Structural damage detection using convolutional neural networks combining strain energy and dynamic response

Meccanica - Based on the classification ability of a convolutional neural network (CNN), this paper proposes a structural damage detection method in which a CNN is used to classify the location and...     

类克尔介质对二能级原子与压缩相干态相互作用的影响

通过研究原子反转和光子数统计分布,讨论包含类克尔介质的双光子二能级原子与压缩相干态相互作用的量予特性.结果表明,在类克尔介质与模场的耦合强度为原子与模场耦合强度的两倍以上时,原子与模场耦合的作用不明显.     

有效二能级原子与压缩相干光场相互作用过程中场熵的特性

本文研究了包括Stark效应时,双光子Jaynes-Cummings模型与单模压缩相干光场发生相互作用过程中场熵的特性,讨论了Stark移动参数、光场参数对场墒演化的影响.     

类Kerr介质中双模SU(1,1)相干态场与Λ型三能级原子相互作用的量子统计性质

导出了类Kerr介质中双模SU(1,1)相干态场与Λ型三能级原子相互作用系统的态函数,研究了Kerr效应对Λ型三能级原子布居概率、双模SU(1,1)相干态场的互关联函数、Cauchy-Schwartz不等式及二阶相干度的影响.结果表明:Kerr效应使原子与光场的耦合减弱,原子布居的崩塌与复苏的周期缩短;在初始光场较弱和较强两种情况下,类Kerr介质对双模SU(1,1)相干态场两模间的相关性、相关程度以及光子的聚束与反聚束效应产生的作用有明显的区别.     

Adsorption and electron-induced dissociation of ethanethiol on au(111)

Dissociation of ethanethiol and the formation of Au-adatom-diethylthiolate rows on the Au(111) surface were investigated using scanning tunneling microscopy (STM) at low temperature. Ethanethiol molecules physisorb on Au(111) at 120 K by sequentially occupation of the elbow site, the fcc domain before covering the whole surface with a semiliquid layer without long-range order. Scanning the physisorbed layer with a sample bias higher than +1.2 V leads to dissociation via cleaving the H-S bond. One of the dissociation products, ethylthiolate, forms a double-row structure with the rows aligned in one of the ?112?? directions. These double rows arise from the Au-adatom-dithiolate species: CH(3)CH(2)S-Au-SCH(2)CH(3).     

Single layer gold islands at the interface between a self-assembled monolayer and the Au(111) substrate: A high-resolution STM study

Physical vapor deposition of gold onto a self-assembled monolayer (SAM) of octanethiol on Au(111) has been studied at the molecular level in ultra-high vacuum (UHV) using atomic-resolution scanning tunneling microscopy (STM). A specially prepared SAM with not only the usual etch pits but also co-existing phases and domain boundaries is used for the purpose of studying details of the nucleation process. Etch pits are found to be filled by deposited Au atoms. At the same time, preferential nucleation and growth of gold islands at intersections of different domains, as well as inside the domains of the less dense striped phase, is observed. We find no gold islands within the densely-packed (√3 × √3)R30° phase. High-resolution STM imaging shows that the SAM over the newly formed gold islands adopts the same structure as that in the immediate surroundings.     

与Λ型三能级原子非共振相互作用的SU(1,1)场的性质

导出了介质中双模SU(1,1)相干态场与Λ型三能级原子非共振相互作用系统的态函数,研究了场模失谐量、克尔介质以及原子初态对场的互关联函数和Mandel Q参量的影响.结果表明:失谐量将削弱光场两模的关联性,并影响场模光子数的统计分布;当SU(1,1)场两模间的光子数之差增大时,失谐量对它们产生的影响变得更弱,此时克尔效应的影响变得明显,它使两模的关联性和光子数的统计分布趋于稳定.     

混合态二能级原子双光子过程的粒子数反转特性

本文采用时间演化算符方法和数值计算研究了相干光场与混合态二能级原子双光子过程的粒子数反转特性,结果表明:量子崩塌与复苏性质和原子初始的混合程度无关,但振荡最大幅值受原子初始混合程度的支配,随着原子初始混合程度的增大,原子反转几率减小;在强场作用下,这种量子崩塌与复苏性质,将随着n值的不断增大而重复地出现复苏收缩现象,且场与原子的非线性耦合越来越强.     

介观二阶并联电路的量子涨落

从有源RLC并联电路的经典运动方程出发,通过引入复正则变量,提出了RLC并联电路的量子化方案.作为应用,研究了压缩真空态下介观并联RLC电路中电压,电流的量子涨落,并对结果进行了讨论.     

Large-scale quantification of aluminum in AlxGa1-xN alloys by ToF-SIMS: The benefit of secondary cluster ions

Precise determination of composition is requisite for Al_xGa_1-xN-based energy band engineering. Secondary cluster ions in a time-of-flight secondary ion mass spectrometry (ToF-SIMS) full spectrum are introduced for accurate quantification of Al in Al_xGa_1-xN for AlGaN-based devices. It was found that statistical analysis with huge number of large secondary cluster ions (without small ions) show much better linear dependence with apparent compensation of matrix effect, particularly in negative polarity. For Al_xGa_1-xN with x = 0 to 0.7, x values calculated based on large negative cluster ions (NCIs) show excellent linear dependence with real values. Besides, atomic count ratio of C (Al)/C (Ga) and C (Ga)/C (Al) also shows great linear relationships with corresponding mole fraction ratios in a large range. Overlap of these linear ranges offers a reliable and convenient quantification protocol of Al_xGa_1-xN covering a full range of x = 0 to 1. This study verifies that the secondary cluster ions are beneficial for quantification of Al_xGa_1-xN-based materials.