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Experimental Investigation of Nozzle Effects on Thrust and Inlet Pressure of an Air-breathing Pulse Detonation Engine

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Chinese Journal of Aeronautics 2012年第3期25卷 381-387页

作者： CHEN Wenjuan FAN Wei ZHANG qun PENG Changxin YUAN cheng YAN Chuanjun School of Power and Energy Northwestern Polytechnical UniversityXi'an 710072China

Nozzle effects on thrust and inlet pressure of a multi-cycle air-breathing pulse detonation engine （APDE） are investigated experimentally. An APDE with 68 mm in diameter and 2 050 mm in length is operated using gasoline/air mixture. Straight nozzle, converging nozzle, converging-diverging nozzle and diverging nozzle are tested. The results show that thrust augmentation of converging-diverging nozzle, diverging nozzle or straight nozzle is better than that of converging nozzle on the whole. Thrust augmentation of straight nozzle is worse than those of converging-diverging nozzle and diverging nozzle. Thrust augmentations of diverging nozzle with larger expansion ratio and converging-diverging nozzle with larger throat area range from 20% to 40% on tested frequencies and are better than those of congeneric other nozzles respectively. Nozzle effects on inlet pressure are also researched. At each frequency it is indicated that filling pressures and average peak pressures of inlet with diverging nozzle and converging-diverging nozzle with large throat cross section area are higher than those with straight nozzle and converging nozzle Pressures near thrust wall increase in an increase order from without nozzle, with diverging nozzle, straight nozzle and converging-diverging nozzle to converging nozzle.

关键词： nozzle effect thrust inlet pressure air-breathing pulse detonation engine

Analysis of Influencing Factors on Lift Coefficients of Autonomous Sailboat Double Sail Propulsion System Based on Vortex Panel Method

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China Ocean Engineering 2019年第6期33卷 746-752页

作者： SUN Zhao-yang YU Jian-cheng ZHANG Ai-qun JIN Qian-long State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang 110016China Institutes for Robotics and Intelligent Manufacturing Chinese Academy of SciencesShenyang 110169China University of Chinese Academy of Sciences Beijing 100049China

Sail is the core part of autonomous sailboat and wing sail is a new type of sail. Wing sail generates not only propulsion but also lateral force and heeling moment. The latter two will affect the navigation status and bring resistance. Double sail can effectively reduce the center of wind pressure and heeling moment. In order to study the effect of distance between two sails, airfoil and attack angle on the total lift coefficient of double sail propulsion system, pressure coefficient distribution and lift coefficient calculation model have been established based on vortex panel method. By using the basic finite solution, the fluid dynamic forces on the two-dimensional sails are *** results show that, the distance in the range of 0 to 1 time chord length, when using the same airfoil in the fore and aft sail, the total lift coefficient of the double sail increases with the increase of distance, finally reaches a stable value in the range of one to three times chord length. Lift coefficients of thicker airfoils are more sensitive to the change of distance. The thicker the airfoil, the longer distance is required of the total lift coefficient toward *** different airfoils are adopted in fore and aft sail, the total lift coefficient increases with the increase of the thickness of aft sail. The smaller the thickness difference is, the more sensitive to the distance change the lift coefficient is. The thinner the fore sail is, the lower the influence will be on the lift coefficient of aft sail.

关键词： autonomous sailboat wing sail double sail vortex panel method lift coefficient

Facile and Controllable Assembly of Multiwalled Carbon Nanotubes on Polystyrene Microspheres

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Chinese Journal of Polymer Science 2014年第6期32卷 711-717页

作者：李云兴 Yan Gao cheng Yang Zhao-qun Wang Gi Xue The Key Laboratory of Food Colloids and Biotechnology Ministry of Education School of Chemical and Material Engineering Jiangnan University Department of Polymer Science and Engineering School of Chemistry and Chemical Engineering Nanjing University

Herein a facile and controllable heterocoagulation between polystyrene （PS） microspheres and multiwalled carbon nanotubes （MWCNTs） is introduced based on colloid thermodynamics. The MWCNTs play the role of steric stabilizer for stabilizing the metastable PS microspheres and thus immobilize spontaneously on the surface of PS microspheres. The synthesized MWCNTs-coated PS composite particles have been extensively characterized by scanning electron microscopy, transmission electron microscopy, thermogravimetry and Raman spectroscopy. The results indicate that the structure and morphology of the resultant MWCNTs-coated PS composite particles are significantly affected by the weight ratio of PS and MWNCTs and the amount of poly（vinylpyrrolidone） that is injected into PS dispersion before they are mixed with MWCNTs. Therefore, these composite particles have the potential to produce MWCNTs-based composite materials with controllable mass loading and dispersity of MWCNTs.

关键词： Multiwalled carbon nanotube Polystyrene microsphere Heterocoagulation Structural control Colloidthermodynamics.

