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Geochemistry of the high-Mg andesites at Zhangwu, western Liaoning: Implication for delamination of newly formed lower crust

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Science china Earth Sciences 2007年第12期50卷 1773-1786页

作者： HUANG Hua1,GAO Shan1,2,HU ZhaoChu1,LIU xiaoMing2 & YUAN HongLing2 1 state key laboratory of Geological Processes and Mineral Resources,china university of Geosciences,Wuhan 430074,china 2.state key laboratory of Continental Dynamics,Department of Geology,Northwest university,xi’an 710069,china 1. state key laboratory of Geological Processes and Mineral Resources China University of Geosciences Wuhan 430074 China 2. state key laboratory of Continental Dynamics Department of Geology Northwest University Xi’an 710069 China

Ten volcanic samples at Zhangwu,western Liaoning Province,North china were selected for a sys-tematic geochemical,mineralogical and geochronological study,which provides an opportunity to ex-plore the interaction between the continental crust and mantle beneath the north margin of the North china *** one basalt sample(SiO2= 50.23%),the other nine samples are andesitic with SiO2 contents ranging from 53% to 59%.They have relatively high MgO(3.4%―6.1%,Mg#=50―64) and Ni and Cr contents(Ni 27×10?6―197×10?6,Cr 51×10?6―478×10?6).Other geochemical characteristics of Zhangwu high-Mg andesites(HMAs) include strong fractionation of light rare earth elements(LREE) from heavy rare earth elements(HREE),and Sr from Y,with La/Yb greater than 15,and high Sr/Y(34― 115).Zircons of andesite YX270 yield three age groups with no Precambrian age,which precludes ori-gin of the Zhangwu HMAs from the partial melting of the Precambrian *** oldest age group peaking at 253 Ma is interpreted to represent the collision of the Siberia block and the North china block,resulting in formation of the Central Asian orogenic belt by closure of the Mongol-Okhotsk *** intermediate age group corresponds to the basalt underplating which caused the wide-spread coeval granitoids in the North china craton with a peak 206Pb/238U age of 172 *** youngest age group gives a 206Pb/238U age of 126±2 Ma,which is interpreted as the eruption age of the Zhangwu *** high 87Sr/86Sri(126 Ma)>0.706 and low εNd(t)= ?6.36―?13.99 of the Zhangwu HMAs are distinct from slab *** common presence of reversely zoned clinopyroxene phenocrysts in the Zhangwu HMAs argues against the origin of the Zhangwu HMAs either from melting of the water saturated mantle or melting of the lower *** light of the evidence mentioned above,the envisaged scenario for the formation of the Zhangwu HMAs is related to the basaltic underplating at the base of the crust,which led to the thickening of the lower crust and

关键词： Zhangwu HMAs, basalt underplating, newly formed lower crust, delamination, North china craton

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An e-quality control model for multistage machining processes of workpieces

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Science china(Technological Sciences) 2008年第12期51卷 2168-2184页

作者： LIU DaoYu,JIANG PingYu & ZHANG YingFeng state key laboratory for Manufacturing Systems Engineering,xi’an Jiaotong university,xi’an 710049,china state key laboratory for Manufacturing Systems Engineering Xi’an Jiaotong University Xi’an 710049 China

To track and control the changes of process quality attributes in multistage machining processes(MMPs),an e-quality control(e-QC) model is *** e-QC model is defined as a quality information service node with e-formalizing technology,whose input/output and intermediate process(that is IPO) are known to other nodes,and its implemention in MMPs is *** order to establish the e-QC model,a measuring network is constructed to acquire the original quality data,and the changes of process quality attributes are monitored and diagnosed by the integrated quality analysis tools attached to the e-QC,which can be tracked by information template network in real ***,a hierarchical control method is adopted to coordinate e-QCs,in which the quality loss and adjusting cost are used to quantify the opportunities for e-QCs to improve process *** last,a prototype is developed to verify the proposed methods.

关键词： machining process flow e-quality control model measuring network information template quality information tracking hierarchical control

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A New Watermarking Protocol against Conspiracy

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Wuhan university Journal of Natural Sciences 2006年第6期11卷 1671-1674页

作者： ZHANG Jun KOU Weidong FAN Kai CAO Xuefei state key laboratory of integrated Service networks Xidian University Xi＇an 710071 Shaanxi China

A trusted third party introduced in watermarking protocols would decrease the security and affect the implementation of the protocols. In this paper, a new watermarking protocol with an un-trusted third party （UTTP） was proposed. Based on the idea of all-or-nothing disclosure of secret （ANDOS）, all of the buyer, the seller and the third party didn＇t know the exact watermark, which was embedded in a digital content for tracing piracy. The proposed protocol provided mechanisms to trace piracy and protect customer＇s right. In addition, the problem that a seller colluded with UTTP to frame the buyer, namely, the conspiracy problem, could be avoided.

