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DIFFERENTIAL SCANNING CALORIMETRY AND X-RAY DIFFRACTION STUDIES ON AGING BEHAVIOR OF z.-Al ALLOYS

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Acta Metallurgica Sinica(English Letters) 2001年第2期14卷 109-114页

作者： X.L. xu, z. W. Yu, S.J. Ji, J.C. Sun and z.K. Hei (Dalian Maritime University, Dalian 116024, China) Dalian Maritime Univ. Dalian 116024 China

Decomposition processes of the quenched z.-Al alloys were studied by differential scanning calorimetry (DSC), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results show that the stabilities of supersaturated solid solution (SSS) of z.-Al alloy and α' phase formed by quenching would reduce with the increase of z. content and the precipitation of η-z. phases even when aging at ambient temperature, so that the exothermic precipitation peak in DSC curve would disappear. The activation energy of the η-z. precipitation and the reaction enthalpy were calculated and measured. The kinetics of α' decomposition or η-z. formation was determined by XRD. The microstructure change during aging was observed by TEM.

关键词： Aging of materials Aluminum alloys Differential scanning calorimetry X ray diffraction

STUDY ON THE CONTROLLED MASS TRANSPORT THROUGH POROUS MEMBRANES

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化工学报 2000年第S1期51卷 15-19页

作者： xu Xia and Cui z. F (Department of Engineering Scinece, University of Oxford,OXI 3PJ, UK)

Cryopreservation of cells and tissues (natural or engineered) usually involves complicated protocols for addition and later removal of cryoprotecting agents to avoid osmotic shock and toxicity to cells. The rate of CPA addition and removal is essential to cell survival. In this study, the feasibility of using porous membrane to control the rate of CPA transfer to cell environment is studied, A purpose designed diffusion chamber was fabricated. The effects of membrane characteristics (porosity and effective thickness), temperature, and initial concentration were experimentally studied. A simplified mathematical model was developed, which provides the basis to desire the membrane parameters based on tile experimental measurements.

关键词： mass transport membranes diffusion rate control cryopreservation

Observation　and　identification　of　X－ray（0．3－30Bnm)　multiple－order　diffraction　spectra

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Chinese Journal of Lasers 1994年第5期 413-420页

作者： FENG X. P HOU X. B z.ANG z. Q xu z. z.(Shanghai Institute of Optics and Fine Mechanics,Acdemaia Sinica, P. O. Box 800-211, Shanghai 201800, China)

ＯｂｓｅｒｖａｔｉｏｎａｎｄｉｄｅｎｔｉｆｉｃａｔｉｏｎｏｆＸ－ｒａｙ（０．３－３０ｎｍ）ｍｕｌｔｉｐｌｅ－ｏｒｄｅｒｄｉｆｆｒａｃｔｉｏｎｓｐｅｃｔｒａＦＥＮＧＸ．Ｐ；ＨＯＵＸ．Ｂ；ＺＨＡＮＧＺ．Ｑ；ＸＵＺ．Ｚ．（... 详细信息

ＯｂｓｅｒｖａｔｉｏｎａｎｄｉｄｅｎｔｉｆｉｃａｔｉｏｎｏｆＸ－ｒａｙ（０．３－３０ｎｍ）ｍｕｌｔｉｐｌｅ－ｏｒｄｅｒｄｉｆｆｒａｃｔｉｏｎｓｐｅｃｔｒａＦＥＮＧＸ．Ｐ；ＨＯＵＸ．Ｂ；ＺＨＡＮＧＺ．Ｑ；ＸＵＺ．Ｚ．（ＳｈａｎｇｈａｉＩｎｓｔｉｔｕｔｅ...

关键词： X-ray spectra laser plasma

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激光熔覆制备金属间化合物抗冲蚀涂层

航空制造技术 2004年第Z1期47卷 79-81,122页

作者： X.Y. xu W.J. Liu M.L. z.ong H.Q. Sun X.Y. xu R. z. Ba

采用同轴送粉方法,激光熔覆制备了WC增强Ni3Al金属间化合物基复合涂层,通过试验,优化了工艺参数,对激光熔覆涂层的成分、组织和硬度进行了测试和分析.结果表明,激光熔覆涂层无裂纹和气孔,与基体形成良好的冶金结合,WC颗粒的添加显著提... 详细信息

采用同轴送粉方法,激光熔覆制备了WC增强Ni3Al金属间化合物基复合涂层,通过试验,优化了工艺参数,对激光熔覆涂层的成分、组织和硬度进行了测试和分析.结果表明,激光熔覆涂层无裂纹和气孔,与基体形成良好的冶金结合,WC颗粒的添加显著提高了涂层硬度.

关键词：激光熔覆金属间化合物镍铝化合物

Excitonic character of nanometer z.O films prepared by thermaloxidation of z.S films

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Excitonic character of nanometer ZnO films prepared by therm...

