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991.
研究汽车安全气囊爆炸风险准确检测问题。假设汽车撞击点分布较为集中,将造成气囊压力分布不均匀,局部承压发生较大突变。传统算法是基于单传感器得到的承压系数进行安全气囊爆炸风险检测的,一旦发生局部承压过大,造成承压系数发生局部突变,将使得检测结果失真。为此,提出了一种基于无线传感网络配合连续压力信号小波变换算法的汽车安全气囊爆炸风险检测方法。对连续压力信号进行小波变换处理,获取汽车安全气囊承压系数极大值。将二者进行对比,从而完成汽车安全气囊压力检测。实验证明,这种算法能够避免由于撞击点分布较为集中造成的检测结果失真的缺陷,提高了汽车安全气囊爆炸风险检测的准确率。 相似文献
992.
993.
An alternative, effective, and solvent-free microextraction method has been developed using weighing paper as the adsorbent for five protoberberine alkaloids from the methanolic extract of Coptidis Rhizoma (C. Rhizoma). Several variables influencing extraction efficiency were optimized. 1.0?×?1.0?cm glassine weighing paper was employed for the isolation of the analytes followed by high-performance liquid chromatography. Under the optimum conditions, the limits of detection were between 0.2 and 0.4?ng/mL with enrichment factors from 41–47. The calibration curves were linear across the concentration ranges examined with correlation coefficients exceeding 0.992. All relative standard deviations were less than 10.0%. The method was employed for the determination of the analytes in C. Rhizoma. Berberine, palmatine, coptisine, epiberberine, and jatrorrhizine were present at concentrations between 9.62?±?0.87?mg/g and 0.48?±?0.05?mg/g. 相似文献
994.
995.
Xi Chen Guo-Ping Wu Qiu-Feng Cai Guang-Ming Liu Kiyoshi Osatomi Wen-Jin Su Min-Jie Cao 《Food chemistry》2012,130(3):679-686
An aminopeptidase was purified from Japanese flounder skeletal muscle to homogeneity by ammonium sulphate fractionation and three chromatographies. The enzyme was approximately 100 kDa with isoelectric point of 5.7 as estimated by two-dimensional polyacrylamide gel electrophoresis. Its optimum temperature and pH were 45 °C and 7.5, respectively. According to peptide mass fingerprinting study, the enzyme revealed high identity to a puromycin-sensitive aminopeptidase. It had a broad specificity toward aminopeptidase substrates and preferred to hydrolyse Lys-MCA with kcat/Km of 8.1 × 106 M?1 s?1, and the activation energy (Ea) of 72.5 kJ M?1. Metal-chelating agents effectively inhibited the enzyme activity, and Zn2+, Mn2+ and Co2+ significantly restored the apoenzymatic activity dialysed by EDTA, whilst inhibitors to other proteinases did not show much effect. Furthermore, bestatin strongly inhibited its activity. These results indicate that the purified enzyme is a metalloaminopeptidase which would possibly contribute to free amino acids increase in fish muscle. 相似文献
996.
Zhang‐Jun Guan Wei‐Jiong Zhang Xi‐Lang Zhou 《International Journal of Communication Systems》2012,25(11):1505-1512
The performance of multi‐antenna relay communication systems is investigated in this letter. The source broadcasts the signal to all the relays and the destination. Decode‐and‐forward scheme is adopted at the relays, and the destination employs maximum ratio combining (MRC) technique to maximize the received signal‐to‐noise ratio. Closed‐form expressions of outage probability are derived in the MRC case and minimum routes MRC case. An adaptive grouping algorithm of relay antennas is also presented under the constraint of total antenna number. Simulation results show that the analytical curves agree with the simulated ones very well, and the performance of the proposed grouping algorithm is very close to the upper bound mentioned in other papers. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
997.
"物理化学"是高职高专理工科的一门重要的专业基础课。针对这门课以及专科生的特点,其教学方法概括为四个结合:理论与实际相结合、化学与数学相结合、公式推导与应用相结合以及课上例题与课下习题相结合;教学改革概括为宏观与微观、理论与实际、内容与方法论、基础知识与前沿知识、课堂教学与教学研究和理论教学与化工生产六个相结合。 相似文献
998.
我国的热处理工艺污染大、能耗高,与世界先进水平有着一定的差距.说明实现热处理工艺绿色性的重要性,并建立热处理工艺的清单分析表及IPO模型,建立模糊度数学评价模型,对其进行资源、环境等方面的分析和评价. 相似文献
999.
1000.
Xiaochao Liu Yuejun Liu Jian Yang Wenzhi Wang Dengwang Lai Long Mao Wei Zheng Jun Yang Xi Chen 《应用聚合物科学杂志》2019,136(21):47504
Polyamide 6–66 (PA6-66)–montmorillonite (MMT)–nanosilica (NS) nanocomposite films were fabricated through a cast film process and then biaxially stretched on a laboratory stretcher. Uniaxial or biaxial stretching induced the elongated conformation of MMT and NS. The b axis of the α crystals and the amorphous phase were revealed to align along the machine direction (MD) after stretching, with the uniaxial orientation playing a more significant role. Furthermore, the crystallinity of PA6-66 stretching increased with the stretching ratio. Uniaxial stretching gave rise to a significantly enhanced tensile strength along the MD, whereas it slightly decreased the mechanical properties along the transverse direction (TD). In contrast, the films subjected to biaxial stretching exhibited more balanced mechanical properties. Uniaxial and biaxial stretching led to decreased transmittance and increased haze in the PA6-66–MMT–NS films; this could have been due to the elongated nanostructure of the two nanofillers, which inhibited the transmission and facilitated the scattering of visible light. The thermal shrinkage of the films increased with increasing stretching ratio, and the biaxially oriented films presented nearly equal shrinkage in the MD and TD. The addition of nanofillers decreased the shrinkage attributed to the mobility inhibition of the polymer chains during heating. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47504. 相似文献