地月平动点导航仿真程序设计及可行性验证

由于我国地面测控资源有限和全球导航卫星系统对深空导航覆盖效果不足，有必要寻找自主导航方式。平动点导航是一种利用星间测距的深空自主导航方式。本文设计了包含 4 个模块的仿真程序，并利用仿真程序进行可行性仿真。地月 L1Halo 轨道卫星与绕月轨道卫星进行测距测速滤波导航定轨，平动点轨道卫星综合位置误差小于 50m，绕月轨道卫星综合位置误差小于 20m，验证了平动点导航的可行性。     

Ultrasoft Liquid Metal Elastomer Foams with Positive and Negative Piezopermittivity for Tactile Sensing

Soft, capacitive tactile (pressure) sensors are important for applications including human–machine interfaces, soft robots, and electronic skins. Such capacitors consist of two electrodes separated by a soft dielectric. Pressing the capacitor brings the electrodes closer together and thereby increases capacitance. Thus, sensitivity to a given force is maximized by using dielectric materials that are soft and have a high dielectric constant, yet such properties are often in conflict with each other. Here, a liquid metal elastomer foam (LMEF) is introduced that is extremely soft (elastic modulus 7.8 kPa), highly compressible (70% strain), and has a high permittivity. Compressing the LMEF displaces the air in the foam structure, increasing the permittivity over a large range (5.6–11.7). This is called “positive piezopermittivity.” Interestingly, it is discovered that the permittivity of such materials decreases (“negative piezopermittivity”) when compressed to large strain due to the geometric deformation of the liquid metal droplets. This mechanism is theoretically confirmed via electromagnetic theory, and finite element simulation. Using these materials, a soft tactile sensor with high sensitivity, high initial capacitance, and large capacitance change is demonstrated. In addition, a tactile sensor powered wirelessly (from 3 m away) with high power conversion efficiency (84%) is demonstrated.     

Retraction: 3D Printing of Bilineage Constructive Biomaterials for Bone and Cartilage Regeneration

Adv. Funct. Mater. 2017 , 27, 1703117 DOI: 10.1002/adfm.201703117 The above article, first published online on 31 July 2017 in Wiley Online Library ( https://doi.org/10.1002/adfm.201703117 ) and corrected on 19 March 2019 ( https://doi.org/10.1002/adfm.201900376 ) has been retracted by agreement with the authors, the journal Editor‐in‐Chief, and Wiley‐VCH Verlag GmbH & Co. KGaA. The retraction has been agreed upon due to several flawed figures as published in the article, containing duplicate images, which calls the validity of these data into question. Reference C. Deng, Q. Yao, C. Feng, J. Li, L. Wang, G. Cheng, M. Shi, L. Chen, J. Chang, C. Wu, Adv. Funct. Mater. 2017 , 27, 1703117.     

功率型白光LED可靠性的实验及仿真建模研究

快速推广LED产品到照明市场最主要的障碍在于长期的可靠性测试问题。由于长期的LED可靠性测试不符合快速且低成本的要求,因此本实验对白光LED进行步进式加速寿命老化测试,步进式环境温度从55oC到145oC变化。同时,对LED进行结温测试,并使用COMSOL仿真软件进行温度场分布仿真来模拟器件的发热情况,结果表明荧光胶处的温度高于LED芯片温度。在长期老化之后,对LED的光度进行测量,可以对LED的失效机理进行分析。通过研究温度对LED的光谱功率分布衰减的影响及光通量衰减的影响,发现在经过近3500 h的老化之后,LED的光衰很严重,表明电流及高温对LED的影响是极大的。     

A non-parametric depth modification model for registration between color and depth images

Multidimensional Systems and Signal Processing - Despite its most popularity among all depth cameras in the computer vision applications, the Microsoft Kinect sensor suffers from low depth...     

Light-Controlled Nanosystem with Size-Flexibility Improves Targeted Retention for Tumor Suppression

Although great promise has been achieved with nanomedicines in cancer therapy, limitations are still encountered, such as short retention time in the tumor. Herein, a nanosystem that can modulate the particle size in situ by near-infrared (NIR) light is self-assembled by cross-linking the surface-modified poly(lactic-co-glycolic acid) from the up-conversion nanoparticle with indocyanine green and doxorubicin–nitrobenezene–polyethylene glycol (DOX–NB–PEG). The nanosystem with its small size (≈100 nm) achieves better tumor targeting, while the PEG on the surface of the nanosystem can effectively shield the adsorption of proteins during blood circulation, maintaining a stable nanostructure and achieving good tumor targeting. Moreover, the nanosystem at the tumor realizes the rapid shedding of PEG on its surface by NIR irradiation, and the enhanced cellular uptake. At the same time, aggregation occurs inside the nanosystem to form bigger particles (≈600 nm) in situ, prolonging the retention time at the tumor and producing enhanced targeted therapeutic effects. In vitro data show higher cellular uptake and a higher rate of apoptosis after irradiation, and the in vivo data prove that the nanosystem have a longer residence time at the tumor site after NIR irradiation. This nanosystem demonstrates an effective therapeutic strategy in targeted synergistic tumors.     

Enhancement of refresh time in quasi-nonvolatile memory by the density of states engineering

The recently reported quasi-nonvolatile memory based on semi-floating gate architecture has attracted extensive at-tention thanks to its potential to bridge the large gap between volatile and nonvolatile memory.However,the further exten-sion of the refresh time in quasi-nonvolatile memory is limited by the charge leakage through the p-n junction.Here,based on the density of states engineered van der Waals heterostructures,the leakage of electrons from the floating gate to the channel is greatly suppressed.As a result,the refresh time is effectively extended to more than 100 s,which is the longest among all pre-viously reported quasi-nonvolatile memories.This work provides a new idea to enhance the refresh time of quasi-nonvolatile memory by the density of states engineering and demonstrates great application potential for high-speed and low-power memory technology.     

基于VISSIM仿真技术的小区交通开放对周边道路通行影响的探究

主要研究居民小区交通开放后对道路通行能力的影响.基于模糊理论的车辆跟驰模型,利用VISSIM仿真软件对不同类型小区周围的道路交通与交叉路口的车辆通行情况进行仿真,分析了仿真获得的数据,得出小区出口所对应路段的理论通行能力.最后根据研究的成果,向相关部门提出合理化建议.