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Structures and potential energy functions for ground states of PuU and U_2 molecules

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Nuclear Science and Techniques 2011年第1期22卷 47-54页

作者： li Rusong he Bin zhang Quanhu Xi'an Research Institute of Hi-Tech Hongqing TownXi'an 710025China

Pu-Pu,Pu-U and U-U interatomic potentials must be known in molecular dynamics (MD) calculation of the effects of U recoil nucleus produced by self irradiation on physical properties and phase stability in δ-*** of the lack of experimental data for fitting Pu-U and U-U potentials,electronic states and potential data of PuU and U2 molecules are obtained by ab initio calculations with B3LYP hybrid exchange-correlation *** valence electrons of Pu and U atoms are treated with contraction basis sets,and the cores are approximated with relativistic effective core *** results show that electronic states for the ground states are X11Σu+ and X9Σg+.The pair potential data are fitted with the Murrell-Sorbie analytical potential *** LDA+U calculations on the Pu-U intermetallic compound are performed with Perdew and Wang exchange-correlation functional at the spin-polarized *** material parameters,such as the cohesive energies,elastic constants,and bulk modulus,are used to fit the 0-K universal Rose EOS,so the Pu-U EAM potential model is obtained.

关键词：解析势能函数基态分子动力学结构从头计算金属间化合物 B3LYP 相稳定性

Preparation of nanocrystalline palladium on p-Si by electroless deposition and its photo-electrochemical hydrogen evolution property

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Rare Metals 2006年第3期25卷 241-245页

作者： YAO Suwei li he zhang Weiguo WANG Hongzhi BEN Yuheng SUGIYAMA Laboratory of Surface Technology School of Chemical Engineering and Technology Tianjin University Tianjin 300072 China

The Pd-modified p-Si electrode was prepared by means of electroless deposition. The average diameter of Pd nanoparticles was about 80 nm from SEM observations. XRD results showed that the structure of Pd coatings was nanocrystalline. The catalyzing properties of the Pd-modified p-Si electrode for hydrogen evolution under illumination and in dark were studied with the constant current polarization method. The polarization potential for hydrogen evolution reac- tion （heR） of the Pd/p-Si electrode under illumination was 250 mV lower than that in dark, and was 450 mV lower than that of p-Si in dark at the current density of 2.5 mA·cm^-2. The results of electrochemistry impedance spectra （EIS） showed that electrochemistry heR resistance of the modified electrode under illumination decreased from 593.12 to 442.20 Ω·cm^2, and the heR rate increased evidently.

关键词： electrochemistry Pd-modified p-Si electrode electroless hydrogen evolution reaction

One-dimensional manganese borate hydroxide nanorods and the corresponding manganese oxyborate nanorods as promising anodes for lithium ion batteries

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Nano Research 2015年第2期8卷 554-565页

作者： Aihua li liqiang Xu Shouli li Yanyan he Ranran zhang Yanjun Zhai Key Laboratory of Colloid & Interface Chemistry (Shandong University) Ministry of Education and School of Chemistry and ChemicalEngineering Shandong University )inan 250100 China

Novel manganese and boron containing nanomaterials have been investigated for applications in rechargeable lithium ion batteries （L1Bs） in recent years owing since they are more environmentally-benign and more abundant in nature than the materials currently employed. In this study, one-dimensional （1D） Mn3B7O13OH nanorods and MnBO2OH nanorod bundles were controllably fabricated by using NH4HB4O7 and Mn（NO3）2 as reagents via a hydrothermal or solvothermal process, respectively, without any surfactants or templates at 220 ℃. It is interesting to find that both materials are transformed into Mn2OBO3 nanorods/nanorod bundles by subsequent calcination. The formation processes of the above 1D borate containing products were investigated and the as-obtained four kinds of borates were studied as novel anode materials. It was found that the Mn2OBO3 nanorods displayed the best performance among the four borates, delivering an initial discharge capacitiy of 1,172 mAh·g^-1 at 100 mA·g^-1, and 724 mAh.g could be retained after 120 cycles. A full battery composed of a Mn2OBO3 nanorod anode and a commercial liFePO4 （or liCoO2） cathode has also been assembled for the first time, which delivered an initial discharge capacity of 949 mAh·g^-1 （779 mAh·g^-1 for liCoO2）. The excellent cycle and rate performances of the products reveal their potential applications as anodes for liBs.

