In-situ microscopic FTIR spectroelectrochemical study of the reduction of K3Fe(CN)(6) in polymer electrolyte

Cyclic voltammetry and in-situ microscopic FTIR spectroelectrochemistry were used for the electrochemical and vibrational characterizations of the reduction process of K3Fe (CN)(6) in polyethylene glycol(PEG) with LiClO4 as supporting electrolyte at a Pt microelectrode. The rate of electron transfer is a function of the concentration of the supporting electrolyte. The redox potentials and cyclic voltammetric currents vary with Li/O molar ratio. The bl-situ spectroelectrochemistry shows that the infrared spectra are influenced by the concentration of LiClO4. The bridging cyanide groups with a structure Fe-I-C drop N ... Fe-I-C drop N are formed during the reduction process of K3Fe (CN)(6). There may be an activated complex between the Lif cation and the complex anion.

Influence of crystal structure on the luminescence properties of bismuth(III), europium(III) and dysprosium(III) in Y2SiO5

The luminescence properties of Bi3+, EU(3+), Dy3+ and energy transfer from Bi3+ to Dy3+ and EU(3+) have been studied in two modifications of Y2SiO5 (low-temperature X(1) type and high-temperature X(2) type) and discussed in relation to their crystal structures. The Bi3+ ion luminesces in the blue region of the spectrum in X(1)-Y2SiO5 but in the UV region in X(2)-Y2SiO5. Two obviously different luminescent centres have been observed for Bi3+ and Eu3+ ill X(1)-Y2SiO5, but only one has been seen in X(2)-Y2SiO5. The Stokes shift (9200 cm(-1)) for Bi3+ in X(1)-Y2SiO5 is much larger than that (5000 cm(-1)) in X(2)-Y2SiO5. This suggests that the host lattice is more rigid in X(2)-Y2SiO5 than in X(1)-Y2SiO5. As a result, the Bi3+, EU(3+) and Dy3+ ions show higher emission intensity in the former than in the latter type. X(1)-Y2SiO5 is more suitable for Bi3+ --> EU(3+) energy transfer and X(2)-Y2SiO5 is more suitable for Bi3+ --> Dy3+ energy transfer.

比光谱-导数-紫外分光光度法同时测定水中硝酸根和亚硝酸根

利用二元混合物的混合光谱与其中某一组分光谱的比值对波长求导，可达到分辨重叠光谱的目的。本文研究了用比光谱-导数-紫外分光光度法同时测定水样中NO3-和NO2-，以“减法技术”求导，兼具导数光度法能消除低频背景和高频噪声干扰及线性回归法分辨能力强的优点。方法避免了一般光度法需加入试剂而可能引起的误差。在pH7～9条件下测量203um～219um的光吸收值，用比光谱-导数技术处理，同时测定合成试样中0～4mg／L的NO3-和NO2-，6次测定相对标准偏差＜7％，加入回收率在95％～101％之间。讨论了干扰离子的影响及消除，并与P-矩阵法作了比较。方法已用于井水、雨水及湖水中NO3-和NO2-的同时测定。

Generation of internal and surface waves by seafloor movement in a two layer fluid system

Internal and surface waves generated by the deformations of the solid bed in a two layer fluid system of infinite lateral extent and uniform depth are investigated. An integral solution is developed for an arbitrary bed displacement on the basis of a linear approximation of the complete description of wave motion using a transform method (Laplace in time and Fourier in space) analogous to that used to study the generation of tsunamis by many researchers. The theoretical solutions are presented for three interesting specific deformations of the seafloor; the spatial variation of each seafloor displacement consists of a block section of the seafloor moving vertically either up or down while the time-displacement history of the block section is varied. The generation process and the profiles of the internal and surface waves for the case of the exponential bed movement are numerically illustrated, and the effects of the deformation parameters, densities and depths of the two layers on the solutions are discussed. As expected, the solutions derived from the present work include as special cases that obtained by Kervella et al. [Theor Comput Fluid Dyn 21:245-269, 2007] for tsunamis cased by an instantaneous seabed deformation and those presented by Hammack [J Fluid Mech 60:769-799, 1973] for the exponential and the half-sine bed displacements when the density of the upper fluid is taken as zero.

