自然灾害遥感应用标准体系构建方法研究

遥感技术不仅能用于获得自然灾害发生之前的背景数据,而且可用于对自然灾害进行监测预警和损失评估,近年来已经成为自然灾害信息获取与分析的重要手段。标准体系构建是开展自然灾害遥感技术标准化应用的一项重要基础性工作,亟需研究和建立满足自然灾害管理需求的遥感技术应用标准体系。对国内外遥感技术标准特别是自然灾害遥感应用相关标准现状进行了综述。分析了自然灾害遥感技术应用标准化需求,探讨了标准体系构建的思路,提出了面向自然灾害遥感技术应用的并列式、串联式和混合式标准体系构建方法和洪涝灾害遥感监测关键技术标准需求。     

青海省井孔水温观测结果分析——以德令哈等5个观测井为例

选取青海前兆台网的德令哈等5个井孔开展水温对比观测,对这五个井孔的水温原始观测数据和对比观测数据进行对比分析,从两组数据变化形态、差值、日变幅等方面发现不同的井孔两套数据的相似程度不同,其中以德令哈台为最好,湟源和格尔木次之,互助和佐署井则较差。分析认为主要原因有探头安装情况、仪器型号和仪器工作状态的影响。     

SVM application in hazard assessment: Self-heating for sulfurized rust

In order to assess the oxidation self-heating hazard of sulfurized rust, for particular ambient conditions in crude oil tanks, the support vector machine (SVM) technique is applied to predict the maximum temperature (T_max) of oxidation self-heating process. Five governing parameters are selected, i.e. the water content, mass of sulfurized rust, operating temperature, air flow rate and oxygen concentration in the respiratory/safety valve. The efficiency and validity of the SVM predictions are investigated in the case of two sets of data: more than 85 experiments performed in academic lab (China) and almost 17 additional results collected from existing literature. Two main steps are also discussed: the training process (on selected subsets of data) and prediction process (for the remaining subsets of data). It can be concluded that for both datasets the maximum temperature (T_max) values calculated by SVM technique were in good accordance with the experimental results, with relative errors smaller than 15% except for a few cases.The SVM technique seems therefore to be relevant and very helpful for complex implicit processes such as chemical reactions, as it is the case of the oxidation of sulfurized rust in oil tanks. Furthermore, such predictive methods can be continuously be improved through additional experiments feedback (larger databases) and can then be of crucial help for monitoring and early warning of hazardous reactions.     

Effect of initial temperature on the explosion pressure of various liquid fuels and their blends

In this work, the effect of initial temperature on the explosion pressure, P_ex, of various liquid fuels (isooctane, toluene and methanol) and their blends (isooctane-toluene and methanol-toluene, with three different fuel-fuel ratios) was investigated by performing experiments in a 20-l sphere at different concentrations of vaporized fuel in air. The initial temperature was varied from 333 K to 413 K.Results show that, as the fuel-air equivalence ratio, Φ, is increased, a transition occurs from a “thermodynamics-driven” explosion regime to a “radiant heat losses-driven” explosion regime. The maximum pressure, P_max, is found in the former regime (Φ < 3), which is characterized by a trend of decreasing P_ex with increasing initial temperature. This trend has been explained by thermodynamics. In the latter regime (Φ > 3), P_ex increases with increasing initial temperature. This trend has been addressed to the decrease in emissivity (and, thus, radiant heat losses) with the increase in temperature.     

某型橡胶密封圈加速贮存试验设计与实践

目的针对某型橡胶密封圈开展加速贮存试验设计,并通过试验预测产品贮存寿命。方法通过分析橡胶密封圈在贮存使用环境下的失效机理,结合橡胶材料性能老化模型,在不改变失效机理、又不增加新的失效机理的前提下,以密封圈整件作为试验对象,用加大温度应力的试验方法加速产品失效过程,根据试验结果预计正常环境应力下的产品贮存寿命。结果采用温度应力作为加速贮存应力开展密封圈加速贮存试验方案设计和验证工作,评估得到其在贮存温度为20℃的环境中,贮存寿命可以达到16.97年,置信度大于0.95。结论以密封圈整件作为试验件,采用温度应力作为贮存敏感应力开展加速贮存试验,所评估得到的贮存寿命与产品已有的自然贮存寿命结果吻合得较好,试验状态更加真实,为橡胶密封圈更换周期提供参考依据,并为密封圈贮存寿命的定量评估提供了一种参考方法。     

