Relationships of Agricultural Land Use to an Expanded Road Network within Tropical Forest Landscapes of Cameroon and Republic of the Congo

Road building in Congo Basin forests has increased due to expansion of commercial logging, with potential to expose intact forests to greater establishment of agriculture. We developed new knowledge of agriculture clearing sizes, spatial patterns, and relationships with roads in seven case study sites comprising 7,529 km². Using very high spatial resolution satellite imagery, we mapped roads and rivers, plus clearings for agriculture, settlements, and logging. Mapped clearings (N = 1,781) ranged in size from 0.008 ha to more than 300 ha; most were smallholder agriculture, with 64 percent ≤ 1 ha. Statistical tests of spatial pattern confirmed that agriculture occurred in an inhomogeneous-aggregated pattern, suggesting interactions with other landscape elements. Proximity analyses showed that 76 percent of clearings were within 1 km of a road or river. Thirty-five percent of agriculture clearings were within 1 km of main public roads built before 1990, compared to 17 percent for logging roads built after 2000. Less than 6 percent of agriculture clearings were within 1 km of logging roads with overgrown canopies, suggesting transient relationships. Results based on fine-scale data provide new empirical support for understanding the interactions between agriculture and roads in one of the remaining relatively intact forest areas of the Congo Basin.     

南京地区降水雨滴谱拟合模型的参数特征分析

根据南京地区2010-2014年雨滴谱观测资料,利用Gamma分布、标准Gamma分布、改进的标准Gamma分布等雨滴谱分布模型,研究了南京地区降水雨滴谱拟合模型的参数特征。结果表明:1)南京地区降水雨强标准差σR和R之间比值为2.29;2)利用阶矩法,按照Gamma模型对雨滴谱进行拟合,形状因子μ、斜率因子λ和截断参数log10N0总的平均值分别为9.2、11.6 mm-1、7.2 mm-1·m-3,众数值分别约为6.0、5.5 mm-1、4.5 mm-1·m-3,并且μ和λ之间均存在较好的二次项函数关系;3)标准化形式下的Gamma分布参数Dm和Nw随雨强的增大而逐渐增大,并且随雨强的增大,Dm增大的幅度越来越大,而Nw增大的幅度却越来越小;4)谱型参数σM随Dm增大而增大,并且Dm和σM之间存在较好的指数型函数关系。     

基于地球物理测井参数的深层卤水矿化度方法研究

深层富矿卤水是一种重要的矿产资源,卤水层的矿化度是评价卤水品位和开展卤水试水及采卤重要的参数,而卤水层矿化度的计算一直是一个难题。文章推导了地层水电阻率法和中子寿命测井法2种利用测井资料计算矿化度的方法,分别适应于低矿化度和高矿化度卤水,应用这2种方法对江汉盆地潜江凹陷潜江组深层卤水矿化度进行了计算,取得了良好的效果。     

HyLogger-3, a visible to shortwave and thermal infrared reflectance spectrometer system for drill core logging: functional description

Australian Geological Surveys are the custodians of a major national asset in the form of historically drilled and archived drill cores of the top few kilometres of the continent acquired by government agencies and companies over many decades. The AuScope National Virtual Core Library (NVCL) component of the AuScope Earth Model comprises geological/rock samples, technology, people and database/delivery infrastructure located in six nationally distributed nodes and is aimed at extracting additional value from this asset. The technology components of the NVCL comprise an integrated suite of hardware (HyLogger-3) and software (TSG-Core) systems for the imaging and hyperspectral characterisation of drill cores in their original core trays and the interpretation of their contained oxide, carbonate, hydrous and anhydrous silicate mineralogy. The HyLogger-3 includes state-of-the-art Fourier Transform Spectrometers that continuously measure calibrated spectral reflectance from nominal 10 by 18 mm fields of view. These spectra are in turn passed through a series of automatic and semi-automatic pre-processing and mineralogical unmixing algorithms. These, along with numerous other tools in TSG-Core, output a variety of mineralogical and image products for use by scientists in many branches of the earth sciences. This paper provides a functional overview of the HyLogging hardware and software tools available in each of Australia's Geological Surveys.     

