甘肃及邻近地区的各向异性介质MT反演及该区地壳深部应力场和形变带

分析了某些条件下地球介质的电导率各向异性行为，并应用一维层找对称各向异性介质大地电磁资料的反演方法，对甘肃及其邻近地区实测MT资料的各向异性模型进行反演解释，由此确定地壳深部应力场和形变带的方向。

弹力的存在与其方向

在中学物理中,弹力是出现最多的一种,同学们在分析有关弹力问题时,经常碰到各种各样的困惑.笔者从实际问题出发,就弹力的存在和方向的判断谈谈自己的浅见.

视调节过程中悬韧带张力分配对晶状体囊膜形态影响的仿真研究

目的调节是人眼调节视力的过程,现有的调节理论对调节过程中悬韧带张力分配的解释存在分歧,由于成像技术的限制,尚无法验证其准确性。在接受囊外摘除术的眼睛中,不同的悬韧带张力分配对囊膜形态有较大影响且容易被在体观测。本研究结合有限元分析方法与眼部超声显微成像,探究悬韧带张力分配对无晶体基质囊膜形态的影响。方法建立接受囊外摘除术后的一系列囊膜有限元模型,设定前囊环切口直径在1.5~6.5 mm之间。模型受前部(AZ)、赤道部(EZ)和后部悬韧带(PZ)的共同作用。设定总悬韧带张力为0.75 m N时为非调节态,模拟两种调节过程中的悬韧带张力分配:(1)EZ上的力逐渐增大至30 m N,AZ和PZ上的合力减小至0 m N;(2)所有悬韧带上的力都减小至0 m N。分析不同悬韧带张力分配下囊膜的形态变化。结果当EZ上的力随着其他悬韧带合力的减小而增加时,后囊表现出向后弯曲,这与恒河猴的超声在体成像结果一致。后囊向后弯曲的程度与前囊切口大小及EZ张力大小呈正相关。当所有悬韧带张力都减小时,囊膜形变方向与在体观测结果相反。结论赤道悬韧带对调节态下的囊膜形态有主要影响,调节态下仅赤道悬韧带紧张的模式与真实情况更加接近,这与Schachar理论的描述一致。

让课堂体验环节成为翻转课堂概念课的有力补充

物理概念的建立一直是物理学习的难点,以往授课往往采用死记硬背的方式建立概念体系,缺失了场景体验的过程,学生没有切身体会,对概念建立的认知生硬,理解生涩,应用必然生疏.翻转课堂的教学模式可以以多种方式提供机会帮助学生完成体验环节,完善学生对概念的认知和理解.学生通过观看、模仿、思考、操作多个环节体验生活中不易觉察的现象,体会概念建立的精妙之处.

Seismic facies response of tectonics and direction of block movement in the northeastern South China Sea

The close relationship between the structure,evolution,and resources environment of the South China Sea is a current research focus and also a focal point of our study.In this paper,we use regional seismic sections to analyze the relationship between seismic facies and the structure and tectonic evolution of the northeastern South China Sea and propose new points about the structure and the direction of block（land mass） motion.First,the tectonic features are clear and can be divided into five different structural units which are both linked and independent of each other.Second,it doesn＇t matter if the South China Sea basin pattern is extensional,weakly compressive,or strongly compressive,the regional tectonic stress field is unified.For the first time we find that two shallow subduction zones are recognized in the seismic profiles.All the tectonic blocks have accordion-fold-style structures,converging in the east,and the South China Sea exhibits different stages of basin development：growth, maturity,end,and termination.The block subduction and regional block dip directions are all aligned with the regional stress field.

简议弹簧的K

轻弹簧的以下两个结论已被公认:1.发生弹性形变时内部弹力处处相等.2.在弹性限度内遵守胡克定律.(?)上式涉及到两个重要物理量:一是形变(?),二是比例系数K.x与弹力f大小成正比,方向相反.实验表明,(?)有一个限度(?),叫做弹簧的弹性限度.任何弹簧形变均不能超过它的(?),否则(1)式不再成立.本文讨论的范围是在弹性限度以内的轻弹簧,并且不再考虑其形变方向.

以弹簧为例谈物理模型的构建

高中物理学习中有许多物理模型,如质点、元电荷、轻杆、滑块、电磁感应中的杆（导轨）、宇宙中的多星等模型.可以说物理的学习过程就是建立物理模型的过程,然而,在实际的学习过程中很多同学都缺乏将实际问题还原成物理模型的能力,最明显的表现就是许多同学上课一听老师讲解就懂,下课一做题就蒙.相反有的同学感觉物理有趣易学,就是因为他们掌握了大量的物理模型,并能在做题的过程中迅速读懂题目中的信息，将信息与相对应的物理模型建立联系，然后用物理模型对应的规律解题．

Effect of processing parameters on the electromagnetic radiation emission during plastic deformation and crack propagation in copper-zinc alloys

This paper presents some investigations on the effect of processing parameters on the emission of electromagnetic radiation （EMR） during plastic deformation and crack propagation in copper-zinc alloys. Timing of the EMR emissions, maximum stress during crack instability, stress-intensity factor, elastic strain energy release rate, maximum EMR amplitude, RMS value of EMR amplitude, EMR frequency and electromagnetic energy release rate were analysed for the effect of rolling directions at different percentage of zinc content in Cu-Zn alloy specimens. The same parameters were also analysed for 68-32 Cu-Zn alloy specimens at different annealing temperatures and at different angles 0, to the rolling direction. EMR emissions are observed to be highly anisotropic in nature. At θ=45° to 60°, marked changes in mechanical and electromagnetic parameters were observed. Specimens annealed at 500℃, just above the recrystallization temperature, and at 700℃, when grain-size growth is rapid, EMR responses have been found to have well-defined patterns.

