SWDC-4A联合POS进行集成传感器定向研究

主要介绍利用国产轻型组合宽角数字测绘相机SWDC-4A联合POS搭载轻型飞机A2C进行航测试验研究,探讨相机联合POS进行集成传感器定向测图的精度。试验采用将POS数据解算的定位定向参数参与到摄影测量区域网平差中,采用统一的数学模型和算法确定像片精确外方位元素的方法,并以常规空三结果对其进行验证,实验结果表明：采用地面元分辨率为6厘米的航摄影像,通过33个地面检查点的验证,表明SWDC-4A联合POS的集成传感器定向满足1:500测图要求。     

Spectral analysis for a semi‐active–passive net‐zero base‐shear design concept

Passive high force‐to‐volume (HF2V) dampers offer significant displacement reduction and energy dissipation, but cannot customise overall response. Semi‐active resettable devices offer adaptive, custom hysteresis loops that reduce displacement and base shear, but have limited dissipation. This paper presents a new, combined concept to maximise displacement reduction without increasing base shear – a net‐zero base‐shear concept. HF2V devices, up to a maximum of 10% structural weight, are combined with fixed stiffness resettable devices. Spectral analyses are run for the three SAC ground motion suites that iteratively size the HF2V device at each structural period to achieve maximum displacement reductions without increasing median base shear. HF2V velocity dependence and the need to scale HF2V capacity to spectral velocity are examined in terms of their impact on the results of these analyses. The net‐zero approach reduces base shear by up to 50% and displacements by 30–70% over all ground motions, exceeding reductions obtained by either device separately by 30–50% (relative). The net‐zero condition is not reached within the device limits defined, except at relatively long periods (>3.5 s) because of a virtuous circle of reduced displacement from the resettable and HF2V devices outweighing the increased base shear from the HF2V devices alone. These results are independent of HF2V device scaling, design and velocity dependence. The overall net‐zero concept offers a significant advantage in a combination that cannot be achieved by passive or semi‐active solutions alone. Copyright © 2011 John Wiley & Sons, Ltd.     

Sediment PAH: Contrasting levels in the Caspian Sea and Anzali Wetland

A comparative study of 23 PAH congeners in sediment of the Caspian Sea coast and Anzali Wetland was conducted in 2010. Surface sediment was analyzed using chromatography and mass spectrometry. Total PAH concentrations ranged between 212 and 9009 ng g⁻¹ dw. Spatial distribution maps revealed that PAH levels were higher in the coastal areas of the Caspian Sea where oil related activities have been common since 1800’s. Diagnostic ratios analysis indicated that PAHs largely originated from petrogenic processes. PAH toxicity level was assessed using sediment quality guidelines and toxic equivalent concentrations to determine toxic effects on marine organism. Based on these investigations, in our study areas, the probability of toxicity for benthic organisms is “low to medium”. The toxic equivalent concentrations of carcinogenic PAHs varied between 11 and 231 ng TEQ/g; higher total toxic equivalent concentrations values were found in the coastal areas of the Caspian Sea.     

Distribution,sources and ecological risk assessment of PAHs in surface sediments from Guan River Estuary,China

The contamination of surface sediments in Guan River Estuary, China, by polycyclic aromatic hydrocarbons (PAHs) has been fully investigated. Total concentrations of 21 PAHs ranged from 90 to 218 ng/g with an average of 132.7 ng/g, which is relatively low in comparison with other estuaries around the world. PAH concentrations appeared to be positively correlated with clay content and negatively correlated with sediment grain size. Source identification implied that the PAHs originated mainly from pyrolytic sources. However, source patterns may be continuously changed to a petrogenic origin due to the heavy ship traffic and continuous discharge of oily sewage in this area. The PAH levels were also compared with international Sediments Quality Guidelines and Sediments Quality Criteria, and the results indicated low negative effects for most individual PAHs. However, toxic effects related to FLO would occur occasionally in most locations in the estuary.     

