冬季黑潮区域海温异常对北太平洋风暴轴的影响

该文对15个冬季北太平洋风暴轴区域500 hPa天气尺度滤波位势高度方差与北太平洋海表温度进行了奇异值分解 (SVD) 分析.结果表明, SVD得到的第二对空间典型分布反映了冬季黑潮区域的海温异常与风暴轴的异常变化密切相关.进一步的分析显示, 黑潮区域海温异常可能通过加强风暴轴入口区的斜压性, 激发或加强500 hPa高度场上的WP遥相关型, 主要影响冬季北太平洋风暴轴在入口区的强度变化和南北位移.     

赞比亚东北部班韦乌卢地块泛非期以来构造演化的裂变径迹约束

本文利用锆石和磷灰石裂变径迹方法探讨了班韦乌卢地块泛非期以来的主要构造演化时间。为研究班韦乌卢地块的构造活动,本文从班韦乌卢地块中部卡帕图地区的沉积盖层姆波罗科索群的姆巴拉组、萨马组和卡布韦卢马组中采集多件新鲜的岩石样品,并获得5件锆石和2件磷灰石样品裂变径迹分析结果。5件锆石裂变径迹年龄介于575±35～380±22 Ma之间,其峰值年龄组为600～572 Ma和420～390 Ma。2件磷灰石裂变径迹年龄介于59±6～27±4 Ma之间,其峰值年龄组为99～80 Ma和19～11 Ma。它们的峰值年龄组分别对应的主要时代为新元古代的埃迪卡拉纪、早泥盆世、晚白垩世和中新世。对比区域上已有的年龄数据可知,南部非洲地区新元古代的埃迪卡拉纪、早泥盆世和晚白垩世的构造活动是一个区域性的构造事件,仅中新世(19～11 Ma)的构造活动在区域上的表现尚不明确。综合前人成果资料,自泛非构造运动以来,班韦乌卢地块至少经历600～572 Ma、488～441 Ma、420～390 Ma、375～293 Ma、99～80 Ma及19～11 Ma六个构造事件。班韦乌卢地块泛非期以来的构造演化研究程度很低,...     

Numerical study on the effect of rigid inclusions on existing railroads

Railroad track problems have been exacerbated by the continuous increase in freight loads and train traffic. The need to implement soil improvement technique in a relatively short window-time (ie, to minimize train-traffic disruption) is a key aspect to be considered when adopting a convenient remedial solution to control settlements in railroads constructed on problematic subgrades. Rigid inclusions are selected in this paper because they are reliable solutions relatively easy to implement. Furthermore, they can be used in different ground conditions and are suitable for short construction times (eg, do not require a curing time, as in grouting methods). Typical (analytical) methods for the design of rigid inclusions are adopted in this paper to define an optimal distribution of piles for the case of existing railroads. The selected layout is then analyzed in detail by means of a 3-D dynamic finite element simulator using both, elastoplastic and elastic models. The performance of rigid inclusions is studied considering different operational scenarios, with dynamic and static loads, as well as involving subgrades with different plasticity index values. It is found that the predictions from the analytical design methods for rigid inclusion tend to be unconservative when compared against the finite element results. As for the numerical solutions, the most unfavorable stress condition is associated with the dynamic elastoplastic finite element solution. It is estimated that the rigid inclusions will contribute to a reduction in the ground settlements of around 15% to 20%, depending on the subgrade plasticity index.     

2010年上海天文台卫星激光测距观测报告

介绍了2010年上海天文台卫星激光测距的常规观测和白天千赫兹激光测距情况。在国际上首次对同步轨道卫星开展了千赫兹激光测距,作用距离达38800多千米,测距系统性能达到国际先进水平。利用2套独立的激光测距系统,开展了激光收发分离测距实验,为行星际异步应答式激光测距模拟试验提供了实测数据。最后概述了空间碎片目标激光测距进展情况。     

鄂尔多斯盆地西南缘中生代中晚期构造体制转化过程及其动力学背景

逆冲推覆构造对含油气盆地有效圈闭形成、源储体系配置影响明显,且其形成时限及演化过程对油气勘探意义重要.鄂尔多斯盆地西南缘中生代中晚期曾发生过强烈的逆冲推覆作用,但其构造体制转化过程一直缺乏年代学的约束.热年代学是揭示构造带隆升剥露和相邻盆地演化过程的有效手段.本文通过对祁连山东缘钻井基岩的磷灰石裂变径迹分析,结合鄂尔多...     

