常用粮仓地坪沉降观测方法及精度分析

中央直属储备粮库是国家重要的基础设施，为确保新建粮库储粮安全，必须进行粮库新仓初始装粮压仓试验，利用仓内地坪沉降观测数据对云梯升降法、悬尺法、倒尺法的精度进行分析，得出倒尺法是仓内地坪沉降观测的最佳方法。     

Numerically modelling groundwater in an arid area with ANN‐generated dynamic boundary conditions

Groundwater is sensitive to the climate change and agricultural activities in arid and semi‐arid areas. Over the past several decades, human activities, such as groundwater extraction for irrigation, have resulted in aquifer overdraft and disrupted the natural equilibrium in these areas. Regional groundwater simulation is important to determine appropriate groundwater management policies, and numerical simulation has become the most popular method. However, most groundwater models were developed with static boundary conditions. In this research, the Minqin oasis, an arid region located in northwest China, was selected as the study area. An artificial neural network (ANN) was developed to simulate effects of weather conditions, agricultural activities and surface water on groundwater level in a dynamic boundary of the domain. Subsequently, a groundwater numerical model, named ANN‐FEFLOW model, was developed, with a dynamic boundary condition defined by the ANN model. The verifying results showed that the model has higher precision, with a root mean square error (RMSE) of 0·71 m, relative error (RE) of 17·96% and R² of 0·84 relative to the great groundwater change. Furthermore, the groundwater model has higher precision than the conventional groundwater model with static boundary condition, particularly in the area near the dynamic boundary. This study demonstrated that dynamic boundaries can improve the precision of the regional groundwater model in an arid area and that ANN can provide higher accuracy prediction capability for groundwater levels with dynamic boundary. Copyright © 2010 John Wiley & Sons, Ltd.     

An Analytic Model of Galactic Winds and Mass Outflows

Galactic winds and mass outflows are observed both in nearby starburst galaxies and in high-redshift star-forming galaxies. We develop a simple analytic model to understand the observed superwind phenomenon with a discussion of the model uncertainties. Our model is built upon the model of McKee & Ostriker for the interstellar medium. It allows one to predict how properties of a superwind, such as wind velocity and mass outflow rate, are related to properties of its starforming host galaxy, such as size, gas density and star formation rate. The model predicts a threshold of star formation rate density for the generation of observable galactic winds. Galaxies with more concentrated star formation activities produce superwinds with higher velocities. The predicted mass outflow rates are comparable to (or slightly larger than) the corresponding star formation rates. We apply our model to both local starburst galaxies and high-redshift Lyman break galaxies, and find its predictions to be in good agreement with current observations. Our model is simple and so can be easily incorporated into numerical simulations and semi-analytical models of galaxy formation.     

射电脉冲星搜寻工作的进展

评述了射电脉冲星搜寻及观测研究的巨大贡献和重要意义，分析了影响脉冲星搜寻工作的几个关键因素（如灵敏度，色散，观测频率及设备等），着重介绍和分析了自发现脉冲星（特别是发现第一颗秒脉冲星）以来所进行的卓有成效的脉冲星搜寻工作（包括脉冲星的早期寻，毫秒脉冲星的初期搜寻，高银续脉冲星搜寻，定向搜寻以及进一步的广域深空搜寻等）的情况，结果，意义和进展。     

A Study of Neutron Star Structure in Strong Magnetic Fields that includes Anomalous Magnetic Moments

We study the effect of strong magnetic fields on the structure of neutronstar. We find that if the interior field is on the same order as the surface field currently observed, then the influences of the field on the star‘s mass and radius arenegligible; if the field is as large as that estimated from the scalar virial theorem,then considerable effects will be induced. The maximum mass of the star will be increased substantially while the central density is greatly reduced. The radius of a magnetic star can be larger by about 10%～20% than a nonmagnetic star of the same mass.     