关键词： watermarking protocol electronic commerce security digital copyright protection conspiracy problem

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Ultralight X-type lattice sandwich structure (Ⅱ):Micromechanics modeling and finite element analysis

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Science china(Technological Sciences) 2009年第9期52卷 2670-2680页

作者： ZHANG QianCheng1,CHEN AiPing 2,CHEN ChangQing2,3 & LU TianJian2 1 state key laboratory for Mechanical Behavior of Materials,School of Material Science and Engineering,xi’an Jiaotong university,xi’an 710049,china 2 MOE key laboratory for Strength and Vibration,School of Aerospace,xi’an Jiaotong university,xi’an 710049,china 3 Department of Engineering Mechanics,AML,Tsinghua university,Beijing 100084,china state key laboratory for Mechanical Behavior of Materials School of Material Science and Engineering Xi’an Jiaotong University Xi’an China MOE key laboratory for Strength and Vibration School of Aerospace Xi’an Jiaotong University Xi’an China Department of Engineering Mechanics AML Tsinghua University Beijing China

The methods of homogenization and finite elements are employed to predict the effective elastic constants and stress-strain responses of a new type of lattice structure,the X-structure proposed by the authors in a companion paper. It is shown that in most cases the predictions by the equivalent homogenization theory agree well with the experimental and 3-dimensional finite element calculated results. The theoretical and numerical study supports the argument that the X-structure is superior to the pyramid lattice structure in terms of mechanical strength.

关键词： sandwich panel lattice structure equivalent homogenization finite element model

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Transmutation Scheme of Coin Flipping Protocol and Utilization

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Wuhan university Journal of Natural Sciences 2006年第6期11卷 1911-1914页

作者： xiE Yumin MING Yang SHI Feng MUHAMMAD Kamran Department of Computer Science and Engineering Beijing Institute of Technology Beijing 100081 China state key laboratory of integrated Service networks Xidian University Xi＇an 710071 Shaanxi China

Coin flipping by telephone protocol（CFP） is utilized in a system to exchange a binary sequence at random between two person apart far from each other. However, CFP cannot he used in a system with many users like in a group environment system. A transmutation of CFP named T-CFP is proposed in this paper. The precondition of T-CFP is the system＇s user trusts the system center and center＇s cheating is meaningless at the same time. The significant difference between CFP and T-CFP is that CFP supports only two users while T-CFP can support many users to exchange special information. The security and efficiency of T-CFP are discussed with a detailed example on T-CFP utilization is demonstrated in this paper.

关键词： coin flipping protocol transmutation-coin flipping protocol one way function Blum

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Multistage evolution of continental collision orogen:A case study for western Dabie orogen

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Chinese Science Bulletin 2009年第15期54卷 2568-2579页

作者： WU YuanBao state key laboratory of Geological Processes and Mineral Resources, Faculty of Earth Sciences, china university of Geosciences, Wuhan 430074, china state key laboratory of Continental Dynamics, Department of Geology, Northwest university, xi’an 710069, china state key laboratory of Geological Processes and Mineral Resources Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China state key laboratory of Continental Dynamics Department of Geology Northwest University Xi’an 710069 China

The foramtion and evolution of collisional orogen is a prominent feature along convergent plate margins, and is generally a complex process. This article presents an integrated study of zircon genesis, U-Pb age and Lu-Hf isotope composition as well as geological characteristics for the western Dabie orogen to constrain its multi-stage evolution history. The results suggest that the formation of oceanic crust in the Huwan area was constrained at ca. 400―430 Ma, which was slightly later than the collision of the northern Qinling with the North china Block. It formed in a marginal basin in the northern margin of the Yangtze Block. The peak metamorphism of eclogite in the Huwan area occurred at ca. 310 Ma, and the timing of the initial exhumation of oceanic eclogite was about 270 Ma. The high to ultrahigh pressure (HP-UHP) metamorphic rocks in the xinxian and the Hong'an metamorphic zones have the same ages and natures as those of the HP-UHP metamorphic rocks in the other Dabie-Sulu terrains, and also have experienced multi-stage exhumation, and thus can be taken as a coherent part of the Dabie-Sulu orogen. Therefore, the Qinling-Dabie-Sulu orogen is a typical multi-stage continental collision orogen, with an amalgamation process extending more than 200 Ma.

关键词：大别造山带大陆碰撞西部演变超高压变质岩碰撞造山带苏鲁造山带变质岩区

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Properties Evolution of a Powder Metallurgical Titanium Alloy with Yttrium Addition

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稀有金属材料与工程 2011年第S3期40卷 298-300页

作者： Liu Haiyan1, Tang Huiping1, He Weiwei1, Liu Yanbin2, Jia Wenpeng1, Liu Yong2 1state key laboratory for Porous Metals Materials, Northwest Institute for Nonferrous Metal Research, xi′an 710016, china 2.state key laboratory for Powder Metallurgy, Central South university, Changsha 410083, china NW Inst Nonferrous Met Res State Key Lab Porous Met Mat Xian 710016 Peoples R China Cent S Univ State Key Lab Powder Met Changsha 410083 Hunan Peoples R China

P/M Ti-Fe-Mo-Y alloys with different Rare-earth Y Content are prepared by blend element method, its sintering and hot deformation behaviors are studied together with microstructure and mechanical properties. The microstructures and properties of the alloying titanium were testified by the analysis of Optical microscopy (OM), X-ray diffraction (XRD), scanning electron microscopy (SEM).The result indicated that Y element absorbs free oxygen and purify the Ti powder surface, promoting densification process. With appropriate vacuum and temperature, the blend element metal powder sintering relative density can reach more than 97%. Microstructure and mechanical properties analysis shown that Y element composed Y2O3 particles which refine grains and improve plasticity, elevate alloy distortion ability. After hot deformation, grains crashed and flow line appears, the mechanical properties of Ti-Fe-Mo-Y alloy prompted which also validated by large amount of dimples appear in tensile fracture surface.

