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New chaos-based encryption scheme for digital sequence

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Journal of Systems Engineering and Electronics 2007年第4期18卷 698-703,709页

作者： Zhang Zhengwei Fan Yangyu Zeng Li School of Electronics and Information Northwestern Polytechnical Univ. Xi'an 710072 P. R. China

To enhance the anti-breaking performance of privacy information, this article proposes a new encryption method utilizing the leaping peculiarity of the periodic orbits of chaos systems. This method maps the secret sequence to several chaos periodic orbits, and a short sequence obtained by evolving the system parameters of the periodic orbits in another nonlinear system will be the key to reconstruct these periodic orbits. In the decryption end, the shadowing method of chaos trajectory based on the modified Newton-Raphson algorithm is adopted to restore these system parameters. Through deciding which orbit each pair coordinate falls on, the original digital sequence can be decrypted.

关键词： encryption scheme LPO (leaping periodic orbits) chaos initial conditions parameter estimation nonlinear system

Novel ensemble learning based on multiple section distribution in distributed environment

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Journal of Systems Engineering and Electronics 2008年第2期19卷 377-380页

作者： Fang Min Inst. of Computer Xidian Univ. Xi'an 710071 P. R. China

Because most ensemble learning algorithms use the centralized model, and the training instances must be centralized on a single station, it is difficult to centralize the training data on a station. A distributed ensemble learning algorithm is proposed which has two kinds of weight genes of instances that denote the global distribution and the local distribution. Instead of the repeated sampling method in the standard ensemble learning, non-balance sampling from each station is used to train the base classifier set of each station. The concept of the effective nearby region for local integration classifier is proposed, and is used for the dynamic integration method of multiple classifiers in distributed environment. The experiments show that the ensemble learning algorithm in distributed environment proposed could reduce the time of training the base classifiers effectively, and ensure the classify performance is as same as the centralized learning method.

关键词： distributed environment ensemble learning multiple classifiers combination.

Synthesis and Crystal Structure of 4-(4,6-dimethoxyl -pyrimidin-2-yl)-3-thiourea Carboxylic Acid Methyl Ester

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Chinese Journal of Structural Chemistry 2006年第2期25卷 168-172页

作者： HUANG Jie SONG Ji-Rong REN Ying-Hui XU Kang-Zhen MA Hai-xia Department of Chemical Engineering Shanxi Key Laboratory of Physico-inorganic Chemistry Northwest Univers＇ity Xi＇an 710069 China

The title compound 4-（4,6-dimethoxylpyrimidin-2-yl）-3-thiourea carboxylic acid methyl ester was synthesized by the reaction of 2-amino-4,6-dimethoxyl pyrimidine, potassium thiocyanate and methyl chloroformate in ethyl acetate. Single crystals suitable for X-ray measurement were obtained by recrystallization with the solvent of dimethyl formamide at the room temperature. The structure was characterized by elemental analysis and IR and determined by X-ray diffraction analysis＇ Crystallographic data： C9H12N4O4S, Mr = 272.29, monoclinic, space group C2/m with a = 1.6672（3）, b = 0.66383（12）, c = 1.1617（2） nm, β = 109.275（2）°, V = 1.2136（4） nm^3, Dc = 1.490 g/cm^3,μ = 0.281 mm^-1, F（000） = 568, Z = 4, R1 = 0.0341and wR2 = 0.1042.

关键词： 4-(4,6-dimethoxylpyrimidin-2-yl)-3-thiourea carboxylic acid methyl ester synthesis X-ray diffraction

Uncatalyzed Condensation Reactions between Aromatic Aldehydes and Thiobarbituric Acid in Water

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Chinese Chemical Letters 2003年第12期14卷 1239-1241页

作者： Bing Qin YANG Jun LU Min TIAN Department of Chemistry Northwest UniversityXi'an 710069

A series of 5-arylidene thiobarbituric acids were prepared from aromatic aldehydes and thiobarbituric acid in water without catalyst conditions in good yields. The structures were characterized by elemental analysis,... 详细信息

关键词： Arylidene thiobarbituric acid uncatalyzed reaction environmentally benign synthesis.

