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Single event effects evaluation on convolution neural network in Xilinx 28 nm system on chip
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作者 赵旭 杜雪成 +4 位作者 熊旭 马超 杨卫涛 郑波 周超 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第7期638-644,共7页
Convolutional neural networks(CNNs) exhibit excellent performance in the areas of image recognition and object detection, which can enhance the intelligence level of spacecraft. However, in aerospace, energetic partic... Convolutional neural networks(CNNs) exhibit excellent performance in the areas of image recognition and object detection, which can enhance the intelligence level of spacecraft. However, in aerospace, energetic particles, such as heavy ions, protons, and alpha particles, can induce single event effects(SEEs) that lead CNNs to malfunction and can significantly impact the reliability of a CNN system. In this paper, the MNIST CNN system was constructed based on a 28 nm systemon-chip(SoC), and then an alpha particle irradiation experiment and fault injection were applied to evaluate the SEE of the CNN system. Various types of soft errors in the CNN system have been detected, and the SEE cross sections have been calculated. Furthermore, the mechanisms behind some soft errors have been explained. This research will provide technical support for the design of radiation-resistant artificial intelligence chips. 展开更多
关键词 single event effects convolutional neural networks alpha particle system on chip fault injection
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R-I subtype single right coronary artery with congenital absence of left coronary system: A case report 被引量:1
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作者 Ya-Ping Zhou Lin-Li Wang +1 位作者 Yuan-Gang Qiu Shu-Wei Huang 《World Journal of Cardiology》 2023年第12期649-654,共6页
BACKGROUND Isolated single coronary artery is a rare congenital anomaly.R-I subtype single coronary artery is even rarer.In this subtype,a very large right coronary artery extends in the coronary sulcus to the anterio... BACKGROUND Isolated single coronary artery is a rare congenital anomaly.R-I subtype single coronary artery is even rarer.In this subtype,a very large right coronary artery extends in the coronary sulcus to the anterior base of the heart where it produces the left anterior descending coronary artery.Currently,only a few case reports are available in the literature for this anomaly.CASE SUMMARY Here,we report the case of a 62-year-old woman who presented to the cardiology clinic with decreased exercise tolerance and poor blood pressure control.The patient underwent coronary angiography(CAG)and emission computed tomography(ECT).CAG images revealed a single gigantic right coronary artery(R-I type)arising from the right coronary sinus with branches supplying the left coronary territory.The ECT results confirmed myocardial ischemia at the location of the absent left coronary artery.The ECT findings confirmed that ischemia was consistent with the vascular loss location in CAG images.In such anomalies,there is a compensatory widening of the coronary artery lumen.Medical treatment was administered,and the patient was discharged.CONCLUSION Isolated single coronary arteries are associated with ischemia and potentially fatal acute coronary events.Hence,controlling risk factors is critical. 展开更多
关键词 single coronary artery R-I type Congenital anomaly Emission computed tomography Coronary angiography Case report
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Single-atom Pt on carbon nanotubes for selective electrocatalysis 被引量:1
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作者 Samuel S.Hardisty Xiaoqian Lin +1 位作者 Anthony R.J.Kucernak David Zitoun 《Carbon Energy》 SCIE EI CAS CSCD 2024年第1期63-71,共9页
Utilizing supported single atoms as catalysts presents an opportunity to reduce the usage of critical raw materials such as platinum,which are essential for electrochemical reactions such as hydrogen oxidation reactio... Utilizing supported single atoms as catalysts presents an opportunity to reduce the usage of critical raw materials such as platinum,which are essential for electrochemical reactions such as hydrogen oxidation reaction(HOR).Herein,we describe the synthesis of a Pt single electrocatalyst inside single-walled carbon nanotubes(SWCNTs)via a redox reaction.Characterizations via electron microscopy,X-ray photoelectron microscopy,and X-ray absorption spectroscopy show the single-atom nature of the Pt.The electrochemical behavior of the sample to hydrogen and oxygen was investigated using the advanced floating electrode technique,which minimizes mass transport limitations and gives a thorough insight into the activity of the electrocatalyst.The single-atom samples showed higher HOR activity than state-of-the-art 30%Pt/C while almost no oxygen reduction reaction activity in the proton exchange membrane fuel cell operating range.The selective activity toward HOR arose as the main fingerprint of the catalyst confinement in the SWCNTs. 展开更多
