催化裂解色谱法及其应用

六十年代后期,人们提出了催化裂解色谱法(Catalytic Pyrolysis-Gas Chromatography,简称CPGC),并应用于某些高分子物质的分析和研究。这种方法是将高分子物质或其他非挥发性有机物同一定量的催化剂均匀混合或接触,裂解时在后者的催化作用下,改变产物的组成和分布,从而有效地对这类物质进行定性定量分析、链结构表征、催化裂解机

THE PHOTOELECTRIC PROPERTIES OF THIN-FILMS OF RARE-EARTH MONOPHOSPHIDES

The optical, electrical and photoelectric properties of rare earth monophosphides (LnP, Ln = La, Nd, Sm, Y, Dy and Yb) have been studied in thin films. The films exhibit semiconducting behaviour with energy gaps of 1.0-1.46 eV and n-type electrical conduction. Their resistivities are 10(-2) OMEGA-cm with corresponding Hall mobilities of 8.5-400 cm2 V-1 s-1. The films are deposited on a p-type silicon substrate in vacuum. Voltage-current characteristic measurements show that a p-n junction has been formed between LnP and silicon. Spectral sensitivity and a photovoltaic effect have been observed in LnP-Si junctions. They may be useful photoelectric materials.

COPU/PBMA交联共聚物网中游离末端对性能的影响

制备出一系列具有不同蓖麻油游离末端含量的样品,研究了它们的力学性能、转变与松弛行为以及形态结构。结果表明,全部样品在动态力学谱上只有一个T_g,呈现出一相行为;而用透射电子显微镜观察到的却是具有微相分离的两相体系。游离末端含量的增加使T_g移向低温,明显地增加了低温区的阻尼因子,使微相分离增大,相区大小约从3.5nm增加到20nm。次级松弛与游离末端含量无关。

Co,Mo在Al_2O_3和K在Co-Mo催化剂上的吸附和分布

钴离子在γ-Al_2O_3上的吸附速度比钼酸根离子的慢,但钴离子的视扩散系数比钼酸根的大(25℃下D_(Co)=1.2×10~(-5)cm~2/s,D_(Mo)=4.4×10~(-6)cm~2/s)。钴的吸附等温线符合Langmuir等温式,而钼的符合Freundlich等温式。在等孔容积共浸法制备催化剂时,低pH值下由于Al_2O_3吸附Mo较多而导致Co、Mo在颗粒中分布不均;在高pH值下由于Mo的吸附量锐减,可用共浸法得到分布均匀的催化剂。K_2CO_3在均匀型Co-Mo/Al_2O_3催化剂上的吸附等温线符合Langmuir等温式,虽然吸附量较大,但在浸渍液中含量足够时也可得到均匀分布的结果。

蓖麻油聚氨酯/聚甲基丙烯酸甲酯交联共聚物中氢键对性能的影响

本文在蓖麻油聚氯酯/聚甲基丙烯酸甲酯交联共聚物体系中,加入不同含量的丙烯酸共聚,详细考察了氢键对力学性能、相容性及形态结构的影响。结果表明:丙烯酸含量为7.5％时,材料的相容性最差,微区尺寸在几十纳米,这时的增韧效果最好。丙烯酸含量在5％和lO％时相容性最佳。

Molecular cloning and expression analysis of Ch-penaeidin, an antimicrobial peptide from Chinese shrimp, Fenneropenaeus chinensis

A new member of antimicrobial peptide genes of the penaeidin family, Ch-penaeidin, has been cloned from the haemocytes of Chinese shrimp, Fenneropenaeus chinensis, by reverse transcription PCR (RT-PCR), 3'-rapid amplification of cDNA end (3'-RACE) and smart cDNA methods. The Ch-penaeidin cDNA was 655 bp and the open reading frame of the cDNA encoded a 71 amino acid peptide. Ch-penaeidin contained a putative NH2-terminal signal Sequence (1-19) followed by a mature peptide (20-71). The sequence identify with other penaeidins from Litopenaeus vannamei and Litopenaeus setiferus is between 48% and 71%. The signal sequence of Ch-penaeidin is almost completely identical to that of other penaeidins, while differing relatively in the N-terminal domain of the mature peptide. Ch-penaeidin was designated as a novel member of class penaeidin 3 according to phylogenetic analysis. The Mature peptide. with a predicted molecular weight of 5589.32 Da, and a pI of 9.77, has eight positively charged amino acids and no negatively charged amino acids. The expression and distribution of Ch-penaeidin in Unchallenged shrimps were studied by RT-PCR, Northern blot and in situ hybridisation. The results showed that the Ch-penaeidin transcripts were detected in haemocytes (granular haemocytes), heart, gill, intestine, and subcuticular epithelia of the shrimp. and that Ch-penaeidin was constitutively expressed mainly in haemocytes. (C) 2003 Elsevier Ltd. All rights reserved.