海水深度对两种可控源电磁勘探方法的影响

在过去的十几年中,海洋可控源电磁法的迅猛发展在油气勘探中起到了重要的作用。在浅海环境中,常见的两种可控源电磁法的数据采集系统采用海底基站式（Sea Bed Logging（SBL））,以及拖缆式（Towed Streamer electromagnetics（TSEM））两种模式。本文的研究目的是研究在不同水深条件下,两种数据采集系统的工作模式以及海水对其的影响。为了更好的比较两种数据采集方式,本文采用了三种不同的分析方法：一维敏感度模型,二维油藏敏感指数,Occam反演。一维敏感度模型能够迅速的给出结果,但是由于结果的信息量有限,不足以给定准确的结论。二维油藏敏感指数可以依据正演的结果快速的给定一个水深和油藏敏感度的关系。Occam反演方法用于对合成数据进行反演计算,估计地下介质电阻率参数。为了更好的评价反演结果,本文引入了横向电阻异常率（ATR）。通过对合成数据的反演结果的分析,本文得出以下结论：在浅水环境中,SBL和TSEM数据采集系统都可以提供较高的分辨率,对高电阻层有很好的敏感度。在深水环境中,SBL数据采集系统具有明显的优势。ATR对于反演的电阻率参数结果具有很好的评价作用。     

川中地区上三叠统须家河组成岩层序地层学特征

充分利用薄片分析以及X-衍射等资料,结合元素俘获(ECS)测井解释所获得的岩石矿物组合特征,从层序界面对成岩特征的控制以及不同基准面旋回内的成岩作用发育规律两个方面分别对川中须家河组层序地层格架内的成岩作用特征进行探讨。结果表明,须家河组可划分为2个超长期和5个长期基准面旋回层序。须二段、须四段底部的层序界面之下碳酸盐胶结物含量普遍增加,而界面之上的砂体普遍见溶蚀现象,储层物性相对变好。须四段基准面上升半旋回时期形成的沉积物颗粒粒度较粗、泥质含量低、砂体厚度大、连通性好,在成岩过程中原生孔隙容易得到保存,再加上受到层序界面所控制的有机酸性水溶蚀作用的影响,有利于次生孔隙的产生。而基准面下降期,砂体的连通性变差、泥质夹层增多,在成岩过程中原生孔隙不易保留同时也不利于次生溶蚀孔隙的产生,因而物性最差。须二段总体也具此规律,但由于其埋藏更深,经历成岩作用更为复杂,因此并不如须四段明显。研究成果可为研究区优质储层追踪对比及预测提供依据,同时也能为成岩层序地层学的研究提供借鉴。     

铀矿测井资料处理解释系统研发

通过铀矿测井资料处理解释系统的研发,实现了从测井曲线计算处理、岩性识别、孔隙度预测、γ测井解释、测斜数据处理到仪器校准核查、物探参数计算、成果输出等铀矿测井资料处理全过程的数字化。系统既适用于地浸砂岩型铀矿又适用于硬岩型铀矿的测井数据处理解释,并且对《γ测井规范》和《地浸砂岩型铀矿地球物理测井规范》提供了充分的支持。系统通过了模型测试和实际应用测试,在一致性、准确性、实用性上均达到了规范的要求,效果良好。     

Batse time-resolved observations of GRBs: the burst ‘topographic’ map

It is a well-known observation that many GRBs have spectra with curvature in the less than 1 MeV regime, but flatten out to approximately a -2 power law at higher energies. The large collecting area of BATSE allows spectral studies with unprecedented time resolution. We are conducting a systematic study of time-resolved spectroscopy of GRBs observed by BATSE. Several aspects of this survey are discussed: correlations among fit parameters and between fit parameters and intensity; screening for spectral features using-residual contour maps; and an introduction to the GRB topographic map and its possible qualitative diagnostic abilities.     

The search for GRB from primordial black hole evaporation

The search for high energy ray bursts (GRBs) from primordial black holes (PBHs) has continued for the past 20 years. We discuss a very interesting group of GRBs of very short time duration and an increasing hard spectrum from the published BATSE catalog. We point out that the trend, i.e. anti-correlation of hardness ratio vs. GRB duration, would be expected if some of the short GRBs came from black holes evaporation. We discuss the possibility that the onset of the quark-gluon plasma can give rise to such GRB from PBH evaporation.