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Numerical Study on the Effect of Current Profiles on Vortex-Induced Vibrations in a Top-Tension Riser

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Journal of Marine Science and Application 2017年第4期16卷 473-479页

作者： Bowen Fu lu zou Decheng Wan State Key Laboratory of Ocean Engineering School of Naval Architecture Ocean and Civil Engineering Shanghai Jiao Tong UniversityCollaborative Innovation Center for Advanced Ship and Deep-Sea Exploration Shanghai 200240 China

In this paper, numerical simulations of vortex-induced vibrations in a vertical top-tension riser with a length-to-diameter ratio of 500 using our in-house code viv-FOAM-SJTU are presented. The time-dependent hydrodynamic forces on two-dimensional strips are obtained by solving the Navier-Stokes equations, which are, in turn, integrated into a finite-element structural model to obtain the riser deflections. The riser is discretized into 80 elements with its two ends set as pinned and 20 strips are located equidistant along the risers. Flow and structure are coupled by hydrodynamic forces and structural displacements. In order to study the effects of the shear rate, of the current profiles on the vortex-induced vibrations in the riser, vibrations, with varying shear rates, in both the in-line and cross-flow directions, are simulated. In addition to the time domain analysis, spectral analysis was conducted in both the temporal and spatial domains. Multi-mode vibration characteristics were observed in the riser. The relationship between dominant vibration mode number and the shear rate of current profiles is discussed. In general, the overall vibrations in the riser pipe include contributions from several modes and each mode persists over a range of shear rates. Moreover, the results suggest that with a larger shear rate the position of the maximum in-line time-averaged displacement will move closer to the end where the largest velocity is located.

关键词： risers vortex-induced vibration multi-modal vibration strip theory computational fluid dynamics fluid-structure interaction

Photocatalytic in situ H_(2)O_(2) production and activation for enhanced ciprofloxacin degradation over CeO_(2)-Co_(3)O_(4)/g-C_(3)N_(4):key role of CeO_(2)

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Rare Metals 2024年第6期43卷 2695-2707页

作者： Hong-Jie Zhu Yi-Kai Yang Ming-Hui Li lu-Ning zou Hai-Tao Zhao Shandong Provincial Key Laboratory of Chemical Energy Storage and Novel Cell Technology School of Chemistry and Chemical Engin College of Ecology and Environment Anhui Normal UniversityWuhu241002China Liaocheng Yilu Advanced Materials Co. LtdLiaocheng 252000China

The abused ciprofloxacin antibiotics have caused significant environmental *** oxidative degradation of ciprofloxacin exhibits promising efficacy,it often entails excessive energy ***,it is necessary to explore an effective and ecologically sustainable degradation ***,we demonstrated that g-C_(3)N_(4) decorated with the coordinated CeO_(2)and Co_(3)O_(4)(CeO_(2)-Co_(3)O_(4)/CN)exhibited effective ciprofloxacin photodegradation via in situ H_(2)O_(2) production and activation *** indicate that the introduced CeO_(2) enhances the transference of photogenerated electrons to O_(2) by adjusting the oxygen vacancy of photocatalyst,thereby increasing the generation of superoxide radicals,which in turn generate H_(2)O_(2),resulting in a 22.4-fold increase in H_(2)O_(2) generation over g-C_(3)N_(4).Moreover,the in situ H_(2)O_(2)generation facilitated by CeO_(2) is confirmed to be essential for ciprofloxacin degradation via CeO_(2)-Co_(3)O_(4)/CN,as it provides enough oxidant for Co_(3)O_(4) to activate into hydroxyl radicals for the pollutants ***,CeO_(2)-Co_(3)O_(4)/CN achieves a ciprofloxacin degradation ratio of 97.7%within 80 *** study introduces a novel approach that combines H_(2)O_(2) generation and activation,offering an innovative perspective for achieving clean and efficient purification of antibiotic-contaminated water.

