慢刀伺服车削刀具半径定向补偿的分段逼近求解

复杂曲面的慢刀伺服车削加工过程中，采用刀具法向补偿算法会在各个直线轴产生补偿量，加工法向矢量突变的曲面时，这种算法并非最优，将补偿量只应用于负载较低的直线轴却是更优的选择。提出一种基于线段逼近的刀具半径定向补偿数值求解算法来求解定向刀位点，通过半径细分的策略使法向误差收敛。算法实例验证及与相关算法的对比结果显示，该算法适用于点云构成的曲面或分段曲面的刀具半径补偿。     

Li ion conduction of perovskite Li0.375Sr0.4375Ti0.25Ta0.75O3 and related compounds

In this work, perovskite-structured Li_0.375Sr_0.4375M_0.25N_0.75O₃ (M=Ti, Sn, N=Nb, Ta) solid electrolytes were synthesized by conventional solid state reaction method. Phase compositions, fractured morphologies and conductivities of these compounds were investigated by X-ray diffraction, scanning electron microscope and AC-impedance spectroscopy, respectively. X-ray diffraction analysis confirms that all of Li_0.375Sr_0.4375M_0.25N_0.75O₃ (M=Ti, Sn, N=Nb, Ta) ceramics present perovskite structure. Pure Li_0.375Sr_0.4375Ti_0.25Ta_0.75O₃ and Li_0.375Sr_0.4375Sn_0.25Ta_0.75O₃ perovskite ceramics were obtained. But impurities were detected in Li_0.375Sr_0.4375Ti_0.25Nb_0.75O₃ and Li_0.375Sr_0.4375Sn_0.25Nb_0.75O₃. Among all investigated compounds, Li_0.375Sr_0.4375Ti_0.25Ta_0.75O₃ shows the highest total ionic conductivity of 2.60 × 10^?4 S cm^?1 at room temperature and the lowest activation energy of 0.347 eV. Conductivities of Li_0.375Sr_0.4375Sn_0.25Ta_0.75O₃ and Li_0.375Sr_0.4375Sn_0.25Nb_0.75O₃ were 4.4 × 10^?5 S cm^?1 and 1.82 × 10^?6 S cm^?1, respectively. Their conductivities were much lower than Li_0.375Sr_0.4375Ti_0.25Ta_0.75O₃ and Li_0.375Sr_0.4375Ti_0.25Nb_0.75O₃.     

Absorption effect of pure nickel on the corrosion behaviors of the GH3535 alloy in tellurium vapor

In this study,pure Ni was demonstrated to pro-tect the GH3535 alloy from Te vapor corrosion because of its strong absorption capacity.Severe Te corrosion of a single GH3535 alloy sample occurred in Te vapor at 700℃,which manifested as complex surface corrosion products and deep intergranular cracks.However,when pure Ni and the GH3535 alloy were put together in the vessel,the GH3535 alloy was completely protected from Te corrosion at the expense of the pure Ni.Thermody-namic calculations proved that the preferential reaction between pure Ni and Te vapor reduced the activity of Te vapor considerably,preventing the corrosion of the GH3535 alloy.Our study reveals one potential approach for protecting the alloys used in molten-salt reactors from Te corrosion.     

Learning Adaptive Classifiers Synthesis for Generalized Few-Shot Learning

International Journal of Computer Vision - Object recognition in the real-world requires handling long-tailed or even open-ended data. An ideal visual system needs to recognize the populated head...     

The crosslinking directing dynamic behavior of polymer latex under the investigation toward waterborne damping coatings

Latex polymers with precisely designed dynamic mechanical behavior are the key for waterborne damping coatings, which are widely desired in noise and vibration reduction with additional environmental benefits. In this work, we synthesized series of polymer latexes with various crosslinking agents (CA) and network distributions through the control on emulsion polymerization processes. We have revealed that the variation on crosslinking can significantly direct the latex behavior under dynamic conditions as well as its films. The variables involve the CA composition, the functionality, the crosslinking manner, the hydrophilic-hydrophobic feature as well as the feeding method. Although all the latex films showed the damping peaks locating in the range from −10 to 70°C, their damping behaviors were quite different. Suggested by the empirical parameters of LA and TA, the product from sequential monomer feeding method tended to give good extensional damping performance. Especially when the crosslinking of diacetone acrylamide (DAAM)/adipic dihydrazide was applied, there was a linear increase on LA with the increasing dosage of DAAM from 0 to 10 mmol in the final monomer addition batch. Meanwhile, good constrained layer damping is expected on the products from the power monomer feeding method with the maximum CA dosage shown below 7.5 mmol. The best TA was achieved when the CA of divinylbenzene was used in the dosage of 5 mmol. These results would be valuable to be referenced in the engineering on organic damping materials toward modern industrial and vehicles applications.     

