某核电厂应急指挥中心基础隔震研究

应急指挥中心是核电厂应为紧急核事故而专设的指挥中心,本文对某核电厂应急指挥中心进行基础隔震设计,分析了隔震效果;建立了各楼层的楼层反应谱,对比分析了隔震前后结构楼层反应谱与目标反应谱的关系。结果表明,隔震后结构明显降低了应急指挥中心的地震反应,同时,其楼层反应谱也大大降低,确保核电厂应急指挥中心在应急抢险中充分发挥其功能作用。     

Molecular clouds and star formation in the Magellanic Clouds and the Milky Way

Star formation is a fundamental process that dominates the life-cycle of various matters in galaxies: Stars are formed in molecular clouds, and the formed stars often affect the surrounding materials strongly via their UV photons, stellar winds, and supernova explosions. It is therefore revealing the distribution and properties of molecular gas in a galaxy is crucial to investigate the star formation history and galaxy evolution. Recent progress in developing millimeter and sub-millimeter wave receiver systems has enabled us to rapidly increase our knowledge on molecular clouds. In this proceedings, the recent results from the surveys of the molecular clouds in the Milky Way and the Magellanic Clouds as well as the Galactic center as the most active regions in the Milky Way are presented. The high sensitivity with unrivaled high resolution of ALMA will play a key role in detecting denser gas that is tightly connected to star formation.     

GPS天线相位中心变化及测试

对GPS天线相位中心随卫星变化的情况及减小和消除天线相位中心误差的方法进行了阐述 ,并详细介绍了对两种型号GPS天线相位中心变化进行比较和测试的结果     

广东省地震前兆台网中心(ADP系统)的构成和功能

介绍了广东省ADP数字地震前兆综合观测台网中心系统的构成、功能以及运行情况。     

Seismic response of deep Quaternary sediments in historical center of L’Aquila City (central Italy)

On 6 April 2009 a M_w=6.1 earthquake produced severe destruction and damage over the historic center of L’Aquila City (central Italy), in which the accelerometer stations AQK and AQU recorded a large amount of near-fault ground motion data. This paper analyzes the recorded ground motions and compares the observed peak accelerations and the horizontal to vertical response spectral ratios with those revealed from numerical simulations. The finite element method is considered herein to perform dynamic modeling on the soil profile underlying the seismic station AQU. The subsurface model, which is based on the reviewed surveys that were carried out in previous studies, consists of 200–400 m of Quaternary sediments overlying a Meso-Cenozoic carbonate bedrock. The Martin-Finn-Seed's pore-water pressure model is used in the simulations. The horizontal to vertical response spectral ratio that is observed during the weak seismic events shows three predominant frequencies at about 14 Hz, 3 Hz and 0.6 Hz, which may be related to the computed seismic motion amplification occurring at the shallow colluvium, at the top and base of the fluvial-lacustrine sequence, respectively. During the 2009 L’Aquila main shock the predominant frequency of 14 Hz shifts to lower values probably due to a peculiar wave-field incidence angle. The predominant frequency of 3 Hz shifts to lower values when the earthquake magnitude increases, which may be associated to the progressive softening of soil due to the excess pore-water pressure generation that reaches a maximum value of about 350 kPa in the top of fluvial-lacustrine sequence. The computed vertical peak acceleration underestimates the experimental value and the horizontal to vertical peak acceleration ratio that is observed at station AQU decreases when the earthquake magnitude increases, which reveals amplification of the vertical component of ground motion probably due to near-source effects.     

近50年来中国经济重心移动路径分析

中国经济重心主要分布在豫皖交界处,1978年前大体位于安徽省西部,1978年后几乎全部分布于河南省东南部;1952～2000年间经济重心移动轨迹呈"士"字型态势发展;近50年来总移动趋势为由北向南,总移动距离为173.14km;每年移动距离和方向与中国区域经济发展政策有密切关系。     

甘肃中部地区景观生态格局与土地利用变化研究

采用1986~2000年TM和ETM+影像数据,计算景观生态指数得出整个地区景观生态空间格局,通过对土地利用/覆盖变化的时空变化分析,实现空间格局和地理时间变化过程的小尺度区域有机结合,对干旱半干旱脆弱生态环境下城镇较为密集地区的人地关系研究具有典型意义。研究表明：低、中覆盖度草地构成本地区基质,沟谷河谷与交通通道是联系乡村和城市的主要廊道,本地区属于人类影响渐强区,在干旱半干旱自然条件下,城镇用地扩张是整个地区土地利用变化主要因素,农业结构调整在空间上改变着空间格局。     

一种新型的宽角范围单脉冲测向方法

针对传统单脉冲测向方法中测向精度与测向范围间难以相互兼顾的缺点,提出一种基于运动相位中心天线阵的新型的宽角范围单脉冲测向方法.利用运动相位中心天线阵能够产生不同边带、不同指向的多波束的特性,在不同方向上同时利用和差比相测角方法对来波方向进行测向,从而达到覆盖较宽测向空域范围的目的.数值仿真结果表明,方法在保留测向精度的前提下能够达到传统单脉冲天线测向范围的4倍以上.     

基于多代理人的零售业空间结构模拟

中心地理论的提出由来已久,但对现实中多种因素复杂作用下的中心地体系进行实证研究并指导规划实践一直难以开展。传统模拟研究方法采用数学线性规划的思路,通过优化目标函数来实现对中心地体系的还原与考察,但复杂程度有限,难以用于实证研究和实践。多代理人技术的出现提供了新的研究思路。本文介绍笔者开发的一个零售业空间结构模拟系统。该系统以多代理人技术为基础,通过模拟商业中心和消费者两类代理人的行为,得出商业中心结构分布。商业中心被分为3 个等级,可以根据经营收入调整空间位置和自身服务等级;消费者以一定的频率产生不同等级的购物需求,并以距离为指标选择商业中心作为出行目的地。模拟过程从产生一定数量的一级商业中心开始,经过循环模拟消费者选择行为和商业中心的位置等级调整,最终达到商业中心等级和空间分布的平衡状态。作为对这个模拟系统的检验,分别对5 种典型的消费者空间分布场景进行模拟,包括：均匀分布、单中心、卫星城、分散组团、带形组团。结果表明这个系统的模拟性能稳定,生成的商业中心结构合理。     

GPS扼径圈天线相位中心偏差检验

GPS接收机天线相位中心偏差是指GPS天线接收卫星信号的电气中心与其机械几何中心之差,在GPS高精度测量中,这是不容忽视的。讨论了采用基线测量相对定位法确定天线相位中心偏差的原理和方法,并利用这一方法计算出天线相位偏差结果。