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Nonlinear Analysis of Bidirectional Vortex-Induced Vibration of A Deepwater Steep Wave Riser Subjected to Oblique Currents

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China Ocean Engineering 2021年第6期35卷 852-865页

作者： CHENG Yong tang Lian-yang JI chun-yan School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China Nippon Kaiji Kyokai(China)Co. LtdShanghai 200336China

An improved three-dimensional(3D)time-domain couple model is established in this paper to simulate the bidirectional vortex-induced vibration(VIV)of a deepwater steep wave riser(SWR)subjected to oblique *** this model,the nonlinear motion equations of the riser are established in the global coordinate system based on the slender rod theory with the finite element *** der Pol equations are used to describe the lift forces induced by the x-and y-direction current components,*** coupled equations at each time step are solved by a Newmark-βiterative scheme for the SWR *** present model is verified by comparison with the published experimental results for a top-tension ***,a series of simulations are executed to determine the influences of the oblique angle/velocity of the current,different top-end positions and the length of the buoyancy segment on the VIV displacement,oscillating frequency as well as hydrodynamic coefficients of the *** results demonstrate that there exists a coupled resonant VIV corresponding to x-direction and y-direction,***,the effective frequency is almost identical between the vibrations at the hang-off segment along x and y *** addition of the buoyancy modules in the middle of the SWR has a beneficial impact on the lift force of three segments and simultaneously limits the VIV response,especially at the decline segment and the hang-off ***,the incident current direction significantly affects the motion trajectory of the SWR which mainly includes the fusiform and rectangle shapes.

关键词： steep wave riser(SWR) bidirectional vortex-induced vibration wake oscillator model time-domain finite element method(TDFEM)

Time-Domain Nonlinear Wave-Current Interaction with A Steep Wave Riser Considering Internal Flow Effect

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China Ocean Engineering 2021年第3期35卷 410-421页

作者： tang Lian-yang CHENG Yong JI chun-yan School of naval architecture and ocean engineering Jiangsu University of Science and TechnologyZhenjiang 212003China Nippon Kaiji Kyokai(China)Co. LtdShanghai 200336China

The nonlinear dynamic response induced by the wave-current interaction on a deepwater steep wave riser(SWR)is numerically investigated based on a three-dimensional(3 D)time-domain finite element method(FEM).The governing equation considering internal flow is established in the global coordinate *** whole SWR consists of three segments:the decline segment,buoyancy segment and hang-off segment,in which the buoyancy segment is wrapped by several buoyancy modules in the middle section,leading to the arch bend and sag bend.A Newmark-β iterative scheme is adopted for the accurate analysis to solve the governing equation and update the dynamic response at each time *** proposed method is verified through the published results for the dynamic response of steel catenary riser(SCR)and static configuration of steel lazy wave riser(SLWR).Simulations are executed to study the influence of wave height,current velocity/direction,internal flow density/velocity and top-end pressure on the tension,configuration and bending moment of the *** results indicate that the influence of the current on the configuration and mechanical behavior of the SWR is greater than that of the wave,especially in the middle *** increasing current velocity,the suspending height of the middle section drops,meanwhile,its bending moment decreases accordingly,but the tension increases *** a fixed external load,the increasing internal flow density induces the amplification of the tension at the hang-off segment and the mitigation at the decline segment,while the opposite trend occurs at the bending moment.

关键词： steep wave riser(SWR) nonlinear dynamic response wave-current interaction time-domain finite element method(FEM)

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非汉字符号"混合序列的强大数律

江汉大学学报（自然科学版） 2004年第1期32卷 14-16页

作者：伍艳春唐国强桂林工学院数理系广西桂林541004

讨论了一类较广泛的φ^～混合序列的收敛性质，获得了与独立情形一样的三级数定理等收敛性质，并由此得到与独立情形一样的Kolmogov强大数律的充分条件．

关键词： φ^~混合序列收敛性质几乎处处收敛 Kolmogov强大数律随变量

Determination of optimum nitrogen application rates in Zhejiang Province, China, based on rice yields and ecological security

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Journal of Integrative Agriculture 2015年第12期14卷 2426-2433页

作者： LI yan CHEN Yi WU chun-yan tang Xu JI Xiao-jiang Institute of Environment Resource and Soil Fertilizer Zhejiang Academy of Agricultural Sciences

