载体钒氧化物中钒-吸附物分子相互作用的ESR研究

电子自旋共振技术已经用来研究还原态V_2O_5/SiO_2催化剂和各种吸附分子的相互作用。实验指出:具有四面体配位结构的V~(4+)离子是活性中心,V~(4+)和CH_2OH,HCl,CH_3CN分子的相互作用导致形成八面体配位结构的表面VO~(2+)络合物,它们的ESR和成键参数计算指出不成对电子主要定位在钒离子的d轨道上。77 K下吸附O_2分子已经观察到氧自由基的ESR信号,但吸附乙烯和丙烯不能改变V~(4+)离子的配位结构。

HEHEHP与PMBP协同萃取希土元素(Ⅲ)的机理研究

本文研究了2-乙基己基膦酸单(2-乙基己基)酯(HEHEHP,HL)和1-苯基-3-甲基-4-苯甲酰基吡唑啉酮-5(PMBP,HA)的苯溶液在不同矿物酸(H_2SO_4,HCl HNO_3)介质中对希土元素(Ⅲ)的协同萃取。并以Nd~(3+),Yb~(3+),Lu~(3+)为例,研究了HEHEHP-PMBP苯溶液从HNO_3介质中协同萃取希土元素(Ⅲ)的机理,用斜率法确定了协萃配合物的组成,轻希土元素为Nd(HL_2)·A_2,重希士元素为Yb(HL_2)·A,Lu(HL_2)_2·A,计算了协萃反应的平衡常数,还研究了温度对协萃反应的影响,求出了萃取过程的热力学函数。观测了协萃配合物的IR及NMR谱。

甲基膦酸二(1-甲庚)酯萃取钪的机理

本文研究了甲基膦酸二(1-甲庚)酯(简称P350)的正庚烷溶液从盐酸溶液中萃取钪(Ⅲ)、HCl和H_2O的机理。用斜率法确定了萃合物的组成为SoCl_3·3P350和3HCl·2H_2O·3P350。讨论了水相酸度、萃取剂浓度、温度对萃取平衡的影响,计算了反应的浓度平衡常数及热力学函数。研究了萃合物的红外光谱。

高性能聚苯胺自支撑膜

本文通过对可溶性聚苯胺(PAn)的特殊处理及成膜工艺的改造,采用溶液浇铸法,首次成功地制备出力学和电学性能均较好的大面积聚苯胺自支撑膜(HSPAn膜).研究结果表明,HSPAn膜的抗张强度、杨氏模量和伸长率分别为87.9MPa,1563.9MPa和10.2％;该膜具有金属光泽、较高的致密性和较好的韧性。分子尺寸较小的质子酸(如HCl,HClO_4,等)可有效掺杂HSPAn膜,使其电导率可达到导电型PAn粉末的数量级。有效掺杂的HSPAn膜均可轻度拉伸(断裂伸长率大于40.0％),拉伸膜的电导率可高达36.7s/cm。本征和掺杂的HSPAn膜均具有良好的环境稳定性,空气中放置数月后,其强度和电导率基本不变。

水中微量汞的快速测定

本文提出了一种快速测定水中微量汞的新方法。采用KBrO_3-HCl-HNO_3体系在室温下破坏水样中的有机汞,产生的无机汞用自制的KBH_4片剂还原,用测汞仪测定。此法具有简便、快速、精密度和灵敏度较好等优点,适合大批量水样的分析。

Extraction behavior of Mo and W as homologs of Sg with α-benzoinoxime

Solvent extraction of molybdenum and tungsten as homologues of Sg with a-benzoinoxime from HCl solutions has been investigated. The extraction equilibration was achieved at 20s for Mo and W. Molybdenum was almost quantitatively extracted from 0.001 to 4M HCl solutions, and the extraction yields decreased at higher and lower acid concentrations due to the formation of anionic oxychloride complex and anionic species MO42-, respectively. The extraction yield of W was lower than that of Mo during the whole range of acid concentration. The composition of the extracted species was determined by using the slope method in present experiment. The elemental analysis, IR and 1H NMR spectra of the extracted species suggest that the extracted complex contain one MoO22+or WO22+ groups bonded with two a-benzoinoxime molecules.

