FAST射电望远镜天文轨迹规划

针对我国500 m球面射电望远镜天线(FAST),提出了一体化天文轨迹规划;给出了详细的数学模型及推导分析。相对于当前采用的FAST轨迹规划,该方法使得馈源位置和反射面位置的控制误差可以相互补偿。指出当馈源系统和反射面系统具有相同的测控延迟误差时,并不影响FAST天线的性能。     

皖江中东部雾的客观预报自动化业务系统

介绍了一种雾的客观预报方法，并研制了一个与ＳＴＹＳ接口的雾的客观预报自动化业务系统，对雾有一定的预报能力。     

Raman Micro-Spectroscopic Study of Sulfate Ion in the System Na2SO4 – H2O

This work aims to quantify sulfate ion concentrations in the system Na₂SO₄-H₂O using Raman micro-spectroscopy.Raman spectra of sodium sulfate solutions with known concentrations were collected at ambient temperature（293 K） and in the 500 cm^₁-4000 cm^-1 spectral region.The results indicate that the intensity of the SO₄^2- band increases with increasing concentrations of sulfate ion.A linear correlation was found between the concentration of SO₄^2-（c） and parameter I₁,which represents the ratio of the area of the SO₄^2- band to that of the O-H stretching band of water（A_s/A_w）:I₁=-0.00102+0.01538 c.Furthermore,we deconvoluted the O-H stretching band of water(2800 cm^-1-3800 cm^-1) at 3232 and 3430 cm^-1 into two sub-Gaussian bands,and then defined Raman intensity of the two sub-bands as A_Bi(3232 cm^-1) and A_B2(3430 cm^-1),defined the full width of half maximum（FWHM） of the two sub-bands as W_B1(3232 cm^-1) and W_B2(3430 cm^-1).A linear correlation between the concentration of SO₄^2-（c） and parameter I₂,which represents the ratio of Raman intensity of SO₄^2-（A_s）(in 981 cm^-1) to(A_B1+A_B2),was also established:I₂=-0.0111+0.3653 c.However,no correlations were found between concentration of SO₄^2-（c） and FWHM ratios,which includes the ratio of FWHM of SO₄^2-（W_s） to W_B1 W_B2 and W_B1+B2(the sum of W_B1 and W_B2),suggesting that FWHM is not suitable for quantitative studies of sulfate solutions with Raman spectroscopy.A comparison of Raman spectroscopic studies of mixed Na₂SO₄ and NaCI solutions with a constant SO₄^2- concentration and variable CI^- concentrations suggest that the I\ parameter is affected by CI^-,whereas the I₂ parameter was not.Therefore,even if the solution is not purely Na₂SO₄-H₂O,SO₄^2- concentrations can still be calculated from the Raman spectra if the H₂O band is deconvoluted into two sub-bands,making this method potentially applicable to analysis of natural fluid inclusions.     

我国电子政务建设的机遇挑战及其对策

通过对电子政务发展战略的深入分析 ,指出我国电子政务的建设正面临四个挑战 ,包括重复建设、无序操作、忽视应用、管理滞后等。面对重复建设、建设无序、忽视应用、管理滞后等问题 ,提出了迎接四个挑战的具体对策     

一种新型海底沉积物声学原位测量系统的研制及应用

为了能够精确地测量海底表层沉积物的声学参数, 自主研制了一种新型海底沉积物声学原位测量系统, 与国内外传统的声学原位测量系统相比, 该系统能够实时显示声波波形, 调整测量参数, 其工作方式除了站位式测量之外, 还实现了拖行式连续测量, 极大地提高了工作效率.根据前期海试情况, 对海底仪器结构进行了重新设计, 使之可以同时测量海底沉积物及海底海水的声学参数, 同时建立了双向数字信道, 解决了测量过程中系统信号的干扰问题.该系统的结构分为两部分:甲板控制单元和水下测量单元, 整套系统通过主机控制程序进行控制, 采用GPS定位系统测定仪器的大地坐标.为了检验系统的稳定性及准确性, 分别进行了实验室水槽实验和海上试验.利用水声测量设备对测量系统进行实验室水槽标定分析, 实验结果表明系统测量值相对误差仅为0.04%, 测量结果具有较高的精度.海上试验在青岛胶州湾和东海海域进行, 获得了试验区域海底沉积物声速和声衰减系数的测量数据, 将测量数据与他人的研究结果进行对比分析, 结果表明测量数据与前人研究结果一致, 较为准确.该原位测量系统在站位式测量和拖行式测量中都能够快速准确地测量出沉积物声速和声衰减系数, 可以作为海底底质声学测量的调查设备.     