Excessive nitrogen（N） fertilization in intensive agricultural areas such as the plain region of South China has resulted in low nitrogen use efficiency and serious environmental problems. To determine the optimum N application rate, grain yield, apparent nitrogen recovery efficiency（ANRE）, apparent N loss, and ammonium（NH_3） volatilization under different N application rates in the three years from 2012 to 2014 were studied. The results showed that the relationship between grain yields and N application rate in the three years were well fitted by quadratic equations. When N application rate reached 197 kg ha^（–1） in 2012, 199 kg ha^（–1） in 2013 and 196 kg ha^（–1） in 2014, the plateau of the grain yields appeared. With the increase of N application rate, the ANRE for rice decreased which could be expressed with sigmoidal equation; when N application rate was 305 kg ha^（–1） in 2012, 275 kg ha^（–1） in 2013 and 312 kg ha^（–1） in 2014, the curves of ANRE appeared turing points. Besides, the relationship between soil Nresidual and N application rate was fitted by the quadratic equation and the maximums of soil Nresidual were reached in the three years with the N application rate of 206, 244 and 170 kg ha^（–1）, respectively. Statistical analysis indicated that NH3 volatilization and apparent N loss in three years all increased with the increasing N application rate. When the amount of NH3 volatilization increased to 11.6 kg N ha^（–1） in 2012, 40.5 kg N ha^（–1） in 2013 and 57.0 kg N ha^（–1）in 2014, the apparent N loss in the three years had obvious increase. To determine the optimum N application rate, the average N application on the plateau of the grain yield was considered as the lower limit while the average N application rate at the turning points of ANRE, the residual N in soil and apparent N loss was taken as the upper limit. According to the results in three years, the optimum N application rate for rice in Zhejiang was 197–255 kg ha^（–1）.

关键词： optimum nitrogen application rate Zhejiang rice yields ecological security

Novel metastable Bi:Co and Bi:Fe alloys nanodots@carbon as anodes for high rate K-ion batteries

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Nano Research 2022年第8期15卷 7220-7226页

作者： Zhongqiu Tong Tianxing Kang yan Wu Fan Zhang Yongbing tang chun-Sing Lee Faculty of Metallurgical and Energy Engineering Kunming University of Science and TechnologyKunming 650093China Department of Chemistry City University of Hong KongHong Kong 999077China Center of Super-Diamond and Advanced Films(COSDAF) City University of Hong KongHong Kong 999077China Shenzhen Institutes of Advanced Technology Chinese Academy of SciencesShenzhen 518055China

Bi is a promising anode material for potassium-ion batteries(PIBs)due to its high theoretical ***,severe pulverization upon cycling limits its practical *** this work,we propose a new approach of using metastable alloys with Bi *** Bi:Co and Bi:Fe alloys nanodots@carbon anode materials(Bi:Co and Bi:Fe@C)are synthesized for the first time via simple annealing of their metal-organic frameworks(MOF)*** prepared materials are demonstrated as ideal hosts for high-rate K-ion ***_(0.85)Co_(0.15)@C and Bi_(0.83)Fe_(0.17)@C electrodes respectively deliver superior 178 and 253 mAh·g^(−1)at 20 A·g^(−1),as well as stable cycling performance at 2 A·g^(−1).Ex situ scanning electron microscopy(SEM),X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD),and transmission electron microscopy(TEM)studies on Bi:Co@C indicate that the elemental Co separates out during the initial potassiation and stands during the following discharge/charge *** situ formed Co precipitates can act as(1)“conductive binders”as well as(2)“separators”to prevent the severe aggregation of adjacent active elemental Bi nanoparticles and(3)accelerate the potassiation/de-potassiation kinetics in elemental Bi precipitates after initial discharge/charge *** work could inspire the development of metal-type anodes.

