陕西渭北煤田5#煤层粘土岩夹矸的研究

渭北煤田面积约１０万ｋｍ２。分布于太原组顶部５＃煤层中的粘土岩夹矸，上部层位分为两上分层，上分层夹矸厚度薄，下分层夹矸厚约０２ｍ，俗称“２００矸”；下部层位夹矸厚度变化较大。该文详细论述了粘土岩夹矸的岩矿特征。根据“２００矸”中含有副象β－石英、高透长石、锆石、磁铁矿等高温矿物组合，特有的粒序层理和岩性在全煤田十分稳定等特点，表明其原始物质来源于降落火山灰。根据ＴｉＯ２／Ａｌ２Ｏ３比值的明显变化，探讨了陆源组分的加入对火山灰蚀变粘土岩夹矸化学成分的影响。以“２００矸”为等时标志层，解决了５＃煤层在区域上的对比。     

超灵敏加速器质谱计测定^32Si样品制备新技术

介绍了制备元素硅的一种化学方法，它可用于ＡＭＳ装置的离子源。含硅的物质溶解在ＨＦ中，用ＬｉＡｌＨ４把ＳｉＦ４还原成ＳｉＨ４，再将ＳｉＨ４加热分解成元素硅，并且沉淀在石墨盘上，用ＡＭＳ测定ｗ３２Ｓｉ／ｗＳｉ总比值，其灵敏度可达１０＾－１３。     

露天矿边坡的位移监测与滑坡预报

对湖北大冶铁矿滑坡区域的长期监测资料进行分析和总结，提出依据位移-时间曲线预报滑坡的方法。     

地球演化中最大的两级节律

地球演化中表现出的最大两级节律为１０×１０８ａ和２×１０８ａ。每２个相邻节律可合并为一个周期，因而地球演化的最大两级周期为２０×１０８ａ和４×１０８ａ。岩石学、地层学和构造地质学方面诸多证据都说明这种划分的合理性。对于地球演化中的这类大型节律及周期性的成因机制，用笔者已提出的“地球多级驻波脉动理论模型”可以得到较合理的解释。     

BECAPEX科学试验城市建筑群落边界层大气环境特征及其影响

20 0 1～ 2 0 0 3年在北京实施了大气边界层动力、热力、化学综合观测试验 (BECAPEX ,BeijingCityAtmosphericPollutionObservationFieldExperiment) ,获取了北京城市大气动力和大气化学三维结构图像。综合观测试验分析研究发现 ,城市区域呈非均匀次生尺度热岛分布 ,并伴随着城市次生尺度环流 ,影响了局地空气污染物分布特征。MODIS卫星遥感 地面观测资料经过变分分析 ,可发现北京城市空气污染与周边区域影响源有密切关系 ,并影响城市群落环境气候特征 ,导致该区域日照、雾日、低云量和能见度呈显著年代际变化趋势。     

偏振激发能量色散X荧光法在地球化学分析中应用及其与波长色散X荧光法的比较

偏振激发能量色散X射线荧光光谱(P-EDXRF)技术是20世纪末出现的新分析技术。国内采用X-Lab2000型仪器的初步研究表明，在总计数时间为600秒时，可以对近30种元素进行定量，检出限为0．5-30μg／g，与国际上发表的文献值基本一致。本工作通过约100个实际样品分析，并与波长色散X射线荧光法(WDXRF)分析结果的比较，对P-EDXRF的分析性能进行了评价。与WDXRF相比，P-EDXRF法具有分析速度快、设备购置费用低、运行成本低、全谱同时采集(有利于发现元素含量异常)等优点，因此特别适合地球化学填图样品的快速分析。而WDXRF在精度要求较高的分析中更具竞争力。     

Spatial character of the gaseous and particulate state compound correlation of urban atmospheric pollution in winter and summer

