Second-order random interfacial wave solutions for two-layer fluid with a free surface

1 Introduction Interfacial waves travelling along the interface between two fluids of different densities can be often observed in subsurface layers of the ocean since the upper subsurface layer is warmer over much of the o- cean (Umeyama, 2002). They are…     

Analysis of Dynamic Characteristics of Submarine Free Spanning Pipelines by Complex Damping Method

Considering the effect of the internal flowing fluid and the external marine environmental condition, the differential equation for the vortex-induced vibration (V1V) of the free spanning pipeline is derived and is discretized by the Hermit interpolation function. The free vibration equation with the damping term is solved by the complex damping method for the natural frequency, and then the effect of fluid damping on the natural frequency of the free spanning pipeline is analyzed.The results show that fluid damping has a significant influence on the damped natural frequency of the free spanning pipeline in the lock-in state, while it has little influence when the pipeline is out of the lock-in state. In the meantime,the change of the free span length has the same effect on the damped natural frequency and the undamped natural frequency.     

3D Numerical Simulation of Overbank Flow in Non-Orthogonal Curvilinear Coordinates

1.Introduction Riverflowsinacompoundchannelofteninundatetheadjacentplainsathighdischarges.This generatesacomplicatedflowstructurebetweenthemainchannelflowandthefloodplainflow.In straightchannels,thevelocitydifferencebetweentheflowinthemainchannelandthatontheflood plainisoneofthemostdistinctivecharacteristics.Thisintroducesseveralphysicalandphenomenologi calfeaturesaroundthejunctionbetweenthemainchannelandthefloodplain,namely,theformation ofahighhorizontalshearlayerandstreamwiseandverticalvorti…     

In-Situ Observation of Fluid Mud in the North Passage of Yangtze Estuary, China

Observations of fluid mud were made in the lower North Passage of the Yangtze Estuary in February 2000, on 10 -11 August 2000, on 30 - 31 August 2000 (after two strong typhoons), on 21 - 24 August 2000 (neap tide) and on 3 -6 September 2000 (mean tide) respectively. In situ data show that the fluid mud in this area consists of fine cohesive sediment (median size 7.23 μm). The formation and movement of fluid mud varied during the neap-spring and flood-ebb tidal cycle. Observations suggest that fluid mud phenomena in this area may be categorised in a three-fold manner as slack water, storm and saltwedge features. The thickness of the fluid mud layer of slack water during the neap tide ranged from 0.2 to 0.96 m, whereas during the mean tide, the thickness ranged from 0.17 to 0.73 m, and the thickness of the fluid mud layer was larger during slack water than at the flood peak. Shoals cover an area of 800 km^2 with a water depth smaller than 5 m. Erosion of these extensive intertidal mudflats due to storm action provides an abundant sediment source. This is particularly significant in this estuary when the tidal level is lower than 5 m. The lower North Passage is a typical zone of saltwater wedging, so the saltwedge fluid mud has the most extensive spatial range in the estuary.     

Experimental research on a new encapsulated heat-generating hydraulic fracturing fluid system

1 IntroductionFracturing plays an important role in increasingthe production and injection and enhancing the final re-covery of oil and gas. At present, the use of ahydroxypropyl guar gum, borate-crosslinked, hydraulicfracturing fluid systemhas become ext…     

欧北-大湾地区火山岩储层成因机制的研究

从分布、成分组成、形成机制等几个方面探讨了辽河油田东部凹陷中段最主要的火山岩储层－－粗面岩的成因机制，并对其成为该区良好储层的原因进行了探讨，通过对比说明了另一类火山岩－－玄武岩不含油的原因，并建立了成因模式，最后得出结论：粗面岩呈喷发状态产出，由于其硅质含量高，流动性小，容易在构造高部位形成巨厚的火山岩锥或火山岩钏，从而造成其大部分在水上，结晶较好且储层物性极佳，同时因其裂缝发育，这些因素结合起来使其成为良好的会层。从供油方式来看，其成藏方式属于侧生式，而从生储盖组合方式来看，其属于自生、自储、自盖式成藏组合。同时给出了其成藏模式。     

Study on the multi-sources of ore-forming materials and ore-forming fluids in the Huize lead-zinc ore deposit

TheHuizelarge sizedPb ZndepositinYunnan ProvinceislocatedinthecenteroftheSichuan Yun nan GuizhouPb Zn Agpolymetalmineralizationzone(SYGPb ZnMMD)inwesternYangtzePlateandis oneofthefamousPb Zn GebasesinChina(Wang Jiangzhenetal.,2003;WangXiaochunetal.,2000).Thisdeposit,whichischaracterizedbylarge scale(Pb+Znmetallicreservesarehigherthan5mil liontons),highPb+Zngrade(thePb+Zngradesof mostoresare25%-35%),highabundanceofuseful associatedelements(Ag,Ge,Cd,Ga,etc.)and someimportantbreakt…     

水泥—丙烯酸盐复合浆液的实验性研究

水泥-丙烯酸盐复合浆液是在丙烯酸盐浆液的基础上研制出来的一种复合浆液，它既保留了丙烯酸盐浆液流动性好，固结体弹性好的优点，又大幅度地提高了浆液的抗压强度和粘结强度，因此在注浆时可以带来良好的综合灌注效果，还对复合浆液的粘度和强度进行了试验性研究。     

以流动看世界——基于彼得·阿迪《流动性》的研究述评

“流动”正改变着人们的生存、生活和生产方式。流动性经历了从学科间独立的分散研究，到以地理学和社会学为主导的多学科研究，再转向新流动性范式下的跨学科研究。其中，彼得·阿迪（Peter Adey）的《流动性》（Mobility）（第二版）是一部梳理流动性演变脉络、解读理论并联系案例和方法的力作。因此，文章从流动性研究产生的背景、主要内容、研究方法与运用3个方面凝练该书观点，指出未来研究要跳出以二元对立看问题的思维方式，用一种网络化、关系式和辩证的思维洞察世界，在深度理解流动的意义、政治、实践和媒介基础上进行流动性研究。最后，文章基于国内研究现状，提出未来可以从流动性政治、流动性时空维度、旅游与流动性、流动主体的多元化、流动性研究方法等几个方面展开深入研究。     

新流动范式下非流动性的研究进展与展望北大核心CSCDCSSCI

新冠疫情下的中断与非流动性改变新流动性范式的叙事逻辑,作为现代社会基本原则的流动性受到挑战与质疑,而正确认识非流动性事关新流动范式的未来转向与变革。为此,本研究对新流动范式下的非流动性研究进行综述,思考流动性与非流动性的辩证关系,为新流动范式的转型提供新的路径。本研究发现,新流动范式下非流动性的研究领域具有四个重要转向:从批判解构到辩证关系的认识;从本体不可能到有可能的思考;从宏观视野到微观解释的叙述;从方法二元到方法平衡的转变。同时,非流动性研究中存在四大重要议题:地方性非流动人口;支撑性的停泊空间;非表征的静默身体;跨时空的节点主体。最后,本研究为非流动性的未来研究提出相关展望:关注非流动性的人口异质性;关注多样化的非流动性空间;认识后人类技术与非流动性身体;探讨可持续发展的流动性。