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Communications in Theoretical Physics 2024年第1期76卷 76-81页

作者： Cheng Xu zhen-hao yang Xiao-Mei Kuang Rui-Hong Yue Center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou225009China

The scalar-free black hole could be unstable against the scalar field perturbation when it is coupled to a Gauss–Bonnet(GB)invariant in a special *** is known that the tachyonic instability in this scenario is triggered by the sufficiently strong GB *** this paper,we focus on the time domain analysis of massive scalar field perturbation around the Schwarzschild de-Sitter black hole in Einstein-scalar–Gauss–Bonnet *** analyzing the scalar field propagation,we find that the scalar field will finally grow when the GB coupling is large *** could lead to the instability of the background black ***,we demonstrate how the mass of the scalar field and the GB coupling strength affect the onset of tachyonic instability.

关键词： black hole perturbation scalar-Einstein-Gauss-Bonnet gravity time domain evolution me

Nonexistence of quantum black and white hole horizons in an improved dynamic approach

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Science China(Physics,Mechanics & Astronomy) 2024年第8期67卷 56-73页

作者： Wen-Cong Gan Xiao-Mei Kuang zhen-hao yang Yungui Gong Anzhong Wang Bin Wang College of Physics and Communication Electronics Jiangxi Normal UniversityNanchang 330022China GCAP-CASPER Physics DepartmentBaylor UniversityWaco 76798-7316USA Institute for Theoretical Physics&Cosmology Zhejiang University of TechnologyHangzhou 310023China United Center for Gravitational Wave Physics(UCGWP) Zhejiang University of TechnologyHangzhou 310023China Center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou 225009China Department of Physics School of Physical Science and TechnologyNingbo UniversityNingbo 315211China School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai 200240China

In this paper,we study the quantum geometric effects near the locations where classical black hole horizons used to appear in Einstein's classical theory,within the framework of an improved dynamic approach,in which the internal region of a black hole is modeled by the Kantowski-Sachs(KS)spacetime and the two polymerization parameters are functions of the phase space *** detailed analysis shows that the effects are so strong that black and white hole horizons of the effective quantum theory do not exist at all and instead are replaced by transition surfaces,across which the metric coefficients and their inverses are smooth and remain finite,as are the corresponding curvatures,including the Kretschmann *** surfaces always separate trapped regions from anti-trapped *** number of such surfaces is infinite,so the corresponding KS spacetimes become geodesically complete,and no black and white hole-like structures exist in this scheme.

关键词： canonical quantization loop quantum gravity quantum aspects of black holes

Non-adiabatic holonomic quantum operations in continuous variable systems

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 12-19页

作者： hao-Long Zhang Yi-hao Kang Fan Wu zhen-Biao yang Shi-Biao zheng Fujian Key Laboratory of Quantum Information and Quantum Optics College of Physics and Information EngineeringFuzhou UniversityFuzhou 350116China

Quantum operations by utilizing the underlying geometric phases produced in physical systems are favoured due to their potential *** a system in a non-degenerate eigenstate undergoes an adiabatically cyclic evolution dominated by its Hamiltonian,it will get a geometric phase,referred to as the Berry *** a non-adiabatically cyclic evolution produces an Aharonov-Anandan geometric *** two types of Abelian geometric phases are extended to the non-Abelian cases,where the phase factors become matrix-valued and the transformations associated with different loops are *** and non-Abelian(holonomic)operations are prevalent in discrete variable systems,whose limited(say,two)energy levels,form the *** their developments in continuous systems have also been investigated,mainly due to that,bosonic modes(in,such as,cat states)with large Hilbert spaces,provide potential advantages in fault-tolerant quantum *** we propose a feasible scheme to realize non-adiabatic holonomic quantum logic operations in continuous variable systems with cat *** construct arbitrary single-qubit(two-qubit)gates with the combination of single-and two-photon drivings applied to a Kerr Parametric Oscillator(KPO)(the coupled KPOs).Our scheme relaxes the requirements of the previously proposed quantum geometric operation strategies in continuous variable systems,providing an effective way for quantum control.

