城市短期燃气负荷具有高随机性和复杂性特征,利用单一的模型难以做出准确预测.以某城市民用类燃气日负荷为研究对象,在分析该市两年多燃气日负荷特征的基础上,建立了基于BP神经网络(BPNN)-经验模态分解(EMD)-长短期记忆(LSTM)神经网络的组合预测模型,对该市短期燃气日负荷进行了预测.首先通过BPNN模型学习温度、日期属性影响下燃气负荷的主要特征,增长趋势等次要特征则体现在BPNN模型预测产生的残差中;然后采用EMD算法分解残差得到有限个本征模函数(IMF),并利用LSTM模型学习各IMF分量的短期时序规律,将各IMF分量的预测值相加得到残差预测值;最后将两部分预测值代数相加得到最终的预测结果.实证结果表明:与单一的LSTM模型和BPNN LSTM模型相比,该组合预测模型半月步长的平均绝对误差为3.4％,预测精度更高,是一种更为有效的城市短期燃气负荷预测方法.

在互联网租车模式中,车辆调度能有效解决"潮汐现象",对降低租车公司运营成本、 提高用户体验起到重要作用.针对用户对服务时间的要求,在车辆调度中引入时间窗,将问题转化为带时间窗的车辆调度问题(Vehicle Rou-ting Problem With Time Windows,VRPTW).根据互联网租车中车辆调度过程的约束建立数学模型,针对模型特点设计遗传算法求解.基于模拟数据做测试案例,对遗传算法的调度结果进行分析,实验结果表明了模型和算法的有效性.

For the current internet rental car industry and the centralization of the existence of the transaction must be carried out at a fixed place, the cost of renting a car is too high, resources are wasted, the system is not stable enough, there is no collaboration between vehicle sharing and berth sharing, this paper presents a semi-centric model of internet car rental named vehicle-berth cooperative sharing mode of Internet car rental, which includes the automobile manufactures, the government, the insurance institutions, the parking company and so on.The model can effectively solve the problem of fixed location rental car, vehicle no place to stop, berth without car parking and other issues, to achieve the efficient use of resources, at the same time, its convenience, low cost and other characteristics destined for the new model can be used as an existing trip way to effectively complement and can bring huge social benefits.

The development of a comprehensive real estate projects have significant impact on the urban space.The development strategy from the view of the city and the characteristics of the project is a critical success factor.The article discusses the Zhejiang Jinhua international trade center from the integrated development,urban design,diversified feature setting,intensive space,commercial pedestrian and the characteristics of the architecture to explore the design features of the large-scale mixed function of the real estate project's development and urban design.

论述了绿色铁路旅客站评价标准对于当前铁路旅客站规划、设计、建设、运营的意义.通过对国内外绿色建筑评估体系的梳理、绿色铁路旅客站评估体系意义与特点的分析,建构了绿色铁路旅客站评估体系内容框架.

混凝土建筑物的结构失效和功能失效不仅影响人们的正常生活且造成巨大的经济损失,所以对复合改性修补水泥混凝土的研究极为重要;而在其修补中经常遇到修补的脱落和失效等问题,且由于修补界面相对于修补材料和基材而言属于薄弱部分,所以这些现象丰要发生在新旧材料之间的修补界面过渡区内.鉴于此,本文的第一部分对聚丙烯纤维聚合物乳液改性硫铝酸盐水泥修补砂浆的性能进行研究,研制高性能改性修补砂浆;第二部分对旧基体界面处理方案与修补粘结性能的关系进行试验研究,探讨提高修补粘结性能的试验方案.

Oxide thermoelectric material Ca3Co4O9 has drawn much attention since it has unique advantages in comparison with those traditional ones.The basic structure,thermoelectric properties and doping research(Na,Bi,Ag,and etc.)of thermoelectric material Ca3Co4O9 were summarized.Future application of the material was also prospected.

Ca3Co4(FxO1–x) 9(x = 0,0.01,0.02) polycrystalline samples were prepared by the solid-state synthesis method and spark plasma sintering,and effect of fluorine(F) doping on the microstructure and thermoelectric properties of Ca3Co4O9 were systemati-cally researched. The results show that F-doped samples are both single compound. In comparison with the pure sample between 300 K and 900 K,the Seebeck coefficients of F-doped samples change little,electrical conductivities increase obviously,and the thermal conductivities decrease at first but increase with further F addition. The sample with x = 0.01 has the highest electrical conductivity and lowest thermal conductivity,which are 14 × 103 S/m and 2.16 W/(m·K) ,respectively. At 900 K,the sample x = 0.01 has the maxi-mum dimensionless figure of merit(ZT) value of 0.16,which is nearly100% greater than that of the pure sample.

利用溶胶凝胶法在900℃、常压烧成制备出了Ca3(Co1-xZnx)4O9(x=0,0.05,0.10)系列块体材料,研究了Zn掺杂对Ca3CO4O9热电性能的影响,结果表明在580--900 K温度范围内,适量的Zn掺杂能使Ca3CO4O9热电材料的Seebeck系数和电导率同时增大,而热导率减小,从而使热电性能得到了提升.在900 K时,x=0.10样品的ZT最大,达到0.08.

The density of states(DOS) of Ca3Co4O9 and Zn-doped ones are calculated by using density functional and discrete variation method(DFT-DVM) . The relation between electronic structure,chemical bond and thermoelectric property is discussed. The research indicates that the highest valence band(HVB) and the lowest conduction band(LCB) are mainly contributed from Co3d,Zn3d and O2p atomic orbits. The property of semiconductor is shown from the gap between HVB and LCB. The gap of Zn-doped ones is less than that of Ca3Co4O9. The covalent and ionic bonds of Zn-doped ones are both weaker than those of Ca3Co4O9. The results imply that the thermoelectric property may be enhanced by adding Zn element into the system of Ca3Co4O9,which has been proved true.

本文从系统学的理论出发,分析了民营企业内外部两种要素相互变化作用下的民营企业危机形成原理。在阐述了导致民营企业危机形成内外部要素的基础上,借助SWOT模型研究了民营企业的危机形成趋势,帮助企业分析自身所处危机状态,减小危机形成几率。

The paper introduces the theory of vulnerability assessment in crisis management.After the introduction of the concept and evaluation content of crisis management vulnerability,an index system of total factor crisis management vulnerability is proposed,and an evaluation model is constructed.It provides a scientific evidence for enterprises to strengthen the construction of crisis management system and improve anti-risk ability.