Electrically supported column of liquid

Applicctiont of an electric field normal to the interface of certain liquids causes a liquid column of uniform diameter to be formed parallel to the electric field. A column of amyl alcohol supported in aim by a high voltage was investigated experimentally; the diameter of the column varied aS the voltage raised to the 3.5 power.     

Experiments with controlled langmuir circulations

Laboratory experiments in which wind was blown gently over a regular crossed-wave pattern have clearly shown the existence of regular, steady, and reproducible Langmuir circulations. The circulations were present only when both the wind and the wave patterns existed at the same time. With circulations having an across-wind wavelength of 44 centimeters, the descending vertical motions carried turbulent surface water downward 39 centimeters to the bottom of the wind and wave tank. The observations are in general agreement with the mathematical model of Craik and Leibovich, although further experiments will be required to definitively test the analytical model.     

红蓝光下光强对生菜电能、光能利用效率及品质的影响

通过调查红蓝LED光源下生菜的光能利用效率(LUE)和电能利用效率(EUE),以期确定人工光栽培环境下红蓝LED的优化光强参数。本试验LED光源的红蓝光配比设定为1∶1,光强分别为200、300和400μmol/(m2·s)的3个处理(分别以L200、L300和L400表示),生菜定植38d后收获。结果表明:1)定植至收获期间,对每次间苗所收获生菜的干重以及定植38d后收获生菜的干重进行累计计算,处理L300下生菜的EUE最大,为0.948%,较处理L200和L400下生菜的EUE分别高5.22%和46.6%;处理L200下生菜的LUE最大,为4.17%,较处理L300和L400下生菜的LUE分别高12.0%和59.3%。2)定植38d后处理L300下生菜地上部分的鲜干重最大,平均值分别为41.3和2.58g,较处理L200和L400下地上部分鲜重分别高23.5%和25.2%;地上部分干重分别高28.4%和12.8%。3)处理L300与处理L200相比,定植38d后前者叶片的可溶性糖含量较高,硝酸盐含量较低;但与处理L400之间无显著性差异。综合考虑光能、电能利用效率及干重累积量,推荐300μmol/(m2·s)作为红蓝LED组合光源下生菜生长较优的光照强度。     

非线性中立型时滞差分方程的振动性

考虑具有可变时滞的非线性非自治中立型差分方程, △(xn-Pnxn-l) qnf(xn-kn)=0,n=0,1,2…,得到了这类方程振动的几个充分条件.     

吸附法油气回收装置油气吸附量的计量方式

活性炭吸附法是目前国内油库使用最广泛的油气回收技术,而油气吸附量计量是活性炭吸附法油气回收装置切换控制的核心和依据,是确保装置正常工作的前提.介绍了吸附法油气回收装置常见的几种油气吸附量计量方式,包括利用进气流量和浓度计量吸附量,利用进气和排气流量计算吸附量,以及根据鹤管发油信号估算吸附量等方式.阐述了不同计量方式的工作原理、吸附量计算方法以及各自的优缺点,给出了各方法在实际运行中出现的问题和应对的措施.对各种计量方式的综合比较结果表明,通过在油气回收装置进气和排气管道上分别安装超声涡街流量计,能够实现对装置的精确测量和控制,降低成本的同时确保装置的稳定运行.（图3,参10）     

活性有机肥快速生成技术的研究

大规模畜禽粪便无害化利用，一直是国内外农业和环保科技工作者的一道技术难题。为此，本课题以长沙沙浩博实业公司的养殖场为试验基地，对活性有机肥快速生成技术进行了深入的研究，成功研发了自动化程度高、操作简便的有机肥成套技术和设备，这对于从根本上解决养殖场的污染问题，改善生态环境，促进农牧有机结合，改良土壤，发展无公害、绿色、有机农产品生产、实现农业增效、农民增收和农村经济可持续性发展具有重大意义。     

Broadband light bending with plasmonic nanoantennas

The precise manipulation of a propagating wave using phase control is a fundamental building block of optical systems. The wavefront of a light beam propagating across an interface can be modified arbitrarily by introducing abrupt phase changes. We experimentally demonstrated unparalleled wavefront control in a broadband optical wavelength range from 1.0 to 1.9 micrometers. This is accomplished by using an extremely thin plasmonic layer (~λ/50) consisting of an optical nanoantenna array that provides subwavelength phase manipulation on light propagating across the interface. Anomalous light-bending phenomena, including negative angles of refraction and reflection, are observed in the operational wavelength range.     

三维电小尺寸目标群的电磁散射分析

利用电场积分方程(EFIE)的矩量法分析了三维电小尺寸目标群的电磁散射问题.目标群表面采用三角形面元进行剖分,面元上的电流分布用子域基函数表示,用伽略金法将电场积分方程转化为矩阵方程求解电流系数,数值计算了目标群的雷达散射截面(RCS)随入射角度的变化,结果显示了目标群的RCS不仅与目标群的种类、目标群的分布有关,还与入射波的方向和极化方向有关.     

Quantum-to-classical transition with single-photon-added coherent states of light

Single-photon-added coherent states are the result of the most elementary amplification process of classical light fields by a single quantum of excitation. Being intermediate between a single-photon Fock state (fully quantum-mechanical) and a coherent (classical) one, these states offer the opportunity to closely follow the smooth transition between the particle-like and the wavelike behavior of light. We report the experimental generation of single-photon-added coherent states and their complete characterization by quantum tomography. Besides visualizing the evolution of the quantum-to-classical transition, these states allow one to witness the gradual change from the spontaneous to the stimulated regimes of light emission.     

Steering attosecond electron wave packets with light

Photoelectrons excited by extreme ultraviolet or x-ray photons in the presence of a strong laser field generally suffer a spread of their energies due to the absorption and emission of laser photons. We demonstrate that if the emitted electron wave packet is temporally confined to a small fraction of the oscillation period of the interacting light wave, its energy spectrum can be up- or downshifted by many times the laser photon energy without substantial broadening. The light wave can accelerate or decelerate the electron's drift velocity, i.e., steer the electron wave packet like a classical particle. This capability strictly relies on a sub-femtosecond duration of the ionizing x-ray pulse and on its timing to the phase of the light wave with a similar accuracy, offering a simple and potentially single-shot diagnostic tool for attosecond pump-probe spectroscopy.