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Numerical Investigation of Transient Temperature Distribution during Ti-6Al-4V Selective Laser Melting

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Journal of Thermal Science 2019年第2期28卷 370-377页

作者： XING Xiaodong ZHOU Qiuyu wang Shiyuan wang liquan JIANG Fengchun College of Mechanical and Electrical Engineering Harbin Engineering University College of Materials Science and Chemical Engineering Harbin Engineering University

The transient temperature field in the powder bed has a crucial effect on the quality of parts fabricated using Selective Laser Melting(SLM). In this study, a finite element model is established regarding the variance of temperature-dependent thermal properties and transformation latent heat. The temperature distribution and melt pool dimensions of a laser scan track were obtained by varying multiple parameters(layer thickness, laser power and scan speed). The effects of transition of material state and heat source model are also analyzed in this paper. The finite element simulation results show that an increased laser power and/or decreased scan speed results in an elevated maximum temperature of the powder layer and a larger melt pool size. Furthermore, it is found that the maximum temperature is significantly lowered due to the heat diffusion into the previous sintered zone. The heat source model has to be selected properly according to the element size.

关键词： Selective Laser Melting transient temperature field process parameters melt pool

On the Geodynamic Mechanism of Episodic Uplift of the Tibetan Plateau during the Cenozoic Era

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Acta Geologica Sinica(English Edition) 2014年第2期88卷 699-716页

作者： wang Guocan CAO Kai wang An SHEN Tianyi ZHANG Kexin wang liquan State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Center for Global Tectonics China University of Geosciences School of Earth Sciences China University of Geosciences Key Laboratory of Biological and Environmental Geology of Ministry of Education China University of Geosciences Chengdu Institute of Geology and Minerals Resources

Multi-stage uplift of the Tibetan Plateau during the Cenozoic implies a complex geodynamic *** this paper,we review main geodynamic models for the uplift of the plateau,and,in particular,analyze the spatio-temporal framework of the Cenozoic deformation structures,which are closely related to the deep geodynamic mechanism for the plateau *** this perspective,significant change of the deformation regime over the Tibetan Plateau occurred by the middle-late Miocene,while thrust and thrust-folding system under NS compression was succeded by extension or ***,a series of large-scale strike-slip faults commenced or was kinemtically *** on a systematic synthesis of the structure deformation,magmatism,geomorphological process and geophysical exploration,we propose a periodical model of alternating crustal compression and extension for episodic uplift of the Tibetan Plateau.

关键词： Tibetan Plateau Cenozoic episodic uplift geodynamic mechanism

ADAPTIVE FEED-FORWARD COMPENSATOR FOR HARMONIC CANCELLATION IN ELECTRO-HYDRAULIC SERVO SYSTEM

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Chinese Journal of Mechanical Engineering 2008年第1期21卷 77-81页

作者： YAO Jianjun wang liquan JIANG Hongzhou WU Zhenshun HAN Junwei College of Mechanical and Electrical Engineering Harbin Engineering University Harbin 150001 China School of Mechatronics Engineering Harbin Institute of Technology Harbin 150001 China

Since the dead zone phenomenon occurs in electro-hydraulic servo system, the output of the system corresponding to a sinusoidal input contains higher harmonic besides the fundamental input, which causes harmonic distortion of the output signal. The method for harmonic cancellation based on adaptive filter is proposed. The task is accomplished by generating reference signals with frequency that should be eliminated from the output. The reference inputs are weighted by the adaptive filter in such a way that it closely matches the harmonic. The output of the adaptive filter is a harmonic replica and is injected to the fundamental signal such that the output harmonic is cancelled leaving the desired signal alone, and the total harmonic distortion （THD） is greatly reduced. The weights of filter are adjusted on-line according to the control error by using least-mean-square （LMS） algorithm. Simulation results performed with a hydraulic system demonstrate the efficiency and validity of the proposed adaptive feed-forward compensator （AFC） control scheme

关键词： Adaptive filter Adaptive feed-forward compensator Least-mean-square algorithm Dead zone Harmonic distortion

Regulating the self-assembly of rigid 2D ribbon-like amphiphilic homopolymer via tailoring its holistic conformation

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Science China Chemistry 2023年第8期66卷 2339-2346页

