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Analytical solutions for the interfacial viscous capillary-gravity waves due to an oscillating Stokeslet

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Journal of Hydrodynamics 2019年第6期31卷 1139-1147页

作者： dong-qiang lu Shanghai Institute of Applied Mathematics and Mechanics School of Mechanics and Engineering ScienceShanghai UniversityShanghai 200072China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai 200072China

The fundamental solutions of the Stokes/Oseen equations due to a point force in an unbounded viscous fluid are referred to as the Stokeslet/Oseenlet,for which a systematic derivation are analytically presented here in terms of a uniform *** means of integral transforms,the closed-form solutions are explicitly deduced in a formula which involves the Hamiltonian,Hessian,and Laplacian operators,and elementary ***,interfacial viscous capillary-gravity waves between two semi-infinite fluids due to oscillating singularities,including a simple source in the upper inviscid fluid and a Stokeslet in the low viscous fluid,were analytically studied by the Laplace-Fourier integral transform and asymptotic *** dynamics responses consist of the transient and steady-state components,which are dealt with by the method of stationary phase and the Cauchy residue theorem,*** transient response is made up of one short capillarity・dominated and one long gravity-dominated wave with the former riding on the *** steady-state wave has the same frequency as that of oscillating *** solutions for the wave profiles and the exact solution for the wave number are analytically derived,which show the combined effects of fluid viscosity,surface capillarity and an upper layer fluid.

关键词： Interfacial wave surface tension viscosity Stokeslet asymptotic solution singularity method

Effects of oceanic ice cover and density stratification on the propagation of hydroacoustic waves

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Journal of Hydrodynamics 2022年第6期34卷 1151-1155页

作者： Ya-dong Liu dong-qiang lu Ming-song Zou Shanghai Institute of Applied Mathematics and Mechanics School of Mechanics and Engineering ScienceShanghai UniversityShanghai200072China China Ship Scientific Research Center Wuxi214082China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai200072China

The propagation characteristic of hydroacoustic waves is studied for an ideal compressible two-layer fluid with different densities covered by an elastic ice *** conditions are simplified by adopting linear assumption and then the dispersion relation is *** analysis and visualization of the dispersion relation present the introduction of compressibility leads to the appearance of hydroacoustic wave modes while the density stratification leads to the appearance of interfacial wave *** ice thickness and the density ratio of the two fluid layers increase the wave number and group speed of hydroacoustic waves at the same frequency while the phase speed decreases.

关键词： Ocean ice sheet density stratified fluid hydroacoustic propagation

Conductive Au nanowires regulated by silk fibroin nanofibers

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Frontiers of Materials Science 2014年第1期8卷 102-105页

作者： Bo-Ju dong qiang lu National Engineering Laboratory for Modern Silk College of Textile and Clothing Engineering Soochow University Suzhou 215123 China

Conductive Au-biopolymer composites have promising applications in tissue engineering such as nerve tissue regeneration. In this study, silk fibroin nanofibers were formed in aqueous solution by regulating silk self-assembly process and then used as template for Au nanowire fabrication. We performed the synthesis of Au seeds by repeating the seeding cycles for several times in order to increase the density of Au seeds on the nanofibers. After electroless plating, densely decorated Au seeds grew into irregularly shaped particles following silk nanofiber to fill the gaps between particles and finally form uniform continuous nanowires. The conductive property of the Au-silk fibroin nanowires was studied with current-voltage （I-V） measurement. A typical ohmic behavior was observed, which highlighted their potential applications in nerve tissue regeneration.

关键词： silk Au nanowire electrical conductivity biological device

Waves propagating over a two-layer porous barrier on a seabed

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Journal of Hydrodynamics 2018年第3期30卷 453-462页

作者： qiang Lin Qing-rui Meng dong-qiang lu China Ship Scientific Research Center Wuxi 214082China Shanghai Oriental Maritime Engineering Technology Company Limited Shanghai 200011China Shanghai Institute of Applied Mathematics and Mechanics Shanghai UniversityShanghai 200072China Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai 200072China

A research of wave propagation over a two-layer porous barrier, each layer of which is with different values of porosity and friction, is conducted with a theoretical model in the frame of linear potential flow theory. The model is more appropriate when the seabed consists of two different properties, such as rocks and breakwaters. It is assumed that the fluid is inviscid and incompressible and the motion is irrotational. The wave numbers in the porous region are complex ones, which are related to the decaying and propagating behaviors of wave modes. With the aid of the eigenfunction expansions, a new inner product of the eigenfunctions in the two-layer porous region is proposed to simplify the calculation. The eigenfunctions, under this new definition, possess the orthogonality from which the expansion coefficients can be easily deduced. Selecting the optimum truncation of the series, we derive a closed system of simultaneous linear equations for the same number of the unknown reflection and transmission coefficients. The effects of several physical parameters, including the porosity, friction, width, and depth of the porous barrier, on the dispersion relation, reflection and transmission coefficients are discussed in detail through the graphical representations of the solutions. It is concluded that these parameters have certain impacts on the reflection and transmission energy.