关键词： CeO_(2) In situ H_(2)O_(2)generation Ciprofloxacin degradation Photocatalyst

A Comprehensive Utilization Process for Black Manganese-silver Ores by Pyrite Reducing Method

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Rare Metals 2001年第3期20卷 142-146页

作者： Huimin lu, Xing zou Department of Nonferrous Metallurgy, University of Science and Technology Beijing, Beijing 100083, China Univ Sci & Technol Beijing Dept Nonferrous Met Beijing 100083 Peoples R China

On a 5 kg bench scale, the separating of Mn-Ag from black manganese-silver ores by pyrite reducing method was investigated. Leached Mn content of 98.3% (mass fraction) along with silver loss of 1.5% is achieved. The purification of solution by the precipitation method was effectively used. Chemical grade gamma -MnO2 with TMn content of 60.13% (mass fraction) and MnO2 content of 92.28% (mass fraction) is obtained. Mn recovery efficiency is 94.04%. The residues from leaching Mn process of black Mn-Ag ores was employed for silver extraction by cyanidation with leached silver content of 92.17% (mass fraction), displacement ratio of 99.5%, recovery efficiency of 90.79%. Therefore, the present study provides a feasible process for making full use of black manganese-silver ore resources.

关键词： black manganese-silver ores leaching cyanidation pyrite manganese silver

Emission and Energy Transfer Characteristics of Coumarin 6 Molecules Doped in Opal Polymer Photonic Crystal

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Chemical Research in Chinese Universities 2015年第3期31卷 466-470页

作者： CHI Xiaochun SUI Ning WANG Yinghui zou lu QIAN Cheng ZHANG Hanzhuang Key Laboratory of Physics and Technology for Advanced Batteries Ministry of EducationCollege of Physics Jilin University Changchun 130012 P.R.China

The emission of coumarin 6（C-6） doped in opal polymethylmethacrylate（PMMA） photonic crystal（PC） was effectively manipulated. Meanwhile the energy transfer（ET） of C-6 in PCs, which are infiltrated with sulforho- damine B（S-B）, was influenced by the concentration of energy acceptor in solution, the size of PMMA micro- sphere（SM） and the photonic stop band（PSB）. The results should be beneficial to people to further understand the potential application of PCs in optoelectronic fields.

关键词： Photonic crvstal: Energy transfer: Conjugated molecule

Magnetic field assisted Fenton reactions for the enhanced degradation of methyl blue

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Chinese Chemical Letters 2009年第1期20卷 99-101页

作者： Xiao Long Hao lu Yi zou Guang Sheng Zhang Yi Bo Zhang Laboratory of Environmental Pollution Prevention School of Environmental and Civil Engineering Jiangnan University Wuxi 214122 China

Magnetic field was tentatively introduced into Fenton reactions system for the degradation and discoloration of methyl blue as the represent of organic chemical dye, which was a bio-refractory organic pollutant in industry wastewater. It was found that under optimal Fenton reaction conditions, with the assistant of magnetic field in Fenton reactions, the degradation rate of methyl blue, the decomposition rate of H2O2 and the conversion rate of Fe^2＋ were accelerated, the extent of them would be improved by the increase of magnetic field intensity. Meanwhile, the mineralization of methyl blue （CODer） was improved by over 10% with magnetic field.

关键词： Magnetic field Fenton reactions Methyl blue Dye

Photo-induced Birefringence of Azo-dye Based on Three-dimensional Opal Photonic Crystals

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Chemical Research in Chinese Universities 2016年第6期32卷 1063-1068页

作者： ZHONG Qiulin zou lu WANG Yinghui SUI Ning LIU Qinghui ZHANG Liquan ZHANG Hanzhuang Key Laboratory of Physics and Technology for Advanced Batteries Ministry of Education College of Physics Jilin University Changchun 130012 P. R. China

A series of three-dimensional opal photonic crystals based on the polymer was synthesized and applied inthe field of photo-induced birefringence. The data show that the photo-induced birefringence（PIB） of pure Sudan IIIfilm could be enhanced by increasing the thickness of azo films. When Sudan III was distributed on thethree-dimensional opal photonic crystals, the photo-induced birefringence process could be modulated. In addition,the data also exhibit that the PIB processes with different pumping polarization directions are sensitive to the role ofphotonic crystals. The results could be beneficial to further understanding the photo-induced birefringence and uti-lizing the photonic crystals.

