feedforward control torque to implement driving force coordination *** results of hardware-in-loop simulation show that this control strategy can accurately estimate tire-roadrces as well as the friction coefficient,and thus,can effectively fulfill the purpose of driving force coordinated control under different driving conditions.

关键词： In-wheel motor Tire-road friction coefficient Slip ratio Sliding mode control Conditional integrator Accelera tion slip regulation

A pixel-level local contrast measure for infrared small target detection

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Defence Technology（防务技术） 2022年第9期18卷 1589-1601页

作者： Zhao-bing Qiu Yong ma Fan Fan Jun Huang ming-hui Wu Xiao-guang Mei School of Electronic Information and the School Aerospace Research Wuhan UniversityWuhan430074China

Infrared(IR) small target detection is one of the key technologies of infrared search and track(IRST)systems. Existing methods have some limitations in detection performance, especially when the target size is irregular or the background is complex. In this paper, we propose a pixel-level local contrast measure(PLLCM), which can subdivide small targets and backgrounds at pixel level *** pixel-level segmentation, the difference between the target and the background becomes more obvious, which helps to improve the detection performance. First, we design a multiscale sliding window to quickly extract candidate target pixels. Then, a local window based on random walker(RW) is designed for pixel-level target segmentation. After that, PLLCM incorporating probability weights and scale constraints is proposed to accurately measure local contrast and suppress various types of background interference. Finally, an adaptive threshold operation is applied to separate the target from the PLLCM enhanced map. Experimental results show that the proposed method has a higher detection rate and a lower false alarm rate than the baseline algorithms, while achieving a high speed.

关键词： Infrared(IR)small target Irregular size Random walker(RW) Pixel-level local contrast measure(PLLCM)

Thermal and Optoelectronic Properties of Anthracene and Dibenz[a,c]Anthracene

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Chemical Research in Chinese Universities 2013年第1期29卷 110-115页

作者： MUDDASIR Hanif WANG Zhi-ming YANG Bing LU Ping ma Yu-guang State Key Laboratory of Supramolecular Structure and materials Jilin University Changchun 130012 P. R. China School of Petrochemical Engineering Shenyang University of Technology Liaoyang 111003 P. R. China

The basic characteristics of anthracene（AN） and dibenz[a,c]anthracene（D[a,c]A） derivatives, important semiconductors, were systematically studied. Differential scanning calorimetry（DSC） shows that D[a,c]A has the reversibility of solid and liquid phases. Thermalgravimetric analysis（TGA） shows that D[a,c]A exhibits higher Td（decomposition temperature）, which indicates D[a,c]A, as active layers, should be more suitable to being made into stable devices. D[a,c]A shows blue-shifted UV-Vis absorption and emission despite increased conjugation compared to anthracene due to different symmetries. Both the compounds are planar and show weak blue fluorescence in the tetrahydrofuran（THF） solution and higher fluorescence in the solid-state, due to different energy levels in solution and solid-state, explained via Jablonski diagram.

关键词： Anthracene Dibenz[a,c]anthracene Molecular property Thermal Electrochemistry

DFT study on mechanism of the classical Biginelli reaction

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Chinese Chemical Letters 2008年第3期19卷 375-378页

作者： Jin guang ma Ji ming Zhang Hai Hui Jiang Wan Yong ma Jian Hua Zhou School of Chemical Engineering Shandong Institute of Light Industry Jinan 250353 China

The condensation of benzaldehyde, urea, and ethyl acetoacetate according to the procedure described by Biginelli was investigated at the B3LYP/6-31G（d）, B3LYP/6-31 ＋G（d,p）, and B3LYP/6-311＋G（3df,2p）//B3LYP/6-31＋G（d,p） levels to explore the reaction mechanism. According to the mechanism proposed by Kappe, structures of five intermediates were optimized and four transition states were found. The calculation results proved that the mechanism proposed by Kappe is right.

关键词： Biginelli reaction Dihydropyrimidines Transition state DFT study

Structural Investigation of Solid Methane at High Pressure

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Chinese Physics Letters 2010年第6期27卷 141-143页

作者： ZHAO Juan FENG Wan-Xiang LIU Zhi-ming ma Yan-ming HE Zhi CUI Tian ZOU guang-Tian State Key Lab of Superhaxd materials College of Physics Jilin University Changchun 130012

High pressure studies of solid methane are performed using both classical simulated annealing and first-principles methods. A series of simulated annealing and geometry optimization reveal a monoclinic P21/b structure with the unit cell containing four methane molecules. The phonon dispersion curves and vibrational density of states indicate that this structure is stable in the pressure range 10-90 GPa. The electronic band structure and density of states show that this structure has not metalized until 90 GPa.

关键词： STRUCTURAL analysis (Science) METHANE HIGH pressure (Science) SIMULATION methods & models ANNEALING of crystals maTHEmaTICAL optimization ELECTRONIC structure PRESSURE