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Influence of cerium and yttrium addition on strength and electrical conductivity of pure aluminum alloys

Journal of Rare Earths 2024年第3期42卷 600-611,I0006页

作者： Guojian Lin Lu Li Zhengwei Guo Xianjun Jia Xiao Wang Zhentao Yuan Guoxing Zhang Yun Zhan Quan Shan Zulai Li Faculty of Materials science and Engineering Kunming University of Science and TechnologyKunming650093China Research center for Analysis and Measurement Kunming University of Science and TechnologyKunming650093China City College Kunming University of Science and TechnologyKunming650051China

To develop pure aluminum alloys with high conductivity and strength, Al-0.2Ce and Al-0.2Ce-0.1Y alloys were prepared by rolling and annealing processes in this study. The effects of trace rare earth elements on the strength and electrical conductivity of the pure aluminum alloys were investigated. It is revealed that the addition of Ce and Y to pure aluminum can effectively enhance the strength and electrical conductivity of the alloys. In Al-0.2Ce, the addition of Ce can effectively refine the grain size of a-Al, with an average grain size of 90.68 μm in the as-cast state. The grain size of the alloy is further reduced to 87.55 μm by the simultaneous addition of Y. The synergistic addition of Ce and Y changes the properties of the alloy. The addition of Ce and Y also produces the Al_(11)Ce_(3) and Al_(3)Y second phases, which have coherent relationship with a-Al. The two-dimensional mismatch degree was calculated to be only 4.43%and 0.85%, respectively, which can provide a certain amount of nucleation substrate for a-Al in the incubation stage. The interfacial match between the L1_(2)structure of Al_(3)Y and a-Al was calculated using first-principles simulations. The results indicate that Al_(3)Y has a strong bonding effect with a-Al. Nanoscale second phases at grain boundaries can be effective in reducing resistivity due to dislocation *** second phases with better matching interfaces to the substrate have no positive effect on the scattering motion of electrons.

关键词： Pure aluminum Rare earths Impurity purification First-principles calculations Strength-conductivity contradiction

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Enhanced and asymmetric signatures of hybridization at climatic margins: Evidence from closely related dioecious fig species

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Plant Diversity 2024年第2期46卷 181-193页

作者： Jian-Feng Huang Clive T.Darwell Yan-Qiong Peng CAS Key Laboratory of Tropical forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMengla 666303China National center for Genetic Engineering and Biotechnology(BIOTEC) 113 Thailand Science ParkPhahonyothin RoadKhlong NuengKhlong LuangPathum Thani 12120Thailand

Hybridization plays a significant role in biological evolution. However, it is not clear whether ecological contingency differentially influences likelihood of hybridization, particularly at ecological margins where parental species may exhibit reduced fitnesses. Moreover, it is unknown whether future ecosystem change will increase the prevalence of hybridization. Ficus heterostyla and F. squamosa are closely related species co-distributed from southern Thailand to southwest China where hybridization, yielding viable seeds, has been documented. As a robust test of ecological factors driving hybridization, we investigated spatial hybridization signatures based on nuclear microsatellites from extensive population sampling across a widespread contact range. Both species showed high population differentiation and strong patterns of isolation by distance. Admixture estimates exposed asymmetric interspecific gene *** of hybridization increase significantly towards higher latitude zones, peaking at the northern climatic margins. Geographic variation in reproductive phenology combined with ecologically challenging marginal habitats may promote this phenomenon. Our work is a first systematic evaluation of such patterns in a comprehensive, latitudinally-based clinal context, and indicates that tendency to hybridize appears strongly influenced by environmental conditions. Moreover, that future climate change scenarios will likely alter and possibly augment cases of hybridization at ecosystem scales.

关键词： Hybridization Heterospecific visitation Fig Pollinator wasp Asymmetric gene flow

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Recent progress in single crystal perovskite X-ray detectors

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science China(Information sciences) 2024年第3期67卷 5-19页

作者： Xiao LIU Jun REN Yu-Ang CHEN Xiangshun GENG Dan XIE Tian-Ling REN School of Integrated Circuits Tsinghua University Beijing National Research center for Information science and Technology (BNRist)

Perovskites have attracted extensive attention as radiation detection material due to their long carrier diffusion length and lifetime, high absorption coefficient, and flexible manufacturing process. Compared with polycrystalline structures, single crystal perovskites improve the performance of optoelectronic devices due to their low defect state density, better photoelectric characteristics, and chemical ***, we review the recent progress of single crystal perovskite X-ray detectors. First, we briefly introduced the basic concepts, detection mechanisms, figure of merits of perovskite X-ray detectors, and the preparation methods of single crystal perovskites. Then, we summarized the significant advancements in single crystal perovskite X-ray detectors in recent times. Finally, we discussed the critical challenges and some practicable solutions for developing high-performance X-ray detectors.

