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A COUPLING MODEL OF WATER FLOWS AND GAS FLOWS IN EXHAUSTED GAS BUBBLE ON MISSILE LAUNCHED UNDERWATER

Journal of Hydrodynamics 2007年第4期19卷 403-411页

作者： CHENG yong-sheng liu Hua Department of Engineering Mechanics Shanghai Jiaotong University Shanghai 200030 China

The gas and water flows during an underwater missile launch are numerically studied. For the gas flow, the explicit difference scheme of Non-oscillation and Non-free-parameter Dissipation (NND) is utilized to solve the Euler equations for compressible fluids in the body-fitted coordinates. For the water flow, the Hess-Smith method is employed to solve the Laplace equation for the velocity potential of irrotational water flows based on the potential theory and the boundary element method. The hybrid Eulerian-Lagrangian formulation for the free boundary conditions is used to compute the changes of the free surface of the exhausted gas bubble in time stepping. On the free surface of the exhausted gas bubble, the matched conditions of both the normal velocities and pressures are satisfied. From the numerical simulation, it is found that the exhausted gas bubble grows more rapidly in the axial direction than in the radial direction and the bubble will shrink at its "neck" finally. Numerical results of the movement of the shock wave and the distribution of the Mach number and the gas pressure within the bubble were presented, which reveals that at some time, the gas flow in the Laval nozzle is subsonic and the gas pressure in the nozzle is very high. Influences of various initial missile velocities and chamber total pressures and water depths on both the time interval when the gas flow in the nozzle is subsonic and the peak of the gas pressure at the nozzle end were discussed. It was suggested that a reasonable adjustment of the chamber total pressure can improve the performance of the engine during the underwater launch of missiles.

关键词： exhausted gas bubble Laval nozzle missile launched underwater shock wave gas jet

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Multi-objective optimization design of deviation-correction trajectory considering the production loss in shale gas cluster well

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Petroleum Science 2022年第6期19卷 2995-3003页

作者： Zi-Jun Dou yong-sheng liu Xing Qin De-Li Gao Gan-sheng Yang Key Laboratory of Deep Geological Drilling Technology of Ministry of Natural Resources China University of GeosciencesBeijing 100083China Sinopec Research Institute of Petroleum Engineering Beijing 100101China MOE Key Lab of Petroleum Engineering China University of PetroleumBeijing 102249China

In shale gas mining,the inter-fracture interference effect will significantly occur if the actual well deviates from the planned *** reduce production loss,operators want to get back on the planned trajectory economically and *** on this,a multi-objective optimization model of deviationcorrection trajectory is established considering the production loss ***,the functional relationship between the production envelope and the fracturing depth is constructed,and the production loss is obtained by combining the calculation method of volume *** on the proposed“double-arc”trajectory design method,the production loss of the fracture on the deviation-correction trajectory is ***,combined with the well profile energy evaluation,a new optimization model of deviation-correction trajectory is *** results demonstrate that after optimizing the fracturing depth,the production loss of the deviation-correction trajectory is reduced by 13.2%.The maximum curvature value results in a trajectory with a minimum production loss yet a maximum well profile *** proposed model reduces the well profile energy by 15.6%compared with the existing *** is proved that the proposed model can reduce the probability of drilling accidents and achieve high gas production in the later mining *** study fully considers various factors affecting horizontal wells in the fracturing area,which can provide theoretical guidance for the design of deviationcorrection trajectory.

关键词： Shale gas Inter-fracture interference effect Production loss Deviation-correction trajectory Multi-objective optimization

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Brachiocephalic artery stenting through the carotid artery: A case report and review of the literature

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World Journal of Clinical Cases 2019年第17期7卷 2644-2651页

作者： Fang Xu Feng Wang yong-sheng liu Department of Interventional Therapy The First Affiliated Hospital of Dalian Medical University

