Fatty-acids and their C-13 signatures in seep carbonates from hydrocarbon seeps on the upper (GC 185) and lower (AC 645) continental slope of the Gulf of Mexico

Here we reported the fatty-acids and their δ 13C values in seep carbonates collected from Green Canyon lease block 185 (GC 185; Sample GC-F) at upper continental slope (water depth: ∼540 m), and Alaminos Canyon lease block 645 (GC 645; Sample AC-E) at lower continental slope (water depth: ∼2200 m) of the Gulf of Mexico. More than thirty kinds of fatty acids were detected in both samples. These fatty acids are maximized at C16. There is a clear even-over-odd carbon number predominance in carbon number range. The fatty acids are mainly composed of n-fatty acids, iso-/anteiso-fatty acids and terminally branched odd-numbered fatty acids (iso/anteiso). The low δ 13C values (−39.99‰ to.32.36‰) of n-C12:0, n-C13:0, i-C14:0and n-C14:0 suggest that they may relate to the chemosynthetic communities at seep sites. The unsaturated fatty acids n-C18:2 and C18:1Δ9 have the same δ 13C values, they may originate from theBeggiatoa/Thioploca. Unlike other fatty acids, the terminally branched fatty acids (iso/anteiso) show lowerδ 13C values (as low as −63.95‰) suggesting a possible relationship to sulfate reducing bacteria, which is common during anaerobic oxidation of methane at seep sites.

Study on the hydrolysis/precipitation behavior of Keggin Al-13 and Al-30 polymers in polyaluminum solutions

The hydrolysis/precipitation behaviors of Al3+, Al-13 and Al-30 under conditions typical for flocculation in water treatment were investigated by studying the particulates' size development, charge characteristics, chemical species and speciation transformation of coagulant hydrolysis precipitates. The optimal pH conditions for hydrolysis precipitates formation for AlCl3, PAC(A113) and PAC(A130) were 6.5-7.5, 8.5-9.5, and 7.5-9.5, respectively. The precipitates' formation rate increased with the increase in dosage, and the relative rates were AlCl3 >> PAC(A130) > PACA113. The precipitates' size increased when the dosage increased from 50 mu M to 200 mu M, but it decreased when the dosage increased to 800 AM. The Zeta potential of coagulant hydrolysis precipitates decreased with the increase in pH for the three coagulants. The isoelectric points of the freshly formed precipitates for AlCl3, PAC(A113) and PAC(A130) were 7.3, 9.6 and 9.2, respectively. The Zeta potentials of AlCl3 hydrolysis precipitates were lower than those of PAC(A113) and PAC(A130) when pH > 5.0. The Zeta potential of PAC(A130) hydrolysis precipitates was higher than that of PACA113 at the acidic side, but lower at the alkaline side. The dosage had no obvious effect on the Zeta potential of hydrolysis precipitates under fixed pH conditions. The increase in Zeta potential with the increase in dosage under uncontrolled pH conditions was due to the pH depression caused by coagulant addition. Al-Ferron research indicated that the hydrolysis precipitates of AlCl3 were composed of amorphous AI(OH)3 precipitates, but those of PACA113 and PACA130 were composed of aggregates of Al-13 and Al-30, respectively. Al3+ was the most un-stable species in coagulants, and its hydrolysis was remarkably influenced by solution pH. Al-13 and Al-30 species were very stable, and solution pH and aging had little effect on the chemical species of their hydrolysis products. The research method involving coagulant hydrolysis precipitates based on Al-Ferron reaction kinetics was studied in detail. The Al species classification based on complex reaction kinetic of hydrolysis precipitates and Ferron reagent was different from that measured in a conventional coagulant assay using the Al--Ferron method. The chemical composition of Al-a, Al-b and Al-c depended on coagulant and solution pH. The Al-b measured in the current case was different from Keggin Al-13, and the high Alb content in the AlCl3 hydrolysis precipitates could not used as testimony that most of the Al3+ Was converted to highly charged Al-13 species during AlCl3 coagulation.