作者： Yumeng Gao Weisheng Feng Yao Sun Yuan Yao liquan wang Shaoliang Lin Shanghai Key Laboratory of Advanced Polymeric Materials Frontiers Science Center for Materiobiology and Dynamic Chemistry of Ministry of EducationSchool of Materials Science and EngineeringEast China University of Science and TechnologyShanghai200237China

Amphiphilic rigid backbone polymers are traditionally seemed as one-dimensional(1D)rods and show distinct self-assembly behavior to flexible polymers,but they could hardly adapt morphology-tunable self-assembly by changing their holistic conformation upon external *** this study,we synthesized a series of amphiphilic homopolymers poly(acetylene azobenzene oligoethylene glycol)(P(AAzo-EGx))containing conjugated polyacetylene mainchain,azobenzene pendants and oligo ethylene glycol tails in each *** comb-like amphiphilic polymer could be treated as two-dimensional(2D)nanoribbons with tunable holistic conformation via meticulous tailoring intrastrand repulsion and interchainπ-πinteraction of azobenzene pendants by light,temperature,and solvent swelling.P(AAzo-EG_(2))could self-assemble into large vesicles in ambient,whereas transformed to supramolecular helix bundles(SHBs)at 65℃as well as depicted by dissipative particle dynamics(DPD)simulation,and then turned into grass leaf-like micelles upon sequential ultraviolet(UV)and blue light *** three assemblies featured different stacking mode of PAAzo skeletons although showed similar aggregate induce emission(AIE)*** this holistic macromolecular chain conformation-induced self-assembly and morphology transformation,temperature influenced the stacking of hydrophobic parts mainly by tuning the torsion of PAAzo *** amount of good solvent played a vital role by swelling of hydrophobic PAAzo skeleton,and helping the movement and rearrangement of azobenzene pendants and polyacetylene mainchains like a *** length and diameter of SHBs could be tuned by changing *** work uncovered a facile strategy to tailor the self-assembly of rigid backbone polymers for fabrication of functional nanodevices.

关键词： self-assembly tunable conformation rigid skeleton two-dimensional nanoribbon stimuli response

Chronology and Geochemistry of the Nadingcuo Volcanic Rocks in the Southern Qiangtang Region of the Tibetan Plateau:Partial Melting of Remnant Ocean Crust along the Bangong-Nujiang Suture

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Acta Geologica Sinica(English Edition) 2010年第6期84卷 1461-1473页

作者： wang Baodi CHEN Jianlin XU Jifeng wang liquan ZENG Qinggao DONG Yanhui Chengdu Institute of Geology and Mineral Resources Chengdu 610081 China Key Laboratory of Geochronology and Geochemistry Guanzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China Regional Geological Surveying Party of the Tibet Bureau of Geology and Exploration Lhasa 851400 China The Second Institute ofOceangraphy SOA Hangzhou 310012 China

The Nadingcuo high-K calc-alkaline rocks mainly composed of trachyte and trachyandesite are the largest outcrop area of volcanic rocks in southern Qiangtang terrane in the Tibetan plateau. However,their exact source and peterogenesis are still debated.^（40）Ar-^（39）Ar and LAM-ICPMS zircon U-Pb isotopic dating confirm that these rocks erupted in *** addition,the Nadingcuo volcanic rocks are characterized by high Sr/Y content ratios,similar with the adakite derived from partial melting of oceanic *** can be further classified as high Mg~#（Mg~#=48-57） and low Mg~# （Mg~#=33-42） *** Nadingcuo adakitic rocks have relatively low（^（87）Sr/^（86）Sr）_i and highε_（Nd）（t）, showing a trend of similarity to the Dongcuo ophiolite present in the Bangong-Nujiang oceanic crust. Simple modeling indicates that the Nadingcuo adakitic rocks are a mix resulting from the basalt of Bangong-Nujiang Ocean with 10%-20%crustal material of Lhasa *** these bases we suggest that the low Mg~# Nadingcuo adakitic rocks are the product of partial melting of remnant oceanic crust with small sediment,and the high Mg~# rocks are the result of reaction between rising melt of remnant oceanic crust with subducted sediment and mantle ***,the origin of Nadingcuo adakitic rocks may be related to intracontinental subduction triggered by collision of India-Asia during Cenozoic.

