多层介质复杂构造的液体—固体物理模型研究

为了获得中扬子地区典型局部构造的波场特征,本文对MYH构造进行了物理模拟研究。本文论述了MYH构造地质模型特点;物理模型的选材及复杂的液体—固体模型的制作技术;观测方式以及资料处理和分析方法。并就盖层的影响,野外记录中短斜同相轴等问题进行了探讨。指出了以多相位形式出现的侧面波是本区值得特别注意的一种规则于扰。

U型弯道流速变化的物理模型研究

每年，邻近河道的农田、公路和建筑物会由于水流冲刷、河道变迁以及河流的弯曲发展而受到破坏，这种现象发生在河流弯道处，这是因为水流流态和流速在弯道处发生变化而影响到泥沙输送、冲坑形状以及泥沙淤积。因此，研究弯道处的水流特性对设计标准的选择和桥梁、防冲坝以及侧入水口等涉河建筑物位置的选定意义重大。同样，对于改善河道亦有效用。

用菲涅尔理论解释反射地质体边界的理论模型研究

本文从地表地震测量和垂直地震剖面(VSP)的观测系统出发,从理论上分析了反射界面上菲涅尔带分布的特点及其对地震波振幅的影响,并由物理地震模型试验资料,证实了各种观测方式及反射地质体处于不同埋置条件下菲涅尔带半径的可测性,由此总结出用反射能量极大点—半幅点间距来估算第一级菲涅尔带半径的方法,验证了半幅点方法确定反射地质体边界的可靠性,为地震资料解释提供了理论及方法依据。

碾压混凝土台阶式溢洪道模型研究

用1：20的碾压混凝土台阶式溢洪道两维空间模型来评估从一定标高溢洪道顶部到斜台阶的流量转变，台阶消能，以及所建议的消力池的动作来指导该模型的研究。台阶在消能方面起一定作用。当最大流量为14．5m3／s／m时，消能为48％的台阶式溢洪道与消能为20％的平滑稽平面的溢洪道进行了比较。当流量为5．8lm3／s／m时，台阶式溢洪道消能为71％，而平滑平面的溢洪道消能为25％。这种比较．可大大减小溢洪道底部消力池的尺寸。考虑到安全问题和台阶式溢洪道常规设计的标准受限等原因，美国TexasTemple提出为SaladoCreekSite10设计一个急流量为1062m／s，宽为73．15m的溢洪道，而单宽流量14．5m／s／m。溢洪道顶部与消力池之间高差为17．07m，在已建的土坝上建成一个下端坡为1V：3H的溢洪道。所建议的台阶尺寸步。下：高为0．61m，长为1．524m，坡比1V：2H。

振幅随偏移距变化的物理模拟

振幅随偏移距变化(AVO)的物理模型研究,首先要解决岩性参数的相似模拟问题,文中提出了密度、泊松比和杨氏模量相似模拟的比例因子关系式。由此设计出研究AVO的两个物理模型,分别采用共炮点和共中心点记录方式进行试验观测。对观测结果的振幅数据作各种补偿校正处理后,得到仅与反射界面的反射系数有关的真振幅数据。它与用Zoeppritz方程的精确解法计算得到的理论结果可以较好地吻合。

无料钟炉顶布料模型的技术路线

建立高炉无料钟布料模型的技术路线可以分成三类:物理模型试验研究、经典力学理论和人工智能技术。本文结合国内外无料钟炉顶布料模型,对这三类技术路线的运用过程进行详细的阐述,总结出这三类技术路线的优缺点,并针对其缺点提出了相应的改进措施。

封离型CO_2波导激光器使用同轴阳极保护金膜的机理探讨

本文以等温等离子体在圆柱形等电位空间中作扩散运动的物理模型研究了同轴阳极保护封离型CO_2波导激光器的金膜的机理。理论计算结果与实验相符。

Evaluation of Surface Air Temperature Change over China and the Globe during the Twentieth Century in IAP AGCM4.0

Based on time series and linear trend analysis, the authors evaluated the performance of the fourth gen- eration atmospheric general circulation model developed at the Institute of Atmospheric Physics, Chinese Academy of Sciences （IAP AGCM4.0）, in simulating surface air temperature （SAT） during the twentieth century over China and the globe. The numerical experiment is con- ducted by driving the model with the observed sea surface temperature and sea ice. It is shown that IAP AGCM4.0 can simulate the warming trend of the global SAT, with the major wanning regions in the high latitudes of the Northern Hemisphere and the mid-latitudes of the South- ern Hemisphere. While the simulated trend over the whole globe is close to the observation, the model trader- estimates the observed trend over the continents. More- over, the model simulates the spatial distribution of SAT in China, with a bias of approximately -2℃ in eastern China, but with a more serious bias in western China. Compared with the global mean, however, the correlation coefficient between the simulation and observation in China is significantly lower, indicating that there is large uncertainty in simulating regional climate change.

