检索结果-南通市图书馆

Research on reliability index of a large communication network with domain partition and interconnection

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

Journal of Systems Engineering and Electronics 2009年第3期20卷 666-674页

作者： dai Fusheng Harbin Inst. of Technology (Weihai Campus) Weihai 264209 P. R. China

In order to indicate the performances of a large-scale communication network with domain partition and interconnection today, a kind of reliability index weighed by normalized capacity is defined. Based on the route rules of network with domain partition and interconnection, the interconnection indexes among the nodes within the domain and among the domains are given from several aspects. It is expatiated on that the index can thoroughly represent the effect on the reliability index of the objective factor and the subjective measures of the designer, which obeys the route rules of a network with domain partition and interconnection. It is discussed that the defined index is rational and compatible with the traditional index.

关键词： communication network reliability interconnection network with domain partition transmission capacity

Behavior of Fe Powder During High-Energy Ball Milling Cooperated with Dielectric Barrier Discharge Plasma

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica Sinica(English Letters) 2013年第1期26卷 63-68页

作者： Leyang dai Marine Engineering Institute Jimei University

In this study, nanostructured Fe powders were synthesized following 10 hours of high-energy ball milling with a superimposed dielectric barrier discharge plasma （DBDP）. The mean size of the milled powder was approximately 100 nm with an average grain size of 16.2 nm. The influence of DBDP on the underlying grain refinement mechanisms during ball milling was investigated by scanning electron microscopy （SEM）, transmission electron microscopy （TEM）, X-ray diffraction （XRD） and BET methods. Our results show that the Fe particles displayed an extraordinary plasticity during the early milling stages under the action of DBDP, and that the plastic deformation experienced by the Fe particles during this stage was more severe than that present in normal milling. A high concentration of spherical Fe particles, approximately 50-100 nm in diameter, was documented via TEM. We propose that these spherical particles were generated via high temperature disintegration as a result of DBDP electron bombardment during ball milling. Our results suggest that it may be possible to significantly refine metallic powders during milling via the superimposition of DBDP.

关键词： Dielectric barrier discharge plasma (DBDP) High-energy ball milling Nano-Fepowder Plastic deformation Elevated temperature disintegration

Can patients with mild non-neoplastic lesions diagnosed at baseline screening be safely exempt from surveillance: evidence from multicenter community-based cohorts

在线全文

学校读者我要写书评

暂无评论

Science China Life Sciences 2025年第1期 263-271页

作者： Siyi He Zhiyi Zhang Guohui Song Zhenhai Wang Chunyun dai Shipeng Yan Kun Jiang Bingbing Song He Li Maomao Cao Dianqin Sun Fan Yang Xinxin Yan Shaoli Zhang Yi Teng Qianru Li Changfa Xia Wanqing Chen Office of Cancer Screening National Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical College Department of Gastroenterology Gansu Wuwei Tumor Hospital Cixian Cancer Institute Linzhou Cancer Hospital Center for Disease Control and Prevention of Sheyang County Department of Cancer Prevention and Control Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of MedicineCentral South University Luoshan Center for Disease Control and Prevention Office for Cancer Control and Research Affiliated Cancer Hospital of Harbin Medical University