关键词： P/M Ti-Fe-Mo-Y alloy blend element method hot deformation

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围长为8的QC-LDPC码的显式构造及其在CRT方法中的应用

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通信学报 2012年第3期33卷 171-176页

作者：张国华孙蓉王新梅西安电子科技大学综合业务网理论及关键技术国家重点实验室陕西西安710071

对于任意码长PL(P≥3L2/4+L 1),利用完全确定的方式构造出一类围长为8的(4,L)QC-LDPC码。将这类码作为分量码,结合中国剩余定理(CRT)构造出一类围长至少为8且码长非常灵活的合成QC-LDPC码。在1/2码率和中等码长条件下的仿真结果表明,这... 详细信息

对于任意码长PL(P≥3L2/4+L 1),利用完全确定的方式构造出一类围长为8的(4,L)QC-LDPC码。将这类码作为分量码,结合中国剩余定理(CRT)构造出一类围长至少为8且码长非常灵活的合成QC-LDPC码。在1/2码率和中等码长条件下的仿真结果表明,这种合成码在AWGN信道下具有优异的性能。

关键词：准循环低密度奇偶校验码围长显式构造中国剩余定理

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Thermoelastic properties of sandwich materials with pin-reinforced foam cores

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Science china(Technological Sciences) 2008年第12期51卷 2059-2074页

作者： LU TianJian1,LIU Tao2,3 & DENG ZiChen2,4 1 MOE key laboratory of Strength and Vibration,School of Aerospace,xi’an Jiaotong university,xi’an 710049,china 2 Department of Engineering Mechanics,Northwestern Polytechnical university,xi’an 710072,china 3 Department of Engineering,university of Cambridge,Cambridge CB2 1PZ,UK 4 state key laboratory of Structural Analysis of Industrial Equipment,Dalian university of Technology,Dalian 116024,china MOE key laboratory of Strength and Vibration School of Aerospace Xi’an Jiaotong University Xi’an 710049 China Department of Engineering Mechanics Northwestern Polytechnical University Xi’an 710072 China Department of Engineering University of Cambridge Cambridge CB2 1PZ UK state key laboratory of Structural Analysis of Industrial Equipment Dalian University of Technology Dalian 116024 China

Pin-reinforced foam is a novel type of sandwich core materials formed by inserting pins(trusses) into a foam matrix to create a truss-like network reinforced foam *** loading,the pins deform predominantly by local stretching whilst the deformation of foam is governed by local *** paper presents a theoretical study on the thermoelasticity of pin-reinforced foam sandwich *** calculate the effective thermoelastic properties of pin-reinforced foam cores,the energy-based homogenization approach is employed to develop a micromechanics-based model,calibrated by the existing experimental *** is found that the stiffness of the sandwich core is mainly governed by pin reinforcements:the foam matrix contributes little to sandwich *** with traditional foam cores without pin reinforcements,the changes in inplane thermal expansion coefficients are not vigorous as a result of pin reinforcements,while the through-thickness thermal expansion coefficient changes *** is also demonstrated that it is possible to design materials with zero or negative thermal expansion coefficients under such a context.

关键词： sandwich panel pin reinforcement analytical solutions homogenization thermoelasticity thermal expansion

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Effect of Heat Treatment on the Microwave Electromagnetic Properties of Carbonyl Iron/Epoxy-Silicone Resin Coatings

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Journal of Materials Science & Technology 2010年第11期26卷 1011-1015页

作者： Yuchang Qing,Wancheng Zhou,Shu Jia,Fa Luo and Dongmei Zhu state key laboratory of Solidification Processing,Northwestern Polytechnical university,xi an 710072,china [a] state key laboratory of Solidification Processing Northwestern Polytechnical university xi'an 710072 china

Microwave absorbing properties of the carbonyl iron particles filled epoxy-silicone resin coatings showed visible degression when the coatings were heat treated at 300 ℃ with different *** complex permittivity and permeability of the coatings before and after heat treatment were *** heat treatment at 300 ℃,the real part of permittivity of the coatings increased with increasing treatment time and showed frequency dependence dielectric *** complex permeability showed remarkable variation while the resonance frequency of the coatings heat treated at 300 ℃ shifted from 7 to 12 *** electromagnetic results indicated that microwave absorbing properties of the coatings showed more dependent on the complex *** results showed that the difference of the electromagnetic and microwave absorbing properties before and after heat treatment was mainly attributed to the crystalline state transition of carbonyl iron particles.

关键词： Microwave absorption Dielectric properties Magnetic properties Heat treatment

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