桑沟湾栉孔扇贝不同季节滤水率和同化率的比较   总被引：33，自引：4，他引：33  

匡世焕  方建光  孙慧玲  李锋 《海洋与湖沼》1996,27(2):194-199

于１９９３年９月和１９９３年１１月在山东省荣成市桑沟湾用半现场法对该湾养殖之栉孔扇贝的滤水率和同化率进行了测定。结果表明：（１）栉孔扇贝的滤水率秋季（９月）明显地高于冬季（１１月）。（２）在同一密度下，单个个体的滤水率随着个体的增大而增大，而单位重量的滤水率随着个体的增大而减小；同一规格的个体，其单个个体和单位重量的滤水率均随着密度的增大而减小。（３）栉孔扇贝的同化率在秋、冬两季无明显差异。（４）  相似文献   

Developing direct shipping across the Taiwan Straits     

Chih-Ching Chang  Kuang Lin  Jya-yuan Bao 《Marine Policy》2006

Direct shipping across the Taiwan Straits has been restricted since 1949 for political reasons. Goods for cross-Straits trade must be transshipped via a third place, such as Hong Kong or a Japanese port. Since commercial activities across the Straits have become increasingly prosperous in recent years, the demand for direct shipping across the Straits is growing critically important and attracts great attention from all sectors. Businessmen who are involved in cross-Straits trade have criticized the higher costs and longer transit time of transshipment. This article explores possible solutions for shipping directly across the Straits. It discusses the mode of negotiation for settling the discrepancies in viewpoints between the two sides, and aims to provide a reference for governments from both sides.  相似文献   

浅海水域水平扩散系数的推算研究     

匡国瑞  陈伯海 《海洋湖沼通报》1992,(2):1-8

本文根据拉格朗日流与欧拉流自相关系数的相似关系,用渤中8号平台1987年1月和8月的实测资料,分别推算了水平扩散系数。推算结果表明:研究长时间水平扩散时,把潮流看作湍流,所求的扩散系数实际上是潮流扩散系数,其值在10~6cm~2/s范围内;研究短时间水平扩散时,把潮流看作平流,用富里叶变换的长周期合成值从实测值中扣除,所求的扩散系数消除了长周期潮流部分,可认为是湍流扩散,其值在10~4cm~2/s范围内。  相似文献   

韶山煤田荷田向斜的发现及研究意义     

肖金成  旷佩林 《中国煤田地质》2007,19(1):11-13

逐一剖析了以往地质资料对荷田含煤区的地质构造解释方案，再现了不同的构造解释方案对应着不同的勘查工作价值，论述了荷田向斜的推断依据和方法，依此提出了湖南今后开展“三下”找煤的重点区。  相似文献   

离散介质波场正演模拟与弱化性影响分析     

邹志辉  於文辉 《应用地球物理》2006,3(2):75-81

从流变力学角度建立的离散介质本构关系同时考虑了介质的弹性、粘性与弱化性,与损伤力学建立的本构关系比较表明弱化因子具有损伤因子的力学意义。本文采用交错网格伪谱法正演模拟了离散介质中波的传播,并以平面波解分析了体波的频散和介质的吸收系数。高频和低频情况下波场数值模拟的结果是:饱和多孔介质中体波速度随弱化因子的增加而降低,介质吸收系数随弱化因子的增加而增加,弱化性对不同体波频散的影响程度不同。  相似文献   

Carbon and hydrogen isotopic characteristics of natural gases from the Luliang and Baoshan basins in Yunnan Province, China   总被引：2，自引：1，他引：2  

XU Yongchang  LIU Wenhui  SHEN Ping  WANG Wanchun  WANG Xiaofeng  Tenger  YAN Yaomin & LIU Ruobin . Lanzhou Center of Oil & Gas Resources  Institute of Geology  Geophsics  Chinese Academy of Sciences  Lanzhou  China  . Research Institute of Petroleum Exploration  Production  SINOPEC  Beijing  China  . South Branch of Petroleum Exploration  Production Company  SINOPEC  Kuming  China 《中国科学D辑(英文版)》2006,49(9):938-946

