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双语推荐：调制

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为探究调制技术与烟草香气物质含量的关系，从调制设施、调制环境、调制方法等方面综述了调制对烤烟、白肋烟等不同烟草类型烟叶香气物质含量的影响，分析并总结了烤房设施、晾房设施及调制温湿度、调制时间、调制方法等烟草调制技术的研究成果及研究中存在的问题，并对该领域的研究方向进行了展望。
To explore the relationship between curing technologies and the contents of aromatic substances of tobacco,the effects of curing technologies on the contents of aromatic substances in respect of curing fa-cilities,curing environment,curing methods were reviewed for flue-cured tobacco and burley tobacco. The existing problems and the results of the study on the flue-curing and air-curing facilities,curing tempera-ture and humidity,curing time and methods were summarized and analyzed. The outlook on research di-rection in this field was also given in the article.

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针对矩阵变换器调制策略电压传输比低的问题,在深入研究矩阵式变换器空间矢量调制策的基础上,提出了一种通过改变电压调制系数提高电压传输比的空间矢量过调制策略。根据电压矢量轨迹与空间矢量六边形位置的关系,将电压空间矢量调制区域分为线性调制区和过调制区,通过改变电压调制系数,从而实现过调制策略。最后建立MATLAB/Simulink仿真,结果表明空间矢量过调制策略可以有效提高电压传输比到0.955。
Based on study of space vector modulation, a novel over-modulation method of matrix converter is proposed for the problem of low voltage transfer ratio of matrix converter. According to the relation of the voltage space vector trace and hexagon trace vector, the control level is divided into linear modulation level and over-modulation level. The over modulation strategy is achieved by transforming the voltage modulation coefficient. The simulation results demonstrate that the voltage transfer ratio can be up to 0 . 955 .

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通常认为,当气室压力提高到一定程度,调制气流声源声压级输出将趋于饱和。为了从基本原理上探讨进一步提高声源输出的途径,设计了收缩-扩张喷口,将调制作用上游的声速流动提高至超声速。理论分析表明,来流气压较高时,超声速调制优于声速调制,可获得一定的声压级增益。增益量随喷口面积比减小而增加。旋笛实验在调制频率较低时得到了超声速调制的声压级增益;调制频率较高时,受瞬态作用的影响,参与调制的气流很可能未完全发展为超声速流动,超声速调制与声速调制的旋笛性能相同。
It is generally acknowledged that the sound pressure level (SPL)of air-modulated speaker (AMS)will finally reach the level of saturation when the chamber pressure increases to a certain degree.As a new approach to obtain higher SPL output,supersonic flow modulation was discussed in which the flow speed of nozzle exit was increased from sonic to supersonic.Results from the quasi-steady theory proved that,when the chamber pressure is high,the SPL in the supersonic case is higher than that in the sonic case.Larger SPL increments generally appear at smaller nozzle area ratio.The improvement of the source intensity was validated by the comparison of sound measurements between the sonic and supersonic cases in low frequency modulation.But in high frequency modulation,due to the transient flow effect,the SPL in the supersonic case is the same as that in the sonic case while the air jet is considered to be not fully developed or sped up to be supersonic.

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[目的]比较三段式调制工艺、提质增香调制工艺、津巴布韦调制工艺3种调制工艺对烟叶调制质量的影响，筛选适宜的烘烤工艺，在生产上示范应用。[方法]采用 KRK26品种下部、中部、上部烟叶，进行调制试验，分析原烟质量性状。[结果]采用提质增香调制工艺，上等烟、中上等烟比例比津巴布韦调制工艺提高了4.68%、1.97%，均价提高了1.15元/kg，比三段式调制工艺处理分别提高了10.33%、9.07%、3.12元/kg。提质增香调制工艺能有效改善烟叶香气质、增加香气量，烟叶香吃味和协调性均较好。[结论]烤烟提质增香调制工艺可供烟叶生产借鉴使用。
[Objective] The aim was to compare the effects of three-phase technique, quality and aromatic-flavor improvement technique and Zimbabwe technique on to-bacco quality to select a suitable technique in tobacco production. [Method] Tobacco leaves in down, middle and upper parts of a tobacco variety KRK26 were col ected to analyze raw tobacco quality characters. [Result] With quality and aromatic-flavor improvement technique, the proportions of high-quality and middle/high quality tobac-cos improved by 4.68% and 1.97% and average price enhanced by 1.15 yuan/kg, increasing by 10.33%, 9.07% and 3.12 yuan/kg, compared with three-phase tech-nique. It is proved that the technique would better improve tobacco fragrance and quality and coordinate tobacco fragrance, taste and throat-irritation. [Conclusion] Quality and aromatic-flavor improvement technique provides references for tobacco production.

