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SIMULATION OF 3-D FLOW AROUND A VAN-BODY TRUCK WITH RNG K-ε TURBULENCE MODEL

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Journal of Hydrodynamics 2001年第4期13卷 98-101页

作者： Du, Guang-Sheng Wang, De-Chang Lei, Li zhou, lian-di Coll. of Water Conservancy Wuhan Univ. Ji'nan 250061 China

It is proved that the calculation precision of the outside flow field of the van-body truck using PNG k-Ε turbulence model is higher than that using standard k-Ε turbulence model by means of experiments. The calculation results of the outside flow field of a certain domestic van-body truck are given. And by analyzing and comparing the different tail flow plots, the tail flow structural characteristics and the relationship between the position and the intensity of the tail vortex and the aerodynamic drag is obtained, which can direct the design of the outside aerodynamic shape of the van-body truck.

关键词： Computer simulation Drag Mathematical models Turbulent flow

DESIGN OF IMPLANTABLE AXIAL-FLOW BLOOD PUMP AND NUMERICAL STUdiES ON ITS PERFORMANCE

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Journal of Hydrodynamics 2009年第4期21卷 445-452页

作者： FAN Hui-min HONG Fang-wen zhou lian-di CHEN Yin-sheng YE liang LIU Zhong-min Shanghai East Hospital Afiliated to Tongji University Shanghai 200120 China China Ship Scientific Research Center Wuxi 214082 China

This article presents the design of a new implantable axial-flow blood pump. The special feature of the flow channel inside the blood pump is that the blood is driven by a big-small tandem impeller installed in the inner hole of the cylinder magnet of a brushless direct current motor. The inner hole makes the main flow channel possible, while the gap between the inner end of the stator and the outer end of the cylinder magnet gives the shape of the tributary flow channel. There is no motor magnet inside the main flow channel, therefore, more blood can pass through it. The gap of the tributary flow channel is very small, but the blood flow in it is not blocked. Thus, the efficiency is increased and the volume and weight of blood pump can be reduced greatly. The outer diameter, length and weight of the manufactured implantable axial-flow blood pump are 29.6 mm, 76 mm and 158 g, respectively. The impeller spins at the speed of 9000 rpm and can generate a pressure head of 100 mmHg and a flow rate of 8 L/rain. In an animal experiment, the blood pump has been successfully applied as a Ventricular Assist Device （VAD） in the chest of a small cow. Besides a mathematical model is established to simulate the flow inside an axial-flow blood pump of implantable VAD. The numerical studies on the performance of the implantable axial-flow blood pump are carried out by combining this mathematical model and the Fluent software. The numerical results agree well with those of experiments, with the maximum error less than 10%.

关键词： implantable axial-flow blood pump CFD numerical prediction performance

AN　INTEGRATEDC　METHOD　FOR　COMPUTING　COMPUTING　THE　INTERNAL　AND　EXTERNAL　VISCOUS　FLOW　FIELD　AROUND　THE　DUCTED　PROPULSOR　BEHIND　AN　AXISYMMETRIC　BODY

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Journal of Hydrodynamics 1995年第3期7卷 72-83页

作者： zhou lian-di Zhao Feng(China Ship Scientific Research Center, P.O. Box 116, Wuxi 214082, P. R. China) China Ship Scientific Research Cent Wuxi China

This paper presents an effective method for computing the internal and external viscous flow field around the ducted propulsor behind an axisymmetric they by using a new Navier-Stokes equations solver with primitive variable continuity equation formulation. In the present numerical method, the calculation equation for pressure with well-defined coefficient,which form is similar to the artificial compressibility method, is developed. A semi-staggered grid system is adopted. Not only the advantage of staggered grid system can be retained but the boundary conditions on the inner and outer surface of the duct can be also carried out easily. By using a special grid system and the programming technique for implementing the jump boundary condition on the duct surfaces, the internal and external viscous flow field around the ducted propulsor behind the axisymmetric they may be calculated integrally in an unified numbered grid system. Some configurations are calculated and compared with experimental date and numerical results of other methods. Illustrative calculations are also presented for a stern of axisymmetric body with the backstep fitted a duct to illustrate the capability of the present method. Beside that, the effect of axial distribution of they force is considered and discussed in order to extend the application range of the present method.