关键词 CONFINEMENT ELECTROCATALYSIS hydrogen PLATINUM single atom catalysts
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Single exposure passive three-dimensional information reconstruction based on an ordinary imaging system
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作者 窦申成 刘璠 +3 位作者 李虎 姚旭日 刘雪峰 翟光杰 《Chinese Physics B》 SCIE EI CAS CSCD 2023年第11期446-455,共10页
Existing three-dimensional(3D) imaging technologies have issues such as requiring active illumination, multiple exposures, or coding modulation. We propose a passive single 3D imaging method based on an ordinary imagi... Existing three-dimensional(3D) imaging technologies have issues such as requiring active illumination, multiple exposures, or coding modulation. We propose a passive single 3D imaging method based on an ordinary imaging system.Using the point spread function of the imaging system to realize the non-coding measurement on the target, the full-focus images and depth information of the 3D target can be extracted from a single two-dimensional(2D) image through the compressed sensing algorithm. Simulation and experiments show that this approach can complete passive 3D imaging based on an ordinary imaging system without any coding operations. This method can achieve millimeter-level vertical resolution under single exposure conditions and has the potential for real-time dynamic 3D imaging. It improves the efficiency of 3D information detection, reduces the complexity of the imaging system, and may be of considerable value to the field of computer vision and other related applications. 展开更多
关键词 passive three-dimensional imaging single exposure point spread function compressed sensing
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Long-Term Outcomes of Systemic-to-Pulmonary Artery Shunt in Patients with Functional Single Ventricle and Heterotaxy Syndrome
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作者 Shota Kawai Takashi Kido +6 位作者 Yuta Teguri Koji Miwa Tomomitsu Kanaya Yoichiro Ishii Hisaaki Aoki Futoshi Kayatani Sanae Tsumura 《Congenital Heart Disease》 SCIE 2023年第4期399-411,共13页
Objectives: We sought to determine the long-term outcomes and mortality-associated factors after systemic-topulmonaryartery shunt (SPS) in patients with heterotaxy syndrome. Methods: We retrospectively analyzed allpat... Objectives: We sought to determine the long-term outcomes and mortality-associated factors after systemic-topulmonaryartery shunt (SPS) in patients with heterotaxy syndrome. Methods: We retrospectively analyzed allpatients with a functional single ventricle and heterotaxy syndrome who underwent SPS at our center from January2001 to April 2022. Results: This study involved 84 patients. Restrictive pulmonary blood flow requiringearly modulation was presented in 34 (40%) patients. Compared with patients without restrictive pulmonaryblood flow (N = 50 [60%]), the postnatal survival of these 34 patients was significantly lower at 10 years (log rank:p = 0.04), but the statistical significance disappeared at 20 years (log rank: p = 0.18). Among 31 patients whounderwent SPS, 11 (35%) had extracardiac total anomalous pulmonary venous connection (TAPVC). The survivalrate after SPS was 80% at 10 years. Cox regression analysis showed that extracardiac TAPVC (hazard ratio6.44, 95% confidence interval 1.23–33.7, p = 0.03) and pulmonary venous obstruction (PVO) at TAPVC repair(hazard ratio 11.2, 95% confidence interval 2.13–58.5, p = 0.004) were significantly associated with death. In25 patients who underwent bidirectional cavopulmonary shunt (BCPS), surgical interventions on the pulmonaryartery (PA) were performed after SPS in 7 of 9 patients with PA coarctation, 3 of 4 with non-confluent PAs, and4 of 12 with normal PAs. At SPS, primary central PA plasty was performed in three patients with PA coarctationand 2 with non-confluent PAs. There was no significant difference in the PA index before BCPS between patientswith and without primary central PA plasty (p = 0.49). Among 20 patients who underwent total cavopulmonaryconnection (TCPC), adverse events occurred in 7 (35%) patients, including death in 1 (5%), intervention for pulmonaryarteriovenous malformation (PAVM) in 3 (15%), and surgical intervention for PVO in 3 (15%). TheB-type natriuretic peptide concentration was significantly higher in patients with than without adverse events(p = 0.02). The adverse event-free survival rate after TCPC was 69% at 10 years. Conclusion: ExtracardiacTAPVC and PVO at TAPVC repair were significantly associated with death after SPS in patients who had heterotaxysyndrome with a single ventricle. Surgical interventions on the PA were frequently required after SPS inpatients with PA coarctation or non-confluent PAs. Although satisfactory survival was achievable after TCPC,late-onset PAVM and PVO remain concerns. 展开更多
