一种适合定点使用的DTZ型质子旋进磁力仪

系统地介绍了ＤＴＺ系列质子旋进磁力仪的思路和性能特点，通过台站使用认为，ＤＴＺ系列仪器能满足地磁台观测精度的要求，具有实际使用的价值。     

郑州地磁台数字化与模拟资料的对比分析

选取郑州台2002年地磁相对观测D、Z分量资料,对同期数字化和模拟观测数据采用日变形态、趋势分析、差值分析、极值时间等方法作对比分析。结果表明:两种观测一致性较好,说明数字化仪器观测的数据是可靠的,用来代替模拟仪器是可行的,但因数字化仪器还存在观测数据突跳的问题,尚需作进一步的改进和完善。     

无磁杜瓦频率特性对高温超导磁强计的影响

无磁杜瓦是高温超导磁强计系统的重要组成部分。无磁杜瓦的频率特性是影响高温超导磁强计在地球物理勘查中的有效应用的一项重要指标。采用新的工艺研制出了频带大于100 kHz的无磁杜瓦,消除了无磁杜瓦对接收信号的影响。     

提高地磁绝对观测数据精度的有效途径

经过长期观察发现用CZM-2型核旋仪(及其同类仪器)进行定点观测读数时,运用分量仪线圈“单向”旋转的方法进行分量观测,再加上做好一些其它辅助措施,能够充分消除人为因素和仪器本身误差所带来的影响,明显提高仪器的观测精度,达到使观测资料更加准确的目的。     

IMP 8 magnetosheath field comparisons with models

This study presents cross-sectional vector maps of the magnetic field derived from IMP 8 magnetometer in the magnetosheath at 30 R_e behind the Earth. In addition the vector patterns of the magnetosheath field for northward, southward, and east-west interplanetary magnetic field (IMF) directions are qualitatively compared with those obtained from the Spreiter-Stahara gas dynamic (GD) and Fedder-Lyon magnetohydrodynamic models (MHD). The main purpose is to display the cross-sectional differences in relation to the dayside merging with different IMF directions, allowing the reader to make direct visual comparisons of the vector patterns. It is seen that for east-west IMF directions, the data-based and MHD-based patterns differ noticeably in a similar way from the GD model, presumably reflecting the influence of dayside magnetic merging of the Earths magnetic field with the y-component of the interplanetary magnetic field. All three northward IMF cross sections show comparable field draping patterns as expected for a closed magnetosphere. For southward IMF case, on the other hand, differences between the three cross-sectional patterns are greater as seen in the field vector sizes and directions, especially closer to the magnetopause where more disturbed magneto-spheric conditions are known to be exist. The data comparisons with the MHD and GD models show that the differences result from the magnetic field-flow coupling and that the effects of dayside reconnection are present in IMP 8 magnetic field measurements.     

简化磁力计非线性误差模型的快速校正算法

针对传统的磁力计校正算法中存在的误差模型复杂、计算时间长、需要保持水平姿态和已知航向信息等弊端,该文从磁力计误差特性入手,推导并建立了简化的磁力计非线性等效误差模型。基于动态调整策略对传统的LM算法进行改进,并利用改进的LM算法求解误差模型,减少计算过程中的迭代次数,实现了磁力计误差的快速估计。实验表明,该方法在有效保证磁力计校正精度的前提下,迭代次数减少25%,计算速度提高了65.59%。     

Primary proton spectrum around the knee deduced from the emulsion-chamber data obtained at Mts. Fuji and Kanbala

We have done extensive Monte Carlo simulations using the new simulation codes of CORSIKA and COSMOS to compare with the gamma-family data obtained at Mts. Fuji (3750 m above sea level) and Kanbala (5500 m above sea level). Then, we estimated the primary proton and helium spectra around the knee energy region using a multiple-layered feed-forward neural network as a classifier of primary particle kind. The selection efficiency of proton-induced family events is estimated to be 82%. The flux value of protons at 2×10¹⁵ eV is (5.5±1.5)×10⁻¹⁴ (m⁻² s⁻¹ sr⁻¹ GeV⁻¹). The result suggests heavy-enriched primary composition around the knee region.     

