实现找矿重大突破的有效途径     

张寿高  劳可通 《中国地质》1989,(12)

湖南省花垣县渔塘铅锌矿田位于湘黔铅锌矿带之北段.自1954年以来,该区的地质工作基本没有间断,认识逐步深入.矿田内有良好的成矿条件,矿化范围广,厚度亦大,但品位低,圈不出富矿段,故30年来只提交2万吨铅锌金属储量(贫矿).1986年,湖南405队再次进入该区工作,目的是要掌握铅锌矿的富集条件,贫中找富,为解决  相似文献   

丰山金铜矿田找矿矿物学研究   总被引：5，自引：0，他引：5  

徐跃通  肖立道 《地质与勘探》1992,28(1):32-35

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饱和湿绝热方程的精确数值计算   总被引：1，自引：0，他引：1       下载免费PDF全文

李任承  王国通 《气象》1988,14(11):17-21

本文根据大气热力学基本原理,探讨了各种不同情形下饱和湿绝热上升气块中温度变化的规律,提出了由饱和湿绝热变态方程进行精确数值计算的结果。  相似文献   

隔离变压器在雷达应急发电机中的防雷应用   总被引：1，自引：0，他引：1  

龙桂才  倾鹏程  杜宇飞  高必通  方亚芬  黎直 《气象研究与应用》2018,(1)

通过使用一组四线三相制的隔离变压器,对天气雷达应急设备中的柴油发电机系统进行处理,将容易遭受雷击的"市电供电-柴油发电机供电"自动切换装置进行电磁耦合隔离,以防止供电自动切换装置在雷雨天气中遭到破坏性的雷击。  相似文献   

华南沿海一次暖区特大暴雨的对流特征和发展机制分析     

蒲义良  卢栩诗  胡胜  刘显通  叶朗明  张楚  李晓惠 《气象》2023,(2):201-212

2017年6月22日华南沿海经历了一次罕见的极端降雨事件(24 h最大累计雨量562.5 mm),刷新了当地多项历史雨量纪录。使用NCEP/NCAR再分析数据和多源观测数据,分析了这次降雨过程的天气背景、天气尺度触发和维持机制、中尺度环流的演变及雷达特征等。结果表明:这次极端降雨发生在暖湿偏南气流中,双低空急流相互配合产生的上升运动是此次暴雨主要的天气尺度触发机制,其中边界层急流的建立也为雨区提供了有利不稳定能量和水汽条件,整个降雨过程随着双低空急流结构配合的减弱而结束。降雨形成较弱的冷池出流边界在锦江南侧和岗美东南侧原地少动,并不断激发新生对流,使得对流云团在锦江和岗美地区准静止,从而产生极端累计降雨量。整个降雨过程中对流结构表现出低质心的结构特点,对流成熟阶段锦江和岗美地区近地面平均雨滴粒径较为接近,锦江降雨效率高于岗美主要体现在更加密集的雨滴数量上。  相似文献   

两种雨滴谱仪观测对比及对雷达降水估测精度影响研究北大核心CSCD     

陈超  刘黎平  罗聪  刘显通  张阿思 《气象》2023,(10):1157-1170

利用广东龙门、新丰和佛冈布设的二维视频雨滴谱仪(2D-video-disdrometer,2DVD)和HY-P1000激光雨滴谱仪观测资料,分析了相同地点和相同时间两类雨滴谱仪降水滴谱观测和降水反演精度的差异。根据收集的2018年和2019年的雨滴谱观测数据,拟合了双偏振雷达定量降水估测基本关系式,并应用于S波段双偏振雷达(CINRAD/SAD)定量降水估测(quantitive precipitation estimation,QPE)优化组合方案中。结果表明:较HY-P1000雨滴谱仪而言,2DVD可观测到更多的1 mm以下的小粒子降水,但观测到的大于3.5 mm的雨滴数明显少于HY-P1000雨滴谱仪;对比由2DVD和HY-P1000观测数据计算得到的双偏振参数与CINRAD-SAD 0.5°仰角观测得到的双偏振参数,发现参数间均存在一定的差别,其中差分反射率因子差别相对较大;此外,利用2DVD观测数据可整体提升双偏振雷达QPE精度,对中雨及以下量级精度提升尤为明显。  相似文献   

