检索结果-南通市图书馆

Surface decomposition and annealing behavior of GaN implanted with Eu

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2002年第3期13卷 167-171页

作者： LIUHua－Ming zhangzhi－Bin 等 LaboratoryofNuclearAnalysesandTechniques ShanghaiInstituteofNuclearResearchtheChineseAcademyofSciencsShanghai201800 LaboratoryofNuclearAnalysesandTechniques ShanghaiInstituteofNuclearResearchtheChi

Investigations on surface decomposition of GaN implanted with low energy (80 keV) Eu ion to a low dose (l×1014 cm-2), and its annealing behavior under high temperature (1050℃) in N2 are performed. The as-grown, as-implanted and annealed GaN films are characterized by proton elastic scattering (PES), Rutherford backscattering spectrometry (RBS), photoluminescence (PL) and atomic force microscopy (AFM). The results show that Eu ion implantation induces radiation defects and decomposition of GaN. The GaN surface decomposition is more serious during high temperature annealing. The atomic ratio of N in as-grown, as-implanted and annealed GaN film is 47 at.%, 44 at.% and 40 at.%, respectively. As a result, a rough Ga-rich layer is formed at the surface, though the lattice defects are partly removed after high temperature annealing.

关键词：半导体材料 GaN 退火行为表面离解

Enhancing anion conductivity in a highly alkali-stable eta topologic Cu(Ⅰ) framework via strong electrostatic repulsion

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2025年

作者： Xiaolu Wang Shaohui Guo chao Suo Fuqiang Zhang Junhao Wang Wenjing Wang Daqiang Yuan Linfeng Liang Xianming Zhang College of Chemistry Taiyuan University of Technology Institute of Crystalline Materials Shanxi University School of Chemistry and Materials Science Shanxi Normal University State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of Matter Chinese Academy of Sciences

Metal-organic frameworks （MOFs） based on anion exchange membranes （AEMs） have garnered considerable interest,particularly for their potential to enhance ion conductivity by pre-introducing anions into *** approach is recognized as straightforward and effective for improving ion ***,developing high-performance AEMs is limited by the inherent instability and low resistance of *** study presents a novel 1,3,5-triazineμ3-bridged neutral Cu（I） framework,designated SXU-120 （where SXU represents Shanxi University）.This framework is synthesized using melamine,a widely available industrial product,as the starting material,achieving a high space-time yield exceeding 1.1 kg *** organic ligands and metal ions in SXU-120 are 3-connected,forming a rare eta topology with the point symbol 8～***-120 exhibits exceptional stability,even in a 10 M KOH solution,due to its high density of uncoordinated–NH2and carbonyl ***,the framework’s unique one-dimensional channels,characterized by their electronegativity,interact electrostatically with OH-ions,thereby accelerating OH-ion transfer along these ***,the OH-conductivity of this material reaches an impressive 0.49 S cm-1at 90°C under full humidity for 100 h,representing the highest OH-conductivity reported for MOF-based conductors to *** properties make SXU-120 a promising candidate for efficient AEM materials in next-generation industrial applications.

关键词：

Coexistance of C40 and C54 TiSi_2 during the solid statereaction of Ti/Mo/Si system

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2002年第1期13卷 19-24页

作者： zhangzhi－Bin ZHANGShi－Li 等 LaboratoryofNuclearAnalysesandTechniques ShanghaiInstituteofNuclearResearctheChineseAcademyofSciencesShanghai201800 KungligaTekniskaHoegskolan DepartmentofElectronicsElectrum229

The effect of a 0.9 nm Mo interlayer at the interface of Ti film deposited on a Si substrate on phase formation of TiSi2 during annealing has been studied by using transmission electron micro-diffraction technique. When Ti/Mo/Si was an- nealed at low temperature as 550℃ for 30 mm in Ar ambient, a metastable phase. i.e., hexagonal C40 TiSi2, and the equilibrium phase. i.e., orthorhombic C54 TiSi2, were both detected. The experimental patterns of the C40 and C54 compare well with the simulated ones.

关键词：钛薄膜硅衬底 TiSi2相电子衍射

Metabolic reprogramming: a new option for the treatment of spinal cord injury

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2025年第4期20卷 1042-1057页

作者： Jiangjie Chen Jinyang Chen chao Yu Kaishun Xia Biao Yang Ronghao Wang Yi Li Kesi Shi Yuang Zhang Haibin Xu Xuesong Zhang Jingkai Wang Qixin Chen Chengzhen Liang Department of Orthopedics The Second Affiliated Hospital of Zhejiang University School of MedicineHangzhouZhejiang ProvinceChina Orthopedics Research Institute of Zhejiang University Zhejiang UniversityHangzhouZhejiang ProvinceChina Key Laboratory of Motor System Disease Research and Precision Therapy of Zhejiang Province HangzhouZhejiang ProvinceChina Clinical Research Center of Motor System Disease of Zhejiang Province HangzhouZhejiang ProvinceChina Qiandongnan Prefecture People’s Hospital KailiGuizhou ProvinceChina Department of Orthopedics Fourth Medical CenterChinese PLA General HospitalBeijingChina

