Article
Astronomy & Astrophysics
P. Zhang, W. Wang, Y. Su, L. M. Song, C. K. Li, D. K. Zhou, S. N. Zhang, H. Tian, S. M. Liu, H. S. Zhao, S. Zhang
Summary: The article reports on the observation of an X9.3 flare by the first Chinese X-ray observatory, Insight-HXMT, using wavelets to detect 22-second quasi-periodic pulsations. Spectral analysis shows the evolution of non-thermal electron density and magnetic field strength over time, indicating that the non-thermal electrons may originate from a lower corona source.
ASTROPHYSICAL JOURNAL
(2021)
Article
Chemistry, Physical
Huiwen Lin, Kohei Uosaki, Hidenori Noguchi
Summary: This study investigated the lithiation behavior of a single-crystal Si(1 1 1) anode using SEM, SEXS, and EDS, revealing a maximum cathodic current during the process and diffusion-controlled behavior of lithiated crystalline Si. The results demonstrated low current density during Si lithiation due to low Li diffusion coefficients in the bulk LixSi alloy and bulk Si.
APPLIED SURFACE SCIENCE
(2021)
Correction
Materials Science, Multidisciplinary
Xinchuan Liu, Yuanxun Li, Jianfeng Xiao, Jiuzhou Zhao, Chi Li, Zhenjun Li
Summary: The study investigates the field emission stability of vertically aligned carbon nanotubes through anchoring for X-ray imaging applications. The results demonstrate that anchoring plays a crucial role in enhancing the field emission performance and stability of carbon nanotubes.
JOURNAL OF MATERIALS CHEMISTRY C
(2023)
Article
Chemistry, Physical
Viktoriia A. Saveleva, Kavita Kumar, Pascal Theis, Nicole Segura Salas, Ulrike I. Kramm, Frederic Jaouen, Frederic Maillard, Pieter Glatzel
Summary: This study investigates the structural composition of Fe-N-C materials for the oxygen reduction reaction in proton-exchange membrane fuel cells, before and after catalyst layer preparation, using X-ray absorption and emission spectroscopies. The results reveal the significant impact of the preparation step on the electronic structure and local coordination of Fe, emphasizing the importance of determining the Fe-N-C catalyst structure in the prepared electrode for further studies of the structure-activity-stability correlations.
ACS APPLIED ENERGY MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Baoqiu Yu, Rui-Biao Lin, Gang Xu, Zhi-Hua Fu, Hui Wu, Wei Zhou, Shanfu Lu, Qian-Wen Li, Yucheng Jin, Jing-Hong Li, Zhenguo Zhang, Hailong Wang, Zier Yan, Xiaolin Liu, Kang Wang, Banglin Chen, Jianzhuang Jiang
Summary: Single-crystal X-ray diffraction demonstrates the single-crystal-to-single-crystal transformations of imine linkages in a flexible covalent organic framework with interpenetrating quartz topology. The material exhibits large anisotropic positive thermal expansion and can undergo structural transformations upon removal of solvent molecules. Redox-induced linkage conversions improve the stability of the COFs towards strong acids and enable high anhydrous proton conductivity.
Article
Nanoscience & Nanotechnology
Xiaoxiao Li, Chenxuan Lou, Weijun Li, Lin Wang, Fengmei Gao, Gang Shao, Shanliang Chen, Weiyou Yang
Summary: This study introduces a high-performance field emitter with designed sharp corners, achieving a low E-to of 0.52 V/μm and a current fluctuation of only 2% over 10 hours. This design enhances electron emission sites and prevents damage during long-term operation.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Astronomy & Astrophysics
Dylan M. M. Pare, Cornelia C. C. Lang, Mark R. Morris
Summary: The nonthermal filament structures clustered near the Galactic center are unique to this region. Recent observations reveal many faint and previously unknown bundles of these filaments. Comparisons between newly discovered NTFBs and the larger NTF population show similarities in their total-intensity properties. The results suggest that NTFs are likely a result of synchrotron emission from relativistic electrons.
ASTROPHYSICAL JOURNAL
(2022)
Article
Astronomy & Astrophysics
Ang Li, Zhiqiang Miao, Sophia Han, Bing Zhang
Summary: In this study, a Bayesian analysis was conducted on the maximum mass of neutron stars with a quark core, revealing the most probable values of the hybrid star maximum mass to be around 2.36 solar masses. The results are robust with respect to uncertainties in the hadronic EOS and have implications for astrophysical phenomena such as post-merger products of neutron star mergers and short gamma-ray bursts.
