检索结果-南通市图书馆

Wear Resistance and Bond Strength of Plasma Sprayed Fe/Mo Amorphous Coatings

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2014年第10期21卷 969-974页

作者： Chao-ping JIANG Ya-zhe XING Feng-ying ZHANG Jian-min HAO Xu-ding SONG School of Materials Science and Engineering Chang'an University Key Laboratory of Road Construction Technology and Equipment MOE School of Construction MachineryChang'an University

Fe-based and Fe/Mo composite amorphous coatings were deposited on the surface of plain carbon steel substrates by atmospheric plasma spraying （APS）. With increasing the Mo alloy content, the microstructure of the coatings revealed more dense structure. The porosities of composite coating were all less than those of Fe-based coat- ing due to Mo alloy self-bonding performance. The ML10 friction and wear tester was employed to investigate the wear behaviors of the coatings under dry sliding conditions. It was found that the mass loss of the resultant coatings decreased with increasing Mo-based powders into the feedstock. This was attributed to the reduction of the delamina- tions resulting from improved intersplat bond with Mo addition.

关键词： atmospheric plasma spraying coating delamination wear bond strength

Petrogenesis of the Late Triassic shoshonitic Shadegai pluton from the northern North China Craton: Implications for crust-mantle interaction and post-collisional extension

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2019年第2期10卷 595-610页

作者： Liqiong Jia Liang Wang Genhou Wang Shibin Lei Xuan Wu Development Research Center China Geological Survey National Geological Archive of China Gold Geology Institute of Chinese Armed Police Force School of Earth Sciences and Resources China University of Geosciences (Beijing) Headquarters of Gold Exploration Branch of Chinese Armed Police Force

Latest Permian to Triassic plutons are widespread in the northern North China Craton(NCC); most of them show calc-alkaline, high-K calc-alkaline, or alkaline geochemical features. The Shadegai pluton in the Wulashan area has shoshonitic affinity and I-type character, and is composed of syenogranites containing abundant mafic microgranular enclaves(MMEs). LA-MC-ICP-MS U-Pb data yield weighted mean 206 Pb/238 U ages of 222 ± 1 Ma and 221 ± 1 Ma for the syenogranites and MMEs, respectively, suggesting their coeval formation during the Late Triassic. The syenogranites have high SiO_2(70.42-72.30 wt%),K_2O(4.58-5.22 wt.%) and Na_2O(4.19-4.43 wt.%) contents but lower concentrations of P_2O_5(0.073-0.096 wt.%) and TiO_2(0.27-0.37 wt.%), and are categorized as I-type granites, rather than A-type granites, as previously thought. These syenogranites exhibit lower(^(87)Sr/^(86)Sr)i ratios(0.70532-0.70547) and strongly negative whole-rock εNd(t) values(-12.54 to-11.86) and zircon εHf(t) values(-17.81 to-10.77),as well as old Nd(1962-2017 Ma) and Hf(2023-2092 Ma) model ages, indicating that they were derived from the lower *** and petrological observations reveal that the MMEs within the pluton probably represent magmatic globules commingled with their host magmas. Geochemically, these MMEs have low SiO_2(53.46-55.91 wt.%)but high FeOt(7.27-8.79 wt.%) contents. They are enriched in light rare earth elements(LREEs) and large ion lithophile elements(LILEs), and are depleted in heavy rare earth elements(HREEs) and high field strength elements(HFSEs). They have whole-rock(^(87)Sr/^(86)Sr)i ratios varying from 0.70551 to 0.70564, εNd(t) values of -10.63 to -9.82, and zircon εHf(t) values of -9.89 to 0.19. Their geochemical and isotopic features indicate that they were derived from the subcontinental lithospheric mantle mainly metasomatized by slab-derived fluids, with minor involvement of melts generated from the ascending asthenospheric mantle. Petrology integrated with elem

关键词： Magma mixing Crust-mantle interaction Lithospheric delamination Post-collision North China Craton

Zircon U–Pb age and geochemical constraints on the origin and tectonic implication of the Tuotuohe Cenozoic alkaline magmatism in Qinghai–Tibet Plateau

在线全文

学校读者我要写书评

暂无评论

Acta Geochimica 2020年第1期39卷 67-84页

作者： Ye Qian Shengnan Tian Yujin Li Fengyue Sun College of Earth Sciences Jilin UniversityChangchunChina Key Laboratory of Mineral Resources Evaluation in Northeast Asia Ministry of Natural Resources of the People's Republic of ChinaChangchunChina