关键词： ducted propulsor viscous flow semi-staggered grid

Compact mid-infrared dual-comb spectrometer over 3-4μm via intra-pulse difference frequency generation in LiNbO_(3) waveguides

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High Power Laser Science and Engineering 2024年第3期12卷 1-8页

作者： lian zhou Haipeng Lou Zejiang Deng Xiong Qin Jiayi Pan Yuanfeng di Chenglin Gu Daping Luo Wenxue Li State Key Laboratory of Precision Spectroscopy East China Normal UniversityShanghaiChina Joint Research Center of Light Manipulation Science and Photonic Integrated Chip of East China Normal University and Shandong Normal University East China Normal UniversityShanghaiChina

The mid-infrared optical frequency comb is a powerful tool for gas *** this study,we demonstrate a simple midinfrared dual-comb spectrometer covering 3±4μm in Li Nb O_(3)*** on a low-power fiber laser system,the mid-infrared comb is achieved via intra-pulse difference frequency generation in the Li Nb O_(3)*** construct pre-chirp management before supercontinuum generation to control spatiotemporal alignment for pump and signal *** supercontinuum is directly coupled into a chirped periodically poled Li Nb O_(3)waveguide for the 3±4μm idler generation.A mid-infrared dual-comb spectrometer based on this approach provides a 100 MHz resolution over25 THz *** evaluate the applicability for spectroscopy,we measure the methane spectrum using the dualcomb *** measured results are consistent with the HITRAN database,in which the root mean square of the residual is 3.2%.This proposed method is expected to develop integrated and robust mid-infrared dual-comb spectrometers on chip for sensing.

关键词： difference frequency generation dual-comb spectroscopy mid-infrared gas sensing nonlinear optics

NUMERICAL STUDY OF THE INFLUENCE OF SURFACE ROUGHNESS OF CYLINDER ON FLOW STRUCTURE

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Journal of Hydrodynamics 2000年第4期12卷 1-7页

作者： Gao Li jin, zhou lian di [WT5BX]China Ship Scientific Research Center, Wuxi 214082, P.R.China (Received Jan. 14, 2000) China Ship Sci. Res. Cent. Wuxi 214082 China

In this paper, the influence of surface roughness on flow structure was numerically studied. An adaptive numerical method, the fast vortex method was employed. A mathematical roughness, which comes from the no slip condition of vortex method, was introduced. The numerical results indicate that the roughness has appreciable influence on the flow structure. The vortex shedding could be controlled if the forward multi layer boundary condition is exerted.

关键词： mathematical roughness fast multipole method (FMM) forward multi layer boundary condition back multi layer boundary conditiont

Parity-dependent skin effects and topological properties in the multilayer nonreciprocal Su−Schrieffer−Heeger structures

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Frontiers of physics 2024年第3期19卷 115-133页

作者： Jia-Rui Li Cui Jiang Han Su di Qi lian-lian Zhang Wei-Jiang Gong College of Sciences Northeastern UniversityShenyang 110819China Basic Department Shenyang Institute of EngineeringShenyang 110136China

We concentrate on the skin effects and topological properties in the multilayer non-Hermitian Su−Schrieffer−Heeger (SSH) structure, by taking into account the nonreciprocal couplings between the different sublattices in the unit cells. Following the detailed demonstration of the theoretical method, we find that in this system, the skin effects and topological phase transitions induced by nonreciprocal couplings display the apparent parity effect, following the increase of the layer number of this SSH structure. On the one hand, the skin effect is determined by the parity of the layer number of this SSH system, as well as the parity of the band index of the bulk states. On the other hand, for the topological edge modes, such an interesting parity effect can also be observed clearly. Next, when the parameter disorders are taken into account, the zero-energy edge modes in the odd-layer structures tend to be more robust, whereas the other edge modes are easy to be destroyed. In view of these results, it can be ascertained that the findings in this work promote to understand the influences of nonreciprocal couplings on the skin effects and topological properties in the multilayer SSH lattices.

关键词： multilayer SSH lattice nonreciprocal couplings band structure skin effect

Caffeic acid 3,4-dihydroxyphenethyl ester prevents colorectal cancer through inhibition of multiple cancer-promoting signal pathways in 1,2-dimethylhydrazine/dextran sodium sulphate mouse model

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Journal of Traditional Chinese Medicine 2024年第1期44卷 70-77页

作者： JIN Tao zhou Qian SHEN Jichen ZHANG Zhizhong lian Xiaoyuan College of Pharmaceutical Sciences Zhejiang UniversityHangzhou 310058China Pharmaceutical Informatics Institute College of Pharmaceutical SciencesZhejiang UniversityHangzhou 310058China Ocean College Zhoushan Campus of Zhejiang UniversityZhoushan 316021China

OBJECTIVE:To elucidate the potential feature and mechanism of the caffeic acid 3,4-dihydroxyphenethyl ester(CADPE)molecule,which can prevent colorectal cancer(CRC)in the 1,2-dimethylhydrazine(DMH)/dextran sodium sulphate(DSS)-induced mouse ***:Institute of cancer research(ICR)male mice were injected with 20 mg/kg DMH for a *** that,2%DSS was administered in the drinking water for another 7 *** CADPE treatment was given to the DMH/DSS induced male mice at three different periods until their *** examination was used for observing the CRC development at colonic ***(IHC),blood cells smearing and crypt damage scoring methods were used for investigating the anti-inflammation feature of CADPE related to *** reversing targets searching method was applied with artificial intelligence(AI),computeraided drug designing(CADD)and Ingenuity Pathway Analysis(IPA)techniques for predicting the potential targets and mechanism of CADPE highly related to ***:The data indicated that CADPE inhibited CRC tumor development in the colitis-associated DMH/DSS induced mouse model after giving the early *** also impeded the acute inflammation by decreasing the infiltration of neutrophils significantly during the initial stage of CRC ***,our data showed that CADPE prevented CRC by blocking active sites of three pivotal protein targets including epidermal growth factor receptor(EGFR),extracellular signal-regulated kinase(ERK)and mammalian target of rapamycin(m TOR)in two major cancer development ***:CADPE effectively prevented CRC at early stage of tumor germination in the DMH/DSS mouse model highly likely due to its anti-acute inflammation characteristic and the ability of blocking EGFR,ERK and m TOR activities in two highly related CRC developing pathways.