ASTROPHYSICAL JOURNAL
(2021)
Article
Astronomy & Astrophysics
F. Verrecchia, C. Casentini, M. Tavani, A. Ursi, S. Mereghetti, M. Pilia, M. Cardillo, A. Addis, G. Barbiellini, L. Baroncelli, A. Bulgarelli, P. W. Cattaneo, A. Chen, E. Costa, E. Del Monte, A. Di Piano, A. Ferrari, V Fioretti, F. Longo, F. Lucarelli, N. Parmiggiani, G. Piano, C. Pittori, A. Rappoldi, S. Vercellone
Summary: This study conducted a systematic search for hard X-ray and gamma-ray emission associated with fast radio bursts (FRBs) observed by the AGILE satellite, finding no significant MeV or GeV emission from any event. Nearby FRBs emit radio pulses of energies significantly larger than recently detected sources, with MeV upper limits equivalent to those observed in giant flares from Galactic magnetars.
ASTROPHYSICAL JOURNAL
(2021)
Article
Chemistry, Multidisciplinary
Jaemyung Kim, Okkyun Seo, L. S. R. Kumara, Toshihide Nabatame, Yasuo Koide, Osami Sakata
Summary: The crystal quality of a 6 inch free-standing GaN substrate grown using a Na-flux based liquid phase epitaxy method was demonstrated by recording rocking curve profiles and analyzing lattice plane anisotropic bowing. The competition between crystallinity and homogeneity was observed in the substrate, with a mean rocking curve width of 0.024 degrees indicating almost single crystal quality.
Article
Chemistry, Multidisciplinary
F. Picollo, A. Battiato, F. Bosia, F. Scaffidi Muta, P. Olivero, V Rigato, S. Rubanov
Summary: This study explores the possibility of creating full-sp(3) amorphous nanostructures within diamond crystals using ion-beam irradiation at room temperature, followed by an annealing process. It also discusses the mechanism of formation of an amorphous sp(2)-free phase in diamond.
NANOSCALE ADVANCES
(2021)
Article
Geosciences, Multidisciplinary
Li Zhuang, Arno Zang
Summary: This article reviews laboratory experimental studies on hydraulic fracturing under triaxial and true triaxial stress conditions in crystalline rock for geothermal purposes, focusing on the stimulation of Enhanced Geothermal Systems. It discusses key factors influencing hydraulic fracture initiation and propagation, innovative injection schemes, and fracture-inspection techniques for quantifying the efficiency of injection protocols. The discussion section includes diagrams connecting injection rate with resulting fluid infiltration zone and fracture process zone, providing insights into potential field applications in geothermal fields.
EARTH-SCIENCE REVIEWS
(2021)
Article
Physics, Multidisciplinary
Vladimir Kirischuk
Summary: Comparing the acquired spectra of two irradiation series, it was observed that the peak intensities of the 178m2Hf isomer were higher at the end of each series, while the intensities of the 150Eu and 133Ba peaks, which are present in the isomeric target, remained stable. This provides support for the hypothesis that additional activity is generated during irradiation. The half-life of this activity appears to be several days.
Article
Engineering, Electrical & Electronic
Rahul Aher, Prashant Gaikwad, Ashwini Punde, Pratibha Shinde, Ashish Waghmare, Yogesh Hase, Shruti Shah, Bharat Bade, Swati Rahane, Somnath Ladhane, Vidya Doiphode, Sachin Rondiya, Mohit Prasad, Sandesh Jadkar
Summary: The thermal properties of PbBi2Se4 composite, such as diffusivity, effusivity, specific heat, Debye temperature, thermal conductivity, and lattice thermal conductivity, have been investigated using temperature and incident laser power-dependent Raman scattering. The results provide insights into the thermal conductivity of layered materials and can be used to tune the thermal properties of topological insulators.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2023)
Article
Materials Science, Multidisciplinary
P. Pokorny, M. Novotny, J. Fara, Y. Dekhtyar, A. Lushchik, R. Jaaniso, P. Fitl, J. Lancok
Summary: This article discusses a method for simultaneous measurements of thermally stimulated processes and analysis of the results, with consistency shown in comparison to previous studies. Using high-purity monocrystalline KBr material under different temperature and pressure conditions, reliable experimental data was obtained.
