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Effect of Low pH on Forming Process of Desulfurization Gypsum Composite Boards Strengthened by Melamine-formaldehyde Resin
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作者 CAO Lijiu ZHANG Jiyao +4 位作者 WANG Xinqi ZHANG Xinhe HUANG Jian CHEN Yufang JIN Tao 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2024年第5期1223-1228,共6页
Through exploring the effects of low pH on the composite system of desulfurization gypsum(DG)enhanced by melamine-formaldehyde resin(MF),it is found that the inducing of sulfate-ion,in contrast to chloride and oxalate... Through exploring the effects of low pH on the composite system of desulfurization gypsum(DG)enhanced by melamine-formaldehyde resin(MF),it is found that the inducing of sulfate-ion,in contrast to chloride and oxalate ions,favors the longitudinal growth of the crystalline form of the hydration product,which was relatively simple and had the highest length to width(L/D)ratio.At the same time,MF can also improve L/D ratio of gypsum hydration products,which favors the formation of hydrated whiskers.Finally,in a composite system composed of hemihydrate gypsum,MF,and glass fibers,when dilute sulfuric acid was used to regulate pH=3-4,the tight binding formed among the components of the composite system compared to pH=5-6.The hydration product of gypsum adheres tightly to glass fiber surface and produces a good cross-linking and binding effect with MF.The flexural strength,compressive strength,elastic modulus,and water absorption of the desulphurized gypsum composite board is 22.7 MPa,39.8 MPa,5608 MPa,and 1.8%,respectively. 展开更多
关键词 MF-reinforced desulphurized gypsum board composite forming system low pH condition hydration process aspect ratio synergistic effect
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FORMING PROCESS OF HOT-EXTRUDED SiCw/6061Al COMPOSITES(Ⅰ) 被引量:3
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作者 Zhang Wenlong, Cai Liuchun, Peng Huaxin, Wang Dezun and Yao Zhongkai School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, P. R. China 《中国有色金属学会会刊:英文版》 CSCD 1998年第3期77-81,共5页
1INTRODUCTIONInrecentyears,moreandmorecontinuouslyordiscontinuouslyreinforcedmetalmatrixcomposites(MMCs)hav... 1INTRODUCTIONInrecentyears,moreandmorecontinuouslyordiscontinuouslyreinforcedmetalmatrixcomposites(MMCs)havebeenusedtomakest... 展开更多
关键词 SiC WHISKER aluminium MATRIX composite forming of HOT EXTRUSION
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Modeling of the Shape Forming of Composite Roll 被引量:2
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作者 Chengsong CUI, Zhenyu LI, Fuyang CAO and Qingchun LI (School of Materials Science and Engineering, Harbin Institute of Technology, 150001, China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2000年第3期337-340,共4页
A shape modeling of spray formed composite roll, which is utilized to predict the shape and dimension of roll during spray forming process, is developed in this paper. The influences of the principal spray forming par... A shape modeling of spray formed composite roll, which is utilized to predict the shape and dimension of roll during spray forming process, is developed in this paper. The influences of the principal spray forming parameters, such as the spatial distribution of melt mass flux, spray distance, rotating and translating speeds of substrate bar etc. , on the geometry and dimension of spray formed product were investigated. 展开更多
关键词 Modeling of the Shape forming of composite Roll
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Effect of Extrusion Forming on Compressive Strength of Al_(18)B_4O_(33)w/Mg Composites 被引量:2
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作者 Li Zhengjia Li Hejun Qi Lehua Oy Haibo 《稀有金属材料与工程》 SCIE EI CAS CSCD 北大核心 2009年第A03期41-44,共4页
The aluminum borate whisker reinforced magnesium matrix composites (Al18B4O33w/Mg) were fabricated by pressure infiltration technique and extrusion-vacuum infiltration technique respectively to study the effect of ext... The aluminum borate whisker reinforced magnesium matrix composites (Al18B4O33w/Mg) were fabricated by pressure infiltration technique and extrusion-vacuum infiltration technique respectively to study the effect of extrusion forming on their mechanical behaviors. The microstructure of the composites was observed by scanning electron microscopy. The compressive strength was investigated and compared with that of the matrix alloy AZ91D. The results show that the extrusion forming could cause fracture of the whisker, but reduce the holes in the composite during impregnation and improve the interfacial bonding between the whisker and the matrix alloy. Compared with that of the matrix as-cast alloy AZ91D, the compressive strength of Al18B4O33w/Mg by the pressure infiltration technique was increased by 22%, while that of Al18B4O33w/Mg by the extrusion-vacuum infiltration technique was increased by 120 %. 展开更多
