山西河东煤田石楼北区块NSL05井煤层气钻井施工工艺

石楼北区块位于鄂尔多斯盆地东缘。该区域表土层松散易坍塌,在以往的钻探施工中,地层中不同程度的存在涌水或者漏失情况。太原组第三层灰岩可钻性较差,取心作业中频繁发生钻头被堵死的情况。为了解决以上问题,缩短施工工期,对钻具组合和钻井参数进行了调整,采用四翼PDC钻头、直螺杆的钻具结构;取心作业主要采用绳索取心,采用①215．9mm的取心钻头代替该区以往的016．9mm钻头,利用Φ127mm钻杆作为绳索取心工具的运行通道,并采用自行研制的内外管总成和内管取心工具．保证了取心效果;将钻头水眼更改为12mm×2＋14mm＋16ram的组合方式,有效保持了钻孔内的清洁,避免岩屑重复破碎,进一步提高钻进效率。同时介绍了钻探施工程中设备的配套、钻井液的配制、钻井技术参数的选择等。结果表明：该井取心岩心总收获率为92．15％,其中8#煤心质量总采取率为93．50％;井斜3°10′,全井水平位移44．17m,最大全角变化率耋1．1。／30m。对该区煤层气井钻探施工有很好的借鉴作用。     

Spike in phytoplankton biomass in Greenland Sea during 2009 and the correlations among chlorophyll-a,aerosol optical depth and ice cover

The distributions and correlations of chlorophyll-a(Chl-a),aerosol optical depth(AOD)and ice cover in the southeast Arctic Ocean-Greenland Sea(10°W–10°E,70°–80°N)between 2003 and 2009 were studied using satellite data and statistical analyses.Regression analysis showed correlations between Chl-a and AOD,Chl-a and ice cover,and AOD and ice cover with different time lags.The time lag of Chl-a and AOD indicated their long-term equilibrium relationship.Peaks in AOD and Chl-a and generally occurred in May and July,respectively.Despite the time lag,the correlation between Chl-a and AOD in the study region was as high as 0.7.The peak gap between Chl-a and AOD shifted for about 6 weeks during 2003–2009.In the summer and autumn of 2009,Chl-a and AOD levels were much higher than during the other years,especially in the northern band of the study region(75°–80°N).The driving forces for this localized increase in phytoplankton biomass could be mainly attributed to the very high rate of ice melting in spring and early summer and the high wind speed in autumn,together with the increased deposition of aerosol throughout the year.The unusually high AOD in the spring of 2003 was mainly due to a massive fi re in Russia,which occurred in the fi rst half of the year.Over the 7 years of the study,the sea surface temperature generally decreased.This may have been due to the release of dimethylsulfi de into the air,excreted in large amounts from abundant phytoplankton biomass,and its subsequent reaction,form large amounts of aerosol,and resulting in regional cooling.     

Enhancing the culturability of bacteria from the gastrointestinal tract of farmed adult turbot Scophthalmus maximus

Eighteen agar media were tested for the culture of gut-associated bacteria from farmed adult turbot(Scophthalmus maximus),including 16 agar media with or without 1% gastrointestinal(GI)supernatant,or with 2% or 4% GI supernatant.A total of 1 711 colonies were analyzed and 24 operational taxonomic units(OTUs)were identifi ed.The greatest bacterial diversity was isolated on Zobell 2216E/Zobell 2216E+ agar media,whereas MRS/MRS+ agar media produced a low diversity of colonies.Agar media with GI supernatant(1%,2%,or 4%)showed increased diversity and yielded different profi les of OTUs from the corresponding original media,suggesting that GI supernatant provides substances that enhance the culture effi ciency of bacteria from the turbot GI tract.The large majority of the colonies(82%)were γ-Proteobacteria,whereas 15.6% and 2.4% of colonies were Firmicutes and Actinobacteria,respectively.At the genus level,49.4% of all colonies were assigned to Vibrio.Other potential pathogens,including Pseudomonas,Photobacterium,and Enterobacter,and potential probiotics,including Bacillus,Paenibacillus,and Pseudomonas,were also isolated on agar media.Most cultured bacteria belonged to species that were fi rst described in the turbot GI tract.The impact of these species on turbot physiology and health should be investigated further.     

On the spread of changes in marine low cloud cover in climate model simulations of the 21st century