Article
Engineering, Electrical & Electronic
Yucheng Liu, Weihao Liu, Qika Jia, Baogen Sun, Jun Chen
Summary: This article introduces an enhanced terahertz laser diode (TLD) that uses multiple field-emitter cathodes with coupled cavities, resulting in improved performance and accessibility. The method reduces the required electric field intensity and emission current density, making it easier to manufacture and widening its range of applications.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Engineering, Electrical & Electronic
Guowei Chen, Min Guo, Xiaojie Li, Weiliang Wang, Fengjuan Liu, Ce Ning, Guangcai Yuan, Jun Chen, Shaozhi Deng, Chuan Liu
Summary: The reliability of amorphous oxide semiconductor thin-film transistors (AOS-TFTs) is crucial for high-definition displays and functional electronic devices. The study reveals that drain current drop (DCD) degradation in short-channel length transistors is a reversible process closely related to reduced metal-oxygen bonds. Using a drain-offset structure can effectively alleviate DCD failure.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2022)
Article
Materials Science, Multidisciplinary
Yangyang Zhao, Yicong Chen, Guofu Zhang, Deyi Huang, Runze Zhan, Shaozhi Deng, Ningsheng Xu, Jun Chen
Summary: In this study, a fully vacuum-sealed flat-panel X-ray source was fabricated with a molybdenum metal anode and ZnO nanowire field emitters array cathode. The device exhibited higher emission current and dose rate when driven by pulsed voltage compared to direct current. The enhanced emission current enabled fast and clear imaging of high-speed moving objects, indicating the significance of this research for the application of large area flat-panel X-ray sources in dynamic imaging.
Article
Chemistry, Multidisciplinary
Yajie Guo, Junfan Wang, Baohong Li, Yu Zhang, Shaozhi Deng, Jun Chen
Summary: In this study, a gated carbon nanotube cold cathode electron gun with high current stability was developed and applied in X-ray source using IGBT modulation. The results demonstrate the feasibility of achieving high current stability and stable X-ray dose rate using this electron source.
Article
Chemistry, Multidisciplinary
Songyou Zhang, Xiuqing Cao, Guofu Zhang, Shaozhi Deng, Jun Chen
Summary: This paper investigates the effect of pixel density on the emission performance of gated ZnO nanowire arrays. Simulation and experimental results show that the fabricated arrays, with optimized gate modulation, exhibit high emission current and effective gate control.
Article
Nanoscience & Nanotechnology
Jinlun Huang, Yifeng Huang, Miaoxuan Zeng, Ningsheng Xu, Yuan Huang, Jun Chen, Juncong She, Shaozhi Deng
Summary: Metal cone-shaped nanotip field-electron emitters, known as Spindt-type tips, have shown great potential in vacuum micro-/nanoelectronics. This study presents an in situ stress-release process for fabricating chromium (Cr) tip arrays. The process involves the use of patterned photoresist microcavities and trenches for the formation and stress release of the metal tips. High-aspect-ratio Cr tips were achieved by plasma etching, and a gated Cr-tip array was fabricated using a self-aligned microfabrication procedure. The Cr tips exhibited good etch resistance and showed emission current suitable for various applications.
ACS APPLIED NANO MATERIALS
(2023)
Article
Physics, Applied
Guichen Song, Yicong Chen, Shaozhi Deng, Jun Chen
Summary: The study establishes a general model for a gated hot carrier tunneling device to determine the optimized thickness of a tunneling barrier for improving the collection efficiency. Simulation results show that the maximum efficiency is influenced by the field strength, tunneling barrier height, mean free path, and threshold energy. Additionally, experimental measurements on a graphene/h-BN/graphene heterostructure confirm the model and provide insight into the emission efficiency as a function of h-BN thickness.
APPLIED PHYSICS LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Zekun Guo, Haojian Lin, Hu Zhang, Yan Tian, Yicong Chen, Jun Chen, Shaozhi Deng, Fei Liu
Summary: Tetragonal borophene sheets with high ambient stability were successfully fabricated by the LPCVD method. Compared with bulk counterparts, 2D borophene has potential applications in high-speed transistors, optoelectronic detection, field emission, and mechanical enforcement areas. The research suggests that LPCVD-grown borophene may be a promising building block for constructing high-performance nanodevices with good ambient stability.
