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Science China(Technological Sciences) 2024年第5期67卷 1391-1400页

作者： HU JiaJun QIAN Shuo WU Hui HU DongXu NIU LiXin BI XiaoXue ZHANG Jie HOU XiaoJuan GENG WenPing MU JiLiang HE Jian CHOU XiuJian Science and Technology on Electronic Test and Measurement Laboratory North University of ChinaTaiyuan030051China school of Software North University of ChinaTaiyuan030051China

In our daily lives,low-frequency kinetic energy primarily manifests as ***,effective harnessing of lowfrequency kinetic energy remains a formidable *** paper proposes a rope-driven rotor that rotates around an axis and consists of an ultra-high-molecular-weight polyethylene(UHMWPE)wire wrapped around a metal *** rotor can convert ultra-low frequency vibration/linear motion into rapid rotation by pressing the top at low frequencies and driving the rope for a quick *** harvester can generate up to 36.25 m W power using a 0.1-mm-diameter UHMWPE wire as the rotor when periodically pressed down to 20 mm at a frequency of 1 Hz.A simple power generation floor is assembled,generating 28.58-m W power with a matching load at a frequency of 1.5 ***,the harvester can increase the charging voltage of a 0.47-F supercapacitor from 0 to 6.8 V within 10 *** addition,the harvester can harvest energy through a light finger press motion,and the energy obtained can also support the continuous operation of multiple electronic devices *** study introduces an effective method for harvesting ultra-low frequency energy and has great prospects in the field of power generation floor and human movement energy harvesting.

关键词： electromagnetic energy harvester rope-shaft coupling structure human motion ultra-low frequency

Formal Verification of Data Modifications in Cloud Block Storage Based on Separation Logic

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Chinese Journal of Electronics 2024年第1期33卷 112-127页

作者： Bowen ZHANG Zhao JIN Hanpin WANG Yongzhi CAO Key Laboratory of high Confidence Software Technologies (MOE) School of Computer Science Peking University school of Computer and Artificial Intelligence Zhengzhou University school of Computer Science and Cyber Engineering Guangzhou University

Cloud storage is now widely used, but its reliability has always been a major concern. Cloud block storage(CBS) is a famous type of cloud storage. It has the closest architecture to the underlying storage and can provide interfaces for other types. Data modifications in CBS have potential risks such as null reference or data *** verification of these operations can improve the reliability of CBS to some extent. Although separation logic is a mainstream approach to verifying program correctness, the complex architecture of CBS creates some challenges for verifications. This paper develops a proof system based on separation logic for verifying the CBS data modifications. The proof system can represent the CBS architecture, describe the properties of the CBS system state, and specify the behavior of CBS data modifications. Using the interactive verification approach from Coq, the proof system is implemented as a verification tool. With this tool, the paper builds machine-checked proofs for the functional correctness of CBS data modifications. This work can thus analyze the reliability of cloud storage from a formal perspective.

关键词： Cloud computing Behavioral sciences Reliability Formal verification

Regulating interfacial behavior of zinc metal anode via metal-organic framework functionalized separator

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Journal of Energy Chemistry 2024年第6期93卷 213-220,I0006页

作者： Ruotong Li Liang Pan Ziyu Peng Ningning Zhao Zekun Zhang Jing Zhu Lei Dai Ling Wang Zhangxing He school of Chemical Engineering North China University of Science and TechnologyTangshan 063210HebeiChina

Aqueous zinc ion batteries(AZIBs)are one of the promising energy storage ***,uncontrolled dendrite and side reactions have seriously hindered its further *** this study,the metal-organic framework(MOF)functionalized glass fiber separator(GF-PFC-31)was used to regulate interfacial behavior of zinc metal anode,enabling the development of high-performance *** PFC-31,there areπ-πinteractions between two adjacent benzene rings with a spacing of 3.199 *** spacing can block the passage of[Zn(H_(2)O)_6]^(2+)(8.6 A in diameter)through the GF-PFC-31 separator to a certain extent,which promotes the deposition process of Zn *** addition,the sulfonic acid group(-S03H)contained in GF-PFC-31 can form a hydrogen bonding network with H_(2)O,which can provide a desolvation effect and reduce the side ***,GF-PFC-31 separator achieves uniform deposition of Zn *** Zn‖GF-PFC-31‖Zn symmetric cell exhibits stable cycle life(3000 h at 1.2 mA cm^(-2),2000 h at 0.3 mA cm^(-2),and 2000 h at 5.0 mA cm^(-2)),and Zn‖GF-PFC-31‖MnO_(2) full cell with GF-PFC-31 separator can cycle for 1000 cycles at 1.2 A g^(-1)with capacity retention rate of 82.5%.This work provides a promising method to achieve high-performance AZIBs.

