Structural,electrical, and linear/nonlinear optical characteristics of thermally evaporated molybdenum oxide thin films

Homogeneous thin films of Molybdenum oxide (MoO₃) were grown on quartz and glass substrates using the thermal evaporation method. XRD results showed that the MoO₃ powder has a polycrystalline structure with an orthorhombic crystal system whereas the MoO₃ thin films have amorphous nature. SEM images showed that the MoO₃ thin films have a nearly uniform surfaces with worm-like shape grains. The film thickness influences on the linear and nonlinear optical characteristics of MoO₃ thin films that were examined using spectrophotometric measurements and from which, the linear optical constants of the MoO₃ thin films were estimated. The electronic transition type was determined as a direct allowed one. The values of the optical band gap were obtained to be in the range of 3.88–3.72 eV. The dispersion parameters, third-order nonlinear optical susceptibility, and the nonlinear refractive index of the MoO₃ thin films were determined and interpreted in the light of the single oscillator model. The temperature dependence of the DC electrical conductivity and the corresponding conduction mechanism for the MoO₃ films were investigated at temperatures ranging from 303 to 463 K.     

超稳光纤链路的理论与实践

超稳光纤链路这个概念包含超稳频率光源和超稳频率传递的光纤链路。从当前看,如何利用已有庞大的公用电信网、专用网的光纤和光网络的资源,选择一个通用的光纤通路改造成超稳光纤链路来实现频率传递,取代基于卫星的频率传递,提高传输的频率精度,这是一个巨大的系统工程。本文对超稳频率光源和超稳频率传递的光纤链路的关键技术进行研究和讨论。     

一种用于电气设备状态监测的新式FBG传感器北大核心CSCD

为了监测绕组变压器的静态应力场和发生短路等故障时的动态应力变化,设计了一种用于电气设备状态监测的新式FBG传感器。该传感器由聚醚醚酮材料封装的FBG构成,通过内部圆锥形空腔结构实现将轴向应力集中于FBG敏感位置。通过仿真对不同压力强度下传感器结构的应力场部分及形变趋势进行了计算与分析,论证了设计的合理性。实验分别对静态载荷和动态冲击进行测试,结果显示,在静态压载测试中,当100 N相似文献   

基于可供性的文化意象交互式智能音箱设计研究

目的 探索将文化民俗有效融入现代产品中的技术思路，保留并延续中华传统文化的生命力，有助于提升用户体验。方法 分析可供性与文化意象之间的主客观互通性;挖掘交互式智能音箱中的可供性触点;构建形态、感官、认知及情境四类可供性的设计框架;以楚文化意象为例进行设计实践，对智能音箱的产品造型与交互操作方式进行设计，并进行设计评价。结果 在可供性理论指导下的楚文化意象交互式智能音箱产品外观及交互体验设计较好地满足了设计目标和用户需求。结论 可供性有助于文化意象的正确提取与转化，可将意象抽象为具有实际意义的设计要素，帮助用户在生理与认知两个层面理解产品的使用方法，同时进一步回味、体验文化内涵和文化精髓。     

Fabrication of high-efficiency Yb:Y2O3 laser ceramics without photodarkening

High-efficiency Yb:Y₂O₃ laser ceramics were fabricated using the vacuum-sintering plus hot isostatic pressing (HIP) without sintering additives. High-purity well-dispersed nanocrystalline Yb:Y₂O₃ powder was synthesized using a modified co-precipitation method in-house. The green bodies were first vacuum sintered at a temperature as low as 1430°C and then HIPed at 1450°C. Finally, the samples were air annealed at 800°C for 10 h. Although no sintering aids were used, full density of the samples with excellent optical homogeneity and an inline transmission of 80% at 400 nm could be obtained. Moreover, photodarkening phenomenon was not detected in the ceramics. Preliminary laser experiment with the fabricated ceramics in a two-mirror cavity has demonstrated 32 W continuous-wave (CW) output at ∼1077 nm with an optical-to-optical conversion efficiency of 58.2%. To the best of our knowledge, this is so far the highest CW output power and optical-to-optical conversion efficiency achieved with the Yb³⁺-doped sesquioxide ceramics in a simple two-mirror cavity.     