关键词： single crystal perovskites carrier transport radiation detection X-ray detectors X-ray imaging

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Near-field wideband beam training for ELAA with uniform circular array

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science China(Information sciences) 2024年第6期67卷 370-383页

作者： Yuhao CHEN Linglong DAI Department of Electronic Engineering Tsinghua UniversityBeijing National Research Center for Information Science and Technology (BNRist)

Extremely large-scale antenna array(ELAA) at millimeter wave(mmWave) and Terahertz(THz)band has been considered a key technology for combating high attenuation in high-frequency bands in future6G communications. Uniform circular arrays(UCAs) have attracted much attention because of their ability to provide flat beamforming gain at all angles. To realize efficient beamforming, beam training is widely used to acquire channel state information. However, with a large antenna number, the beam training overhead in ELAA systems becomes overwhelming. Moreover, with a large bandwidth, the beam defocus effect severely degrades beam training accuracy. To address these issues, this paper proposes a frequency-dependent focusing(FDF)-based beam training scheme to realize effective beam training in near-field wideband ELAA systems with UCA. Specifically, we first analyze the FDF property of UCA, where signals at different subcarriers can simultaneously focus on different distances. Then, by exploiting the FDF property to search different distances using different subcarriers simultaneously, we design a hierarchical codebook and propose an FDFbased beam training scheme. To reveal the effectiveness of the proposed scheme, we compare its necessary beam training overhead with that of existing schemes. Finally, the simulation results demonstrate that the proposed scheme can achieve accurate beam training in near-field wideband UCA systems with a low beam training overhead.

关键词： extremely large-scale antenna array (ELAA) uniform circular array (UCA) near-field wideband beam training

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Cardiac energy metabolism disorder mediated by energy substrate imbalance and mitochondrial damage upon tebuconazole exposure

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Journal of Environmental sciences 2024年第2期136卷 270-278页

作者： Tingting Ku Jindong Hu Mengmeng Zhou Yuanyuan Xie Yutong Liu Xin Tan Lin Guo Guangke Li Nan Sang College of Environmental science and Resources Research Center of Environment and HealthShanxi UniversityTaiyuan 030006China

Tebuconazole exposure has been described as an increasing hazard to human *** increasing number of recent studies have shown a positive association between tebuconazole exposure and cardiovascular disease risk,which is characterized by the reduction of adenosine triphosphate(ATP)***,researches on the damage of tebuconazole exposure to energy metabolism and the related molecular mechanisms are *** the present study,male C57BL/6 mice were treated with tebuconazole at different low concentrations for 4 *** results indicated that tebuconazole could accumulate in the heart and further induce the decrease of ATP content in the mouse ***,tebuconazole induced an obvious shift in substrate utilization of fatty acid and glucose by disrupting their corresponding transporters(GLUT1,GLUT4,CD36,FABP3 and FATP1)expression,and significantly repressed the expression of mitochondrial biogenesis(Gabpa and Tfam)and oxidative phosphorylation(CS,Ndufa4,Sdhb,Cox5a and Atp5b)related genes in a dosedependent *** investigation revealed that these alterations were related to the IRS1/AKT and PPARγ/RXRα*** findings contribute to a better understanding of triazole fungicide-induced cardiovascular disease by revealing the key indicators associated with this phenomenon.

关键词： Tebuconazole Cardiotoxicity Energy metabolic disorders Energy substrate Mitochondrial damage

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Homochirality in Ferroelectrochemistry

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Chinese Journal of Chemistry 2024年第10期42卷 1133-1144页

作者： Hang Peng Jun-Chao Qi Yu-Si Liu Jia-Mei Zhang Wei-Qiang Liao Ren-Gen Xiong Ordered Matter science Research center Nanchang UniversityNanchangJiangxi 330031China

What is the most favorite and original chemistry developed in your research group?We originally proposed the design principle for molecular ferroelectrics:ferroelectrochemistry,including quasi-spherical theory,the introduction of homochirality,and H/F *** changed the blind search for molecular ferroelectrics into targeted chemical design,which will develop into a new discipline.

关键词： Molecular ferroelectrics Homochirality Ferroelectricity Chemical design Point groups

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Pressure-induced hydrogen-dominant high-temperature superconductors

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National science Review 2024年第7期11卷 14-16页

作者： Ho-kwang Mao Shanghai Advanced Research in Physical sciences center for High Pressure science and Technology Advanced Research

Recent studies of hydrogen-dominant（superhydride） materials have led to putative discoveries of near-room temperature superconductivity at high pressures. The idea started more than half-a-century ago as a by-product of the quest for metallic hydrogen for which a natural consequence of its very high Debye temperature and phonon frequency due to the very low mass of the hydrogen atoms would lead to a high superconducting critical temperature （Tc） in weak coupling Bardeen-Cooper-Schrieffer（BCS） expression.