关键词： one-dimensional manganese boratehydroxide manganese oxyborate lithium ion battery

Stereoselective Synthesis of N^1-Lyxitol Inosine Derivative

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Chinese Chemical Letters 2001年第7期12卷 575-578页

作者： li Jun HUANG Yan PANG Ji Mei MIN li he zhang National Research Laboratory of Natural and Biomimetic Drugs Peking UniversityBeijing 100083

1,4-anhydro-2-trifiyl-3,5-O-benzenylidene-L-xylitol (5) was constructed in six steps from protected D-xylose. Substitution of 5 with protected 8-bromoinosine 6 gave the key intermediate 5 ' -O-TBS-2 ' ,3 ' -di-O-acctyl-N-1-(2 ' -deoxy-1 ' ,4 ' -anhydro-3 ' ,5 ' -O-benzenylidene (14). Selective removal of 5 ' -O-TBS-group gave the corresponding though phosphorylation which was characterized by X-ray crystallographical analysis.

关键词： Cyclic ADP-ribose analogues synthesis X-ray crystallographic analysis

Development of New Wear-Resistant Surface Coating at Elevated Temperature

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Journal of Iron and Steel Research International 2006年第5期13卷 37-40,59页

作者： li Shang-ping FENG Di LUO he-li zhang Xi-e CAO Xu Institute of Superalloy Central Iron and Steel Research Institute Beijing 100081 China

Because of good oxidation resistance at high temperature and excellent mechanical properties of Ni3 Al and high hot hardness, and good oxidation resistance of chromium carbide, chromium carbide particle reinforced Ni3Al matrix composite would possess excellent wear resistance at elevated temperature. Cr3 C2-NiAl-Ni welding wire was produced by pressureless sintering process in vacuum. When the welding wire was welded on the surface of carbon steel, under the action of the physical heat of arc, NiAl reacted with nickel to form Ni3 Al and carbide particle reinforced Ni3 Al matrix composite was formed on the welding layers. Cr3 C2 was dissolved during welding and dispersed Cr7C3 was formed, which strengthened the Ni3Al matrix significantly. The CrTC3-Ni3Al interface was broadened, and a zone of interdiffusion and a new phase M23 C6 were formed, indicating that a good bond has been formed. The hardness of Cr7 C3/Ni3 Al composite at room and elevated temperatures is much higher than that of stellite alloys. In addition, CrTC3/Ni3Al composite possesses better high temperature oxidation resistance than stellite 12 alloy. So Cr7 C3/ Ni3 Al composite can become an attractive potential candidate for elevated temperature wear-resistant surface material.

关键词： Ni3Al chromium carbide composite wear resistance elevated temperature

Effect of geometry simplification and boundary condition specification on flow field and aerodynamic noise in the train head and bogie region of high-speed trains

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第9期25卷 716-731页

作者： Jiawei SHI Yuan he Jiye zhang Tian li State Key Laboratory of Rail Transit Vehicle System Southwest Jiaotong UniversityChengdu 610031China Institute of Sound and Vibration Research Faculty of Engineering and Physical SciencesUniversity of SouthamptonSouthampton SO171BJUK

The purpose of this study is to determine a suitable modeling method to make computational fluid dynamics(CFD)simulation more efficient for aeroacoustics optimization of the bogie region of high-speed *** this end,four modeling methods are considered,which involve different geometry simplifications and boundary condition *** corresponding models are named the three-car marshalling model,computational domain shortening model,carbody shortening model,and sub-domain *** the detached eddy simulation(DES)model and Ffowcs Williams-Hawkings(FW-H)equation,the unsteady flow field and far-field noise of the four models are *** evaluate the effect of the different modeling methods,the time-averaged flow field,fluctuating flow field,and far-field noise results of the four models are compared and analyzed in detail with the results of the three-car marshalling model used as basis for *** results show that the flow field results of the bogie region predicted by the four models have relatively high ***,the usage of the non-time varying outlet boundary conditions in the computational domain shortening model and sub-domain model could affect the pressure fluctuation on the upstream carbody *** only the bogie region is used as the source surface,the differences between the far-field noise results of the three simplified models and the three-car marshalling model are all within 1 dB;when the train head is used as the source surface,the results of the carbody shortening model and the three-car marshalling model are more consistent.