Effects of liquefaction-induced large lateral ground deformation on pile foundations

The pile-soil system interaction computational model in liquefaction-induced lateral spreading ground was established by the finite difference numerical method.Considering an elastic-plastic subgrade reaction method,numerical methods involving finite difference approach of pile in liquefaction-induced lateral spreading ground were derived and implemented into a finite difference program.Based on the monotonic loading tests on saturated sand after liquefaction,the liquefaction lateral deformation of the site where group piles are located was predicted.The effects of lateral ground deformation after liquefaction on a group of pile foundations were studied using the fmite difference program mentioned above,and the failure mechanism of group piles in liquefaction-induced lateral spreading ground was obtained.The applicability of the program was preliminarily verified.The results show that the bending moments at the interfaces between liquefied and non-liquefied soil layers are larger than those at the pile＇s top when the pile＇s top is embedded.The value of the additional static bending moment is larger than the peak dynamic bending moment during the earthquake,so in the pile foundation design,more than the superstructure＇s dynamics should be considered and the effect of lateral ground deformation on pile foundations cannot be neglected.

Revisiting the response of western North Pacific tropical cyclone intensity change to vertical wind shear in different directions

The effect of vertical wind shear(VWS)directions on the change in western North Pacific tropical cyclone(TC)intensity is revisited in this study.Results show that the differences in the correlations between VWS in different orientations and the change in TC nondimensional intensity highly diminish,although slight differences are still present.The subtle differences in the correlations are likely associated with different synoptic-scale patterns at upper and lower levels.This result suggests that,in addition to thermodynamic effects,dynamic roles of the synoptic-scale patterns associated with the VWS should also be taken into account when the authors examine how VWS in different directions affects TC intensity change.

弹力方向的正确理解与分析——从一道选择题的剖析谈起

1问题的由来我们在高考备考的静力学复习专题中,给出这样一道课堂练习的选择题：轻绳的一端拴住一物体、另一端固定在竖直墙壁上,用一带手柄的重质定滑轮将轻绳支撑而处于平衡状态,如图1所示.不计一切摩擦,现保持滑轮位置不变而将手柄缓慢向下旋转一个小角度,在此过程中手柄对滑轮的作用力大小将怎样变化？（A）增大.（B）减小.（C）不变.（D）条件不足,不能确定.

农村中学弹力教学的创新

弹力这一节的学习在学生进入高一不久,此时学生还缺乏很强的分析概括能力,教师也可能还没从教毕业班的兴奋状态中转变过来,往往出现进度偏快、难度加大的倾向,导致弹力成为学生学习高中物理的第一个障碍。但从另一个方面来看,弹力教学又具有独天独厚的优势,它具有极广泛的生活背景,日常生活中的推、拉、提、压都是弹力,从本质上看都是因形变而致,为此我在教学中进行了探索,努力还原物理知识的生活场景。

Upper mantle anisotropy in the Ordos Block and its margins

Based on the polarization analysis of teleseismic data,SKS (SKKS) fast-wave directions and delay times between fast and slow shear waves were determined for each of the 111 seismic stations from both permanent and temporary broadband seismograph networks deployed in the Ordos Block and its margins.Both the Silver and Chan and stacking analysis methods were used.In this way,an image of upper mantle anisotropy in the Ordos Block and its margins was acquired.In the western and northern margins of the Ordos Block,the fast-wave directions are consistently NW-SE.The fast-wave directions are mainly NWW-SEE and EW in the southern margin of the Ordos Block.In the eastern margin of the Ordos Block,the fast-wave directions are generally EW,although some run NEE-SWW or NWW-SEE.In the Ordos Block,the fast-wave directions trend near N-S in the north,but switch to near EW in the south.The delay time between fast and slow waves falls into the interval 0.48-1.50 s,and the average delay time at the stations in the Ordos Block is less than that in its margins.We suggest that the anisotropy of the stable Ordos Block is mainly caused by "fossil" anisotropy frozen in the ancient North China Craton.The NE-trending push of the northeastern margin of the Tibetan Plateau has caused NW-SE-trending lithospheric extension in the western and northern margins of the Ordos Block,and made the upper mantle flow southeastwards.This in turn has resulted in the alignment of the upper mantle peridotite lattice with the direction of material deformation.In the southern margin of the Ordos Block,the collision between the North China and Yangtze blocks resulted in the fast-wave direction running parallel to the collision boundary and the Qinling Orogen.Combining this with the APM and velocity structure of the Qinling Orogen,we propose that eastward-directed asthenospheric-mantle channel flow may have occurred beneath the Qinling Orogen.In the eastern margin of the Ordos Block,the complex anisotropic characteristics of the Fenhe Graben and Taihang Orogen may be caused by the interaction of western Pacific Plate subduction,regional extensional tectonics,and the orogeny.For station YCI,the apparent splitting parameters (the fast-wave directions range from 45° to 106° and the delay times range from 0.6 to 1.5 s) exhibit systematic variations as a function of incoming polarization with a periodicity of π/2.This variation can be best explained by a two-layer anisotropic model (φlower=132°,δtlower=0.8 s,φupper=83°,δtupper=0.5 s).The upper layer anisotropy beneath station YCI can again be attributed to "fossil" anisotropy frozen in the ancient North China Craton.The lower layer anisotropy is affected by the tectonic activity of the western Ordos Block.The NW-SE trending extension caused by the NE trending push of the northeastern margin of the Tibetan Plateau affected the deformation of the lower anisotropic layer beneath station YCI.By comparing the fast-wave directions with GPS velocity directions,we see that the crust and upper mantle possibly have vertically coherent deformation in the margins of the Ordos Block,whereas the internal deformation characteristics of the Ordos Block are complex and require further study.

