现场型过程仪表校验仪的设计及应用

本文较为详细地说明了现场型过程仪表校验仪硬件及软件的设计方法,特别讨论了设计现场型校验仪所采用的低功耗设计和面板校准技术.     

Novel prenylated and geranylated aromatic compounds isolated from Polysphondylium cellular slime molds

We have studied the diversity of secondary metabolites of cellular slime molds to utilize them as new biological resources for natural product chemistry. From the methanol extract of fruiting bodies of Polysphondylium tenuissimum, we obtained five prenylated and geranylated aromatic compounds, Pt-1-5 (1-5). An additional aromatic compound, Ppc-1 (6), was isolated from Polysphondylium pseudo-candidum. The structures of these compounds were determined by spectral analysis, and synthetic routes to 4, 5, and 6 were developed. Compound 5 showed the glucose consumption-promotive activity on 3T3-L1 cells.     

一种低功耗降压型整流器的研究

介绍了一种低功耗降压型整流器。该整流器使用两个自换向开关（IGBT＇s）对直流电流做精确整形,并将回灌电路连接交直流侧。实验结果表明：不管晶闸管桥的触发角和负载类型如何,该整流器都产生流自交流电源的纯正弦波电流。与类似的拓扑结构相比,文中提出的降压型整流器拓扑更简单、通用、可靠。     

基于硬件构件的嵌入式系统低功耗研究

降低系统功耗不仅要考虑硬件方面的因素,同时也要分析因软件引起的功耗。为了降低系统整体功耗,首先需要明确影响系统功耗的软硬件因素。在硬件方面,通过对硬件构件进行选择、设计和整合等方法降低功耗;软件方面则是重点优化与功耗密切相关的要素,如算法、指令与方法等。这些因素往往是相互制约、相互影响的。设计一个成功的低功耗系统,需要通过分析与实验,明确一个以硬件构件为思想的嵌入式系统低功耗设计时所需考虑的一些问题。     

基于MSP430的无线传感器节点动态功率管理研究

针对无线传感器网络节点低功耗设计问题,介绍无线传感器节点组成及其能耗,分析动态功率管理原理及其算法,研究混合自动控制并对其进行改进。改进的混合自动控制算法通过对环境变量的变化值划分来控制无线收发模块的收发频率,能减少收发次数,降低系统功耗。最后介绍了在MSP430,nRF905和SCA3000组成的无线加速度传感器系统中对倾斜角测量时改进的混合自动控制算法的应用。     

无线传感器网络能耗分析与策略研究

无线传感器网络技术得到了广泛应用,但是该技术一直受能量的制约,因此能量始终是无线传感器网络的核心问题。通过对传感器节点结构与网络体系的分析,得出了传感器网络的能耗特性。为了延长无线传感器网络的生命周期,对传感器节点工作能耗与传感网络能耗做了具体研究,再从低功耗节点设计、网络协议及环境中能量补给三个方面总结出了一套有效的节能策略。     

星型WSN的低功耗通信方案设计

主要讨论具有双通道的无线传感器网络的节能通信方案设计和仿真问题。先简述了单片无线收发芯片的技术特点。然后设计了汇交和测量节点的操作流程图。还讨论了通信过程关键参数选择问题,和估算了此类网络的能耗、数据传送速率等指标。提出的通信方案在保证正常数据交换的同时能大幅度地减少测量节点的能耗。     

How Do Cultural Classes Emerge from Assimilation and Distinction? An Extension of the Cucker-Smale Flocking Model

When cultural tastes are not neutral but hierarchically matched to social status, people assimilate themselves to higher status by consuming cultural goods while distinguishing themselves from lower status by developing new tastes. Extending the Cucker-Smale model for mutual influence among agents, we examine when and how many cultural classes emerge from continuous distributions of tastes and what conditions those classes satisfy, through the assimilation-distinction mechanism. We simulate the models with different initial distributions of tastes (uniform, normal, and chi-square), given various ranges of 2 parameters: (a) the strength and (b) the range of distinction relative to assimilation. Tastes are flocking and cultural classes emerge when the range of assimilation is much larger than that of distinction. The number of classes increases with the strength of distinction, whereas the distance between classes equals the range of distinction. Some properties of emergent classes are mathematically proved. First, in a two-class system, the stronger distinction, the larger the upper class. Second, in a three-class system, the middle class is necessarily larger than the lower class and likely larger than the upper class. Third, a 3-class system cannot emerge if distinction is weaker than assimilation. These properties are universal and do not depend on the initial distribution of cultural tastes. This independence predicts homogeneous cultural classes emerging across different social conditions. Also, the cultural middle class as the largest group may explain why subjective class consciousness is often higher than objective position. Unless assimilating efforts can reach an infinite range, there emerges a cultural outcast at the lowest end of the cultural hierarchy.     

广西能源、环境和经济增长的动态关系研究——基于VAR模型的实证分析

利用广西1990-2011年GDP、能源消费和工业废气排放总量的数据,应用基于VAR模型的动态计量分析方法,对广西经济、能源和环境的关系进行实证研究.结果表明:三者之间存在长期稳定的协整关系,能源消耗是经济增长和环境污染的Granger原因,经济增长是能源消耗和环境污染的Granger原因.能源消耗对经济增长的正向影响效应时间较长且较稳定,环境污染初期对经济增长的抑制作用较弱却呈现缓慢增强的趋势;而经济增长对能源消耗和环境污染的影响持续时间较短.经济增长与能源消耗两者之间的相互影响较大,而环境污染受能源消耗变化影响较明显.     

GM(1,N)与GM(0,N)模型在能源消费碳排放预测中的比较研究

近年来,减少碳排放已成为缔约国家社会经济发展和生产经营活动的重要目标之一,研究并使用科学的方法对我国未来碳排放进行分析与预测对我国应对气候变化政策的制定具有重要意义.拟将GM(1,N)和GM(0,N)模型用于能源消费碳排放量的预测,建立能源消费碳排放量的多因素灰色预测模型,并对GM(1,N)和GM(0,N)模型预测能源消费碳排放量的精度进行了检验和对比分析.结果表明:在对四川省能源消费碳排放预测中,GM(0,N)具有更高的预测精度和可靠性.