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基于Optisystem和Matlab软件构建相干解调光正交频分复用(CO-OFDM)系统仿真平台。从O-OFDM的调制出发,在Optisystem中用幅度相位键控(APSK)调制代替现在主流使用的方形正交振幅调制(QAM)。分析APSK调制在光通信中的优越性,并将得到的仿真星座图、误码率、线宽与QAM调制下的结果相互对比,从而区分APSK调制比QAM调制优越性并总结规律。
A system simulation platform of CO-OFDM (coherent detection optical orthogonal frequency division multiplex-ing)was established on the basis of the softwares Optisystem and Matlab. Starting from the O-OFDM(optical orthogonal frequen-cy division multiplexing)modulation,APSK(amplitude and phase shift keying)modulation was adopted in the software Optisys-tem to replace the square QAM(quadrature amplitude modulation)modulation that is prevalently used in the software Optisys-tem and Matlab. The the advantages of APSK in optical communication is analyzed. The constellation graph,BER and linewidth getting from the simulating results are compared with the results from QAM,so as to determine the superiority of APSK modula-tion which is better then QAM modulation. The relative law is summarized.

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基于发光二极管(LED)调制带宽限制了可见光通信(VLC)系统传输速率这一问题,从VLC系统的先进调制技术出发,探讨了类平衡-正交频分复用、无载波幅相调制和频域均衡单载波调制3种调制技术。对这3种调制技术原理和实验结果的分析与讨论,验证了先进调制技术在提升VLC系统传输容量上的可行性。
We introduce three formats, based on advanced modulation, that improve transmission. These formats are quasi-balanced detection orthogonal frequency-division multiplexing (OFDM), carrier-less amplitude and phase modulation, and single carrier-frequency domain equalization (SC-FDE). We determine the feasibility of these schemes for improving transmission in a VLC system. We analyze the principles of these three modulation formants and provide experimental results.

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[目的]为筛选优化烤烟调制工艺，提升烟叶风格特征、品质特征及卷烟工业可用性。[方法]以云烟87品种烟叶为材料，设置3种调制工艺处理（烟叶调制全过程中等强度工艺；烟叶调制变黄期、凋萎期高强度，干叶期、干筋期中等强度工艺；烟叶调制全过程高强度工艺），分析不同强度调制工艺对烟叶致香成分含量及评吸质量的影响。[结果]烟叶调制全过程高强度工艺，48种致香物质中有28种含量高，其余20种致香物质受调制工艺影响不明显；烟叶感官评吸质量较好。其次是烟叶调制变黄期、凋萎期高强度，干叶期、干筋期中等强度工艺；烟叶调制全过程中等强度工艺，较差。[结论]综合分析认为，烟叶全过程高强度处理调制工艺，烤后烟叶致香成分含量和评吸质量较高。
[Objective]This study aimed to optimize the conditions for curing tobacco leaf, so as to improve its flavor and quality. [Method] Leaves of Yuanyan 87 were col ected and cured by three different techniques (moderate-intensity conditions throughout the curing course; high-intensity conditions at leaf yel owing and wilting stages, moderate-intensity conditions at leaf drying and vein drying stages; high-in-tensity conditions throughout the curing course), and then the contents of 48 aroma substances and taste indices of the finished tobacco leaves were measured. [Result] The contents of 28 aroma substances in the tobacco leaves cured under high-inten-sity conditions throughout the course were higher and the taste indices of these to-bacco leaves were better, compared with those flue-cured by the other two tech-niques. The contents of the other 20 aroma substances were not significantly af-fected by the curing techniques. The second best technique was high-intensity con-ditions at leaf ye