关键词： intracontinental subduction adakitic rocks remnant oceanic crust Nadingcuo Qiangtang Tibetan plateau

Ages and tectonic significance of the collision-related granite porphyries in the Lhunzhub Basin, Tibet, China

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Chinese Science Bulletin 2007年第12期52卷 1669-1679页

作者： wang liquan ZHU DiCheng GENG QuanRu LIAO ZhongLi PAN GuiTang Chengdu Institute of Geology and Mineral Resources Chengdu 610082 China

The Paleocene collision-related granite porphyries are identified for the first time along the western margin of the Lhunzhub Basin, Tibet. SHRIMP U-Pb zircon analysis indicates that the granite porphyries were emplaced at 58.7±1.1 Ma (MSWD = 0.79) during the Indo-Asian continental collision. The granite porphyries are peraluminous and high in K, belonging to the calc-alkaline to high-K calc-alkaline series. They are relatively enriched in LILE, Th and LREE and depletion in Ba, Nb, P and Ti, characterized by LREE-enriched patterns with slightly to moderately negative Eu anomalies. These Paleocene granite porphyries are interpreted as the products generated by partial melting of the pre-existing arc crustal rocks caused by the increase of pressures and temperatures during the crustal shortening at the early stages of the Indo-Asian continental collision since 65 Ma. Despite inherited geochemical features and tectonic settings of the arc protoliths, they are significantly different from the volcanic rocks of the Dianzhong Formation within the Linzizong Group and the Miocene granite por- phyries in the Gangdise belt.

关键词：中国西藏林周盆地古新世花岗石斑岩 U-Pb锆石测年

Geochemistry and Petrogenesis of Volcanic Rocks in the Yeba Formation on the Gangdise Magmatic Arc, Tibet

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Journal of China University of Geosciences 2005年第4期16卷 283-296页

作者： Geng Quanru Pan Guitang Jin Zhenmin wang liquan Liao Zhongli Faculty of Earth Sciences China University of Geosciences Wuhan 430074 China Chengdu Institute of Geology and Mineral Resources Chengdu 610082 China

The Early Jurassic bimodal volcanic rocks in the Yeba Formation, situated between Lhasa, Dagze and Maizhokunggar, composed of metabasalt, basaltic ignimbrite, dacite, silicic tuff and volcanic breccia, are an important volcanic suite for the study of the tectonic evolution of the Gangdise magmatic arc and the Mesozoic Tethys. Based on systematic field investigations, we carried out geochemical studies on representative rock samples. Major and trace element compositions were analyzed for these rock samples by XRF and ICP-MS respectively, and an isotope analysis of Rb-Sr and Sm-Nd was carried out by a MAT 262 mass spectrograph. The results show that the SiO2 contents in lava rocks are 41 %-50.4% and 64 % -69 %, belonging to calc-alkaline basalt and dacite. One notable feature of the basalt is its low TiO2 content, 0.66%-1.01%, much lower than those of continental tholeiite. The ∑REE contents of basalt and dacite are 60.3-135 μg/g and 126, 4--167.9μg/ g respectively. Both rocks have similar REE and other trace element characteristics, with enriched LREE and LILE relative to HREE and HFS, similar REE patterns without Eu anomaly. The basalts have depleted Ti, Ta and Nb and slightly negative Nb and Ta anomalies, with Nb = 0.54--1.17 averaging 0. 84. The dacites have depleted P and Ti and also slightly negative Nb and Ta anomalies, with Nb= 0. 74 -1. 06 averaging 0. 86. Major and trace elemental and isotopic studies suggest that both basalt and dacite originated from the partial melting of the mantle wedge at different degrees above the subduction zone. The spinal Iherzolite in the upper mantle is likely to be their source rocks, which might have been affected by the selective metasomatism of fluids with crustal geochemistry. The LILE contents of both rocks were affected by metamorphism at later stages. The Yeba bimodal volcanic rocks formed in a temporal extensional situation in a mature island arc resulting from the Indosinian Gangdise magmatic arc.

关键词： bimodal volcanic rock geochemistry petrogenesis Gangdise magmatic arc late Indosinian to early Yanshannian.

