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Effect of vanadium carbide on commercial pure aluminum

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International Journal of Minerals,Metallurgy and Materials 2017年第7期24卷 833-841页

作者： hua-ping Sun Jun Wu Tian tang Bo Fan Zheng-hua tang School of Materials Science and Engineering Sichuan University Chengdu 610065 China

The effect of vanadium carbide（VC） on the grain size of commercial pure aluminum was experimentally investigated by varying the content of VC, the holding time, and casting temperature. The refining efficiencies of VC and Al5Ti1 B were also compared. The refined samples of commercial pure aluminum were examined using optical microscopy, scanning electron microscopy（SEM） and energy-dispersive spectroscopy（EDS）. The results suggest that VC is a good refiner of commercial pure aluminum. The addition of only 0.3wt% VC can decrease the grain size of aluminum to 102 μm, whereas the casting temperature and holding time have little effect on the grain size. The refining efficiency of VC is better than that of Al5Ti1 B. The VC particles in molten aluminum act as nuclei and the grain refinement of aluminum alloys by VC particles is achieved via heterogeneous nucleation.

关键词： grain refinement vanadium carbide heterogeneous nucleation aluminum

Optical propagation through non-Kolmogorov turbulence

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Science China(Information Sciences) 2013年第4期56卷 69-74页

作者： tang hua OU BaoLin School of Electronic and Information Engineering Beihang University

In this paper,the effects of the generalized exponent,the height and the zenith angle on the log-amplitude variance in the weak fluctuation are *** theoretical results indicate that for the downlink,the log-amplitude variance of the Kolmogorov model is always smaller than that of the three-layer model,while for the uplink,there is a point of intersection in the log-amplitude variance curves of the two *** different phenomena for the downlink and uplink are analyzed in ***,we find a method to ascertain precise values of the boundary layer altitudes for the three-layer model under various atmospheric conditions through the analysis for the point of *** at the point of intersection,the Kolmogorov model can be used to replace the three-layer model to simplify the analysis of the system ***,the log-amplitude variance increases with the increase of the zenith angle.

关键词： atmospheric turbulence three-layer model log-amplitude variance power spectral density generalized exponent

Effects of hot compression deformation temperature on the microstructure and properties of Al–Zr–La alloys

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International Journal of Minerals,Metallurgy and Materials 2018年第2期25卷 236-243页

作者： Xian-hua Yue Chun-fang Liu Hui-hua Liu Su-fen Xiao Zheng-hua tang Tian tang College of Materials Science and Engineering Sichuan University TBEA Deyang Cable Stock Co. Ltd.

The main goal of this study is to investigate the microstructure and electrical properties of Al–Zr–La alloys under different hot compression deformation temperatures. In particular, a Gleeble 3500 thermal simulator was used to carry out multi-pass hot compression tests. For five-pass hot compression deformation, the last-pass deformation temperatures were 240, 260, 300, 340, 380, and 420°C, respectively, where the first-pass deformation temperature was 460°C. The experimental results indicated that increasing the hot compression deformation temperature with each pass resulted in improved electrical conductivity of the alloy. Consequently, the flow stress was reduced after deformation of the samples subjected to the same number of passes. In addition, the dislocation density gradually decreased and the grain size increased after hot compression deformation. Furthermore, the dynamic recrystallization behavior was effectively suppressed during the hot compression process because spherical Al;Zr precipitates pinned the dislocation movement effectively and prevented grain boundary sliding.

关键词： microstructure Al–Zr–La alloys hot compression deformation dislocation

Synthesis of a novel calix[4]arene-based fluorescent ionophore and its metal ions recognition properties

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Chinese Chemical Letters 2009年第1期20卷 13-16页

作者： Qiang Peng Xing hua tang College of Environmental and Chemical Engineering Nanchang Hangkong University Nanchang 330063 People's Republic of China

A novel fluorescent ionophore derived from calix[4]arene and pyrazoline was designed and *** molecular structure was confirmed by ^1H NMR and element *** resulting material shows specific fluorescent behavior toward the Zn^2＋ion among the other divalent metal ions,such as Co^2＋,Ni^2＋,Cu^2＋.The primary results indicate this ionophore material is a potential material for developing efficient fluorescent Zn^2＋ chemosensors.