等离子喷涂制备 ZrB2-SiC 复合涂层及其静态烧蚀性能

目的提高C/C复合材料的抗静态烧蚀性能。方法利用大气等离子喷涂技术在C/C复合材料表面制备ZrB_2-SiC复合涂层,对其进行1500℃的静态烧蚀实验。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)及能谱分析仪(EDS)对涂层的物相成分、微观形貌等进行检测分析。结果采用大气等离子喷涂制备的ZrB_2-SiC涂层是由熔融的粉末粒子紧密堆积而成,呈现典型的层状结构,涂层均匀完整地覆盖于C/C基体表面,厚度约为200μm。涂覆有ZrB_2-SiC复合涂层的C/C复合材料试样在1500℃分别氧化2,3,4 h后,试样依旧保持完整,C/C基体未遭受损伤,试样的质量增加率依次为3.39%,2.95%,4.25%。结论采用大气等离子喷涂技术能够在C/C复合材料表面制备出厚度均匀、结构致密的ZrB_2-SiC复合涂层,ZrB_2-SiC复合涂层使C/C复合材料的抗静态烧蚀性能显著提高。     

贵州省土壤温度状况估算

土壤温度是土壤重要的内在属性,亦是反映区域环境特征和土壤系统分类体系中的重要基础性指标。但在贵州省境内,由于缺乏数据观测体系,目前还缺乏完整的土壤温度报道和估算方法。介于此,本文收集了贵州省境内84个气象站多年的地面气候资料数据,通过拟合土壤温度与年平均气温、纬度、经度和海拔高度之间的关系,构建了相应的土壤温度估算模型,并与其他三种地区性土温测算方法进行比对,得到了相对一致的分析结果。模型估算的区域土壤温度结果显示,贵州省各地区土壤温度以"热性土壤"为主(15℃≤Y22℃),少数地区如:毕节的大方、威宁和六盘水的水城三个地方为"温性土壤"(8℃≤Y15℃)。     

过氧化氢除藻及相关环境条件优化

采用室内培养的方式,通过正交试验研究了H_2O_2质量浓度、光照、pH值和温度4个因素复合作用对铜绿微囊藻去除的影响。结果表明,在所设置的各因素梯度范围内,对去除铜绿微囊藻影响最大的因素是H_2O_2质量浓度;光照和pH值对藻细胞数和叶绿素a的去除,以及H_2O_2残留量的影响各不相同;温度对藻细胞数的影响最小,对H_2O_2残留量的影响较小,对叶绿素a质量浓度的影响较大。除藻的最佳组合为A_1B_2C_3D_2,即光照为1 500 lx,H_2O_2质量浓度为50mg/L,pH值为8.5,温度为25℃。     

认知资源对公众城市气象灾害防御支付意愿的影响研究#br# ——基于南京市暴雨灾害防御的实证

城市气象灾害防御措施的改进是防灾减灾的有效手段，但如何在辨识公众支付意愿的基础上，构建多方成本分担的灾害防御制度是解决问题的关键。从成本分担的视角出发，以南京暴雨灾害防御为例，分析公众对增强型城市气象灾害防御的支付意愿及认知资源在其中的重要作用。通过构建由Probit模型和有序Probit模型组成的递归混合模型，探讨认知资源和经济资源在公众支付决策中的重要性。研究表明:认知资源的作用十分明显，且随着公众对暴雨灾害风险感知、防御措施了解程度、防御制度认可程度的提高，公众支付意愿越强。而暴雨灾害风险感知又受到灾害趋势认知和经历的共同影响，这两个变量分别影响风险感知的广度和深度，但受教育程度对风险感知深度的影响并不显著。核心建议是从满足公众对城市暴雨灾害风险、防御措施、灾害趋势等知识的需求，政府应该加强暴雨灾害科普宣传的主动性、提升主管和协同部门的公信力；规范科普知识内容、拓宽科普渠道。     

输油管道冻胀安全性温度场有限元分析

冻土区输油管道在投产运行过程中,由于管道沿线受到冻融影响引起的管线变形破坏现象比较普遍。已建的中俄原油管线由漠河进入中国,经过我国北方多年冻土区和季节冻土区直至大庆。输油管道在寒区运行过程中与周围土体发生了热交换,使原自然土层热交换体系改变,进而对运行的管线造成不利的影响如冻胀和融沉。本文对此进行研究为管道安全运行提供参考依据。