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Heteroscedasticity and/or Autocorrelation Checks in Longitudinal Nonlinear Models with Elliptical and AR(1) Errors

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Acta Mathematicae Applicatae Sinica 2012年第1期28卷 49-62页

作者： Chun-Zheng CAO jin-guan LIN College of Math&Physics Nanjing University of Information Science&TechnologyNanjing 210044China Department of Mathematics Southeast UniversityNanjing 210096China

The aim of this paper is to study the tests for variance heterogeneity and/or autocorrelation in nonlinear regression models with elliptical and AR（1） errors. The elliptical class includes several symmetric multivariate distributions such as normal, Student-S, power exponential, among others. Several diagnostic tests using score statistics and their adjustment are constructed. The asymptotic properties, including asymptotic chi-squave and approximate powers under local alternatives of the score statistics, are studied. The properties of test statistics are investigated through Monte Carlo simulations. A data set previously analyzed under normal errors is reanalyzed under elliptical models to illustrate our test methods.

关键词： autocorrelation elliptical distributions heteroscedasticity longitudinal data nonlinear model,score test

Block Copolymer Colloidal Particles with Unique Structures through Three-dimensional Confined Assembly and Disassembly

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Chinese Journal of Polymer Science 2019年第8期37卷 744-759页

作者： Jiang-ping Xu jin-Tao Zhu Key Laboratory of Material Chemistry for Energy Conversion and Storage Ministry of Education Hubei Key Laboratory of Materials Chemistry and Service Failure School of Chemistry and Chemical Engineering Huazhong University of Science and Technology (HUST) Wuhan 430074 China State Key Laboratory of Materials Processing and Mold Technology HUST Wuhan 430074 China

Structured block copolymer(BCP) particles have gained increasing attention due to their potential applications in separation,catalysis, controlled release, and other fields. Three-dimensional(3D) confined assembly has been proved as a facile yet robust approach for generating BCP particles with controllable shapes and internal structures. In this feature article, we summarized the preparation of structured polymeric particles through 3D confined self-assembly of BCPs. The effects of interfacial interactions, degree of confinement,and additives on the shape and internal structure of BCP microparticles were comprehensively discussed. In addition, we highlighted the recent progress in using disassembly as a route to synthesize colloidal particles with unique structures. Two strategies were introduced in this part:(a) disassembling the discrete domains resulted in mesoporous microparticles;(b) disassembling the continuous domains led to the dissociation of microparticles into micelle-like nano-objects. The applications of the structured colloidal particles in photonic crystals,controlled release, and directed growth of inorganic materials were also presented. Finally, we discussed the current challenges and future opportunities in this promising area.

关键词： Block copolymers Self-assembly Confinement Polymer particles Nano-objects

On Moments of the Maximum of Partial Sums of Moving Average Processes under Dependence Assumptions

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Acta Mathematicae Applicatae Sinica 2011年第4期27卷 691-696页

作者： Xing-cai ZHOU jin-guan LIN Department of Mathematics Southeast University Nanjing 210096 China Department of Mathematics and Computer Science Tongling University Tongling 244000 China

Let{Yi;-∞〈i〈∞}be a doubly infinite sequence of identically distributed φ-mixing random variables and let{ai;-∞〈i〈∞}be an absolutely summable sequence of real numbers. In this paper we study the moments of su... 详细信息

关键词： Moving average φ-mixing Moments

Collision Attacks against AEZ-PRF for Authenticated Encryption AEZ

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China Communications 2018年第2期15卷 46-53页

作者： Tairong Shi Chenhui jin Jie guan Information Science and Technology Institute Science Avenue High-Tech Zone Zhengzhou Henan 450001 China

AEZ is an AES-based authenticated encryption submitted to the ongoing CAESAR competition and was presented at Eurocrypt2015 with AEZ v3. There are three models for AEZ, AEZ-core, AEZ-tiny and AEZ-prf. In this paper, we consider the security of AEZprf for AEZ v4.2, the latest version of *** major finding is a collision of any 256-bit associated data for AES-prf. Then we launch collision attacks in a quantum setting and a classical setting respectively under different assumptions. In the quantum setting, by Simon's quantum algorithm, we amount a forgery with O(n) quantum superposition queries and an overwhelming probability close to *** the classical setting, one with the key of AEZ-prf can also construct the forgeries. Our results show that the AEZ-prf models of AEZ v4.2 is not secure in both the quantum setting and classical world. Furthermore, our results can also be applied to AEZ v3, which has been published on Eurocrypt 2015. As far as we know, no cryptanalysis of AEZ v4.2 has been published so far.

关键词： CAESAR competition authen-ticated encryption AEZ collision attacks quantum attacks

STUDY ON THE STRUCTURE AND PROPERTIES OF HIGH CHROMIUM WHITE CAST IRON AND ITS TEMPERING STANDARD

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Journal of Central South University 1999年第1期11卷 9-13页

作者： Yingfeng guan Zhanpeng jin 1. Department of Materials Science and Engineering Central South University of Technology 410083 Changsha China

The structure and properties of high chromium white cast iron in different treatment states were studied. Using X ray diffraction method, observing their metallograph and measuring their microhardness, the phases involved in the iron were determined. The notch toughness, macrohardness and the fractograph of the samples are compared and their performance was determined, which mainly depends on the matrix structure. Relatively good comprehensive properties can be obtained in the tempering state. Improvements have been made on the commonly used tempering standard. Tempering for a short period at low temperature can improve the materials′ service performance obviously.

