Key Engineering Materials Vols. 474-476

Abstract: A new photochromic diarylethene, 1-(2-ethyl-3-benzothienyl)-2-[2-methyl-5-(3-trifluoromethylphenyl)-3-thieny] perfluorocyclopentene (1a) was synthesized, and its photochromic and fluorescent properties were also investigated. such as photochromism in solution as well as in polymethylmethacrylate (PMMA) amorphous films, Diarylethene 1a changed the color from colorless to purple upon irradiation with 297 nm UV light, in which absorption maxima were observed at 555 nm in hexane and at 581nm in PMMA amorphous film, the result showed that it can be useful in molecular scale optoelectronics and potential use for data storage. In hexane solution, the open-ring isomer of the diarylethene 1 exhibited relatively strong fluorescence at 413 nm when excited at 303 nm. The fluorescence intensity decreased along with the photochromism upon irradiation with 297 nm light and its closed-ring isomer showed weak fluorescence.

Abstract: In this work, advanced treatment of leachate after biological treatment was performed using sodium hypochlorite solution (NaClO) + ferric chloride (FeCl₃) + polyacrylamide (PAM) and NaClO + aluminum poly-chloride (PAC) + PAM, respectively, to determine the optimal condition for removal of COD and color. It was found that the optimal condition was: PAM 5 mg/L, FeCl₃ 420 mg/L, NaClO 6 mL/L, reaction time 15 min for treatment using FeCl₃ + NaClO + PAM, and PAM 5 mg/L, PAC 800 mg/L, NaClO 6 mL/L, reaction time 15 min for PAC + NaClO + PAM. After being treated at the optimal conditions, the effluent quality met requirements of the tertiary grade described in “Integrated wastewater discharge standard”.

Abstract: The main factors of impacting Cone-Beam Computed Tomography (CBCT) image quality and their causes were studied, and an integrated method of enhancing CBCT image quality was proposed according to the Digital Radiography (DR) imaging model. First, the original polychromatic X-ray was filtered into quasi-monochromatic X-ray by the filter plate of copper-tungsten alloy, in order to improve the quality of the original projection images. Then, the integrated artifact corrections for projection images were processed on the order of dark field correction, gain non-uniformity correction, scatter correction and beam hardening correction, to avoid the one-sidedness of only correcting a certain kind of artifact. Experimental results show that the method can almost eliminate the main artifacts of CBCT system and improve image clarity and signal to noise ratio.

Abstract: A failure analysis of mechanical seals of centrifugal pumps was presented with fuzzy comprehensive evaluation method. Both failure probability and failure consequence were analyzed to evaluate the risk grade of the mechanical seals. The potential risk level of a mechanical seal was estimated by the application of risk matrix. The proposed fuzzy comprehensive evaluation method can be used to judge the reliability of mechanical seals and provide an important reference for the safe and stable operation of centrifugal pumps.

Abstract: The chlorophyll-a and the primary production on different sections in the Luanhe-Beidaihe Estuary in August 2007 respectively ranged from (2.9 ± 0.5) to (10.5 ± 2.0) ( mg/m³ ), and from (14.9 ± 3.4) to (84.0 ± 7.6) (mgC/m²∙d). The chlorophyll-a concentration and the primary production in the southern part (section A-section E) were more than that in the northern part (section F- section H). It would suggested that the agriculture and aquiculture in the southern part imported more nutrients than that of the leisure and recreation industries imported in the the northern part, and the discrepancy of chlorophyll-a concentrations and primary production of different sections should be resulted from the different intensity of people activity in these areas.

Abstract: To study the microstructure of white band is helpful for revealing formation mechanism of serrated chip. This paper investigates the microstructural characteristics of white band_s at primary and second deformation zone within the serrated chips produced during High Speed Machining (HSM) of AISI 1045 hardened steel usingoptical microscope, SEM, TEM, and electron microprobe, X-Ray diffraction. It was found that the white bands within primary and second deformation zone consist of small equiaxed grains which formed due to dynamic recrystallization during adiabatic shear, however, martensitic transformation just only taken place within the white band in second deformation zone. The re-distribution of chemical elements between the composition phases occurred due to the combined effect of adiabatic temperature rise and high speed deformation in formation process of white band. The former is result from adiabatic shear in primary deformation zone during formation of chip, while the latter is caused by the intense shear and friction between tool and chip.

Abstract: Due to the high level complexity of the structure of trees, physical-based simulation of tree’s motion is a difficult task. Many visual simulation platforms and modeling tools are developed to simplify the process of simulation. In a variety of modeling tools, Creator is a simple and convenient modeling tool. It works with the visual simulation platform Vega Prime. They play an important role in the field of visualized simulation. Thus, a solution for simulating tree’s motion in the environment of Creator and Vega Prime is proposed. Each of branches around the tree’s 3D shape is built in Creator, and then is gradually merged together into a tree in Vega Prime. The Vega Prime APIs are used to realize the simulation of tree’s motion. The software development circle is shortened in the solution. The simulation of tree’s motion is accomplished faithfully. Experiment results show that the solution reduces the process of development and realizes the vivid simulation.

Abstract: This research utilizes type-2 fuzzy logic system to a wheeled mobile robot (WMR) for moving object avoidance. A CCD camera and a localization system are integrated in the control scheme. The wheeled mobile robot can adjust moving path by the position and heading angle, which are given from the localization system. Dynamic obstacle avoidance strategy is implemented in fuzzy rules. Distance between the WMR and an obstacle, center coordinate, heading angle, and displacement of the obstacle can all be obtained by image process and distance computation algorithm. Experiments show that the WMR can perform dynamic obstacle avoidance successfully.

Abstract: Xinjiang is rich in mountain and lake tourist resources; however, they are complex and vulnerable. In line with the features of mountain and lake tourist attractions in Xinjiang and based on ecology theory, environment theory, tourism theory, sustainable development theory, this text chooses the evaluation indicators and develops a universal environmental quality comprehensive evaluation index for mountain and lake tourist attractions, aiming to propose solutions for the existing problems and then improve it.

Abstract: Xinjiang is rich in tourist resources, and tourism is embracing a good opportunity, taking a trend of sound development. As the scale of tourism expands and the tourist-guest structure changes, Xinjiang tourism must achieve strategic transformation and structure innovation in such aspects as industrial structure, development mode, industrial function, tourist forms and tourism management to realize a leapfrog development.