On the acid-base stability of Keggin Al-13 and Al-30 polymers in polyaluminum coagulants

The acid-base stabilities of Al-13 and Al-30 in polyaluminum coagulants during aging and after dosing into water were studied systematically using batch and flow-through acid-base titration experiments. The acid decomposition rates of both Al-13 and Al-30 increase rapidly with the decrease in solution pH. The acid decompositions of Al-13 and Al-30 with respect to H+ concentration are composed of two parallel first-order and second-order reactions, and the reaction orders are 1.169 and 1.005, respectively. The acid decomposition rates of Al-13 and Al-30 increase slightly when the temperature increases from 20 to ca. 35 A degrees C, but decrease when the temperature increases further. Al-30 is more stable than Al-13 in acidic solution, and the stability difference increases as the pH decreases. Al-30 is more possible to become the dominant species in polyaluminum coagulants than Al-13. The acid catalyzed decomposition and followed by recrystallization to form bayerite is one of the main processes that are responsible for the decrease of Al-13 and Al-30 in polyaluminum coagulants during storage. The deprotonation and polymerization of Al-13 and Al-30 depend on solution pH. The hydrolysis products are positively charged, and consist mainly of repeated Al-13 and Al-30 units rather than amorphous Al(OH)(3) precipitates. Al-30 is less stable than Al-13 upon alkaline hydrolysis. Al-13 is stable at pH < 5.9, while Al-30 lose one proton at the pH 4.6-5.75. Al-13 and Al-30 lose respective 5 and 10 protons and form [Al-13] (n) and [Al-30] (n) clusters within the pH region of 5.9-6.25 and 5.75-6.65, respectively. This indicates that Al-30 is easier to aggregate than Al-13 at the acidic side, but [Al-13] (n) is much easier to convert to Alsol-gel than [Al-30] (n) . Al-30 possesses better characteristics than Al-13 when used as coagulant because the hydrolysis products of Al-30 possess higher charges than that of Al-13, and [Al-30] (n) clusters exist within a wider pH range.

激光衍射法与吸管法对东北黑土区土壤粒径分布测定的差异性研究

目前激光衍射法(laser diffraction method,LD)逐步被用于土壤颗粒粒径分布(particle size distribution, PSD)的分析,为了对比LD法和吸管法测定东北黑土区土壤PSD的差异性,采用LD法和吸管法分别对东北黑土区宾州河流域36个土壤剖面不同层次178个土壤样品的PSD值进行了测定与分析。结果表明,同吸管法相比,LD法低估了土壤的黏粒含量,平均低估幅度19.69%,而高估了土壤的粉粒和砂粒含量,平均高估幅度分别为14.66%和5.13%。LD法所得PSD结果依据美国土壤质地分类制判定的土壤质地,相对于吸管法总体由粉黏质偏向粉砂质方向。建立了LD法与吸管法测定PSD结果的转换模型,将LD法测定的PSD结果利用转换模型校正后,其测定的各土壤粒级同吸管法相比,准确度达96.97%～98.71%,判定土壤质地的准确率也达83.15%。

含硒抗体酶及酶法合成~（13）C尿苷二磷酸葡萄糖

胞质谷胱甘肽过氧化物酶（cGPX）是生物体内重要的抗氧化含硒酶，在保护机体免受活性氧损伤方面起着重要作用，因此利用抗体酶技术进行cGPX的人工模拟具有重要意义。本文在疏水腔修饰法指导下，设计合成了两种新的具有GSH特征的半抗原Hp4和Hp5。通过单克隆抗体及化学诱变技术制备得到三种针对半抗原Hp4的含硒抗体酶和两种针对Hp5 特异的含硒抗体酶。其中SeHB5(1867 U/μmol)和SeIA7（3567U/μmol）活力达到和天然酶同一数量级，进一步验证了疏水腔修饰法。本文还对含硒抗体酶SeHB5和SeIA7的酶学性质进行了系统的研究。生物活性实验表明含硒抗体酶对不同浓度H_2O_2损伤的小鼠心肌细胞均有一定程度的保护作用。本文同时报道了三种硒代β-环糊精作为cGPX模拟物的活力，其中6,6'-(O-亚苯基）二硒基桥联-β-环糊精二聚体的活力超过目前被认为最理想的补硒试剂Ebselen。~（13）C标记UDPG在利用核磁手段发现新的UDPG依赖糖基转移酶和检测新的糖基化合物，确定糖基间连接方式，合成同位素标记寡糖和多糖等方面具有广阔的应用前景。本文首次从植物培养细胞Rauvolfia serpentina经四步纯化得到具有一定纯度的UDPG焦磷酸化酶，并应用该酶建立了经济，简便，高产率的从葡萄糖出发，酶法大量合成UDPG的方法。利用该方法首次合成得到0.5克级的UDP-[4-~（13）C]-glucose，产率高达～70%。在NMR谱学方面确定了UDPG中葡萄糖基上4位C的归属，从而纠正了文献中关于UDPG核磁谱归属中的部分错误。

