国内发现锌铝磷酸盐矿物──水羟磷铝锌石

水羟磷铝锌石是一种罕见的磷酸盐类矿物,在我国该矿物于1983年始发现于广东宝坑的锰矿区。该矿物的化学成分为ZnO 20.79,P_2O_5 34.76,FeO 0.67,Al_2O_3 24.38,H_2O 19.79(%)。晶体浅黄色、透明,X射线衍射特征强线为:4.76(10),9.095(8),3.638(6),3.333(6),3.313(6),3.095(6),4.91(5),晶胞参数a_0=7.274?,b_0=7.185?,c_0=9.788?,β=110.244°,单斜晶系,其矿物学特征与澳大利亚发现的水羟磷铝锌石基本一致。     

新一代中国数字地震台网（NCDSN）台站系统

以白家疃数字地震台为例，介绍了新一代中国数字地震台网（ＮＣＤＳＮ）台站系统的各种硬件单元及它们的相互联系与特征。同时介绍了系统的频率响应、数据流和动态范围，并与中国数字地震台网（ＣＤｓＮ）—期设备进行了简单比较。     

老厂铅锌矿床地质地球化学的研究

根据老厂铅锌矿床的地质特征、稀土元素地球化学、气液包裹体、稳定同位六、容矿地层元素丰度等方面的研究，认为该矿床成因属溶滤－再造后成矿床。     

基于Meta分析的中国森林生态系统生态服务功能价值转移研究

构建中国森林生态系统生态服务功能价值的数据库和Meta模型,分析价值评估的影响因素,检验模型的有效性。研究表明：①研究方法、生态系统生态服务功能、植被类型、所处植被区域、受益人口数量及集聚程度是影响森林生态系统生态服务功能价值变化的主要影响因素;②有效性检验证明将基于Meta分析的价值转移运用在森林生态系统生态服务功能价值评估上是一种快速且有效的方法;③中国森林生态系统生态服务功能价值呈现东高西低、南高北低的特征,价值随时间推移而增加,涵养水源功能价值最高,提供林果产品功能价值最低。     

Analyzing vegetation dynamic trend on the Mongolian Plateau based on the Hurst exponent and influencing factors from 1982–2013

This study analyzed the spatial and temporal variations in the Normalized Difference Vegetation Index (NDVI) on the Mongolian Plateau from 1982–2013 using Global Inventory Modeling and Mapping Studies (GIMMS) NDVI3g data and explored the effects of climate factors and human activities on vegetation. The results indicate that NDVI has slight upward trend in the Mongolian Plateau over the last 32 years. The area in which NDVI increased was much larger than that in which it decreased. Increased NDVI was primarily distributed in the southern part of the plateau, especially in the agro-pastoral ecotone of Inner Mongolia. Improvement in the vegetative cover is predicted for a larger area compared to that in which degradation is predicted based on Hurst exponent analysis. The NDVI-indicated vegetation growth in the Mongolian Plateau is a combined result of climate variations and human activities. Specifically, the precipitation has been the dominant factor and the recent human effort in protecting the ecological environments has left readily detectable imprints in the NDVI data series.     

Frost heave analysis of ballasted track above box culvert and its influence on train vibration

The uneven frost heave of frost-susceptible subgrade soil causes track irregularity, which highly enhances train vibration and affects the comfort and safety of railway transportation. This paper presents a coupled thermo-hydro-mechanical (THM) analysis for the freezing behavior of railway located above a box culvert. The vertical acceleration of the vehicle, an indicator of riding comfort, is predicted through a vehicle dynamic model. The results reveal that the existence of a box culvert changes the subgrade thermal pattern, leading to a deeper frost penetration depth. The frost heave amount above the box culvert is larger than the adjacent section, resulting in uneven track structure upheave and track irregularity. This frost-induced track irregularity highly affects train vibration.     

