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Acta Oceanologica Sinica 2014年第3期33卷 58-78页

作者： huang rui xin Department of Physical Oceanography Woods Hole Oceanographic Institution

Gravitational potential energy （GPE） source and sink due to stirring and cabbeling associated with sigma dif fusion/ advection is analyzed. It is shown that GPE source and sink is too big, and they are not closely linked to physical property distribution, such as temperature, salinity and velocity. Although the most frequently quoted advantage of sigma coordinate models are their capability of dealing with topography; the exces sive amount of GPE source and sink due to stirring and cabbeling associated with sigma diffusion/advec tion diagnosed from our analysis raises a very serious question whether the way lateral diffusion/advection simulated in the sigma coordinates model is physically acceptable. GPE source and sink in three coordinates is dramatically different in their magnitude and patterns. Overall, in terms of simulating lateral eddy diffu sion and advection isopycnal coordinates is the best choice and sigma coordinates is the worst. The physical reason of the excessive GPE source and sink in sigma coordinates is further explored in details. However, even in the isopycnal coordinates, simulation based on the Eulerian coordinates can be contaminated by the numerical errors associated with the advection terms.

关键词： energetics of horizontal advection energetics of horizontal eddy diffusion energetics ofisopycnal advection energetics of isopycnal eddy diffusion energetics of sigma advectiondiffusion energetics of sigma eddy diffusion

Energetics of lateral eddy diffusion/advection: Part II. Numerical diffusion/diffusivity and gravitational potential energy change due to isopycnal diffusion

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Acta Oceanologica Sinica 2014年第3期33卷 19-39页

作者： huang rui xin Department of Physical Oceanography Woods Hole Oceanographic Institution

Study of oceanic circulation and climate requires models which can simulate tracer eddy diffusion and ad vection accurately. It is shown that the traditional Eulerian coordinates can introduce large artificial hori zontal diffusivity/viscosity due to the incorrect alignment of the axis. Therefore, such models can smear sharp fronts and introduce other numerical artifacts. For simulation with relatively low resolution, large lateral diffusion was explicitly used in models; therefore, such numerical diffusion may not be a problem. However, with the increase of horizontal resolution, the artificial diffusivity/viscosity associated with hori zontal advection in the commonly used Eulerian coordinates may become one of the most challenging ob stacles for modeling the ocean circulation accurately. Isopycnal eddy diffusion （mixing） has been widely used in numerical models. The common wisdom is that mixing along isopycnal is energy free. However, a careful examination reveals that this is not the case. In fact, eddy diffusion can be conceptually separated into two steps： stirring and subscale diffusion. Due to the thermobaric effect, stirring, or exchanging water masses, along isopycnal surface is associated with the change of GPE in the mean state. This is a new type of instability, called the thermobaric instability. In addition, due to cabbeling subscale diffusion of water parcels always leads to the release of GPE. The release of GPE due to isopycnal stirring and subscale diffusion may lead to the thermobaric instability.

关键词： Eulerian coordinates numerical diffusivity numerical dissipation energetics of isopycnal eddydiffusion

Energetics of lateral eddy diffusion/advection: Part III. Energetics of horizontal and isopycnal diffusion/ advection

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Acta Oceanologica Sinica 2014年第3期33卷 40-57页

作者： huang rui xin Department of Physical Oceanography Woods Hole Oceanographic Institution

Gravitational Potential Energy （GPE） change due to horizontal/isopycnal eddy diffusion and advection is examined. Horizontal/isopycnal eddy diffusion is conceptually separated into two steps： stirring and sub scale diffusion. GPE changes associated with these two steps are analyzed. In addition, GPE changes due to stirring and subscale diffusion associated with horizontal/isopycnal advection in the Eulerian coordinates are analyzed. These formulae are applied to the SODA data for the world oceans. Our analysis indicates that horizontal/isopycnal advection in Eulerian coordinates can introduce large artificial diffusion in the model. It is shown that GPE source/sink in isopycnal coordinates is closely linked to physical property distribution, such as temperature, salinity and velocity. In comparison with z-coordinates, GPE source/sink due to stir ring/cabbeling associated with isopycnal diffusion/advection is much smaller. Although isopycnal coordi nates may be a better choice in terms of handling lateral diffusion, advection terms in the traditional Eule rian coordinates can produce artificial source of GPE due to cabbeling associated with advection. Reducing such numerical errors remains a grand challenge.

