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Interface defeat studies of long-rod projectile impacting on ceramic targets

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Defence Technology（防务技术） 2020年第1期16卷 50-68页

作者： Y.X.Zhai H.Wu q.fang Amy Engineering University of PLA Nanjing210007China Research Institute of Structural Engineering and Disaster Reduction College of Civil EngineeringTongji UniversityShanghai200092China

The interface defeat phenomenon always occurs when a long-rod projectile impacting on the ceramic target with certain velocity,i.e.,the projectile is forced to flow radially on the surface of ceramic plates for a period of time without significant *** defeat has a direct effect upon the ballistic performance of the armor piercing projectile,which is studied numerically and theoretically at ***,by modeling the projectiles and ceramic targets with the SPH(Smoothed Particle Hydrodynamics)particles and Lagrange finite elements,the systematic numerical simulations on interface defeat are performed with the commercial finite element program *** different responses,i.e.,complete interface defeat,dwell and direct penetration,are reproduced in different types of ceramic targets(bare,buffered,radially confined and oblique).Furthermore,by adopting the validated numerical algorithms,constitutive models and the corresponding material parameters,the influences of projectile(material,diameter,nose shape),constitutive models of ceramic(JH-1 and JH-2 models),buffer and cover plate(thickness,constraints,material),as well as the prestress acted on the target(radial and hydrostatic) on the interface defeat(transition velocity and dwell time) are syste matically ***,based on the energy conservation approach and taking the strain rate effect of ceramic material into account,a modified model for predicting the upper limit of transition velocity is proposed and *** present work and derived conclusions can provide helpful reference for the design and optimization of both the long-rod projectile and ceramic armor.

关键词： Interface defeat Ceramic Transition velocity Numerical simulation Parametric study

Modified spherical cavity-expansion model for projectile penetration into concrete targets

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Acta Mechanica Sinica 2019年第3期35卷 518-534页

作者： Y.Peng H.Wu q.fang X.Z.Kong College of Liberal Arts and Sciences National University of Defense TechnologyChangsha 410073China Key Laboratory of Performance Evolution and Control for Engineering Structures Tongji UniversityShanghai 200092China Research Institute of Structural Engineering and Disaster Reduction College of Civil EngineeringTongji UniversityShanghai 200092China State Key Laboratory for Disaster Prevention and Mitigation of Explosion and Impact PLA Amy Engineering UniversityNanjing 210007China

A modified spherical cavity-expansion model is developed in this paper.(1) We introduce a piecewise hyperbolic yield criterion suitable for pressure less than fc/3 to describe the mechanical behavior in the elastic region for the elastic-plastic response and modify the crack occurrence condition for the elastic-cracked-plastic response.(2) The hyperbolic yield criterion and a piecewise equation of state (EOS) are adopted for a better description of the plastic behavior of concrete material. Then, the modified model is validated by several projectile penetration tests in both the normal strength concrete (NSC) and ultra-high performance cement-based composite (UHPCC) targets. Finally, the hydrostatic pressure of the targets under rigid ogive-nosed projectile penetrations is found to be nearly within (0, 1.6 GPa), which usually exceeds the range that the shear strength-pressure test data covered. The influence of yield criterion on depth of penetration is discussed and it is recommended that the pressure should arrive at least 400 MPa in the related triaxial compression tests.

