69 resultados para indirizzo :: 908 :: Processi e materiali


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以高纯氧化钇中稀土杂质的ICP-AES测定为例,研究了基体对分析元素谱线强度的影响及基体效应与工作条件的关系,指出基体效应除主要来自分析物进样效率的降低外,大量基体进入ICP降低了激发温度并对分析物的电离产生抑制作用,提出用Sc内标法代替通常的基体匹配法来补偿基体效应。进行了折衷条件选择及取样量确定等研究。实样分析表明,内标法和基体匹配法所得结果一致,加入回收率为87—120%,精度也符合分析要求。

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The full-length cDNA sequence (3219 base pairs) of the trehalose-6-phosphate synthase gene of Porphyra yezoensis (PyTPS) was isolated by RACE-PCR and deposited in GenBank (NCBI) with the accession number AY729671. PyTPS encodes a protein of 908 amino acids before a stop codon, and has a calculated molecular mass of 101,591 Daltons. The PyTPS protein consists of a TPS domain in the N-terminus and a putative TPP domain at the C-terminus. Homology alignment for PyTPS and the TPS proteins from bacteria, yeast and higher plants indicated that the most closely related sequences to PyTPS were those from higher plants (OsTPS and AtTPS5), whereas the most distant sequence to PyTPS was from bacteria (EcOtsAB). Based on the identified sequence of the PyTPS gene, PCR primers were designed and used to amplify the TPS genes from nine other seaweed species. Sequences of the nine obtained TPS genes were deposited in GenBank (NCBI). All 10 TPS genes encoded peptides of 908 amino acids and the sequences were highly conserved both in nucleotide composition (>94%) and in amino acid composition (>96%). Unlike the TPS genes from some other plants, there was no intron in any of the 10 isolated seaweed TPS genes.

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2007年夏季对黄海冷水团及邻近海域共48个站位的小型底栖动物组成、丰度和生物量,以及环境因子进行了科考研究。所调查站位的小型底栖动物平均丰度达2194 ± 1598 inds./10cm2,其中北黄海17个站位平均丰度为3408 ± 1578 inds./10cm2,南黄海31个站位平均丰度为1529 ± 1121 inds./10cm2。调查站位平均生物量为1839 ± 1289 g dwt/10cm2,其中北黄海站位平均生物量为2760 ± 1340g dwt/10cm2,南黄海平均生物量为1335 ± 902g dwt/10cm2。在分选出的共18个小型底栖动物类群中,丰度上均以自由生线虫占绝对优势,达总量的88%,且在南(88.3%)、北黄海(87.7%)基本无差异。在生物量上,同样以自由生线虫贡献最多(42%),多毛类居次(22%),其他生物量较多的还有桡足类(13%)和甲壳类幼体(12%)。在小型底栖动物的垂直分布上,分布于沉积物表层0-2cm的小型底栖动物占79%,次表层2-5cm占17%,最底层5-8cm仅占4%。统计分析表明研究站位小型底栖动物丰度和生物量与沉积物叶绿素a、有机质含量、中值粒径显著或极显著正相关,与水深呈极显著负相关,此外小型底栖动物生物量与沉积物粉砂粘土含量显著负相关。 同年秋季搭载开放航次对黄海5个站位、东海3个站位、南海2个站位的小型底栖动物组成、丰度和生物量,以及环境因子进行了调查研究。对三个海域小型底栖动物的比较研究发现,平均丰度以黄海最高,达2132 ± 946 inds./10cm2,东海次之,为1954 ± 2047 inds./10cm2,而南海仅156 ± 56 inds./10cm2;三海域的平均生物量依次为2193 ± 1148 g dwt/10cm2、1865 ± 1555 g dwt/10cm2和212 ± 22 g dwt/10cm2。在分选出的共14个小型底栖动物类群中,丰度上均以自由生线虫占绝对优势,分别占总量的85%、89%、85%。在生物量上,黄海以自由生线虫贡献最多(33%),多毛类居次(18%);东海二者比例相近(约37%),而南海则以多毛类占绝对优势(56%),线虫居次(25%)。在小型底栖动物的垂直分布上,三个海区差异较大:分布于沉积物表层0-2cm的小型底栖动物在黄海高达90%,东海仅46%,在南海为63%。统计分析表明,本研究站位小型底栖动物丰度与沉积物中的叶绿素a及脱镁叶绿素a含量和底温呈显著正相关,与水深呈显著负相关。该结果与本航次之后在广东湛江和海南以东的南海海域开展的908调查结果形成了鲜明对照,后者的小型底栖动物及线虫丰度与沉积物中有机质含量呈显著正相关,与水深呈显著负相关,表明近海受人类干扰影响较大。 本文利用微宇宙实验方法,来确定不同浓度梯度的Cu、Pb以及Cu/ Pb混合重金属污染物对青岛湾小型底栖动物(主要是线虫)的影响。加入污染物后,分别在1、3、7、14、21天进行取样分析。结果显示,Cu和Cu/Pb混合高浓度实验单元组的线虫丰度除在第21天有较明显减少外,在整个实验周期内基本没有变化,分析可能系高浓度Cu的固定作用从而使小型底栖动物无法腐烂降解造成的。同一时间尺度上,各重金属污染物实验单元的线虫丰度均高于(或接近于)空白对照组,较高浓度的重金属污染物实验单元的线虫丰度高于(或接近于)较低浓度重金属污染物实验单元,Cu/Pb混合低浓度实验单元的线虫丰度高于同一时间尺度Cu低浓度和Pb低浓度实验单元。推测是由于采样点的线虫群落中存在对Cu和Pb的耐受种或者“机会种”造成的。