高位虾池水色及其它环境因子变化对凡纳滨对虾生长的影响

本文研究了16口虾塘的饲料投喂量、水位、盐度、透明度、水温、pH、溶解氧浓度、NH3-N浓度、水色、对虾体长及浮游植物的种类和数量等水体理化因子和生物因子的变化。经过统计分析结果如下： 在养殖前4个月饲料的日平均投喂量基本上呈一个倒“U”型。即随着养殖时间的推移，饲料日平均投喂量逐渐增大，到养殖60 d左右，饲料日平均投喂量达到了最大值，然后进入一个平台期，平台期大约维持30 d左右，随后饲料日平均投喂量逐渐减少。在120 d~130 d饲料日平均投喂量降到最低点后又逐渐回升。 水位平均值变化趋势基本相同，均为前浅后深，即随着养殖时间的推移养殖水位平均值逐渐加深 。 盐度变化趋势基本相同，均为前低后高，即随着养殖时间的推移养殖水体盐度逐渐升高。 透明度的总体变化趋势为：早上透明度比下午大，前期透明度比后期大。 水温基本上是随着养殖时间的推移而逐渐下降。6:30的水温比17:30的水温低。且6:30水温与17:30水温基本上呈平行趋势。 pH变化的总体趋势为：前期较高，随着养殖时间的推移pH逐渐下降，到中期（90d左右）pH降到最低点，尔后又逐渐上升，略呈“V”字形。早上的pH比下午的低。且早上的pH与下午的pH基本上呈平行趋势，间或有较大波动。 6:30时溶解氧浓度的平均值随着养殖时间的推移而逐渐增高。17:30时溶解氧浓度的平均值在整个养殖过程中比较平稳。同时，17:30时溶解氧浓度的平均值高于6:30，养殖前期（前90d）这种趋势更明显。 NH3-N浓度的平均值随着养殖时间的推移而逐渐增高。在养殖后期NH3-N浓度的波动较大。同时，养殖过程中17:30时NH3-N浓度的平均值高于6:30。 6:30时出现9~21号水色，它们出现的比例分别为：9号占0.1%，10号占0.3%，11号占1.1%， 12号0.6%，13号1.5%，14号占3.7%，15号占7.1%，16号占17.5%，17号占22.0%，18号占15.9%，19号占13.7%，20号10.9%，21号占5.8%；17:30时出现11~21号水色，它们出现的比例分别为11号占0.1%， 12号占0.3%，13号占1.2%，14号占4.0%，15号占6.0%，16号占17.8%，17号占24.7%，18号占18.1%，19号占11.8%，20号占9.7%，21号5.7%。 在11种典型水色中共检出浮游植物67种。其中11号水色检出16种，优势种为诺马斜纹藻（占总数47.1%）和菱形海线藻（占总数29.8%）。12号水色共检出16种，优势种为原甲藻（占总数40.85%）和圆筛藻（占总数20.73%）。13号水色共检出16种，优势种为颤藻（占总数45.58%）。14号水色共检出18种，优势种为拟货币直链藻（占总数56.73%）和膝沟藻（占总数12.87%）。15号水色共检出18种，优势种为诺马斜纹藻（占总数64.76%）。16号水色共检出16种，优势种为拟货币直链藻（占总数69.93%）。17号水色共检出14种，优势种为诺马斜纹藻（占总数62.56%）和膝沟藻（占总数15.76%）。18号水色共检出21种，优势种为拟货币直链藻（占总数71.19%）。19号水色共检出18种，优势种为圆筛藻（占总数94.99%）。20号水色共检出18种，优势种为圆筛藻（占总数87.14%）。21号水色共检出15种，优势种为拟货币直链藻（占总数59.80%）和萎软几内亚藻（占总数17.57%）。 相关分析结果表明高位池理化因子中对水色的主要影响因素：17:30PH值、养殖生物量、17:30NH3-N、17:30 透明度、水交换量。 对体长的主要影响因素为 6:30溶解氧、水交换量、17：30水色、饲料投喂量、盐度、17:30透明度、17:30水温、6:30NH3-N。 对对虾本身生物学形状对体重的影响研究表明体长、头胸甲长、胸宽、额剑下缘刺数目对体重的通径系数达到显著水平，它们是直接影响体重的重要指标，其中体长对体重的直接影响（0.428**）最大，是影响体重的最主要因素，其次为头胸甲长（0.290**）和胸宽（0.245**），额剑下缘刺数对体重的直接影响（0.070*）较小；胸高与体重的相关程度很大（0.7923），但它与额剑上缘刺数对体重的直接影响都非常小，主要通过其他性状间接影响活体重，是影响体重的次要因素。

