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Testing the first law of black hole mechanics with gravitational waves

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Science China(physics,Mechanics & Astronomy) 2024年第10期Mechanics & Astronomy) .卷 80-86页

作者： Chao-Wan-Zhen Wang Jin-Bao Zhu Guo-Qing Huang Fu-Wen Shu department of physics Nanchang University Center for Relativistic Astrophysics and High Energy physics Nanchang University GCAP-CASPER Physics DepartmentBaylor University

The successful observation of gravitational waves has provided humanity with an additional method to explore the universe, particularly black holes. In this study, we utilize data from LIGO and Virgo gravitational wave observations to test the first law of black hole mechanics, employing two different approaches. We consider the secondary compact object as a perturbation to the primary black hole before the merger, and the remnant black hole as a stationary black hole after the merger. In the pre-merger and post-merger analysis, our results demonstrate consistency with the first law, with an error level of approximate 25% at a68% credibility level for GW190403 051519. In the full inspiral-merger-ringdown analysis, our results show consistency with the first law of black hole mechanics, with an error level of about 6% at a 68% credibility level and 10% at a 95% credibility level for GW191219 163120. Additionally, we observe that the higher the mass ratio of the gravitational wave source, the more consistent our results are with the first law of black hole mechanics. Overall, our study sheds light on the nature of compact binary coalescence and their implications for black hole mechanics.

关键词： gravitational waves black hole mechanics data analysis ringdown

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Injection of a Self-propelled Polymer into a Small Circular Cavity

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Chinese Journal of Polymer Science 2024年第6期42卷 886-894页

作者： Chao Wang Yan-Li Zhou Xiao Yang Fan Wu Meng-Bo Luo department of physics Taizhou UniversityTaizhou318000China department of physics Zhejiang UniversityHangzhou310027China

The injection of a polymer chain into a small circular cavity under tangential self-propelled force is studied by using Langevin dynamics *** indicate that the injection dynamics of the active polymer shows strong correlation with the polymer conformation inside the cavity depending on the polymer rigidity(k_(b)).The injection timeτvaries nonmonotonously with increasing k_(b),and reaches its minimum at k_(b)^(*).When k_(b) is small(k_(b)≪k_(b)^(*)),the polymer is nearly random coil in the cavity,and spends a long time at the final stage of the injection process due to the large repulsion between monomers inside the *** k_(b) is moderate(k_(b)∼k_(b)^(*)),the part of polymer inside the cavity forms spiral configuration under the tangential active force,and the whole polymer moves synchronously with a constant velocity during the injection process,leading to a small injection *** k_(b) is large(k_(b)≫k_(b)^(*)),the polymer is nearly straight at the initial stage of the injection process,and takes a long time to bend itself,leading to a large injection time.

关键词： Active Polymer Injection Dynamics Simulation

Holographic superfluid ring with a weak link

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Science China(physics,Mechanics & Astronomy) 2024年第11期Mechanics & Astronomy) .卷 33-42页

作者： Zhi-Hong Li Huai-Fan Li department of physics Shanxi Datong University Institute of Theoretical physics Shanxi Datong University

We explore the generation of topological defects in the course of a dynamical phase transition in a ring with a weak link, i.e., a SSS Josephson junction, from the AdS/CFT correspondence. By setting different parameters of the junction(width, steepness,depth) and the final temperature of the quench, the configurations of the charge density and condensate of the order parameters of the dual field theory are presented. Meanwhile, we observe that in the final equilibrium state, variations in parameters of the junctions only affect the configurations of the charge density and condensate of the order parameters, without altering their values outside the junction. However, variations in the final temperature will directly affect the values of the charge density and condensate of the order parameters outside of the junction. Moreover, in the final equilibrium state, we propose an analytic relation between the gauge-invariant velocity in the two superconducting states in the SSS Josephson junction, which agrees well with the numerical results.

