Catalytic combustion of CH4 and CO on La1-xMxMnO3 perovskites

The activities of perovskites depend on compositions and preparation methods. Various perovskites, La1-xMxMnO3 (M=Ag, Sr, Ce, La), have been prepared by two different methods (co-precipitation and spray decomposition). The new preparation method, spray decomposition, produced perovskites of a high surface area of over 10 m(2)/g. The catalytic activities for CH4 and CO oxidation have been studied on a series of catalysts, La1-xMxMnO3. The perovskite-type oxide, La0.7Ag0.3MnO3, shows the highest catalytic activity: the complete conversion of CO and CH4 at 370 and 825 K, respectively. (C) 1999 Elsevier Science B.V. All rights reserved.

Studies of ferrocene derivative diffusion and heterogeneous kinetics in polymer electrolyte by using microelectrode voltammetry

The heterogeneous electron transfer rate constants (k(s)) of seven ferrocene derivatives were estimated using cyclic voltammograms under mixed spherical/semi-infinite linear diffusion and steady-state voltammetry at a microdisk electrode in polymer electrolyte. The k(s) and diffusion coefficient (D) are both 100 to 1000-fold smaller in polymer solvent than in monomeric solvents, and the D and k(s) decrease with increasing polymer chain length. The results conform to the difference of viscosity (eta) or relaxation time (tau(L)) for these different solvents. The k(s) and D increase with increasing temperature, and the activation barriers of the electrode reaction are obtained. The influences of the substituting group in the ferrocene ring on k(s) and D are discussed. The k(s) are proportional to the D of the ferrocene derivatives, which indicates that solvent dynamics control the electrode reaction. (C) 1998 Elsevier Science S.A.

BaLaB_9O_(16):Re(Re=Eu,Tb)的真空紫外光谱特性的研究

近几十年来,人们对稀土离子的发光已进行了大量的研究,这些研究主要集中在紫外可见波段,对真空紫外区的光谱与能级研究的较少,相关光谱与能级缺乏足够的认识。近年来,随着大屏幕PDP的发展,寻找新型高效真空紫外激发的荧光体(等离子荧光体)已成为目前发光领域的研究热

Intel 8279芯片在8位和16位米字LED显示电路中的应用

本文简要介绍了16段米字LED字符管的动态扫描，以及通用显示和键盘接口器件Intel8279芯片的显示接口结构和功能，讨论了通过一定的附加电路来扩展Intel8279的显示功能，使之控制8位和16位的米字LED字符管的动态显示，并结合两种具体的硬件电路和程序，说明了两种方案的实现方法和工作原理。

CRYSTAL-STRUCTURES OF LN(NO3)(3) (LN=EU,LU) COMPLEXES WITH A CROWN-ETHER (16-CROWN-5)

The crystal structures of Ln(NO3)(3)(Ln = Eu,Lu) complexes with 16-crown-5 are reported. In [Eu(NO3)(2)(CH3CN)(16-crown-5)][Eu(NO3)(4)(H2O)2].1/2(16-crown-5) one Eu-III ion is coordinated to two bidentate nitrate ions, one acetonitrile molecule and five o

水溶性聚合物和两亲聚合物 16.聚苯乙烯/聚丙烯酰胺嵌段聚合物的合成和表征

采用聚偶氮酯引发剂,合成了聚苯乙烯/聚丙烯酰胺嵌段聚合物(PSt/PAM)。考察了含偶氮基聚苯乙烯预聚物(pre-PSt)在1,4-二氧六环中引发AM的聚合反应行为,讨论了影响第二单体转化率和聚苯乙烯均聚物含量的因素。用元素分析、溶解性、红外光谱、DSC、TG和裂解色谱表征了PSt/PAM嵌段聚合物。

水溶性聚合物和两亲聚合物——10.两亲聚合物PAMC_(16)S的自组装有序膜

用自组装技术在金(纯金和经阳极氧化的金)表面上获得了新型两亲聚合物PAMC_(16)S的有序膜。用接触角测试,XPS谱和电化学分析等方法对自组装膜进行了表征。根据膜表面的润湿性,金表面的自组装膜是疏水的,亲水的磺酸基团连于金表面,而疏水的碳氢链从表面伸展出。XPS实验结果支持金表面上单层膜的疏水结构。聚合物单层膜复盖的金电极起到含有针孔缺陷的阻膈型电极的作用。单层膜在法拉第反应中显示很强的吸附稳定性,说明聚合物LB膜在潜在应用中有其特有的特点。

