无限饱水孔隙弹性空间中由运动源所产生的位移场

基于Ｂｉｏｔ的饱和孔隙弹性介质的运动方程和利用复变函数方法，本文研究了无限饱水孔隙弹性空间中由常速运动源所产生的位移场。考虑了两种类型源：ａ．沿无限空间水平轴运动的斜向集中力源；ｂ．运动双力偶源。关于力源的运动速度，考虑了４种情形：ａ．力源的运动速度Ｕ小于饱水孔隙弹性介质的三种体波速度一亚音速情形；ｂ．速度Ｕ小于介质的第一纵波过度和横波速度，但大于第二纵波速度─—弱跨音速情形；ｃ．速度Ｕ小于第一纵波速度，但大于横波速度和第二级波速度─—强跨音速情形；ｄ．速度Ｕ大于介质的所有三种体波速度─—超音速情形。结果表明，在跨音达和超音速情形里，解呈现出与力源相联系的平面冲击波特征，位移出现了相应的跳跃。     

夏垫活动断层土壤氡地球化学特征

夏垫活动断层为首都圈重要的断层之一。本文用土壤中气氡测量法在齐心庄和东柳河屯区段进行了野外现场勘测,揭示了研究区土壤氡的地球化学异常,绘制出研究区的氡浓度等值线图,分析了该区段活动断层的上下盘、空间位置及断层走向,并探讨了研究区断裂带的规模及活动性。综合分析认为,断裂带规模较大和断层活动性较强的齐心庄处的夏垫活动断层应为今后地震监测的重点。     

GESE: a small UV space telescope to conduct a large spectroscopic survey of z∼1 Galaxies

One of the key goals of NASA’s astrophysics program is to answer the question: How did galaxies evolve into the spirals and elliptical galaxies that we see today? We describe a space mission concept called Galaxy Evolution Spectroscopic Explorer (GESE) to address this question by making a large spectroscopic survey of galaxies at a redshift, z～1 (look-back time of ～8 billion years). GESE is a 1.5-m space telescope with an ultraviolet (UV) multi-object slit spectrograph that can obtain spectra of hundreds of galaxies per exposure. The spectrograph covers the spectral range, 0.2–0.4 μm at a spectral resolving power, R～500. This observed spectral range corresponds to 0.1–0.2 μm as emitted by a galaxy at a redshift, z=1. The mission concept takes advantage of two new technological advances: (1) light-weighted, wide-field telescope mirrors, and (2) the Next-Generation MicroShutter Array (NG-MSA) to be used as a slit generator in the multi-object slit spectrograph.     

A new asteroid-associated meteor shower and notes on comet-asteroid connection

The calculation of the orbit of the potentially hazardous Asteroid 2001 YB₅ suggests a possible meteor shower around January 7.5, 2002 UT. Video observations revealed an unidentified radiant around the predicted maximum time, at RA=121.5°, Dec=+11.5°(for solar longitude 287.30°). Visual observers also reported unusually high rates from that region on the same night, indicating that 2001 YB₅ did produce a weak meteor shower. Furthermore, it is noticed that 2001 YB₅ is a rare B-type asteroid in same spectral class with Asteroid (3200) Phaethon, the parent body of the only previously known asteroid-associate meteor shower, Geminids.     

Characterization of Asian Dust during ACE-Asia

ACE-Asia was a multi-national collaboration organized to investigate and understand the chemistry, radiative properties, and climatic effects of mineral dust and other aerosol particles in the East Asia/Northwest Pacific region. Studies conducted at the Gosan and Zhenbeitai surface supersites show striking variations in aerosol concentrations and properties that were affected by the occurrence and origins of the Asian dust storms, air mass pathways, and mixing during the transport. Investigations conducted on the R/V Ronald H. Brown (RHB) showed that dust had a pervasive influence on the chemical composition, size distribution, and optical properties of the aerosol. Analyses using an aerosol time-of-flight mass spectrometer on the RHB showed that most of the coarse-particle nitrate and sulfate in post-frontal air was associated with dust, and more remarkably, that competitive or exclusionary processes evidently are involved in the uptake or production of these substances. Studies conducted onboard the NCAR C-130 aircraft showed that coarse-mode dust was less absorbing and less hygroscopic than pollution aerosol and that there was little correlation in light scattering and absorption by the sub- vs. super-micrometer aerosol. Below 2 km, dust was commonly mixed with pollutants, and this had a stronger influence on the optical properties of the submicrometer particles than the coarse-mode dust; at higher altitudes, the dust was less affected by pollution. Single particle analyses of C-130 samples showed that the mixing of black carbon (BC) with dust was common, but only certain types of BC particles were aggregated. Models were used in the planning, execution and interpretative phases of ACE-Asia; and summaries of modeling results are presented to illustrate the progress being made in identifying new dust sources; in depicting the time-varying, three-dimensional structure of dust plumes; and in quantifying the production, transport, and deposition of Asian dust.     