Surveillance recommendations for gastric cancer（GC） in current guidelines focused on advanced precancerous lesions and were based on precise diagnosis of severity/extent of baseline lesions. We aimed to develop a less endoscopy-related equipment-dependent risk-stratification tool, and assessed whether mild-precursor-lesion patients can be safely exempt from surveillance. In the multicenter communitybased cohort, 75,051 participants receiving baseline endoscopy were enrolled during 2015–2017 and followed-up until 2021. Cumulative incidence rates（CIRs） of GC for precancerous-conditions were calculated by Kaplan-Meier method and compared by Log-rank tests. Mixedeffects Cox regression models were used to detect potential factors for progression towards GC. A risk score was calculated as counts of selected factors. An independent cohort, including 26,586 participants was used for external validation. During a median follow-up of 6.25 years, CIRs of GC were 0.302%, 0.436%, and 4.756% for normal group, non-neoplastic（atrophic gastritis/intestinal metaplasia） and neoplastic lesions（low-grade/high-grade dysplasia）, respectively(Ptrend<0.001). Four predictors, including male, ≥60 years, smoking, and limited vegetable consumption, were selected for risk-stratification. High-risk patients（≥3 risk factors） with non-neoplastic lesions showed higher GC risks（adjusted HR=7.73, 95%CI: 4.29–13.92）, and their four-year CIR reached the one-year CIR of neoplastic lesions. Further categorizing non-neoplastic lesions by histological grade, both patients with moderate-to-severe lesions（aHR=3.07, 95%CI: 1.67–5.64） and high-risk patients with mild lesions（aHR=7.29, 95%CI: 3.58–14.86） showed higher risks. Consistent trends were observed in validation cohort. High-risk mild-precursor-lesion patients should receive surveillance within 3–5 years after baseline screening. Our study provides evidence on supplementing current guideline recommendations.

关键词：

同方期刊数据库

Synthesis of 2,5-diformylfuran from renewable carbohydrates and its applications: A review

在线全文

学校读者我要写书评

暂无评论

Green Energy & Environment 2021年第1期6卷 22-32页

作者： Jinhang dai College of Environment and Resources Chongqing Technology and Business UniversityChongqing400067China

The synthesis of fine chemicals and fuel candidates from renewable biomass-based feedstocks has attracted much attention due to declining fossil *** value-added furan derivatives,such as 5-hydroxymethylfurfural(HMF),2,5-diformyfuran(DFF)and 2,5-furandicarboxylic acid,have been successfully produced from *** these,DFF,the aerobic oxidation product of HMF,is a key chemical and can be used in organic synthesis and functional polymer *** this review,different catalytic systems for the synthesis of DFF from monosaccharide,disaccharide and polysaccharide were summarized,while reaction pathways and catalyst stability were also ***,the applications of DFF were introduced in ***,prospects of more effective methods to DFF production and application were discussed.

关键词： 2,5-Diformyfuran Oxidation HMF Carbohydrate Biomass

Fe_(3)C@C/C for catalytic ozonation of silicon-containing wastewater:Dual improvement of silicon resistance and catalytic effect

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2023年第5期136卷 65-77页

作者： shengzhe Wang Lei Ma Rui Wang Chengyu Jin Ying Zhao Xuefei Tan Yanan Zhang Mengyang Liu Chenxing Yao Huangzhao Wei Chenglin Sun Dalian Institute of Chemical Physics Chinese Academy of SciencesDalian 116023China University of Chinese Academy of Sciences Beijing 100049China Beijing Key Laboratory of Fuels Cleaning and Advanced Catalytic Emission Reduction Technology/College of Chemical Engineering Beijing Institute of Petrochemical TechnologyBeijing 102617China College of Materials and Chemical Engineering Heilongjiang Institute of TechnologyHarbin 150050China School of Light Industry and Chemical Engineering Dalian Polytechnic UniversityDalian 116034China

The improvement of catalysts’stability under harsh reaction conditions is vital for their practical ***,iron carbide(Fe_(3)C)nanoparticles were encapsulated in graphitic carbon in situ and a carbon ball served as the *** synthesized Fe_(3)C@C/C was first utilized to treat an m-cresol wastewater containing Si via catalytic *** with the commercial Fe/Al_(2)O_(3)catalyst,the resistance to Si of the Fe_(3)C@C/C was improved 22.68 times,while the TOC removal rate increased by a factor of 2.9,and it remained stable during 10 cycles and 12000 min of continuous reaction,which further demon-strated its potential for diverse *** catalyst exhibits improved resistance to Si because of the dual protection from the carbon-encapsulated structure and carbon *** functional theory calculations show that the encapsulation of Fe_(3)C using carbon significantly increases the resistance to adsorption of Si on its active *** addition,the activation of O_(3)is unimpeded on the Fe_(3)C adsorption sites by the protection from C,thus the generation of reactive oxygen species(ROS)by ozone is largely *** mechanism associated with the resistance of the Fe_(3)C@C/C catalyst to Si and its elevated activity are also elucidated.

