“810■”号登陆台风暴雨的诊断研究

本文在统计华南登陆台风暴雨的基础上,着重对8107号台风登陆后的强度变化及其暴雨过程进行了诊断研究.结果表明,华南登陆台风及其降水的强度变化主要取决于水汽输送条件的变化,Q_1、Q_2的变化则表明,积云对流及其潜热加热的反馈作用是登陆台风及其暴雨维持和加强的主要机制.     

北京地区局地强风暴发生的环境条件

采用１９８０～１９８８年北京地区局地强风暴和北京探空资料，研究了本地区局地强风暴发生的环境条件，有利的环境条件是：对流层低层为低压；层结不稳定和中下层位势不稳定；中低层水汽含量高和对流层深厚气层中相对湿度大．局地强风暴生成与中层干燥、高空强风和垂直风速切变无明显关系．     

GPS铁路航测外控点的高程计算模型

首先从理论上说明ＧＰＳ点高程计算模型中拟合参数的物理意义，并论证一般计算模型所能达到的精度，然后提出铁路测量中ＧＰＳ点的高程计算模型，对试验结果进行分析．理论分析和试验结果充分说明，利用铁路初测水准测量成果进行拟合，所求定的ＧＰＳ点高程精度完全可以满足１∶２０００或更小比例尺成图对航测外控点高程的要求，从而大幅度节省外业工作量．     

京沪高速铁路建设管理模式的研究

在回顾我国铁路建设管理模式的基础上,提出了京沪高速铁路建设管理模式．它不仅是优质、高效、快速建设京沪高速铁路的前提条件,同时也是京沪高速铁路建成之后按现代企业制度运营的基础     

社会声望:民间花会人士的价值追求

通过对一个民间花会人士追逐社会声望经历的考察 ,展示了北京民间社会近百年行香走会历史的一个侧面 ,分析了“社会声望”在中国传统社会的价值和意义及其存在与消亡的社会文化背景 ,说明了社会对人们主观价值追求的制约。     

临猗县防氟供水工程自动化监控系统设计研究

结合临猗防氟供水工程的具体情况,对当地建设供水自动化监控系统的必要性,监控系统的总体结构,各部分功能、硬件选型以及软件系统进行了全面介绍。     

南海北部大陆架海洋生态系统Ecopath模型的应用与分析

过度捕捞和环境恶化导致渔业资源和海洋生态系统逆向发展。采用EwE5.1软件,对南海北部大陆架建立Ecopath(生态通道模型)模型。通过各级流量、生物量、生产量、捕捞量、系统总流量以及生态位和混和营养效应等方面的分析,得出营养流通主要有2种途径,肉食鱼类间饵料竞争非常激烈,低值鱼类间具相似的捕食压力,顶级捕食者对大部分鱼类负效应不明显。系统受过度捕捞渔业影响很大,并存在营养级I利用效率低和渔业资源小型化、低值化等不稳定的幼态特征。     

Benthic foraminiferal fauna turnover at 2.1 Ma in the northern South China Sea

Quantitative analysis of benthic foraminifera from ODP Site 1146 in the northern South China Sea (SCS) shows that abundance of Bulimina alazanensis, sometimes up to about 90%, decreased gradually since 3.2 Ma, especially at 2.1 Ma. Abundance of other benthic foraminiferal species, Globobulimina sub-globosa and Cibicidoides wuellerstorfi, increased after 2.1 Ma. Comparison with changes in oxygen and carbon isotopes of planktonic and benthic foraminifera shows that high abundance values of B. alazanensis corresponded with lower values of oxygen isotope, but for carbon isotope, high values of the species were consistent with heavier carbon isotope of benthic foraminifera and lighter carbon isotope of planktonic foraminifera, respectively, and vice versa. Considering factors such as uplift of Bashi Strait, expansion of the North Hemisphere Glaciation, strengthening of East Asian winter mon-soon and variations in oxygen and carbon isotope of foraminifera, changes of B. alazanensis in ODP Site 1146 suggest that the source of deep water masses of the northern South China Sea changed from the warm Pacific deep water with high oxygen content to Pacific Intermediate water with low oxygen content at 2.1 Ma. In addition, the strengthened East Asian winter monsoon resulted in increased pri-mary productivity, high nutrient and suboxic bottom water. Variations in species of B. alazanensis seemed to be unable to tolerate environmental stress induced by deep water masses and productivity changes.     

Estimation and prediction of black carbon emissions in Beijing City

Black carbon is a by-product of incomplete combustion of carbon containing fuels. It can alter atmospheric radiation property and make adverse impacts on human health. The energy consumption in Beijing City depends largely on coal burning. Recently, Beijing City has been performing the municipal energy structure adjustment as a tool for air pollution abatement, aiming at the air quality goal for the Beijing 2008 Olympic Games. Based on Beijing energy use data in 2000, combined with emission factors of major sources of black carbon, the emission of black carbon in Beijing City is estimated to be 7.77 Gg. Coke, raw coal and biomass as non-commercial energy are the main contributors to municipal black carbon emissions. Based on Beijing energy planning in the year 2008, the emission of black carbon in 2008 will be 2.97 Gg if the contribution from biomass is not taken into account. Assuming that the black carbon emission from rural biomass in 2008 is the same as that in 2004, the biomass burning will be the largest emitter of black carbon to Beijing City in 2008.     

Coupling and propagating of mesoscale sea level variability between the western Pacific and the South China Sea

The coupling and propagating features of mesoscale sea level variability between the western Pacific (WP) and the South China Sea (SCS) were studied based on time series analyses of satellite altimeter measured, along-track sea surface height anomalies (SSHA) along 21°N and the slope of the northern SCS. The analyses show that mesoscale sea level fluctuations in the WP have rather limited coherent effects on the SCS, and no statistically significant propagation of mesoscale variability through the Luzon Strait was observed except in the 45-day band. Evidence suggests that the 45-day fluctuation is very much likely a character of the Kuroshio originating from its low-latitude beginning. It is also sug- gested that the westward propagating Rossby waves will deform when they encounter the dynamical barrier of the Kuroshio. The Kuroshio will then acts on the SCS in its own way. The SCS is a relatively isolated system in the sense of coupling and propagating of oceanic mesoscale waves.