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根据对激光器施加的调制信号是否连续,波长调制光谱分为连续和准连续调制激光吸收光谱技术。为了深入的比较研究这两种方案,设计准连续调制谱专用的软件锁相放大器,将准连续调制信号因间断产生的无效信号滤除后,再对吸收信号解调得到二次谐波信号。与连续激光调制谱软件解调的二次谐波信号进行了比较,结果表明,参数相同,准连续调制谱比连续调制谱的信噪比提高5%、检测限降低11.3%。在滤除无效信号后,准连续调制谱也可以解调出标准的二次谐波信号,因此有望用于与气体线型相关的研究中。该工作为选取更加适用的激光调制谱技术,提供了准确依据。
According to the modulation signal applied on laser diodes ,wavelength modulation spectroscopy (WMS) can be divid-ed into continuous wave (CW) WMS and quasi-continuous wave (QCW) WMS .In order to deeply compare CW-WMS and QCW-WMS ,we used a specific software-realized lock-in amplifier for continuous and quasi-continuous modulation signal demod-ulation .The invalid signal in quasi-continuous modulation spectrum was filtered off ,and then the effective detection signal was demodulated to obtain the second harmonic signal (WMS-2f) .It was compared with the 2f signal demodulated continuous laser modulation spectrum with software .The results show that while the same system parameters are set ,the signal-to-noise of the quasi-continuous modulation spectrum is 5% higher than the continuous modulation spectrum with software demodulation meas-urements ,and the detection limit is 11 .3% lower .And without the invalid signal in quasi-continuous modulation spectrum ,the standard WMS-2f signal can

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为了改善脉冲位置调制需要符号同步和数字脉冲间隔调制、双头脉冲间隔调制、多幅度脉冲间隔调制符号长度不固定所引起的接收发机结构复杂和调制器速率不固定等问题，提出将定长数字脉冲间隔调制应用于水下无线光通信系统。分析了带宽需求、传输容量，并与其它调制方式进行了比较；在给出水下无线光通信信道模型的基础上，推导了该信道中定长数字脉冲间隔调制方式的误包率表达式。结果表明，定长数字脉冲间隔调制适用于水下无线光通信系统。
In order to improve the complex structure of the receiver and the transmitter and the unfixed rate of the modulator while pulse position modulation ( PPM ) needed symbol synchronization and digital pulse interval modulation (DPIM), dual-header pulse interval modulation ( DHPIM), multilevel digital pulse interval modulation ( MDPIM) had unfixed symbol length , fixed-length digital pulse interval modulation ( FDPIM ) used in underwater wireless optical communication system was put forward .Bandwidth requirement and transmission capacity were analyzed , compared with on-off keying ( OOK ) , PPM, DPIM and MDPIM.Based on the model of underwater wireless optical communication channel, packet error rate (PER) of FDPIM for this channel was presented .The results show that FDPIM is suitable for underwater optical wireless communication system.

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为同时改善不对称的随机极性甚小幅相（ARP—VMAP）调制信号的频谱利用率和能量利用率，提出了一种多元位置3值VMAP调制方式，设计了基于BP神经网络或支持向量机解调器的接收机。对比和分析了ARP—VMAP调制、3值VMAP调制、多元位置ARP—VMAP调制和多元位置3值VMAP调制信号的功率谱特性、-60dB带宽、频谱利用率和解调性能。仿真结果表明，新的调制方式不仅提高了频谱利用率，而且显著改善了解调性能。
In order to improve the spectral efficiency and energy efficiency of asymmetry, random-polar and very mini-mum amplitude and phase (ARP-VMAP) modulated signal simultaneously, an M-ary position and three-valued VMAP modulation was presented, and the receiver based on BP neural network or support vector machine demodulator was also designed. The contrast and analysis of the power spectrum, the?60 dB bandwidth, the spectral efficiency, and the demo-dulation performance among modulations as the ARP-VMAP, the three-valued VMAP, the M-ary position ARP-VMAP, and the M-ary position and three-valued VMAP, were carried out. Simulation results show that the new modem not only raise spectral efficiency, but also improve demodulation performance significantly.

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