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Simulation of Temperature and Flow Field by Three Dimension Finite ElementMethod for Castex Process of AS Wire

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International Journal of Minerals,Metallurgy and Materials 1999年第4期13卷 262-267页

作者： Zhiyuan Shi1 Wanjun Wang1 Zhigang Kan2 Jinglin Wen3.Xinhua Wang1(l Metallurgy School, university of Science and Technology beijing, beijing 100083,{3.2 university of AViation and Spaceflight beijing, beijing 100083,{3.3.Northeastern university, Metallurgy School University of Science and Technology Beijing Beijing 100083 China university of Aviation and Spaceflight beijing Beijing 100083 China Northeastern university Shenyang China

Castex of AS wire is a new technology of near net shape. To study the variation of temperature and velocity of liquid (or semisolid) aluminum during dynamic solidification the numerical simulation was carried out with the theory of heat-transfer and hydrodynamics by means of 3.dimensional finite element method. From simulation results, it is found that the variation of temperature and velocityis mainly influenced by the casting temperature of aluminum, rotating speed of Castex wheel and flow of cooling water. Among theseinfluencing factors, the casting temperature distributes most to the length of liquid phase metal. Moreover, the faster the metal solidifies,the higher the metal there moves with the overall trend of descending from the bottom of the wheel to the shoe wall as well as from sidewalls to the center of wheel groove. In comparison with the practical value, the simulation is reliable.

关键词： Castex dynamic solidification AS wire temperature and flow field, finite element method

Recommendation Method for Contrastive Enhancement of Neighborhood Information

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Computers, Materials & Continua 2024年第1期78卷 453-472页

作者： Hairong Wang beijing Zhou Lisi Zhang He Ma School of Computer Science and Engineering North Minzu UniversityNingxia750021China

Knowledge graph can assist in improving recommendation performance and is widely applied in various person-alized recommendation ***,existing knowledge-aware recommendation methods face challenges such as weak user-item interaction supervisory signals and noise in the knowledge *** tackle these issues,this paper proposes a neighbor information contrast-enhanced recommendation method by adding subtle noise to construct contrast views and employing contrastive learning to strengthen supervisory signals and reduce knowledge ***,first,this paper adopts heterogeneous propagation and knowledge-aware attention networks to obtain multi-order neighbor embedding of users and items,mining the high-order neighbor informa-tion of users and ***,in the neighbor information,this paper introduces weak noise following a uniform distribution to construct neighbor contrast views,effectively reducing the time overhead of view *** paper then performs contrastive learning between neighbor views to promote the uniformity of view information,adjusting the neighbor structure,and achieving the goal of reducing the knowledge noise in the knowledge ***,this paper introduces multi-task learning to mitigate the problem of weak supervisory *** validate the effectiveness of our method,experiments are conducted on theMovieLens-1M,MovieLens-20M,Book-Crossing,and Last-FM *** results showthat compared to the best baselines,our method shows significant improvements in AUC and F1.

关键词： Contrastive learning knowledge graph recommendation method

Phase relationship of complex multi-component system in chromate cleaner production

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Progress in Natural Science:Materials International 2007年第7期17卷 845-850页

作者： Ge Xinlei~1 Wang Xidong~(1,3.*) Zheng Shili~2 Zhang Mei~1 Zhang Yi~2 (1.department of Physical Chemistry,university of Science and Technology beijing,beijing 100083,china 2.Institute of Process Engineering,Chinese Academy of Sciences,beijing 100080,china 3.College of Engineering,peking university,beijing 100871,china) department of Physical Chemistry University of Science and Technology Beijing Beijing 100083 China College of Engineering Peking University Beijing 100871 China Institute of Process Engineering Chinese Academy of Sciences Beijing 100080 China

The phase relationships of the complex multi-component systems in the liquid-phase oxidization and separation process related with the chromate cleaner production are investigated theoretically and *** phase diagram of main system Fe- Cr2O4-KOH-O2of oxidization process and the relationship of its standard Gibbs free energy change with temperature are calculated.A se- ries of phase diagrams of the separation process at different temperatures,such as K（Na）OH-K（Na）2CrO4-H2O,KOH-KAlO2-H2O, K（Na）OH-K（Na）2CO3.H2O,K（Na）OH-K（Na）HCO3.H2O and K（Na）HCO3.K（Na）2CrO4-H2O have also been *** ex- periments are carried out to verify the calculated *** results showed that the sub-molten salt media are suitable for the oxidization and separation processes;FeCr2O4can be oxidized across a wide range of temperature;K（Na）2CrO4can be separated from K（Na）AlO2system at appropriate temperature and proper concentration;the crystallization of carbonate is easier than that of K（Na）2CrO4.