A novel polypeptide from shark cartilage with potent anti-angiogenic activity

Using guanidine-HCl extraction, acetone precipitation, ultra-filtration and chromatography, a novel polypeptide with potent anti-angiogenic activity was purified from cartilage of the shark, Prionace glauca. N-terminal amino acid sequence analysis and SDS-PAGE revealed that the substance is a novel polypeptide with MW 15500 (PG155). The anti-angiogenic effects of PG155 were evaluated using zebrafish embryos model in vivo. Treatment of the embryos with 20 mu g/ml PG155 resulted in a significant reduction in the growth of subintestinal vessels (SIVs). A higher dose resulted in almost complete inhibition of SIV growth, as observed by endogenous alkaline phosphatase (EAP) staining assay. An in vitro transwell experiment revealed that the polypeptide inhibited vascular endothelial growth factor (VEGF) induced migration and tubulogenesis of human umbilical vein endothelial cells (HUVECs). Exposure of HUVECs in 20 mu g/ml PG155 significantly decreased the density of migrated cells. Almost complete inhibition of cell migration was found when HUVECs were treated with 40-80 mu g/ml PG155. PG155 (20 mu g/ml) markedly inhibited the tube formation of HUVECs and a dose-dependent effect was also found when treatment of HUVECs with PG155 at the concentration from 20 to 160 mu g/ml.

Nd isotope as the tracer of seawater evolution of early Miocene in the eastern Pacific Ocean

Fifty-six samples of nannofossil ooze were collected from Core PC5794 in the northern equatorial Pacific at 5 em intervals. With the methods of mass spectrometer (VG354) and ICP, the Nd isotopic compositions (epsilon(Nd)(t)), Mn contents and Mg/Sr ratios of carbonate phase have been analyzed. CaCO3 contents of bulk sediments were obtained by dissolution of 0.5 mol/L HCl. Based on these data, the high-resolution epsilon(Nd)(t) profile of seawater in early Miocene with core depth(or time) have been established. The values of epsilon(Nd)(t) range from -6.2 to -2.97 and 4 fluctuation cycles existed during 24.06-22.02 Ma. 4 low epsilon(Nd)(t) values (about -6.4) correspond to high CaCO3 contents, which implicates that there were 4 cold epochs or 4 times of Antarctic Bottom Water activity. They occurred at the time of 24.06 Ma, 23.85 Ma, 22.88 Ma and 22.26 Ma, respectively. High epsilon(Nd)(t) values correspond to the high Mn contents and high values of Mg/Sr ratio, which indicates the existence of 4 intense hydrothermal activity periods during 24.06-22 Ma, the durations of them are 4.05-23.98 Ma, 23.69-23.15 Ma, 22.74-22.37 Ma and 22.06-22.02 Ma, respectively.

Distribution and mobility of metals in agricultural soils near a copper smelter in South China

The distribution and mobility of heavy metals in the paddy soils surrounding a copper smelting plant in south China was investigated. We assessed the degree of metal contamination using an index of geoaccumulation. The metals were divided into two groups: (1) Cu, Zn, Pb and Cd, whose concentrations were heavily affected by anthropogenic inputs, and (2) Ni, Co and Cr, which were mainly of geochemical origin. Concentrations of Cu, Cd, Zn, and Pb in the polluted soils were higher than the Chinese soil quality criteria. The chemical partitioning patterns of Pb, Zn and Cu indicated that Pb was largely associated with the residual and NH2OH HCl extractable fractions. In contrast, Cd was predominantly associated with the MgCl2 extractable fraction. A large proportion of Cu was bound to the acidic H2O2 extractable fractions, while Zn was predominantly found in the residual phase. The fraction of mobile species, which potentially is the most harmful to the environment, was found to be elevated compared to unpolluted soils in which heavy metals are more strongly bound to the matrix. The mobility of the metals was studied by water extraction using a modification of Tessier's procedure, and the order of mobility was Zn > Cd > Cu > Ce > Pb.