Protein kinase C-δ and -β coordinate flow-induced directionality and deformation of migratory human blood T-lymphocytes

T-tym phocyte migration under flow is critical for immune responses, but the mechanisms by which flow modulates the migratory beha- viors of T-lymphocytes remain unclear. Human peripheral blood T-lymphocytes （PBTLs）, when stimulated with phorboL 12-myristate 13-acetate （PMA）, stretched their ceU bodies dramatically and moved alongthe flow direction. In contrast, stromal ceil-derived factor- lα-stimulated PBTI.s deformed and migrated in a random manner. Here we elucidated the molecular mechanisms underlying flow- induced directionality and deformation of PMA-stimulated PBTLs. PMA primed PBTLs for polarization under flow, with protein kinase C （PKC）-δ enriched in the leading edge, PKC-β1 in the microtubuie organizing center, and PKC-1311 in the uropod and peripheral region. PKC-δ regulated cell protrusions in the leading edge through Tiaml/Racl/caLmoduUn, whereas PKC-β regulated RhoA/Rho- associated kinase activity and microtubule stability to modulate uropod contractility and detachment. Our findings indicate that PKC-δ and -β coordinate in the cell Leading edge and uropod, respectively, to modu｜ate the directionality and deformability of migratory T-Lymphocytes under flow.

Upper mantle anisotropy and crust-mantle deformation pattern beneath the Chinese mainland

Over the past 10 years, the number of broadband seismic stations in China has increased significantly. The broadband seismic records contain information about shear-wave splitting which plays an important role in revealing the upper mantle anisotropy in the Chinese mainland. Based on teleseismic SKS and SKKS phases recorded in the seismic stations, we used the analytical method of minimum transverse energy to determine the fast wave polarization direction and delay time of shear-wave splitting. We also collected results of shear-wave splitting in China and the surrounding regions from previously published papers. From the combined dataset we formed a shear-wave splitting dataset containing 1020 parameter pairs. These splitting parameters re- veal the complexity of the upper mantle anisotropy image. Our statistical analysis indicates stronger upper mantle anisotropy in the Chinese mainland, with an average shear-wave time delay of 0,95 s; the anisotropy in the western region is slightly larger （1.01 s） than in the eastern region （0.92 s）. On a larger scale, the SKS splitting and surface deformation data in the Tibetan Plateau and the Tianshan region jointly support the lithospheric deformation mode, i.e. the crust-lithospheric mantle coherent deformation. In eastern China, the average fast-wave direction is approximately parallel to the direction of the absolute plate motion; thus, the upper mantle anisotropy can be attributed to the asthenospheric flow. The area from the Ordos block to the Sichuan Basin in central China is the transition zone of deformation modes between the east and the west regions, where the anisotropy images are more complicated, exhibiting ＂fossil＂ anisotropy and/or two-layer anis^3trc^py. The c^llisi（3n between the Indian Plate and the Eurasian Plate is the main factor of upper mantle anisotropy in the western region of the Chinese mainland, while the upper mantle anisotropy in the eastern region is related to the subduction of the Pacific Plate and the Philippine Sea Plate beneath the Eurasian Plate.

GALERKIN ALTERNATING-DIRECTION METHODS FOR NONRECTANGULAR REGIONS FOR THE TRANSIENT BEHAVIOR OF A SEMICONDUCTOR DEVICE

For the transient behavior of a semiconductor device, the modified method of characteristics with alternating-direction finite element procedures for nonrectangular region is put forward. Some techniques, such as calculus of variations, isoparametric transformation，patch approximation, operator-splitting, characteristic method, symmetrical reflection,energy method, negative norm estimate and a prior estimates and techniques, are employed. In the nonrectangular region case, optimal order estimates in L^2 norm are derived for the error in the approximation solution. Thus the well-known theoretical problem has been thoroughly and completely solved.