排序方式: 共有37条查询结果,搜索用时 0 毫秒
1.
ABSTRACTBayfol (PC-PBT blend ?lm) is a class of polymeric solid-state nuclear track detector which has a lot of applications in several radiation detection ?elds. It is a bisphenol-A polycarbonate PC blended with polybutylene terephthalate PBT. Bayfol/Palladium (PC-PBT/Pd) nanocomposite films have been deposited using the molding technique. It is worth mentioning that this report is almost the first one dealing with the topic of the changes of physical properties of Bayfol/Pd nanocomposite due to laser exposure. Samples from PC-PBT/Pd (5?wt%) nanocomposite were exposed to IR-pulsed laser of 5-W power, capable of producing 2000 pulses per second with pulse duration of 200?ns at 904?nm. The laser fluences were in the range 2–25?J/cm2. The resultant modi?cations in the exposed nanocomposite samples have been studied as a function of fluence using different characterization techniques such as X-ray diffraction (XRD), UV spectroscopy and color difference studies. The results indicate the proper dispersion of Pd nanoparticles in the PC-PBT matrix that causes a strong intermolecular interaction between Pd and PC-PBT, resulted in an increase in refractive index and the amorphous phase. Also, it is found that the laser exposure reduces the optical energy gap that could be attributed to the increase in structural disorder of the exposed PC-PBT/Pd nanocomposites due to crosslinking. Further, the color intensity ΔE, which is the color difference between the exposed samples and the non-exposed one, was increased with increasing the laser fluence, convoyed by a significant increase in the green and yellow color components. 相似文献
2.
Bulk superconducting samples of type Tl0.5Pb0.5Sr1.6Ba0.4CaCu2−x
Ru
x
O7−δ, (Tl, Pb)/Sr-1212, with 0.0 ≤ x ≤ 0.525 were prepared by the conventional one-step solid-state reaction technique. The prepared samples were investigated
using X-ray powder diffraction, electrical resistivity and electron paramagnetic resonance (EPR) measurements. Enhancement
of the phase formation, superconducting transition temperature T
c and hole carriers concentration P was observed up to x = 0.075. For x > 0.075, a reverse trend was observed. EPR spectra were measured at different temperatures (120–290 K) for all prepared samples.
The number of spins N participating in the resonance and the paramagnetic susceptibility χ were calculated as a function of both Ru-content and
temperature. N and χ increased as the Ru-content increased. A linear relationship between logN and 1/T was established, from which the activation energy E
a was calculated as a function of the Ru-content. The temperature dependence of χ was fitted according to Curie–Weiss type
of magnetic behavior. Curie constant C, Curie temperature θ, the effective magnetic moment μ and the electronic specific heat γ were estimated as a function of the Ru-content. 相似文献
3.
Andrei Hutanu Steffen Kiessig Andrea Bathke Rolf Ketterer Sonja Riner Jan Olaf Stracke Markus Wild Bernd Moritz 《Electrophoresis》2019,40(22):3014-3022
Charge heterogeneity profiling is important for the quality control (QC) of biopharmaceuticals. Because of the increasing complexity of these therapeutic entities [1], the development of alternative analytical techniques is needed. In this work, flow‐through partial‐filling affinity capillary electrophoresis (FTPFACE) has been established as a method for the analysis of a mixture of two similar monoclonal antibodies (mAbs). The addition of a specific ligand results in the complexation of one mAb in the co‐formulation, thus changing its migration time in the electric field. This allows the characterization of the charged variants of the non‐shifted mAb without interferences. Adsorption of proteins to the inner capillary wall has been circumvented by rinsing with guanidine hydrochloride before each injection. The presented FTPFACE approach requires only very small amounts of ligands and provides complete comparability with a standard CZE of a single mAb. 相似文献
4.
5.
6.