EFFECTS OF TREATMENT TIME ON CORROSION OF DIFFUSION-ALLOYED COATINGS OF PURE MAGNESIUM

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Acta Metallurgica Sinica(English Letters) 2007年第1期20卷 72-78页

作者： Y.P. Ma J. Li J. Zhu L. Yang Y.G. Liu Z.Y. Li F. Zhao School of Metallurgic Engineering Xi＇an University of Architecture ＆ Technology Xi＇an 710055 China

The corrosion resistance of pure magnesium with surface alloying layer obtained by a solid diffusion alloying technique has been analyzed. To establish the optimum treatment time, the experiments were performed at 480℃ for different solid diffusion time （8, 16, and 24h）. The diffusion interaction effectiveness between Zn, Al mix powder and the sample surface, depending on the treatment time for diffusion at given temperatures, has an obvious influence on corrosion resistance and corrosion mechanism. Corrosion properties were studied using the constant immersion test （in 3.0% NaCl solution, temperature is （28±1）℃, and time is 96h）. Optical microscopy （OM） and EDS （energy dispersive spectrum） composition analysis were used to examine the cross-sectional microstructural characteristics of alloyed layer of treated samples. It is shown that in comparison with the untreated samples, the treated ones possess a better corrosion resistance. The Al5Mg11Zn4 phase, which formed as a continuous phase due to the diffusion of Al, Zn, and Mg elements and subsequent interaction on the outermost layer of diffusion alloying zones （especially the samples treated for 24h at 480℃）, was inert to the chloride solution compared with pure magnesium and acted as a corrosion barrier, and therefore the best corrosion resistance was obtained. This protective action of Al5Mg11Zn4 phase was found to change with its amount, which was controlled by the diffusion time at given temperature. It was concluded that the continuous Al5Mg11Zn4 phase （WP-zone） of the reacted layer in pure magnesium was beneficial from the point of view of corrosion resistance.

关键词： pure magnesium solid diffusion treatment time microstructure corrosion

An optically controlled SiC lateral power transistor based on SiC/SiCGe superjunction structure

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Journal of Semiconductors 2010年第4期31卷 17-19页

作者：蒲红斌曹琳任杰陈治明南雅公 xi'an University of Technology

An optically controlled SiC/SiCGe lateral power transistor based on superjunction structure has been proposed, in which n-SiCGe/p-SiC superjunction structure is employed to improve device figure of merit. Performance of the novel optically controlled power transistor was simulated using Silvaco Atlas tools, which has shown that the device has a very good response to the visible light and the near infrared light. The optoelectronic responsivities of the device at 0.5 μm and 0.7 μm are 330 mA/W and 76.2 mA/W at 2 V based voltage, respectively.

关键词： SiC/SiCGe superjunction optically controlled transistor

Metabolomic profiles in a green alga (Raphidocelis subcapitata) following erythromycin treatment: ABC transporters and energy metabolism

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Journal of Environmental sciences 2023年第2期124卷 591-601页

作者： Jiezhang Mo Zhihua Ma Shiwei Yan Napo KM Cheung Fangshe Yang xiunan Yao Jiahua Guo shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity College of Urban and Environmental SciencesNorthwest UniversityXi’an 710127China State Key Laboratory of Marine Pollution and Department of Chemistry City University of Hong KongKowloonHong KongChina

A recent study showed that erythromycin(ERY)exposure caused hormesis in a model alga(Raphidocelis subcapitata)where the growth was promoted at an environmentally realistic concentration(4μg/L)but inhibited at two higher concentrations(80 and 120μg/L),associated with opposite actions of certain signaling pathways(e.g.,xenobiotic metabolism,DNA replication).However,these transcriptional alterations remain to be investigated and verified at the metabolomic *** study uncovered metabolomic profiles and detailed toxic mechanisms of ERY in *** using *** analysis showed that metabolomic pathways including ABC transporters,fatty acid biosynthesis and purine metabolism were associated with growth promotion in algae treated with 4μg/L *** overcompensation was possibly activated by the low level of ERY in algae where more resources were reallocated to efficiently restore the temporary impairments,ultimately leading to the outperformance of *** contrast,algal growth inhibition in the 80 and 120μg/L ERY treatments was likely attributed to the dysfunction of metabolomic pathways related to ABC transporters,energy metabolism and metabolism of *** from binding of ERY to the 50S subunit of ribosomes to inhibit protein translation as in bacteria,the data presented here indicate that inhibition of protein translation and growth performance of algae by ERY may also result from the suppression of amino acid biosynthesis and aminoacyl-tRNA *** study provides novel insights into the dose-dependent toxicity of ERY on ***.

