基于多尺度投入-产出表的中国对外贸易产业结构调整多目标优化

出口贸易引发的资源流失风险是当今研究的热点. 本文动态地分析了出口贸易引起的资源流出变动及其影响因素, 并对2018-2022年中国地区出口贸易进行优化调整. 首先, 本文利用行业间投入-产出表和资源消耗数据计算中国各行业的直接和完全资源消耗系数; 其次, 利用结构分解模型挖掘出口导向的隐含资源流出量变动的主要原因; 随即, 将45个行业进行聚类分析, 探讨未来各行业的节约资源潜力和调整路径; 最后基于情景分析和多目标优化理论, 从出口贸易结构, 贸易额和技术发展视角对中国未来出口贸易进行模拟分析. 实证分析结果表明: (1) 直接消耗强度, 技术进步, 出口总量和出口结构等4个影响因素中, 出口额对资源流失风险的贡献率最大. 直接能源消耗强度有助于降低因出口导致的能源流出, 而完全消耗水资源强度的降低大大减少了资源流失风险, 符合现实； (2) 以2017 年为基准年, 利用多目标优化模型求解2018-2022年出口结构和出口量, 结果表明优化结果有利于降低资源流出量. 通过调整未来各行业资源消耗强度, 优化结果发现技术提升带来的资源节约优势逐渐增强, 本文认为, 为技术改善的资金(人员)投入的边际产出呈现逐渐增强效应.     

国际石油价格波动的结构性因素分析

文章将石油供给性冲击、需求性冲击和投机行为冲击3方面结构性因素细分为5个内生变量,构建反映油价波动的结构向量自回归(SVAR)模型,并运用模型对1999—2012年期间油价波动的原因进行了实证分析。结果表明:需求性冲击无论是长期还是短期都是油价波动的最主要因素;其次,投机性冲击对油价波动的影响也较大,不容忽视;短期突发事件和供给冲击短期对油价有些影响,长期影响基本消失。     

s-III型低密度甲烷气体水合物物性的理论研究

本文利用基于密度泛函理论的第一性原理赝势平面波方法研究了s-III型水分子笼状结构和s-III型CH4气体水合物笼状结构的晶格常数、体弹模量等基本物性参数,发现在0~2.6 GPa压强范围内两种笼状结构均可以稳定存在,晶胞体积随着压强增大而近似线性减小. s-III型CH4气体水合物中由于CH4分子间的作用力导致甲烷水合物体积发生膨胀,但是体积增大幅度较小且比较均匀,平均增幅在3.97%左右. 最后根据能带结构和电子态密度计算结果发现s-III型CH4气体水合物为绝缘体,不具有导电性.     

Electric Multiple Unit Bogie Maintainability Allocation with Interval Analysis and Fuzzy Evaluation Method

Based on the failure rate and design features allocation method,considering the multiple influential factors which affect electric multiple unit（ EMU） bogies,maintainability allocation on EMU bogie was presented by interval analytic hierarchy analysis and fuzzy comprehensive assessment. The maintainability allocation model was established. Weight based on the influence degree of each factor on maintenance was assigned. Fuzzy interval numbers were used to substitute real numbers and express uncertain information.The maintenance weighting factors for each subsystem were calculated by fuzzy comprehensive assessment. Then the allocation method was applied to EMU bogie. The results show that the method is feasible. The problem difficult to quantify for EMU bogie maintenance allocation is solved effectively.     

基于数学形态学的车牌定位算法

在汽车牌照识别系统中,车牌定位是整个识别模块实现的前提,为了能对汽车牌照精确定位,提出了一种基于数学形态学的车牌定位方法。首先利用中值滤波方法对汽车图像进行消噪处理,然后用迭代阈值选择法将图像进行二值化,并运用数学形态学的膨胀、腐蚀对二值图像进行处理,得到几个车牌候选区,然后利用面积、长宽比以及垂直投影特征值等进行综合分析,准确定位车牌区域。实验结果表明,该方法简单易行、准确率高、并且具有一定实效性,可用于对实际车牌图像的准确定位。     

Hydrothermal synthesis,structures and properties of metal phosphonates based on m-xylylenediphosphonic acid