“苏拉”台风引发福建西部大暴雨成因分析

利用常规天气资料、NCEP 1°×1°再分析资料、地面降水资料以及福建新一代天气雷达资料对2012年"苏拉"台风登陆后引发福建西部大暴雨天气成因进行分析,结果表明:"苏拉"登陆后高空涡旋受大陆高压东侧偏北气流引导向偏南方向移动,同时,台风登陆后进入大的环境风垂直切变区并向切变左侧倾斜,使得台风南倾结构进一步加大。台风结构南倾为福建西部大暴雨区提供了良好的动力条件,"苏拉"自身带来的水汽及台风南侧西南气流为暴雨区提供了充足的水汽来源,高空冷空气入侵与低层的高温高湿区形成上冷下暖结构呈现出条件不稳定层结,有利于深厚湿对流产生,结合充分的水汽供应,出现大暴雨天气。大范围暖平流配合风速辐合,中高层冷空气入侵与低层西南暖湿空气结合以及低层的西南急流建立是三个强降水阶段对应的中尺度天气特征。     

Trends and uncertainties in surface air temperature over the Tibetan Plateau, 1951–2013

Trends and uncertainties of surface air temperature over the Tibetan Plateau (TP) are evaluated by using observations at 100 meteorological stations during the period 1951–2013. The sampling error variances of gridded monthly data are estimated for every month and every grid box of data. The gridded data and their sampling error variances are used to calculate TP averages, their trends, and associated uncertainties. It is shown that large sampling error variances dominate northern and western TP, while small variances appear over southern and eastern TP. Every month from January to December has a positive linear trend during the study period. February has the largest trend of 0.34 ± 0.18°C (10 yr)^–1, and April the smallest at 0.15 ± 0.11°C (10 yr)^–1. The uncertainties decrease steadily with time, implying that they are not large enough to alter the TP warming trend.     

Coarse sediment supply sets the slope of bedrock channels in rapidly uplifting terrain: Field and topographic evidence from eastern Taiwan

The incision rate and steepness of bedrock channels depend on water discharge, uplift rate, substrate lithology, sediment flux, and bedload size. However, the relative role of these factors and the sensitivity of channel steepness to rapid (>1 mm yr⁻¹) uplift rates remain unclear. We conducted field and topographic analyses of fluvial bedrock channels with varying channel bed lithology and sediment source rock along the Coastal Range in eastern Taiwan, where uplift rates vary from 1.8 to 11.8 mm yr⁻¹ and precipitation is relatively consistent (1.5–2.7 m yr⁻¹), to evaluate the controls on bedrock channel steepness. We find that channel steepness is independent of rock uplift rate and annual precipitation but increases monotonically with sediment size and substrate strength. Furthermore, in reaches with uniform substrate lithology (mudstone and flysch), channel steepness systematically varies with sediment source rock but not with channel width. When applied to our data, a mechanistic incision model (saltation-abrasion model) suggests that the steepness of Coastal Range channels is set primarily by coarse-sediment supply. We also observe that larger particles are mainly composed of resistant lithologies derived from volcanic rocks and conglomerates. This result implies that hillslope bedrock properties in the source area exert a dominant control on the steepness of proximal channels through coarse-sediment production in this setting. We propose that channel steepness may be insensitive to uplift rate and flow discharge in fast-uplifting landscapes where incision processes are set by coarse sediment size and supply. Models assuming a proportionality between incision rate and basal shear stress (stream power) may not fully capture controls on fluvial channel profiles in landslide-dominated landscapes. Processes other than channel steepening, such as enhanced bedload impacts and debris-flow scour, may be required to balance rock uplift and incision in these transport-limited systems.     

Probabilistic seismic hazard assessment of Italy using kernel estimation methods

A representation of seismic hazard is proposed for Italy based on the zone-free approach developed by Woo (BSSA 86(2):353–362, 1996a), which is based on a kernel estimation method governed by concepts of fractal geometry and self-organized seismicity, not requiring the definition of seismogenic zoning. The purpose is to assess the influence of seismogenic zoning on the results obtained for the probabilistic seismic hazard analysis (PSHA) of Italy using the standard Cornell’s method. The hazard has been estimated for outcropping rock site conditions in terms of maps and uniform hazard spectra for a selected site, with 10 % probability of exceedance in 50 years. Both spectral acceleration and spectral displacement have been considered as ground motion parameters. Differences in the results of PSHA between the two methods are compared and discussed. The analysis shows that, in areas such as Italy, characterized by a reliable earthquake catalog and in which faults are generally not easily identifiable, a zone-free approach can be considered a valuable tool to address epistemic uncertainty within a logic tree framework.