Jackson E. A. Ketterer F. D. 《IEEE transactions on plasma science. IEEE Nuclear and Plasma Sciences Society》1974,2(4):215-221
An application is made of lumped feedback to achieve stability of a distributed electromechanical system. A conducting elastic wire, placed in an axial magnetic field and carrying a current, exhibits instability at a certain threshold of magnetic pressure. The two dimensional transverse displacement of the wire is sampled and these signals are used to produce proportional feedback forces which allow stable equilibrium to be restored. A stability diagram is determined indicating the minimum feedback force to prevent static instability. For one station feedback, there is a maximum allowable feedback to prevent overstabil1 ity. In addition, the maximum value of destabilizing force which can be stabilized is somewhat less than that required for the second mode to become unstable. The wave dynamics of this corkscrew instability are related to several types of electromechanical interaction. The pinch confinement of a plasma, proposed as a scheme for containing a controlled thermonuclear reaction, suffers from a similar corkscrew instability. 相似文献
7.
H. Michel M. E. Ketterer G. Barci-Funel 《Journal of Radioanalytical and Nuclear Chemistry》2007,273(2):485-490
Plutonium isotopes were measured by alpha-spectrometry and ICP-MS in sediment samples from two European lakes: Blelham Tarn
in U.K. and Stechlin lake in Germany. The ICP-MS measurements were made after alpha-spectrometry counting of the planchets.
The planchets were prepared by traditional electrodeposition method after radiochemical extraction, separation and purification
of the Pu fraction. A short radiochemical separation using plutonium selective resin, between the two spectrometry measures,
is presented. The results show that these two complementary methods are in good agreement, the plutonium activity concentrations
are the same. Alpha-spectrometry allows the 238Pu determination and ICP-MS individual measurement of 239Pu and 240Pu. 238Pu/239+240Pu and 240Pu/239Pu ratios are calculated to determine the plutonium contamination source. With the results of these two techniques, it could
be demonstrate that the plutonium is of global fallout origin. 相似文献
8.
9.
Salah E. M. Eltom Ahmed A. H. Abdellatif Hamzah Maswadeh Mohsen S. Al-Omar Atef A. Abdel-Hafez Hamdoon A. Mohammed Eiman ME. Agabein Ibrahim Alqasoomi Salem A. Alrashidi Mohammed S. M. Sajid Mugahid A. Mobark 《Molecules (Basel, Switzerland)》2021,26(12)
The ostrich oil of Struthio camelus (Ratite) found uses in folk medicine as an anti-inflammatory in eczema and contact dermatitis. The anti-inflammatory effect of a γ-lactone (5-hexyl-3H-furan-2-one) isolated from ostrich oil and its formulated nano-emulsion in formalin-induced paw edema was investigated in this study. Ostrich oil was saponified using a standard procedure; the aqueous residue was fractionated, purified, and characterized as γ-lactone (5-hexyl-3H-furan-2-one) through the interpretation of IR, NMR, and MS analyses. The γ-lactone was formulated as nano-emulsion using methylcellulose (MC) for oral solubilized form. The γ-lactone methylcellulose nanoparticles (γ-lactone-MC-NPs) were characterized for their size, shape, and encapsulation efficiency with a uniform size of 300 nm and 59.9% drug content. The γ-lactone was applied topically, while the formulated nanoparticles (NPs) were administered orally to rats. A non-steroidal anti-inflammatory drug (diclofenac gel) was used as a reference drug for topical use and ibuprofen suspension for oral administration. Edema was measured using the plethysmograph method. Both γ-lactone and γ-lactone-MC-NPs showed reduction of formalin-induced paw edema in rats and proved to be better than the reference drugs; diclofenac gel and ibuprofen emulsion. Histological examination of the skin tissue revealed increased skin thickness with subepidermal edema and mixed inflammatory cellular infiltration, which were significantly reduced by the γ-lactone compared to the positive control (p-value = 0.00013). Diuretic and toxicity studies of oral γ-lactone-MC-NPs were performed. No diuretic activity was observed. However, lethargy, drowsiness, and refusal to feeding observed may limit its oral administration. 相似文献
10.
羧甲基纤维素钠水凝胶的制备及其生物降解性研究 总被引:9,自引:0,他引:9
用羧甲基纤维素钠(CMC—Na)制得了含水量高达98%的水凝胶,考察了防腐剂、交联剂、无机态氮素、有机态氮素、碳水化合物的加入量以及环境中pH值等因素对生物降解性的影响。结果表明:制备条件不同,水凝胶的生物降解性不同;环境中一定量铵根离子的存在有利于水凝胶的生物降解;在pH=5.2的环境中纤维素酶活性最高,降解程度最大。 相似文献