关键词： chromite chromate system thermodynamics calculation phase diagram

A preliminary analysis of arcuate structures-relationship of the island arc and deep-sea trench to the dip angle of Benioff zone

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Acta Oceanologica Sinica 1989年第1期8卷 125-136页

作者： Wu Lun, Liang Haihua, Ren Fuhu and Li Maosong The department of Geography, peking university, beijing,{3. The department of Geology, peking university, beijing,{3. Dept of Geography Peking Univ. Beijing China China

The origin of arcuate islands and deep-sea trenches has been studied for a long time and various interpretations have been proposed. In this paper, some analytical models are put forward from a geometrical viewpoint and then the theoretical dip angles of the underthrusting slabs of circum-Pacific island arcs are computed and compared with those of the Benioff zone. As a result, it is found that the dip angle of the underthrusting slab is one of the main factors determining the curvature of the arcuate structure. The authors consider that this result may contribute to the plate theory.

关键词： A preliminary analysis of arcuate structures-relationship of the island arc and deep-sea trench to the dip angle of Benioff zone deep

Adhesion of NiCu Films DC Biased Plasma-Sputter-Deposited on MgO (001)

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International Journal of Minerals,Metallurgy and Materials 2000年第3期14卷 218-221页

作者： Hong Qiu, Mituru Hashimoto ( beijing Keda-Tianyu Microelectronic Material Technology Development Corporation, beijing 100083, china Applied Science School, {3. of Science and Technology beijing, beijing 100083, china department of Applied Phys beijing Keda-Tianyu Microelectronic Material Technology Development Corporation Beijing 100083 China Applied Science School University of Science and Technology Beijing Beijing 100083 China department of Applied Physics and Chemistry University of Electro-Communications 1-5-1 Chofugaoka Chofu-shi Tokyo 182-8585 Japan

NiCu films about 60nm thick were deposited on MgO (001) substrates at 23.℃ by DC plasma-sputtering at 2.7kV and 8mA in pure Ar gas using a Ni90Cu10 target. A DC bias voltage of 0, 60, 110 or 140V was applied to the substrate during deposition. The adhesion of the film to the substrate was studied using a scratch test as a function of . The application of is very effective in increasing the adhesion of the film to the substrate. In conclusion, the adhesion increases with cleaning the substrate surface by sputtering off impurity admolecules during the film initial formation due to the energetic Ar ion particle bombardment.

关键词： NiCu film plasma-sputter-deposition negative bias voltage adhesion

A class of discounted models for singular diffusion control

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Chinese Science Bulletin 2000年第5期45卷 405-408页

作者： LIU Kunhui, QIN Mingda & LU Chuanlai1. College of Sciences, Northern Jiaotong university, beijing 100044, china 2. {3. of Mathematics and Mechanics, beijing university of Science and Technology, beijing 100083 .china 3. {3. of Information Engineering, beijing university of Posts and Telecommunications, beijing 100876, china Correspondence should be addressed to Lu Chuanlai College of Sciences Northern Jiaotong University Beijing China department of Mathematics and Mechanics Beijing University of Science and Technology Beijing China department of Information Engineering Beijing University of Posts and Telecommunications Beijing China

A kind of discounted problems for singular diffusion control have been studied. The drift and diffusion coefficients of state process are nonlinear. The class of models has been basically extended from a corresponding one established by Karatzes et al. before. By applying some analysis methods different from earlier works, the sufficient and necessary conditions of the existence of optimal control have been obtained. If an optimal control exists, it is a 'transient reflection' of state process for two lines.

关键词： stochastic control variational equation singular stochastic control.

