豫西崤山后河岩体LA-ICP-MS锆石U-Pb定年

与豫西小秦岭和熊耳山地区相类似,崤山北部也出露一系列中酸性小岩体,但与之相关的成矿作用明显较弱,因此长期未获得应有的关注。崤山北部小岩体的形成时代与区域成岩成矿时代之间的匹配关系对其深部构造演化研究及成矿潜力评价具有重要意义,鉴于此,作者对后河岩体进行了LA—ICP—MS锆石U-Db定年。后河岩体定年样品HH01的岩性为中一细粒黑云母二长花岗岩,30个锆石测点中有27个测点的测定值位于207PB/235U-206Pb/238U一致线上,相应的206Pb/238U年龄介于124～134Ma之间,加权平均年龄为128±1Ma（MSWD=I．02）,属早白垩世。后河岩体是岩石圈拆沉作用的产物,其形成时代处在东秦岭地区广泛而强烈的成岩成矿作用时限内,且显示了Au、Ag、Cu、Mo、W等元素的异常富集,具有较大的内生金属成矿潜力。     

贵州西南部近5a突发性暴雨时空特征分析

利用2014—2018年5—10月贵州西南部的黔西南州、六盘水市、安顺市以及黔南州长顺县、惠水县、罗甸县共20个气象观测站小时降水资料,分析近5 a 5—10月贵州省西南部突发性暴雨的时空变化,结果表明：突发性暴雨呈逐年减少的趋势;月际变化特征为6月“爆发”,7月“回落”,而8月略增,9—10月呈不断减少趋势;具有白天少、夜间多的日变化特征,且突发性暴雨的高发时段主要是在午后至凌晨。从各等级小时降水骤增量的站次空间分布情况来看,突发性暴雨空间分布与地形分布具有较好的对应关系,骤增等级大时,主要出现在北盘江河谷一带,而镇宁一直是一个高发中心。从突发性暴雨站次的整个时空演变来看,5月从东南部开始,6月兴义和六枝成为南北两个高发中心,7月总体减少,中部为多发中心,8月略有增加,分布呈现出南北盘江河谷一带多发;从逐年的演变来看,“突发性”的特点在地域分布上也有体现,每一年的分布情况均不相同。     

热带气旋“利奇马”(1909)暖心演变分析及变性过程探讨

利用NCEP GDAS/FNL再分析数据,根据TFP(Thermal Front Parameter)参数和锋生函数,对1909号热带气旋“利奇马”生命史中各主要阶段暖心特征和变性过程进行了诊断分析。结果表明:“利奇马”强度为热带风暴时,其暖心结构较为松散,500 hPa以上和600 hPa以下分别存在一个最强中心,在强度减弱阶段上下层暖心均偏离气旋中心;当其强度升至强热带风暴及以上级别时,低层暖心消失,高层暖心显著增强,结构变得紧凑,气旋中心上空暖区呈棒槌状分布。高层暖心强度与“利奇马”强度呈正相关,当“利奇马”维持超强台风时,其暖心可达10~14℃。“利奇马”与中纬度西风槽接触后,冷空气开始自对流层中低层进入其环流,低层冷空气入侵的程度比中层更明显;低层暖心被冷空气侵蚀而消失,高层暖心则逐渐减弱,结构亦变得松散。TFP参数和锋生函数计算结果表明受冷空气影响,“利奇马”斜压性逐渐增强,其中心西北侧形成一支暖锋,逐渐变性为温带气旋,但冷锋未见发展。变性过程中“利奇马”高层暖心强度虽减弱但仍然维持,但低层暖区被冷空气完全填塞,导致其变性后较快消亡。     

清江盆地沉积构造分类及其特征分析

本文提出了我国东南地区中新生代的清江盆地沉积构造的分类,分析了该盆地沉积构造的特征、形成条件和沉积环境,并指出了某些沉积构造为同类型含盐盆地所特有。     

The Total Diet Study: Changes in Food Safety Since the First TDS

This article discusses what we know about some of the main food safety risks in China. The focus is on role of the China Total Diet Study (TDS) as a tool for food safety risk assessment and the selection of priorities for monitoring. We compare the strengths and weaknesses of the TDS with those of two other major sources of information about food safety and nutrition: the National Food Safety Contamination Monitoring Network (FSCN) and the China Health and Nutrition Survey (CHNS), showing how the different methods they use produce different but complementary information. We then use an analysis of lead, cadmium and pesticide residues to demonstrate that, despite its shortcomings, the TDS provides the most reliable source of information about the actual dietary intake of harmful substances.     

