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The role of magnetic damping in the r-mode evolution of accreting neutron stars

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Science China(Physics,Mechanics & Astronomy) 2015年第3期58卷 90-95页

作者： CAO GuoJie zhou xia WANG Na Xinjiang Astronomical Observatory Chinese Academy of Sciences University of Chinese Academy of Sciences Key Laboratory of Radio Astronomy Chinese Academy of Sciences

The magnetic damping rate was introduced in the evolution equations of r-modes,which shows that r-modes can generate strong toroidal magnetic fields in the core of accreting millisecond pulsars inducing by differential *** consideration of the coupling evolution of r-modes,spin and thermal evolution,we investigated the influence of the magnetic damping on the differential rotation of nonlinear r-modes of accreting neutron *** derived the coupling evolution equations of the star involving the magnetic damping rate in the framework of second-order r-mode *** numerical results show that the magnetic damping suppressed the nonlinear evolution of r-modes since the saturation amplitude is reduced to a great *** particular,because of the presence of the generated toroidal magnetic field,the spin-down of the stars is terminated and the viscous heating effects are also ***,we could obtain a stronger generated toroidal magnetic field in the second-order r-mode *** gravitational radiation may be detected by the advanced laser interferometer detector LIGO if the amount of differential rotation is small when the r-mode instability becomes active and the accretion rate is not very high.

关键词： neutron stars r-mode instability differential rotation gravitational waves

Quantum corrections to the thermodynamics and phase transition of a black hole surrounded by a cavity in the extended phase space

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Communications in Theoretical Physics 2022年第8期74卷 116-124页

作者： Zhongwen Feng xia zhou Shiqi zhou Shuzheng Yang Physics and Space Science College China West Normal UniversityNanchong 637009China School of Physics and Astronomy Sun Yat-sen UniversityZhuhai 519082China

In the extended phase space,we investigate the rainbow gravity-corrected thermodynamic phenomena and phase structure of the Schwarzschild black hole surrounded by a spherical *** results show that rainbow gravity has a very significant effect on the thermodynamic phenomena and phase structure of the black *** prevents the black hole from total evaporation and leads to a remnant with a limited temperature but no ***,we restore the P-V criticality and obtain the critical quantities of the canonical *** the temperature or pressure is smaller than the critical quantities,the system undergoes two Hawking-Page-like phase transitions and one first-order phase transition,which never occurs in the original ***,our findings demonstrate that the thermodynamic behavior and phase transition of the rainbow SC black hole surrounded by a cavity in the extended phase space are analogous to those of the Reissner–Nordstr?m anti-de Sitter black ***,rainbow gravity activates the effect of electric charge and cutoff factor in the evolution of the black hole.

关键词： rainbow gravity phase transitions extended phase space

Retinal stem cells transplantation combined with copolymer-1 immunization reduces interferon-gamma levels in an experimental model of glaucoma

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International Journal of Ophthalmology(English edition) 2011年第6期4卷 594-598页

作者： xia zhou xiao-Bo xia Department of Ophthalmology Xiangya Hospital of Central South University Changsha 410006 Hunan Province China

AIM: To explore the effect of immunization with copolymer-1 (COP-1) and retinal stem cells (RSCs) transplantation on interferon-gamma (IFN-gamma) levels in a rat experimental glaucoma model. METHODS: An experimental glaucoma was induced by argon laser photocoagulation of the episcleral veins and limbal plexus in the right eye of rats. Immediately following glaucoma induction, rats were immunized with COP-1. RSCs were cultured and transplanted intravitreally into the eyes of glaucoma model animals 1 week post-laser treatment. Six experimental groups were used: COP-1/RSC, PBS/RSC, COP-1/PBS, PBS/PBS, glaucoma model group, and a normal control group. The concentration of IFN-gamma in aqueous humor (AH) and serum was measured by enzyme-linked immunosorbent assay (ELISA) in each of the six groups. Retinal ganglion cell (RGC) survival was assessed by quantifying apoptosis using Hoechst staining. RESULTS: Concentrations of IFN-gamma in AH and serum of rats that had undergone glaucoma induction were higher than those of non-induced control rats. The concentrations of IFN-gamma in AH and serum of the COP-1/RSCs treated group were determined to be 2371.9ng/L and 710.9ng/L, respectively, which were significantly lower than those in the other treated groups (P<0.05). In fact, IFN-gamma levels in the dual treated group were reduced to background levels. The COP-1/RSC group had lower number of apoptotic RGCs than the other three experimental groups (P<0.05). CONCLUSION: The reduced levels of IFN-gamma in AH and serum of the COP-1/RSC group may be related to synergistic effects between RSCs transplantation and COP-1 immune modulation. It is likely that the lower levels of IFN-gamma prevented RGCs glaucomatous apoptasis.

