柴北缘绿梁山地区早古生代弧后盆地型蛇绿岩的年代学、地球化学及大地构造意义   总被引：12，自引：5，他引：7  

朱小辉  陈丹玲  刘良  赵姣  张乐 《岩石学报》2014,30(3):822-834

岩石学、地球化学、年代学及Lu-Hf同位素综合研究表明在柴北缘西段绿梁山大平沟地区出露一套弧后盆地型蛇绿岩,岩石类型主要包括变质橄榄岩、变火山岩、变辉长岩及斜长花岗岩。其中变火山岩具有LREE亏损,类似N-MORB的稀土配分模式,同时又具有富集大离子亲石元素,亏损Nb、Ta等高场强元素的岛弧火山岩的地球化学特征,应形成在弧后盆地环境。斜长花岗岩为低钾准铝质花岗岩,具有LREE略微富集,HREE平坦的稀土配分型式,显示强烈Eu正异常,其εHf(t)值介于13.7～15.3之间,为变辉长岩部分熔融的产物,熔融温压条件可能为P=0.8～0.9GPa和T=～800℃。年代学研究结果表明变辉长岩的形成时代为535±2Ma,斜长花岗岩的形成时代为493±3Ma,指示本地区弧后盆地拉张时限至少介于493～535Ma之间,而柴北缘地区古大洋俯冲消减作用应早于535Ma。  相似文献   

真空预压法在珠江流域某冲填土场地的应用     

秦皎 《岩土工程技术》2014,(1):45-47,55

依托珠江流域某冲填土场地工程实例,介绍了真空预压法的施工参数及应用效果,另对“薄弱部位”泥浆搅拌桩密封墙处地层的强度进行了定量分析,结果表明真空预压法适用于此类场地,加固效果明显,但密封墙位置强度降幅较大,需采取换填等措施二次处理后才能使用,可为其他类似工程提供参考经验.  相似文献   

Effects of Bioflocs on Artemia Growth and Water Quality     

WANG Jiao  SUI Liying  DENG Yuangao 《《地质学报》英文版》2014,88(Z1):111-113

正1 Introduction Bioflocs is a heterogeneous mixture of the microorganisms,particles,organic polymers and dead cells,etc.(Hargreaves,2006).Among which,heterotrophic bacteria convert efficiently the ammonia nitrogen into the bacterial protein,which provides the supplementary feed for culture animals and reduces the nitrogen level in the culture system(De Schryver et al,2008).In the closed aquaculture system,the growth of  相似文献   

Adsorption of anionic dye on magnesium hydroxide-coated pyrolytic bio-char and reuse by microwave irradiation     

X. N. Zhang  G. Y. Mao  Y. B. Jiao  Y. Shang  R. P. Han 《International Journal of Environmental Science and Technology》2014,11(5):1439-1448

Magnesium hydroxide-coated pyrolytic bio-char composite was prepared by chemical precipitation, and the adsorption behavior of anionic dye (directly frozen yellow) onto magnesium hydroxide-coated pyrolytic bio-char was investigated in the batch mode. The Fourier transform infrared spectroscopy, X-ray diffraction spectroscopy and X-ray fluorescence spectroscopy of adsorbents were characterized. Adsorption studies were performed at different pH, salt concentration, contacting time and dye concentration. The pH value of the solution influenced the adsorption capacity significantly, and adsorption is favored of pH 6–8. Salt coexisted in solution increased slightly directly frozen yellow adsorption capacity. The isotherm data were analyzed by Langmuir and Freundlich isotherm model, and Langmuir model was better to predict the equilibrium data. Thermodynamic calculations showed that the adsorption was a spontaneous and endothermic process. Exhausted magnesium hydroxide-coated pyrolytic bio-char was treated by microwave irradiation, and yield of regeneration was 98 % in the case of microwave irradiated time 5 min at 320 W. The magnesium hydroxide-coated pyrolytic bio-char can be reused.  相似文献   

Investigating soil thermodynamic parameters of the active layer on the northern Qinghai-Tibetan Plateau   总被引：3，自引：1，他引：2  

Ren Li  Lin Zhao  Tonghua Wu  Yongjian Ding  Yao Xiao  Yongliang Jiao  Yanhui Qin  Yufei Xin  Erji Du  Guangyue Liu 《Environmental Earth Sciences》2014,71(2):709-722

The soil thermodynamic parameters, including thermal conductivity, diffusivity and volumetric capacity within the active layer on the northern Tibetan Plateau, were calculated using the measured data of soil temperature gradient, heat flux, and moisture at four stations from October 2003 to September 2004. The results showed that the soil thermodynamic parameters exhibited clear seasonal fluctuation. The thermal conductivity and diffusivity in summer and autumn at Beiluhe, Kexinling, and Tongtianhe were larger than those in winter. The volumetric thermal capacity causes an opposite change; it was larger in autumn and winter than in summer. In spring, the soil thermal conductivity at the Kekexili station was larger than that in summer. Generally, fine-grained soils and lower saturation degrees in the topsoil might be a reason for the lower soil thermal conductivity in winter. For a given soil, soil moisture was the main factor influencing the thermodynamic parameters. The unfrozen water content that existed in frozen soils greatly affected the soil thermal conductivity, whose contribution rate was estimated to be 55 %. The thermodynamic parameters of frozen soils could be expressed as a function of soil temperature, volumetric ice content and soil salinity, while for the unfrozen ground the soil moisture content is the dominant factor for those thermal parameters. As for the soil thermal diffusivity, there exists a critical value of soil moisture content. When the soil moisture content becomes less than a critical value, the soil thermal diffusivity increases as the soil moisture content rises.  相似文献   