Determination of Total Arsenic and Arsenic Metabolites in Human Liver Hepatocytes

The effects of direct sampling and three digestion methods were investigated on the determination of arsenic in Chang liver hepatocytes after ultrasonic disintegration were investigated. The results showed that the efficiency of microwave digestion and obturator digestion was better than cold digestion and direct sampling. The day precision (present as RSD) of microwave digestion and obturator digestion were 2.1% and 1.2% the inter-day precision were 1.2% and 2.0%, respectively. The spike recovery for the total As in the sample is 95.7% - 108.1%. The As detection limits with these four sample treatment methods (including direct sampling) were 0.74 - 0.93 mu g/L. In addition, arsenic speciation in Chang liver hepatocytes was also analyzed using the hyphenated technique of high performance liquid chromatography coupled with inductively coupled plasma-mass spectrometry. The experimental results indicated that dimethylarsinic acid (DMA) and an intermediate metabolite of DMA were found lit Chang liver hepatocytes besides inorganic arsenic (As(III) and As(V)).

Factors influencing hemolytic activity of venom from the jellyfish Rhopilema esculentum Kishinouye

In this study, hemolytic activity of venom from the jellyfish Rhopilema esculentum Kishinouye and some factors affecting it were assayed. The HU50 of R. esculentum full venom (RFV) against chicken erythrocytes was 3.40 mu g/ml and a Hill coefficient value was 1.73 suggesting at least two molecules participated in hemolytic activity. The hemolytic activity of RFV was affected by some chemical and physical factors such as divalent cations, EDTA, (NH4)(2)SO4, pH and temperature. In the presence of Mg2+, Cu2+, Zn2+, Fe2+, Ca2+ ( >= 2 mM), Mn2+ (>= 1 mM), EDTA (>= 2 mM) and (NH4)(2)SO4, the hemolytic activity of RFV was reduced. RFV had strong hemolytic activity at the pH 6-10 and the hemolytic ratios were 0.95-1.19. Hemolytic activity was temperature-sensitive and when RFV was pre-incubated at temperatures over 40 degrees C, it was sharply reduced. (c) 2007 Elsevier Ltd. All rights reserved.

围栏封育对青海湖地区芨芨草草原群落特征的影响

选择青海湖地区围栏内封育和围栏外自由放牧的芨芨草草地为研究对象，用样线和样方相结合的方法进行群落调查，分析了围栏内外芨芨草草地的群落特征和地上生物量特点。结果表明：多年围栏封育使围栏内外群落类型发生了变化，围栏内为芨芨草＋裸花碱茅群落，围栏外为芨芨草＋赖草群落，且每个小样方中的物种数围栏内大于围栏外。围栏内外芨芨草群落的相似性系数达0．743。围栏外自由放牧区域的芨芨草种群优势地位有所加强，其重要值也大于围栏内的芨芨草。物种丰富度指数围栏外大于围栏内，多样性指数中Shannon-winner指数、Hill指数和丰富度指数具有同样的趋势，而均匀度指数和Simpson指数则是围栏内大于围栏外。围栏封育后群落地上生物量发生变化，地上总生物量和禾草类生物量均为围栏内〉围栏外，而杂类草和豆类毒杂草则是围栏内〈围栏外。

青藏高原高寒灌丛CO2通量日和月变化特征

采用涡度相关法对青藏高原高寒灌丛CO2通量进行连续观测的结果表明,青藏高原高寒灌丛CO2通量呈明显的日和月变化特征.就日变化而言,暖季(7月)CO2通量峰值出现在12:00左右(-1.19 g CO2/(m2•h)-1),08:00～19:00时CO2净吸收,而20:00～07:00为CO2净排放; 冷季(1月)CO2通量变化振幅极小,除11:00～17:00时少量的CO2净排放以外(0.11 g CO2/(m2•h)-1左右),其余时段CO2通量接近于零.从月变化来看,6～9月为CO2净吸收阶段,8月CO2净吸收最大,6～9月CO2净吸收的总量达673 g CO2/m2; 1～5月及10～12月为CO2净排放,共排放446 g CO2/m2,4月CO2净排放最大.全年CO2通量核算表明,无放牧条件下青藏高原高寒灌丛是显著的CO2汇,全年CO2净吸收量达227 g CO2/m2.