关键词： energetics of horizontal eddy diffusion energetics of horizontal advection energetics ofisopycnal eddy diffusion energetics of isopycnal advection

Energetics of lateral eddy diffusion/advection: Part I. Thermodynamics and energetics of vertical eddy diffusion

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Acta Oceanologica Sinica 2014年第3期33卷 1-18页

作者： huang rui xin Department of Physical Oceanography Woods Hole Oceanographic Institution

Two important nonlinear properties of seawater thermodynamics linked to changes of water density, cab beling and elasticity （compressibility）, are discussed. Eddy diffusion and advection lead to changes in den sity; as a result, gravitational potential energy of the system is changed. Therefore, cabbeling and elasticity play key roles in the energetics of lateral eddy diffusion and advection. Vertical eddy diffusion is one of the key elements in the mechanical energy balance of the global oceans. Vertical eddy diffusion can be con ceptually separated into two steps： stirring and subscale diffusion. Vertical eddy stirring pushes cold/dense water upward and warm/light water downward; thus, gravitational potential energy is increased. During the second steps, water masses from different places mix through subscale diffusion, and water density is increased due to cabbeling. UsingWOA01 climatology and assuming the vertical eddy diffusivity is equal to a constant value of 2x103 pa2/s, the total amount of gravitational potential energy increase due to vertical stirring in the world oceans is estimated at 263 GW. Cabbeling associated with vertical subscale diffusion is a sink of gravitational potential energy, and the total value of energy lost is estimated at 73 GW. Therefore, the net source of gravitational potential energy due to vertical eddy diffusion for the world oceans is estimated at 189 GW.

关键词： cabbeling compressibility elasticity energetics of vertical eddy diffusion gravitationalpotential energy parameterization of eddy diffusion

Scientific questions about South China Sea ocean dynamics

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Acta Oceanologica Sinica 2015年第11期34卷 1-5页

作者： huang rui xin DU Yan State Key Laboratory of Tropical Oceanography South China Sea Institute of Oceanology Chinese Academy of Sciences Woods Hole Oceanographic Institution

South China Sea, its circulation and connection with other parts of the world oceans, poses important scientific questions. From the prospective view, we postulate ten key research directions to be pursued in the coming future, including ventilation of a monsoon dominated sea, water mass formation/transformation, heat/salt and water mass balance, energetics and mixing, mesoscale eddies, the role of typhoon, deep circulation and paleoclimate records, interaction with adjacent oceans, upwelling and ecology system, and response to climate changes.

关键词： South China Sea ocean dynamics circulation gyre interaction ventilation mixing

Zonal overturning circulation and heat flux induced by heaving modes in the world oceans

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Acta Oceanologica Sinica 2015年第11期34卷 80-91页

作者： TAN Wei huang rui xin WANG Weiqiang WANG xin Hohai University State Key Laboratory of Tropical Oceanography South China Sea Institute of Oceanology Chinese Academy of Sciences Woods Hole Oceanographic Institution

Zonal overturning circulation （ZOC） and its associated zonal heat flux （ZHF） are important components of the oceanic circulation and climate system, although these conceptions have not received adequate attentions. Heaving induced by inter-annual and decadal wind stress perturbations can give rise to anomalous ZOC and ZHF. Based on a simple reduced gravity model, the anomalous ZOC and ZHF induced by idealized heaving modes in the world oceans are studied. For example, in a Pacific-like model basin intensified equatorial easterly on decadal time scales can lead to a negative ZOC with a non-negligible magnitude （-0.3×10^6 m^3/s） and a considerable westward ZHF with an amplitude of -11.2 TW. Thus, anomalous ZOC and ZHF may consist of a major part of climate signals on decadal time scales and thus play an important role in the oceanic circulation and climate change.

