New progress of research on water cycle in atmosphere in China

1 Precipitation characteristics Since the 1980s, Chinese climatologists have conducted a lot of researches on the law of precipitation variation in recent 100 years. Zhang Xiangong et al. (1982)[1], Tu Qipu (1984)[2], Wang Shaowu (1994)[3], Chen Longxun, et al. (1998)[4] have carried out researches on temperature and precipitation changes of the last 100 years in China, viewing that China has the characteristics of cold-wet and warm-dry alternations. Shi Neng et al. (1983) studied the rel…     

GPS变形监测网的优化

讨论了ＧＰＳ变形监测网一类和二类优化设计，并与一个具有相同网形的经典平面网进行比较。ＧＰＳ测量建模和线性化时构成的设计矩阵与网点位置无关。ＧＰＳ及无水准测量的这一特点使得能够动用数学工具来解决二类设计问题，甚至是一类设计中的某些问题。     

日本Se型和Te型浅成低温热液金矿床的地球化学、矿物学及地质学特征

日本的浅成低温热液金矿床可分为Se型和Te型。Se型矿床产于沉积岩及火山岩中,而所有的Te型矿床则赋存于火山岩内。将这类矿床的地质学、矿物学和地球化学特征与伴随浅成矿化活动地热系统的特点进行比较表明:(1)Se型和Te型矿床形成于同一地热系统的两个不同部位;(2)Te型矿床的形成比Se型更靠近热源;(3)在比酸式硫酸盐型更远离火山中央的矿化区形成Te型矿床;(4)火山成因的SO_2气体的影响及主岩的类型是造成矿液化学性质(氧活度、硫活度、pH值、硫同位素成分)不同的重要因素,它们对日本的Se型和Te型浅成低温热液金矿床的形成起了重要的作用。     

The impact of the 1998 coral mortality on reef fish communities in the Seychelles

Coral reef fish communities in the Seychelles are highly diverse and remain less affected by the direct impacts of human activities than those on many other coral reefs in the Indian Ocean. These factors make them highly suitable for a detailed survey of the impacts of the 1998 mass coral mortality, which devastated the coral faunas of the region. Using underwater visual census (UVC) techniques. fish communities were sampled in three localities in the southern Seychelles and one locality in the northern (granitic) Seychelles. Initial surveys were undertaken from the latter site in 1997. Surveys were undertaken at all sites during the coral bleaching episode in 1998 prior to any major changes in the reef fish communities. Repeat surveys were undertaken in 1999 one year after the coral mortality. Over 250 fish species were sampled from 35 families. Results suggest that changes in the overall fish community structures are not great, despite massive changes in the benthic cover. Significant changes have been observed in a number of individual species. These include those most heavily dependent on live coral cover for shelter or sustenance. Future potential changes are discussed, and potential management interventions are considered.     

TRMM/PR资料在中尺度模式MM5中的应用(英)

将中尺度非静力模式MM5中的积云参数化Grell方案作了改进,使它含有降水云的云水,即雨水含量,并用该模式对1998年6月29日08时-30日08时(北京时)和1998年7月1日08时-2日08时(北京时)发生在淮河流域的两次特大暴雨进行数值模拟研究,同时通过采用R-qr关系将TRMM/PR(Tropical Rainfall MeasuringMission/Precipition Radar)得到的降水强度资料R计算出比含水量qr,然后用q'v=qv+qr取代原模式中的比湿qv。结果表明将TRMM/PR资料加入模式后,由于PR雷达具有较高的空间分辨率,能够很好地反映中小尺度系统的空间结构,能够使湿度值接近实际,缩短了中尺度系统的发展时间,使得模拟出来的降雨强度、雨量中心位置以及雨带形状更接近实况。     

用非线性近似方法反演单多普勒雷达风场(英)

回顾了近年来由单多普勒雷达观测反演风场的各种方法。这些方法大部分基于线性假设,因此风场的非线性变化经常影响反演结果,使得反演的风场误差增大。我们提出一种以非线性近似理论为基础的反演方法,该方法主要考虑了风场分片光滑的特点并充分利用了雷达的径向风场数据。我们把该方法应用到1998年淮河能量与水循环实验的两个个例中。通过同双多普勒雷达观测的结果比较,发现该方法能反演较高分辨率和准确性的水平风场,反演的垂直风场也比较合理。     

苏格兰南部高原金矿化的流体包裹体及同位素研究

苏格兰南部高原与金矿化有关的石英流体包裹体有4种类型。矿区中水溶液包体的含盐度高于伴生的碳质包体。以花岗闪长岩、闪长岩、沉积岩为容矿岩石的矿区中,甲烷含量突出,说明流体与围岩之间存在混溶作用。