关键词： caffeic acids colorectal neoplasms inflammation chemoprevention Sarcandra glabra

Realizing high initial Coulombic efficiency in manganese-based layered oxide cathodes for sodium-ion batteries via P2/O'3 biphasic structure optimization

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Rare Metals 2024年第5期43卷 2093-2102页

作者： Bo Peng Zi-Hao zhou Ping Xuan Jie Xu lian-Bo Ma School of Materials Science and Engineering Anhui University ofTechnologyMa'anshan 243002China Anhui Product Quality Supervision&Inspection Research Institute Hefei 230051China

Mn-based layered oxides are among the most promising cathode materials for sodium-ion batteries owing to the advantages of abundance,environmenta friendliness,low cost and high specific capacity.P2 and O'3 are two representative structures of Mn-based layered ***,the P2 structure containing insufficien Na generally exhibits low initial charge capacity,while O'3structure with sufficient Na delivers high initial charge capacity but poor cycle *** study prepared a multitude of Na_(x)MnO_(2)(x=0.7,0.8,0.9)cathode materials with varying P2/O'3 ratios and further investigated their electrochemical *** optimized Na_(0.8)MnO_(2) comprising 69.9 wt%O'3 and 30.1 wt%P2 phase,exhibited relatively balanced specific capacity,Coulombic efficiency and cycle ***,it achieved a high specific capacity of 128.9 mAh·g^(-1) with an initia Coulombic efficiency of 98.2%in half-cell configuration The Na_(0.8)MnO_(2)//hard carbon full cell also achieved a high specific capacity of 126.7 mAh·g^(-1) with an initia Coulombic efficiency of 98.9%.Moreover,the capacity fading mechanism was revealed by combining in-situ and ex-situ X-ray *** findings of this study provide theoretical guidance for further modification design of Mnbased layered cathodes.

关键词： Sodium-ion batteries Cathode materials Mn-based layered oxides P2/0'3 composites

Microstructure,wear and friction behavior of CoCrAITaY-xCNTs composite coatings deposited by laser-induction hybrid cladding

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Rare Metals 2024年第4期43卷 1815-1827页

作者： Sheng-Feng zhou Yu Long Yan-liang Yi Cheng Deng lian-Xi Hu Institute of Advanced Wear&Corrosion Resistant and Functional Materials Jinan UniversityGuangzhou510632China Wuhan National Laboratory for Optoelectronics(WNLO) Huazhong University of Science and TechnologyWuhan430074China MOE Key Laboratory of New Processing Technology for Non-Ferrous Metals and Materials Guangxi Key Laboratory of Processing for Non-Ferrous Metals and Featured MaterialsGuangxi UniversityNanning530004China School of Mechatronics Engineering Guangdong Polytechnic Normal UniversityGuangzhou510635China School of Materials Science and Engineering Harbin Institute of TechnologyHarbin150001China

To improve the wear performance of CoCrAlYTa coating,part of the carbon nanotubes(CNTs)chemically reacted with Ta to form reinforcement phase(TaC),while the other CNTs were retained as lubrication ***,the CoCrAlYTa-xCNTs(x=0,1,2,and 4;wt%)composite coatings were prepared by laserinduction hybrid cladding(LIHC),and the microstructure and wear resistance of coatings were systematically *** show that the coatings are mainly composed of TaC,y-(Co,Cr)andβ-(Co,Cr)*** the CNTs content increases from 0 wt%to 4 wt%,the volume fraction of TaC increases from 13.11 vol%to 16.12 vol%.Meanwhile,the nano-hardness ofγ-(Co,Cr)andβ-(Co,Cr)Al are improved from 7.49 and 9.72 to 9.36 and 11.19 GPa,*** a result,the microhardness of coating increases from HV536.25 to HV 738.16,the wear rate decreases from32.4×10^(-3)to 6.1×10^(-3)mg·m^(-1),and the average friction coefficient decreases from 0.55 to *** good wear performance of the coating is attributed to the formation of TaC and the existence of remained CNTs lubricant film.

关键词： Carbon nanotube MCrAlY coating Friction and wear performance Laser-induction hybrid cladding