山西余吾井田山西组沉积环境演化及聚煤规律

通过对研究区163个钻孔岩心、测井资料以及煤矿开采揭露资料进行解释和对比,同时结合岩石组合、沉积构造、剖面结构、测井相组合以及华北晚古生代早二叠世陆表海盆地地质背景,分析了山西组的岩性组合、展布特征及演化历史。研究认为,山西组底部为陆表海环境,含菱铁质泥岩是有力证据;区内主采3号煤层形成于华北大海退之后废弃的三角洲前缘之上,煤层厚度的变化主要受沉积环境的控制和后期局部冲刷的影响,与基底环境关系不大;井田山西组沉积环境演化及厚煤层展布特征表明华北晚古生代早二叠世为一个稳定的克拉通盆地。     

Microscopic modelling of the hydraulic fracturing process

A microscopic perspective is introduced in this study which offers a detailed insight at the inter-particle level to the geo-mechanical responses caused by fluid injection and the resulting pressure build-up. This was achieved by employing the Discrete Element Method (DEM) to model the pressure development and the subsequent fracturing and/or cavity propagation. This technique represents the formation material as an assembly of discrete particles linked to each other through contacts. Numerical experiments were carried out on two sample materials. For the first instance, tests were carried out on a bulk material, representative of a generic intact rock, with the breakage of inter-particle bonds indicating the formation of cracks. The second series of tests was carried out on granular type materials such as sand, where particle separation signified cavity initiation and separation. It was observed from the DEM modelling results that the intact rock material showed a predominance of mode II fracturing at high fluid velocities. However, when the fluid velocity is reduced considerably the fracturing behaviour tended towards more of mode I. Also, records of the pressure development were taken from the numerical results and were used to monitor the fracturing events. The outcome of this study highlights important aspects of the hydraulic fracturing process especially at the particle–particle scale, and thus provides a strong basis for more exhaustive studies involving larger scale reservoir modelling and more complex fracturing scenarios.     

缅甸硬玉岩地区的热液型钠长石岩

产于俯冲带内的低温高压带的由单矿物构成的硬玉岩通常伴有钠长石岩,目前对于硬玉岩研究的关注度较高,而对于钠长石岩则相对较低,很少有相关论文报导.产于缅甸翡翠矿区的钠长石岩,经常与硬玉岩相伴而生,是良好的研究样品.钠长石岩的主要矿物成分是低温钠长石,其次含有硬玉、绿辉石、透辉石等辉石类矿物和钠透闪石、蓝透闪石、镁钠闪石等闪石类矿物,此外还有钠沸石等.钠长石沿着解理和裂隙交代硬玉,说明钠长石形成晚于硬玉岩.钠长岩中的主要组成矿物钠长石的形成温度小于300℃,且其形成压力小于0.5kb,推测是在硬玉岩抬升程中通过交代与沉淀作用形成.其内的透辉石有两种类型,一类可能是被交代的硬玉中的透辉石组分会渐进增加,最终形成透辉石.另一类是被绿辉石包裹的透辉石残留,其很有可能是早期来自地幔楔或者俯冲带岩石中的矿物残留,即异剥钙榴岩或辉石岩类,可以视作硬玉化绿辉石岩和硬玉化异剥钙榴岩的矿物学证据.热液型钠长石岩的存在进一步说明缅甸翡翠矿区钠化热液存在现象的普遍性与穿越性.     

多种媒介融合 拓展天气预报节目传播空间

文章主要讨论了传统媒体和新媒体对气象节目的需求、发展以及创新。认为:气象信息的传播实现新旧媒体的互补是电视天气预报今后改革和创新的必然趋势;在巩固传统媒体的基础上,充分把握新媒体的特点,寻找和开发适合新媒体的天气预报节目,拓宽气象信息的传播渠道,增强气象服务的能力。     

The spatial patterns and determinants of internal migration of older adults in China from 1995 to 2015

Although China was one of the countries with the fastest-growing aging population in the world, limited scholarly attention has been paid to migration among older adults in China. The full picture of their migration in the entire country over time remains unknown. This study examines the spatial patterns of older interprovincial migration flows and their drivers in China over the period 1995 to 2015, using four waves of census data and intercensal population sample survey data. Results from eigenvector spatial filtering negative binomial regressions indicate that older adults tend to migrate away from low cost-of-living rural areas to high cost-of-living urban and rural areas, moving away from areas with extreme temperature differences. The location of their grandchildren is among the most important attractions. Our findings suggest that family-oriented migration is more common than amenity-led migration among retired Chinese older adults, and the cost-of-living is an indicator of economic opportunities for adult children and the quality of senior care services.     

The results of positional observations of near earth asteroids using the combined observation method

The high velocity of the apparent motion of near Earth asteroids (NEAs) is the main problem in their observation. This problem is solved at the Research Institute Nikolaev Astronomical Observatory (RI NAO) with a combined observation method using the time delay and integration mode of a CCD array and a camera rotator. A total of 1317 positions of 74 NEAs were obtained at RI NAO in 2008–2012. All the observations were made using the combined-observation method. The error in observations made at RI NAO is compared with the results that were obtained at other observatories in this work.     

山东省高密市高氟区地球化学及水文地球化学特征

为查明高密市高氟地下水的地球化学及水文地球化学背景,了解地下水中氟的来源、运移及富集规律,对采集到的382件岩土样品,300件地下水样品进行了主要组分的分析测试;将F-与岩土类别,地下水pH值,Na+、Ca2+等阳离子以及Cl-、SO2-4等阴离子进行相关性分析;对F-在高密市的水平分布特征和垂向分布特征进行了细致研究。结果表明:该区地下水中主要供氟源为南部丘陵基岩区的砂岩、砾岩、泥岩及火山岩、火山碎屑岩;土壤氟含量水平分布由南向北递增,垂向分布为上高下低;高氟水中F-含量与Na+呈正相关、与Ca2+呈负相关,与Mg2+无明显相关性,与阴离子含量无明显相关性,与矿化度无明显相关性,与pH值呈微弱正相关。通过开展高氟区地球化学和水文地球化学背景研究,对地氟病高发区高氟地下水的形成、运移与富集研究起到一定的参考作用。