Flexible management of fishing rights and a sustainable fisheries industry in Europe

Although overexploitation of commercial fish stocks in European waters has been in the public debate now for more than 20 years, the European Union has so far failed to implement sustainable fisheries management. Millions in subsidies paid to the fishing industry have led to significant excess capacity in the fishing fleet. Various feeble attempts to stop overexploitation of marine resources have failed. The cause is that fishing policy is highly dominated by short-term socioeconomic interests. There is an urgent need for a new fisheries management system in Europe that supports reductions in the fishing fleet, increases responsibility among fishers and guarantees long-term conservation of natural marine resources.Transferable rights to fish have proved a reliable and effective means of creating incentives to conserve marine resources. By strengthening individual fishing rights under flexible quota management systems, the EU Member States could, within the Common Fisheries Policy, make a significant contribution to conserving fish stocks, to reducing excess capacity and to raising the profitability of the fisheries industry. A closer look at existing reservations against a flexible management system shows most of the objections to be overstated or capable of resolution.     

华南花岗岩型铀矿床成矿机理研究进展

本文介绍了华南花岗岩型铀矿床地质特征,系统总结了前人对其成矿热液来源、物质来源,铀的迁移沉淀机制、碱交代及花岗岩与成矿的关系等方面的研究成果。指出铀源体中的晶质铀矿及富铀矿物在深部相对还原的环境中被氧化而进入成矿热液中起主要作用的可能是大量幔源F和放射性衰变诱发产生的氧及碱交代溶蚀作用,热液中的大部分U6 主要被S2-和Fe2 等还原剂在浅部相对氧化的环境中还原成矿;给出了一种较简易的物质来源定量方法和铀成矿模式。     

华南寒武系年代地层系统的修订及相关问题

将早先提出的华南寒武系4统9阶的年代地层系统,修订成4统10阶,除王村阶的底界略高于全球鼓山阶(Drumian Stage)的底界外,其余界线都与目前的全球4统10阶的年代地层界线一致。新系统采纳了在我国华南建立的全球芙蓉统、排碧阶和古丈阶,在原桃源阶的上部另建"牛车河阶"。原王村阶和桃源阶的时限因这一修订有所缩减。全球鼓山阶的底界与台江阶上部的Ptychagnostus atavus带底界可以精确对比。滇东统包含晋宁阶和梅树村阶(狭义)两个年代地层单位,晋宁阶的底界采用全球寒武系的底界,梅树村阶的底界采用罗惠麟等1994年正式修订后的定义,即位于梅树村剖面的"B"点。梅树村阶的原始定义仅指梅树村剖面的磷块岩层(即现今的中谊村段),它的底界高于现在的以Tricophycus pedum首现定义的全球寒武系底界。     

华南地区崩岗侵蚀灾害及其防治

根据区域调查和定位研究资料,介绍了华南地区崩岗侵蚀及其灾害特点,概述了崩岗的形成、发育规律及其演变过程,分析了崩岗侵蚀及其灾害的影响因素.提出进行崩岗灾害防治时,应在水土保持传统方法基础上,整合水文地质学和工程地质学及其它相关学科理论,应用GIS技术对崩岗侵蚀进行科学监测和管理,为坡地利用和环境整治以及灾害防治提供依据.     

中国海相探矿权区块定量评价方法

在研究了我国海相油气探矿权区块基本油气地质条件、勘探程度、技术经济条件等要素和特点的基础上,给出了48个评价参数和归一化取值参照表,建立了探矿权区块评价工作流程、评分参数及计算公式。提出对我国海相勘探层探矿权区块评价应该注意:与国外海相碳酸盐岩评价的差别;与国内陆相碎屑岩评价的差别;成藏组合的划分;评价内容的有效性、不确定性和评价参数的可信度;成败经验的总结和勘探程度的研究。     

中国太阳总辐射的多元逐步回归模拟

研究采用年日照时数、年均总云量、年均水汽压、维度等常规气象要素及地理要素为解析变量,建立起估算全国范围内太阳年辐射总量的多元逐步回归模拟模型;利用全国730多个地面站1951—2002年间的常规气象观测资料,通过所构建的模型对中国太阳年辐射总量进行模拟分析,模型模拟分辨率为1km×1km,规模为4173×4847格网。模型数值计算结果显示:中国太阳辐射资源最丰富的地区为西藏自治区、青海东北部及甘肃西部边境等,高达6700MJ·m-2·a-1以上(一类地区),总面积约130万km2;最低的为四川盆地、青藏高原南部的雅鲁藏布峡谷地区,低于4200MJ·m-2·a-1(五类地区),总面积约75万km2;中国陆地表面每年接受的总太阳辐射能约为52.4×1018kJ;单位面积上太阳年辐射总量约介于2780—7560MJ·m-2·a-1;分布具有明显的地域性,呈现西北、北部高,东南、东部及东北的部分地区低的特点,模拟值较好拟合实际的太阳年辐射总量。研究所构建模型实现了太阳年辐射总量空间分布的连续模拟,模型在保证足够的模拟精度条件下,提高了运算效率,简化了模拟过程,适于全国尺度下太阳年辐射总量的数值模拟计算。     

