清镇式铁矿矿石特征及加工技术性能探讨 ——以猫场铝土矿红花寨、白浪坝矿段铁矿床为例

贵州中部清镇、修文等地石炭系铝土矿底部的铁矿俗称为"清镇式铁矿",与黔中铝土矿共同赋存于下石炭统九架炉组之中。本文在实际勘探工作及通过勘探阶段在钻孔副样中采集的铁矿进行可选性试验基础上,以同类型的清镇市猫场铝土矿红花寨、白浪坝矿段铝土矿共生的铁矿为研究对象,指出该类型铁矿矿石自然类型为赤铁矿和褐铁矿;工业类型为需选铁矿石;矿石矿物主要为赤铁矿,部分赤铁矿水化为针柱状褐铁矿;脉石矿物则以白云石和方解石为主。矿石中可供利用的主要元素是铁,造渣组分主要是硅、铝,其次为钙、镁等。试验结果表明,该矿采用一粗一精一扫的强磁选试验可获得铁精矿TFe含量55. 58%,回收率80. 11%的良好指标,精矿中各元素含量达到H55-Ⅰ类赤铁精矿质量要求,在当前市场条件下采用推荐工艺处理该矿可获利。结论对黔中铝土矿资源的综合勘查开发具有借鉴意义。     

安徽巢湖苏湾地区综合地质特征及找矿远景

安徽巢湖苏湾地区构造格架位于郯庐断裂带东侧滁州—苏湾金多金属矿成矿带。对近年来取得的地质成果,包括成矿地质特征、物化探特征、地球化学特征、矿化蚀变特征等进行系统分析研究,认为灯影组中段为研究区主要赋矿层位,是研究区重要找矿远景区,F1断层为主要控岩控矿构造,地磁异常为寻找类似山里许铁铜金矿的远景部位。     

鄂西南岩溶地貌遗迹类型与特征分析

岩溶地貌是整个鄂西南地区综合价值最高、数量最丰富、可代表全区地质遗迹典型特色的地质遗迹类型,具有重要保护与开发利用价值。基于全省重要地质遗迹调查项目,按照地质遗迹调查标准有关要求,通过对前人成果系统收集整理并开展补充调查,筛选汇总鄂西南全区重要岩溶地貌地质遗迹25处。本文将岩溶地质遗迹分为地表类型、过渡类型、地下类型三种类型,结合典型地质遗迹点对岩溶地貌的形态特征和成因进行分析,为鄂西南地区地质旅游产业高质量发展提供依据。     

Dependence of Tropical Cyclone Intensification on the Latitude under Vertical Shear

The sensitivity of tropical cyclone (TC) intensification to the ambient rotation effect under vertical shear is investigated. The results show that the vortices develop more rapidly with intermediate planetary vorticity, which suggests an optimal latitude for the TC development in the presence of vertical shear. This is different from the previous studies in which no mean flow is considered. It is found that the ambient rotation has two main effects. On the one hand, the boundary layer imbalance is largely controlled by the Coriolis parameter. For TCs at lower latitudes, due to the weaker inertial instability, the boundary inflow is promptly established, which results in a stronger moisture convergence and thus greater diabatic heating in the inner core region. On the other hand, the Coriolis parameter modulates the vertical realignment of the vortex with a higher Coriolis parameter, favoring a quicker vertical realignment and thus a greater potential for TC development. The combination of these two effects results in an optimal latitude for TC intensification in the presence of a vertical shear investigated.     

A Climate Prediction Method Based on EMD and Ensemble Prediction Technique

Observed climate data are processed under the assumption that their time series are stationary, as in multi-step temperature and precipitation prediction, which usually leads to low prediction accuracy. If a climate system model is based on a single prediction model, the prediction results contain significant uncertainty. In order to overcome this drawback, this study uses a method that integrates ensemble prediction and a stepwise regression model based on a mean-valued generation function. In addition, it utilizes empirical mode decomposition (EMD), which is a new method of handling time series. First, a non-stationary time series is decomposed into a series of intrinsic mode functions (IMFs), which are stationary and multi-scale. Then, a different prediction model is constructed for each component of the IMF using numerical ensemble prediction combined with stepwise regression analysis. Finally, the results are fit to a linear regression model, and a short-term climate prediction system is established using the Visual Studio development platform. The model is validated using temperature data from February 1957 to 2005 from 88 weather stations in Guangxi, China. The results show that compared to single-model prediction methods, the EMD and ensemble prediction model is more effective for forecasting climate change and abrupt climate shifts when using historical data for multi-step prediction.     

Measuring place-based accessibility under travel time uncertainty

Travel time uncertainty has significant impacts on individual activity-travel scheduling, but at present these impacts have not been considered in most accessibility studies. In this paper, an accessibility evaluation framework is proposed for urban areas with uncertain travel times. A reliable space-time service region (RSTR) model is introduced to represent the space-time service region of a facility under travel time uncertainty. Based on the RSTR model, four reliable place-based accessibility measures are proposed to evaluate accessibility to urban services by incorporating the effects of travel time reliability. To demonstrate the applicability of the proposed framework, a case study using large-scale taxi tracking data is carried out. The results of the case study indicate that the proposed accessibility measures can evaluate large-scale place-based accessibility well in urban areas with uncertain travel times. Conventional place-based accessibility indicators ignoring travel time reliability can significantly overestimate the accessibility to urban services.     

日长的十年尺度变化研究

用高精度的日长资料和由人卫激光测距（ＳＬＲ） 解算出的地球引力场系数Ｊ２ 的变化序列ΔＪ２ ,证明地球各圈层的物质迁移对日长１０ 年尺度变化贡献仅占日长１０ 年尺度变化的４ ％ ,可以忽略;认为１０ 年尺度变化主要来源于地球各圈层的内力矩或相对角动量部分,其优点是可以不顾及地球各圈层物质迁移复杂的物理机制     

山东乳山海滩岩及其重要科学意义

乳山海滩岩,经过室内对微体化石、大化石和沉积岩石学研究,查明该岩体具有典型的海滩岩特征:含有两种文石胶结物、滨海相微体古生物和热带大化石。该岩体形成在全新世最佳气侯期,至少有3次成岩期,对研究古环境变化规律具有重要的科学意义。     

滇黔桂岩溶地区农业地域类型分区之研究

本文针对滇黔桂岩溶地区农业自然环境特征、农村社会经济条件及其岩溶对农业生产发展和农业生态环境建设影响等的显著地域差异和显著地域分异规律,根据分区指标选择原则,建立起以地貌类型、岩溶地貌景观类型、农民人均纯收入为内容的分区指标体系,把全区划分为三大类、九个农业地域类型区。对三大类型区作了简述。