BACKGROUND As the population ages and people’s living standards gradually improve,the incidence of cerebrovascular disease in China is increasing annually,posing a serious threat to people’s *** incidence of brachiocephalic artery stenosis in ischemic cerebrovascular disease is relatively low,accounting for 0.5% to 2% of patients,but its consequences are very ***,we report a case of brachiocephalic artery stenting through the carotid *** SUMMARY The patient was a 66-year-old *** came to our hospital because of repeated dizziness and was diagnosed with ischemic cerebrovascular disease (stenosis at the beginning of the brachiocephalic artery).Cerebral angiography suggested that the stenosis of the brachiocephalic artery had almost occluded *** agent threaded a line through the stenosis,and there was reversed blood flow through the right vertebral artery to compensate for the subclavian steal syndrome in the right subclavian *** improve the symptoms,we placed an Express LD (8 mm × 37 mm) balloon expanding stent in the stenosis *** the operation,the patient’s dizziness significantly ***,after 6 mo,the patient was re-admitted to the hospital due to dizziness.A computed tomography scan of the head revealed multiple cerebral infarctions in bilateral basal ganglia and the right lateral *** auxiliary examination including computerized tomography angiography of the vessels of the head and cerebral angiography both showed severe stenosis in the brachiocephalic artery *** the operation,the guidewire and catheter were matched to reach the opening of the brachiocephalic ***,we decided to use a right carotid artery approach to complete the *** sutured the neck puncture point with a vascular stapler and then ended the *** the operation,the patient recovered well,his symptoms related to dizziness disappeared,and his right radial artery pulsation could be ***

关键词： Stenosis of the brachiocephalic artery Trans-carotid approach Vascular stapler Case report

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Microstructure and mechanical properties of 3D printed ceramics with different vinyl acetate contents

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Rare Metals 2021年第11期40卷 3241-3250页

作者： He Li yong-sheng liu Yan-Song liu Qing-Feng Zeng Jing-Jing Liang Science and Technology on Thermostructural Composite Materials Laboratory Northwestern Polytechnical UniversityXi’an 710072China NPU-SAS Joint Research Center of Advanced Ceramics Northwestern Polytechnical UniversityXi’an 710072China Institute of Metal Research Chinese Academy of SciencesShenyang 110016China

Stereolithography(SL)-based three-dimensional(3D) printing technique is an efficient method for the fabrication of alumina *** alumina slurry is difficult to obtain due to the barrier between hydrophilic alumina and oleophilic *** not only requires that the ceramic slurry possessed low viscosity and uniformity,but also requires that the slurry could complete the photocuring *** this study,vinyl acetate was added in the ceramic slurry as a bridge to connect alumina and resin,and the effects of vinyl acetate content on the microstructure and mechanical properties of the alumina ceramics were systematically *** results showed that the alumina ceramics were composed of three types of particles which included large aggregates,individual particles,and long-columnshaped *** shrinkage,bulk density,and crystallite size of the ceramics increased with the increase in vinyl acetate *** open porosity decreased with the increase in vinyl acetate *** flexural strength of the ceramics first increased and subsequently decreased with the increase in vinyl acetate *** shrinkage in Z direction was much greater than that in X or Y *** on the above results,the optimum vinyl acetate content for alumina slurry was 10 wt%,which resulted in sintered ceramic with the shrinkage of 15.6% in X direction,13.5% in Ydirection,21.9% in Z direction,bulk density of 1.9 g·cm^(-3),open porosity of 50.1%,and flexural strength of 24.4 *** sintered ceramics satisfy the requirement of alumina ceramic cores.

关键词： Stereolithography Alumina ceramics Vinyl acetate Microstructure Mechanical properties

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A preliminary study of isopropyl alcohol matrix effect and correction in ICP-MS

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Chinese Chemical Letters 2007年第10期18卷 1297-1300页

作者： Zhao Chu Hu Shan Gao sheng Hong Hu yong sheng liu Hai Hong Chen State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences Wuhan 430074 China ＇State Key Laboratory of Continental Dynamics Northwest University Xi＇an 710069 China

Isopropyl alcohol matrix effect was found to be element specific by using the defined matrix effect factor in ICP-MS, which could not be corrected by using the conventional internal reference method. Unlike the conventional internal reference method, the presented method allows for the analyte to behave differently from the internal reference under the influence of the matrix.

关键词： ICP-MS Isopropyl alcohol Matrix effect

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Synthesis and Structure of a New Dinuclear Uranyl Complex

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Chinese Chemical Letters 2002年第6期13卷 583-586页

作者： Shang Ying liu yong sheng liu Wen Xing ZHANG Chang Qin MA De Hua JIANG College of Chemistry and Chemical Engineering Shandong UniversityJinan 250100

With a heptadentate compartmental Schiff-base ligand H3L (1, 3-di[o-(salicylimino) ph- enoxyl]-2-propanol), a new binuclear diuranyl complex [(UO2)2L(OH)]?DMF, C38H45N5O13U2, was synthesized and the crystal structure was determined by X-ray diffraction techniques. The coordination geometry are two pentagonal bipyramids. In each pentagon four kinds of U-O (phenoxido, hydroxo, alkoxo and ether oxo) bonds are discussed.

