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Effect of milling process on the core-shell structures and dielectric properties of fine-grained BaTiO_3-based X7R ceramic materials

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International Journal of Minerals,Metallurgy and Materials 2009年第3期16卷 345-348页

作者： Tian wang xiao-hui wang Hai Wen Long-tu Li State Key Laboratory of New Ceramics and Fine Processing Department of Materials Science and Engineering Tsinghua University Beijing 100084 China

Fine-grained BaTiO3-based X7R ceramic materials were prepared and the effects of milling process on the core-shell structures and dielectric properties were investigated using scanning electron microscope, transmission electron microscope, and energy dispersive spectroscopy （EDS）. As the milling time extends, the dielectric constant of the ceramics increases, whereas the temperature coefficient of capacitance at 125℃ drops quickly. The changes in dielectric properties are considered relevant to the microstructure evolution caused by the milling process. Defects on the surface of BaTiO3 particles increase because of the effects of milling process, which will make it easier for additives to diffuse into the interior grains. As the milling time increases, the shell region gets thicker and the core region gets smaller; however, EDS results show that the chemical inhomogeneity between grain core and grain shell becomes weaker.

关键词： fine-grain barium titanate core-shell structure milling process microstructure capacitor

Exploiting the Community Structure of Fraudulent Keywords for Fraud Detection in Web Search

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Journal of Computer Science & Technology 2021年第5期36卷 1167-1183页

作者： Dong-hui Yang Zhen-Yu Li xiao-hui wang Kavé Salamatian Gao-Gang Xie Network Technology Research Center Institute of Computing TechnologyChinese Academy of Sciences Beijing 100190China University of Chinese Academy of Sciences Beijing 100049China Global Energy Interconnection Research Institute Co. Ltd.Beijing 102209China LISTIC Laboratory of Computer Science SystemsInformation and Knowledge ProcessingUniversitéSavoie Mont BlancChambéry 73011France Computer Network Information Center Chinese Academy of SciencesBeijing 100190China

Internet users heavily rely on web search engines for their intended *** major revenue of search engines is advertisements(or ads).However,the search advertising suffers from *** generate fake traffic which does not reach the intended audience,and increases the cost of the ***,it is critical to detect fraud in web *** studies solve this problem through fraudster detection(especially bots)by leveraging fraudsters'unique ***,they may fail to detect new means of fraud,such as crowdsourcing fraud,since crowd workers behave in part like normal *** this end,this paper proposes an approach to detecting fraud in web search from the perspective of fraudulent *** begin by using a unique dataset of 150 million web search logs to examine the discriminating features of fraudulent ***,we model the temporal correlation of fraudulent keywords as a graph,which reveals a very well-connected community ***,we design DFW(detection of fraudulent keywords)that mines the temporal correlations between candidate fraudulent keywords and a given list of *** particular,DFW leverages several refinements to filter out non-fraudulent keywords that co-occur with seeds *** evaluation using the search logs shows that DFW achieves high fraud detection precision(99%)and accuracy(93%).A further analysis reveals several typical temporal evolution patterns of fraudulent keywords and the co-existence of both bots and crowd workers as fraudsters for web search fraud.

关键词： community structure fraud analysis fraudulent keyword detection web search

Immune Responses to Trichloroethylene and Skin Gene Expression Profiles in Sprague Dawley Rats

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Biomedical and Environmental Sciences 2006年第5期19卷 346-352页

作者： xiao-YAN CHEN ZHI-XIONG ZHUANG xiao-hui wang JIN-ZHOU ZHANG Shenzhen Futian People＇s Hospital Shenzhen 518033 Guangdong China Shenzhen Control and Prevention Shenzhen 518020 Guangdong China

Objective To characterize the immune reaction in SD rats exposed to trichloroethylene （TCE） and to identify the gene expression profiles involved in skin after TCE exposure. Methods Fifteen percent of TCE was injected intradermally into the rat back （100 μL/120 g） at intervals of 7 days. Whole blood was collected 24 h after the fifth or seventh intradermic administration of TCE. The percentages of CD4＋ and CD8＋ of T lymphocytes were measured by a flow cytometer. The concentrations of IFN-gamma and 1L-4 in the serum were semi-quantified by ELISA. Total RNAs of skin samples at 3 h or 24 h after the seventh dose of TCE in SD rats were extracted, and gene expression proftles of these tissues were analyszed by rat toxicology U34 array of Affymetrix. Results Obvious decline of CD4＋ in T lymphocytes was observed in the TCE-administer group. No significant concentration differences in IFN-gamma and IL-4 were found between TCE-treated and control rats. Gadd45a and Mel were significantly up regulated in skin tissue 24 h after TCE exposure. The expression regulation of immune response factors was as active as proteins associated with lipid metabolism and synthesis process in these skin samples of SD rats exposed to TCE. Conclusion T-helper type 1 cells mediate immune response can not be elicited in TCE-treated SD rats, but certain immune disorder can be induced.

