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991.
《Quaestiones Mathematicae》2013,36(2):137-159
Abstract The Σλ-calculus is an extension of an applied λ-calculus designed to abstract parallel and non-deterministic function application evaluation. The abstraction is extended to include Landin's closure, and constant terms and a special form of the conditional allows the regular logics to be developed along the lines of the Hilbert-Ackermann approach. The regular logics are used to characterize derived conditionals in extensions to Dijkstra's weakest preconditions. It is shown that various styles of programming—top-down, bottom-up, recursive and iterative—axe expressible in the Σλ-calculus. Lists and streams are found to be useful in expressing time-dependent behaviour of computational systems. An approximate Church-Rosser Theorem is given. 相似文献
992.
Hongyan Xia Yangyang Xu Guang Yang Hao Jiang Gang Zou Qijin Zhang 《Macromolecular rapid communications》2014,35(3):303-308
Here, a novel multi‐stimuli‐responsive fluorescence probe is developed by incorporating spiropyran group into the coumarin‐substituted polydiacetylene (PDA) vesicles. The fluorescence of PDA can be turned on upon heating, and can be quenched upon exposure to UV light irradiation or pH stimuli owing to the fluorescene resonance energy transfer (FRET) between the red‐phase PDA and the open merocyanine (MC) form of spiropyran. Moreover, we have designed and experimentally realized a set of logic gate operations for the first time based on the fluorescence modulation of the designed system upon thermal, photo, and pH stimuli. This novel type of resettable logic gates augur well for practical applications in information storage, optical recording, and sensing in complicated microenvironments.
993.
994.
We report the static and dynamic properties of an all-optical inverter based on an 850 nm Vertical Cavity Semiconductor Optical Amplifier (VCSOA). The inverter exhibits low switching power requirements (~ 15 μW), large on/off contrast ratio (> 11 dB), and high speed operation (~ 1.4 GHz). Large and small signal measurements show that the speed of operation and the on/off contrast ratio improve with increased bias current. This holds important prospects for the development of VCSOA-inverters for high-speed, low-power optical logic applications. Finally, a theoretical model of the VCSOA-inverter has been employed giving good agreement with experiments. 相似文献
995.
The application of multi-valued (non-binary) signals can provide a considerable relief in transmission, storage and processing of large amount of information in digital signal processing. Optical multi-valued logical operation is an interesting challenge for future optical signal processing where we can expect much innovation. A novel all-optical quaternary successor (QSUC) circuit with the help of semiconductor optical amplifier (SOA)-assisted Sagnac switch is proposed and described. This circuit exploits the polarization properties of light. Different logical states are represented by different polarization state of light. Simulation result confirming described method is given in this paper. Proposed all-optical successor circuit can take an important and significant role in designing of all-optical quaternary universal inverter and modulo arithmetic unit (addition and multiplication). 相似文献
996.
Yuhei Ishizaka Yuki Kawaguchi Kunimasa Saitoh Masanori Koshiba 《Optics Communications》2011,284(14):3528-3533
We propose a novel ultra-compact all-optical XOR and AND logic gates without using nonlinear optics. In order to realize these devices, we adopt photonic crystal waveguides (PCWs) based on multi-mode interference devices. Numerical results show that the operating bandwidth of the ON to OFF logic-level contrast ratio of not less than 6.79 dB is 35 nm for XOR logic gate and 9 nm for AND logic gate. Proposed logic gates have the potential to be key components for an optical packet switching system due to their small feature sizes and low power consumption. 相似文献
997.
Semiconductor optical amplifier (SOA) has already been established itself as a strong all-optical switching element for conducting super fast optical operations. Many all optical logic operations have been proposed by the use of SOA. Here in this paper the authors proposed a new method of implementing all-optical frequency encoded logic operations and half-adder by the use of SOA as well as Mach Zehnder interferometer. The advantage of frequency encoding has been strongly exploited here. 相似文献
998.
对苯二甲醛缩二氨基硫脲-钆配合物的合成及阴离子识别研究 总被引:1,自引:0,他引:1
合成了化合物(2E,2′E)-2,2′-(1,4-苯基双亚甲基双硫代氨基脲)(C10H12N6S2)(L),利用L与钆离子形成了配合物(GdL)。用UV-Vis吸收光谱考察其与F-、Cl-、Br-、I-、Ac-、NO3-、HSO4-和H2PO4-等阴离子的识别。研究表明,加入F-或H2PO4-时,溶液颜色由无色变为黄色,加入其它阴离子没有变化,从而实现受体对这两种阴离子的检测。Job法表明主客体间形成1∶1配合物。受体对两种离子的识别作用主要源于配合物多余的结合位点。在此基础上,以GdL的DMSO溶液作为起始状态,以F-和H2PO4-为两化学输入,构建了一个"或"(OR)分子逻辑门。 相似文献
999.
理论上利用两个混沌半导体激光器的耦合反馈,构建了两种基本的光电及全光门.基本方法是,让外部光注入到两个激光器中而导致激光混沌,通过两激光器激光的相互耦合及反馈实现同步;在这基础上,一是让两激光器分别在电流调制下,控制混沌同步或者非同步,实现光电逻辑门的功能与计算;二是利用光的外部调制方法让两相互耦合激光分别在相位调制下,控制混沌同步或者非同步,并最终实现全光逻辑门的功能与计算.数值结果证明了两方法的可行性.
关键词:
混沌
逻辑门
激光器
同步 相似文献
1000.
三值函数表格法最小化中的消变量与消闭化简 总被引:1,自引:0,他引:1
本文在讨论Post代数中三值函数的代数基础、成本计算方法与函数简化准则的基础上提出了兼考虑消变量与消阑化简的三值函数表格法最小化程序.通过实例的化简表明考虑消阂化简后所得的函数的最小化SOP形式要比只考虑消变量化简所得的形式更简单,相应电路的成本更低. 相似文献