检索结果-南通市图书馆

Ni-Ag双原子团簇催化甲烷干法重整反应的理论研究

在线全文

学校读者我要写书评

暂无评论

原子与分子物理学报 2025年第3期42卷 13-20页

作者：刘佳慕红梅张明明李文雅李东东张建辉兰州资源环境职业技术大学黄河流域生态环境产教融合研究院兰州730021 贵州民族大学化学工程学院贵阳550025

甲烷干重整制合成气是将温室气体转换为合成气的有效途径,兼具环境效益和经济效益.本文采用密度泛函理论方法对Ni-Ag双原子团簇催化甲烷干重整反应的体系进行理论研究,对势能面上各驻点进行了全几何参数优化,通过频率分析确认了过渡态,... 详细信息

甲烷干重整制合成气是将温室气体转换为合成气的有效途径,兼具环境效益和经济效益.本文采用密度泛函理论方法对Ni-Ag双原子团簇催化甲烷干重整反应的体系进行理论研究,对势能面上各驻点进行了全几何参数优化,通过频率分析确认了过渡态,并通过内禀反应坐标方法进行了验证,得出各基元反应的能量最低路径.研究结果对于理解在Ni上引入第二种金属Ag形成双原子团簇催化甲烷干法重整的理论研究有一定的意义,并为下一步实验研究提供理论基础.

关键词：甲烷干重整 Ni-Ag双原子团簇密度泛函理论活化能

维普期刊数据库博看期刊

Analysis of blade vibration response induced by rotating stall in axial compressor

在线全文

学校读者我要写书评

暂无评论

航空动力学报 2012年第10期27卷 2269-2277页

作者： zhang, ming-ming Hou, An-Ping Li, Jian-Xiong Yao, Juan Chen, Ying-Xiu School of Jet Propulsion Beijing University of Aeronautics and Astronautics Beijing 100191 China

An experimental and numerical study was conducted to investigate the forced response of blade vibration induced by rotating stall in a low speed axial *** have been made of the transient stalling process in a low speed axial compressor *** CFD study was performed using solution of 3-dimensional Navier-Stokes equations,coupled with structure finite element models for the blades to identify modal shapes and structural deformations *** between fluid and structure were managed in a coupled manner,based on the interface information exchange until convergence in each time *** on the rotating stall measurement data obtained from a low speed axial compressor,the blade aeroelastic response induced by the rotating stall flow field was analyzed to study the vibration characteristics and the correlation between the *** this approach,good agreement between the numerical results and the experimental data was *** flow phenomena were well captured,and the results indicate that the rotating field stall plays a significant role in the blade vibration and stress affected by the flow excitation.

关键词： compressor rotating stall blade forced response CFD fluid-structure interaction

Dynamic Properties of Two-Dimensional Polydisperse Granular Gases

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2007年第2X期48卷 343-347页

作者： LI Rui zhang Duan-ming HUANG ming-Tao SU Xiang-Ying CHEN Zhi-Yuan ZHU Hong-Ying zhang Lin Department of Physics Huazhong University of Science and Technology Wuhan 430074 China

We propose a two-dimensional model of polydisperse granular mixtures with a power-law size distribution in the presence of stochastic driving. A fractal dimension D is introduced as a measurement of the inhomogeneity of the size distribution of particles. We define the global and partial granular temperatures of the multi-component mixture. By direct simulation Monte Carlo, we investigate how the inhomogeneity of the size distribution influences the dynamic properties of the mixture, focusing on the granular temperature, dissipated energy, velocity distribution, spatial clusterization, and collision time. We get the following results： a single granular temperature does not characterize a multi-component mixture and each species attains its own ＂granular temperature＂; The velocity deviation from Gaussian distribution becomes more and more pronounced and the partial density of the assembly is more inhomogeneous with the increasing value of the fractal dimension D; The global granular temperature decreases and average dissipated energy per particle increases as the value olD augments.