关键词 Heterotaxy syndrome single ventricle total anomalous of pulmonary venous connection pulmonary artery coarctation
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Improved Interleaved Single-Ended Primary Inductor-Converter forSingle-Phase Grid-Connected System
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作者 T.J.Thomas Thangam K.Muthu Vel 《Intelligent Automation & Soft Computing》 SCIE 2023年第3期3459-3478,共20页
The generation of electricity based on renewable energy sources,parti-cularly Photovoltaic(PV)system has been greatly increased and it is simply insti-gated for both domestic and commercial uses.The power generated fr... The generation of electricity based on renewable energy sources,parti-cularly Photovoltaic(PV)system has been greatly increased and it is simply insti-gated for both domestic and commercial uses.The power generated from the PV system is erratic and hence there is a need for an efficient converter to perform the extraction of maximum power.An improved interleaved Single-ended Primary Inductor-Converter(SEPIC)converter is employed in proposed work to extricate most of power from renewable source.This proposed converter minimizes ripples,reduces electromagnetic interference due tofilter elements and the contin-uous input current improves the power output of PV panel.A Crow Search Algo-rithm(CSA)based Proportional Integral(PI)controller is utilized for controlling the converter switches effectively by optimizing the parameters of PI controller.The optimized PI controller reduces ripples present in Direct Current(DC)vol-tage,maintains constant voltage at proposed converter output and reduces over-shoots with minimum settling and rise time.This voltage is given to single phase grid via 1�Voltage Source Inverter(VSI).The command pulses of 1�VSI are produced by simple PI controller.The response of the proposed converter is thus improved with less input current.After implementing CSA based PI the efficiency of proposed converter obtained is 96%and the Total Harmonic Distor-tion(THD)is found to be 2:4%.The dynamics and closed loop operation is designed and modeled using MATLAB Simulink tool and its behavior is performed. 展开更多
关键词 Improved interleaved DC-DC SEPIC converter crow search algorithm PI controller voltage source inverter PV array single phase grid
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Metal-organic framework-based single-atom electro-/ photocatalysts: Synthesis, energy applications, and opportunities
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作者 Munir Ahmad Jiahui Chen +10 位作者 Jianwen Liu Yan Zhang Zhongxin Song Shahzad Afzal Waseem Raza Liaqat Zeb Andleeb Mehmood Arshad Hussain Jiujun Zhang Xian-Zhu Fu Jing-Li Luo 《Carbon Energy》 SCIE EI CAS CSCD 2024年第1期1-43,共43页
Single-atom catalysts(SACs)have gained substantial attention because of their exceptional catalytic properties.However,the high surface energy limits their synthesis,thus creating significant challenges for further de... Single-atom catalysts(SACs)have gained substantial attention because of their exceptional catalytic properties.However,the high surface energy limits their synthesis,thus creating significant challenges for further development.In the last few years,metal–organic frameworks(MOFs)have received significant consideration as ideal candidates for synthesizing SACs due to their tailorable chemistry,tunable morphologies,high porosity,and chemical/thermal stability.From this perspective,this review thoroughly summarizes the previously reported methods and possible future approaches for constructing MOF-based(MOF-derived-supported and MOF-supported)SACs.Then,MOF-based SAC's identification techniques are briefly assessed to understand their coordination environments,local electronic structures,spatial distributions,and catalytic/electrochemical reaction mechanisms.This review systematically highlights several photocatalytic and electrocatalytic applications of MOF-based SACs for energy conversion and storage,including hydrogen evolution reactions,oxygen evolution reactions,O_(2)/CO_(2)/N_(2) reduction reactions,fuel cells,and rechargeable batteries.Some light is also shed on the future development of this highly exciting field by highlighting the advantages and limitations of MOF-based SACs. 展开更多
关键词 carbon energy generation MOF-derived-supported MOF-supported single atoms
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Enhancing thermodynamic stability of single-crystal Ni-rich cathode material via a synergistic dual-substitution strategy
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作者 Jixue Shen Hui Li +6 位作者 Haoyu Qi Zhan Lin Zeheng Li Chuanbo Zheng Weitong Du Hao Chen Shanqing Zhang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第1期428-436,I0010,共10页
