RE_(0.06)La_(0.94)Nb_2O_6Cl的制备与光谱性质(RE=Pr、Eu、Tb、Dy)

本文采用真空下气体输运技术制备RE_(0.06)La_(0.94)Nb_2O_6Cl(RE=Pr、Eu、Tb、Dy)小单晶和多晶粉末样品。测定其晶体结构与LaNb_2O_6Cl的晶体结构相同,为正交晶系;Eu_(0.06)La_(0.94)Nb_2O_6Cl小单晶的晶胞参数为:a=9.751,b=7.321,c=8.364。观察RE_(0.06)La_(0.94)Nb_2O_6Cl(RE=Pr、Eu、Tb、Dy)的特征激发光谱和发射光谱及其能量传递现象。

渤海沿岸第四纪地下卤水的水化学特征及其形成研究

中国北方的渤海沿岸地区是第四纪滨海相地下卤水最为典型的分布区。本文在收集前人有关该地区第四纪地下卤水的勘探和分析资料的基础上，通过与海水蒸发浓缩过程的对比研究，并运用多种数学统计分析方法、水文地球化学分析及化学热力学的地球化学模拟方法，全面分析了整个渤海沿岸地区第四纪地下卤水的水化学特征及其形成演化机制。研究结果表明：1.渤海沿岸的第四纪地下卤水具有与海水相近的元素化学组成，不同矿化度的卤水中各离子组分的含量变化关系与海水的蒸发浓缩过程相类似，地下卤水的形成与海水的蒸发浓缩过程有着密切的联系。 2.地下卤水中宏量离子组分的相对含量关系与单纯的蒸发浓缩海水之间存在着明显的差异，卤水中K~+、Na~+ 和SO_4~(2-)离子的含量普遍偏低，Mg~(2+)离子的含量总体偏高，反映出地下卤水水化学特征的形成并不仅是简单的海水蒸发浓缩的结果。3.研究结果还表明，在卤水的形成、演化过程中，石膏和碳酸盐的相转过程是影响卤水中Ca~(2+)、 HCO_3~-和SO_4~(2-)离子含量变化的主要地球化学过程，其中SO_4~(2-)离子的含量偏低还与地下还原环境中发生的脱硫酸反应过程有关。4.卤水中 K~+、 Na~+离子的含量偏低和Ma~(2+)离子含量的明显偏高是由卤水与围岩之间发生的阳离子交换吸附过程形成的；受钙的碳酸盐和硫酸盐转移过程及淡水的混合作用的影响， Ca~(2+)离子的含量变化在离子交换反应过程中表现得并不显著。5.对莱州湾南岸昌邑廒里地区地下卤水的地球化学模拟研究进一步表明，在渤海沿岸第四纪地下卤水的形成演化过程中，石膏和钙的碳酸盐的沉淀析出及阳高子交替吸附反应过程是影响卤水水化学特征形成的主要地球化学过程，很好地验证了前述水文行球化学推断。由于分析数据的欠缺，本文的研究对卤水中微量元素和同位素组分的地球化学过程未做讨论.

Metabolism of polychaete Neanthes japonica Izuka: relations to temperature, salinity and body weight

Polychaete Neanthes japonica is a species geographically specific in China and Japan with important scientific implication and commercial value. In this study, the relations of body weight, salinity and temperature to oxygen consumption and ammonia excretion of N. japonica were determined. Three different groups in body weight (large: 2.34 +/- 0.36 g, middle: 1.50 +/- 0.21 g and small: 0.62 +/- 0.12 g) were set for all experiments. Results show that the body weight is negatively related to the rates of oxygen consumption and ammonia excretion; and the relationship is significant. The oxygen consumption and ammonia excretion at 24A degrees C decreased at salinity from 5 to 30 and increased above 30, indicating that both lower and higher salinity are adverse and certain degree of salinity stress is necessary for enhancing the energy demand. At salinity 30, rising temperature from 18A degrees C to 30A degrees C, the oxygen consumption increased before 27A degrees C and then decreased. However, the relation of ammonia excretion and temperature seems more complex. Two-way ANOVA shows that salinity, temperature and body weight all have a significant effect on the oxygen consumption and ammonia excretion of the worm. Moreover, interaction between salinity/temperature and body weight is also significant. O:N (oxygen/nitrogen) ratio varies greatly in this case from 5.97 to 463.22, indicating that N. japonica can regulate the type of metabolic substrate against environment changes.

