Petroleum Hydrocarbon Contamination in Surface Sediments of Beiluohe Basins,China

Twenty-two surface sediment samples were collected from Beiluohe River, China, in 2005. Saturated hydrocarbons analysis was carried out on different river sediments in order to detect possible contaminations by petroleum development. Total concentrations of hydrocarbons in the sediments ranged from 6.4-147.3 mug g(-1) (dry wt) with an average of 76.8 mug g(-1), revealing relatively low to medium contamination in studied areas in spite of oil development for many years. The THC levels in the mainstream of Beiluohe River were relatively low. Sediment samples with higher total hydrocarbon concentrations were from the sites related to the petroleum activities or urban discharges. Gas chromatographic distribution patterns of n-alkanes are characteristic of petroleum in most samples. They show a strong unresolved complex mixture (UCM) with a small predominance of odd on even numbered n-alkanes. On the other hand, pentacyclic triterpanes and steranes occurred in all analyzed sediments and displayed similar signatures that are characteristic of mature organic matter contribution from oil contaminations. Hydrocarbons of terrestrial origin were also detected in the samples. However, contribution from plantwax hydrocarbons is overshadowed in samples by hydrocarbons of petroleum origin. This is obvious by the presence of the high relative abundance of UCM, and the identification of mature hopane and sterane in samples.     

塔里木盆地子午沙鼠对北天山灰旱獭鼠疫菌的感受性实验

目的研究塔里木盆地子午沙鼠对鼠疫菌的敏感性、感受性和母系抗体在仔鼠体维持时间.方法用分离自北天山灰旱獭体内的鼠疫强毒菌2101号,以1×101～1×109个菌皮下接种子午沙鼠;二次接种(1×109)后存活鼠配对饲养,产仔后观察仔鼠抗体维持时间.结果 1×109个菌可使该组动物全部死亡.其它组的存活鼠再次接种后其耐受性有所增强.仔鼠F1抗体效价3 个月时为1:32,4个月时为1:4.结论子午沙鼠对北天山灰旱獭分离的鼠疫菌敏感性较高,个体差异较大,血清抗体维持时间长.母系抗体在仔鼠体可维持3～4个月之久.     

基于COI基因的柴达盆地常见寄生蚤种的DNA条形码分析

目的 COI基因对柴达木盆地部分蚤种进行分子生物学鉴定,旨在完善蚤类传统形态分类法的不足。方法 PCR扩增68份蚤类标本的COI基因片段(约600 bp)并进行测序和比对;用MEGA 6软件的K2-P双参数模型计算种内及种间遗传距离,以邻接法(neighbor-joining,NJ)构建系统发育树。结果 共测得柴达木盆地19种蚤的68条COI基因序列,种内遗传距离0.01%~2.9%,种间遗传距离3%~15.4%,种间遗传距离显著大于种内遗传距离。结论 NJ树显示同一物种形成高支持率的单系,种间分支很明显,表明COI可以作为DNA条形编码基因对柴达木盆地的常见蚤类进行物种鉴定。     

Characteristics of sparsely encoded associative memory

Characteristics of an autocorrelation or crosscorrelation associative memory largely depend on how items are encoded in pattern vectors to be stored. When most of the components of encoded patterns to be stored are 0 and only a small ratio of the components are 1, the encoding scheme is said to be sparse. The memory capacity and information capacity of a sparsely encoded associative memory are analyzed in detail, and are proved to be in proportion of n²/logn², n being the number of neurons, which is very large compared to the ordinary non-sparse encoding scheme of about 0.15n. Moreover, it is proved that the sparsely encoded associative memory has a large basin of attraction around each memorized pattern, when and only when an activity control mechanism is attached to it.     

塔里木盆地寒武系烃源岩分布重新认识及其意义

塔里木盆地台盆区海相烃源岩的分布是制约油气勘探的重要因素。在构造—古地理背景分析基础上,通过典型井地球化学分析,结合新近地震资料解析,重新厘定寒武系主力烃源岩分布。结果表明,东部烃源岩主要分布在中下寒武统泥页岩,西部烃源岩主要分布在下寒武统泥页岩、泥灰岩中,单井纵向厚度标定不足100m,中上寒武统—下奥陶统碳酸盐岩缺乏有效烃源岩。结合构造—古地理研究新进展,发现寒武系烃源岩主要分布在满东凹陷、满西台内洼、塔西南南缘等3片区域,而巴楚、塘古地区分布少,有利面积约为18×10^4km2。受控于前寒武纪古隆起与寒武纪弱伸展背景,寒武系主要发育台间盆、台内洼烃源岩,可能存在被动陆缘斜坡、板块边缘裂谷烃源岩。新成果揭示台盆区虽然经历复杂的油气演化,但油气分布仍受控于“源控论”,围绕烃源岩的凹陷区、盐下原生油气藏、裂解气等是进一步勘探的有利方向。     

塔里木油田大尺寸超深井干法固井技术研究

空气钻井后常将空气转换为钻井液,但这容易出现井壁不稳定、垮塌、漏失等现象,井壁易形成巨厚虚滤饼致下套管困难和固井质量差,此外,大尺寸套管常规固井还存在顶替效率较差的情况,以上因素最终导致固井准备时间长和固井质量难以保证。为此,空气钻井后采用了干法固井工艺,并根据塔里木油田套管尺寸大、井深的技术难点,建立了干法固井水泥浆实验评价方法,对干法固井井下水泥浆性能进行了评价和优选,最终取得成功,下套管质量达572×10^3kg,固井深度达3602m,同时减少了现场排污,有利于环境保护。     