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本论文依托我国近海海洋综合调查与评价专项(908专项)的“CJ12区块海底底质调查与研究”课题,利用专项课题调查所获的927个表层沉积物、4条悬浮体断面和7根重力柱样进行了沉积学、矿物学、元素地球化学和同位素地球化学的分析测试以及水文与悬浮体的现场观测,编制了研究区沉积物类型图,探讨了全新世以来沉积环境的演化。 沉积物粒度、常微量元素、粘土矿物资料表明东海内陆架泥质区现代沉积作用稳定,沉积物总体呈NE-SW方向运移,它们主要受控于长江来源物质与闽浙沿岸流、台湾暖流等水动力条件。沉积物空间分布上可划分为长江物质控制区和闽江物质控制区两部分。因子分析表明,研究区沉积物主要为陆源细颗粒碎屑沉积,还有少量陆源粗颗粒碎屑和海洋自生的混合沉积、火山碎屑和海洋化学混合沉积。 东海内陆架泥质区夏季悬浮体质量浓度平面分布,近岸浓度明显高于远岸,最高值出现在闽江、瓯江等河口区附近。垂向上浓度随水深的增加而增大,海底地势凸起位置出现高浓度区。控制东海内陆架泥质区悬浮体质量浓度分布规律的主要因素为物源供给和海流状况。现场体积浓度平面分布表现出自北向南逐渐降低的趋势,而垂向分布总的规律表现为表层水体浓度较低,且分布均匀,而在水深10m和30m左右浓度出现高值,30m以下水体随着深度增大,呈小幅度增大趋势。现场平均粒径垂向分布的最大值出现在不同的层位,但总体表现出由北向南逐渐降低的趋势,且多数站位粒度频率曲线尾部出现了“上升尾”。 基于对7个沉积物柱样的分析,探讨了研究区全新世以来沉积作用与沉积环境的演化。年代学结果表明全新世以来泥质区沉积速率介于26.41-50.41cm/ka之间,在此基础上以粒度敏感粒级、粘土矿物组合恢复了闽浙沿岸流强度,以敏感性微量元素指标恢复了氧化还原环境,以有机碳、生物硅、微量元素组合指标推断了古生产力演化。结果表明,研究区8400-4000aB.P.表现为氧化还原环境偏向于富氧,沿岸流较强,古生产力和上升流强度较弱;4000-1300aB.P.期间沿岸流、氧化还原环境、古生产力和上升流强度均表现为高度波动期;1300aB.P.至今,表现为氧化还原环境偏向于贫氧,沿岸流逐渐变弱,古生产力和上升流则有逐渐增强的趋势。根据CJ12-1011孔沉积物<9.71µml粒级平均粒径、TiO2/Al2O3比值、(蒙皂石+伊利石)/高岭石比值推断东亚冬季风演化过程,可以识别出全新世12次降温事件,与格陵兰冰心和敦德冰心氧同位素测试结果对应性较好,且在其它区域不同的材料中也能找到相应的降温证据,揭示全球气候变化的区域性相应。