Seawater intrusion and coastal aquifer management in China: a review   总被引：1，自引：1，他引：0  

Lei Shi  Jiu Jimmy Jiao 《Environmental Earth Sciences》2014,72(8):2811-2819

Seawater intrusion has been an important topic in hydrogeology in China in recent decades. The rapid growth of the population and economy in the coastal regions has been consuming a tremendous amount of groundwater resources and has increased the extent of seawater intrusion. The spatial discrepancy of water resource distribution has caused the studies of seawater intrusion into China to mainly be concentrated on the area around the Bohai Sea in the northern part of China. The total area of seawater-intruded land due to excessive groundwater utilization in the area was estimated to be approximately 2,457 km² in 2003. Great efforts have been made to mitigate the extent of seawater intrusion and to secure more freshwater resources, including building monitoring networks, subsurface barrier and groundwater reservoirs, and artificial infiltration facilities. Management projects over the years were evaluated to satisfy the objectives and to provide valuable experiences for future research and planning. It is expected that the coastal groundwater conditions of the northern region will improve through the development of a national water resource plan, such as the ongoing south-to-north water diversion project.  相似文献   

Dynamic Response Analysis and Vibration Control for A Fixed-Bottom Offshore Wind Turbine Subjected to Multiple External Excitations     

XIE Shuang-yi  ZHANG Cheng-lin  HE Jiao  JIANG Jing  GAO Jian 《中国海洋工程》2022,36(1):50-64

For the offshore wind turbines installed in earthquake areas, their operation is affected by seismic loads in addition to wind and wave loads. Therefore, it is necessary to study the dynamic responses and vibration control of the wind turbines. In previous studies, the structural responses of offshore wind turbines are usually investigated in the parked case, while the blade rotation effect is usually not considered. The evaluation on the structural responses may be inaccurate under this conditi...  相似文献   

Profiling Planctomycetales diversity with reference to anammox‐related bacteria in a South China Sea,deep‐sea sediment     

Qinglong Shu  Nianzhi Jiao 《Marine Ecology》2008,29(4):413-420

A systematic assessment of Planctomycetales diversity in a South China Sea, deep‐sea sediment (1657 m) was conducted using the 16S rRNA gene analysis approach. PCR amplification of the samples from seven sediment layers (0.1, 1, 3, 5, 7, 9 and 11 m below the surface sediment) using the primer set Pla‐46‐F/1392‐R showed that the Planctomycetales existed within a limited range of sediment depths (≤ 5 m), and had a decreasing trend in diversity with increasing depth. The majority of the retrieved Pla‐46‐F/1392‐R sequences belonged to Pirellula‐related Planctomycetales, and two sequences retrieved from the 0.1‐m layer (GenBank accession numbers: DQ996944 and DQ996945 ) shared the same anammox‐related signature oligonucleotides and were closely related to commonly recognized anammox organisms. To identify new anammox‐related biomarkers, three primer sets were designed for amplifying the fragments of hydroxylamine oxidoreductase and S‐adenosylmethionine radical enzyme genes, but no related sequences were found. Our multiple 16S rRNA gene primer sets (Journal of Rapid Methods and Automation in Microbiology, 2008, in press) revealed even an higher diversity of Planctomycetales in the 0.1‐m layer of the sediment, especially at genus level. Our data profiled the distribution pattern of Planctomycetales diversity along sediment depths, and provided molecular evidence for the existence of anammox‐related bacteria in a new location, which broadens our understanding of Planctomycetales diversity in deep sea sediments.  相似文献   

一种基于可扩展编码的P2P网络视频仿真系统的设计与实现     

曾蕉  方勇  郑崴中 《成都信息工程学院学报》2008,23(6):614-617

可扩展编码从编码入手解决网络带宽自适应问题,同时一定程度上增强了视频流的抗误码性。在opnet仿真平台上搭建了基于可扩展编码的P2P网络视频仿真系统,对仿真系统中的资源发现型机制和流媒体的传输机制做了详细的阐述,并具体描述了仿真系统的搭建过程,最后给出了仿真分析和测试结果。  相似文献   

Hierarchical Bayesian approach for population dynamics modelling of fish complexes without species-specific data   总被引：1，自引：0，他引：1  

Jiao  Yan; Hayes  Christopher; Cortes  Enric 《ICES Journal of Marine Science》2009,66(2):367-377

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