中国钨矿成矿地质特征与资源潜力分析

钨矿是中国传统优势矿种,前人在钨矿成矿理论方面积累了非常丰富的研究成果。然而,随着近年来在江西、云南和新疆等地取得的多项钨矿重大找矿突破,对原有的钨成矿带地质认识提出了挑战,急需进一步分析和总结其地质特征、成矿规律和资源潜力,为今后地质找矿工作提供理论指导。文中采用矿床模型综合地质信息预测方法,在各省区钨矿资源潜力预测成果的基础上,以MapGIS为平台,进行数据库汇总与综合分析研究。首先,基于全国1 538处钨矿产地数据的统计分析,初步总结了中国钨矿时空分布特征,以及岩浆岩、构造和地层等控矿因素。其次,根据钨矿床及预测区的空间分布和大地构造单元,划分了56个钨矿成矿区带。再次,将钨矿的预测类型划分为石英脉型、夕卡岩型、斑岩型、云英岩型、陆相火山岩型、沉积变质型、层控夕卡岩型和砂矿型,并建立了主要钨矿类型的预测模型。最后,在全国范围累计圈定的1 357个最小预测,累计预测资源量(WO3)2 973×104 t。根据钨矿区域成矿特征,将最小预测区归并为461个二级预测区,并进一步合并为118个钨矿三级预测区,其中,找矿潜力大的河南卢氏-栾川、新疆白干湖、湖南香花岭-瑶岗仙、甘肃野马滩-干巴河脑、江西坪背山-八仙脑和大湖塘等6个三级预测区可优先部署钨矿勘查工作。     

Diurnal Variations of Hydrochemistry in a Travertine-depositing Stream at Baishuitai, Yunnan, SW China

Diurnal variations of hydrochemistry were monitored at a spring and two pools in a travertine-depositing stream at Baishuitai, Yunnan, SW China. Water temperature, pH and specific conductivity were measured in intervals of 5 and 30 min for periods of 1 to 2 days. From these data the concentrations of Ca²⁺, HCO₃⁻, calcite saturation index, and CO₂ partial pressure were derived. The measurements in the spring of the stream did not show any diurnal variations in the chemical composition of the water. Diurnal variations, however, were observed in the water of the two travertine pools downstream. In one of them, a rise in temperature (thus more CO₂ degassing) during day time and consumption of CO₂ due to photosynthesis of submerged aquatic plants accelerated deposition of calcite, whereas in the other pool, where aquatic plants flourished and grew out of the water (so photosynthesis was taking place in the atmosphere), the authors suggest that temperature-dependent root respiration underwater took place, which dominated until noon. Consequently, due to the release of CO₂ by the root respiration into water, which dominated CO₂ production by degassing induced by temperature increase, the increased dissolution of calcite was observed. This is the first time anywhere at least in China that the effect of root respiration on diurnal hydrochemical variations has been observed. The finding has implications for sampling strategy within travertine-depositing streams and other similar environments with stagnant water bodies such as estuaries, lakes, reservoirs, pools and wetlands, where aquatic plants may flourish and grow out of water.     

山西地下水氡中短期异常识别标志及预报方法研究

采用“九五”地震科技攻关地下水化学及 EIS2 0 0 0提供的多种数据处理和异常识别方法 ,对山西省地下水氡观测资料进行了较详细的处理 ,筛选出较好的数据处理方法和异常标志。结果表明 ,除常规的数学处理方法外 ,用水氡的基值变化率和滑动变化率提取异常效果较好 ,如果基值变化率 R0 ≥ 0 .0 6 ,持续时间大于等于 12个月 ,滑动变化率 R≥ 0 .0 5 ,持续时间大于等于 12个月 ,则视为异常     

中更新世气候转型时期南海生态环境的南北差异

中更新世气候转型在南海浮游有孔虫、氧同位素和其它生物记录上主要反映在900 ka BP前后发生高频率变化,特别是指示表层水骤然降温。北部冬季表层水温从24~25℃降至17~28℃,而南部也从26~27℃降至23~24℃。总的降温趋势与开放西太平洋一致,直接反映了西太平洋暖池在900 ka BP之后MIS22期间有明显的减弱。表层水大幅度降温还发生在后继的MIS 20、18、16几大冰期,说明主要冰期旋回周期由41 ka转变为100 ka经历了长达400 ka的过渡时期,并且冬季风增强也在过渡时期的后半段最明显。南海南北生物组合和δ18O值的差异,突出了中更新世气候转型期边缘海区南北气候梯度反差和冬季风在冰期增强的讯号。结论是：生态环境系统反应总体表现与冰期旋回一致的同时,还包含了独特的地区性系统演变特征。但是,南海—西太平洋地区在0.9 Ma BP前后表层海水盐度因东亚冬季风和海平面下降的定量变化,以及这些变化对气候转型时期海—气耦合过程和生态环境系统的影响,尚缺乏足够的资料和证据。