关键词： Photonic crystal Photo-reduced birefringence Azo-dye

FICW: Frequent Itemset Based Text Clustering with Window Constraint

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Wuhan University Journal of Natural Sciences 2006年第5期11卷 1345-1351页

作者： ZHOU Chong lu Yansheng zou Lei HU Rong College of Computer Science and Technology HuazhongUniversity of Science and Technology Wuhan 430074Hubei China

Most of the existing text clustering algorithms overlook the fact that one document is a word sequence with semantic information. There is some important semantic information existed in the positions of words in the sequence. In this paper, a novel method named Frequent Itemset-based Clustering with Window （FICW） was proposed, which makes use of the semantic information for text clustering with a window constraint. The experimental results obtained from tests on three （hypertext） text sets show that FICW outperforms the method compared in both clustering accuracy and efficiency.

关键词： text clustering frequent itemsets search engine

NUMERICAL STUDY OF FLOW PAST AN AXISYMMETRIC BODY WITH A RING WING AT VARIOUS ATTACK ANGLES

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Journal of Hydrodynamics 2003年第5期15卷 49-53页

作者： Ren An lu, zou Jian feng, Dai Zhi qian Department of Mechanics, Zhejiang University, 310027, China, Dept. of Mech. Zhejiang Univ. Zhejiang 310027 China

The laminar and turbulent flows past an axi-symmetric body with a ring wingwere investigated numerically at various attack angles (0°-20°) for the Reynolds numbers rangingfrom 10~3 to 10~7. The DDM (Domain Decomposition Method) with the Schwarz iterative method based onfinite difference approximation was applied to simulate this problem. The primitive variableformulation was used for the solution of the incompressible Navier-Stoke equations. The velocityfield was calculated from the unsteady momentum equation by marching in time. The continuityequation was replaced by a Poisson-type equation for the pressure with the Neumann boundaryconditions. The Baldwin-Lomax model was adopted to simulate turbulence effect. The leap frogimplicit iterative method was used for the time difference approximations. The computed pressure atthe front stagnation point is found to have a small deviation, less than 10%, from the theoreticalvalue. The outlet flux has a loss about 5%. The lift coefficients increase linearly with the attackangle, but for attack angles greater than 15° the lift coefficients show mild decrease. Thefriction drag coefficients are insensitive to the attack angles, but the pressure drag coefficientsincrease markedly with the attack angles. In addition, complex flow patterns are revealed within thevicinity of the ring wing.

关键词： an axisymmetric body domain decomposition method (DDM) baldwin-lomax model non-staggered grid

浅水中低速斜航船舶水动力预报及验证与确认分析

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船舶力学 2016年第7期20卷 841-848页

作者：邹璐上海交通大学船舶海洋与建筑工程学院高新船舶与深海开发装备协同创新中心上海200240

浅水中的斜航船舶受到浅水阻塞效应和不对称流的综合影响。为预报该运动中的船舶水动力,文章采用基于定常雷诺平均纳维—斯托克斯方程的计算流体动力学方法,对浅水中做斜航运动的船舶粘性绕流场进行数值模拟。考虑低航速运动的特点,忽... 详细信息

浅水中的斜航船舶受到浅水阻塞效应和不对称流的综合影响。为预报该运动中的船舶水动力,文章采用基于定常雷诺平均纳维—斯托克斯方程的计算流体动力学方法,对浅水中做斜航运动的船舶粘性绕流场进行数值模拟。考虑低航速运动的特点,忽略航速影响下的自由面兴波,由数值计算得到水动力系数在漂角影响下的变化规律。针对计算精度问题,在数值模拟中从验证和确认角度分析和评估计算结果:通过网格收敛性分析分析数值误差与不确定度;结合试验数据考察计算模型的误差。此外,从计算区域尺度、湍流模型、边界条件、船体下沉和纵倾作用方面对模型误差的影响因素进行探讨,可为改进计算模型、提高数值模拟精度提供参考依据。

关键词：浅水斜航运动 CFD 水动力系数误差和不确定度验证和确认