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Experimental study on detonation parameters and cellular structures of fuel cloud

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Acta Mechanica Sinica 2012年第2期28卷 438-443页

作者： Li-feng Xie bin Li yu-Lei Zhang School of Chemical Engineering Nanjing University of Science and Technology210094 NanjingChina

In this paper, detonation parameters of fuel cloud, such as propylene oxide （PO）, isopropyl nitrate （IPN）, hex- ane, 90# oil and decane were measured in a self-designed and constructed vertical shock tube. Results show that the deto- nation pressure and velocity of PO increase to a peak value and then decrease smoothly with increasing equivalence ra- tio. Several nitrate sensitizers were added into PO to make fuel mixtures, and test results indicated that the additives can efficiently enhance detonation velocity and pressure of fuel cloud and one type of additive n-propyl nitrate （NPN） played the best in the improvement. The critical initiation energy that directly initiated detonation of all the test liquid fuel clouds showed a U-shape curve relationship with equiva- lence ratios. The optimum concentration lies on the rich-fuel side （;b 〉 1）. The critical initiation energy is closely related to molecular structure and volatility of fuels. IPN and PO have similar critical values while that of alkanes are larger. Detonation cell sizes of PO were respectively investigated at 25;C, 35;C and 50;C with smoked foil technique. The cell width shows a U-shape curve relationship with equivalence ratios at all temperatures. The minimal cell width also lies on the rich-fuel side （;b 〉 1）. The cell width of PO vapor is slightly larger than that of PO cloud. Therefore, the deto- nation reaction of PO at normal temperature is controlled by gas phase reaction.

关键词： Cloud detonation Detonation velocity Deto- nation pressure - Critical initiation energy Cell size

Stability Analysis and Design of Impulsive Control Lorenz Systems Family

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Communications in Theoretical Physics 2009年第5期51卷 869-875页

作者： yu Yong-bin ZHANG Hong-bin ZHANG feng-Li yu Jue-Bang LIAO Xiao-feng School of Computer Science and Engineering University of Electronic Science and Technology of China Chengdu 610054 China School of Electronic Engineering University of Electronic Science and Technology of China Chengdu 610054 China College of Computer Science Chongqing University Chongqin 400044 China

Lorenz systems family unifying Lorenz system, Chen system and Lü system is a typical chaotic family. In this paper, we consider impulsive control Lorenz chaotic systems family with time-varying impulse intervals. By establishing an effective tool of a set of inequalities, we analyze the asymptotic stability of impulsive control Lorenz systems family and obtain some new less conservative conditions. Based on the stability analysis, we design a novel impulsive controller with time-varying impulse intervals. Illustrative examples are provided to show the feasibility and effectiveness of our method. The obtained results not only can be used to design impulsive control for Lorenz systems family, but also can be extended to other chaotic systems.

关键词： Lorenz systems family impulsive chaotic system asymptotic stability

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8～14μm波段低发射率涂层的制备研究

现代涂料与涂装 2017年第9期20卷 1-3,32页

作者：张明月余凤斌赵衍松天诺光电材料股份有限公司济南250000

采用着色颜料、低发射率填料、水性聚氨酯树脂等制备了中绿色低发射率涂层。分别研究了铝浆粉粒径、铝浆粉含量以及定向排列剂的含量对涂层性能的影响。测试结果表明:在相同含量下,添加粒径为18μm铝浆粉制备的涂层发射率最低;当铝浆粉... 详细信息

采用着色颜料、低发射率填料、水性聚氨酯树脂等制备了中绿色低发射率涂层。分别研究了铝浆粉粒径、铝浆粉含量以及定向排列剂的含量对涂层性能的影响。测试结果表明:在相同含量下,添加粒径为18μm铝浆粉制备的涂层发射率最低;当铝浆粉的含量为8.59%~10.14%时,随着铝浆粉含量的增加,涂层发射率降低,进一步增大铝浆粉含量至12.36%,对涂层的发射率影响不大;此外,添加定向排列剂可改善铝浆粉的定向排列方式,有效降低涂层发射率。

关键词：红外隐身发射率铝浆粉粒径含量定向排列剂

An Improved Time Domain Approach for Analysis of Floating Bridges Based on Dynamic Finite Element Method and State-Space Model

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China Ocean Engineering 2022年第5期36卷 682-696页

作者： XIANG Sheng CHENG bin ZHANG feng-yu TANG Miao State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China Shanghai Key Laboratory for Digital Maintenance of Buildings and Infrastructure Shanghai Jiao Tong UniversityShanghai 200240China Department of Civil Engineering Shanghai Jiao Tong UniversityShanghai 200240China College of Civil Engineering Fuzhou UniversityFuzhou 350108China

The floating bridge bears the dead weight and live load with buoyancy,and has wide application prospect in deep-water transportation *** structural analysis of floating bridge is challenging due to the complicated fluid-solid coupling effects of wind and *** this research,a novel time domain approach combining dynamic finite element method and state-space model(SSM)is established for the refined analysis of floating *** dynamic coupled effects induced by wave excitation load,radiation load and buffeting load are carefully ***-precision fitted SSMs for pontoons are established to enhance the calculation efficiency of hydrodynamic radiation forces in time *** dispersion relation is also introduced in the analysis model to appropriately consider the phase differences of wave loads on *** proposed approach is then employed to simulate the dynamic responses of a scaled floating bridge model which has been tested under real wind and wave loads in *** numerical results are found to agree well with the test data regarding the structural responses of floating bridge under the considered environmental *** proposed time domain approach is considered to be accurate and effective in simulating the structural behaviors of floating bridge under typical environmental conditions.

