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Chinese physics B 2015年第7期24卷 518-523页

作者：林冬风徐余颛石将建张瑜罗艳红李冬梅孟庆波 key laboratory for Renewable Energy Chinese Academy of Sciences Beijing key laboratory for New Energy Materials and Devices Institute of PhysicsChinese Academy of Sciences

A real-time quantitative optical method to characterize crack propagation in colloidal photonic crystal film（CPCF）is developed based on particle deformation models and previous real-time crack observations. The crack propagation process and temperature dependence of the crack propagation rate in CPCF are investigated. By this method, the crack propagation rate is found to slow down gradually to zero when cracks become more numerous and dense. Meanwhile, with the temperature increasing, the crack propagation rate constant decreases. The negative temperature dependence of the crack propagation rate is due to the increase of van der Waals attraction, which finally results in the decrease of resultant force. The findings provide new insight into the crack propagation process in CPCF.

关键词： colloidal photonic crystal crack propagation temperature real-time quantitative optical method

Towards an optical coupler using fine-wire:a study of the photovoltaic effect of a heterojunction formed in a single fine-wire of tungsten oxides

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Chinese physics B 2010年第3期19卷 557-562页

作者：陈尚辉陈建邓少芝许宁生 State key laboratory of Optoelectronic Materials and Technologies and Guangdong Province Key Laboratory for Display Material and TechnologySchool of Physics and EngineeringSunYat-Sen University

Nanodevices using the photovoltaic effect of a single nanowire have attracted growing interest. In this paper, we consider potential applications of the photovoltaic effect to optical signal coupling and optical power transmission, and report on the realization of a heterojunction formed between WO2 and WO3 in a fine-wire having a diameter on the micrometer scale. Using a laser beam of 514.5 nm as a signal source, the WO2-WO3 heterojunction yields a maximum output power of up to 37.4 pico watt per heterojunction. Fast responses （less than a second） of both photovoltaic voltage and current are also observed. In addition, we demonstrate that it is a simple and effective way to adapt a commercial Raman spectrometer for the combined functions of fabrication, material characterization and photovottaic measurement of an optical signal coupler and optical power transmitter based on a fine-wire. Our results show an attractive perspective of developing nanowire or fine-wire elements for coupling optical signals into and for powering a nanoelectronic or nano-optoelectronic integrated circuit that works under the condition of preventing it from directly electrically connecting with the optical coupler.

关键词： optical coupler heterojunction tungsten oxide fine-wire photovoltaic

Anisotropic and mutable magnetization in Kondo lattice CeSb2

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Chinese physics B 2017年第6期26卷 319-323页

作者：张云朱燮刚胡丙锋谭世勇谢东华冯卫刘琴张文刘瑜宋海峰罗丽珠张政军赖新春 Science and Technology on Surface physics and Chemistry laboratory Department of Engineering physics Tsinghua University key laboratory of Neutron physics Institute of Nuclear Physics and ChemistryChina Academy of Engineering Physics laboratory of Computational physics Institute of Applied Physics and Computational Mathematics Software Center for High Performance Numerical Simulation China Academy of Engineering Physics key laboratory of Advanced Materials (MOE) School of Materials Science and EngineeringTsinghua University

We have systematically studied the behaviors of the resistivity and magnetization of CeSb2 single crystals as a function of temperature and external field. Four anomalies in the resistivity/magnetization-versus-temperature curves are observed at low magnetic field. They are located at 15.5 K, 11.5 K, 9.5 K, and 6.5 K, corresponding to the paramagnetic–magnetically ordered state（MO）, MO-antiferromagnetic（AFM）, AFM–AFM, and AFM–ferromagnetic（FM） transitions, *** anomaly at 9.5 K is only visible with H‖[010] by magnetic susceptibility measurements, indicating that the AFM–AFM transition only happens along [010] direction in ab-plane. The four magnetic transitions are strongly suppressed by high external field. Finally, the field-temperature phase diagrams of CeSb2 with different orientations of the applied field in ab-plane are constructed and indicate the highly anisotropic nature of the magnetization of CeSb2.

关键词： CeSb2 electronic properties magnetic properties

Recent progress in econophysics： Chaos, leverage, and business cycles as revealed by agent-based modeling and human experiments

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Frontiers of physics 2017年第6期12卷 139-161页

作者： Chen Xin Ji-Ping Huang Department of physics and State key laboratory of Surface physics Fudan University Shanghai 200433 China

Agent-based modeling and controlled human experiments serve as two fundamental research methods in the field of econophysics. Agent-based modeling has been in development for over 20 years, but how to design virtual agents with high levels of human-like ＂intelligence＂ remains a challenge. On the other hand, experimental econophysics is an emerging field; however, there is a lack of experience and paradigms related to the field. Here, we review some of the most recent research results obtained through the use of these two methods concerning financial problems such as chaos, leverage, and business cycles. We also review the principles behind assessments of agents＇ intelligence levels, and some relevant designs for human experiments. The main theme of this review is to show that by combining theory, agent-based modeling, and controlled human experiments, one can garner more reliable and credible results on account of a better verification of theory; accordingly, this way, a wider range of economic and financial problems and phenomena can be studied.

