检索结果-南通市图书馆

China Foundry 2025年

作者： wen-tong Liu Yi-dong Wu Lei Gao Jing-yang Chen Cheng-bo Xiao Xi-dong Hui State Key Laboratory for Advanced Metals and Materials University of Science and Technology Beijing Science and Technology on Advanced High Temperature Structural Materials Laboratory Beijing Institute of Aeronautical Materials

The size and shape effect(SSE) of components has become a critical issue for mechanical properties, application reliability, and processing. In this study, the creep rupture life(CRL) of components with different wall thicknesses and positions in a combustion chamber casing simulator made of K439B superalloy was investigated. The intrinsic mechanisms of the SSE were explored from the dendrite structure, volume fraction and size of the γ' phase, and element segregation, etc. It is shown that this casting exhibits a strong SSE of creep rupture life, characterized by a significant difference in the CRL values up to 60% with the variation of wall thickness and position in the casing. In terms of casting technology, the influence of SSE on CRL is actually determined by the cooling rate. The SSE on the creep rupture life originates from the dendrite structure(such as the secondary dendrite arm spacing), volume fraction size of the γ' phase in the dendrite trunk, and elements segregation rate. This work may have implications for the design and application of engineering components with large sizes and complex structures.

关键词：

Aggregation of the Adsorbed Proteinsin Solution or on the Surface?

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2002年第3期13卷 262-265页

作者： tong wen XU 不详

The adsorption of bovine serum albumin (BSA) on porous polyethylene (PE) membrane was studied based on adsorption and desorption measurements as well as FTIR analysis. A different mechanism was proposed which showed that a critical concentration existed in the adsorptional process. Below this concentration, the adsorption seems to be conducted in a normal side-on way; above this concentration, the adsorption is in an aggregation way.

关键词： Bovine serum albumin adsorption desorption FTIR.

HYDRODYNAMIC STUDY ON A PECTORAL FIN ROWING MODEL OF A FISH

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2009年第4期21卷 463-472页

作者： HU wen-tong Department of Engineering Mechanics Shanghai Jiao Tong University Shanghai 200240 China

Fish pectoral fin movement involves primarily a drag-based and a lift-based mechanisms to produce thrust. A numerical study on a pectoral fin rowing propulsion model based on the drag-based mechanism is presented in this article. The propulsive mechanism of the pectoral fin rowing model is related with the voriticity and pressure in the flow field. The relationship between the thrust and kinematic parameters and the wake-captured problem are analyzed. It is shown that a high thrust is produced in the power stroke, mainly due to the backward translation acceleration, the anticlockwise angular acceleration and the absence of stall in the uniform translation. Moreover, the flow control mechanism and the effect of dynamic flexible deformation are further analyzed. To properly choose controllable factors and adopt an appropriate dynamic deformation can improve the propulsive performance.

关键词： pectoral fin drag-based propulsion propulsion mechanism computational fluid dynamics

Structure and Photophysical Properties of an Upconversion Holmium-mercury Compound with a 2-D Layer-like Motif

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Structural Chemistry 2021年第1期40卷 70-78,3页

作者： CHEN wen-tong Institute of Applied Chemistry School of Chemistry and Chemical EngineeringJi’an Key Laboratory of Photoelectric Crystal Materials and DeviceHumic Acid Utilization Engineering Research Center of Jiangxi ProvinceJiangxi Province Key Laboratory of Coordination ChemistryJinggangshan UniversityJi’an 343009China Department of Ecological and Resources Engineering Fujian Key Laboratory of Eco-industrial Green TechnologyWuyi UniversityWuyishan 354300China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China

Using a hydrothermal reaction,a novel holmium-mercury compound{[Ho(IA)(HIA)_(2)(H2 O)_(2)]_(2-)(Hg_(3)Br_(8))}n(nHgBr_(2))·2 nNO_(3)(1,HIA is isonicotinc acid)was synthesized and its crystal structure was characterized by single-crystal X-ray *** 1 crystallizes in monoclinic system,space group P2/c with a=13.0647(6),b=9.4659(3),c=26.0832(14)Å,β=97.522(4)°,V=3197.9(2)Å^(3),C_(36)H_(36)Br_(10)Hg_(4)Ho_(2)N_(8)O_(22),M_(r)=2863.95,Z=2,D_(c)=2.974 g/cm^(3),μ(Mo Kα)=18.331 mm^(–1) and F(000)=*** displays a two-dimensional(2 D)layer-like structure.A solid-state photoluminescence experiment revealed that it shows upconversion green *** emission peaks should come from the ^(5)I_(8)→^(5)G_(6) and ^(5)S_(2)→^(5)I_(8) characteristic emission of the 4 f electrons of the Ho3+*** 1 has a CIE chromaticity coordinate(0.1774,0.526).A solid-state UV-visible diffuse reflectance spectrum unveiled that this compound has a wide optical band gap of 3.26 eV.

