一种复杂过程与复合对象三维建模的实现方法

伴随着虚拟现实技术研究的深入和应用的推广,建模方法作为核心内容也会应用于越来越复杂的系统。现有的建模技术将模型,运动和模型与周围环境的关系相互孤立,这不利用高效和快捷地实现复杂系统。针对这些问题,文章首先使用过程建模方法对复杂系统层次化,然后提出关系建模方法对模型,运动和关系建立标准结构,最后针对复杂过程和复合对象两种应用提出实现方法,验证了方法的可行性和有效性。     

Tunable Optical Mode Ferromagnetic Resonance in FeCoB/Ru/FeCoB Synthetic Antiferromagnetic Trilayers under Uniaxial Magnetic Anisotropy

Ferromagnetic resonance (FMR) is one of the most important characteristics of soft magnetic materials, which practically sets the maximum operation speed of these materials. There are two FMR modes in exchange coupled ferromagnet/nonmagnet/ferromagnet sandwich films. The acoustic mode has relatively lower frequency and is widely used in radio‐frequency/microwave devices, while the optical mode is largely neglected due to its tiny permeability even though it supports much higher frequency. Here, a realistic method is reported to enhance the permeability in the optical mode to an applicable level. FeCoB/Ru/FeCoB trilayers are carefully engineered with both uniaxial magnetic anisotropy and antiferromagnetic interlayer exchange coupling. This special magnetic structure exhibits a high optical mode frequency up to 11.28 GHz and a maximum permeability of 200 at resonance. An abnormally low inverse switch field (<200 Oe, less than 1/5 of the single layer) is observed which can effectively switch the system from optical mode with higher frequency into acoustic mode with lower frequency. The optical mode frequency and inverse switch field can be controlled by tailoring the interlayer coupling strengths and the uniaxial anisotropy fields, respectively. The tunable optical mode resonance thus can increase operation frequency while reduce operation field overhead in FMR based devices.     

基于扩散小波的社会网络多尺度分析简

针对社会网络中的同质性关系提出一个基于扩散小波的多尺度分析框架,通过局部相似性度量构造扩散算子,在统一的框架下对社会网络中的结构、内容、用户行为等进行多尺度分析。在合成和真实网络数据上进行实验,与典型算法的对比表明,本算法在无参数的条件下快速收敛并得到更好的结果。     

AN INVERSE PROBLEM OF WATER WAVE GENERATION IN A WAVE TANK

ＡＮＩＮＶＥＲＳＥＰＲＯＢＬＥＭＯＦＷＡＴＥＲＷＡＶＥＧＥＮＥＲＡＴＩＯＮＩＮＡＷＡＶＥＴＡＮＫＭｉａｏＧｕｏ－ｐｉｎｇ；ＹｏｕＹｕｎ－ｘｉａｎｇ；ＬｉｕＹｉｎｇ－ｚｈｏｎｇ（ＳｈａｎｇｈａｉＪａｏＴｏｎｇＵｎｉｖｅｒｓｉｔｙＳｈａｎｇｈａｉ２０００...     

Anodization for Simplified Processing and Efficient Charge Transport in Vertical Organic Field‐Effect Transistors

Vertical organic transistors are an attractive alternative to realize short channel transistors, which are required for powerful electronic devices and flexible electronic circuits operating at high frequencies. Unfortunately, the vertical device architecture comes along with an increased device fabrication complexity, limiting the potential of this technology for application. A new design of vertical organic field‐effect transistors (VOFETs) with superior electrical performance and simplified processing is reported. By using electrochemical oxidized aluminum oxide (AlO_x) as a pseudo self‐aligned charge‐blocking structure in vertical organic transistors, direct leakage current between the source and drain can be effectively suppressed, enabling VOFETs with very low off‐current levels despite the short channel length. The anodization technique is easy to apply and can be surprisingly used on both n‐type and p‐type organic semiconductor thin films with significant signs of degradation. Hence, the anodization technique enables a simplified process of high‐performance p‐type and n‐type VOFETs, paving the road toward complementary circuits made of vertical transistors.     

微透镜阵列的制作及其在光场成像中应用的研究进展

文章综述了微透镜阵列制备技术的最新研究进展,并将这些制备方法分为直接法和间接法进行了对比分析。回顾了微透镜在光场成像应用中的研究进展,指出目前该领域的研究重点是光场相机设计的新思路及提高分辨率的相应模型算法。     

Analysis of Power Consumption on Laser Solder Joints of Electric Connector

Laser soldering process was introduced in Universal serial bus （USB） 2.0 electric connector to improve the mechanical and electrical bonding reliabil- ity. While, the effects of laser soldering technology on electric connector solder joints need to be estimated com- pletely, especially on power consumption. The combined method based on numerical simulation and the Accelerated temperature experiment （ATE） was developed to analyze the power consumption of USB 2.0 electric connector in this paper. The ATE contains thermal cycle and thermal shock tests, and the four-electrode method is used to ob- tain the conductivity of solder joints. Numerical modeling and analysis was used to quantify the power consumption and optimize the geometry of solder joints, because the electric experimental measurements of power consumption during ATE are time-costing and often intractable. Accurate knowledge of the power consumption is a prerequisite for the reliability of the electric connector.     

WCDMA网络容量优化策略研究

容量分析是WCDMA无线网络规划优化中的一个重要课题。从限制高比特用户覆盖范围以及调整公共信道功率两个角度探讨其对容量分析的影响,旨在为WCDMA无线网络规划优化提供决策参考。     

Efficient Assembly of Bridged β‐Ga2O3 Nanowires for Solar‐Blind Photodetection

An increasing number of applications using ultraviolet radiation have renewed interest in ultraviolet photodetector research. Particularly, solar‐blind photodetectors sensitive to only deep UV (<280 nm), have attracted growing attention because of their wide applicability. Among recent advances in UV detection, nanowire (NW)‐based photodetectors seem promising, however, none of the reported devices possesses the required attributes for practical solar‐blind photodetection, namely, an efficient fabrication process, a high solar light rejection ratio, a low photocurrent noise, and a fast response. Herein, the assembly of β‐Ga₂O₃ NWs into high‐performance solar‐blind photodetectors by use of an efficient bridging method is reported. The device is made in a single‐step chemical vapor deposition process and has a high 250‐to‐280‐nm rejection ratio (～2 × 10³), low photocurrent fluctuation (<3%), and a fast decay time (<<20 ms). Further, variations in the synthesis parameters of the NWs induce drastic changes in the photoresponse properties, which suggest a possibility for tuning the performance of the photodetectors. The efficient fabrication method and high performance of the bridged β‐Ga₂O₃ NW photodetectors make them highly suitable for solar‐blind photodetection.     

高精度平面绝对标定

在高精度面形检测中,绝对标定是提高检测精度的重要方法。但在平面绝对标定中,无论是经典的三平板绝对检测还是旋转平移绝对检测都无法对平面的power项进行绝对标定。而利用液面进行绝对标定虽然可以给出完整的平面标定,但是液面易受环境影响,重复性难以提高,因此标定精度往往不高。针对这一难题,利用Fizeau干涉仪,采用液面方法对平面的power项单独进行绝对标定,结合旋转平移绝对标定方法对平面其他Zernike项进行标定,从而得到了完整的高精度的平面绝对标定。不仅提高了检测精度,也对平面进行了完整的高精度标定,大大提高了干涉仪的检测精度。