Nickel(Ni)-rich cathode materials have become promising candidates for the next-generation electrical vehicles due to their high specific capacity.However,the poor thermodynamic stability(including cyclic performance ... Nickel(Ni)-rich cathode materials have become promising candidates for the next-generation electrical vehicles due to their high specific capacity.However,the poor thermodynamic stability(including cyclic performance and safety performance or thermal stability)will restrain their wide commercial application.Herein,a single-crystal Ni-rich Li Ni_(0.83)Co_(0.12)Mn_(0.05)O_(2) cathode material is synthesized and modified by a dual-substitution strategy in which the high-valence doping element improves the structural stability by forming strong metal–oxygen binding forces,while the low-valence doping element eliminates high Li^(+)/Ni^(2+)mixing.As a result,this synergistic dual substitution can effectively suppress H2-H3 phase transition and generation of microcracks,thereby ultimately improving the thermodynamic stability of Ni-rich cathode material.Notably,the dual-doped Ni-rich cathode delivers an extremely high capacity retention of 81%after 250 cycles(vs.Li/Li+)in coin-type half cells and 87%after 1000 cycles(vs.graphite/Li^(+))in pouch-type full cells at a high temperature of 55℃.More impressively,the dual-doped sample exhibits excellent thermal stability,which demonstrates a higher thermal runaway temperature and a lower calorific value.The synergetic effects of this dual-substitution strategy pave a new pathway for addressing the critical challenges of Ni-rich cathode at high temperatures,which will significantly advance the high-energy-density and high-safety cathodes to the subsequent commercialization. 展开更多
关键词 Ni-rich cathode single crystalline Dual-substitution strategy High-temperature cathode Li-ion batteries
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Cooperation between single atom catalyst and support to promote nitrogen electroreduction to ammonia:A theoretical insight
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作者 Wanying Guo Siyao Wang +2 位作者 Hongxia Wang Qinghai Cai Jingxiang Zhao 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第9期336-344,共9页
The co-catalysis between single atom catalyst(SAC)and its support has recently emerged as a promising strategy to synergistically boost the catalytic activity of some complex electrochemical reactions,encompassing mul... The co-catalysis between single atom catalyst(SAC)and its support has recently emerged as a promising strategy to synergistically boost the catalytic activity of some complex electrochemical reactions,encompassing multiple intermediates and pathways.Herein,we utilized defective BC_(3)monolayer-supported SACs as a prototype to investigate the cooperative effects of SACs and their support on the catalytic performance of the nitrogen reduction reaction(NRR)for ammonia(NH_(3))production.The results showed that these SACs can be firmly stabilized on these defective BC_(3)supports with high stability against aggregation.Furthermore,co-activation of the inert N_(2)reactant was observed in certain embedded SACs and their neighboring B atoms on certain BC3 sheets due to the noticeable charge transfer and significant N–N bond elongation.Our high-throughput screening revealed that the Mo/DV_(CC)and W/DV_(CC)exhibit superior NRR catalytic performance,characterized by a low limiting potential of−0.33 and−0.43 V,respectively,which can be further increased under acid conditions based on the constant potential method.Moreover,varying NRR catalytic activities can be attributed to the differences in the valence state of active sites.Remarkably,further microkinetic modeling analysis displayed that the turnover frequency of N_(2)–to–NH_(3)conversion on Mo/DV_(CC)is as large as 1.20×10^(−3)s^(−1)site−1 at 700 K and 100 bar,thus guaranteeing its ultra-fast reaction rate.Our results not only suggest promising advanced electrocatalysts for NRR but also offer an effective avenue to regulate the electrocatalytic performance via the co-catalytic metal–support interactions. 展开更多
关键词 CO-CATALYSIS single atom catalyst Nitrogen reduction DFT computations
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Preparation of single atom catalysts for high sensitive gas sensing
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作者 Xinxin He Ping Guo +7 位作者 Xuyang An Yuyang Li Jiatai Chen Xingyu Zhang Lifeng Wang Mingjin Dai Chaoliang Tan Jia Zhang 《International Journal of Extreme Manufacturing》 SCIE EI CAS CSCD 2024年第3期216-248,共33页