聚丁二烯的序列结构Ⅰ. ~(13)C-NMR研究聚丁二烯的序列结构 Ⅱ. 1,2-聚丁二烯的构象分析

本文详细分析了聚丁二烯分子链的序列结构，以聚丁二烯的(13)C-NMR波谱测试为依据，划分聚丁二烯分子链为三种序列、十七类脂碳碳核。在此基础上发现并论证了T_4碳核的存在，同时在聚丁二烯的~(13)C-NMR谱图上确认了与之对应的共振吸收峰－T_4峰。通过处理谱峰化学位移数据，得到一组计算聚丁二烯~(13)C-NMR谱图脂碳部分各谱峰化学位移的经验参数。应用这一组参数于聚丁二烯的~(13)C-NMR谱图（脂碳部分），各谱峰化学位移的计算值和实验值有良好的一致性。但是，与聚丁二烯分子链的1,2－序列两端的四类碳核：C_4、T_4、V_2和V_8相对应之谱峰的化学位移，其实验值一致地大于计算值而趋向低场方面，为深入研究聚丁二烯的链结构提供了有价值的情报。本文还讨论了对于4'峰和8'峰的归属，并对定量表征聚丁二烯分子链的序列结构进行了初步尝试。

全同1，2－聚丁二烯的合成及用~(13)C-NMR方法研究1，2－聚丁二烯的序列结构

采用Cr／Al催化体系，成功地合成了全同1，2－聚丁二烯（PBD），并用DSC方法、X－射线衍射、红外光谱及~(13)C－NMR的方法进行结构与物性测定，得如下结果：全同1，2－PBD的熔点为124.3℃；三角晶系中，分子链成了螺旋，晶胞参数为a＝17.3A，c＝ 6.5A；在红外光谱中，其特征谱带出现在694.4 cm~(-1)处；在~(13)C－NMR谱中仅出现四条谱峰，其化学位移分别为142.51、111.56、39.26、37.43 ppm。全同1，2－PBD的~(13)C－NMR谱提供的实验数据表明，在~(13)C－NMR谱中1，2－PBD－CH二碳十个五元组谱峰的归属是有别于Elgert、Kumar已有的归属。它属于一种新的归属，与半经验方法所推演的结果相符。它恰巧同聚丙烯侧甲基五元组谱峰的归属一致。采用半经验方法研究了1，2－PBD的~(13)C－NMR增中CH二碳五元组、CH_2－碳四元组及六元组共振谱峰，同时讨论了模型链的链长、温度以及立构序列的排列对各立构序列键概率的影响，求得了相应的r值。同时采用经验方法对1，2－PBD的~(13)C－NMR谱中CH_2=碳、CH－碳五元组及CH_2－碳四元组谱峰做了归属。两种方法对CH_2－碳谱峰的归属得到了一致的结果。

EV共聚物序列结构的~(13)C NMR研究

本工作以EV共聚物为研究对象，明确地提出了共聚物的序列结构与其~(13)C NMR谱，包括符号表示在内的一致性问题。通过对EVAc共聚物~(13)C NMR谱的分析认为，共聚物的序列结构与其~(13)C NMR谱之间存在着某种内在的联系。我们从EV共聚物序列结构的符号表示和Bovey关系出发，阐述了它们之间的一致性，即一一对应关系，并发现了EV共聚物~(13)C NMR谱的两种类型，提出了利用取代基参数进行EV共聚物~(13)C NMR谱分类的判别标准及其衍生出的两种判别方法，阐述了关于EV共聚物~(13)C NMR谱峰分布的预见性。

南沙群岛海区NS97-13柱样沉积物磁化率各向异性研究

二类水体光学活性成分的复杂性导致了水体光学特性的复杂性。通过对太湖区域

光子晶体波导定向耦合型1×3光分束器

将五光子晶体单模波导平行、邻近放置构成定向耦合器,依据自映像原理,数值分析了输入光场对称入射时,该系统中光的传播行为.基于此结构,设计了1×3光分束器,其器件长度可短至14.26μm.仅仅通过对称地改变耦合区中两个介质柱的有效折射率,使光场在横向发生重新分布,便可实现输出能量的均分或自由分配.通过非对称地改变耦合区中的一个介质柱,可实现3个输出端的输出能量的自由分配.该光分束器具有微小尺寸和各输出端输出能量的比例可自由调制的特点,在未来集成光回路中具有广泛的应用价值.

