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用表面张力法研究了可聚合硼酸酯表面活性剂(BES)水溶液不同温度下(288-313 K)的表面活性和热力学函数变化;考察了BES与十二烷基苯磺酸钠(LAS)在0.5 mol·L-1 NaCl溶液中的相互作用. 结果表明, 298 K时, BES临界胶束浓度cmc达到0.066 mmol·L-1, γcmc为29.2 mN·m-1;在所考察的温度范围内BES胶束形成自由能(ΔG0m)在-22.4 - -25.8 kJ·mol-1之间, 胶束形成是熵驱动过程. BES/LAS混合体系为具有较大负偏差的非理想体系, BES/LAS分子间平均相互作用参数βm=-3.48;当溶液体相中BES摩尔分数αBES=0.5时, 混合胶束中BES摩尔分数X1m为0.46, |βm|达到最大, 而且此时混合溶液cmc为0.017 mmol·L-1, 达到最低, γcmc为27.8 mN·m-1. 相似文献
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基于多层深度卷积特征的抗遮挡实时跟踪算法 总被引:1,自引:0,他引:1
为提高复杂场景中目标跟踪算法的准确性与实时性,提出一种基于多层深度卷积特征的抗遮挡实时目标跟踪算法。针对目标跟踪任务,先对深度卷积网络VGG-Net-19进行微调,再提取目标区域的多层深度卷积特征。根据相关滤波框架构建位置相关滤波器,确定目标中心位置。设计尺度相关滤波器对目标区域进行不同尺度采样,确定目标尺度。目标遮挡时,采用阶段性评估策略进行模型更新与恢复,解决模型误差积累问题。选取目标跟踪评估数据集OTB-2015(100组视频序列)与UAV123(123组视频序列)进行测试。实验结果表明,本文算法具有更高的准确性,能够适应目标遮挡、外观变化及背景干扰等复杂情况,平均速度为29.6 frame/s,满足目标跟踪任务的实时性要求。 相似文献
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在同构理论的框架下,线性空间V的任一向量对应于P~n的一个n维向量,V的任一线性变换对应于P~(n×n)的一个n阶矩阵.因此,用矩阵的方法,即解析法,处理线性空间和线性变换的问题,或用几何法处理矩阵问题变成了现实.作为教材内容的补充,本文试图通过若干例子探讨如何综合运用解析法与几何法解决高等代数问题. 相似文献
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Dependence of nitrogen vacancy color centers on nitrogen concentration in synthetic diamond 下载免费PDF全文
Crystallization of diamond with different nitrogen concentrations was carried out with a FeNiCo-C system at pressure of 6.5 GPa. As the nitrogen concentration in diamond increased, the color of the synthesized diamond crystals changed from colorless to yellow and finally to atrovirens (a dark green). All the Raman peaks for the obtained crystals were located at about 1330 cm-1 and contained only the sp3 hybrid diamond phase. Based on Fourier transform infrared results, the nitrogen concentration of the colorless diamond was < 1 ppm and absorption peaks corresponding to nitrogen impurities were not detected. However, the C-center nitrogen concentration of the atrovirens diamond reached 1030 ppm and the value of A-center nitrogen was approximately 180 ppm with a characteristic absorption peak at 1282 cm-1. Furthermore, neither the NV0 nor the NV- optical color center existed in diamond crystal with nitrogen impurities of less than 1 ppm by photoluminescence measurement. However, Ni-related centers located at 695 nm and 793.6 nm were observed in colorless diamond. The NE8 color center at 793.6 nm has more potential for application than the common NV centers. NV0 and NV- optical color centers coexist in diamond without any additives in the synthesis system. Importantly, only the NV- color center was noticed in diamond with a higher nitrogen concentration, which maximized optimization of the NV-/NV0 ratio in the diamond structure. This study has provided a new way to prepare diamond containing only NV- optical color centers. 相似文献
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报道了以乙酰丙酮配合物为催化剂, 氧气为氧源, 在乙醛存在下对氯甲苯的液相选择性氧化, 研究了不同中心金属离子、催化剂用量、乙醛用量、氧气压力、反应时间及反应介质对反应的影响. 结果表明, 在金属配合物中三(乙酰丙酮)合钴(III)的催化性能最好, 在其用量为0.764 mmol、乙醛用量为反应物物质的量的10%、氧气压力为2 MPa时, 以乙腈为反应介质, 室温下反应11 h, 反应的转化率和选择性可达15.3%, 87.16%, 对氯苯甲醛收率可达13.34%. 反应也可在无溶剂时进行, 此时反应的转化率、选择性及醛的收率分别为8.14%, 89.08%, 7.25%. 相似文献
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