关键词： Dinuclear uranyl complex synthesis structure.

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Microstructure and properties of 3D-printed alumina ceramics with different heating rates in vacuum debinding

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Rare Metals 2020年第5期39卷 577-588页

作者： He Li yong-sheng liu Yan-Song liu Qing-Feng Zeng Ke-Hui Hu Jing-Jing Liang Zhi-Gang Lu Science and Technology on Thermostructural Composite Materials Laboratory Northwestern Polytechnical UniversityXi'an 710072China NPU-SAS Joint Research Center of Advanced Ceramics Northwestern Polytechnical UniversityXi'an 710072China Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China State Key Laboratory of Tribology Tsinghua University Beijing 100084China Institute of Metal Research Chinese Academy of Sciences Shenyang 110016China

The effect of heating rates during vacuum debinding on the microstructure and mechanical properties of alumina ceramics are discussed in this *** threedimensional(3D)-printed alumina ceramics examined in this study were found to have a layered structure,and interlayer spacing increased as the heating rate increased The pore diameter,shrinkage,flexural strength and hardness were found to decrease as the heating rate increased due to weak interfacial bonding between alumina particles Shrinkage was found to be much larger along the Z direction than along the X or Y directions due to the layer-bylayer forming mode during 3D printing.0.5°C·min-1is considered the optimum heating rate,yielding ceramics with interlayer spacing of 0.65 lm,shrinkage of 2.6%2.3%and 4.0%along the X,Y and Z directions,respectively,flexural strength of 27.5 MPa,hardness of29.8 GPa,Vickers hardness of HV 266.5,pore diameter of356.8 nm,bulk density of 2.5 g·cm-3,and open porosity of38.4%.The debinding procedure used in this study could be used to produce a high-quality ceramic which can be used for fabricating alumina ceramic cores.

关键词： Heating rate Vacuum debinding Alumina ceramics Three-dimensional(3D)printing Stereolithography

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Effect of tramadol on immune responses and nociceptive thresholds in a rat model of incisional pain

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2008年第11期9卷 895-902页

作者： yong-min liu sheng-mei ZHU Kui-rong WANG Zhi-ying FENG Qing-lian CHEN Department of Anesthesiology the First Affiliated Hospital School of Medicine Zhejiang University Hangzhou 310003 China

Objective： To evaluate the effects oftramadol on the proinflammatory responses in a rat model of incisional pain by investigating its effects on nociceptive thresholds and serum interleukin-6 （IL-6） and IL-2 levels. Methods： Forty-two male Sprague-Dawley （SD） rats scheduled for plantar incision were randomly divided into 7 groups 01=6 in each group）. Rats in Group 1 receiving general anesthesia with no incision were served as control; At 30 min before skin incision, Groups 2-5 were given 5 ml normal saline or 1, 10, and 20 mg/kg tramadol, respectively, intraperitoneally （i.p.）; Group 6 received 10 mg/kg tramadol after operation; Group 7 received 10 mg/kg tramadol before incision, followed by 200 μg/kg naloxone after operation. Mechanical allodynia was measured by electronic yon Frey filament to evaluate the nociceptive thresholds 1 h before incision, and 1 h and 2 h after operation. Serum IL-6 and IL-2 levels were measured by enzyme-linked immunosorbent assay （ELISA） 2 h after operation. Results： Mechanical thresholds decreased significantly and serum IL-6 level increased significantly after operation in Group 2 compared with control （P〈0.01）, and these changes were reversed respectively by tramadol in a dose-dependent manner （P〈0.05 and P〈0.01, respectively）. IL-2 level remained unchanged after operation in Group 2, but decreased in Group 3 （P〈0.05）, then gradually returned to the normal level in Groups 4 and 5. The intraperitoneally injected tramadol （10 and 20 mg/kg） produced a potent and dose-dependent antinocicptive effect on the lesioned paw. The antinocicptive effects of tramadol were partially an- tagonized by naloxone （200 μg/kg）, suggesting an additional non-opioid mechanism. Conclusion： The results suggest that tramadol could be a good choice for the treatment of pain under the conditions that immunosuppression may be particularly contraindicated.