Acoustic Theory Application in Ultra Short Baseline System for Tracking AUV

The effective tracking area of ultra short baseline (USBL) systems strongly relates to the safety of autonomous underwater vehicles (AUVs). This problem has not been studied previously. A method for determining the effective tracking area using acoustic theory is proposed. Ray acoustic equations are used to draw rays, which ascertain the effective space. The sonar equation is established in order to discover the available range of the USBL system and the background noise level using sonar characteristics. The available range defines a hemisphere like enclosure. The overlap of the effective space with the hemisphere is the effective area for USBL systems tracking AUVs. Lake and sea trials show the proposed method's validity.     

双线铁路CRTSⅢ型板式无砟轨道布板设计系统研制

深入研究了CRTSⅢ型板式(简称Ⅲ型)无砟轨道布板设计关键技术,设计并研制了基于C/S(客户端/服务器)结构模式的Ⅲ型无砟轨道布板设计系统,可以实现双线铁路并行等高段的布板计算并获得轨道板各承轨台轨顶中心(简称承轨台定位点)的线路空间三维坐标信息。文中阐述了双线铁路Ⅲ型无砟轨道布板设计关键技术和系统设计实现流程,对我国Ⅲ型无砟轨道技术体系向智能化发展具有一定借鉴和参考意义。     

长江中下游成矿带抛刀岭金矿裂变径迹研究及大地构造意义

抛刀岭金矿位于长江中下游成矿带中的安庆-贵池矿集区,是长江中下游多金属成矿带中首次发现的斑岩型独立金矿床。通过磷灰石裂变径迹研究分析区内的构造演化特征,裂变径迹长度处于11.9±1.8μm和13.2±1.6μm之间,表明样品在后期受构造热事件的影响,样品长时间处于退火带温度,长度直方图总体呈现单峰特征,受隆升冷却作用控制明显。通过对同组年龄(x2检验值>5%)和混合年龄(x2检验值<5%)进行分析,所测年龄位于123Ma和19Ma之间,可以将年龄分为5组:123.0Ma,107Ma,86Ma,52Ma,19Ma。裂变径迹热历史可以分为4个时期:缓慢冷却期,从150～90Ma;快速冷却期,从90Ma至65～58Ma;缓慢冷却期,从65～58Ma至18～12Ma;快速降温期,从18～12Ma至今。自中侏罗世以来,江南隆起带受控于太平洋板块构造,太平洋板块在不同时期有着不同的活动,其运移方向和活动强度直接控制着中国东部的构造演化。研究地区所测裂变径迹年龄划分时代与太平洋形成后不同产状洋岛链出现的时代吻合,热历史模拟结果和太平洋板块不同期次活动相关。通过热历史模拟和构造分析,可推测热历史不同阶段的形成是不同时期太平洋板块运动的结果,样品混合年龄亦证明了构造活动的多期次性。可以推断贵池地区自白垩纪以来的构造运动与太平洋构造带活动密切相关,其多期构造演化是对太平洋板块活动的响应。     

工商巡查管理信息系统的技术与实现

在河南省大力开展数字城市建设之际,我院经过对工商部门的需求调查和分析后,利用Java,C#,JavaS-cript,HTML等语言,采用无线、有线网络的HTTP通信技术,数据库技术和GPS技术自主研发了工商巡查管理信息系统,该系统分为服务器端、手机端和监控端,实现了条码录入、人员位置监控、实时定位、轨迹显示和信息查询的功能。     

Dynamic response of double beam rested on stochastic foundation under harmonic moving load

This paper deals with the dynamic response of infinite double Euler–Bernoulli beam supported by elastic foundation with stochastic stiffness subjected to an oscillating moving load, which is the first research in relevant literature review. In this matter, equations of motion for double beam are formulated in a moving frame of reference. Moreover, by employing the first order perturbation theory and calculating contour integration, the response of double beam is obtained analytically and validated by a stochastic finite element model. Sensitivity analyses on the various parameters of closed form solution such as velocity, load frequency, coefficient of variation of soil foundation and rail and slab bending stiffness show the significant effect of load frequency on the dynamic response of the doubled beam. From practical point of view, the obtained results of the present study can be utilized efficiently in analysis and design of slab track systems. Copyright © 2013 John Wiley & Sons, Ltd.