关键词 硼酸铝 复合材料 电子显微镜 抗压强度
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Numerical simulation of temperature field in plasma-arc flexible forming of laminated-composite metal sheets 被引量:3
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作者 宋文庆 徐文骥 +2 位作者 王续跃 孟建兵 李洪友 《中国有色金属学会会刊:英文版》 CSCD 2009年第B09期61-67,共7页
Flexible forming of laminated-composite metal sheets (LCMS) using plasma arc is a latest technique, which produces LCMS components by thermal stress without mould and external force. Considering that the controllable ... Flexible forming of laminated-composite metal sheets (LCMS) using plasma arc is a latest technique, which produces LCMS components by thermal stress without mould and external force. Considering that the controllable temperature field is the key during the forming process, a three-layer FEM model, based on the characteristics along LCMS thickness direction, was developed to study the variation rules of temperature field, which was verified robustness by experimental validation. Besides, the influences of process parameters such as plasma arc power, scanning speed and plasma arc diameter on LCMS temperature field were performed. The comparisons of LCMS with single layer metal sheet (SLMS) show the temperature difference of LCMS along thickness direction is smaller than that of SLMS, but the heat-affected zone of LCMS along X axis is wider than that of SLMS under the same process parameters. 展开更多
关键词 电弧温度场 复合金属 弹性夹层 数值模拟 内容管理系统 板成形 血浆 等离子弧
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The Designation Method of Bend Forming Dies for Aluminum Tube of PE-Al-PE Composite Pipe
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作者 LIANG Yan-fei, AN Jun (Mechatronics Department, Foshan University, Foshan 528000, China) 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期159-160,共2页
The PE-Al-PE composite pipe is a multiplayer pipe t hat is composed of PE (polyethylene) and Aluminum. Al is inlayed the inner PE la yer and the outer PE layer. In the producing technological process of this kind of p... The PE-Al-PE composite pipe is a multiplayer pipe t hat is composed of PE (polyethylene) and Aluminum. Al is inlayed the inner PE la yer and the outer PE layer. In the producing technological process of this kind of pipe the bend forming of Al belt to tube is very important. It is the bend fo rming dies that are used in the process of producing PE-Al-PE pipe that is stu died in this article. To make a elaborate division, these dies can be classified as bending dies and forming dies here. In this paper, the designation of bendin g dies and forming dies that are used in producing technological process of PE- Al-PE pipe is put forward. The process starts from a coil of Al belt, in the ac tion of pulling force, passes between several bending dies to change its shape. The first step is to change Al belt to U shape. A couple of rolling wheels can b e used to shape the Al belt. The Al belt goes between the two rolling wheels, dr ives the wheels, at the same time is formed as the shape of the rolling wheels. Considering of the factors such as spring of the bend Al belt, frictional force between Al and the die, bending force needed to bend Al belt, etc., it must be s haped gradually into U by several dies. The designation of these dies has been g iven in this paper. The next step is to forming the U shape into a circle. The U shape Al belt goes through a round that is formed with a four-roller die, and then is shaped to a circle. Because the latter procedure requires the Al circle has a laminated area to be ultrasonic welded, this die must be designed to let t he two edges of the circle belt to be piled up to a definite width. But except f or the laminated area the other of the circle should be as round as possible. So the four rollers are not the same. The calculation and designation of the rolle rs of this four-roller die has also been given. The designation of the roller w hich is supposed to leave a gap to let the two edges of the circle belt to be pi led up is to make a fine rotation of an original circle. Then calculates the cen ter of the rotated arc and defines the arc completely. The designation method of the other rollers has also been given in this paper. 展开更多
