高精度薄壁钢套类零件制造工艺

薄壁钢套类零件是机械制造中常碰到的一类难加工零件,由于其不同的功能用途和典型结构特点,其制造有一定难度,在实际生产过程中,经常出现加工制造后的零件尺寸精度、形状精度、形位精度达不到使用及设计要求。本文较系统地阐述了薄壁钢套类零件的典型制造工艺方法以及在制造过程中的变形分析和应对措施。     

Expanded coprime array for DOA estimation: augmented consecutive co-array and reduced mutual coupling

Multidimensional Systems and Signal Processing - Generalized coprime structure decomposes the interleaved subarrays in the conventional coprime array by introducing a displacement and the resulting...     

A Preamble Re-utilizing Access Scheme for Machine-Type Communications with Optimal Access Class Barring

Wireless Personal Communications - The existing long term evolution networks originally designed for human-to-human communications are hard to tackle numerous and bursty random access requests from...     

压水堆核电厂一回路首次钝化工艺研究

压水堆核电厂热态功能试验中的一回路首次钝化对核电厂一回路材料腐蚀控制和减少腐蚀产物等方面具有重要作用。本文结合理论研究与工程实际情况，提出了在热态功能试验过程中钝化膜的生成包含电化学反应和化学反应的观点，阐述了双层膜的生长机理，解释了用电化学测试方法分析钝化工艺过程的合理性，推导出钝化温度与钝化膜反应速率的函数关系式，钝化温度升高，反应速率升高，钝化时间缩短；明确了钝化工艺温度的理论限值应不低于260℃。      

Enhanced linear magneto-resistance near the Dirac point in topological insulator Bi2(Te1−xSex)3 nanowires

Nano Research - We report the composition and back-gate voltage tuned transport properties of ternary compound Bi2(Te1−xSex)3 nanowires synthesized by chemical vapor deposition (CVD). It is...     

核电厂中间量程保护定值标定方法改进

基于目前中国改进型三环路压水堆（CPR1000）部分机组存在因中间量程电流饱和导致无法在48%额定功率（Pn）完成定值标定及核电厂大修经济性考虑，采用MCNP程序及核设计软件包SCIENCE，研究分析中间量程保护定值标定的新方法。分析结果表明，中间量程保护定值标定调整至30%Pn功率平台实施，采用改进方法标定的保护定值更接近于设计值。      

基于滑模的运载器主动段俯仰通道姿控系统设计

与传统比例-积分-微分（PID）控制方法相比，滑模控制（SMC）方法可以比较容易地将不确定性纳入控制器设计中，从而增强系统的鲁棒性。探索了SMC技术在运载器主动段姿态控制中的工程应用，首先通过分析基于趋近律的SMC系统，提出了降低不连续切换项系数的需求，然后研究了基于干扰上界的SMC方法。三通道小偏差仿真结果验证了两种方法的控制效果，表明第2种控制器的鲁棒性更好，稳态误差小，同时发动机喷管摆角需求较小。     

A new territory and its pioneer: opening up a dominant research stream for a translational research area

Scientometrics - An academic pioneer makes many trials to find relations and results that were unknown before. The verified relations and repeatable results the pioneer finds guide followers to...     

A mini review on two-dimensional nanomaterial assembly

Two-dimensional (2D) nanomaterials have attracted a great deal of attention since the discovery of graphene in 2004, due to their intriguing physicochemical properties and wide-ranging applications in catalysis, energy-related devices, electronics and optoelectronics. To maximize the potential of 2D nanomaterials for their technological applications, controlled assembly of 2D nanobulding blocks into integrated systems is critically needed. This mini review summarizes the reported strategies of 2D materials-based assembly into integrated functional nanostructures, from in-situ assembly method to post-synthesis assembly. The applications of 2D assembled integrated structures are also covered, especially in the areas of energy, electronics and sensing, and we conclude with discussion on the remaining challenges and potential directions in this emerging field.

     

Plasmonic Oxygen-Deficient TiO2-x Nanocrystals for Dual-Band Electrochromic Smart Windows with Efficient Energy Recycling

Dual-band electrochromic smart windows capable of the spectrally selective modulation of visible (VIS) light and near-infrared (NIR) can regulate solar light and solar heat transmittance to reduce the building energy consumption. The development of these windows is however limited by the number of available dual-band electrochromic materials. Here, plasmonic oxygen-deficient TiO_2-x nanocrystals (NCs) are discovered to be an effective single-component dual-band electrochromic material, and that oxygen-vacancy creation is more effective than aliovalent substitutional doping to introduce dual-band properties to TiO₂ NCs. Oxygen vacancies not only confer good near-infrared (NIR)-selective modulation, but also improve the Li⁺ diffusion in the TiO_2-x host, circumventing the disadvantage of aliovalent substitutional doping with ion diffusion. Consequently optimized TiO_2-x NC films are able to modulate the NIR and visible light transmittance independently and effectively in three distinct modes with high optical modulation (95.5% at 633 nm and 90.5% at 1200 nm), fast switching speed, high bistability, and long cycle life. An impressive dual-band electrochromic performance is also demonstrated in prototype devices. The use of TiO_2-x NCs enables the assembled windows to recycle a large fraction of energy consumed in the coloration process (“energy recycling”) to reduce the energy consumption in a round-trip electrochromic operation.