雷达回波垂直廓线及其生成方法   总被引：6，自引：4，他引：6       下载免费PDF全文

吴翠红  万玉发吴涛 金鸿祥 《应用气象学报》2006,17(2):232-239

研究雷达回波Z (R) 垂直廓线VPR有两个重要内容: 一是VPR的生成方法, 二是用VPR订正雷达估算降水的技术。在简要比较现有生成方法———参数法、平均法和识别法的主要特点后, 认为平均垂直廓线MVPR具有简便、实用的优点。文章着重对MVPR的生成方法作了细致的探讨, 形成了4种生成算法, 并作了比较; 展示了各种生成参数对MVPR的不同作用, 并简要介绍了一个应用程序框图。对两个降水实例实施订正后初步评估表明, 用MVPR订正雷达估算降水可使评估因子R/G从0.84 (0.86) 提高到0.93 (0.97), 而绝对误差率则下降4%。  相似文献   

工业废铁链在煤矿特大动水条件下溃水灾害的应用     

乔军王铁记  王君现 《中国煤田地质》2006,18(4):47-48

在牛儿庄矿特大溃水事故的治理中，利用工业废铁链作骨料，建立短距巷道堵水塞，并进行孔组并列式双液注浆技术，是治理煤矿突水事故的一项行之有效、经济合理的手段与方法，为综合治理水患提供了一条新的途径。  相似文献   

FRESHWATER ALGAE COMMUNITY OF A MELTWATER RUNNEL,REEVE HILL, CASEY STATION, ANTARCTICA     

FaradinaMerican WanMaznahWO WanAsmadiWA MashhorMansor 《湿地科学》2007,5(3):243-252

Researches on the Antarctic microalgal diversityand distributions in the freshwater environment ran-ging from snow to large lakes and well-definedstreams are extensive.For instance,studies on thestream microalgal community have been conducted onthe Pervay…  相似文献   

地下水库及其在水资源开发和保护中的应用     

付晓刚  万伟锋  毛正君 《地下水》2007,29(1):65-67,77

从地下水库的不同概念出发,探讨了地下水库的定义,指出地下水库并不是单纯的含水层或者储水构造,而是一种地下水开发系统工程.在此基础上介绍了地下水库的基本组成及各组成部分的作用、地下水库的优缺点以及其发展趋势,最后分析了地下水库在我国不同地区水资源开发和保护中的广阔应用前景.  相似文献   

13X沸石处理含赖氨酸废水的实验研究     

王英滨姜波  李婧婧肖万 《岩石矿物学杂志》2007,26(1):90-94

用合成的13X沸石对废水中氨基酸(赖氨酸)进行静态吸附实验,研究了pH、温度、吸附时间、沸石用量等对吸附率的影响,结果表明,室温下沸石对赖氨酸的吸附平衡时间为30min,pH=pKa1=2.2时,赖氨酸在沸石上的吸附效果最好,吸附率大于82%,饱和吸附量达51.73mg.g-1。吸附等温线近似呈直线型,表明离子交换机制是沸石吸附氨基酸的主要方式。对已饱和吸附的沸石用饱和氯化钠溶液进行再生实验,赖氨酸的解吸率大于95%,沸石可重复使用。实验研究表明可用13X分子筛处理含氨基酸废水,为实际处理含氨基酸废水提供了可行性依据。  相似文献   

青藏高原东北部的库仑应力积累演化对大地震发生的影响   总被引：27，自引：4，他引：27       下载免费PDF全文

万永革  沈正康  曾跃华  盛书中 《地震学报》2007,29(2):115-129

假定地震可以模拟为多层弹粘性介质中的位错，考虑大地震(Mge;7.0)和GPS数据得出的长期构造加载为形变源，依据多层麦克斯韦弹粘性介质中位错产生的应力变化，计算得到了地震产生的应力变化，给出了青藏高原东北部1920年以来积累库仑破裂应力演化. 地震破裂的断层长度、宽度和滑动量根据前人统计公式和野外地质调查得到. 研究表明，20次Mge;7.0地震中， 除1990年共和地震、1952年当雄地震和1976年松潘双震的后一个事件外，17次大地震均发生在库仑破裂应力变化为正的区域， 触发率达85%. 本研究为中长期地震危险性估计在一定程度上提供了基础数据.   相似文献   

Quantifying drainage components and salt and water balance in YinNan Irrigation District,China, based on a controlled drainage experiment   总被引：1，自引：0，他引：1  

