Applied Mechanics and Materials Vols. 333-335

Abstract: NaYF₄:Yb,Tm nanoparticles possessing blue upconversion emission were prepared by microwave-assisted solvothermal method, and used as the donor to set up a luminescence resonance energy transfer system with doxorubicin for rapid detection of doxorubicin. There was a linear relationship of I = 4.98×102 - 9.92C (R = 0.9995) between luminescent intensity and concentration of doxorubicin in the range of 0-66.23 mmol·L^-1. A detection limit of 0.69 mmol·L^-1 (3s) was obtained by the LRET system with a RSD of 1.6% (60 mmol·L^-1 , n=11). This approach is expected to be used for the clinical detection of doxorubicin in medicine.

Abstract: Catalyst-free InGaP nanoneedles were grown on Si substrate via metalorganic chemical vapor deposition. From scanning electron microscope (SEM) images, various nanoneedles were observed and the relevant growth mechanism was discussed.

Abstract: Hydrolyzed polyacrylamide (HPAM) has been widely used for enhanced oil recovery in oil production. However, metal ions existed may reduce the system viscosity and further impact the displacement efficiency. Thus, it is of importance to know the mechanism between HPAM and metal ions. UV spectrophotometry method can be effectively applied in this work. It is suggested that the extent of various metal ions on HPAM viscosity is in the order of Fe²⁺ >Ca²⁺>Na⁺. By shielding effect, the presence of large amount of Na⁺ reduces HPAM solution viscosity. The result also demonstrates that multivalent cations can form polyion-metal complexes which affect the solution viscosity. The viscosity degraded by Fe²⁺ is attributed to its reducing action. With oxygen in sewage, Fe²⁺ initiates a free radical reaction and causes the disintegration of the polymer.

Abstract: We studied the influence on the organic electroluminescent device performance with different DPAVBi position. When DPAVBi was the separate blue light emitting layer and its thickness was 20 nm, the performance of the device is better than others. The yellow light device performance with DPAVBi behind the Rubrene layer is better than the device with it in front of Rubrene layer. The device has a maximum luminous 23560 cd/m² at 17V and maximum efficiency 6.63cd/A at 16 V. We have received the blue-green light device with the Rubrene doped to DPAVBi. The maximum efficiency is 5.37 cd/A at 9 v and the maximum luminance is 6377 cd/m² at 16 V. The efficiency drops slowly when the voltage increases. So, all the devices have the current weak fluorescence quenching.

Abstract: In this paper a finite element analysis (FEA) of machining for AISI1045 is presented. In particular, the thermodynamical constitutive equation (T-C-E) in FEA is applied for both workpiece material and tool material. Cutting temperature and tool wear depth are predicted. The comparison between the predicted and experimental cutting temperature and tool wear depth are presented and discussed. The results indicated that a good prediction accuracy of both principal cutting temperature and tool wear depth can be achieved by the method of FEA with thermodynamical constitutive equation.

Abstract: A method based on reversed-phase liquid chromatography-tandem mass spectrometry (LC/MS/MS) combined with solid phase extraction (SPE) was developed and validated for qualitative and quantitative detection of eight parabens in three types of water-based food simulants including distilled water, 3% acetic acid, 10% alcohol. Detection limits of eight parabens after SPE procedure were 0.005-0.010 μg/L in distilled water, 0.006-0.015 μg/L in 3% acetic acid and 0.005-0.017 μg/L in 10% alcohol. The relative standard deviations (RSDs) were in the range of 1.90-8.48% for distilled wsater, 1.01-3.73% for 3% acetic acid and 5.78-12.97% for 10% alcohol. The method could make a complement for detecting parabens migrated to food and feeds.

Abstract: The texture of agricultural crops changes during harvesting, post harvesting and processing stages due to different loading processes. There are different source of loading that deform agricultural crop tissues and these include impact, compression, and tension. Scanning Electron Microscope (SEM) method is a common way of analysing cellular changes of materials before and after these loading operations. This paper examines the structural changes of pumpkin peel and flesh tissues under mechanical loading. Compression and indentation tests were performed on peel and flesh samples. Samples structure were then fixed and dehydrated in order to capture the cellular changes under SEM. The results were compared with the images of normal peel and flesh tissues. The findings suggest that normal flesh tissue had bigger size cells, while the cellular arrangement of peel was smaller. Structural damage was clearly observed in tissue structure after compression and indentation. However, the damages that resulted from the flat end indenter was much more severe than that from the spherical end indenter and compression test. An integrated deformed tissue layer was observed in compressed tissue, while the indentation tests shaped a deformed area under the indenter and left the rest of the tissue unharmed. There was an obvious broken layer of cells on the walls of the hole after the flat end indentations, whereas the spherical indenter created a squashed layer all around the hole. Furthermore, the influence of loading was lower on peel samples in comparison with the flesh samples. The experiments have shown that the rate of damage on tissue under constant rate of loading is highly dependent on the shape of equipment. This fact and observed structural changes after loading underline the significance of deigning postharvesting equipments to reduce the rate of damage on agricultural crop tissues.

Abstract: To better understand the sedimentation processes of bentonite, the sedimentation characteristic of bentonite suspension was studied by using the sedimentation analysis module of Dynamic Contact Angle Meter and Tensiometer. The results indicated that sedimentation characteristics of bentonite suspension were affected by the concentration and pH values of the suspension together with the dosage of dispersants. The natural sedimentation rates of bentonite suspension declined firstly with prolonging the sedimentation time and soon stabilized after about 50s. The sedimentation weight of particles hardly changed when the concentration ranged from 0.5% to 5.0%, while it increased significantly when ranged from 5.0% to 10.0%. The sedimentation weight and rate were relatively bigger at 4.4, 11.8 than that of 6.0, 7.9, and the maximum values appeared at pH11.8. Adding sodium pyrophosphate could improve the dispersibility of bentonite suspension.

Abstract: A double-sphericity abnormity media as grinding media was presented, and the grinding laws of cassiterite-polymetallic sulfide ore by the abnormity media and single ball media with different combinations were discussed in this paper. The results show that when adopting the abnormity media to replace its mother balls for grinding, the mother ball size is smaller, the grinding effect is better, and adding the abnormity media was helpful to decrease overgrinding. And for cassiterite grinding process, the desirable results could be achieved by using small size abnormity media to replace large single ball media.

Abstract: Four kinds of bentonite samples were studied in this paper. Mainly discussing the particle size distribution, mineral composition and physicochemical properties of bentonite, the aim was to provide a useful reference for the efficient development and utilization of bentonite resources. The results indicated that NM-bent., HB-bent. and EZ-bent. were Ca (Mg)-bentonite while XZJ-bent. was Na-bentonite. The physicochemical properties of bentonite mainly depended on interlayer cations. Many properties indexes of Na-bentonite were better than that of Ca (Mg)-bentonite. Some properties indexes showed a poor reproducibility when tested by standard methods. The natural Na-bentonite has excellent properties and extensive application prospects while Ca (Mg)-bentonite needed for further processing to meet the demand of the application field.