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Rare Metals 2024年第10期43卷 5403-5409页

作者： Jian-Qiu Sun Yue Ma Chong Gao Hong-Yun Luo School of Materials science and Engineering Beihang University Chinalco research institute of science and technology

In order to improve the comprehensive mechanical properties,deep cryogenic treatment （DCT）prior to aging was carried out on friction-stir-welded（FSW） 2198 Al-Li alloy;afterward,the microstructure and tensile properties were characterized by means of optical microscopy （OM）,transmission electron microscopy（TEM） and tensile *** results show that FSW 2198 alloy through DCT prior to aging （DAT） possesses superior tensile properties than conventional aging treatment （AT）The microstructural analysis reveals that DAT alloy exhibits a finer grain structure,since DCT might effectively alleviate the residual stress in FSW 2198 alloy and thus decrease the driving force for grain coarsening in subsequent aging ***,DCT generates dislocation multiplication,which provides more preferential nucleation sites for T1 （Al2CuLi） phase during subsequent aging treatment,resulting in high-density fine T1 phases and thin precipitate-free zone within DAT *** reasonable microstructure leads to DAT alloy possessing better strength-ductility combination compared to AT alloy.

关键词： Al–Li alloy Deep cryogenic treatment Friction stir welding Tensile properties

A model reduction approach for discrete-time linear time-variant systems with delayed inputs

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science China(Information sciences) 2024年第4期67卷 197-217页

作者： Ai-Guo WU Guang-Ren DUAN Yu WANG Jie ZHANG School of Mechanical Engineering and Automation Harbin Institute of Technology(Shenzhen) HIT Wuhu Robot technology research institute Center for Control science and technology Southern University of Science and Technology

A model reduction approach is presented for discrete-time linear time-variant input-delayed systems. According to this proposed approach, a dynamical variable is constructed by taking advantage of the current state and historical information of input. It is revealed that the behavior of this dynamical variable is governed by a discrete-time linear delay-free system. It is worth noting that the presented variable transformation does not require the system matrix to be invertible. Based on the reduced delay-free models,stabilizing control laws can be easily obtained for the original delayed system. For the case with a single input delay, the constructed variable is an exact prediction for the future state, and thus the stabilizing control law could be designed by replacing the future state with its prediction. Finally, three discrete-time periodic systems with delayed input are employed to illustrate how to utilize the presented model reduction approaches.

关键词： reduction approach predictor-based feedback time-varying systems delayed input periodic system

Perspective on powder technology for all-solid-state batteries:How to pair sulfide electrolyte with high-voltage cathode

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Particuology 2024年第3期86卷 55-66页

作者： Jiangkui Hu Shijie Yang Yingying Pei Xilong Wang Yulong Liao Shuai Li Aolong Yue Jia-Qi Huang Hong Yuan School of Materials science&Engineering Beijing Institute of TechnologyBeijing100081China Advanced research institute of Multidisciplinary science Beijing Institute of TechnologyBeijing100081China

Sulfide solid electrolytes(SEs)have attracted ever-increasing attention due to their superior roomtemperature ionic conductivity(~10^(-2) S cm^(-1)).Additionally,the integration of sulfide SEs and highvoltage cathodes is promising to achieve higher energy ***,the incompatible interfaces between sulfide SEs and high-voltage cathodes have been one of the key factors limiting their ***,this review presents a critical summarization of the interfacial issues in all-solid-state lithium batteries based on sulfide SEs and high-voltage cathodes and proposes strategies to stabilize the electrolyte/cathode ***,the future research direction of electrolyte/cathode interfaces and application prospects of powder technology in sulfide-based ASSLBs were also discussed.

关键词： Sulfide solid electrolytes High-voltage cathodes Electrode/electrolyte interfaces All-solid-state lithium batteries

Random pinhole attenuator for high-power laser beams

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High Power Laser science and Engineering 2024年第3期12卷 116-121页

作者： Seong Cheol Park Hyeok Yun Jin Woo Yoon Seong Ku Lee Jae Hee Sung Il Woo Choi Chang Hee Nam Kyung Taec Kim Department of Physics and Photon science Gwangju Institute of Science and TechnologyGwangjuRepublic of Korea Center for Relativistic Laser science Institute for Basic ScienceGwangjuRepublic of Korea Advanced Photonics research institute Gwangju Institute of Science and TechnologyGwangjuRepublic of Korea

The intensity attenuation of a high-power laser is a frequent task in the measurements of optical *** intensity can be attenuated by inserting an optical element,such as a partial reflector,polarizer or absorption *** devices are,however,not always easily applicable,especially in the case of ultra-high-power lasers,because they can alter the characteristics of a laser beam or become easily *** this study,we demonstrated that the intensity of a laser beam could be effectively attenuated using a random pinhole attenuator(RPA),a device with randomly distributed pinholes,without changing the beam *** this device,a multi-PW laser beam was successfully attenuated and the focused beam profile was measured without any alterations of its *** addition,it was confirmed that the temporal profile of a laser pulse,including the spectral phase,was ***,the RPA possesses significant potential for a wide range of applications.