关键词： Aqueous zinc ion batteries Interfacial behavior Metal-organic framework Sulfonic acid group Separator

A widely used nonionic surfactant with desired functional groups as aqueous electrolyte additives for stabilizing Zn anode

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Rare Metals 2024年第8期43卷 3692-3701页

作者： Yue-Xian Song Xiao-Feng Wang Cai-Bin Liu Kai-Xuan Guo Xu-Huan Guo Xiao-Bin Zhong Yao-Hui Zhang Kai Wang Hui-Juan Guo Li-Xin Zhang Jun-Fei Liang school of Energy and Power Engineering North University of China Key Laboratory of Green Chemical Process of Ministry of Education Hubei Key Laboratory of Novel Chemical Reactor and Green Chemical TechnologySchool of Chemical Engineering and PharmacyWuhan Institute of Technology Shanxi Provincial Key Laboratory for high Performance Battery Materials and Devices

Aqueous Zn-ion batteries（AZIBs） have emerged as potential candidates for Li-ion batteries due to their intrinsic safety and high ***,metallic Zn anodes encounter dendrite growth and water-induced corrosion,rendering poor stability and severe irreversibility at the electrode/electrolyte interface during *** stabilize the Zn anode,we report a low-cost and effective nonionic surfactant,Tween-20 polymer,as an electrolyte additive for *** Tween-20,sequential oxyethylene groups tended to be preferentially adsorbed on the Zn electrode to form a shielding layer for regulating uniform Zn ***,the hydrophobic hendecyl chains prevented H2O-induced corrosion on the Zn anode *** from the desired functional groups,when only trace amounts of Tween-20(0.050 g·L-1) were used,the Zn anode displayed good cycling stability over 2170 h at10 mA·cm-2and a high average Coulombic efficiency of98.94% over 1000 *** Tween-20 polymer can also be effectively employed in MnO2/Zn full *** their toxicity,price and amount of usage,these surfactant additives provide a promising strategy for realizing the stability and reversibility of high-performance Zn anodes.

关键词： Zn anode Dendrite growth Tween-20 polymer Surfactant additive Aqueous electrolyte

NbB_(2)Modified Al-Cu Alloys Fabricated by Freeze-Ablation Casting under high Cooling Rate Solidification

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Acta Metallurgica Sinica(English Letters) 2024年第5期37卷 921-938页

作者： Xiang Kong Yu Wang Hong Xu Haotian Fan Yuewu Zheng Beibei Xie school of Materials Science and Engineering North University of ChinaTaiyuan 030051China

At present,improving the properties of aluminum alloys is generally achieved by increasing the cooling rate of the melt and adding micro-nano *** the cooling rate of the melt to improve the refining effect of grain refiner is still a difficult problem in the aluminum alloy casting *** innovative and environmentally friendly casting process,known as freeze ablation,was introduced during the preparation of an Al–NbB_(2) intermediate *** process significantly enhanced the cooling rate of the *** results indicated that the Al–NbB_(2) intermediate alloy produced under high cooling rates had a noticeable refining effect on Al–Cu alloys,with smaller NbB2 particles demonstrating superior refining *** average grain size of the refined Al–Cu alloy decreased from 154 to 69μm,the tensile strength increased by 12%,the fluidity increased by 18.4%,and the hot tearing index decreased from 144 to *** matching degree between NbB_(2) andα-Al was calculated using high-resolution transmission electron microscopy and the edge-to-edge *** was found that the atomic interplanar spacing and the interatomic spacing mismatch between NbB_(2)’splane and Al were both less than 10%,which further proved that NbB2 could serve as an effective nucleation site forα-Al grains to achieve grain refinement.

