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NUMERICAl SIMUlATION OF INDUCTION SKUll MElTING PROCESS FOR TITANIUM-AlUMINIUM BASE AllOY

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Acta Metallurgica Sinica(English letters) 2004年第6期17卷 928-933页

作者： Z.Y.Chen l.j.xu F.T.Kong Q.Shu Y.Y.Chen SchoolofMaterialsScienceandEngineering HarbinInstituteofTechnologyHarbin150001China

The mathematics model for temperature field of water-cooling copper crucible induction skull melting process was established. The program for simulating temperature field of melting process was developed with finite element method. The temperature field of the melting process for Ti-47Al-2Cr-2Nb alloy was calculated. During melting period, the temperature is raised gradually along radius augmentation direction. The elements of the charge near the crucible wall are molten first. The center elements of the charge are molten last. The melting time of the center element is just that of all the charge melting. The melting time of Ti-47Al-2Cr-2Nb alloy is 15min. In which, the charge was heated by low power 80kW for 9min and by high power 300kW for 6min. When melting Ti-47Al-2Cr-2Nb alloy, the loading power is nearly direct proportion to melt temperature. Increasing loading power may raise melt temperature. The best melting power of Ti-47Al-2Cr-2Nb alloy is 305-310kW. This is identical with the melting test and has guidance sense to the melting process of actual titanium alloy.

关键词： TiAl base alloy melting numerical simulation

Emerging role of A-kinase anchoring protein 5 signaling in reward circuit function

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Neural Regeneration Research 2025年第10期20卷 2913-2914页

作者： William j.Flerlage Mark l.Dell’Acqua Brian M.Cox Fereshteh S.Nugent Uniformed Services University of the Health Sciences Department of Pharmacology and Molecular TherapeuticsBethesdaMDUSA Department of Pharmacology University of Colorado School of MedicineAnschutz Medical CampusAuroraCOUSA

There is a strong evidence supporting the hypothesis of synaptic dysfunction as a major contributor to neural circuit and network disruption underlying emotional and mood dysregulation in psychiatric disorders(Simmons et al.,2024).Diverse sets of distinct molecular signaling pathways converge on the synapse to regulate synaptogenesis,synaptic function,and synaptic plasticity in brain regions and circuits through complex interactions organized by numerous multivalent protein scaffolds,including the family of proteins known as A-kinase anchoring proteins(AKAPs).

关键词： function supporting

Apples to oranges:environmentally derived,dynamic regulation of serotonin neuron subpopulations in adulthood?

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Neural Regeneration Research 2025年第9期20卷 2596-2597页

作者： Christopher j.O’Connell Matthew j.Robson Department of Genetics College of MedicineHarvard UniversityBostonMAUSA james l.Winkle College of Pharmacy Division of Pharmaceutical SciencesUniversity of CincinnatiCincinnatiOHUSA Neuroscience Graduate Program College of MedicineUniversity of CincinnatiCincinnatiOHUSA

Traumatic brain injury(TBI)is a public health problem with an undue economic burden that impacts nearly every age,ethnic,and gender group across the globe(Capizzi et al.,2020).TBIs are often sustained during a dynamic range of exposures to energetic environmental forces and as such outcomes are typically heterogeneous regarding severity and pathology(Capizzi et al.,2020).

关键词： sustained orange dynamic

Extragalactic dispersion measures of fast radio bursts

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Research in Astronomy and Astrophysics 2015年第10期15卷 1629-1638页

作者： jun xu j.l.Han National Astronomical Observatories Chinese Academy of Sciences

Fast radio bursts show large dispersion measures, much larger than the Galactic dispersion measure foreground. Therefore, they evidently have an extragalac- tic origin. We investigate possible contributions to the dispersion measure from host galaxies. We simulate the spatial distribution of fast radio bursts and calculate the dis- persion measures along the sightlines from fast radio bursts to the edge of host galaxies by using the scaled NE2001 model for thermal electron density distributions. We find that contributions to the dispersion measure of fast radio bursts from the host galaxy follow a skew Gaussian distribution. The peak and the width at half maximum of the dispersion measure distribution increase with the inclination angle of a spiral galaxy, to large values when the inclination angle is over 70~. The largest dispersion measure produced by an edge-on spiral galaxy can reach a few thousand pc cm-3, while the dispersion measures from dwarf galaxies and elliptical galaxies have a maximum of only a few tens of pc cm-3. Notice, however, that additional dispersion measures of tens to hundreds of pc cm-3 can be produced by high density clumps in host galaxies. Simulations that include dispersion measure contributions from the large Magellanic Cloud and the Andromeda Galaxy are shown as examples to demonstrate how to ex- tract the dispersion measure from the intergalactic medium.

关键词： galaxies: ISM -- radio continuum: ISM -- ISM: general

Aero-Acoustics of Modern Transonic Fans—— Fan Noise Reduction from Its Sources

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journal of Thermal Science 2003年第2期12卷 104-113页

作者： l.xu j.D.Denton Whittle laboratory University of CambridgeUKWhittle LaboratoryUniversity of CambridgeUK

The noise of aerodynamics nature from modern transonic fan is examined from its sources with the perspective of noise reduction through aero-acoustics design using advanced Computational Fluid Dynamics (CFD) tools. In particular the problems associated with the forward propagating noise in the front is addressed. It is identified that the shock wave spillage from the leading edge near the fan tip is the main source of the tone noise. Two different approaches have been studied to reduce the forward arc tone noise and two state-of-art transonic fans are designed using the strategies developed. The following rig tests show that while the fans exhibit other noise problems, the primary goals of noise reduction have been achieved through both fans and the novel noise reduction concept vindicated.

关键词： transonic fan aero-acoustics noise reduction.

