Regional characteristics of stress field in the southern part of the north－south seismic belt in China and its relation with plate movement

The regional characteristics of stress field in the southern part of the northusouth seismic belt (NSB) have beenanalyzed in detail based on the mechanism solutions of 134 medium and large earthquakes from 1933 to 1991.The results show that the southern part of the NSB is a shallow earthquake zone where most earthquakes arecaused by the strike-slip faulting. There is a systematic distribution of the directions of P-and T-axes in thewestern and the eastern regions of the southern part of the NSB. P-and T-axes in the western region are in theNE-SW direction and in the NW-SE direction. P-and T-axes in the eastern region are oriented in NW-SE andNE-SW, respectively. The directions of p-axes in the western and the eastern regions show a pattern of a reversal 'V' as a whole. The boundary between the eastern and western regions coincides with that between the Tibetan Plateau and the Yangtze crustal block. Based on a lot of mechanism solutions, the result indicates that thedirection of P-axes roughly shows the consistent distributions from the Himalayan collision zone to the easternregion and from the eastern coast collision zone in Taiwan to the eastern region of southern part of the NSB, respectively. It is suggested that the tectonic force due to relative movement between the indo-Australian and theEurasian plates is transmitted from the Himalayan collision zone to the western region of the southern part ofNSB, simultaneously, the tectonic force due to the relative movement between the Philippine Sea and theEurasian plates is transmitted from the eastern region coast in Taiwan to the eastern region of the southern partof NSB, and control the stress field there, respectively.

The Rigid body of Paleo－continent in the crust of Taiwan and the recent plate movement

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Global crustal movement and tectonic plate boundary deformation constrained by the ITRF2008

On the basis of the newly released International Terrestrial Reference Frame（ITRF2008） by the International Earth Rotation Service （IERS）, a new global plate model ITRF2008 plate for the major plates is established. This ITRF2008-derived model is analyzed in comparison with NNR-NUVEL1A model, which is mainly based on geological and geophysical data. The Eurasia and Paeifi6 plates display obvious differences in terms of the velocity fields derived from the two plate motion models. Plate acceleration is also introduced to characterize the differences of the two velocity fields which obtained from ITRF2008-plate and NNR-NUVEL1A models for major individual plates. The results show that the Africa, South America and Eurasia plates are undergoing acceleration, while the North America and Australia plates are in the state of deceleration motion

Recent crustal movement and great earthquakes in Qinghai-Tibet sub-plate

Crustal movement and incremental-movement data observed repeatedly at GPS stations during 1999-2009 were analyzed to study the effect of two earthquakes of Ms8.1 and Ms8.0 that occurred in 2001 and 2008, respectively, in Qinghai-Tibet sub-plate and its eastern margin. The result revealed certain anomalous pre-earthquake deformation and some large co-seismic changes. Prior to the 2008 Wenchuan Ms8.0 earthquake, the seismogenic Kunlunshan fault zone became a geographic boundary between different regional movements. At the time of the earthquake, there was an average cross-fault crustal shortening of -1.04 m and an average right-lateral strike slip of 0.76 m along the ruptured segment, as well as a strain-energy release of -62.66×10.7.

The Earth's inner core deviation to plate movement

Under the premise of the Earth’s layer structure and mass distribution, the solid inner core cannot be stable in the center of the sphere. Thus, the deviation of the inner core is towards the sphere’s center and the liquid outer core must have asymmetrical thermal convection. Based on the two suggestions, a concise and self-consistent global motion model can be built. The model consists of the following cycle: an asymmetrical thermal convection structure in the outer core led by the dislocation of the inner core→the plume is in special upwell position because of differential activation→the formation and split of lithosphere→the split plates drift and assemble in a new location, the mass of which causes the inner core to deviate towards this direction again→the new asymmetry is formed. As this circulation continues, a definite and periodical motion emerges/forms. Its nonlinear features result in the Earth’s motion with simple mechanisms but complex behavior. Ultraterrestrial events may disturb or

ANALYTICAL SOLUTION WITH SYSTEM METHOD FOR THE MODEL OF ROCK STRATA MOVEMENT AS COMPLEX LAMINATED PLATES

Starting from the basic equation of elastic mechanics, without any additional hypotheses of displacement or stress model, just introducing state space and state equation, the model of rock strata movement as complex laminated plates is presented. In addition, using displacement as a basic unknown quantity, the accurate analytical series solution for the problem of strata movement induced by extraction of horizontal seam is worked out when crosswise isotropic elastic layers are in sliding contact condition. A new approach is put forward to solve the complicated system of mining subsidence.