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本研究利用皱纹盘鲍的EST序列进行单核苷酸多态(SNP)标记开发;对等位基因特异性PCR(AS-PCR)方法进行了优化,使之适合SNP基因型分析;对一个作图家系开发基因相关SNP标记,并对标记在子代个体中的分离情况进行了分析,探讨了借助SNP在遗传连锁图谱上定位功能基因的方法。 对大约5800条EST序列进行拼接,共获得含有4条以上序列的contig 150个,在86个含有单碱基突变位点的contigs中发现SNP 302个,碱基置换类型A/G(C/T)、A/C(G/T)、A/T、C/G的位点数目分别为147、90、21、16个。50个contigs在BLASTx分析后具有匹配(E值小于1E-5),其中的220个SNPs全部为同义cSNPs,位于遗传密码子的第三简并位。粗略估算,皱纹盘鲍核基因组中SNP的平均分布密度不低于1%。 通过扩增DNA pool后产物直接测序共验证了28个SNP。PCR直接测序法操作简单,结果可靠,一次测序可能验证多个位点,有时还可以发现新的突变位点。通过重点研究引物3’端不同错配对PCR扩增的影响,对AS-PCR的引物设计原则及反应条件进行了探讨及优化,发现在AS引物的3’端倒数第二位引入额外的强错配后,AS-PCR检测SNP的特异性会得到很大的提高,从而使AS-PCR可以满足小规模的SNP基因型分析。 根据EST-contig或者单一的EST序列设计PCR引物74组,其中43组可以特异扩增皱纹盘鲍基因组DNA。用这些引物扩增一个作图家系的父母本,并对PCR产物纯化后分别进行双向直接测序,在18个基因片段中发现了86个SNP,其中82个是新SNP,并且绝大多数SNP位于内含子序列中。这些SNP在父母本中的基因型,在多数情形下,是一方为纯合(AA),而另一方为杂合(AB);父母本均为杂合和均为纯合的形式则较少。在父母本中杂合形式的SNP位点,理论上可以在子代中发生分离。 在每个基因的内含子中选择父母本基因型为AA×AB或者AB×AA的SNP位点,设计AS-PCR分型引物并检测123个子代个体的基因型。在对9个基因中的11个SNP位点(包括5个母本标记和6个父本标记)进行子代基因型分析后发现,2个位点不符合孟德尔1:1分离(P < 0.05),符合预期分离比率的9个位点存在较大可能定位于遗传连锁图谱。通过分析两组父母本标记(F142和M142,F459和M459)发现,在根据父母本序列设计SNP分型引物时,可以设计指向同一基因的成对的父母本标记,从而使两个单亲标记可作为一个共同标记使用。

