废弃矿山变身休闲旅游地

废弃矿山,过去人们往往把它们视为无用之物。然而,经过重新开发建设,甚至只需要简单的投入改造,无用的矿山可以旧貌换新颜,成为各种有用的场所,供人们休闲、娱乐甚至观赏。桐庐县的瑶琳镇沈村废弃矿山就正在经历这么一个“换颜”过程。     

基于Markov chain理论的科技成果转化的市场预测

科技成果成功转化的主要标志是其产品的市场畅销度。产品的畅销度由于受各种内外部不确定因素影响，具有随机不确定性。基于这种随机不确定性，运用Markov chain对其产品进行市场预测，并通过实证分析说明其有效性，为科技成果的转化提供具体可行的定量依据。     

8.4 ka 以来纳木错湖芯介形类组合的环境变化意义

对青藏高原中南部纳木错长332cm的NMLC1孔湖芯研究发现,沉积物的介形类动物群计有6属15种。介形类属种生态特征和组合变化分析表明这些介形类对环境条件具有敏感性,其组合能够很好地反映过去环境变化的特征。结果表明,8．4ka以来具有三个不同的环境变化时期：早期在8400～6800aBP,湖泊由浅向深发展,环境具有相对冷湿的特征：中期在6800～2500aBP,湖泊深度逐渐加大,环境经历了暖湿-冷湿-冷干的变化．其中由冷湿向冷干的转化奠定了纳木错现今环境条件的基础：晚期在2500--9aBP,湖泊深度继续增加,这个时期的较早阶段,继续保持了前一时期的冷干特点,但湖水盐度可能开始增加．较晚阶段的冷干化加剧,陆面流水的活跃性大大降低。研究发现,纳木错NMLC1钻孔介形类黑色壳体的高峰值与介形类的最大生产量相一致,并且与沉积水动力条件增强相适应．指示了这些黑壳的产生与介形类的大量繁殖处于同一阶段．并且主要为异地搬运为主。钻孔中出现大量Candona幼虫壳体．其原因可能与沉积环境的水动力条件迅速改变有关。     

8.4 ka以来纳木错湖芯介形类组合的环境变化意义

A 332-cm long lacustrine core was drilled in the Nam Co in the central-southern part of the Tibetan Plateau. From the core, 15 species of ostracods (Crustacea: Ostracoda), which belong to 6 genera have been identified. According to the variations of the ostracod assem-blages and the ostracods ecological features, which are sensitive to the changing environ-ment, three main stages can be distinguished as follows: Stage I was from 8400 to 6800 a BP, during which the climate was cold-humid, and the lake depth changed from shallow to deep. Stage II was from 6400 to 2500 a BP, during which the climate changed from warm-humid to cold-humid, and then to cold-dry. The lake depth gradually became deep. The shifting of cli-mate, from wet-cold to dry-cold during this period, had constructed the basis of present en-vironment in the Nam Co. Stage III was from 2500 a BP to the present, which showed a trait of lake depth increasing. At the earlier period of this stage, the climate kept as cold-dry as that in the former stage, but the salinity of the lake increased. At the later period of this stage, the degree of cold-dry was enhanced, and the activities of land surface runoff tended to be weakened. Our research also found that the peak values of ostracods with black shell was coherent with the maximum production of the ostracods, and agreed with the increasing sedimentary water dynamics. This indicated that the ostracods with black shell was simulta-neous with the high prolificacy of ostracod, and transported from other places. The abun-dance of Candona juvenile shells reflected the high mortality of that kind of ostracods under an unfavorable condition. This was probably a result of the rapid change of water dynamics of sedimentary environment.     

西藏玛旁雍错和拉昂错水深、水质特征及现代沉积速率

基于2009年和2010年分别在玛旁雍错和拉昂错开展的2次野外湖泊调查,本文简要报道这2个藏南内流水系湖泊的水深分布、湖水理化特征及湖泊现代沉积速率.测深结果显示玛旁雍错湖盆形状规则,深水区坡度平缓,最大水深为72.6 m;拉昂错北部为较浅的河流冲积扇,通过狭长的水道与开阔的南部湖区相连,南部湖区中心平坦,实测最深处49.03 m;根据水深数据计算的玛旁雍错和拉昂错水量分别为1.462×10¹⁰m³和5.711×10⁹m³.玛旁雍错湖水剖面水质在垂直方向上呈现明显的分层结构,温跃层介于25~35 m之间,温度梯度为0.17℃/m,水体pH、电导率和溶解氧在温跃层具有同步变化特征;拉昂错湖水温跃层与玛旁雍错相比不明显,5~15 m间温度梯度为0.16℃/m,湖水pH与溶解氧呈反相变化,这可能与水生植物呼吸作用有关.2个湖泊湖水的主要离子组成特征除Ca²⁺外基本相同,拉昂错主要离子浓度约为玛旁雍错的3倍,而Ca²⁺则约为玛旁雍错的1/2;利用²¹⁰Pb和¹³⁷Cs方法对玛旁雍错和拉昂错的短岩芯进行了测试,结果表明2个湖泊近代沉积速率分别约为0.31 mm/a和0.65 mm/a.     