关键词： Calixarene Pyrazoline Recognition Metal ions

Average Capacity of OAM-Multiplexed FSO System with Vortex Beam Propagating Through Non-Kolmogorov Turbulence

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China Communications 2016年第10期13卷 153-159页

作者： hua tang Wei Xu Guohua Wu School of Electronics and Information Engineering Beihang University Schoolof Electronic Engineering Beijing University of Posts and Telecommunications

The propagation of vortex beam in atmospheric turbulence is of significant importance in theoretical study and practical applications. Based on extended Huygens-Fresnel integral and the Rytov approximation, the average capacity of orbital angular momentum(OAM)-multiplexed Laguerre-Gaussian(LG) beam propagating through non-Kolmogorov turbulence is presented, and the analytical expression of spiral spectrum of LG beam has been deduced. The average capacity of FSO system is numerically calculated and the influence of exponent parameter, transmission height, structure constant, wavelength, outer scale and inner scale on average capacity are also analyzed in detail. Outcomes show that smaller structure constant, outer scale, higher transmission height and larger wavelength, inner scale are conducive to improve average capacity in different extent. Results acquires in this paper have potential application value in optical communication within non-Kolmogorov turbulence.

关键词： laguerre-gaussian beam non-kolmogorov turbulence multiple topological charges average capacity

Homoclinic Solutions for a Class of Second Order Discrete Hamiltonian Systems

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Acta Mathematica Sinica,English Series 2012年第3期28卷 609-622页

作者： Xian hua tang Xiao Yan LIN School of Mathematical Sciences and Computing Technology Central South University Department of Mathematics Huaihua College

Consider the second order discrete Hamiltonian systems

关键词： Homoclinic solution discrete Hamiltonian system critical point

Advances and challenges in quantitative delineation of the genetic architecture of complex traits

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Quantitative Biology 2021年第2期9卷 168-184页

作者： hua tang Zihuai He Department of Genetics Stanford UniversityStanfordCA 94305USA Department of Neurology and Neurological Sciences Stanford UniversityStanfordCA 94305USA Quantitative Sciences Unit Department of MedicineStanford UniversityStanfordCA 94305USA

Background:Genome-wide association studies(GWAS)have been widely adopted in studies of human complex traits and ***:This review surveys areas of active research:quantifying and partitioning trait heritability,fine mapping functional variants and integrative analysis,genetic risk prediction of phenotypes,and the analysis of sequencing studies that have identified millions of rare *** challenges and opportunities are ***:GWAS have fundamentally transformed the field of human complex trait *** statistical and computational methods have expanded the scope of GWAS and have provided valuable insights on the genetic architecture underlying complex phenotypes.

关键词： genome-wide association study heritability rare variants biobank colocalization eQTL polygenic risk scores transcriptome-wide association study

Complex interactions between microRNAs and hepatitis B/C viruses

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World Journal of Gastroenterology 2014年第37期20卷 13477-13492页

作者： Hong-Xia Fan hua tang Tianjin Life Science Research Center and Department of Microbiology School of Basic Medical SciencesTianjin Medical University

MicroRNAs(miRNAs) are a class of small noncoding RNAs that post-transcriptionally regulate the expression of many target genes via mRNA degradation or translation inhibition. Many studies have shown that miRNAs are involved in the modulation of gene expression and replication of hepatitis B virus(HBV) and hepatitis C virus(HCV) and play a pivotal role in host-virus interactions. Increasing evidence also demonstrates that viral infection leads to alteration of the miRNA expression profile in hepatic tissues or circulation. The deregulated miRNAs participate in hepatocellular carcinoma(HCC)initiation and progression by functioning as oncogenes or tumor suppressor genes by targeting various genes involved in cancer-related signaling pathways. The distinct expression pattern of miRNAs may be a useful marker for the diagnosis and prognosis of virus-related diseases considering the limitation of currently used biomarkers. Moreover, the role of deregulated miRNA in host-virus interactions and HCC development suggested that miRNAs may serve as therapeutic targets or astools. In this review, we summarize the recent findings about the deregulation and the role of miRNAs during HBV/HCV infection and HCC development, and we discuss the possible mechanism of action of miRNAs in the pathogenesis of virus-related diseases. Furthermore, we discuss the potential of using miRNAs as markers for diagnosis and prognosis as well as therapeutic targets and drugs.

关键词： MicroRNA Hepatitis B/C virus Host-virus interaction Biomarker Therapy

SNMS: an intelligent transportation system network architecture based on WSN and P2P network

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The Journal of China Universities of Posts and Telecommunications 2007年第1期14卷 65-70页

作者： LI Li LIU Yuan-an tang Bi-hua Wireless Center Beijing University of posts and TelecommunicationsBeijing 100876 China

With the development of city road networks, the question of how to obtain information about the roads is becoming more and more important. In this article, sensor network with mobile station （SNMS）, a novel two-tiered intelligent transportation system （ITS） network architecture based on wireless sensor network （WSN） and peer-to-peer （P2P） network, is proposed to provide significant traffic information about the road and thereby, assist travelers to take optimum decisions when they are driving. A detailed explanation with regard to the strategy of each level as well as the design of two main components in the network, sensor unit （SU） and mobile station （MS）, is presented. Finally, a representative scenario is described to display the operation of the system.

关键词： SNMS WSN P2E SU MS