Sub-mm and far-infrared continuum observations of herbig-haro exciting stars and other yso's

We show initial results from a survey of the mm to far-IR continuum spectra of 30 YSO's known to be exciting Herbig-Haro objects. The data are also compared with line intensities of C¹⁸O and H₂CO. We include in this analysis results from other sub-mm continuum surveys of compact HII regions, T-Tauri stars and class 0 YSO's. The results provide a statistical sample of the long-wavelength dust spectra of 60 Young Stellar Objects. Data are displayed on mm to FIR colour-colour diagrams, with the aim of trying to discriminate between different stages of star formation through general spectral characteristics, rather than detailed model fits to individual sources.     

Mid-IR (8–13 μm) images of the 21 μm,carbon rich proto-planetary nebulae

We present 9.7 and 11.8 m narrow band (/=10%) images of three carbon (C-) rich proto-planetary nebulae with an unusual 21 m feature: IRAS 07134+ 1005, IRAS 22272+5435, and IRAS 04296+3429. The images were taken at UKIRT using the Berkeley/IGPP/LEA mid-IR camera. All three objects have a bipolar shape adding to the existing evidence that C-rich PPNe are by nature bipolar. Furthermore, we find the same bipolar morphology in a previous study of the C-rich, young planetary nebula, IRAS 21282+5050. We believe these four objects form an evolutionary sequence which links the C-rich asymptotic giant branch (AGB) stars with the C-rich planetary nebulae (PNe). From this evolutionary sequence, we conclude that bipolarity in C-rich PNe begins on the AGB and that the dynamical ages of these PPNe are in fair agreement with theoretical ages for a 0.6 M hydrogen burning core star.     

Coordinated Simultaneous Freja Satellite and Niemegk Observatory ULF Measurements

The standard FFT analysis was applied to thirteen pulsation events selected from the March–April 1993 simultaneous measurements in space (Freja satellite) and on the ground (Niemegk Observatory). The spectral processing of the six-minute sections of record in two coordinate components perpendicular to the magnetic field lines had two principal subjects in view: a) Frequency-amplitude satellite-ground relations. The average values of smoothed spectral amplitude transmission coefficients in the total Pc4-3 and, separately, in Pc4 and Pc3 bands were 0.60, 0.48 and 0.70, respectively. The maximum values were observed within the Pc3 band, near f 30 mHz. b) Estimation of frequency bands of field line resonances (FLRs) recorded on Freja. Freja's motion in a broad latitude range (±5° around Niemegk) during the measurements enabled two frequency bands of FLRs with a width of 10's of mHz to be identified on Freja. The weighted frequencies of the FLRs bands on Freja were f _wA 36 mHz and f _wB 18 mHz with fine structure separations of about 5 mHz and 4 mHz, respectively. The second band with f _wB 18 mHz was mostly not observed at Niemegk, and this could be the consequence of the satellite moving partly through regions of L greater than that of Niemegk.     

Mass loss mechanisms in evolved stars

Summary Mass loss is a very important phenomenon for stellar evolution. In the late stages of stars it becomes fairly high (up to 10^–4 M/yr) though with a much decreased expansion velocity (about 30 kms^–1). It can also be variable, sporadic. Now, though the first observational evidence for mass loss from cool stars is usually attributed to Adams and McCormak in 1935 and though a lot of observational and theoretical papers have been devoted to it since this discovery, we only know mechanisms which are probably efficient under the dominant physical conditions, but neither one mechanism nor a combination of mechanisms is able to produce the observed effects. Those most invoked (thermal gas pressure, radiation pressure, acoustic waves, shock waves, Alfvén waves, ) will be described and criticized, with emphasis on the radiation pressure on dust grains at work at least in the outer part of cool atmospheres. The geometry and the content of expanding atmospheres are also discussed together with the mechanisms that may be important at small scales. Both theory and observations are taken into accout.     

