碳纳米管(CNT)场发射显示器的关键技术的研究

对碳纳米管阴极的制备以及场发射显示器的真空封装技术进行了研究.利用一种新的碳纳米管生长工艺制备出了具有优良场发射性能的碳纳米管阴极.并将这种直接生长的碳纳米管薄膜作为阴极,结合一种弹性封装工艺,开发了一种具有简单字符显示功能的场发射显示器.该显示器在较低的工作电压下就可获得高亮度的显示效果,并且器件的亮度与驱动电压成较好的线性关系,这将有利于未来的碳纳米管场发射显示器实现高亮度和多级灰度显示.器件的持续工作寿命测试已经超过5500小时,充分验证了碳纳米管作为场发射阴极的应用潜力.     

Analysis of Loess Slope Stability Considering Cracking and Shear Failures

The cracks caused by tension are commonly observed on the upper border of loess slope. Most researchers assume that shear failure is the main reason for slope instability. The existing cracks and their development are not fully considered. The finite element method is applied widely in the numerical simulations of slope stability, but it converges and time problems must be considered when a crack occurs. The extended finite element method provides a new way to solve discontinuous media problems. In this paper, a composite model of cracking and shear failure is introduced. The extended finite element method was used to simulate the cracking in loess slope. The model used here had a unified enrichment function and the enriched freedom had a clear physical meaning. Numerical analyses were performed and the simulation results showed that the stress field redistributes. The crack propagated almost vertically at the beginning. The slope stability safety factor was less than that obtained without considering tension failure. Furthermore, the critical sliding surface was determined. This model can be used for analyzing the stability of loess slope and provides a reference for slope safety analyses.     

Blockchain in global supply chains and cross border trade: a critical synthesis of the state-of-the-art,challenges and opportunities

Blockchain possesses the potential of transforming global supply chain management. Gartner predicts that blockchain could be able to track $2?T of goods and services in their movement across the globe by 2023, and blockchain will be a more than $3 trillion business by 2030. Nowadays, a growing number of blockchain initiatives are disrupting traditional business models in each sector. In this paper, we provide a timely and holistic overview of the state-of-the-art, challenges, gaps and opportunities in global supply chain and trade operations for both the private sector and governmental agencies, by synthesising a wide range of resources from business leaders, global international organisations, leading supply chain consulting firms, research articles, trade magazines and conferences. We then identify collaborative schema and future research directions for industry, government, and academia to jointly work together in ensuring that the full potential of blockchain is unleashed amidst the socioeconomic, geopolitical and technological disruptions that global supply chains and trade are facing.     

引信软件可靠性测试与评估的工程技术研究

对引信软件的特点进行了分析，从可靠性指标的内涵和可靠性指标的分配、测试用例的构造、测试环境与方法、可靠性估计、可靠性增长试验及可靠性验证等方面阐述了引信软件可靠性测试与评估技术，为引信软件进行可靠性测评提供了参考。     

Effects of Nano-TiO2 additions on thermal analysis, microstructure and tensile properties of Sn3.5Ag0.25Cu solder

For development of a lead-free composite solder for advance electrical components, a series of Sn3.5Ag0.25Cu (SAC) solders containing TiO₂ nanopowders have been studied. The results showed that the addition of 0.25–1 wt.% TiO₂ nanopowders into the lead-free SAC solder caused its liquidus temperature to increase by about 3.5–5.9 °C. Metallographic observations of the lead-free SAC composite solders revealed a reduction in the grain size of β-Sn, Ag₃Sn phase and Ag₃Sn phase located between the spacing lamellae. In terms of mechanical behavior, the addition of larger weight fractions of TiO₂ nanopowders in lead-free SAC solder matrix led to an improvement in microhardness, 0.2%YS and UTS. However, ductility of the lead-free SAC composite solders was observed to decrease.     

Real-time photorefractive interferometer for dynamic phase perturbation by self-interference in LiNbO(3)

We propose a simple real-time system and demonstrate its use for measuring dynamic optical phase perturbation. In this system we used a 0.1-wt. % Fe:LiNbO(3) to record the self-interference grating with incident light. The system is a new kind of real-time holographic interferometer. After rise time in the interferometer, the speed for showing the fringes is as fast as that of dynamic phase perturbations. Characteristics of the interferometer are proposed and examined.     

低比特率无线可视电话压缩编码方法研究

系统地研究了甚低比特率无线信道可视电话自适应压缩编码方法，其中包括帧间运动估计及运动补偿的范围和精度，自适应量比、传输缓存器和比特率控制、抗信道误码等。计算机模拟结果表明，此方法适于甚低比特率下无线可视电话的压缩编码，且恢复图像主观质量良好。     

Revisiting the procedure for characterising mechanical properties in welded joints through nanoindentation

Owing to the microstructural inhomogeneities and residual stresses that are generated during welding, welded joints are the weakest parts of structures. Nanoindentation, a non-destructive technique, is commonly used to analyse the local mechanical properties and residual stresses in welded joints. However, the pile-up effect is often neglected during the nanoindentation procedure, which results in inaccurate measurements. In this study, an alternative procedure, based on a previous study, was used to measure the local mechanical properties and residual stresses in metal inert gas (MIG) welded joints. Moreover, a new equation is proposed for estimating the residual stresses.     

A Triode Device with a Gate Controllable Schottky Barrier: Germanium Nanowire Transistors and Their Applications

Electrical contacts often dominate charge transport properties at the nanoscale because of considerable differences in nanoelectronic device interfaces arising from unique geometric and electrostatic features. Transistors with a tunable Schottky barrier between the metal and semiconductor interface might simplify circuit design. Here, germanium nanowire (Ge NW) transistors with Cu₃Ge as source/drain contacts formed by both buffered oxide etching treatments and rapid thermal annealing are reported. The transistors based on this Cu₃Ge/Ge/Cu₃Ge heterostructure show ambipolar transistor behavior with a large on/off current ratio of more than 10⁵ and 10³ for the hole and electron regimes at room temperature, respectively. Investigations of temperature‐dependent transport properties and low‐frequency current fluctuations reveal that the tunable effective Schottky barriers of the Ge NW transistors accounted for the ambipolar behaviors. It is further shown that this ambipolarity can be used to realize binary‐signal and data‐storage functions, which greatly simplify circuit design compared with conventional technologies.