我国铅锌资源现状及发展政策建议

一、我国铅锌资源状况1.储量状况我国铅锌资源储量丰富。根据美国地调局《Mineral Commodity Summaries 2008》最新数据显示,截至2007年底,我国铅、锌资源储量和基础储量均仅次于澳大利亚,居世界第二位。     

基于轨道精炼控制点精选的极艰险区域时序InSAR地表形变监测

极艰险区域具有地形起伏极大、地理环境复杂和永久散射体稀少的特点,为此文章设计了一种改进的SBAS-InSAR技术进行地表形变监测。文章先从相干性、振幅离差指数、形变速率三个方面获得候选的永久性散射体点,之后辅以光学影像精选出最终的永久性散射体点,将其作为轨道精炼控制点引入SBAS-InSAR解算过程,最终完成了研究区的地表形变监测。通过对比分析常规的PS-InSAR技术与SBAS-InSAR技术,该技术在极艰险区域具有良好的应用价值。     

空间数据库中查询处理的探讨

查询是数据库管理系统中一项基本的功能。简要介绍了三种不同的查询,重点对空间连接与非空间连接的区别进行了说明,阐述了过滤-精炼策略来处理范围查询,最后描述了一个处理空间连接查询过滤阶段的算法。     

《云南地理环境研究》稿约简则

本刊为国内外公开发行的学术类科技期刊,登载有关自然环境、经济环境、社会环境研究的论文。来稿力求精炼,立意新颖,论点明确,数据可靠,并遵守国家保密等政策法规。以7000字为宜,特殊情况可适当伸缩。     

贴现因子不同的劳动力市场博奕

主要讨论了贴现因子不同下的两阶段劳动力市场动态博奕，给出了各局中人各自的精炼贝叶斯均衡（PBE），并据此对现实中的失业下岗现象进行了分析。     

金枪鱼油的精炼工艺对脂肪酸组成的影响

粗鱼油通过精炼可以除去非甘油三酯杂质成分，研究表明黄鳍金枪鱼鱼油精炼的工艺参数为：800g，L的H3PO4脱胶，添加量为油量的1％（体积分数）；300g／L的Na0H脱酸，添加量为油量的2％（体积分数）；活性土脱色。添加量为油量的10％（质量分数）；85℃下减压蒸馏脱臭15min。经过精炼，鱼油呈淡黄色，澄清透明，有淡鱼腥昧，理化指标达到鱼油SC/T3502—2000标准的精制鱼油一级要求，精制鱼油中PUFA的总含量（w）达37．06％，DHA和EPA含量（w）分别为25．10％和4．45％。     

Characterization of red mud derived from a combined Bayer Process and Calcining method for alumina refining

Red mud is the residue of bauxite processing for alumina. Red mud varies in physical, chemical and mineralogical properties due to differing mineral sources and refining processes adopted. In this project, red mud produced using a combined Bayer Process and Calcining （BPC） method was investigated. Red mud samples of varying ages were collected from the red mud storage facilities of the Zhenzhou Changcheng Aluminium Limited. The objective of this study is to （1） characterize the BPC red mud, and （2） examine the effects of this red mud on treating heavy metal-containing water and soil. Red mud samples were analyzed for pH, EC, water extractable salts and exchangeable basic cations, total element composition （by XRF）, mineral composition （by XRD）, micromorphological characteristics （by SEM） and thermogravimetric analysis （TGA）. The results show that the pH of the red mud decreased with increasing duration of storage time. The pH of the fresh, 5-year-old and 10-year-old red mud was 11.58, 10.56 and 9.61, respectively. Sodium dominated among the soluble cations, but the concentration of soluble Na decreased with increasing duration of storage time as a result of leaching. Cation exchange capacity as estimated from the sum of exchangeable cations also decreased with increasing duration of storage time, probably due to the decreasing pH which causes a reduction in negatively charged sites of the red mud. Calcium was the predominant exchangeable cation in the fresh red mud but the concentrations of exchangeable Ca markedly decreased in the old red mud which was dominated by exchangeable Na.XRF results showed that the red mud consists mainly of oxygen, calcium, iron, silicon, aluminium and titanium. Other important elements include sodium, carbon, magnesium and potassium. It is important to note that the red mud also contains elevated concentrations of radioactive elements, predominantly thorium （Th）, cerium （Ce） and rubidium （Rb）. XRD results showed that the major mineral types in the red mud were calcite, perovskite, illite, hematite and magnetite. There is a trend that the contents of magnetite decreased while the contents of hematite increased with increasing storage time, suggesting the conversion of magnetite to hematite. Observation using a SEM revealed that fresh red mud sample was amorphous while the 10-year-old red mud sample was fairly well crystallized. TGA results showed that the temperature at which the valley of weight loss occurred increased from 681.9℃ for fresh red mud to 722.9℃ for the 5-year-old red mud to 734.7℃ for the 10-year-old red mud. These results suggest that the contents of calcium carbonate increased with increasing storage time. Slow titration of the red mud samples with standardized acid solutions for two years indicated that the fresh red mud had an acid neutralizing capacity （ANC） of about 10 mol/kg while the ANC of old red mud samples was around 9 mol/kg. The ANC values obtained from the determination of BPC red mud here are much higher than those previously reported for red mud derived from the pure Bayer Process at the Queensland Alumina Limitd, Australia, and at the Pinggno Alumina Refinery, China.     

征稿启事

正《地球》杂志全新改版,现面向全社会及国土资源系统专业人士征集相关原创稿件。具体说明如下:1.文字稿件要求系作者本人原创,论点明确、数据可靠、逻辑严密、文字精炼、深入浅出。2.来稿请注明笔名、作者真     

鳐鱼肝油的制备及其脂肪酸组成分析

本研究采用冷冻 解冻的方法提取鳐鱼肝粗脂肪油,并利用响应面法优化了精炼过程中影响较大的脱酸工艺,分析了精炼后鳐鱼肝油的理化性质、脂肪酸组成及含量变化。结果表明：使用5%(质量分数)脱胶剂脱胶,20%(质量分数)氢氧化钠、75 ℃加热20 min进行脱酸,8%(质量分数)活性白土脱色,以及减压蒸馏(60 r/min,40 ℃)60 min脱臭的鳐鱼肝油精炼工艺为最优精炼工艺条件,所得精炼鳐鱼肝油呈色及各项理化性质均符合国家一级鱼油标准。脂肪酸组成与粗鳐鱼肝油、鳕鱼肝油以及鲨鱼肝油无明显差别,均含有C14~C22脂肪酸23种,但在含量上存在一定差别,其中精炼鳐鱼肝油中EPA含量为8.65%,低于粗鳐鱼肝油(10.17%),远高于鲨鱼肝油(2.74%),约等于鳕鱼肝油(8.78%)。精炼鳐鱼肝油中DHA含量则为最高,为15.04%。