The Luliang and Baoshan basins are two small ba- sins in Yunnan Province. In the recent ten years or so, there have been found a number of natural gas pools of commercial importance in the two basins. Although the gas pools are small in size, the natural …  相似文献   

气象执法经验点滴谈     

原文国  李文辉 《山西气象》2003,(3):43-44

1概述为加强对气象行政执法工作的管理,进一步引深行政执法责任制,既规范气象行政处罚行为,维护气象工作秩序,又能更好地服务于地方经济建设,我们于2002年开始从事气象执法工作,在实际工作中体会到气象执法不是单纯的行政处罚手段的运用,它还有更丰富的内涵。随着依法治国的不断深入,气象行政执法工作必将在更深入的层次上展开。2案例2003年6月27日,山西省晋中市气象局接到举报,称本市某地有人在违法施放氢气球,共计5颗。接到举报后,执法队副队长立即会同有关部门商讨。由于《山西省气象条例》及《通用航空飞行管制条例》中都有关于违法施放…  相似文献   

雷州半岛第四纪台地区的崩岗侵蚀地貌--一种后果严重的水土流失现象   总被引：2，自引：1，他引：1  

匡耀求  孙大中 《热带地理》1998,18(1):42-49

雷州半岛中段西部的第四纪台地区,水土流失十分严重,崩岗地貌在水土流失面积中所占的比例已接近２０％,对区域生产环境造成了严重的破坏,若任其发展下去,数百年后可能将侵蚀区蚀切到海平面以下,形成一条横切雷州半岛的海峡,严重威胁到区域的可持续发展。通过实地调查,分析了水土流失的发育背景,总结其发育特点,认为造成其水土流失不断加剧的原因主要是其特殊的地层结构和岩性特点以及不合理的土地利用方式。因此应高度重视  相似文献   

桂东南金银矿床类型成矿规律和找矿方向     

王正云  汪劲草  尹意求  耿文辉  杨明寿 《南方国土资源》1998,(3)

文章重新厘定了桂东南原定为“寒武系”地层的时代,确立了海西期云开变质核杂岩体结构;提出本区金银矿床分为混合岩化—岩浆热液型和变质—岩浆热液型的成因类型,建立了金银矿床成矿模式,即地槽发展时期形成矿源层,变质—混合岩化作用促进金银组分活化迁移与初始富集,剥离作用使金银组分再次迁移富集,燕山期构造—岩浆作用成矿,指出找矿重点为云开隆起区外侧及边部断裂带。  相似文献   

Geochemical characteristics of organic matter-rich strata of lower Cambrian in Tarim Basin and its origin     

CHEN Jianfa  Sun Shengli  LIU Wenhui  ZHENG Jianjing 《中国科学D辑(英文版)》2004,47(Z2)

The organic matter-rich strata of the Yurtusi Formation of Lower Cambrian are wildly spread and steady in the Tarim Basin, in which cherts are developed, companied with phosphorite. Al/(Al+Fe+Mn) ratio and Si/(Si+Al+Fe) ratio of cherts range from 0.0023 to 0.0046 and 0.965 to 0.98, respectively, suggesting that cherts are formed in submarine hydrothermal activity and far away from terrestrial. Trace elements, such as As, Hg, Pb, Zn, Cu, Co, P, V, Ba, etc., are markedly rich in organic matter-rich sedimentary rocks of which Ba/Sr ratios are between 21.2 and 158.1. Compared with modern hydrothermal sediments, their Ba/Sr ratios are similar, it indicates that the organic matter-rich strata have the geochemical feature of submarine hydrothermal sediments. The total content of rare earth elements (ЕREE) in cherts is from 8.81 to 56.682 μg/g, on average 31.41 μg/g and the ΕREE of cherts is between continental margin chert's and abyssal chert's. The LREE/HREE ratio of cherts varies from 1.01 to 3.56, which reveals the characteristics of hydrothermal sediments. There is positive correlation between the total organic content (TOC) and Ba/Sr ratio which is geochemical index of submarine hydrothermal activity, which indicates that the submarine hydrothermal activity obviously influences the richness of organic matter in the Yurtusi Formation.  相似文献