Inbreeding depression for various traits in two cultured populations of the American bay scallop, Argopecten irradians irradians Lamarck (1819) introduced into China

This paper examines the effect of inbreeding level of population on the magnitude of inbreeding depression expressed by comparing them between two cultured populations (A and B) in the hermaphroditic animal of the bay scallop Argopecten irradians irradians. Population A is expected to have less genetic variations and higher inbreeding level due to longer cultured history (20 generations) and less "ancestral" individuals (26 individuals) than population B due to shorter cultured history (4 generations) and more "ancestral" individuals (406 individuals). Two groups within each population were produced, one using self-fertilization and one using mass-mating within the same population. Selfed offspring (AS and BS) from two populations both had lower fitness components than their mass-mated counterparts (AM and BM) and exhibited inbreeding depression for all examined traits, e.g. lower hatching, less viability and slower growth, indicating that inbreeding depression is a common feature in this animal. Fitness components in all traits of offspring from population A significantly differed those from population B and the magnitude of inbreeding depression for all traits in population A with higher inbreeding level was significantly smaller than that in population B with lower inbreeding level, indicating that both fitness components and magnitude of inbreeding depression were significantly affected by inbreeding level of populations and genetic load harbored in population A may be partially purged through inbreeding. Moreover, the magnitude of inbreeding depression in the two populations both varied among traits and life history stages. The present results support the partial-dominance hypothesis of inbreeding depression. (C) 2008 Elsevier B.V. All rights reserved.

荧光衍生试剂1-[2-（对甲苯磺酸醋）乙基]2-苯基咪唑[4,5-f]9,10-菲的合成及其在长链脂肪酸分析中的应用

合成了新的荧光衍生试剂1-[2-（对甲苯磺酸酯）乙基]-2-苯基咪唑[4,5-f]9,10-菲（TsEPIP），并将其作为柱前衍生化试剂，在Eclipse XDB-C：色谱柱上采用梯度洗脱实现了11种长链（C_(20)～C_(30)）游离脂肪酸（FFA）衍生物的基线分离。利用柱后在线的串联质谱并以大气压化学电离源（APCI）的正离子模式实现了各组分的质谱定性。对土壤及3种苔醉（东亚毛灰鲜、锦丝鲜、羽平鲜）中FFA组分的定量结果表明，苔鲜植物从土壤中富集了大量的长链游离脂肪酸。荧光检测的激发波长和发射波长分别为260 nm和380 nm。线性回归系数大于0.9996，检测限为26.19～76.67 fmol。所建立的方法具有良好的重现性，对实际样品的测定结果令人满意。

青海柴达木盆地都兰地区农田杂草的综合防治

通过轮作并结合化学药剂防治的方法对青海柴达木盆地农田杂草的防治进行了有益的探索，即利用春小麦与春油菜2种作物轮作，在苗期分别采用不同的化学药剂混剂对单子叶和双子叶杂草进行综合防治，并且筛选出了用于春小麦田和春油菜田苗期施用的一次性复混化学除草剂应用于大面积生产，从而达到综合控制该地区农田杂草的目的。

唐古特瑞香提取物对菜粉蝶幼虫的毒杀作用

生测表明, 唐古特瑞香Daphne tangutica 的甲醇抽提物具有明显的拒食和胃毒活性, 活性跟踪得到流分9 。流分9 导致菜粉蝶Pieris rapae 幼虫体小, 中肠组织细胞受到破坏, 脂肪体呈消融状；对试虫生理指标的影响主要表现在降低血淋巴蛋白质含量和抑制中肠酯酶活力。