关键词： high-power laser intensity attenuation laser diagnostics

A highly sensitive LITES sensor based on a multi-pass cell with dense spot pattern and a novel quartz tuning fork with low frequency

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Opto-Electronic Advances 2024年第3期7卷 26-34页

作者： Yahui Liu Shunda Qiao Chao Fang Ying He Haiyue Sun Jian Liu Yufei Ma National Key Laboratory of science and technology on Tunable Laser Harbin Institute of TechnologyHarbin 150000China Zhengzhou research institute Harbin Institute of TechnologyZhengzhou 450000China Advanced Microscopy and Instrumentation research Center School of Instrumentation Science and EngineeringHarbin Institute of TechnologyHarbin 150080China.

A highly sensitive light-induced thermoelectric spectroscopy(LITES)sensor based on a multi-pass cell(MPC)with dense spot pattern and a novel quartz tuning fork(QTF)with low resonance frequency is reported in this *** erbi-um-doped fiber amplifier(EDFA)was employed to amplify the output optical power so that the signal level was further *** optical path length(OPL)and the ratio of optical path length to volume(RLV)of the MPC is 37.7 m and 13.8 cm^(-2),respectively.A commercial QTF and a self-designed trapezoidal-tip QTF with low frequency of 9461.83 Hz were used as the detectors of the sensor,*** target gas selected to test the performance of the system was acetylene(C2H2).When the optical power was constant at 1000 mW,the minimum detection limit(MDL)of the C2H2-LITES sensor can be achieved 48.3 ppb when using the commercial QTF and 24.6 ppb when using the trapezoid-al-tip *** improvement of the detection performance by a factor of 1.96 was achieved after replacing the commer-cial QTF with the trapezoidal-tip QTF.

关键词： light-induced thermoelectric spectroscopy quartz tuning fork multi-pass cell gas sensing

HEN:a novel hybrid explainable neural network based framework for robust network intrusion detection

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science China(Information sciences) 2024年第7期67卷 72-90页

作者： Wei WEI Sijin CHEN Cen CHEN Heshi WANG Jing LIU Zhongyao CHENG Xiaofeng ZOU School of Computer science and Engineering Xi'an University of TechnologyShaanxi Key Laboratory for Network Computing and Security Technology School of Computer science and technology Wuhan University of Science and Technology School of Future technology South China University of Technology Shenzhen research institute of Hunan University School of Computer science Hunan University of Technology and Business institute for Infocomm research (I2R) Agency for Science Technology and Reseach (A*STAR)

With the rapid development of network technology and the automation process for 5G, cyberattacks have become increasingly complex and threatening. In response to these threats, researchers have developed various network intrusion detection systems(NIDS) to monitor network traffic. However, the incessant emergence of new attack techniques and the lack of system interpretability pose challenges to improving the detection performance of NIDS. To address these issues, this paper proposes a hybrid explainable neural network-based framework that improves both the interpretability of our model and the performance in detecting new attacks through the innovative application of the explainable artificial intelligence(XAI)method. We effectively introduce the Shapley additive explanations(SHAP) method to explain a light gradient boosting machine(Light GBM) model. Additionally, we propose an autoencoder long-term short-term memory(AE-LSTM) network to reconstruct SHAP values previously generated. Furthermore, we define a threshold based on reconstruction errors observed during the training phase. Any network flow that surpasses the specified threshold is classified as an attack flow. This approach enhances the framework's ability to accurately identify attacks. We achieve an accuracy of 92.65%, a recall of 95.26%, a precision of 92.57%,and an F1-score of 93.90% on the dataset NSL-KDD. Experimental results demonstrate that our approach generates detection performance on par with state-of-the-art methods.

关键词： explainable artificial intelligence light gradient boosting machine machine learning network intrusion detection Shapley additive explanation hybrid explainable neural network (HEN)

Coordination-environment regulation of atomic Co-Mn dual-sites for efficient oxygen reduction reaction

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Nano research 2024年第8期17卷 6841-6848页

作者： Caiting Sun Yarong Liu Zunhang Lv Rui Liu Changli Wang Liuhua Li Jinming Wang Yu Zhang Wenxiu Yang Bo Wang Key Laboratory of Cluster science(Ministry of Education) Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion MaterialsAdvanced Technology Research Institute(Jinan)Advanced Research Institute of Multidisciplinary ScienceSchool of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 100081China Beijing institute of technology Library Beijing Institute of TechnologyBeijing 100081China

