RESEARCH ON MOIST SYMMETRIC INSTABILITY IN A STRONG SNOWFALL IN NORTH CHINA

The concept of wet bulb potential vorticity and SCAPE (slantwise convective available potentialenergy) is used to calculate the horizontal and vertical distribution of moist symmetric instabilityincluding convective symmetric instability (CSI) and local symmetric instability (LSI) in the processof a storm snowfall in North China.The potential contribution of moist symmetric instability to anarrow storm snowfall belt occurring in the Hetao and Lindong,Linxi region of Inner Mongolia andthe relationship between moist symmetric instability and direction of the basic flow,wind shear andmoisture are discussed.It is found that the strong snowfall belt is almost parallel with negative valuearea of wet bulb potential vorticity at low levels in the vicinity of snow area.And the dynamicalmechanism of the strong snowfall center in the Lindong,Linxi region is different from that in theHetao region.The former is induced by frontogenetical forcing with weak symmetric instability in thewarm section of frontal area and the latter triggered by obvious moist symmetric instability.     

后置群体评价方法在天气预报决策中的应用

在应用各种预报方法作每日的天气预报时，常遇到的各种预报方法的结果不一致的情形，这时需集各预报结果为一体作为群体决策意见，作者介绍了后置群体评价方法在天气预报决策中的具体应用，用该方法进行决策，取得了较理想的效果。     

隧道工程地质预报方法探讨

本文从一些隧道工程事故实例出发，讨论了引起坍方和涌水灾害的工程、水文地质条件，不同工程阶段的预报方法以及预报研究的重大经济效益。最后提出五点提高预报符合率的原则和方法。     

浙江长兴煤山二叠-三叠系界线层牙形石序列及其全球对比

在详细研究全球二叠－三叠系界线层候选剖面───中国浙江长兴煤山剖面Ｐ／Ｔ界线层牙形石动物群序列基础上，自下而上识别出４个牙形石带：（１）ＣｌａｒｋｉｎａｃｈａｎｇｘｉｎｇｅｎｓｉｓＣｌａｒｋｉｎａｄｅｆｌｅｃｔａ带；（２）Ｉｓａｒｃｉｃｅｌｌａｐａｒｖａ带；（３）Ｉｓａｒｃｉｃｅｌｌａｉｓａｒｃｉｃａ带；（４）ＣｌａｒｋｉｎａｃａｒｉｎａｔａＣｌａｒｋｉｎａｐｌａｎａｔａ带，并在第一带中划分出３个动物群，从下向上是：ＣｌａｒｋｉｎａｃｈａｎｇｚｉｎｇｅｎｓｉｓＣｌａｒｋｉｎａｄｅｆｌｅｃｔａ－Ｃｌａｒｋｉｎａｓｕｂｃａｒｉｎａｔａ动物群，Ｈｉｎｄｅｏｄｕｓｌａｔｉｄｅｎｔａｔｕｓ－Ｃｌａｒｋｉｎａｍｅｉｓｈａｎｅｎｓｉｓｓｐ．ｎｏｖ．动物群和Ｈｉｎｄｅｏｄｕｓｔｙｐｉｃａｌｉｓ动物群，煤山剖面二叠、三叠系界线层牙形石序列的建立、完善，对确立该剖面在全球二叠、三在系界线高精度对比中的标准地位具重要意义。     

微量元素及重矿物判别分析在西昆仑山前第三系划分对比中的应用

采用微量元素和重矿物判别分析方法解决百昆仑山前长期未解决的红色哑地层划分对比问题。微量元素和重矿物与沉积环境及物源性质密切相关。不同时期，不同水系（物源区）的沉积岩具有不同的重矿物和微量元素特征。在西昆仑山前初步建立了３条微量元素和重矿物标准剖面，每条剖面均建立了划分组段的微量元素和重矿物两套判别函数。用以解决地面或井下未知层位样品的判别归属问题，经地面和井下验证取得初步成效。     

降低金刚石钻头烧结温度的方法

人相图上分析了制取预合金胎体粉末以降低钻头烧结温度的可行性，并结合生产实践介绍了２种预合金粉末的制备方法，从而把制造金刚石钻头的烧结温度降低到９００℃。     

耀斑环动力学的数值研究

数值模拟了太阳耀斑环动力学演化的二维磁重联过程。结果表明,在重联Ｘ 点比较高时,演化过程能再现双带耀斑中的耀斑环活动;而重联Ｘ 点比较低时,演化情况能解释致密耀斑的观测特征     

Extracting commuter-specific destination hotspots from trip destination data – comparing the boro taxi service with Citi Bike in NYC

ABSTRACT

Taxi trajectories from urban environments allow inferring various information about the transport service qualities and commuter dynamics. It is possible to associate starting and end points of taxi trips with requirements of individual groups of people and even social inequalities. Previous research shows that due to service restrictions, boro taxis have typical customer destination locations on selected Saturdays: many drop-off clusters appear near the restricted zone, where it is not allowed to pick up customers and only few drop-off clusters appear at complicated crossing. Detected crossings imply recent infrastructural modifications. We want to follow up on these results and add one additional group of commuters: Citi Bike users. For selected Saturdays in June 2015, we want to compare the destinations of boro taxi and Citi Bike users. This is challenging due to manifold differences between active mobility and motorized road users, and, due to the fact that station-based bike sharing services are restricted to stations. Start and end points of trips, as well as the volumes in between rely on specific numbers of bike sharing stations. Therefore, we introduce a novel spatiotemporal assigning procedure for areas of influence around static bike sharing stations for extending available computational methods.     

X线CT机选型的依据

本文描述了X 线CT 机的几个主要技术特性,并根据这些特性,计论如何去选择一台价格低、图像质量高的CT 扫描机。     

德都地震前湾井水位的四步段映震异常及其预报意义

本文归纳了德都中强地震发生前湾_1井水位动态异变的基本特征,指出湾,井水位的四步段映震异常:骤然陡降—缓慢回升—高位跳动—高位稳定发震。并对短、临异常作了对比分析,探讨四步段映震异常对地震短临预报的重要意义。还就区域应力异常场和灵敏性问题进行了讨论。