关键词 BENDING forming AL composite pipe
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High Speed Steel and WC Particle-Reinforced Composites Produce by Spray Forming
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作者 ZHANG Wing HUANG Thuo +2 位作者 TIAN Haige WU Qinghua WU Chengyi(Materials Science and Engineering School, USTB, Beijing 100083, China)(Research Institute of Powder Metallurgy, General Research Institute for Non-ferrous Metals)(Institute of Agriculture Mechaniz 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 1997年第4期47-51,共5页
The process of spray forming utilized to fabricate WC particle-reinforced high speed steel composites has been studied. In addition, microstructures and mechanical properties of M2 high speed steel and its composites ... The process of spray forming utilized to fabricate WC particle-reinforced high speed steel composites has been studied. In addition, microstructures and mechanical properties of M2 high speed steel and its composites made by spray forming have been analyzed. The results show that the primary carbides of high speed steel are of two types: MC and MbC. With the increase in flight distance, the morphology of the primary carbides varies from fine fish-bone-like to islandlike and both bending strength and hardness increase. With the increase in volume fraction of WC reinforcement particles,hardness of the composites increases considerably, but bending strength, however, appears to be a decreasing tendency. 展开更多
关键词 spray forming WC particle high speed steel composite microstructures and mechanical properties
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Stretch Forming Simulation of Woven Composites Based on an Orthotropic Non-Linear Material Model
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作者 N. A. Zanjani S. Kalyanasundaram 《Journal of Materials Science and Chemical Engineering》 2015年第7期168-179,共12页
Characterisation experiments have been conducted on a woven self-reinforced polypropylene composite (SRPP) including uniaxial and bias extension tests. Outcomes of these experiments were employed to develop a non-line... Characterisation experiments have been conducted on a woven self-reinforced polypropylene composite (SRPP) including uniaxial and bias extension tests. Outcomes of these experiments were employed to develop a non-linear orthotropic material model within an incremental deformation framework. The material model of the woven composite was implemented into a finite element simulation to predict stretch forming behaviour of SRPP specimens. The predicted strain paths at the pole of specimens were verified against experimental outcomes. It was shown that specimens possessing different aspect ratios deform under a wide range of deformation modes from uniaxial extension to biaxial stretch modes. Finally, the effect of different forming parameters on the strain path evolution of the woven composite was elucidated through numerical simulations. It was shown that the aspect ratio of the samples plays an important role in forming behaviour of woven composites. Development of a reliable and accurate numerical model for predicting forming behaviour of woven composites and understanding their main forming mechanisms promote and encourage the extensive application of these materials systems in a wide range of mass producing industries. Adopting woven composites in manufacturing industrial components facilitates addressing environmental concerns such as recyclability and sustainability issues. 展开更多
关键词 Woven composite STRETCH forming FINITE ELEMENT Analysis Nonlinear ORTHOTROPIC Material
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A Comparison between Forming Behaviours of Two Pre-Consolidated Woven Thermoplastic Composites
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作者 N. A. Zanjani S. Kalyanasundaram 《Journal of Materials Science and Chemical Engineering》 2015年第7期180-189,共10页
