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Investigation of Impact Toughness of Electromagnetic Centrifugal Cast High Speed Steel

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Journal of Iron and Steel Research International 2012年第S1期19卷 335-340页

作者： WANG Ming-jia gu Tao WANG Zi-xi State Key Laboratory of Metastable Materials Science and Technology Yanshan University

The effect of external magnetic field on the solidification structure and impact toughness of high-speed steel(HSS)produced by electromagnetic centrifugal casting(EMCC)have been *** was found that the solidification structure could be improved effectively by electromagnetic stirring,which was characterized by elimination of the inclined columnar dendrites and refinement of the grain *** results may be related to the changes of the fluid layers of liquid-solid phase ***,the impact toughness of the test steel increased with the exciting current increasing from 12 to 18 A,but decreased when the current was above 18 *** analysis showed that impact fracture surface was dimple fracture due to effect of the refined equiaxed grains when the current was 18 A,which was considered an important reason for the improvement of impact toughness.

关键词： electromagnetic centrifugal casting high speed steel Impact toughness grain refinement

Modified robust optimal adaptive control for flight environment simulation system with heat transfer uncertainty

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Chinese Journal of Aeronautics 2021年第2期34卷 420-431页

作者： Meiyin ZHU xi WANG xitong PEI Song ZHANG Zhihong DAN Nannan gu Shubo YANG Keqiang MIAO Huairong CHEN Jiashuai LIU School of Energy and Power Engineering Beihang UniversityBeijing 100083China Collaborative Innovation Center for Advanced Aero Engine Bejing 100083China Science and Technology on Altitude Simulation Laboratory AECC(Aero Engine Corporation of China)Sichuan Gas Turbine EstablishmentMianyang 621000China

To solve the rapid transient control problem of Flight Environment Simulation System(FESS) of Altitude Ground Test Facilities(AGTF) with large heat transfer uncertainty and disturbance, a new adaptive control structure of modified robust optimal adaptive control is *** mathematic modeling of FESS is given and the influence of heat transfer is analyzed through energy view. To consider the influence of heat transfer in controller design, we introduce a matched uncertainty that represents heat transfer influence in the linearized system of FESS. Based on this linear system, we deduce the design of modified robust optimal adaptive control law in a general way. Meanwhile, the robust stability of the modified robust optimal adaptive control law is proved through using Lyapunov stability theory. Then, a typical aero-engine test condition with Mach Dash and Zoom-Climb is used to verify the effectiveness of the devised adaptive controller. The simulation results show that the designed controller has servo tracking and disturbance rejection performance under heat transfer uncertainty and disturbance;the relative steady-state and dynamic errors of pressure and temperature are both smaller than 1% and 0.2% respectively. Furthermore,the influence of the modification parameter c is analyzed through simulation. Finally, comparing with the standard ideal model reference adaptive controller, the modified robust optimal adaptive controller obviously provides better control performance than the ideal model reference adaptive controller does.

关键词： Altitude ground test facilities Flight environment simulation system Heat transfer Model reference adaptive control Optimal control modification Uncertainty

Chiral amino acid recognition in water:A BINOL-based fluorescent probe

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Chinese Chemical Letters 2023年第12期34卷 136-140页

作者： Meng-xin Sun Chuan-Zhi Ni Fang-Qi Zhang Yuan-Yuan Zhu Jie Zeng Shuang-xi gu School of Chemistry and Environmental Engineering Wuhan Institute of TechnologyWuhan 430205China Hubei Key Laboratory of Novel Reactor and Green Chemical Technology Wuhan Institute of TechnologyWuhan 430205China Pharmaceutical Research Institute Wuhan Institute of TechnologyWuhan 430205China Key Laboratory for Green Chemical Process of Ministry of Education School of Chemical Engineering&PharmacyWuhan Institute of TechnologyWuhan 430205China

A novel BINOL-based fluorescence probe(S)-6 featuring a sodium sulfonate fragment at the 2'-position was designed and synthesized via simple synthetic procedures under mild reaction *** watersoluble probe(S)-6 displays excellent enantioselective recognition toward 15 common amino acids,and it can be used for enantiomeric excess determination of amino *** fluorescence intensity of(S)-6 treated with amino acids reaches the maximum after standing for only 30 min at room temperature and remains stable in the following 5.5 h,which has great potential in the application of chiral fluorescence analysis due to its timeliness and outstanding fluorescent stability.

