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991.
从辽河口湿地污染土壤样品中分离筛选出2株高效石油降解茵lhk-2和lhk-10,经鉴定lhk-2为巴氏萄萄球菌(Staphylococcus pasteuri),lhk-10为嗜麦芽寡养单胞菌(Stenotrophomonasmaltophili).两株菌的石油降解能力研究结果表明,培养8d后,加菌组的石油烃降解率均在...  相似文献   
992.
方芳  张鹏 《海洋技术学报》2011,30(2):88-90,122
文中主要以SZC16-1型XBT测量电路为例,从固有可靠性预计的理论基础出发,通过对基本元器件、单元电路及整个可靠度的计算,给出了目前该型号XBT测量电路的可靠性参数,同时阐述了硬件电路可靠性研究的方法和步骤.  相似文献   
993.
Seven compounds (1–7) were identified from the cultivation of the endophytic fungus Exophiala oligosperma (EN-21) that was isolated from the inner tissue of the marine red alga Laurencia similis. Their structures were identified with spectroscopic and chemical methods as 2-phenoxynaphthalene (1), (2S, 3R, 4E, 8E)-1-O-β-D-glucopyranosyl-3-hydroxy-2-[(R)-2′-hydroxyoctadecanoyl] amino-9-methyl-4, 8-octadeca-diene (2), (22E,24R)-ergosta-7,22-dien-3β,5α,6β-triol (3), (22E, 24R)-3β, 5α, 9α-trihydroxy- ergosta-7, ...  相似文献   
994.
栖霞牙山地区地处华北地台东部,对该区的似斑状花岗闪长岩体所作的岩石地球化学研究表明,该区岩石为钙碱性偏铝质岩石;微量元素MORB标准化蛛网图显示富集大离子亲石元素Ba、Sr,亏损高场强元素Nb、Ta、Hf、Y;K/Rb比值为295.34~388.88,Rb/Sr比值为0.21~0.29;稀土元素蛛网图表现为较平滑的具微弱负Eu异常向右陡倾的稀土元素配分模式曲线,∑LREE/∑HREE为9.14~12.22,显示轻重稀土元素分异较好。结合构造背景分析,认为牙山花岗闪长岩体为早白垩世太平洋板块向欧亚板块俯冲诱发的地幔柱活动,造成地幔底辟,引起地壳部分熔融,形成壳幔混合岩浆并进一步侵入形成。  相似文献   
995.
The 16S and 18S ribosomal ribonucleic acid genes of microbial organisms collected from the contrasting environments (temperature, salinity, silicate, phosphate and nitrate, p <0.05) of the inner and outer basins of Kongsfjorden (Spitsbergen, Arctic) were studied using polymerase chain reaction-denaturing gradient gel electrophoresis(DGGE) fingerprinting. Comparison of the microbial fingerprints and the physicochemical parameters revealed that molecular methodology exhibited a greater sensitivity. Sequences obtained from bacterial DGGE were affiliated with four main phylogenetic groups of bacteria:Proteobacteria(Alpha, Beta and Gamma), Bacteroidetes, Verrucomicrobia and Cyanobacteria. The relationships between the genotype distribution of these microbes and associated biotic/abiotic factors, revealed by canonical correspondence analysis, showed that Station 1 at 30 m (outer fjord) was grouped separately from the other sites. This difference could be a consequence of the thermocline and base of the euphotic layer at this depth where the Atlantic and Arctic-type waters overlapped.  相似文献   
996.
We conducted a manipulative experiment to investigate the influential factors of locomotor ability in steppe toad-headed lizards. By using a video-base method, we measured running speed of the lizards when they run on sands of different grain sizes. We also considered body condition, tail length and sex as fixed factors to analyze their effects on running speed of the lizard. Results showed that running speed of the lizard significantly differed among different trials of sand grain size. Specifically, the peak and the nadir values of the running speed were found on sands of 0.5-1 mm and 0.075-0.25 mm grains, respectively. When lizards ran on sands of different grain size their running speed changed significantly. Body condition and tail length also had significant effects on running speed. The findings indicated that locomotor ability of lizards depended on both body condition and the external environment. We hypothesized that sand grain size is one of the factors that influence the habitat selection in steppe toad-headed lizards. Moreover, this lizard may be used as an indicator of the development of sand dunes.  相似文献   
997.
The northwestern China is a typical dry-land region of Inner Asia, where significant climate change has been observed over the past several decades. How the regional vegetation, particularly the grassland-oasis-desert complex, responds to such climatic change is poorly understood. To address this question, we investigated spatio-temporal changes in vegetation growth and their responses to a changing climate by biome and bioregion, using satellite-sensed Normalized Difference Vegetation Index (NDVI) data from 1982 to 2003, along with corresponding climate data. Over the past 22 years, about 30% of the total vegetated area showed an annual increase of 0.7% in growing season NDVI. This trend occurred in all biomes and all bioregions except Sawuer, a subregion of the study area with no significant climate change. Further analyses indicated that NDVI change was highly correlated with the current precipitation and evapotranspiration in growing season but was not associated with temperature. We also found that NDVI was positively correlated with the preceding winter precipitation. These findings suggest that precipitation may be the key cause of vegetation growth in this area, even for mountain forests and grasslands, whose growth are often regarded to be limited by low temperate in winter and early spring.  相似文献   
998.
天山托木尔自然遗产地地理多样性价值评估与保护分区   总被引:2,自引:1,他引:1  
在系统分析托木尔自然遗产地地理多样性要素组成的基础上,运用ArcGIS空间叠加分析,划定地理多样性特征区,主要包括极高山、高山冰川和冰缘区、南坡中山区、南坡红层地貌区和北坡中山区;通过对已有研究和相关文献资料的分析,对地理多样性价值构成进行解析,采用层次分析法提出了地理多样性综合价值评估指标体系,确定了具有不同价值特征...  相似文献   
999.
以和田绿洲湿地为研究靶区,针对干旱区特有的地貌、气候特点,利用热红外波段在解译水体、湿地信息方面具有独特的优势,提出了基于热红外特征的干旱区湿地指数AZWI( Arid Zone Wetlands Index),详细叙述了AZWI的计算方法及过程,在总结传统主流方法的基础上,分别采用非监督分类、监督分类、决策树法和AZ...  相似文献   
1000.
对北山地区坡一和罗东含铜镍的镁铁-超镁铁质岩体铂族元素研究表明,两个岩体的铂族元素(PGE)总量较低,PPGE较IPGE富集,原始地幔标准化模式呈正斜率,均较原始地幔亏损,具Ir和Rh的弱负异常。较低的Pd/Ir比值表明岩石主要受岩浆作用控制,后期热液作用影响不明显。两个岩体的原生岩浆均为MgO 含量较高的PGE不亏损的拉斑玄武质岩浆,较高的Cu/Pd、Ti/Pd比值表明岩浆在演化过程中发生了硫化物的熔离。罗东岩体早期矿物相(橄榄石、铬铁矿)的分离结晶作用对岩浆中的硫达到饱和具有重要的贡献,而坡一岩体该作用对硫化物熔离的贡献不明显。坡一和罗东岩体的R值表明两岩体均具有达到中型Ni矿床的潜力。  相似文献   
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