Single atom catalysts(SACs)have garnered significant attention in the field of catalysis over the past decade due to their exceptional atom utilization efficiency and distinct physical and chemical properties.For the ... Single atom catalysts(SACs)have garnered significant attention in the field of catalysis over the past decade due to their exceptional atom utilization efficiency and distinct physical and chemical properties.For the semiconductor-based electrical gas sensor,the core is the catalysis process of target gas molecules on the sensitive materials.In this context,the SACs offer great potential for highly sensitive and selective gas sensing,however,only some of the bubbles come to the surface.To facilitate practical applications,we present a comprehensive review of the preparation strategies for SACs,with a focus on overcoming the challenges of aggregation and low loading.Extensive research efforts have been devoted to investigating the gas sensing mechanism,exploring sensitive materials,optimizing device structures,and refining signal post-processing techniques.Finally,the challenges and future perspectives on the SACs based gas sensing are presented. 展开更多
关键词 single atom catalysts PREPARATION sensing mechanism gas sensing
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Oxidation behavior of 4774DD1 Ni-based single-crystal superalloy at 980℃ in air
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作者 Yu Fang Ya-zhou Li +7 位作者 Qiang Yang Qun-gong He Xiu-fang Gong Qian Duan Hai-yang Song Fu Wang Qiong-yuan Zhang Hong Zeng 《China Foundry》 SCIE EI CAS CSCD 2024年第2期116-124,共9页
The oxidation behavior of a novel Ni-based single-crystal 4774DD1 superalloy for industrial gas turbine applications was investigated by the isothermal oxidation at 980℃ and discontinuous oxidation weight gain method... The oxidation behavior of a novel Ni-based single-crystal 4774DD1 superalloy for industrial gas turbine applications was investigated by the isothermal oxidation at 980℃ and discontinuous oxidation weight gain methods.The phase constitution and morphology of surface oxides and the characteristics of the crosssection oxide film were analyzed by XRD,SEM and EDS.Results show that the oxidation kinetics of the 4774DD1 superalloy follows the cubic law,indicating its weak oxidation resistance at this temperature.As the oxidation time increases,the composition of the oxide film evolves as following:One layer consisting of a bottom Al_(2)O_(3)sublayer and an upper(Al_(2)O_(3)+NiO)mixture sublayer after oxidized for 25 h.Then,two layers composed of an outermost small NiO discontinuous grain layer and an internal layer for 75 h.This internal layer is consisted of the bottom Al_(2)O_(3)sublayer,an intermediate narrow CrTaO_(4)sublayer,and an upper(Al_(2)O_(3)+NiO)mixture sublayer.Also two layers comprising an outermost relative continuous NiO layer with large grain size and an internal layer as the oxidation time increases to 125 h.This internal layer is composed of the upper(Al_(2)O_(3)+NiO)mixture sublayer,an intermediate continuous(CrTaO_(4)+NiWO_(4))mixture sublayer,and a bottom Al_(2)O_(3)sublayer.Finally,three layers consisting of an outermost(NiAl2O_(4)+NiCr2O_(4))mixture layer,an intermediate(CrTaO_(4)+NiWO_(4))mixture layer,and a bottom Al_(2)O_(3)layer for 200 h. 展开更多
关键词 nickel-base single crystal superalloy oxidation kinetics oxide film MICROSTRUCTURE mechanism
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Cryptanalysis of efficient semi-quantum secret sharing protocol using single particles
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作者 高甘 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第4期254-257,共4页
In paper[Chin.Phys.B 32070308(2023)],Xing et al.proposed a semi-quantum secret sharing protocol by using single particles.We study the security of the proposed protocol and find that it is not secure,that is,the three... In paper[Chin.Phys.B 32070308(2023)],Xing et al.proposed a semi-quantum secret sharing protocol by using single particles.We study the security of the proposed protocol and find that it is not secure,that is,the three dishonest agents,Bob,Charlie and Emily can collude to obtain Alice's secret without the help of David. 展开更多
关键词 security loophole rearranging orders semi-quantum secret sharing single particles
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Achieving Negatively Charged Pt Single Atoms on Amorphous Ni(OH)_(2)Nanosheets with Promoted Hydrogen Absorption in Hydrogen Evolution
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作者 Yue Liu Gui Liu +6 位作者 Xiangyu Chen Chuang Xue Mingke Sun Yifei Liu Jianxin Kang Xiujuan Sun Lin Guo 《Nano-Micro Letters》 SCIE EI CAS CSCD 2024年第10期213-224,共12页
