二氧化碳-环氧丙烷共聚物的链结构控制

针对制约二氧化碳-环氧丙烷共聚物(PPC)规模化应用的玻璃化温度低的问题,提出了改进PPC链结构的3个方法,即提高共聚物的分子量、制备交联型PPC、合成区域规整结构PPC.通过研究链结构变化对PPC热性能和机械性能的影响,证明通过共聚物链结构的设计和控制,可以大幅度增强PPC的分子间作用力,从而提高了PPC的使用温度,改善了PPC的使用性能.

Sm~(3+)对甲醇电化学氧化反应的助催化作用

分别以相同面积的光滑 Pt电极和吸附了 Sm3+ 的铂电极作为工作电极 ,在酸性介质中采用循环伏安法对甲醇氧化进行测定 .结果表明 ,吸附了 Sm3+ 的 Pt电极上产生了更大的氧化电流 ,表明 Sm3+ 的加入对甲醇的电催化氧化起到了促进作用 .这一研究结果在直接甲醇燃料电池 ( DMFC)阳极催化剂研制方面具有较大的应用潜力

Water-soluble fluorescent nanospheres as fluorosensor for detection of Cu2+

A novel water-soluble fluorescent nanosphere as fluorosensor was prepared by emulsifier-free emulsion copolymerization of styrene with naphthalimide derivative (A). The fluorosensor was high sensitive for detection of Cu2+. Comparied with other fluorosensors based on organic fluorophore, it has two advantages. First, there is no pollution to environment in the use of it. Second, it can be used repeatedly.

顺、反式环丙烷衍生物异构体的区分

在化学电离条件下，研究了４种顺、反式环丙烷衍生物与丙酮和醋酸乙烯酯的分子－离子反应。异构体１，２的丙酮ＣＩ谱及其加合离子［Ｍ＋Ｈ＋Ａ］＋的ＣＩＤ谱都可以区分该对异构体。化合物２，３和４可以和质子化丙酮及质子化二聚体发生加合反应，但化合物１仅能与质子化丙酮发生加合反应。在醋酸乙烯酯的ＣＩ谱中，观察到４个化合物的质子化二聚体，其中异构体１，２的质子化Ｍ聚体的ＣＩＤ谱也能反映它们立体结构的差异。

A study of cokes used as anodic materials in lithium ion rechargeable batteries

A variety of cokes pretreated at different temperatures are used as anodic materials and their electrochemical characteristics are examined by cyclic voltammetry. It is found that for some cokes such as petroleum coke (preheated at 1300 degrees C), pitch coke (1300 degrees C), needle coke (1900 degrees C), metallurgical coke (1900 degrees C), high capacity and cyclic efficiency are achieved. Needle coke (1900 degrees C) and metallurgical coke (1900 degrees C) in particular give a capacity of over 200 mAh/g and a cyclic efficiency of nearly 100%, whereas poor performance is exhibited by those pretreated at higher or lower temperatures, e.g., petroleum cokes (500 degrees C, 2800 degrees C), pitch coke (500 degrees C) and needle coke (2800 degrees C). The cyclic voltammograms show two electrochemical processes, one at about 0.1 V vs. Li+/Li which is electrochemically reversible, and may be attributed to the intercalation/deintercalation of lithium ions while the other, at about 0.6 V vs. Li+/Li, is electrochemically irreversible and may be assigned to the decomposition of the electrolyte solvent, which leads to formation of the passive film on the anode surface. The experimental results strongly suggest that the pretreatment temperature of cokes and of the solvent are determining factors for the growth, structure and properties of the passive film.

C_(60)与苯及氘代苯的气相反应

1985年Kroto首先用质谱在激光蒸发石墨的氦气氛中检测到丰度占优势的以C_(60)和C_(70),从而以质谱法为主要手段的C_(60)研究迅速开展起来。一系列实验结果支持了Kroto猜测的C_(60)球形结构,并对C_(60)的气相反应行为有所认识。 1990年实现宏观量制取C_(60)后,气相C_(60)离子的研究内容更加广泛,Frieser在气相中

硝酸镧与冠醚(2,2)配合物的晶体及电子结构研究

用X-射线单晶衍射法测定了硝酸镧与冠醚(2,2)配合物的晶体结构,发现其具有与报道的Eu(NO_3)_3(2,2)配合物不同的配位方式.晶体属于三斜晶系,空间群P(?),晶胞参数为a=10.312(2)(?);b=12.745(3)(?);c=8.917(2)(?);α=103.79(2)°;β=112.73(2)°;γ=83.68(2)°;V=1049.5(5)(?)~3;F(000)=587.88;Z=2.结构用重原子法解出;R值为0.0292.用INDO法计算了配合物的净电荷分布,电子结构、键级.结果表明,镧与配位原子间的键具有一定程度的共价性.镧的5d轨道对共价性的贡献最大,而4f轨道基本上不参与成键.La-N比La-O(醚)间存在较强的作用,增大了配合物的稳定性.

