青海省阿尼玛卿山地区植物区系研究

阿尼玛卿山地区位于青海省东南部,约占北纬33°25′～ 36°20′,东经98°50′～102°25′.本地区共有种子植物56科、251属、752种.区系特征如下:(1)种类相对较少,特有属相对较多;(2)以北温带为主的温带性质明显;(3)在种一级水平上,以中亚成分和东亚成分,特别是其中各自联系着喜马拉雅的变型成分为主的分布,形成了区内以欧亚大陆温、寒地带典型成分为优势的、明显的温带性质及其高原、高山分布的特点;(4)植物的生活型以多年生草本为主,木本种较少,乔木更少;(5)在中国特有种的分析中,本区系与横断山和甘肃南部区系的联系最为密切;(6)生态环境对本区系特征的塑造表现为高寒生态因子的选择和高山特化的作用强烈,而在一定程度上湿冷生性质和寒旱生性质的高山特化作用更为明显;(7)表现出青藏高原植物区系的衍生性和年轻性;(8)植被以由嵩草属植物为建群种的高寒草甸和由金露梅、山生柳等分别为建群种的高寒灌丛为主;(9)以绿绒蒿等所体现的地区特色明显.综上所述,本区同唐古特地区在区系性质和特点等方面基本一致,所以,本地区不仅是唐古特地区植物区系中的一个具有代表性的区系之一,而且是其核心区系之一.

植物化学防卫与植食性哺乳动物的适应对策

植物化学防卫与植食性哺乳动物的适应是动物—植物系统协同进化研究的重要内容。植物次生化合物可降低动物的食物摄入量及消化率、蛋白质可利用率。某些次生化合物还影响植食性哺乳动物的正常繁殖活动。单宁是动物的重要觅食阻遏剂之一。动物在学习食物选择的过程中, 通过认知过程和感知过程处理食物信息, 选择食物项目。幼体在胚胎期和哺乳期能从母体获得食物信息, 或向有觅食经验的同胞伙伴学习处理食物的经验。动物亦可通过形成络和物, 改变体内环境, 通过微生物降解、氧化还原、基础代谢率等降低生理对策, 以降低植物次生化和物的影响。

催化极谱法测定产妇、新生儿全血和胎盘中的微量钼

在0.225 mol/L H2SO4 – 0.25 %苯羟乙酸- 3 % KC1O3 底液体系中, 钼有一个灵敏的极谱催化波, 用于测定临床样品中的Mo , 其峰电位- 0.30 V (对S.C.E ) 。23 种共存离子的含量低于允许存在量, 不干扰测定。方法的检出限1.4 ×10 - 10 g/ mL , 线性范围0.001～0.500 mg/L , 11 次测定的相对标准偏差为1.89 %～3.42 % , 标准回收率97.2 %～102.8 %。方法简便、快速。测定了西宁市35例分娩孕妇全血、新生儿脐血和胎盘中的钼, 获得了理想的结果。

矮嵩草草甸植物群落的光合特性研究

矮嵩草草甸植物群落的光合、暗呼吸和土壤呼吸的研究表明：光合作用的日变化在６月份接近平坦型，７、８月份呈午间降低型。矮嵩草草甸植物群落的光合作用受较低的光合面积指数及冠层叶片的受光势态的影响，存在着明显的光饱和现象，光补偿点及光饱和点相对于全日照光合有效辐射均较低，接近于单叶的光响应特性。裸露地面的土壤呼吸和植物与土壤体系的暗呼吸不仅与温度有关，而且与土壤水分状况和降雨量也有密切联系。影响草甸群落光合特性的主要因素有：高原地区强烈的太阳辐射，较低的光合面积指数和植物根系与土壤紧密结合所形成的草结皮层结构。

