Li Z.,Shanghai JiaoTong University |
Jiao F.,China Construction Industrial Equipment Installation Co. |
Kou X.,Shanghai JiaoTong University |
Zhang Y.,Shanghai JiaoTong University
Applied Mechanics and Materials | Year: 2012
Failure probability of a component is the major project of engineering probability. The reliability of a mechanical system or a structural system is calculated by components in the system. However, statistics data shows that the distribution of test data of components is not according with the distribution by theory as normal distribution. Normal distribution is extensively applied in the component reliability nowadays. Its domain is the field of real numbers, whereas, test data of experiments are on a finite field. Consequently, the component reliability used the normal distributions has some limitations. It is necessary to choose a suitable distribution in the calculating method. Comparing the normal distribution density curve and the statistics graph, a new distribution is presented in this paper. The examples by both normal distribution and the new distribution are given, respectively. The results suggest that the new distribution is more accurate than normal distribution in the component reliability. © (2012) Trans Tech Publications.
Yang Y.,Air Force Engineering Design and Research Institute |
Xu W.,Air Force Engineering Design and Research Institute |
Qian Q.,China Construction Industrial Equipment Installation Co.
Journal of Geomatics | Year: 2015
This paper analyzes the errors affecting precision positions, directional measurement, and precision level of installation during the construction of building specifically designed for some special devices. Appropriate technical strategies are proposed to realize the on-site processing of observational data by applying Leica GeoMoS to the automated data collection and using VBA in Excel. These strategies, which can guarantee the installation accuracy and improve the efficiency of installation, are successful examples and solutions to similar engineering issues in the future.
Wang Y.,Nanjing University of Science and Technology |
Xu Y.,Nanjing University of Science and Technology |
Cao X.,Nanjing University of Science and Technology |
Li B.,China Construction Industrial Equipment Installation Co. |
Chen X.,China Construction Industrial Equipment Installation Co.
Hanjie Xuebao/Transactions of the China Welding Institution | Year: 2011
Q390 steel exists certain cold crack tendency during weld. For Q390 steel structure having larger cabined stress, the factors of affecting hydrogen induced cracking of important bearing steel structure need to be studied. Hydrogen induced cracking is caused by diffusible hydrogen during weld, so the glycerol test was used to measure diffusible hydrogen content of Q390 steel welded metal, and the effects of different conditions including different humidity and different types of filler metal were compared and analyzed. Results show that under same humidity, diffusible hydrogen content in metal welded with solid wires is significantly smaller than that with flux-cored wires; under large humidity, the increase tendency of diffusible hydrogen content in the metal welded with flux-cored wires is less than that with solid wires due to the joint protection of slag and gas; the view of diffusible hydrogen content in the metal welded with flux-cored wires is more than that with solid wires, and so they should be used to weld the position of bearing steel structure which has a small restrain intensity, and filler metal must be dried before use.
Pan Y.,Dalian University of Technology |
Wang T.,Dalian University of Technology |
Wang T.,Northwest University for Nationalities |
Sun H.,Dalian University of Technology |
And 2 more authors.
Separation and Purification Technology | Year: 2012
An experimental investigation was carried out on preparation and application of titanium dioxide dynamic membranes in separation of oil-in-water emulsions via. crossflow microfiltration. The dynamic membrane was formed on a porous carbon tube support. Effects of preparation factors on oil-in-water emulsion separation were studied and the optimal preparation conditions were determined using orthogonal experiments. The dynamic membrane prepared under the optimal conditions was characterized to be uniform, dense and hydrophilic. Experimental results show that oil rejection efficiencies are all higher than 98% with the permeate concentrations less than 8.3 mg/l. The steady permeate flux increases at first, and then decreases with increase in the average support pore size. A novel concept, the steady flux decay ratio (FDR) of dynamic membrane was proposed for the first time as an indicator of anti-fouling ability of dynamic membrane in this work. Analysis displays that the steady FDR first increases and then decreases with increase in the support pore size during which the dynamic membrane type changes from the complete blocking filtration type to the intermediate blocking filtration type. As the pore size increases, the steady permeate flux of dynamic membranes has a slow decline during intermediate blocking filtration of the oil-in-water emulsion. © 2012 Elsevier B.V. All rights reserved.
Yan Y.,Zhejiang University |
Luo N.,China Construction Industrial Equipment Installation Co. |
Xiang X.,China Construction Industrial Equipment Installation Co. |
Xu Y.,China Construction Industrial Equipment Installation Co. |
And 2 more authors.
Progress in Chemistry | Year: 2014
Ice adhesion and accretion on the facilities of aviation, telecommunication, electricity and transportation can lead to major inconvenience for our daily life and can even cause great economic losses. Therefore, it is worthwhile to study anti-icing and icephobic technology. Among all of them, concerning mechanical removing, electrothermal methods, spraying chemicals and coatings, anti-icing & icephobic coating is the research hotspot due to its obvious advantages such as low energy consumption, environmentally friendly and so on. It focuses on mitigating or even eliminating ice accumulation by extending freezing time and reducing ice adhesion strength. Extending freezing time is conducive to condensed water rolling off the substrates before it freezes via outside power, such as gravity, wind power and centrifugal force. Reducing ice adhesion strength makes de-icing procedure facile even if the condensed water has frozen on the substrates. It has been proved that by optimizing surface physicochemical properties and surface topography, both ideal effects can be achieved. On the basis of analyzing the mechanism, the influencing factors of anti-icing and icephobic properties are comprehensively discussed. Taking relative factors into consideration, a balance need to be reached between contradictory ones. Furthermore, the research progress of designing and fabricating anti-icing & icephobic coating is reviewed, including hydrophilic coating, hydrophobic coating and multi-functional composite coating. Finally, the prospective tendency of anti-icing & icephobic coating is proposed based on the current challenges.