Distribution of uranium isotopes in the main channel of Yellow river (Huanghe), China

Uranium isotopes were measured in waters and suspended particulate matters (SPM) of the main channel of Yellow River, China that were sampled during four field trips between August 2005 and July 2006. The results show that the concentration of dissolved U (2.04-7.83 mu g/l) and the activity ratio of U-234/U-238 (1.36-1.67) are much higher than the average U concentrations and activity ratios of global major rivers. Mass balance calculations using the results of simulated experiments and measurement data show that the section of the Yellow River between Lanzhou and Sanmenxia has its dissolved U derived from two sources: suspended sediments (68%) and groundwater/runoff from loess deposits (32%). Both sources are related to the heavy erosion of the Chinese Loess Plateau. (C) 2008 Elsevier Ltd. All rights reserved.

Element enrichment and U-series isotopic characteristics of the hydrothermal sulfides at Jade site in the Okinawa Trough

The geochemical and U-series isotopic characteristics of hydrothermal sulfide samples from the Jade site (127A degrees 04.5'E, 27A degrees 15'N, water depth 1300-1450 m) at Jade site in the Okinawa Trough were analyzed. In the hydrothermal sulfide samples bearing sulfate (samples HOK1 and HOK2), the LREEs are relatively enriched. All the hydrothermal sulfide samples except HOK1 belong to Zn-rich hydrothermal sulfide. In comparison with Zn-rich hydrothermal sulfides from other fields, the contents of Zn, Pb, Ag, Cd, Au and Hg are higher, the contents of Fe, Al, Cr, Co, Ni, Sr, Te, Cs, Ti and U lower, and the Pb-210 radioactivity ratios and Pb-210/Pb ratios very low. In the hydrothermal sulfide mainly composed of sphalerite, the correlations between rare elements Hf and U, and Hf and Mn as well as that between dispersive elements Ga and Zn, are strongly positive; also the contents of Au and Ag are related to Fe-sulfide, because the low temperature promotes enrichment of Au and Ag. Meanwhile, the positive correlations between Fe and Bi and between Zn and Cd are not affected by the change of mineral assemblage. Based on the Pb-210/Pb ratios of hydrothermal sulfide samples (3.99x10(-5)-5.42x10(-5)), their U isotopic composition (U-238 content 1.15-2.53 ppm, U-238 activity 1.07-1.87 dpm/g, U-234 activity 1.15-2.09 dpm/g and U-234/U-238 ratio 1.07-1.14) and their Th-232 and Th-230 contents are at base level, and the chronological age of hydrothermal sulfide at Jade site in the Okinawa Trough is between 200 and 2000 yr.

Effective AC and DC responses of nonlinear composites at higher concentration

For higher concentration of inclusions, an effective medium approximation (EMA) method is used to investigate the bulk effective response of weakly nonlinear composites, which are subject to the constitutive relation of electric displacement and electric field, D-alpha = epsilon E-alpha + chi(alpha)|E|(2) E. As an example of three dimensions, under the external AC and DC electric fields E-app = E-a (1 + sin omega t), we have derived the general effective nonlinear response of composites by the EMA method for higher concentration of spherical inclusions. Furthermore, the effective nonlinear responses at harmonics are predicted.

富营养化环境下的海洋微藻生理生化特性研究

本论文以中肋骨条藻和东海原甲藻为研究对象，研究了富营养化条件下，两种主要赤潮藻的磷酸酶活性变化、主要生化组成特征变化以及光合作用特性变化，分析了营养盐条件与微藻的主要生理生化特性之间的关系。结果表明中肋骨条藻和东海原甲藻均能诱导碱性磷酸酶和酸性磷酸酶，且两种磷酸酶具有相似的变化趋势。外界磷酸盐和胞内磷酸盐浓度越低，酶活性越高。另外两种藻均能吸收利用有机磷化合物（ATP、G-6-P和G-P），生物量明显增加。在试验初期，两种赤潮藻的单位细胞总脂和总碳水化合物含量随着营养盐的消耗而呈下降趋势，在试验后期，环境中营养盐限制时，胞内总脂和总碳水化合物含量呈上升趋势。单位细胞总蛋白含量在整个实验期间也随着营养盐的消耗呈下降趋势，但无上升现象。两种藻在低营养盐浓度处理组的单位细胞光合色素含量分别低于相对应的高营养盐浓度处理组。当P源充足时，低N处理组的藻细胞叶绿素活性较高，光合速率高于高N处理组；N源充足时，低P处理组的光合速率低于高P处理组。对两种藻的主要生理生化特性指标与营养盐浓度进行相关性分析发现，微藻的生理生化指标变化与磷酸盐浓度尤其是胞内磷酸盐浓度呈好的相关关系，而与硝酸盐浓度无显著相关性。

Behavior of uranium in the Yellow River plume (Yellow river estuary)