高寒小嵩草草原化草甸植物群落结构特征及其生物量

小嵩草（Ｋｏｂｒｅｓｉａｐｙｇｍａｅａ）草原化草甸的主要植物有３５种，隶属１１科，３０属。小嵩草为优势种，次优势种有异针茅（Ｓｔｉｐａａｌｌｉｅｎａ）、美丽风毛菊（Ｓａｕｓｓｕｒｅａｓｕｐｅｒｂａ）、紫羊茅（Ｆｅｓｆｕｃａｒｕｂｒａ）等；生活型以地面芽植物为主（６５．７１％），其次为地下芽植物（３４．２９％）；地上、地下部分生物量垂直分布呈典型的金字塔模式。地上、地下生物量主要分布在０－１０ｃｍ冠层和土层中，分别占地上、地下总生物量的９１．７９％和９０．４３％。每个植物类群生物量季节变化可由Ｌｏｇｏｓｔｉｃ模型表示：ＷＩ＝ｋｉ／［１＋ｅｘｐ（ＡＩ－Ｂｉｔ）］枯枝落叶生物量变化呈“Ｖ”型曲线。在生长季各类群生物量绝对增长速率具明显的差异，平均每天每平方米可生产干物质２．７９ｇ．年地上净生产量为３６８．４ｇ／ｍ￣２。所固定太阳能值为６６５５．１６ｋＪ／ｍ￣２．其中莎草类占３５．１０％，禾草类占２３．３３％，杂类草占３４．１５％，枯枝落叶占７．４２％。光能利用率为０．１０９７％。

Analysis of saturated free fatty acids from pollen by HPLC with fluorescence detection

A sensitive method for the determination of free fatty acids using 2-(2-(anthracen-10-yl)-1H-naphtho[2,3-dimidazol-1-yl) ethyl-p-toluenesuIfonate (ANITS) as tagging reagent with fluorescence detection has been developed. ANITS could easily and quickly label fatty acids in the presence of the K2CO3 catalyst at 90 degrees C for 40 min in N,N-dimethylformamide solvent. From the extracts of rape bee pollen samples, 20 free fatty acids were sensitively determined. Fatty acid derivatives were separated on a reversed-phase Eclipse XDB-C8 column by HPLC in conjunction with gradient elution. The corresponding derivatives were identified by post-column APCI/MS in positive-ion detection mode. ANITS-fatty acid derivatives gave an intense molecular ion peak at mlz [M+H](+); with MS/MS analysis, the collision-induced dissociation spectra of m/z [M+H](+) produced the specific fragment ions at mlz [M-345](+) and mlz 345.0 (here, m/z 345 is the core structural moiety of the ANITS molecule). The fluorescence excitation and emission wavelengths of the derivatives were lambda(ex) = 250 nm and lambda(em) = 512 nm, respectively. Linear correlation coefficients for all fatty acid derivatives are > 0.9999. Detection limits, at a signal-to-noise ratio of 3 : 1, are 24.76-98.79 fmol for the labeled fatty acids.

Reproductive ecology of the Qinghai-Tibet Plateau endemic Gentiana straminea (Gentianaceae), a hermaphrodite perennial characterized by herkogamy and dichogamy

The combined occurrence of both herkogamy and dichogamy in a hermaphrodite species has been considered to strongly favour outcrossing. In this study, we investigated in detail the reproductive ecology of Gentiana straminea Maxim. (Gentianaceae), a hermaphrodite perennial endemic to the Qinghai-Tibet Plateau. In a series of observations and experiments over four consecutive years, we examined whether the combination of dichogamy and herkogamy in individual flowers completely prevents geitonogamous pollen transfer in this species. The mode of floral development clearly indicates that autonomous self-pollination is completely avoided through herkogamy and dichogamy in individual flowers. This implication was confirmed by the breeding experiments, since no seed was produced when flowers were isolated. However, this gentian proved to be highly self-compatible when geitonogamous selfing was artificially induced. Many flowers opened simultaneously on individual plants, the ratio of male to female phase flowers was close to 2:1 in each inflorescence, at the full anthesis phase, and they were randomly distributed amongst the upper, middle and lower parts of each stem's inflorescence. On average, Bombus sushikini Skorikov, the most frequent visitor and only legitimate pollinator of G. straminea, visited nearly two flowers per inflorescence, and four flowers per plant. Among the pollinators' foraging bouts, the proportions of geitonogamous visits to inflorescences or flowers within an individual plant were 29% and 37%, respectively. Therefore, despite the strict dichogamous and herkogamous characteristics of the individual flowers, geitonogamous selfing might still prevail in G. straininea because of the size of its floral displays and the continuous visiting behavior of B. sushkini. (C) 2005 Elsevier SAS. All rights reserved.