关键词： Chiral recognition Fluorescent probe Amino acid Water-soluble Enantiomeric excess determination

Basic mechanisms of peripheral nerve injury and treatment via electrical stimulation

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Neural Regeneration Research 2022年第10期17卷 2185-2193页

作者： xiao-Lei Chu xi-Zi Song Qi Li Yu-Ru Li Feng He xiao-Song gu Dong Ming Academy of Medical Engineering and Translational Medicine Tianjin UniversityTianjinChina Department of Rehabilitation Tianjin HospitalTianjinChina College of Exercise&Health Sciences Tianjin University of SportTianjinChina College of Precision Instruments&Optoelectronics Engineering Tianjin UniversityTianjinChina

Previous studies on the mechanisms of peripheral nerve injury(PNI)have mainly focused on the pathophysiological changes within a single injury ***,recent studies have indicated that within the central nervous system,PNI can lead to changes in both injury sites and target organs at the cellular and molecular ***,the basic mechanisms of PNI have not been comprehensively *** electrical stimulation was found to promote axonal regeneration and functional rehabilitation after PNI,as well as to alleviate neuropathic pain,the specific mechanisms of successful PNI treatment are *** summarize and discuss the basic mechanisms of PNI and of treatment via electrical *** PNI,activity in the central nervous system(spinal cord)is altered,which can limit regeneration of the damaged *** example,cell apoptosis and synaptic stripping in the anterior horn of the spinal cord can reduce the speed of nerve *** pathological changes in the posterior horn of the spinal cord can modulate sensory abnormalities after *** can be observed in cases of ectopic discharge of the dorsal root ganglion leading to increased pain signal *** injured site of the peripheral nerve is also an important factor affecting post-PNI *** PNI,the proximal end of the injured site sends out axial buds to innervate both the skin and muscle at the injury site.A slow speed of axon regeneration leads to low nerve ***,it can take a long time for the proximal nerve to reinnervate the skin and muscle at the injured *** the perspective of target organs,long-term denervation can cause atrophy of the corresponding skeletal muscle,which leads to abnormal sensory perception and hyperalgesia,and finally,the loss of target organ *** mechanisms underlying the use of electrical stimulation to treat PNI include the inhibition of synaptic stripping,addressing the excessive excitability of the dorsal r

关键词： axonal transport brain-derived neurotrophic factor dorsal horn stimulation dorsal root ganglion stimulation electrical stimulation nerve regeneration neuropathic pain peripheral nerve injury spinal cord dorsal stimulation

Physiological property and yield of the sweet sorghum mutants induced by heavy ion irradiation

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Nuclear Science and Techniques 2016年第4期27卷 83-88页

作者： Wen-Ting gu Wen-Jian Li Rui-Yuan Liu Wen-Jie Jin Tao-Li-Wei Yang xi-Cun Dong Institute of Modern Physics Chinese Academy of Sciences

Soil salinity can limit plant growth and productivity. The cultivation of tolerant varieties is convenient and cost-effective for making good use of the saline *** sweet sorghum plant has a high tolerance for saline alkaline soils. The KF1210-3 and KF1210-4 early-maturity mutants of sweet sorghum were obtained via carbon ion irradiation. The study assesses the productivity of three sweet sorghum cultivars(KF1210-3, KF1210-4, and KFJTCK) which were grown in intermediate(4.6 d S m^(-1)) and high(11.9 d S m^(-1)) soil salinity. The sweet sorghum grown in the soil salinity of 4.6 d S m^(-1)produced 50.00–57.30 %greater fresh weight than that in the soil salinity of11.9 d S m^(-1), while the difference was not as obvious among the dry biomass of the three sweet sorghum cultivars. Moreover, the Brix degree of the sweet sorghum grown in the soil salinity of 11.9 d S m^(-1)was greater than that grown in the soil salinity of 4.6 d S m^(-1). The heavy ion irradiation experiment is of great significance in screening plant mutants, improving environmental conditions, and assessing the productivity. This process, in turn, aids in the understanding of the effects of the biochemical and physiological mechanisms of salt stress.

关键词：早熟突变体甜高粱重离子生理特性辐照诱导土壤含盐量产量土壤盐分

Achieving Privacy-Preserving Iris Identification Via El Gamal

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Computers, Materials & Continua 2019年第8期61卷 727-738页

作者： Yong Ding Lei Tian Bo Han Huiyong Wang Yujue Wang james xi Zheng guangxi Key Laboratory of Cryptography and Information Security School of Computer and Information SecurityGuilin University of Electronic TechnologyGuilin541004China School of Mathematics and Computer Science Guilin University of Electronic TechnologyGuilin541004China Software Engineering Department of Computing Macquarie UniversitySydneyNSW 2109 Australia

Currently,many biometric systems maintain the user’s biometrics and templates in plaintext format,which brings great privacy risk to uses’biometric *** are unique and almost unchangeable,which means it is a great concern for users on whether their biometric information would be *** address this issue,this paper proposes a confidential comparison algorithm for iris feature vectors with masks,and develops a privacy-preserving iris verification scheme based on the El Gamal encryption *** our scheme,the multiplicative homomorphism of encrypted features is used to compare of iris features and their mask ***,this paper improves the Hamming distance of iris features,which makes the similarity matching work better than existing *** results confirm the practicality of our proposed schemes in real world applications,that is,for the iris feature vectors and masks of 2048 bits,nearly 12 comparisons can be performed per second.

