排序方式: 共有22条查询结果,搜索用时 15 毫秒
1.
2.
The chemical states of iron in near-shore and deep-sea sediments were investigated by means of57Fe Mössbauer spectroscopy using selective and chemical leachings. The Fe2+/Fe3+ ratios of deep-sea sediments were much smaller than those of near-shore sediments, while the total contents of iron in the former were much higher than those in the latter. This is principally due to the high content of hydrogenous ferric oxyhydroxide in deep-sea sediments. Also, in the aluminosilicate fraction, the Fe2+/Fe3+ ratios of deep-sea sediments were smaller than those of near-shore sediments. This is probably attributed to the difference in the silicate mineral composition between deep-sea and near-shore sediments. X-ray reflections of clay minerals normalized to those of feldspars and quartz were more intense in deep-sea sediments than in near-shore sediments. 相似文献
3.
D. A. H. Ament J. J. Nuño-Ballesteros B. Oréfice-Okamoto J. N. Tomazella 《Bulletin of the Brazilian Mathematical Society》2016,47(3):955-970
Given an analytic function germ f: (X, 0) → C on an isolated determinantal singularity or on a reduced curve, we present formulas relating the local Euler obstruction of f to the vanishing Euler characteristic of the fiber X ∩ f-1(0) and to the Milnor number of f. Restricting ourselves to the case where X is a complete intersection, we obtain an easy way to calculate the local Euler obstruction of f as the difference between the dimension of two algebras. 相似文献
4.
5.
M. S. Jovanović J. Brborić S. Vladimirov B. Zmbova LJ. Vuksanović D. Živanov-Stakić V. Obradović 《Journal of Radioanalytical and Nuclear Chemistry》1999,240(1):321-324
A new diiodine substituted IDA derivative, 2,4-diiodine-6-methyl IDA (DIIODIDA) was synthesized and labeled with99mTc. It was established that99mTc-DIIODIDA had high radiochemical purity. Biodistribution and influence of bilirubin on99mTc-DIIODIDA biokinetics has been studied in rats and compared to the corresponding results for99mTc-SOLCOIODIDA. Related to99mTc-SOLCOIODIDA,99mTc-DIIODIDA has much better biliary exretion (55.18 versus 43.63%). No change of99mTc-DIIODIDA biokinetics, under influence of bilirubin was noticed. Biliary excretion of99mTc-SOLCOIODIDA has been reduced for about 60%. The protein binding of99mTc-DIIODIDA and99mTc-SOLCOIODIDA were also determined, using in vitro method of precipitation. These results showed that99mTc-DIIODIDA hepatobiliary imaging agent is superior to the presently used99mTc-monoiodine IDA derivatives. 相似文献
6.
7.
本文获得了有各种相互作用的一般n阶特征量泛函,其耦合系数反映了不同特征量泛函之间的耦合强度.依据定量因果原理,导出了一般n阶特征量泛函的变分原理,获得了一般n阶特征量泛函的Euler-Lagrange方程,它的不同系数可拟合不同的物理现实,如从线性到任意n阶非线性物理系统,使复杂难解的任意n阶非线性物理系统变得具体可解.并获得了该对称变换下不变的m个的守恒量,以及它们之间的关系和统一描述.依据定量因果原理导出了相对性原理,证明了绝对加速参考系、牵连参考系和相对参考系的力都有来自加速度和质量变化的贡献.利用定量因果原理自然导出了广义牛顿第一定律和广义牛顿第二定律,而且还导出了一个新定律,即广义牛顿第三定律,亦即平移不变性系统合力为零定理.进而将研究结论应用于对银河系的修正引力势、分子势、夸克禁闭势等,且其结果与物理实验一致. 相似文献
8.
We report experiments and numerical simulations on supercontinuum generation with femtosecond Airy pulses in a highly nonlinear optical fiber. The ability of the Airy waveform to regenerate its dominant intensity peak results in the generation of distinct spectral features. Airy pulses and other self-healing temporal waveforms may be useful for the generation of spectra with desired properties. 相似文献
9.
Kevin Ament Daniel R. Wagner Frederieke E. Meij Friedrich E. Wagner Josef Breu 《无机化学与普通化学杂志》2020,646(14):1110-1115
Maghemite (γ-Fe2O3) is a metastable iron oxide phase and usually undergoes fast phase transition to hematite at elevated temperatures (>350 °C). Maghemite nanoparticles were synthesized by the polyol method and then intercalated into a highly swollen (>100 nm separation) nematic phase of hectorite. A composite of maghemite nanoparticles sandwiched between nanosheets of synthetic hectorite was obtained. The confinement of the nanoparticles hampered Ostwald ripening up to 700 °C and consequently the phase transition to hematite is suppressed. Only above 700 °C γ-Fe2O3 nanoparticles started to grow and undergo phase transition to α-F2O3. The structure and the phase transition of the composite was evaluated using X-ray diffraction, TEM, SEM, physisorption, TGA/DSC, and Mößbauer spectroscopy. 相似文献
10.
The dispersion of the elusive elementary excitations of orbital ordered systems, orbitons, has escaped detection so far. The recent advances in resonant inelastic x-ray scattering (RIXS) techniques have made it, in principle, a powerful new probe of orbiton dynamics. We compute the detailed traces that orbitons leave in RIXS for an e{g} orbital ordered system, using the ultrashort core-hole lifetime expansion for RIXS. We observe that both single- and double-orbiton excitations are allowed, where the former, at lower energy, have sharper features. The rich energy- and momentum-dependent intensity variations that we observe make clear that RIXS is an ideal method to identify and map out orbiton dispersions. 相似文献