云南金顶超大型铅锌矿区镉的地球化学特征及其环境效应

云南金顶铅锌矿是镉元素富集区，采矿活动导致镉元素释放出来进入地表环境造成镉污染。矿区不同岩石中镉分布差异比较大，围岩中镉含量范围在50×10^-6-650×10^-6之间，平均310×10^-6，原生矿中镉含量范围14×10^-6-2800×10^-6，平均767×10^-6，氧化矿中镉含量范围110×10^-6-8200×10^-6，平均1661×10^-6，其平均值最高。氧化矿是镉元素的主要载体和释放源。淋滤实验表明矿石易氧化而释放出镉等有害元素，滤出元素可以迅速发生沉淀或被沉淀物包裹，其能力表现为Zn〉Pb〉Cd。研究结果表明，矿区下游江河段水体中隔的平均值为15.7μg/L，悬浮物中镉平均值为49.3 mg/kg，沉积物中镉平均值为203.7 mg/kg。矿区富镉岩石和矿物的自然风化是造成江水体和沉积物中镉污染的直接原因，对流域水生态环境造成潜在危害.

富镉锌矿成矿流体地球化学研究：以贵州都匀牛角塘富镉锌矿为例

通过对贵州都匀牛角塘富镉锌矿包裹体的研究，发现有一定数量的有机包裹体。该矿床与密西西比河谷型（ＭＶＴ）矿床相似，均属于Ｎａ＾＋－Ｃａ＾２＋－Ｋ＾＋－Ｍｇ＾２＋－Ｃｌ＾－体系，同时，两者在成矿流体温度、盐度和密度方面也有一定差别。该矿床成矿流体组分与油田卤水相似，仅Ｃａ＾２＋和Ｍｇ＾２＋含量偏高，这可能与晚阶段的碳酸盐有关。笔者认为，成矿流体可能与麻江古油藏的油田卤水有关，正是由于油田卤水携带了Ｃｄ

会泽超大型铅锌矿床成矿时代研究

云南会泽超大型铅锌矿床由麒麟厂和矿山厂两个独立的铅锌矿床组成。利用两组同源矿物组合Rb-Sr等时线方法测定了麒麟厂6号矿体的成矿时代，测定结果分别为(225．1±2．9)Ma和(225．9±3．1)Ma，根据已知的分布于该矿床北部和西南部分布的峨眉山玄武岩成岩时代为250Ma左右，有多个火山喷发旋回，显示多期次的喷发活动，认为川-滇-黔成矿区内铅锌成矿作用与蛾眉山玄武岩岩浆活动存在成因联系。

三叠纪右江盆地构造-沉积演化

采用沉降分析的"反剥法",建立了三叠纪右江盆地的构造沉降曲线.该曲线具有4个较清楚的代表沉降加速的坡折,这说明在三叠纪华南板块南缘上曾发生过4次明显的构造负荷的叠加过程,这些坡折之间的构造沉降曲线较平缓,说明主要是热沉降造成.通过对盆地沉降史的定量分析和沉积特征研究,认为华南板块南缘在晚二叠世末期开始由离散边缘转为汇聚边缘,右江盆地也随之从裂谷盆地转为前陆盆地.前陆盆地的构造-沉积演化分为三个阶段:(1)早期阶段(晚二叠世长兴末期-中三叠世安尼初期,即251～239 Ma)为初始沉降和非补偿充填阶段;中期阶段(中三叠世安尼早期-晚三叠世卡尼早期,即239～225.5 Ma)主要以浊流沉积充填为特征,并伴有盆缘隆起的形成,且从早到晚盆地沉降中心自南向北推进,而盆缘隆起则由北往南位移;晚期阶段(晚三叠世卡尼晚期-瑞替期,即225.5～210 Ma)盆地由深变浅,并最终被陆相磨拉石沉积覆盖.

Study on thermodynamic properties of polypyromellitimide molding powder

Polypyromellitimide molding powder has been prepared. In the 78-370 K range, the dependence of the specific heat capacity (c(p)) on the temperature (T) is given by the polynomial: c(p)=0.8163+0.4592X+0.02468X(2)+0.1192X(3)+0.05659X(4) (J K-1 g(-1)) where X=(T-225.5)/144.5. Thermal decomposition in air starts at 716 K, and is complete at 1034 K. The standard combustion enthalpy is Delta(c)H=-26.442 kJ g(-1). (C) 2000 Elsevier Science B.V. All rights reserved.