东海颗粒有机碳通量的模式计算

本研究论文属于国家科学基金重点研究项目“东海关键海洋通量过程的研究”计划的一个组成部分，通过1998年夏季东海航次，测定了颗粒有机碳的(Particulate Organic Carbon)含量，并研究了东海夏季POC含量的分布特点以及影响因素。同时，通过模式计算了部分站位的POC的垂直表观通量。然后，根据海水悬浮物质、底质物和浮游生物中的DOC的含量，定量的研究了东海的再悬浮现象，计算得到32°N断面和PN断面部分站位的再悬浮比，并计算得到了这些站位的POC净垂直通量，使我们对东海的POC净沉积通量有了一个定量的认识和把握。通过研究，我们发现东海夏季的POC的分布特点是：（1）近岸区域有明显的高值区的存在，并随离岸距离的增加而降低，这主要是受长江径流的影响；（2）在以(32°N, 125°E-125.5°E)为中心的冷涡表层海域存在着另一个POC含量的高值区，随深度增加而降低，在25米层以下随深度的增加而增加，在近底层形成一个新的高值区，研究表明表层高值区主要受生物生长的控制，而底层的高值区的存在与该区域的涡动层或上升流的存在有一定的关系；（3）同时，在东海所研究的两个断面，TSM（Total Suspended Materials）和POC的含量之间表现出了较好的相关性。通过模式研究，计算了六个站位八个层次的POC的垂直通量，其垂直通量为12.43 mg·m~(-2)·d~(-1)-148.23 mg·m~(-2)·d~(-1)，最大值为148.23 mg·m~(-2)·d~(-1)，出现在107站(32°N, 125°E)10米层，最小值为12.43 mg·m~(-2)·d~(-1)，出现在111站(32°0.08N, 125°59.57'E)的底层。通过对东海再悬浮比率的定量研究，计算了五个站和个层次的再悬浮比率。结果表明：（1）表层海水中悬浮物质的再悬浮比率在47.4%-79.18%之间；底层的再悬浮比率在72.75%-96.96%之间；（2）再悬浮比率的最大值出现在106站(32°N, 124°30'E)的底层，而再悬浮比率的最小值出现在102站(32°N, 122°30'E)的表层。在POC重直通量和再悬浮模式计算的基础上，我们计算得到了六个站位八个层次的POC净垂直通量，颗粒有机碳的净垂直通量最大值出现在107站(32°N, 125°E)的10米层，为117.4 mg·m~(-2)·day~(-1)；最小值出现在111站(32°0.08'N, 125°59.57'E)的底层为0.79 mg·m~(-2)·day~(-1)。通过几个站位的模式计算估算了东海颗粒有机碳平均的净沉积通量，其大约为6.55 mgC·m~(-2)·day~(-1)，即2.39gC·m~(-2)·y~(-1)。从而使我们对东海的颗粒有机碳的净垂直通量有了一个定量的认识。

Characterization of 12 single nucleotide polymorphisms (SNPs) in Pacific abalone, Haliotis discus hannai

We report here for the first time 12 polymorphic single nucleotide polymorphisms (SNPs) in a commercially important gastropod, Pacific abalone (Haliotis discus hannai) that were identified by searching expressed sequence tag database. These SNP loci (seven nuclear and five mitochondrial SNPs) were polymorphic among 37 wild abalone individuals, based on a four-primer allele-specific polymerase chain reaction analysis. All loci had two alleles and the minor allele frequency ranged from 0.027 to 0.473. For the seven nuclear SNPs, the expected and observed heterozygosities ranged from 0.053 to 0.499 and from 0.054 to 0.811, respectively.

高寒草原3种蓼科植物酚类物质含量及存在状态分析

对高寒草原3种蓼科植物全株不同部位的酚类物质含量进行了测定和比较.结果表明：植物不同的部位的酚类物质含量不同.珠芽蓼、西伯利亚蓼和圆穗蓼酚类物质含量最高的部位分别为根、茎叶和花穗,总酚含量分别为67.18、72.41、98.12 g/kg;简单酚含量分别为31.32、34.90、30.16 g/kg;单宁含量分别为35.86、37.51、67.96g/kg;缩合单宁含量依次为26.09、36.90、31.69 g/kg.珠芽蓼与西伯利亚蓼茎叶与根中酚类物质含量高于圆穗蓼,花穗中含量反之.3种植物酚类物质的蛋白质结合能力为珠芽蓼〉西伯利亚蓼〉圆穗蓼.

Theoretical investigation on the adsorption of Ag+ and hydrated Ag+ cations on clean Si(111) surface

In this paper, the adsorption of Ag+ and hydrated Ag+ cations on clean Si(111) surface were investigated by using cluster (Gaussian 03) and periodic (DMol(3)) ab initio calculations. Si(111) surface was described with cluster models (Si14H17 and Si22H21) and a four-silicon layer slab with periodic boundary conditions. The effect of basis set superposition error (BSSE) was taken into account by applying the counterpoise correction. The calculated results indicated that the binding energies between hydrated Ag+ cations and clean Si(111) surface are large, suggesting a strong interaction between hydrated Ag+ cations and the semiconductor surface. With the increase of number, water molecules form hydrogen bond network with one another and only one water molecule binds directly to the Ag+ cation. The Ag+ cation in aqueous solution will safely attach to the clean Si(111) surface.

