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971.
972.
通过对30%玻纤增强ABS材料微观形态观察和分析,探寻了加工工艺条件和加入马来酸酐接枝ABS对材料力学性能的影响,结果表明,加入马来酸酐接枝ABS可明显改善基体材料与玻纤的粘结状况,使力学性能得到较大幅度的变化,加工温度的提高和适当的螺杆转速可提高玻纤在基体中的分散性,尽管玻纤分散性较好的材料其玻纤含量较低,玻纤长度较短,但仍使力学性能得到改善。 相似文献
973.
974.
975.
976.
Michail V. Kozlov Junwei Zhu Peter Philipp Wittko Francke Elena L. Zvereva Bill S. Hansson Christer Löfstedt 《Journal of chemical ecology》1996,22(3):431-454
The fifth abdominal segment of femaleEriocrania semipurpurella (Stephens) andE. sangii (Wood) contains a pair of exocrine glands. Hexane extracts of this segment were prepared from both species and analyzed by gas chromatography with simultaneous flame ionization and electroantennographic detection (EAD). For both species, the EAD active peaks were identified as nonan-2-one, (Z)-6-nonen-2-one, and (Z)-6-nonen-2-ol by means of mass spectrometry and comparison of retention indices with those of synthetic standards. Enantiomeric separation of chiral alcohols from the female extracts was achieved by gas chromatographic analysis on a cyclodextrin column. InE. semipurpurella, a mixture of (2S,6Z)-nonen-2-ol and (2R,6Z)-nonen-2-ol (2: I) was found, whereas inE. sangii (2S,6Z)-nonen-2-ol was the predominant enantiomer and only traces of theR enantiomer were indicated by the antennal response. In field tests, a blend of the three compounds was not attractive to conspecific males. A subtractive assay showed that the alcohol in various enantiomeric mixtures was the only attractive compound, whereas addition of (Z)-6-nonen-2-one to the alcohol completely inhibited the attraction of both species. A trapping experiment including a wide range of ratios between theR andS enantiomers showed that baits containing 95–100% of theS enantiomer were attractive to maleE. sangii, whereas males ofE. semipurpurella were attracted to all tested ratios of the enantiomers. However, the response profiles of maleE. semipurpurella differed between populations from southern Sweden, south Finland, and the Kola Peninsula in Russia. In south Sweden males were maximally attracted to a racemic mixture of the alcohols. At the Kola PeninsulaE. semipurpurella was attracted to baits containing 95–100% of theR enantiomer. In south Finland all tested ratios between 0 and 100%R enantiomer trappedE. semipurpurella, but the trap catches appeared to be bimodally distributed with peaks around 15 and 70%R enantiomer. The trapping results suggest the existence of pheromone races or sibling species among the specimens identified asE. semipurpurella.Dedicated to Prof. H. J. Bestmann on the occasion of his 70th birthday. 相似文献
977.
978.
Relationship of structure to properties of surfactants. 16. Linear decyldiphenylether sulfonates 总被引:1,自引:0,他引:1
Milton J. Rosen Zhen Huo Zhu Xi Yuan Hua 《Journal of the American Oil Chemists' Society》1992,69(1):30-33
The properties of some well-characterized sodium linear decyldiphenylether (C10DPE)sulfonates have been studied. Among the properties investigated are dynamic and equilibrium surface tension, critical
micelle concentration (CMC), area per molecule at the aqueous solution/air interface, wetting time by the Draves technique,
foaming by the Ross-Miles method, solubilization, and hydrotropy. The decyldiphenylether moiety appears to be equivalent to
a terminally substituted straight alkyl chain of 16 carbon atoms. The trialkyl- and dialkyl-mono-sulfonates have solubilities
of < 0.01 g/dm3 in water, but are readily soluble in hexane. The didecyldiphenyl ether disulfonate (DADS) has a very low CMC value (1.0 ×
10−5 mol dm−3) in aqueous 0.1 N Na+ solution (NaCl), characteristic of surfactants with two hydrophilic and two hydrophobic groups. It also has a much larger
area per molecule at the aqueous solution/air interface than the monodecyldiphenyl-ether monosulfonate (MAMS) and a much higher
surface tension at the CMC. MAMS has a much lower surface tension at a surface age of 1 second (γ1s) than either DADS or the monodecyldiphenylether disulfonate (MADS). In agreement with γ1s and γeq values, wetting times increase in the order: MAMS < DADS < MADS and initial foam heights decrease in the order: MAMS > DADS
> MADS. Solubilization for three water-insoluble surfactants decreases in the order: DADS > MAMS > MADS, while hydrotropy
is most pronounced with the disulfonates. 相似文献
979.
In this paper, we propose a new hard problem, called bilateral inhomogeneous small integer solution (Bi-ISIS), which can be seen as an extension of the small integer solution problem on lattices. The main idea is that, instead of choosing a rectangle matrix, we choose a square matrix with small rank to generate Bi-ISIS problem without affecting the hardness of the underlying SIS problem. Based on this new problem, we present two new hardness problems: computational Bi-ISIS and decisional problems. As a direct application of these problems, we construct a new lattice-based key exchange (KE) protocol, which is analogous to the classic Diffie- Hellman KE protocol. We prove the security of this protocol and show that it provides better security in case of worst-case hardness of lattice problems, relatively efficient implementations, and great simplicity. 相似文献
980.
焙烧高岭土的结构特征和吸附性能 总被引:5,自引:0,他引:5
通过对焙烧高岭土的矿物特性和表面吸附性质的研究。用化学分析,XRD、IR、XPS、Raman光谱和SEM观察证明焙烧高岭土的羟基基团完全消失,等温吸附,粒度分布试验证明焙烧高岭土水化能力较大,但吸附能力较弱。 相似文献