地震动有效幅值不对称性特征研究

利用国内外287次5级以上的实际地震记录,研究了地震动有效幅值的不对称性特征及其规律。分别用有效幅值不对称比和有效幅值作用次数不对称比来描述地震动的不对称性,统计结果具有规律性,并提出了其估计公式。结果表明:地震动有效幅值不对称性和有效幅值作用次数不对称性特征明显,幅值不对称比的平均值不受震级影响,但与截断比呈非线性递增关系,截断比小于1/3时不对称比在1.07～1.20之间,截断比大于1/3时不对称比在1.13～1.96之间;有效幅值作用次数不对称比的平均值不受震级影响,但与截断比呈非线性递增关系,截断比小于1/3时作用次数不对称比在1.04～1.31之间变化,截断比大于1/3时作用次数不对称比在1.22～1.80之间。     

紧急救援有关问题的探讨与思考

首先简要回顾了紧急救援的发展过程；简述了与紧急救援有关的一些概念；讨论了城市搜索与救援、地震灾害紧急救援两个概念的由来和区别；回顾了国家地震灾害紧急救援队的设计并提出了地方救援力量建立的原则。最后是关于紧急救援未来发展的思考，并对保障措施提出了建议。     

土体动力一维非线性本构关系剖析与评价

土体动力一维非线性本构关系是场地及地基动力响应、土工数值分析的关键。回顾和总结了国内外的发展状况及研究进展,对其分析方法、等幅循环荷载到不规则荷载的扩展及应用规则、试验阻尼比的等效、滞回曲线形状等核心问题进行剖析、评价和探讨,并对各种模型的优缺点进行了比较和讨论,着重介绍了最近研究结果。最后指出未来发展方向及有待进一步研究的问题。     

江西信江盆地红层及其地貌发育研究

江西信江盆地丹霞地貌的成景地层为晚白垩系陆相红色碎屑岩,红层的厚度、岩石学和地球化学特征及其在盆地内出露制约着丹霞地貌的发育、景观类型及其组合以及在盆地内的分布。信江盆地边缘主要出露茅店组、河口组和莲荷组巨厚层砾岩、含砾砂岩和砂岩,以铁质胶结和少量钙质胶结为主,可溶性成分含量低,这些红层以发育高大的顶斜型峰林型、峰丛型丹霞地貌组合为特征。盆地中部的河口组上部和塘边组地层含砾砂岩和砂岩为主,以钙质胶结为主,可溶性成分含量较低,常发育低矮的圆丘状丹霞地貌组合为特征,大型岩洞是其典型的景观类型。过渡地带主要为河口组上部、塘边组和莲荷组下部的砂岩、含砾砂岩,丹霞地貌只发育于断层或河流发育地区,以顶平型丹霞地貌组合为特征。以钙泥质胶结为主,可溶性成分含量高的细碎屑岩中一般不发育丹霞地貌。     

CT技术在诊断肝占位性病变的运用

本文对１２６例肝脏占位性病变的ＣＴ表现进行了分析,其中原发性肝癌４１例,３２．８％,转移性肝癌２１例,占１６％,肝囊肿者４１例,占３２．８％,肝海绵状血管瘤１９例,占１５．２％,肝脓肿２例,肝结核和肝肉瘤各１例。肝脏占位性病变的ＣＴ检出率为腹部ＣＴ检出率的１９．７５％,ＣＴ是肝脏占位性病变鉴别诊断的重要的方法之一。     

波列振幅衰减测桩法的研究与应用(Ⅰ)--单桩竖向承载力的测定

通过研究打桩公式法和应力波动法(如CASE法),作者提出：用重锤或小型火箭筒一次冲击桩顶,用桩顶附近的检波器记录振波图和检测静、动位移,通过实测冲击能(总能量)转换系数、波动和振动各自消耗的能量等各物理量,测定计算单桩竖向承载力．利用振波图计算力(P)和位移(S)动态关系曲线、确定屈服点。并利用静载荷试验检验动测结果和确定动静PS曲线的相关常数,进而确定与承载力相应的沉降量。     