含孔板微通道内随流气泡运动的两相格子Boltzmann模拟

带有气泡的两相流系统存在于各种工业过程中,涉及复杂的相界面变化,但气泡在管道中伴随液相流动时,通过孔板的运动过程尚未有充分的研究结果.相场格子Boltzmann模型在模拟复杂界面方面具有优势,适合研究气泡两相流在含孔板微通道内的运动,分析We数、气泡相对大小和孔板表面润湿性等因素对气泡动力学特性的影响.数值计算结果显示,随着We数增加,气泡表面张力减小,导致其穿过孔板结构时更易被撕裂,峰值速度降低.在研究的参数范围内存在两个临界直径比,这两个临界值将气泡通过孔板的运动分成三种形态,而且临界直径比会随We数的增加而减小.另外,随着接触角的增大,孔板表面对气体的吸附能力加强,气泡与孔板表面的接触面积增加,引起穿过孔板气泡的质量减少和气泡通过的速度增加.

Stress and Strain Accumulation Due to a Long Dip-Slip Fault Movement in an Elastic-Layer over a Viscoelastic Half Space Model of the Lithosphere-Asthenosphere System

Most of the earthquake faults in North-East India, China, mid Atlantic-ridge, the Pacific seismic belt and Japan are found to be predominantly dip-slip in nature. In the present paper a dip-slip fault is taken situated in an elastic layer over a viscoelastic half space representing the lithosphere-asthenosphere system. A movement of the dip-slip nature across the fault occurs when the accumulated stress due to various tectonic reasons e.g. mantle convection etc., exceeds the local friction and cohesive forces across the fault. The movement is assumed to be slipping in nature, expressions for displacements, stresses and strains are obtained by solving associated boundary value problem with the help of integral transformation and Green’s function method and a suitable numerical methods is used for computation. A detailed study of these expressions may give some ideas about the nature of stress accumulation in the system, which in turn will be helpful in formulating an earthquake prediction programme.

Implementation Methods of Computer Aided Design-Drawing and Drawing Management for Plate Cutting-Machine

The implementation methods of computer aided design,drawing and drawing management for plate cuttingmachine are discussed. The system structure for plate cutting- machine design is put forward firstly, then some key technologies and their implementation methods are introduced, which include the structure management of graphics, the unification of graph and design calculation, information share of part, assemble and drawing management system, and movement simulation of key components.

不同厚度岩层破断模式转变机理及力学模型分析

采动岩层的变形、破断、运动模式与采场矿压显现、地表沉陷等密切相关。薄岩层与厚岩层的破断模式又呈现出显著的差异,如何将不同厚度岩层的破断模式统一描述并建立力学模型是岩层移动理论难题。统计了23个典型工作面采动岩层破断结构,基于断裂力学理论对岩层的破断力学因素及运动模式进行了分类,详细分析了其与岩层厚度之间的关系。基于中厚板理论建立了不同厚度岩层破断力学模型,揭示了不同厚度岩层的破断力学机理及破断模式,并给出了相应的判据。结合数值模拟分析了不同厚度岩层在开采过程中的变形、破断和运动规律。研究表明,不同的应力边界条件作用在不同厚度的岩层上面,再加上开采条件的不同,岩层会出现不同的破断模式。随着岩层厚度的增加,岩层所受剪力不断增大,岩层的破断力学机理呈现出拉破断、拉剪破断及剪破断的演化规律;其相应的岩块结构则分别表现为砌体梁结构、分层破断以及台阶岩梁;统计数据表明岩块厚跨比大于0.5的岩层更易发生剪切破断而形成台阶岩梁。基于上述统计和分析,针对厚岩层可能发生的拉剪破断问题,提出混合破断模式的概念,将岩层破断力学因素细化为拉破断、拉剪破断及剪切破断3种;将不同厚度岩层的破断模式分为薄岩层常见的拉破断及遇断层引起的剪破断,厚岩层出现的拉破断、拉剪破断及剪切破断,其中拉剪混合破断分为端部拉剪混合破断、分层联动运动及分层非协调运动等7类破断模式。对岩层破断模式的进一步研究可为采场矿压控制及地表沉陷灾害的防治提供有益的理论支持。

Recent Study of Drag Embedment Plate Anchors in China

试验性、理论的研究拖最近在天津执行的埋入板锚大学在这篇研究论文被总结，它包含与学习相关的一系列重要话题拖锚。为测量轨道和运动方向的技术在土壤拖锚，为测量动人的埋入的技术削尖并且逆行链状的形状嵌入拖线，穿入机制和运动学的行为拖锚，最终的埋入深度拖锚，有任意的吸虫节的锚的运动方向，反向的链状的性质嵌入拖线， interactional 性质在之间拖锚和安装现在的工作显著地在设计和分析减少无常拖埋入板抛锚，并且对改进这种新类型的申请有益在近海的设计拖锚。

