一种用硅橡胶载网夹进行超薄切片染色的有效方法

本文介绍了一种能减少污染、省时省力的电镜超薄切片染色方法。     

类胡萝卜素抑制食用油脂光敏氧化的研究

业甲基蓝作光敏剂,研究了类胡萝卜素在豆油、菜油中的抗油脂光敏氧化作用。结果表明,类胡萝卜素可有效抑制油脂的光敏氧化剂且抑制作用随浓度升高而增强,类胡萝卜素抑制油脂光敏氧化的与其结构中的共轭双键数有关。     

Hierarchical steganography using novel optimum quantization technique

Security and imperceptibility are fundamental issues for steganography. This paper presents a multi-level steganography system based on concealing and deception. Basically, the secret image is embedded in a cover image, which in turn is embedded in another higher-level cover image. Each steganography level provides additional security, with lower levels implemented using stronger steganography methods. Furthermore, in the event that the higher level steganography is compromised, it would include misleading information to deceive the attacker that he/she is successfully eavesdropping. One challenge of hierarchical system is retaining hidden data in lower level in a higher level stenographic technique. To mitigate this issue, we designed a novel technique which combines discrete cosine transform and least significant bit (LSB). The technique objective is to maximize the capacity and invisibility of the secret image with minimal modification to the cover image (at most k-bits per block). The performance (capacity and peak signal-to-noise ratio) of the proposed method has superior performance compared with LSB since it combines the benefits of 1-bit and 3-bit LSBs. Furthermore, the paper demonstrates that the secret message is successfully embedded and extracted in two-level steganography system with peak signal-to-nose ratio greater than 20 dB.     

电力系统远动传输规约实验软件的设计

本文介绍了一种用于电力系统远动传输规约教学实验的软件系统。该系统利用Visual C++编写完成,模拟了主站和分站之间利用循环式、问答式传输规约进行数据传输的过程,学生可通过上机操作学习不同规约中数据帧(报文)的生成与传输过程,有效改善了专业课的教学效果。     

Investigation of Ionospheric Electron Density Change During Two Partial Solar Eclipses and Its Comparison with Predictions of NeQuick 2 and IRI-2016 Models

Wireless Personal Communications - In the present study, the results obtained by incoherent scatter radar (ISR) and empirical models (NeQuick2 and IRI-2016) of the variations in mid-latitude...     

基于微信小程序的通达交流墙设计

近年来,随着高校学生们的情感需求愈发强烈,学生们也愈来愈需要平台来释放。由此,"表白墙"作为虚拟社区开始迅猛发展。而微信小程序经过数年的发展,已经相当完善,可以充当各行各业的工具与平台。微信小程序的轻应用、低成本等优点契合"表白墙"所需要的特性。因此,文章基于微信小程序,使用MINA框架开发出一款适合在校大学生的"表白墙"微信小程序。     

Indexing of satellite images with different resolutions by wavelet features

Space agencies are rapidly building up massive image databases. A particularity of these databases is that they are made of images with different, but known, resolutions. In this paper, we introduce a new scheme allowing us to compare and index images with different resolutions. This scheme relies on a simplified acquisition model of satellite images and uses continuous wavelet decompositions. We establish a correspondence between scales which permits us to compare wavelet decompositions of images having different resolutions. We validate the approach through several matching and classification experiments, and we show that taking the acquisition process into account yields better results than just using scaling properties of wavelet features.     

Cobalt Assisted Synthesis of IrCu Hollow Octahedral Nanocages as Highly Active Electrocatalysts toward Oxygen Evolution Reaction

Development of oxygen evolution reaction (OER) catalysts with reduced precious metal content while enhancing catalytic performance has been of pivotal importance in cost‐effective design of acid polymer electrolyte membrane water electrolyzers. Hollow multimetallic nanostructures with well‐defined facets are ideally suited for saving the usage of expensive precious metals as well as boosting catalytic performances; however, Ir‐based hollow nanocatalysts have rarely been reported. Here, a very simple synthetic scheme is reported for the preparation of hollow octahedral nanocages of Co‐doped IrCu alloy with readily tunable morphology and size. The Co‐doped IrCu octahedral nanocages show excellent electrocatalytic activity and long‐term durability for OER in acidic media. Notably, their OER activity represents one of the best performances among Ir‐based acidic OER catalysts.     

电视频道包装的核心内涵和品牌建设

通过对电视频道整体包装和品牌建设的关系再认识,具体分析了电视频道包装系统的核心内涵,从理念识别系统、视觉识别系统、行为识别系统入手,详细阐述了建立频道形象包装识别系统,打造优势品牌的具体内容,并指出电视品牌时代频道包装的个性化、人文化、内在化、规范化和时尚化的发展趋势.     

Preparation and characterization of conductive polypyrrole/kaolinite composites

Conductive polypyrrole (PPy)/kaolinite clay composites were prepared by in situ chemical polymerization of pyrrole in the presence of kaolinite using FeCl₃ as oxidant. The PPy content and conductivity of the composites reached 32.8% and 8.3×10^?2 S/cm at HCl concentrations of 1.5 M and 0.5 M, respectively. The microhardness of the composites containing different amounts of PPy was higher than that of the PPy and kaolinite components. The highest microhardness observed was 30.17 kg/mm² for the composite containing 9.6% PPy. The electrical resistance of the composites was monitored during heating–cooling cycles over the range 5–120 °C. The change in resistance with temperature was more repeatable for the composite than for PPy. The composites were characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). The humidity-sensing properties were also examined.