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Károly J. Böröczky Erwin Lutwak Deane Yang Gaoyong Zhang Yiming Zhao 《纯数学与应用数学通讯》2020,73(7):1406-1452
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The definition of Minkowski–Firey Lp-combinations is extended from convex bodies to arbitrary subsets of Euclidean space. The Brunn–Minkowski–Firey inequality (along with its equality conditions), previously established only for convex bodies, is shown to hold for compact sets. 相似文献
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Minkowski's projection bodies have evolved into Lp projection bodies and their asymmetric analogs. These all turn out to be part of a far larger class of Orlicz projection bodies. The analog of the classical Petty projection inequality is established for the new Orlicz projection bodies. 相似文献
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利用支持向量机(support vector machine,SVM)在两类模式识别中所表现出的良好适应性,采用SVM把网站服务质量的评价信息分成两类:服务投诉和非服务投诉.通过服务质址监控表格对投诉率的上限进行控制,实现了系统对服务质量的自动监控.实验结果表明,采用基于SVM网站服务质量监控方法能够对网站的服务质量进行实时临控,并且优于基于指标的服务质量监控方法. 相似文献
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1. Introduction As we know, the structure and performance of γ-Al2O3 are determined by the pore structure of its precursor, namely, the pseudoboehmite. Some factors influencing the pore structure of the pseudoboehmite have been reported, and among them the washing process is one of the important factors because: (1) the adsorbing on the surface of the pseudoboehmite acts as a stabilizing factor for amorphous particles [1], and washing can remove the Cl- anions, thus enhanc- ing the transform… 相似文献
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Huijuan Lu Lei Mei Gaoyong Zhang Xiaohai Zhou 《Journal of inclusion phenomena and macrocyclic chemistry》2007,59(1-2):81-90
The interaction between cucurbit[6]uril and N,N′-(m-bispyridinecarboxamide)-1,n-alkane (m = 2, 3, 4; n = 4, 6, 8) has been investigated by 1H-NMR, ESI-MS and single crystal X-ray diffraction method. The results show that cucurbit[6]uril can form pseudorotaxanes with N,N′-(m-bispyridinecarboxamide)-1,6-hexane (m = 2, 3, 4) easily. When the alkyl chain length increases (n = 8), the binding mode is identical, but the binding ability of the host towards guest decreases. In both two cases cucurbit[6]uril shows no selectivity towards positional isomers. However, in the case of n = 4, the binding mode is different, having relations with positional substitution of the guest. Only N,N′-(m-bispyridinecarboxamide)-1,4-butane (m = 2) can form pseudorotaxane with cucurbit[6]uril, while the other two (m = 3, m = 4) form external complex with cucurbit[6]uril. The possible reason for the difference has been discussed. 相似文献
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采用差示扫描量热法研究了原始聚酰胺材料在经历不同的预剪切过程或应用不同设备进行剪切后其结晶行为的变化,结果表明,原始样品经过预剪切后,结晶温度升高5~10℃,半结晶时间降低到原始样品的一半.当聚酰胺材料经历很低的剪切时其结晶温度就有很大的提高,进一步提高剪切强度,结晶温度的增加趋势变缓.偏光显微镜观察表明有剪切历史的样品,球晶尺寸减小.作为对此,聚烯烃和聚酯材料的结晶对剪切历史不敏感,剪切与非剪切样品的结晶行为基本相同,据此推测聚酰胺分子间氢键可能是这种剪切记忆效应产生的原因. 相似文献
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DNA与两性表面活性剂相互作用研究 总被引:1,自引:0,他引:1
本文综述了DNA与两性表面活性剂相互作用的研究进展,主要介绍了利用荧光显微镜、动静态光散射、相图及浊度等方法对DNA与两性表面活性剂相互作用的观察与形成复合物的表征。由于两性表面活性剂所具有的独特性质,可以实现在特定pH范围通过静电作用诱导DNA构象发生线圈状向小球状的不连续转变,并可通过调节溶液pH值、离子强度等实现对DNA-两性表面活性剂复合物的稳定性的调控。DNA与两性表面活性剂相互作用形成的复合物在非病毒基因载体研究方面具有潜在的应用价值。 相似文献
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Gao Y Li N Zheng L Zhao X Zhang J Cao Q Zhao M Li Z Zhang G 《Chemistry (Weinheim an der Bergstrasse, Germany)》2007,13(9):2661-2670
The ionic liquid (IL) 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF4]) forms nonaqueous microemulsions with benzene with the aid of nonionic surfactant TX-100. The phase diagram of the ternary system was prepared, and the microstructures of the microemulsion were recognized. On the basis of the phase diagram, a series of ionic liquid-in-oil (IL/O) microemulsions were chosen and characterized by dynamic light scattering (DLS), which shows a similar swelling behavior to typical water-in-oil (W/O) microemulsions. The existence of IL pools in the IL/O microemulsion was confirmed by UV/Vis spectroscopic analysis with CoCl2 and methylene blue (MB) as the absorption probes. A constant polarity of the IL pool is observed, even if small amounts of water are added to the microemulsion, thus suggesting that the water molecules are solubilized in the polar outer shell of the microemulsion, as confirmed by FTIR spectra. 1H NMR spectroscopic analysis shows that these water molecules interact with the electronegative oxygen atoms of the oxyethylene (OE) units of TX-100 through hydrogen-bonding interactions, and the electronegative oxygen atoms of the water molecules attract the electropositive imidazolium rings of [bmim][BF4]. Hence, the water molecules are like a glue that stick the IL and OE units more tightly together and thus make the microemulsion system more stable. Considering the unique solubilization behavior of added water molecules, the IL/O microemulsion system may be used as a medium to prepare porous or hollow nanomaterials by hydrolysis reactions. 相似文献