黄河上游调节性水库对河段水温的影响及其环境效应分析

大型水库对河道水温会产生一定的影响,特别是其累积影响是否会对生态环境产生衍生影响是很多专家关注的重点之一,因此,如何在水电规划环评或单项工程环评中选用合适的方法判断出准确的水温影响尤为重要。根据黄河上游龙羊峡一刘家峡河段多年的实测数据,分析黄河上游水电站运行产生的河段水温时空分布变化,研究大型调节性水库对河道水温的影响及其环境效应,同时将回顾成果与原环评结论进行对比,并针对刘家峡水电站这一具有特殊形态和运行方式的水库的水温结构分型方法进行探讨,提出了水温分析中所采用的模型及分析方法的合理性建议。     

当前规划环评存在的问题与对策

以流域综合规划及梯级开发规划为例,分析了目前规划环评中存在的早期介入不足、整体性作用不明显、片面追求经济利益忽视规划环评、编制主体主动性不强和规划环评技术力量薄弱等问题。提出了加强法规宣传、抓紧相关法规和技术标准的完善与出台、重视技术力量建设及提高政策公开性等措施,解决目前规划环评存在的问题。     

南方山地丘陵区规模畜禽养殖对水环境影响及评价

选择南方山地丘陵区典型规模畜禽养殖集中地为研究区域,通过对该研究区域周边地表水及地下水的调查采样,分析主要污染物时空变异及污染物形态之间的变化,并对周边水环境进行初步评价。结果表明:规模化畜禽养殖区域的浅层地下水和地表水已经受到严重污染;养殖场的环保处理设施与养殖规模不配套造成大量污染物进入地表水环境;生物氧化塘的护堤和塘底未经防渗处理,造成下游地下水污染;养殖场排放的污水经厌氧和好氧生物处理后富含有机质、氨氮、可溶态有机磷,利于作物吸收和生长,应尽量循环使用。指出由于养殖污水变化较大,为避免二次环境污染,必须处理达标后结合配方施肥技术按需回用农田。     

基于实时预测的传感器信号倍频算法

可穿戴助力机器人是一种能够根据传感器获得的力信号和位置信号进行自主控制的装置,其助力效果与传感器信号的响应频率密切相关.为了改善机器人助力效果,提出了一种提高传感器信号响应频率的算法.该算法首先利用MWQAR预测修正算法获得预测信号,然后利用三样条插值法,在真实信号与预测信号之间插入补偿信号.该算法在保证系统实时性的前...     

MATLAB在《信号与系统》教学中的应用

本文首先指出了《信号与系统》课程教学中存在的不足,其次给出了MATLAB简介,最后着重介绍MATLAB在《信号与系统》教学中的应用,并给出了应用实例。     

Separating mixed multi-component signal with an application in mechanical watch movement

This paper presents a method to combine signal decomposition with blind signal separation for separating one-dimensional mixed multi-component signal of mechanical watch movement. The method consists of three steps. First, a multi-component signal is decomposed into a set of redundant signals, called pseudo multi-channel mixtures, using the continuous wavelet transform (CWT). Then, independent component analysis (ICA) is used to acquire the independent components. Finally, a correlation criterion is applied to automatically select the source components. The new method can effectively separate a multi-component signal into a series of independent components corresponding to different sources. The effectiveness of this method is demonstrated by means of a computer simulation example. And the proposed method is applied for analyzing and diagnosing mechanical watch movements. It is found that the separated source components effectively reveal the insight of the mechanical watch movement, and can be used for fault diagnosis.     

The choice of the optimum frequency band for correlation measurements of the time delay of steady signals

Algorithms for choosing the optimum frequency band for the correlation processing of steady signals are proposed and specific examples are considered. The particular features of the problem of filtering received signals for optimum and nonparametric detection algorithms are considered. Translated from Izmeritel'naya Tekhnika, No. 11, pp. 55–61, November, 2008.     

Ballistic limit equation for equipment placed behind satellite structure walls

A new ballistic limit equation has been developed for the case of a Whipple shield configuration or a sandwich panel with honeycomb core placed in front of a backwall. This “triple plate” ballistic limit equation considers explicitly the thicknesses, materials and spacings of each of the three plates. The third plate, i.e., the backwall, represents the cover plate or external wall of the equipment that is placed behind the satellite structure wall. The ballistic limit equation has been calibrated with experimental results obtained from hypervelocity impact tests on satellite equipment that was placed behind typical satellite structure walls. The equipment considered were fuel and heat pipes, pressure vessels, electronic boxes, harness, and batteries, all representative of real satellite equipment. The new equation was applied to prove that if the inherent protection capability of satellite equipment against hypervelocity impacts is explicitly considered in a ballistic limit equation, the critical projectile diameters for failure of such equipment are raised considerably compared to the case where equipment is assumed to fail as soon as the structure wall that protects it is perforated.     

Modified atmosphere packaging of fresh meats–sudden partial adaptation caused an increase in sustainability of dutch supply chains of fresh meats

In the past decade, a major transition evolved in the Dutch fresh meat industry with ramifications for the entire meat business. In 1995, more than 95% of all fresh meat products for consumers were either sold loose or packed in the traditional way, i.e. on a white styrofoam tray with stretch wrap. Almost a decade later, about half of the meat industry has adapted the modified atmosphere packaging (MAP) technology. Strikingly, the first trials with this technology had already been conducted in The Netherlands in 1964, but it took four decades for the technology to conquer the Dutch meat industry. This paper argued that the partial adaptation of MAP diminished the product losses in fresh meat sales and hence the environmental impact of meat production and consumption. Copyright © 2007 John Wiley & Sons, Ltd.     

An iterative approach to enhanced traffic signal optimization

Recent advances in Intelligent Transportation Systems (ITS) provide large quantities of data that can be exploited for the development of improved traffic management systems. However, mining this data to extract useful patterns and information also presents significant challenges. In an earlier presentation we presented a novel method for optimising traffic timing plans via the use of clustering algorithms to automatically generate Time-Of-Day (TOD) intervals. By detecting time intervals which share common traffic conditions, it was possible to obtain TOD intervals which better reflect the underlying generators of traffic patterns. However, the above-mentioned procedure suffers from a problem: the data that is used to find the clusters was generated using the original traffic patterns, which means that the estimates of the true underlying TOD intervals could be inaccurate. In this paper, we present a refinement of the method which is based on iteratively re-estimating the TOD intervals. Experiments have been conducted to test the usefulness of this additional step and the results are presented and discussed in detail.