Ab-initio calculations of the proton location in topaz-OH,Al<Subscript>2</Subscript>SiO<Subscript>4</Subscript>(OH)<Subscript>2</Subscript>

The position of hydrogen in the structure of topaz-OH was determined by means of ab-initio quantum-mechanic calculations. Static lattice energy calculations predict the existence of four non-equivalent positions of protons, which are characterized by O4–H1... O1, O4–H2... O2, O4–H3... O3 and O4–H4... O4 hydrogen bonds. The distribution of the protons between positions of local equilibrium is controlled by the proton–proton avoidance rule and the strength of the hydrogen bonds. The most favourable configuration of hydrogen atoms is achieved for adjacent protons, which form O4–H3... O3 and O4–H4... O4 hydrogen bonds, respectively. The thermal excitation of atoms at a temperature of 55 K is large enough for the hydrogen atoms occasionally to change their positions to form O4–H1... O1 and O4–H2... O2 bonds. At ambient pressures and higher temperatures the protons are in a dynamic exchange between the allowed positions of local minima. As a consequence, for nearly room-temperature conditions, the dynamic change between different structural configurations leads to the violation of all possible symmetry elements and with that to space group #E5/E5#1. The flipping of the protons between different sites is achieved by simple rotation of the OH-dipole and does not produce any significant distortion of the framework of topaz, whose symmetry remains that of the space group Pbnm. Therefore, no reduction of symmetry has been observed in former X-ray studies on topaz-OH. Calculated IR absorption spectra of topaz-OH were found to be in good agreement with measured spectra. According to the calculations, the two favourable configurations of protons might correspond to the measured peak splitting within the OH-stretching range. An experimentally observed low-frequency band at 3520 cm^–1 was assigned to the OH-stretching of the O4–H3... O3 bond, while the band at 3600 cm^–1 was attributed to OH-stretching of the O4–H4... O4 hydrogen bond. The broad peak in FAR-IR frequency range at 100–150 cm^–1 is attributed to the stretching of H3... O3 and H4... O4 contacts. The rate of proton exchange at 670 K among different sites was estimated by ab-inito molecular dynamic simulations. The calculations predict that flipping of adjacent protons between O4–H3... O3 and O4–H4... O4 bonds at 670 K occur at a rate of about 1.96 THz.     

深空探测科学仪器研究进展

深空探测是对宇宙中地球以外的行星、卫星、小行星和彗星等星体或空间环境的探测活动.合理选择深空探测科学仪器,了解被测星体的物理及化学性质、地表地貌、动态特性以及有机物和水的存在,对人类了解地外水和生命信息、认识太阳系的起源和演化有着重要意义,是深空探测的重要任务.本文总结了深空探测的科学目标,介绍了近50年来典型深空探测任务中探测器所搭载的科学仪器及其特点,包括质谱仪、光谱仪、探地雷达和磁力计等,整理了其性能参数及面向的探测功能任务,最后讨论了深空探测科学仪器目前呈现出的小型化、低功耗、更强的环境适应能力和多仪器联合使用的发展趋势.     

中近磁尾等离子体片统计特性研究

本文使用Cluster-C1卫星的CIS仪器和FGM仪器测量得到的质子通量数据和计算的β数据,判断Cluster卫星在地球磁尾不同位置位于等离子体片内的概率.使用2001—2004年7—11月的Cluster-C1数据,分别在行星际磁场南向和北向时,得出X-10RE区域内卫星位于等离子体片的概率在Y-Dz平面的分布图(Dz是卫星到中性片的距离).通过对比行星际磁场南向和北向时的卫星位于等离子体片的概率的分布图,我们发现等离子体片在行星际磁场南向时比在行星际磁场北向时要薄,并且这个效应在磁尾晨昏两侧比在午夜附近明显,同时我们还发现等离子体片在晨侧比在昏侧厚.