关键词： Two-layer porous barrier inner product matched eigenfunction expansions

Propagating characteristics of waves on a thin layer of mud

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Journal of Hydrodynamics 2021年第5期33卷 1078-1088页

作者： Hai-jue Xu Jin-sen Wu Yu-chuan Bai dong-qiang lu Chiu-On Ng State Key Laboratory of Hydraulic Engineering Simulation and Safety Tianjin UniversityTianjin 300072China Shanghai Institute of Applied Mathematics and Mechanics School of Mechanics and Engineering ScienceShanghai UniversityShanghai 200072China Department of Mechanical Engineering The University of Hong KongHong KongChina

The propagating characteristics of the water and muddy waves are one of the concerns of theoretical studies because of the following facts:(1)With the development of the economy in the estuaries,local residents and government paid increasing attention to the ecological environment of the estuarine beaches The propagating characteristics of the water and muddy waves are closely related to the ecological environment,the concern of the government and the residents.(2)The propagating characteristics of the mud are the bottleneck of the study of the coastal and beach dynamics because of the complicated constitutive relation of the *** different constitutive models may lead to different explanations of its ***,the proper selection of the model is one of the keys to reveal the true kinematic properties of the mud in the *** paper first establishes a power law model of the constitutive relation of the *** on this model,a gravity wave theory is *** to the mechanism of the mud wave transportation,the coupled mud-water wave field can be divided into two *** upper layer is described as the viscous Newtonian fluid,whereas the lower high-concentration mud layer is described as the power law ***,the equations of the proposed model are discretized and the calculations are made by using the difference ***,the propagating characteristics are discussed,and the dispersion relations of the water and mud waves are analyzed in detail.

关键词： Estuary two-layer fluid model power law model gravity wave Introduction

Scattering of gravity waves by a porous rectangular barrier on a seabed

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Journal of Hydrodynamics 2016年第3期28卷 519-522页

作者：孟庆瑞卢东强 Shanghai Institute of Applied Mathematics and Mechanics Shanghai University Shanghai Key Laboratory of Mechanics in Energy Engineering Shanghai University

Within the frame of linear potential flow theory, the impact of a porous rectangular barrier on a seabed on the dynamic characteristics of gravity waves is investigated. The porous barrier can be regarded as an abstract representative such as a seabed plant, a wave breaker, inhomogeneous topography, and trussed supporting of ocean engineering platform, etc. In the process of mathematical modeling, the method of matched eigenfunction expansions is employed for analysis, where a newly defined form of inner product is introduced to improve the simplicity of derivation. Under this definition, the inner product is automatically orthogonal, which will provide great simplification to obtain the expansion coefficients. Once the wave numbers for the fluid region and the barrier region are obtained, the reflection and transmission coefficients of the wave motion can readily be calculated.

关键词： gravity waves dispersion relation permeability orthogonality

Fasudil inhibits platelet-derived growth factor-induced human pulmonary artery smooth muscle cell proliferation by up-regulation of p27^kipl via the ERK signal pathway

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Chinese Medical Journal 2011年第19期124卷 3098-3104页

作者： LIU Ai-jun LING Feng WANG dong WANG qiang lu Xiao-dong LIU Ying-long Department of Pediatric Cardiac Surgery Center Fuwai Hospital Chinese Academy of Medical Sciences ＆ Peking Union Medical College Beijing 100037 China