关键词： Bogie region Train head Flow field Aerodynamic noise Geometry simplification Boundary conditions

Image Segmentation-P300 Selector: A Brain–Computer Interface System for Target Selection

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Computers, Materials & Continua 2024年第5期79卷 2505-2522页

作者： Hang Sun Changsheng li he zhang Mechanical Engineering Nanjing University of Science and TechnologyNanjing210018China

Brain–computer interface (BCI) systems, such as the P300 speller, enable patients to express intentions withoutnecessitating extensive ***, the complexity of operational instructions and the slow pace of characterspelling pose challenges for some patients. In this paper, an image segmentation P300 selector based on YOLOv7-mask and DeepSORT is proposed. The proposed system utilizes a camera to capture real-world objects forclassification and tracking. By applying predefined stimulation rules and object-specificmasks, the proposed systemtriggers stimuli associated with the objects displayed on the screen, inducing the generation of P300 signals in thepatient’s brain. Its video processing mechanism enables the system to identify the target the patient is focusing oneven if the object is partially obscured, overlapped, moving, or changing in number. The system alters the target’scolor display, thereby conveying the patient’s intentions to caregivers. The data analysis revealed that the selfrecognitionaccuracy of the subjects using this method was between 92% and 100%, and the cross-subject P300recognition precision was 81.9%–92.1%. This means that simple instructions such as “Do not worry, just focuson what you desire” effectively discerned the patient’s intentions using the Image Segmentation-P300 selector. Thisapproach provides cost-effective support and allows patients with communication difficulties to easily express theirneeds.

关键词： Brain-computer interface deep learning electroencephalogram P300 YOLOv7-mask

Rockburst prediction and prevention in underground space excavation

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Underground Space 2024年第1期14卷 70-98页

作者： Jian Zhou Yulin zhang Chuanqi li Haini he Xibing li School of Resources and Safety Engineering Central South UniversityChangsha 410083China Laboratory 3SR CNRS UMR 5521Grenoble Alpes UniversityGrenoble 38000France

The technical challenges associated with deep underground space activities have become increasingly *** these challenges,one major concern is the assessment of rockburst risks and the instability of rock *** research has been conducted by numerous scholars to mitigate the risks and prevent occurrences of rockburst through various assessment *** incidents commonly occur during the excavation of hard rock in underground environments,posing severe threats to personnel safety,equipment integrity,and operational ***,it is crucial to systematically document real cases of rockburst,allowing for a comprehensive understanding of the underlying mechanisms and triggering *** understanding will contribute to the advancement of rockburst prediction and prevention *** selection of an appropriate rockburst assessment method is a fundamental aspect in underground ***,there is a limited number of studies that summarize and compare different prediction and prevention methods of *** paper aims to address this gap by analyzing global trends using CiteSpace software since *** discusses rockburst classification and characteristics,comprehensively reviews research findings related to rockburst prediction,including empirical,simulation,mathematical modeling,and microseismic monitoring ***,the paper presents a compilation of current rockburst prevention ***,the paper emphasizes the significance of control strategies,which provide key insights into the effective utilization of stored energy within ***,the paper concludes by suggesting six directions for implementing intelligent management techniques to mitigate hazards during underground operations and reduce the probability of rockburst incidents.

关键词： Rockburst Underground space Scientometric analysis Characteristic analysis Rockburst prediction Rockburst prevention

pH Induced Self-assembly of AIE Fluorescent Probe for Tumor Imaging

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Chinese Journal of Polymer Science 2024年第1期42卷 7-13,I0005页

作者： Jing-Yuan Xiang Wen-Long zhang he-Ting li Ya-Ning he Department of Chemical Engineering Key Laboratory of Advanced Materials(MOE)Tsinghua UniversityBejing 100084China

This work reported an AIE fluorescent probe for tumor imaging based on the p H induced self-assembly strategy. The fluorescent probe was composed of an acid-responsive soluble copolymer PEG-b-PAMA-DMMA with a maleic acid amide group and an anionic soluble aggregation-induced emission fluorogen(AIEgen) TPE-2SO_(3)^(-). The polymer could be transformed into a protonated amine-containing polymer after the hydrolysis of maleic acid amide in acidic tumor microenvironment, which would be further self-assembled with TPE-2SO_(3)^(-)to form aggregated nanoparticles. The transition of TPE-2SO_(3)^(-)from dispersed state to aggregated state led to an obvious increase in fluorescence intensity due to its AIE characteristics.

关键词： p H-responsive Self-assembly Fluorescent probe AIE Tumor imaging