关键词： adiabatic motions heaving wind-driven circulation zonal overturning circulation zonal heat flux

Evolution of oceanic circulation theory: From gyres to eddies

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热带海洋学报 2013年第2期32卷 1-14页

作者： huang rui-xin Department of Physical Oceanography Woods Hole Oceanographic Institution

Physical oceanography is now entering the eddy-resolving *** are commonly referred to the so-called mesoscale or submesoscale eddies;by definition,they have horizontal scales from 1 to 500 km and vertical scales from meters to hundreds of *** one word,the ocean is a turbulent environment;thus,eddy motions are one of the fundamental aspects of oceanic *** of these eddies,including observations,theory,laboratory experiments,and parameterization in numerical models,will be the most productive research frontiers for the next 10 to 20 years,although we have made great efforts to collect data about eddies in the ocean;thus far,we know very little about the three-dimensional structure of these eddies and their contributions to the oceanic general circulation and ***,the most important breakthrough may come from observations and physical reasoning about the fundament aspects of eddy structure and their contributions to ocean circulation and climate.

关键词：海洋学海洋调查海洋观测海洋水文学

Adiabatic density surface,neutral density surface, potential density surface,and mixing path

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热带海洋学报 2014年第4期33卷 1-19页

作者： huang rui-xin Department of Physical Oceanography Woods Hole Oceanographic Institution

In this paper,adiabatic density surface,neutral density surface and potential density surface are *** adiabatic density surface is defined as the surface on which a water parcel can move adiabatically,without changing its potential temperature and *** a water parcel taken at a given station and pressure level,the corresponding adiabatic density surface can be determined through simple *** family of surface is neutrally buoyant in the world ocean,and different from other surfaces that are not truly neutrally *** order to explore mixing path in the ocean,a mixing ratio m is introduced,which is defined as the portion of potential temperature and salinity of a water parcel that has exchanged with the environment during a segment of migration in the *** extreme situations of mixing path in the ocean are m=0(no mixing),which is represented by the adiabatic density curve,and m=1,where the original information is completely lost through *** latter is represented by the neutral density *** reality lies in between,namely,0xing paths,some of which may be identified by using different tracers(or their combinations)and different mixing *** for mixing paths in the real ocean presents a great challenge for further research.

关键词： adiabatic density surface neutral density surface potential density surface mixing path

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试析陈独秀等人的“美术革命”的思想内涵

河南大学学报（社会科学版） 2005年第6期45卷 203-206页

作者：黄瑞欣河南大学艺术学院美术教育系河南开封475001

陈独秀在投身政治的前夕提出了“美术革命”,“美术革命”淹没在陈氏的政治热情里而成了一句口号。美术在五四新文化运动寻求民族解放的泛政治化趋势的影响下,无法摆脱对政治、社会伦理的依附性、工具性和功利性。当时的众多有关的主张... 详细信息

陈独秀在投身政治的前夕提出了“美术革命”,“美术革命”淹没在陈氏的政治热情里而成了一句口号。美术在五四新文化运动寻求民族解放的泛政治化趋势的影响下,无法摆脱对政治、社会伦理的依附性、工具性和功利性。当时的众多有关的主张与改革,也大多倾向于此。当然,也有个别学人对此表示忧虑。这些很值得我们今天研究与反思。

关键词：美术革命民族主义美育

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冷冻电镜成像中噪声的滤波方法进展

北京大学学报（医学版） 2021年第2期53卷 425-433页

作者：黄新瑞李莎高嵩北京大学基础医学院生物化学与生物物理学系北京100191 北京大学医学部医学技术研究院北京100191

1冷冻电镜的发展背景在人类基因组测定之后,人们发现仅从基因组序列的角度无法完整、系统地阐明生物体的功能,因此,研究以蛋白质为主体的生物大分子三维结构和功能之间的关系成为现代生命科学的一个重要研究领域,尤其是生物大分子高分... 详细信息

1冷冻电镜的发展背景在人类基因组测定之后,人们发现仅从基因组序列的角度无法完整、系统地阐明生物体的功能,因此,研究以蛋白质为主体的生物大分子三维结构和功能之间的关系成为现代生命科学的一个重要研究领域,尤其是生物大分子高分辨率三维结构的研究甚至原子水平结构的研究[1-2]。透射电镜本质上有原子尺度分辨率的能力,但由于生物样品易受辐照损伤、图像衬度差、信噪比低的特点,使其对生物大分子的高分辨率结构解析比较困难[3-4]。

关键词：冷冻电子显微镜图像处理,计算机辅助成像,三维信噪比