The responses of the estuarine bivalve mollusc Scrobicularia to the first hydrolytic product of the insecticide Sevin®

The effects of 1-naphthol, the first hydrolytic product of the insecticide Sevin^®, have been studied on the estuarine bivalve Scrobicularia. Median lethal times for 5 and 10 mg l^?1 1-naphthol were 15 and 9 days respectively. Final concentrations of 1, 5, 10 and 20 mg l^?1 of 1-naphthol resulted in the immediate contraction of the isolated siphon. The contractions were more pronounced at higher concentrations. Application of the same range of concentrations of 1-naphthol to intact Scrobicularia resulted in valve closure and bradycardia. The similarity between the results of median lethal time experiments and the isolated siphonal and behavioural responses of Scrobicularia indicates the feasibility of the use of the isolated siphon preparations to make rapid assessments of environmental stress conditions.     

Features of Tight Sandstone Reservoir and Origin of Tightness: An Example from Chang-7 Member, Triassic Yanchang Formation in Chenghao Area, Ordos Basin

<正>1 Introduction Permeability of Member-6,Member-7,and Member-8,Triassic Yangchang Formation in Ordos Basin is lower than 1?0~(-3)μm~2,so sandstone in those formations are typical tight reservoir(Zhao et al.,2012a,2012b;Yang et al.,2013).Because of the maximum flooding event of Late Triassic during deposition of Chang-7 Member,the lacustrine basin had a wide range of deposition area and     

基于SOA的地理信息数据整合技术研究

为了解决异构地理信息系统平台间不同格式的地理信息数据的共享与互操作问题,本文对地理信息数据整合技术进行了深入的研究,提出了基于面向服务架构的地理信息数据整合方法,使不同厂商、不同平台、不同数据结构的地理信息数据能够有机地整合并实现信息的共享和交互。我们通过对密云县政务地理空间数据库共享服务平台建设的实例应用研究,可以看到采用基于SOA的Web Service技术来整合异构的地理信息数据的方法取得了很好的效果。     

Volunteer and professional macroinvertebrate monitoring provide concordant assessments of stream health

Whilst volunteer monitoring has many benefits for both volunteers and professionals, volunteer data must be validated to understand the value and potential applications of information from volunteer monitoring programmes. Our study aimed to assess the concordance between volunteer and professional data, including state and trend assessments. We compared macroinvertebrate data collected by volunteers using a simplified identification protocol to data collected by professionals following standard national protocols for collection and identification. We found that volunteer and professional macroinvertebrate data expressed as summary indices of ecological health were significantly correlated. However, the coarser level of taxonomic identification in the volunteer dataset limited the use of taxon richness as a biodiversity measure. We also demonstrated that the ability of volunteer data to detect long-term trends in ecological health is comparable to professional data. Overall, stream monitoring data collected by volunteers provided an assessment of stream health that was concordant with assessments based on data collected by professionals, indicating that volunteer data could be used to support professional monitoring programmes.     

基于Flex技术的公众出行服务系统的研究与实现

随着交通事业的迅猛发展以及人民群众生活水平的不断提高,公众的出行需求发生了巨大的变化,除传统的出行方式外,越来越多的人选择公路自驾车出行,这使得出行服务的内容也随之发生了变化。本文提出了基于Web Service和Flex客户端开发技术建设出行服务系统的思路,设计并实现了青海省便民出行服务系统,系统的建设提高了居民出行的安全性和便利性。     

嵌埋星团质量分层的数值模拟研究

目前,对大质量恒星形成的初始条件不很清楚,特别是大质量恒星是否形成于星团中心仍有争议.有人从时标上考虑,认为嵌埋星团的质量分层现象意味着大质量恒星只能在星团中心诞生.利用Monte Carlo方法对嵌埋星团的动力学演化进行了数值模拟,并与观测进行了比较.假设初始时刻大质量恒星随机分布,一定比例的嵌埋星团因为大质量恒星的随机运动,在演化的某个时刻会呈现暂态质量分层,其中一部分相当明显.这说明,大质量恒星在中心形成并非嵌埋星团质量分层现象的唯一解释.此外,气体的动力学摩擦能有效地减小动力学质量分层的时标,从而增大暂态质量分层的概率.     

Protracted diagenetic alteration of REE contents in fossil bioapatites: Direct evidence from Lu-Hf isotope systematics

Fossil bones and teeth are potentially important repository for geochemical proxy data and a target for radiometric dating. The concentration of many trace elements in bones and teeth increases by orders of magnitude after death and it is this diagenetic incorporation that forms the basis for several areas of geochemical study. The use of bones and teeth in this context relies on two assumptions: first, that target metal ions are incorporated rapidly after death, reflecting a known environmental signal, and second, that after early incorporation, the bone or tooth remains as an essentially closed system, resistant to later diagenetic change. A wide literature has developed exploring these assumptions, but relatively little direct evidence has been used to assess the long-term diagenetic stability of trace elements within bones and teeth. In this study, we use the Lu-Hf isotope system to show that bones and teeth of Cretaceous and Triassic age from both terrestrial and marine settings experience continued, long-term diagenetic change, most likely through gradual addition of trace elements. Modelling suggests that diagenetic addition after initial recrystallisation may account for >50% of the total REE content in the sampled bones, the extent depending on initial uptake conditions. Tooth enamel and enameloid may be more resistant to late diagenetic changes, but dentine is probably altered to the same extent as bone. These results have significant implications for the use of bones and teeth as hosts of chronological, palaeoceanographic, palaeoenvironmental and taphonomic information, particularly in Mesozoic and Palaeozoic contexts.     

准噶尔盆地克-百地区中二叠统坡折带与岩性地层圈闭的关系

克拉玛依至百口泉地区中二叠世的坡折带十分发育,表现为顺物源方向具多级坡折的特点,按其发育的位置可分为盆缘坡折带和盆内坡折带,受边界逆冲断裂持续活动、盆内次级断裂活动的影响,坡折带的演化表现为多期、幕次性、差异活动以及继承性等特征。坡折带对地层超覆叠置、层序构成样式及沉积相的展布具有重要的控制作用。建立了受多级坡折带控制的圈闭发育模式,在坡折带附近,可形成岩性圈闭、地层超覆圈闭、不整合面遮挡圈闭等类型。