Q P and Q S in Beijing and Jianchuan, Yunnan areas

Events from the December 1982 Huairou County, Beijing, and the July 1982 Jianchuan, Yunnan earthquake series were recorded at one station in Beijing City and at four stations in Eryuan area, Yunnan, respectively. Dividing the spectra (for P and S waves) from the smaller events in the series by spectra (for corresponding P and S waves) from the larger events in cach region, we have determined the high frequency source spectral decay rate to be ω⁻¹in both cases. Through trial and error method, we are able to determine the appropriate constantQ _P andQ _S that corrects the individual spectra to the proper high frequency decay rate. It is found that aQ _P of 800 and aQ _S of 550 can adequately compensate for the attenuation of the waves in Beijing area. For Jianchuan, Yunnan area the corresponding values are 900 and 400. This subject is supported by Chinese Joint Seismological Science Foundation.     

高分辨率勘探与地震仪器

本文较系统地讨论了地震勘探中振幅动态范围与仪器动态范围的基本概念,指出仪器动态范围是开展高分辨率勘探的极为重要的一个基本条件,它要根据浅层强信号与深层高频弱信号的振幅动态范围来设计.如果仪器动态范围小,就录制不上高频信号,必然降低分辨率.文中也简介了在高分辨率地震勘探中如何选取最佳仪器因素的一些做法.     

谱特征参数在评价激电异常源性质中的应用

从研究激电场频谱特征及充、放电时间特征出发,根据实验观测结果,总结了硫化物矿化体(黄铜矿)及含石墨白云质大理岩等岩性的频谱特征及充放电时间特征,探索到新的定性评价激电异常源参数——频率谱及时间谱、视衰减速度。实践证明,利用频率谱定性评价硫化物矿化体(黄铜矿)与含石墨白云质大理岩激电异常源取得较佳效果。     

The role of saline solution properties on porous limestone salt weathering by magnesium and sodium sulfates

Saline solution properties, viscosity in particular, are shown to be critical in salt weathering associated with sodium and magnesium sulfate crystallization in porous limestone. The crystallization of sodium and magnesium sulfate within a porous limestone has been studied at a macro- and microscale using different techniques, including mercury intrusion porosimetry, environmental scanning microscopy and X-ray computed tomography. Such analysis enabled the visualization of the crystallization process in situ, and at high magnification, yielding critical information as to where and how salts crystallize. Sodium sulfate decahydrate (mirabilite) tends to crystallize in large pores as euhedral micron-sized crystals formed at low supersaturation near to the surface of the stone. In contrast, magnesium sulfate heptahydrate (epsomite) tends to precipitate as anhedral wax-like aggregates formed at high supersaturation and distributed homogeneously throughout the stone pore system filling large and small pores. While the former crystallization behavior resulted in scale formation, the latter led to crack development throughout the bulk stone. Ultimately, the contrasting weathering behavior of the two sulfates is explained by considering differences in flow dynamics of solutions within porous materials that are mainly connected with the higher viscosity of magnesium sulfate saturated solution (7.27 cP) when compared with sodium sulfate saturated solution (1.83 cP). On the basis of such results, new ways to tackle salt weathering, particularly in the field of cultural heritage conservation, are discussed.     

Evaluating and re-demarcating the Hospital Service Areas in Florida

The Hospital Service Areas (HSAs) better portray underlying local patterns of hospitalization than administrative units, and offer a promising analysis unit for studies of healthcare market. The widely used Dartmouth HSAs in the U.S. were solely based on Medicare inpatient records about two decades ago. Our analysis used all discharge records from Florida hospitals in the 2011 Healthcare Cost and Utilization Project (HCUP) dataset from the Agency for Healthcare Research and Quality (AHRQ). We first matched Medicare-paid hospitalization records in 2011 to the Dartmouth HSAs for demonstrating the temporal variation of the Medicare-derived HSAs. We then compared the HSA configurations based on the overall hospitalization records to Medicare-derived HSAs in the same year (2011) for assessing the representativeness of the Medicare-derived HSAs. Results indicate the boundaries of the Medicare-derived HSAs have significantly shifted over two decades and are inadequate in representing the overall population. The Huff model was used to generate more solid HSAs than traditional approaches.     

Analytical solutions for sequentially coupled one-dimensional reactive transport problems – Part II: Special cases,implementation and testing

This is Part-II of a two-part article that presents analytical solutions to multi-species reactive transport equations coupled through sorption and sequential first-order reactions. In Part-I, we provide the mathematical derivations and in this article we discuss the computational techniques for implementing these solutions. We adopt these techniques to develop a general computer code and use it to verify the solutions. We also simplify the general solutions for various special-case transport scenarios involving zero initial condition, identical retardation factors and zero advection. In addition to this, we derive specialized solution expressions for zero dispersion and steady-state conditions. Whereever possible, we compare these special-case solutions against previously published analytical solutions to establish the validity of the new solution. Finally, we test the new solution against other published analytical and semi-analytical solutions using a set of example problems.     

