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Correlation analysis between underwater noise and Liutex for DTMB4119 propeller

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Journal of Hydrodynamics 2022年第4期34卷 585-595页

作者： lian-jie Yu jian-wei Wu De-cheng Wan Computational Marine Hydrodynamics Lab(CMHL) School of Naval ArchitectureOcean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China Wuhan Second Ship Design and Research Institute Wuhan 430205China

Propeller is an important equipment of ocean *** has characteristics of complex geometry and periodic vortex shed,which means high research *** paper takes DTMB419 propeller as the research object.A detailed study is conducted on the wake vortices in non-cavitation state and cavitation *** vortex identification methods are used to compare the vortices capture effects from downstream sections and three-dimensional *** results show that,the third-generation vortex identification technologyΩ_(R)shows obvious *** the same time,FW-H equation is used to predict propeller noise,and the relationship between nonlinear sound source distribution and vortices distribution is *** is found that the distribution of Lighthill tensor is consistent withΩ_(R),which proves the advantages and potential of third-generation vortex identification technology from acoustic perspective.

关键词： Third-generation vortex DTMB4119 propeller cavitation FW-H formulation

Numerical investigation of shallow wake behind a patch of rigid emergent vegetation

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Journal of Hydrodynamics 2021年第4期33卷 673-687页

作者： jian Wang Jing-xin Zhang Dongfang liang lian Gan School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai200240China Key Laboratory of Hydrodynamics(Ministry of Education) Shanghai Jiao Tong UniversityShanghai200240China Department of Engineering University of CambridgeCambridgeUK Department of Engineering Durham UniversityDurhamUK

The shallow water flow through and around a patch of rigid emergent vegetation was investigated numerically. The mean flow field and turbulent structures were studied, especially their dependence on the solid volume fraction (SVF) of the patch and the bed friction. Two streamwise velocity scales, U1s at the starting point of the steady wake and U1e at the downstream end of the steady wake, and the length of the steady wake L1 were used to describe the steady wake behind the patch. U1s was found to be related to SVF only. However, U1e and L1 were influenced by both the SVF and the wake stability parameter S. For a sparse patch, U1e was equal to U1s, and L1 decreased with the increase of S. For a mid-dense patch, U1e was always smaller than U1s, and it increased with S and gradually approached U1s. The increase of U1e reduced the lateral velocity difference between the flows inside and outside the wake, which resulted in the increase of L1. For a highly dense patch, U1e and L1 did not increase unless S was larger than a critical value. A new parameter, r, was proposed to represent the development rate of the steady wake. The numerical results showed that r increased monotonously with S for mid-dense patches.

关键词： Shallow water vegetated flow wake bed friction

Hot Rolled Strip Re-reddening Temperature Changing Law during Ultra-fast Cooling

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Journal of Iron and Steel Research International 2015年第8期22卷 694-702页

作者： lian-yun jianG Chun-jiang ZHAO jian-hui SHI Guo YUAN Xue-qiang WANG Qing-xue HUANG State Key Laboratory of Rolling and Automation Northeastern University School of Mechanical Engineering Taiyuan University of Science and Technology Shougang Qian'an Iron and Steel Co. Ltd.

Temperature deviation between surface and the center of hot rolled strip is formed during ultra-fast cooling （UFC）. Surface temperature would rise when temperature deviation goes up to an extent, and strip re-reddening phenomenon will appear. Strip re-reddening affects the stability of strip microstructure, property and temperature control precision. Thus, it is necessary to conduct research on re-reddening temperature changing law to improve strip property and temperature control precision. Strip temperature trends for various strip thicknesses and ultra-fast cooling rates were obtained by numerical calculation method. Re-reddening temperature, temperature deviation between surface and center, and boundary layer position changing law were obtained. By comparison, some conclusions were obtained： UFC re-reddening temperature and laminar cooling （LC） re-reddening temperature were linear to ultra-fast cooling rate respectively. Ultra-fast cooling rate affected UFC re-reddening temperature greatly, but it had little effect on LC re-reddening temperature. Equations which were used to calculate UFC re-reddening temperature, LC re-reddening temperature and maximum temperature deviation were obtained. The position of boundary layer stayed in 1/4 strip thickness.

