Nutrient Dynamics in the Upwelling Area of Changjiang (Yangtze River) Estuary

Nutrient dynamics and its influence on the distribution of chlorophyll-a in the upwelling area of the Changjiang (Yangtze) River estuary were investigated in the spring (May) and summer (August) of 2004. In the spring, upwelling was apparent in the region of 122 degrees 20'-123 degrees 00' E, 31 degrees 00'-32 degrees 00' N and was associated with low temperature (16-21 degrees C), high salinity (24-33 practical salinity units [psu]), and low dissolved oxygen (2.5-6.0 mg L-1) in the upper 10 m of the water column. The spring upwelling increased the mixed-layer phosphate, nitrate, and silicate concentrations to roughly 1, 15, and 15 mu mol L-1, respectively, and improved the light transparency in the euphotic zone. This improvement in phytoplankton growing conditions was followed by an increase in chlorophyll-a concentrations. The summer upwelling was weaker and occurred over a smaller geographical area (122 degrees 20'-123 degrees 00' E, 31 degrees 15'-31 degrees 50' N). Strongly influenced by turbid Changjiang diluted water (CDW), it had little impact on the upper 10 m of the water column but instead increased nutrient concentrations at greater depths. The high concentration of particulates in the CDW reduced light transmission in the upper 10 m and, hence, limited phytoplankton growth throughout the water column. Chlorophyll-a concentrations in the summer upwelling area were roughly an order of magnitude lower than in the spring. Water clarity, as influenced by the CDW, appears to be the principal factor limiting the impact of upwelling on phytoplankton biomass in this area.

Three-dimensional fluorescence characteristics of dissolved organic matter produced by Prorocentrum donghaiense Lu

Filtration and cross-flow ultrafiltration techniques were used to separate culture media of Prorocentrum donghaiense at the exponential growth, stationary and decline stages into < 0.45 mu m filtrate, 100 kDa-0.45 mu m, 10-100 kDa and 1-10 kDa retentate and < 1 kDa ultrafiltrate fractions. The fluorescence. properties of different molecular weights of dissolved organic matter (DOM) were measured by excitation-emission matrix spectra. Protein-like and humic-like fluorophores were observed in the DOM produced by P. donghaiense. The central positions of protein-like fluorophores showed a red shift with prolonged growth duration, shifting from tyrosine-like properties at the exponential growth stage to tryptophan-like properties at the stationary and decline stages. The excitation wavelengths of protein-like fluorophores exhibited some change in the exponential growth and stationary stages with increased molecular size, but showed little change in the decline stage. However, the emission wavelengths in the decline stage exhibited a blue shift. Very distinct C type and A type peaks in humic-like fluorophores were observed. With a prolonged culture time, the intensities of both of the peaks became strong and the excitation wavelengths of peak A showed a red shift, while the A:C ratios fell. More than 94% of fluorescent DOM was in the lower than 1 kDa molecular weight fraction.

白刺种子黄酮类化合物最佳提取工艺研究

本文通过单因素及正交实验探讨了白刺种子内黄酮类化合物的最佳提取工艺.实验结果表明:在提取温度80℃的条件下用70%乙醇回流提取3次,每次1.5h,料液比为1:6(W/V).在此条件下,黄酮类化合物的得率最高.

基于EDDL和FDT的设备描述技术研究及开发

化程度的不断提高，在过程控制的现场对设备的种类要求越来越广泛。在这种情况下，大量不同厂商不同类型的设备应用到实际现场中。由此带来的设备配置工作越来越烦索。电子设备描述技术（EDD）和现场设备类型管理技术（FDT/DTM）的出现解决了这个问题。EDDL是描述电子（仪表）设备的语言，是各个不同设备进行互操作的基础。EDDL提供了一整套可裁剪的基本结构元素，用于对简单、复杂或模块化的设备进行描述。EDD是一种统一的、独立于平台的设备操作的基础。FDT/DTM技术是基于软件的设备集成解决方案，采用具有统一接口规范的FDT框架和DTM软件组件，其基本思想是提供标准的方法来管理现场设备。国内外对这两种技术的研究和技术推广逐年升温，研究开发具有自主知识产权的解决方案具有十分重要的意义。本文通过深入研究协议，掌握其关键技术，实现其实际的应用，并开发相应的软件。 介绍了两种协议的原理及应用设计实现过程。根据对协议的研究以及国内外相关应用现状的分析提出设备集成方案设计的思路，以达到实际工程应用的目的。详细介绍了EDD协议与FDT/DTM协议的主要机制，包括设备描述语言、描述方法、编译解释原理、组件技术、COM/ActiveX控件、组件通信等。并以博微公司生产的变送器为例，实现了设备集成的具体应用，包括基于EDDL技术的压力变送器与AMS和PDM集成、基于FDT技术的与美名fdtContainer集成。详细描述了设备集成的原理、集成的方案、设备描述文件的编写、设备DTM的开发等。