n-C_(16)H_(33)NH_3X和(n-C_(16)H_(33)NH_3)_2MX_4的红外光谱研究

在室温和液氮温度下研究了(n-C_(16)H_(33)NH_3)_2MX_4(简称C_(16)MX)及其相应化合物n-C_(16)H_(33)NH_3X(简称C_(16)X)于4000～50cm~(-1)范围的红外光谱。结果表明,它们都形成N-H…X型氢键,氢键强度是C_(16)X大于C_(16)MX。后者氢键的强度是按Cl>Br>I的顺序递减。C_(16)MX的光谱性质可按金属离子性质分为Cu~(2+)(Cu~(2+)、Cd~(2+)、Mn~(2+))和Zn~(2+)(Zn~(2+)、Co~(2+))两组,阴离子配位多面体的形状对其光谱性质有明显影响。还比较了室温与低温下的远红外光谱,证明了M—X键是离子键。

核磁共振波谱仪MLEV-16宽带去耦系统

在FX-100核磁共振波谱仪上建立了MLEV-16宽带去耦系统.对去耦电路的各级信号进行了分析,说明了MLEV-16去耦电略的控制关系.利用去耦电路实现了由计算机和可编程序器控制的宽带去耦,用波谱仪原有去耦功率作了~(13)C{F~(19)}氟宽带去耦的碳-13谱的观测,去耦范围达12.4kHz,可以满足大部分有机氟化物的~(13)C核磁共振研究。

Molecular identification of 16 Porphyra lines using sequence-related amplified polymorphism markers

Sequence-related amplified polymorphism (SRAP) is a novel molecular marker technique designed to amplify open reading frames (ORFs). The SRAP analytic system was set up and applied to Porphyra germplasm identification in this study for the first time. Sixteen Porphyra lines were screened by SRAP technique with 30 primer combinations. In the analysis, 14 primer combinations produced stable and reproducible amplification patterns in three repetitive experiments. Among the total 533 amplified fragments, 522 (98%) were polymorphic, with an average of 38 fragments for each primer combination, ranging in size from 50 to 500 bp. The 533 fragments were visually scored one by one and then used to develop a dendrogram with Unweighted Pair-Group Method Arithmetic Average (UPGMA), and the 16 Porphyra lines were divided into two major groups at the 0.68 similarity level. From the total 533 fragments, I I amplified by two primer combinations, ME1/EM1 and ME4/EM6, were used to develop the DNA fingerprints of the 16 Porphyra lines. The DNA fingerprints were then converted into binary codes, with I and 0 representing presence and absence of the corresponding amplified fragment, respectively. In the DNA fingerprints, each of the 16 Porphyra lines has its unique binary code and can be easily distinguished from the others. This is the first report on the development of SRAP technique and its utilization in germplasm identification of seaweeds. The results demonstrated that SRAP is a simple, stable, polymorphic and reproducible molecular marker technique for the classification and identification of Porphyra lines. (c) 2007 Elsevier B.V. All rights reserved.

Development of expressed sequence tags from the bay scallop, Argopecten irradians irradians

The bay scallop, Argopecten irradians irradians, introduced from North America, has become one of the most important aquaculture species in China. Inan effort to identify scallop genes involved in host defense, a high-quality cDNA library was constructed from whole body tissues of the bay scallop. A total of 5828 successful sequencing reactions yielded 4995 expressed sequence tags (ESTs) longer than 100 bp. Cluster and assembly analyses of the ESTs identified 637 contigs (consisting of 2853 sequences) and 2142 singletons, totaling 2779 unique sequences. Basic Local Alignment Search Tool (BLAST) analysis showed that the majority (73%) of the unique sequences had no significant homology (E-value >= 0.005) to sequences in GenBank. Among the 748 sequences with significant GenBank matches, 160 (21.4%) were for genes related to metabolism, 131 (17.5%) for cell/organism defense, 124 (16.6%) for gene/protein expression, 83 (11.1%) for cell structure/motility, 70 (9.4%) for cell signaling/communication, 17 (2.3%) for cell division, and 163 (21.8%) matched to genes of unknown functions. The list of host-defense genes included many genes with known and important roles in innate defense such as lectins, defensins, proteases, protease inhibitors, heat shock proteins, antioxidants, and Toll-like receptors. The study provides a significant number of ESTs for gene discovery and candidate genes for studying host defense in scallops and other molluscs.

