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Optimal maneuvering strategy of spacecraft evasion based on angles-only measurement and observability analysis

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Journal of Systems Engineering and Electronics 2023年第1期34卷 172-184页

作者： ZHANG Yijie WANG Jiongqi HOU Bowen WANG Dayi CHEN Yuyun college of liberal arts and sciences National University of Defense TechnologyChangsha 410073China Beijing Institute of Spacecraft System Engineering Beijing 100190China School of Mathematics and Big Data Foshan UniversityFoshan 528000China

Spacecraft orbit evasion is an effective method to ensure space safety. In the spacecraft’s orbital plane, the space non-cooperate target with autonomous approaching to the spacecraft may have a dangerous rendezvous. To deal with this problem, an optimal maneuvering strategy based on the relative navigation observability degree is proposed with angles-only measurements. A maneuver evasion relative navigation model in the spacecraft’s orbital plane is constructed and the observability measurement criteria with process noise and measurement noise are defined based on the posterior Cramer-Rao lower bound. Further, the optimal maneuver evasion strategy in spacecraft’s orbital plane based on the observability is proposed. The strategy provides a new idea for spacecraft to evade safety threats autonomously. Compared with the spacecraft evasion problem based on the absolute navigation, more accurate evasion results can be obtained. The simulation indicates that this optimal strategy can weaken the system’s observability and reduce the state estimation accuracy of the non-cooperative target, making it impossible for the non-cooperative target to accurately approach the spacecraft.

关键词： rendezvous evasion orbit maneuver angles-only measurement observability degree posterior Cramer-Rao lower bound

Genetic diseases conferring resistance to infectious diseases

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Genes & Diseases 2015年第3期2卷 247-254页

作者： Isabelle C.Withrock Stephen J.Anderson Matthew A.Jefferson Garrett R.McCormack Gregory S.A.Mlynarczyk Aron Nakama Jennifer K.Lange Carrie A.Berg Sreemoyee Acharya Matthew L.Stock Melissa S.Lind K.C.Luna Naveen C.Kondru Sireesha Manne Bhavika B.Patel Bierlein Mde la Rosa Kuei-Pin Huang Shaunik Sharma Hilary Z.Hu Sri Harsha Kanuri Steve A.Carlson Department of Biomedical sciences Iowa State University College of Veterinary MedicineAmesIA 50011USA Department of Psychology Iowa State University College of Liberal Arts and SciencesAmesIA 50011USA Department of Kinesiology Iowa State University College of Liberal Arts and SciencesAmesIA 50011USA Department of Genetics Developmental and Cell BiologyIowa State University College of Liberal Arts and SciencesAmesIA 50011USA Neuroscience Interdepartmental Program Iowa State UniversityAmesIA 50011USA

This review considers available evidence for mechanisms of conferred adaptive advantages in the face of specific infectious *** short,we explore a number of genetic conditions,which carry some benefits in adverse circumstances including exposure to infectious *** examples discussed are conditions known to result in resistance to a specific infectious disease,or have been proposed as being associated with resistance to various infectious *** infectious diseasedgenetic disorder pairings include malaria and hemoglobinopathies,cholera and cystic fibrosis,tuberculosis and Tay-Sachs disease,mycotic abortions and phenylketonuria,infection by enveloped viruses and disorders of glycosylation,infection by filoviruses and NiemannePick C1 disease,as well as rabies and myasthenia *** also discuss two genetic conditions that lead to infectious disease hypersusceptibility,although we did not cover the large number of immunologic defects leading to infectious disease *** of the resistance-associated pairings(malaria/hemogloginopathies,cholera/cystic fibrosis,tuberculosis/Tay-Sachs,and mycotic abortions/phenylketonuria)appear to be a result of selection pressures in geographic regions in which the specific infectious agent is *** other pairings do not appear to be based on selection pressure and instead may be ***,research investigating these relationships may lead to treatment options for the aforementioned diseases by exploiting established mechanisms between genetically affected cells and infectious *** may prove invaluable as a starting point for research in the case of diseases that currently have no reliably curative treatments,e.g.,HIV,rabies,and Ebola.

