Measurements of Trace Gases in the Inflow of South China Sea Background Air and Outflow of Regional Pollution at Tai O, Southern China

We present a 16-month record of ozone (O₃), carbon monoxide (CO), total reactive nitrogen (NO_y), sulphur dioxide (SO₂), methane (CH₄), C₂ – C₈ non-methane hydrocarbons (NMHCs), C₁ – C₂ halocarbons, and dimethyl sulfide (DMS) measured at a southern China coastal site. The study aimed to establish/update seasonal profiles of chemically active trace gases and pollution tracers in subtropical Asia and to characterize the composition of the `background' atmosphere over the South China Sea (SCS) and of pollution outflow from the industrialized Pearl River Delta (PRD) region and southern China. Most of the measured trace gases of anthropogenic origin exhibited a winter maximum and a summer minimum, while O₃ showed a maximum in autumn which is in contrast to the seasonal behavior of O₃ in rural eastern China and in many mid-latitude remote locations in the western Pacific. The data were segregated into two groups representing the SCS background air and the outflow of regional continental pollution (PRD plus southern China), based on CO mixing ratios and meteorological conditions. NMHCs and halocarbon data were further analyzed to examine the relationships between their variability and atmospheric lifetime and to elucidate the extent of atmospheric processing in the sampled air parcels. The trace gas variability (S) versus lifetime (τ) relationship, defined by the power law, S_lnx = Aτ^{− b}, (where X is the trace gas mixing ratio) gives a fit parameter A of 1.39 and exponent b of 0.42 for SCS air, and A of 2.86 and b of 0.31 for the regional continental air masses. An examination of ln[n-butane]/ln[ethane] versus ln[propane]/ln[ethane] indicates that their relative abundance was dominated by mixing as opposed to photochemistry in both SCS and regional outflow air masses. The very low ratios of ethyne/CO, propane/ethane and toluene/benzene suggest that the SCS air mass has undergone intense atmospheric processing since these gases were released into the atmosphere. Compared to the results from other polluted rural sites and from urban areas, the large values of these species in the outflow of PRD/southern China suggest source(s) emitting higher levels of ethyne, benzene, and toluene, relative to light alkanes. These chemical characteristics could be unique indicators of anthropogenic emissions from southern China.     

Automatic Interpretation of Magnetic Data Using Euler Deconvolution with Nonlinear Background

The voluminous gravity and magnetic data sets demand automatic interpretation techniques like Naudy, Euler and Werner deconvolution. Of these techniques, the Euler deconvolution has become a popular choice because the method assumes no particular geological model. However, the conventional approach to solving Euler equation requires tentative values of the structural index preventing it from being fully automatic and assumes a constant background that can be easily violated if the singular points are close to each other. We propose a possible solution to these problems by simultaneously estimating the source location, depth and structural index assuming nonlinear background. The Euler equation is solved in a nonlinear fashion using the optimization technique like conjugate gradient. This technique is applied to a published synthetic data set where the magnetic anomalies were modeled for a complex assemblage of simple magnetic bodies. The results for close by singular points are superior to those obtained by assuming linear background. We also applied the technique to a magnetic data set collected along the western continental margin of India. The results are in agreement with the regional magnetic interpretation and the bathymetric expressions.     

依据化探成果对东昆仑地质背景的讨论

在东昆仑地区 6 0 0 0 0多km2 的地域内 ,按照 4km2 的采样单元 ,共采集了 15 0 0 0多件水系沉积物样品。按照 16km2 的网格加工成 4 0 0 0多件组合样后 ,定量分析了 4 0种微量元素的含量。在对这些数据进行数学处理的基础上 ,利用斜交因子的分析结果 ,讨论了东昆仑地区的区域地层、断裂构造和中酸性岩浆岩的特征。根据区域地球化学成果 ,进一步明确了昆中、昆南断裂对本区地层和侵入岩分布的控制作用。基于元素区域地球化学背景的对比 ,提出了昆中断裂应向东延伸的证据 ,并指出了东大滩、布青山两个地区经历了相似的地质 地球化学作用     

低本底液闪仪计算机控制系统的改进

新研制改进的低本底液闪计算机控制系统，具有数据获取和数据处理、实时能谱测量、谱显示选取工作点以及测量中断后继续测量等功能，从而使液闪仪的自动化和智能化程度得到了进一步提高。     

陆相盆地沉积作用与构造作用的关系

构造作用与沉积作用两者之间的联系性和统一性正受到人们重视。陆相盆地沉积作用受构造作用的控制极为明显。沉积演化就是构造演化的反映,陆相盆地沉积作用直接反映了构造活动的特征。陆相盆地沉积作用最主要的特征是相变快和幕式沉积作用。按构造动力学背景,可将陆相盆地分为三大类型:张性盆地、压性盆地和剪性盆地。这三类盆地在沉积作用上有很大差异。     

湖南地热资源分布及远景区划

湖南中新生代地质构造背景特殊，因而发育了丰富的地下热水资源。初步总结了省内地下热水资源的分布规律、水化学特征及其与地质构造的关系，划分了湘西北慈利－桑植－吉首、湘中隆回－武岗－洞口、湘东娄底－株洲－衡阳及湘南郴州－宜章－汝城4个地热异常区，为地热远景开发区划提供了基础资料。     

区域站和基准站气溶胶的分析

文章讨论了秋季（1994年10月）和冬季（1995年1月）在中国西部青海省共和县瓦里关山（36°17′N，100°54′E，海拔3816 m）基准站和中国东北黑龙江省五常县的龙凤山（44°44′N，127°36′E，海拔331 m）及中国东南沿海的浙江省临安县的横畈乡（30°18′N，119°44′E，海拔131 m）两个区域本底站（上述3站均属WMO）所采集的气溶胶样品的质量浓度、可溶性离子浓度的时空分布特征和变化规律。初步得出:气溶胶质量浓度和可溶性离子浓度以临安为最高。其次是龙凤山，而瓦里关山为最低     

发展“三高”果业需重视大生态系统的耗散协调性──剖析龙泉花果山的大生态环境

发展高产优质高效果业，常会涉及到大生态系统的各类环境因子群。龙泉花果山的大生态系统主要是以风化岩体→紫色土容库→蜜桃等构成的向量大系统的综合反映，并呈现非均衡耗散结构的复杂协调性，这些因素直接制约“三高”果业的发展。     

Spectral index determination between 408 MHz and 5 GHz in the northern sky

We present the joint analysis of two 5-GHz interferometric surveys of the northern sky, taken with different baselines. The two surveys were carried out on the Jodrell Bank 5-GHz interferometer based at Manchester. The Maximum Entropy Method is used to check the consistency of the two surveys and the final two-dimensional maps are used, together with low-frequency full sky surveys, to put constraints on the Galactic spectral index. It is found that synchrotron emission is the dominant process at high Galactic latitudes below 5 GHz.     

南海诸岛外来地名的命名背景及其历史影响

19世纪中叶至20世纪30年代英美等国在我国南海海域的测绘活动,给这里的岛礁留下了一大批以英语为主的外语名称。文中论述了南海诸岛外来地名的命名背景及其对我国三次公布官方名称所产生的深刻影响,在总结历史教训的基础上,分析了当前处理南海地名问题的缺陷,提出了若干改进建议。