Applied Mechanics and Materials Vols. 138-139

Abstract: Humic acids are biological macromolecules. It has been 500 years since “WU-JIN-SAN” (i.e. humic acid) reported in Compendium of Materia Medica. In recent 30 years tens of medical companies and institutions have done regular clinical trials, toxicological and harmacological research on bio-humic acids. Besides, German, Polish, Swiss, Finland et al. have also done similar research, with the similar efficacy of Chinese herbal medicine like “Streagthening Vital Qi's Capacity to Resist Pathogens”, “Readjusting Yin and Yang”, “remedy defects and rectify errors” which build a scientific fundament for medical application of bio-humic acid. Although bio-humic acids was relatively weak in pharmacological studies, it was still traceable. As a drug, how to make a prescription in the pharmacopoeia This is the key issues which affect the progress in humic medical research. The author consider: First, the use of low-carbon biodegradation reduces the complexity of bio-humic acid molecules,then acoording to the active component by bio-humic acid, Pharmacological-pharmacodynamic, and determining the scope of medical applications could gradually overcome the bottleneck of medical research in bio-humic acid, accelerat the progress of medical research of bio-humic acid.

Abstract: P2P network is autonomous of sharing file quickly and easily. In recent years, a large number of free-riding nodes and malicious nodes emerge in P2P network, which can’t provide services and have malicious damage to the network system, the result is significant declines of system performance and user satisfaction. In order to solve the problems, a P2P incentive mechanism based on static game of incomplete information is proposed in this paper. The new proposed mechanism has been analyzed and simulated with a series of tests. Experimental results show that the proposed P2P incentive mechanism can solve problem simply and effectively.

Abstract: Based on the analysis of 30 provinces ( except Tibet) in China , this paper used the environmental staffs' number, completed industrial pollution abatement investment amount, waste treatment facilities’ number, the three wastes’ comprehensive utilization output value, and harmless waste treatment capacity as input and output index. The paper evaluated the 30 provinces’ environmental management efficiency (except Tibet) in 2008 and 2009 by Data Envelopment Analysis, then analyzed the time series data of the 30 provinces from 2003 to 2009 by Malmquist index. Study finds that overall Chinese environmental management efficiency’s TFP index is 0.942 in 2009, and decreasing year by year. Besides, it shows that technology is dominant factor of restricting Chinese environmental management efficiency, So, we should increase the investment in science and technology as to improve the efficiency. In addition, the environmental management scale’ expansion and structure optimization are also necessary methods of improving the efficiency.

Abstract: The dynamic minimum thickness of cut for the ultra-precision machining surface quality is important influence. Between tool and the workpiece for the friction coefficient were analysised, the relationship of the friction coefficient and the MTC were discussed, and the MTC and its effects on surface roughness were a theoretical analysised and experimental verification with processed single crystal copper and single crystal aluminum by AFM’s diamond tip. The results show: the MTC of single-crystal copper (single crystal aluminum) is 5.2nm (8.2nm) in stable cutting conditions. Further processing single crystal copper (ingle crystal aluminum) with cutting thickness of 5.2nm (8.2nm), and the surface roughness Ra160nm (Ra110nm) is obtained. So the MTC is evolving with the friction coefficient and the force ratio, theoretical MTC tends to be minimal value then before the adhering effect to reach remarkable. Appropriate adjustments cutting parameters, the cutting process can always micro-cutting phase to reach the steady-thin chip, and no plowing phenomenon. So the surface residues highly were reduced and higher surface quality was achieved.

