数字调制类型的识别及实现

通信信号的调制识别是目前研究的热点问题.本文给出一种新的数字调制信号识别方法.高速数字专用芯片ADSP2101是此方法具体实现的重要器件,这一方法在实际通信中有着广泛的应用.     

Influence of moderate intensity physical activity levels and gender on conditioned pain modulation

This study examined the potential influence of moderate intensity physical activity (PA) levels and gender on central pain modulation using conditioned pain modulation (CPM) in healthy men and women. Twenty four individuals (12 men and 12 women) who reported engaging in the moderate intensity PA for 150 min or more per week and 24 individuals (12 men and 12 women) who reported engaging in moderate intensity PA for 60 min or less per week completed a self-report PA questionnaire and a 7-day PA assessment using an accelerometer. Furthermore, the participants completed the CPM testing to evaluate the efficiency of central pain modulation. The active individuals scored higher on the PA questionnaire and spent more minutes for light, lifestyle, moderate and vigorous intensity PA than the less active individuals. The active men and women exhibited comparable magnitudes of CPM, and showed a greater magnitude of CPM when compared to their less active counterparts. However, these beneficial effects of higher dose moderate intensity PA disappeared when time spent for vigorous intensity PA was statistically controlled for. These results suggest that the higher dose moderate intensity PA does not add to the benefits from vigorous intensity PA to further improve central pain modulatory systems.     

谈古代诗歌的平仄

唐代近体诗的格律就是平仄交替，它是我国特有的诗律。它与我国古代汉语相适应，又符合美学和生理学的要求。它是我国古代诗人们在创作实践中不断探索的成果。千余年来，平仄律已经影响到中国文化的各个方面。     

多载波系统中低复杂度的改进比特和功率分配算法

基于迭代的比特和功率分配机制,提出了一种低复杂度的比特和功率分配算法.与传统的迭代分配算法不同,该算法在每次迭代中只需要比较几个特定的子载波.该方法在保持传统迭代算法性能的前提下极大地减小了迭代分配算法的复杂度.此外,通过选择等功率分配方案作为初始方案加快了算法的收敛速度,进一步降低了算法复杂度.仿真结果表明,提出的改进算法在基本不牺牲系统性能的前提下有效地降低了算法复杂度.     

自聚焦克尔类电介质中非傍轴光束调制非稳的研究

Propagation stability of non-paraxial beam in nonlinear Kerr media is investigated with a linear stability method.Both theoretical analysis and numerical simulation show that modulation instability(MI) gain spectrum has three different distribution features determined by the times of incident power P0 and the non-paraxial parameter a. Furthermore,the corresponding criterion is put forward to distinguish the three different distributions.     

浅析赵翼论六言诗兼谈六言诗的发展

赵翼在《陔馀丛考》中有关六言诗的评价可谓触及六言诗发展的实质问题。本文通过解读赵翼关于六言诗的一些观点。例如,赵翼认为六言诗的起源不始于谷永,偏爱王维的六言绝句,并认为六言诗没能兴盛是因为“其虽工但非天地自然之音节”,结合赵翼的诗学理论,客观分析上述观点。与此同时。试对六言诗的发展和最终没能繁荣的原因做一个粗浅探究。     

Optical QPSK/16QAM modulation based on serial-parallel MZM scheme in radio-over-fiber system

A novel scheme of optical modulation in 40 GHz radio-over fiber (RoF) system is proposed. It generates optical QPSK/16QAM signals in a serial-parallel structure of Mach-Zehnder modulators (MZMs). The millimeter-wave is obtained with optical frequency multiplication (OFM). Furthermore, modulation on optical-wave is transferred onto millimeter-wave. It can be used to increase transmission capacity of millimeter-wave RoF systems.     

沿海地区计算机制造产业集群跨区域网络构建研究

经过近20年的发展,沿海地区几大产业集群都具备了相当大的规模。但由于受经济区划及行政区划的限制,各大产业集群之间虽然在地理位置上成带状相连,却缺少足够的协同合作与互动,由此导致了各产业集群间产品结构雷同、恶性竞争愈演愈烈的局面。产业集群跨区域网络的构建,特别是跨区域交易网络和创新网络的建设,则可以有效地解决上述问题,有利于提高我国计算机制造产业协同竞争的能力,实现从产业链低端向高端的升级。     

基于AT89C55的单工无线呼叫和数据传输系统设计

基于STC89C55,使用模拟调频技术,设计了一种单工无线呼叫数据传送系统,在30～40 MHz频段上,实现了话筒输入和线路输入语音信号的小功率远距离单工发送和接收.其数据通信采用FSK调制方式,主、从机可实现智能控制通信,可连接多达256个从站,构成一点对多点的单工无线呼叫系统.     

汉语成语平仄律浅论

汉语成语的声调搭配形式具有其自身的特点,根据现代汉语语音划分平仄的理论可予以分类统计。分类统计表明：平平仄仄式、平平平仄式和仄仄平平式是最重要的声调组合形式,根据一、三位上的声调可以不论的原则,可以得出汉语成语平仄搭配具有对称性特点。同时,在并列式成语中,以第二字是平声字、第四字是仄声字的居多,即先＂平＂后＂仄＂的形式居多。