关键词： ultra-fast cooling laminar cooling cooling rate re-reddening temperature

The Synchrotron Emission of Jets with Transverse Velocity Discrepancy

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Chinese Journal of Astronomy and Astrophysics 2004年第4期4卷 311-319页

作者： hui-QuanLi jian-ChengWang LiXue NationalAstronomicalObservatories YunnanObservatoryChineseAcademyofSciencesKunming650011 UnitedLaboratoryforOpticalAstronomy ChineseAcademyofSciences GraduateSchooloftheChineseAcademyofSciences

It has been commonly accepted that the bulk velocity of extragalactic jets varies in all directions. We examined the synchrotron radiation of a jet with velocity structure in the direction perpendicular to its axis and found that the spectral energy distribution (SED) is not strongly influenced by this circumstance, that there is only a small increase in the emission intensity and almost no shift in the peak frequency. For objects with smaller inclined angles θ0 between the jet axis and the line of our sight, such as Blazars, the effect is more important. When θ0 exceeds a critical value there is no longer any change in the SED. To compare the bulk speed with different velocity structure, an equivalent speed β is defined which would reproduce the same spectral profile. There possibly exists a stress fμ(y) between layers of the outflow when the velocity is not the same in the jet.

关键词： galaxies: jets radiation mechanisms: non-thermal methods: numerical

A consistent projection-based SUPG/PSPG XFEM for incompressible two-phase flows

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Acta Mechanica Sinica 2012年第5期28卷 1309-1322页

作者： jian-hui Liao Zhuo Zhuang School of Aerospace Tsinghua University

In this paper, a consistent projection-based streamline upwind/pressure stabilizing Petrov-Galerkin （SUPG/PSPG） extended finite element method （XFEM） is presented to model incompressible immiscible two-phase flows. As the application of linear elements in SUPG/PSPG schemes gives rise to inconsistency in stabilization terms due to the inability to regenerate the diffusive term from viscous stresses, the numerical accuracy would deteriorate dramatically. To address this issue, projections of convection and pressure gradient terms are constructed and incorporated into the stabilization formulation in our method. This would substantially recover the consistency and free the practitioner from burdensome computations of most items in the residual. Moreover, the XFEM is employed to consider in a convenient way the fluid properties that have interfacial jumps leading to discontinuities in the velocity and pressure fields as well as the projections. A number of numerical examples are analyzed to demonstrate the complete recovery of consistency, the reproduction of interfacial discontinuities and the ability of the proposed projection-based SUPG/PSPG XFEM to model two-phase flows with open and closed interfaces.

关键词： Two-phase flow XFEM SUPG/PSPG algorithm Consistency Discontinuous projection

Sulfonated Hollow Covalent Organic Polymer： Highly-Selective Adsorption toward Cationic Organic Dyes over Anionic Ones in Aqueous Solution

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Chinese Journal of Chemistry 2018年第9期36卷 826-830页

作者： jian-Hong Wang Yue Zhang lian-dai An Wen-He Wang Ying-hui Zhang Xian-He Bu College of Chemistry Key Laboratory of Advanced Energy Materials Chemistry (MOE) Nankai University Tianjin 300071 China TEDA Institute of Applied Physics Nankai University Tianjin 300457 China CSchool of Materials Science and Engineering National Institute for Ad- vanced Materials Tianjin Key Laboratory of Metal and Molecule-Based Material Chemistry Nankai University Tianjin 300350 China

A sulfonated hollow covalent organic polymer （sh-COP-P） was prepared by post sulfonation of hollow covalent organic polymer （h-COP-P） synthesized through poly-condensation of tetrabiphenylporphyrin （TBPP）. In comparison with h-COP-P, sh-COP-P exhibits significantly enhanced adsorp- tion capacity of organic cationic dyes in aqueous solutions accompanied with notably reduced adsorption capacity of anionic dyes. This gives sh-COP-P a satisfactory performance in selectively separating cationic organic dyes from anionic ones, mainly attributed to the electrostatic interaction between polymer backbone and the guest molecules.

