Photometric Studies of Twelve Deep, Low-mass Ratio Overcontact Binary Systems

The formations of the blue straggler stars and the FK Com-type stars are unsolved problems in stellar astrophysics. One of the possibilities for their formations is from the coalescence of W UMa-type overcontact binary systems. Therefore, deep (f > 50%), low-mass ratio (q < 0.25) overcontact binary stars are a very important source to understand the phenomena of Blue Straggler/FK Com-type stars. Recently, 12 W UMa-type binary stars, FG Hya, GR Vir, IK Per, TV Mus, CU Tau, V857 Her, V410 Aur, XY Boo, SX CrV, QX And, GSC 619-232, and AH Cnc, were investigated photometrically. Apart from TV Mus, XY boo, and GSC 619-232, new observations of the other 9 binaries were obtained. Complete light curves of the 10 systems, FG Hya, GR Vir, IK Per, TV Mus, CU Tau, V857 Her, GSC 619-232, V410 Aur, XY Boo, and AH Cnc, were analyzed with the 2003 version of the W-D code. It is shown that all of those systems are deep (f > 50%), low-mass ratio (q < 0.25) overcontact binary stars. We found that the system GSC 619-232 has the highest degree of overcontact (f = 93.4%). The derived photometric mass ratio of V857 Her, q = 0.0653, indicates that it is the lowest-mass ratio system among W UMa-type binaries.Of the 12 sample stars, long-term period changes of 11 systems were found. About 58% (seven) of the sample binaries show cyclic period oscillation. No cyclic period changes were discovered for the other 5 systems, which may be caused by the short observational time interval or by insufficient observations. Therefore, we think that all W UMa-type binary stars may contain cyclic period variations. By considering the long-term period changes (both increase and decrease) of those binary stars, we proposed two evolutionary scenarios evolving from deep, low-mass ratio overcontact binaries into Blue Straggler/FK Com-type stars.     

一种基于SX10点云的单株树木骨架点提取方法

骨架点是单株树木几何模型重建的基础。本文结合水平集、聚类方法和图论3种方法,采用ILMSVP和天宝SX10获取模拟与实测单株树木点云数据,并实现单株树木骨架点提取,其中模拟数据用于方法实现,实测数据用于验证。为解决单株树木点云数据缺失情况,本文重复利用水平集、聚类方法和图论方法得到较完整的单株树木骨架点。结果表明:本文采用的单株树木骨架点提取方法可行。     

天宝SX10影像扫描仪在测绘工程中的应用

随着城市不断发展,科学技术不断提升,对测绘工程的发展来说,现有的社会背景给测绘技术提出了全新的要求。Trimble SX10影像扫描仪通过为测绘、工程和扫描专业人士提供世界上最创新的解决方案,重新定义了日常测量设备的能力。本文简要介绍了Trimble SX10影像扫描仪的核心技术,并结合其在边坡变形监测与治理工程及航道通航安全管理工程中的应用案例详解Trimble SX10影像扫描仪在测绘项目中的应用及与传统测绘方式相比的优越性。     

天宝SX10影像扫描仪在水文泥沙监测中的应用北大核心CSCD

基于水文泥沙监测的应用需要,采用天宝SX10影像扫描仪进行地形测量,并与传统观测方法进行比较分析,通过三维激光扫描技术获取海量点云数据,进而提取断面数据并进行质量监测。项目实施和成果分析表明,三维激光扫描技术能够满足水文泥沙监测要求,有效降低山区河道作业风险,提高工作效率,技术方案具有可行性。     

Mt. Suhora M dwarf survey - Detection of eight short-period variable stars

The Mt. Suhora M dwarf survey searching for pulsations in low mass main sequence stars has acquired CCD photometry of 46 M dwarf stars during the first year of the project (Baran et al., 2011). As a by-product of this search hundreds field stars have been checked for variability. This paper presents our initial result of a search for periodic variables in field stars observed in the course of the survey. On the basis of the periodicity and the shape of the light curves, eight new variables has been detected, among which five are δ Scuti stars and three likely RR Lyrae stars. Although variation in one of the stars has been previously detected, it was classified incorrectly. To support our classification, in August 2010, we performed spectroscopic observations to derive spectral types and luminosity classes for all eight variable stars.     

菲和Cd2+单一及复合污染对毛蚶氧化胁迫效应的比较

采用半静态染毒实验研究了菲和Cd²⁺单一及复合污染下胁迫9 d和清水释放2 d过程中毛蚶体内活性氧(ROS)、谷胱甘肽(GSH)含量和谷胱甘肽硫转移酶(GST)活性的变化。结果表明,菲和Cd²⁺单独胁迫能诱导毛蚶体内ROS含量的增加及GSH含量、GST活性的降低,且随染毒浓度的增加,对各指标影响愈明显,存在剂量-效应关系。毛蚶体内GSH和GST的变化趋势具有一致性。菲和Cd²⁺复合污染对毛蚶体内的氧化胁迫效应整体大于二者单独污染。在清水释放阶段,单一及复合污染胁迫组各指标均能恢复至对照组水平。表明毛蚶体内抗氧化系统适合作为监测海洋多环芳烃和重金属复合污染的生物标志物。     

纳米氧化锌和菲对长江口附近海域沉积物反硝化作用及功能菌群落结构的影响

本研究在长江口附近海域采集表层沉积物,采用实验室模拟培养与分子生物学手段相结合的方法,通过测定纳米氧化锌(ZnO NPs)和菲(Phe)胁迫下沉积物中NO-3-N和NO-2-N浓度和反硝化还原酶活性及反硝化细菌基因丰度和群落多样性变化,目的是比较研究ZnO NPs和Phe对河口区沉积物反硝化作用及功能菌群落结构的影响,...     

三维激光扫描技术在地铁隧道中的应用

Trimble SX10影像扫描仪在隧道内单站有效扫描距离为200 m,具有单人可操作、自定义不规则区域扫描、内业数据免拼接、隧道竣工报告全自动生成等特性。因其简单的作业模式、高效的扫描速率、便捷的内业处理,深受广大施工单位的认可。