关键词： Dynamic cavity-expansion model Projectile Penetration Concrete Depth of penetration

The phylogenetic relationships of introduced Aphelinus （Hymenoptera： Aphelinidae）, biological control agents of the Russian wheat aphid （Homoptera： Aphididae）

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Insect Science 2009年第3期16卷 277-285页

作者： Yu Cheng Zhu quentin q. fang USDA-ARS-JWDSRC Stoneville MS 38776 Department of Biology Georgia Southern University Statesboro GA 30460 USA

Several species of Aphelinus have been introduced to the US from the Old World for biological control of the Russian wheat aphid, Diuraphis noxia （Modvilko）. Reproductive incompatibility has been observed among populations collected from different geographic areas. We examined whether or not the reproductive incompatibility between strains of A. asychis was caused by distant phylogenetic relationships. Ribosomal DNA sequences of internal transcribed spacers 2 （ITS2） were analyzed in several species of Aphelinus collected from multiple sites of Europe and Asia. Yhe phylogenetic analysis showed that strains within the species A. albipodus and A. asychis are not monophyletic, and two clearly divergent clades were revealed among sequenced samples. Our results suggest that the reproductive incompatibility between three exotic strains ofA. asychis was more likely caused by divergence of phylogeny than by symbiotic bacteria.

关键词： Aphelinus Aphidius ITS molecular systematics phylogeny rDNA

Stability analyses of the mass abrasive projectile high-speed penetrating into a concrete target Part III: Terminal ballistic trajectory analyses

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Acta Mechanica Sinica 2015年第4期31卷 558-569页

作者： H.Wu X.W.Chen q.fang X.Z.Kong L.L.He Institute of Systems Engineering China Academy of Engineering Physics State Key Laboratory for Disaster Prevention & Mitigation of Explosion & Impact PLA University of Science and Technology

During the high-speed penetration of projectiles into concrete targets （the impact velocity ranges from 1.0 to 1.5 km/s）, important factors such as the incident oblique and attacking angles, as well as the asymmetric abrasions of the projectile nose induced by the target-projectile interactions, may lead to obvious deviation of the terminal ballistic tra- jectory and reduction of the penetration efficiency. Based on the engineering model for the mass loss and nose-blunting of ogive-nosed projectiles established, by using the Differ- ential Area Force Law （DAFL） method and semi-empirical resistance function, a finite differential approach was pro- grammed （PENTRA2D） for predicting the terminal ballistic trajectory of mass abrasive high-speed projectiles penetrating into concrete targets. It accounts for the free-surface effects on the drag force acting on the projectile, which are attributed to the oblique and attacking angles, as well as the asymmetric nose abrasion of the projectile. Its validation on the prediction of curvilinear trajectories of non-normal high-speed pene- trators into concrete targets is verified by comparison with available test data. Relevant parametric influential analyses show that the most influential factor for the stability of ter- minal ballistic trajectories is the attacking angle, followed by the oblique angle, the discrepancy of asymmetric nose abrasion, and the location of mass center of projectile. The terminal ballistic trajectory deviations are aggravated as the above four parameters increase.

关键词： Projectile Penetration Concrete Massabrasion Terminal ballistic trajectory

Population structure of the Atlantic sand fiddler crab Uca pugilator along the eastern coast of US revealed by molecular data

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Current Zoology 2009年第2期55卷 150-157页

作者： David A. WEESE Denson K. MCLAIN Ann E. PRATT quentin q. fang Department of Biological Sciences Auburn University Department of Biology Georgia Southern University

The Atlantic sand fiddler crab Uca pugilator is an extremely abundant crab found along the eastern coast of the United States. Fiddler crabs have a life cycle with an obligatory planktonic larval phase of 30-90 days,which might be expected to lead to widespread larval dispersal and consequent genetic homogeneity over considerable distances. However,a large amount of morphological and behavioral variation is found between northern and southern populations along the eastern coast. This study was undertaken to determine the population genetic structure of *** and to determine whether these differences may have a genetic basis. The population structure of the fiddler crab was analyzed using 472 individuals collected from 12 sites along the eastern coast. PCR-based single stand conformation polymorphism (SSCP) was used to investigate between-site variation in the mitochondrial 16S rRNA gene of these individuals. Analysis of genetic variation indicated frequent gene flow between nearby localities,but much reduced levels between populations separated by larger geographic distances. Thus,despite the potential for high dispersal by planktonic larvae,population differentiation and isolation by distance is evident between northern and southern populations of ***. A high amount of genetic differentiation (F ST =0.3468) was found between northern and southern regions suggesting that the morphological and behavioral differences between these two regions have a genetic basis and may represent subspecies.