关键词： CIE holmium lanthanide photoluminescence upconversion

Water Dissociation Phenomena on a Bipolar Membrane──Current-voltage Curve in Relation with IonicTransport and Limiting Current Density

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2001年第4期17卷 457-464页

作者： XU tong-wen YANG Wei-hua Department of Applied Chemistry University of Science and Technology of ChinaHefei 230026P.R.China

The water dissociation mechanism on a bipolar membrane under the electrical field was investigated and characterized in terms of ionic transport and limiting current density. It is considered that the depletion layer exists at the junction of a bipolar membrane, which is coincided with the viewpoint of the most literatures, but we also consider that the thickness and conductivity of this layer is not only related with the increase of the applied voltage but also with the limiting current density. Below the limiting current density, the thickness of the depletion layer keeps a constant and the conductivity decreases with the increase of the applied voltage; while above the limiting current density, the depletion thickness will increase with the increase of the applied voltage and the conductivity keeps a very low constant. Based on the data reported in the literatures and independent determinations, the limiting current density was calculated and the experimental curves Ⅰ-Ⅴ in the two directions were com

关键词： Bipolar membrane Water dissociation Ionic transport Limiting current density

New families of p-ary sequences with low correlation and large linear span

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2007年第4期14卷 53-56,92页

作者： tong Xin wen Qiao-yan State key Laboratory of Networking and Switching Technology BeijingUniversity of Posts and Telecommunications Beijing 100876 China

This article presents a new family of p-ary sequences. The proposed sequences are proved to have not only low correlation property, but also large linear span and large family size. Furthermore, it shows that the new ... 详细信息

关键词： p-ary sequences correlation function family size,linear span quadratic form

Synthesis of Cubic Mesoporous Silica MCM-48by Mixed Micellar Templates

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2000年第12期11卷 1107-1110页

作者： tong wen WANG Le Rong DAI Institute of Physical Chemistry Peking UniversityBeijing 100871 Department of Chemistry Yunnan Normal UniversityKunming 650092

High-quality mesoporous silica MCM-48 were synthesized under basic conditions by using the mixture of cetyltrimethylammonium bromide (CTAB) and alkylamine (CnNH2n+3 n=8,10,12,14, respectively) as templates. The effects of the alkylamines with different chain lengths (n=8,10,12,14,16,18, respectively) on the silica structure were investigated.

关键词： Cubic mesoporous silica Mixed micellar template Synthesis

Effects of ultrasonic vibration on plastic deformation of AZ31 during the tensile process

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2011年第1期18卷 70-76页

作者： tong wen Li Wei Xia Chen Chun-lei Pei College of Material Science and Engineering Chongqing University Chongqing 400044 China

An investigation on the plastic behavior of AZ31 magnesium alloy under ultrasonic vibration（with a frequency of 15 kHz and a maximum output of 2 kW） during the process of tension at room temperature was conducted to reveal the volume effect of the vibrated plastic deformation of *** characteristics of mechanical properties and microstructures of AZ31 under routine and vibrated tensile processes with different amplitudes were *** is found that ultrasonic vibration has a remarkable influence on the plastic behavior of AZ31 which can be summarized into two opposite aspects：the softening effect which reduces the flow resistance and improves the plasticity,and the hardening effect which decreases the *** a lower amplitude or vibration energy is applied to the tensile sample,the softening effect dominates,leading to a decrease of AZ31 deformation resistance with an increase of *** the application of a high-vibrating amplitude,the hardening effect dominates,resulting in the decline of plasticity and brittle fracture of the samples.

关键词： ultrasonic effects tensile testing magnesium alloys plastic deformation

Partition Equilibrium on the Interface Between a Charged Membrane and a Mixed Electrolyte Aqueous Solution

在线全文

学校读者我要写书评

暂无评论

Chemical Research in Chinese Universities 2003年第1期19卷 63-69页

作者： XU tong wen YANG Wei hua Department of Chemistry University of Science and Technology of ChinaHefei 230026P.R.China

Ionic partition equilibrium on a charged membrane immersed in a mixed electrolyte solution was systematically investigated and several models were established for the determination of partition coefficients. On the basis of theoretical models, the effects of the concentration ratio λ of the fixed group(charged density) to reference electrolyte, the concentration ratio η between the two electrolytes existing in the solution and the valence of the electrolyte ions on the partition equilibrium in a positively charged membrane were analyzed and simulated within the chosen parameters in detail. The obtainable results can also be applicable to a sytem of mixed electrolytes contacting with a negatively charged membrane. The theoretical calculations were confirmed with the experimental data of model mixed electrolytes, NaCl+HCl and CaCl 2+NaCl partitioned in the system of self made negatively charged membrane sulphonated poly(phenylene oxide)(SPPO) with different charge densities.

关键词： Partition coefficient Donnan equilibrium Mixed electrolyte Charged membrane

Chord length sampling correction analysis for dispersion fuel in Monte Carlo simulation

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2024年第4期35卷 57-64页

作者： Zhao-Yu Liang Ding She Yu-tong wen Lei Shi Institute of Nuclear and New Energy Technology(INET) Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of EducationTsinghua UniversityBeijing 100084China

Dispersion fuels,knowned for their excellent safety performance,are widely used in advanced reactors,such as hightemperature gas-cooled *** with deterministic methods,the Monte Carlo method has more advantages in the geometric modeling of stochastic *** explicit modeling method has high computational accuracy and high computational *** chord length sampling(CLS)method can improve computational efficiency by sampling the chord length during neutron transport using the matrix chord length?s probability density *** study shows that the excluded-volume effect in realistic stochastic media can introduce certain deviations into the CLS.A chord length correction approach is proposed to obtain the chord length correction factor by developing the Particle code based on equivalent transmission *** numerical analysis against reference solutions from explicit modeling in the RMC code,it was demonstrated that CLS with the proposed correction method provides good accuracy for addressing the excludedvolume effect in realistic infinite stochastic media.

关键词： Stochastic media Monte Carlo Chord length sampling Excluded-volume effect Chord length correction