西藏当惹雍错和扎日南木错现代湖泊基本特征

湖泊现代特征的调查和对比研究是湖泊学和古湖泊学研究工作的基础,青藏高原大部分湖泊目前仍缺少详细的基本特征考察资料.基于2009年9月实地考察,本文报道藏北高原腹地的两个内陆封闭大湖——扎日南木错和当惹雍错的水深分布和现代湖水基本特征.测深结果显示扎日南木错大部分湖区水下地形较为平坦,最大水深为71.55m;当惹雍错实测最大水深为214.48m,是青藏高原上已知最深的湖泊,也是我国已知的第二深水湖.湖水理化性质显示在垂直方向上两湖都呈现明显的分层结构,温跃层的温度梯度分别为1.1℃/m和0.57℃/m,当惹雍错底层水温最低仅为1.6℃;两湖表水层的电导率分别高达18500μS/cm和12900μS/cm;两湖表水层pH都超过10,而底层水的pH都降低到5左右,上下层湖水显示了不同的酸碱性质.湖水电导率和溶解氧在温跃层都具有同步跃变特征,反映了温度对湖水性质的影响.     

藏南普莫雍错流域水体离子组成与空间分布及其环境意义(英文)

The chemistry of major cations (Mg²⁺, Ca²⁺, Na⁺, and K⁺) and anions (HCO₃ ⁻, SO₄ ²⁻, and Cl⁻) in the water of Lake Pumayum Co and its inflow river was studied, revealing the obvious ionic difference among various inflow rivers and the lake. The chemical type of the lake water was Mg²⁺-Ca²⁺-HCO₃ ⁻-SO₄ ²⁺, but the major ions of the main inflow rivers were Ca²⁺-Mg²⁺-HCO₃ ⁻. In the lake inlet of Jiaqu River, the main inflow river, there was significant variance of water chemistry within the depth less than 2 m. However, it was almost homogeneous at other area of the lake. Therefore, with the evidence of distribution of water chemistry and oxygen isotope of lake water, a conclusion can be outlined that Jiaqu River had a distinct effect on the hydrochemistry of the water on the submerged delta, whereas this is not the case for other rivers. The Gibbs plot revealed that the dominant mechanism responsible for controlling chemical compositions of the lake water was rocks weathering in the drainage area. Ion ratios and ternary plots further explored the main processes controlling the water chemistry of the catchment, i.e., carbonate weathering, pyrite weathering, and silicate weathering. The different hydrochemistry characteristics between river water and lake water may result from the CaCO₃ precipitation. The findings will benefit the explanation of the environmental significance of carbonate in paleolimnological studies in the lake.     

西藏普莫雍错介形类反映的中晚全新世以来湖面波动与环境变化

西藏普莫雍错位于喜马拉雅山脉印度季风雨影区,主要由冰川融水补给。根据湖泊的等深线分布和主要补给河流的入湖路径,对采自普莫雍错1～62 m水深范围的表层沉积物介形类和相关水环境参数进行了分析。结果表明,普莫雍错表层沉积物中含有7属9种介形类,其分布主要受湖泊水深、pH值、温度和光合有效辐射等环境因子的影响。介形类与水环境因子的降维对应分析、典型对应分析结果显示,水深是影响表层沉积物介形类分布的最重要的环境因子,用偏最小二乘法加权平均回归与校正模型建立的介形类-水深转换函数具有较高的精度与可靠性。利用此转换函数模型和一个72 cm长重力湖芯的介形类属种分析结果,定量重建了湖泊水深波动历史。湖面波动与湖芯的总有机碳、总无机碳、粒度等代用指标比较结果表明,普莫雍错6.0 kaBP以来的环境变化具有6.0～4.3 kaBP的温凉浅湖面期、4.3～2.0 kaBP温暖的湖面波动期及2.0 kaBP以来温暖的湖面扩张期。     

增长曲线模型均值矩阵的一种新的相对效率

对于一般增长曲线模型,当设计阵和协方差阵满足一定的条件时,均值矩阵(XBZ)的最小二乘估计(LSE)与最佳线性无偏估计(BLUE)相等,可用LSE代替BLUE。当这些条件不满足时,用LSE代替BLUE就要蒙受一些损失,有时这种损失很大,因而研究这种损失的大小显得相当重要,通常用它们协方差阵的差异来度量,从不同的准则出发,可以定义不同的相对效率,利用广义行列式定义了一种新的相对效率,并给出了它们的下界。     

西藏纳木错表层沉积物中正构烷烃的来源与空间分布特征

通过测定纳木错现代植物和表层沉积物样品中的正构烷烃,结合主成分分析方法,明确了表层沉积物中烷烃的主要来源,并初步分析了它们在湖泊中的空间分布特征.研究结果显示,沉水植物所含烷烃以n-C21-C25为主,具有n-C23的峰值;陆生植物主要含n-C27-C33烷烃,具有n-C29或n-C31的峰值;但垫状点地梅(Androsace tapete)和香柏(Sabina pingii)的主峰碳却是n-C33烷烃,这在以往研究中鲜有报道.在纳木错表层沉积物中,正构烷烃具有典型的n-C31和n-C23双峰分布形式,来源于低等菌藻类、沉水植物以及陆生植物,其中碳数小于C20的短链烷烃主要来源于低等菌藻类,其空间分布均一,由低等菌藻类的浮游生活型所决定;长链烷烃主要来源于高等植物,含量从滨岸到湖中心逐渐减少,这与其在运移和沉积过程中受微生物的持续降解作用有关,此外,来源于陆生植物的n-C27-C33烷烃因河流汇水面积和流量不同而存在空间差异,这值得重视和进一步研究.