A large number of Eocene-Oligocene alkaline/alkali-rich igneous rocks were developed in the Tuotuohe region of the Qinghai-Tibetan *** this study,we present zircon U-Pb ages,Hf isotope data,and major and trace element compositions of the Cenozoic alkaline rocks from the Tuotuohe region in order to constraint the petrogenesis and tectonic evolution history of Qiangtang *** U-Pb ages were measured via LA-ICP-MS to be39.6,37.6 and 32.0 *** 39.6 Ma trachyte was characterized by low SiO2 and high K2O and MgO *** 37.6 and 32.0 Ma orthophyres show enrichment in SiO2 and K2O,but deficient in *** of the samples belong to the alkaline *** rocks display enrichment in REE,LREE,and LILE,depletion in HFSE,and no obvious Eu *** and geochemical features suggest that there were two possible mechanisms for the origin of the alkaline rocks in the Tuotuohe region:(1)the removed mafic lower crust dropped into the asthenosphere,forming the mix magma(Nariniya trachyte);(2)the upwelling asthenosphere triggered the crustal melting(Nariniya and Zamaqu orthophyre).The Eocene-Oligocene alkaline rocks in the study and adjacent areas are likely to be the result of the same tectonic-magmatic event of deep lithospheric evolution that is the crustal material melting triggered by lithospheric *** conclusion extends the influence scope of lithospheric delamination eastward to the Tuotuohe region(*92°E)from Banda Co(*82°E).

关键词： Zircon U-Pb chronology Zircon Hf isotopic delamination Tuotuohe region Qinghai–Tibetan Plateau

Eclogite-melt/peridotite reaction: Experimental constrains on the destruction mechanism of the North China Craton

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2010年第6期53卷 797-809页

作者： WANG Chao JIN ZhenMin GAO Shan ZHANG JunFeng ZHENG Shu State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesWuhan 430074China State Key Laboratory of Inorganic Synthesis and Preparative Chemistry College of ChemistryJilin UniversityChangchun 130012China

To study the mechanism of melt-peridotite reaction pertinent to the destruction of the North China Craton (NCC) lithosphere, a series of experiments were performed at a pressure of 2.0 GPa and temperatures from 1250 to 1400°C using Bixiling eclogite and Damaping peridotite as starting materials. The experimental results show that the reaction between eclogite melt and peridotite causes dissolution of olivine and orthopyroxene and precipitation of clinopyroxene in the melt. The experimental run products, characterized by a lherzolite/pyroxenite/garnet-pyroxenite sequence, are consistent with the mantle xenoliths in the Neogene Hannuoba basalt of the NCC found by Liu et al. (2005). It suggests that the mafic lower continental crust was probably recycled into the mantle during the Mesozoic Era. In the experiments conducted at 1300 and 1350°C, the resulting melts have a high Mg# andesite signature, indicating that the melt-peridotite reaction may have played a major role in the generation of high Mg# andesite. Our experimental results support the hypothesis that melts derived from foundered eclogite in the asthenosphere will consume the lithospheric peridotites. Therefore, melt-peridotite reaction is an important mechanism for the destruction/thinning of the lithosphere.

关键词： eclogite peridotite melt/peridotite reaction high Mg# andesite delamination destruction of lithosphere

ON RESIDUAL COMPRESSIVE STRENGTH PREDICTION OF COMPOSITE SANDWICH PANELS AFTER LOW-VELOCITY IMPACT DAMAGE

在线全文

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2006年第1期19卷 9-17页

作者： Xie Zonghong Anthony J. Vizzini Tang Qingru College of Astronautics Northwestern Polytechnical University Xi＇an 710072 China Department of Aerospace Engineering Mississippi State University MS 39762 USA Aviation Engineering Institute Civil Aviation Flight University of China Guanghan 618307 China

This paper introduces a nonlinear finite element analysis on damage propagation behavior of composite sandwich panels under in-plane uniaxial quasi-static compression after a low velocity impact. The major damage modes due to the impact, including the residual indentation on the impacted facesheet, the initially crushed core under the impacted area, and the delamination are incorporated into the model. A consequential core crushing mechanism is incorporated into the analysis by using an element deactivation technique. Damage propagation behavior, which corresponds to those observed in sandwich compression after impact （SCAI） tests, has been successfully captured in the numerical simulation. The critical far field stress corresponding to the onset of damage propagation at specified critical locations near the damage zone are captured successfully. They show a good correlation with experimental data. These values can be used to effectively predict the residual compressive strength of low-velocity impact damaged composite sandwich panels.

关键词： sandwich structures impact delamination damage growth honeycomb core finite element method

Nonlinear progressive damage model for composite laminates used for low-velocity impact

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2013年第9期34卷 1145-1154页

作者：郭卫薛璞杨军 School of Aeronautics Northwest Polytechnical University Chengdu Aircraft Design and Research Institute

In order to effectively describe the progressively intralaminar and interlam- inar damage for composite laminates, a three dimensional progressive damage model for composite laminates to be used for low-velocity impact is presented. Being applied to three-dimensional （3D） solid elements and cohesive elements, the nonlinear damage model can be used to analyze the dynamic performance of composite structure and its failure be- havior. For the intralaminar damage, as a function of the energy release rate, the damage model in an exponential function can describe progressive development of the damage. For the interlaminar damage, the damage evolution is described by the framework of the continuum mechanics through cohesive elements. Coding the user subroutine VUMAT of the finite element software ABAQUS/Explicit, the model is applied to an example, i.e., carbon fiber reinforced epoxy composite laminates under low-velocity impact. It is shown that the prediction of damage and deformation agrees well with the experimental results.

