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说到北美系的音响器材,不少朋友脑子里首先冒出的会是"技术狂人"和"声猛力大"这两个词. 相似文献
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研究了具有双延迟反馈的液晶混合光学双稳器件的不稳定性,首先从实验上观察到了"frustrated instability",类似“魔梯”的锁频台阶以及它的滞后等新现象。实验结果与Ikeda 相似文献
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自从人类观察、感知到所谓"信号"的存在后,便开始试图加以测量、分析并控制,以为己所用.信号历经机械、模拟电信号、固态电子模拟、固定功能数字、硬编码软件等几种型态的演变后,如今已进化到以更高级的编译软件来"处理"了.整个发展历程,就宛若一部人类演进史. 相似文献
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最近发现一个值得关注的现象,越来越多的人开始抱怨微信占据了他们的大部分时间,号称“the new way to connect”的微信不但没能帮助大家解决“社交恐惧”的问题,反而成了“时间杀手”.除此之外,我还观察到几个有趣的现象.
首先是社交关系从“熟人”到“生人”.有没有发现,你微信里的陌生人越来越多? 相似文献
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本文针对跳频信号检测的问题,研究并设计了一种新的检测算法.该方法对信道进行由"粗"到"细"的分层检测,降低了很多无谓的资源消耗.文章首先介绍了传统信道化处理的思想并推导出其模型的数学表达式.然后分析了这种模型在跳频信道数较多时难于实现的原因,进而提出分层信道化处理的检测模型.接下来对该模型的运算量进行了推导并与传统结构... 相似文献
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利用低压-金属有机汽相外延(LP-MOCVD) 工艺首先在二氧化硅衬底上生长硫化锌(ZnS)薄膜,然后,将硫化锌薄膜在氧气中于不同温度下进行热氧化,制备出高质量的纳米氧化锌(ZnO)薄膜.X射线衍射(XRD)结果表明,氧化锌具有六角纤锌矿晶体结构.900℃氧化样品的光致发光(PL)谱中,在波长为3.3eV处观察到一束强紫外光致发光和相当弱的深能级发射.紫外发光强度与深能级发射强度之比是80,表明纳米ZnO薄膜的高质量结晶.在受激发射实验中观察到紫外激光发射. 相似文献
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FlexRay communication protocol is expected to become the de-facto standard for distributed safety-critical systems. This paper classifies the effects of transient single bit-flip fault injections into the FlexRay communication controller. In this protocol, when an injected fault is activated, this may result in one or more error types, i.e.: Boundary violation, Conflict, Content, Freeze, Synchronization, Syntax, and Invalid frame. To study the activated faults, a FlexRay bus network, composed of four nodes, was modeled by Verilog HDL; and a total of 135,600 transient faults was injected in only one node, called the target node. The results show that only 9,342 of the faults (about 6.9%) were activated and their effects were observed in the network nodes. The results also show that the Synchronization error is the widespread error with the occurrence rate of 70.1%. The Invalid frame, Boundary violation, Syntax, Content, Freeze, and Conflict errors have the occurrence rates of 51.1%, 32.4%, 24.6%, 20.6%, 17.3%, and 0.0%, respectively. Among the error types, the Freeze errors are the most critical errors as they mostly result in system failures. The results also show that most of the activated faults, about 75.3%, were observed simultaneously in the target node and a neighbor node. About 11.1% of the activated faults were observed only in the target node and about 13.5% only in the neighbor node. 相似文献
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高双折射液晶在液晶显示中具有重要的应用价值,但是由于分子结构中含有不饱和共轭结构,在紫外下不稳定,本文对高双折射液晶紫外不稳定的问题进行了研究。首先在混晶母体A中分别加入几种不同结构的添加剂三苯氧膦、丙基双环己基甲醛、丙基苯(3,5-2F)溴苯、UV-P,搅拌使其溶解均匀,将液晶灌入TN-7.0-R测试盒,在紫外下曝光后测试混晶的各项参数。实验结果表明:UV-P明显提高了高双折射液晶的抗紫外性能,因为UV-P的紫外吸收光谱带与高双折射液晶母体A的紫外吸收光谱带最接近。 相似文献
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A wavelength-tunable, single-frequency GaInAsP-InP laser diode using an intracavity electrooptic LiNbO3 crystal as the wavelength selective component is discussed. Wavelength tuning is achieved by applying a driving voltage on the crystal electrodes. First results indicate a tuning rate of 1 GHz/V over a tuning range of about 4 nm. This performance was obtained using a nonoptimized X -cut, Z -propagating LiNbO3 crystal. A potential tuning rate of 6.5 GHz/V is possible with reasonable improvements 相似文献
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李应选 《大气与环境光学学报》2001,(1)
以红外光学晶体材料锗(Ge)为重点,介绍红外光学元件的精密切削加工技术及其最新进展。首先主要介绍红外晶体材料及其性能;然后重点叙述晶体材料的切削加工特性,分析晶向对切削面的影响,给出切削条件与切削面质量的关系,列举锗非球面透镜的切削加工以及一些相关问题,最后介绍红外光学元件的镀膜技术。 相似文献
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In Japan, there has been considerable activity in the research and manufacturing of quartz crystal filters, ceramic filters and mechanical filters. This paper reviews some of these contributions. An emphasis is placed on filters actually used. First multiple-mode resonators are reviewed; this concept having had profound effects on all types of filters. Quartz-crystal filters as well as other crystal filters are discussed. Then follow reviews on ceramic and mechanical filters. 相似文献