关键词： Trichloroethylene SD rat CD4+/CD8+ IFN-gamma IL-4 Gene expression profiles

Effect of deformation parameters in unrecrystallization range on microstructural characteristics in Al-bearing hot-rolled TRIP steel

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Journal of Iron and Steel Research International 2019年第12期26卷 1329-1339页

作者： xiao-hui wang Jian Kang Yun-jie Li Guo Yuan RDKMisra Guo-dong wang State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang 110819LiaoningChina Laboratory for Excellence in Advanced Steel Research Department of MetallurgicalMaterials and Biomedical EngineeringUniversity of Texas at El PasoEl PasoTX 79968USA

The scanning electron microscope,transmission electron microscope,optical microscope,X-ray diffraction and hardness tests were used to investigate the effect of deformation parameters in unrecrystallization range on microstructural characteristics in Al-bearing hot-rolled transformation-induced plasticity *** thermomechanical-controlled processing was carried out with thermomechanical simulation machine,and the samples were compressed to compression strains of 0,0.15,0.25 and 0.35 at compression temperatures of 850,900 and 950°*** results showed that the volume fraction of polygonal ferrite increased with the increasing compression strain,while the volume fraction of retained austenite reached the maximum value at compression strain of *** volume fraction of polygonal ferrite decreased with the increasing compression temperature,whereas the volume fraction of retained austenite possessed the maximum value at compression temperature of 850°*** granular retained austenite was present in uncompressed samples,and some pearlite appeared at large compression strain,while the hardness of the samples exhibited the similar variation tendency to the volume fraction of retained austenite.

关键词： Hot-rolled TRIP steel Deformation parameter Compression strain Compression temperature Microstructural characteristic

Flat Currents of Green-Schwarz Superstring in AdS2 × S^2 Background

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Communications in Theoretical Physics 2006年第4期45卷 663-668页

作者： wang xiao-hui wang Zhan-Yun CAI xiao-Lin SONG Pei HOU Bo-Yu SHI Kang-Jie Institute of Modern Physics Northwest University Xi＇an 710069 China

From the κ symmetric action of IIB string in AdS2 × S^2 background given by Zhou, we derive the equations of motion. By using the twisted dual transformation which was introduced by Hou, we construct the flat curren... 详细信息

关键词： Green-Schwarz superstring integrability AdS2 × S^2

Effect of irradiation on temperature performance of dispersioncompensation no-core cascade optical-fiber sensor coated with polydimethylsiloxane film

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Nuclear Science and Techniques 2022年第9期33卷 10-20页

作者： Fang wang Qiu-Feng Wu Yu-Rong Jiang Chan Jin xiao-hui wang Ben-Shang Zhang Chun-wang Ma College of Electronic and Electrical Engineering Henan Normal UniversityXinxiang 453007China Key Laboratory of Optoelectronic Sensing Integrated Application of Henan Province Xinxiang 453007China School of Physics Henan Normal UniversityXinxiang 453007China Engineering Laboratory of Intelligent Additive Manufacturing of Henan Province Xinxiang 453007China Key Laboratory of Interfacial Physics Technology Project Chinese Academy of SciencesShanghai 201800China Institute of Isotope Research Henan Academy of SciencesZhengzhou 450000China

A temperature measurement device can produce data deviations and can even be damaged in a high-dose radiation *** reduce the radiation damage to such a device and improve the temperature measurement accuracy in a radiation environment,a temperature sensor based on optical-fiber sensing technology is *** sensor has a cascade structure composed of a single-mode fiber(SMF),a dispersion-compensation fiber(DCF),a nocore fiber(NCF),and another SMF(SDNS).The DCF and NCF are coated with a polydimethylsiloxane(PDMS)film,which is a heat-sensitive material with high thermal optical and thermal expansion *** experiments,PDMS was found to produce an irradiation crosslinking effect after irradiation,which improved the temperature sensitivity of the SDNS *** experimental results showed that within a range of 30–100℃,the maximum temperature sensitivity after irradiation was 62.86 pm/℃,and the maximum transmission sensitivity after irradiation was 3.353×10^(-2)dB/℃,which were 1.22 times and 2.267 times the values before irradiation,*** addition,repeated temperature experiments verified that the SDNS sensor coated with the PDMS film had excellent temperature ***,it was found that with an increase in the irradiation intensity,the irradiation crosslinking degree of PDMS increased,and the temperature sensitivity of the sensor was *** proposed sensor could potentially be applied to temperature measurement in a nuclear-radiation environment.

