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排序方式: 共有590条查询结果,搜索用时 15 毫秒
1.
海尔做为知名家电企业,进入笔记本市场已经很长时间了。从其陆续推出的产品来看,主要集中在时尚方面,今天我们要说的这款海尔W12,走的就是轻薄时尚路线。 相似文献
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大码:一般来讲,相对高端的品牌都不会走电视购物的路线,明基手机为什么选择电视购物这个销售渠道?今后还有多少手机会走这个渠道?姚洪州总经理(以下简称姚总):首先我纠正一下你的话,其实不是相对高端,应该是相对有知名度的品牌一般不会走电视购物的,明基手机现在用电视或电子媒体是希望在短时间内达到一定的曝光率,实际上是 相似文献
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A novel optical interconnection is introduced for a multistage optical switching network that uses orthogonally polarized data and address information. The network is unique in that the data information is never regenerated and remains in optical form throughout (i.e., it is never converted into electrical information). This has two main consequences: (1) the bandwidth of the data is not restricted by electrical circuit considerations, and (2) the optical interconnections from one stage of the network to the next must be highly efficient. The interconnection meets several goals: high efficiency, preservation of cross polarization of data and address, low cross talk between polarizations, good manufacturability, resistance to misalignment caused by thermal expansion, and absence of significant aberrations. In addition, sychronization of the signals is maintained, as the optical path lengths for all routes through the system are equal. 相似文献
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We use numerical calculations to examine the relation between adaptive optics (AO) turbulence compensation and power coupled through a spectrometer slit for both laser and natural guide-star AO systems. The AO system and observing parameters used are relevant to the Gemini-North 8-m telescope. For this study, we separate residual tilt from residual higher-order aberrations to isolate their relative effects under a variety of operating conditions. Our results demonstrate that slit-coupled intensity is not uniquely determined by system Strehl alone; we show that this is due to the differing effects of higher-order and tilt aberrations on the shape of the compensated point-spread function. For the Gemini spectrometer and AO system, the wider point-spread function halo associated with an added residual higher-order aberration reduces slit-coupled intensity more rapidly than a broad point-spread function core induced by residual tilt. 相似文献
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Planar optical waveguides are an attractive tool for use in analytical chemistry and spectroscopy. Although similar to fiber optics, planar waveguides have been slow to be commercially accepted due to the difficulty of coupling light into the guide. Generally, prism coupling is the method of choice in the laboratory, as efficiencies approaching 80% can be reached. However, prisms are impractical for routine use for several reasons: expensive positioning equipment is required, coupled power is sensitive to environmental fluctuations, and prism coupling prohibits the fabrication of a truly planar device. The use of thin gratings on the surface of the waveguide allows for a two-dimensional structure to be maintained, while providing enough efficiency to be useful as a sensor. Our research efforts focus on developing a technique to make inexpensive, reproducible gratings that are easy to fabricate. By chemically modifying the surface of a commercial grating with a suitable release agent, it is possible to emboss replica gratings onto a variety of waveguide types. The fabrication of embossed gratings will be described, and their performance on glass, ion-diffused, polymer, and semiconductor waveguides will be presented. 相似文献
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Schilling JB Cepa SP Menacherry SD Bavda LT Heard BM Stockwell BL 《Analytical chemistry》1996,68(11):1905-1909
A specific chromatographic LC/MS/MS assay is described for the confirmatory identification of residues of sarafloxacin, an arylfluoroquinolone antibacterial agent, in catfish tissue. This confirmatory method takes advantage of the specificity provided by sample preparation, liquid chromatography, and tandem mass spectrometry. This kind of multidimensional analysis is commonly used in environmental, pharmacokinetic, residue, and other studies. However, we demonstrate the addition of a previously unreported criterion, the use of ion ratio ranges from the tandem mass spectrometry (MS/MS) experiment as an aid in confirmation. Using the described method, we were able to achieve MS/MS product ion ratios with <7% variation during 1 day of analysis for over 25 injections. We believe the addition of this criterion will increase the scientific certainty of the confirmatory method. 相似文献