Si(100)衬底上n-3C-SiC／p-Si异质结构研究

利用LPCVD方法在Si(100)衬底上获得了3C-SiC外延膜，扫描电子显微镜(SEM)研究表明3C-SiC／p—Si界面平整、光滑，无明显的坑洞形成。研究了以In和Al为接触电极的3C-SiC／p—Si异质结的I—V，C-V特性及I—V特性的温度依赖关系，比较了In电极的3C-SiC／p—Si异质结构和以SiGe作为缓冲层的3C-SiC／SiGe／p—Si异质结构的I—V特性，实验发现引入SiGe缓冲层后，器件的反向击穿电压由40V提高到70V以上。室温下A1电极3C-SiC／p—Si二极管的最大反向击穿电压接近100V，品质因子为1．95。

长白山阔叶红松林与大气间CO2及H2O交换的过程与模拟

在全球变化背景下，森林生态系统CO2和H2O交换过程已经成为国际研究的前沿问题。本研究以长白山阔叶红松林为研究对象，利用基于生理生态学过程的多层模型，考虑了混交林中不同树种的生物量、冠层高度和厚度，对冠层及生态系统尺度的碳水通量进行了详细模拟及分析，同时用涡动相关实测数据对模拟结果进行检验，并模拟和预测了阔叶红松林生态系统碳水收支对气候变化的响应，以期为我国研究区域甚至更大尺度碳水平衡的时间和空间格局特征提供模型储备。本文的主要结论如下： 1）长白山阔叶红松林主要优势树种红松、紫椴、水曲柳、色木槭和蒙古栎的生理生态学参数（初始量子效率α、光饱和时的最大净光合作用速率Pmax、最大Rubisco催化反应速率Vcmax、CO2饱和时的最大净光合作用速率Jmax）有着明显且不同的季节变化。6、8月的α值较大，Pmax、Vcmax和Jmax的最大值也出现在6—8月，而5、9月的各项参数值均较小。 2）对阔叶红松林冠层结构的观测，发现各树种在冠层中所处位置有明显差异。假设各树种水平分布均匀，以各树种的冠高、冠厚和叶片生物量为依据，将冠层垂直分为20层，模拟出各层各树种的CO2和H2O通量。这与传统的假设各树种垂直均匀分布相比，更加符合阔叶红松林的实际群落结构。 3）长白山阔叶红松林的能量平衡比EBR为0.800，居于国际同类观测的中上水平，涡相关观测数据较为可靠。CO2和H2O通量有明显日变化，夜间值较小且变化平缓，白天值呈单峰形的日变化。对2003—2007年生长季的模拟结果分析表明，CO2和H2O通量模拟值与涡相关实测值的回归线斜率分别为0.935和0.875，截距为-0.0136 mg•m-2•s-1和13.7 W•m-2，相关系数为0.655和0.622（n=30107）；CO2通量模拟和实测的平均值分别为-0.138和-0.134 mg•m-2•s-1，模型高估了2.99%；H2O通量模拟和实测的平均值分别为88.5和85.4 W•m-2，模型高估了3.63%，模拟效果较好。从季节变化来看，生长季初、末期（5月和9月）CO2和H2O通量较小，生长旺盛期（6—8月）通量值较高。CO2和H2O通量受环境因子的综合影响，其中，辐射和气温是主要限制因子。 4）对模型的主要参数和环境因子的敏感性分析表明，CO2通量对a1 (气孔导度的参数)、Vcmax、Ca (大气CO2浓度)变化的响应较强，而H2O通量对a1、LAI (叶面积指数)、Ta (气温)变化的响应较强。CO2通量对Ca的变化最为敏感，而H2O通量对其它环境因子的响应程度均高于CO2通量。与将冠层分为20层的方法相比，5层方法（Gaussion五点积分法）得到的碳吸收量和蒸发散量分别低估了25.3%和11.1%。这两种分层方法产生的差异，主要来自于不同层的辐射吸收和权重分配。