甜玉米芯多糖对胰岛素抵抗HepG2细胞糖代谢功能的影响

目的：探讨甜玉米芯多糖（sweet corncob polysaccharide，SCP）组分SCP-80-I对胰岛素抵抗HepG2（insulin resistant HepG2，IR-HepG2）细胞糖代谢功能的影响。方法：确立IR-HepG2细胞模型建立的最佳条件，并由此建立IR-HepG2细胞模型；分别以50、100、200、400 μg/mL剂量的SCP-80-I孵育细胞24 h，评价其对细胞葡萄糖消耗的影响，同时利用噻唑蓝法评价其细胞毒性；检测氧化应激标志物超氧化物歧化酶（superoxide dismutase，SOD）、丙二醛（malondialdehyde，MDA）及活性氧（reactive oxygen species，ROS）的水平，测定细胞内糖原积累水平及糖酵解关键限速酶己糖激酶（hexokinase，HK）、丙酮酸激酶（pyruvate kinase，PK）的活力。结果：确立以1×10－6 mol/L胰岛素处理24 h作为诱导IR-HepG2细胞形成的最佳条件，并成功建立IR-HepG2细胞模型；在孵育实验中，SCP-80-I能极显著增加IR-HepG2细胞的葡萄糖摄取量（P＜0.01），细胞活力随SCP-80-I质量浓度的增加呈先上升后下降的趋势；200 μg/mL SCP-80-I处理组与模型对照组相比，胞内MDA含量极显著下降，SOD活力极显著提高，ROS水平极显著下降（P＜0.01）；胞内糖原含量极显著增加（P＜0.01），HK与PK活力极显著增加（P＜0.01）。结论：推测SCP-80-I的降血糖功效与其缓解氧化应激所造成的肝脏细胞损伤，改善胰岛素抵抗肝脏细胞的糖代谢功能有关。     

Systematic study of short circuit activation on the performance of PEM fuel cell

During the operation of proton exchange membrane fuel cell (PEMFC), it always suffers from reversible performance loss caused by the oxidation of platinum catalyst on its electrode, which reduces the electrochemical active surface area. Short circuit method has been found to improve the performance of fuel cells by stripping of oxides and other adsorbed species from platinum, which needs systematical understanding the effective parameters of short circuit method on fuel cell performance. In this paper, the effects of different short circuit activation parameters (duration, interval, cycles, cut-off voltage, operating current) are carefully studied and analyzed during short circuit operations. In addition, the mechanism revealing how relevant parameters influence short circuit activations is deeply analyzed. The results show that five groups of activation parameters have obvious influence on the activation of fuel cell, indicating that the short-circuit activation effect can be optimized. Among these parameters, the short-circuit duration parameter have the greatest impact on activation, because the platinum hydroxides and oxides is gradually removed during short-circuit duration and results in a larger effective surface area of the platinum catalyst for the electrochemical reaction. However, the smallest impact is short-circuit interval. Another finding is that the five activation parameters are not independent, so the optimal activation parameter value needs to be analyzed in combination with the operating conditions. Finally, according to the activation principle, selection of appropriate short circuit activation parameters for application are proposed to further improve performance and fuel utilization by considering the safety of the stack.     

Infusion efficiency of fluorescein derivatives of different molecular sizes into various starches under atmospheric and high hydrostatic pressures

Food Science and Biotechnology - Fluorescein isothiocyanate-dextrans (FDs) of different molecular weights were infused into corn, waxy rice, tapioca, and potato starches under atmospheric and high...     

Effects of methyl cellulose-based coating on physiochemical properties and chemical hazards of Chinese fried dough cake during storage

Coating has been used as a practical method to ensure the physiochemical properties and reduce the chemical hazard of fried foods. Methyl cellulose (MC) was used as a coating material to pretreat Chinese fried dough cake (CFDC) before frying. The results showed that the water content, hardness and L* value of the 1% MC coated sample were 31.67%, 848.54 g and 51.62, respectively, at the seventh day at 25 °C. Coating contents 1% MC could reduce the oil content, hardness, and extent of browning and improve the physiochemical properties of CFDC on 7 days of storage. Coating contents 1% MC also reduced the acid value, peroxide value, p-anisidine value, malondialdehyde content, 4-hydroxy-2-(E)-hexenal content, 4-hydroxy-2-(E)-nonenal content, acrylamide content and glycidyl ester content in CFDC on 7 days of storage. Our work contributes to the control of the oil content and chemical hazards for fried food during storage by applying an edible coating.     

A 6-sigma robust optimization method for stamping forming of automobile covering parts based on residual error and radial basis interpolation

Journal of Mechanical Science and Technology - Reducing the disturbance of parameter fluctuations to the system is very important to the robustness of stamping product quality. In this paper, a...