A comparative analysis of accessibility measures by the two-step floating catchment area (2SFCA) method

The recent decade has witnessed a new wave of development in the place-based accessibility theory, revolving around the two-step floating catchment area (2SFCA) method. The 2SFCA method, initially serving to evaluate the spatial inequity of health care services, has been further applied to other urban planning and facility access issues. Among these applications, different distance decay functions have been incorporated in the thread of model development, but their applicability and limitations have not been thoroughly examined. To this end, the paper has employed a place-based accessibility framework to compare the performance of twenty-four 2SFCA models in a comprehensive manner. Two important conclusions are drawn from this analysis: on a small analysis scale (e.g., community level), the catchment size is the most critical model component; on a large analysis scale (e.g., statewide), the distance decay function is of elevated importance. In sum, this comparative analysis provides the theoretical support necessary to the choice of the catchment size and the distance decay function in the 2SFCA method. Justification of model parameters through empirical evidence (e.g., field surveys about local travel activities) and model validation through sensitivity analysis are needed in future 2SFCA applications for various urban planning, service delivery, and spatial equity scenarios.     

The influence of wind speed on infrared temperature in impervious surface areas based on in situ measurement data

Wind perturbations can cause a relatively rapid decay in infrared temperature, thus resulting in abnormal spatial patterns of infrared temperature in urban areas and the subsequent reduction in the reliability of infrared temperature measurements. To increase the reliability of such measurements, the effects of wind speed must be evaluated and removed. However, studies on the quantitative estimation of wind speed effects on infrared temperature are limited. In this study, in situ infrared temperature measurements and synchronous meteorological data were used to evaluate the influence of wind speed on in situ infrared temperature measurements of impervious surfaces. Five different impervious surfaces were selected in this study. The technical schemes are proposed for quantitative estimation of wind speed effects: (1) the residual-based method from the diurnal temperature cycle model was proposed to estimate the infrared temperature decay (ITD) due to wind fluctuations; (2) quantile regression method was introduced to define the relationship between wind speed fluctuations and the ITD; and (3) An improved probabilistic prediction interval as well as a ratio method were developed to estimate the magnitude and duration of the ITD. The results indicated that relative extreme wind speed (EWS) was significantly correlated with the range of ITD over 5-min intervals; the hourly decay rate and impact duration of ITD varied with changes in relative wind speed and impervious surface type; and the impact duration of ITD increased with an increase in the relative EWS and lasted more than 1.3 h for the studied impervious surfaces. The above findlings provide us a guidance for in situ measurement of infrared temperature and could be utilized for correcting thermal infrared images.     

黄渤海底栖纤毛虫分子多样性和生物地理学研究

对中国渤海、北黄海和南黄海三个海域底栖纤毛虫的分子多样性与生物地理学进行了研究。从底栖真核微生物18S rDNA的焦磷酸测序数据中提取出隶属于纤毛门的序列,并在此基础上分析了纤毛虫群落的阿尔法多样性和贝塔多样性。结果表明,纤毛虫操作分类单元的丰富度在渤海比北黄海和南黄海都高,但夏冬两季无显著差异。在所有检测的环境因子中,水体深度与阿尔法多样性的相关性最强。就纤毛虫群落组成上看,总体上旋唇纲的序列及操作分类单元丰富度均占优势地位（占比分别为77.0%和66.5%）;旋唇纲主要由环毛亚纲以及未能进一步分类的类群组成。底栖纤毛虫群落结构在三个海域之间显著不同,但夏冬两季无显著差异。从各主要类群的相对比例来看,唯有侧口纲的序列比例在三个区域间呈现显著的不同。偏门特尔分析表明,相对于地理距离和环境因子而言,水体深度在调控底栖纤毛虫群落结构中扮演者更为重要的角色。本研究同时也发现,超过60%的操作分类单元未能被进一步分类到纲或目级水平,约45%的操作分类单元与GenBank数据库中已描述种类的序列相似度低于或等于97%,表明在近海沉积物中可能存在大量待发现的纤毛虫类群或物种。本研究发现底栖纤毛虫阿尔法多样性从北黄海到南黄海降低的趋势,这一点与之前基于形态学方法的调查结果相似。然而,测序数据显示旋唇纲是最主要类群,而形态学调查表明前口纲和核残迹纲是主要类群。本文也探讨了可能造成分子与形态学研究结果差异的一些潜在原因。     

库尔勒断层氡气观测实验研究

根据库尔勒断层氡气在观测中遇到的一些问题,做了一系列观测实验,结果表明,氡探头的标定值的大小反映了氡探头的灵敏度,决定了测值的高低,因为地下１ｍ内的浅层气体与大气连通,所以观测值受气象因素影响较大,同时认为,在土壤相对潮湿的寒冷地区,冬季较厚的冻土层形成了良好的封闭系统,使地下氡气浓度相对增高,测值呈“冬高夏低”的变化形态,实验中还根据氡的衰变规律验证了所观测的大幅变化的测值确为氡气含量。