关键词： dye adsorption sulfonated hollow COPs organic dyes selective separation

Survivin antisense oligodeoxynucleotide inhibits growth of gastric cancer cells

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World Journal of Gastroenterology 2004年第8期10卷 1121-1124页

作者： lian-huiYang Yi-ChuZhang hui-QingQian DepartmentofOncologicalSurgery ShidongHospital200090ShanghaiChina DepartmentofGeneralSurgery XinhuaHospitalAffiliatedtoShanghaiSecondMedicalUniversityShanghai200092China DepartmentofSurgicalLaboratory XinhuaHospitalAffiliatedtoShanghaiSecondMedicalUniversityShanghai200092China

AIM:To investigate the effect of transfected survivin antisense oligonucleotide (ASODN) on proliferation and apoptosis of gastric cancer ceils. METHODS:The authors designed ASODNs targeting different regions of survMn mRNA,including surviving ASODN1,ASODN2 and *** were transfected into gastric cancer cell line SGC 7901,cell growth was detected by MTT *** exposed to the potent oligonucleotide were also examined for apoptosis induction by FCM and fluorescence *** RT-PCR and Western blot examinations were carried for expression of survivin mRNA and protein. RESULTS:ASODN3 caused a statistically significant reduction of cell viability to 60.6% (±2.9%) (P0.05).The cell growth was also significantly inhibited by ASODN3, compared with reversal and scrambled sequence.A significant loss of survivin mRNA was presented in ASODN3 treated ceils and this was not seen in treatment with sense ODN or scramble *** level was significantly decreased 48 h after survivin ASODN trasfected by approximately 2-fold decrease comparedwith untreated ***. ASODN3 did not induce significant apoptosis response until 48 h after transfection (P>0.05). CONCLUSION:ASODN3,which targets translation initiation part,can be identified as a most potent antisense compound. Srvivin ASODN3 may provide a novel approach to therapy of gastric cancer.

关键词：尾加压素反义寡核苷酸胃癌肿瘤抑制细胞凋亡免疫组织化学

Modal parameter identification for a roof overflow powerhouse under ambient excitation

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Water Science and Engineering 2016年第1期9卷 67-80页

作者： Yan Zhang Ji-jian lian Fang Liu State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China State Key Laboratory of Simulation and Regulation of Water Cycle in River Basin China Institute of Water Resources and Hydropower ResearchBeijing 100038China

Modal parameter identification is a core issue in health monitoring and damage detection for hydraulic structures. For a roof overflow hydropower station with a bulb tubular unit under ambient excitation, a complex unit-powerhouse-dam coupling vibration system increases the difficulties of modal parameter identification. In this study, in view of the difficulties of modal order determination and the noise jamming caused by ambient excitation, along with false mode identification and elimination problems, the ensemble empirical mode decomposition （EEMD） method was used to decrease noise, the singular entropy increment spectrum was used to determine system order, and multiple criteria were used to eliminate false modes. The eigensystem realization algorithm （ERA） and stochastic subspace identification （SSI） method were then used to identify modal parameters. The results show that the relative errors of frequencies in the first four modes were within 10% for the ERA method, while those of SSI were over 10% in the second and third modes. Therefore, the ERA method is more appropriate for identifying the structural modal parameters for this particular powerhouse layout.

关键词： Hydraulic structure Order determination Ensemble empirical mode decomposition Singular entropy Eigensystem realization algorithm Bulb tubular unit

Readout electronics for a high-resolution soft X-ray spectrometer based on silicon drift detector

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Nuclear Science and Techniques 2017年第1期28卷 94-99页

作者： Er-Lei Chen Chang-Qing Feng Shu-Bin Liu Chun-Feng Ye Dong-Dong Jin jian lian hui-Jun Hu State Key Laboratory of Particle Detection and Electronics University of Science and Technology of ChinaHefei 230026 China Department of Modern Physics University of Science and Technology of China Hefei 230026 China 705 Research Division Electronic Engineering InstituteHefei 230037 China Shandong Aerospace Electro-technology Institute Yantai 264670 China

The readout electronics for a prototype soft X-ray spectrometer based on silicon drift detector(SDD),for precisely measuring the energy and arrival time of X-ray photons is presented in this *** system mainly consists of two parts,i.e.,an analog electronics section(including a pre-amplifier,a signal shaper and filter,a constant fraction timing circuit,and a peak hold circuit)and a digital electronics section(including an ADC and a TDC).Test results with X-ray sources show that an energy dynamic range of 1-10 keV with an integral nonlinearity of less than 0.1%can be achieved,and the energy resolution is better than 160 eV @ 5.9 keV *** a waveform generator,test results also indicate that time resolution of the electronics system is about 3.7 ns,which is much less than the transit time spread of SDD(<100 ns)and satisfies the requirements of future applications.

关键词： Energy and time measurement Soft X-ray detection Silicon drift detector Readout electronics