关键词： glaucoma interferon-gamma RSC transplantation COP-1 immunization

Thermoluminescence dating of the ancient Chinese porcelain using a regression method of saturation exponential in pre-dose technique

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Science China(Technological Sciences) 2006年第2期49卷 194-209页

作者： WANG Weida xia Junding zhou Zhixin Research Laboratory for Conservation & Archaeology Shanghai Museum Shanghai 200050 China Research Laboratory for Conservation & Archaeology Shanghai Museum Shanghai 200050 China Research Laboratory for Conservation & Archaeology Shanghai Museum Shanghai 200050 China

This paper studies the thermoluminescence (TL) dating of the ancient por- celain using a regression method of saturation exponential in the pre-dose technique. The experimental results show that the measured errors are 15% (±1σ) for the paleodose and 17% (±1σ) for the annual dose respectively, and the TL age error is 23% (±1σ) in this method. The larger Chinese porcelains from the museum and the nation-wide collectors have been dated by this method. The results show that the certainty about the authenticity testing is larger than 95%, and the measurable porcelains make up about 95% of the por- celain dated. It is very successful in discrimination for the imitations of ancient Chinese porcelains. This paper describes the measured principle and method for the paleodose of porcelains. The TL ages are dated by this method for the 39 shards and porcelains from past dynasties of China and the detailed data in the measurement are reported.

关键词： ancient porcelain, thermoluminescence dating, pre-dose technique, saturation exponential regression.

Compositions and Transformations on Spherical Convex Sets

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Wuhan University Journal of Natural Sciences 2020年第4期25卷 277-285页

作者： zhou xia GUO Qi Department of Mathematics Suzhou University of Science and TechnologySuzhou 215009JiangsuChina

In this paper,we first study some compositions/transformations,such as the scalar-multiplication,spherical addition and canonical transformation,etc.,on the unit sphere of Euclidean spaces,and in turn on spherically convex sets in the unit *** we study valuations on the families of spherically convex *** particular,we show that the spherical projections defined recently by Ferreira et al are valuations in some cases.

关键词： spherical convexity radial projection projection to sphere valuation

Simultaneous CO2 capture and H2 generation using Fe2O3/Al2O3 and Fe2O3/CuO/Al2O3 as oxygen carriers in single packed bed reactor via chemical looping process

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Frontiers of Environmental Science & Engineering 2015年第6期9卷 1117-1129页

作者： Jie ZHU Wei WANG Xiuning HUA zhou xia zhou DENG School of Environment Tsinghua University Beijing 100084 China Jian Kun New Energy Technology Co. Ltd. Beijing 100085 China

The chemical looping concept provided a novel way to achieve carbon separation during the production of energy or substances. In this work, hydrogen generation with inherent CO2 capture in single packed bed reactor via this concept was discussed. Two oxygen carriers, Fe203 60 wt.% and Fe2O3 55 wt.%/CuO 5 wt.% supported by Al2O3, were made by ball milling method. First, according to the characteristics of the reduction breakthrough curve, a strict fuel supply strategy was selected to achieve simultaneous CO2 capture and HE production. Then, in the long term tests using CO as fuel, it was proved that CuO addition improved hydrogen generation with the maximum intensity of 3700 μmol H2·g^-1 Fe2O3 compared with Fe-Al of 2300 μmol HE.g^-1 Fe2O3. The overall CO2 capture efficiency remained 98%- 98.8% over 100 cycles. Moreover, the reactivity of deactivated materials was recovered nearly like that of fresh ones by sintering treatment. Finally, two kinds of complex gases consist of CO, HE, CH4 and CO2 were utilized as fuels to test the feasibility. The results showed all components could be completely converted by Fe-Cu- Al in the reduction stage. The intensity of hydrogen production and the overall CO2 capture efficiency were in the range of 2000-2400 μnol H2^g^-1 Fe2O3 and 89%, 95%, respectively.

