吉林古陆成岩背景及边缘金构造-成矿系统

吉林克拉通广泛出露的粗粒黑云长英片麻岩是以英云闪长岩为主的TTG深成侵入体 ,原始岩浆来自幔源物质的部分熔融作用 ,同源岩浆不同演化阶段形成多种岩石类型 (Gnbd、GnblⅠ、GnblⅡ ) ,后经变质构成统一古陆。古陆隆升 ,边缘滑脱和裂解并接受元古宙地层沉积。层间滑动和韧性剪切达上地幔 ,使部分太古宙黑云长英片麻岩被卷进地层 ,幔源物质加入成矿。这使人们打破原层控金矿的认识 ,将整个古陆边缘金矿床统归于构造 -成矿系统 ,依构造动力学特征的不同划分为三类 :离散型陆缘构造 -成矿系统 ,以中型金矿和Fe、Al、P、B为主 ;会聚型陆缘构造 -成矿系统 ,以金矿化和Ni、Cr为主 ;走滑型陆缘构造 -成矿系统 ,以大型金矿和Cu、Pb、Zn为主 ,该系统有助于全面认识构造特征和矿床分布规律 ,为区域成矿预测和勘查提供科学依据。     

元素地球化学不活动组分判别——以库布苏金矿中矿带研究为例

本文从探讨元素不活动组分的原理出发 ,利用Gresens(196 7)质量平衡方程及Brimhall等 (1987)提出的元素不活动组分ΔX -fv 图解 ,对复杂热液成矿体系的元素不活动组分进行了深入探讨。指出了复杂体系内部各个子体系间元素不活动组分及体积变化上的差异。并结合实际 ,对库布苏金矿中矿带元素不活动组分进行了研究。同时对一些矿床地质现象的形成及成矿物质来源从元素地球化学角度进行了解释和判断。     

西部开发环境保护工作的几点思考

本文就西部大开发中的环境保护工作提出十个方面的想法：认为应当明确环境保护是西部大开发的基本目标之一；弄清“家底，搞好区划，心快进入西部大开发的前沿阵地；编制西部大开发的环境保护规划；建立综合决策机制；重视资源型产业结构的污染问题；完善法规制度，强化环境管理；加强城镇环境建设与管理；研究包括农村环境保护、水环境保护、生态补偿机制环境投入等环境保护政策；重视环境保护宣传教育；加强基层组织建设和能力建设     

氢化物发生-原子荧光法测定废气中的锡

运用氢化物发生-原子荧光法测定废气中锡的含量,选择了更高效、安全的硝酸-双氧水电热板消解体系对样品进行前处理,调节最佳仪器参数进行测定。研究表明：在0-10μg/L线性范围内,曲线相关系数可以达到0.999 6,方法检出限为0.003μg,加标回收率在92.7%-95.9%之间,RSD≤2.1。氢化物-原子荧光法测定废气中的锡,方法灵敏度高,干扰少,线性范围宽,操作简单、快捷。     

高职院校思想政治理论课实践教学探究

2011年教育部一号文件明确规定要把思想政治理论课（以下简称＂思政课＂）实践教学纳入正式教学环节。只有对思政课实践教学进行科学定义,厘清思政课实践教学与其他教学的区别和联系,找准当前存在的问题和不足,提炼出思政课实践教学的特点,进而建立科学规范的教学内容、教学方法、教学形式和考评机制,才能使其落到实处。     

刺茶美登木的化学成分研究

从刺茶美登木地上部分的95%乙醇提取物中分离并鉴定了27个化合物:prinsepiol(1),( )-松脂醇(2),(-)-松脂醇(3),(-)-丁香树脂醇(4),( )-cycloolivil(5),(-)-橄榄树脂素(6),1-羟基-松脂醇(7),ilelatifolD(8),东莨菪素(9),β-香树素乙酸酯(10),α-香树素乙酸酯(11),fupenzicacid(12),( )-儿茶素(13),secoisolariciresinol(14),软脂酸-1-甘油单酯(15),植物醇(16),咖啡酸(17),3,4-二甲氧基肉桂酸(18),(-)-massoniresinol(19),tanegool(20),β-谷甾醇(21),羽扇豆醇(22),白桦酯醇(23),β-胡萝卜甙(24),齐墩果酸(25),熊果酸(26)和(-)-橄榄树脂素乙酸酯(27).图1表1参34     

