Multiplex localization imaging and sub-diffraction limited measurement

A novel technique, multiplex localization imaging, is proposed to enhance the image reconstruction of point sources beyond the diffraction limit for an incoherent remote sensing system. The technique utilizes position localization of point sources to create an image of a scene and to allow sub-diffraction limited measurement. Two types of algorithms, mean calculations and chi-square statistics, are implemented to analyze the limits of position localization. Three different multiplex localization imaging methods, time-, color-, and polarization-multiplexing, were investigated experimentally. The resolution of multiplex localization imaging was found to be 14 times better than the diffraction limit of the optics. The multiplex localization imaging technique has applications in remote sensing and astronomy, such as position measurement, multiple targets tracking, and image enhancement.     

The effect of drawing temperature on multi-stage drawn ultra-high molecular weight polyethylene

The effect of drawing temperature on multi-stage drawn ultra-high molecular weight polyethylene (UHMWE) fiber, produced by gel spinning, has been studied. Drawing at higher temperature generally gives higher crystal orientation, as expected. The activation energy of drawing increased with the draw ratio and raw 4sequence. It varied at a given draw ratio and draw stage between two temperature ranges, 85 to 115°C and 115 to 135°C. Thus, for the first draw stage, the activation energy is ～ 19—35 KJ/Moe in the range of 85 to 115°C, and ～ 60—99 KJ/mole in the range of 115 to 135°C. In the second stage, the activation energy is 40 KJ/mole in the range of 105 to 115°C and 70—99 KJ/mole in the range of 115 to 135°C. In the third stage, the activation energy is ～ 92—100 KJ/mole in the range of 115 to 135°C.     

Data Hiding in DNA for Authentication of Plant Variety Rights

Hiding data in the deoxyribose nucleic acid (DNA) can facilitate the authentication and annotation of important plant variety rights. A grant of plant variety rights for a new plant variety gives you the exclusive right to produce for sale and sell propagating material of the variety. Digital watermarking techniques have been proposed for a wide range of applications, including ownership protection, copy control, annotation, and authentication. However, existing data hiding methods for DNA change the functionalities of DNA sequences, which induce morphological changes in biological patterns. This paper proposes a high capacity data hiding scheme for DNA without changing the functionalities of DNA sequences. This scheme adaptively varies the embedding process according to the amount of hidden data. Experimental results show that the proposed scheme gives a significantly improved hiding performance than previous schemes. And the robustness and security issues are also analyzed.     

THREE-DIMENSIONAL NUMERICAL SIMULATION OF INTAKE MODEL WITH CROSS FLOW

The hydrodynamics of a pump sump consisting of a main channel,pump sump,and intake pipe is examined using Truchas,a three-dimensional Navier-Stokes solver,with a Large Eddy Simulation(LES) turbulence model.The numerical results of streamwise velocity profiles and flow patterns are discussed and compared with experimental data of Ansar and Nakato.Fairly good agreement is obtained.Furthermore,unlike Ansar et al.'s inviscid solution,the proposed numerical model includes the effect of fluid viscosity and consid...     

Preparation of yolk–shell Fe<Subscript>3</Subscript>O<Subscript>4</Subscript>@N-doped carbon nanocomposite particles as anode in lithium ion batteries

The yolk–shell-structured Fe₃O₄ nanocomposite particles (Fe₃O₄@Void@C–N NPs) with Fe₃O₄ as the yolk and N-doped carbon as the shell were prepared by using melamine formaldehyde resin as the N and C sources. When used as anode material for lithium ion battery, the yolk–shell structure could not only afford adequate void to accommodate the large volume change during charge/discharge process but also improve structural stability and electrical conductivity. The anode material demonstrated superior long-term and high-rate performance because of the novel structure and the N-doped carbon shell with mesopore. Thus, Fe₃O₄@Void@C–N NPs exhibited a high reversible capacity of 1530 mAh g^?1 after 300 cycles at a current density of 500 mA g^?1, which were approximately 1.5 and 6 times higher than Fe₃O₄@C–N NPs and pure Fe₃O₄ particles, respectively. Even at the higher current density of 2000 mA g^?1, the reversible capacity remained at 651 mAh g^?1 after 500 cycles.     