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以16年观测资料,分析了高原草甸地区寒冻雏形土土壤热量状况在时间进程及垂直方向的变化特征。同时,比较分析了裸露地表与有自然植被覆盖条件下地温之间关系。地温不仅随着时间进程表现有一高一低的日年变化规律,而且在0~40cm土层地温变化强烈,随深度加深地温的振幅按指数规律减小;地温的日变化约在0.6m处消失,年变化约在10.5m消失。裸地0~20cm地温变化明显大于有植被下的地温变化。

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In recent years, with the discovery oil and gas reservoirs in volcanic rocks, the exploration and development of these reservoirs have attracted widespread attention because of the urgent need for increasing oil and gas production in the world and volcanic rocks has currently become an important exploration target in Liaohe depression. The study area of this dissertation is in the middle section of the easternern sag of Liaohe depression that have been confirmed by studying structural fractures, which constitute a key factor impacting volcanic rocks reservoirs. Substantial reserves and large production capacity in the areas with widely distributed volcanic rocks are important reasons for examining volcanic rocks in the study area. The study began with classification and experimental data analysis of volcanic rocks fractural formation, then focused on the mechanism of fracturing and the development of volcanic rocks structural fracture prediction methodology.and Lastly, predicted volcanic rocks structural fracture before drilling involved a comprehensive study of the petroleum geology of this area, which identified favorable traps thereby reducing exploration risks and promoting the exploration and development of volcanic rocks reservoirs. 3Dstress and 3Dmove software were applied to predict structural fracture by combining the core data, well-logging data and seismic data together and making the visualization of a fracture possible. Base on the detailed fracture prediction results, well OuO48 and well Ou52 were drilled and successfully provided a basis for high efficiency exploration and development of fractured reservoir in the middle section of the eastern sag. As a result of what have been done, a new round of exploration of volcanic rocks was developed. Well OU48 and well OU52 successfully drilled in this area resulted in the in-depth study of the mechanism of structural fracture formation, technological innovation of structural fracture prediction of volcanic rocks , which guided to oil and gas exploration effectively and made it possible for high production of volcanic rocks. By the end of August 2005, the cumulative oil and gas production of Ou48 block were 5.1606 × 104 t and 1271.3× 104 m3 respectively, which made outstanding contributions to the oilfield development. Above all this work not only promoted exploration and structural fracture prediction in volcanic rocks in Liaohe depression, but also applied to in the low-permeability and fractured sandstone reservoir.

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采用同位素稀释ICP—MS测定法,对中国东海陆架及日本冲绳海槽的6个沉积物芯中U和Th的同位素地球化学行为进行了研究,以了解氧化还原敏感元素U在近海次氧化性沉积物中的蓄积行为,并评价其在全球海洋铀平衡中的意义。东海沉积物芯中,^238U浓度及^238U/^232Th比值随深度变化不明显。但是在冲绳海槽沉积物芯中,^238U浓度及^238U/^232Th比值在沉积芯表层氧化带显示较低值,然后在次氧化层随深度增加而增加。^230Th和^232Th浓度在所有沉积物芯中基本不随深度变化。这些结果说明,冲绳沉积物中有“自生铀”的蓄积过程发生,蓄积速率约为(47±5)-(90±8)ng/(cm^2·a),与文献报道的世界其他海域次氧化性沉积区大致相当。进一步证明了U在近海次氧化性沉积区的蓄积对于全球海洋铀平衡有重要意义。“自生铀”的主要蓄积机制是海水U(Ⅵ)向沉积物迁移,在还原条件下被还原为惰性的U(Ⅳ)并被吸附在沉积物固体相上。

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Simultaneous nitrobenzene and phenol wet air oxidation was investigated in a stainless autoclave at temperature range of 180-220 &DEG; C and 1.0 MPa oxygen partial pressure. Compared with the single oxidation of nitrobenzene under the same conditions, the presence of phenol in the reaction media greatly improved the removal efficiency of nitrobenzene. The effect of temperature on the reaction was studied. Phenol was considered as a type of initiator in the nitrobenzene oxidation. © 2004 Elsevier Ltd. All rights reserved.