Characterizing CO2 fluxes for growing and non-growing seasons in a shrub ecosystem on the Qinghai-Tibet Plateau

To assess carbon budget for shrub ecosystems on the Qinghai-Tibet Plateau, CO2 flux was measured with an open-path eddy covariance system for an alpine shrub ecosystem during growing and non-growing seasons. CO2 flux dynamics was distinct between the two seasons. During the growing season from May to September, the ecosystem exhibited net CO2 uptake from 08:00 to 19:00 (Beijing Standard Time), but net CO2 emission from 19:00 to 08:00. Maximum CO2 uptake appeared around 12:00 with values of 0.71, 1,19, 1.46 and 0.67 g CO2 m(-2) h(-1) for June, July, August and September, respectively. Diurnal fluctuation Of CO2 flux showed higher correlation with photosynthetic photon flux density than temperature. The maximum net CO2 influx occurred in August with a value of 247 g CO2 m(-2). The total CO2 uptake by the ecosystem was up to 583 g CO2 m(-2) for the growing season. During the non-growing season from January to April and from October to December, CO2 flux showed small fluctuation with the largest net CO2 efflux of 0.30 g CO2 m(-2) h(-1) in April. The diurnal CO2 flux was close to zero during most time of the day, but showed a small net CO2 eff lux from 11:00 to 18:00. Diurnal CO2 flux, is significantly correlated to diurnal temperature in the non-growing season. The maximum monthly net CO2 eff lux appeared in April, with a value of 105 g CO2 m(-2). The total net CO2 eff lux for the whole non-growing season was 356 g CO2 m(-2).

由多个8031组成的锥体结构计算机

本文介绍了一种新型的并行计算机结构。这种结构是由21个8031单片机组成的.它特别适合于图像处理和模式识别.文中描述了该结构的原理,分析了它的特点,并举出几种算法的例子。

发育完整的灰岩风化壳及其矿物学与地球化学特征

对于碳酸盐岩土覆土壤成因、尽管碳酸盐岩风化残积成土说被多数学者认同，但由于碳酸盐岩中酸不溶物含量极低，在风化成土过程中会伴随着巨大的体积缩小变化，原岩结构和半风化带无法保留，从而缺失了探索上覆土壤物质来源的重要中间环节，使得这种观点缺乏野外宏观证据的支持。最近，我们在贵州、湖南等地发现了数个以泥质灰岩和泥质白云岩为基岩的碳酸盐岩风化壳剖面,尚保留有较好的原岩结构，具有明显的风化壳分带和过渡现象。这些风化壳剖面的发现为深入研究碳酸盐岩风化成土过程提供了良好的研究场所。本文选取了较为典型的吉首泥灰岩风化壳剖面，从矿物学地球化学的角度来探讨碳酸盐岩风化壳的形成过程和发育特征，结果表明该风化壳既遵循非碳酸盐岩（主要是结晶岩类）风化壳的发育特征，也具有自己独特的地球化学演化规律。风化壳总体特点受碳酸盐中的酸不溶物矿物组合及化学成分的影响甚至控制，风化非碳酸盐风壳相似的发育特征。吉首泥灰岩风化壳剖面的发育特征和作者早先提出 的碳酸盐岩风化成土的两阶段模式是一致的，即以碳酸盐矿物大量淋失、酸不溶物逐渐堆积或残积为特征的早期阶段和残积物进一步风化成土的阶段，后一阶段的演化类似非碳酸盐岩类的风化过程。

封闭式城市生活垃圾填埋场向大气释放汞的途径

利用自动测汞仪和动力学通量箱技术, 对武汉市某生活垃圾填埋场封闭的扩建部分向大气释放汞的途径进行了研究1结果发现, 封闭式垃圾填埋场释放汞的途径主要是通过地表, 而排气筒的释放很小. 观测期间地表汞的释放强度平均为(19215 ±24513) ng·(m2·h) - 1 , 比世界背景区域高出1～2 个数量级. 释放过程具有明显的昼夜变化规律, 白天高于夜间, 并在午间达到峰值. 光照强度与汞释放通量间的相关性最高, 达到0177 , 说明Hg( Ⅱ) 的光致还原作用是挥发态Hg0 生成的主要途径. 垃圾填埋场排气筒释放的气体中Hg0 的平均浓度为710～6819 ng·m- 3 , 远低于运行中的垃圾填埋场, 并且流速也很小.