CRYSTAL GROWTH & DESIGN
(2023)
Article
Engineering, Electrical & Electronic
Song Kang, Yicong Chen, Chengyun Wang, Guofu Zhang, Shaozhi Deng, Jun Chen
Summary: In this article, a fully vacuum-encapsulated transparent flat-panel X-ray source was prepared using ZnO nanowires cold cathode and indium-tin-oxide (ITO) transmission anode. The effect of ITO film thickness on X-ray radiation intensity was studied. The results showed a radiation dose rate of 6.85 mGy/s measured at 5 cm in front of the flat-panel X-ray source (FPXS) and an optical transmittance of 72.63% at 550-nm light. X-ray spectra indicated indium as the main element for X-ray generation. With the device used in an X-ray and visible light dual-functional inspection setup, simultaneous X-ray and visible light imaging of objects was demonstrated.
IEEE TRANSACTIONS ON ELECTRON DEVICES
(2023)
Article
Chemistry, Physical
Manni Chen, Zhipeng Zhang, Bin Wen, Runze Zhan, Kai Wang, Shaozhi Deng, Jiangsheng Xie, Jun Chen
Summary: This study presents the use of Ga2O3 compact layer to form a heterojunction structure with FAPbI3 for perovskite-based X-ray detectors. The FAPbI3/Ga2O3 detector exhibits significantly reduced dark current and increased photo-to-dark current ratio compared to the bare FAPbI3 detector. It also achieves a lower detection limit and shorter response time. Furthermore, the FAPbI3/Ga2O3 device demonstrates better repeatability due to the suppression of ion migration.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Multidisciplinary Sciences
Jingshun Pan, Qiang Li, Yaoming Feng, Ruifeng Zhong, Zhihao Fu, Shuixian Yang, Weiyuan Sun, Bin Zhang, Qi Sui, Jun Chen, Yuecheng Shen, Zhaohui Li
Summary: Photoacoustic tomography (PAT) is an attractive imaging modality that provides optical contrast with acoustic resolutions. In this work, we demonstrate PAT with a chalcogenide-based micro-ring sensor array and develop an effective means of parallel interrogation using a digital optical frequency comb.
NATURE COMMUNICATIONS
(2023)
Article
Computer Science, Information Systems
Jiaquan Kong, Chuan Liu, Xiaojie Li, Hai Ou, Juncong She, Shaozhi Deng, Jun Chen
Summary: In this study, equations were derived to describe the current-voltage relations of offset Corbino thin film transistors. The influence of offset position and parameters on saturation voltage and current was quantitatively described. The theoretical physical model was verified through computer-aided design simulation and experimental results.
Article
Radiology, Nuclear Medicine & Medical Imaging
Xu Li, Shuang Huang, Zengxiang Pan, Peishan Qin, Wangjiang Wu, Mengke Qi, Jianhui Ma, Song Kang, Jun Chen, Linghong Zhou, Yuan Xu, Genggeng Qin
Summary: This study demonstrates the feasibility of using an end-to-end U-net for deblurring and deoverlapping in the flat-panel X-ray source domain. The neural network successfully converts overlapping cone beam projections to parallel beam projections, and the resulting images have high structural similarity to the original parallel beams. The model achieves excellent performance on different tasks and shows good generalization ability.
PHYSICA MEDICA-EUROPEAN JOURNAL OF MEDICAL PHYSICS
(2023)
Review
Chemistry, Multidisciplinary
Yicong Chen, Jun Chen, Zhibing Li
Summary: This article reviews the recent progress on cold cathodes with graphene as the direction, including both experimental and theoretical studies. The review emphasizes the phenomena that are absent in conventional cold cathodes but present in two-dimensional van der Waals materials, such as directionality and coherence. It also covers the fabrication of emitter structures for field emission applications, their field emission properties, and the existing field emission model.
Article
Engineering, Electrical & Electronic
Weiwen Wu, Jianjia Zhang, Shaoyu Wang, Jun Chen
Summary: A new stationary CT scanner called FANS, based on a flat-panel addressable nanowire-cold-cathode architecture, is proposed. The FANS scanner is a small and cheap system as it utilizes a low-cost compact flat-panel X-ray source. It is also a stationary CT system with fast-switching capabilities. Moreover, the FANS system provides high-quality image output by incorporating superior regularization priors.
IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT
(2023)