Protective effect of tubuloside B on TNFα-induced apoptosis in neuronal cells

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Acta Pharmacologica Sinica 2004年第10期 36-44页

作者： Min DENG, Jin-yuan ZHAO, Xiao-dong JU, Peng-fei TU, Yong JIANG, Zheng-bin LIResearch Center of Occupational Medicine, department of Orthopaedics, peking university third hospital,{3., china peking university Modem Research Center for Traditional Chinese Medicine,{3., china Institute of Materia Medica, Chinese Academy of Medical Sciences, peking Union Medical College, beijing 100050, china

AIM: To investigate the neuroprotective effect of tubuloside B, one of the phenylethanoids isolated from the stems of Cistanche salsa, on tumor necrosis factor-alpha (TNFα)-induced apoptosis in SH-SY5Y neuronal cells. METHODS: Cell viability was analyzed using MTT assay. Apoptotic cells were detected using Hoechst3.3.2 staining, and confirmed by DNA fragmentation and flow cytometric analysis. The activity of caspase-3.was measured with special assay kit. The concentration of free intracellular calcium was determined with the probe Indo-1 by spectrometer. The level of intracellular reactive oxygen species and the potential of mitochondrial membrane were determined by laser scanning confocal microscopy (LSCM) combined with fluorescence probe H2DCFDA or JC-1 respectively. RESULTS: SH-SY5Y cells treated with TNFa 100 μg/L for 3. h showed typical morphological changes of apoptosis. DNA ladder could be observed by agarose gel electrophoresis. The highest percentage of apoptotic cells accumulated to 3..5 %. F

关键词： tubuloside B apoptosis tumor necrosis factor SH-SY5Y cells mitochondria membrane potential reactive oxygen species caspase-3 calcium

Calculating model of mass action concentrations for Ag-Au-Cu melts

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Rare Metals 2002年第1期21卷 43-47页

作者： ZHANG Jian Metallurgy School, university of Science and Technology beijing, beijing 100083,{3. Metallurgy School University of Science and Technology Beijing 北京 100083

Based on phase diagrams and measured activities, the calculatingmodel of mass action concentrations for het- erogeneous meltsAg-Au-Cu was formulated. Calculated results agree with the improvedresults of recent research work, Showing that the model formulatedcan reflect the structural characteristics of these melts. In thismodel, without the help Of any empirical parameters, only threeequilibrium constants are used, hence it is simple, lear, andfavorable to the sim- Plification of calculation.

关键词： activity mass action concentration eutectic Solid solution

Circadian expression of clock genes and angiotensin Ⅱ type 1 receptors in suprachiasmatic nuclei of sinoaortic-denervated rats

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Acta Pharmacologica Sinica 2007年第4期28卷 484-492页

作者： Hui LI~2,Nmg-ling SUN~(2,4),Jin WANG~3.Ai-jun LIU~3.Ding-feng SU~(3.4)~2department of Cardiology,peking university People's {3.,beijing 100044,china ~3.0} of Pharmacology,Second MilitaryMedical university,Shanghai 20043.,china department of Cardiology Peking University People's Hospital Beijing China department of Pharmacology Second Military Medical University Shanghai China

Aim:To investigate whether the circadian expression of central clock genes andangiotensin Ⅱ type 1 (AT1) receptors was altered in sinoaortic-denervated (SAD)***:Male Sprague-Dawley rats underwent sinoaortic denervation or asham operation at the age of 12 *** weeks after the operation,bloodpressure and heart period were measured in the conscious state in a group ofsham-operated (n=10) and SAD rats (n=9).Rest SAD and sham-operated ratswere divided into 6 groups (n=6 in each group).The suprachiasmatic nuclei (SCN)tissues were taken every 4 h throughout the day from each group for the determi-nation of the mRNA expression of clock genes (Per2 and Bmal1) and the AT1receptor by RT-PCR;the protein expression of Per2 and Bmal1 was determined byWestern ***:Blood pressure levels in the SAD rats were similar tothose of the sham-operated ***,blood pressure variabilities signifi-cantly increased in the SAD rats compared with the sham-operated *** variation of clock genes in the SCN of the sham-operated rats was char-acterized by a marked increase in the mRNA and protein expression during ***2 and Bmal1 mRNA levels were significantly lower in the SAD rats,especially during dark *** blot analysis confirmed an attenuation ofthe circadian rhythm of the 2 clock proteins in the SCN of the SAD ***1receptor mRNA expressions in the SCN were abnormally upregulated in the lightphase,changed to a 12-h cycle in the SAD ***:The circadian varia-tion of the 2 central clock genes was attenuated in the SAD *** baroreflexdysfunction also induced a disturbance in the expression of AT1 receptors in theSCN.

关键词： circadian rhythm arterial baroreflex clock genes sinoaortic denervation reninangiotensin system