This paper presents the results of an investigation on stretch forming behaviour of two consolidated woven thermoplastic composites: a self-reinforced polypropylene (SRPP) and a glass-fibre reinforced polypropylene (G... This paper presents the results of an investigation on stretch forming behaviour of two consolidated woven thermoplastic composites: a self-reinforced polypropylene (SRPP) and a glass-fibre reinforced polypropylene (GRPP) composite. A custom-built press with a hemispherical punch was employed to deform composites’ specimens possessing different aspect ratios into an open die. The induced strains on the outer surface of specimens were measured continuously through two high speed, high resolution CCD cameras by employing a Digital Image Correlation (DIC) technique. The strain paths at three different locations on the surface of specimens were compared to elucidate the effect of fibre and matrix on the formability of a woven composite. The fractured surface of specimens was investigated to reveal the effect of fibre mechanical properties on failure morphologies in woven composites. It was found out that the main mode of failure in GRPP is fibre fracture while observed failure morphologies in SRPP were a complex combination of different failure mechanisms. It was revealed that the combination of applied boundary conditions and specimen’s width determines the effective forming mechanisms. 展开更多
关键词 Woven composite STAMP forming Self-Reinforced POLYPROPYLENE Glass-Fibre Reinforced POLYPROPYLENE Failure
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Microstructural and mechanical behavior of blended powder semisolid formed Al7075/B_4C composites under different experimental conditions 被引量:7
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作者 A.JAVDANI A.H.DAEI-SORKHABI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2018年第7期1298-1310,共13页
This work aimed to fabricate B4C reinforced aluminum matrix composites via blended powder semisolid forming that is an implementation of the benefits of semisolid forming to the powder metallurgy. Al7075 elements were... This work aimed to fabricate B4C reinforced aluminum matrix composites via blended powder semisolid forming that is an implementation of the benefits of semisolid forming to the powder metallurgy. Al7075 elements were incrementally added to ethanol solution under mechanical mixing. Al7075 constituents and B4C particles were blended in a high energy ball mill. Cold compacted Al7075/B4C blends were pressed at semisolid state. The effects of the size of the matrix(20, 45 and 63 μm), reinforcing volume fraction(5%, 10% and 20%) and semisolid compaction pressure(50 and 100 MPa) on the morphology, microstructure, density, hardness, compression and bending strength were thoroughly analyzed. Experimental results revealed that the highest microstructural uniformity was achieved when large B4C particles(45 μm) were distributed within the small particles(20 μm) of the matrix phase. Composites with matrix particles larger than reinforcing phase indicated agglomerations in loadings more than 10%(volume fraction). Agglomerated regions resisted against penetration of the liquid phase to the pores and lowered the density and strength of these composites. Composites with 20 μm Al7075 and 20%(volume fraction) 45 μm B4C powder pressed under 100 MPa exhibited the highest values of hardness(HV 190) and compressive strength(336 MPa). 展开更多
关键词 blended powder mechanical alloying semisolid forming B4C aluminum matrix composite
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Sulfur isotopic composition of the Tianqiao Pb-Zn ore deposit,Northwest Guizhou Province,China:Implications for the source of sulfur in the ore-forming fluids 被引量:17
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作者 ZHOU Jiaxi HUANG Zhilong +3 位作者 ZHOU Guofu LI Xiaobiao DING Wei BAO Guangping 《Chinese Journal Of Geochemistry》 EI CAS 2010年第3期301-306,共6页
