基于CALIPSO对中国春季一次沙尘暴的研究

文章利用CALIPSO卫星观测资料,结合气溶胶模式模拟,分析了2013年入春以来发生的第1次强沙尘天气过程中的沙尘气溶胶垂直分布特征及输送特性.结果表明:此次沙尘事件有两个源区,南疆盆地(源区一),沙尘先后输送影响我国内蒙古西南部、甘肃、宁夏等地区.2月27日沙尘在甘肃西部河西走廊附近,沙尘气溶胶分布在2~5 km,退偏振比在0.1~0.5之间,色比在0.4~0.8之间;28日新疆地区沙尘气溶胶分布在4~12 km,退偏振比在0.3~0.5,色比在0.5~1.0之间.蒙古国西南部地区(源区二),沙尘先后影响我国内蒙古中西部地区、甘肃、山西北部、陕西北部、河北北部和东北西南部地区,2月28日内蒙古沙尘气溶胶分布在4~11 km,退偏振比在0.2~0.5之间,色比在0.5~1.2之间.     

基于红外吸收法的哈龙替代灭火剂HFC－125的浓度监测技术

HFC-125(五氟乙烷)有较好性能,可替代哈龙灭火剂应用于飞机灭火系统中。在飞机灭火系统的评估实验中,模拟地面或是飞行状态,灭火剂浓度测量设备都是必不可少的。基于非色散红外光谱技术(NDIR),初步设计了HFC-125灭火剂浓度监测设备,该设备采用硅碳红外光源,入射光经过斩波器调制转变为交变光,通过单光路测量气室后,被碲镉汞红外探测器转化为电压信号并被前置放大电路放大。通过电压比与体积分数的对应关系,可以实现对HFC-125浓度的监测。     

A parametric model of child body shape in seated postures

Objective: The shape of the current physical and computational surrogates of children used for restraint system assessments is based largely on standard anthropometric dimensions. These scalar dimensions provide valuable information on the overall size of the individual but do not provide good guidance on shape or posture. This study introduced the development of a parametric model that statistically predicts individual child body shapes in seated postures with a few given parameters.

Methods: Surface geometry data from a laser scanner of children ages 3 to 11 (n = 135) were standardized by a 2-level fitting method using intermediate templates. The standardized data were analyzed by principal component analysis (PCA) to efficiently describe the body shape variance. Parameters such as stature, body mass index, erect sitting height, and 2 posture variables related to torso recline and lumbar spine flexion were associated with the PCA model using regression.

Results: When the original scan data were compared with the predictions of the model using the given subject dimensions, the average root mean square error for the torso was 9.5 mm, and the 95th percentile error was 17.35 mm.

Conclusions: For the first time, a statistical model of child body shapes in seated postures is available. This parametric model allows the generation of an infinite number of virtual children spanning a wide range of body sizes and postures. The results have broad applicability in product design and safety analysis. Future work is needed to improve the representation of hands and feet and to extend the age range of the model. The model presented in this article is publicly available online through HumanShape.org.     

A study on operation problems of hydropower plants integrated with irrigation schemes operated in Turkey

In this study, Hydroelectric Power Plants, which have been built and integrated with irrigation schemes by the State Hydraulic Works which is a government agency and private companies in Turkey, have been examined. Technical, environmental, structural and social problems encountered during their operation have been analyzed, and appropriate solution proposals have been presented in the study for a sustainable irrigation and Hydroelectric Power Plant operation. Consequently, Hydroelectric Power Plants which have been integrated with irrigation schemes should be operated efficiently and they should be operated in attenuation with the environment. However, when hydroelectric projects are developed without preparing their necessary integrated basin management plans, then this will cause environmental, operation and maintenance, administrative, monitoring and evaluation problems. In order to ensure sustainability of hydroelectricity production and also in order to use water resources more efficiently for irrigation; it is very important to find permanent solutions to these problems.     

IPP图像分析技术在长霉面积定量测量中的应用

介绍了应用IPP图像分析软件对数码相机采集的霉菌试验样品长霉面积的定量分析方法,包括测量单位标定、AOI的参数选取和使用、面积测量和计数等。结果表明,利用IPP可便捷、准确地测量长霉面积,测量结果可靠。该方法有助于对长霉等级和霉菌试验结果做出正确评定。     

堆芯中子注量率测量系统核级阀门的型式试验

堆芯中子注量率测量系统是30万千瓦核电厂监测系统的重要组成部分。该系统中的手动阀、止回阀和电动阀(阀体)属于核级阀门。介绍了堆芯中子注量率测量系统的组成和功能,并根据ASMEQME-1—2002规范从试验项目、环境条件和考核指标等方面对手动阀、止回阀和电动阀提出了型式试验技术要求。制造厂根据型式试验技术要求制定了手动阀、止回阀和电动阀试验大纲,并对样机进行了型式试验和检验,试验结果满足试验大纲要求。     

机动车车载尾气检测技术研究综述

车载尾气检测技术的出现和发展为机动车尾气的相关研究提供了一种较为准确、便捷、实时反映城市路网排放的测试方法。本文详细介绍了车载尾气检测技术的发展历程和原理,综述了该技术在行驶周期开发、尾气排放特性和规律研究、建立机动车尾气排放数据库和建立城市路网排放清单等领域的应用现状,并通过比较该技术在国内、外的应用差距,提出了在绿色交通领域充分利用该技术进行机动车污染评价与控制的合理建议。     

下沉式地铁车辆段环境噪声特性试验研究*

针对下沉式地铁车辆段环境噪声问题,采用问卷调查与现场实测相结合的方法,对下沉式地铁车辆段环境噪声特性开展研究。结果表明:通风噪声是下沉式地铁车辆段主要噪声源,其次为列车噪声;办公区域噪声强度超出标准限值3~5 dB（A）,其中1 000 Hz左右中频段噪声带给人的烦恼度最高;检修库内存在严重低频噪声,尽管各测点均未超过标准限值,但由于风机长期24 h运行,仍会引起员工不舒适感;上盖司机公寓内二次结构噪声强度不满足环境标准限值要求,对公寓居民睡眠产生不良影响;结构振动噪声具有明显的低频特征,主要对16~250 Hz起作用,其中250 Hz频段超标最严重。     

An alternative work measurement method and its application to a manufacturing industry

Difficulties in determining the standard time justify the need to develop alternative methods to direct measurement procedures. The indirect methods which are comparison and prediction, standard data and formulation, predefined movement-time systems have several deficiencies in time measurement procedures. In this study, an alternative indirect work measurement method based on artificial neural networks (ANNs) is presented which is simple and inexpensive. For the application of the proposed method, the products that have similar production processes are selected among the whole product family produced in a manufacturing company. The standard times of the sampled products that are previously measured are used and the standard times of the remaining several products and semi-products are predicted by the proposed method. The model results show that the proposed method can be applied accurately in companies which produce similar products.     

气相色谱-质谱联用法在线观测大气中的氢氟碳化物和全氟化碳

利用组装的气相色谱-质谱联用系统(GC-MS)同时测定大气中6种氢氟碳化物(HFCs)和4种全氟化碳(PFCs),空气样品采样的时间分辨率120 min,精度范围0.15%—3.11%,准确度范围-1.52%—0.63%.对2011年2月在北京上甸子站的实验观测结果进行分析,获得HFC-23、HFC-32、HFC-134a、HFC-143a、HFC-125、HFC-152a、CF4、PFC-116、PFC-218、PFC-318的本底和非本底浓度,表明该系统适用于大气中HFCs和PFCs浓度在线观测.