关键词： agent-based modeling controlled human experiment minority game econophysics chaos,leverage business cycle

Pathogenesis, diagnosis, and treatment of epilepsy: electromagnetic stimulation-mediated neuromodulation therapy and new technologies

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Neural Regeneration Research 2025年第4期20卷 917-935页

作者： Dian Jiao Lai Xu Zhen Gu Hua Yan Dingding Shen Xiaosong Gu Academy of Medical Engineering and Translational Medicine Tianjin UniversityTianjinChina key laboratory of Advanced Drug Delivery Systems of Zhejiang Province College of Pharmaceutical SciencesZhejiang UniversityHangzhouZhejiang ProvinceChina Affiliated Hospital of Nantong University NantongJiangsu ProvinceChina

Epilepsy is a severe,relapsing,and multifactorial neurological *** regarding the accurate diagnosis,prognosis,and in-depth pathogenesis are crucial for the precise and effective treatment of *** pathogenesis of epilepsy is complex and involves alterations in variables such as gene expression,protein expression,ion channel activity,energy metabolites,and gut microbiota *** results are lacking for conventional treatments for *** resection of lesions,drug therapy,and non-drug interventions are mainly used in clinical practice to treat pain associated with ***-pharmacological treatments,such as a ketogenic diet,gene therapy for nerve regeneration,and neural regulation,are currently areas of research *** review provides a comprehensive overview of the pathogenesis,diagnostic methods,and treatments of *** also elaborates on the theoretical basis,treatment modes,and effects of invasive nerve stimulation in neurotherapy,including percutaneous vagus nerve stimulation,deep brain electrical stimulation,repetitive nerve electrical stimulation,in addition to non-invasive transcranial magnetic stimulation and transcranial direct current *** studies have shown that electromagnetic stimulation-mediated neuromodulation therapy can markedly improve neurological function and reduce the frequency of epileptic ***,many new technologies for the diagnosis and treatment of epilepsy are being ***,current research is mainly focused on analyzing patients’clinical manifestations and exploring relevant diagnostic and treatment methods to study the pathogenesis at a molecular level,which has led to a lack of consensus regarding the mechanisms related to the disease.

关键词： diagnosis drug treatment electroencephalography epilepsy monitoring epilepsy nerve regeneration neurostimulation non-drug interventions pathogenesis prediction

Multi-Modality Medical Image Fusion Based on Wavelet Analysis and Quality Evaluation

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Journal of Systems Engineering and Electronics 2001年第1期12卷 42-48页

作者： Yu Lifeng & Zu Donglin Institute of heavy ion physics, Peking University, 100871, P. R. China Wang Weidong General Hospital of PLA, Beijing 100853, P. R. China Bao Shanglian Institute of heavy ion physics, Peking University, 100871, P. R. China Institute of heavy ion physics Peking University 100871 P. R. China General Hospital of PLA Beijing 10085. P. R. China

Multi-modality medical image fusion has more and more important applications in medical image analysis and understanding. In this paper, we develop and apply a multi-resolution method based on wavelet pyramid to fuse medical images from different modalities such as PET-MRI and CT-MRI. In particular, we evaluate the different fusion results when applying different selection rules and obtain optimum combination of fusion parameters.

关键词： Computer simulation Computerized tomography Image analysis Image quality Image understanding Magnetic resonance imaging Optical resolving power

Duration-Dependent Asymmetry in Photoionization of H atoms in Few-Cycle Laser Pulses

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Chinese physics Letters 2006年第12期23卷 3249-3252页

作者：张晓明张敬涛白丽华龚旗煌徐至展 State key laboratory for Mesoscopic physics Department of Physics Peking University Beijing 100087 State key laboratory of High Field Laser physics Shanghai Institute of Optics and Fine Mechanics Chinese Academy of Sciences Shanghai 201800

The photoionization of H atoms irradiated by few-cycle laser pulses is studied numerically. The variations of the total ionization, the partial ionizations in opposite directions, and the corresponding asymmetry with the carrier-envelope phase in several pulse durations are obtained. We find that besides a stronger modulation on the partial ionizations, the change of pulse duration leads to a shift along carrier-envelope （CE） phase in the calculated signals. The phase shift arises from the nonlinear property of ionization and relates closely to the Coulomb attraction of the parent ion to the ionized electron. Our calculations show good agreement with the experimental observation under similar conditions.