Numerical Study on Density Residual Currents of the Bohai Sea in Summer

M 2 tide and density residual currents in the Bohai Sea were examined using the Blumberg and Mellor 3D nonlinear numerical coastal circulation model incorporating Mellor and Yamada level 2.5 turbulent closure model. The tidal results showed good agreement with previous work. The model results indicated that the density residual currents are robust in summer; and that at the transition zone between well-mixed and stratified water, the horizontal velocity is high and the vertical velocity is positive.

New animal models for hepatitis C viral infection and pathogenesis studies

Hepatitis C virus （HCV） is a major cause of chronic liver disease, cirrhosis and hepatocellular carcinoma （HCC）. In man, the pathobiological changes associated with HCV infection have been attributed to both the immune system and direct viral cytopathic effects. Until now, the lack of simple culture systems to infect and propagate the virus has hampered progress in understanding the viral life cycle and pathogenesis of HCV infection, including the molecular mechanisms implicated in HCV-induced HCC. This clearly demonstrates the need to develop small animal models for the study of HCV-associated pathogenesis. This review describes and discusses the development of new HCV animal models to study viral infection and investigate the direct effects of viral protein expression on liver disease.

Shielding Effect and Emission Criterion of a Screw Dislocation Near an Interfacial Crisscross Crack

Shielding effect and emission criterion of a screw dislocation near an interracial crisscross crack are dealt within this paper. Utilizing the conformal mapping technique, the closed-form solutions are derived for complex potentialsand stress fields due to a screw dislocation located near the interracial crisscross crack. The stress intensity factor onthe crack tips and the critical stress intensity factor for dislocation emission are also calculated. The influence of theorientation of the dislocation and the morphology of the crisscross crack as well as the material elastic dissimilarity onthe shielding effect and the emission criterion is discussed in detail. The results show that positive screw dislocations canreduce the stress intensity factor of the interracial crisscross crack tip (shielding effect). The shielding effect increases withthe increase of the shear modulus of the lower half-plane, but it decreases with the increase of the dislocation azimuthangle and the distance between the dislocation and the crack tip. The critical loads at infinity for dislocation emissionincreases with the increase of emission angle and the vertical length of the crisscross crack, and the most probable anglefor screw dislocation emission is zero. The present solutions contain previous results as special cases.

Nonliner Analysis of a Synthesized Optimal Velocity Model for Traffic Flow

We analyze a new car-following model described by a differential-difference equation with a synthesized optimal velocity function (SOVF),which depends on the front interactions between every two adjacent vehicles instead of the weighted average headway.The model is analyzed with the use of the linear stability theory and nonlinear analysis method.The stability and neutral stability condition are obtained.We also derive the modified KdV (Korteweg-de Vries) equation and the kink-antikink soliton solution near the critical point.A simulation is conducted with integrating the differential-difference equation by the Euler scheme.The results of the numerical simulation verify the validity of the new model.

Non-Topological Domain Walls in a Model with Broken Supersymmetry

We study non-topological, charged planar walls （Q-walls） in the context of a particle physics model with supersymmetry broken by low-energy gauge mediation. Analytical properties are derived within the fiat-potential approximation for the flat-direction raising potential, while a numerical study is performed using the fall two-loop supersymmetric potential. We analyze the energetics of finite-size Q-walls and compare them to Q-balls, non-topological solitons possessing spherical symmetry and arising in the same supersymmetric model. This allows us to draw a phase diagram in the charge-transverse length plane, which shows a region where Q-wall solutions are energetically favored over Q-balls. However, due to their finiteness, such finite-size Q-walls are dynamically unstable and decay into Q-balls in a time which is less than their typical scale-length.

East China Summer Rainfall during ENSO Decaying Years Simulated by a Regional Climate Model

The performance of the Climate version of the Regional Eta-coordinate Model （CREM）, a regional climate model developed by State Key Laboratory of Numerical modeling for Atmospheric Science and Geophysical Fluid Dynamics/Institute of Atmospheric Physics （LASG/IAP）, in simulating rainfall anomalies during the ENSO decaying summers from 1982 to 2002 was evalu- ated. The added value of rainfall simulation relative to reanalysis data and the sources of model bias were studied. Results showed that the model simulated rainfall anomalies moderately well. The model did well at capturing the above-normal rainfall along the Yangtze River valley （YRV） during E1 Nifio decaying summers and the below and above-normal rainfall centers along the YRV and the Huaihe River valley （HRV）, respectively, during La Nifia decaying summers. These features were not evident in rainfall products derived from the reanalysis, indicating that rainfall simulation did add value. The main limitations of the model were that the simulated rainfall anomalies along the YRV were far stronger and weaker in magnitude than the observations during E1 Nifio decaying summers and La Nifia decaying summers, respectively. The stronger magnitude above-normal rainfall during E1 Nifio decaying summers was due to a stronger northward transport of water vapor in the lower troposphere, mostly from moisture advection. An artificial, above-normal rainfall center was seen in the region north to 35°N, which was associated with stronger northward water vapor transport. Both lower tropospheric circulation bias and a wetter model atmosphere contributed to the bias caused by water vapor transport. There was a stronger southward water vapor transport from the southern boundary of the model during La Nifia decaying summers; less remaining water vapor caused anomalously weaker rainfall in the model as compared to observations.

