基于Profibus智能化DP从站的温度采集模块的设计

介绍了使用热偶信号调理专用芯片AD595及Profibus总线用于从站的智能通信芯片SPC3,设计智能温度采集模块的方法,该温度采集模块不再需要调零、冷端补偿、电压放大和线性化等繁琐的工作,并可以直接测量热电偶输出的mv级电压信号.     

Short-term measures for the control of ozone peaks: expertise from CTM simulations

In Europe, in case of the observation or the forecast of a photochemical event, punctual and local reductions in anthropogenic emissions can be triggered at the regional scale. Although the necessity for the establishment of such measures appears to be justified by bad air quality records over large European cities, individual short-term action plans (STAPs) have been blindly elaborated by regional authorities. Moreover, as they impose industrial and road traffic emission restrictions, these measures have an elevated economical cost. It is consequently crucial to determine their efficiency and potential for ozone peak reduction. The study presented in this paper aims to draw up an expertise on standard European STAPs, through the example of a French Mediterranean city. The objective is to determine and investigate the impact of current STAPs on ozone peak formation and to test ways to optimise their efficiency. In this frame, a set of emission scenarios has been elaborated and tested with the chemistry-transport model CHIMERE on the Berre–Marseille area. Simulations have shown that the tested action plans are not sufficient to eradicate severe ozone peaks and that more drastic restrictions on emissions are required to significantly affect ozone plumes. However, results also showed that the potential for ozone reduction remains small, with a maximum impact of only 5 ppbv for feasible STAPs. Finally, a temporal analysis of the ozone-emission relationship was engaged in order to optimise their application.     

北魏(AD386——534)鄂尔多斯高原的自然一人文景观

通过使用历史地理学研究方法，对北魏时期（ＡＤ３８６－５３４）历史文献记录进行断代考证研究，参用研究精度较高的第四纪地质实验分析资料，围绕鄂尔多斯高原景观问题按地理要素展开探讨，取得的结果是本时段内库布齐沙漠沙深，面积广大，毛乌素沙地已有风成沙丘，植被不丰，干燥气候条件下多个季节仍有雨雪冷湿天气，高原上呈现沙草并存的荒漠－荒漠草原景观，居住其上的人民在套上黄河支流发育地段务农，牧民和载畜量由北向南增多，东南缘边最为集中。     

广交会与2010年亚运会对广州酒店空间格局的影响

2010年亚运会落户广州,有关这一重大事件对城市酒店业发展的影响的研究已提上日程.对广州来说,已具有50余年历史的广交会(中国进出口商品交易会)是这个城市常年举办的一项大型活动.在广州酒店形成5个主要集群区的过程中.广交会作为主要的社会经济推动力量之一,发挥着重要的影响.结合对多年统计数据的整理以及对亚运会实际需求的分析预测,指出广交会作为一种周期性事件(periodic event),对于广州酒店业的长期稳定发展具有更重要的战略意义.     

Climate and causation in the Swedish Iron Age: learning from the present to understand the past

The paper reassesses the role of climate as a factor shaping changes in settlement and landscape in the Swedish Iron Age (500 BC–AD 1050). Two reasons motivate this re-evaluation. First, high-resolution data based on climate proxies from the natural sciences are now increasingly available. Second, the climate-related social sciences have yielded conceptual and theoretical developments regarding vulnerability and adaptability in the present and recent past, creating new ways to analyse the effects of climatic vs. societal factors on societies in the more distant past. Recent research in this field is evaluated and the explicitly climate deterministic standpoint of many recent natural science texts is criticized. Learning from recent approaches to climate change in the social sciences is crucial for understanding society–climate relationships in the past. The paper concludes that we are not yet in a position to fully evaluate the role of the new evidence of abrupt climate change in 850 BC, at the beginning of the Iron Age. Regarding the crisis in the mid-first millennium AD, however, new climate data indicate that a dust veil in AD 536–537 might have aggravated the economic and societal crisis known from previous research.     

Optimum seismic design of reinforced concrete frames according to Eurocode 8 and fib Model Code 2010

Traditional seismic design, like the one adopted in Eurocode 8 (EC8), is force‐based and examining a single level of seismic action. In order to provide improved control of structural damage for different levels of seismic action, the new fib Model Code 2010 (MC2010) includes a fully fledged displacement‐based and performance‐based seismic design methodology. However, the level of complexity and computational effort of the MC2010 methodology is significantly increased. Hence, the use of automated optimization techniques for obtaining cost‐effective design solutions becomes appealing if not necessary. This study employs genetic algorithms to derive and compare optimum seismic design solutions of reinforced concrete frames according to EC8 and MC2010. This is important because MC2010 is meant to serve as a basis for future seismic design codes. It is found that MC2010 drives to more cost‐effective solutions than EC8 for regions of low seismicity and better or similar costs for regions of moderate seismicity. For high‐seismicity regions, MC2010 may yield similar or increased structural costs. This depends strongly on the provisions adopted for selecting the set of ground motions. In all cases, MC2010 provides enhanced control of structural damage. Copyright © 2016 John Wiley & Sons, Ltd.     

静态应力触发在应用中存在问题的讨论以玉树地震为例

大地震应力触发概念自提出至今被广泛应用。 库仑应力与后续地震活动对应效果受到多种因素影响。 其中, 不同深度断层滑动量不同导致不同深度静态库仑应力图像差异, 选取哪一个深度的应力图像来讨论后续地震趋势是一个重要问题。 本文提出一个计算方法, 首先计算不同深度静态库仑应力, 然后在同一个位置取不同深度库仑应力最高值, 绘制静态应力分布图像, 并以2010年玉树地震为例, 结合地震活动及静态库仑应力分布对这种计算方法的效果进行对比。 结果显示, 按照本文提出的计算方法, 利用不同学者给出的玉树地震破裂模型计算均显示, 玉树地震后2年内3级以上余震几乎全部发生在库仑应力增加区。     

基于DDS技术的噪声分析及抑噪实现

直接数字合成(DDS)是一种重要的频率合成技术,具有分辨率高、频率变换快等优点,在雷达、海洋ADCP及通信等领域有着广泛的应用前景。文中对DDS技术所含有的噪声进行了剖析,并得出结论,在量化字长一定的情况下,产生波形的频率误差与参考频率有很大的关系,参考频率越高,波形质量越好,并且当信号的当参考时钟频率与所发射波形频率之比小于10：1时,波形会产生明显的失真;针对DDs技术的噪声,结合具体的数字合成芯片AD9854,提出了一种设计Butterworth滤波器去噪的方法,该方法简单,易行,具有良好的通用性。     

Cartographic Support for the 2010 Decennial Census of the United States

As this article is published, the U.S. Census Bureau is completing work for the twenty third decennial census of the United States. Once again, the MAF/TIGER system served as the geospatial infrastructure supporting numerous census operations and data collection, tabulation, and dissemination activities. From data collection to data dissemination we trace the recent activities of the 2010 Decennial Census of the United States to illustrate the role maps and geospatial data play in an increasing variety of public and private sector activities across the nation. To ensure a successful 2010 Census, millions of maps had to be created. This article will give an overview of the automated mapping system designed to create these maps. This includes a discussion about associated software needed and the variety of map types that were developed. Finally, future map production and geospatial activities at the Census Bureau will be discussed.