我国高铁建设融资模式再探索

作为公共基础设施建设的重要组成部分,高铁建设具有自然垄断性、地方公共产品性、成本积聚性以及收益长期性等经济属性。高铁建设一般采取政府投资为主、BOT项目融资为辅的融资模式,而政府投资和BOT项目融资模式都存在一定的限制,为满足高铁建设的巨大资金需求,需要探索和尝试更可行、合理的融资模式,制定支持性政策和配套制度。     

Purification and Characterization of Aporphine Alkaloids from Leaves of Nelumbo nucifera Gaertn and Their Effects on Glucose Consumption in 3T3-L1 Adipocytes

Aporphine alkaloids from the leaves of Nelumbo nucifera Gaertn are substances of great interest because of their important pharmacological activities, particularly anti-diabetic, anti-obesity, anti-hyperlipidemic, anti-oxidant, and anti-HIV’s activities. In order to produce large amounts of pure alkaloid for research purposes, a novel method using high-speed counter-current chromatography (HSCCC) was developed. Without any initial cleanup steps, four main aporphine alkaloids, including 2-hydroxy-1-methoxyaporphine, pronuciferine, nuciferine and roemerine were successfully purified from the crude extract by HSCCC in one step. The separation was performed with a simple two-phase solvent system composed of n-hexane-ethyl acetate-methanol-acetonitrile-water (5:3:3:2.5:5, v/v/v/v/v). In each operation, 100 mg crude extracts was separated and yielded 6.3 mg of 2-hydroxy-1-methoxyaporphine (95.1% purity), 1.1 mg of pronuciferine (96.8% purity), 8.5 mg of nuciferine (98.9% purity), and 2.7 mg of roemerine (97.4%) respectively. The chemical structure of four aporphine alkaloids are identified by means of electrospray ionization MS (ESI-MS) and nuclear magnetic resonance (NMR) analysis. Moreover, the effects of four separated aporphine alkaloids on insulin-stimulated glucose consumption were examined in 3T3-L1 adipocytes. The results showed that 2-hydroxy-1-methoxyaporphine and pronuciferine increased the glucose consumption significantly as rosiglitazone did.     

基于相机的转台稳定性检测方法研究

高精密转台常用于高精度测量仪器的性能测试,或作为激光扫描仪的稳定平台使用,而转台的稳定性直接影响仪器的测量精度.提出一种利用数码相机对转台稳定性进行标定的方法,在转台运动时,安装在转台上的相机连续获取相片,基于摄影测量原理,计算相机的空间位置和姿态,从而确定转台的运动轨迹.实验结果表明,该方法可以有效地检测转台运动的稳定性.     

航空相机检测仪系统的设计与实现

航空相机是一种重要的机载光电设备，在航空对地测绘等领域有着较为广泛的应用，为方便、直观地对航空相机进行地面检测，设计和实现了一种配套某型航空相机的检测仪系统。根据航空相机地面保障设备任务书和相机与地保设备通讯协议，给出了检测仪系统的功能需求。根据相机的接口要求和系统计算能力的要求，设计了检测仪系统的硬件方案。根据软件部分的功能需求，提出了一种新的分层架构，同时详细论述了软件系统的关键技术，描述了程序的运行流程，给出了检测仪系统的软件设计方案，并在VC6.0环境下实现了检测仪软件系统。针对检测仪的工作方式，设计了测试流程，并根据流程对检测仪进行了详尽的测试，经多次测试，检测仪工作正常。测试结果表明，检测仪系统满足了对其功能的全部要求，运行稳定，操作简便，显示直观，可以应用于航空相机地面保障任务。     

Adaptive beamforming of massive MIMO based on DoA in high mobility scenarios

A direction of arrival based (DoA-based) beamforming of massive MIMO was proposed for high-speed railway scenarios.In order to guarantee that the optimal system capacity can be obtained during traveling,an iterative multi-beams scheme was proposed.It aimed to design different beams for different mobile carriage terminals (MCT) respectively.The proposal adaptively selected the number of antennas for each beam,and adaptively designed the number of beams according to system capacity.Moreover,the scheme didn’t need channel state information (CSI) that can reduce system implementation complexity and cost.Numerical results indicate that the proposed scheme is suitable for high-speed scenarios,the system performance can be improved more efficiently compared to conventional methods.     