The spatial/temporal variation information of atmospheric dynamic-chemical processes at observation site points of the "canopy" boundary of Beijing urban building ensemble and over urban area "surface", as well as the seasonal correlation structure of the gaseous and particulate states of urban atmospheric pollution (UAP) and its seasonal conversion feature at observation points are investigated, using the comprehensive observation data of the Beijing City Air Pollution Observation Experiment (BECAPEX) in winter and summer 2003 with a "point-surface" combined research approach. By using "one dimension spatial empirical orthogonal function (EOF)" principal component analysis (PCA) mode, the seasonal change of gaseous and particulate states of atmospheric aerosols and the association feature of pollutant species under the background of the complicated structure of urban boundary layer (UBL) are analyzed. The comprehensive analyses of the principal components of particle concentrations,gaseous pollutant species, and meteorological conditions reveal the seasonal changes of the complex constituent and structure features of the gaseous and particulate states of UAP to further trace the impact feature of urban aerosol pollution surface sources and the seasonal difference of the component structure of UAP. Research results suggest that in the temporal evolution of the gaseous and particulate states of winter/summer UAP, NOx, CO, and SO2 showed an "in-phase" evolution feature, however, O3 showed an "inverse-phase" relation with other species,all possessing distinctive dependent feature. On the whole, summer concentrations of gaseous pollutants CO, SO2, and NOx were obviously lower than winter ones, especially, the reduction in CO concentration was most distinctive, and ones in SO2 and NOx were next. However, the summer O3 concentration was more than twice winter one. Winter/summer differences in PM10and PM2.5 particle concentrations were relatively not obvious, which indicates that responses of PM10 and PM2.5 particle concentrations to the difference of winter/summer heating period emission sources are far less distinctive than those of NOx, SO2, and CO. The correlation feature of winter/summer gaseous and particulate states depicts that both PM10 and PM2.5 particles were significantly correlated with NOx, and their correlations with NOx are more significant than those with other pollutants. Through PCA, it is found that there was a distinctive difference in the principal component combination structure of winter/summer PM10 and PM2.5 particles: SO2 and NOx dominated in the principal component of winter PM10 and PM2.5 particles; while CO and NOx played the major role in the principal component of summer PM10 and PM2.5 particles. For winter/summer PM10 and PM2.5 particles, there might exist the gaseous and particulate states correlation structures of different "combinations" of such dependent pollutant species. Research results also uncover that the interaction processes of gaseous and particulate states were also related with the vertical structure of UBL, that is to say, the low value layer of UBL O3 concentration was associated with the collocation of atmospheric vertical structures of the low level inversion,inverse humidity, and small wind, which depicts summer boundary layer atmospheric character, i.e.the compound impact of the dependent factor "combination" of wind, temperature, and humidity elements and their collocation structure on the variations of different gaseous pollutant concentrations. Such a depth structure of the extremely low value of O3 concentration in the UBL accords with its "inverse-phase" relation with other gaseous pollutant species. The PCA of meteorological factors associated with PM10 and PM2.5 concentrations also reveals the sensitivity of PM10 and PM2.5 concentration to the combinatory feature of local meteorological conditions.     

Piecewise prediction model for watershed‐scale erosion and sediment yield of individual rainfall events on the Loess Plateau,China

Establishing a universal watershed‐scale erosion and sediment yield prediction model represents a frontier field in erosion and soil/water conservation. The research presented here was conducted on the Chabagou watershed, which is located in the first sub‐region of the hill‐gully area of the Loess Plateau, China. A back‐propagation artificial neural model for watershed‐scale erosion and sediment yield was established, with the accuracy of the model, then compared with that of multiple linear regression. The sensitivity degree of various factors to erosion and sediment yield was quantitatively analysed using the default factor test. On the basis of the sensitive factors and the fractal information dimension, the piecewise prediction model for erosion and sediment yield of individual rainfall events was established and further verified. The results revealed the back‐propagation artificial neural network model to perform better than the multiple linear regression model in terms of predicting the erosion modulus, with the former able to effectively characterize dynamic changes in sediment yield under comprehensive factor conditions. The sensitivity of runoff erosion power and runoff depth to the erosion and sediment yield associated with individual rainfall events was found to be related to the complexity of surface topography. The characteristics of such a hydrological response are thus closely related to topography. When the fractal information dimension is greater than the topographic threshold, the accuracy of prediction using runoff erosion power is higher than that of using runoff depth. In contrast, when the fractal information dimension is smaller than the topographic threshold, the accuracy of prediction using runoff depth is higher than that of using runoff erosion power. The developed piecewise prediction model for watershed‐scale erosion and sediment yield of individual rainfall events, which introduces runoff erosion power and runoff depth using the fractal information dimension as a boundary, can be considered feasible and reliable and has a high prediction accuracy. Copyright © 2013 John Wiley & Sons, Ltd.     

The effect of expansion ratio on the critical Reynolds number in single fracture flow with sudden expansion

Flow in a single fracture (SF) is an important research subject in groundwater hydrology, hydraulic engineering, radioactive nuclear waste repository and geotechnical engineering. An abruptly changing aperture is a unique type of SF. This study discusses the relation between the values of the critical Reynolds number (Re_c) for the onset of symmetry breaking of flow and the expansion ratio (E) of SF, which is defined as the ratio between the outlet (D) and inlet (d) apertures. This study also investigates the effect of inlet aperture d on Re_c for flow in an SF with abruptly changing apertures (SF‐ACA) using the finite volume method. Earlier numerical and experimental results showed that flow is symmetric in respect to the central plane of the SF‐ACA at small Reynolds number (Re) but becomes asymmetric when Re is sufficiently large. Our simulations show that the value of Re_c decreases with the increasing E, and the relationship between the logarithm of Re_c and E can be described accurately using either a quadratic polynomial function or a logarithmic function. However, the relationship of Re_c and d for a given E value is vague, and Re_c becomes even less sensitive to d when E increases. This study also reveals that the hydraulic gradient (J) and flow velocity (v) follow a super‐linear relationship that can be fitted almost perfectly by the Forchheimer equation. The inertial component (J_i) of J increases monotonically with Re, whereas the viscous component (J_v) of J decreases monotonically with Re. The Re value corresponding to equal inertial and viscous components of J (named as the transitional point Re) decreases when E increases, and such a transitional point Re should be closely related to the critical Reynolds number Re_c, although a rigorous theoretical proof is not yet available. Copyright © 2015 John Wiley & Sons, Ltd.