LiF-KCl熔体的X-射线结构分析

目前多采用径向分布函数来描述熔盐的结构,虽然这种一维统计描述给出的信息有限,但它是迄今为止较为成熟的一种方法。实验上获得熔体的径向分布函数主要通过衍射法。在国际上日本等国家的研究人员对纯熔盐的衍射结构分析已经进行了多年的研究,由于混合熔盐的结构比较复杂,所以近些年才有关于混合熔盐X-射线衍射结构分析的报道,但只限于相同阳离子或相同阴离子的体系,对于LiF-KCl体系至今未见报道。

同位素稀释-火花源质谱法分析人参样品中微量元素

本文采用同位素稀释-火花源质谱法定量分析了吉林野山参,园参及高丽参中30多种微量元素的含量。测定下限2μg/g,相对标准偏差在5～28％以内。

Sources and preservation of organic matter in Plum Island salt marsh sediments (MA, USA): long-chain n-alkanes and stable carbon isotope compositions

Elemental (TOC, TN, C/N) and stable carbon isotopic (delta(13)C) compositions and n-alkane (nC(16-38)) concentrations were measured for Spartina alterniflora, a C-4 marsh grass, Typha latifolia, a C-3 marsh grass, and three sediment cores collected from middle and upper estuarine sites from the Plum Island salt marshes. Our results indicated that the organic matter preserved in the sediments was highly affected by the marsh plants that dominated the sampling sites. delta(13)C values of organic matter preserved in the upper fresh water site sediment were more negative (-23.0+/-0.3) as affected by the C-3 plants than the values of organic matter preserved in the sediments of middle (-18.9+/-0.8) and mud flat sites (-19.4+/-0.1) as influenced mainly by the C4 marsh plants. The distribution of n-alkanes measured in all sediments showed similar patterns as those determined in the marsh grasses S. alterniflora and T. latifolia, and nC(21) to nC(33) long-chain n-alkanes were the major compounds determined in all sediment samples. The strong odd-to-even carbon numbered n-alkane predominance was found in all three sediments and nC(29) was the most abundant homologue in all samples measured. Both delta(13)C compositions of organic matter and n-alkane distributions in these sediments indicate that the marsh plants could contribute significant amount of organic matter preserved in Plum Island salt marsh sediments. This suggests that salt marshes play an important role in the cycling of nutrients and organic carbon in the estuary and adjacent coastal waters. (C) 2003 Elsevier Ltd. All rights reserved.

紫花冷蒿挥发油成分的研究

采用水蒸气蒸馏法提取, 运用气相色谱-质谱联用法对香叶蒿挥发油化学成分进行了分析, 用气相色谱面积归一化法测定了各成分的质量分数. 结果鉴定出72个化合物, 主要成分为樟脑(33.136%), 桉树脑(23.419%), 6-甲基-2-乙烯基-1,3-庚二烯醛(8.414%), 孟烯醇(3.819%), 桥环萜烯酮(3.276%), 莰烯(2.454%), 1R-α-蒎烯(1.917%), 去甲基丁香酚(1.550%), α-松油醇(1.449%), 冰片(1.674%), β-香叶烯(1.165%), 百里香酚(0.329%)等. 研究表明紫花冷蒿挥发油主要为单萜及其氧化衍生物. 其挥发油成分的研究为挖掘其药用及食品香料工业的应用价值提供了科学依据.

不同放牧强度对植物及啮齿动物作用的研究

从栖息地结构特征决定啮齿动物群落组成的角度出发，通过分析不同放牧强度下植物地上部分生物量、植被组成、种的多样性以及不同放牧处理间相似性系数的变化，初步探讨了小哺乳动物对植被变化的反应，得到如下结论：１）在不同放牧强度下，植物地上部分生物量随放牧强度的增加而减少；植被组成中，优良牧草的比例随放牧强度的增加而降低，杂类草的比例随放牧强度的增加而升高。２）植物种的多样性指数随放牧强度的增加而升高。３）根田鼠种群密度随放牧强度的增加而逐渐降低。４）甘肃鼠兔种群受到重度、次重度放牧强度的严重影响而在这两个处理没有出现。其余处理中，随放牧强度的增加而逐渐减少，其平均密度与放牧强度呈显著的负相关（ｒ=-0.9321,df＝４，p＜0.01）。。5) 高原鼢鼠的新土丘数在重度、次重度放牧处理有大幅度的增加, 且明显高于次轻度和轻度放牧处理, 此时的新土丘数与放牧强度呈显著的正相关（ｒ=0.9383，df＝４，p＜0.01）。