The Tianqiao Pb-Zn ore deposit of Guizhou Province, China, is located in the mid-east of the Sichuan-Yunnan-Guizhou Pb-Zn-Ag multi-metallic mineralization area, which is representative of the Pb-Zn ore de-posits in th... The Tianqiao Pb-Zn ore deposit of Guizhou Province, China, is located in the mid-east of the Sichuan-Yunnan-Guizhou Pb-Zn-Ag multi-metallic mineralization area, which is representative of the Pb-Zn ore de-posits in this area. It consists of three main orebodies, whose Pb+Zn reserves are more than 0.2 million ton. This paper analyzes the sulfur isotopic composition of these orebodies. The data show that the ore minerals (galena, sphalerite, pyrite) in these orebodies are enriched in heavy sulfur, with δ34SV-CDT values varying between 8.35‰ and 14.44‰, i.e. the δ34SV-CDT values of pyrite are between 12.81‰ and 14.44‰, the mean value is 13.40‰; the δ34SV-CDT values of sphalerite are range from 10.87‰ to 14.00‰, the mean value is 12.53‰; the δ34SV-CDT values of galena are range from 8.35‰ to 9.83‰, the mean value is 8.84‰, and they have the feature of δ34Spyrite>δ34Ssphalerite>δ34Sgalena, which indicates the sulfur isotope in ore-forming fluids has attained equilibrium. The δ34S V-CDT values of the deposit are close to those of sulfates from carbonate strata of different ages in the ore-field (15‰), which suggests that the sulfur in the ore-forming fluids should be derived from the thermo-chemical sulfate reduction of sulfates from the sedimentary strata. 展开更多
关键词 硫同位素组成 成矿流体来源 铅锌矿 贵州省 天桥 中国 西北部 硫酸盐还原
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Draping Behavior of Carbon Non-Crimp Fabrics and Its Effects on Mechanical Performance of the Hemispherical Composites 被引量:1
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作者 李龙 肇研 +3 位作者 LIU Gang ZHAO Xiaoran SONG Jiupeng GONG Ming 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2018年第3期720-728,共9页
In order to investigate the draping behavior of non-crimp fabrics(NCFs), two types of carbon NCFs with tricot-chain stitches or chain stitches were formed on a hemispherical mould via a stretch forming process. The ... In order to investigate the draping behavior of non-crimp fabrics(NCFs), two types of carbon NCFs with tricot-chain stitches or chain stitches were formed on a hemispherical mould via a stretch forming process. The shear angle and forming defects of the fabrics were measured on the hemisphere, under different blank holder forces(BHFs). The results showed that increasing BHF could enhance the shear angle slightly, reduce the asymmetry for the deformation of the fabrics, and change the main type of the process-induced defects. Besides, compression tests were performed on the corresponding composite components. By analyzing the change of fiber volume fraction and structural parameters of the textile reinforcements, the effects of draping behavior of NCFs on the mechanical performance of the composites were studied. The results reveal that draping process has distinguishable impacts on the mechanical properties of the final components, which is closely related to the stitching pattern of the NCFs. 展开更多
关键词 non-crimp fabric hemispherical forming shear deformation mechanical properties liquid composite molding
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Effect of carbide formers on microstructure and thermal conductivity of diamond-Cu composites for heat sink materials 被引量:16
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作者 夏扬 宋月清 +2 位作者 林晨光 崔舜 方针正 《中国有色金属学会会刊:英文版》 EI CSCD 2009年第5期1161-1166,共6页
Diamond-copper composites were prepared by powder metallurgy,in which the diamond particles were pre-coated by magnetic sputtering with copper alloy containing a small amount of carbide forming elements(including B,Cr... Diamond-copper composites were prepared by powder metallurgy,in which the diamond particles were pre-coated by magnetic sputtering with copper alloy containing a small amount of carbide forming elements(including B,Cr,Ti,and Si).The influence of the carbide forming element additives on the microstructure and thermal conductivity of diamond composites was investigated.It is found that the composites fabricated with Cu-0.5B coated diamond particles has a relatively higher density and its thermal conductivity approaches 300 W/(m·K).Addition of 0.5%B improves the interfacial bonding and decreases thermal boundary resistance between diamond and Cu,while addition of 1%Cr makes the interfacial layer break away from diamond surface.The actual interfacial thermal conductivity of the composites with Cu-0.5B alloy coated on diamond is much higher than that of the Cu-1Cr layer,which suggests that the intrinsic thermal conductivity of the interfacial layer is an important factor for improving the thermal conductivity of the diamond composites. 展开更多
关键词 铜复合材料 硬质合金 导热系数 钻石 显微结构 散热片 金刚石复合材料 金刚石颗粒
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Sulfur isotopic composition of the Bainiuchang super-large Ag polymetallic deposit,Yunnan Province,China: Implications for the source of sulfur in ore-forming fluids 被引量:7
