Key Engineering Materials Vols. 474-476

Abstract: A novel photochromic diarylethene, 1-(2-ethyl-3-benzothiophenyl)-2-(2-methyl-5- (3-methoxyphenyl)-3-thienyl)perfluorocyclopentene (1o) was synthesized, and its photochromic and fluorescent properties were investigated. This compound exhibited reversible photochromism, changing from colorless to purple after irradiation with UV light both in solution and in PMMA amorphous film. Also, it exhibited good fluorescence switching in solution. Fatigue-resistant experiments showed that this compound had attractive properties for rewritable optical recording or photoswitches.

Abstract: A new photochromic diarylethene of bis(4-isoxazolyl)ethene and bis(2-phenyl)ethene was synthesized. Its properties, including photochromism and fluorescence were investigated in detail. It underwent reversible cyclization and cycloreversion reactions upon alternating irradiation with UV and visible light in hexane. The results showed that this compound exhibited reversible photochromism and good fluorescent switching in solution after irradiation with UV light and visible light. Using this dithienylethene 1c as optical storage recording was performed successfully.

Abstract: With the rapid growth of population of Internet, social network site has become a communicable platform that people share some information themselves or connecting whit friends, such as MySpace, Facebook, Twitter. This study uses TRA and TAM as basic model, and combined with the Social Identity Theory to explore what factors affect internet users to stick on the social network site. The study adopts the Facebook as experiment platform, and collects 318 Taiwanese samples from internet. After the analysis of structural equation model, main results are the followings: (1)Users’ social identity, perceived usefulness, perceived entertainment, attitude toward a social network site will significantly and positively affect their stickiness on a social network site; (2)Users’ perceived usefulness, perceived ease of use, perceived entertainment will significantly and positively affect their attitude toward a social network site; (3)Users’ social identity will affect their perceived usefulness and perceived entertainment toward a social network site.

Abstract: In this paper, based on the series of test images which are synthesized through the linear motion blur model with continue variable parameters, we define the sensitivity of image definition assessments. Experimental data are presented that the validity of definition assessments for motion blur identification closely relates to the sensitivity of definition assessments. The higher the sensitivity is, the better the validity of definition assessments for identification performs.

Abstract: It is of great importance to manage the energy split of plug-in hybrid electric vehicle during the driving process.In this paper, principle of energy control in plug-in hybrid electric vehicle was first presented. And then, two energy control strategies, including fuel control strategy and engine efficiency control strategy, were analyzed, respectively. Finally, comparision simulation experiments were carried on electric vehicle platform ADVISOR software. Simulation results show that, using fuel control strategy can get a better economy performance but worse engine efficiency; while using engine efficiency control strategy can get a better engine efficiency but higher fuel consumption.

Abstract: Centrifugal compressor is one of the most typical equipment of all rotary machinery equipment, which is used widely and largely in petrochemical settings. Thus it is necessary to study the reliability of centrifugal compressor. The fault tree has been introduced and applied to the practical facilities. The reliability of centrifugal compressor also has been analyzed. Qualitative analysis aims to find the minimum cut and calculate the failure probability of compressors.

Abstract: A unsymmetrical photochromic diarylethene, 1-[2-methyl-5-(3,4-difluorophenyl) -3-thienyl]-2- (2-cyano-1,5-dimethyl-4-pyrryl) perfluorocyclopentene (1o), was synthesized, and its optoelectronic properties were also investigated. The results showed that this compound exhibited reversible photochromism changing from colorless to blue after irradiation with UV light both in solution and in PMMA amorphous film. The open-ring isomer of the diarylethene 1 exhibited relatively strong fluorescence both in hexane solution. The fluorescence intensity decreased along with the photochromism upon irradiation with 297 nm light and its closed-ring isomer showed almost no fluorescence. Using diarylethene 1 as recording medium, polarization holographic optical recording was carried out successfully.

Abstract: A new green photochromic diarylethene compound, 1,2-bis[2-n-hexyl-5- (2,2-dicyanovinyl)-3-thienyl]-perfluorocyclopentene (1o), was synthesized and its photochemical properties were investigated in detail. The measurement results demonstrated that the compound has good photochromism in solution and in PMMA amorphous film. Upon irradiation with 365 nm light, the colorless of the hexane solution and the PMMA film turned colored and under the visible light irradiation (λ > 510 nm) the colored hexane solution and the colored PMMA film return to colorless.

Abstract: Railway turnout, an integrated mechatronics equipment of track technology, is one of key equipments that control the running speed of high-speed railway. During the conversion of turnout, the friction, inclusion of foreign matter and deficient displacement of conversion caused by its own structural characteristics may lead to severe wheel/rail impact. In order to study the influence of conversion deviation on safety and comfort of a train during passing the turnout, train/turnout dynamic model was applied. Taking No.18 turnout on a Passenger Dedicated Line (PDL) with 350km/h as a case study, when the train passed it, the influences of its deficient displacement and inclusion of foreign matter on the following dynamic responses were studied, i.e. wheel load distribution, wheel flange force, dynamic stress of rail, wheel unloading rate, derailment coefficient, as well as the lateral displacements of switch rail and nose rail, etc. Result shows that: (1) the deficient displacement and the inclusion of foreign matter will severely influence the normal operation of the turnout, so the safety and comfort during the train passing through turnout may be affected; (2) During the conversion of turnout, its deficient displacement should be controlled properly, and the foreign matter should be removed during routine maintenance, moreover, a reliable detection system should be set.

Abstract: The mechanical properties and wear behavior of short carbon fiber reinforced copper matrix composites was studied. In order to avoid any interfacial pronlems in the carbon fibre reinforced composites, the carbon fibers were coated with copper. The fibers were coated by electroless coating method and then characterized. Composites containing different amounts of carbon fibers were prepared by hot pressing technique. The results show that Carbon fiber/Cu–Ni–Fe composites showed higher hardness, higher wear resistance and bending strength than the common copper alloy when carbon fibers content is less than 15 vol.%. The predominant wear mechanisms were identified as adhesive wear in the alloy and adhesive wear accompanied with oxidative wear in the 12 vol.% carbon fiber/Cu–Ni–Fe composites.