关键词： fractal fractal dimension polydisperse mixture

Effect and Safety of Penetrating Moxibustion in Treatment of Migraine without Aura:A Randomized Controlled Trial

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Integrative Medicine 2021年第12期27卷 927-932页

作者： GAO Ling XIE Jin LI Xiao GUO Ya-jing zhang ming-ming MENG Ling-yan LIN Qian-ting GAO Xi-yan College of Acupuncture and Tuina Henan University of Chinese MedicineZhengzhou(450008)China Acupuncture Clinic of the Third Affiliated Hospital of Henan University of Chinese Medicine Zhengzhou(450008)China College of Acupuncture and Tuina Shanghai University of Traditional Chinese MedicineShanghai(201203)China

Objective To observe the clinical effect of penetrating moxibustion on migraine without aura(MO)*** Totally 60 MO patients from the Acupuncture Clinic of the Third Affiliated Hospital of Henan University of Chinese Medicine were collected from November 2015 to February *** patients were assigned to a treatment group and a control group using a random number table,30 cases in each *** treatment group was treated with penetrating moxibustion,and the control group was treated with mild moxibustion,thrice a week for 4 consecutive *** total effective rate,Visual Analogue Scale(VAS)scores,headache intensity,and Migraine Specific Quality of Life Questionnaire(MSQ)scores of patients after treatment were compared between the two *** moxibustion sensation and reaction after moxibustion were observed,and the adverse reactions were *** patients were followed up at 4 and 16 weeks after *** The total effective rate of the treatment group was significantly higher than that of the control group(93.33%vs.80.00%,P0.05).Conclusions Penetrating moxibustion can significantly relieve pain and improve quality of life of MO *** penetrating moxibustion,flushing and sweating of patients were obvious,and the curative effect was superior to the mild moxibustion.

关键词： penetrating moxibustion randomized controlled trial migraine without aura Chinese medicine

Activation of Growth-associated Protein by Intragastric Brazilein in Motor Neuron of Spinal Cord Connected with Injured Sciatic Nerve in Mice

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2011年第2期27卷 254-257页

作者： CAO Jian LI Li-sen LIU Biao LIU Hao-yu zhang Hui ZHAO ming-ming YIN Wei-tian China-Japan Union Hospital of Jilin University Changchun 130033 P. R. China

The purpose of this study is to explore the expression of growth-associated protein（GAP-43） in spinal cord segments connected with injured sciatic nerve by the treatment with brazilein in mice. Unilateral sciatic nerve interruption and anastomosis were performed. Physiological saline（blank group）, high dose, middle dose and low dose of brazilein were administrated intragastrically to healthy adult BALB/c mice in separate groups. L4―6 spinal segments connected with the sciatic nerve were harvested. Real-time PCR（Polymerase chain reaction） and Western blot analysis were performed to detect the expression of GAP-43 in spinal segments. Histological staining on myelin and the electrophysiology were performed to examine the sciatic nerve recovery. GAP-43 was activated in spinal cord L4―6 connected with injured sciatic nerve. In the survival time of 12 h, 24 h, 3 d, 5 d, 7 d and 14 d, GAP-43 expression in the motor neurons of spinal cord of the high dose group and that in the middle dose group were significantly higher than those on the low dose and blank groups. Myelin in the high dose group and that in the middle dose group were more mature and the potential amplitude and MNCV（motor nerve conduction velocity） in the high and middle dose groups were obviously higher than those in the low dose group and blank group. Brazilein facilitates the expression of GAP-43 in neurons in spinal cord L4―6 segments connected with injured sciatic nerve, which promotes nerve regeneration.

关键词： Brazilein Growth-associated protein(GAP-43) Injury of sciatic nerve Regeneration

Yield and water use responses of winter wheat to irrigation and nitrogen application in the North China Plain

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2018年第5期17卷 1194-1206页

作者： zhang ming-ming DONG Bao-di QIAO Yun-zhou SHI Chang-hai YANG Hong WANG Ya-kai LIU Meng-yu Key Laboratory of Agricultural Water Resources Hebei Laboratory of Agricultural Water-Saving Center for Agricultural Resources Research Institute of Genetics and Developmental Biology Chinese Academy of Sciences Shijiazhuang 050021 P.R. China University of Chinese Academy of Sciences Beijing 100049 P.R. China Qingdao Agricultural University Qingdao 266109 P.R.China

