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排序方式: 共有149条查询结果,搜索用时 15 毫秒
1.
Alignment of photon-induced L3 vacancies is studied in rare earth and highZ elements at energies of experimental interest, near thresholds to 60 keV, under nonrelativistic dipole approximation. Numerical
calculations of the matrix element are undertaken to produce theoretical data for comparison with the experimental findings.
The A2 values being s>0.1 at photoelectron energies <20 keV are certainly higher than 5–8% uncertainties quoted in experimental
results. Present findings are from a very basic model, hydrogen-like and can further be treated as reference to observe the
impact of screening, relativistic, multipole and retardation corrections to the model 相似文献
2.
3.
The thermolysis of sodium hexa/benzoato/ferrate/III/, i. e. Na3[Fe/C6H5COO/6].4.5H2O has been investigated at different temperatures in air using Mössbauer, infrared spectroscopic and derivatographic techniques /DTG, DTA, TG/. The thermal decomposition proceeds without the reduction of iron/III/. An increase in particle size of -Fe2O3 formed during thermolysis has been observed with increasing temperature. The end product, -NaFeO2 is formed as a result of the solid state reaction between -Fe2O3 and sodium carbonate. 相似文献
4.
Narula Suraj P. Soni Sajeev Malhotra Rajesh Meenu Puri Jugal K. 《Transition Metal Chemistry》2002,27(7):795-798
Si(NHC6H4F-o)4 · 3TiCl4
(1) has been obtained from the disproportionation of (CF3CH2O)3SiNHC6H4F-o and TiCl4 in petroleum ether (40–60 °C) at –10 °C. The analytical (elemental analysis, molar conductance) and spectral (i.r., 1H- and 19F-n.m.r.) data suggested that (1) behaves as [Si(NHC6H4F-o)4 · Ti2Cl7]+ [TiCl5]–. The presence of these ions has been confirmed by characterising the products of metathetical reactions of (1) with R4NX (R = Bu and Et; X = I and Br) and with AgNO3. The data suggest the presence of a new titanium cation [Ti2Cl7]+. 相似文献
5.
Complexes of CoII with N,N-bis-(3-carboxy-1-oxopropanyl)-1,2-ethylenediamine(L1), N,N-bis-(3-carboxy-1-oxopropanyl)-1,2-phenylenediamine(L2), N,N-bis-(2-carboxy-1-oxophenelenyl)-1,2-phenylenediamine(L3) and N,N-bis-(3-carboxy-1-oxoprop-2-enyl)-1,2-phenylenediamine(L4) have been prepared and characterized by elemental analysis, vibrational spectra, magnetic susceptibility measurements, electronic spectra and thermal studies. Stability constants of the complexes have been evaluated potentiometrically. Vibrational spectra indicate coordination of amide and carboxylate oxygens of the ligands along with two water molecules giving a MO6 weak field octahedral chromophore. Electronic spectra support octahedral geometry around CoII. The [Co(L1)-(H2O)2] · 2H2O complex has the maximum activation energy and [Co(L3)(H2O)2] complex has the minimum activation energy. The order of stability constants of the CoII complexes with various ligands is due to their -donor abilities. 相似文献
6.
J. M. Ferreira Liliana Caramelo R. P. Chhabra 《International Journal of Mathematical Education in Science & Technology》2013,44(4):545-552
A curve fitting model is presented which minimizes the sum of squares of relative residues and expressions for the fit coefficients and their respective errors are derived. The new model is compared to the normal least squares model, using as an example the Reynolds number-drag coefficient data for a sphere. The results show that the best fit was obtained with the new model, indicating it may provide a useful tool for data analysis. 相似文献
7.
K. K. Verma Seema Shashi Chhabra 《Phosphorus, sulfur, and silicon and the related elements》2013,188(12):3037-3045
The synthesis and structural features of some newly synthesized 1,10-phenanthroline complexes of p-hydroxyphenyl-and 3-methyl-4-hydroxyphenyltellurium trihalides (chlorides, bromides, and iodides) are reported. The resulting complexes have been subjected to elemental analyses, conductance and cryoscopic measurements, infra-red and proton magnetic resonance spectral studies. Solution studies reveal the weak to 1:1 electrolyte type behavior of these complexes in solution. Spectral studies indicate the linkage of phenanthroline to the tellurium atom through the nitrogen atoms. Central tellurium atom in these complexes is hexa-coordinated in an octahedral way. 相似文献
8.
Navjeet Kaur Pooja Grewal Pranshu Bhardwaj Meenu Devi Neha Ahlawat Yamini Verma 《合成通讯》2013,43(22):3058-3100
The heterocyclic chemistry field has been revolutionized using transition metal catalyst in recent years. Various research groups have focused on the development of general protocols to achieve better functional group compatibilities and greater levels of molecular complexity under mild reaction conditions using easily available starting substrates. These methods afford many advantages as compared to alternative pathways involved in the synthesis of heterocyclic compounds. In this review article, we have concentrated on the synthesis of nitrogen-containing five-membered heterocylces in the presence of silver catalyst. 相似文献
9.
Gagan Chhabra Chandra K. Singh Deeba Amiri Neha Akula Nihal Ahmad 《Molecules (Basel, Switzerland)》2021,26(5)
Immunomodulation of the tumor microenvironment is emerging as an important area of research for the treatment of cancer patients. Several synthetic and natural agents are being investigated for their ability to enhance the immunogenic responses of immune cells present in the tumor microenvironment to impede tumor cell growth and dissemination. Among them, resveratrol, a stilbenoid found in red grapes and many other natural sources, has been studied extensively. Importantly, resveratrol has been shown to possess activity against various human diseases, including cancer. Mechanistically, resveratrol has been shown to regulate an array of signaling pathways and processes involving oxidative stress, inflammation, apoptosis, and several anticancer effects. Furthermore, recent research suggests that resveratrol can regulate various cellular signaling events including immune cell regulation, cytokines/chemokines secretion, and the expression of several other immune-related genes. In this review, we have summarized recent findings on resveratrol’s effects on immune regulatory cells and associated signaling in various cancer types. Numerous immunomodulatory effects of resveratrol suggest it may be useful in combination with other cancer therapies including immunotherapy for effective cancer management. 相似文献
10.