Materials Literature
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Stearic acid nanoparticles were prepared by a melt-emulsification method. The nanoparticles were stable in terms of the size and the appearance when the concentrations of sodium lauryl sulfate in the suspensions were less than 1.443%. And, they were stable in the aspect of their integrity when the concentrations of et…
Abstract Metallic contaminant was found in the liquid oxygen (LOX) pre-valve screen of the shuttle main engine propulsion system on two orbiter vehicles. To investigate the potential for an ignition, NASA Johnson Space Center White Sands Test Facility performed (modified) rotating friction ignition testing in LOX. Thi…
Our recent advances in modeling of colloidal superstructures in spatially confined nematic liquid crystals are briefly reviewed. The approach is phenomenological and is based on Landau- de Gennes type free energy, where the effects of confinement and external fields are also taken into account. The inter-particle coup…
A series of well defined semifluorinated diblock copolymers of poly(1H,1H-dihydroperfluorooctyl methacrylate)-block-polyethylene oxide (poly(FOMA-b-EO)) were used for the preparation of self-assembled structures. The morphologies of the poly(FOMA-b-EO) aggregates formed from solvent casting were investigated in terms…
Dielectric properties of several compounds with cyano and fluoro substituents were studied in the frequency range of 1 kHz − 3 GHz. Most of compounds exhibit nematic mesophase in a broad temperature range. The principal permittivity components and the relaxation processes were studied in the isotropic and the nematic…
This paper describes the preparation and thermal properties for homologous series of 2-oxochromen-6-yl 4-(4-alkoxyphenylazo)benzoates (compounds 1-n). Compounds 1-n show nematic phase exclusively, where the nematic–isotropic phase transition temperatures are between 293°C for 1–4 and 256°C for 1–8. Interestingly, comp…
在固定化脂肪酶Novozym 435催化下，分别以2-巯基乙醇、单甲氧基聚乙二醇(MPEG)为引发剂引发 e-己内酯(e-CL)开环聚合制备了末端巯基化的聚己内酯(HS-PCL)和两亲性嵌段共聚物聚乙二醇-b-聚己内酯(PEG-b-PCL)；用IR、1H-NMR、GPC对聚合产物结构进行了表征；研究了引发剂/单体投料比、聚合时间和温度对聚合产物的影响；考察了HS-PCL的巯基在二甲亚砜、四氢呋喃、丙酮中氧化生成二硫键的活性；用动态激光光散射法和 1H-NMR研究了PEG-b-PCL在水溶液中自组装体的尺寸和结构.结果表明，合成产物具有预期结构；固定化脂肪酶Novozym 435具有较高催化活性，在70℃下催化 e-CL本体聚合，2…
In the title compound, [Fe(H(2)O)(6)][FeBr(3)(CO)(3)](2), both Fe atoms have an octa-hedral coordination and the bromide carbonyl complex has a fac-stereochemistry. The [Fe(H(2)O)(6)](2+) octa-hedron has point symmetry and is slightly compressed along one O-Fe-O axis. The [FeBr(3)(CO)(3)](-) anion has point symmetry 1…
Ferromagnetic metallic flakes show high magnetic permeability in gigahertz frequency due to their large saturation magnetization and the effect of particles shape.However,their permittivity is too large to wave impedance matching and to application as microwave absorbent.In this paper,the surfaces of micrometer Fe fla…
Electrical current can induce very large amplitude of precession in nanomagnets, resulting in highly nonlinear dynamical regimes unattainable by any other means of excitation. We performed spectroscopic measurements of magnetic nanodevices whose geometry was optimized for coherent dynamics at high currents. The depend…
ZnO-ZnMgO multiple quantum-well (MQW) thin-film waveguides with ridge structures have been fabricated on quartz substrates. Low-temperature deposition of high-quality ZnO-ZnMgO MQW thin films was achieved by filtered cathodic vacuum arc technique. A ridge is defined on the thin film by plasma etching. Room-temperature…
在聚苯乙烯（PS）/聚烯烃弹性体（POE）/AlCl3共混物中引入苯乙烯（St）单体,增加了共混体系中的不饱和结构,AlCl3催化剂与St反应生成大量的初始碳正离子,这些初始碳正离子进攻POE链生成更多的大碳正离子,进而形成更多的PS-graft-POE共聚物,提高了接枝效率.进而,采用＂两次挤出＂技术,即先原位增容制成接枝母料,然后接枝母料再与PS和POE二次挤出,可以在一定程度上缓解组份的降解,使共混物的力学性能得到进一步的改善.
Property characterization of Chusquea culeou Desv. (colihue), a bamboo growing in Chile, was conducted. Physical, chemical and mechanical properties were determined as a function of plant dia-meter, position in culm length and nodal or internodal sections. The results show that fi bre length increased from the base to…
Single crystalline body-centered-cubic (bcc) Co films were achieved on ${\text{FeCu}}_{3}$ buffer layer by molecular-beam epitaxy. Fourfold symmetric magnetic hysteresis loops for bcc Co were obtained unambiguously with the easy axes along $\text{Co}⟨110⟩$. The in-plane uniaxial anisotropy is significantly reduced by…
Calculations of inductance for helical toroidal coils are of great interest to researchers since they are the basis of optimal design with target functions such as the maximization of the ratio of the stored magnetic energy with respect to the volume of the toroid or the used conductor, the elimination or the balance…
Several agar media (Mueller-Hinton agar, MHA; diagnostic sensitivity test agar, DSTA; Schaedler agar, SchA; Todd-Hewitt agar with added yeast extract, THYA; Wilkins-Chalgren agar, WCA) were compared using the Bauer-Kirby agar disk diffusion test against six nonfastidious quality control strains: Staphylococcus aureus…
Abstract The photo‐polymerization of amphiphilic monomers, two isomers of N,O‐diacylated serine (AM and EM), has been studied. Self‐assembling properties of the monomers were characterized in aqueous media by NMR and fluorescence techniques. These data show that both can form micellar structures by forming hydrophobic…
To understand the effects of magnetic fields on the evolution behaviours of thermocapillary convection in a two-layer fluid system under the absence of gravity, we conducted a series of unsteady three-dimensional numerical simulations of thermocapillary flows in a rectangular cavity. The results show that the convecti…
We propose a system of dynamical equations coupling a tensor Qij related to the molecular order with the flow velocity, whose structure is very similar to the Leslie-Ericksen equations. In particular, the Leslie viscosities and the Frank elastic constants appear explicitly, which contrasts with constitutive equations…
We show that the elastic charge of colloids in a nematic liquid crystal can be generated by the vector of external torque. The torque components play the role of two component charge (dyad) and give rise to the Coulomb-like potential, while their conservation law plays the role similar to that of Gauss' theorem in the…