关键词： Grain refinement Freeze ablation Particle size control Mechanical properties Process properties

Recommendation Method for Contrastive Enhancement of Neighborhood Information

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Computers, Materials & Continua 2024年第1期78卷 453-472页

作者： Hairong Wang Beijing Zhou Lisi Zhang He Ma school of Computer Science and Engineering North Minzu UniversityNingxia750021China

Knowledge graph can assist in improving recommendation performance and is widely applied in various person-alized recommendation ***,existing knowledge-aware recommendation methods face challenges such as weak user-item interaction supervisory signals and noise in the knowledge *** tackle these issues,this paper proposes a neighbor information contrast-enhanced recommendation method by adding subtle noise to construct contrast views and employing contrastive learning to strengthen supervisory signals and reduce knowledge ***,first,this paper adopts heterogeneous propagation and knowledge-aware attention networks to obtain multi-order neighbor embedding of users and items,mining the high-order neighbor informa-tion of users and ***,in the neighbor information,this paper introduces weak noise following a uniform distribution to construct neighbor contrast views,effectively reducing the time overhead of view *** paper then performs contrastive learning between neighbor views to promote the uniformity of view information,adjusting the neighbor structure,and achieving the goal of reducing the knowledge noise in the knowledge ***,this paper introduces multi-task learning to mitigate the problem of weak supervisory *** validate the effectiveness of our method,experiments are conducted on theMovieLens-1M,MovieLens-20M,Book-Crossing,and Last-FM *** results showthat compared to the best baselines,our method shows significant improvements in AUC and F1.

关键词： Contrastive learning knowledge graph recommendation method

Microstructure Characteristics and Possible Phase Evolution of the Coal Gangue-Steel Slag Ceramics Prepared by the Solid-State Reaction Methods

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Journal of Wuhan University of Technology(Materials Science) 2024年第4期39卷 921-930页

作者：刘文洁 WANG Yang LI Jingtao 李宝让 school of Energy Power and Mechanical EngineeringNorth China Electric Power UniversityBeijing 102206China

Industrial wastes such as steel slag and coal gangue *** chosen as raw materials for preparing ceramic via the conventional solid-state reaction *** steel slag and coal gangue mixed in various mass ratios,from 100%steel slag to 100%coal gangue at 10%intervals,microstructure and possible phase evolution of the coal gangue-steel slag ceramics were investigated using X-ray powder diffraction,scanning electron microscopy,mercury intrusion porosimetry and Archimedes boiling *** experimental results suggest that the phase compositions of the as-prepared ceramics could be altered with the increased amount of coal gangue in the *** anorthite-diopside eutectic can be formed in the ceramics with the mass ratios of steel slag to coal gangue arranged from 8:2 to 2:8,which was responsible for the melting of the steel slag-coal gangue ceramics at relatively high *** investigations on the microstructure suggested that the addition of the proper amount of steel slag in ceramic compositions was conducive to the pore formation and further contributed to an increment in porosity.

关键词： steel slag-coal gangue ceramics synthesis phase evolution microstructure characteristics

Hole mobility enhancement in monolayer WSe2 p-type transistors through molecular doping

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Science China(Information Sciences) 2024年第6期67卷 207-213页

作者： Shiyuan LIU Xiong XIONG Xin WANG Xinhang SHI Ru HUANG Yanqing WU school of Integrated Circuits and Beijing Advanced Innovation Center for Integrated Circuits Peking University Wuhan National high Magnetic Field Center and school of Integrated Circuits Huazhong University of Science and Technology

Two-dimensional （2D） transition metal dichalcogenide （TMDC） semiconductor materials exhibit extraordinary electrical properties,holding promise for the realization of next-generation complementary metal-oxide-semiconductor （CMOS） devices at ultimate ***,constrained by effective device doping strategies,the hole mobility and device performance of tungsten diselenide （WSe2） p-type transistors,especially monolayer chemical vapor deposition （CVD）-grown WSe2,have not met *** this paper,an effective performance enhancement of monolayer WSe2p-type transistor was achieved through a molecular doping *** monolayer WSe2directly on SiO2back-gated substrates and leveraging energy band alignment design,4-nitrobenzenediazonium tetrafluoroborate （4-NBD） molecular dopant with a concentration of 10 m M was utilized to modulate the Fermi level position of monolayer WSe2for hole *** devices demonstrated a more than 98%increase in hole mobility,reaching up to 97 cm2·V-1·s-1while maintaining the current on/off ratio of *** p-type WSe2transistors with 1μm channel length exhibit a high drive current surpassing 176μA·μm-1,exceeding previous CVD-WSe2devices with similar channel *** straightforward and effective approach to improving the electrical performance of WSe2transistors paves the way for advanced logic technologies based on transition metal dichalcogenide semiconductors.