关键词： Catalytic ozonation Silicon-resistant catalyst Carbon-encapsulated Fe_(3)C@C/C Density functional theory

Rabi oscillations in a stretching molecule

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

Light(Science & Applications) 2023年第2期12卷 239-247页

作者： shengzhe Pan Chenxi Hu Wenbin Zhang Zhaohan Zhang Lianrong Zhou Chenxu Lu Peifen Lu Hongcheng Ni Jian Wu Feng He State Key Laboratory of Precision Spectroscopy East China Normal UniversityShanghai 200241China Key Laboratory for Laser Plasmas(Ministry of Education)and School of Physics and Astronomy Collaborative Innovation Center of IFSA(CICIFSA)Shanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuanShanxi 030006China Chongqing Key Laboratory of Precision Optics Chongqing Institute of East China Normal UniversityChongqing 401121China SCAS Center for Excellence in Ultra-intense Laser Science Shanghai 201800China

Rabi oscillation is an elementary laser-driven physical process in atoms and artificial atoms from solid-state systems,while it is rarely demonstrated in ***,we investigate the bond-length-dependent Rabi oscillations with varying Rabi frequencies in strong-laser-field dissociation of H2+.The coupling of the bond stretching and Rabi oscillations makes the nuclei gain different kinetic energies while the electron is alternatively absorbing and emitting *** resulting proton kinetic energy spectra show rich structures beyond the prediction of the Floquet theorem and the well-accepted resonant one-photon dissociation *** study shows that the laser-driven Rabi oscillations accompanied by nuclear motions are essential to understanding the bond-breaking mechanism and provide a time-resolved perspective to manipulate rich dynamics of the strong-laser-field dissociation of molecules.

关键词： stretching dissociation resonant

Beam dynamics design of an SP-FEL compact THz source

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

Nuclear Science and Techniques 2010年第5期21卷 266-270页

作者： dai Dongdong dai Zhimin Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 China Graduate School Chinese Academy of Sciences Beijing 100049 China

In recent years,people are looking for a new compact THz source with high emission power,one potential choice is to build small accelerator with Smith-Purcell *** main difficulty is how to obtain high quality electron *** this paper,the beam dynamics design of a compact THz source is *** electron beam is produced by an electron gun and compressed by permanent *** electron gun is similar to the Shanghai EBIT,but permanent magnets are used,instead of the superconducting magnets in Shanghai *** this design,we can reduce the size and cost of the whole ***/Pandira was employed to simulate and optimize the magnetic *** was used to simulate the beam trajectories from the electron gun to the *** 2 centimeters around the center of longitudinal magnetic field,the calculation showed that the beam satisfies to our design aim.

关键词：动力学设计太赫兹紧凑型 FEL SP 束流永久磁铁 EBIT

Ethanol steam reforming over Ni/ZSM-5 nanosheet for hydrogen production

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2024年第3期67卷 247-256页

作者： Porapak Suriya Shanshan Xu shengzhe Ding Sarayute Chansai Yilai Jiao Joseph Hurd Daniel Lee Yuxin Zhang Christopher Hardacre Prasert Reubroycharoen Xiaolei Fan Department of Chemical Engineering School of EngineeringThe University of ManchesterManchester M139PLUnited Kingdom Program of Petrochemistry and Polymer Science Faculty of ScienceChulalongkorn UniversityBangkok10330Thailand Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China Liaoning Academy of Materials Shenyang 110167China Center of Excellence in Catalysis for Bioenergy and Renewable Chemicals(CBRC) andDepartment of Chemical TechnologyFaculty of ScienceChulalongkorn UniversityBangkok 10330Thailand Nottingham Ningbo China Beacons of Excellence Research and Innovation Institute University of Nottingham Ningbo ChinaNingbo315100China

