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On conformal measures for infinitely renormalizable quadratic polynomials

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science china.Mathematics 2005年第10期48卷 1411-1420页

作者： HUANG Zhiyong~1 jiang Yunping~(2.3. & WANG Yuefei~3.1. school of Information,Renmin University of {2.beijing 100872.{2.2. department of Mathematics,Queens College,City University of New York,NY 113.7,USA department of Mathematics,Graduate school,City University of New York,New York,NY 10016,USA 3. Academy of Mathematics and systems science,Chinese Academy of sciences,beijing 100080,{12. 1. school of Information Renmin University of China 100872 Beijing China 2. department of Mathematics Queens College City University of New York 11367 NY USA 3. department of Mathematics Graduate School City University of New York 10016 New York NY USA 4. Academy of Mathematics and systems science Chinese Academy of Sciences 100080 Beijing China

We study a conformal measure for an infinitely renormalizable quadratic polynomial. We prove that the conformal measure is ergodic if the polynomial is unbranched and has complex bounds. The main technique we use in t... 详细信息

关键词： Julia set, conformal measure, three-dimensional puzzle, infinitely renormalizable quadratic polynomial.

Novel Sum-of-Sinusoids Simulation Channel Modeling for 6G Multiple-Input Multiple-Output Vehicle-to-Everything Communications

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china.Communications 2024年第1期21卷 242-259页

作者： Hao jiang Hongming zhang Ting Liu College of Artificial Intelligence Nanjing University of Information Science and Technology210044China National Mobile Communications Research Laboratory Southeast UniversityNanjing 210096China school of Information and Communication Engineering Beijing University of Posts and TelecommunicationsChina

In this paper,a statistical cluster-based simulation channel model with a finite number of sinusoids is proposed for depicting the multiple-input multiple-output(MIMO)communications in vehicleto-everything(V2.)*** the proposed sum-of-sinusoids(SoS)channel model,the waves that emerge from the transmitter undergo line-of-sight(LoS)and non-line-of-sight(NLoS)propagation to the receiver,which makes the model suitable for describing numerous V2. wireless communication scenarios for sixth-generation(6G).We derive expressions for the real and imaginary parts of the complex channel impulse response(CIR),which characterize the physical propagation characteristics of V2. wireless *** statistical properties of the real and imaginary parts of the complex CIRs,i.e.,autocorrelation functions(ACFs),Doppler power spectral densities(PSDs),cross-correlation functions(CCFs),and variances of ACFs and CCFs,are derived and *** results are generated and match those predicted by the underlying theory,demonstrating the accuracy of our derivation and *** proposed framework and underlying theory arise as an efficient tool to investigate the statistical properties of 6G MIMO V2. communication systems.

关键词： complex CIRs LoS and NLoS propagation components MIMO V2. communication environments SoS simulation channel model statistical properties

A Nonparametric Model Checking Test for Functional Linear Composite Quantile Regression Models

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Journal of systems science & Complexity 2024年第4期37卷 1714-1737页

作者： XIA Lili DU jiang zhang Zhongzhan Faculty of science Beijing University of TechnologyBeijing 100124China

This paper is focused on the goodness-of-fit test of the functional linear composite quantile regression model.A nonparametric test is proposed by using the orthogonality of the residual and its conditional expectation under the null *** proposed test statistic has an asymptotic standard normal distribution under the null hypothesis,and tends to infinity in probability under the alternative hypothesis,which implies the consistency of the ***,it is proved that the test statistic converges to a normal distribution with nonzero mean under a local alternative *** simulations are reported,and the results show that the proposed test has proper sizes and is sensitive to the considered model *** proposed methods are also applied to two real datasets.

