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1PAL-D制NICAM数字声技术简介PAL-D制NICAM数字声技术,简称“丽音”技术,适合于中国现行的PAL-D制电视系统附加数字立体声或双声道广播接收,使中国的电视伴音由模拟单声道广播跨入了数字立体声广播。附加NICAM数字声电视,采用了NICAM-728技术,NICAM是Near InstantaneousCompanded Audio Multi-plex的缩写,含义为准瞬时压扩音频复用,传输速率为728kb/s。NICAM是由英国BBC公司研究成功的,用于地面和卫星广播,已有PAL-… 相似文献
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例 1[现象 ]某山区乡站遭受雷击后无任何显示 ,无图 (无杂波 )无声。[检查与分析 ]测电源板上的 3组电源电压分别为 14V、 8V、 19V。测主板上稳压IC(LM 7812 )无输出电压 ,手摸无温升。焊下电源控制管 (B772 )和LM 7812检查 ,都损坏。[措施 ]更换B772和LM 7812后 ,12V电源正常供电 ,该机恢复正常工作。例 2[现象 ]机内CPU损坏 ,可以显示与调节 ,收视不到电视节目 ,有杂波信号。[检查与分析 ]测高频调谐器 (H78G0 8·F9315B或F770 8·S6 6 2 6D)的VT点电压为 2V ,并不受频道上下键控制 ,伴音为静音状态。[措施 ]… 相似文献
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AV1001解码器采用日本YAMAHA公司先进的24bit杜比数字(AC-3)解码芯片YSS243B和数字DOLBY-PROLOGIC解码芯片YSS241B,兼有杜比数字解码和杜比环绕声解码两大功能。AV1001与市面上现有的DOLBY-PROLOGIC环绕声处理器或AV功放完全兼容,并且有更高的声道分离度,可还原出更逼真的音场效果来。AV1001拥有杜比数字(AC-3)解码的全部功能,包括对白归一化、自动动态范围控制、向下混合等。设有中置和环绕声道的延时调节,超低音、中置和环绕声道的电平微调,… 相似文献
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刘长占 《广播电视网络技术》2000,(8):25-32
本就在实验室内进行DAB系统模拟测试的方法和参数设置做了初步探讨,并重点分析了MUSICAM压缩质量、复用控制信息和载噪比和误码率(BER)的关系,从系统模拟的角度阐述了影响DAB信号传输质量的因素。 相似文献
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介绍了用VISUALBASIC编制串口通讯程序的两种方法,即如何用Communicationst控件提供的串行端口通讯功能,来创建功能完备、事件驱支斩通讯程序,以及自定义API函数的使用。 相似文献
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例1故障现象 :某市话局有7000门HICOM交换机和5000门华为的C &C08交换机 ,要求释放方式为互不控方式。但当C &C08机的用户呼叫HICOM用户时 ,HICOM用户作为被叫并先挂机后 ,不能立即拆线。故障分析 :在市话局要求MFC的KB信号中 ,一般被叫用户空闲状态用“1”表示 ,而HICOM系统内部默认的KB信号为“6” ,因此需要修改HICOM的系统参数。故障处理 :输入下列命令 ,故障即可排除。<CHA -MFCTA:MFCVAR=1,TYPE=TBLB ,OPT=BSIGB,EODTYPE=FRCH… 相似文献
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1 IntroductionAsisknown ,therearevarioussystemsoffuzzylogic[1~2 ] .ThemostpopularoneisbasedonZadeh’sfuzzysetoperators.ThereafterwewilldenotethissystemasZadeh’sFuzzyLogic(ZFL) .Anewsys temwas proposed[3~ 5] whichiscalledMeasure BasedFuzzyLogic(MBFL) .Itisfoundedont… 相似文献
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By means of exact conformal mapping method we have defined character of dependence of squares amounts of angular part of film
element on angled part dimension. We propose relations, approximating obtained dependence. Calculation results and experimental
researches of large-scale models are represented. 相似文献
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Moshrefzadeh R.S. Radcliffe M.D. Lee T.C. Mohapatra S.K. 《Lightwave Technology, Journal of》1992,10(4):420-425
The temperature dependence of refractive index of polymer films was determined for a number of slab waveguides by a grating coupling method. This dependence was examined as a function of parameters such as molecular weight and glass transition temperature of the polymer. Temperature-induced changes in N TE-N TM , N being the effective index, were studied systematically for different slab waveguide compositions. It is shown that with proper device design and choice of polymeric materials, thermal effects can be reduced 相似文献
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The article describes a model representation of radar probing data in form of a mixture of background and target samples, which is the sum of two random variables with very different parameters. For model development we research the behavior of the central moments of the distribution mix without assuming the distribution law form. An example it is described the detection of the signal at the output of compression system of chirp ionosonde. 相似文献
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解决IP网QoS问题是目前通信领域的研究热点之一.虽然研究已经取得了一定的进展,但人们对于IP 网QoS本身的含义及相关的问题还有着不同的理解.本文将从IP网QoS的定义入手讨论相关的一些问题以及解决IP网QoS问题所做的各种努力. 相似文献
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《Proceedings of the IEEE. Institute of Electrical and Electronics Engineers》1968,56(6):1024-1032
Assuming that visual responses are due to the action of particles on the membrane of the visual cells, the stochastic variability of the response should be a function of the number of particles producing it. Quantitative predictions can be made with the aid of a model proposed in previous articles. It is found that responses produced in visual cells of Limulus by absorption of a single photon have the stochastic properties which would be expected if the response to one photon were brought about by 25 particles. It is concluded from this that the processes leading to visual responses produce multiplication of particles. The effects of temperature and of metabolic poisons suggest that these processes are of chemical nature. 相似文献
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The approaches to prepare a uniform and unified scientific terminology of chemical carcinogenesis are presented. The main definitions proposed (carcinogen, initiation, promotion, mutagen, multistage carcinogenesis, anti-carcinogen, cocarcinogen, carcinogenic risk, etc.) are based on the current state of comprehending mechanisms of the action of chemical carcinogens. 相似文献
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近红外光谱技术在水果品质无损检测中应用的研究与现状 总被引:6,自引:0,他引:6
简单概述了我国水果产业的发展现状,着重阐述了国内外利用近红外光谱技术进行水果品质无损检测的最新研究进展,分析了当今研究中存在的问题,并对利用近红外光谱技术进行水果检测的前景进行了展望,提出了一些建议。 相似文献