羟基自由基降解琼胶及其产物的活性研究

琼胶是一种从石花菜等红藻中提取的，目前生产工艺和结构等方面研究比较成熟的海藻多糖，广泛应用于医药、仪器等行业。但是，海藻多糖因为具有分子量大，粘度大，溶解度较小的等特点，而使其应用范围受到限制。利用降解的手段对其进行修饰，降低分子量和粘度，改善溶解性，可以拓展其应用范围。并且根据文献报道，琼 胶寡糖具有一些特殊的生物活性，如抗氧化性，抗炎症等。因此，对琼胶降解的研究具有生要意义。本研究中，为了选择一种合适的降解方法，进行了几种水解方法的尝试，其中包括在不同湿度和酸度下盐酸水解，过氧化氢和醋酸催化水解，Fenton体系羟基自由基降解。对于酸水解和Fenton体系氧化还原降解方法，通过粘度法对反应的速度进行了比较，表明氧化还原降解反应中琼胶的粘度降低比较快，并且具有代表性和新意，确定为本实验的降解琼胶的方法并对氧化还原降解所得的产物进行了活性实验。通过模仿自然界普遍存在的氧化还原降解反应，利用Vc诱导的Fenton体系产生的羟基自由基氧化还原降解琼胶得到低分子量的琼胶。降解产物经过高速离心、60％乙醇沉淀，除去分子量比较大的降解产物和磷酸盐，得到可溶于60％乙醇的分子量估计小于3000的降争产物，其产率为85％。利用经Sephadex-G25凝胶色谱分离所香的不同分子量的级分进行分子量和α－葡萄糖苷酶抑制活性关系的实验。降解产物对α－葡萄糖苷酶的抑制率和各级分的浓度呈线性正相关，并且各级分的IC_(50)则随着分子量的降低而降低。另外，对所得的降解产物混合物进行了红外吸收光谱、质子去偶核磁共震碳谱和负离子基质辅助激光诱导－飞行时间质谱结构分析。结果表明，氧化还原降解反应的专一性差，在得到寡糖的同时，在光谱图中出现一些比较复杂的副产物的结构信息。最后，根据MTT法的原理，以有体皮肤成纤维细胞为材料，通过紫外线辐射产生自由基造成氧化损伤，研究降解产物对成纤维细胞的保护作用。当无紫外线辐射时，降解产物对成纤维细胞具有显著的促进生长增殖作用：当经UVa、UBb辐射时则可以显著地表现出对损伤的保护作用，并且这种促进生长和保护作用呈显著的量效关系，表明降解产物具有清除基自由基的作用。但是，因为氧化还原降解以应的机理尚不十分明的以及琼羟胶的特殊结构，使得反应的副产物很难预测，也就使得分离工作难以进行，所以，根据目前所得的信息，尚不能确定是降解产物的什么级分产生的以上两种生物活性。

中国河口、近岸海洋沉积物酸提取相中元素相关性及其背景值的研究

本文详细研究了黄河口（五、八月）、长江口、龙口湾、日照近海以及冀东唐海近岸海域表层沉积物中元素Zn、Pb、Ni、Cu、Co、Fe、K、Corg、Cr、Mn、P的总量和元素Zn、Cu、Pb、Co、Cr、Li、Ni、Mn、Fe、K 、Al、P的可提取量。在此基础上，着重研究了沉积物中元素总量间的相关性、元素可提取量间的相关性、元素的含量与粒度组成之间的关系、元素的总量与可提取量的关系以及可提取部分背景值等几个方面的内容。通过对不同地区不同类型的大量沉积物的研究结果表明：沉积物中元素Cu、Zn、Ni、Fe、Corg、Cr的总量在不同河口、不同类型的沉积物中与其它元素存在着显著的正相关关系。考虑到参比元素的限制条件，可以利用Ni、Fe、Corg、Cr作为参比元素，这些参比元素在不同地区、不同类型的沉积物中具有普遍性。元素Cu、Zn、Pb、Ni、Fe、K、Cr、Corg、Mn的总量与粘土含量呈显著的正相关关系。用1N HCl或0.5N HCl+H_2O_2提取沉积物，元素Cu、Zn、Pb、Co、Li、Ni、Fe、K、Al的提取量之间以及与其它元素的可提取量存在显著的正相关关系。Li、Ni、Fe、Al、Co同样可以作为参比元素，这比用总量来评价环境质量具有更方便的特点。元素Zn、Cu、Pb、Co、Li、Ni、Fe、K的可提取量与粘土含量成显著的正相关关系。与1N HC1、0.5N HCl+H_2O_2两种提取方法相比较，25%(V/V) CH_3COOH只提取了部分结合松散的金属，元素的可提取量之间以及与粘土含量之间的相关关系较差。采用不同的提取方法，元素的提取率的大小顺序与提取方法是一致的，与沉积物的区域及类型关系不明显。元素的提取率与粘土之间相关性差，说明虽然随着颗粒变细，各元素含量的绝对值增加，但相对比例变化不明显。在以上内容研究的基础上，提出了沉积物中元素可提取部分背景值的概念，这个概念具有一定的普遍性，对今后环境质量的正确评价，特别是评价对生物体影响方面，更具有重要的意义。Li、Al、K三种元素在采用提取量进行环境质量评价时，可以作为参比元素。这在以前的文献中尚没有报道，是在前人工作的基础上的又一发展。初步发现了沉积物中部分元素可提取相的元素粒度控制规律。

