51 resultados para Pontes, Belchior de, 1644-1719.


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在湖北武汉市天兴洲江滩边采到一种红色的藻类 ,经鉴定为原管藻 (Protosiphonbotryoides (Kuetzing)Klebs) ,原管藻属是单种属 ,中国新记录。通过野外观察和室内培养 ,对其形态学和繁殖方式进行了研究。其红色多核胞囊在水淹时能迅速产生大量游泳细胞 ,直接萌发成球形幼体或相互结合成星形或不规则分叶的合子。幼细胞球形 ,向两端生长 ,上部为绿色球形 ,下部是长而无色的假根 ;上部绿色球形部分可以以出芽方式形成新个体 ,新细胞和母体大小接近 ,这点和以往文献报道的稍有不同。成熟的

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Sapphire substrates were nanopatterned by dry (inductively coupled plasma, ICP) etching to improve the performance of GaN-based light-emitting diodes (LEDs). GaN-based LEDs on nanopatterned sapphire substrates (NPSS) were fabricated by metal organic chemical vapor deposition (MOCVD). The characteristics of LEDs fabricated on NPSS prepared by dry etching were studied. The light output power and wall-plug efficiency of the LEDs fabricated on NPSS were greater than those of the conventional LEDs fabricated on common planar sapphire substrates when the injection currents were the same. The LEDs on NPSS and common planar sapphire substrates have similar I-V characteristics.

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A triplexer is fabricated based on SOI arrayed waveguide gratings (AWGs). Three wavelengths of the triplexer operate at different diffraction orders of an arrayed waveguide grating. The signals of 1490 nm and 1550 nm, which are input from central input waveguide of an AWG, are demultiplexed and the signal of 1310 nm, which is input from central output waveguide of an AWG, is uploaded. The tested results show that the downloaded and uploaded signals have flat-top response. The insertion loss is 9 dB on chip, the nonadjacent crosstalk is less than -30 dB for 1490 nm and 1301 nm, and is less than -25 dB for 1550 nm, the 3 dB bandwidth equates that of the input light source.

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J.Dj,Golic运用线性序列电路逼进的方法来分析具有任意个输入的求和生成器,他猜想可以通过这种方法来获得所有具有最大相关系数的输入和输出线性函数对,但是他未给出证明。利用Walsh变换技术证明了当n是偶数的时候这个猜想成立。另外,还研究了求和生成器的相关系数总和,发现它与带1比特组合器的相关系数总和非常类似。

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结合制作光子晶体结构的具体要求,研究了电子束曝光得到的电子束胶上(GaAs衬底)随实验条件变化的图形.结果表明,胶的厚度、曝光剂量、显影/定影时间等参数对图形的质量有重要影响.通过合理优化这些参数,我们得到了高质量的掩膜图形.