Effects of the anthropogenic activities on the morphological evolution of the Modaomen Estuary,Pearl River Delta,China

Owing to the intensive human activities, the Modaomen Estuary has been significantly modified since 1950s, which has resulted in considerable changes of hydrodynamics and morphodynamics in the area. In this paper, the effects of the anthropogenic activities on the hydrodynamics and morphological evolution in the estuary at different stages are systematically assessed based on the detailed bathymetric data and field survey. The results show that the human activities have caused the channelization of the enclosed sea area in the Modamen Estuary;fast seaward movement of the mouth bar with high siltation;expansion of the channel volume due to channel deepening. The paper also highlights the main hydrodynamic changes in the estuary, including the rise of the water level;the distinguishing changes of tidal range before and after the 1990s （decrease and increase respectively）; as well as the increase of the divided flow ratio. It is found that reclamation is the main factor promoting the transition of nature of the estuary from runoff dominant to runoff and wave dominant, and sand mining activities are mainly to strengthen the tidal dynamic and to low the water level. The results provide useful guidance for better planning of the future developments in the estuary and further research in the area.     

都兰地震台不同地磁观测仪产出资料分析

通过对都兰地震台同场地不同地磁观测仪器(GM4-XL型磁通门磁力仪与FHD-2质子矢量磁力仪)产出的观测资料进行对比,系统地分析日均值、分钟值、背景噪声等数据,认为3套仪器产出的数据差异较大,质子磁力仪较磁通门磁力仪长期趋势更加稳定,磁通门磁力仪存在长期漂移现象,且质子磁力仪噪声与磁通门磁力仪噪声相比较大.对引起数据曲...     

冶金地质系统首届青年科技工作者学术报告会在保定召开

1988年11月22～25日，来自全国各地冶金地地质部门从事科研、设计、找矿勘探、教育、管理、科技情报以及武警黄金部队、矿山工作的青年科技工作，齐集保定，参加了“冶金地质系统首届青年科技工作学术报告会”。这次会议是由冶金地质学会青年科拄工作委员会组织的。出席报告会的共78名青年代表。冶金地质学会秘书长马念高级工程师致开幕词，副理事长王继伦高级工程师和冶金物探公司领导到会讲了话。     

凭祥-东门大断裂中段特征及控岩控相初析--以宁明-板利地区为例

文章收集了凭祥-东门大断裂在宁明-板利地区的详细资料,研究该断裂在该地区的表现特征,分析其活动性质及期次,阐明了该大断裂具有多期次活动的特点,并且在不同期次和不同地段具有不同的活动特点和表现形式,在此基础上结合区域地层、岩石特征,阐明其对区域的控岩、控相作用,为三级构造单元界线的划分提供了基础资料.     

张家口探矿机械总厂

企业简介 张家口探矿机械总厂始建于1910年，其前身为我国著名铁路工程师詹天佑建成京绥铁路后随之开办的铁路工厂。1953年划归地质部门，被列为国家“一无”期间156项重点建设项目，经过五十年的发展和完善，目前已成为技术力量雄厚，加工能力强大，产品品种齐全，质量价格比优越，集新产品研究、开发、生产、贸易为一体的国有大中型骨干企业。1993年被评为全国500家最大机械制造企业之一。     

新疆气象地质部门加强技术合作

7月7日，自治区气象局和地震局正式签定《技术合作意向书》。自治区气象局党组书记、局长史玉光和自治区地震局党组书记、局长张云峰在意向书上签字。自治区科技厅副厅长高峰、自治区气象局副局长魏文寿参加了签字仪式。双方决定，由气象局、地震局局长挂帅组成技术合作领导小组，推动技术合作的实施。建立台站技术合作和资料共享的机制，充分利用气象、地震现有测站网。     

珠江口磨刀门枯季表层沉积物特征

根据2003年12月在珠江口磨刀门附近水域采集的河口表层沉积物粒度分析资料,研究了磨刀门河口表层沉积物的组成、分布、运动等特征及其动力环境指示作用。研究表明,磨刀门口枯季表层沉积物组成以粉砂为主,其次为粘土和砂。表层沉积物平均中值粒径为6．356Ф(0．0122mm),表层沉积物的级配与悬沙的级配较接近。口门附近表层沉积物的中值粒径、分选性沿程没有明显的变化。枯季表层沉积物的形成以悬移质沉积为主,跃移和推移运动形式很少。磨刀门由于受人类活动的影响枯季表层沉积物与历史相比出现明显的细化,磨刀门口附近枯季表层沉积物的特征在一定程度上反映了枯季以潮流作用为主的相对较弱的动力环境。     

新疆中天山巴仑台闪长岩成因及其地质意义

巴仑台闪长岩反映的大洋俯冲信息为对比乌瓦门蛇绿岩与西侧长阿吾子和东侧库米什蛇绿岩的关系,探讨南天山洋的洋-陆演化过程具有重要意义。闪长岩具高碱和高铝特征,(Na2O+K2O)=4.14%~7.05%,Al2O3为14.62%~17.35%,为一套高钾钙碱性系列岩石,(La/Yb)N平均10.46,以富集轻稀土元素和大离子亲石元素(如K、Rb、Ba、Pb等)、亏损Nb、Ta、Ti等高场强元素为特征,形成于岛弧环境。闪长岩LA-ICP-MS锆石U-Pb年龄为(430.1±1.1)Ma,锆石εHf(t)=-12.7~-7.6,二阶段Hf模式年龄TDM2为1895~2219 Ma,指示巴仑台闪长岩为早志留世南天山洋北向俯冲,导致中天山古老结晶基底部分熔融形成。     

珠江河口磨刀门水道的亚潮振荡特征及其对水文气象要素的响应

根据珠江河口磨刀门水道的三灶站、大横琴站、灯笼山站、竹银站2010年全年的逐时潮位资料,利用小波分析方法研究磨刀门河口区亚潮变化的周期特征。采用小波相干方法,分析亚潮与气压、风速、流量之间的相关关系。研究结果表明:(1)磨刀门河口亚潮主要存在5~6 d、14 d、21 d周期性波动。(2)亚潮5~6 d的周期波动的能量来源于气象要素及入海径流;亚潮14 d左右的周期波动的能量来源于天文大小潮、气象要素及入海径流的叠加效应;磨刀门水道下游站点亚潮21 d的周期性波动受到气象要素及入海径流的联合作用,而上游站点亚潮21 d的周期性波动主要受到入海径流因素的影响。(3)在不同季节,亚潮对气象要素的响应情况会产生不同影响。     

A Comparison of Different Gracilariopsis lemaneiformis （Rhodophyta） Parts in Biochemical Characteristics,Protoplast Formation and Regeneration

Gracilariopsis lemaneiformis is a commercially exploited alga.Its filaceous thallus can be divided into three parts,holdfast,middle segment and tip.The growth and branch forming trend and agar content of these three parts were analyzed,respectively,in this study.The results showed that the tip had the highest growth rate and branched most,although it was the last part with branch forming ability.The holdfast formed branches earliest but slowly.Holdfast had the highest agar content.We also assessed the difference in protoplast formation and regeneration among three parts.The middle segment displayed the shortest enzymolysis time and the highest protoplast yield; whereas the tip had the strongest vitality of protoplasts formation.Juvenile plants were only obtained from the protoplasts generated from the tip.These results suggested that the differentiation and function of G.lemaneiformis was different.