南海夏季风季节内振荡的年际变化研究

利用NCEP/NCAR风场、 垂直速度再分析资料和NOAA的逐日向外长波辐射 (简称OLR) 资料, 运用Butterworth带通滤波方法, 对南海夏季风季节内振荡 (简称ISO) 的特征和年际变化情况进行了初步研究。气候平均状况下ISO在亚洲季风区存在5个活动中心, 其中包括南海南部地区 (5°N～15°N, 110°E～120°E)。气候平均状况下南海ISO在5～9月有三次比较明显的活跃过程。以850 hPa风在西南方向上的投影 (Vsw) 经30～60天带通滤波后的绝对值在南海区域的夏季平均定义了当年南海夏季风ISO活动指数, 以此确定了南海夏季风ISO活跃年和不活跃年, 并由此提取了两者在逐日序列和水平分布场特征上的差异。通过对南海夏季风ISO活跃年与不活跃年ISO信号差别的研究发现: 在南海夏季风ISO活动较活跃年份的一个完整周期的8个位相合成中, 低频对流中心从热带印度洋西部东传到达南海后, 受Walker环流和西太平洋副热带高压底层东风气流阻挡等其它动力和热力因素的影响转向东北传。春季南海地区较强的Walker环流和对流活动有可能作为南海夏季风ISO活跃的前期信号。     

The GeoPT Proficiency Testing Programme as a Scheme for the Certification of Geological Reference Materials

ISO Guide 35:2017 provides, for the first time, an alternative way of characterising certified reference materials using proficiency testing. In this paper, the properties of assigned values derived from the well‐established GeoPT proficiency testing scheme are examined. This scheme, designed for laboratories that undertake the routine analysis of silicate rocks and related materials, routinely has over 100 participants contributing results. Following a detailed assessment of the metrological properties of GeoPT assigned values in relation to Guide 35 recommendations, it is demonstrated that these values may be regarded as certified values, provided a number of criteria are met. These criteria include the following: a demonstration of sufficient homogeneity of the candidate CRM; circulation, when judged to be appropriate, of an established matrix‐matched CRM for co‐analysis in that round; the robust statistical analysis of data sets using GeoPT established criteria; a decision whether assigning a value is justified (including a requirement of a minimum of fifteen valid results); and an expert group to manage the certification and the maintenance of appropriate records. In summary, the GeoPT proficiency testing scheme, subject to the arrangements summarised above, is considered to be competent for the certification of geological reference materials.     

THE INTRASEASONAL OSCILLATION AND ITS INTERANNUAL VARIABILITY—A SIMULATION STUDY

The atmospheric intraseasonal oscillation(ISO)and its interannual variability are simulatedby the atmospheric general circulation model,which was developed at the Institute of AtmosphericPhysics.Two numerical experiments were performed,corresponding to the AMIP-Ⅰ and AMIP-Ⅱsimulations,respectively.The model reasonably reproduces the major aspects of the intraseasonaloscillation,including the propagating property and the seasonal differences in the tropics,thewavenumber structure of ISO in the globe,and the global coincidence in the interannual variationof ISO.Comparison of the results between the two experiments suggests that improvement of theboundary forcing or considering the air-sea interaction may help to improve the simulation on theISO and its interannual variability.     

ISO9002质量体系认证在测绘数字化生产管理中的作用

国际标准ISO9002是由ISO(国际标准化组织)质量标准和质量保证技术委员会制定的。建立质量体系的过程是质量体系的策划与准备、质量体系文件的编制、质量体系程序文件的运行、以及改进和完善质量体系并保证其有效运行的全过程。     

基于数据库的海量GDF导航电子地图数据处理方法

改进的GDF4.0拓展了GDF3.0标准的灵活性,允许非完全拓扑的表达方式存在,大大降低了GDF的处理难度,具有更强的实用性。目前全球最大的导航电子地图供应商Navteq和Tele Atlas所发布的GDF数据还是基于3.0的标准,本文借助于关系数据库作为中间平台,采用脚本和模板技术,结合一定的控制台程序开发,有效地将海量GDF3.0数据转化更实用的GDF4.0数据,并已应用在实际的工作中。