中国海塔螺科系统分类学和动物地理学研究

塔螺科是软体动物门中种类最多的科，全世界种类超过5，000种，在分类系统学中占有相当重要的地位。塔螺为世界性分布，以热带、亚热带和温带海域分布最多。塔螺科动物肉体可食用，贝壳造型独特、色泽鲜丽，深受贝壳收藏爱好者喜爱。作为重要的捕食者和被捕食者，塔螺是底栖生物食物链的重要环节。 中科院海洋生物标本馆现馆藏大量的塔螺标本，但一直没有进行系统的分类学研究，仅有一些零星的报道，咫需进行深入研究。本论文主要采用传统的形态分类方法结合其生态习性和地理分布，对其进行系统的分类学研究,详细描述中国的属、种及分布，澄清近似种和疑难种，发现新种和新记录种，从而丰富了我国海洋生物多样性的资料。同时研究了该动物类群区系组成分析和动物地理学，阐明了我国塔螺科的区系特点，并确定其在世界上的地位。 经系统研究和鉴定，发现中国科学院海洋生物标本馆馆藏塔螺种类共203种，隶属于8亚科，54属，其中发现1新亚属，16新种，81新记录种。我国塔螺动物在区系组成上属印度－马来区系的一部分。中国海塔螺科区系组成中，以热带和亚热带成分占绝对优势，在这两个区系中共发现分布种类160种，占总种数的79.8％。中国海塔螺科物种组成与日本南部和菲律宾塔螺的物种组成有些差异，本文描述的203种笔螺与日本共有种为93种，与菲律宾共有种为63种，相似性指数分别为41.99％和41.86％。塔螺科种大多属热带和亚热带种类，因此在中国常见于浙江、福建、广东、台湾、海南附近海域和西沙、南沙群岛。

菲律宾蛤(Ruditapes philippinarum)生理能量学的研究

本研究在实验室内采用静水系统以典型滤食性贝类菲律宾蛤仔为实验对象，从生理生态学的角度研究了体重和环境因子对菲律宾蛤仔摄食生理活动的影响，探讨了滤食性贝类的摄食机制和贝类本身对环境的适应性。同时，对蛤仔的碳代谢和能量收支进行了研究，建立了不同温度和饵料浓度下的能量收支方程。实验的主要结果如下：1．温度的影响在9±0.1℃，16±0.5℃，22±0.2℃，26±0.6℃四个温度下对菲律宾蛤仔的滤食率FR、清滤率CR、吸收率AE进行了测定。结果表明：在9-22℃温度范围内蛤仔滤食率、清滤率、吸收率均随温度的升高而增大，在22℃达到最大值，并且各温度间差异显著(ANOVA，P<0．05)。当温度达到26℃时，滤食率、清滤率、吸收率均有所下降，但和22℃值相比较差异并不显著(ANOVA，P>0．2)。这表明蛤仔生长的最适温度应当在22℃左右。对不同体重蛤仔的实验表明小个体蛤仔比大个体对温度有更高的敏感性。碳最小需求量MCR、生长余力(SFG)和生长效率均受温度的显著影响，在较低温度下(9℃)SFG出现负值。经计算9℃，16℃，22℃，26℃下的能量收支方程分别为：2．体重的影响蛤仔摄食率、清滤率、呼吸率都随个体体重的增加而增大，它们之间呈幂函数关系Y=aX~b(b值均小于1)；而单位体重的摄食率、清滤率、呼吸率随个体体重的增加而减小。吸收率和体重无明显的相关性，体重对生长效率无显著影响。蛤仔的碳最小需求量MCR、生长余力均和软体部干重呈幂函数关系Y=aX~b，b值在实验的四个温度下分别为0．43±0．12和0,78±0．09。3．饵料浓度的影响在实验的饵料浓度范围内(2．33-6．15mgPOM／L)，水温15℃，蛤仔摄食率和清滤率随着饵料浓度的增加而增大，呈幂函数关系(y=aX~b)。当饵料浓度达到一定值后，清滤率迅速下降，而摄食率只略微有所下降，基本上保持平稳不变。这说明蛤仔可以通过调节清滤率来稳定其摄食率，对环境具有生理适应性。蛤仔吸收率与饵料浓度无显著的相关性，不同饵料浓度其吸收率始终保持在57．93±2．94％左右。水温15℃，投喂小球藻的条件下，计算得出蛤仔(壳长3．53±0．02cm、软体部干重0．41±0．02g)产生假粪的饵料阈值为2.16mgPOM／L。饵料浓度对蛤仔生产碳有明显的影响，在实验的饵料范围内生产碳随着饵料浓度的增加而增加，在低浓度饵料时，生产碳出现负值。蛤仔的SFG随饵料浓度的增加而增加，在1．54±0．12mgPOM／L时蛤仔的生长余力出现负值。实验发现摄食能随温度变化显著而代谢能变化相对不明显，这表明对蛤仔生长来说饵料浓度可能是比温度更重要的环境因子。16℃投喂小球藻时蛤仔在不同饵料浓度下的能量收支方程为：4．底质的影响温度为17℃，饵料为三角褐指藻、浓度为2．87±1．07mgPOM／L(无假粪产生)。实验测定蛤仔在铺砂以后，摄食率和清滤率都增加了大约2倍，差异极显著(ANOVA，P<0．01)。实验中对蛤仔的吸收率也进行了对比研究。结果表明：铺砂组蛤仔的吸收率比未铺砂组提高了10．71士4．57％，经单因子方差检验铺砂和未铺砂时蛤仔吸收率差异显著(ANOVA，P<0．05)。实验表明底质对蛤仔摄食生理和代谢有显著的影响，这和实际生产中发现底质对蛤仔生长有明显影响是一致的。

