Implementation of New OPAL Tables in Eggleton's Stellar Evolution Code

Based on previous works of OPAL, we construct a series of opacity tables for various metallicities Z=0, 0.000 01, 0.000 03, 0.000 1, 0.000 3, 0.001, 0.004, 0.01, 0.02, 0.03, 0.04, 0.05, 0.06, 0.08 and 0.1. These tables can be easily used in Eggleton's stellar evolution code in place of the old tables without changing the code. The OPAL tables are used for log10(T/K) > 3.95 and Alexander's for log10(T/K) < 3.95. At log10(T/K) = 3.95, the two groups' data fit well for all hydrogen mass fractions. Conductive opacities are included by reciprocal addition according to the formulae of Yakovlev and Urpin. A comparison of 1 and 5 M models constructed with the older OPAL tables of Iglesias and Rogers shows that the new opacities have most effect in the late stages of evolution, the extension of the blue loop during helium burning for intermediate-mass and massive stars.     

基于GeoSOS的城市扩展模拟——以旅顺口区为例

运用MCE-CA和Logistic-CA两种基本的元胞自动机模型作为理论模型,考虑边界到市中心、镇中心、铁路和主要公路等作为区位因素的空间距离约束条件,以及地形和禁止建设区作为区位因素的全局限制约束条件,在地理模拟优化系统(Geographical Simulation and Optimization System,GeoSOS)的支持下,对1990~2000年和2000~2010年辽宁省大连市旅顺口区的城市空间扩展进行了模拟,并取得较好效果。结果表明,MCE-CA模型的Kappa系数分别为0.71和0.64,Logistic-CA模型分别为0.54和0.55,两者均达到较好的模拟精度;MCECA模型适用于主观变量较多的CA模型,Logistic-CA模型更适合于客观因素较多的CA模型;利用合理的CA模型模拟旅顺口区城市未来土地利用变化,可为今后的土地规划以及制定有效的土地管理措施和方针政策提供依据。     

全国农村民居抗震性能综述

地震灾害对农村的影响巨大,如何提高农村民居工程的抗震性能变得至关重要。通过文献调查、对比的方法,重点阐述全国农村民居的抗震性能现状,在对比基础上提出各地农村民居抗震性能的优劣情况,并探寻提高农村民居抗震性能的方式方法。     

Association between Tropical Convection and Boreal Wintertime Extratropical Circulation in 1982／83 and 1988／89

Boreal wintertime extratropical circulation is studied in relation to the tropical convection during the 1982/83 El Nino and 1988/89 La Nina. The anomaly structure of 1982/83 and 1988/89 over the extratropics reveals remarkably different features as the longitudinal tropical forcing region changes. The Rossby wave source (Positive) shows the largest maximum over East Asia in both years due to the persistent heating from the western Pacific warm pool area. However, the sink term shows contrasting features over the subtropics and extratropics between the two years. In the El Nino year, enhanced tropical convection over the eastern Pacific produces the Rossby wave sink at 10?N and shifted eastward over the North Pacific, while in the La Nina year, the sink area is shifted westward over the North Pacific. The contrasting features between the two events in mean-eddy interaction appears especially over the downstream area of the East Asian Jet. The extension (retraction) of the meanflow eastward (westward) to     

High U/Th partitioning by clinopyroxene from alkali silicate and carbonatite metasomatism: an origin for Th/U disequilibrium in mantle melts?

Clinopyroxene/melt pairs in strongly potassic silicate and carbonatite melts exhibit unusually high U/Th partitioning ratios of ˜ 3 and ˜ 2, respectively. These values are much higher than those found for aluminous clinopyroxenes in peridotite, and have the potential to cause significant (²³⁰Th)/(²³⁸U) isotope enrichment in volcanics. The potassic silicate (lamproite) and carbonatite melts correspond closely to the main agents of mantle metasomatism, indicating that clinopyroxene in metasomatized regions of the mantle may greatly affect U/Th disequilibria. Recycling of alkali pyroxenite veins in the oceanic lithosphere formed by solidification of melt in the extremities of the MORB melting region presents an alternative to eclogite recycling in MORB and OIB genesis.     