中国和欧盟阻尼器检测标准比较

国内阻尼器工程应用越来越多,阻尼器生产和应用时需要进行型式检验和出厂检验。中国和欧盟均制定了阻尼器产品检验标准,但在检测参数、检测方法和数据处理等方面存在一些差异,有些参数的检测还存在一些困难和争议,通过比较研究,指出中欧阻尼器检测标准的异同点,并分析各自的特点。以应用量较大的位移型软钢阻尼器和速度型黏滞流体阻尼器为例,比较中国和欧盟检测标准的异同点,内容包括检测方法、检测设备和数据处理方法等,提出一些对现有检测标准的改进建议,供同行参考。     

多层螺旋CT三维重建对小肾癌的诊断及分型

目的：根据CT扫描图像及三维重建表现,探讨多层螺旋CT扫描对小肾癌的诊断及鉴别诊断的价值,并对小肾癌进行分型。资料与方法：收集行多层螺旋CT扫描并经临床病理证实的43例小肾癌病例资料,就其CT表现进行分析并进行分型。结果：凸出型小肾癌23例,CT表现为肿瘤凸向肾轮廓之外或凸向肾盂、肾盏,增强扫描时,肿瘤内部造影剂呈明显...     

系统聚类法在华北地区的地震分期和预测中的应用

本文用修改了的系统聚类法研究华北地区地震活动期,结果表明,当类间距离用离差平方和增量距离,且样品间用欧氏距离时,能较好地划分该地区的地震活动期。而样品间用相似系数时,不论类间距离是哪一种,所得结果均较差。本文还作了地震活动期的后验预测尝试,还通过逐次筛选方法对21个特征进行了选择。     

Modeling the interaction between water flows

Approaches to schematization used in the models of interacting water flows in different media are considered. Studies of the interaction between subsurface and surface waters are analyzed. Specific features of water flow-out from watercourses (channels), pipelines, etc. are discussed. Some steady-state problems are formulated, and their solutions are given. Dynamic effects of pressure changes in water flows are shown based on these solutions. The effects that appear in such cases are explained theoretically and correlated with experiments.     

俯冲带的后撤与弧后扩张

西太平洋地壳年龄较老,因而岩石层较冷和比重较大,俯冲带的角度也较大,活动和成熟的弧后盆地则较多;条件与之相反的东太平洋弧后盆地则较少.本文探讨这种相关关系的力学成因,计算了俯冲板块诱生的弧后上涌地幔流动.计算表明,俯冲角度大及存在后撤俯冲时,有利于在弧后地区产生明显的上涌地幔流,这种深部热物质的上涌会导致弧后扩张.反之,年龄较轻的海洋地块较热和较轻,俯冲角度一般也较小,不易诱生上涌地幔物质流动和弧后扩张.大陆地壳密度小于地幔物质,大陆碰撞区就更不具备弧后扩张的条件.     

Ridge subduction and porphyry copper-gold mineralization:An overview

Many large porphyry Cu-Au deposits are connected to adakitic rocks known to be closely associated with ridge subduction. For example, there are several subducting ridges along the east Pacific margin, e.g., in Chile, Peru, and South America, most of which are associated with large porphyry Cu-Au deposits. In contrast, there are much fewer ridge subductions on the west Pacific margin and porphyry Cu-Au deposits are much less there, both in terms of tonnage and the number of deposits. Given that Cu and Au are...     

The formation of ice sails

Debris-covered glaciers are prone to the formation of a number of supraglacial geomorphological features, and generally speaking, their upper surfaces are far from level surfaces. Some of these features are due to radiation screening or enhancing properties of the debris cover, but theoretical explanations of the consequent surface forms are in their infancy. In this paper we consider a theoretical model for the formation of “ice sails”, which are regularly spaced bare ice features which are found on debris-covered glaciers in the Karakoram.     

