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排序方式: 共有28条查询结果,搜索用时 62 毫秒
1.
在相对碰撞平动能为 0 .0 5eV的分子束实验条件下 ,研究了亚稳态CO(a) +NO(X)的E E传能通道 .通过测量和分析交碰区的传能发射光谱 ,在 780和 860nm处观测到了NO(b -a)跃迁Ogawa带的△v =+ 4和△v =+ 3序的发射光谱 .从而首次在实验上直接证实了传能过程中第四通道的存在 (CO (a) +NO(X)→CO (X) +NO(b) ) .这一通道的发现解释了前人测量到的在CO(a)与NO(X)碰撞传能过程中CO(a)的猝灭速率远大于NO(A ,B)生成速率的实验结果 ,并进一步证实了这一“经典”E E传能体系为电子交换机理的传能观点  相似文献   
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高铁酸钾的合成与电化学性能研究   总被引:4,自引:0,他引:4  
本文主要研究了锂离子电池正极材料高铁酸钾的合成,表征和电化学性质.用次氯酸钾与硝酸铁于碱性介质中反应得到高铁酸钾粗品,重结晶后成纯度大于97%的产品,用XRD和FTIR等方法对高铁酸钾进行表征和分析.初步研究了K2FeO4/Li电池的充放电性能.  相似文献   
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Recently Kim has given a general method, using group-invariant orbit parameters, for determining the energy and residual symmetry of the Higgs potential minimum. In this paper we illustrate the method by working out the case of a quartic SU(5) Higgs potential with 5 and 24 higgsons. In this method the Gell-Mann-Slansky conjecture concerning possible little groups of the potential minimum takes a geometric form, which is verified for our case. The results are used to discuss the hierarchical symmetry breaking of SU(5) grand unification theory. We generalize our results to the SU(N) adjoint + vector models, which are all closely related.  相似文献   
4.
pp annihilations, leading to the production of at least one neutral K meson in the final state, have been studied in the incident momentum region of 700–760 MeV/c. Topological cross sections and cross sections for the various exclusive final states are presented. Detailed analyses of the different final states have been carried out to study the importance of resonance production and of quasi two-body and quasi three-body processes. A detailed study of the KKπ system in the four-body final states shows that the F1 meson is a spurious effect due to systematic biases. In the momentum range investigated, the C = +1 final states are strongly suppressed.  相似文献   
5.
Palladium nanoparticles have been evaluated as a viable candidate in the realm of biological applications due to their unique features. Saussurea costus extract was used as a stabilizing and reducing agent for the synthesis of palladium nanoparticles with average grain size of 17.6 ± 1.2 nm. The synthesized PdNPs were evaluated for their antioxidant activity, anti Alzheimer's activity, antibacterial and anticancer activities. The nanocharacterization was carried out using different spectroscopic techniques, including UV–visible spectroscopy, Transmission Electron Microscopy, Fourier Transformed Infrared spectroscopy, X-ray Diffraction analysis, X-ray Photoelectron spectroscopy, Energy Dispersive X-ray Spectroscopy, Size distribution, and Zeta potential. The characterization data explained the PdNPs mediated by S.costus extract have spherical form and are disseminated without agglomeration. FTIR and XPS supported the hypotheisis that the biomolecules of S.costus are activing as a reducing and stabilizing agents. The antioxidant activity of PdNPs was assessed using a free radical scavenging assay (DPPH) which exhibited similar results to the ABTS assay i.e. 90 μg/mL IC50 value. Moreover Alzheimer's disease can easily be inhibited by S.costus@PdNPs at 400 mg/mL, with 79.23 ± 1.11 % of inhibition rate against AChE and 76.13 ± 0.43 % towards BChE. S.costus@PdNPs showed comparatively greater antibacterial activity against all four Staphylococcus aureus, Bacillus subtilis Escherichia coli and Pseudomonas aeruginosa microorganisms. Supplementary research carried out on the anti-tumor effects of the generated PdNPs using the colon cancer (HCT-116), hepatocellular carcinoma (HepG2), and breast adenocarcinoma (MCF-7) cell lines. PdNPs showed potent anticancerous activity against all the cell lines. Thus we recommend S.costus@PdNPs as a thearapeutic agent after successful clinical trails in future.  相似文献   
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In this paper, we obtain a necessary and sufficient condition for functions in an unified class of univalent functions of complex order involving the Sal?ge?n operator. Some of our results generalize previously known results.  相似文献   
8.
《Comptes Rendus Chimie》2016,19(9):1090-1100
Nettle (Urtica dioica L.) is a herbaceous perennial that has been used for centuries in folk medicine. More recently, nettle extracts have also been used in cosmetics because of the many benefits of their topical application for skin health. Their potential anti-aging action is of particular interest and is primarily ascribed to their antioxidant capacity. Here, using an experimental design approach and a clustering analysis, we linked the phytochemical composition of nettle extracts to their biological activities. This approach confirmed the antioxidant capacity of nettle extracts as well as providing the first evidence of another mechanism for their anti-aging potential involving the inhibition of enzyme activities, such as elastase and collagenase. We attributed these inhibitory effects to ursolic acid and quercetin present in the nettle extracts. Our results also demonstrated the possibility of extracting ursolic acid, quercetin and other phenolic compounds differentially to obtain an extract with a strong antioxidant capacity and anti-aging activities toward both elastase and collagenase. This could be of particular interest for cosmetic applications of nettle extracts.  相似文献   
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Rezensionen     
《Nachrichten aus der Chemie》2014,62(12):1205-1210
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