检索结果-南通市图书馆

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

在线全文

学校读者我要写书评

暂无评论

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

在线全文

学校读者我要写书评

暂无评论

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

在线全文

学校读者我要写书评

暂无评论

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

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

在线全文

学校读者我要写书评

暂无评论

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

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

在线全文

学校读者我要写书评

暂无评论

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

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

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

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

Subnatural-linewidth fluorescent single photons

在线全文

学校读者我要写书评

暂无评论

Photonics Research 2024年第4期12卷 625-637页

作者： he-BIN zhang GAO-XIANG li YONG-CHUN liU State Key Laboratory of Low-Dimensional Quantum Physics Department of PhysicsTsinghua UniversityBeijing 100084China Department of Physics Huazhong Normal UniversityWuhan 430079China Frontier Science Center for Quantum Information Beijing 100084China

Subnatural-linewidth single photons are of vital importance in quantum optics and quantum information *** to previous research, it appears difficult to utilize resonance fluorescence to generate single photons with subnatural linewidth. here we propose a universally applicable approach to generate fluorescent single photons with subnatural linewidth, which can be implemented based on Λ-shape and similar energy ***, the general condition to obtain fluorescent single photons with subnatural linewidth is *** single-photon linewidth can be easily manipulated over a broad range by external fields, which can be several orders of magnitude smaller than the natural linewidth. Our study can be easily implemented in various physical platforms with current experimental techniques and will significantly facilitate the research on the quantum nature of resonance fluorescence and the technologies in quantum information science.

关键词： quantum utilize optics

From Digital Human Modeling to Human Digital Twin: Framework and Perspectives in Human Factors

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2024年第1期37卷 1-14页

作者： Qiqi he li li Dai li Tao Peng Xiangying zhang Yincheng Cai Xujun zhang Renzhong Tang State Key Laboratory of Fluid Power Components and Mechatronic Systems Zhejiang UniversityHangzhou 310027China ZJU-Sunon Joint Research Center for Smart Furniture Zhejiang UniversityHangzhou 310027China PICO-Lab Bytedance Inc.Shanghai 200233China Sunon Technology Co. Ltd.Hangzhou 311215China

The human digital twin(HDT)emerges as a promising human-centric technology in Industry 5.0,but challenges remain in human modeling and *** human modeling(DHM)provides solutions for modeling and simulating human physical and cognitive aspects to support ergonomic ***,it has limitations in real-time data usage,personalized services,and timely *** emerging HDT concept offers new possibilities by integrating multi-source data and artificial intelligence for continuous monitoring and ***,this paper reviews the evolution from DHM to HDT and proposes a unified HDT framework from a human factors *** framework comprises the physical twin,the virtual twin,and the linkage between these *** virtual twin integrates human modeling and AI engines to enable model-data-hybrid-enabled *** can potentially upgrade traditional ergonomic methods to intelligent services through real-time analysis,timely feedback,and bidirectional ***,the future perspectives of HDT for industrial applications as well as technical and social challenges are *** general,this study outlines a human factors perspective on HDT for the first time,which is useful for cross-disciplinary research and human factors innovation to enhance the development of HDT in industry.

关键词： Human digital twin Digital human modeling Human factors Human-centric technology