Approach for electrodynamic force for compensation in low voltage circuit breaker WP 630-1.2 type

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journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第3期8卷 393-396页

作者： lU Na xu l.j Miedzifiski B Automation School Beijing University of Posts and Telecommunications Beijing 100876 China Electrical Power Engineering Institute Wroclaw University of Technology Wroclaw Poland

Undesirable repulsive force between contact members due to both a current path shrink near a real contact area and/or so-called pinch effect is particularly onerous for power switch applications, and results in either contact floating or bouncing which are associated with an electric arc following contact welding. This problem is of great importance for any circuit breaker especially for compact low voltage vacuum circuit breakers. To avoid contact floating at closure and during any inrush current under short circuit conditions, the electrodynamic repulsive force can be employed successfully if we use a special compensation system flexibly combined with the contact itself. However to select and design the compensation system properly, its efficiency has to be known. This paper presents an approach to obtain the electrodynamic force value depending on different shaped (rectangular, square, circle and arch) copper plates used in the compensator by using ANSYS for current values 40 kA RMS. Curve-fitting was done according to the calculating results, the optimization designing of compensation unit is based on them.

关键词： Compensation. Electrodynamic force. FEM (Finite Element Method)

Numerical Simulation of Natural Convection in Circular Enclosures with Inner Polygonal Cylinders,with Confirmation by Experimental Results

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journal of Thermal Science 1992年第4期1卷 249-258页

作者： H. l. Zhang (1) W. Q. Tao (1) Q. j. Wu (1) 1. Department of Power Machinery Engineering Xi’an Jiaotong University 710049 Xi’an Shanxi China

Numerical computations are performed for the natural convection in circular enclosures with inner polygonal *** polygon surface and the outer envelope are at constant but different temperatures,A body-fitted coordinate system is used,The coordinate system is generated via simple algebraic *** transformed governing equations are discretized on a control volume basis with power-law finite difference *** SIMPlE-like algorithm is used to deal with the linkage between pressure and *** numerical results are compared with the experimental data available in the literature,and the agreement between the numerical and experimental results are very good.

关键词： Natural convection circular enclosure body-fitted coordinates

A NOVEl METHOD FOR EVAlUATING PlANE STRESS DYNAMIC FRACTURE TOUGHNESS OF 0Cr18Ni10Ti STAINlESS STEEl WElDED jOINTS

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Acta Metallurgica Sinica(English letters) 2008年第4期21卷 303-312页

作者： Z.j. xu Y.l. li School of Aeronautics Northwestern Polytechnical University Xi＇an 710072 China

A novel method was proposed for the evaluation of Mode I dynamic fracture toughness （DFT） under plane stress and small scale yielding conditions for welded joints of stainless steel （SS）, 0Cr18Ni10Ti. In a hybrid experimental-numerical approach, the experiments were carried out on the Hopkinson pressure bar apparatus, and three dimensional （3D） transient numerical simulations were performed by a finite element （FE） computer program. Macroscopical plastic deformation was observed at the loading and supporting points, on the specimens, after the test, which could cause a large error if omitted in the numerical simulation. Therefore, elustic-viscoplustic analysis was performed on the specimen by adopting the johnson-Cook （j-C） model to describe the rate-dependent plastic flow behavior of the material. The material heterogeneity in the mismatched welded joints, induced by the difference in the base metal （BM） and the weld metal （WM） in yield stress, has also been taken into consideration by using the j-C models separately. Good accordance was obtained between the experimental and the computational results by the present approach. The relationship between plane stress DFT and loading rate was also obtained on the order of 108 MPa.m^1/2.s^-1.

关键词： 0Cr18Ni10Ti Welded joint High strain rate Dynamic fracture Plane stress

Alpha-latrotoxin Triggers Extracellular Ca2+-dependent Exocytosis and Sensitizes Fusion Machinery in Endocrine Cells

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Acta Biochimica et Biophysica Sinica 2006年第1期38卷 8-14页

作者： Zhi-Tao HU~(1#),Ping ZHAO~(1#),jie lIU~(1#),Zheng-Xing WU~(1*),and Tao xu~(1,2*) ~1 School of life Science and Technology,Huazhong University of Science and Technology,Wuhan 430074,China ~2 National laboratory of Biomacromolecules,Institute of Biophysics,Chinese Academy of Sciences,Beijing 100101,China School of life Science and Technology Huazhong University of Science and Technology Wuhan 430074 China National laboratory of Biomacromolecules Institute of Biophysics Chinese Academy of Sciences Beijing 100101 China

α-latrotoxin from the venom of black widow spider induces and augments neurotransmitterand hormone release by way of extracellular Ca2+influx and cellular signal transduction *** usingwhole cell current and capacitance recording,the photolysis of card Ca2+,and Ca2+microfluorometry andamperometry,we investigated the stimulating effect and mechá（?）ism of α-latrotoxin on exocytosis in ratpancreatic β cells,lβT2 cells and latrophilin plasmid-transfected INS-1 *** data indicated that:（1）α-latrotoxin increased cytosolic Ca2+concentration through the formation of cation-permitting pores and sub-sequent Ca2+influx with the presence of extracellular Ca2+;（2）α-latrotoxin stimulated exocytosis in normalbath solution and its stimulating effect on secretion was eradicated in Ca2+-free bath solution; and （3）α-latrotoxin sensitized the molecular machinery of fusion through activation of protein kinase C and increasedthe response of cells to Ca2+photolysed by a flash of ultraviolet *** summary,α-latrotoxin inducedexocytosis by way of Ca2+influx and accelerated vesicle fusion by the sensitization of fusion machinery.

关键词： α-latrotoxin exocytosis calcium Ca2+-sensitivity of fusion protein kinase C(PKC) capacitance measurement amperometry