旋流式喷嘴内流场的数值模拟

基于单流体模型,建立了旋流式喷嘴内流场的数学模型,应用 VOF 方法捕获气液分界面进行数值计算,模拟喷嘴出口处空气锥形状和气液分界面,得到了一组流量与喷嘴工作压降的关系曲线,其结果与前人的经验相符合.     

Investigation of physicochemical composition and microbial communities in traditionally fermented vrum from Inner Mongolia

Mongolian traditionally fermented vrum is known for its functional characteristics, and indigenous microbial flora plays a critical role in its natural fermentation. However, studies of traditionally fermented vrum are still rare. In this study, we investigated the artisanal production of traditionally fermented vrum from Inner Mongolia. In general, its physicochemical composition was characterized by 34.5 ± 8% moisture, 44.9 ± 12.1% fat, 10.6 ± 3.2% protein, and 210 ± 102°T. The total lactic acid bacteria and yeast counts ranged from 50 to 2.8 × 10⁸ cfu/g and from 0 to 1.1 × 10⁶ cfu/g, respectively. We studied bacterial and fungal community structures in 9 fermented vrum; we identified 5 bacterial phyla represented by 11 genera (an average relative abundance >1%) and 8 species (>1%), and 3 fungal phyla represented by 8 genera (>1%) and 8 species (>1%). Relative abundance values showed that Lactococcus and Lactobacillus were the most common bacterial genera, and Dipodascus was the predominant fungal genus. This scientific investigation of the nutritional components, microbial counts, and community profiles in Mongolian traditionally fermented vrum could help to develop future functional biomaterials and probiotics.     

分布式拉曼光纤测温系统研究进展

分布式拉曼光纤测温系统是一种快速、可靠、稳定的实时在线测量系统,它已经成为工业过程中一种重要的新检测技术.详细介绍了分布式光纤拉曼温度传感原理与系统结构,总结了国内外研究历史,重点介绍了主要应用领域和实际应用案例.     

Optical watermark scheme based on singular value decomposition ghost imaging and particle swarm optimization algorithm

An optical image watermarking algorithm, based on singular value decomposition (SVD) ghost imaging and multiple transforms, is designed. The watermark image is first encrypted by applying an SVD ghost imaging system, then the encrypted watermark is embedded into the cover image with the help of multiple transforms, including lifting wavelet transform (LWT), discrete cosine transform (DCT), discrete fractional angular transform (DFAT) and SVD. Four sub-band images are produced from the host image by LWT and DCT. The improved DFAT, whose scaling factors and parameter are optimized by particle swarm optimization algorithm, is operated in the new matrix. Afterwards, SVD is executed in the two-part image and the encrypted watermark is embedded in the host image by mutual operation of different matrices. Simulation results validate that the proposed watermark scheme is superior in the aspects of security, robustness and imperceptibility.     

A stochastic damage model for evaluating the internal deterioration of concrete due to freeze–thaw action

This paper presents a stochastic damage model for evaluating the internal deterioration of concrete due to freeze–thaw action, which involves great uncertainty and randomness. In this model, the structural element of concrete is discretized into infinite microelements, whose lifetimes are assumed to be independent random variables. Then expressions for the mean and variance of the damage of concrete are analytically derived. To calibrate the model parameters, a series of freeze–thaw tests in water on non-air-entrained concrete were conducted and back-calculation analyses were performed on the test results of dynamic modulus. The reliability of the proposed stochastic damage model is further validated through comparisons with the results of 80 other existing test specimens. The present model offers a theoretical basis for exploring the statistical aspect of concrete behavior during freeze–thaw.