Single-atom(SA)catalysts with nearly 100%atom utilization have been widely employed in electrolysis for decades,due to the outperforming catalytic activity and selectivity.However,most of the reported SA catalysts are... Single-atom(SA)catalysts with nearly 100%atom utilization have been widely employed in electrolysis for decades,due to the outperforming catalytic activity and selectivity.However,most of the reported SA catalysts are fixed through the strong bonding between the dispersed single metallic atoms with nonmetallic atoms of the substrates,which greatly limits the controllable regulation of electrocatalytic activity of SA catalysts.In this work,Pt-Ni bonded Pt SA catalyst with adjustable electronic states was successfully constructed through a controllable electrochemical reduction on the coordination unsaturated amorphous Ni(OH)_(2)nanosheet arrays.Based on the X-ray absorption fine structure analysis and first-principles calculations,Pt SA was bonded with Ni sites of amorphous Ni(OH)_(2),rather than conventional O sites,resulting in negatively charged Pt^(δ-).In situ Raman spectroscopy revealed that the changed configuration and electronic states greatly enhanced absorbability for activated hydrogen atoms,which were the essential intermediate for alkaline hydrogen evolution reaction.The hydrogen spillover process was revealed from amorphous Ni(OH)_(2)that effectively cleave the H-O-H bond of H_(2)O and produce H atom to the Pt SA sites,leading to a low overpotential of 48 mV in alkaline electrolyte at-1000 mA cm^(-2)mg^(-1)_(Pt),evidently better than commercial Pt/C catalysts.This work provided new strategy for the control-lable modulation of the local structure of SA catalysts and the systematic regulation of the electronic states. 展开更多
关键词 Hydrogen evolution reaction AMORPHOUS Pt single atoms Hydrogen spillover
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Countermeasure against blinding attack for single-photon detectors in quantum key distribution
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作者 Lianjun Jiang Dongdong Li +12 位作者 Yuqiang Fang Meisheng Zhao Ming Liu Zhilin Xie Yukang Zhao Yanlin Tang Wei Jiang Houlin Fang Rui Ma Lei Cheng Weifeng Yang Songtao Han Shibiao Tang 《Journal of Semiconductors》 EI CAS CSCD 2024年第4期76-81,共6页
Quantum key distribution(QKD),rooted in quantum mechanics,offers information-theoretic security.However,practi-cal systems open security threats due to imperfections,notably bright-light blinding attacks targeting sin... Quantum key distribution(QKD),rooted in quantum mechanics,offers information-theoretic security.However,practi-cal systems open security threats due to imperfections,notably bright-light blinding attacks targeting single-photon detectors.Here,we propose a concise,robust defense strategy for protecting single-photon detectors in QKD systems against blinding attacks.Our strategy uses a dual approach:detecting the bias current of the avalanche photodiode(APD)to defend against con-tinuous-wave blinding attacks,and monitoring the avalanche amplitude to protect against pulsed blinding attacks.By integrat-ing these two branches,the proposed solution effectively identifies and mitigates a wide range of bright light injection attempts,significantly enhancing the resilience of QKD systems against various bright-light blinding attacks.This method forti-fies the safeguards of quantum communications and offers a crucial contribution to the field of quantum information security. 展开更多
关键词 quantum key distribution single photon detector blinding attack pulsed blinding attack COUNTERMEASURE quan-tum communication
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Analysis of deformation mechanisms in magnesium single crystals using a dedicated four-point bending tester
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作者 Yutaka Yoshida Rikuto Izawa Kenji Ohkubo 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2024年第5期1911-1917,共7页
In this study,we explored the deformation mechanisms of Mg single crystals using a combination of scanning electron microscopy and electron backscattered diffraction in conjunction with a dedicated four-point bending ... In this study,we explored the deformation mechanisms of Mg single crystals using a combination of scanning electron microscopy and electron backscattered diffraction in conjunction with a dedicated four-point bending tester.We prepared two single-crystal samples,oriented along the<1120>and<1010>directions,to assess the mechanisms of deformation when the initial basal slip was suppressed.In the<1120>sample,the primary{1012}twin(T1)was confirmed along the<1120>direction of the sample on the compression side with an increase in bending stress.In the<1010>sample,T1 and the secondary twin(T2)were confirmed to be along the<1120>direction,with an orientation of±60°with respect to the bending stress direction,and their direction matched with(0001)in T1 and T2.This result implies that crystallographically,the basal slip occurs readily.In addition,the<1010>sample showed the double twin in T1 on the compression side and the tertiary twin along the<1010>direction on the tension side.These results demonstrated that the maximum bending stress and displacement changed significantly under the bend loading because the deformation mechanisms were different for these single crystals.Therefore,the correlation between bending behavior and twin orientation was determined,which would be helpful for optimizing the bending properties of Mg-based materials. 展开更多
