Dynamic watermarking scheme for quantum images based on Hadamard transform

In this paper, a novel watermarking scheme for quantum images based on Hadamard transform is proposed. In the new scheme, a unitary transform controlled by a classical binary key is implemented on quantum image. Then, we utilize a dynamic vector, instead of a fixed parameter as in other previous schemes, to control the embedding process. The dynamic embedding vector is decided by both the carrier quantum image and the watermark image, which is only known by the authorized owner. The proposed scheme is analyzed from visual quality, computational complexity, and payload capacity. Analysis and results show that the proposed scheme has better visual quality under a higher embedding capacity and lower complexity compared with other schemes proposed recently.     

Memristor crossbar-based unsupervised image learning

This letter presents a new memristor crossbar array system and demonstrates its applications in image learning. The controlled pulse and image overlay technique are introduced for the programming of memristor crossbars and promising a better performance for noise reduction. The time-slot technique is helpful for improving the processing speed of image. Simulink and numerical simulations have been employed to demonstrate the useful applications of the proposed circuit structure in image learning.     

A polyamide-silica composite prepared by the sol-gel process

Summary A new kind of organic-inorganic hybrid composite was prepared by means of the sol-gel process. The polymer employed was a mixed-isomer aromatic polyamide having good solubility and thermal stability. The silica constituting the inorganic phase was produced by the hydrolysis and condensation of tetramethoxysilane. The bonding between the phases involved aminophenyl-trimethoxysilane, in which the amino group can react with the phthaloyl chloride end-capped polymer, and the methoxysilane groups undergo hydrolysis. The composition of these composites was varied by changing the linear polymer chain length and relative amount of tetramethoxysilane. The gelation time was found to range from a few minutes to several days. Thermogravimetric analyses showed that decomposition starts at approximately 450 °C. Thin films cast from materials having a relatively high silica content were opaque and rigid, but those with low silica content were flexible and transparent.     

数据驱动的冷却水塔建模与节能优化操作

针对冷却水塔的节能操作给出了一种数据驱动的建模与优化方法。首先,基于冷却水塔实际运行数据,应用非负绞杀变量选择方法给出一个自适应模型用于描述冷却水塔过程,该模型对于冷却水塔出口水温具有良好的预测精度。根据变量选择结果,分析了外界空气温度与湿度对冷却能力的影响。然后,提出了基于模型的冷却水塔风机的优化操作策略,并进行实验将之应用于冷却水塔的操作。研究结果显示,基于模型的优化操作具有较大的节能空间。     

β-甘露聚糖酶理化性质与其最适pH的相关性

为了探究影响GH5家族β-甘露聚糖酶最适pH的各种因素,利用该酶的序列信息,构建了基于氨基酸组成的β-甘露聚糖酶理化性质与其最适pH的相关性模型。结果表明:该酶N端氨基酸序列是影响其最适pH的重要因素,在243个理化性质中有17个呈极显著相关,其中7个呈正相关。优化的转移能量参数相关性最高,为0.78:7个正相关的理化性质中,与螺旋相关的理化性质占3个。优化的转移能量参数和螺旋是影响pH稳定性的最重要的因素。所建立的模型为研究该酶酸碱适应性机理提供了一种简单有效的方法。     

Living carbocationic polymerization

Summary The living synthesis of ,-di-tert.-chloropolyisobutylene ( ^t -Cl-telechelic PIB) has been accomplished by the use of the sterically hindered bifunctional initiator 1,3-di-(2-methoxy-2-propyl)-5-tert.-butylbenzene (tBu-m-DiCuOMe) in conjunction with BC1₃ coinitiator in CH₃Cl or CH₂Cl₂ diluents at –30°C and –10°C. The living nature of the polymerizations was demonstrated by linear ¯M_n versus W_PIB (g of PIB formed) plots starting at the origin and horizontal N (number of PIB moles) versus W_PIB plots. The molecular weight distributions are narrow (¯M_W/¯M_n < 2.0) and tend to decrease with increasing molecular weights. Number average end functionalities have been quantitated and found to be ¯F_n = 2.0±0.1.     

采用主监视窗扩展技术的增强现实三维注册方法

在增强现实三维注册中,采用重新检测策略时顿卡现象严重。提出一种采用主监视窗扩展技术的增强现实三维注册方法。在检测阶段,引入特征点可信度和主监视窗,并设计主监视窗的分割、扩展和调控策略,大幅提升了计算速度;在跟踪阶段,采用基于图像金字塔的光流算法进行特征点跟踪。实验证明,该方法不仅有效缓解了顿卡现象,也提升了系统整体的实时性。     

Industrial TiO2 based nacreous pigments as functional building materials: Photocatalytic removal of NO

In this paper, the photocatalytic activity of industrial titanium dioxide (TiO₂) based nacreous pigments was researched as functional building materials for photocatalytic NO remove. Three industrial TiO₂ based nacreous pigments were selected to estimate the photocatalytic activity for NO remove. This study is a good proof that pearlescent pigments can eliminate NO, and its performance is positively correlated with its titanium dioxide content. And this research will widen the application of nacreous pigments in functional building materials, and provide a new way to eliminate in door nitric oxide pollution.     

中央空调的水处理

本文扼要介绍了中央空调循环冷却水和冷冻水系统中常见的问题及其原因,并对冷却水和冷冻水的处理程序作了初步的阐述.     

The determination of the pore structural parameters of isoporous resins by inverse GPC

The swollen pore structure of a series of microporous isoporous resins (7.4–140 Å) are investigated with inverse GPC, n-alkylbenzenes and linear polystyrenes being used as probe molecules. The results indicated that, with the lowering of crosslinking degree of isoporous resins, the average pore diameter increased and the pore distribution curve broadened. All pore volume distribution obeyed a log-normal distribution. Based on the linear regression method, the experimental data were fitted to a monotonously declining exponential function and a normal distribution function by a computer, and some important structural parameters such as average pore diameter, pore volume distribution, specific surface area, etc. were obtained. The specific surface area of swollen gels were found much greater than those in the dry state measured by N₂ adsorption.