关键词： Disease Infectious Pathogen Polymorphism Resistance Susceptibility

Vulnerable Public Keys in NTRU Cryptosystem

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Chinese Annals of Mathematics,Series B 2020年第5期41卷 657-664页

作者： Liqing XU Hao CHEN Chao LI Longjiang QU The college of Information Science and Technology/college of Cyber Security Jinan UniversityGuangzhou 510632China The college of liberal arts and Science National University of Defence TechnologyChangsha 410073China

In this paper the authors give an efficient bounded distance decoding(BDD for short)algorithm for NTRU lattices under some conditions about the modulus number q and the public key *** then use this algorithm to give plain-text recovery attack to NTRUEncrypt and forgery attack on *** particular the authors figure out a weak domain of public keys such that the recent transcript secure version of NTRU signature scheme NTRUMLS with public keys in this domain can be forged.

关键词： Lattice CVP NTRU Lattice

The Cauchy problem for the stochastic generalized Benjamin-Ono equation

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Science China Mathematics 2021年第2期64卷 331-350页

作者： Wei Yan Jianhua Huang Boling Guo college of Mathematics and Information Science Henan Normal UniversityXinxiang 453007China college of liberal arts and sciences National University of Defense TechnologyChangsha 410073China Institute of Applied Physics and Computational Mathematics Beijing 100088China

The current paper is devoted to the Cauchy problem for the stochastic generalized Benjamin-Ono *** establishing the bilinear and trilinear estimates in some Bourgain spaces,we prove that the Cauchy problem for the stochastic generalized Benjamin-Ono equation is locally well-posed for the initial data u0(x,w)∈L^(2)(Ω;H^(s)(R))which is F0-measurable with s≥1/2-α/4 andΦ∈L20,*** particular,whenα=1,we prove that it is globally well-posed for the initial data u0(x,w)∈L2(Ω;H1(R))which is F0-measurable andΦ∈L20,*** key ingredients that we use in this paper are trilinear estimates,the Ito formula and the Burkholder-Davis-Gundy(BDG)inequality as well as the stopping time technique.

关键词： Cauchy problem stochastic generalized Benjamin-Ono equation bilinear estimate trilinear estimate

Temperature effects of GaAs/Al_(0.45)Ga_(0.55)As superlattices on chaotic oscillation

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Chinese Physics B 2021年第10期30卷 481-487页

作者： Xiao-Peng Luo Yan-Fei Liu Dong-Dong Yang Cheng Chen Xiu-Jian Li Jie-Pan Ying Department of Basic Courses Rocket Force University of EngineeringXi’an 710025China college of liberal arts and sciences National University of Defense TechnologyChangsha 410073China Suzhou Institute of Nano-tech and Nano-bionics Chinese Academy of SciencesSuzhou 215123China

For widespectrum chaotic oscillation,superlattice cryptography is an autonomous controllable brand-new *** from sequential resonance tunneling of electrons,the chaotic oscillation is susceptible to temperature change,which determines the performance of *** this paper,the temperature effects of chaotic oscillations are investigated by analyzing the randomness of a sequence at different temperatures and explained with superlattice *** results show that the bias voltage at different temperatures makes spontaneous chaotic oscillations *** the temperature of superlattices changing,the sequence dives in entropy value and randomness at specific *** work fills the gap in the study of temperature stability and promotes superlattice cryptography for practice.

关键词： superlattices chaotic oscillation temperature randomness

A STUDY OF THE POLYMERIZATION MECHANISM OF ACETONITRILE IN GLOW DISCHARGE

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Chinese Journal of Polymer Science 1988年第2期6卷 172-177页

作者：余青松叶牧卢丽珍陈捷王佛松长田义仁 Academia Sinica Changchun Institute of Applied Chemistry college of liberal arts Science Department of Chemistry Ibaraki University Japan

Plasma polymerization of acetonitrile was carried out by a capacitively coupled RF plasma apparatus with external electrodes under some different reaction conditions such as discharge power. By investigating the informations provided by the polymer deposition regularities, IR spectra and elementary analysis results, the polymerization mechanism of acetonitrile in glow discharge have been investigated. The results show that acetonitrile polymerized in glow discharge mainly through hydrogen detachment for initiation at lower energy levels and the role that opening C≡N triple bond played in polymerization became more important at higher energy levels.

