资源类型

期刊论文 6

年份

2023 1

2022 1

2008 1

2007 2

2001 1

关键词

宏观裂缝 1

宏观静摩擦系数 1

微分静摩擦系数 1

微牛纳牛静摩擦系数 1

气体传输 1

混凝土 1

渗透率 1

表观静摩擦系数 1

展开 ︾

检索范围：

排序： 展示方式：

宏观裂缝混凝土中表观气体渗透率的测定 Article

Pierre Rossi

《工程（英文）》 2022年 第17卷 第10期   页码 93-98 doi: 10.1016/j.eng.2020.11.008

摘要：

本文报道了一项旨在测定开裂混凝土表观气体渗透率的实验研究分析。由于难以对气体渗透率进行可靠的实验测试，国际文献中缺乏对这一问题的研究。本研究的主要目的是提供新颖可靠的实验结果，并提出表观裂缝渗透率演化与表观裂缝张开度之间的解析函数。考虑Poiseuille 定律，这些函数似乎是相关的。

关键词： 混凝土     宏观裂缝     气体传输     渗透率    

HTML PDF 收藏

微分和表观静摩擦系数的表式

王渭源

《中国工程科学》 2001年 第3卷 第8期   页码 29-32

摘要：

当前，工程师和科学家都对微牛和纳牛量级载荷静摩擦系数（以下简称微牛纳牛静摩擦系数）很感兴趣。但文献中至今没有详细讨论过微牛纳牛静摩擦系数与载荷的关系，而且发表的实验结果都不相互讨论。从微分静摩擦系数的定义出发，导出几种典型模型下微分静摩擦系数和表观静摩擦系数的表式，并据此广泛讨论这些文献中的实验结果。

关键词： 微分静摩擦系数     微牛纳牛静摩擦系数     表观静摩擦系数     宏观静摩擦系数    

HTML PDF 收藏

Effect of denitrifying bacteria on the electrochemical reaction of activated carbon fiber in electrochemical biofilm system

YING Diwen, JIA Jinping, ZHANG Lehua

《环境科学与工程前沿（英文）》 2007年 第1卷 第3期   页码 305-310 doi: 10.1007/s11783-007-0051-z

摘要： An electrochemical-activated denitrifying biofilm system consisting of activated carbon fiber electrodes immobilized with denitrifying bacteria film as cathode was studied. A revised model for an electrochemical-activated denitrifying biofilm was developed and validated by electrochemical analysis of cathodal polarization curves and nitrate consumption rate. The cathodal polarization curve and nitrate consumption rate were introduced to verify the rate of electrochemical reaction and the activity of denitrifying bacteria, respectively. It was shown that the denitrification process effectively strengthened the electrochemical reaction while the electron also intensified denitrification activity. Electron was transferred between electrochemical process and biological process not only by hydrogen molecule but also by new produced active hydrogen atom. Additionally, a parameter of apparent exchange current density was deprived from the cathodal polarization curve with high overpotential, and a new bio-effect current density was defined through statistical analysis, which was linearly dependent to the activity of denitrification bacteria. Activated carbon fiber (ACF) electrode was also found to be more suitable to the electrochemical denitrifying system compared with graphite and platinum.

关键词： ACF     apparent exchange     hydrogen molecule     activated     biological process    

HTML PDF 收藏

Synthesis of TiO2 nano-particles and their photocatalytic activity for formaldehyde and methyl orange degradation

XIAO Xinyan, ZHANG Huiping, CHEN Huanqin, LIAO Dongliang

《化学科学与工程前沿（英文）》 2007年 第1卷 第2期   页码 178-183 doi: 10.1007/s11705-007-0033-5

摘要： TiO nano-particles were synthesized by sol-gel technique and characterized by X-ray diffractometer (XRD) and transmission electron microscope (TEM). Their photocatalytic activities for formaldehyde (FA) and methyl orange (MO) degradation were tested using degradation rate (η) as an evaluation index. Based on the orthogonal test results, the optimal condition for TiO preparation was obtained. Results showed that particle sizes were in the range of 10 40 nm, and that prepared TiO had better photocatalytic activity than P25. A simplified model was developed to evaluate the apparent quantum efficiency (Φapp) of this photocatalytic reaction system.