关键词： high chromium white cast iron structure property performance tempering

Resting Study of Tracer Experiment on Catalytic Wet Oxidation Reactor under Micro-gravity and Earth Gravity Conditions

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Chemical Research in Chinese Universities 2005年第6期21卷 702-706页

作者： YANG Ji JIA jin-ping School of Environmental Science and Engineering Shanghai Jiaotong University Shanghai 200240 P. R. China

The International Space Station（ISS） employs catalytic wet oxidation carried out in a Volatile Reactor Assembly （VRA） for water recycling. Previous earth gravity experiments show that the VRA is very effective at removing polar, low molecular weight organics. To compare the reactor performance under micro-gravity and Earth gravity conditions, a tracer study was performed on a space shuttle in 1999 by using 0.2% potassium carbonate as the chemical tracer. In this paper, the experimental data were analyzed and it is indicated that the reactor can be considered as a plug flow one under both micro-gravity and earth gravity experimental conditions. It has also been proved that dispersion is not important in the VRA reactor under the experimental conditions. Tracer retardation was observed in the experiments and it is most likely caused by catalyst adsorption. It is concluded that the following reasons may also have influence on the retardation of mean residence time ：（1） the liquid can be held by appurtenances, which will retard the mean residence time; （2） the pores can hold the tracer, which can also retard the mean residence time.

关键词： Tracer study Micro-gravity Dispersion model Tank in series model Catalytic wet oxidation

Volcanic structure of the Tarim flood basalt revealed through 3-D seismological imaging

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Science Bulletin 2015年第16期60卷 1448-1456页

作者： Lei Wang Wei Tian Yongmin Shi ping guan School of Earth and Space Sciences Peking University

The detailed structures of the volcanic edifice and plumbing system of the early Permian Tarim flood basalt were investigated by three-dimensional seismic imaging. The images show that the Tarim flood basalt erupted from central volcanoes distributed along major faults. The uppermost magma formed a single lava lobe with a volume of *0.74 km3 and an aspect ratio of 50,implying a sheet flow eruption with a high effusion rate. At the subsurface level, all central volcanoes, irrespective of size, had a separate pipe-like feeder vent. Only thirteen dikes were identified at shallow depths of \100 m below the lava surface; deeper dikes were even rarer. The pipelike plumbing system and the paucity of dilational dikes were different from the typical plumbing system of flood basalt provinces on Earth, which are normally buoyancycontrolled dike–sill networks. A gas-driven vigorous eruption can be inferred from the imaged structure, which means that the Tarim flood basalt may have carried and released a large proportion of volcanic gas, similar to some mafic volcaniclastic deposit-bearing continental flood basalt provinces.

关键词： Tarim flood basalt - 3-D seismicimaging Central volcano Lava lobe Plumbing system Eruption style

X-ray Flashes from Off-axis Nonuniform Jets

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Chinese Journal of Astronomy and Astrophysics 2004年第5期4卷 473-480页

作者： Zhi-ping jin Da-Ming Wei Purple Mountain Observatory Chinese Academy of SciencesNanjing 210008 National Astronomical Observatories Chinese Academy of SciencesBeijing 100012

It has been widely believed that the outflows in gamma-ray bursts are jetted and some jets may have structures like ∈(θ)∝θ-k. We check the possibility that X-ray flashes come from such jets. Both qualitative and quantitative analyses have shown that this model can reproduce most of the observational features of both X-ray flashes and gamma-ray bursts. Using the usual parameters of gamma-ray bursts, we have carried out numerical calculations for both uniform and nonuniform jets, of their fluxes, spectra and peak energies. It seems that nonuniform jets are more appropriate to these observational properties than uniform jets. We have also shown that in our model the observational ratio of gamma-ray bursts to X-ray flashes is about a few units.

关键词： X-rays general-gamma rays bursts-ISM jets and outflows

Experimental study of hydrogen-rich/oxygen-rich gas–gas injectors

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Chinese Journal of Aeronautics 2013年第5期26卷 1164-1172页

作者： jin ping Li Mao Cai Guobiao School of Astronautics Beihang University

Five types of coaxial injectors were investigated experimentally using hot hydrogen-rich gas and oxygen-rich gas, which were respectively provided by a GH2/GO2 hydrogen-rich perburner and a GH2/GO2 oxygen-rich preburner. The injectors were the shear coaxial injector, the oxidizer post expansion coaxial injector, the fuel impinging coaxial injector, the central body coaxial injector, and the shear tri-coaxial injector. The characteristic velocity efficiency and the combustor＇s wall temperatures were obtained for different design parameters through the experiments. It can be con- cluded that angles of the oxidizer post expansion and the fuel impinging have little influence on the combustion performance and the wall temperatures. The contact area between fuel and oxidizer and the mass flow rate have significant impacts on the combustion performance. The shear tri-coaxial injector has the best combustion performance but also the highest wall temperatures among the five types of injectors.

关键词： Combustion performance Experiment Gas-gas injector High mass flow rate Wall temperature