排序方式: 共有24条查询结果,搜索用时 15 毫秒
1.
The time delay experiment proposed by I.I. Shapiro in 1964 and conducted in the seventies was the most precise experiment
of general relativity until that time. Further experimentation has improved the accuracy level of both the time delay and
the light deflection experiments. A simulation model is proposed that involves only a simple mass and time transformation
factor involving velocity of light. The light deflection and the time delay experiments are numerically simulated using this
model that does not use the general relativistic equations. The computed values presented in this paper compare well with
recent levels of accuracy of their respective experimental results. 相似文献
2.
Dhaka Ram Bhandari Tian Shen Andreas Römpp Holger Zorn Bernhard Spengler 《Analytical and bioanalytical chemistry》2014,406(3):695-704
Fungal secondary metabolites in both fruiting bodies and pellets from submerged cultures of basidiomycetes were analyzed by atmospheric pressure matrix-assisted laser desorption/ionization-mass spectrometry imaging at a lateral resolution of 15 μm, a mass resolution of 140,000 at m/z 200 and a mass accuracy of better than 2 ppm. The striatals A, B, C, and D, and a number of erinacine type metabolites were detected in the basidiomycetes Cyathus striatus and Hericium erinaceus, respectively. The two fungi were selected as model species, as they are well-known for efficient production of terpenoid secondary metabolites with interesting biological activities, e.g., antibacterial, fungicidal, cytotoxic properties, and stimulating effects on nerve growth factor synthesis. The localization of metabolites revealed a mostly homogeneous distribution of the striatals in the pellets of C. striatus, while a concentration gradient, increasing to the center, was observed in the pellets of H. erinaceus. A mostly homogeneous distribution of metabolites was also found in the fruiting body of H. erinaceus. 相似文献
3.
Pandey A Dhaka RS Lamsal J Lee Y Anand VK Kreyssig A Heitmann TW McQueeney RJ Goldman AI Harmon BN Kaminski A Johnston DC 《Physical review letters》2012,108(8):087005
The compound BaMn2As2 with the tetragonal ThCr2Si2 structure is a local-moment antiferromagnetic insulator with a Néel temperature T(N)=625 K and a large ordered moment μ=3.9μ(B)/Mn. We demonstrate that this compound can be driven metallic by partial substitution of Ba by K while retaining the same crystal and antiferromagnetic structures together with nearly the same high T(N) and large μ. Ba(1-x)K(x)Mn2As2 is thus the first metallic ThCr2Si2-type MAs-based system containing local 3d transition metal M magnetic moments, with consequences for the ongoing debate about the local-moment versus itinerant pictures of the FeAs-based superconductors and parent compounds. The Ba(1-x)K(x)Mn2As2 class of compounds also forms a bridge between the layered iron pnictides and cuprates and may be useful to test theories of high T(c) superconductivity. 相似文献
4.
5.
Navneet Kaur Jasvinder Singh Gargi Dhaka Richa Rani Vijay Luxami 《Supramolecular chemistry》2013,25(7-8):453-459
2-Hydroxy-1-naphthaldehyde-based benzothiazole chemosensor (1) undergoes absorption and fluorescence changes with addition of CN? and Cu2+ ions. Addition of CN? ions results in the appearance of two new bands at 420 and 440 nm. However, Cu2+ addition causes decrease in absorption band at 370 nm up to 12 equiv., while addition of higher equiv. of Cu2+(~190 equiv.) results in the appearance of two new bands at 400 and 800 nm. Differential absorption changes observed with addition of Cu2+ and CN? ions results in the construction of ‘NOR’ and ‘INHIBIT’ logic gates at 370 and 440 nm, respectively. 相似文献
6.
Arun Dhaka Olivier Jeannin Emmanuel Aubert Enrique Espinosa Marc Fourmigu 《Molecules (Basel, Switzerland)》2021,26(13)
The ability of alkylseleno/alkyltelluroacetylenes such as bis(selenomethylethynyl)-perfluorobenzene (4F-Se) to act as a ditopic chalcogen bond (ChB) donor in co-crystals with ditopic Lewis bases such as 4,4′-bipyridine is extended here to the octafluorobiphenylene analog, 4,4′-bis(selenomethylethynyl)-perfluorobiphenyl (8F-Se), with the more electron-rich 4,4′-bipyridylethane (bpe), showing in the 1:1 (8F-Se)•(bpe) co-crystal a shorter and more linear C−Se•••N ChB interaction than in (4F-Se)•(bpe), with Se•••N distances down to 2.958(2) Å at 150 K, i.e., a reduction ratio of 0.85 vs. the van der Waals contact distance. 相似文献
7.
Dhaka RS Liu C Fernandes RM Jiang R Strehlow CP Kondo T Thaler A Schmalian J Bud'ko SL Canfield PC Kaminski A 《Physical review letters》2011,107(26):267002
We use high resolution angle-resolved photoemission to study the electronic structure of the iron based high-temperature superconductors Ba(Fe(1-x)Ru(x))(2)As(2) as a function of Ru concentration. We find that substitution of Ru for Fe is isoelectronic, i.e., it does not change the value of the chemical potential. More interestingly, there are no measured, significant changes in the shape of the Fermi surface or in the Fermi velocity over a wide range of substitution levels (0相似文献
8.
The ‘anomalous perihelion precession’ of Mercury, announced by Le Verrier in 1859, was a highly controversial topic for more
than half a century and invoked many alternative theories until 1916, when Einstein presented his theory of general relativity
as an alternative theory of gravitation and showed perihelion precession to be one of its potential manifestations. As perihelion
precession was a directly derived result of the full General Theory and not just the Equivalence Principle, Einstein viewed
it as the most critical test of his theory. This paper presents the computed value of the anomalous perihelion precession
of Mercury's orbit using a new relativistic simulation model that employs a simple transformation factor for mass and time,
proposed in an earlier paper. This computed value compares well with the prediction of general relativity and is, also, in
complete agreement with the observed value within its range of uncertainty. No general relativistic equations have been used
for computing the results presented in this paper. 相似文献
9.
A new anisidine possessing benzothiaozle-based chemosensor (1) has been designed and synthesized. The chemosensor 1 was designed to provide hard base environment for ratiometric detection of comparatively less studied Al3+ ions. In CH3CN, the fluorescence spectra of chemosensor 1 red shifted from 368 to 430 nm with addition of Al3+ and Hg2+ ions; while Cu2+ ions caused quenching of emission intensity of 1. These differential changes observed with Al3+ and Cu2+ ions addition enabled chemosensor 1 to construct “NOR” and “TRANSFER” logic gates. 相似文献
10.
In this article, we present electron momentum density distribution and phase transition in SrO. The experimental values of momentum density have been measured using 5Ci 241Am Compton spectrometer and analyzed using theoretical data obtained from the ab-initio linear combination of atomic orbitals method. The first-principles calculations of the total energy of SrO as a function of cell volume have also been carried out for the cubic rocksalt (B1) and cesium chloride (B2) phases. Several structural parameters, i.e. equilibrium lattice constant, transition pressure, bulk modulus, etc. of B1 and B2 phases have been calculated and compared with the previous investigations. We conclude that the stable phase of SrO is B1 and the phase transition from B1 to B2 occurs at 35.8?GPa. 相似文献