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ANALYSIS OF CRACK-TIP SINGULARITIES FOR AN INTERFACIAL PERMEABLE CRACK IN METAL/PIEZOELECTRIC BIMATERIALS

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Acta Mechanica Solida Sinica 2007年第3期20卷 247-257页

作者： Li Qun Chen Yiheng~* (School of Aerospace,xi’an jiao-tong university,xi’an 710049,China) Faculty of Engineering and Design Kyoto Institute of Technology Sakyo-ku Kyoto 606-8585 School of Aerospace Xi\'an Jiao-Tong University Xi\'an 710049 China

By modeling metal as a special piezoelectric material with extremely small piezoelec- tricity and extremely large permittivity,we have obtained the analytical solutions for an interfacial permeable crack in metal/piezoelectric bimaterials by means of the generalized Stroh formalism. The analysis shows that the stress fields near a permeable interfacial crack tip are usually with three types of singularities:r;and r;.Further numerical calculation on the oscillatory indexεare given for 28 types of metal/piezoelectric bimaterials combined by seven commercial piezoelectric materials: PZT-4,BaTiO;,PZT-5H,PZT-6B,PZT-7A,P-7 and PZT-PIC 151 and four metals:copper,silver,lead and aluminum,*** explicit expressions of the crack tip energy release rate（ERR）and the crack tip generalized stress intensity factors（GSIF）are *** is found that both the ERR and GSIF are independent of the electric displacement loading,although they seriously depends on the mechanical loadings.

关键词： interfacial permeable crack metal/piezoelectric bimaterials energy release rate intensity factor

The Evaluation of Connection Coefficients on an Interval

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Communications in Nonlinear Science and Numerical Simulation 1998年第4期3卷 252-255页

作者： xiaolin ZHOU and Wu ZHANG(Department of Applied Mathematics, xi’an jiao tong university, xi’an 710049, China) Department of Applied Mathematics Xi'an Jiaotong University Xi'an 710049 China

A connection coefficient is an interval of products of wavelet basis functions,their derivatives and their translates. It can be used to solve PDEs numerically by the wavelet- Galerkin method. This paper presents an e... 详细信息

关键词： connection coefficients wavelets

Discussion　on　the　physics　phenomena　and　the　mechanism　of　forming　weld　joint　in　the　process　of　copper－stainless　steel　friction　welding

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China Welding 1995年第1期4卷 19-27页

作者： Shi Kai(xi’an Petroleum Institute)Wang Shiyan Qiu Fengxiang and xia Wei(xi’an jiao tong university)

The physics phenomena of copper and stainless steel in the process of forming friction welding joint are recorded and observed by the interrupted test *** test shows that the butt friction welding process of copper and stainless steel bar can be divided into three stages approximately: the adhesion at the beginning friction stage, the friction inside the copper and the plastic ring expansion, and the friction on the bound surface of copper-stainless steel and in stainless steel. During the process,the friction surface was transformed twice.

关键词： copper-stainless steel friction welding interrupted test method

Transonic flow of moist air around an NACA 0012 airfoil with non-equilibrium condensation

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Progress in Natural Science:Materials International 2005年第9期15卷 838-842页

作者： LI Liang**, SUN xiuling, FENG Zhenping and LI Guojun(School of Energy & Power Engineering, xi’an jiao tong university, xi’an 710049, China) School of Energy & Power Engineering Xi'' an Jiao Tong University Xi'' an 710049 China

The classical condensation model of water vapor is coupled with the Euler equations to calculate transonic flows of moist air with non-equilibrium condensation. By means of this model, numerical computations are implemented to investigate the aerodynamic characteristics of an NACA 0012 airfoil in transonic flows of moist air at various angles of attack and relative humidities, and the results are compared with those in dry air flows. For different angles of attack considered at 50% relative humidity, the lift decreases 30%—40%. The pressure drag increases when the angle of attack is smaller than 1.4° and decreases when higher than 1.4°. At zero angle of attack, with the relative humidity rising from zero to 90%, the pressure drag increases exponentially. At 90% relative humidity, the pressure drag increases 160%, and self-oscillation takes place periodically and alternately over the upper and lower surfaces of the airfoil. The oscillation is caused by the interactions of local supersonic flow and heat release in the condensation process.

关键词： NACA 0012 airfoil moist air non-equilibrium condensation.