基于X波段双偏振相控阵雷达的超级单体风暴观测分析     

张羽  陈炳洪  曾琳  沈晓钿  傅佩玲  刘显通 《热带气象学报》2023,(2):218-229

为了研究X波段双偏振相控阵雷达对超级单体风暴的探测能力,利用X波段双偏振相控阵雷达和S波段双偏振天气雷达资料,分析了一次发生在华南地区的超级单体风暴在成熟阶段的精细结构观测特征,结果表明：X波段双偏振相控阵雷达较高的时空分辨率有利于精细监测超级单体快速演变过程,但同时受衰减影响明显,超级单体核心区后侧出现明显的“V”型缺口;超级单体的低层观测到CC谷和ZDR弧,中层观测到ZDR环和CC环,高层高ZH区对应较小的ZDR和CC,这些都是超级单体发展旺盛的重要特征;垂直方向上观测到ZDR柱,ZDR柱与上升气流密切相关。降雹前ZDR柱迅速增加,冰雹降落后ZDR柱高度迅速降低。冰雹降落到地面后会部分融化,导致含水量显著增加,因此在近地层出现KDP大值区,冰雹与降水的混合相态则使得CC降低,这对冰雹的临近预警和识别冰雹在地面的降落位置具有很好的指示意义。研究结果可为X波段双偏振相控阵雷达在强对流天气监测预警中的应用提供参考。  相似文献   

The Longmen Cloud Physics Field Experiment Base, China Meteorological Administration     

刘显通  阮征  胡胜  万齐林  刘黎平  罗亚丽  胡志群  黎慧琦  肖辉  雷卫延  夏丰  饶晓娜  冯璐  赖睿泽  吴翀  叶朗明  郭泽勇  张羽  王瑶  颜朝潮  袁锦涵 《热带气象学报(英文版)》2023,29(1):1-15

Aiming at the needs of mechanism analysis of rainstorms and development of numerical prediction models in south China, the Guangzhou Institute of Tropical and Marine Meteorology of China Meteorological Administration and the Chinese Academy of Meteorological Sciences jointly set up the Longmen Cloud Physics Field Experiment Base,China Meteorological Administration. This paper introduces the instruments and field experiments of this base, provides an overview of the recent advances in retrieval a...  相似文献   

Statistical Characteristics of Raindrop Size Distribution in the South China Monsoon Region (Guangdong Province)     

陈超  张阿思  吴乃庚  刘显通  孙晓光  王洪 《热带气象学报(英文版)》2023,29(1):55-67

While heavy rainfall frequently takes place in southern China during summer monsoon seasons,quantitative precipitation forecast skills are relatively poor.Therefore,detailed knowledge about the raindrop size distribution(DSD)is useful in improving the quantitative precipitation estimation and forecast.Based on the data during 2018-2022 from 86stations in a ground-based optical disdrometer measurement network,the characteristics of the DSD in Guangdong province are investigated in terms of the pa...  相似文献   

Thermodynamics and Microphysical Characteristics of an Extreme Rainfall Event Under the Influence of a Low-level Jet over the South China Coast     

徐碧裕  黎慧琦  叶朗明  刘显通  饶晓娜  肖辉  徐加民  林青蒲义良  黄青兰 《热带气象学报(英文版)》2023,29(2):216-235

In this paper, the data of Automatic Weather Stations (AWSs), ERA5 reanalysis, sounding, wind profile radar, and dual-polarization radar are used to study an extreme rainfall event in the south China Coast on 11 to 12 May 2022 from the aspects of thermodynamics and microphysical characteristics under the influence of low-level jets (LLJs). Results show that: (1) The extreme rainfall event can be divided into two stages: the first stage (S1) from 0000 to 0600 LST on May 12 and the second stage (S2) from 0700 to 1700 LST on the same day. During S1, the rainfall is mainly caused by the upper-level shortwave trough and the boundary layer jet (BLJ), characterized by strong upward motion on the windward side of mountains. In S2, the combined influence of the BLJ and synoptic-system-related low-level jet (SLLJ) increases the vertical wind shear and vertical vorticity, strengthening the rainstorm. In combination with the effect of topography, a warm and humid southwest flow continuously transports water vapor to farther north, resulting in a significant increase in rainfall over the study area (on the terrain’s windward slope). From S1 to S2, the altitude of a divergence center in the upper air decreases obviously. (2) The rainfalls in the two stages are both associated with the mesoscale convergence line (MCL) on the surface, and the wind field from the mesoscale outflow boundary (MOB) in S1 is in the same direction as the environmental winds. Due to a small area of convergence that is left behind the MOB, convection moves eastward quickly and causes a short duration of heavy rainfall. In S2, the convergence along the MOB is enhanced, which strengthens the rainfall and leads to strong outflows, further enhancing the surface convergence near the MOB and forming a positive feedback mechanism. It results in a slow motion of convection and a long duration of heavy rainfall. (3) In terms of microphysics, the center of a strong echo in S1 is higher than in S2. The warm-rain process of the oceanic type characterizes both stages, but the convective intensity in S2 is significantly stronger than that in S1, featuring bigger drop sizes and lower concentrations. It is mainly due to the strengthening of LLJs, which makes small cloud droplets lift to melting levels, enhancing the ice phase process (riming process), producing large amounts of graupel particles and enhancing the melting and collision processes as they fall, resulting in the increase of liquid water content (LWC) and the formation of large raindrops near the surface.  相似文献