关键词： prepared     photocatalytic activity     apparent     photocatalytic     orthogonal    

HTML PDF 收藏

Fabrication of titania thin film with composite nanostructure and its ability to photodegrade rhodamine B in water

ZHANG Gaojie, WU Jinming, LIU Shaoguang, YAN Mi

《化学科学与工程前沿（英文）》 2008年 第2卷 第1期   页码 44-48 doi: 10.1007/s11705-008-0001-8

摘要： A titania nanorod film was synthesized by direct oxidation of metallic Ti with hydrogen peroxide solution under a low temperature. Titania nanoparticles were then filled into the gaps among the nanorods through an infiltration sol-gel procedure to form a composite titania film with an ordered nanostructure. X-ray diffraction spectra indicate that the composite film was a mixture of anatase and rutile while the titania film obtained by only using a sol-gel procedure was pure anatase. Field emission scanning electron microscopy observations show that titania nanoparticles were embedded into the titania nanorod film. Photoluminescence spectra suggest the enhanced separation of electron and hole pairs for the obtained composite titania film over the corresponding titania nanorod film. The composite titania film exhibited improved ability to photodegrade rhodamine B in water compared with the titania nanorod film. The apparent photodegradation rate constant, fitting a pseudo-first-order, was 3 times of that obtained by the sol-gel derived titania film at the same weight. The improved photocatalytic activity for the composite titania film could be attributed to the enhanced separation of electron and hole pairs due to the embedding of the titania nanoparticles within the titania nanorods.

关键词： constant     weight     apparent photodegradation     hydrogen     nanorod    

HTML PDF 收藏

Vibration characteristics and machining performance of a novel perforated ultrasonic vibration platform in the grinding of particulate-reinforced titanium matrix composites

《机械工程前沿（英文）》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0730-2

摘要： Ultrasonic vibration-assisted grinding (UVAG) is an advanced hybrid process for the precision machining of difficult-to-cut materials. The resonator is a critical part of the UVAG system. Its performance considerably influences the vibration amplitude and resonant frequency. In this work, a novel perforated ultrasonic vibration platform resonator was developed for UVAG. The holes were evenly arranged at the top and side surfaces of the vibration platform to improve the vibration characteristics. A modified apparent elasticity method (AEM) was proposed to reveal the influence of holes on the vibration mode. The performance of the vibration platform was evaluated by the vibration tests and UVAG experiments of particulate-reinforced titanium matrix composites. Results indicate that the reasonable distribution of holes helps improve the resonant frequency and vibration mode. The modified AEM, the finite element method, and the vibration tests show a high degree of consistency for developing the perforated ultrasonic vibration platform with a maximum frequency error of 3%. The employment of ultrasonic vibration reduces the grinding force by 36% at most, thereby decreasing the machined surface defects, such as voids, cracks, and burnout.

关键词： ultrasonic vibration-assisted grinding     perforated ultrasonic vibration platform     vibration characteristics     apparent elasticity method     grinding force     surface integrity    

HTML PDF 收藏

标题 作者 时间 类型 操作

宏观裂缝混凝土中表观气体渗透率的测定

Pierre Rossi

期刊论文

微分和表观静摩擦系数的表式

王渭源

期刊论文

Effect of denitrifying bacteria on the electrochemical reaction of activated carbon fiber in electrochemical biofilm system

YING Diwen, JIA Jinping, ZHANG Lehua

期刊论文

Synthesis of TiO2 nano-particles and their photocatalytic activity for formaldehyde and methyl orange degradation

XIAO Xinyan, ZHANG Huiping, CHEN Huanqin, LIAO Dongliang

期刊论文

Fabrication of titania thin film with composite nanostructure and its ability to photodegrade rhodamine B in water

ZHANG Gaojie, WU Jinming, LIU Shaoguang, YAN Mi

期刊论文

Vibration characteristics and machining performance of a novel perforated ultrasonic vibration platform in the grinding of particulate-reinforced titanium matrix composites

期刊论文