关键词： HYDRIDE LANTHANUM

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New insights into the therapeutic approaches for the treatment of tauopathies

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Neural Regeneration Research 2024年第5期19卷 1020-1026页

作者： Himanshi Singh Asmita Das Mohammad Moshahid Khan Tayebeh Pourmotabbed Department of Microbiology Immunology and BiochemistryUniversity of Tennessee Health Science CenterMemphisTNUSA Department of Biotechnology Delhi Technological UniversityShahbad DaulatpurDelhiIndia Department of Neurology College of MedicineUniversity of Tennessee Health Science CenterMemphisTNUSA Neuroscience Institute University of Tennessee Health Science CenterMemphisTNUSA center for Muscle Metabolism and NeuropathologyDivision of Regenerative and Rehabilitation Sciences and Department of Physical TherapyCollege of Health ProfessionsUniversity of Tennessee Health Science CenterMemphisTNUSA

Tauopathies are a group of neurological disorders,including Alzheimer’s disease and frontotemporal dementia,which involve progressive neurodegeneration,cognitive deficits,and aberrant tau protein *** development of tauopathies cannot currently be stopped or slowed down by treatment *** the significant contribution of tau burden in primary tauopathies and the strong association between pathogenic tau accumulation and cognitive deficits,there has been a lot of interest in creating therapies that can alleviate tau pathology and render neuroprotective ***,small molecules,immunotherapies,and gene therapy have been used to reduce the pathological tau burden and prevent neurodegeneration in animal models of ***,the major pitfall of the current therapeutic approach is the difficulty of drugs and gene-targeting modalities to cross the blood-brain barrier and their unintended side *** this review,the current therapeutic strategies used for tauopathies including the use of oligonucleotide-based gene therapy approaches that have shown a promising result for the treatment of tauopathies and Alzheimer’s disease in preclinical animal models,have been discussed.

关键词： dementia gene therapies immunotherapy neurodegeneration oligonucleotides tau tauopathies therapies

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Correction of microwave pulse reflection by digital filters in superconducting quantum circuits

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Chinese Physics B 2024年第9期33卷 117-123页

作者： Liang-Liang Guo Peng Duan Lei Du Hai-Feng Zhang Hao-Ran Tao Yong Chen Xiao-Yan Yang Chi Zhang Zhi-Long Jia Wei-Cheng Kong Zhao-Yun Chen Guo-Ping Guo CAS Key Laboratory of Quantum Information University of Science and Technology of ChinaHefei 230026China CAS center for Excellence and Synergetic Innovation center in Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China Origin Quantum Computing Company Limited Hefei 230088China Institute of Artificial Intelligence Hefei Comprehensive National Science CenterHefei 230088China

Reducing the control error is vital for high-fidelity digital and analog quantum *** superconducting circuits,one disagreeable error arises from the reflection of microwave signals due to impedance mismatch in the control ***,we demonstrate a reflection cancelation method when considering that there are two reflection nodes on the control *** propose to generate the pre-distortion pulse by passing the envelopes of the microwave signal through digital filters,which enables real-time reflection correction when integrated into the field-programmable gate array(FPGA).We achieve a reduction of single-qubit gate infidelity from 0.67%to 0.11%after eliminating microwave ***-time correction of microwave reflection paves the way for precise control and manipulation of the qubit state and would ultimately enhance the performance of algorithms and simulations executed on quantum processors.

关键词： reflection cancelation digital filter single-qubit gate superconducting circuit

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Organic ferroelastic enantiomers with high Tc and large dielectric switching ratio triggered by order-disorder and displacive phase transition

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Chinese Chemical Letters 2024年第10期35卷 228-232页

作者： Zhaohong Chen Mengzhen Li Jinfei Lan Shengqian Hu Xiaogang Chen Ordered Matter science Research center Nanchang UniversityNanchang 330031China

Molecular-based ferroelastics with dielectric switching properties are highly desirable for their applications on microelectronic dielectric switches,sensors,data storage,and so ***,the current reports mostly focus on organic-inorganic hybrids containing toxic heavy metal atoms,and the relatively low phase transition temperature limits their *** this paper,low-toxic organic salt ferroelastic enantiomers(R/S)-4-fluoro-1-azabicyclo[3.2.1]octonium chloride[(R/S)-F-321]were designed and synthesized under the introducing chirality *** undergo a 432F422-type ferroelastic phase transition with a high Curie temperature(Tc)of 470 K,simultaneously exhibiting excellent dielectric switching *** addition to the ordered-disordered movement of cations,the significant displacement of anions is also responsible for such high Tc and large dielectric switching ratios,which is very rare in molecular-based switching *** work enriches the development of molecular ferroelastic switching materials and gives inspiration for the exploration of environmentally friendly high Tc organic salt ferroelastics with prominent switching performances.

关键词： Organic salt Enantiomers Ferroelastic Dielectric switching Phasetransition

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