The Present-Day Crustal 3D Movement and Geodynamic Mechanisms in Hainan Island

The characteristics of the present-day crustal three dimensional (3D) movement with GNSS data during 1999-2018 and the precise leveling data during 1970s-2018 in Hainan Island and its adjacent area are analyzed. Based on the data and the horizontal movement field in the region of Southeast Asia, we discuss how the horizontal velocities in Hainan and the continental margin of the South China block (SCB) are affected by the Eurasian plate, the India-Australia plate and the Philippine Sea plate. The results show the movement of Hainan Island is the same as SCB. The horizontal velocities of the continental margin in South China are different in the east and the west along the boundary of the Northeastern Coast block and Yangtze Block. In Hainan Island, the 3D movement is different in two regions divided by Baisha fault. The movement of SCB is affected by Indo-European collision and extrusion. The movement of the continental margin is affected by both the Pacific Ocean plate, the Philippine Sea plate, the expansion of the South China Sea (SCS), the hot materials underplating and subsequent lithospheric extension. The effect on the regional movement by the Australia plate is smaller, but it can cause co-seismic step to SCB when there had a giant earthquake in Sumatra which is caused by the convergence of the Australia with the Sunda Plate in the NE direction.

胫骨干骨折骨不连患者使用加压钢板和带锁髓内钉治疗的临床效果比较

目的 :比较加压钢板与带锁髓内钉在胫骨干骨折骨不连患者中的临床治疗效果。方法 :将84例胫骨干骨折骨不连患者随机分为对照组(n=42,加压钢板治疗)和观察组(n=42,带锁髓内钉治疗)。比较两组围术期指标、治疗效果、肢体运动能力、术后并发症。结果 :观察组手术时间长于对照组,术中出血量、术后引流量、切口长度、住院时间均少于对照组,治疗有效率高于对照组(95.24%vs 76.19%),下肢FMA评分改善优于对照组,术后并发症发生率低于对照组(均P <0.05)。结论:在胫骨干骨折骨不连患者的临床治疗中,带锁髓内钉的整体治疗效果优于加压钢板。

邻近海底基准站坐标时序联合处理模型

海底基准站复测观测可用于海底构造和海底地震等灾害研究。然而,受观测条件和供电等因素影响,难以实现长时间不间断观测。为解决时间序列观测中新旧海底基准站替换位移补偿和站点偏移量计算问题,可采用中心点法求取相对于海底基准站网的虚拟中心点坐标的位移量,进而构造海底基准坐标时序,以监测海底构造运动。针对相同的问题,本文借鉴地球参考框架维持方式,直接利用可能存在间断的海底基准站网时序观测数据,提出了基于参考协议历元的海底基准坐标时序多站联合处理模型,即在一个区域基准站网内,各站点坐标作为局部参数,而站速度作为公共参数。本文方法适合于海底参考框架的建立与动态维持,利于对区域网内各站点坐标时序实施精细质量控制。结果表明,本文方法可以代替中心点法,且抗差估计结果更为可靠,与中心点法确定的海底基准站年速度估计之间的差值平均为3 mm/a,可为国家海底空间基准维持提供一种途径。

新型辐照容器内部流场及温度场数值计算

辐照容器属于核级设备辐照鉴定试验装置的一个重要组成部件,是承载需要辐照的1E级设备的压力容器。针对新型辐照容器,采用ANSYS软件对容器内部流场及温度场进行了数值计算,研究了在实际工况下,辐照容器不同截面位置的温度分布和气流运动轨迹,以及分流板对温度分布和气流运动的影响,并经由试验验证了模拟结论。结果表明:增加分流板的辐照容器内部温度分布和气流运动更均匀,气流运动轨迹更集中于中间区域;内部温度分布更均衡,温差在5K以内,为新型辐照容器的设计提供了理论依据。

柴北缘东段及周缘侏罗系发育特征及其对构造活动的响应

为研究柴北缘东部及周缘侏罗系发育特征及其对构造活动的响应,笔者等基于柴北缘东段红山、霍布逊及德令哈凹陷侏罗系野外地质调查,通过地层接触关系追踪、二维地震资料解释以及岩性岩相突变特征分析,同时与中国西北地区其他典型的盆地侏罗系发育特征进行对比分析,研究表明,在中国西北多个板块的相互作用的构造背景之下,柴北缘东段燕山期构造运动Ⅰ幕发生在早—中侏罗世,以古地理与古构造环境较为均一、发育粗碎屑凹陷、每个凹陷内具有幕式沉积充填特征,与中国西北其他盆地对比,此幕构造运动波及面大,但强度较弱,推测与中国西北周边各板块碰撞造山之后的伸展作用相关;燕山期构造运动Ⅱ幕发生在晚侏罗世—早白垩世,此幕构造运动导致古地理与古构造环境向新的环境转变,以中—上侏罗统之间的角度不整合、白垩系及晚侏罗统的残缺不全为特征,推测与拉萨地块与欧亚板块碰撞以及蒙古—鄂霍茨克洋的关闭及Kolyma—Omolon地块的碰撞有关。