关键词： cat qubit continuous variable systems non-Abelian

Enhanced red luminescence of Ca_(3)Si_(2−x)M_(x)O_(7):Eu^(3+)(M=Al,P)phosphors via partial substitution of Si^(4+) for applications in white light-emitting diodes

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Rare Metals 2024年第2期43卷 736-748页

作者： Yu-hao Ma Xi Gao Wen-Tao Zhang zhen-Rui yang Zhou Zhao Chen Qu College of Materials and Chemistry and Chemical Engineering Chengdu University of TechnologyChengdu610059China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu610059China International Advanced Energy Science Research and Education Center Graduate School of Energy ScienceKyoto UniversityYoshida-HonmachiKyoto606-8501Japan

A red-emitting phosphor Ca_(2.91)Si_(2)O_(7):0.09Eu^(3+) with partial Al^(3+)/P^(5+) substitution on Si^(4+) was synthesized via a simple solid-state method,and the effects of the introduction of the M^(3+/5+)(M=Al,P)ions on the crystal structure and photoluminescence performance of Ca_(2.91)Si_(2−x)M_(x)O_(7):0.09Eu^(3+) phosphors were *** X-ray diffraction(XRD),energy-dispersive X-ray spectroscopy(EDS),and X-ray photoelectron spectroscopy(XPS)results revealed that the structure of Ca_(3)Si_(2)O_(7) remained the same after the introduction of Al^(3+) and P^(5+) *** characteristic emission of Eu^(3+)-doped Ca_(3)Si_(2−x)M_(x)O_(7) phosphors exhibited two main peaks at 617 nm(red)and 593 nm(orange)under excitation at 394 nm,which originated from the^(5)D_(0)→^(7)F_(2)and^(5)D_(0)→^(7)F_(1) electron transitions of Eu^(3+) *** the partial substitution of Al^(3+) and P^(5+),the red emission intensities of the Ca_(2.91)Si_(2)O_(7):0.09Eu^(3+) phosphors were significantly enhanced by 1.88-and 1.42-fold,respectively,which is attributed to the crystal-field effect around Eu^(3+).Meanwhile,the luminescence intensities of the Ca_(2.91)Si_(1.96)Al_(0.04)O_(7):0.09Eu^(3+) and Ca_(2.91)Si_(1.94)P_(0.06)O_(7):0.09Eu^(3+) phosphors at 210℃ were 79.36%and 77.53%of those at 30°C,respectively,indicating their excellent thermal ***,the as-prepared Ca_(2.91)Si_(1.96)Al_(0.04)O_(7):0.09Eu^(3+)and Ca_(2.91)Si_(1.94)P_(0.06)O_(7):0.09Eu^(3+) red-emitting phosphors were combined with a near-ultraviolet chip of 395 nm to fabricate red-light-emitting diode(LED)and white(w)-LED devices with excellent chromaticity *** summary,Al^(3+)/P^(5+)-substituted Ca_(2.91)Si_(2)O_(7):0.09Eu^(3+) can serve as red-emitting phosphors for applications in w-LEDs.

关键词： Ca_(3)Si_(2)O_(7) Red-emitting phosphor Structure substitution Luminescence enhancement Crystal-field effect White light-emitting diode

Design Optimization and Operating Performance of S-CO_(2) Brayton Cycle under Fluctuating Ambient Temperature and Diverse Power Demand Scenarios

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Journal of Thermal Science 2024年第1期33卷 190-206页

作者： yang Jingze yang zhen DUAN Yuanyuan Key Laboratory for Thermal Science and Power Engineering of MOE Beijing Key Laboratory for CO_(2) Utilization and Reduction TechnologyTsinghua UniversityBeijing 100084China

The supercritical CO_(2)(S-CO_(2)) Brayton cycle is expected to replace steam cycle in the application of solar power tower system due to the attractive potential to improve efficiency and reduce *** the concentrated solar power plant with thermal energy storage is usually located in drought area and used to provide a dispatchable power output,the S-CO_(2) Brayton cycle has to operate under fluctuating ambient temperature and diverse power demand *** addition,the cycle design condition will directly affect the off-design *** this work,the combined effects of design condition,and distributions of ambient temperature and power demand on the cycle operating performance are analyzed,and the off-design performance maps are proposed for the first time.A cycle design method with feedback mechanism of operating performance under varied ambient temperature and power demand is introduced *** show that the low design value of compressor inlet temperature is not conductive to efficient operation under low loads and sufficient output under high ambient *** average yearly efficiency is most affected by the average power demand,while the load cover factor is significantly influenced by the average ambient *** multi-objective optimization,the optimal solution of designed compressor inlet temperature is close to the minimum value of35℃ in Delingha with low ambient temperature,while reaches 44.15℃ in Daggett under the scenario of high ambient temperature,low average power demand,long duration and large value of peak load during the peak temperature *** the cycle designed with compressor inlet temperature of 35℃ instead of 44.15℃ in Daggett under light industry power demand,the reduction of load cover factor will reach 0.027,but the average yearly efficiency can barely be improved.