关键词： CO2 capture chemical looping hydrogengeneration iron based oxygen carriers single packed bedreactor long-term test complex gases fuel

Sound velocity in dense stellar matter with strangeness and compact stars

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Chinese Physics C 2021年第5期45卷 237-246页

作者： Chengjun xia Zhenyu Zhu xia zhou Ang Li School of Information Science and Engineering Zhejiang University Ningbo Institute of Technology.Ningbo 315100 China Department of Astronomy Xiamen UniversityXiamen 361005China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China

The phase state of dense matter in the intermediate density range(~1-10 times the nuclear saturation density)is both intriguing and unclear and can have important observable effects in the present gravitational wave era of neutron *** matter density increases in compact stars,the sound velocity is expected to approach the con-formal limit(cs/c=1/√3)at high densities and should also fulfill the causality limit(cs/c<1).However,its de-tailed behavior remains a prominent topic of *** was suggested that the sound velocity of dense matter could be an important indicator of a deconfinement phase transition,where a particular shape might be expected for its density *** this work,we explore the general properties of the sound velocity and the adiabatic index of dense matter in hybrid stars as well as in neutron stars and quark *** conditions are employed for the had-ron-quark phase transition with varying interface *** find that the expected behavior of the sound velocity can also be achieved by the nonperturbative properties of the quark phase,in addition to a deconfinement phase ***,it leads to a more compact star with a similar *** then propose a new class of quark star equation of states,which can be tested by future high-precision radius measurements of pulsar-like objects.

关键词： quark matter hadron-quark phase transition neutron star

Congruences for finite triple harmonic sums

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2007年第6期8卷 946-948页

作者： FU Xu-dan zhou xia CAI Tian-xin Department of Mathematics Zhejiang University Hangzhou 310028 China Hangzhou Foreign Language School Hangzhou 310023 China

Zhao （2003a） first established a congruence for any odd prime p〉3, S（1,1,1 ;p）=-2Bp-3 （mod p）, which holds when p=3 evidently. In this paper, we consider finite triple harmonic sum S（α,β, γ,ρ）（modp） is considered for all positive integers α,β, γ. We refer to w=α＋β＋ γ as the weight of the sum, and show that if w is even, S（α,β, γ,ρ）=0 （mod p） for p≥w＋3; if w is odd, S（α,β, γ,ρ）=-rBp-w （mod p） for p≥w, here r is an explicit rational number independent ofp. A congruence of Catalan number is obtained as a special case.

关键词： Finite triple harmonic sums Recursive relation Bernoulli numbers Catalan numbers

Enhancing anaerobic biodegradability and dewaterability of sewage sludge by microwave irradiation

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International Journal of Agricultural and Biological Engineering 2017年第2期10卷 224-232页

作者： Gao Fang xia zhou Wang Wei Center for Environmental Education and Communications of Ministry of Environmental Protection Beijing 100029China Department of Environmental Science and Engineering Tsinghua UniversityBeijing 100084China

Thermal hydrolysis was an effective pretreatment for the sewage sludge by improving dewatering and anaerobic digestion but the heating was a time-consuming *** study focused on the effects of the microwave irradiation by using high temperature and pressured system on sewage sludge *** results obtained in current research showed that sludge could absorb microwave energy with high efficiency and then be hydrolyzed *** solubilization of suspended solid(SS),volatile suspended solids(VSS)and the increasing of the level of soluble chemical oxygen demand(SCOD)in liquid fraction showed that the microwave irradiation could be shortened to 5 min under a temperature range of 80℃-170℃.The highest value of VSS dissolution ratio(36.4%)was obtained at 170℃for 30 *** COD dissolution ratio was about 25%at 170℃.The improvement of the biogas production from both mixture sludge and waste activated sludge was 20.2%and 25.9%respectively at 170℃for 10 *** dewaterability of sludge was greatly ***,the sludge volume could be reduced by 60%with microwave irradiation.

关键词： sludge microwave irradiation biogas production dewaterability