关键词： ^(60)Co-γirradiation Optical-fiber sensor Temperature performance PDMS Radiation crosslinking

Investigation of stress corrosion cracking behavior and mechanism analysis of a 1900 MPa-grade ultra-high-strength stainless steel

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Journal of Iron and Steel Research International 2022年第9期29卷 1474-1484页

作者： Shuai Tian Zhen-bao Liu Ren-li Fu xiao-hui wang Jian-xiong Liang School of Materials Science and Technology Nanjing University of Aeronautics and AstronauticsNanjing 210016JiangsuChina Instiute for Special Steel Institute Central Iron and Steel Research InstituteBeijing 100081China

The stress corrosion cracking(SCC)behavior of a 1900 MPa-grade ultra-high-strength stainless steel in 3.5 wt.% NaCl solution was investigated by X-ray diffractometer,scanning electron microscopy,electron back-scattered diffraction,X-ray photoelectron spectroscopy,and potentiodynamic polarization *** results showed that USS122G stel has good SCC resistance,and the critical stress intensiy factor(K_(iscc))of USS122G steel was about 68.906 MPa m^(1/2) and Kiscc/K_(ic)=0.76(K_(ic) is plane strain fracture toughness).The existence of film-like austenite along the lath martensite boundary and the protective effect of thecc passivation flm were the main factors for its high *** them,the main components of the passivation film on the surface of USS122G steel were Cr_(2)O_(3),Cr(OH)_(3),FeOOH,and Ni(OH)_(2).The fracture morphology of SCC zone was intergranular and *** the slow and fast scanning rate polarization curve test results,it can be concluded that SCC mechanism of USS122G steel in 3.5 wt.%NaCl solution at the open-circuit potential was a mixed mechanism involving hydrogen embritlement and anodic dissolution.

关键词： Ultra-high-strength stainless steel.Critical stress intensity factor-Film-like austenite Hydrogen embrittlement Anodic dissolution

Comparative study of mutations in SNP loci of K-RAS, hMLH1 and h MSH2 genes in neoplastic intestinal polyps and colorectal cancer

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World Journal of Gastroenterology 2014年第48期20卷 18338-18345页

作者： Zhi-hui Yan Li-Hong Cui xiao-hui wang Chao Li Xing He Department of Gastroenterology Navy General Hospital of PLA

AIM: To clarify the molecular mechanism involved in pathogenesis of colorectal cancer as well as clinical significance of genetic analysis of histological samples.

关键词： Neoplastic intestinal polyp Colorectal cancer Single nucleotide polymorphisms K-RAS hMLH1 hMSH2

Quantitative estimation of land surface evapotranspiration in Taiwan based on MODIS data

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Water Science and Engineering 2011年第3期4卷 237-245页

作者： Che-sheng ZHAN Jie ZHAO hui-xiao wang Jian YIN Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 P. R. China Beijing Tsinghua Urban Planning and Design Institute Beijing 100085 P R. China Key Laboratory of Water and Sediment Sciences Ministry ofEducation College of Water Sciences Beijing Normal University Beijing 100875 P R. China

Land surface evapotranspiration （ET） determines the local and regional water-heat balances. Accurate estimation of regional surface ET provides a scientific basis for the formulation and implementation of water conservation programs. This study set up a table of the momentum roughness length and zero-plane displacement related with land cover and an empirical relationship between land surface temperature and air temperature. A revised quantitative remote sensing ET model, the SEBS-Taiwan model, was developed. Based on Moderate Resolution Imaging Spectroradiometer （MODIS） data, SEBS-Taiwan was used to simulate and evaluate the typical actual daily ET values in different seasons of 2002 and 2003 in Taiwan. SEBS-Taiwan generally performed well and could accurately simulate the actual daily ET. The simulated daily ET values matched the observed values satisfactorily. The results indicate that the net regional solar radiation, evaporation ratio, and surface ET values for the whole area of Taiwan are larger in summer than in spring, and larger in autumn than in winter. The results also show that the regional average daily ET values of 2002 are a little higher than those of 2003. Through analysis of the ET values from different types of land cover, we found that forest has the largest ET value, while water areas, bare land, and urban areas have the lowest ET values. Generally, the Northern Taiwan Region, including llan County, Nantou County, and Hualien County, has higher ET values, while other cities, such as Chiayi, Taichung, and Tainan, have lower ET values.

关键词： evapotranspiration quantitative remote sensing, MODIS SEBS model, Taiwan