关键词： Composite quantile regression consistent test functional data nonparametric test quadratic form

Bioinspired Scraper-File Type Frequency-Doubling Ultrasonic Exciter

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Journal of Bionic Engineering 2024年第4期21卷 1801-1816页

作者： Wenshuai Wu Mingshuo zhang Zeming Li Guang Yao Xinggang jiang Deyuan zhang school of Mechanical Engineering and Automation Beihang UniversityBeijing100191China Institute of Bionic and Micro-Nano systems Beihang UniversityBeijing100191China Guangdong Provincial Key Laboratory of Minimally Invasive Surgical Instruments and Manufacturing Technology Guangdong University of TechnologyGuangzhou510006China

In the natural world,leaf-cutting ants cause vibrations through their mutual scraping of file-scraper *** this study,we designed a Biomimetic Ultrasonic Exciter(BUE)that imitates leaf-cutting *** operating characteristics of the BUE were studied through experimental testing and finite element *** results showed that the BUE could generate stable ultrasonic vibrations,and that the excitation frequency only needed to be half the Output Frequency(OF).This frequency-doubling phenomenon was conducive to achieving BUE *** further explore the phenomenon of frequency-doubling vibration output,this study designed scrapers of five different sizes,conducted excitation and first-order natural frequency measurement tests,and the corresponding finite element *** was found that each scraper could operate in frequency-doubling mode,but the operating frequency and natural mode frequencies did not correspond with one *** further explicate experimental and simulation results,a two-degrees-of-freedom vibration model was *** was evident that the contact relationship between the dentate disc and scraper introduced strong nonlinear factors into the system,accounting for the frequency-doubling phenomenon and the difference between the BUE’s operating and mode *** BUE could be expected to facilitate the production of high-power micro-ultrasonic generators and has potential application value in the fields of mechanical processing,industrial production,and medical health.

关键词： Leaf-cutting ants Power ultrasound Nonlinear vibration Ultrasonic scalpel Micro vibrator

Phase relationship of complex multi-component system in chromate cleaner production

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Progress in Natural science:Materials International 2007年第7期17卷 845-850页

作者： Ge Xinlei~1 Wang Xidong~(1,3.*) Zheng Shili~2.zhang Mei~1 zhang Yi~2.(1.{2. of Physical Chemistry,University of science and Technology beijing,beijing 100083.china.2.Institute of Process Engineering,Chinese Academy of sciences,beijing 100080,china.3.College of Engineering,Peking University,beijing 100871,china. [a]department of Physical Chemistry University of Science and Technology Beijing Beijing China [b]College of Engineering Peking University Beijing China [c]Institute of Process Engineering Chinese Academy of Sciences Beijing China

The phase relationships of the complex multi-component systems in the liquid-phase oxidization and separation process related with the chromate cleaner production are investigated theoretically and *** phase diagram of main system Fe- Cr2.4-KOH-O2.f oxidization process and the relationship of its standard Gibbs free energy change with temperature are calculated.A se- ries of phase diagrams of the separation process at different temperatures,such as K（Na）OH-K（Na）2.rO4-H2.,KOH-KAlO2.H2., K（Na）OH-K（Na）2.O3.H2.,K（Na）OH-K（Na）HCO3.H2. and K（Na）HCO3.K（Na）2.rO4-H2. have also been *** ex- periments are carried out to verify the calculated *** results showed that the sub-molten salt media are suitable for the oxidization and separation processes;FeCr2.4can be oxidized across a wide range of temperature;K（Na）2.rO4can be separated from K（Na）AlO2.ystem at appropriate temperature and proper concentration;the crystallization of carbonate is easier than that of K（Na）2.rO4.

关键词： chromite chromate system thermodynamics calculation phase diagram

Subchronic toxicological effects of aquatic nitrobenzene on Medaka and Chinese rare minnow

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science china.Chemistry 2007年第5期50卷 707-717页

作者： ZHOU QunFang1, FU JianJie1,2. MENG HaiZhen1,2. ZHU XueYan1,2. {3. GuiBin1, zhang JianBin1, LIU JieMin2.& SHI GuoQing2.1 State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-environmental {2.s, Chinese Academy of {2.s, beijing 100085, china.2.department of Chemistry, {13. of Applied {2., University of {2. and Technology beijing, beijing 100083. {12. State Key Laboratory of Environmental Chemistry and Ecotoxicology ResearchCenter for Eco-environmental SciencesChinese Academy of SciencesBeijing 100085China department ofChemistry School of Applied ScienceUniversity of Science and Technology B