上海一次连续大雾过程的成因分析

利用上海市遥测能见度数据、常规气象资料和T213、GFS分析资料以及GPS-PWV资料,分析了2008年1月5-11日发生在上海地区的一次连续大雾天气过程.分析表明当有天气尺度西风槽频繁活动、槽前暖湿气流不断向气层输入暖湿空气,如再遇特定暖水面或暖海面从近地面向气层输送暖湿气流时,在晴天和微风的早晨极易形成辐射雾;当东、黄海暖湿空气从近地面流向冷水面或冷陆面,如再遇江南低空偏南暖湿气流辐合聚积时,极易形成平流雾.雾区登陆距离与东风气流强弱有关,东风气流越强,雾区西进距离越长.在平流雾期间,0～300 m平均相对湿度的高湿区与雾区吻合.当绝对湿度小于3 g/kg时不会有大雾发生,绝对湿度在9～1 5 g/kg和GPS-PWV值在15 mm左右时,在合适的大气条件下容易形成大雾.     

随机取向沙尘气溶胶激光雷达线退偏比特性研究

利用离散偶极子近似法,数值计算分析了随机取向旋转椭球体沙尘气溶胶粒子在尺度参数为0.1~23时（波长0.55 μm对应有效半径为0.01~2 μm）的激光雷达线退偏比特性,通过比较其不同旋转椭球体轴半径比下的差别,研究了粒子非球形性程度对单分散和多分散沙尘气溶胶激光雷达线退偏比特性的影响.单分散旋转椭球体沙尘气溶胶的激光雷达线退偏比对粒子的轴半径比和尺度参数有很强的依赖性;对于长旋转椭球体,沙尘激光雷达线退偏比较小值出现在瑞利散射区,而较大的值出现在米散射区;对于扁旋转椭球体,在米散射区较大沙尘粒子也可以产生较小的激光雷达线退偏比,例如,轴半径比为1/16,尺度参数为3时的沙尘激光雷达线退偏比仅为0.1%.就随机取向旋转椭球体沙尘粒子而言,对于单分散系,仅当尺度参数小于0.5时,非球形特征越明显,其激光雷达线退偏比越大;而对多分散系,非球形特征越明显,其激光雷达线退偏比越大.     

Planktic Foraminiferal Biostratigraphy of the Cretaceous Oceanic Red Beds in Kangmar,Southern Tibet,China

The planktic foraminifera of the Chuangde Formation (Upper Cretaceous Oceanic Red Beds, CORBs) as exposed at Tianbadong section, Kangmar, southern Tibet has been firstly studied for a detailed for a detailed biostratigraphy elaboration. A rich and well-preserved planktic foraminifera were recovered from the Chuangde Formation of the Tianbadong section and the Globotruncanita elevata, Globotruncana ventricosa, Radotruncana calcarata, Globotruncanella havanensis, Globotruncana aegyptiaca, Gansserina gansseri and Abathomphalus mayaroensis zones have been recognized. The planktic foraminiferal assemblage points to an early Campanian to Maastrichitian age for the CORBs of the eastern North Tethyan Himalayan sub-belt, which also provides a better understanding of the shifting progress of the Indian Plate to the north and the evolution of the Neotethyan ocean. The lithostratigraphy of the Chuangde Formation of the Tianbadong section comprises two lithological sequences observed in ascending succession: a lower unit (the Shale Member) mainly composed of purple (cherry-red, violet-red) shales with interbedded siltstones and siliceous rocks; and an upper unit (the Limestone Member) of variegated limestones. The strata of the Chuangde Formation in the Tianbadong section are similar to CORBs in other parts of the northern Tethyan Himalaya area of Asia (Gyangze, Sa’gya, Sangdanlin, northern Zanskar, etc.). The fossil contents of the Chuangde Formation in the sections (CORBs) studied provide a means of correlation with the zonation schemes for those of the northern Tethyan Himalayan sub-belt and the Upper Cretaceous of the southern Tethyan Himalayan sub-belt. Paleogeographic reconstruction for the Late Cretaceous indicates that the Upper Cretaceous Chuangde Formation (CORBs) and correlatable strata in northern Zanskar were representative of slope to basinal deposits, which were situated in the northern Tethyan Belt. Correlatable Cretaceous strata in Spiti and Gamba situated in the southern Tethyan Belt in contrast were deposited in shelf environments along the Tethyan Himalayan passive margin. CORBs are most likely formed by the oxidation of Fe(II)-enriched, anoxic deep ocean water near the chemocline that separated the oxic oceanic surface from the anoxic.