Abstract: The giant magnetostrictive transducer is a prospective kind of transducer for precession position and actuator utilization. The transducer design need cooperated with the mechanics, electrics and magnetics knowledge. It designs the giant magnetostrictive transducer and employed the finite element method to simulate and analysis the transducer’s prestress mechanism and modal analysis, Meanwhile, It uses the Ansoft software simulated and calculated the electrical and magnetical performance of the designed transducer. It presents the calculating method of the actuator’s mechanical, magnetic and thermal system, and utilizes the finite element method to analysis the actuator’s prestress mechanism, modal mode, permanent and electromagnetic magnetic circuit. The simulation results verified the design is reasonable and effective. The discussion of the model, analysis and simulation method of the transducer can direct the future transducer design and manufacture.
Abstract: A Ternary Model is established for heat transfer in a reheating furnace. Temperature field for furnace walls was solved by implicit difference of non-uniform gridding. The temperature of billet surface was dealt with for coupling the finite difference method with the Ternary Model reasonably. Finally the 3# reheating furnace in Baosteel was simulated. Temperature fields of billet and walls are solved by the proposed approach, and the results are analyzed, which provides theoretical basis for thermal operations as well as the online applications of the Ternary Model.
Abstract: As source of ceramic core, the raw materials play an important role in determining the properties of ceramic core. In this paper, the effect of matrix Al2O3 particle size on the properties of ceramic core during fabricating is mainly studied and discussed, the test results show that reasonable particle size match of coarser, middle and finer matrix Al2O3 will be beneficial for properties of ceramic core. Matrix Al2O3 powders with double peak or multi-peak can form denser packing and help to increase the ceramic core’s strength than powders with single peak can. The influence of middle Al2O3 particle size is great for its large proportion in matrix materials, and its optimal particle size range is between 23~28µm.
Abstract: By introducing the principle,classification and characteristics of optical fiber sensor ,we can understand the optical fiber sensor to some extent.Based on this,it introduces a filter which is used in lockmaking industry.This device is mainly made up of vibrating disk,optical fiber sensor and solenoid valve.By this filter,including vibration,detection and blowing,we can distinguish different kinds of marbles, also,we can distinguish the front-end and back-end of some kind of mables to meet special need.In this case,just connecting every part to each other and make a special angle of fiber head,then,the filter can distinguish marbles automatically an it improves the efficiency heavily.
Abstract: Nanocrystalline diamond films have been synthesized by microwave plasma enhanced chemical vapour deposition using H2/CH4 as the reactant gas. Nanocrystalline diamond thin films with surface roughness of 11.8 nm were obtained on silicon substrates. The nanocrystallinity, surface roughness and hardness were characterized by the Raman spectroscopy, X-ray diffraction (XRD), atomic force microscopy and Nano Indentation, respectively. The Raman spectra of the films exhibit a band near 1145 cm-1 and XRD patterns indicate the presence of nanocrystalline diamond. The hardness value of individual test point is approximately 102 GPa and the average hardness of thin film could reach 86 GPa.
Abstract: By simulating the solid-gas duplex erosive wear condition, the fabricating process of the metal matrix ceramic coating was investigated, and the properties of the ceramic coating under different fabricating conditions were studied, and the erosive wear behaviour of the ceramic coating with different volume fraction of Al2O3 particles and the mechanisms of material removal were researched and discussed. The results show that the metal matrix ceramic coating should be fabricated on the enamel coating which was prepared in advance on Q235A steel surface, and the anti-wear property of the ceramic coating containing Al2O3 is better than the coating without Al2O3, and the coating with 40% volume fraction particles, eroded at velocity of 20 m/s at 45° impact angle, is the best, which is 3.67 times than that of the enamel coating.