关键词： supercritical CO_(2)Brayton cycle ambient temperature fluctuating power demand scenarios design optimization off-design performance

A late Carboniferous transition from subduction to collision:Tectonosedimentary evidence from southern Junggar,NW China

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Geoscience Frontiers 2024年第3期15卷 166-179页

作者： Shuoqin Hou Di Li Dengfa He Yu Lu Yu zhen hao yang Dan Fan Key Laboratory of Marine Reservoir Evolution and Hydrocarbon Accumulation Mechanism the Ministry of Educationand School of Energy ResourcesChina University of Geosciences(Beijing)Beijing 100083China

The Carboniferous to Permian tectono-sedimentary evolution of the southern Junggar area brings new insights into understanding the subduction-collision processes in the northern Tianshan *** geophysics,geochemistry,and geochronology approaches,this study investigates the Carboniferous-Permian strata in the southern Junggar *** results have revealed three distinct tectono-stratigraphic evolutionary stages,each marked by a distinctive volcano-sedimentary *** Early Carboniferous strata suggest intense volcanic activities in the southern Junggar *** the Late Carboniferous,the southern Junggar Basin was controlled by normal faulting in an extensional setting,receiving sedimentary inputs from the Junggar *** Lower Permian,unconformably overlying the Upper Carboniferous,was shaped by an extensional regime and is comprised by volcano-clastic sequences that received detritus from the Yili-Central Tianshan *** findings indicate that a Late Carboniferous forearc basin developed in the southern Junggar area,and it evolved into a post-collisional rift in the Early *** period marked a dynamic shift from bidirectional subduction(rollback)to the detachment of the North Tianshan oceanic *** propose that the collision between the YiliCentral Tianshan block and the Junggar terrane,along with the closure of the North Tianshan Ocean,likely occurred in the Late Carboniferous(ca.306-303 Ma).

关键词： Tectono-sedimentary evolution Tectonic transition Carboniferous-Permian Junggar Basin North Tianshan Ocean

Experimental observation of spontaneous symmetry breaking in a quantum phase transition

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Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 34-39页

作者： Wen Ning Ri-Hua zheng Jia-hao Lu Fan Wu zhen-Biao yang Shi-Biao zheng Fujian Key Laboratory of Quantum Information and Quantum Optics College of Physics and Information EngineeringFuzhou UniversityFuzhou 350108China Hefei National Laboratory Hefei 230088China

Spontaneous symmetry breaking(SSB)plays a central role in understanding a large variety of phenomena associated with phase transitions,such as superfluid and *** far,the transition from a symmetric vacuum to a macroscopically ordered phase has been substantially *** process bridging these two distinct phases is critical to understanding how a classical world emerges from a quantum phase transition,but so far remains unexplored in *** here report an experimental demonstration of such a process with a quantum Rabi model engineered with a superconducting *** move the system from the normal phase to the superradiant phase featuring two symmetry-breaking field components,one of which is observed to emerge as the classical *** results demonstrate that the environment-induced decoherence plays a critical role in the SSB.

关键词： quantum phase transition Rabi model spontaneous symmetry breaking superconducting circuit Schrodinger cat states

Neural network study of the nuclear ground-state spin distribution within a random interaction ensemble

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Nuclear Science and Techniques 2024年第3期35卷 216-227页

作者： Deng Liu Alam Noor A zhen-zhen Qin yang Lei School of Mathematics and Physics Southwest University of Science and TechnologyMianyang 621010China School of Nuclear Science and Technology Southwest University of Science and TechnologyMianyang 621010China

The distribution of the nuclear ground-state spin in a two-body random ensemble(TBRE)was studied using a general classification neural network(NN)model with two-body interaction matrix elements as input features and the corresponding ground-state spins as labels or output *** quantum many-body system problem exceeds the capability of our optimized NNs in terms of accurately predicting the ground-state spin of each sample within the ***,our NN model effectively captured the statistical properties of the ground-state spin because it learned the empirical regularity of the ground-state spin distribution in TBRE,as discovered by physicists.