关键词： Tramadol Pain Mechanical allodynia lnterleukin-6 (IL-6) Interleukin-2 (IL-2) Rat

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Strategies and challenges in treatment of varicose veins and venous insufficiency

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World Journal of Clinical Cases 2022年第18期10卷 5946-5956页

作者： Rong-Ding Gao Song-Yi Qian Hai-Hong Wang yong-sheng liu Shi-Yan Ren Department of Laser and Vascular Surgery Aviation General HospitalChina Medical UniversityBeijing 100012China Department of Cardiac Surgery Zhongshan Hospital(Xiamen Brach)Fudan UniversityXiamen 361015Fujian ProvinceChina Department of Peripheral Vascular Disease The Affiliated Hospital of Shanxi University of Chinese MedicineTaiyuan 030024Shanxi ProvinceChina Department of Dermatology Aviation General HospitalChina Medical UniversityBeijing 100012China

Patients with varicose veins can be treated with conservative or surgical approaches based on the clinical conditions and patient *** the recent decade,the recommendations for managing symptomatic varicose veins have changed dramatically due to the rise of minimally invasive endovascular *** literature was systematically searched on Medline without language *** papers on the treatment of varicose veins and venous insufficiency with different procedures were included and *** laser ablation(EVLA)and radiofrequency ablation(RFA)both are same safe and effective in terms of occlusion rate,and time to return to normal *** comparison with RFA or EVLT,Cure conservatrice et Hemodynamique de l’Insufficience Veineuse en Ambulatoire(CHIVA)may cause more bruising and make little or no difference to rates of limb infection,superficial vein thrombosis,nerve injury,or *** terms of recurrence of varicose veins,there is little or no difference between CHIVA and stripping,RFA,or *** saphenous vein recanalization is highest in the ultrasound-guided foam sclerotherapy(FS)group(51%)during 1 year of *** 2013 National Institute for Health and Care Excellence clinical guidelines recommend surgery as a third-line therapeutic option after EVLA or RFA and *** the mechanochemical endovenous ablation(MOCA)is a non-thermal,non-tumescent option and appears to be of similar efficacy to stab avulsion with no potential risk of nerve damage,the overall success rate of MOCA is lower than those of other procedures such as EVLA,RFA,or high ligation and *** is the most cost-effective therapeutic option,with RFA being a close second for the treatment of patients with varicose *** thermal ablation(EVLA or RFA)is recommended as a first-line treatment for varicose veins and has substituted the high ligation of saphenofemoral junctional reflux and stripping of varicose ***

关键词： Varicose veins Venous insufficiency High ligation and stripping Endovenous laser ablation Radiofrequency ablation Cure conservatrice et Hemodynamique de l’Insufficience Veineuse en Ambulatoire

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Low temperature ferromagnetism in CaCu_(3)Ti_(4)O_(12)

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Chinese Physics B 2021年第9期30卷 579-586页

作者： Song Yang Xiao-Jing Luo Zhi-Ming Shen Tian Ga yong-sheng liu Shao-Long Tang Shanghai Key Laboratory of Materials Protection and Advanced Materials in Electric Power Shanghai 200090China Nanjing National Laboratory of Microstructures Jiangsu Provincial Laboratory for Nanotechnology and Department of PhysicsNanjing UniversityNanjing 210093China

The low-temperature magnetic order behaviors of perovskite oxide CaCu_(3)Ti_(4)O_(12)(CCTO)ceramics prepared by different methods are discussed.X-ray diffraction,scanning electron microscope,x-ray photoelectron spectroscopy,and direct current(DC)magnetization are used to characterize the structures,microscopic morphologies,valence states,and magnetic properties of the *** results show that the magnetic behaviors of CCTO ceramics are very sensitive to the preparation *** quenched CCTO ceramic and CCTO powders grown in a molten salt crystal,which contain much more oxygen vacancies and Ti^(3+),show the coexistence of weak ferromagnetic order and antiferromagnetic order below the Neel *** suggests that the bound magnetopolaron formed by oxygen vacancies and Ti^(3+)ion composite defects are responsible for the weak ferromagnetic order at low temperature.

关键词： CaCu_(3)Ti_(4)O_(12) oxygen vacancies magnetic ordering

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