关键词： floating bridge time domain analysis dynamic analysis state-space model environmental load

Additive Manufacturing of Nickel-Based Superalloy Single Crystals with IN-738 Alloy

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Acta Metallurgica Sinica(English Letters) 2022年第3期35卷 369-374页

作者： Yang Li Ye-feng yu Zhi-bin Wang Xiao-yu Liang Wen-bin Kan feng Lin Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China Key Laboratory for Advanced Materials Processing Technology Ministry of Education of ChinaBeijing 100084China Bio-Manufacturing and Rapid Forming Technology Key Laboratory of Beijing Beijing 100084China

The production of non-weldable nickel-based superalloys,especially single-crystal superalloys,is important for additive ***-crystal specimens of non-weldable nickel-based superalloys were produced by electron beam selective melting using an IN-738 *** this study,single-crystal nickel-based superalloy specimens of diff erent sizes were prepared by a multiple preheating process and tight control of the melting parameters without the need for a grain selector or single-crystal seed for the first *** backscattered diff raction measurements were performed to confi rm the presence of a single *** transition boundaries between the polycrystalline and single-crystal regions at the edges and bottom of the samples were characterized to analyze the formation of single crystals.

关键词： Non-weldable superalloys Electron beam selective melting Single crystal Grain selection

On Blocks in Restricted Representations of Lie Superalgebras of Cartan Type

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Acta Mathematica Sinica,English Series 2020年第9期36卷 1061-1075页

作者： Fei Fei DUAN bin SHU yu feng YAO School of Mathematical Sciences Hebei Normal UniversityShijiazhuang 050024P.R.China School of Mathematical Sciences East China Normal UniversityShanghai 200241P.R.China Department of Mathematics Shanghai Maritime UniversityShanghai 201306P.R.China

Let g be a restricted Lie superalgebra of Cartan type W(n),S(n)or H(n)over an alge-braically closed field k of prime characteristic p>3,in the sense of modular version of Kac's definition in *** this note,we show that the restricted representation category over g has only one block(reckoning parities in).This phenomenon is very diff erent from the case of characteristic zero.

关键词： Lie superalgebra of Cartan type restricted representation block

A Green Synthesis of Diisopropyl Phosphoryl Amino Acid

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Chinese Chemical Letters 2003年第2期14卷 121-124页

作者： Xiao bin SUN yu Ping feng 等 TheKeyLaboratoryofBio-organicPhosphorusChemistry EducationofMinistryDepartmentofChemistrySchoolofLifeScienceandEngineeringTsinghuaUniversityBeijing100084 TheKeyLaboratoryofBi

In this paper, we report that diisopropyl phosphoryl amino acid could be prepared with reasonable yields under solvent-free condition by adding amino acid to the mixture of diisopropyl phosphite and N-chlorodiisopropy... 详细信息

关键词： Phosphoramidates amino acids N-chlorodiisopropylamine phosphorylation.

Some notes on numerical investigation of three cavitation models through a verification and validation procedure

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Journal of Hydrodynamics 2023年第1期35卷 185-190页

作者： Lin-feng Deng yun Long Huai-yu Cheng bin Ji State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan430072China Wuhan Second Ship Design and Research Institute Wuhan430064China

The present paper investigates the turbulent cavitating flow around the Clark-Y hydrofoil with special emphasis on the influence of cavitation models by verification and validation(V&V)*** solver coupled with the three major cavitation models(i.e.,Zwart-Gerber-Belamri,Schnerr and Sauer and full cavitation model,which are abbreviated to ZGB model,SS model and FC model respectively)is employed in this *** results indicate that the three cavitation models can properly reproduce the cavitation *** model and SS model give better prediction in the overall cavitation *** model exhibits an obvious under-estimation for the sheet cavity,and the predicted volume fraction is closely related to the turbulent *** verification and validation procedure is involved to quantitatively assess the accuracy of these three cavitation *** is indicated that the V&V procedure is suitable for the unsteady cavitating *** errors estimate is robust and conservative within the cavitation region,while gets closer to zero in the no-cavitation *** addition,ZGB model exhibits the highest overall accuracy among the three models,which further verifies its wide applicability.

关键词： Cavitating flow cavitation model verification and validation(V&V) error estimate

A Copyright-Preserving and Fair Image Trading SchemeBased on Blockchain

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Tsinghua Science and Technology 2023年第5期28卷 849-861页

作者： feng yu Jiahui Peng Xianxian Li Chunpei Li bin Qu School of Computer Science&Engineering Guangxi Normal UniversityGuilin 541004Chinaand with the Key Lab of Education Blockchain and Intelligent TechnologyMinistry of EducationGuangxi Normal UniversityGuilin 541004Chinaand also with Guangxi Collaborative Innovation Center of Multi-Source Information Integration and Intelligent ProcessingGuangxi Normal UniversityGuilin 541004China Guangxi Power Grid Materials Co Ltd Nanning 530022China

With the proliferation of the Internet,particularly the rise of social media,digital images have gradually become an important part of life,and trading platforms have emerged for buying and selling ***,traditional image trading service providers may disclose users’private information for ***,many image trading platforms disregard the fairness of a transaction and the issue of copyright protection after an image is *** neglect harms the interests of users and affects their enthusiasm for trading.A secure way to safely transact images is *** proposed a copyright-preserving and fair image trading scheme based on blockchain,which combines amplifying locality-sensitive hashing with searchable symmetric encryption to achieve safe image retrieval on blockchain and ensure the credibility of the image retrieval ***,we use digital fingerprint and watermark technologies to realize the copyright protection of images and use smart contracts to achieve fair transaction *** experimental results show that our scheme can protect image copyrights and realize a fair trading process while ensuring efficiency.

关键词： blockchain copyright-preserving trade fair trade tadors code