腹压板不同压腹位置对肝癌立体定向放射治疗精度的影响

目的:探究肝癌立体定向放射治疗中腹压板在不同位置施压对摆位误差及肿瘤移动度的影响。方法:选取经病理诊断为肝癌的患者共30例,根据腹压板施压位置不同分为腹压组和剑突组各15例。获取30例肝癌患者共180组4D-CBCT扫描数据,记录并分析每组内摆位误差大小,并利用Elekta直线加速器自带的XVI(X线容积影像系统)软件分析肿瘤随肝脏的移动度。结果:剑突组在Y方向上的摆位误差小于腹压组(P<0.05)。剑突组的肿瘤移动度均值在Y方向上小于腹压组(P<0.05),但在X和Z方向上差异无统计学意义(P>0.05);剑突的肿瘤移动度均方差在Z方向上小于腹压组(P<0.05),但在X和Y方向上差异无统计学意义(P>0.05);剑突组的肿瘤最大移动度在X和Y方向上小于腹压组(P<0.05),但在Z方向上差异无统计学意义(P>0.05)。剑突组在3个方向上的靶区外放边界值均比腹压组小。结论:在肝癌立体定向放射治疗中,腹压板压迫在剑突下位置比腹部肚脐位置的呼吸抑制效果更为明显,更大程度上减小摆位误差和肿瘤移动度,提高放疗的精确度。

我国大陆地区ITRF坐标系统转换研究

在研究ITRF坐标系统转换理论和方法的基础上,提出了一种实际可行的框架、历元转换方法,并应用于实际工程快速获得了CGCS2000坐标。结果表明,不同框架坐标在相同历元下坐标差异较小,ITRF2014与ITRF2008、ITRF2005在2021.00历元下的坐标偏差小于5 mm;不同地区地壳构造程度差异导致坐标历元间差别很大。提出了两套中国大陆地区3°×3°速度格网(CGCS2000和ITRF14),可用于快速获取测站速度和历元坐标转换,精度可达厘米级,能在工程中广泛应用。

热轧带钢粗轧工作辊轴向窜动问题的探讨分析

粗轧机工作辊轴向窜动是热轧带钢生产过程中比较常见的问题,它反映了粗轧机组的工作状态,同时工作辊轴向窜动会严重影响粗轧板型,导致粗轧中间坯镰刀弯,对热轧带钢生产稳定性影响较大,从受力分析的角度入手探讨粗轧工作辊轴向窜动机理,并结合生产实际分析粗轧工作辊轴向窜动的原因并提出相应的解决措施。

大南海地区新生代板块构造活动

在新生代澳大利亚板块和欧亚板块之间的大洋中,存在一些地块(微板块);同时,澳大利亚板块北部边缘的一些地块先后和澳大利亚板块分离,向北运动,与一些和欧亚板块分离出来的地块先后发生碰撞缝合。在此期间,由于地块分离而发生海底扩张,产生许多小洋盆,如南海、苏录海、苏拉威西海、安达曼海等,最后形成了东南亚地区今日的构造景观。笔者从大南海地区新生代的构造演化史之框架来研究南海地区新生代的构造演化历史,认为南海地区新生代的构造活动既与印度板块和欧亚板块的碰撞有关,也与太平洋板块向欧亚板块的俯冲活动有联系;同时,还受到澳大利亚板块向北运动之影响。南海地区在新生代发生过两次海底扩张,第一次海底扩张发生在42～35Ma前,是受印度板块和欧亚板块碰撞而引起欧亚大陆之下向东南方向之地幔流的影响而发生的,其海底扩张方向为NW-SE,产生了南海西南海盆;第二次海底扩张发生于32～17Ma前。由于太平洋板块向欧亚板块俯冲,俯冲的大洋岩石圈已达700km深处,阻挡了欧亚大陆的上地幔向东南方向之流动,从而转向南流动,引起南海地区南北向海底扩张,即新生代第二次海底扩张,产生了南海中央海盆。南海新生代洋盆诞生之后,由于大南海地区继续有地块碰撞和边缘海海底扩张,对南海南部地区产生挤压。