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作者 XIE Hongjing ZHU Chaohui +2 位作者 ZHANG Qian WANG Dapeng FAN Liangwu 《Chinese Journal Of Geochemistry》 EI CAS 2009年第3期284-292,共9页
The Bainiuchang deposit in Yunnan Province, China, is located geographically between the Gejiu ore field and the Dulong ore field. In addition to >7000 t Ag reserves, the deposit possesses large-scale Pb, Zn, Sn re... The Bainiuchang deposit in Yunnan Province, China, is located geographically between the Gejiu ore field and the Dulong ore field. In addition to >7000 t Ag reserves, the deposit possesses large-scale Pb, Zn, Sn reserves and a mass of dispersed elements (i.e., In, Cd, Ge, Ga, etc.). Based on systematic studies of sulfur isotopic composition, the authors conclude: The Bainiuchang deposit experienced two epochs of metallogenesis, i.e., the Middle-Cambrian sea-floor exhalative sedimentary metallogenic epoch and the Yanshanian magmatic hydrothermal superimposition metallogenic epoch. In the two metallogenic epochs, the δ34S values of sulfides were all near 0, showing a tendency of being enriched slightly in heavy sulfur. The δ34S values of sulfides in the early metallogenic epoch are within the range of 2‰–5‰ with a peak value range of 2‰–3‰ and an average of 3.0‰, and those of sulfides in the late metallogenic epoch are within the range of 2‰–6‰ with a peak value of 3‰–4‰ and an average of 3.9‰. For the single metallogenic epoch, sulfur in the ore-forming fluids in the early epoch already reached isotopic equilibrium and was derived mainly from underneath the magma chamber or basement metamorphic igneous rocks. Sulfur in the sulfides in the late epoch was derived mainly from magmatic hydrothermal fluids formed in the process of remelting of the basement metamorphic igneous rocks. 展开更多
关键词 硫同位素组成 银多金属矿床 成矿流体 白牛厂 云南省 中国 超大型 成矿时代
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The Isotopic Composition of Noble Gases in Gold Deposits and the Source of Ore-Forming Materials in the Region of North Hebei, China 被引量:9
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作者 王宝德 牛树银 +1 位作者 孙爱群 李红阳 《Chinese Journal Of Geochemistry》 EI CAS 2003年第4期313-319,共7页
The source of ore\|forming materials has long been a controversial focus both in metallogenic theory and in ore\|searching practice. This study deals with the helium and argon isotopic characteristics of pyrites from ... The source of ore\|forming materials has long been a controversial focus both in metallogenic theory and in ore\|searching practice. This study deals with the helium and argon isotopic characteristics of pyrites from 11 gold deposits and some country rocks in the gold mineralization\|concentrated areas within the three mantle\|branch structures in the region of North Hebei Province. It is indicated that \{\}\+3He/\+4He ratios in the gold deposits are within the range of \{0.93×10\+\{-6\}\}-\{7.3×10\+\{-6\}\}, with an average of \{3.55\} ×10\+\{-6\}; R/Ra=\{0.66\}-\{4.93\}, averaging \{2.53\}; \{\{\}\+\{40\}Ar/\+\{39\}Ar\} ratios vary between 426 and 2073, with the average value of \{\}\+\{40\}Ar being \{8.32\}; and the average of \{\}\+4He/\{\}\+\{40\}Ar ratios is 2.17. \{\}\+3He/ \{\}\+4He ratios in gneiss and granite in the periphery of the mining district are within the range of \{0.001×10\+\{-6\}\}-\{0.55×10\+\{-6\}\}, reflecting significant differences in their sources. \{\}\+3He and \{\}\+4He fall near the mantle, as is shown in the He concentration diagram. Studies have shown that the ore\|forming materials in this region should come from the deep interior of the Earth. With the multi\|stage evolution of mantle plume, ore\|forming fluids in the deep interior were moving upwards to shallow levels (crust). Under such circumstances, there would be inevitably occur crust/mantle fluid mixing, so their noble gas isotopic characteristics are intermediate between the mantle and the crust. 展开更多
关键词 gold DEPOSIT source of 0re-forminE nmterial He Ar ISOTOPIC composition mantle-branch structure MANTLE PLUME
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Feasibility of developing composite action between concrete and cold-formed steel beam
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作者 S.O.Bamaga M.Md.Tahir +6 位作者 T.C.Tan S.Mohammad N.Yahya A.L.Saleh M.Mustaffar M.H.Osman A.B.A.Rahman 《Journal of Central South University》 SCIE EI CAS 2013年第12期3689-3696,共8页