Probability Distribution Function of Passive Scalars in Shell Models

A shell-model version of passive scalar problem is introduced, which is inspired by the model of K. Ohkitani and M. Yakhot [K. Ohkitani and M. Yakhot, Phys. Rev. Lett. 60 （1988） 983; K. Ohkitani and M. Yakhot, Prog. Theor. Phys. 81 （1988） 329]. As in the original problem, the prescribed random velocity field is Gaussian and 5 correlated in time. Deterministic differential equations are regarded as nonlinear Langevin equation. Then, the Fokker-Planck equations of PDF for passive scalars are obtained and solved numerically. In energy input range （n 〈 5, n is the shell number.）, the probability distribution function （PDF） of passive scalars is near the Gaussian distribution. In inertial range （5≤ n ≤ 16） and dissipation range （n ≥ 17）, the probability distribution function （PDF） of passive scalars has obvious intermittence. And the scaling power of passive scalar is anomalous. The results of numerical simulations are compared with experimental measurements.

Thermal Phase in Bubbling Geometries

We use matrix model to study thermal phase in bubbling half-BPS type liB geometries with SO（4） × SO（4） symmetry. Near the horizon limit, we find that thermal vacua of bubbling geometries have disjoint parts, and each part is one kind of phase of the thermal system. We connect the thermal dynamics of bubbling geometries with one-dimensional fermions thermal system. Finally, we try to give a new possible way to resolve information loss puzzle.

关于高中物理力学综合题的解答途径

高中物理作为一门逻辑性、抽象性学科,也不再单纯地教授学生物理知识内容,更为看重学生思维及能力发展,高中物理力学综合试题是一个很好的考察点,不仅题目难度大、试题类型多,而且解题思维能力要求高.

A method of shadow puppet figure modeling and animation

To promote the development of the intangible cultural heritage of the world, shadow play, many studies have focused on shadow puppet modeling and interaction. Most of the shadow puppet figures are still imaginary,spread by ancients, or carved and painted by shadow puppet artists, without consideration of real dimensions or the appearance of human bodies. This study proposes an algorithm to transform 3D human models to 2D puppet figures for shadow puppets, including automatic location of feature points, automatic segmentation of 3D models, automatic extraction of 2D contours, automatic clothes matching, and animation. Experiment proves that more realistic and attractive figures and animations of the shadow puppet can be generated in real time with this algorithm.

Bounding species distribution models

Species distribution models are increasing in popularity for mapping suitable habitat for species of management con- cern. Many investigators now recognize that extrapolations of these models with geographic information systems （GIS） might be sensitive to the environmental bounds of the data used in their development, yet there is no recommended best practice for ＂clamping＂ model extrapolations. We relied on two commonly used modeling approaches： classification and regression tree （CART） and maximum entropy （Maxent） models, and we tested a simple alteration of the model extrapolations, bounding ex- trapolations to the maximum and minimum values of primary environmental predictors, to provide a more realistic map of suit-able habitat of hybridized Africanized honey bees in the southwestern United States. Findings suggest that multiple models of bounding, and the most conservative bounding of species distribution models, like those presented here, should probably replace the unbounded or loosely bounded techniques currently used [Current Zoology 57 （5）： 642-647,2011].

A physical mechanism based investigation on the elasto-plastic-damage behavior of anisotropic aluminum alloys under finite deformation

The elasto-plastic-damage behavior of anisotropic aluminum alloys is investigated under finite deformation using a physical mechanism based constitutive model.With an application to the structural calculation,the present model is used to describe and analyze the mechanical response of anisotropic 6260-T6 aluminum alloy extrusions.For the tensile specimens extracted along three different material orientations from the extruded aluminum profile,twelve simulations are carried out covering four different specimen geometries.The simulation results in force-displacement response and central logarithmic axial strain evolution are compared with experimental results.From the comparisons,it can be concluded that the present model has the capacity to describe the behavior of anisotropic material.From the force-displacement curves,the anisotropy is observed in different material orientations,and the physical mechanism of anisotropy is analyzed.