Fluvial-aeolian interactions: Part II, ancient systems

An understanding of fluvial-aeolian deposition derived from modern case-examples in a previous study is applied to the Permian Cutler Formation and Cedar Mesa Sandstone on the Colorado Plateau. These formations supply an excellent three-dimensional exposure of intertonguing fluvial and aeolian strata. Four distinct facies associations form the bulk of the Cutler Formation and Cedar Mesa Sandstone: (1) aeolian dune deposits; (2) wet interdune deposits; (3) fluvial channel deposits; and (4) overbank-interdune deposits. In addition, two distinctive types of erosion surfaces are found within the Cutler Formation and Cedar Mesa Sandstone: pebble- to granule-rich erosion surfaces (aeolian deflation surfaces) and flood surfaces. Fluvial and aeolian intertonguing result in extensive tabular sheets of aeolian sandstone separated by flood surfaces and overbank-interdune deposits. Fluvial channels are associated with the deposits overlying flood surfaces and are incised into the underlying aeolian sandstones. Overbank-interdune deposits and wet interdune deposits cover flood surfaces and intertongue with overlying aeolian sandstones. The primary characteristics of ancient fluvial-aeolian deposition are overbank-interdune deposits and pronounced extensive erosion surfaces (flood surfaces), which are parallel to underlying fluvial sandstones and thus trend parallel to the palaeoslope and palaeohydrological gradient.     

A SENSITIVE AUTOMATED METHOD FOR DETERMINATION OF MERCURY IN GEOLOGICAL MATERIALS BY COLD VAPOR ATOMIC ABSORPTION

An improved sensitive automated method for the determination of mercury in geological materials by cold vapor atomic absorption has been developed. Sample is digested with nitric and hydrochloric acids at low heat. Mercuric ions in the digested sample solution are reduced to elemental mercury by stannous chloride. The gaseous mercury separated from the solution is swept by a stream of argon into the absorption cell of an LDC/Milton Roy Mercury Monitor where the atomic absorption at 253.7 nm is measured. The precision of the method is 2.7% r.s.d., and the detection limit is 1 ppb. The results on 53 international geochemical reference samples are presented.     

IKONOS立体影像全数字摄影测量试验研究

介绍了IKONOS立体影像应用于测图试验的情况,并对成果进行了分析和评价。通过试验研究其对于基本空间数据获取的可行性;考查其经济效益;综合评定其对于工程用图成图的可适用性。     

三丁基氟化锡对内刺盘管虫的实验性中毒研究

评价防污涂料的毒效，通常采用以附着生物的幼虫作室内药物筛选和外海挂板检验的方法，前者常在解剖镜下检查幼虫是否变态，后者是检查附着的成体数量，但这两者都不能说明药物进入附着生物体内的途径及其作用机制。 本文通过有机锡药物——三丁基氟化锡(tributyltin fluoride)对内刺盘管虫Hydroides ezoensis的实验性中毒观察，试图解答上述问题。     

NUMERICAL SIMULATION ON THE WIND FIELD STRUCTURE OF A MOUNTAINOUS AREA BESIDE SOUTH CHINA SEA DURING THE LANDFALL OF TYPHOON MOLAVE

Leveraging the commercial CFD software FLUENT, the fine-scale three-dimensional wind structure over the Paiya Mountains on the Dapeng Peninsula near Shenzhen, a city on the seashore of South China Sea, during the landfall of Typhoon Molave has been simulated and analyzed. Through the study, a conceptual wind structure model for mountainous areas under strong wind condition is established and the following conclusions are obtained as follows： （1） FLUENT can reasonably simulate a three-dimensional wind structure over mountainous areas under strong wind conditions; （2） the kinetic effect of a mountain can intensify wind speed in the windward side of the mountain and the area over the mountain peak; and （3） in the leeward side of the mountain, wind speed is relatively lower with relatively stronger wind shear and turbulence.     

香港与珠三角地区海陆联合地震探测的数据处理

介绍了香港与珠三角地区海陆联测地震数据处理的一般流程及方法,讨论了导航数据记录时间存在误差的问题及其解决方法,对数据处理程序进行了改进,使之更加通用化。提出了数据处理中需要改进之处,对较远的地震台站采用滤波、均衡、剪切等处理手段,突出弱震相,压制强噪音。广东和香港地区的大部分固定台站均可清晰识别出有效信号,这是首次利用固定台站记录到远距离海上气枪信号,最远接收距离达到240多公里,获得了较好的观测结果。     

在特殊疫情背景下《城市地理资讯学》MOOC课程教学实施效果分析

在新冠肺炎疫情期间,线上教学大规模开展,相关线上教学问题逐渐成为研究热点.传统的测绘地理类课程的教学方式主要是上课时以老师传授知识为主,课后以学生完成作业为辅的方式进行.但是,这种教学方式比较单一,并且在科学化考核和促进学生学习主动性等方面存在诸多问题.然而,线上网络课程是通过互联网以电子设备为教学平台,具有不受教学时...     

东南亚地区生物体燃烧影响华南地区对流层臭氧垂直分布的个例分析

2001年3月7日与8日在香港与昆明用电化学臭氧探空仪探测到了对流层低层异常的高浓度臭氧分布. 本文使用NCEP（美国环境预报中心）分析资料、中尺度数值模式MM5模拟的大气环流数据、卫星观测的东南亚地区的生物体燃烧状况、气溶胶指数等资料,分析了这段时间的天气形势、大气环流、空气的后向轨迹以及生物体燃烧产生的烟尘的轨迹,结果发现高浓度的臭氧空气来源于有生物体燃烧的中南半岛地区. 燃烧烟尘的轨迹还表明生物体燃烧地区的下风方的对流层低层臭氧的分布会受到上游地区生物体燃烧产物的影响.     

综合治理太湖污染的一种方法：为环境目的而挖泥

The eutrophication of Lake Taihu is becoming more serious day by day and more urgent to be comprehensively harnessed. The lake sludge is considered as a important polluting factor. To control the internal pollution source of Lake Taihu and restore its water ecological environment, this paper put forward an idea of the dredging for environmental purposes. It was on the basis of the research on the sludge storage and physical/chemical characteristics. The technical keys are sludge-dredging depth, time, method and sludge treatment. The requirements and scheme for the environmental dredging work in Lake Taihu were also analyzed in detail.