Precisely designing atomic metal-nitrogen-carbon(M-N-C)catalysts with asymmetric diatomic configurations and studying their structure–activity relationships for oxygen reduction reaction(ORR)are important for zinc-air batteries(ZABs).Herein,a dualatomic-site catalyst(DASC)with CoN_(3)S-MnN_(2)S_(2) configuration was prepared for the cathodes of *** with Co-N-C(Mn-free)and CoMn-N-C(S-free doping),CoMn-N/S-C exhibits excellent half-wave potential(0.883 V)and turnover frequency(1.54 e·s^(−1)·site^(−1)),surpassing most of the reported state-of-the-art Pt-free ORR *** CoMn-N/S-C-based ZABs achieve extremely high specific capacity(959 mAh·g^(−1))and good stability(350 h@5 mA·cm^(−2)).Density functional theory(DFT)calculation shows that the introduction of Mn and S can break the electron configuration symmetry of the original Co 3d orbital,lower the dband center of the Co site,and optimize the desorption behavior of*OH intermediate,thereby increasing the ORR activity.

关键词： metal organic frameworks oxygen reduction reaction dual-atom catalyst coordination-environment regulation zinc-air batteries

Amphipathic Janus Nanofibers Aerogel for Efficient Solar Steam Generation

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Energy & Environmental Materials 2024年第4期7卷 422-432页

作者： Rui Wang Jinshuo Deng Ping Wu Qianli Ma Xiangting Dong Wensheng Yu Guixia Liu Jinxian Wang Lei Liu Chongqing research institute Changchun University of Science and Technology Key Laboratory of Applied Chemistry and Nanotechnology at Universities of Jilin Province Changchun University of Science and Technology

Solar steam generation is a promising water purification technology due to its low-cost and environmentally friendly applications in water purification and ***,hydrophilic or hydrophobic materials alone are insufficient in achieving necessary characteristics for constructing highquality solar steam generators with good comprehensive properties.

关键词： aerogels electrospinning photothermal materials solar desalination solar steam generation

Experimental and numerical study of hypervelocity impact damage on composite overwrapped pressure vessels

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Defence technology（防务技术） 2024年第1期31卷 58-72页

作者： Yong-Pan Duan Run-Qiang Chi Bao-Jun Pang Yuan Cai Hypervelocity Impact research Center Harbin Institute of TechnologyHarbin150080China College of science Heilongjiang University of Science and TechnologyHarbin 150022China

Ground-based tests are important for studying hypervelocity impact(HVI)damage to spacecraft pressure vessels in the orbital debris *** analyzed the damage to composite overwrapped pressure vessels(COPVs)in the HVI tests and classified the damage into non-catastrophic damage and catastrophic *** proposed a numerical simulation method to further study non-catastrophic damage and revealed the characteristics and mechanisms of non-catastrophic damage affected by impact conditions and internal *** fragments of the catastrophically damaged COPVs were collected after the *** crack distribution and propagation process of the catastrophic ruptures of the COPVs were *** findings contribute to understanding the damage characteristics and mechanisms of COPVs by HVIs.

关键词： Orbital debris Hypervelocity impact Composite overwrapped pressure vessels Damage mechanisms

Combinations of electron and proton donors in transition-metal complex mediated nitrogen reduction reactions

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science China Chemistry 2024年第7期67卷 2136-2154页

作者： Delong Han Li Yang Hao Huang Priyanka Chakraborty Shashikant U.Dighe Kuo-Wei Huang KAUST Catalysis Center and Division of Physical science and Engineering King Abdullah University of Science and TechnologyThuwal 23955Saudi Arabia Agency for science Technologyand ResearchInstitute of Materials Research and Engineering and Institute of Sustainability for ChemicalsEnergy and EnvironmentSingapore 138634Singapore

Nitrogen fixation is a complex process involving the transfer of six electrons and *** from the conventional Haber-Bosch process,which relies on hydrogen(H_(2))to provide both electrons and protons to reduce nitrogen(N_(2)),homogeneous transition metal complex-catalyzed N_(2)reduction reactions(NRR)employ an array of electron and proton donors or even electron donors combined with *** the synthesis of diverse catalytic progress,the categories of donors have seen rapid ***,existing literature only provides summaries regarding the metal,ligands,and *** the significance of electron and proton donor combinations in nitrogen reduction reactions,no literature has thoroughly reviewed this ***,we hereby compiled a comprehensive list of commonly used reagents in N_(2)reduction and classified them according to their specific donor *** review presents clear and organized information about these combinations,along with a summary of their general performance trend in NRR with related ***,we conclude the discussion by highlighting key points for researchers to consider when selecting catalysts and donor combinations,with the ultimate goal of advancing the field of nitrogen fixation.

关键词： dinitrogen reduction reaction reducing donor combination transition metal complexes homogeneous catalysis