With increasing water shortage resources and extravagant nitrogen application, there is an urgent need to optimize irrigation regimes and nitrogen management for winter wheat（Triticum aestivum L.） in the North China Plain（NCP）. A 4-year field experiment was conducted to evaluate the effect of three irrigation levels（W1, irrigation once at jointing stage; W2, irrigation once at jointing and once at heading stage; W3, irrigation once at jointing, once at heading, and once at filling stage; 60 mm each irrigation） and four N fertilizer rates（N0, 0; N1, 100 kg N ha-（-1）; N2, 200 kg N ha-（-1）; N3, 300 kg N ha-（-1）） on wheat yield, water use efficiency, fertilizer agronomic efficiency, and economic benefits. The results showed that wheat yield under W2 condition was similar to that under W3, and greater than that under W1 at the same nitrogen level. Yield with the N1 treatment was higher than that with the N0 treatment, but not significantly different from that obtained with the N2 and N3 treatments. The W2 N1 treatment resulted in the highest water use and fertilizer agronomic efficiencies. Compared with local traditional practice（W3 N3）, the net income and output-input ratio of W2 N1 were greater by 12.3 and 19.5%, respectively. These findings suggest that two irrigation events of 60 mm each coupled with application of 100 kg N ha-（–1） is sufficient to provide a high wheat yield during drought growing seasons in the NCP.

关键词： winter wheat irrigation regime nitrogen application grain yield water use efficiency

Study on Solidification Microstructure of Slab by Numerical Simulation

在线全文

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2011年第S2期18卷 371-376页

作者： LIU Zhi-ming, zhang Jiong-ming, LUO Yan-zhao, WU Lian (School of Metallurgical and Ecological Engineering, University of Science and Technology Beijing, Beijing 100083, China) Univ Sci & Technol Beijing Sch Met & Ecol Engn Beijing 100083 Peoples R China

The solidification structure was simulated by the commercial software CALCOSOFT under the real cooling condition during the continuous casting processes in this paper. The cellular automation-finite element model (CA-FE) was applied to simulate the microstructure of the slab, and the results were compared with the actual macrostructure. The results of microstructure simulated were in good agreement with that detected in the slabs. In addition, the solidification structure under different secondary cooling intensity was simulated. The results show that when specific water flows increase, the average grain surface area reduces, and columnar grains have the tendency to be longer.

关键词： numerical simulation continuous casting solidification structure

Preparation and Structural Characterization of Polystyrene-Rectorite Nanocomposites

在线全文

学校读者我要写书评

暂无评论

Wuhan University Journal of Natural Sciences 2003年第03A期8卷 817-820页

作者： Fang Peng\|fei, Liu Li\|ming, zhang ming, zhang Shao\|ping, Wang Bo, Wang Shao\|jie School of Physics and Technology, Wuhan University, Wuhan 430072, Hubei,China Wuhan University

The polystyrene/rectorite nanocomposites were prepared by free radical polymerization of styrene containing dispersed organophilic rectorite. The structures and thermal properties of these hybrids have been investigated by X\|ray diffraction (XRD), fourier transform infrared (FT\|IR), positron annihilation spectroscopy (PAS) and thermal gravimetric analysis (TGA) techniques. It was found that exfoliation of rectorite in polystyrene (PS) matrix was achieved. The average free\|volume radius in the PS/clay nanocomposites is generally same as that in PS. Along with increment of rectorite contents, the interface between rectorite and polystyrene matrix increases, and the free\|volume concentration decreases obviously. And the polystyrene nanocomposites have higher thermal decomposition temperature than pure PS.

关键词： polystyrene rectorite nanocomposites positron annihilation spectroscopy

在线全文

学校读者我要写书评

暂无评论

大型海上风电叶片载荷智能控制研究

工程热物理学报 2017年第7期38卷 1363-1375页

作者：张明明中国科学院工程热物理研究所北京100190

近年来海上风电机组大型化已成为风电行业主要发展趋势之一。与此相应,柔性大变形风电叶片气弹效应将更加增强,致使叶片乃至整机载荷更大,严重危及机组的安全、可靠运行。为此,本文根据国际叶片载荷控制新概念—"智能叶片",系统地总结... 详细信息

近年来海上风电机组大型化已成为风电行业主要发展趋势之一。与此相应,柔性大变形风电叶片气弹效应将更加增强,致使叶片乃至整机载荷更大,严重危及机组的安全、可靠运行。为此,本文根据国际叶片载荷控制新概念—"智能叶片",系统地总结了团队过去相关气动-伺服-弹性模型构建、系统在通常和极限风况下可靠性与参数影响等工作和取得的进展,并在此基础上,在国际上首次揭示了气弹耦合控制机理。这些成果的取得为未来大型海上风电机组叶片和机组优化设计提供了有价值的理论依据。

关键词：大型海上风电叶片智能叶片柔性尾缘襟翼气弹控制