Onshore-offshore variations of copepod community in northern South China Sea

Copepod communities in onshore and offshore waters show a gradient from primarily near shore to primarily oceanic species. Understanding the transition between these communities is fundamental to determining the range of coastal influence. Copepod communities in the northern South China Sea (nSCS) were studied based on samples collected by vertically towing a net in 10 February-6 March (winter) and 26 August-6 September (summer) of 2004. Calanoida species richness, total copepod abundance, Shannon-Weaver diversity index, and onshore-offshore occurrence of dominant species showed obvious change from onshore to offshore waters. Although the offshore stations had lower abundance than the shelf stations, they had more species and larger diversity index. Abundance of some species (groups) with dominance index > 5% (Calanus sinicus, Euchaeta spp., Temora spp., Paracalanus parvus, and Subeucalanus subtenuis) declined from onshore to offshore waters. Warm water species (Pleuromamma abdominalis, P. gracilis, and P. robusta) occurred in offshore waters in both cruises. Station (q-type) cluster analysis in winter and summer separated copepod community into onshore and offshore communities at similar to 40% level of similarity. The two communities were divided at the position of similar to 100-m isobath. In summer, C. sinicus occurred in the upwelling area east of Hainan Island, indicating the presence of an oversummering stock of this species.

Divergent selection and realized heritability for growth in the Japanese scallop, Patinopecten yessoensis Jay

In order to improve the production and accurately estimate response to selection, divergent selection for growth in shell height was conducted in a cultured population of the Japanese scallop Patinopecten yessoensis. Applying the same selection intensity +/- 1.756 in upward and downward directions, three groups including two selected groups of Fast and Slow and one non-selected Control group were created, which were reared under the same environmental conditions at any stage. Differences always significantly existed among the three groups (P < 0.05), except for larvae at day 1 and at day 5, and in the order of Fast > Control > Slow. The average standardized response to selection (SR), realized heritability (h(R)2) and genetic gain (GG) was 0.473%, 0.269% and 7.85% for the Fast group and 0.381%, 0.217% and 6.60% for the Slow group respectively. Moreover, significant differences (P < 0.05) were detected between the fast and the slow lines in both SR and h(R)2, providing evidence for an asymmetric response in two directions. Performance in shell height is improved by 7.85% in the fast line after one generation selection, suggesting that mass selection for faster growth in a cultured population of the Japanese scallop is effective.

Preparation of high-molecular weight and high-sulfate content chitosans and their potential antioxidant activity in vitro

The influence of molecular weight and substitution degree of sulfated polysaccharides on their biological activity is considered in majority of works involving the anticoagulant or antiviral properties of these substances. Therefore, the present paper describes the effect of preparation conditions of sulfated chitosans on their molecular weight and sulfur content, such as different reaction time, acid solvent and temperature. Foregoing literature expounded the action of dichloroacetic acid (DCAA) as acid solvent in homogeneous reaction. However, DCAA is expensive and noxious, therefore, in the present paper cheap and non-noxious formic acid (88%) was in place of DCAA. Furthermore, during reaction formic acid was not dehydrated. Under formic acid we obtained the satisfying results that was higher yield and equivalent sulfur contents compared to DCAA. IR and C-13 NMR spectrums proved the structure of the resultant obtained under formic acid or DCAA to be same. Now, it has not been reported for formic acid as acid solvent in homogeneous reaction of chitosan sulfatation. In this present paper, we also determined antioxidant activity of high-molecular weight and high-sulfate-content chitosans (HCTS). The results showed that HCTS could scavenge superoxide and hydroxyl radical. Its IC50 is 0.012 and 3.269 mg/mL, respectively. It had obviously reducing power and slight chelating activity. The data obtained in in vitro models clearly establish the antioxidant potency of HCTS. It is a potential antioxidant in vitro. (C) 2005 Elsevier Ltd. All rights reserved.