关键词： AdS/CFT correspondence holographic superfluid holographic Josephson junction

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Efficient degradation of dye pollutant via Z-scheme ball milled ZnO-LaO-S powder photocatalyst

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Transactions of Nonferrous Metals Society of China 2024年

作者： Saeid ZAREI Hossein RAANAEI Sara AHMADI Saeed KAMALI department of physics， Faculty of Nano and Bio Science and Technology， Persian Gulf university Chemistry department， Faculty of Science， university of malaya department of physics and Astronomy， Middle Tennessee State university

This investigation aimed to analyze the degradation of Eriochrome Black T （EBT） dye using a semiconductor photocatalyst synthesized through mechanical alloying. Various characterization methods， including X-ray diffraction （XRD）， energy-dispersive X-ray spectroscopy （EDX）， and X-ray photoelectron spectroscopy （XPS）， were employed to study the properties of the photocatalysts. After 35 h of milling， a ball milled mixed metal oxides was formed as confirmed by XRD analysis. EDX and XPS analyses revealed significant differences in adsorption features with and without light exposure. The band gap of the 35 h ball milled sample was determined to be 4.08 eV. To optimize the EBT degradation， artificial neural network genetic algorithms were used to determine the optimal values for ZnO-La2O3dosage， lamp power， and pH， which were found to be 0.43， 52.06， and 3， respectively. The Z-scheme mechanism， supported by band gap， Fermi level， and work function analysis， was found to be responsible for the photocatalytic process. The photocatalysts demonstrated good reusability and high stability. Overall， the results suggest that the synthesized photocatalyst holds promising potential for the degradation of EBT dye in wastewater treatment.

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Domain wall network:A dual solution for gravitational waves and Hubble tension?

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Science China(physics,Mechanics & Astronomy) 2024年第11期Mechanics & Astronomy) .卷 43-50页

作者： Ligong Bian Shuailiang Ge Changhong Li Jing Shu Junchao Zong department of physics and Chongqing Key Laboratory for Strongly Coupled physics Chongqing University Center for High Energy physics Peking University School of physics and State Key Laboratory of Nuclear physics and Technology Peking University department of Astronomy Key Laboratory of Astroparticle Physics of Yunnan Province School of Physics and AstronomyYunnan University Beijing Laser Acceleration Innovation Center department of physics Nanjing University CAS Key Laboratory of Theoretical physics Institute of Theoretical Physics Chinese Academy of Sciences

We explore the possibility that domain wall networks generate the stochastic gravitational wave background（SGWB） observed as a strong common power-law process in the Data Release-2 of Parkes Pulsar Timing Array. We find that a broad range of parameters, specifically wall tension around σDW～（29-414 TeV）3and wall-decay temperature within Td～ 20-257 MeV, can explain this phenomenon at a 68% credible level. Meanwhile, the same parameters could ease the Hubble tension if particles from these domain wall networks decay into dark radiation. We establish a direct analytical relationship, ?GW（fp, T0）h2～ ?radh2(?ν?Neff)2,to illustrate this coincidence, underlining its importance in the underlying physics and potential applicability to a wider range of models and data. Conversely, if the common power-law process is not attributed to domain wall networks, our findings impose tight limits on the wall tension and decay temperature.

关键词： domain wall gravitational waves Hubble tension

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Can the Bass innovation diffusion model describe adsorption breakthrough curves of pharmaceutical contaminants?

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Green Chemical Engineering 2024年第2期5卷 145-149页

作者： Khim Hoong Chu Mohd Ali Hashim department of Chemical Engineering Faculty of EngineeringUniversity of MalayaKuala Lumpur50603Malaysia

*** Fixed bed adsorption is a widely used separation process in the chemical industry for the processing of liquids and *** performance of fixed bed adsorption systems is often evaluated by analyzing the breakthrough curves,which represent the variation of the solute concentration in the effluent stream as a function of time or bed volume.

关键词： adsorption breakthrough curves

4He monolayer on graphene: a quantum Monte Carlo study

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Communications in Theoretical physics 2024年第9期76卷 151-159页

作者： S Yu M Boninsegni department of physics University of Alberta

We revisit the problem of adsorption of a single4He layer on graphene, focusing on the commensurate(C1/3) crystalline phase, specifically on whether it may possess a nonzero superfluid response, and on the existence of superfluid phases, either（metastable） liquid or vacancy-doped crystalline. We make use of canonical quantum Monte Carlo simulations at zero and finite temperature, based on a realistic microscopic model of the system. Our results confirm the absence of any superfluid response in the commensurate crystal, and that no thermodynamically stable uniform phase exists at lower coverage. No evidence of a possibly long-lived, metastable superfluid phase at C1/3coverage is found. Altogether, the results of ground-state projection methods and finite-temperature simulations are entirely consistent.