沙丘背风侧气流的变化特征及其意义

对腾格里沙漠东南缘格沙丘主、副梁和新月形形沙丘表面气流的野外发现分离流、附着未偏向流和附着偏向流等３种背风坡次生气流。前者以弱的反向流为特征，多发生在横向气流条件下，坡度较陡的背风坡上；后二者具有相对高的风速，多发生在坡度缓和的背风坡上，其方向在横向气流条件下保持原来的方向，在斜向气流作用下发生偏转，且其强度为原始风入射角的余统函数，根据３种次生气流强度，方向等特征，阐述了其相应的风成沉积过程和可能产生的层理类型，并对利用风成交错层理恢复古气流环境中的有关问题作了初步探讨。     

"美丽冰冻圈"融入区域发展的途径与模式

在探讨“美丽冰冻圈”内涵的基础上,从自然属性与社会经济两个层面、致利与致害两条线,分析了“美丽冰冻圈”与区域可持续发展的关系,“美丽冰冻圈”、区域社会经济发展、人类福祉构成冰冻圈—人类社会经济复合命运共同体。基于中国冰冻圈要素及其变化影响的区域差异性,选取祁连山—河西地区、青藏高原三江源地区、横断山大香格里拉地区,分别代表冰冻圈水资源影响区、冰冻圈灾害影响区、冰冻圈旅游经济区,围绕冰冻圈水资源服务与绿洲经济、雪灾害风险与畜牧业经济、冰雪旅游与区域经济等核心问题,从冰冻圈资源服务与灾害风险视角,详细阐述了冰冻圈融入不同区域发展的途径与模式。在干旱半干旱内陆地区,冰冻圈主要以水源涵养、水量供给与径流调节服务,融入绿洲社会经济发展,是一种冰冻圈水资源支撑型区域发展模式;在青藏高原高寒区,冰冻圈生态环境决定了畜牧业经济的脆弱性,冰冻圈灾害负向影响畜牧业经济,是一种冰冻圈生态支撑+灾害影响型区域发展模式;在冰冻圈旅游经济区,直接依托冰雪资源发展冰雪旅游业,是一种基于冰冻圈资源的旅游经济驱动型区域发展模式。     

Tolerance of five species of tropical marine mussels to continuous chlorination

The paper examines the relative lethal and sublethal response of five important tropical marine mussels (Perna viridis, Perna perna, Brachidontes striatulus, Brachidontes variabilis and Modiolus philippinarum) to different chlorine concentrations varying from 0.25 to 15 mg l(-1). The mussels were observed to co-exist in the cooling water circuits of a coastal power station that adopted intermittent chlorination as a fouling control technique. The five mussel species showed, in response to chlorination, 100% mortality at significantly different exposure times, indicating significant species-specific variability in chlorine tolerance. For example, at 1 mg l(-1) residual chlorine, B. variabilis and P. viridis took 288 and 816 h, respectively, to achieve 100% mortality. The time taken for 100% mortality decreased with increasing chlorine residual concentration. The effect of mussel size (= mussel age) of P. viridis, P. perna, B. striatulus and M. philippinarum on mortality was significant between 1 and 5 mg l(-1) residual chlorine, with larger mussels showing greater resistance than smaller ones. All mussel species showed progressive reduction in physiological activities when chlorine residuals were increased from 0 to 1 mg l(-1). However, species-specific differences in the relative rate of physiological activities were observed. Accordingly, relative reduction in physiological activities in response to chlorination was the lowest in P. viridis and the highest in B. variabilis. The data clearly indicate significant differences in the lethal and sublethal responses of the five mussel species to chlorination. The results, therefore, suggest that for effective fouling control, chlorine treatment against mussels has to be employed judiciously, depending on the mussel species involved.     

Chlorination by-products in chlorinated cooling water of some European coastal power stations

Chlorination by-products (CBPs) are formed as a result of the cnlorination of power station cooling water for anti-fouling purposes. Their production was studied at 10 coastal power stations in the UK, France and The Netherlands. Three categories of CBPs were determined: trihalomethanes; haloacetonitriles; and halophenols. Bromoform was the CBP most abundantly present in the effluents of all 10 power stations. At a mean chlorine dosage of 0.5–1.5 mg/litre (as Cl₂) the mean bromoform concentration was 16.32 ± 2.10 μg/litre. The CBP found in second highest concentrations was dibromoacetonitrile (DBAN) with mean concentrations of 1.48 ± 0.56 μg/litre. Other CBPs detected were dibromochloromethane, bromodichloromethane and 2,4,6-trichlorophenol; concentrations of these three compounds were very low (< 1 μg/litre). At those sites at which bromoform was measured in the dispersing effluent plume it was found to behave as a conservative parameter (Significant direct correlation with plume ΔT).