气象计量实验室量值比对和能力验证的意义

实验室能力验证是为了确定实验室的检验和测量能力而采取的一种实验室间比对活动。本文结合西北区域气象计量检定所实验室比对的试验结果,针对在比对中发现的问题,并分析问题存在的原因,总结经验,浅述实验室间比对和实验室能力验证的体会及其意义。气象计量实验室能力验证工作有利于提高业务人员整体水平和实验室质量管理水准,使气象计量检定工作能更好地开展。     

Typical gait analysis of a six-legged robot in the context of metamorphic mechanism theory

The equivalent mechanism of the system is often considered as one specific mechanism in most existing studies of multi-legged robots, however the equivalent mechanism is varying while the robot moves on the ground. Four typical tripod period gaits of a radial symmetrical six-legged robot are analyzed. Similar to the metamorphic mechanism, the locomotion of multi-legged robot is considered as a series of varying hybrid serial-parallel mechanisms by assuming the constraints of the feet on the ground with hinges. One gait cycle is divided into several periods, and in different walking period there is a specific equivalent mechanism corresponding to it, and the walking process of multi-legged robot is composed by these series of equivalent mechanisms. Walking performance can be got by analyzing these series of equivalent mechanisms. Kinematics model of the equivalent mechanism is established, workspaces of equivalent mechanisms are illustrated by simulation and a concept of static stability workspace is proposed to evaluate the static stability of these four gaits. A new method to calculate the stride length of multi-legged robots is presented by analyzing the relationship between the workspace of two adjacent equivalent parallel mechanisms in one gait cycle. The stride lengths of four gaits are given by simulations. Comparison of stride length and static stability among these four typical tripod gaits are given. It has been proved that mixed gait and insect-wave gait II have better static stability than mammal kick-off gait and insect-wave gait I. Insect-wave gait II displays its advantage on stride length while the height of robot body lower than 87 mm, mammal kick-off gait has superiority on stride length while the height of robot body higher than 115 mm, and insect-wave gait I shows its shortcoming in stride length. The proposed method based on metamorphic theory and combining the footholds and body height of robot provides a new method to comprehensive analyze the performance of multi-legged robot.     

激光器重复频率对多普勒激光雷达信噪比影响的模拟研究

多普勒激光雷达在风场测量和数值天气预报等方面有重要意义,而信噪比则是衡量系统测量精度的重要参数.以2007年中国海洋大学研制的我国第一台车载多普勒测风激光雷达系统为参考,模拟了在相同平均功率下,使用4种重复频率不同的激光器的激光雷达系统测量海面风场中的信噪比,并与汕尾测量的海面风场数据进行了对比,模拟数据和实测数据能够较好吻合,模拟结果证明使用低重复频率激光器的激光雷达系统能够获得较高的信噪比.而根据多普勒激光雷达业务测量要求,要求比较高的激光重复频率,通过模拟研究,建议选择激光器激光重复频率500～1000 Hz.     

Towards a quantitative approach for comparing crowds

In this paper, we propose a new model to quantitatively compare global flow characteristics of two crowds. The proposed approach explores a 4‐D histogram that contains information on the local velocity (speed and orientation) of each spatial position, and the comparison is made using histogram distances. The 4‐D histogram also allows the comparison of specific characteristics, such as distribution of orientations only, speed only, relative spatial occupancy only, and combinations of such features. Experimental results indicate that the proposed quantitative metric correlates with visual inspection. Copyright © 2012 John Wiley & Sons, Ltd.     

浅析经济型连锁酒店的能耗评估管理

介绍了酒店能耗评估管理工作的基本要素及范畴。结合目前经济型酒店能耗管理现状,提出了采用“三步评估法”提高能耗管理水平。通过具体项目的能耗评估实例,指出有效的能耗评估管理在连锁酒店综合节能及成本控制方面具有重要意义。     

江苏省农作物废弃物-煤混燃与生物质气化发电模式的综合比较与分析

农作物废弃物是江苏省最主要的生物质资源,利用其进行发电可以有效地解决能源紧张以及在秸秆就地焚烧引发的一系列问题.江苏省生物质发电技术发展较早,其中混燃与气化技术是两种具有代表性的发电模式.目前,国内外通常对这些技术的进行单独研究,但是还没有针对两种技术路线的综合比较与分析的系统研究.通过对现有的混燃和气化发电案例进行充分调研,从燃料、进料系统、发电技术、经济性、污染物减排及面临的主要问题等方面,对两种模式的优缺点进行综合比较与分析.并在此基础上,探讨了这两种模式的合理发展路线.     

认真进行乙烯技术的比选

我国近年还将建设多套大型乙烯装置,而不同专利商的乙烯技术是有优劣之分的。将丽家专利商的技术进行比较,专利商Ⅰ的技术存在投资高、能耗高、乙烯损失大等问题;由于辐射炉管构型和急冷油系统技术存在缺陷．大大缩短了装置运行周期;在“只提供工艺包”的情况下,有加大设备尺寸的现象。而专利商Ⅱ的技术在投资和能耗方面相对较低,并且由于裂解炉采用U型辐射炉管,使炉管寿命达到8年以上。在引进技术时要认真进行不同专利技术的比选,重视生产实践经验和数据,将能耗的高低作为衡量技术优劣的重要标准之一。     

不同来源葛根淀粉的理化性质比较

为快速检定葛根淀粉,取7 种市售葛根淀粉与自制的葛根淀粉进行理化性质比较。经淀粉颗粒形态观测和直链淀粉含量、吸光度、黏度、透明度、凝沉性、冻融稳定性、膨胀度、溶解度、葛根素含量等检测显示自制葛根淀粉与7 种市售葛根淀粉的理化性质有多项差别。     

彭水水电站工程安全监测自动化系统方案比选

自动化监测系统对确保工程安全运行具有举足轻重的作用。结合彭水水电站安全监测自动化系统的建设经验,介绍了系统方案比选原则及比选过程,对选定方案的适合、先进性做了阐述。     

金属矿床开采岩体移动预测系统的开发

分析目前岩体移动预测的各类方法,指出每一类方法适用条件和存在的问题,提出了以工程类比、数值分析与现场监测三者相结合的综合预测理论,进行了"金属矿床开采岩体移动预测辅助系统"的结构设计与开发。