In this work, a series of new metal phosphonates were hydrothermally synthesized and structurally characterized based on m-xylylenediphosphonic acids （H4L）, including [M（H2L）（bpy）] （M = Mn 1, Co 2）, [MH2L）（phen）] （M = Co 3, Cu 4）, and [Cu2（H2L）2（bpy＂）2] 5 （bpy = 2,2＇-bipyfidine, phen = 1,10-phenanthroline, bpy＂ = 4,4＇-dimethyl-2,2＇- bipyridine）. X-ray diffraction indicated that compounds 1 and 2 were isomorphic. Complexes 3 and 4 were shown to crystallize in different space groups but had similar crystallographic units. In the complexes, H4L was seen to partially deprotonate to afford H2L^2-. The H2L^2- ligands in 1-4 functioned as tetradentate ligands with each phosphonate group adopting bidentate coordination mode with two M centers to generate a 2D layer. In addition, the H2L^2- anions in 5 functioned as tfidentate ligands with one phosphonate group adopting the bidentate mode and another phosphonate group adopting the monodentate mode, thus linking three Cu atoms to provide a 1D chain. The IR and thermal stabilities of these compounds were subsequently examined.     

机务维修中人的安全状态评估分析

在所发生的众多航空事故中,人为因素所占的比例居高不下,而其中机务维修中的差错也尤为突出。只有从根本上控制机务维修工作中的人为差错,才能对事故的发生起到预防的作用。本文旨在探讨机务维修中人的状态能否保证维修工作顺利可靠进行的评估方法和体系的建立。本文的研究范围主要是机务维修的各个岗位中,在维修人员的各种不同状态下的调查,引用AHP层次分析法和模糊数学分析法等科学方法,科学处理数据,确定影响机务维修中人的安全状态的重要方面,从而对机务维修中人安全状态进行全面的评估。为航空公司、机场等保障机务维修工作安全进行提供了科学的方法,对保障航空安全具有现实的意义。     

基于层次分析法的供应商评价体系研究

为了选择优质供应商,为高校教学科研一线提供更好的物资设备保障,提出了基于层次分析法构建供应商评价体系,这种方法相较传统方法更科学合理。最后,通过实例验证了供应商评价体系的可行性。     

Template/surfactant free and UV light irradiation assisted fabrication of Mn-Co oxides composite nanorings: Structure and synthesis mechanism

A facile, green, cost effective, and template or surfactant free strategy via a two-step route i.e. UV irradiation followed by dissolution-growth for the controlled synthesis of Mn-Co composite nanorings at room temperature was proposed. The nanorings structures and the process were systematically studied via TEM, HRTEM, EDX and XRD. Bir-MnO_2 nanosheets first formed through the direct photolysis of KMnO_4 under UV light irradiation. This was followed by a dissolution-growth process via the dissolution of Bir-MnO_2 nanosheets by the generated H~+ from the redox reaction between the added Co(NO_3)_2 and residual KMnO_4, as well as the accompanied formation of CoOOH, and Mn-Co composite nanorings. It was found that a balance between the dissolution and growth rate was needed. Suitable pH, KMnO_4 presence and the starting nanosheets like Bir-MnO_2 were the key factors for the formation of nanorings. The obtained Mn-Co nanorings/TiO_2 showed enhanced efficiency for the catalytic oxidation of HCHO. Based on the above understandings, it is believed that the developed dissolution-growth method can be adopted for the designing and preparation of other Mn-Co composite nanostructures which can be further applied for environmental pollution remediation.     

国际石油公司人才效能评价指标体系研究

人才效能评价有助于提高石油企业人才管理的科学化、精细化.根据国际石油公司的特征,从3个维度构建了人才效能评价指标体系,并利用层次分析法(AHP)确定各指标的相应权重.通过把我国石油企业的人才效能综合指标值与其他国际石油企业进行纵向对比,了解了我国石油企业在人才使用效率上与其他国际石油企业的差距.通过与自身的横向对比,发现我国石油企业现有的优势与劣势,为我国石油企业提高人才效能提供了可借鉴的管理和改进信息.