Addition reaction of nitrones on the reconstructed Si(100)-2 x 1 surface

The reaction of nitrone, N-methyl nitrone, and their hydroxylamine tautomers (vinyl-hydroxylamine and N-methyl vinyl-hydroxylamine) on the reconstructed Si(100)-2 x 1 surface has been investigated by means of hybrid density functional theory (B3LYP) and Moller-Plesset second-order perturbation (MP2) methods. The calculations predicted that both of the nitrones should react with the surface dimer via facile concerted 1,3-dipolar cycloaddition leading to 5-member-ring compounds. The reaction of hydroxylamine tautomers on the Si(100) surface follows pi-complex (intermediate) mechanism. For the reaction of N-methyl vinyl-hydroxylamine, the pi-complex intermediate undergoes [2+2] cycloaddition leading to a 4-member-ring compound. But in the reaction of vinyl-hydroxylamine, the intermediate undergoes H-migration reaction ("ene" reaction) resulting in the oxime-terminated Si surface. All the surface reactions result in the hydroxyl-terminated silicon surfaces, which are very useful for the further modification of the semiconductor.

Theoretical study on adsorption of Na+ and Na+(H2O)(n) (n=1-6) on a clean Si(111) surface

To model the adsorption of Na+ in aqueous solution on the semiconductor surface, the interactions of Na+ and Na+(H2O)(n) (n = 1-6) with a clean Si(111) surface were investigated by using hybrid density functional theory (B3LYP) and Moller-Plesset second-order perturbation (MP2) methods. The Si(111) surface was described with Si8H12, Si16H20, and Si22H21 Cluster models. The effect of the basis set superposition error (BSSE) was taken into account by applying the counterpoise (CP) correction. The calculated results indicated that the interactions between the Na+ cation and the dangling bonds of the Si(111) surface are primarily electrostatic with partial orbital interactions. The magnitude of the binding energies depends weakly on the adsorption sites and the size of the clusters. When water molecules are present, the interaction between the Nal and Si(I 11) surfaces weakens and the binding energy has the tendency to saturate. On a Si22H21 cluster described surface, the optimized Na+-surface distance for Na+(H2O)(5) adsorbed at on-top site is 4.16 angstrom and the CP-corrected binding energy (MP2) is -35.4 kJ/mol, implying a weakly adsorption of hydrated Na+ cation on clean Si(111) surface.

Theoretical study of interaction between atoms of Au, Ag, Cu and clean Si(111) surface

To evaluate the interactions between the atoms of An, Ag and Cu and clean Si(111) surface, two types of silicon clusters Si4H7 and Si16H20 together with their metal complexes were studied by using hybrid (U)B3LYP density functional theory method. Optimized geometries and energies on different adsorption sites indicate that: (1) the binding energies at different adsorption sites are large (ranging from similar to 1.2 to 2.6 eV depend on the metal atoms and adsorption sites), suggesting a strong interaction between metal atom and silicon surface; (2) the most favorable adsorption site is the on top (T) site. Mulliken population analysis indicated that in the system of on top (T) site, a covalent bond is formed between metal atom and dangling bond of surface Si atom. (c) 2006 Elsevier B.V. All rights reserved.

SZJ-12机器人通用控制器系统

本文介绍了一种通用的机器人二级控制系统,该机器人控制器已成功地用于四种不同类型的机器人本体,完成了各种PTP和CP控制功能.

贵阳地下水硝酸盐氧同位素特征及应用

利用硝酸盐氮氧同位素讨论地下水硝酸盐来源和转化是地下水硝酸盐研究的热点之一。本研究利用燃烧管法测试了贵阳地下水、部分地表水, 以及雨水中硝酸盐氧同位素, 结果表明地下水中硝酸盐D18O 冬季平均值为+ 12. 6‰±5. 6 (n= 17) , 夏季为+ 11. 1‰±4. 8 (n= 22)。结合氮同位素揭示了贵阳市地下水硝酸盐污染来源的季节性转化, 郊区地下水夏季主要受硝态氮肥等影响, 而市区地下水受人为排污影响严重。

近百年巢湖的生态环境记录

巢湖位于安徽省中部,是合肥市的重要水源地,也是我国富营养化严重的三大湖泊之一.湖中风浪扰动作用强烈,入湖河流携带大量泥沙,湖水总悬浮物含量高,蓝藻发育,透明度低.近百年来,由于流域农业和城市化的发展,巢湖营养盐含量增加,逐渐形成富营养化湖泊.

四川冕宁稀土矿床碳酸岩PGE地球化学初步研究

报道了四川冕宁稀土矿床碳酸岩7件样品的PGE和Au含量分析结果，其含量（WB／10^-9）范围分别为Ir0．5～0．78，Ru 1．61～6．75，Rh 0．08～0．14，Pt 2．62～12．15，Pd 1．11γ3．65和Au1．24～8．61。原始地幔标准化的PGE模式呈Ru、Pt、Pd相对富集和Ir、Rh相对亏损的“燕子型”。分析认为，碳酸岩具有一定携带PGE的能力；本区碳酸岩具“燕子型”PGE配分模式可能是其源区地幔PGE配分模式的反演；深源富CO2流体交代作用原始地幔可能是形成其“燕子型”PGE配分模式主要因素。