Based on the simulative exposure experiments of nitrobenzene to two small experimental fishes, Medaka (Oryzias latipes) and Chinese Rare Minnow (Gobiocypris rarus), it was found that nitrobenzene could decrease in a linear way in the static aquatic system. Both fishes could accumulate dose-related levels of nitrobenzene quickly and eliminate the compound rapidly when they were transferred to clean water. The Chinese rare minnow showed more sensitivity to the acute toxicity exposure of nitrobenzene than Medaka. Typical molecular biomarkers in oxidative defense system including superoxide dismu- tase (SOD), catalase (CAT) showed the chemical induced alterations. The changes of acetylcholi- nesterase (AChE) activities indicated that nitrobenzene might affect the normal neural function. Nitro- benzene exposure could also lead to obvious damaging effects on the target organs, such as gill and liver by hitopathological studies.

关键词： nitrobenzene, Medaka, Chinese rare minnow, bioaccumulation, elimination, molecular biomarkers, histopathological effects

Gut microbial-host-isozymes are new targets for diseases

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science china.Life sciences) 2024年第7期67卷 1525-1527页

作者： Zhiwei zhang Kai Wang Changtao jiang department of Physiology and Pathophysiology School of Basic Medical SciencesState Key Laboratory of Female Fertility PromotionCenter for Reproductive MedicinePeking UniversityBeijing 100191China Center for Obesity and Metabolic Disease Research School of Basic Medical SciencesState Key Laboratory of Vascular Homeostasis and RemodelingPeking UniversityBeijing 100191China

Gut microbiota can interact with the host through lots of media including small molecular metabolites and proteins(Cani,2.19;Fan and Pedersen,2.2.;Krautkramer et al.,2.2.).Recently,a new interaction pattern was identified,i.e.,gut microbiota can mimic the function of the host by producing a variety of enzymes with functions homologous to host enzymes.

关键词： diseases pattern

Approximation bounds for quadratic maximization and max-cut problems with semidefinite programming relaxation

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science china.Mathematics 2007年第11期50卷 1583-1596页

作者： Da-chuan XU~(1+) Shu-zhong zhang~2.1 department of Applied Mathematics,{2. University of Technology,{2. 10002.,china.2.department of systems Engineering and Engineering management,The Chinese University of Hong Kong,Shatin,Hong Kong,china 1. department of Applied Mathematics Beijing University of Technology Beijing 100022 China 2. department of systems Engineering and Engineering {2. The Chinese University of Hong Kong Shatin Hong Kong China

In this paper,we consider a class of quadratic maximization *** a subclass of the problems,we show that the SDP relaxation approach yields an approximation solution with the worst-case performance ratio at leastα=0.87856….In fact,the estimated worst-case performance ratio is dependent on the data of the problem withαbeing a uniform lower *** light of this new bound,we show that the actual worst-case performance ratio of the SDP relaxation approach (with the triangle inequalities added) is at leastα+δ_d if every weight is strictly positive,whereδ_d>0 is a constant depending on the problem dimension and data.

关键词： quadratic maximization max-cut problem semideflnite programming relaxation approximation algorithm performance ratio

Reducibility of hyperplane arrangements

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science china.Mathematics 2007年第5期50卷 689-697页

作者： Guang-feng jiang & Jian-ming YU department of Mathematics, {2. University of Chemical Technology, {2. 10002., china.Academy of Mathematics and systems science, Chinese Academy of sciences, {2. 100080, china 1. department of Mathematics Beijing University of Chemical Technology Beijing 100029 China 2. Academy of Mathematics and systems science Chinese Academy of Sciences Beijing 100080 China

Certain problems on reducibility of central hyperplane arrangements are settled. Firstly, a necessary and sufficient condition on reducibility is obtained. More precisely, it is proved that the number of irreducible components of a central hyperplane arrangement equals the dimension of the space consisting of the logarithmic derivations of the arrangement with degree zero or one. Secondly, it is proved that the decomposition of an arrangement into a direct sum of its irreducible components is unique up to an isomorphism of the ambient space. Thirdly, an effective algorithm for determining the number of irreducible components and decomposing an arrangement into a direct sum of its irreducible components is offered. This algorithm can decide whether an arrangement is reducible, and if it is the case, what the defining equations of irreducible components are.

关键词： hyperplane arrangement irreducible component logarithmic derivation 3.0}2. 14N2.