美国公众对全球变暖的认知和对气候政策的支持

利用民意调查数据,以相关研究作为补充,分析美国公众对全球变暖的认知、减缓行为和气候政策的支持等。分析表明,大部分美国民众认为全球在变暖,但很多人不了解全球变暖与温室气体的关系,把全球变暖混为大气污染和臭氧层耗竭等;不到一半的公众认为全球变暖对个人和美国是现实威胁,更多的公众认为全球变暖对后代和发展中国家是严重威胁;大部分公众认为减缓全球变暖需要改变现有的生活方式和行为,他们愿意选择较容易从事和成本低的行为减少碳排放,但不愿意从根本上改变生活方式,改变自驾车、乘飞机长途旅游这些碳排放量更大的行为;公众普遍支持政府采取措施限制温室气体排放,但不希望所采取的措施对就业和经济带来不利影响;支持通过技术进步和减免税收等措施提高能效,减少碳排放,但大部分反对为节能而提高能源税收。     

基于岩土材料软化特性的滑坡多级滑动面分析方法研究

在实际工程中,滑坡经常呈现出多级破坏的特征,而一般计算和设计中仅关注最危险的滑动面及对应的最小安全系数,这往往遗留安全隐患。在考虑岩土材料软化特性的基础上,借助FLAC3D和Matlab软件平台构建了无需人工干预便可有效模拟与评价滑坡多级破坏的理论框架。以旬阳县党家坝廉租房小区滑坡为例,通过对塑性剪应变、塑性拉应变、剪切应变增量等特征变量的渐进发展规律分析发现：滑坡多级滑动面的形成,其时间和空间顺序并不一定相对应。各级滑动面在时间上按产生的先后顺序依次为第1级主滑面、第2级主滑面、次级滑面;而在空间上按照从前到后的顺序依次为第1级主滑面、次级滑面、第2级主滑面。从计算所得的滑坡最终破坏形态中发现,坡体内部出现的滑动面条数与现场采集的拉裂缝数基本保持一致;第1级主滑面的入口位置与滑坡前缘拉裂缝位置基本吻合;而第2级主滑面及次级滑面的位置与现场勘查到的拉裂缝位置出现偏差。从材料参数的渐进发展规律中发现,滑面上强度参数的分布及大小均随着滑面的产生、发展而逐渐变化,其变化区间为峰值强度到残余强度,这是此方法可以有效模拟多级滑动面形成过程与各级滑动面之间相互影响的核心所在。借助矢量和法成功地实现了基于滑面上强度参数渐进发展规律的安全系数演化过程的确定。通过对安全系数演化过程的分析发现,在滑坡多级滑动面的形成过程中安全系数大小顺序呈现出3种不同的状态,这很好地揭示了各级滑动面在形成过程中的主、被动关系。     

Application of food waste based diets in polyculture of low trophic level fish: Effects on fish growth,water quality and plankton density

Food waste was collected from local hotels and fish feed pellets were produced for a 6 months long field feeding trial. Three types of fish feed pellets (control diet: Jinfeng® 613 formulated feed, contains mainly fish meal, plant product and fish oil; Diet A: food waste based diet without meat and 53% cereal; Diet B: food waste based diet with 25% meat and 28% cereal) were used in polyculture fish ponds to investigate the growth of fish (grass carp, bighead and mud carp), changes in water quality and plankton density. No significant differences in the levels of nitrogen and phosphorous compounds of water body were observed between 3 fish ponds after the half-year feeding trial, while pond receiving Diet A had the highest density of plankton. The food waste combination of Diet B seems to be a better formulation in terms of the overall performance on fish growth.     

地震报道中死亡人数估计方法的适用性分析

基于国内外8次地震报道死亡人数的统计数据,采用修正指数曲线、龚铂茨曲线、罗吉斯蒂曲线分别进行震后死亡人数估计。对比分析表明三种模型均适合地震报道死亡人数估计;用剔除前两个拟合值后的拟合精度作为预测误差在实际应用中具有实际参考价值。对中国3次强震报道死亡人数拟合结果分析显示,联合三种模型,采用相对误差较小的模型为主、另两种模型为参考的方法进行最终死亡人数预测,可为抗震救灾指挥部署提供参考依据。     

Magnetostratigraphy and fold tests from Račiška pečina and Pečina v Borštu caves (Classical Karst,Slovenia)

Clastic and chemogenic cave sediments were sampled and analyzed from Račiška pečina and Pečina v Borštu caves of southwestern Slovenia. Samples were subjected to both thermal and alternating field demagnetization; specimens belonging to the same sample of the same layer produce identical results. Unblocking temperatures of 540 to 560°C on average suggests magnetite as the principal carrier of magnetization. These directions also pass a reversals test indicating the demagnetization results are free of secondary overprints and have adequately averaged out paleosecular variation. Normally magnetized clays containing fauna belonging to the MN17 mammal biozone at a depth of ∼ 4 m in Račiška pecina cave indicate these clays were deposited at the beginning of the Olduvai subchron (1.95 Ma). Correlation with the Geomagnetic Polarity Time Scale (GPTS) indicates the base of the speleothems in Račiška pečina terminate in the upper part of subchron C2An.3n with numerous breaks in deposition, lasting up to 250 ka and more. Therefore rates of speleothem growth cannot be calculated. Fold tests on dome-like stalagmites of differing sizes and ages (Pleistocene, Pliocene) from the two caves indicate the domelike structures are primary.     

物联网技术的研究与应用

近年来,物联网的研究与发展引起了人们的广泛关注,国内外政府和企业都采取行动参与物联网的构建,这可能对未来全球的发展产生深远影响.物联网是把所有物品通过射频识别等信息传感设备与互联网连接起来的技术,以实现智能化识别和管理,是继计算机、互联网与移动通信网之后的又一次信息产业浪潮.本文介绍了物联网技术的概念、基本特征及发展现状;探讨了物联网研究中的关键技术,包括传感网技术、射频识别技术、产品电子码、地理信息系统以及智能技术;从物流管理、城市管理、智能交通等厅而分析了物联网技术在社会中的应用.最后展望了物联网技术的前景,一定程度上促进了物联网的建设与发展.     

A modified normalized input-output minimization （Mod-NIOM） method for seismic wave propagation modeling

A new method for wave propagation modeling is introduced in this paper. By using the constraint optimization (Lagrange multiplier) method, the sum of weighted squared Fourier amplitudes is minimized when subjected to a constraint. The sum of the maximum amplitudes obtained from all output models is normalized to unity and is taken as a constraint. In this method, all the actual time histories are considered as outputs and dealt with equally. Independently of the combinations of time histories (or the first ...     

酒西坳陷青西凹陷富油的地质-地球化学因素分析

青西凹陷下白垩统暗色半深湖相-深湖相的泥岩、白云质泥岩和泥质白云岩为研究区主力烃源岩,其沉积时为整体上处于封闭-半封闭强还原-还原环境的断陷湖泊,有利于有机质的保存和转化,且烃源岩厚度占地层比例均大于 5 0%以上,加之有机质类型以混合型为主、有机碳含量普遍大于 1%,为油田形成提供了重要的物质基础。喜山期构造运动形成了许多挤压逆断层、剪切性断层和构造缝,造成地层和构造叠覆,为有机质成熟、运移和聚集提供了动力和空间,从而为该区油藏的形成提供了有利条件.