协同演化与集群成长——河南禹州钧瓷产业集群的案例分析

集群演化是经济地理研究的一个前沿方向,演化经济地理学和新生命周期理论可用于解释集群从形成、成长、成熟到衰退或再生的过程。与已有文献强调企业—产业—网络的协同演化不同,本文构建了以企业为核心的技术—制度—政府—市场协同演化的分析框架,通过对禹州钧瓷产业集群的案例分析,结果发现：① 集群的浮现与成长是一个多因素、多机制协同演化的过程,技术—制度—政府—市场的相互作用以及内在的路径依赖与路径创造、知识外溢与企业衍生、规模报酬与循环累积等机制,在集群发展的不同阶段发挥着各自不同但彼此协同的作用。② 以本地资源禀赋和历史文化传统为基础的制度—技术的协同,具有路径依赖机制,塑造了钧瓷产业发展的初始优势,是集群浮现和生命力维持的基础。③ 由政府主导的市场经济转型与国企改革等制度转型,通过企业衍生机制促成了民营钧瓷企业的兴起;而钧瓷消费市场扩大与新市场空间拓展所形成的市场规模效应,则为企业衍生和规模扩张提供了有效的需求;政府—市场的协同在循环累积机制作用下,形成了钧瓷生产规模与市场规模相互强化机制,促进了钧瓷产业集群的快速成长。④ 集群演化是路径依赖与路径创造相互制约又相互促进的复杂自适应过程,钧瓷烧制技术、工艺、釉料、产品和造型及功能创新成为企业生存和竞争力的根本来源,地方独特的产业氛围使知识外溢和路径创造成为钧瓷产业集群持续壮大的核心动力。     

Vertical Distribution Characteristics of PM_(2.5) Observed by a Mobile Vehicle Lidar in Tianjin,China in 2016

We present mobile vehicle lidar observations in Tianjin, China during the spring, summer, and winter of 2016. Mobile observations were carried out along the city border road of Tianjin to obtain the vertical distribution characteristics of PM_(2.5). Hygroscopic growth was not considered since relative humidity was less than 60% during the observation experiments. PM_(2.5) profile was obtained with the linear regression equation between the particle extinction coefficient and PM_(2.5) mass concentration. In spring, the vertical distribution of PM_(2.5) exhibited a hierarchical structure. In addition to a layer of particles that gathered near the ground, a portion of particles floated at 0.6–2.5-km height. In summer and winter, the fine particles basically gathered below 1 km near the ground. In spring and summer, the concentration of fine particles in the south was higher than that in the north because of the influence of south wind. In winter, the distribution of fine particles was opposite to that measured during spring and summer. High concentrations of PM_(2.5) were observed in the rural areas of North Tianjin with a maximum of 350 μg m–3 on 13 December2016. It is shown that industrial and ship emissions in spring and summer and coal combustion in winter were the major sources of fine particles that polluted Tianjin. The results provide insights into the mechanisms of haze formation and the effects of meteorological conditions during haze–fog pollution episodes in the Tianjin area.     

Response of Freezing/Thawing Indexes to the Wetting Trend under Warming Climate Conditions over the Qinghai–Tibetan Plateau during 1961–2010: A Numerical Simulation

Since the 1990s, the Qinghai–Tibetan Plateau(QTP) has experienced a strikingly warming and wetter climate that alters the thermal and hydrological properties of frozen ground. A positive correlation between the warming and thermal degradation in permafrost or seasonally frozen ground(SFG) has long been recognized. Still, a predictive relationship between historical wetting under warming climate conditions and frozen ground has not yet been well demonstrated,despite the expectation that it will b...     

基于《测绘工程》期刊的测绘技术动态可视化分析

结合文献计量方法与可视化技术,以《测绘工程》期刊1996-2015年间发表的论文为数据源,进行关键词、摘要的统计分析,并将统计结果以统计图表和地图的形式展现,直观地反映工程技术实践类测绘研究的研究热点以及核心研究区的地理分布。从研究结果可以得出我国工程技术实践类测绘研究每年的研究热点都不相同,学科的发展地理分布较不平衡,一定程度上反映我国工程技术实践类测绘研究的水平。