关键词： Neural network Two-body random ensemble Spin distribution of nuclear ground state

Analysis of vascular thrombus and clinicopathological factors in prognosis of gastric cancer:A retrospective cohort study

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World Journal of Gastrointestinal Oncology 2024年第8期16卷 3436-3444页

作者： Guo-Yue Chen Ping Ren zhen Gao hao-Ming yang Yan Jiao Department of Radiology Jinan Central HospitalJinan 250013Shandong ProvinceChina Department of Gastrointestinal Surgery Jiangsu Provincial People's HospitalNanjing 210029Jiangsu ProvinceChina

BACKGROUND Gastric cancer(GC)is one of the most common malignant tumors in the world,and its prognosis is closely related to many *** recent years,the incidence of vascular thrombosis in patients with GC has gradually attracted increasing attention,and studies have shown that it may have a significant impact on the survival rate and prognosis of ***,the specific mechanism underlying the association between vascular thrombosis and the prognosis of patients with GC remains *** To analyze the relationships between vascular cancer support and other clinicopathological factors and their influence on the prognosis of patients with *** This study retrospectively analyzed the clinicopathological data of 621 patients with GC and divided them into a positive group and a negative group according to the presence or absence of a vascular *** difference in the 5-year cumulative survival rate between the two groups was compared,and the relationships between vascular cancer thrombus and other clinicopathological factors and their influence on the prognosis of patients with GC were *** Among 621 patients with GC,the incidence of vascular thrombi was 31.7%(197 patients).Binary logistic regression analysis revealed that the degree of tumor differentiation,depth of invasion,and extent of lymph node metastasis were independent influencing factors for the occurrence of vascular thrombi in GC patients(P<0.01).The trend of the χ^(2) test showed that the degree of differentiation,depth of invasion,and extent of lymph node metastasis were linearly correlated with the percentage of vascular thrombi in GC patients(P<0.01),and the correlation between lymph node metastasis and vascular thrombi was more significant(r=0.387).Univariate analysis revealed that the 5-year cumulative survival rate of the positive group was significantly lower than that of the negative group(46.7%vs 73.3%,P<0.01).Multivariate analysis revealed that age,tumor diam

关键词： Vascular cancer thrombus Gastric cancer Survival prognosis TNM staging Retrospective study

Robust textile-based spoof plasmonic frequency scanning antenna for on-body IoT applications

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Science China(Information Sciences) 2024年第8期67卷 269-284页

作者： Zhao-Min CHEN Jun-Lin ZHAN hao CHEN Ya LI Hongjun HE Wu yang zhen-Guo LIU Wei-Bing LU State Key Lab of Millimeter Waves School of Information Science and EngineeringSoutheast University Center for Flexible RF Technology Frontiers Science Center for Mobile Information Communication and SecuritySoutheast University Future Research Laboratory China Mobile Research Institute Purple Mountain Laboratories

Securing a comfortable, wearable compact frequency beam scanning antenna(FBSA) with robustness to deformation, low specific absorption rate(SAR), and good coverage of the surrounding environment for Internet of Things(IoT) applications, such as on-body navigation and wireless communication is an emerging challenge. In this work, a robust textile-based spoof plasmonic frequency scanning antenna utilizing higher-order modes is presented, which is also robust to deformation caused by the activities of the human body. The innovative design of the element ensures the high-efficiency transmission of the fundamental mode of spoof surface plasmon polaritons(SSPP) structure, providing the potential of being a multifunctional composite device in the compact on-body network. Besides, an artificial magnetic conductor(AMC) is designed underneath the SSPP structure, obtaining a low SAR value(0.113 W/kg), which ensures the safety of users. As a practical realization of this concept, a textile-based spoof plasmonic antenna was fabricated in the microwave regime and the performed experimental results show the proposed antenna has a single-beam radiation characteristic with a 70° beam scanning angle range when the frequency is 4.7–6.0 GHz with a high average realized gain of 13.15 dBi. And it still maintains a steady performance when faced with structure deformation, which proves its robustness. Wireless communication quality experiments are performed to demonstrate the proposed antenna can measure the angles of targets and realize wireless signal transmission to specific targets as the frequency varies, it may find great potential in the field of on-body IoT applications.

关键词： frequency beam scanning antenna (FBSA) Internet of Things (IoT) on-body communication spoof surface plasmon polaritons (SSPP) textile-based antenna