微动技术在堤坝渗漏探测中的应用

堤坝是重要的水利工程,其安全性至关重要。坝体渗漏是常见的安全隐患之一,对坝体渗漏位置、程度以及坝体结构变化的探测一直是重要的物探课题。微动勘探作为一种新兴的物探手段,应用范围正逐步拓展,通过某水库大坝渗漏检测实例,展示频率-波数法微动线性点阵剖面测量进行大坝渗漏检测的效果,该技术通过提取频散曲线及视S波速度成像,刻画地层速度结构并圈定异常,可实现对大坝渗漏快速精确的无损探测,具有一定的方法优势和广泛的应用前景。     

Would different methodologies for assessing carbon leakage exposure lead to different risk levels? A case study of the Brazilian industry

Energy-intensive industries play an important role in low-carbon development, being particularly exposed to climate policies. Concern over possible carbon leakage in this sector poses a major challenge for designing effective carbon pricing instruments (CPI). Different methodologies for assessing carbon leakage exposure are currently used by different jurisdictions, each of them based on different approaches and indicators. This paper aims to analyse the extent to which the use of different methodologies leads to different results in terms of exposure to the risk of carbon leakage, using the Brazilian industry sector as a case study. Results indicate that carbon leakage exposure is an expected outcome of eventual CPI implementation in Brazilian industry. However, results vary according to the chosen methodology, so the definition of the criteria is paramount for assessing sectoral exposure to the risk of carbon leakage.

Key policy insights

• Despite increasing discussion about the implementation of carbon pricing on the Brazilian industrial sector, the evaluation of carbon leakage risks is still neglected.

• Assessments of the risk of carbon leakage are directly related to the indicators and criteria used by each methodology. Thus, a given subsector may present different levels of exposure to carbon leakage depending on the methodological choice.

• More than a purely technical discussion, the methodological definition of carbon leakage risk is a political discussion – it can be well-conducted, leading to the success of a CPI, or even sabotaged, by implicitly subsidizing energy-intensive industries.

     

数字化水位仪漏电干扰因素的分析与排除

主要针对数字化水位仪在运行过程中产生的漏电干扰进行了分析,并结合实际情况提出了具体有效的解决方案.     

地下RC结构物地震响应特征土工离心试验的模拟

地下结构物抗震稳定性的研究具有重要实际意义。基于动态土工离心试验,应用有效应力法分析了不同水平地震作用下土层和地下RC结构物的最大水平位移、不同埋深的土层加速度和超孔隙水压力变化规律,以及结构物的破坏发展特征,并进一步与试验结果进行了相互验证和对比,取得了较好效果,为重要地下结构物的抗震设计提供了依据和参考。     

Dynamic metabolite alterations of Portunus trituberculatus during larval development

A mass mortality often occurs from molting to the megalopa stage during the larval development of the swimming crab Portunus trituberculatus. Larvae with insuffcient nutrient accumulation during the zoeal stages are probably unable to develop into juvenile swimming crabs. However, the nutritional information such as the primary metabolites is scarce for P. trituberculatus larvae. The aim of this work is to obtain an insight into the metabolite traits of P. trituberculatus at early developmental stages. 1 H nuclear magnetic resonance spectroscopy coupled with multivariate data analysis was used to determine how the metabolite pro?les shift during larval development in P. trituberculatus. Our results show that the trend of total metabolites exhibited a rise from zoea 1 to zoea 3, followed by a drop from zoea 4 to megalopa and recovery during the ?rst juvenile stage. A large-scale depletion of total metabolites in the zoea 4 and megalopa stages suggests a deep depression of metabolic activity, which may be linked to the mass mortality from molting to the megalopa stage. These ?ndings provided essential metabolic information about the larval development of P. trituberculatus and important clues for understanding the nutritional requirements of P. trituberculatus in early developmental stages.     

The symmetry energy and incompressibility constrained by the observations of glitching pulsars

We investigate the masses of glitching pulsars in order to constrain their equation of state(EOS). The observations of glitches(sudden jumps in rotational frequency) may provide information on the interior physics of neutron stars. With the assumption that glitches are triggered by superfluid neutrons, the masses of glitching neutron stars can be estimated using observations of maximum glitches.Together with the observations of thermal emission from glitching pulsars Vela and J1709–4429, the slope of symmetry energy and incompressibility of nuclear matter at saturation density can be constrained.The slope of symmetry energy L should be larger than 67 MeV while the lower limit of incompressibility for symmetric nuclear matter K_0 is 215 MeV. We also obtain a relationship between L and K_0:6.173 MeV + 0.283 K_0≤ L ≤ 7.729 MeV + 0.291 K_0. The restricted EOSs are consistent with the observations of 2-solar-mass neutron stars and gravitational waves from a binary neutron star inspiral.     

基于分布式检测与决策融合的海底油气管线检漏

利用多传感器的信息融合思想,提出分布式检测与决策融合方法进行长距离海底管线泄漏监测。试验水管和天然气／凝析油管线现场数据分析表明此算法不仅降低了误报警概率,且对流体在输送过程中动态变化具有稳健性。     

考虑土-结构相互作用和岩土参数不确定性的核电厂结构地震响应分析

针对核电厂结构,在考虑土-结构相互作用(SSI)的情况下进行随机地震反应分析,探讨地基岩土参数的不确定性对反应堆厂房楼层反应谱(FRS)的影响。运用ANSYS软件模块建立核电厂(NPP)结构有限元模型,通过设置边界弹簧单元和阻尼装置来考虑SSI效应;并且通过设置具有概率意义的弹簧刚度和阻尼系数,来模拟土特性参数的不确定性。随机响应分析与确定性分析的结果对比,揭示了岩性地基条件下SSI效应对核电厂FRS的影响以及地基岩土参数不确定性对FRS的影响程度。研究表明,在岩性地基条件下,亦不应忽略SSI效应;考虑SSI效应的随机分析模型同确定性模型相比,二者的分析结果较为接近,两方法都可用于NPP的FRS敏感性分析评估之中,并可进行相互比照。     

应用泉水均衡法分析四川省兴文县新坝水库岩溶渗漏问题

岩溶地区水库渗漏是碳酸盐岩地区兴建水利枢纽的主要工程地质问题之一,尤其是在可溶岩广布、岩溶发育强烈、地形复杂地区。拟建兴文县新坝水库地处岩溶地区,存在岩溶渗漏的可能性。通过对该水库库区地质概况、岩溶水系统进行分析研究,论证了水库潜在的三条岩溶渗漏途径均不会发生渗漏;并利用库区降雨量与泉流量进行水均衡计算,计算结果进一步论证了该水库不存在岩溶渗漏问题。     

考虑主余震作用下的核岛厂房结构易损性研究

一次强震常伴随着多次余震作用,且时间间隔较短.研究表明,主震诱发的系列余震会对原有结构造成进一步的累积损伤.核岛厂房结构作为核反应堆的最后一道防线,其在服役期间可能遭受主震和余震的累积作用.参考我国现行规范,定义了四类性能水准(PL)和三种极限状态(LS),以混凝土最大应变作为结构破坏指数(DI),以谱加速度Sa作为地...