东昆仑阿拉克湖地区第四纪水系演化过程及其趋势

根据第四系沉积物的沉积时代、沉积类型及盆山耦合与迁移规律,将东昆仑阿拉克湖地区第四纪水系变迁划分了4个阶段：早更新世小型内陆盆地无序水系阶段;中更新世冰川水系与东流水系阶段;晚更新世柴达木盆地内陆水系向南溯源侵蚀阶段;全新世黄河外泄水系形成与发展阶段。根据研究区及相邻地区黄河水系和柴达木盆地内陆水系的溯源侵蚀发展历史及趋势分析,认为研究区未来水系发展趋势不一定是加鲁河袭夺鄂陵湖、扎陵湖两湖及黄河水系,而可能是黄河加快下蚀作用和溯源侵蚀,鄂陵湖和扎陵湖将逐渐消失成为河流,黄河水系最终将袭夺柴达木内陆盆地水系。     

中国西北内陆盆地水分垂直循环及其生态学意义

中国西北内陆盆地中的地下水系统,对维系其浅表水分、热量、盐分均衡以及地表的生态平衡、土壤的资源属性和局部地域气候相对稳定性具有不可或缺的调节作用,这种调节作用是通过饱和带水、包气带水(土壤水)、近地表大汽水和植物体内水("四水")之间的垂直循环来实现的.目前的相关研究主要侧重于地下水与地表植被类型间对应关系的统计分析,较少涉及水分运移的机制;而以水分垂直循环的动力学机制为研究对象的SPAC系统(土壤-植物-大气连续体),则对地下水的重视程度不够,且存在着尺度转换的困难,更为完整的应该是GSPAC系统(地下水-土壤-植物-大气连续体).干旱区内陆盆地地下水生态效应的研究需要开展以下的工作:"四水"垂直循环的动力学过程与机制研究,尤其是饱水带-包气带界面水、汽、热转化过程的研究;人类活动影响下地下水系统演化特征的研究,它不仅是实现水分垂直循环研究的最终目的——水资源合理开发利用的中间环节,更是将"四水"垂直循环这一微观水文循环过程与区域水文循环过程相结合,实现尺度转化的关键所在.     

Photon in a cavity – a Gedankenexperiment

The inertial and gravitational mass of electromagnetic radiation (i.e., a photon distribution) in a cavity with reflecting walls has been treated by many authors for over a century. After many contending discussions, a consensus has emerged that the mass of such a photon distribution is equal to its total energy divided by the square of the speed of light. Nevertheless, questions remain unsettled on the interaction of the photons with the walls of the box. In order to understand some of the details of this interaction, a simple case of a single photon with an energy $E_{\nu }=h\nu$ bouncing up and down in a static cavity with perfectly reflecting walls in a constant gravitational field $\mathit{g}$, constant in space and time, is studied and its contribution to the weight of the box is determined as a temporal average.     

A Simulation Study on the Evolution of Groundwater Circulation Systems in Cenozoic Basins of Northern China

Three Cenozoic basins-the Qaidam basin, the Weihe graben-type basin and the North China plain-which are different in climatic conditions, geological settings and run-off types, are selected for the study. Based on an analysis of background information of the transect along the middle-latitude region, studies of groundwater dynamics, geochemistry, simulation of water circulation of the main elements as well as isotopic chronology, the information on global changes is collected, the formation of groundwater circulation systems and their evolution under stacked impacts of natural conditions and human activities are discussed, and a correlation is made between the evolutionary features of the above systems in these basins since 25 ka B.P. All these have laid a good foundation for further generalizing the evolutionary model of land water in northern China.     

713天气雷达数字化系统

本文介绍了用IBM-PC/XT(AT)实现的天气雷达数字化系统的众多功能,分析了系统的工作原理。对于几个关键的技术问题——高速数据录取、软件数字视频积分、地物杂波抑制、座标变换及图象传输,分别给出了解决的方法和详尽的程序方框图。