检索结果-南通市图书馆

Nuclear Science and Techniques 2024年第2期35卷 170-182页

作者： Gao-Yi Cheng Qian-Min Su Xi-Guang Cao Guo-Qiang Zhang School of Electronic and Electrical Engineering Shanghai University of Engineering ScienceShanghai 201620China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China

Traditional particle identification methods face timeconsuming,experience-dependent,and poor repeatability challenges in heavy-ion collisions at low and intermediate *** urgently need solutions to the dilemma of traditional particle identification *** study explores the possibility of applying intelligent learning algorithms to the particle identification of heavy-ion collisions at low and intermediate *** intelligent algorithms,including XgBoost and TabNet,were selected to test datasets from the neutron ion multi-detector for reaction-oriented dynamics(NIMROD-ISiS)and Geant4 ***-based machine learning algorithms and deep learning algorithms *** show excellent performance and generalization *** additional data features besides energy deposition can improve the algorithm’s performance when the data distribution is *** learning algorithms can be applied to solve the particle identification problem in heavy-ion collisions at low and intermediate energies.

关键词： Heavy-ion collisions at low and intermediate energies Machine learning Ensemble learning algorithm Particle identification Data imbalance

Multifunction-oriented high-mobility polymer semiconductors

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第3期11卷 16-19页

作者： Mingliang Zhu Yunlong Guo Yunqi Liu Beijing National Laboratory for Molecular sciences Organic Solids Laboratory Institute of Chemistry Chinese Academy of Sciences School of Chemical sciences University of Chinese Academy of Sciences

The discovery of conductive polyacetylene has initiated interdisciplinary research into condensed matter physics and synthetic chemistry in organic electronics. Unlike their inorganic and small-molecule counterparts, polymer semiconductors possess the inherent advantages of facile solution processing,large-area manufacturing, excellent mechanical strength and intrinsic flexibility.

关键词：

Theoretical understanding of correlation between magnetic phase transition and the superconducting dome in high-Tc cuprates

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 167-173页

作者： Chen Zhang Cai-Xin Zhang Su-Huai Wei Haiqing Lin Hui-Xiong Deng State Key Laboratory of Superlattices and Microstructures Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China Beijing Computational Science Research Center Beijing 100193China

Many issues concerning the origin of high-temperature superconductivity(HTS)are still under *** example,how the magnetic order varies with doping and its relationship with the superconducting temperature(Tc);and why Tcalways peaks near the quantum critical *** this paper,taking hole-doped La_(2)CuO_(4)as a classical example,we employ the first-principles band structure and total energy calculations with Monte Carlo simulations to explore how the symmetry-breaking magnetic ground state evolves with hole doping and the origin of a dome-shaped superconductivity region in the phase *** demonstrate that the local antiferromagnetic order and doping play key roles in determining the electron-phonon coupling,thus ***,the La_(2)CuO_(4)possesses a checkerboard local antiferromagnetic ground *** the hole doping increases,Tcincreases with the enhanced electron-phonon coupling *** as the doping increases further,the strength of the antiferromagnetic interaction weakens and spin fluctuation *** the critical doping level,a magnetic phase transition occurs that reduces the local antiferromagnetism-assisted electron-phonon coupling,thus diminishing the *** superconductivity disappears in the heavily overdoped region when the ferromagnetic order *** observations could account for why cuprates have a dome-shaped superconductivity region in the phase *** study,thus,contributes to a fundamental understanding of the correlation between doping,local magnetic order,and superconductivity of HTS.

关键词： high-temperature superconductivity antiferromagnetic order electron-phonon coupling doping effect cuprates

Searching for the Highest Energy of Pulsation and Critical Luminosity of Swift J0243.6+6124 Observed by Insight-HXMT

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第5期24卷 61-69页

作者： Qing-Xia Zhao Xian Hou Ming-Yu Ge Shuang-Nan Zhang Yun-Xiang Xiao You-Li Tuo Zi-Xu Yang Ling-Da Kong Jin-Lu Qu Shu Zhang Jian-Cheng Wang Yunnan Observatories Chinese Academy of SciencesKunming 650216China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of chinese academy of sciences ChineseAcademy of SciencesBeijing 100049China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China Institut fur Astronomic und Astrophysik Sand 1D-72076 TabingenGemany School of Physics and Optoelectronic Engineering Shandong University of TechnologyZibo 255000China

Owing to the broad energy coverage of Insight-HXMT in the hard X-ray band,we detected the highest energy of pulsation exceeding 200 keV around the 2017–2018 outburst peak of the first Galactic pulsating ultraluminous X-ray source (PULX) Swift J0243.6+6124,which is the highest energy detected from PULXs to *** also obtained the highest energy of pulsation of every exposure during the outburst in 2017–2018,and found the highest energy is roughly positively correlated with *** our newly developed method,we identified the critical luminosity being 4×10^(38)erg s^(-1) when the main peaks of the low and high energy pulse profiles became aligned,which separates the fan-beam dominated and pencil-beam dominated accretion *** the critical luminosity,the phase of the main peak shifted gradually from 0.5 to 0.8 until the outburst peak in al energy bands is reached,which is in agreement with the phase shift found previously at low *** result is consistent with what is derived from spectral analysis.