The Yellow River (Huanghe) is the second largest river in China and is known for its high turbidity. It also has remarkably high levels of dissolved uranium (U) concentrations (up to 38 nmol l(-1)). To examine the mixing behavior of dissolved U between river water and seawater, surface water samples were collected along a salinity gradient from the Yellow River plume during September 2004 and were measured for dissolved U concentration, U-234:U-238 activity ratio, phosphate (PO43-), and suspended particulate matter. Laboratory experiments were also conducted to simulate the mixing process in the Yellow River plume using unfiltered Yellow River water and filtered seawater. The results showed a nonconservative behavior for dissolved U at salinities < 20 with an addition of U to the plume waters estimated at about 1.4 X 10(5) mol yr(-1). A similarity between variations in dissolved U and PO43- with salinity was also found. There are two major mechanisms, desorption from suspended sediments and diffusion from interstitial waters of bottom sediments, that may cause the elevated concentrations of dissolved U and PO43- in mid-salinity waters. Mixing experiments indicate that desorption seems more responsible for the elevated dissolved U concentrations, whereas diffusion influences more the enrichment of PO43-.

Immunomodulation and antitumor activity of kappa-carrageenan oligosaccharides

The modulation of carrageenan oligosaccharides from Kappaphycus striatum on the immune system in S 180-bearing mice was investigated. The mice inoculated with S180 cell suspension were treated p.o. with carrageenan oligosaccharides (50, 100 and 200 mu g/g) for 14 days. The effects of carrageenan oligosaccharides on transplantable tumors and macrophage phagocytosis, quantitative hemolysis of sheep red blood cells (QHS),. lymphocyte proliferation, the activity of natural killer cells (NK), production of interleukin-2 (IL-2) and tumor necrosis factor-alpha (TNF-alpha) were studied. Carrageenan oligosaccharides could significantly inhibit the growth of transplantable sarcoma S180 and increase macrophage phagocytosis, the form of antibody secreted by spleen cells, spleen lymphocyte proliferation, NK cells activity, serumal IL-2 and TNF-alpha level in S 180-bearing mice. Considering all these results, it is suggested that carrageenan oligosaccharides exert their antitumor effect by promoting the immune system. (c) 2005 Elsevier Ireland Ltd. All rights reserved.

青海省不同地区羌活脂溶性化学成分的研究

采用毛细管气相-质谱法对青海省不同地区羌活脂溶性化学成分进行分析和鉴定，共分离出80余个成分，鉴定了60个，并用面积归一法确定其相对含量。结果表明，其化学成分以亚油酸、水菖蒲酮、十六烷酸及3，5-豆甾二烯为主，不同地区间羌活脂溶性化学成分种类和含量均有明显的差异。

线叶龙胆的胚胎学研究

首次报道了龙胆属华丽组的胚胎发育过程, 其代表种线叶龙胆花药四室; 药壁发育为双子叶型; 绒毡层两型起源, 细胞具双核和多核, 绒毡层细胞1- 3次分裂形成“横格”和“类胎座”, 原位退化, 属非典型的腺质型; 中层细胞两层; 药室内壁纤维状加厚。小孢子母细胞减数分裂为同时型, 四分体的排列主要为四面体形; 成熟花粉为3-细胞型。子房为2 心皮, 1室, 超侧膜胎座。胚珠10- 15列, 腹维管束彼此靠近, 并在中下部融合。薄珠心, 单珠被, 倒生胚珠。大孢子母细胞减数分裂形成的4个大孢子呈直列式排列。胚囊发育为蓼型。成熟胚囊为矩圆形。极核在受精前融合为次生核。雄蕊先熟, 异花传粉, 珠孔受精。受精作用属于有丝分裂前配子融合类型。胚乳发育为核型。胚胎发育为茄型酸浆Ⅱ变型, 当种子散落时胚只发育至球形胚阶段。结合已有的资料, 还总结了龙胆属的胚胎学特征。

高原鼠兔松果腺褪黑激素含量昼夜节律的研究

自然光照条件下，高原鼠兔（Ｏｃｈｏｔｏｎａｃｕｒｚｏｎｉａｅ）松果腺褪黑激素（Ｍｅｌａｔｏｎｉｎ，ＭＬＴ）含量呈现明显的昼夜节律（Ｐ＜０．００１，夜间组含量均值与白天组含量均值差异显著性比较）。在２月份的实验中，对１８只鼠兔（体重１２２—１６４克）松果腺的采样时间分别为０２．００，０９．００，１２．００，１８．００，２２．００和２４．００时。白天ＭＬＴ含量波动为５６—６４微微克／松果腺，夜间波动为１１３—１７０微微克／松果腺。夜间ＭＬＴ含量高峰值出现在２４．００时。在１０月份的实验中，对６０只鼠兔（体重１０２—１５３克）松果腺的采样时间分别为０３．００，０６．００，０９．００，１２．０...