三门峡宋家店黄土－古土壤序列的地层学研究及其古环境记录

The Sanmen Gorge area is located in the southernmost margin of the Chinese Loess Plateau with well developed eolian deposit sequence for the past 2.6 Ma, providing a key site for further understanding of the evolution history of the East Asian monsoon since late Pliocene. This study attempted to characterize the stratigraphy and paleoclimate record of the loess-paleosol sequence in the Songjiadian section. The work involved includes systematic field investigation, paleomagnetic and rock magnetic analyses, grain size and major chemical composition analyses, and multiple proxy measurements of magnetic susceptibility, color reflectance and the ratio of CBD-dissolvable iron to the total iron (FeD/FeT). By comparisons of the Songjiadian section with well studied loess sections in the west of the Sanmen Gorge, the spatial variations of the East Asian monsoon was evaluated for some periods during which typical loess or paleosols developed. The following conclusions have been obtained. 1. Stratigraphic correlation and paleomagnetic result demonstrate that the loess-paleosol sequence in the Songjiadian section was accumulated from 2.6Ma, and is generally a complete and continuous loess sequence. However, notable differences from type loess sections have been identified for a few loess and paleosol units, featured by absence or anomalous thickness in the Songjiadian section. 2. Magnetic susceptibility and chromaticity records clearly reveal the loess-paleosol cycles, and indicate that the Sanmen Gorge area has been warmer and more humid than the Lingtai and Jingchuan sections in the western central Loess Plateau since the Early Pleistocene. 3. Grain size distribution patterns are typical of eolian dust, and show a great similarity between various units of loess and paleosols, and between the S32 and the underlying Red Clay through the Songjiadian profile, suggesting the eolian origin for the loess, paleosols and the Red Clay. 4. Comparison of the FeD/FeT curves from different loess sections indicates a stronger chemical weathering in the Songjiadian section and notable enhancement around 1800, 800 and 600 ka BP, implying the strengthening of the East Asian monsoon during these periods. In contrast, it was weakened at 1100 ka BP. Generally, the summer monsoon shows a gradually decreasing trend during the entire Pleostocene, but the spatial pattern typified by an increasing trend in weathering intensity from north to south remained the same. 5. The loess unit L9 in the Songjiadian section displays two geomagnetic field anomalies with the midpoint ages of 0.917 and 0.875 Ma respectively, with a segment of 12 ka. They are demonstrated to be equivalent to the Santa Rosa and Kamikatsura geomagnetic excursions. 6. Magnetite is the main magnetic carrier for both loess and paleosols. Maghemite concentration is higher in paleosols than in loess, and is an important carrier for the enhanced magnetic susceptibility in paleosols. Magnetic fabric analysis suggests a dominant N-S wind direction prevailing in the L9 and L15, while the summer winds were dominantly in NNE-SSW direction during the S8 period, notably differing from previous studies.

滇西北雪鸡坪斑岩铜矿S，Pb同位素组成及对成矿物质来源的示踪

雪鸡坪斑岩铜矿位于西南三江构造火成岩带义敦岛孤带，其成矿斑岩为印支期石英闪长玢岩和石英二长宽岩。研究对该矿区安山岩、矿化斑岩和矿石矿物系统进行S，Pb同位素分析结果表明：金属硫化物的δ34S值为-3．1‰～＋0．7‰，平均值为-1．1‰，与矿化斑岩的硫同位素组成（-1．4‰和-1．5‰）一致，均落入幔源硫范围，表明硫主要来自岩浆；δ34S黄铁矿（-1．8‰～＋0.7‰，平均0．5‰）〉δ34S黄铜矿（-2．2‰～0．0‰，平均-1．2‰）〉δ34S方铅矿（-3．1‰～1．3‰，平均-2．4‰），硫同位素分馏基本达到平衡。矿石矿物（208Pb／204Pb=37．917～38．230，平均值38．075；207Pb／204Pb-15．528～15．614，平均值15．571；206Pb／204Pb=17．929～18．082，平均值17．981）与矿化斑岩（208Pb／204Pb=37．832、37．883，207Pb／204Pb=15．529、15．538，206Pb／204Pb=17．906、17．910）以及安山岩（208Pb／204Pb=37．816～37．884，207Pb／204Pb-15．549～15．562,206Pb／204Pb=17．845～17．919）的初始铅组成基本一致，变化范围较小，表明三者具有相同的来源；在铅构造模式图上，所有样品铅同位素均位于造山带演化线上或附近，在铅同位素源区判别图中，均落入造山带和下地壳区域，这表明Pb主要来源于壳幔混合。雪鸡坪铜矿S，Pb同位素组成共同指示成矿物质主要来自于深部岩浆，这种岩浆可能主要起源于俯冲洋壳板片的部分熔融并受到少量地壳物质的混染。