Petrogenesis of highly fractionated I-type granites in the Zayu area of eastern Gangdese, Tibet: Constraints from zircon U-Pb geochronology, geochemistry and Sr-Nd-Hf isotopes

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Science China Earth Sciences 2009年第9期52卷 1223-1239页

作者： ZHU DiCheng MO XuanXue wang liquan ZHAO ZhiDan NIU Yaoling ZHOU ChangYong YANG YueHeng State Key Laboratory of Geological Processes and Mineral Resources and School of Earth Science and ResourcesChina University of GeosciencesBeijing 100083China Chengdu Institute of Geology and Mineral Resources Chengdu 610082China Department of Earth Sciences Durham UniversityDurham DH1 3LEUK Institute of Geology and Geophysics Chinese Academy of SciencesBeijing 100029China

The Cretaceous granitoids in the middle and northern Gangdese, Tibet are generally interpreted as the products of anatexis of thickened deep crust genetically associated with the Lhasa-Qiangtang collision. This paper reports bulk-rock major element, trace element and Sr-Nd isotopic data, zircon U-Pb age data, and zircon Hf isotopic data on the Zayu pluton in eastern Gangdese, Tibet. These data shed new light on the petrogenesis of the pluton. Our SHRIMP zircon U-Pb age dates, along with LA-ICPMS zircon U-Pb age dates recently reported in the literature, indicate that the Zayu pluton was emplaced at about 130 Ma, coeval with Early Cretaceous magmatic rocks in other areas of eastern Gangdese (e.g., Rawu, Baxoi areas) and the Middle Gangdese. The Zayu pluton samples lack amphibole and muscovite, and are compositionally characterized by high SiO2 (69.9%–76.8%), K2O (4.4%–5.7%), and low P2O5 (0.05%–0.12%). These samples also have A/CNK values of 1.00–1.05, and are enriched in Rb, Th, U, and Pb, and depleted in Ba, Nb, Ta, Sr, P, Ti, and Eu. These geochemical features suggest that the Zayu pluton samples are metaluminous to slightly peraluminous and are of highly fractionated I-type granite. The Zayu pluton samples have high ? Nd(t) values (?10.9–?7.6) and low initial 87Sr/86Sr ratios (0.7120–0.7179) relative to melts derived from mature continental crust in the Gangdese (e.g., Ningzhong Early Jurassic strongly peraluminous granite). The Zayu pluton samples are heterogeneous in zircon ? Hf(t) values (?12.8–?2.9), yielding ancient zircon Hf crustal model ages of 1.4–2.0 Ga. The data obtained in this study together with the data in the recent literature suggest that the Early Cretaceous granitoids in eastern Gangdese represent the eastward extension of the Early Cretaceous magmatism in the middle Gangdese, and that the Lhasa micro-continent block with ancient basement may extend for ～2000 km from east to west. Zircon Hf isotopic data and bulk-rock zircon saturation temperat

关键词： zircon U-Pb dating Sr-Nd-Hf isotope highly fractionated I-type granite Zayu pluton eastern Gangdese Tibet

Therapeutic applications of exosomes from adipose-derived stem cells in antifibrosis

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Chinese Journal of Plastic and Reconstructive Surgery 2021年第3期3卷 161-166页

作者： liquan wang Zhujun Li Yunzhu Li Jiuzuo Huang Nanze Yu Xiao Long Department of Plastic and Reconstructive Surgery State Key Laboratory of Complex Severe and Rare DiseasesPeking Union Medical College Hospital of Peking Union Medical College and Chinese Academy of Medical SciencesBeijing 100730China

Fibrosis is a condition in which connective tissue replaces normal parenchymal tissue,resulting in significant tissue *** can affect several organs and pose a serious threat to human health and *** stem cells(ASCs)have been suggested as promising candidates for antifibrotic *** secretion is one of the key processes in stem cell therapy due to its critical function in cellular ***-derived exosomes(ASC-exos)are used as tools for restoring and regenerating damaged tissue,and they are now thought to orchestrate antifibrosis-related *** this review,we summarize the recent findings and present an extensive view of the therapeutic applications of ASC-exos in fibrotic diseases.

关键词： Mesenchymal stem cell Adipose-derived stem cell Exosome Fibrosis Animal experiment Therapeutic application