全球变暖背景下中国北方沙尘暴变化及其对黄土高原成壤的影响研究

黄土的风成说表明粉尘黄土沉积及其成壤与沙尘暴之间存在着密切的联系,作为粉尘搬运的典型:沙尘暴是一种在强冷空气条件下粉尘快速而大规模被搬运和沉降事件,而长时间尺度的沙尘暴事件受全球气候变化的控制和影响;同时,沙尘暴发生的频次和强度变化进而会影响黄土高原地区的黄土粉尘沉积及其成壤强度的变化。本文是在考察中国北方沙尘暴成因机制与黄土高原粉尘沉积和成壤之间关系的基础上,探讨了在全球持续变暖背景下中国北方沙尘暴的发生频次变化及其对黄土高原地区粉尘沉积和成壤强度的可能影响。主要结论是:在全球持续变暖的背景下,虽然粉尘沉积区的降水并没有显著增加,但粉尘源区气候趋于暖湿化,导致中国北方沙尘暴有逐年减少的趋势,使得黄土高原粉尘堆积的速率减小,因而,黄土高原地区将进入一个成壤相对强的时期。     

我国干旱半干旱地区气候变化及其影响

全球气候变化正在直接或间接地对自然生态系统和人类经济社会产生影响,而干旱、半干旱地区的生态系统非常脆弱,对气候变化异常敏感,通过对我国干旱半干旱地区气候变化及影响研究,认为在近50年我国干旱半干旱地区气温上升了1.8℃、降水增多29mm、地表蒸发加大、径流量减少、水资源供求矛盾加剧;农业结构调整,绿洲灌溉区农作物气候产量提高,雨养旱作区农作物产量减少;部分草原生产力下降,病虫害加剧;沙尘暴总体呈减少趋势,但局部地区由于气温升高,土壤水分耗减加速,风沙活动加剧;农业、航空、建筑、渔业、交通、工业均受到影响。     

Monitoring of Bark and Wood-Boring Beetles in France after the December 1999 Storms

After the December 1999 storms, two networks were set up over 2 years (2000 and 2001) to assess the scale and type of insect colonisation on storm damaged trees and to interpret these events for the future. The Level 1 network, was a large-scale survey that covered the entire storm area and provided qualitative observations on its 898 plots in which every major tree species was assessed. The Level 2 network, was a regional survey set up only in two regions: the 'Landes' region and the Northeast of France. The observations were intensive and quantitative, devoted only to maritime pine in the 'Landes' region and to Norway spruce in the Northeast of France. The Level 1 network indicated that less than 40% of the storm damaged trees were colonised by bark beetles in September 2000. No attacks were observed on standing trees in 2000 but many occurred during 2001 in spruce and maritime pine stands. The Level 2 network in the Vosges mountains showed a late colonisation in October and November 2000. The emerging population of Ips typographus on attacked trees reached 25 000–30 000 insects/m³. This huge population combined with the low rate of parasitism in 2001 leads to the expectation of increasing damage in spruce stands next year.     

河西走廊绿洲区沙尘暴灾害的发生及其防治

甘肃省河西走廊绿洲地区是严重受荒漠化威胁的地区，而沙尘暴在该区的发生强烈地影响了当地人民的日常生活和社会经济的发展。尽管河西地区的沙尘暴和当地的自然因素息息相关，但人类的活动加剧了现代沙漠化的发展进程。恶劣的自然条件，如持续干旱、大风天气、丰富的沙源、植被稀疏、滥用水、土地以及植物资源等，导致了河西绿州区沙尘暴的频频发生。从沙尘暴的发生和发展的原因予以分析，最后提出了切实可行的防治措施。     

浅析沙漠化与沙尘暴对中国生态环境的影响

深入分析了沙漠化、沙尘暴形成的原因和沙漠化、沙尘暴对国民经济发展所造成的危害，并系统地提出了相应对策。     

一次深对流长寿命冰雹过程分析

2005年6月14日夜到15日凌晨受1个生命史达4 h之久超级单体影响,安徽东部出现罕见的冰雹天气过程。该文利用多普勒雷达、卫星云图、MM5、地面遥测和高空天气图等资料分析,试图揭示该次冰雹过程的天气特征。结果表明:该次大范围风雹强对流天气系统是在东北低涡下,高空前倾槽与地面辐合线有利的大环流背景下,一个中尺度对流系统MCS影响所致。     

1105号热带风暴“米雷”造成辽南大暴雨过程分析

[目的]分析2011年第5号强热带风暴"米雷"影响辽宁地区造成局地大暴雨过程。[方法]利用高空地面资料、雷达资料、数值预报资料、加密自动站以及NCEP提供的再分析资料,对2011年第5号强热带风暴"米雷"影响辽宁形成大暴雨过程的成因进行了分析,探讨热带气旋北上过程中各物理量的变化。[结果]副热带高压和大陆高压打通后形成的高压坝持续维持,迫使"米雷"在登陆山东后部向西北转向;伴随"米雷"形成的低空东南急流将低层的暖湿空气持续向暴雨区输送,为暴雨的产生提供了充分的水汽输送和层结不稳定条件;暴雨主要分布在高能舌内,高能舌的移动和消失对应暴雨雨带的移动和过程的结束,能量的分布情况对暴雨的落区有一定的指示作用。[结论]该研究为预报业务提供参考。     

人工暗河城市雨洪蓄排系统

针对郑州水资源紧缺、城市雨洪资源化程度低、城市绿化与河流生态治理缺乏雨水集蓄利用系统和建筑垃圾负担过重等问题,借鉴自然暗河原理,提出人工暗河新技术,给出人工暗河设计方法,开发出集雨水收集、存蓄、利用和生态排放于一体的人工暗河城市雨洪蓄排系统。该系统具有资源性、节能性、实用特性和生态环保等特性,为解决城市雨洪资源化这个水资源领域重大难题提供了参考。     

Pathophysiology of acute pancreatitis: potential application from experimental models and human medicine to dogs

The cellular events leading to pancreatitis have been studied extensively in experimental models. Understanding the cellular events and inciting causes of the multisystem inflammatory cascades that are activated with this disease is of vital importance to advance diagnosis and treatment of this condition. Unfortunately, the pathophysiology of pancreatitis in dogs is not well understood, and extrapolation from experimental and human medicine is necessary. The interplay of the inflammatory cascades (kinin, complement, cytokine) is extremely complex in both initiating leukocyte migration and perpetuating disease. Recently, nitric oxide (NO) and altered microcirculation of the pancreas have been proposed as major initiators of inflammation. In addition, the role of the gut is becoming increasingly explored as a cause of oxidative stress and potentiation of systemic inflammation in pancreatitis.