关键词 Four-point bending Magnesium single crystal TWINNING Basal slip Scanning electron microscopy Electron backscatter diffraction
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Purification of copper foils driven by single crystallization
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作者 寇金宗 赵孟泽 +10 位作者 李兴光 何梦林 杨方友 刘科海 成庆秋 任云龙 刘灿 付莹 吴慕鸿 刘开辉 王恩哥 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第2期506-511,共6页
High-purity copper(Cu) with excellent thermal and electrical conductivity, is crucial in modern technological applications, including heat exchangers, integrated circuits, and superconducting magnets. The current puri... High-purity copper(Cu) with excellent thermal and electrical conductivity, is crucial in modern technological applications, including heat exchangers, integrated circuits, and superconducting magnets. The current purification process is mainly based on the zone/electrolytic refining or anion exchange, however, which excessively relies on specific integrated equipment with ultra-high vacuum or chemical solution environment, and is also bothered by external contaminants and energy consumption. Here we report a simple approach to purify the Cu foils from 99.9%(3N) to 99.99%(4N) by a temperature-gradient thermal annealing technique, accompanied by the kinetic evolution of single crystallization of Cu.The success of purification mainly relies on(i) the segregation of elements with low effective distribution coefficient driven by grain-boundary movements and(ii) the high-temperature evaporation of elements with high saturated vapor pressure.The purified Cu foils display higher flexibility(elongation of 70%) and electrical conductivity(104% IACS) than that of the original commercial rolled Cu foils(elongation of 10%, electrical conductivity of ~ 100% IACS). Our results provide an effective strategy to optimize the as-produced metal medium, and therefore will facilitate the potential applications of Cu foils in precision electronic products and high-frequency printed circuit boards. 展开更多
关键词 PURIFICATION copper foil thermal annealing technique single crystallization
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Single Photon Detection Technology in Underwater Wireless Optical Communication:Modulation Modes and Error Correction Coding Analysis
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作者 GAI Lei LI Wendong WANG Guoyu 《Journal of Ocean University of China》 CAS CSCD 2024年第2期405-414,共10页
This study explores the application of single photon detection(SPD)technology in underwater wireless optical communication(UWOC)and analyzes the influence of different modulation modes and error correction coding type... This study explores the application of single photon detection(SPD)technology in underwater wireless optical communication(UWOC)and analyzes the influence of different modulation modes and error correction coding types on communication performance.The study investigates the impact of on-off keying(OOK)and 2-pulse-position modulation(2-PPM)on the bit error rate(BER)in single-channel intensity and polarization multiplexing.Furthermore,it compares the error correction performance of low-density parity check(LDPC)and Reed-Solomon(RS)codes across different error correction coding types.The effects of unscattered photon ratio and depolarization ratio on BER are also verified.Finally,a UWOC system based on SPD is constructed,achieving 14.58 Mbps with polarization OOK multiplexing modulation and 4.37 Mbps with polarization 2-PPM multiplexing modulation using LDPC code error correction. 展开更多
关键词 error correction coding modulation mode single photon detection underwater communication wireless optical communication
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Comprehensive integration of single-cell transcriptomic data illuminates the regulatory network architecture of plant cell fate specification
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作者 Shanni Cao Xue Zhao +6 位作者 Zhuojin Li Ranran Yu Yuqi Li Xinkai Zhou Wenhao Yan Dijun Chen Chao He 《Plant Diversity》 SCIE CAS CSCD 2024年第3期372-385,共14页
