星际宝贝

这是迪斯尼推出的第41部经典动画大片。它一改迪斯尼动画设计的传统风格,创造了一个全 新面貌的角色——外星小怪物斯迪奇(Stitch),它形象怪异又擅长俏皮动作甚至恶作剧。它与夏威夷一个名叫     

Quantum key distribution transmitter chip based on hybrid-integration of silica and lithium niobates

A quantum key distribution transmitter chip based on hybrid-integration of silica planar light-wave circuit (PLC) and lithium niobates (LN) modulator PLC is presented. The silica part consists of a tunable directional coupler and 400-ps delay line, and the LN part is made up of a Y-branch, with electro-optic modulators on both arms. The two parts are facet-coupled to form an asymmetric Mach-Zehnder interferometer. We successfully encode and decode four BB84 states at 156.25-MHz repetition rate. Fast phase-encoding of 0 or $\pi $ is achieved, with interference fringe visibilities 78.53% and 82.68% for states $|+\rangle$ and $|-\rangle$, respectively. With the aid of an extra off-chip LN intensity modulator, two time-bin states are prepared and the extinction ratios are 18.65 dB and 15.46 dB for states $|0\rangle$ and $|1\rangle$, respectively.     

一种改进的智能Fuzzing平台设计方案

随着软件安全问题的日趋严重,智能Fuzzing技术被广泛应用于漏洞挖掘、软件安全领域.基于符号执行和污点分析技术的各种智能Fuzzing平台相继诞生.该文首先以漏洞安全问题以及软件测试方法学为背景,介绍了智能Fuzzing技术中用到的理论,包括符号执行、污点分析等;然后介绍了现有成型智能Fuzzing平台,包括SAGE、KLEE、BitBlaze等,并且提出它们现存的主要问题;最后通过总结智能Fuzzing平台的可改进之处,提出了一种更有效的智能Fuzzing平台的设计方案,该方案基于全系统的符号执行技术,利用云计算平台进行调度,可以有效应用于商业级软件的Fuzzing工作.     

基于时频域深度网络的海面小目标特征检测

为了提升海杂波背景下小目标探测性能,本文提出一种基于时频域深度网络的特征检测方法。首先,将观测向量转换为归一化时频图（Normalized Time-Frequency Graph, NTFG）,实现海杂波抑制。在时频域,建立海杂波、含正多普勒偏移目标回波、含负多普勒偏移目标回波的三分类问题,精细化目标落在主杂波带内外的不同特性。其次,引入Inception-ResNet V2深度网络作为特征提取器,自主学习不同类别在NTFG上的深层差异性,并将差异性浓缩为一个2D特征向量。然后,在2D特征空间中,设计具有引导的三次样条曲线,获得虚警可控的判决区域,实现异常检测。最后,IPIX实测数据验证了所提算法的性能优势,能深入挖掘时频域的特性。     

基于二氧化硅平面光波导的强度均衡的光脉冲对的产生

提出了一种基于平面光波导工艺的带有可调定向耦合器的非对称MZI结构.模拟结果显示,当定向耦合器的两个耦合臂的折射率独立改变时,定向耦合器的调制效果较好;当调制电极与耦合区的波导间距为0时,两个耦合臂的温度差达到最大.测试得到,AMZI的插入损耗为2.05 dB,延迟时间为151.4 ps,脉冲对的功率比近似为1.该器件有助于提高集成QKD器件的性能.     

天才小子吉米

近年来,高品质 的电脑动画片如 雨后春笋般接连 搬上银幕,而且不断推陈出新。丰富的片种,吊足了小观众们的胃口。这部片子的主角是一个叫吉米·纽特隆的     

格鲁克:歌剧《奥菲欧与尤利狄斯》

在古典歌剧领域,德国作 曲家克里斯托夫 威利巴尔德·格鲁 克(ChristophWillibald Gluck,1714～1787)可能是一位被忽略的人才。他一生创作歌剧百部以上,流传下来特别是经常搬上舞台的确实不多。不管怎样,这部《奥菲欧与尤丽狄斯》却是他最著名的一部歌剧。该剧作于1761～1762年间,歌剧采用意大利     

Temperature characterizations of silica asymmetric Mach-Zehnder interferometer chip for quantum key distribution

Quantum key distribution (QKD) system based on passive silica planar lightwave circuit (PLC) asymmetric Mach-Zehnder interferometers (AMZI) is characterized with thermal stability, low loss and sufficient integration scalability. However, waveguide stresses, both intrinsic and temperature-induced stresses, have significant impacts on the stable operation of the system. We have designed silica AMZI chips of 400 ps delay, with bend waveguides length equalized for both long and short arms to balance the stresses thereof. The temperature characteristics of the silica PLC AMZI chip are studied. The interference visibility at the single photon level is kept higher than 95% over a wide temperature range of 12 ℃. The delay time change is 0.321 ps within a temperature change of 40 ℃. The spectral shift is 0.0011 nm/0.1 ℃. Temperature-induced delay time and peak wavelength variations do not affect the interference visibility. The experiment results demonstrate the advantage of being tolerant to chip temperature fluctuations.     

Absorption enhancement of silicon solar cell with Ag nanoparticles by surface plasmons resonance

The absorption enhancements of silicon layer in silicon solar cells with three kinds of Ag nanoparticles including sphere, cylinder and cuboid are studied by the finite difference time domain （FDTD） method, respectively. The results show that the light absorption of silicon is significantly improved due to the localized surface plasmon （LSP） reso- nance. The relations of the absorption enhancement with the parameters of nanoparticles are thoroughly analyzed. The optimal absorption enhancement can be achieved by adjusting the relevant parameters. Among the three types of Ag nanoparticles, i.e., sphere, cylinder and cuboid, the silicon with the cubical Ag nanopaticles shows the most efficient absorption enhancement at optimal conditions, its maximum absorption enhancement factor is 1.35, and that with the spherical Ag nanopaticles gets the lowest absorption enhancement. The work is useful for the further theoretical study and design for the plasmonic thin-film solar cell.