高速电梯补偿绳张紧装置设计中的两个问题

针对高速电梯补偿绳张紧装置，提出了补偿绳张紧重量的计算和选取方法。详细分析了电梯紧急制动状态下补偿绳张紧装置及防跳装置的工作状态，并建立了相应的动力学方程，通过相关数学推导和分析得出了防跳装置动作反力的计算方法。     

中国轨道铁路建设及其对铝材需求(2)

主要介绍中国可制造铝合金轨道车辆企业生产的动车组列车的性能特点,以及中国轨道车辆、城市轨道建设等对铝材的需求.在铝合金机车车辆制造中,单车的平均用铝量约10.3 t.其中挤压铝材约占78％,其他铝材占22％左右.     

Analysing observer preferences when presenting a product in a rendered scene: 2D vs. autostereoscopic 3D displays

ABSTRACT

This research compares the way the image of a product included within a rendered scene shown on an autostereoscopic 3D display is rated versus the same image shown in a 2D display. The purpose is to understand the observer's preferences and to determine the features that a composition should have to highlight the product and to make its presentation more attractive to observers, thereby helping designers and advertisers who use both displays to prepare images to make them more effective when visually presenting a product.

The results show that observers like the images on autostereoscopic 3D displays slightly more than those presented by means of 2D displays. On both displays the product is perceived more quickly when it is larger than the other elements and is shown with greater chromatic contrast, but a composition is seen as more attractive when the chromatic relationship between all the elements is more harmonious.     

Passenger comfort on high-speed trains: effect of tunnel noise on the subjective assessment of pressure variations

When passing through a tunnel, aerodynamic effects on high-speed trains may impair passenger comfort. These variations in atmospheric pressure are accompanied by transient increases in sound pressure level. To date, it is unclear whether the latter influences the perceived discomfort associated with the variations in atmospheric pressure. In a pressure chamber of the DLR-Institute of Aerospace Medicine, 71 participants (M = 28.3 years ± 8.1 SD) rated randomised pressure changes during two conditions according to a crossover design. The pressure changes were presented together with tunnel noise such that the sound pressure level was transiently elevated by either +6 dB (low noise condition) or +12 dB (high noise condition) above background noise level (65 dB(A)). Data were combined with those of a recent study, in which identical pressure changes were presented without tunnel noise (Schwanitz et al., 2013, ‘Pressure Variations on a Train – Where is the Threshold to Railway Passenger Discomfort?’ Applied Ergonomics 44 (2): 200-209). Exposure-response relationships for the combined data set comprising all three noise conditions show that pressure discomfort increases with the magnitude and speed of the pressure changes but decreases with increasing tunnel noise.

Practitioner Summary: In a pressure chamber, we systematically examined how pressure discomfort, as it may be experienced by railway passengers, is affected by the presence of tunnel noise during pressure changes. It is shown that across three conditions (no noise, low noise (+6 dB), high noise (+12 dB)) pressure discomfort decreases with increasing tunnel noise.     

一种新的低渗透气藏产能方程

综合分析滑脱效应、启动压力梯度效应和高速非达西效应,依据渗流力学原理建立稳定渗流条件下综合考虑三种效应影响的低渗透气藏产能方程.应用该方程对不同滑脱系数和不同启动压力梯度下的流入动态曲线进行比较.在相同井底流压下,随着滑脱效应影响因子的增大,气井产能逐渐增大；随着启动压力梯度的增大,气井产能逐渐减小.