一种基于动态分析的突变和异常波动预警方法

针对模拟量的突变和异常波动预警,给出一种基于动态分析的、可以应用于各种模拟量的统一预警方法,该方法已被应用于CSM-TH型集中监测程序和智能分析系统中,在多条线700余站现场运行的7年中,收到良好效果,得到用户认可。     

反应条件对产物晶型和形貌的影响以二氧化锰为例

本文采用水热法制备了一系列的二氧化锰粉末状晶体。探索了反应温度、氧化剂浓度、压力等因素对二氧化锰晶型、结晶度与形貌的影响及其内在联系。结果表明反应温度、氧化剂浓度、压力对二氧化锰晶型均有影响,氧化剂浓度对其晶型影响尤为明显。温度对形貌影响较为明显。在晶型相同情况下,二氧化锰结晶度正相关于其形貌规整度。     

基于STM32的蓄电池检测系统设计

蓄电池检测系统是蓄电池质量指标中非常重要的一环,直接影响蓄电池的性能和寿命。本文介绍一种以STM32微处理器STM32F103RCT6为核心的铅酸蓄电池高精度智能检测系统,可以同时检测电压、温度、液位,并根据神经网络计算得到电解液密度,用户在上位机完成测试参数设置,自动对电池的各项数据进行存储和报警。文中详细介绍了系统组成、硬件和软件设计。实践证明该检测系统满足实际需求。     

Uncertainty analysis of value for money assessment for public-private partnership projects

In recent years, private sectors are encouraged to take an active part in franchising of urban infrastructure investments and operations, which promotes the rapid development of public-private partnership (PPP) in infrastructure and public service supply. Value for money (VFM) assessment has been officially proposed to provide a reference for selection of projects planning to adopt PPP. Based on the bottlenecks of VFM application in China and the uncertainties for urban infrastructure PPP projects, a discounted cash flow (DCF) model is established for VFM of infrastructure PPP projects. Then, a Monte Carlo simulation model is established on the basis of uncertainty factors for VFM. Through the analysis of Huai’an trams PPP project, coping strategies of uncertainties for VFM are put forward. Findings of the research may propel the establishment of a complete VFM evaluation system for PPP projects. Key instructional functions of VFM during the process of decision-making can be brought into full play and PPP may develop orderly.     

Geometric calibration algorithm of polarization camera using planar patterns

Polarization pattern provides additional information besides spectral signatures. It can be used in many applications, such as navigation, defect detection and object identification. A novel polarization camera composed of four synchronized cameras is proposed, and it can realize real-time polarization measurement. This study particularly concentrates on the geometric calibration of the system. The projection model is analyzed and the multi-camera calibration algorithm is proposed. Firstly, each camera is calibrated separately using planar patterns, and then the geometric calibration algorithms are performed. Due to the geometrical constraint, a global optimization method results in smaller estimation uncertainties. A mean rotation error of 0.025° and a mean translation error of 0.26mm are achieved after geometric calibration. The images are rectified to establish a correspondence among cameras and are combined to acquire the polarization measurement. The polarization pattern of the skylight is measured by the system and the results are consistent with the previous studies.     

Response-based analysis for Tension Leg Platform

The typical industry practice for Tension Leg Platform (TLP) design focuses on a conventional short-term design recipe, which assumes that an N-year design environment leads to an N-year response. In the response-based design method, the TLP is designed to withstand N-year responses rather than respond to N-year environmental conditions. In this paper, we present an overview and a general procedure for the response-based design method and use a case study to compare the critical TLP responses between the two methods. The results of our comparison show that the conventional short-term design method often contains an element of conservatism and that the response-based design method can reduce the design conditions and thereby achieve cost savings.     

进气掺氢与富氧燃烧对汽油机性能影响的试验研究

在JL3G10汽油机的基础上,搭建了发动机台架以进行掺氢富氧条件下的台架试验。利用该台架分别对不同进气含氧量(体积比),不同进气掺氢比以及富氧掺氢时汽油机的动力性与排放进行了试验研究。研究表明:相比原机,进气含氧量为25%时汽油机功率与扭矩提高了20.7%,HC排放减少36%,CO排放减少10.6%,但NOx排放增加了149.6%;2%进气掺氢比下的HC排放相比原机降低31.2%,CO排放降低46.1%,NOx排放则增加12.6%;富氧掺氢(氢氧体积比为2∶1)时,掺混比例为5.06%的汽油机较原机在动力性与排放上均有提升。     

客运专线抗台风措施研究

客运专线高速车辆轻量化,使其抗强风能力减弱。为保证客运专线安全运输,从线路、路基、桥梁、隧道、站场及电气化设施等方面提出抗台风的设计原则,可采用的运输安全监控预警及运营安全措施。以上研究成果可确保沿海铁路的运营安全,进一步提高沿海铁路建设质量。     

Identity-based broadcast encryption with shorter transmissions

This paper describes two identity-based broadcast encryption(IBBE) schemes for mobile ad hoc networks.The first scheme proposed achieves sub-linear size cipertexts and the second scheme achieves O(1)-size ciphertexts.Furthermore, when the public keys are transmitted, the two schemes have short transmissions and achieve O(1) user storage cost, which are important for a mobile ad hoc network.Finally, the proposed schemes are provable security under the decision generalized bilinear Di?-Hellman(GBDH) assumption in the random oracles model.     

TNFα、Leptin-Rb、NF-κB和PPAR-γ在酒精性肝病大鼠肝细胞中的表达

目的 探讨TNFα、NF-κB、Leptin-Rb和PPAR-γ等在大鼠酒精性肝病中与肝组织炎症、坏死和纤维化的关系.方法 胃造瘘法建立长期大鼠酒精性肝病模型,分别在第4、8、12、24和52周用免疫组化、原位杂交和RT-PCR技术检测不同阶段大鼠肝组织中TNFα、NF-κB、PPAR-γ和Leptin-Rb等的表达.结果 TNFα、NF-κB和Leptin-Rb水平在模型组大鼠肝细胞中,第8周表达逐渐增强,第24周起高水平表达一直持续至52周(P<0.01).PPAR-γ在对照组和第4、8周模型组肝细胞中表达最强,第12周表达开始减弱.TNFα和NF-κB在肝细胞中的表达呈明显正相关关系,与PPAR-γ则呈负相关关系(P<0.01).结论 TNFα和NF-κB与肝细胞病变程度有很好的一致性关系,Leptin-Rb在肝细胞的表达与肝纤维化发展相一致,PPAR-γ则刚好相反.