Spinal cord injuries impose a notably economic burden on society,mainly because of the severe after-effects they *** the ongoing development of various therapies for spinal cord injuries,their effectiveness remains ***,a deeper understanding of metabolism has opened up a new therapeutic opportunity in the form of metabolic *** this review,we explore the metabolic changes that occur during spinal cord injuries,their consequences,and the therapeutic tools available for metabolic *** spinal cord metabolism is characterized by independent cellular metabolism and intercellular metabolic ***,spinal cord injury results in metabolic disorders that include disturbances in glucose metabolism,lipid metabolism,and mitochondrial *** metabolic disturbances lead to corresponding pathological changes,including the failure of axonal regeneration,the accumulation of scarring,and the activation of *** rescue spinal cord injury at the metabolic level,potential metabolic reprogramming approaches have emerged,including replenishing metabolic substrates,reconstituting metabolic couplings,and targeting mitochondrial therapies to alter cell *** available evidence suggests that metabolic reprogramming holds great promise as a next-generation approach for the treatment of spinal cord *** further advance the metabolic treatment of the spinal cord injury,future efforts should focus on a deeper understanding of neurometabolism,the development of more advanced metabolomics technologies,and the design of highly effective metabolic interventions.

关键词： axons glycolysis metabolic reprogramming metabolism mitochondria neural regeneration neuroprotection oxidative phosphorylation spinal cord injury therapy

High-selectivity electroreduction of low-concentration CO2 with large concentration fluctuation

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2025年

作者： Mengyu Qi Yanbin Ma chao Zhang Bingwei Li Xueqing Yang Zhaolin Shi Simeng Liu Changhua An Jiqing Jiao Tongbu Lu MOE International Joint Laboratory of Materials Microstructure Analysis and Testing CenterInstitute for New Energy Materials and Low Carbon TechnologiesSchool of Materials Science and EngineeringSchool of Chemistry and Chemical EngineeringTianjin University of Technology Key Laboratory of Advanced Energy Materials Chemistry (Ministry of Education) Nankai University

Electrochemical CO2reduction reaction（CO2RR） has been regarded as one of the most promising solutions to achieving “zero carbon emission”. In most of the CO2RR-related studies, high-purity CO2has been employed as the feed gas; however, in practice, CO2is generally emitted in low concentrations, so it is of great significance to realize high-selectivity electroreduction of low-concentration CO2with large concentration fluctuation. In this work, we constructed a dual-active-site catalyst and successfully achieved CO2local enrichment and conversion for low-concentration CO2. Operando experiments reveal that the catalyst has one type of site for activating CO2and one type of site for binding the reaction intermediates. The dual-active-site catalyst displays a selectivity for formic acid consistently above 97% over a broad potential window（from-0.9 to-1.6 V ***）. Even when fed with a low-concentration CO2stream（volume ratio from 50% down to 10%）, the dual-active-site catalyst could display high activity and selectivity（>91%）. In particular, the selectivity is still above 85% when the CO2volume ratio is as low as 5%. This work offers a feasible route for converting low-concentration CO2via a synergistic effect for dual-active-site catalysts.

关键词：

Design Pattern Mining Using Graph Matching

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2004年第4期9卷 444-448页

作者： LIQing-hua zhangzhi-xiang BENKe-rong SchoolofComputerScienceandTechnology HuazhongUniversityofScienceandTechnologyWuhan430074HubeiChina DepartmentofComputerScience NavalUniversityofEngineeringWuhan430033HubeiChina

The identification of design pattern instances is important for program understanding and software maintenance. Aiming at the mining of design patterns in existing systems, this paper proposes a subgraph isomorphism approach to discover several design patterns in a legacy system at a time. The attributed relational graph is used to describe design patterns and legacy systems. The sub-graph isomorphism approach consists of decomposition and composition process. During the decomposition process, graphs corresponding to the design patterns are decomposed into sub-graphs, some of which are graphs corresponding to the elemental design patterns. The composition process tries to get sub-graph isomorphism of the matched graph if sub-graph isomorphism of each subgraph is obtained. Due to the common structures between design patterns, the proposed approach can reduce the matching times of entities and relations. Compared with the existing methods, the proposed algorithm is not linearly dependent on the number of design pattern graphs. Key words design pattern mining - attributed relational graph - subgraph isomorphism CLC number TP 311.5 Foundation item: Supported by the National Natural Science Foundation of China (60273075) and the Science Foundation of Naval University of Engineering (HGDJJ03019)Biography: LI Qing-hua (1940-), male, Professor, research direction: parallel computing.

