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1.
Output nonlocality and nonclassicality for the two modes are investigated in an entanglement laser sys-tem. Within the framework of a quantum theory of multiwave mixing,nonlocality and nonclassicality are discussed according to the violations of Bell inequality and Cauchy-Schwarz inequality. It is found that both nonlocality and nonclassicality can be fulfilled in the outside cavity fields under certain conditions. It is also shown that there are some nonclassical states that do not show nonlocality. 相似文献
2.
Gang Feng Guo Mingsheng He Xiang Yang Kong Hong Lin Jianbao Li Li-Zhen Fan 《Applied Physics A: Materials Science & Processing》2009,97(4):729-734
A unique Si3N4 sandwich-like nanosaw has been successfully fabricated by the catalyst-assisted pyrolysis of polymeric precursors. The nanosaws
are configured as nanoteeth “welded” to the sidewall of a conventional nanobelt and the “soldering region” between the nanobelt
and nanoteeth. For each nanosaw, there are numerous defects in the central “soldering region”, but little defects in the zigzag
or flat sidewalls. The teeth (zigzag sidewalls) are terminated by the {11[`2]0}\{11\bar{2}0\} family of planes with a lower surface energy. The sandwich-like nanosaw exhibits unique optical properties, which are different
from previously reported Si3N4 nanostructures, demonstrating a likelihood of constructing sandwich-like nanosaw devices with functionalities applicable
for working in high-temperature and harsh environments. 相似文献
3.
均值矩阵的函数的所有可容许估计 总被引:1,自引:0,他引:1
对于多元正态线性模型Ynxm~N(Xθ,σ2∑V),在四种不同的可容许意义下,本文研究了SXθ的线性估计LY+D在一切估计类中的可容许性在适当条件下得到了充要条件,在一般情况给出了充分条件和必要条件. 相似文献
4.
采用蒙特卡罗方法模拟了直接转换X射线探测材料HgI2在医用X射线范围的固有空间分辨性能,模拟基于最新版本的EGSnrc模拟软件的用户代码DOSRZnrc,模拟了HgI2材料对无限小锥束入射X射线的调制传递函数(MTF)。考虑到荧光光子和散射光子重吸收,高速电子射程扩展以及离轴X射线入射对空间分辨力的影响,把模拟结果和文献解析方法获得的结果做了对比,两者符合较好。模拟结果表明,初级高速电子射程和入射角度对材料固有空间分辨力影响很大,材料分辨对入射X光子能量很敏感,高能时分辨力特性急剧变差,而对材料厚度很不敏感。相对于非晶硒(α-Se),HgI2材料具有更好的固有空间分辨力,尤其在50 keV能量以上时。在fMTF=0.5时,能量为20 keV,50 keV和100 keV的X射线入射,HgI2和非晶Se固有空间分辨力分别为390 lp/mm,170lp/mm,52 lp/mm和390 lp/mm,80 lp/mm,22 lp/mm。 相似文献
5.
For the general fixed effects linear model:Y=X+, N(0,V),V0, we obtain the necessary and sufficient conditions forLY+a to be admissible for a linear estimable functionS in the class of all estimators under the loss function (d -S)D(d -S), whereD0 is known. For the general random effects linear model:
=XV
11
X+XV
12+V
21
X+V
220, we also get the necessary and sufficient conditions forLY+a to be admissible for a linear estimable functionS+Q in the class of all estimators under the loss function (d -S -Q)D(d -S -Q), whereD0 is known. 相似文献
6.
基于染料敏化太阳能电池发展起来的有机-无机杂化钙钛矿太阳能电池经过不到5年的快速发展, 光电转换效率从最初的3.8%提高到了经过认证的17.9%. 但是常用结构的钙钛矿太阳能电池在性能测试过程中的电流-电压(I-V)曲线会随着测试器件扫描方向的不同而明显不同. 该现象被称为I-V滞回现象. 进一步研究发现I-V曲线还与扫描速度、起始测试的偏压值和光照历史明显相关. 本工作结合不同的器件构造, 就可能造成这种I-V滞回现象的不同原因进行了总结和分析, 并对如何获得可靠的光电转换效率的测试方法进行了评述. 相似文献
7.
本文以五氧化二钽、活性炭为主要原料,氟化钾为熔盐介质,通过碳热还原氮化法在氨气气氛下成功制备了氮化钽(Ta5N6)晶须.运用X射线衍射仪(XRD)、场发射扫描电子显微镜(FESEM)、透射电子显微镜(TEM)对合成产物的组成、结构和形貌进行了表征.研究了升温方式、氮化气氛、氮化时间和催化剂含量对产物形成的影响.当Ni与Ta2O5的摩尔比为0.1、氮化气氛为氨气(流量为300 mL/min)、氮化时间为6h时制备的晶须形貌最佳,晶须直径80~250 nm,长为1~5μm,晶须的生长机制为气-液-固(VLS)和气-固(VS)两种机理的混合机制. 相似文献
8.
Ruiju Wei Bin Wu Huanyu Zhao Jianbao Li Cunfu He 《Solid State Communications》2010,150(31-32):1463-1466
Using symmetry reduction concept, the band gap properties of a two-dimensional hybrid triangular lattice phononic crystal were investigated both theoretically and experimentally. The band structure was calculated with the plane wave expansion (PWE) method. The results revealed that the band degeneracy at high symmetry point in the first Brillouin zone was lifted due to reducing symmetry, and hence a new low-frequency absolute band gap between the first and the second bands appeared. The measured transmission spectra were found to be in good agreement with the numerical results. 相似文献
9.
10.
Gang Feng Guo Mingsheng He Xiang Yang Kong Hong Lin Jianbao Li Li-Zhen Fan 《Applied Physics A: Materials Science & Processing》2010,98(2):321-326
In a previous paper (G.F. Guo et al., Appl. Phys. A, 2009), the microstructures of sandwich-like nanosaws have been revealed clearly. Here, the growth mechanism and optical properties
of Si3N4 sandwich-like nanosaws were further investigated. It is assumed that the growth atmosphere with a large amount of *N (active nitrogen) from the decomposition of NH3 would be the key factor for the formation of sandwich-like nanosaws during the catalyst-assisted pyrolysis of the polymeric
precursors. From the characterizations of TEM together with the systematic composition analysis, we found that a large excess
of nitrogen element occurred in the central “soldering” region as well as high density defects, which induced the asymmetric
growth of nanoteeth on the original nanobelt sidewall, forming into a sandwich-like nanosaw morphology. The unique optical
properties of sandwich-like nanosaws could be attributed from the presence of a large amount of nitrogen dangling bond defects
in the central “soldering” region, and a new optical band-gap model was proposed for the interpretation of the photoluminescence
spectra. 相似文献