Abstract: Micro wire electrical discharge machining (Micro-WEDM) is one key micro-processing technology for intricate micro parts. The surface texture is different with a single mechanical cutting surface and conventional spark-erosion formation machined surface. Assessment of the existing surface texture roughness parameters in terms of accuracy, or in the characterization of fine sense, can not meet the Micro-WEDM surface texture characterization needs. Through the analyses of surface autocorrelation function, structural shape ration, steepest attenuation autocorrelation function and surface texture direction, explicit the precise meaning of surface texture parameter characterization, make it really reflect the actual condition of Micro wire electrical discharge machining surface, modify Characterization Parameter algorithm, simplify the calculation process, make the results more accurate and more intuitive. Keywords: Micro wire electrical discharge machining; autocorrelation function; surface texture

Abstract: Microinjection molding has been drawing more and more attention due to its great advantages such as cost effectiveness and mass production capability. In this work, an experimental study was carried out in order to investigate the effect of the mold surface roughness on the achieved filled length of the molded microfeatures. For this purpose, an aluminum mold insert with microchannels having different surface roughness values was designed and fabricated using ultraprecision diamond machining and micromilling method. The experimental results revealed that increasing surface roughness of the microchannel wall led to a decrease in the filled length of the molded microfeatures. It was also found that with increased melt temperature or injection velocity, the effect of surface roughness was weakened by high-pressure trapped air inside the microchannels during injection process. Finally, the influence mechanism of the mold surface roughness was discussed.

Abstract: Airborne 3-D focal imaging LiDAR can take images in a very short gating time (3~5ns), so it can shield background noise instantaneously. Since the area of laser irradiated surface is about when the detected distance is about 3km, to ensure high imaging quality the laser beam needs to be smoothed before it arrives the ground. In this paper, based on self-developed airborne 3-D focal imaging LiDAR system, a beam homogenization device by using lens array method is presented for the detection range from 1km to 3km. The experimental result indicates that the smoothing rate can reach 89%. Subsequent tests in LiDAR system show that the homogenization device is reliable and effective.

Abstract: The stochastic properties and discreteness of macroscopic property for concrete appear on mechanical property and fracture surface. In consideration of stochastik and discreteness of fracture surface, a class of mesoscopic damage mechanics model of concrete based on spring model, are put forward to understand the real damage evolution characteristics of concrete at the level of constitutional law. A kind of spring-slipper model is introduced to reflect the elastic-plastic damage behavior. It has been confirmed that fracture surface of concrete has self-affine fractal characteristic only on a certain spatial scale, but the actual fracture surface of concrete is a stochastic surface with multi-fractal characteristics. Uniaxial test was operated, combined with the Computerized Tomography test of concrete, to study the evolution of crack surface from mesoscopic level to macroscopic level. Compared with the existing damage constitutive law and experimental results preliminarily, the feasibility of fractal damage constitutive law is verified.

Abstract: According to the price volume relationship of the stock, with the help of the elasticity and plasticity theory in the physics, some new ideas like stock equilibrium price, share price elasticity, and share price plasticity are put forward. Then elasticity and plasticity model of the stock price are built on account of the relationship between share price and trading volume, and model parameters are tested by a kind of software calling Eviews from econometrics. In the end, we get relatively scientific result.

Abstract: The dielectric properties of Sb₂O₃-doped (Ba_0.732Sr_0.26Nd_0.008)TiO_3.004 ceramics fabricated by conventional solid state method were investigated. The structure was identified by X-ray diffraction method and scanning electron microscope was also employed to observe the surface morphologies. It is confirmed that Sb₂O₃-doped (Ba_0.732Sr_0.26Nd_0.008)TiO_3.004 ceramics exhibit perovskite structure and with increasing Sb₂O₃ content Ba₆Ti₁₇O₄₀ (space group C2/c (15) ) forms as a secondary phase. The experimental results reveal that the addition of Sb₂O₃ into (Ba_0.732Sr_0.26Nd_0.008)TiO_3.004 ceramics reduce the dielectric constant and Curie temperature due to the substitution for A/B-sites with Sb³⁺ ions. The standing voltage increases with increasing Sb₂O₃ content while the dielectric loss and resistivity initially decrease and then increase with the increase of Sb₂O₃ concentration. The temperature dependence of dielectric properties at different frequencies was studied as well. It indicates that the tetragonal-cubic phase transition peak is suppressed as the Sb₂O₃ content increases and the peak value reduces with the increase of frequency.