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FOULING DETECTION IN FOOD VESSELS USING INTERDIGITAL LAMB WAVE TRANSDUCER

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Chinese Journal of Mechanical Engineering 2007年第1期20卷 111-114页

作者： JIAO Jingpin ge Haiyan wu Bin HE Cunfu College of Mechanical Engineenng and Applied Electronic Technology Beijing University of Technology Beijing 100022 China

Lamb waves are used to detect fouling in food vessels. The propagation of the Lamb waves in plates exhibits many modes and dispersion characteristics, which have great influence on fouling detection. The relative distribution of the in-plane and out-of-plane displacement of the mode across the thickness of the plate will determine the sensitivity of the mode to a particular loading condition. By considering the dispersion and multi-mode characteristics of guided waves, an interdigital polyvi- nylidene fluoride （PVDF） transducer is designed to realize the mode selection of gnided waves, and a single a0 mode is used for guided wave detection. Fouling detection experiments are conducted in the laboratory using epoxy adhesive on a thin plate. Using the interdigital PVDF transducer, three fouled areas are detected. Using one of the time-frequency analysis methods, the waveforms are further processed. This also demonstrates the validity of this method of fouling detection.

关键词： Lamb waves Interdigital transducer Fouling detection

Robust stability of discrete-time nonlinear system with time-delay

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Journal of Central South University of Technology 2005年第z1期12卷 227-231页

作者： LIU Xin-ge wu Min School of Information Science and Engineering Central South University Changsha 410083 China School of Information Science and Engineering Central South University Changsha 410083 China

The robustly asymptotical stability problem for discrete-time nonlinear systems with time-delay was investigated. Positive definite matrix are constructed through Lyapunov functional. With the identity transform, property of matrix inverse and S-procedure, a new sufficient condition independent of the size of time-delay for robust stability of discrete-time nonlinear systems with time-delay is established. With Schur complement, another equivalent sufficient condition for robust stability of discrete-time nonlinear systems with time-delay is given. Finally, a sufficient condition dependent on the size of time-delay for robust stability of discrete-time nonlinear systems with time-delay is obtained. A unified approach is used to cast the robust stability problem into a convex optimization involving linear matrix inequalities.

关键词： discrete-time system time-delay robust stability linear matrix inequality

Minimizing pest aluminum in magnesium for the production of high-purity titanium

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Journal of Magnesium and Alloys 2023年第11期11卷 4189-4196页

作者： Bo Yang Rui Zheng ge wu Zhi-Min Chang Zhi-Wei Shan Engineering Research Center for Magnesium-based New Materials Center for Advancing Materials Performance from the Nanoscale(CAMP-Nano)State Key Laboratory for Mechanical Behavior of MaterialsXi’an Jiaotong UniversityXi’an 710049PR China

It is practically difficult to find titanium sponges with low and stable aluminum impurities on the market even though it is the precondition to prepare high-purity titanium. Analysis indicates that almost all the aluminum impurities in the titanium sponge are inherited from the magnesium used to reduce titanium tetrachloride. However, it remains elusive for decades why magnesium produced through the silicothermic reduction method contains a high content of aluminum impurities with large fluctuations. By recourse to thermodynamic calculations and comparative experiments, we demonstrate that fluorite, a material used as a catalyst in the silicothermic reduction method to produce magnesium, is the chief culprit for the pest aluminum and propose a mechanism to rationalize the observed phenomena. Our findings indicate that one practical way to produce qualified magnesium for the production of high-purity titanium is to abandon fluorite during the production of magnesium with the silicothermic reduction method.

关键词： High-purity titanium Titanium sponge Magnesium Aluminum impurity Silicothermic reduction

Synthesis and Optical Properties of ZnO Nanoparticles in Submicron PS Hollow Reactors

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Chinese Journal of Chemical Physics 2012年第6期25卷 719-724,I0004页

作者： Xue-feng Huang Fei-fei Ju Mo-zhen Wang Xue-wu ge CAS Key Laboratory of Soft Matter Chemisry Department of Polymer Science and EngineeringUniversity of Science and Technology of China Hefei 230026 China

ZnO nanoparticles were first encapsulated in submicron PS hollow microspheres through two-step swelling process of core-shell structured PMMA/PS （PMMA： polymethyl methao- rylate） microspheres in acid-alkali solution, and the ZnO precursors, i.e. the ethanol solu- tions of （CHaCOO）2Zn and LiOH. The transmission electron microscope, X-ray diffraction, and thermogravimetric analysis results show that the feeding order of ethanol solutions of （CH3COO）2Zn and LiOH in the second swelling step has great influence on the loading efficiency and the size of ZnO nanoparticles, but little on their crystal form. The photolumi- nescence and UV-Vis absorption behavior of ZnO/PS microspheres show that the PS shell can effectively avoid the fluorescence quenching effect.