Background RhoA/ Rho kinase （ROCK） pathway is involved in pulmonary arterial hypertension （PAH） and pulmonary artery smooth muscle cell （PASMC） proliferation. Inhibition of ROCK has been proposed as a treatment for PAH. But the mechanism of RhoA/ROCK pathway and its downstream signaling in proliferation of human PASMCs is unclear. We investigated the effect of fasudil, a selective ROCK inhibitor, on platelet-derived growth factor （PDGF） induced human PASMC proliferation, and the possible association between RhoA/ROCK and extracellular signal-regulated kinase （ERK）,*** Human PASMCs were cultured with the stimulation of 10 ng/ml PDGF, and different concentrations of fasudil were added before the addition of mitogen. Cell viability and cell cycle were determined with MTT and flow cytometry respectively. ROCK activity, ERK activity and protein expression of proliferating cell nuclear angigen （PCNA） and p27Kip1 were measured by *** By MTT assay, PDGF significantly increased the OD value that represented human PASMC proliferation, and pretreatment with fasudil significantly reversed this effect in a dose-dependent manner. After PDGF stimulation, the percentage of cells in S phase increased dramatically from 15.6% to 24.3%, while the percentage in G0/G1 phase was reduced from 80.6% to 59%. And pretreatment with fasudil reversed the cell cycle effect of PDGF significantly in a dose-dependent manner. PDGF markedly induced ROCK activity and ERK activity with a peak at 15 minutes, which were significantly inhibited by fasudil. In addition, fasudil significantly inhibited PDGF-induced PCNA expression and fasudil also upregulated p27Kip1 expression in human PASMCs, which decreased after PDGF *** RhoA/ROCK is vital for PDFG-induced human PASMC proliferation, and fasudil effectively inhibited PDGF-induced human PASMC proliferation by up-regulation of p27Kip1, which may be associated with inhibition of ERK activity.

关键词： human pulmonary smooth muscle cell proliferation Rho-kinase fasudil extracellular signal-regulated kinase p27^kip1

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海上水平井砾石充填顶部封隔器研制与应用

中国海上油气 2017年第3期29卷 85-90页

作者：董社霞李强路振兴徐凤祥谢涛中海油田服务股份有限公司天津300459 中海石油(中国)有限公司天津分公司天津300452

顶部封隔器是水平井砾石充填管柱中最重要的组件之一。研制了一种新型顶部封隔器,该封隔器通径大(ф152.4 mm),采用C型单面齿锁环机构和双向卡瓦锚定来保证密封可靠性及降低管柱上下串动的风险。对新型顶部封隔器的卡瓦、锁环、上短节... 详细信息

顶部封隔器是水平井砾石充填管柱中最重要的组件之一。研制了一种新型顶部封隔器,该封隔器通径大(ф152.4 mm),采用C型单面齿锁环机构和双向卡瓦锚定来保证密封可靠性及降低管柱上下串动的风险。对新型顶部封隔器的卡瓦、锁环、上短节、芯轴、胶筒组等关键零部件进行了力学分析,均能满足要求。高温(165℃)高压室内坐封试验和上、下压试验表明,当加压至坐封压力19 MPa时,保压15 min,坐封正常完成;继续加压至46 MPa时,上、下压试验均能保压30 min;下入回取工具,将封隔器取出套管,胶筒及卡瓦均未损坏。利用新型顶部封隔器在陆上和海上3口井进行了现场试验,均圆满完成作业。新型顶部封隔器目前已成功应用100井次以上,可广泛应用于海上水平井砾石充填、简易防砂及相关技术领域。

关键词：水平井砾石充填新型顶部封隔器单面齿锁环双向卡瓦力学分析高温高压试验现场作业

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坝下地区防护林不同树种生长特征

应用生态学报 2017年第10期28卷 3174-3180页

作者：张杰铭余新晓贾国栋刘自强路伟伟北京林业大学水土保持学院/教育部水土保持与荒漠化防治重点实验室北京100083

采用标准样地调查法对防护林林分结构指标进行调查,研究河北坝下地区丰宁县小坝子乡不同防护林树种榆树、杨树及油松的动态变化规律.结果表明:该区域榆树、杨树和油松纯林的平均年龄均为10年,杨树纯林的平均胸径和树高分别是榆树纯林的... 详细信息

采用标准样地调查法对防护林林分结构指标进行调查,研究河北坝下地区丰宁县小坝子乡不同防护林树种榆树、杨树及油松的动态变化规律.结果表明:该区域榆树、杨树和油松纯林的平均年龄均为10年,杨树纯林的平均胸径和树高分别是榆树纯林的2.3和3.8倍,是油松纯林的2.3和3.0倍.杨树纯林的平均胸径、树高、叶面积指数(LAI)、活枝下高等指标显著大于榆树纯林和油松纯林.与杨树混交林相比,杨树纯林的林分密度高10.8%,纯林平均胸径则低5.2%,平均树高低11.3%;与榆树混交林相比,榆树纯林的林分密度高6.6%,纯林平均胸径、树高分别低7.8%和14.2%;与油松混交林相比,油松纯林的林分密度大4.9%,纯林平均胸径和树高分别低29.3%和31.8%.各林分类型的平均胸径、树高与密度呈显著负相关;平均LAI与密度和活枝下高呈显著正相关,与胸径、树高呈显著负相关;平均活枝下高与密度呈显著正相关.针阔混交林的胸径和树高生长显著优于针叶纯林.该区域防护林综合生长潜力呈上升趋势,而横向生长潜力总体上呈下降趋势.

关键词：防护林生长特征榆树杨树油松