Recyclable High-performance Carbon Fiber Reinforced Epoxy Composites Based on Dithioacetal Covalent Adaptive Network

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Chinese Journal of Polymer Science 2024年第10期42卷 1514-1524,I0011页

作者： gui-Lian Shi Ting-cheng Li Dao-Hong Zhang Jun-Heng Zhang Key Laboratory of Catalysis and Energy Materials Chemistry of Ministry of Education&Hubei Key Laboratory of Catalysis and Materials Science Hubei R&D Center of Hyperbranched Polymers Synthesis and ApplicationsSouth-Central Minzu UniversityWuhan430074China State Key Laboratory of New Textile Materials and Advanced Processing Technologies Wuhan Textile UniversityWuhan430200China Ministry-of-Education Key Laboratory for the Green Preparation and Application of Functional Materials Hubei UniversityWuhan430062Chin

Recycling of carbon fiber reinforced composites is important for sustainable development and the circular *** the use of dynamic chemistry,developing high-strength recyclable CFRPs remains a major challenge due to the mutual exclusivity between the dynamic and mechanical properties of ***,we developed a high-strength recyclable epoxy resin(HREP)based on dynamic dithioacetal covalent adaptive network using diglycidyl ether bisphenol A(DGEBA),pentaerythritol tetra(3-mercapto-propionate)(PETMP),and vanillin epoxy resin(VEPR).At high temperatures,the exchange reaction of thermally activated dithioacetals accelerated the rearrangement of the network,giving it significant reprocessing ***,HREP exhibited excellent solvent resistance due to the increased cross-linking *** this high-strength recyclable epoxy resin as the matrix and carbon fiber modified with hyperbranched ionic liquids(HBP-AMIM+PF6-)as the reinforcing agent,high performance CFRPs were successfully *** tensile strength,interfacial shear strength(IFSS)and interlaminar shear strength(ILSS)of the optimized formulation(HREP20/CF-HBPPF6)were 1016.1,70.8 and 76.0 MPa,*** addition,the CFRPs demonstrated excellent solvent and acid/*** CFRPs could completely degrade within 24 h in DMSO at 140℃,and the recycled CF still maintained the same tensile strength and ILSS as the original after multiple degradation cycles.

关键词： Epoxy resin Hyperbranched ionic liquid Recycling Carbon fiber Composites

Spatio-temporal-spectral-angular observation model that integrates observations from UAV and mobile mapping vehicle for better urban mapping

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Geo-Spatial Information Science 2021年第4期24卷 615-629页

作者： Zhenfeng Shao gui cheng Deren Li Xiao Huang Zhipeng Lu Jian Liu State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhanChina Department of Geosciences University of ArkansasFayettevilleARUSA Leador Spatial Information Technology Corporation WuhanChina

In a complex urban scene,observation from a single sensor unavoidably leads to voids in observations,failing to describe urban objects in a comprehensive *** this paper,we propose a spatio-temporal-spectral-angular observation model to integrate observations from UAV and mobile mapping vehicle platform,realizing a joint,coordinated observation operation from both air and *** develop a multi-source remote sensing data acquisition system to effectively acquire multi-angle data of complex urban ***-source data fusion solves the missing data problem caused by occlusion and achieves accurate,rapid,and complete collection of holographic spatial and temporal information in complex urban *** carried out an experiment on Baisha Town,Chongqing,China and obtained multi-sensor,multi-angle data from UAV and mobile mapping *** first extracted the point cloud from UAV and then integrated the UAV and mobile mapping vehicle point *** inte-grated results combined both the characteristics of UAV and mobile mapping vehicle point cloud,confirming the practicability of the proposed joint data acquisition platform and the effectiveness of spatio-temporal-spectral-angular observation *** with the observation from UAV or mobile mapping vehicle alone,the integrated system provides an effective data acquisition solution toward comprehensive urban monitoring.

关键词： Urban remote sensing data fusion spatio-temporalspectralangular observation model UAV mobile mapping vehicle

Real-Time Position and Attitude Estimation for Homing and Docking of an Autonomous Underwater Vehicle Based on Bionic Polarized Optical guidance

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Journal of Ocean University of China 2020年第5期19卷 1042-1050页

作者： cheng Haoyuan CHU Jinkui ZHANG Ran gui Xinyuan TIAN Lianbiao The Key Laboratory for Micro/Nano Technology and System of Liaoning Province Dalian University of TechnologyDalian 116024China

As an important tool for marine exploration, the autonomous underwater vehicle(AUV) must home in and dock at a docking station(DS) to be recharged, repaired, or to exchange information at set intervals. However, the complex and hostile underwater environment makes this process challenging. This study proposes a real-time method based on polarized optical guidance for determining the position and attitude of the AUV relative to its DS. Four polarized artificial underwater landmarks are positioned at the DS, which are recognized by the AUV vision system. Compared with light intensity, the polarization of a light beam is known to be better maintained at greater propagation distances, especially in underwater environments. The proposed method, which is inspired by the ability of marine animals to communicate, calculates the pose parameters in less than 10 ms without any other navigational information. The simulation results reveal that the angle errors are small and the position errors are no more than 0.116 m within 100 m in the coastal ocean. The results of underwater experiments further demonstrate the feasibility of the proposed method, which extends the operating distance of the AUV beyond what is currently possible while maintaining the precision of traditional optical guidance.