Cold-formed steel structures are steel structure products constructed from sheets or coils using cold rolling, press brake or bending brake method. These structures are extensively employed in building construction in... Cold-formed steel structures are steel structure products constructed from sheets or coils using cold rolling, press brake or bending brake method. These structures are extensively employed in building construction industry due to their light mass, ductility by economic cold forming operations, favorable strength-to-mass ratio and other factors. The utilization of cold formed steel sections with concrete as composite can hugely reduce the construction cost. However, the use of cold formed steel members in composite concrete beams has been very limited. A comprehensive review of developments in composite beam with cold formed steel sections was introduced. It was revealed that employing cold-formed steel channel section to replace reinforcement bars in conventional reinforced concrete beam results in a significant cost reduction without reducing strength capacity. The use of composite beam consisting of cold-formed steel open or close box and filled concrete could also reduce construction cost. Lighter composite girder for bridges with cold-formed steel of U section was introduced. Moreover, types of shear connectors to provide composite action between cold-formed steel beam and concrete slab were presented. However, further studies to investigate the effects of metal decking on the behavior of composite beam with cold-formed steel section and introduction of ductile shear connectors were recommended. 展开更多
关键词 cold formed steel BEAM composite shear connection thin-wall composite girder
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Flexural and eigen-buckling analysis of steel-concrete partially composite plates using weak form quadrature element method
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作者 XIA Jun SHEN Zhi-qiang +1 位作者 LIU Kun SUN Cheng-ming 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第11期3087-3102,共16页
Flexural and eigen-buckling analyses for rectangular steel-concrete partially composite plates(PCPs)with interlayer slip under simply supported and clamped boundary conditions are conducted using the weak form quadrat... Flexural and eigen-buckling analyses for rectangular steel-concrete partially composite plates(PCPs)with interlayer slip under simply supported and clamped boundary conditions are conducted using the weak form quadrature element method(QEM).Both of the derivatives and integrals in the variational description of a problem to be solved are directly evaluated by the aid of identical numerical interpolation points in the weak form QEM.The effectiveness of the presented numerical model is validated by comparing numerical results of the weak form QEM with those from FEM or analytic solution.It can be observed that only one quadrature element is fully competent for flexural and eigen-buckling analysis of a rectangular partially composite plate with shear connection stiffness commonly used.The numerical integration order of quadrature element can be adjusted neatly to meet the convergence requirement.The quadrature element model presented here is an effective and promising tool for further analysis of steel-concrete PCPs under more general circumstances.Parametric studies on the shear connection stiffness and length-width ratio of the plate are also presented.It is shown that the flexural deflections and the critical buckling loads of PCPs are significantly affected by the shear connection stiffness when its value is within a certain range. 展开更多
关键词 weak form quadrature element method partially composite plates interlayer slip flexural analysis eigen-buckling analysis
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Composite bioabsorbable vascular stents via 3D bio-printing and electrospinning for treating stenotic vessels 被引量:13
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作者 刘媛媛 向科 +2 位作者 李瑜 陈海萍 胡庆夕 《Journal of Southeast University(English Edition)》 EI CAS 2015年第2期254-258,共5页