关键词： Hormesis Metabolome ABC transporters DNA replication Microalgae Macrolide antibiotic

Distributed user pairing and effective computation offloading in aerial edge networks

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Chinese Journal of Aeronautics 2024年第4期37卷 378-390页

作者： Wei LIANG Shuhui WEN Lixin LI Jingjing CUI School of Electronics and Information Northwestern Polytechnical UniversityXi’an CN710072China The State Key Laboratory of Integrated Services Networks Xidian UniversityXi’an CN710126China School of Electronics and Computer science University of SouthamptonSouthampton SO167NSUK

Future Sixth-Generation (6G) mobile communication networks extremely require the global connectivity and the ground Base Stations (BSs) are difficult to develop in some specific areas,such as mountainous ***,the aerial networks are the key framework for the future communications,in which the aerial vehicle could act as the access ***,Mobile Edge Computing (MEC) is also essential to enhance the data processing capabilities of aerial *** this paper,we study a comprehensive communication-computation resource management problem for jointly optimizing user pairing,power and time allocation in the MEC aided Cognitive Radio (CR) aerial networks,namely CR-MEC aerial ***,this multilevel optimization problem could be decomposed into the user pairing and power allocation as well as time allocation *** the conceived CR-MEC aerial networks,we propose a User Pairing and Computation Offloading Management Algorithm (UPCOMA) based on three-sided matching theory,aiming to minimize the system’s energy *** the first step of UPCOMA,multiple Primary Users (PUs) and Cognitive Users (CUs) on the ground negotiate to each other with the suitable power allocation coefficients and construct the stable user ***,the stable user pairs would match to a high altitude platform who act as the base station,which is for appropriately allocating Transmission Time Slots (TSs) at the second step of ***,a hybrid offloading mode is proposed in our conceived networks in order to support ground users to offload their tasks adaptively according to their individual ***,the simulation results reveal that the relative performance of UPCOMA is close to that of the Brute-Force Search Algorithm (BFSA) with low ***,the hybrid offloading mode with less energy consumption supports much more ground user pairs to offload tasks compared to the binary mode.

关键词： Aerial edge computing Binary offloading Cognitive radio Hybrid offloading Resource management

Macromolecule’s Orientation in a Nanofiber by Bubble Electrospinning

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Fluid Dynamics & Materials Processing 2021年第4期17卷 711-720页

作者： Dan Tian Danni Yu Chunhui He School of science Xi’an University of Architecture and TechnologyXi’an710055China National Engineering Laboratory for Modern Silk College of Textile and Clothing EngineeringSoochow UniversitySuzhouChina School of Civil Engineering Xi’an University of Architecture&TechnologyXi’an710055China

In the search for sustainable alternatives to harmful synthetic fibers,an increasing amount of research focuses on biomimicry and natural *** silk is an exceptional textile *** is a kind of natural silk produced using the long silky filaments secreted by a specific bivalve mollusk(Pinna nobilis);now at edge of *** paper suggests a simple but effective way to prepare artificial sea silk from Mytilus edulis.A sea silk solution is prepared using a Mytilus edulis protein,and a polyvinyl alcohol(PVA)solution is mixed with the sea silk solution in order to produce artificial sea silk through a bubble electrospinning *** effects of the sea silk concentration on the nanofiber’s morphology and mechanical properties are studied experimentally.

关键词： Mollusk sea-silk solution collagenous fibers bubble electrospinning