Radical scavenging activity of protein from tentacles of jellyfish Rhopilema esculentum

In this study, radical scavenging activity of protein from tentacles of jellyfish Rhopilema esculentum (R. esculentum) was assayed including superoxide anion radical and hydroxyl radical scavenging. The protein samples showed strong scavenging activity on superoxide anion radical and values EC50 of full protein (FP), first fraction (IFF), second fraction (SF), and 30% (NH4)(2)SO4 precipitate (Fr-1) were 2.65, 7.28, 1.10, and 22.51 mu g/mL, respectively, while values EC50 of BHA, BHT, and alpha-tocopherol were 31, 6 1, and 88 pg/mL, respectively. Also, the protein samples had strong scavenging effect on hydroxyl radical and the values EC50 of FP, FF, SF, Fr-1, and Fr-2 were 48.91, 27.72, 1.82, 16.36, and 160.93 mu g/mL, but values EC50 of Vc and mannitol were 1907 and 4536 mu g/mL, respectively. Of the five protein samples, SF had the strongest radical scavenging activity and may have a use as a possible supplement in the food and pharmaceutical industries. The radical scavenging activity was stable at high temperature so that R. esculentum may be used as a kind of natural functional food. (c) 2005 Elsevier Ltd. All rights reserved.

Spatial variations of size-fractionated chlorophyll, cyanobacteria and heterotrophic bacteria in the Central and Western Pacific

Geographic and vertical variations of size-fractionated (0.2-1 mu m, 1-10 mu m, and >10 mu m) Chlorophyll a (Chl.a) concentration, cyanobacteria abundance and heterotrophic bacteria abundance were investigated at 13 stations from 4 degrees S, 160 degrees W to 30 degrees N, 140 degrees E in November 1993. The results indicated a geographic distribution pattern of these parameters with instances of high values occurring in the equatorial region and offshore areas, and with instance of low values occurring in the oligotrophic regions where nutrients were almost undetectable. Cyanobacteria showed the highest geographic variation (ranging from 27x10(3) to 16,582x10(3) cell l(-1)), followed by Chl.a (ranging from 0.048 to 0.178 mu g l(-1)), and heterotrophic bacteria (ranging from 2.84x10(3) to 6.50 x 10(5) cell l(-1)). Positive correlations were observed between nutrients and Chl.a abundance. Correspondences of cyanobacteria and heterotrophic bacteria abundances to nutrients were less significant than that of Chl.a. The total Chl.a was accounted for 1.0-30.9%, 35.9-53.7%, and 28.1-57.3% by the >10 mu m, 1-10 mu m and 0.2-1 mu m fractions respectively. Correlation between size-fractionated Chl.a and nutrients suggest that the larger the cell size, the more nutrient-dependent growth and production of the organism. The ratio of pheophytin to chlorophyll implys that more than half of the > 10 mu m and about one third of the 1-10 mu m pigment-containing particles in the oligotrophic region were non-living fragments, while most of the 1-10 mu m fraction was living cells. In the depth profiles, cyanobacteria were distributed mainly in the surface layer, whereas heterotrophic bacteria were abundant from surface to below the euphotic zone. Chl.a peaked at the surface layer (0-20 m) in the equatorial area and at the nitracline (75-100 m) in the oligotrophic regions. Cyanobacteria were not the principle component of the picoplankton. The carbon biomass ratio of heterotroph to phytoplankton was greater than 1 in the eutrophic area and lower than 1 in oligotrophic waters.