A new type of vascular stent is designed for treating stenotic vessels. Aiming at overcoming the shortcomings of existing equipment and technology for preparing a bioabsorbable vascular stent (BVS), a new method whi... A new type of vascular stent is designed for treating stenotic vessels. Aiming at overcoming the shortcomings of existing equipment and technology for preparing a bioabsorbable vascular stent (BVS), a new method which combines 3D bio-printing and electrospinning to prepare the composite bioabsorbable vascular stent (CBVS) is proposed. The inner layer of the CBVS can be obtained through 3D bio- printing using poly-p-dioxanone (PPDO). The thin nanofiber film that serves as the outer layer can be built through electrospinning using mixtures of chitosan-PVA (poly (vinyl alcohol)). Tests of mechanical properties show that the stent prepared through 3D bio-printing combined with electrospinning is better than that prepared through 3D bio- printing alone. Cells cultivated on the CBVS adhere and proliferate better due to the natural, biological chitosan in the outer layer. The proposed complex process and method can provide a good basis for preparing a controllable drug-carrying vascular stent. Overall, the CBVS can be a good candidate for treating stenotic vessels. 展开更多
关键词 3D three-dimensional bio-printing bioabsorbable vascular stent (BVS) ELECTROSPINNING CELLPROLIFERATION composite forming
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Laser induced TiC particle reinforced composite layer on Ti6Al4V and their microstructural characteristics 被引量:7
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作者 张松 吴维 +1 位作者 王茂才 董世运 《中国有色金属学会会刊:英文版》 CSCD 2000年第1期6-9,共4页
An in situ synthesized TiC particle reinforced composite layer on Ti6Al4V were fabricated by laser induced reaction of the pre placed mixed powders of Ti and Cr 3C 2. The microstructure of the composite layer was stro... An in situ synthesized TiC particle reinforced composite layer on Ti6Al4V were fabricated by laser induced reaction of the pre placed mixed powders of Ti and Cr 3C 2. The microstructure of the composite layer was strongly related to the composition of original powders and also the laser processing parameters. Under certain processing parameters, the matrix of the composite layer was transferred from dual α + β to single phase β with increasing Cr 3C 2 content in the original powder mixture. The TiC particles were fine and uniformly dispersed in the matrix. Furthermore, the fine TiC particles show excellent compatibility with the matrix, thus offering good wear performance. 展开更多
关键词 METALLIC composite TIC PARTICLES in SITU forming coatingDocument code: A
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Study on Material Composition and REE-host Forms of Ion-type RE Deposits in South China 被引量:5
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作者 张培善 陶克捷 杨主明 《Journal of Rare Earths》 SCIE EI CAS CSCD 1995年第1期37-41,共5页
in the ion-type RE deposite in South China, the host rocks of REE minerals are igneous and metamorphic rocks , such as granite, granite-porphyry, granitite, muscovite granite, granodiorite, rhyolite, tuff, lamprophyre... in the ion-type RE deposite in South China, the host rocks of REE minerals are igneous and metamorphic rocks , such as granite, granite-porphyry, granitite, muscovite granite, granodiorite, rhyolite, tuff, lamprophyre, alkaline rocks, granite-gneiss, stuff, gneissic granite.These various types of rocks occurred in the environment of humid subtropical zone with a specific topographic relief. During a long-term geological process, they were weathered and alterated into montmorillonite, gibbstite, vermiculite and the dioctahedral type of clay minerals, such as kaolinite, halloysite-0. 7 nm , halloysite-1. 0 nm and ferrohalloysite. All of these clay minerals are the REE carriers. The REE in the ion-type RE deposits came from there source: 1) the REE -bearing rock-forming minerals in host rock, such as microcline and amphibole:2) the accessory minerals in host rocks, such as allanite, gadolinite-(Y), sphene , parisite-(Y), and fergusonite-(Y). For a long geological time the weathering and leaching processes caused the minerals to be disintegrated and to free REE ions. The REE cations can be adsorbed on various clay minerals associated. The categories of ion -type RE deposite depend on the species of RE minerals and the lithological characters of the host geological body in the ore deposit area. 展开更多
关键词 Ion -type RE deposit Material composition RE-host forms Clay minerals Adsorption
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