贵州百花湖分层晚期有机质降解过程与溶解N2O循环

百花湖是一个具有季节性分层的富营养小型湖泊,在秋季湖水倒转期经常发生水质恶化事件,碳氮循环出现异常。文章研究特选择在秋初,湖泊分层开始消失时,测定了湖水中不同深度的N2O ,CH4 ,CO2 ,有机和无机碳同位素以及其他化学参数变化。结果发现:采样时百花湖在约6m和16m 深度附近出现了两个温度不连续层(SDL和PDL) ,并影响到有机颗粒的沉降和分解。相对而言,有较多的有机质在这两个层内发生降解,但降解的途径有所不同,上部主要是有氧降解,下部则主要是无氧降解过程。N2O 的产生和消耗与有机质的降解过程完全对应:PDL 层以上,ΔN2O 与AOU 的线性关系反映了N2O 主要形成于硝化作用;PDL 层以下反硝化作用导致N2O 严重不饱和;PDL 内位于硝化作用和反硝化作用过渡带的N2O 峰,显然是硝化与反硝化联合作用的结果。PDL 层内较大的CH4 浓度变化梯度,说明嗜甲烷细菌可能通过氧化NH+4 贡献了部分N2O。百花湖秋、冬季表层湖水N2O 都是过饱和的,都是大气N2O 的源,依据分子扩散模型计算湖泊N2O 的释放通量在12～14μmol/ m·day 之间,秋、冬季没有明显的差别。秋季底层湖水的反硝化作用是湖泊N2O 的汇,其消耗通量与表层的释放通量基本相当。

金属矿床的卤素元素异常及其形成机理——以粤西茶洞银金矿床为例

金属矿床中卤素元素参与了金属元素的活化，迁移互沉淀成矿的全过程，然而，除F能作为萤石和云母类矿物的组成部分有时富集于矿石中外，Cl,Br,I很难在矿石中富集。在成矿过程中尤其在成矿孤后期，它们能在矿体上部形成范围较广的卤素扩散晕，在茶洞矿床，这种上部扩散晕范围可达200米，其中以I扩散范围最大，Br扩散晕在距矿体50－130米的范围内最明显，Cl扩散晕在距矿体30－110米范围内最明显，卤素元素的这种变化特点，一方面可用来解释成矿热液的演化过程，另一方面可用来作为勘查深部隐伏矿体的地球化学标志，成矿流体中卤素元素与金属元素的配合物着成矿条件的改变而不断被破坏，金属元素作为硫化物等矿物的组成部分沉淀下来，随着热液蚀变的发生和进行，部分瞄卤素元素被带入蚀变带，大部分仍残留在流体相，在成矿的后期，和残余热液一道，以排泄和渗透等方式，在矿体上方或残余热液流经的途中形成大范围的异常。

Retention behavior of hydrophobic organic chemicals as a function of temperature in soil leaching column chromatography

To study the transport mechanism of hydrophobic organic chemicals (HOCs) and the energy change in soil/solvent system, a soil leaching column chromatographic (SLCC) experiment at an environmental temperature range of 20-40 degreesC was carried out, which utilized a reference soil (SP 14696) packed column and a methanol-water (1:4 by volume ratio) eluent. The transport process quickens with the increase of column temperature. The ratio of retention factors at 30 and 40 degreesC (k'(30)/k'(40)) ranged from 1.08 to 1.36. The lower enthalpy change of the solute transfer in SLCC (from eluent to soil) than in conventional reversed-phase liquid chromatography (e.g., from eluent to C-18) is consistent with the hypothesis that HOCs were dominantly and physically partitioned between solvent and soil. The results were also verified by the linear solvation energy relationships analysis. The chief factor controlling the retention was found to be the solute solvophobic partition, and the second important factor was the solute hydrogen-bond basicity, while the least important factors were the solute polarizability-dipolarity and hydrogen-bond acidity. With the increase of temperature, the contributions of the solute solvophobic partition and hydrogen-bond basicity gradually decrease, and the latter decreases faster than the former. (C) 2002 Elsevier Science Ltd. All rights reserved.

Calculations of the minimal perimeter for N deformable cells of equal area confined in a circle

Cox, S.J. (2006) Calculations of the minimal perimeter for N deformable cells of equal area confined in a circle. Philosophical Magazine Letters. 86:569-578.

Cloning and characterization of a putative fructosyltransferase and two putative invertase genes from the temperate grass Lolium temulentum L.

J. A. Gallagher, A. J. Cairns and C. J. Pollock (2004). Cloning and characterization of a putative fructosyltransferase and two putative invertase genes from the temperate grass Lolium temulentum L. Journal of Experimental Botany, 55 (397) pp.557-569 Sponsorship: BBSRC RAE2008

Diseño, asistencia técnica en sistema de broches y acabados en piezas de joyería.

[111] hojas : ilustraciones, fotografía.

Model and visualise the relationship between energy consumption and temperature distribution in cold rooms

In the area of food and pharmacy cold storage, temperature distribution is considered as a key factor. Inappropriate distribution of temperature during the cooling process in cold rooms will cause the deterioration of the quality of products and therefore shorten their life-span. In practice, in order to maintain the distribution of temperature at an appropriate level, large amount of electrical energy has to be consumed to cool down the volume of space, based on the reading of a single temperature sensor placed in every cold room. However, it is not clear and visible that what is the change of energy consumption and temperature distribution over time. It lacks of effective tools to visualise such a phenomenon. In this poster, we initially present a solution which combines a visualisation tool with a Computational Fluid Dynamics (CFD) model together to enable users to explore such phenomenon.