暴雨云团的多尺度识别方法及其在临近预报中的应用

将一种暴雨云团的多尺度识别方法——层级聚类法,应用于β中尺度对流系统识别及临近预报中。该方法的基本思路是:将笛卡尔坐标下的雷达反射率因子进行聚类,得到比较详细的较小尺度的暴雨云团,然后设定阈值,将云团之间差异小于阈值的进行合并,可以得到较大尺度的云团,逐步放宽合并阈值,可得到更大尺度的云团。选取广州雷达2005年3月的飑线过程和温州2005年9月的台风过程对这种方法的识别结果进行了详细说明,结果表明:该方法能够识别不同系统的β中尺度对流云团,并能识别出其中反射率较强的γ中尺度云团,识别结果合理。采用这种方法识别不同尺度的暴雨云团,有利于跟踪、预报造成中国暴雨主要原因的β中尺度系统,也可兼顾β中尺度系统中的γ中尺度对流单体。根据预报时效的不同,可以选择不同的云团识别尺度。     

Progress in the Development and Application of Climate Ocean Models and Ocean-Atmosphere Coupled Models in China

A review is presented about the development and application of climate ocean models and oceanatmosphere coupled models developed in China as well as a review of climate variability and climate change studies performed with these models. While the history of model development is briefly reviewed, emphasis has been put on the achievements made in the last five years. Advances in model development are described along with a summary on scientific issues addressed by using these models. The focus of the review is the climate ocean models and the associated coupled models, including both global and regional models, developed at the Institute of Atmospheric Physics, Chinese Academy of Sciences. The progress of either coupled model development made by other institutions or climate modeling using internationally developed models also is reviewed.     

星斑川鲽(Platichthys stellatus)养殖群体的RAPD分析

利用RAPD技术对星斑川鲽养殖群体的遗传多样性进行了研究。将实验用星斑川鲽养殖群体的活鱼苗解剖,取其肌肉,高盐法抽提获得总DNA,质量鉴定和浓度测定后用随机引物进行PCR扩增,从20个随机引物中筛选出18个用于群体遗传学分析,共扩增出133条带,谱带大小为100~2 000 bp,大多数谱带分布在250~1 000bp。多态谱带数为83,每个引物扩增谱带数为1~14条,平均为7条。多态谱带比例为62.41%,Shannon的信息指数和Nei的多样性指数分别为0.21和0.316 6。     

Degradation stage effects on vegetation and soil properties interactions in alpine steppe

In recent decades,overgrazing and the warming and drying climate have resulted in significant degradation of alpine grasslands in the source region of the Yellow River.However,research into the relationships between vegetation and soil properties has mainly focused on an overall degradation stage,and few studies have investigated which soil properties can impact vegetation change at different stages of degradation.Vegetation and soil properties were observed in the field and measured in the laboratory for different predefined stages of degradation for alpine grassland in Maduo County in the source region of the Yellow River.Results show that:1)the aboveground and belowground biomass,soil organic carbon,total nitrogen,nitrate,and ammonia content did not decrease significantly from the intact to moderate degradation stage,but decreased significantly at severe and very severe stages of degradation;2)dominant plant species shifted from gramineaes and sedges to forbs;3)the species richness and Pielou evenness indices decreased significantly at the very severe degradation stage,the Shannon-Wiener diversity index increased at the slight and moderate degradation,but decreased at the severe and very severe degradation stages;4)soil bulk density was the strongest soil driver for changes in the plant biomass and community diversity at the intact,slight and moderate degradation stages,whereas soil organic carbon and nitrate nitrogen content were the main driving factors for changes in plant biomass and diversity at the severe and very severe degradation stages.Our results suggest that there may be different interactions between soil properties and plants before and after moderate stages of degradation.     

湘西南金矿成矿规律与成矿预测研究

湘西南金矿主要有石英大(单)脉型和石英细(网)脉型两类.赋存于新元古界板溪群火山-沉积含金建造中.金矿化严格受脆-韧性剪切带控制.通过地质-遥感成矿特征揭示,表明该区金矿具有较大的找矿潜力.成矿类型除石英脉型金矿外,还应加强破碎带蚀变岩型金矿的找矿研究工作.     

泥石流排导槽水力最佳断面

根据怕导出三角形和复式三角形排导槽的最佳水力断面,三角形水力最佳断面β＝√１＋ｍ＾２－１,对梯形、矩形、三角形排导槽优化断面进行了比较,研究结果对规划设计有很强适用性。     

磁中子星的一维吸积柱模型

本文给出了改进的一维吸积柱模型,探讨了在大吸积率下吸积柱的结构及物理性质,并理论推导吸积柱内下落物质的温度、密度及速度的变化．计算结果表明,它自上而下可以分为几个部分：冲击区（辐射压减速区）、理想气体压减速区、简并气体压减速区、外流区．作为例证,详细计算了吸积率Ｍ≈１０~１７ｇ／ｓ,极区磁场强度Ｂｍ≈１０~８Ｔ的中子星吸积柱．探讨了吸积柱内的热核反应,认为它可能与低质量Ｘ射线双星的低频ＱＰＯ（准周期振荡）现象有关．     

小波变换在短期气候预测模型研究中的应用

用小波变换的小波系数以及其反演建立了不同时间心渡的气候预测模型,并对昆明,玉溪和楚雄１９９１～１９９６的月气温距平值以及滇中月降水距平值在月,季,年三种时间尺度上进行了预测试验和检验,结果表明,所建立的气候预测模型对月气温距平值预测的效果在月,季,年三种时间尺度上均是十分显著的,共对月气温距平值预测的距平符号相关准确率在月,季,年三种时间尺度的预测中已分别达到了７３．１％,７３．１％和６９．４％,     

几种海水鱼人工育苗饵料系列的比较

海水鱼人工育苗的饵料系列一般大致相近,基本为轮虫（或双壳类幼体）一浮游甲壳类一鱼虾贝肉糜。但由于种间的特异性,各育苗饵料系列在饵料品种、投喂时间、使用期限上有所差别（见图１）,现比较、分述如下。１大黄鱼（Ｐｓｅｉｄｐｓｃｏａｅｍａｃｒｏｃｅａ）［１］初孵仔鱼全长３ｍｍ左右,口裂、卵黄囊相应较大,３日龄后仔鱼口径按下颌长计算达４００ｕｍ左右,因此开口饵料用Ｌ型轮虫即可,并添加适量小球藻,进行“绿水”培育。一可以作为轮虫的饵料,既增加轮虫的营养,又增强轮虫的背景反差,易被仔鱼发现,提高摄食率;二可以…     

适用于机载三维遥感的动态GPS定位技术及其数据处理

机载三维遥感采用动态ＧＰＳ定位技术提供遥感器的空中精确位置,能快速高效获得遥感地学编码图像和ＤＥＭ,雇地中国自行研制、具有独创性的机载三维遥感影像制图系统中的动态ＧＰＳ定位技术特点和要求进行了分析。论述了应用三维遥感的ＧＳＰ定位数据处理和算流程。法