Positron-Cyclotron Maser for the Core Emissions from Pulsars

We use the cyclotron-maser theory to explain the core emission from the magnetosphere of pulsars. As a kind of direct and efficient maser type of emission, it can give rise to escaping radiation with extremely high brightness temperature and narrow angle with respect to the magnetic axis. We find that the growth rates and real frequencies of the O-mode electromagnetic wave propagating parallel to the magnetic fields depend on the ratio of the plasma frequency ωp and the gyrofrequencyωb rather than the plasma frequency alone, as described by other models. The emission takes place in the region where the magnitude ofωp / ωb is 10-2. The corresponding altitude is about a few decades of neutron star radius, where the magnetic field strength is about 106 - 108 G. We find that the growth rates of the cyclotron maser instability change very sensitively with the ratio ωp /ωb,which is the function of radius r from the center of the neutron star. It results in a very steep radius-to-frequency mapping of radio emissions from the magnetospheres, thus a very compact emission region. A qualitative spectrum and a lower frequency cut-off of the radio emission could be obtained by this model. This revised version was published online in July 2006 with corrections to the Cover Date.     

关于气候的概念及气候学与地理学的关系问题

本文包括以下内容:(1)从气候概念的历史源流、感性基础、气候与天气的关系及气候与地理的关系、气候形成过程五个方面论述了人类对气候认识的发展情况。(2)把现代气候的概念总结为:统计气候学、天气气候学、地理气候学和动力气候学四个方面。(3)在批判流行多年的鲁宾施晋和特洛兹多夫气候定义的基础上提出气候的新定义,即气候是宏观的大气物理过程。(4)明确指出气候学不是地理学的部门学科,它们在科学分类中是并列的。     

THE APPROACH TO REMOTE SENSING OF WATER VAPOR BASED ON GPS AND LINEAR REGRESSION Tm IN EASTERN REGION OF CHINA

The approach to remote sensing of water vapor by using global positioning systems(GPS) isdiscussed.In order to retrieve the vertical integrated water vapor(IWV) or the precipitable water(PW),the weighted "mean temperature" of the atmosphere,T_m would be estimated to the specificarea and season.T_m depends on surface temperature,tropospheric temperature profile,and thevertical distribution of water vapor.The surface temperature dependence is borne out by acomparison of T_m and the values of surface temperature T_s using radiosonde profiles of BeijingStation(No.54511) throughout 1992.The analysis of radiosonde profiles spanning a one-yearinterval(1992) from sites in eastern region of China with a latitude range of 20-50°N and alongitude range of 100-130°E yields the coefficients a and b of a linear regression equation T_m=a+bT_s.     

13.7米射电望远镜谱线观测系统的稳定性与观测时间的优化使用

本文介绍紫金山天文台青海13.7M毫米波射电望远镜谱线观测系统稳定性的测试,并讨论如何根据测试结果选择最佳观测模式与积分时间,以提高望远镜的使用效率。     

地震动触发滑坡体滑动的机理

论证并探讨了地震动触发滑坡体滑动的机理,认为地震时的坡体波动振荡在斜坡岩土体变形破坏过程中产生三种效应：累进破坏效应、启动效应和启程加速效应,并得出了一些既有理论研究意义,又有一定实际应用价值的论断。     

桩体复合地基柔性垫层的效用研究

从阐述复合地基与桩基之间的区别入手,通过对桩体刺入垫层的研究,寻找在桩头呈理想球形孔条件下,垫层、桩体、桩间土三者模量与刺入量之间的关系,进而讨论了在刺入模式下的加固区复合模量计算问题。还讨论了复合地基桩上材料最优发挥状态问题,力图寻找最佳的桩土荷载分担比。     

含油气盆地储层建模和模拟研究评述

概述了国内外储层建模和的研究现状和进展,对储层建模和模拟的主要方法进行了评述,并对我国在该领域中存在的主要总是作解决途径作了探讨,建立了该项研究工作的一航流程。     

垃圾和粪便快速除臭方法研究

研究了城市生活垃圾及粪便混合物中恶臭气体的脱除方法。利用所筛选的高效除臭菌种配成不同比例的菌剂,在自然通气的条件下脱臭,８～１２ｈ便可完全脱臭。脱臭后的干燥混合物经加工可用于制备高效生物有机肥料,具有较高的经济价值和应用价值。     

Distribution of Lg coda <Emphasis Type="Italic">Q</Emphasis> in Xinjiang and its adjacent regions

In this study, we collected 1 156 broadband vertical components records at 22 digital seismic stations in Xinjiang region, Ürümqi station, and 7 stations in the adjacent regions during the period of 1999–2003. The records were firstly processed by the stacked spectral ratio method to obtain Q ₀ (Q at 1 Hz) and the frequency correlation factor η corresponding to each path. Based on the results, the distribution images of Q ₀ and η in 1°×1° grids for Xinjiang region were gained by the back-projection technique. The results indicate that Q ₀ is high (300–450) in the Tarim platform and marginal Siberian platform, while Q ₀ is low (150–250) in the southern regions as west Kunlun fold system and Songpan-Ganzi fold system. In the northern regions as Junggar fold system and Tianshan fold system, Q ₀ is also low (250–300) and η varies between 0.5 and 0.9.     

Phonon density of states in iron at high pressures and high temperatures

The phonon density of states (DOS) in iron has been measured in situ by nuclear resonance inelastic X-ray scattering (NRIXS) at high pressures and high temperatures in a resistively heated diamond anvil cell. The DOS data provide a variety of thermodynamic and elastic parameters essential for characterizing iron at depth in the Earth interior, such as average sound velocity, Debye temperature, atomic mean square displacement, average kinetic energy, vibrational entropy and specific heat. The NRIXS data were collected at 6, 20, and 29 GPa and at temperatures up to 920 K. Temperatures were directly determined from the measured spectra by the ratio of intensities of the phonon creation/annihilation side bands that are determined only by the Boltzmann factor. The change of the DOS caused by the structural transition from -Fe to -Fe is small and not resolvable within the experimental precision. However, the phonon energies in -Fe are clearly shifted to lower values with respect to - and -Fe. The temperature dependence of derived thermodynamic parameters is presented and compared with those obtained by Debyes model. The Debye temperatures that best describe the data decrease slightly with increasing temperature.