关键词： Plasma polymerization Acetonitrile Glow discharge Mechanism

Adsorption of Cr(Ⅵ) in wastewater using magnetic multi-wall carbon nanotubes

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Water Science and Engineering 2015年第3期8卷 226-232页

作者： Zhuo-nan Huang Xiao-ling Wang De-suo Yang Key Laboratory for Phytochemistry of Shaanxi Province Baoji University of Arts and Sciences college of Chemistry and Chemical Engineering Baoji University of Arts and Sciences

Magnetic multi-wall carbon nanotubes were prepared with wet chemical treatments and characterized by a transmission electron microscope （TEM） and X-ray diffraction （XRD）. They were used as adsorbents for the removal of Cr（VI） in aqueous solutions. The effects of adsorbent dosage, the concentration of Cr（VI） in aqueous solution, temperature, and pH value on the removal efficiency were studied. Results showed that the adsorption capacity of the magnetic multi-wall carbon nanotubes increased with the initial Cr（VI） concentration, but decreased with the increase of adsorbent dosage. The adsorption amount increased with contact time. The adsorption kinetics were best represented by the pseudo second-order kinetic model, and the adsorption isotherms indicated that the Langmuir model better reflected the adsorption process. The ob- tained calculation results for the Gibbs free energy revealed that the adsorption was a spontaneous and endothermic process. The enthalpy deviation was 3.835 *** 1. The magnetic multi-wall carbon nanotubes showed significant potential for application in adsorption of heavy metal ions.

关键词： Magnetic multi-wall carbon nanotubes Cr(VI) Adsorption Kinetics Thermodynamics

Gravitational wave footprints from Higgs-portal scalegenesis with multiple dark chiral scalars

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Chinese Physics C 2024年第4期 213-225页

作者：张贺旭 Shinya Matsuzaki Hiroyuki Ishida Center for Theoretical Physics and college of Physics Jilin University Center for liberal arts and sciences Toyama Prefectural University

We discuss the gravitational wave(GW) spectra predicted from the electroweak scalegenesis of the Higgs portal type with a large number of dark chiral flavors, which many flavor QCD would underlie and give the dynamical explanation of the negative Higgs portal coupling required to trigger the electroweak symmetry *** employ the linear-sigma model as the low-energy description of dark many flavor QCD and show that the model undergoes ultra-supercooling due to the produced strong first-order thermal phase transition along the(approximately realized) flat direction based on the Gildener-Weinberg mechanism. Passing through evaluation of the bubble nucleation/percolation, we address the reheating and relaxation processes, which are generically non-thermal and nonadiabatic. Parametrizing the reheating epoch in terms of the e-folding number, we propose proper formulae for the redshift effects on the GW frequencies and signal spectra. It then turns out that the ultra-supercooling predicted from the Higgs-portal scalegenesis generically yields none of GW signals with the frequencies as low as nano Hz,unless the released latent heat is transported into another sector other than reheating the universe. Instead, models of this class prefer to give the higher frequency signals and still keeps the future prospected detection sensitivity, like at LISA, BBO, and DECIGO, etc. We also find that with large flavors in the dark sector, the GW signals are made further smaller and the peak frequencies higher. Characteristic phenomenological consequences related to the multiple chiral scalars include the prediction of dark pions with the mass much less than Te V scale, which is also briefly addressed.

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The contribution of mediated oxidation mechanisms in the electrolytic degradation of cyanuric acid using diamond anodes

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Journal of Environmental sciences 2016年第7期28卷 115-123页

作者： Nasr Bensalah Sondos Dbira Ahmed Bedoui Department of Chemistry and Earth sciences College of Arts and Sciences Qatar University Department of Chemistry Faculty of Sciences of Gabes University of Gabes

In this work, the contribution of mediated oxidation mechanisms in the electrolytic degradation of cyanuric acid using boron-doped diamond（BDD） anodes was investigated in different electrolytes. A complete mineralization of cyanuric acid was obtained in Na Cl;however lower degrees of mineralization of 70% and 40% were obtained in Na2SO4 and Na Cl O4, respectively. This can be explained by the nature of the oxidants electrogenerated in each electrolyte. It is clear that the contribution of active chlorine（Cl2, HCl O, Cl O-）electrogenerated from oxidation of chlorides on BDD is much more important in the electrolytic degradation of cyanuric acid than the persulfate and hydroxyl radicals produced by electro-oxidation of sulfate and water on BDD anodes. This could be explained by the high affinity of active chlorine towards nitrogen compounds. No organic intermediates were detected during the electrolytic degradation of cyanuric acid in any the electrolytes, which can be explained by their immediate depletion by hydroxyl radicals produced on the BDD surface. Nitrates and ammonium were the final products of electrolytic degradation of cyanuric acid on BDD anodes in all electrolytes. In addition, small amounts of chloramines were formed in the chloride medium. Low current density（≤ 10 m A/cm2） and neutral medium（p H in the range 6–9） should be used for high efficiency electrolytic degradation and negligible formation of hazardous chlorate and perchlorate.

关键词： Electrolytic degradation Diamond anode Supporting electrolyte Mediated oxidation Cyanuric acid