关键词： ELECTRON LOCALIZATion ABSOLUTE-PHASE SCALING LAW ionIZATion SUPPRESSion FIELDS

Charge storage characteristics of Ni nanocrystals formed by synchronous crystallization

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Journal of Semiconductors 2014年第10期35卷 17-22页

作者：程佩红黄仕华陆昉 physics Department Zhejiang Normal University Surface physics National key laboratory Fudan University

The rapid thermal annealing （RTA） nano-crystallization method is widely used in the metal nanocrystal fabrication process. However, the high temperature （usually 600 900 ℃） in the RTA process will worsen the per- formance and reliability of devices. A novel method has been proposed to grow metal nanocrystal by synchronous in situ nano-crystallization of metal thin film （SINC）, which is able to resolve the problems mentioned above. Com- pared with Ni nanocrystals （NCs） formed by RTA, Ni NCs prepared by SINC can obtain more energy to crystallize, and its crystallization temperature is greatly reduced. A large memory window （2.78 V） was observed for Ni NCs deposited by SINC at 300 ℃. However, the largest window is only 1.26 V for Ni NCs formed by RTA at 600 ℃. A large change （from 0.20 to 4.59 V） of the memory window was observed while the operation voltage increased from 0 to 4-10 V, which is due to an occurrence of strong carrier trapping in Ni NCs. Flat-band voltage shift rapidly increases to its saturation value, which indicates that electron/hole trapping in Ni NCs mainly occurs at the initial stage of the program/erase process. A theoretical model was proposed to characterize the charging and discharging processes.

关键词： metal nanocrystal memory synchronously crystallization C-V characteristics

Ultrahigh spatiotemporal resolved spectroscopy

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Science China(physics,Mechanics & Astronomy) 2007年第6期50卷 681-690页

作者： LI Zhi ZHANG JiaSen YANG Jing GONG QiHuang Department of physics and State key laboratory for Mesoscopic physics Peking UniversityBeijing 100871China

We review the technique and research of the ultrahigh spatiotemporal resolved spectroscopy and its applications in the field of the ultrafast dynamics of mesoscopic systems and nanomaterials. Combining femtosecond time-resolved spectroscopy and scanning near-field optical microscopy (SNOM),we can obtain the spectra with ultrahigh temporal and spatial resolutions simultaneously. Some problems in doing so are discussed. Then we show the important applications of the ultrahigh spatiotemporal resolved spectroscopy with a few typical examples.

关键词： ultrahigh spatiotemporal resolved spectroscopy femtosecond near-field spectroscopy scanning near-field optical microscopy (SNOM) femtosecond time-resolved nanomaterial

Evidence for reversible oxygen ion movement during electrical pulsing:enabler of emerging ferroelectricity in binary oxides

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Materials Futures 2024年第3期3卷 195-205页

作者： Huan Liu Fei Yu Bing Chen Zheng-Dong Luo Jiajia Chen Yong Zhang Ze Feng Hong Dong Xiao Yu Yan Liu Genquan Han Yue Hao State key Discipline laboratory of Wide Band Gap Semiconductor Technology School of MicroelectronicsXidian UniversityXi’an 710071People’s Republic of China Research Center for Intelligent Chips and Devices Zhejiang LabHangzhou 311121People’s Republic of China Engineering Research Center of Thin Film Optoelectronics Technology Ministry of EducationNankai UniversityTianjin 300350People’s Republic of China

Ferroelectric HfO_(2)-based materials and devices show promising potential for applications in information technology but face challenges with inadequate electrostatic control,degraded reliability,and serious variation in effective oxide thickness *** demonstrate a novel interface-type switching strategy to realize ferroelectric characteristics in atomic-scale amorphous binary oxide films,which are formed in oxygen-deficient conditions by atomic layer deposition at low *** approach can avoid the shortcomings of reliability degradation and gate leakage increment in scaling polycrystalline doped HfO_(2)-based *** theoretical modeling and experimental characterization,we show the following.(1)Emerging ferroelectricity exists in ultrathin oxide systems as a result of microscopic ion migration during the switching process.(2)These ferroelectric binary oxide films are governed by an interface-limited switching mechanism,which can be attributed to oxygen vacancy migration and surface defects related to electron(de)trapping.(3)Transistors featuring ultrathin amorphous dielectrics,used for non-volatile memory applications with an operating voltage reduced to±1 V,have also been experimentally *** findings suggest that this strategy is a promising approach to realizing next-generation complementary metal-oxide semiconductors with scalable ferroelectric materials.

关键词： ferroelectric binary oxide mobile ion amorphous dielectric nonvolatile memory