A Least-Squares Solution to Nonlinear Steady-State Multi-Dimensional IHCP

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Journal of Thermal Science 1996年第1期5卷 39-41页

作者： Bai Bofeng Guo Liejin Chen Xuejun (State Key Lab of Multiphase Flow in Power Engineering,xi’an jiao tong university,xi’an 710049,China) State Key Lab of Multiphase Flow in Power Engineering Xi’an Jiao Tong University Xi’an China

In this paper,the least-squares method is used to solve the Inverse Heat Conduction Problem(IHCP)to determine the space-wise variation of the unknown boundary condition on the inner surface of a helically coiled tube with fluid flow inside,electrical heating and insulation *** sensitivity coefficient is analyzed to give a rational distribution of the thermocouples. The results demonstrate that the method effectively extracts information about the unknown boundary condition for the heat conduction problem from the experimental measurements. The results also show that the least-squares method converges very quickly.

关键词： helically coiled tube least-squares method IHCP.

Top 10 Influential Events in carbon neutrality and climate change response for 2023

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Frontiers in Energy 2024年第1期18卷 1-3页

作者： Research Institute of Carbon Neutrality of Shanghai jiao tong university Research Institute of Carbon Neutrality Shanghai Jiao Tong UniversityShanghai 200240China

In 2023, the global community intensified its efforts towards achieving carbon neutrality and addressing climate change, witnessing several impactful events. Research Institute of Carbon Neutrality, Shanghai jiao tong university compiled the Top 10 Events (in chronological order) in the field of global carbon neutrality and climate change response for 2023, to share with readers these significant moments that document the ongoing ambition and collective efforts of human society.

关键词： neutral collective intensified

Diagnosis and treatment of polypoid lesions of the gallbladder:report of 194 cases

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Hepatobiliary & Pancreatic Diseases International 2004年第4期3卷 591-594页

作者： Xue-Jun Sun, Jing-Sen Shi, Yue Han, Jian-Sheng Wang and Hong Ren xi’ an, China Department of Surgery, First Hospital of xi’ an jiao- tong university, xi’ an 710061 , China Department of Surgery First Hospital of Xi'an Jiaotong University Xi'an 710061 China. Sunxy@***

BACKGROUND: With the wide use of B-ultrasonography in recent years, the polypoid lesion of the gallbladde ( PLG) has been one of the most common diseases detected in biliary surgery. This study was to investigate the diag nostic method and operative indications of PLG. METHODS: The clinical and pathological data of 194 pa tients with PLG who had received operation at our hospita from January 1994 to September 2002 were analyzed retro spectively. Categorized data were analyzed by the chi square test. RESULTS: All the patients received preoperative B-ultra- sonography. 185 of the 194 PLG patients were diagnosed as having cholecystic polyp, and 9 adenomas. Among the 42 patients who received CT, 6 showed early gallbladder can cer. Pathologically, cholesterol polyps were mostly multi ple lesions (64.7%) with a mean diameter of3.86±2.2 mm in 136 patients. Of 16 patients with adenomas, 10 had a tumor diameter of more than 10 mm (62.5%). In 11 pa tients with gallbladder carcinoma, 7 were accompanied with gallbladder stone (63.6%). In addition, inflammatory polyps and adenomyomas were found in 25 and 6 patients respectively. CONCLUSIONS: B-ultrasonography is the most effective diagnostic method for detecting PLG. When large or irreg- ular lesions are found, CT should be performed in order to avoid missing of gallbladder carcinoma. Operative indica- tions for PLG include; a maximal tumor diameter of more than 10 mm; an over 50-year-old patient with a wide-base and a single polyp lesion; a wide-base lesion or a lesion showing a tendency to enlargement; co-existing gallbladder stone or cholecystitis; a patient without other diseases but obvious clinical features and failure of general ma- nagement ; big or long pedicels or polyps at the neck of the gallbladder for preventing the empty of the gallbladder and a history of biliary colic; and PLG with irregularly thick- ened local gallbladder wall.

关键词： polypoid lesions of the gallbladder diagnosis operation

Research for Signal Power Spectrum Distribution in Laser Doppler Rotational Speed Measurement

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Chinese Journal of Lasers 1997年第6期 10-19页

作者： LUO Deyuan ZHOU Jian TAN Yushan( Laser and Infrared Institute, xi’an jiao tong university, xi’an 710049, China)

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关键词： optical field coherence function optical intensity coherence function time space coherence function power spectrum density composite speckle field

A NOTE OF KAMIEN’S PAPER ABOUT ABSORPTIVE CAPACITY AND R＆D INVESTMENTS

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A NOTE OF KAMIEN’S PAPER ABOUT ABSORPTIVE CAPACITY AND R＆D...