关键词： helium low-dimensional systems quantum Monte Carlo superfluidity supersolids

On the half-quantized Hall conductance of massive surface electrons in magnetic topological insulator films

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Science China(physics,Mechanics & Astronomy) 2024年第6期67卷 127-136页

作者： Rui Chen Shun-Qing Shen department of physics The University of Hong KongHong Kong 999077China department of physics Hubei UniversityWuhan 430062China

In topological insulators,massive surface states resulting from local symmetry breaking were thought to exhibit a half-quantized Hall conductance,obtained from the low-energy effective model in an infinite Brillouin *** a lattice model,the surface band is composed of a combination of surface states and bulk *** massive surface states alone may not be enough to support an exact one-half quantized surface Hall conductance in a finite Brillouin zone and the whole surface band always gives an integer quantized Hall conductance as enforced by the TKNN *** explore this,we investigate the band structures of a lattice model describing the magnetic topological insulator film that supports the axion insulator,Chern insulator,and semi-magnetic topological insulator *** reveal that the gapped and gapless surface bands in the three phases are characterized by an integer-quantized Hall conductance and a half-quantized Hall conductance,*** propose an effective model to describe the three phases and show that the low-energy dispersion of the surface bands inherits from the surface Dirac *** gapped surface band manifests a nearly half-quantized Hall conductance at low energy near the center of Brillouin zone,but is compensated by another nearly half-quantized Hall conductance at high energy near the boundary of Brillouin zone because a single band can only have an integer-quantized Hall *** gapless band hosts a zero Hall conductance at low energy but is compensated by another half-quantized Hall conductance at high energy,and thus the half-quantized Hall conductance can only originate from the gapless ***,we calculate the layer-resolved Hall conductance of the *** conclusion suggests that the individual gapped surface band alone does not support the half-quantized surface Hall effect in a lattice model.

关键词： magnetic topological insulator Dirac equation half-quantized Hall conductance

Insights into adsorbent tortuosity across aqueous adsorption systems

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Particuology 2024年第5期88卷 71-88页

作者： Ackmez Mudhoo Marta Otero Khim Hoong Chu department of Chemical and Environmental Engineering Faculty of EngineeringUniversity of MauritiusRéduit 80837Mauritius department of Applied Chemistry and physics Universidad de LeónCampus de Vegazana 24071 LeónSpain department of Chemical Engineering Faculty of EngineeringUniversity of MalayaKuala Lumpur 50603Malaysia

Pore network,pore connectivity,and the resulting effective adsorbate pore diffusivity within an adsorbent are critical physical considerations in mass transport modeling of aqueous *** to these three adsorbent features are the adsorbent tortuosity and tortuosity factor *** concepts encompass the collective hindrance to intra-adsorbent adsorbate transport arising because of a disorderly adsorbent porous *** is crucial for materials scientists,chemists,chemical engineers,and water treatment specialists to understand the complex and variable connections among adsorbate chemistry,adsorbent chemistry,adsorbent porosity,pore shape,size,and tortuosity,pore wall effect,adsorbate-adsorbent interactions,and adsorbate-adsorbate interactions in competitively contaminated aqueous *** tortuosity has been sporadically studied in aqueous adsorption *** the small population of these studies,insightful observations and inferences have been ***,as it appears,no review has been published to compile,compare,and contrast these ***,this review concisely brings up those observations and interpretations around adsorbent tortuosity for aqueous adsorption *** notion of an adsorbent's tortuosity being single-valued is argued to be ***,perspectives are aired on possible research and development directions for elucidating the dynamic attributes of adsorbent tortuosity and applying them in real-scale adsorption-oriented water *** data acquired by filling in these research gaps can enable the design of adsorbents more adapted for real-scale water purification.

关键词： Adsorbent Tortuosity Porosity Pore diffusion models Aqueous systems