In 36 climate change simulations associated with phases 3 and 5 of the Coupled Model Intercomparison Project (CMIP3 and CMIP5), changes in marine low cloud cover (LCC) exhibit a large spread, and may be either positive or negative. Here we develop a heuristic model to understand the source of the spread. The model’s premise is that simulated LCC changes can be interpreted as a linear combination of contributions from factors shaping the clouds’ large-scale environment. We focus primarily on two factors—the strength of the inversion capping the atmospheric boundary layer (measured by the estimated inversion strength, EIS) and sea surface temperature (SST). For a given global model, the respective contributions of EIS and SST are computed. This is done by multiplying (1) the current-climate’s sensitivity of LCC to EIS or SST variations, by (2) the climate-change signal in EIS or SST. The remaining LCC changes are then attributed to changes in greenhouse gas and aerosol concentrations, and other environmental factors. The heuristic model is remarkably skillful. Its SST term dominates, accounting for nearly two-thirds of the intermodel variance of LCC changes in CMIP3 models, and about half in CMIP5 models. Of the two factors governing the SST term (the SST increase and the sensitivity of LCC to SST perturbations), the SST sensitivity drives the spread in the SST term and hence the spread in the overall LCC changes. This sensitivity varies a great deal from model to model and is strongly linked to the types of cloud and boundary layer parameterizations used in the models. EIS and SST sensitivities are also estimated using observational cloud and meteorological data. The observed sensitivities are generally consistent with the majority of models as well as expectations from prior research. Based on the observed sensitivities and the relative magnitudes of simulated EIS and SST changes (which we argue are also physically reasonable), the heuristic model predicts LCC will decrease over the 21st-century. However, to place a strong constraint, for example on the magnitude of the LCC decrease, will require longer observational records and a careful assessment of other environmental factors producing LCC changes. Meanwhile, addressing biases in simulated EIS and SST sensitivities will clearly be an important step towards reducing intermodel spread in simulated LCC changes.     

The Effect of Air Density on Sand Transport Structures and the Adobe Abrasion Profile: A Field Wind-Tunnel Experiment Over a Wide Range of Altitude

Aeolian sand transport results from interactions between the surface and the airflow above. Air density strongly constrains airflow characteristics and the resulting flow of sand, and therefore should not be neglected in sand transport models. In the present study, we quantify the influence of air density on the sand flow structure, sand transport rate, adobe abrasion profiles, and abrasion rate using a portable wind-tunnel in the field. For a given wind speed, the flow’s ability to transport sand decreases at low air density, so total sand transport decreases, but the saltation height increases. Thus, the damage to human structures increases compared with what occurs at lower altitudes. The adobe abrasion rate by the cloud of blowing sand decreases exponentially with increasing height above the surface, while the wind erosion and dust emission intensity both increase with increasing air density. Long-term feedback processes between air density and wind erosion suggest that the development of low-altitude areas due to long-term deflation plays a key role in dust emission, and will have a profound significance for surface Aeolian processes and geomorphology.     

Isolation and characterization of fucoidans from five brown algae and evaluation of their antioxidant activity

In this study, we evaluated the chemical property and antioxidant activity of fucoidans isolated from brown algae, Laminaria japonica(LJF), Lessonia nigrescens(LNF), Lessonia trabeculata(LTF), Ascophyllum mackaii(AMF), and Ecklonia maxima(EMF). LJF was less in sulfate content(14.16%) and more in galactose and mannose content(1.08 and 0.68) than the documented early. EMF contained 20%–30% of sulfate and fucose, 0.97 in molar ratio which was lower than that of sulfate to other four fucoidans(1.21–1.41). AMF(162 kDa) and EMF(150 kDa) were the first two largest in molecular weight, which were followed by LJP(126 kDa), LNF(113 kDa) and LTF(105 kDa). The fucoidans isolated these algae showed a wide range of antioxidant activity in vitro. It was found that the reducing power of the isolated fucoidans was positively correlated with their sulfate content and molecular weight. In addition, LNF and LTF at low concentrations exhibited high superoxide and hydroxyl radical scavenging activity. This demonstrated that low molecular weight fucoidans may perform a high antioxidant activity.     

Coordinated development of land multi-function space: An analytical framework for matching the supply of resources and environment with the use of land space for ecological protection,agricultural production and urban construction

Journal of Geographical Sciences - Based on the carrying capacity of the resources and the environment, this article defines the connotation of the land multifunctional space (LMFS) from three...     

基于动态执行的基带固件函数安全性分析

移动通信设备中的基带固件运行于独立的计算环境,其漏洞既可危及设备安全,又无法通过设备主操作系统的安全机制进行防护,因此其安全性备受攻防研究者的关注。实验中发现,得到的基带固件由于函数重写、调试信息剥离等原因,现有对比工具难以准确识别其危险函数,进而无法进行后续的漏洞发掘工作。本文提出一种基于动态执行的函数安全性分析方法DEx。根据预处理过程得到的基带固件的函数信息和段内容,在交叉编译和虚拟机环境下对基带固件函数实现动态执行。基于运行过程中产生的语义特征,设计优先级排序以对函数的安全性进行分析,识别得到内存拷贝函数。基于DEx方法构造了dyndiff工具,与基于二进制代码相似性方法的主流工具BinDiff对比,dyndiff的危险函数识别率是BinDiff的5.5倍。最后,阐述了本文工作在后续漏洞挖掘工作中的应用。     

省级国土资源综合监管平台建设探讨

国土资源综合监管平台建设是国土资源信息＂十二五＂期间的重要工作,是国土资源＂一张图＂建设成果的展现形式。目前各省都在积极推进各项建设工作,但其建设的基本思路、内容和技术方法都无固定格式,是目前业界讨论与争论较多的领域,本文以重庆市国土资源综合监管平台建设实践为基础,提出作者对省级国土资源综合监管平台建设的思路、内容和技术方法的界定和思考。