Abstract: In order to evaluate the high-value application of squid by-products yielded hydrolysate, the process of preparation and purification technology, chemical composition and in vitro antioxidant activity of the hydrolysate were investigated. The optimal conditions of papain hydrolysis were obtained by single-factor experiments and orthogonal test with the DPPH• scavenging ratio as index, amino acid composition was analysed by automatic amino acid analyzer, the hydrolysate was isolated with a Sephadex G-25 column. Based on single-factor experiments, the hydrolysate with the DPPH• scavenging ratio being 53.96 % was gained under the optimal condition of enzymolysis temperature of 45 °C, enzymolysis time of 3 h, total enzyme dose of 1.2 %, and the pH value of 7. The protein content of the hydrolysate reached up to 17.53 %, and the essential amino acids were accounted for 51.06 % of total amino acids. The largest content amino acid was glutamic acid, which accounted for 10.74 % of total amino acids. Compared with the amino acid profiles recommended by FAO/WHO, the quality of the protein hydrolysate was high, as it was rich in essential amino acids, including isoleucine, leucine, lysine, methionine and cystine, threonine, tryptophan, and valine, which covered 88 %-100 % of the FAO/WHO recommended. The hydrolysate was divided into three fractions (F1-F3) using a Sephadex G-25 column, the F1 possessed the highest antioxidation activity with the reducing power, •OH and DPPH• scavenging ratio being 0.236, 18.13 % and 63.85 % at the concentration of 5 mg/mL. Compared with the retention time of the reduced glutathione chromatomap, the relative molecular mass of F1 was higher than 307, F2 and F3 was lower than 307. The result revealed that the protein hydrolysate from squid by-products by papain had strongly antioxidant capacity in vitro and high nutrition, and this finding provided a new way of advanced exploitation of squid scrap resources.
Abstract: An efficient microwave-assisted extraction (MAE) technique was developed to extract polysaccharides from Enteromorpha prolifera (PEP). The operating parameters, such as microwave power, liquid/material ratio, temperature and extraction time, were optimized using orthogonal array design coupled with single factor method. PEP yield was determined by the phenol-sulfuric acid method. The optimum extraction conditions were determined as follows: microwave power, 700 W; liquid/material ratio, 40:1 (mL/g); temperature, 70 °C; and extraction time, 25 min. Under such conditions, PEP yield reached to 10.79 %. In comparison with conventional hot water extraction and ultrasonic-assisted extraction, MAE showed obvious advantages in terms of high extraction efficiency, saving energy, rapidity, solvent consumption, and so on. The data demonstrated that MAE could be a fast and reliable method for quantitative analysis of PEP. The scavenging capability of PEP to DPPH/hydroxyl radical reached to 65.2 % and 41.2 % at the concentration of 0.5 mg/mL. The reducing power of PEP was 0.354. Compared with butylated hydroxytoluene (BHT) and gallic acid (GA), the experimental results showed that DPPH radical scavenging activity of PEP was higher than that of BHT. Thus, PEP had good potential as a natural antioxidant used in functional food or medicine industries.
Abstract: The miscibility of chitosan/ethylcellulose (CH/EC) blends was studied by FT IR, wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), and scanning electronic microscopy (SEM). The regular changes of FT IR and WAXD spectra of CH/EC blend powder indicated the miscibility of the blends. DSC curves and SEM images of cross-sections of the blends films showed partly miscibility. CH/EC blends could form anisotropic phase in their formic acid solutions observed on a polarizing light microscope (PLM).
Abstract: Hydrogen peroxide is a very versatile reagent for many industrial processes. Nevertheless, it is very sensitive to impurities that can catalyze its decomposition violently. Combining the recent year’s hydrogen peroxide explosion accidents, this paper seeks to establish the evaluation model for its safe storage and transportation. Firstly, the runaway scenario that can serve as a basis for the assessment of the thermal risk was briefly described. Secondly, the adiabatic temperature increase () and the pressure for closed systems were used as the severity of the assessment criteria. Both closed and open systems were discussed. Thirdly, the time to maximum rate (TMRad) was presented as the probability of occurrence of the scenario. Finally, the established model was exemplified by two examples both with and without contamination. The results show that at 20°C the severity of 30(wt.) % H2O2 is critical and a small amount of Fe3+ (12.7mg∙L-1) reduces the TMRad of 30(wt.) % H2O2 by almost a factor of eleven. This approach can assess the safety of hydrogen peroxide for storage and transportation in advance.