第九届全国发光学术会议

作者： X. T. z.ang, Y. C. Liu. z. z. z.i, J. Y. z.ang, Y. M. Lu, W. xu, D. z. Shen, G. z. z.ong, X. W. Fan and X. G. Kong Open Laboratory of Excited State Processes, Chinese Academy of Science, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Science, 1- Yan An Road, Changchun, 130021, P. R. China

As a wide band gap (Eg=3.37 eV), z.O has attracted considerable attention due to potentialapplications, such as ultraviolet light-emitting devices and laser devices. A large exciton binding energy (59 eV)permits excit...

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论软件工程发展的三个方面—C~2F

武汉大学学报(自然科学版) 1988年第3期 117-122页

作者：徐仁佐

本文论述软件工程发展的三个方面:1.对软件生产过程的控制(Controling the Software Production process),2.根本改变软件生产的过程(Changing the Software production process),3.寻找新的计算机系统与方法(Finding new Computer Syst... 详细信息

关键词：软件工程软件生产过程集成化环境智能环境软件产业

Enantio-divergent C–H borylation with two different ligands from a single chiral source

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Science China Chemistry 2025年第1期68卷 226-232页

作者： Rongrong Du Senmiao xu State Key Laboratory for Oxo Synthesis and Selective Oxidation Lanzhou Institute of Chemical Physics Chinese Academy of Sciences College of Material Chemistry and Chemical Engineering Key Laboratory of Organosilicon Chemistry and Material TechnologyMinistry of Education Hangzhou Normal University University of Chinese Academy of Sciences

Reported here is an iridium-catalyz.d enantio-divergent C（sp3）–H borylation of α-gem-dimethyl groups of trifluoromethyl ketone-derived hydraz.nes to construct a series of acyclic all-carbon quaternary stereocenters with a high level of chiral induction. Two different chiral bidentate boryl ligands from a common chiral source not only can switch the enantioselectivity but also are complementary in terms of the substrate scope.

关键词： asymmetric catalysis C–H borylation all-carbon quaternary stereocenters synthetic methods

Aquaporin-4-IgG-seropositive neuromyelitis optica spectrum disorders:progress of experimental models based on disease pathogenesis

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Neural Regeneration Research 2025年第2期20卷 354-365页

作者： Li xu Huiming xu Changyong Tang Department of Neurology The Third Affiliated Hospital of Sun Yat-sen UniversityGuangzhouGuangdong ProvinceChina

Neuromyelitis optica spectrum disorders are neuroinflammatory demyelinating disorders that lead to permanent visual loss and motor *** date,no effective treatment exists as the exact causative mechanism remains ***,experimental models of neuromyelitis optica spectrum disorders are essential for exploring its pathogenesis and in screening for therapeutic *** most patients with neuromyelitis optica spectrum disorders are seropositive for IgG autoantibodies against aquaporin-4,which is highly expressed on the membrane of astrocyte endfeet,most current experimental models are based on aquaporin-4-IgG that initially targets *** experimental models have successfully simulated many pathological features of neuromyelitis optica spectrum disorders,such as aquaporin-4 loss,astrocytopathy,granulocyte and macrophage infiltration,complement activation,demyelination,and neuronal loss;however,they do not fully capture the pathological process of human neuromyelitis optica spectrum *** this review,we summariz. the currently known pathogenic mechanisms and the development of associated experimental models in vitro,ex vivo,and in vivo for neuromyelitis optica spectrum disorders,suggest potential pathogenic mechanisms for further investigation,and provide guidance on experimental model *** addition,this review summariz.s the latest information on pathologies and therapies for neuromyelitis optica spectrum disorders based on experimental models of aquaporin-4-IgG-seropositive neuromyelitis optica spectrum disorders,offering further therapeutic targets and a theoretical basis for clinical trials.

关键词： aquaporin-4 experimental model neuromyelitis optica spectrum disorder pathogenesis

Reducing the measurement errors in nonadiabatic holonomic quantum computers

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 64-70页

作者： Guo-Fu xu Department of Physics Shandong University

Nonadiabatic holonomic quantum computers serve as the physical platform for nonadiabatic holonomic quantum *** quantum computation has entered the noisy intermediate-scale era, building accurate intermediate-scale nonadiabatic holonomic quantum computers is clearly necessary. Given that measurements are the sole means of extracting information, they play an indispensable role in nonadiabatic holonomic quantum computers. Accordingly, developing methods to reduce measurement errors in nonadiabatic holonomic quantum computers is of great importance. However, while much attention has been given to the research on nonadiabatic holonomic gates, the research on reducing measurement errors in nonadiabatic holonomic quantum computers is severely lacking. In this study, we propose a measurement error reduction method tailored for intermediate-scale nonadiabatic holonomic quantum computers. The reason we say this is because our method can not only reduce the measurement errors in the computer but also be useful in mitigating errors originating from nonadiabatic holonomic gates. Given these features,our method significantly advances the construction of accurate intermediate-scale nonadiabatic holonomic quantum computers.

关键词： quantum holonomy quantum computation measurement errors