Kinematics of relativistic ejection with Hubble flow

What we observe as an apparent superluminal motion is the resultant velocity of Hubble flow and a local ejection. Taking Hubble flow into account, one can explain, problems posed for the relativistic beaming model, such as the one-sidedness problem and the untolerable extension of the depromected structure of some superluminal sources; the misalignment of small-and large-scale jets can be analyzed more appropriately. A significant by-product of the present investigation is the initiation to find a new way to determine the value of the Hubble constantH ₀, provided that one can observe the superluminal motion at much longer wavelengths, say, meter wavelengths.     

拟合后剩余残差的统计检验与待估参数的选择

在空间技术的实际资料处理中,经常遇到不同待估参数组合解算的ＲＭＳ水平大致相当而估值结果相差甚远的情况．本文提出采用残差统计检验的方法,结合ＲＭＳ的大小,来判断精密定轨和参数解算的好坏．将拟合后的剩余残差序列看作一个随机变量样本,并假设其满足正态分布,采用高阶矩和皮尔逊χ２ 统计量来度量残差序列偏离正态分布的程度．根据统计检验的结果,提出选择合适的待估参数的标准     

青藏高原东部拉萨河下游地区大气湍流交换特征研究

地气之间物质和能量随湍流运动进行输送,涡度相关技术是研究地气交换过程和评估大气资源的重要手段,它对湍流特征和精确的通量观测研究具有重要的作用.本研究利用拉萨蔡公堂通量站的闭路涡度相关系统,观测了 2020年8-11月青藏高原东部拉萨河下游地区典型高寒草甸下垫面的通量特征,并分析了该区域生长季和非生长季不同大气稳定条件下...     

柴达木盆地昆北油田路乐河组辫状三角洲沉积特征

柴达木盆地昆北油田路乐河组主要为砂砾岩、含砾砂岩、砂岩、粉砂岩及泥岩构成的陆源碎屑岩组合,通过详细的岩心特征和区域地质分析,将其确定为辫状三角洲沉积,其微相包括(水下)分流河道、河口坝、席状砂、泛滥平原、分流间湾和前三角洲泥等,其中以(水下)分流河道沉积为主体。该辫状三角洲的纵向岩石组合序列反映为典型的退积型三角洲,即发育于可容纳空间与沉积物补给速率比值(A/S比值)逐渐增大的湖侵环境。沉积旋回早期发育辫状三角洲平原,旋回中后期发育辫状三角洲前缘和前三角洲。辫状三角洲整体呈自南西向北东的扇形展布,平面上发育两期分支物源体系,分别位于Q6和Q16井区。实验分析测试、试油等资料揭示辫状三角洲(水下)分流河道砂体储集性能较好,它的发育控制路乐河组油气的纵向与平面分布。     

天气预报的业务技术进展

该文总结回顾了中央气象台近年来的天气预报业务技术进展。天气预报质量的历史演变显示了预报业务水平的提高, 这种业务能力的提高既反映了预报技术的发展, 也带来了天气预报业务的变化。对业务天气预报中各种预报技术应用进展的分析表明:数值预报在天气预报业务能力提高中发挥着重要的基础性作用; 同时, 基于对不同尺度天气影响系统发展演变过程深入认识的基础上, 天气学的预报方法依然是预报业务中的重要技术方法; 动力诊断预报已成为灾害性天气预报中的重要手段之一, 数值预报产品的解释应用是实现气象要素精细定量预报的技术途径。