关键词： CVD-grown WSe$_2$ molecular doping 4-NBD p-type transistors hole mobility

Process and performance of DAAF microspheres prepared by continuous integration from synthesis to spherical coating based on microfluidic system

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Defence Technology（防务技术） 2024年第2期32卷 629-643页

作者： Bidong Wu Jiahui Shi Mengsen Wei Rui Zhu Yi Liu Jinqiang Zhou Chongwei An Jingyu Wang school of Environment and Safety Engineering North University of ChinaTaiyuan 030051China Shanxi Engineering Technology Research Centre for Ultrafine Powder North University of ChinaTaiyuan 030051China school of Mechatronical Engineering Beijing Institute of TechnologyBeijing 100081China

In order to improve the energy output consistency of 3, 3’-diamino-4, 4’-azoxyfurazan(DAAF) in the new insensitive booster and the safety and efficiency in the preparation process, a continuous preparation system of DAAF from synthesis to spherical coating was designed and established in this paper, which combined ultrasonic micromixing reaction with microdroplet globular template. In the rapid micromixing stage, the microfluidic mixing technology with ultrasonic was used to synergistically strengthen the uniform and rapid mass transfer mixing reaction between raw materials to ensure the uniformity of DAAF particle nucleation-growth, and to prepare high-quality DAAF crystals with uniform structure and morphology and concentrated particle size distribution. In the microdroplet globular template stage, the microfluidic droplet technology was used to form a droplet globular template with uniform size under the shear action of the continuous phase of the dispersed phase solution containing DAAF particles and binder. The size of the droplet template was controlled by adjusting the flow rate ratio between the continuous phase and the dispersed phase. In the droplet globular template, with the diffusion of the solvent in the dispersed phase droplets, the binder precipitates to coat the DAAF into a ball, forming a DAAF microsphere with high sphericity, narrow particle size distribution and good monodispersity. The problem of discontinuity and DAAF particle suspension in the process was solved, and the coating theory under this process was studied. DAAF was coated with different binder formulations of fluororubber(F2604), nitrocellulose(NC) and NC/glycidyl azide polymer(GAP), and the process verification and evaluation of the system were carried out. The balling effects of large, medium and small droplet templates under different binder formulations were studied. The scanning electron microscope(SEM) results show that the three droplet templates under the three binder formul

关键词： DAAF Micromixing technology Microdroplet technology Synthesis Spherical coating Continuousization

Flexible multilayer MEMS coils and their application in energy harvesters

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Science China(Technological Sciences) 2024年第4期67卷 1282-1293页

作者： ZHANG Jie HOU XiaoJuan QIAN Shuo BI XiaoXue HU DongXu LIU JianJun GENG WenPing MU JiLiang HE Jian CHOU XiuJian Science and Technology on Electronic Test and Measurement Laboratory North University of ChinaTaiyuan 030051China school of Software North University of ChinaTaiyuan 030051China

Electromagnetic vibration energy harvesters are promising for the power supply of wireless sensor nodes,small electronic devices,and wearable *** electromagnetic harvesters usually increase output by increasing the size of coils and magnets,limiting the improvement of energy conversion efficiency and power *** this study,multilayer microelectromechanical system(MEMS)coils were prepared using flexible electronics,and their high integration performance in arbitrary space was utilized to greatly improve the utilization of the space magnetic field by the electromagnetic *** core magnet of the generator was magnetically balanced to achieve levitation,which improved the sensitivity and reduced fatigue damage compared with traditional spring *** wound coils on the top and bottom of the magnet and the flexible coils on the sides worked together to improve the energy efficiency and output of the *** output performance of the device with different number distributions was simulated using mathematical models to obtain the optimal structural *** results show that by introducing flexible multilayer MEMS coils on the side surface of the energy harvester,the open-circuit voltage of the energy generators increased from 7 to 10 V by more than 43%.Flexible multilayer MEMS coils can enhance energy conversion rates and possess compact dimensions,making them suitable for integration onto complex *** the vibration energy harvesting system testing,the maximum peak power of the harvester was 7.1 m W at an acceleration of1 g and a resonant frequency of 11 Hz with a resistor of 3.5 kΩinternal ***,a 470μF capacitor can be charged to 3.5 V within 10 s to drive a hygrothermograph to work for more than 80 s and can supply a light bulb *** strategy shows the great potential of vibration-energy-driven electromagnetic generators for powering small electronics in limited spaces.

关键词： electromagnetic harvester mechanical energy harvesting multilayer MEMS coils magnetic levitation overall space magnetic field flexible planar coils