关键词： polarization optical guidance AUV underwater docking position and attitude estimation

Effect of FeSi additive in dual-chamber sample cup on thermal analysis characteristic values and vermiculating rate of compacted graphite iron

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China Foundry 2024年第1期21卷 91-100页

作者： De-quan Shi Ze-yu Liu gui-li Gao Yi-cheng Feng School of Materials and Chemistry University of Shanghai for Science and TechnologyShanghai 200093China School of Materials Science and Chemical Engineering Harbin University of Science&TechnologyHarbin 150040China School of Mechanical and Energy Engineering Shanghai Technical Institute of Electronics and InformationShanghai 201411China

Thermal analysis plays a key role in the online inspection of molten iron *** solidification process of molten iron can be reflected by thermal analysis curves,and silicon is one of important elements affecting the solidification of molten *** this study,FeSi75 was added in one chamber of the dual-chamber sample cup,and the influences of FeSi75 additive on the characteristic values of thermal analysis curves and vermiculating rate were *** results show that with the increase of FeSi75,the start temperature of austenite formation TALfirstly decreases and then increases,but the start temperature of eutectic growth TSEF,the lowest eutectic temperature TEU,temperature at maximum eutectic reaction rate TEM,and highest eutectic temperature TERkeep always an *** temperature at final solidification point TEShas little *** FeSi75 additive has different influences on the vermiculating rate of molten iron with different vermiculation,and the vermiculating rate increases for lower vermiculation molten iron while decreases for higher *** to the thermal analysis curves obtained by a dual-chamber sample cup with 0.30wt.%FeSi75 additive in one chamber,the vermiculating rate of molten iron can be evaluated by comparing the characteristic values of these *** time differenceΔtERcorresponding to the highest eutectic temperature TERhas a closer relationship with the vermiculating rate,and a parabolic regression curve between the time differenceΔtERand vermiculating rateηhas been obtained within the range of 65%to 95%,which is suitable for the qualified melt.

关键词： FeSi75 additive characteristic value vermiculating rate thermal analysis compacted graphite iron

Extraction of Tungsten and Molybdenum by Various Organic Compounds as Extractants

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Rare Metals 1989年第3期9卷 15-19页

作者： Yuan, qun cheng, Xin Luo, Jiazhen Yuan, chengye Shanghai Inst of Organic Chemistry China

Seventy organic compounds including various organophosphorus esters, amines and oxygen-based ligands were investigated as extractants. The experiment results show that amines are excellent extractants for W and Mo. Their sequence of extraction ability for W is as follows: quarternary amine > tertiary amine > secondary amine > primary amine. Acidic organophosphorus extractants do not extract W, but can extract Mo with high extraction ability from the acidic solution. These extractants could provide a potential process for separating W from Mo.

关键词： Alcohols Applications Amines Applications Molybdenum Ore Treatment Solvent Extraction Phosphorus Compounds Organic Solvents Organic

CuS nanoenzyme against bacterial infection by in situ hydroxyl radical generation on bacteria surface

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Rare Metals 2023年第6期42卷 1899-1911页

作者： Zhao Li cheng-Jia Xie Xiao-Wei Ren qun Zhang Bao-Jin Ma Department of Tissue Engineering and Regeneration School and Hospital of StomatologyCheeloo College of MedicineShandong University&Shandong Key Laboratory of Oral Tissue Regeneration&Shandong Engineering Laboratory for Dental Materials and Oral Tissue Regeneration&Shandong Provincial Clinical Research Center for Oral DiseasesJinan250012China Jinan Food and Drug Inspection and Testing Center Jinan250010China

Nanoenzyme-mediated antibacterial strategies have been widely exploited to overcome the shortcomings(such as drug resistance and mild-to-severe side effects) of antibiotic *** peroxidase-like activity of nanoenzymes possesses great potential against bacterial infection by the generation of hydroxyl radical(·OH) in the specific ***,the lifetime of-OH is extremely short,and a large amount of the ·OH generated within the infection microenvironment cannot come into contact with bacteria quickly enough,thus resulting in low treatment ***,chitosan-oligosaccharide-modified CuS nanoparticles possessing positive charges(PCuS NPs) were prepared using a one-pot *** NPs exhibited efficient peroxidase-like ***,the PCuS NPs can combine with bacteria via electrostatic *** direct contact between the PCuS NPs and bacteria enabled the generation of ·OH in situ on the bacterial surface,ultimately leading to a high antibacterial efficacy at a low concentration in the presence of H_(2)O_(2).At an effective antibacterial concentration,the PCuS NPs exhibited high ***,in vivo results revealed that PCuS NPs not only decreased the size of abscesses but also reduced inflammation and promoted collagen fiber ***,PCuS NPs possess great potential against bacterial infection via in situ ·OH generation based on electrostatic attraction.

关键词： Antibacterial CuS Nanoenzyme In situ ·OH generation Electrostatic attraction