栉孔扇贝Chlamys farreri生态免疫机制的基础研究

针对目前栉孔扇贝Chlamys farreri养殖亟待解决的种质、病害、环境和产品质量等日趋严重的问题，从栉孔扇贝本身的防御机制和神经内分泌机制入手，较为系统地研究了环境胁迫，应激激素与血细胞免疫功能之间的相互作用机制；从生态免疫学角度，探讨了栉孔扇贝大规模死亡的原因，为栉孔扇贝病害防治和种质优化提供了一些理论依据。主要研究结果如下： 1.较为系统地综述了贝类生态免疫机制的研究进展。分析了应激激素对贝类细胞免疫活性的抑制作用，以及生态免疫过程中免疫成本的投入与其他生态因子之间的内在联系，分析了病原体与宿主之间的相互作用机制，提出了贝类生态免疫机制研究新见解和新思路。 2.筛选出一种较适用的抗凝剂配方：Glucose 20.8 gL-1，EDTA 20mM, Sodium chloride 20 gL-1，Tris-HCl 0.05M，pH=7.4。 3.模拟研究了栉孔扇贝养殖过程中的主要环境胁迫因子，包括露空胁迫（5°C，17°C和25°C露空最长持续24小时），急性温度胁迫（从17°C分别直接升至23°C和28°C或降至11°C），急性盐度胁迫（从盐度31直接升至盐度35或降至盐度25和20），饥饿胁迫（持续40天）和密度胁迫（分为低、中和高密度），对栉孔扇贝血细胞免疫功能的影响，养殖过程中的露空胁迫对栉孔扇贝的血细胞免疫功能具有抑制作用，从而削弱了扇贝胁迫后恢复的最初24小时中抗击病原体的能力。高温下（25°C）的露空胁迫能够显著地降低扇贝的成活率。急性升温胁迫（从17°C突变至28°C）会严重的破坏栉孔扇贝的内稳态，损伤其血细胞免疫功能，从而增加了扇贝对病原体的易感性。而扇贝对快速的降温胁迫（从17°C突变至11°C）则具有较高的耐受性。盐度20的低盐胁迫能够显著抑制栉孔扇贝的血细胞防御功能，同时低盐有利于许多病原体的繁殖，两方面的协同作用，将大大增加扇贝大规模死亡的几率。饥饿胁迫（40天）能够显著地抑制血细胞的免疫活性，然而在实验室饵料充足的条件下，养殖密度除了对血细胞的吞噬活性有一定的抑制作用外，对血细胞其他的免疫活性影响不明显。 4.揭示了环境胁迫因子，包括露空胁迫（17°C 露空24小时），温度胁迫（从17°C分别直接升至28°C或降至11°C持续7天），低盐胁迫(从盐度31直接降至盐度20持续7天)和饥饿40天胁迫，对栉孔扇贝血细胞超微结构的影响，露空胁迫（17°C 露空24小时），低盐胁迫(盐度20持续7天)和饥饿40天胁迫严重损伤了血细胞的膜系统及各种细胞器的结构。 5.利用酶联免疫法测定了栉孔扇贝血淋巴中应激激素（肾上腺素，去甲肾上腺素和多巴胺）的基础浓度，分别为0.088±0.11, 18.63±1.96 和 2.59±0.46ng/ml。研究了血淋巴中应激激素对环境胁迫（包括露空，急性升温和急性降盐）的响应水平，急性露空，升温和降盐能够显著提高血淋巴中肾上腺素和去甲肾上腺素的浓度，而多巴胺浓度变化却呈现出完全相反的趋势。 6.肾上腺素和去甲肾上腺素体外诱导栉孔扇贝血细胞研究结果表明：浓度为30ng/ml或50ng/ml的去甲肾上腺素能够显著抑制血细胞的吞噬活性，浓度为50ng/ml的去甲肾上腺素能够显著抑制血细胞的活性氧产物，而肾上腺素对血细胞免疫功能的影响则不显著。