Numerical comparisons of the damping of internal gravity waves in stratified fluids

Summary Comparisons are made of the attenuation of progressive internal waves in stratified fluids consisting of (a) a representation of a single thermocline, (b) a weak exponential density distribution and (c) a two-layer system. Effects of the earth's rotation are neglected, as also are heat and salt diffusion. Significant differences are found in the decay characteristics of the three density structures. Internal waves are most strongly damped in the layered system (c) whilst the calculated attenuation rates are least for the thermoclinic structure (a). All the internal modes investigated are, however, shown to be more strongly damped than the associated surface wave.     

组合网壳屋盖结构风振响应分析及等效静风荷载

结合惠州会议展览中心风洞试验结果,对波浪形组合网壳结构的风荷载和风振响应进行了分析,包括：24个风向角下屋盖荷载分布特性分析;结构整体和局部的自振特性分析;根据风洞试验结果对6个风向角（0°、30°、45°、90°、135°和180°）进行结构的风致动力响应分析。根据风振响应分析结果,基于响应的不同振动特点,提出将屋盖结构分为独立屋盖结构、屋盖结构两端挑棚结构和整体屋盖结构3个部分,指出对这3部分最不利的风向角分别为0°、30°、90°。最后综合考虑各个风向角下结构的响应及风振系数,给出了最终的风振系数建议值。     

Asteroids: Distributions,morphologies, origins and evolution

A review is presented of dynamical and physical properties of asteroids. Discovery methods are discussed and some distributions of the orbital elements and the absolute magnitudes are presented as are properties of planet-crossing asteroids, Hildas and Trojans. Various observational methods such as polarimetry, radar and occultations are briefly introduced and lightcurve data are more extensively described. Asteroid taxonomy in the Barucci classifiction is thoroughly discussed as are asteroid spins and shapes and the origin and the evolution of these bodies. Space missions to asteroids and space observations of asteroids are also introduced.     

Vibration analysis of steel structures including the effect of panel zone flexibility based on the energy method

New approximate formulas are proposed to determine the natural frequencies of structures considering the effects of panel zone flexibility and soil-structure interaction. Several structures with various earthquake resisting systems are idealized as prismatic cantilever flexural-shear beams. Floor masses are considered as lumped masses at each story level and masses of columns are evenly distributed along the cantilever beam. Soil-structure interaction is considered as axial and rotational springs, whose potential energy are formulated and incorporated into overall potential energy of the structure. Subsequently, natural frequency equations are derived on the basis of energy conservation principle. The effect of axial forces on natural frequency is also considered in the proposed formulas. Using the method presented in this study, natural frequencies are computed using a simplified method with no complex numerical modeling. The proposed formulas are verified via experimental and numerical methods. Close agreement between the results from these three approaches are observed. Furthermore, the effects of panel zone flexibility, continuity plates and doubler plates on the natural frequencies of buildings are investigated.     

On the use of biorthogonalization for solving systems of linear equations in numerical weather forecasting

Summary The paper deals with the solving of large systems of linear equations which are created when implicit and semi-implicit differential methods are used to solve the primitive equations of the atmosphere. Systems with similar properties are also created in solving boundary problems of multi-level filtered models. First, the specific properties of these systems, which are then used to construct an efficient method of solving them, are described.     

Influence of crude oil,derivatives and dispersants on larvae

Crude oils, oil derivatives and especially mixtures of oil and dispersant are harmful to larvae of some marine bivalve molluscs, but high concentrations are needed to cause death. Such high concentrations are unlikely to be reached in the open sea but are possible inshore or in estuaries which are the site of commercial shell-fisheries. The fact that spermatozoa are particularly sensitive to these compounds may have important consequences for the breeding success of contaminated bivalve populations.     

震级与地震破裂参数统计关系式系数的讨论

在收集６种类型震级与地震破裂参量的统计关系式的基础上，系统分析和总结了各类统计式的系数ａｉ和ｂｉ的变化范围以及二者的关系。发现ａｉ和ｂｉ之间均有或强或弱的负相关性；不同类型统计式的系数有一定的变化范围，且稳定性和收敛度不同。一般来说，涉及的破裂参量越多系数越稳定。最后依据位错公式，解释了ａｉ和ｂｉ的关系