CNO燃烧核反应的研究

本文利用势垒穿透模型计算重离子融合反应截面,我们发现理论计算结果同现有的实验数据符合得相当好。在此基础上,对~(12)C+~(12)C,~(12)C+~(14)N,~(12)C+~(16)O,~(14)N+~(14)N,~(14)N+~(16)O和~(16)O+~(16)O六种融合反应,在T_9=-0.1—5.0温度范内数值计算了这些热核反应率,并给出了它们随温度变化的近似解析表达式.对~(12)C+~(12)C,~(12)C+~(16)O和~(16)O+~(16)O这三种热核反应率,我们的新结果明显地低于Caughlan等人在1985年的列表值,特别是~(16)O+~(16)O的热核反应率比文[21中值低7—20倍,这将对整个大质量恒星的演化、超新星爆发以及核合成带来较大的影响,本文简略地讨论了这些影响.     

对银川地磁台磁通门磁力仪观测数据的初步分析

选取2001年1月－6月中美合作项目（SMALL）中磁通门磁力仪的数据和同期磁变仪的数据进行对比分析。结果表明，两种仪器记录的日变形态、日变幅、极值及极值时间具有较好的一致性，说明该项目中磁通门磁力仪的资料真实可靠。给出的典型地磁脉动事件表明，该仪器可提供精确定时的高质量地磁资料。     

Fluvial gravel facies architecture of late Pleistocene age at Po Chue Tam, Lantau Island, Hong Kong: tectonic versus climatic control?

A cross-section of fluvial gravel deposits of late Pleistocene age exposed at Po Chue Tam, Lantau Island, Hong Kong contains two facies: a lower facies of planar cross-bedded gravel (Gp) and an overlying facies of clast-supported, massive gravels (Gcm). The Gp gravels include five gravel couplets. Each couplet consists of a clast-supported, coarse gravel-dominated bed and an overlying clast-supported, fine gravel-dominated bed with a discrete bounding surface. Tectonic uplift predating the last interglacial transgression produced a large amount of detritus in the source area. Excessive peak rainfall intensity resulting from enhanced seasonality of monsoonal precipitation in the following glacial period triggered catastrophic floods, which transported mature detritus in large quantities into a fault-controlled piedmont basin. The Gp gravels were deposited by pulsating flood flows. In relation to kinematic waves of particles, bedload sediment was longitudinally sorted and segregated into a train of gravel sheets. They draped over each other and accreted laterally due to expansion of flow, producing planar cross stratifications that are characteristic of recurrent, couplet-style coarse/fine cross beds. In contrast, Gcm gravels were laid down as a single, nearly horizontal bed by a catastrophic flood that was not subject to flow pulsation.     

全球构造研究的简要回顾

全球构造研究可分为：（１）１９世纪后期“固定论”占统治地位阶段；（２）２０世纪６０年代前“活动论”曲折发展阶段；（３）６０年代以来板块学说占统治地位阶段。当代全球构造研究以地球深部构造与物质研究为关键。日本学者提出了“幔柱构造”和新的全球构造体系，其它学者提出了不同形式的“膨胀论”和“脉动论”。全球构造研究应注意思想创新，冲破均变论思想的局限性。建议以突变观点和“阶段论”为依据，使观察、推理和实验三者适当配合，发挥优势，逐步建立自己的地球动力学及其演化模型。     

1989年3月13日武昌地区太阳耀斑事件效应的观测结果

1989年3月13日太阳耀斑事件产生了丰富的地球物理效应。耀斑激波和耀斑粒子流引起强烈地磁暴。在武昌地区,磁暴急始发生于地方时3月13日09h30min,其初相期持续10小时(3月13日09h30min—19h20min),主相期持续13小时(3月13日19h20min—3月14日08h20min),至3月16日05h20min始恢复平静(图1)。     

山东招掖金矿带焦家式金矿的矿床分带

本文从矿化、蚀变、构造岩、矿物组合、元素组合、矿床类型等方面,论述了招掖地区焦家式金矿矿床分带规律问题。认为该区焦家式金矿矿床分带以脉动、逆向、不对称为特征。可分出叠加式和更替式两类分带,分别与控矿断裂断面的递进式迁移和跳跃式迁移相联系,反映了构造活动中心的间歇性迁移。论文最后提出了最佳分带组合,有重要的理论和实际意义。