关键词： (stars:)pulsars-individual(Swift J0243.6+6124)-X-rays binaries–stars neutron

XOR spin logic operated by unipolar current based on field-free spin-orbit torque switching induced by a lateral interface

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2024年第8期43卷 3868-3875页

作者： Yan-Ru Li Mei-Yin Yang Guo-Qiang Yu Bao-Shan Cui Jin-Biao Liu Yong-Liang Li Qi-Ming Shao Jun Luo Key Laboratory of Microelectronic Devices and Integrated Technology Institute of MicroelectronicsChinese Academy of Sciences (IMECAS) University of chinese academy of sciences (Ucas) Songshan Lake Materials Laboratory Institute of Physics Chinese Academy of Sciences Key Laboratory for Magnetism and Magnetic Materials of Ministry of Education Lanzhou University Department of Electronic and Computer Engineering The Hong Kong University of Science and Technology

Spin logics have emerged as a promising avenue for the development of logic-in-memory *** particular,the realization of XOR spin logic gates using a single spin-orbit torque device shows great potential for low-power stateful logic circuits in the next *** this study,we successfully obtained the XOR logic gate by utilizing a spin-orbit torque device with a lateral interface,which was created by local ion implantation in the Ta/Pt/Co/Ta Hall device exhibiting perpendicular magnetic *** angle of the lateral interface is set at 45°relative to the current direction,leading to the competition between symmetry breaking and current-driven Néel-type domain wall ***,the field-free magnetic switching reversed is realized by the same sign of current amplitude at this *** on this field-free magnetic switching behavior,we successfully proposed an XOR logic gate that could be implemented using only a single spin-orbit torque Hall *** study provides a potentially viable approach toward efficient spin logics and in-memory computing architectures.

关键词： Filed-free magnetic switching Spin–orbit torque XOR logic gate Lateral interface

Layered kagome compound Na_(2)Ni_(3)S_(4)with topological flat band

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

chinese Physics B 2024年第5期33卷 153-159页

作者：叶君耀林益浩王浩哲宋志达冯济谢韦伟贾爽 International Center for Quantum Materials School of PhysicsPeking UniversityBeijing 100871China Department of Chemistry Michigan State UniversityMI48824USA Hefei National Laboratory Hefei 230088China Interdisciplinary Institute of Light-Element Quantum Materials and Research Center for Light-Element Advanced Materials Peking UniversityBeijing 100871China

We report structural and electronic properties of Na_(2)Ni_(3)S_(4),a quasi-two-dimensional compound composed of alternating layers of[Ni_(3)S_(4)]^(2-)and Na^(+).The compound features a remarkable Ni-based kagome lattice with a square planar configuration of four surrounding S atoms for each Ni *** and electrical measurements reveal a weak paramagnetic insulator with a gap of about 0.5 *** band structure calculation highlights a set of topological flat bands of the kagome lattice derived from the rotated dxz-orbital with C_(3)+T symmetry in the presence of crystal-field splitting.

关键词： kagome lattice flat band

Simulation of RFI Cancellation Using Subspace Projection Algorithm for PAF Receiver

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2024年第1期24卷 237-244页

作者： Peng Wu Jian Li Mao-Zheng Chen Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of chinese academy of sciences Beijing 100049China Xinjiang Key Laboratory of Microwave Technology Urumqi 830011China

The simulation of radio frequency interference(RFI) cancellation by applying a spatial filtering technique for phased array feed(PAF) is presented. In order to better reflect the characteristics of PAF, a new signal model is to add the coupling coefficient among elements of PAF to the conventional array signal model. Then the subspace projection(SP) algorithm is used to cancel RFI from the correlation matrix of the signal, and finally, the 2D power image is drawn. The power variation of signal-of-interest direction and RFI direction before and after using the SP algorithm is analyzed. The new signal model and simulation strategy can be used to test and verify the beamformer.