关键词： metastable alloys metal anode potassium-ion battery metal-organic frameworks(MOF)-derived materials

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汽车牌照自动定位方法

指挥技术学院学报 2001年第6期12卷 53-56页

作者：李迎春孙华燕唐黎明装备指挥技术学院测量控制系

汽车牌照定位是一个较难解决的图像分割问题。采用灰度图像分割、数学形态学、颜色搜索相结合的方法 ,进行汽车牌照定位 ,充分利用了颜色信息和牌照特点。实验表明 ,检测出的牌照区域准确率高 ,适用于任意背景、位置和光照下的牌照定位 ... 详细信息

汽车牌照定位是一个较难解决的图像分割问题。采用灰度图像分割、数学形态学、颜色搜索相结合的方法 ,进行汽车牌照定位 ,充分利用了颜色信息和牌照特点。实验表明 ,检测出的牌照区域准确率高 ,适用于任意背景、位置和光照下的牌照定位 ,且通用性较好。

关键词： Prewitt边缘检测牌照定位颜色特征搜索

Molecular ferroelectrics for efficient perovskite solar cells

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Science China Chemistry 2021年第2期64卷 169-170页

作者： chun-Hua yan Beijing National Laboratory for Molecular Sciences State Key Laboratory of Rare Earth Materials Chemistry and ApplicationsPKU-HKU Joint Laboratory in Rare Earth Materials and Bioinorganic ChemistryCollege of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China College of Chemistry and Chemical Engineering Lanzhou UniversityLanzhou 730000China

During the past decade,the power conversion efficiencies(PCEs)of organic-inorganic hybrid perovskite solar cells(PSCs)have exceeded 25%[1],which is expected to be one of the candidates for the next generation of thin-film photovoltaic *** speaking,the performance of PSCs mainly depends on the light absorption capacity,defect passivation and photo-induced exciton separation and extraction of perovskite *** the light illumination,photo-induced excitons were separated and extracted by the built-in electric field of PSCs.

关键词： perovskite illumination inorganic

Recent development of hydrodynamic modeling in heavy-ion collisions

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Nuclear Science and Techniques 2020年第12期31卷 88-121页

作者： chun Shen Li yan Department of Physics and Astronomy Wayne State UniversityDetroitMI 48201USA RIKEN BNL Research Center Brookhaven National LaboratoryUptonNY 11973USA Key Laboratory of Nuclear Physics and Ion-Beam Application(MOE) Institute of Modern PhysicsFudan University220 Handan RoadShanghai 200433China

We present a concise review of the recent development of relativistic hydrodynamics and its applications to heavy-ion *** progress on the extended formulation of hydrodynamics toward out-ofequilibrium systems is addressed,with emphasis on the socalled attractor ***,recent phenomenological improvements in the hydrodynamic modeling of heavy-ion collisions with respect to the ongoing beam energy scan program,the quantitative characterization of transport coefficients in three-dimensionally expanding quark–gluon plasma,the fluid description of small colliding systems,and certain other interdisciplinary connections are discussed.

关键词： Heavy-ion collisions Hydrodynamics QCD

耳穴压豆联合磁刺激治疗产后压力性尿失禁临床观察

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中国中医药现代远程教育 2025年第2期23卷 108-110页

作者：何艳唐慧潜江市中心医院产科湖北潜江433199

目的探究耳穴压豆联合磁刺激治疗产后压力性尿失禁的效果。方法选取潜江市中心医院2021年1月—2022年6月收治的产后压力性尿失禁患者60例作为研究对象,按照治疗方式的不同分为对照组、研究组,各30例。对照组予耳穴压豆治疗,研究组予耳... 详细信息

目的探究耳穴压豆联合磁刺激治疗产后压力性尿失禁的效果。方法选取潜江市中心医院2021年1月—2022年6月收治的产后压力性尿失禁患者60例作为研究对象,按照治疗方式的不同分为对照组、研究组,各30例。对照组予耳穴压豆治疗,研究组予耳穴压豆联合磁刺激治疗。比较两组临床疗效及治疗后盆底肌力、60 min漏尿量、3 d漏尿次数、生活质量评分。结果研究组治疗总有效率为96.67%(29/30),高于对照组的80.00%(24/30)(P<0.05)。治疗后,研究组盆底肌肌力、生活质量评分均高于对照组,60 min漏尿量、3 d漏尿次数均低于对照组(P<0.05)。结论耳穴压豆联合磁刺激治疗产后压力性尿失禁的临床效果显著,不仅能够缓解盆底肌肌力、降低漏尿量及漏尿次数,还能促进产妇生活质量提高,缓解焦虑、降低压力,值得临床推广使用。

关键词：产后压力性尿失禁耳穴压豆疗法磁刺激疗法