Microcystis Sp. Co-Producing Microcystin and Saxitoxin from Songkhla Lake Basin,Thailand

The Songkhla Lake Basin (SLB) located in Southern Thailand, has been increasingly polluted by urban and industrial wastewater, while the lake water has been intensively used. Here, we aimed to investigate cyanobacteria and cyanotoxins in the SLB. Ten cyanobacteria isolates were identified as Microcystis genus based on16S rDNA analysis. All isolates harbored microcystin genes, while five of them carried saxitoxin genes. On day 15 of culturing, the specific growth rate and Chl-a content were 0.2–0.3 per day and 4 µg/mL. The total extracellular polymeric substances (EPS) content was 0.37–0.49 µg/mL. The concentration of soluble EPS (sEPS) was 2 times higher than that of bound EPS (bEPS). The protein proportion in both sEPS and bEPS was higher than the carbohydrate proportion. The average of intracellular microcystins (IMCs) was 0.47 pg/cell on day 15 of culturing, while extracellular microcystins (EMCs) were undetectable. The IMCs were dramatically produced at the exponential phase, followed by EMCs release at the late exponential phase. On day 30, the total microcystins (MCs) production reached 2.67 pg/cell. Based on liquid chromatograph-quadrupole time-of-flight mass spectrometry, three new MCs variants were proposed. This study is the first report of both decarbamoylsaxitoxin (dcSTX) and new MCs congeners synthesized by Microcystis.     

基于DNA条形码技术鉴定青海柴达木盆地小型兽类

目的 为弥补传统形态分类方法不足,提高小型兽类现场鉴定成功率和准确性。方法 将采自青海省柴达木盆地总计3目5科12属145只小型兽类进行COI基因序列检测。结果 分析所测全部COI基因序列,种内遗传距离0.01%~2.2%,种间遗传距离10.9%~15.6%,种间遗传距离显著大于种内遗传距离。属间遗传距离16.2%~21.3%,科间遗传距离16.2%~27.0%, NJ树显示同种个体聚为高支持度的单一分支,在14个形态种中共发现17个分子种。讨论 研究结果表明DNA条形码技术能纠正传统形态学鉴定中的错误, 提高动物分类鉴定的准确性。     

青海省青南高原与柴达木盆地细粒棘球蚴实验感染犬体内成虫形态学比较观察

目的 比较青南高原与柴达木盆地两地细粒棘球绦虫成虫形态学特征，为虫株研究提供依据。方法 选择青南高原的黄南州同仁县、柴达木盆地的德令哈市为采样点，采集当地自然感染，发育良好的绵羊棘球蚴囊，分别人工感染实验犬，45d后粪检绦虫卵阳性时剖杀，取其肠道成虫，AAF固定液固定，成虫虫体用洋红或苏木素染液染色，切取的顶突钩用4％孔雀绿染液染色。低倍镜下观察其形态学特征并用测微尺测量，记录结果。结果 德令哈株细粒棘球绦虫成虫多数为4节，黄南株多数为5节；德令哈株成虫链体较细长，黄南株较宽短，两株虫体总长度差异有显著性（P〈0．05）；黄南株成虫成熟节片睾丸数与德令哈株比较差异无显著性；黄南株睾丸在生殖孔前后的分布相当，而德令哈株睾丸多分布于生殖孔前。两成虫生殖孔位置都位于链体节片偏后，但德令哈株有6．84％的生殖孔偏前。黄南株成虫雄茎囊明显小于德令哈株；虫体头钩总数多于德令哈株，大钩、小钩总宽均〉德令哈株，头钩总长两成虫间差异无显著性（P〉0．05）。结论 青南高原和柴达木盆地两地细粒棘球绦虫虫体在某些形态特征上显著不同，提示我国可能存在不同的地理株。     

塔里木盆地蜱类群落结构的研究

为掌握塔里木盆地蜱类群落的结构特征,探讨该地区生态环境的差异对蜱类群落结构的影响,按照地理区划和生境类型选择调查点进行蜱类种类和数量调查,采用群落生态学技术方法,分析不同生态环境条件下的蜱类群落的丰富度、多样性和均匀性。共在该地区采获蜱类5属10种,扇头蜱和革蜱在盐碱湿地生态景观中占主要地位,亚洲璃眼蜱是植被发育良好的盐碱沙地或沙漠化生态景观中的优势蜱类。在土壤以盐碱湿地为主的生态环境中,游离蜱群落组成单一,优势种类突出,优势度高,丰富度、多样性和均匀性低;在草本植物和灌木发育良好,地质较为干燥的盐碱和盐碱沙化生态环境中,蜱类群落的丰富度、多样性和均匀性高,优势度适中等;在草本和灌木发育良好的漠化的生态环境中,蜱类的组成较为简单,优势度高,丰富度、多样性和均匀性低,优势种的蜱指数高;在乔木密集,草本植物和灌木稀少的干旱的盐碱和盐碱沙化生态环境中,地面游离蜱的种类和数量均十分稀少。高海拔戈壁湿地生态景观的蜱类群落与其他生态景观的蜱类群落的相似性指数最低,其次为沙漠化生态景观,但该生态景观的2类生境中的蜱类群落具有非常高的相似性;盐碱类生态景观中的各蜱类群落间具有较高相似性,均在0.9以上,且该类生态景观中的蜱类群落与具有较高植被覆盖度的盐碱沙化生态景观和戈壁原生景观的蜱类群落也具有较高的相似性;盐碱沙化生态景观的蜱类群落与其他生态景观中的蜱类群落具有中等水平的相似性指数,在0.5～0.9之间,蜱类群落结构的类型介于盐碱和沙漠化类生态景观的蜱类群落结构形态之间。