Mass spectrometric identification of multihydroxy phenolic compounds in Tibetan herbal medicines

A highly selective and accurate method based on derivatization with dansyl chloride coupled with liquid chromatography-mass spectrometry has been developed for identification of natural pharmacologically active phenolic compounds in extracts of Lomatogonium rotatum plants (Tibetan herbal medicine) obtained by solid-phase extraction. The number of hydroxyl groups on the dansylated phenols was estimated by LC-MS-MS analysis in positive-ion mode. Dansyl derivatization of the compounds introduced basic secondary nitrogen into the phenolic core structures and this was readily ionized when acidic HPLC mobile phases were used. MS fragmentation of the derivatives generated intense protonated molecular ions of m/z [MH](+) (phenol aglycones were transformed into the corresponding free phenols by cleavage of an aglycone bond). Collision-induced dissociation of the protonated molecule generated characteristic product ions of m/z 234 and 171 corresponding to the protonated 5-(dimethylamino)naphthalene sulfoxide and 5 -(dimethylamino) naphthalene moieties, respectively. Selected reaction monitoring based on the m/z [MH](+) to 234 and 171 transitions was highly specific for these phenolic compounds. Characteristic ions with m/z values of [MH - 234](+), [MH 2 x 234](+), and [MH - 3 x 234](+) were of great importance for estimation of the presence of multihydroxyl groups on the phenolic backbone.

Depression of net ecosystem CO2 exchange in semi-arid Leymus chinensis steppe and alpine shrub

Uptake and release of carbon in grassland ecosystems is very critical to the global carbon balance and carbon storage. In this study, the dynamics of net ecosystem CO2 exchange (FNEE) of two grassland ecosystems were observed continuously using the eddy covariance technique during the growing season of 2003. One is the alpine shrub on the Tibet Plateau, and the other is the sem-arid Leymus chinensis steppe in Inner Mongolia of China. It was found that the FNEE of both ecosystems was significantly depressed under high solar radiation. Comprehensive analysis indicates that the depression of FNEE in the L. chinensis steppe was the results of decreased plant photosynthesis and increased ecosystem respiration (R-eco) under high temperature. Soil water stress in addition to the high atmospheric demand under the strong radiation was the primary factor limiting the stomatal conductance. In contrast, the depression of FNEE in the alpine shrub was closely related to the effects of temperature on both photosynthesis and ecosystem respiration, coupled with the reduction of plant photosynthesis due to partial stomatal closure under high temperature at mid-day. The R,c of the alpine shrub was sensitive to soil temperature during high turbulence (u* > 0.2 m s(-1)) but its FNEE decreased markedly when the temperature was higher than the optimal value of about 12 degrees C. Such low optimal temperature contrasted the optimal value (about 20 degrees C) for the steppe, and was likely due to the acclimation of most alpine plants to the long-term low temperature on the Tibet Plateau. We inferred that water stress was the primary factor causing depression of the FNEE in the semi-arid steppe ecosystem, while relative high temperature under strong solar radiation was the main reason for the decrease of FNEE in the alpine shrub. This study implies that different grassland ecosystems may respond differently to climate change in the future. (c) 2006 Elsevier B.V All rights reserved.

Meat characteristics of Qinghai yak and semi-wild yak

Six domestic yaks aged 6 years, comprising three culling male and three culling female yaks, from the Qinghai Lake area and three male semi-wild yaks aged 6 months from Datong Yak Farm were used to detect the levels of amino acids, mineral elements, residual heavy metals and pesticides in yak meat. The results showed that there was little difference in amino acid levels for different types of yak by age and sex. The meat of the adult male yak was 7.35 mg/kg higher in calcium (P < 0.05) and 124 mg/kg higher in phosphorus (P < 0.01) than that of the adult female yak. There was an obvious difference in zinc content, and there was also a significant difference for copper and sulfur between adult male and female yaks (P < 0.01). Iron was 8.85 mg/kg higher in semi-wild yaks than in domestic yaks, but there were no differences for other minerals. The levels of residual heavy metals and residual pesticides were well within those allowed by the National Standard of China. Furthermore, the data showed that introducing wild yak's blood did not result in a quality change in the domestic yak meat. Yak meat from Qinghai Plateau has the characteristics of being non-polluted and rich in amino acids in comparison with local yellow cattle meat.

基于港航运输供应链管理

大文以大连港DP-CIMS资管理系统开发为背景，根据港航运输的特点，利用供应链管协调机制与方法，采用CORBA面向对象技术，开展了基于港航运输的供应链管理模设计与实施技术研究，提出了适合企业的供应链管理总体功能的结构框架，并着手在供应链管理系统网络环境下进行模型建立与开发。

《陕西铜厂矿田构造成矿动力学》书评

该书以陕西勉(县)-略(阳)-阳(平关)地区铜厂铜金多金属矿田为例，在总结构造成矿动力学的理论和方法基础上，从成矿地质背景、矿床地球化学、矿田地质力学、矿田构造地球化学及矿田构造应力场等方面对研究区进行了系统地构造成矿动力学研究，根据所获研究成果对该区进行了隐伏矿定位预测。全书约35万字，共分7章，其中图¨6幅、表53个、照片62张。陈庆宣院士为该书作了序。