关键词： design pattern mining attributed relational graph subgraph isomorphism

Freeliving marine nematodes as a pollution indicator of the Bohai Sea

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2002年第4期14卷 558-562页

作者： GUOYu-qing R.M.Warwick zhangzhi-nan MUFang-hong CollegeofLifeSciences OceanUniversityofQingdaoQingdao266003China CCMSPlymouthMarineLaboratory ProspectPlacePlymouthPL13DHUK

A hierarchical diversity index—taxonomic distinctness index Δ +, which was first defined by Warwick and Clark in 1998, was employed to evaluate the pollution status of the Bohai Sea with freeliving marine nematodes. The result showed that the Bohai Bay and other coastal sampling sites might be affected by oil and gas production and other anthropogenic influences. In other words,anthropogenic disturbance was affecting this component of the benthos in these locations. And most offshore sampling sites in the middle of the Bohai Sea were clear and unpolluted.

关键词： taxonomic distinctness index Δ + freeliving marine nematodes the Bohai Sea

Response of Watermelon to Gravel-Mulch and Supplementary Irrigation: Yield, Water Use Efficiency and Root Distribution

在线全文

学校读者我要写书评

暂无评论

Agricultural Sciences in China 2004年第12期3卷 914-922页

作者： zhangzhi-shan LIXin-rong ZHANGPei-dong ZHANGJing-guang WANGXin-ping LIULi-chao ShapotouDesertExperimentalResearchStation ColdandAridRegionsEnvironmentalandEngineeringResearchInstituteTheChineseAcademyofSciencesLanzhou730000P.R.China LanzhouCommercialCollege Lanzhou730020P.R.China

A field experiment was conducted to investigate the effect of supplementary irrigation on watermelon (Citullus lanatus) yield, water-use efficiency (WUE) and root distribution in gravel-mulched field in northwest Loess Plateau, China, during 2001 and 2002 growing seasons. The results showed that gravel mulch significantly improved seedling emergence, increased yield and WUE, and alleviated the influence of drought on plant growth. Regardless of gravel mulch application, supplementary irrigation increased watermelon yields, average fruit weight and number of fruit, especially yield increased as the amount of irrigation increased (P<0.05). Generally, WUE of irrigated treatments were higher than that of non-irrigation treatment in gravel-mulched field. The effect of water supply on root distribution was different in two years. In 2001, average root length density (RLD) and root weight density (RWD) whole the soil profile increased. In 2002, however, RLD and RWD decreased as water supply increased. The average RLD and RWD in 2001 were significantly higher than those in 2002. Maybe we can interpret the phenomenon with the theory that there is a need to optimize root distribution (in terms of water relations) and aboveground biomass for a given water *** yield may not depend as much on root growth as on the amount of water required at critical stages. A significant effect of soil depth on RLD and RWD were observed in both years, but did not rapidly decrease with depth.

关键词： Northwest Loess Plateau C. lanatus Gravel-mulch Supplementary irrigation

Tunable non-Markovian and quantum coherence in the single-qubit dephasing noise channel

在线全文

学校读者我要写书评

暂无评论

Science China(Physics,Mechanics & Astronomy) 2025年

作者： Na-Na Zhang chao-Yi Wu Xu Zhou Qi-Yuan Liu Cheng-Ge Liu Yong-Rui Guo Ren-Pu Li School of Optoelectronic Engineering Chongqing University of Posts and Telecommunications Department of Physics Applied Optics Beijing Area Major Laboratory Beijing Normal University

In this paper, we construct a single-qubit dephasing noise channel based on the nuclear magnetic resonance（NMR） system by employing the bath-engineering technology, and achieve the construction of the tunable non-Markovian environment in the dephasing noise channel. Our findings indicate that for the single-qubit system, the transition of system dynamics from Markovian to non-Markovian can be achieved by adjusting the base frequency of the noise power spectrum. However, the base frequency corresponding to this phase transition point is not fixed, and there is a certain relationship between it and the total evolution time of the single-qubit system. Through our research, we discovered a fundamental relationship: if the single-qubit system dynamics undergoe a transition from Markovian to non-Markovian at ω0within 0-2t ms, shortening the evolution time to 0-t ms results in an increase of the phase transition point to 2ω0. This insight offers crucial guidance for artificially crafting non-Markovian environments across arbitrary time scales in single-qubit systems, and it is not limited by the type of noise. Apart from system dynamics, quantum coherence is also a focal point of our research. We find that when the system dynamics exhibit non-Markovian behavior, the quantum coherence of the single-qubit system experiences revivals. Notably, the timing of these coherence revivals aligns with the instants of the non-Markovianity enhancement. Therefore, our research also serves as a pivotal foundation for the artificial manipulation and realization of quantum coherence revivals within diverse single-qubit systems.

关键词：