关键词： ZnO/PS hybrid material Core-shell polymer Swelling PS hollow microsphere Optical property

In-situ Enhanced Toughening of Poly（ethylene terephthalate）/elastomer Blends via Gamma-Ray Radiation at Presence of Trimethylolpropane Triacrylate

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Chinese Journal of Chemical Physics 2016年第6期29卷 703-709,I0001,I0002页

作者： Li-zhao Xie Le-chen Chen Mo-zhen Wang Qi-chao wu Xiao Zhou Xue-wu ge CASKeyLaboratoryofSoftMatterChemistry DepartmentofPolymerScienceandEngineeringUniversityofScienceandTechnologyofChinaHefei230026China GuangdongTiananNewMaterialCo. Ltd.Foshan528000China

Gamma-ray radiation has always been a convenient and effective way to modify the inter- facial properties in polymer blends. In this work, a small amount of trimethylolpropane triacrylate （TMPTA） was incorporated into poly（ethylene terephthalate）（PET）/random terpolymer elastomer （ST2000） blends by melt-blending. The existence of TMPTA would induce the crosslinking of PET and ST2000 molecular chains at high temperatures of blend- ing, resulting in the improvement in the impact strength but the loss in the tensile strength. When the PET/ST2000 blends were irradiated by gamma-ray radiation, the integrated me- chanical properties could be enhanced significantly at a high absorbed dose. The irradiated sample at a dose of 100 kGy even couldn＇t be broken under the impact test load, and at the same time, has nearly no loss of tensile strength. Based on the analysis of the impact- fractured surface morphologies of the blends, it can be concluded that gamma-ray radiation at high absorbed dose can further in situ enhance the interfacial adhesion by promoting the crosslinking reactions of TMPTA and polymer chains. As a result, the toughness and strength of PET/ST2000 blend could be dramatically improved. This work provides a facial and practical way to the fabrication of polymer blends with high toughness and strength.

关键词： Toughened PET blend Interracial interaction Gamma-ray radiation Radia- tion crosslink Trimethylolpropane triacrylate

Tightly Secure Public-Key Cryptographic Schemes from One-More Assumptions

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Journal of Computer Science & Technology 2019年第6期34卷 1366-1379页

作者： ge wu Jian-Chang Lai Fu-Chun Guo Willy Susilo Fu-Tai Zhang School of Cyber Science and Engineering Southeast UniversityNanjing 211189China Institute of Cybersecurity and Cryptology School of Computing and Information Technology University of WollongongWollongong 2522Australia Purple Mountain Laboratories Nanjing 211111China School of Mathematics and Computer Science Fujian Normal UniversityFuzhou 350117China School of Computer Science and Technology Nanjing Normal UniversityNanjing 210023China

A tightly secure cryptographic scheme refers to a construction with a tight security reduction to a hardness assumption,where the reduction loss is a small constant.A scheme with tight security is preferred in practice since it could be implemented using a smaller parameter to improve ***,Bader et al.(EUROCRYPT 2016)have proposed a comprehensive study on the impossible tight security reductions for certain(e.g.,key-unique)public-key cryptographic schemes in the multi-user with adaptive corruptions(MU-C)setting built upon non-interactive *** assumptions of one-more version,such as one-more computational Diffie-Hellman(n-CDH),are variants of the standard assumptions and have found various ***,whether it is possible to have tightly secure key-unique schemes from the one-more assumptions or the impossible tight reduction results also hold for these assumptions remains *** this paper,we give affirmative answers to the above question,i.e.,we can have efficient key-unique public-key cryptographic schemes with tight security built upon the one-more ***,we propose a digital signature scheme and an encryption scheme,both of which are key-unique and have tight MU-C security under the one-more computational Diffie-Hellman(n-CDH)*** results also reflect from another aspect that there indeed exists a gap between the standard assumptions and their one-more version counterparts.

关键词： public-key cryptography multi-user setting tight security one-more assumption

Synthesis and morphology control of raspberry-like poly(ethylene terephthalate)/polyacrylonitrile microspheres

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Chinese Chemical Letters 2016年第2期27卷 195-199页

作者： Yong-Fei Xu Mo-Zhen Wang Qi-Chao wu Xiao Zhou Xue-wu ge CAS Key Laboratory of Soft Matter Chemistry Department of Polymer Science and Engineering University of Science and Technology of China School of Materials and Chemical Engineering Anhui Jianzhu University Guangdong Tianan New Material Co. Ltd.