关键词： Atlantic sand fiddler crab Uca pugilator Deeapoda Molecular population genetics Gene flow SSCP 16S rDNA

INTERMOLECULAR INTERACTIONS IN A CONDUCTING COBALTOCENIUM SALT OF A NICKEL-DMIT COMPLEX

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INTERMOLECULAR INTERACTIONS IN A CONDUCTING COBALTOCENIUM SA...

Synthesis　and　Biological　Evaluation　of　Substituted　3＇－N－Benzoyl　Taxol　Analogs

Sixteenth Congress of the International Union of Crystallography

作者： q.fang J.H.Cai Institute of Crystal Materials Shandong Univ Fuzhou Lab.of Structure Chemistry Chinese Academy of Sciences

Zx[M(dait)](Hzdmit=4,5-diaercapto-l,3-dithiole-2- thione ) is known for its electrical conductivity or *** anionic interaction,indicated by S---S distances shorter than the Van der Waals separation 3.70A,significantly affects the conducting ability of this kind of *** views of(010),(001) of our synthesized conducting coaplex[Co(CH)z][Ni(dmit)z]are as follows:

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来源： cnki会议评论

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Chinese Chemical Letters 1996年第11期7卷 984-986页

作者： Yue, q.fang, qC Liang, XT BEIJING UNION MED COLL BEIJINGPEOPLES R CHINA CHINESE ACAD MED SCI INST MAT MEDBEIJING 100050PEOPLES R CHINA

A series of subshtuted 3'-N-benzoyl taxol analogs [7a￣i] were synthesized by Schotten-Baumann acylation of the key intermediate, 13-O-[(2'R, 3' S) -3'-phenylisoserinoyl]baccatin Ⅲ[6]. Evaluation of the newly ￣ derivatives for cytotoxicity against KB Cell line revealed that electrondon-donating groups at the para position (such as -CH3, -OCH3, etc.) havepositive effect on achvity, while electron-attracting groups(such as -NO2, -Br, etc.) have negativeeffect. Sterically hindered substituents at the ortho position could dramatically reduce the *** none of the analogs had higher cytotoxicity than taxol.

关键词： Evaluation Substituted Biological and Analogs Benzoyl

TAXAYUNTIN G:A NEW TAXOID FROM TAXUS YUNNANENSIS

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Chinese Chemical Letters 1995年第3期6卷 225-228页

作者： Yue, q.fang, qC Liang, XT Chinese Acad Med Sci Inst Mat Med Beijing 100050 Peoples R China Beijing Union Med Coll Beijing 100050 Peoples R China

A new taxoid, taxayuntin G, was isolated from the leaves and stems of Taxus yunnanensis. Its structure was elucidated by spectroscopic methods(MS, H-1-NMR, C-13-NMR, H-1-H-1 COSY, H-1-C-13 COSY, NOE and HMBC).

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Semisynthesis　and　Biological　Evaluation　of　Taxayuntin　13－［N－Benzoyl－（2’R，3’S）－3’－phenylisoserinate］

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Chinese Chemical Letters 1996年第10期7卷 8-8页

作者： Yue, q.fang, qC Liang, XT CHINESE ACAD MED SCI INST MAT MEDBEIJING 100050PEOPLES R CHINA BEIJING UNION MED COLL BEIJING 100050PEOPLES R CHINA

A novel taxol analog with 5/7/6/4 skeleton,taxayuntin 13-[N-benzoyl-(2'R. 3'S)3'phenylisoserinate](8) was semisynthesized with an ED50 of 11.0 μg/ml in cytotoxicity assay against KB cell line.

关键词： and Biological Evaluation Semisynthesis Taxayuntin Benzoyl