关键词： methods:analytical techniques:radar astronomy telescopes

黄花三宝木中高度芳香化的降二萜异源二聚体及其单体（英文）

在线全文

学校读者我要写书评

暂无评论

Engineering 2024年第7期 144-154页

作者：周均愫成龙高源葛战鹏周彬李静雅赵金鑫岳建民 State Key Laboratory of Drug Research Shanghai Institute of Materia Medica Chinese Academy of Sciences Shandong Laboratory of Yantai Drug Discovery Bohai Rim Advanced Research Institute for Drug Discovery

Four new norditerpenoid heterodimers with different dimerization patterns-namely,trigofragiloids A–C(denoted as compounds 1–3) and (+)-and (—)-trigofragiloid D (compound 4)-and three new phenanthrenone norditerpenoids-namely,trigofragiloids E–G (compounds 5–7)-were isolated from Trigonostemon *** 1 and 2 feature a novel heterodimeric carbon skeleton formed by the conjugation of a tetra-norditerpenoid and an ennea-norditerpenoid;they have been identified as class 2 atropisomers by means of quantum chemical *** 3 is an unprecedented phenylpropanoid–norditerpenoid adduct with a new dimerization *** (+)-and (—)-4are the first example of S-shaped 1,4-dioxane-fused norditerpenoid *** by the structure elucidation of compound 4,two co-occurring analogues,actephilol A and epiactephilol A,were structurally revised as a pair of geometrical isomers and were identified as two pairs of enantiomers,(+)-and (—)-8and (+)-and (—)-9,*** structures were characterized using a combined ***,compound 7 exhibits remarkable adenosine triphosphate-citrate lyase (ACLY) inhibition with a halfmaximal inhibition concentration (IC50) value of (0.46±0.11)μmol·L—1,as active as the positive control BMS-303141,and a molecular docking study offers deep insight into the interaction between compound7 and ACLY.

关键词：

基于h-BN的方向依赖高次谐波产生（特邀）（英文）

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

光子学报 2024年第6期 108-116页

作者：郑文洋刘灿东白亚刘鹏李儒新中国科学院上海光学精密机械研究所强场激光物理国家重点实验室中国科学院大学张江实验室

利用紧束缚电子能带结构并结合求解两能带半导体Bloch方程的方法，研究了单层h-BN的高次谐波产生过程。结果显示平行于驱动光偏振方向的谐波分量在截止区表现出异常的晶格取向依赖关系，当光子能量超过7.31 eV时，奇次谐波的取向依赖相... 详细信息

利用紧束缚电子能带结构并结合求解两能带半导体Bloch方程的方法，研究了单层h-BN的高次谐波产生过程。结果显示平行于驱动光偏振方向的谐波分量在截止区表现出异常的晶格取向依赖关系，当光子能量超过7.31 eV时，奇次谐波的取向依赖相对于较低级次的奇次谐波取向依赖表现出明显的30°角度偏移。确定了能够发生偏移的那些谐波光子能量与布里渊区M点处的载流子动力学相关。进一步的时频分析表明，当驱动光偏振沿zigzag方向时，截止区谐波仅在特定极性的激光半周期内产生，这导致了zigzag方向谐波的急剧减弱，从而造成了截止区晶格取向分布的偏移。这一现象对利用高次谐波光谱重建电子能带结构具有重要意义。

关键词：高次谐波二维材料强场动态方向依赖角度偏移

同方期刊数据库

Effect of reduction pretreatment on the structure and catalytic performance of Ir-In_(2)O_(3)catalysts for CO_(2) hydrogenation to methanol

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental sciences 2024年第6期140卷 2-11页

作者： Changyu Ding Feifei Yang Xue Ye Chongya Yang Xiaoyan Liu Yuanlong Tan Zheng Shen Hongmin Duan Xiong Su Yanqiang Huang cas Key Laboratory of Science and Technology on Applied Catalysis Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China University of chinese academy of sciences Beijing 100049China

In_(2)O_(3)has been found a promising application in CO_(2)hydrogenation to methanol,which is beneficial to the utilization of CO_(2).The oxygen vacancy(O_(v))site is identified as the catalytic active center of this ***,there remains a great challenge to understand the relations between the state of oxygen species in In_(2)O_(3)and the catalytic performance for CO_(2)hydrogenation to *** the present work,we compare the properties of multiple In_(2)O_(3)and Ir-promoted In_(2)O_(3)(Ir-In_(2)O_(3))catalysts with different Ir loadings and after being pretreated under different reduction *** CO_(2)conversion rate of Ir-In_(2)O_(3)is more promoted than that of pure In_(2)O_(3).With only a small amount of Ir loading,the highly dispersed Ir species on In_(2)O_(3)increase the concentration of O_(v)sites and enhance the *** finely tuning the catalyst structure,Ir-In_(2)O_(3)with an Ir loading of 0.16 wt.%and pre-reduction treatment under 300℃exhibits the highest methanol yield of 146 mgCH_(3)OH/(gcat·hr).Characterizations of Raman,electron paramagnetic resonance,X-ray photoelectron spectroscopy,CO_(2)-temperature programmed desorption and CO_(2)-pulse adsorption for the catalysts confirm that more O_(v)sites can be generated under higher reduction temperature,which will induce a facile CO_(2)adsorption and desorption *** performance for methanol production requires an adequate dynamic balance among the surface oxygen atoms and vacancies,which guides us to find more suitable conditions for catalyst pretreatment and reaction.

关键词： Carbon dioxide Hydrogenation Methanol In_(2)O_(3) Fixed-bed Reduction temperature