倾斜入射下的单截面平面度绝对检验

针对大尺寸光学平面的直线度的纳米级测量精度需求，提出了倾斜入射下单截面平面度绝对检验方法，实现了对超过相移干涉仪口径的长平晶绝对检验。利用棱镜转向实现倾斜入射角度的精密预标定，棱镜标定角度的精度高于圆光栅和图像分析等方法，可提高测量不确定度到0.0042 μm。对比了常规三面互检绝对检验结果与本方法的差异，在相同尺寸下，直线度误差仅为1.2 nm。在确认标定反射镜位置后，整个倾斜入射的干涉图调整过程将被完全集中到待测长平晶的工作面上，不需要再对反射平晶进行操作。调整长平晶时各个维度的操作互不干涉，可快速简便地得到测量结果。     

Green Measurements for Software Product Based on Sustainability Dimensions

Software is a central component in the modern world and vastly affects the environment’s sustainability. The demand for energy and resource requirements is rising when producing hardware and software units. Literature study reveals that many studies focused on green hardware; however, limited efforts were made in the greenness of software products. Green software products are necessary to solve the issues and problems related to the long-term use of software, especially from a sustainability perspective. Without a proper mechanism for measuring the greenness of a particular software product executed in a specific environment, the mentioned benefits will not be attained. Currently, there are not enough works to address this problem, and the green status of software products is uncertain and unsure. This paper aims to identify the green measurements based on sustainable dimensions in a software product. The second objective is to reveal the relationships between the elements and measurements through empirical study. The study is conducted in two phases. The first phase is the theoretical phase, where the main components, measurements and practices that influence the sustainability of a software product are identified. The second phase is the empirical study that involved 103 respondents in Malaysia investigating current practices of green software in the industrial environment and further identifying the main sustainability dimensions and measurements and their impact on achieving green software products. This study has revealed seven green measurements of software product: Productivity, Usability, Cost Reduction, Employee Support, Energy Efficiency, Resource Efficiency and Tool Support. The relationships are statistically significant, with a significance level of less than 0.01 (p = 0.000). Thus, the hypothesised relationships were all accepted. The contributions of this study revolve around the research perspectives of the measurements to attain a green software product.     

样品前处理QuEChERS法及新型吸附材料在水产品中抗生素残留分析中的应用进展

抗生素的不合理使用，给水产品带来了一系列的潜在食用安全风险。品种繁多且残留痕量的抗生素也为食品安全检测带来了新的挑战，发展准确、快速、简便、高效且安全的前处理方法尤为重要。QuEChERS法作为一种新型样品前处理技术，现已逐渐应用到水产品抗生素残留检测中，并可实现较好的回收率。由于水产品中蛋白质和脂类含量高，样品基质复杂，使用经典QuEChERS法无法满足抗生素分析需求，改良其提取方法和净化方法是保证分析结果的关键。本文综述QuEChERS法原理特点，总结归纳其在针对水产品抗生素分析上的主要方法改良手段，并就近十年来改良QuEChERS法在水产品抗生素残留分析中的应用进行文献归纳，同时介绍新型吸附材料在该领域的使用，为探索新的净化方式提供参考，以期帮助检测人员持续优化改进QuEChERS法，推动和扩大QuEChERS法在水产品抗生素残留分析中的应用范围。     

Sugar-Pucker Force-Induced Transition in Single-Stranded DNA

The accurate knowledge of the elastic properties of single-stranded DNA (ssDNA) is key to characterize the thermodynamics of molecular reactions that are studied by force spectroscopy methods where DNA is mechanically unfolded. Examples range from DNA hybridization, DNA ligand binding, DNA unwinding by helicases, etc. To date, ssDNA elasticity has been studied with different methods in molecules of varying sequence and contour length. A dispersion of results has been reported and the value of the persistence length has been found to be larger for shorter ssDNA molecules. We carried out pulling experiments with optical tweezers to characterize the elastic response of ssDNA over three orders of magnitude in length (60–14 k bases). By fitting the force-extension curves (FECs) to the Worm-Like Chain model we confirmed the above trend:the persistence length nearly doubles for the shortest molecule (60 b) with respect to the longest one (14 kb). We demonstrate that the observed trend is due to the different force regimes fitted for long and short molecules, which translates into two distinct elastic regimes at low and high forces. We interpret this behavior in terms of a force-induced sugar pucker conformational transition (C3′-endo to C2′-endo) upon pulling ssDNA.     

基于现代审美下的赣傩艺术元素分析与设计应用

目的 赣傩艺术元素内容丰富并保存完整,是研究我国古代赣傩地区文化与艺术的珍贵史料.研究赣傩艺术元素的提取及衍生图案的设计方法,在设计应用中表达赣傩傩面具、选取傩舞形和构筑傩庙魂,能给当代赣傩艺术元素的产品设计以指引.方法 通过直接引用、形意结合和局部强化的设计方法,增厚其丰富内涵、设计个性和主题意蕴.通过现代化审美中"绿色化、感性化、地域化"的要求,遵循"以退为进,化繁为简""多元并存,个性体现"的原则,强化赣傩艺术元素的独特风格.结论 用现代的手法,将特色的赣傩艺术元素植入到理性的产品设计中去,使赣傩艺术元素与现代设计思想有机结合.在继承传统文化与现代流行中找到契合点,深入挖掘赣傩艺术元素蕴含的文化精神、文化胸怀和文化自信,使中华传统文化在现代审美下进行创新再现.