关键词： Homomorphic encryption template matching Hamming distance

FATIguE DISLOCATION CONFIguRATIONS IN HEXAGONAL ZIRCALOY-4

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Chinese Journal of Aeronautics 1996年第2期9卷 122-125页

作者： xiao Lin(Institute of Engineering Mech., xi’an Jiaotong University, xi’an, China, 710049)gu Haicheng(Institute for Strength of Metals, xi’an Jiaotong University, xi’an, China, 710049) Institute of Engineering Mech. Xi'an Jiaotong University Xi'an 710049 China Institute for Strength of Metals Xi'an Jiaotong University Xi'an 710049 China

Fatigue dislocation configurations of Zircaloy-4 at 470℃×1h stress-relieved condition and 620℃×1h recrystallized condition were analyzed using TEM. Theresults show that: {1 0 1 0} prismatic slip is the primary deformation mode at RT. Prismatic and pyramidal slips are activated simultaneously at 400℃. The typicalsubstructure is the elongated dislocation lines at RT; whereas at 400℃, it is rectangularcells in stress-relieved specimens, and elongated cells plus dipole perpendicular cellboundary in recrystallized specimens. The relationship map among dislocation configuration, test temperature and cyclic strain range is established, finally.

关键词： Zircaloy (trademark) fatigue (materials) dislocations (materials) configuration interaction slip

Analysis of optical properties of bio-smoke materials in the 0.25–14 μm band

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Chinese Physics B 2019年第3期28卷 168-174页

作者： xinying Zhao Yihua Hu Youlin gu xi Chen xinyu Wang Peng Wang xiao Dong State Key Laboratory of Pulsed Power Laser Technology National University of Defense TechnologyHefei 230037China Anhui Province Key Laboratory of Electronic Restriction National University of Defense TechnologyHefei 230037China Key Laboratory of Ion Beam Bioengineering Hefei Institutes of Physical ScienceChinese Academy of SciencesHefei 230001China

At present, research into optical properties of bio-smoke materials mostly concentrates on single band or single germplasm. Herein, we measured the spectral reflectance of three eukaryotic bio-smoke materials and three prokaryotic bio-smoke materials in the waveband from 0.25 μm to 14μm. Based on the Kramers-Kroning algorithm, the complex refractive index m(λ) was calculated and the Fourier-transform infrared(FTIR) spectra of materials were analyzed. The results show that n(λ) of bio-smoke materials varies between 1.1-2, and n(λ) values in the visible light to near-infrared wavebands are significantly larger than those in other wavebands. The k(λ) of bio-smoke materials varies between *** 6-6.5 μm, k(λ) of prokaryotic materials is 3 times that of eukaryotic materials, which is caused by C=O stretching vibration of amide I and C-N stretching vibration of amide Ⅱ in proteins. At 2.5-3 μm and 9.75 μm, k(λ) values of eukaryotic bio-smoke materials are nearly 2 times that of prokaryotic ones. The absorption peak at 2.5-3 μm is mainly triggered by C-H stretching vibration in lipid and O-H stretching vibration in bound water. The absorption peak at 9.75 μm is mainly caused by symmetric stretching vibration of PO2-in nucleic acids.

关键词： bio-smoke materials complex refractive index eukaryotic prokaryotic

Formation Process and Mechanical Deformation Behavior of a Novel Laser-Printed Compression-Induced Twisting-Compliant Mechanism

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Engineering 2022年第8期8卷 133-142页

作者： Jie Gao Dongdong gu Chenglong Ma Donghua Dai Lixia xi Kaijie Lin Tong Gao Jihong Zhu Yuexin Du College of Materials Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016China Jiangsu Engineering Laboratory for Laser Additive Manufacturing of High-Performance Metallic Components Nanjing University of Aeronautics and AstronauticsNanjing 210016China State IJR Center of Aerospace Design and Additive Manufacturing MIIT Key Laboratory of Metal High Performance Additive Manufacturing and Innovative DesignNorthwestern Polytechnical UniversityXi’an 710072China NPU-QMUL Joint Research Institute of Advanced Materials and Structure Northwestern Polytechnical UniversityXi’an 710072China

A novel compression-induced twisting(CIT)-compliant mechanism was designed based on the freedom and constraint topology(FACT)method and manufactured by means of laser powder bed fusion(LPBF).The effects of LPBF printing parameters on the formability and compressive properties of the laserprinted CIT-compliant mechanism were *** the range of optimized laser powers from 375 to 450 W and with the densification level of the samples maintained at above 98%,changes in the obtained relative densities of the LPBF-fabricated CIT-compliant mechanism with the applied laser powers were not *** laser power led to the elimination of residual metallurgical pores within the inclined struts of the CIT *** highest dimensional accuracy of 0.2% and the lowest surface roughness of 20μm were achieved at a laser power of 450 *** deformation behavior of the CIT-compliant mechanism fabricated by means of LPBF exhibited four typical stages:an elastic stage,a heterogeneous plastic deformation stage,a strength-destroying stage,and a deformation-destroying stage(or instable deformation stage).The accumulated compressive strain of the optimally printed CIT mechanism using a laser power of 450 W went up to 20% before fracturing,demonstrating a large deformation *** twisting behavior and mechanical properties were investigated via a combination of finite-element simulation and experimental *** approximately linear relationship between the axial compressive strain and rotation angle was achieved before the strain reached 15% for the LPBF-processed CIT-compliant mechanism.

关键词： Laser 3D printing Laser powder bed fusion Compression-induced twisting-compliant mechanism Compression-torsion property Mechanical properties