Forms and functions of inorganic carbon in the Jiaozhou Bay sediments

Inorganic carbon forms and their influencing factors, mutual transformation and contribution to carbon cycling in the Jiaozhou Bay sediments were discussed. The results show that inorganic carbon in sediments could be divided into five forms: NaCl form, NH3 center dot H2O form, NaOH form, NH2OH center dot HCl form and HCl form. Thereinto, NH2OH center dot HCl form and HCl form account for more than 70% of total inorganic carbon. There was close relationship among every form of inorganic carbon and their correlativity was clearly different with different sedimentary environment except the similar strong positive correlation among NH2OH center dot HCl form, HCl form and total inorganic carbon in all regions of the Jiaozhou Bay. All forms of inorganic carbon were influenced by organic carbon, pH, Eh, Es, nitrogen and phosphorus in sediments, but their influence had different characteristics in different regions. Every farm of inorganic carbon transformed into each other continuously during early diagenesis of sediments and the common phenomenon was that NaCl form, NH3 center dot H2O form, NaOH form and NH2OH center dot HCl form might transform into steady HCl form. NaCl form, NH3 center dot H2O form, NaOH form and NH2OH center dot HCl form could participate in carbon recycle and they are potential carbon source; HCl form may be buried for a long time in sediments, and it may be one of the final resting places of atmospheric CO2. Inorganic carbon which entered into sediments was about 4.98 x 10(10) g in the Jiaozhou Bay every year, in which about 1.47x10(10) g of inorganic carbon might be buried for a long time and about 3.51. x 10(10) g of inorganic carbon might return into seawater and take part in carbon recycling.

Determination for the different combined-form inorganic carbon in marine sediments

Marine sediment is the important sources and sinks of carbon. The inorganic carbon(IC) in marine sediments plays an important role in carbon cycling. In order to understand IC function in carbon cycling, sequential extraction method based on IC combined chemical strength difference were established to get five phases: NaCl phase (step I), NH3 - H2O phase (step II), NaOH phase (step III), NH2OH . HCl phase (step IV) and HCl phase(step V). The best extraction conditions were obtained by a series of experiments. Extractants were added into plastic centrifuge tubes in Step I - M, the capped tube were placed on a shaker table to keep the solids suspended for two hours. The suspended solution was separated by centrifugal, the residues were washed with water. The two supernatant were combined and the CO, was finally determined by volumetric analysis. The residues were transferred into conical flask in step IV and V, and then the extractants were added. The produced CO2 was adsorbed by saturated Ba(OH)(2) solution, and determined by volumetric analysis. This method for IC has a good precision in the analysis sediment samples.

A simple and accurate method for determining accurately dissolved inorganic carbon in seawaters

Dissolved inorganic carbon (DIC) account for more than 95% of total carbon in seawater, so it is necessary to make reliable and precise measurements of DIC to study marine carbon cycling. In order to establish a simple and speed method, an airproof device of gas extraction-absorption was designed. Finally a simple method was developed for the determination of DIC in seawater through a large mount of experiments. The determination procedure is as follows: 100 similar to 150 mL seawater was put into conical flask, then add 10% H3PO4, the DIC in seawater sample was dissolved to form CO2 gas and carried by pure N-2, then the CO2 gas was absorbed by two grades 0.1 mol/L NaOH solution. Finally the absorbed solution was titrated by HCl standard solution of 0.01000 mol/L with the end points detected with the indicator phenolphthalein and bromocresol green-methyl red mixture. The precision and accuracy of the method were satisfied. This method was used to analyse seawater samples from Jiaozhou bay in June, 2003. The result shows that the average DIC in surface seawater is 2066 mumol/L, DIC in bottom seawater is 2075 mumol/L inside bay, but the average DIC in surface seawater is 1949 mumol/L, DIC in bottom seawater is 2147 mumol/L outside bay.