Plant morphogenesis relies on precise gene expression programs at the proper time and position which is orchestrated by transcription factors(TFs)in intricate regulatory networks in a cell-type specific manner.Here we... Plant morphogenesis relies on precise gene expression programs at the proper time and position which is orchestrated by transcription factors(TFs)in intricate regulatory networks in a cell-type specific manner.Here we introduced a comprehensive single-cell transcriptomic atlas of Arabidopsis seedlings.This atlas is the result of meticulous integration of 63 previously published scRNA-seq datasets,addressing batch effects and conserving biological variance.This integration spans a broad spectrum of tissues,including both below-and above-ground parts.Utilizing a rigorous approach for cell type annotation,we identified 47 distinct cell types or states,largely expanding our current view of plant cell compositions.We systematically constructed cell-type specific gene regulatory networks and uncovered key regulators that act in a coordinated manner to control cell-type specific gene expression.Taken together,our study not only offers extensive plant cell atlas exploration that serves as a valuable resource,but also provides molecular insights into gene-regulatory programs that varies from different cell types. 展开更多
关键词 ARABIDOPSIS single cell transcriptome Gene regulatory network Data integration Plant cell atlas
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Optimizing high-coordination shell of Co-based single-atom catalysts for efficient ORR and zinc-air batteries
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作者 Yugang Qi Qing Liang +9 位作者 Kexin Song Xinyan Zhou Meiqi Liu Wenwen Li Fuxi Liu Zhou Jiang Xu Zou Zhongjun Chen Wei Zhang Weitao Zheng 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第8期306-314,I0007,共10页
Atom-level modulation of the coordination environment for single-atom catalysts(SACs)is considered as an effective strategy for elevating the catalytic performance.For the MNxsite,breaking the symmetrical geometry and... Atom-level modulation of the coordination environment for single-atom catalysts(SACs)is considered as an effective strategy for elevating the catalytic performance.For the MNxsite,breaking the symmetrical geometry and charge distribution by introducing relatively weak electronegative atoms into the first/second shell is an efficient way,but it remains challenging for elucidating the underlying mechanism of interaction.Herein,a practical strategy was reported to rationally design single cobalt atoms coordinated with both phosphorus and nitrogen atoms in a hierarchically porous carbon derived from metal-organic frameworks.X-ray absorption spectrum reveals that atomically dispersed Co sites are coordinated with four N atoms in the first shell and varying numbers of P atoms in the second shell(denoted as Co-N/P-C).The prepared catalyst exhibits excellent oxygen reduction reaction(ORR)activity as well as zinc-air battery performance.The introduction of P atoms in the Co-SACs weakens the interaction between Co and N,significantly promoting the adsorption process of ^(*)OOH,resulting in the acceleration of reaction kinetics and reduction of thermodynamic barrier,responsible for the increased intrinsic activity.Our discovery provides insights into an ultimate design of single-atom catalysts with adjustable electrocatalytic activities for efficient electrochemical energy conversion. 展开更多
关键词 ELECTROCATALYTIC Oxygen reduction reaction single atom catalyst Shell coordination optimization
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Comparative analysis of single-crater parameters in ultrasonic-assisted and unassisted micro-EDM of Ti6Al4V using discharge plasma imaging
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作者 Sohaib Raza Chandrakant Nirala 《Nanotechnology and Precision Engineering》 EI CAS CSCD 2024年第2期11-24,共14页
Ultrasonic-assisted micro-electro-discharge machining(EDM)has the potential to enhance processing responses such as material removal rate(MRR)and surface finish.To understand the reasons for this enhancement,the physi... Ultrasonic-assisted micro-electro-discharge machining(EDM)has the potential to enhance processing responses such as material removal rate(MRR)and surface finish.To understand the reasons for this enhancement,the physical mechanisms responsible for the individual discharges and the craters that they form need to be explored.This work examines features of craters formed by single discharges at various parameter values in both conventional and ultrasonic-assistedEDM of Ti6Al4V.High-speed imaging of the plasma channel is performed,and data on the individual discharges are captured in real-time.A 2D axisymmetric model using finite element software is established to model crater formation.On the basis of simulation and experimental results,a comparative study is then carried out to examine the effects of ultrasonic vibrational assistance on crater geometry.For every set ofEDM parameters,the crater diameter and depth from a single discharge are found to be higher in ultrasonic-assistedEDM than in conventionalEDM.The improved crater geometry and the reduced bulge formation at the crater edges are attributed to the increased melt pool velocity and temperature predicted by the model. 展开更多
关键词 Ultrasonic vibration Discharge crater Plasma diameter single discharge
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