WR 7a: a V Sagittae or a qWR star?

The star WR 7a, also known as SPH 2, has a spectrum that resembles that of V Sagittae stars although no O  vi emission has been reported. The Temporal Variance Spectrum – TVS – analysis of our data shows weak but strongly variable emission of O  vi lines which is below the noise level in the intensity spectrum.
Contrary to what is seen in V Sagittae stars, optical photometric monitoring shows very little, if any, flickering. We found evidence of periodic variability. The most likely photometric period is   P _phot= 0.227(±14) d  , while radial velocities suggest a period of   P _spec= 0.204(±13) d  . One-day aliases of these periods can not be ruled out. We call attention to similarities with HD 45166 and DI Cru (= WR 46), where multiple periods are present. They may be associated to the binary motion or to non-radial oscillations.
In contrast to a previous conclusion by Pereira et al., we show that WR 7a contains hydrogen. The spectrum of the primary star seems to be detectable as the N  v 4604 Å  absorption line is visible. If so, it means that the wind is optically thin in the continuum and that it is likely to be a helium main sequence star.
Given the similarity to HD 45166, we suggests that WR 7a may be a qWR – quasi Wolf–Rayet – star. Its classification is WN4h/CE in the Smith, Shara & Moffat three-dimensional classification system.     

H I distribution in the region of the supernova remnant G78.2+2.1

Based on RATAN-600 21-cm line observations with an angular resolution of 2.4′ over a wide range of radial velocities, we analyze the neutral-hydrogen distribution in the region of the SNR G78.2+2.1. In addition to an H I shell at low radial velocities immediately surrounding the radio remnant, we detected an extended expanding H I shell, ≈3° in diameter, at a radial velocity of ?25 km s^?1, which closely coincides in coordinates and angular sizes with the outer X-ray shell discovered by Lozinskaya et al. (2000). The Hα emission studied by these authors in the SNR region also has a secondary peak at radial velocities from ?45 to ?20 km s^?1. Since the radial velocities of these two objects differ significantly, their distances can be assumed to differ as well; i.e., a chance projection of two distinct objects is observed.     

Nitrogen utilisation by size‐fractionated phytoplankton assemblages associated with an upwelling event off Westland,New Zealand

Abstract

Uptake rates of ammonium (NH₄ ⁺ ), nitrate (NO₃ ^? ), and urea by three subgroups of phytoplankton (< 200, < 20, < 2 μm) off Westland, were measured using ¹⁵ N tracer techniques in midwinter 1988, after a recent upwelling. For all size fractions at surface irradiance (I₁₀₀), nitrogen (N) was taken up primarily as NO₃ ^?. This accounted for 67–85% of total N uptake (SρN), whereas at 40 and 7% of surface irradiance, the regenerated N (NH₄ ⁺ ) and urea) made up 31–72% of SρN. Depth profile experiments for all three size components showed that uptake of NO₃ ^? was most light‐sensitive, followed by that of NH₄ ⁺ and urea. The irradiance and nutrient availability plot indicated that light was substantially more important than the nutrient concentrations in controlling the assimilation of N by microplankton (20–200 μm). Nano‐ (2–20 μm) and picoplankton (< 2 μm) however, were not as sensitive to either light or nutrient concentrations. High winds and the resulting deep mixing, combined with offshore and alongshore advection in the midwinter, were suggested to be the major cause of the low biomass and N productivity.     

推进煤矸石资源化利用的对策建议

煤矸石是我国排放量和堆存量最大的工业固体废弃物之一，但又是可以利用的资源，只要加以资源化利用，就能会变废为宝。在研究我国煤矸石综合利用现状的基础上，指出了煤矸石综合利用中存在的主要问题，从制定规划、完善经济政策、加强法制建设等方面提出了加快推进煤矸石资源化利用的建议。     

微粉末油浸法在珠宝文物鉴定中的应用

微粉末油浸法主要用于微观研究,对样品进行结晶光学测试。本文提供几个检测实例：高色翡翠戒指、手镯,新石器时代玉斧,被称为“江川出土的古代手镯”,新类型“天然田黄石工艺品（斜绿泥石型）”,微晶含铬云母玉及“天然彩色玻璃石”;并以其他方法测试资料相互验证和补充,使结果更为准确可靠。     

一种新型双磙子FPS隔振系统的动力学模型

本文基于多体动力学理论建立了一种新型双磙子FPS(Friction Pendu lum System)隔振系统动力学模型。在对该系统进行运动学分析的基础上,可将它归结为一个单自由度系统。应用非惯性系中质点系相对动能定理的微分形式可推导出该系统的运动微分方程,它是一个非线性方程。在小角位移的情形下,可近似得到相应的无阻尼线性系统的固有频率,它与观测结果吻合。这一双磙子FPS隔振系统的动力学方程的建立有助于对该系统动力学行为的研究,对方程的直接求解可提高仿真设计中正问题计算的效率,为设计包含该系统的半主动控制奠定了基础。     

数字强震仪在大坝安全监测中的应用研究

介绍了一种新型的数字强震仪（GDQJ-2型数字强震仪）,该强震仪以其独特的结构原理和技术性能, 在强震观测、大坝安全监测等地震领域得到广泛的应用.介绍了大坝安全监测的重要意义以及安全监测设备中地震监测设备的进展,介绍了GDQJ-2型数字强震仪的结构原理、技术指标以及在大坝安全监测中的应用,为大坝安全规范设计提出直接依据.     

探索地震安全农居推广机制

地震安全农居工程是新时期地震工作主管部门根据新形势、新任务、新目标而启动的一项具有开创性、探索性的工作。这项工作的开展,既是落实科学发展观,全面建设小康和构建和谐社会的需要,又是立党为公、执政为民、防灾利民的实际行动。许昌市主要做法有：调整成立地震安全农居工程推广领导小组,加强组织领导工作;建立健全农村建筑工匠防震抗震技术培训机制,培养一大批掌握农村民居抗震基础知识和操作技能的新型农村建筑工匠;免费设计不同类型、不同造价、不同规格的建筑施工图纸,供群众选择使用;组织施工、监理等有关工程技术人员对建房户现场进行指导,建房农户按图纸规范施工,保证了施工质量。     

Study on the Phenomenon of Geomagnetic Low-value Displacement before Moderately Strong Earthquakes in Gansu

This paper analyzes the distribution characteristics of geomagnetic low-value displacement in Gansu and its adjacent areas from 1995 to 2003 on the basis of the data of the daily amplitude minimum value time of the geomagnetic vertical component. It is shown that in addition to the changing rules of geomagnetic low-value displacement itself, there is a better correlation between geomagnetic low-value displacement and the occurrence of moderately strong earthquakes. There appeared to be geomagnetic low-value displacement before the moderately strong earthquakes in Gansu in the 9 years from 1995 to 2003. This result indicates that geomagnetic low-value displacement is of instructive significance for earthquake prediction to some extents.     

用数字测高仪漂移测量研究电离层声重波扰动

数字测高仪Digisonde中的漂移测量,常用来研究小尺度电离层扰动,如电离层小不均匀体的漂移。文中提出一种新的分析方法,利用漂移测量数据中多普勒频移和到达角参量的最大熵动态功率谱,估算声重波一类大尺度电离层扰动的水平传播速度和传播方向。作为实例,研究了Millstone Hill测高仪站的漂移观测资料,并对处理结果进行了初步分析。分析结果表明,从数字测高仪漂移测量数据中,可有效地提取声重波一类大尺度电离层扰动的传播参量,在电离层动力过程的研究中很有意义。