1961-2013年东北与华北气温变化速度空间差异

全球气候的不断变化使得生物生境受到极大影响。气温作为最基本的气候要素,其变化迁移会胁迫生物对此做出响应,造成生物群落的迁徙。气温变化速度将气温看作物质的运动,能够直观地表示气温时空变化特征,对研究生物分布地理界限变化具有重要的指导意义。本文利用1961-2013年的全国每月平均温度数据集,分析了过去50多年中国东北与华北地区之间气温变化速度的区域差异。结果表明：东北与华北两地区整体气温变化速度均值为5.60 km/year,速度范围主要集中于0~9 km/year之间,约占总数的90%。东北地区气温变化速度均值大于华北地区。其中,东北速度均值为5.85 km/year,华北为5.41 km/year。从区域内部来看,东北地区气温变化速度整体较高,三省中黑龙江与吉林速度较高,辽宁省速度变化相对较小。华北气温变化速度高值区域主要分布在内蒙古高原与河北、天津的小部分地区,其他地区的气温变化速度则相对较小。     

A modular injection system, multilevel sampler, and manifold for tracer tests

Ground water injection and sampling systems were developed for bacterial transport experiments in both homogenous and heterogeneous unconsolidated, surficial aquifers. Two types of injection systems, a large single tank and a dynamic mixing tank, were designed to deliver more than 800 L of amended ground water to the aquifer over 12 hours, without altering the ground water temperature, pH, Eh, or dissolved gas composition. Two types of multilevel samplers (MLSs) were designed and installed. Permanent MLSs performed well for the homogenous surficial aquifer, but their installation procedure promoted vertical mixing, which could obfuscate experimental data obtained from vertically stratified, heterogeneous aquifers. A novel, removable MLS was designed to fit in 2- and 4-inch wells. Expandable O-rings between each sampling port hydraulically isolated each port for sample collection when a nut was tightened at the land surface. A low-cost vacuum manifold system designed to work with both MLS designs used 50 mL centrifuge tubes to efficiently sample 12 MLS ports with one peristaltic pump head. The integrated system was developed and used during four field campaigns over a period of three years. During each campaign, more than 3000 ground water samples were collected in less than one week. This system should prove particularly useful for ground water tracer, injection, and push-pull experiments that require high-frequency and/or high-density sampling.     

面向21世纪的地貌学教学改革的几点思考

地貌学是自然地理学中重要的传统分支学科之一。在跨入新世纪的今天 ,高校地貌学教学亟待改革。笔者认为 ,教学改革不应囿于形式 ,而应注重实质。从培养学生坚实的专业基础考虑 ,教学改革的指导思想应是加强基础教学。教学内容的更新是其中心环节 ,首先是要加强和拓展基础理论 ,其次应密切联系实际 ,突出应用性和环境教育。面对教学内容与课时不足的矛盾 ,应积极进行教法的改革和完善。     

震中区电磁辐射异常的观测

用余震的活动性测定预报参数——在靠近震中区进行测量的可能性很小.震中区有何特点,越靠近震中区的这种效应越强的假设是否合理?直接靠近震中区进行测量是极少的.这些想法是1984年4月20日加兹利地震后余震活动期间在震源进行试验的基础.对电磁辐射异常的观测是在200—1000赫;3—9千赫和80.5千赫((?)f=100赫)3个频段上进行的.高频信号包络线的记录接到КГП—4多频道自动记录仪上,走纸速度为每小时60毫米,每72秒钟在每一通道上取样一次.1984年9月16日～10月18日观测地震活动时发现,余震活动性与前几个月相比呈衰减趋势;但有感地震在几天之内仍不少于1次.在弱震群中1984年9月27日当地时间