两种常见沉水植物与藻的相互作用

选用太湖常见的沉水植物苦草(VallisneriaspiralisL.)和轮叶黑藻(HydrillaverticillataRoyle),构建微型生态系统。通过对沉水植物作用下水体中藻类叶绿素a及试验前后沉水植物生物量变化的观测,分析沉水植物与藻类的相互作用。结果表明,(1)相同条件下,苦草和轮叶黑藻对藻类变化的影响没有显著差异。(2)在苦草生物量相同的情况下,藻类叶绿素a初始值越大,其变化速率也越快。叶绿素a初始值差别越大,其变化速率差异越显著。轮叶黑藻也有相似的结果。(3)从试验前后苦草和轮叶黑藻生物量的变化可知,苦草受藻类影响较大,轮叶黑藻几乎没有受到藻的影响。     

河北省钢铁工业主要大气污染物减排潜力分析

通过对河北省钢铁工业存在问题的分析,得出我省钢铁行业主要大气污染物为二氧化硫和粉尘.结合我省钢铁企业的实际情况,从工程技术、政策管理等方面提出相应治理措施,并对"十一五"期间我省钢铁行业二氧化硫和粉尘减排效益进行预测.预测结果显示:采用所建议的减排措施后,我省钢铁工业二氧化硫减排量对全省"十一五"减排计划的贡献率为81.4%;粉尘可减排60%.     

Estimating Forest Ecosystem Evapotranspiration at Multiple Temporal Scales With a Dimension Analysis Approach1

Abstract:  It is critical that evapotranspiration (ET) be quantified accurately so that scientists can evaluate the effects of land management and global change on water availability, streamflow, nutrient and sediment loading, and ecosystem productivity in watersheds. The objective of this study was to derive a new semi‐empirical ET modeled using a dimension analysis method that could be used to estimate forest ET effectively at multiple temporal scales. The model developed describes ET as a function of water availability for evaporation and transpiration, potential ET demand, air humidity, and land surface characteristics. The model was tested with long‐term hydrometeorological data from five research sites with distinct forest hydrology in the United States and China. Averaged simulation error for daily ET was within 0.5 mm/day. The annual ET at each of the five study sites were within 7% of measured values. Results suggest that the model can accurately capture the temporal dynamics of ET in forest ecosystems at daily, monthly, and annual scales. The model is climate‐driven and is sensitive to topography and vegetation characteristics and thus has potential to be used to examine the compounding hydrologic responses to land cover and climate changes at multiple temporal scales.     

Watershed Evapotranspiration Increased due to Changes in Vegetation Composition and Structure Under a Subtropical Climate1

Abstract: Natural forests in southern China have been severely logged due to high human demand for timber, food, and fuels during the past century, but are recovering in the past decade. The objective of this study was to investigate how vegetation cover changes in composition and structure affected the water budgets of a 9.6‐km² Dakeng watershed located in a humid subtropical mountainous region in southern China. We analyzed 27 years (i.e., 1967‐1993) of streamflow and climate data and associated vegetation cover change in the watershed. Land use/land cover census and Normalized Difference of Vegetation Index (NDVI) data derived from remote sensing were used to construct historic land cover change patterns. We found that over the period of record, annual streamflow (Q) and runoff/precipitation ratio did not change significantly, nor did the climatic variables, including air temperature, Hamon’s potential evapotranspiration (ET), pan evaporation, sunshine hours, and radiation. However, annual ET estimated as the differences between P and Q showed a statistically significant increasing trend. Overall, the NDVI of the watershed had a significant increasing trend in the peak spring growing season. This study concluded that watershed ecosystem ET increased as the vegetation cover shifted from low stock forests to shrub and grasslands that had higher ET rates. A conceptual model was developed for the study watershed to describe the vegetation cover‐streamflow relationships during a 50‐year time frame. This paper highlighted the importance of eco‐physiologically based studies in understanding transitory, nonstationary effects of deforestation or forestation on watershed water balances.