The fabrication of raspberry-like poly（ethylene terephthalate）/polyacrylonitrile（PET/PAN） microspheres by g-ray radiation-induced polymerization of acrylonitrile on micron-sized PET microspheres were first reported in this work. A PET emulsion was firstly prepared by dispersing a PET solution with 1,1,2,2-tetrachloroethane/phenol mixture as the solvent into an aqueous solution of sodium dodecyl ***, PET microspheres were formed by precipitating the PET emulsion droplets from ethanol. The influence of the PET solvent and the weight ratio of ethanol to PET emulsion on the morphology of the PET microspheres had been investigated. After the surface of the prepared PET microspheres was grafted with poly（acrylic acid）, the grafting polymerization of AN also had been successfully initiated by g-ray radiation to form PAN microspheres with a size of about 100 nm on the PET microspheres. This work provides a new method to fabricate micron-sized PET microspheres, and further expands the functionalization of PET and its application fields.

关键词： PET emulsion Emulsion precipitation PET microsphere Raspberry-like microsphere PET/PAN composite microspheres

Preparation and Structure-Property Regulation Mechanism of Reversible Thermochromic Polydiacetylene

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Chinese Journal of Polymer Science 2024年第8期42卷 1111-1121页

作者： Zhi-Qing ge Shuo Yan Zu-Xiong Pan Shan Lei Xuan-Zhi Mao Chu Zhao Mo-Zhen Wang Xue-wu ge Key Laboratory of Precision and Intelligent Chemistry Department of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026China Marshall Laboratory of Biomedical Engineering International Cancer CenterLaboratory of Evolutionary Theranostics(LET)School of Biomedical EngineeringShenzhen University Medical SchoolShenzhen UniversityShenzhen 518055China Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China

The thermochromic mechanism and the structure-property regulation principle of reversible thermochromic polydiacetylene(PDA)materials have always been a challenging *** this work,a series of diacetylene monomers(m-PCDA)containing phenyl and amide or carboxyl groups were synthesized from 10,12-pentacosadiynoic acid(PCDA)through the esterification or amidation *** effects of the number and the distribution of the functional groups in m-PCDA molecules on their solid-state polymerization capability,and the thermochromic mechanism of their corresponding polymers(m-PDA)were investigated and discussed in *** results show that the m-PCDA monomers containing both benzene ring and groups that can form hydrogen bonding interactions have strong intermolecular interaction,and are easy to carry out the solid phase polymerization under 254-nm UV irradiation to obtain the corresponding new thermochromic m-PDA *** thermochromic behavior of m-PDA depends on its melting *** initial color-change temperature(blue to red)is determined by the onset melting tem perature,and the temperature range in which reversible color recovery can be achieved by repeat heating-cooling treatment is determined by its melting *** to the proposed thermochromic mechanism of PDA,various new PDA materials with precise thermochromic temperatu res and reversible thermochromic temperature ra nges can be designed and synthesized through the appropriate introduction of benzene ring and groups that can form hydrogen bonding interactions into the molecular structure of linear diacetylene *** work provides a perspective to the precise molecular structure design and the property regulation of the reversible thermochromic PDA materials.

关键词： Polydiacetylene Thermochromism Hydrogen bonding Chemical modification

Artificial intelligence in medical imaging of the liver

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World Journal of Gastroenterology 2019年第6期25卷 672-682页

作者： Li-Qiang Zhou Jia-Yu Wang Song-Yuan Yu ge-ge wu Qi Wei You-Bin Deng Xing-Long wu Xin-wu Cui Christoph F Dietrich Sino-german Tongji-Caritas Research Center of Ultrasound in Medicine Department of Medical Ultrasound Tongji Hospital Tongji Medical College Huazhong University of Science and Technology Department of Ultrasound Tianyou Hospital Affiliated to Wuhan University of Technology School of Mathematics and Computer Science Wuhan Textitle University Medical Clinic 2 Caritas-Krankenhaus Bad Mergentheim Academic Teaching Hospital of the University of Würzburg

Artificial intelligence(AI), particularly deep learning algorithms, is gaining extensive attention for its excellent performance in image-recognition tasks. They can automatically make a quantitative assessment of complex medical image characteristics and achieve an increased accuracy for diagnosis with higher efficiency. AI is widely used and getting increasingly popular in the medical imaging of the liver, including radiology, ultrasound, and nuclear medicine. AI can assist physicians to make more accurate and reproductive imaging diagnosis and also reduce the physicians' workload. This article illustrates basic technical knowledge about AI, including traditional machine learning and deep learning algorithms, especially convolutional neural networks, and their clinical application in the medical imaging of liver diseases, such as detecting and evaluating focal liver lesions, facilitating treatment, and predicting liver treatment response. We conclude that machine-assisted medical services will be a promising solution for future liver medical care. Lastly, we discuss the challenges and future directions of clinical application of deep learning techniques.

关键词： Liver Imaging Ultrasound Artificial intelligence Machine learning Deep learning