Compared to reforming reactions using hydrocarbons,ethanol steam reforming(ESR)is a sustainable alternative for hydrogen(H_(2))production since ethanol can be produced sustainably using *** work explores the catalyst design strategies for preparing the Ni supported on ZSM-5 zeolite catalysts to promote ***,two-dimensional ZSM-5 nanosheet and conventional ZSM-5 crystal were used as the catalyst carriers and two synthesis strategies,i.e.,in situ encapsulation and wet impregnation method,were employed to prepare the *** on the comparative characterization of the catalysts and comparative catalytic assessments,it was found that the combination of the in situ encapsulation synthesis and the ZSM-5 nanosheet carrier was the effective strategy to develop catalysts for promoting H_(2) production via ESR due to the improved mass transfer(through the 2-D structure of ZSM-5 nanosheet)and formation of confined small Ni nanoparticles(resulted via the in situ encapsulation synthesis).In addition,the resulting ZSM-5 nanosheet supported Ni catalyst also showed high Ni dispersion and high accessibility to Ni sites by the reactants,being able to improve the activity and stability of catalysts and suppress metal sintering and coking during ESR at high reaction ***,the Ni supported on ZSM-5 nanosheet catalyst prepared by encapsulation showed the stable performance with~88% ethanol conversion and~65% H_(2) yield achieved during a 48-h longevity test at 550-C.

关键词： ZSM-5 nanosheet In situ encapsulation Ni catalyst Ethanol steam reforming Hydrogen production

槟榔干燥动力学模型及微观结构、代谢物变化规律研究

在线全文

学校读者我要写书评

暂无评论

热带作物学报 2025年第1期46卷 222-235页

作者：张晶代佳慧王世萍代文婷康效宁吉建邦胡玉娟海南省农业科学院三亚研究院海南三亚572000 海南省农业科学院农产品加工设计研究所海南海口570100 海口市槟榔加工研究重点实验室海南海口570100

干燥是槟榔加工的第1步,干燥过程直接影响槟榔的品质和货架期。为了明确槟榔热风干燥过程的水分变化、纤维微观结构及代谢物的变化规律,以期对槟榔干燥时间进行精准调控。本研究以槟榔鲜果和槟榔杀青果为研究对象,利用5种模型对不同温... 详细信息

干燥是槟榔加工的第1步,干燥过程直接影响槟榔的品质和货架期。为了明确槟榔热风干燥过程的水分变化、纤维微观结构及代谢物的变化规律,以期对槟榔干燥时间进行精准调控。本研究以槟榔鲜果和槟榔杀青果为研究对象,利用5种模型对不同温度下槟榔热风干燥曲线进行拟合,建立槟榔干燥动力学模型,同时利用扫描电子显微镜、LC-MS等探讨干燥过程中槟榔微观结构、代谢物的变化规律。结果表明:槟榔干燥曲线呈指数下降,干燥速率曲线分为加速和降速2个阶段,温度对干燥速率有显著影响;Page模型对槟榔热风干燥曲线拟合较好,模型决定系数(R^(2))在0.98以上,均方差(mean square deviation,RMSE)在0.02~0.06范围内,模型预测值和真实值差异不显著,可以较好地反映槟榔干燥过程中的水分变化规律。微观结构分析表明,随着干燥时间的增加槟榔纤维层变得致密、紧实,杀青处理导致槟榔纤维结构松散。质构结果表明,随着干燥时间的增加,槟榔硬度和咀嚼度增加,弹性降低。差异代谢物结果显示,干燥过程通过影响氨基酸代谢通路、中心碳代谢通路、亚油酸代谢通路、黄酮类生物合成、苯丙烷类生物合成进而影响有机酸、脂质和类脂分子等发生变化。研究结果为丰富槟榔加工基础研究,以及为槟榔热风干燥时间的选择提供理论依据。

关键词：槟榔干燥动力学模型微观结构代谢物质构