唐古特大黄染色体的核型分析

目的对蓼科（Polygonaceae）植物唐古特大黄（Rheum tanguticum Maxim、ex Balf．）染色体核型进行研究。方法采用常规压片方法，并结合显微摄影对染色体进行检测分析。结果唐古特大黄体细胞染色体数目为2n=22；核型公式为K（2n）=22=20m＋2sm，核型为“1A”型。结论唐古特大黄染色体的核型属于较原始的类型。

艾虎对猎物和捕食者气味的反应

在室内条件下通过双通道选择实验确定艾虎（Mustela eversmanni）在通过不同气味源的场所中的取食量以及利用时间和利用频次，由此分析捕食者气味和猎物气味对艾虎取食行为的影响。研究结果表明，在无任何气味源存在时，艾虎在对照气味和对照气味组这两个场所中的取食量、活动时间和活动频次基本一致。在猎物高原鼠兔（Ochotona curzoniae）气味和对照气味组及高原鼢鼠（Myospalax baileyi）气味和对照气味组的两组实验中，艾虎在通过猎物气味的场所中的取食量、活动时间和活动频次与对照气味场所中比较也无明显的差异，但是在天敌动物赤狐（Vulpes vulpes）气味存在的条件下，艾虎明显减少在通过赤狐气味的场所中的取食量、活动时间和活动频次。同时，当间接捕食风险天敌动物赤狐气味存在时，艾虎明显增加了总的取食量，减少了在巢箱中居住的时间，而将更多的时间停留在无风险的场所中，这说明艾虎能够利用天敌动物赤狐的气味，采用增加取食量和减少高风险区域活动时间的策略来降低被捕食风险。

黄绿蜜环菌蘑菇圈生长对土壤及植物群落的影响

通过调查青海省祁连县峨堡乡野生黄绿蜜环菌蘑菇圈发生季节蘑菇圈上、圈外植物群落的物种多样性、植物群落种类组成及多度变化,分析了蘑菇圈上、圈外土壤主要微生物类群的数量变化、土壤水分、速效养分、交换性阳离子及pH等的差异.结果表明,蘑菇圈上和圈外植物群落组成种类不同,圈上物种数明显高于圈外物种数;圈上各物种分盖度总和比圈外高出49.16%,但圈上和圈外优势种及主要伴生种相同.在0～10 cm土壤层,圈上土壤含水量、速效磷、硝态氮、氨态氮的含量明显高于圈外,但土壤有机质、交换性Ca2+、交换性Mg2+和pH值的变化不明显;在10～20 cm土壤层,圈上速效磷、硝态氮、氨态氮的含量仍明显高于圈外,但土壤含水量变化趋势相反,圈外高于圈上.在0～10cm土壤层,细菌、放线菌、真菌及纤维素分解菌的数量,均以圈上显著高于圈外(P＜0.05);在10～20cm土层,它们的数量差异不显著(P＜0.01).在两层土壤中,各类微生物数量表现为:细菌＞放线菌＞真菌＞纤维素分解菌.

土壤／沉积物中微量重金属的化学萃取方法研究进展

用化学萃取法，包括连续萃取法和单一萃取法，研究土壤/沉积物中的微量重金属的活动性和生物可利用性是环境土壤化学领域内的热点问题之一。这里我们将对今年来该方法取得的一些进展、存在的问题进行详细评述。

云南会泽铅锌矿床构造控矿规律及其隐伏矿预测

本文对会泽铅锌矿成矿构造体系、构造控矿型式进行研究，认为小江深断裂带和曲靖-昭通隐伏断裂带为矿床形成提供了有利的构造背景，矿床严格受北东向压扭性断裂控制，“阶梯状”和“多字型”构造是矿区具有普遍性的控矿构造型式，北东构造带是主要的成矿构造体系，提出麒麟厂矿床主矿体向南西向侧伏，通过工程验证新增铅锌矿金属储量近100万吨。