石笋的荧光特征及其高分辨率气候环境记录

在分析石笋荧光特征的基础上,综述了石笋荧光应用于高分辨率气候环境记录的研究进展。石笋荧光强度反映了石笋中的有机酸含量,荧光波长特征受石笋中有机酸类型的控制,石笋中的有机酸由地表有机质经土壤水、洞穴滴水运移随碳酸盐而淀积,荧光强度与波长特征都是对地表气候环境信息的响应。通过提高荧光谱扫描精度,可得到高分辨率(1～10 a) 的气候环境变迁记录。分析了目前研究中存在的问题,并对发展趋势和进一步研究方向提出看法。

贵州老万场金矿成矿物质来源的研究

硅酸盐成分研究表明老万场红土化过程经历了粘土化、铝土矿化、铁化三种化学风化作用;风化中化学蚀变较强,K2O、Na2O、CaO 相对于Al2O3 的淋失量很高。在红土剖面上成矿元素的含量变化很大。相关性分析表明,红土化过程中,Au、As 的富集与脱硅富铝化程度关系不大,而与铁的富集有明显的关系;Au、As 的富集与相对还原的环境有关,而Sb 则在相对氧化的环境中易于聚集。可能反映了红土剖面中潜水面下部附近相对还原的环境Au、As 易于富集。大厂层样品和老万场红土剖面样品在成矿元素(Au、As、Sb) 含量、稀土元素含量、轻重稀土比值、配分曲线上以及微量元素特征包括大离子亲石元素、不相容元素上的较大差异,显示了红土层的发育与大厂层岩石有较大的差别,暗示它们物质来源上的一定差异性。

恩施富硒碳质岩风化体系中硒的结合态与形态分析

地质环境中硒具有多种形态,不同形态的硒具有显著差异的地球化学特性差异,影响着地质环境中硒的迁移、循环、生物可利用性和毒性.

分散元素独立矿床刍议

1分散元素成矿研究概况。分散元素通常是指镉、镓、锗、铟、硒、碲、铊和铼等8种元素。由于它们在地壳中的平均含量低(一般为10^-9～10^-6级)，不易形成独立矿物，难以发生有意义的富集。大百科全书云：“分散元素不形成独立矿床，它们以伴生元素方式存于其他元素的矿床内”。因此，长期以来，分散元素多被作为其他矿床的伴生组分，并侧重于含量和赋存状态两方面研究。

八方山大型多金属矿床热水沉积岩相特征与矿化剂组分关系

陕西八方山大型(金)多金属矿床赋存在于中泥盆统吉维特晚期的热水沉积岩相中。富SiO2酸酐型热水同生—交代沉积作用形成热水同生沉积微相(层状硅质岩)、热水同生交代微相(微晶石英岩及硅化灰岩)；富Fe^2+ - Mg^2+碳酸盐型热水同生沉积作用形成层状含铜硅质铁白云岩；在同生断裂附近，因热水液压致裂-隐爆作用形达含铜黄铁矿硅质铁白云石角砾岩；富Na^+铝硅酸盐型／富Fe^2+、Mg^2+碳酸盐型热流体在同生断裂中形成热水充填微相(穿层脉状钠长石碳酸岩)；低温热卤水(富F、Ba、B、As、Sb)形成热卤水同生沉积微相。矿质大规模沉淀的地球化学动力学因素为：在热水沉积成矿盆地中，在单一成分热水体系的温度、压力改变而发生快速化学沉淀；不同成分、性态的热水混合后，强烈的酸—碱作用及Eh-pH剧变等，触发热水体系失稳，引起矿质大规模沉积。[SiO2]和F可能是重要的矿化剂。

Influence of electrode structure on the performance of a direct methanol fuel cell

Direct methanol fuel cells (DMFCs) consisting of multi-layer electrodes provide higher performance than those with the traditional electrode. The new electrode structure includes a hydrophilic thin film and a traditional catalyst layer. A decal transfer method was used to apply the thin film to the Nafion(R) membrane. Results show that the performance of a cell with the hydrophilic thin film is obviously enhanced. A cell with the optimal thin film electrode structure operating at I M CH3OH, 2 atm oxygen and 90degreesC yields a current density of 100 mA/cm(2) at 0.53 V cell voltage. The peak power density is 120 mW/cm(2). The performance stability of a cell in a short-term life operation was also increased when the hydrophilic thin film was employed. (C) 2002 Elsevier Science B.V. All rights reserved.