Zhonghua Jia  Wan Luo  Shuxing Fang  Liang Wang  ShiYing Tian 《水文研究》2007,21(14):1875-1881

YinNan Irrigation District (YNID) is located in the upper reaches of the Yellow River in NingXia, China. Its irrigated area is about 80 000 ha, with one‐third of it for rice production. The major part of its drainage system was constructed between the 1950s and 1970s to maintain the salt and water balances of the district. The system, however, has been reported as draining the agricultural lands excessively by several studies. In addition to field, lateral and main drainage ditches, agricultural fields of YNID are also under the influence of the Yellow River channel and some low‐lying depressions, thus forming a dual drainage system. Owing to difficulties in irrigation inflow measurement, evaluation of the existing drainage system often appears to be elusive. Based on a dual drainage assumption and an on‐site controlled drainage experiment, we present a detailed analysis on drainage components and the salt and water balance of YNID. Results show that, by implementing controlled drainage, shallow drainage from field ditches can be reduced by 60%. Deep drainage from main ditches, the Yellow River channel and low‐lying depressions is relatively stable year around, and it neutralized the potential effect of controlled drainage on salinity increase. Drainage water salinity calculated from the dual subsurface drainage model was consistent with field observations, proving that the dual drainage assumption is valid for the study area. Based on this study, field water management practices of the irrigation district can be better targeted and fairly evaluated. Copyright © 2006 John Wiley & Sons, Ltd.  相似文献   

Comparison Between GAMIL, and CAM2 on Interannual Variability Simulation     

杨军丽  王斌  郭裕福  万慧  季仲贞 《大气科学进展》2007,24(1):82-88

Recently, a new atmospheric general circulation model （GAMIL： Grid-point Atmospheric Model of IAP LASG） has been developed at the Institute of Atmospheric Physics （IAP）, Chinese Academy of Sciences （CAS）, which is based on the Community Atmospheric Model Version 2 （CAM2） of the National Center for Atmospheric Research （NCAR）. Since the two models have the same physical processes but different dynamical cores, the interannual variability simulation performances of the two models are compared. The ensemble approach is used to reduce model internal variability. In general, the simulation performances of the two models are similar. Both models have good per- formance in simulating total space-time variability and the Southern Oscillation Index. GAMIL performs better in the Eastern Asian winter circulation simulation than CAM2, and the model internal variability of GAMIL has a better response to external forcing than that of CAM2. These indicate that the improvement of the dynamic core is very important. It is also verified that there is less predictability in the middle and high latitudes than in the low latitudes.  相似文献   

云南5月雨量的多尺度变化及与其相联系的大气环流异常   总被引：1，自引：1，他引：1  

万云霞  程建刚  陈新梅  孙绩华  严华生 《气象科学》2007,27(5):543-548

本文运用小波分析和功率谱分析方法对云南5月雨量的多尺度时间演变特征进行了分析,结果表明,云南5月雨量具有明显的年际和年代际变化特征。对与这两种时间尺度相关联的大气环流异常进行了分析,发现两者具有显著的差异。云南5月雨量的年际变化与冰岛低压、欧洲槽、南亚高压、中西太平洋ITCZ以及孟湾附近的低压系统的变化有着密切的关系,云南5月雨量的年代际-气候态变化与热带各系统的强度、乌山脊、阿留申低压关系密切。  相似文献   

A holistic approach to aligning geospatial data with multidimensional similarity measuring     

Li Yu  Peiyuan Qiu  Xiliang Liu  Bo Wan 《International Journal of Digital Earth》2018,11(8):845-862

Semantically aligning the heterogeneous geospatial datasets (GDs) produced by different organizations demands efficient similarity matching methods. However, the strategies employed to align the schema (concept and property) and instances are usually not reusable, and the effects of unbalanced information tend to be neglected in GD alignment. To solve this problem, a holistic approach is presented in this paper to integrally align the geospatial entities (concepts, properties and instances) simultaneously. Spatial, lexical, structural and extensional similarity metrics are designed and automatically aggregated by means of approval voting. The presented approach is validated with real geographical semantic webs, Geonames and OpenStreetMap. Compared with the well-known extensional-based aligning system, the presented approach not only considers more information involved in GD alignment, but also avoids the artificial parameter setting in metric aggregation. It reduces the dependency on specific information, and makes the alignment more robust under the unbalanced distribution of various information.  相似文献