关键词： composite laminate progressive damage delamination energy release rate low-velocity impact

Tool geometry based prediction of critical thrust force while drilling carbon fiber reinforced polymers

在线全文

学校读者我要写书评

暂无评论

Advances in Manufacturing 2015年第4期3卷 300-308页

作者： Y. Karpat O. Bahtiyar Department of Industrial Engineering Bilkent UniversityAnkara 06800 Turkey Turkish Aerospace Industries Inc. Ankara 06980 Turkey

Carbon fiber reinforced polymers （CFRPs） are known to be difficult to cut due to the abrasive nature of carbon fibers and the low thermal conductivity of the polymer matrix. Polycrystalline diamond （PCD） drills are commonly employed in CFRP drilling to satisfy hole quality conditions with an acceptable tool life. Drill geometry is known to be influential on the hole quality and productivity of the process. Considering the variety of CFRP laminates and available PCD drills on the market, selecting the suitable drill design and process parameters for the CFRP material being machined is usually per- formed through trial and error, In this study, machining performances of four different PCD drills are investigated. A mechanistic model of drilling is used to reveal trade-offs in drill designs and it is shown that it can be used to select suitable feed rate for a given CFRP drilling process.

关键词： Machining Drilling - Carbon fiber reinforced polymer (CFRP) Polycrystalline diamond (PCD) delamination

Petrogenesis and tectonic implications of the Early Cretaceous Dagushan adakitic porphyries in the Anshan area,North China Craton

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Geochimica 2022年第1期41卷 24-38页

作者： Xiaohui Sun Haoshu Tang Yan Luan Key Laboratory of Western China’s Mineral Resources and Geological Engineering MOESchool of Earth Science and ResourcesChang’an UniversityXi'an 710054China State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China

The eastern part of the North China Craton suffered significant lithospheric thinning since the Mesozoic,and petrogenesis of the Dagushan adakitic diorite porphyries provides an excellent opportunity to investigate the lithospheric thinning mechanism and geodynamic *** zircon LA-ICP-MS U–Pb geochronology reveals that the representative Dagushan adakitic porphyry was formed at 120.5±0.5 *** Dagushan diorite porphyries are characterized by the relatively high contents of SiO_(2)(64.25–65.70 wt%),Al_(2) O_(3)(15.00–15.38 wt%),Sr(333–491 ppm),low contents of Y(6.50–10.3 ppm),and Yb(0.57–0.85 ppm),and resultant high Sr/Y(47–57)and La/Yb(37–55)ratios,exhibiting geochemical characteristics of typical ***,the relatively high Mg O contents(MgO=2.23–2.29 wt%)and Mg numbers(Mg^(#)-=54–56)of the Dagushan adakitic rocks imply that the pristine adakitic magma interacted with mantle ***,the zircon Hf isotopic signatures(εHf(t)=-19.0 to-28.0;TDM2=2378–2944 Ma)suggest an ancient lower crustal ***,it is proposed that the Dagushan adakitic rock was probably generated by partial melting of delaminated lower crust which was triggered by the Tan-Lu Fault Zone,and the interaction of pristine adakitic magma with mantle peridotite during the ascent finally generated the Dagushan high Mg^(#)adakitic *** is suggested that delamination was an important mechanism for lithospheric thinning of the NCC.

关键词： Diorite porphyry Adakite Lower crust delamination NCC

STUDY ON THE TENSILE FATIGUE DAMAGE OF QUASI-ISOTROPIC COMPOSITE LAMINATES

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2003年第1期16卷 1-7页

作者： I.G.Kim I.S.Kim O.S.Kim YaragarraK.D.V.Prasad Dept. of Aerosp. Eng. Chosun Univ. Gwangju 501-759 South Korea Dept. of Mech. Eng. Mokpo Natl. Univ. Chonam 534-729 South Korea Dept. of Mech. Eng. Yosu Natl. Univ. Chonnam 550-749 South Korea Sch. of Mech. and Med. Eng. Queensland Univ. of Technol. Brisbane QLD 4001 Australia

Quasi-isotropic laminates have isotropic elastic properties in all in-plane directions. Therefore, this kind of laminate is widely used for structural elements. The simplest stacking sequence of quasi-isotropic laminates is [0/-60/60]s. When the direction of applied axial load to [0/-60/60]S laminate is inclined at a 30-degree angle, we have the other quasi-isotropic laminate [30/-30/90]s under axial load. The failure mechanisms of these two laminates are, however, entirely different from each other because these two laminates have different distribution of the interlaminar stresses. It was confirmed by tensile fatigue tests that the [0/-60/60]s laminate does not show any visible fatigue damage, but the [30/-30/90]s laminate develops edge-delamination during cyclic loading. The analytical results were in good agreement with the experimental results.

关键词： composite material delamination fatigue fracture mechanics interlaminar stress