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排序方式: 共有134条查询结果,搜索用时 15 毫秒
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32.
We investigate the influence of the first-order correction of entropy caused by thermal quantum fluctuations on the thermodynamics of a logarithmic corrected charged black hole in massive gravity. For this black hole, we explore the thermodynamic quantities, such as entropy, Helmholtz free energy, internal energy, enthalpy, Gibbs free energy and specific heat. We discuss the influence of the topology of the event horizon, dimensions and nonlinearity parameter on the local and global stability of the black hole. As a result, it is found that the holographic dual parameter vanishes. This means that the thermal corrections have no significant role to disturb the holographic duality of the logarithmic charged black hole in massive gravity, although the thermal corrections have a substantial impact on the thermodynamic quantities in the high-energy limit and the stability conditions of black holes. 相似文献
33.
M. H. Abdallah Y. Ramaden S. A. Jawad M. Hassan M. S. Ahmad A. M. Zihlif 《Applied Physics A: Materials Science & Processing》1995,60(5):437-440
The effect of annealing on the electrical properties and the refractive index of red mercuric iodide (HgI2) single crystals is investigated. The ac-impedance and phase angle were measured in the frequency range from 100 Hz to 10 kHz at different annealing temperatures. The ac-conductivity, dielectric constants, loss tangent and the refractive index as a function of frequency are determined. The results are discussed in terms of structural changes taking place as a result of the heat treatment of the HgI2 single crystals. 相似文献
34.
P. S. Pereira Silva Raza Murad Ghalib Sayed Hasan Mehdi Rokiah Hashim Othman Sulaiman Ali Jawad 《Journal of chemical crystallography》2010,40(12):1150-1154
Abstract
Cyclohexyl N-phenylcarbamate, C13H17NO2 (I), which is a useful target for biotransformations by fungi, has been synthesized and the structure has been solved by X-ray diffraction. The crystals are triclinic, space group P [`1] bar{1} , with a = 5.2581 (2) ?, b = 9.5080 (3) ?, c = 12.6165 (4) ?, α = 70.544 (2)°, β = 89.075 (2)°, γ = 80.447 (2)°, M r = 219.28, V = 585.96 (3) ?3, Z = 2 and R = 0.065. In the title compound the phenyl ring makes a dihedral angle of 30.68(7)° with the carbamate group The molecules are linked into infinite chains via N–H···O hydrogen bonds along the a axis. These hydrogen-bonded chains are further linked by weaker C–H···π interactions. Quantum-mechanical ab initio calculations for the free molecule reproduce well the observed bond lengths and valency angles but show that the crystal packing might be responsible for the rotation of the phenyl ring out of the carbamate plane in the solid state conformation. 相似文献35.
Jawad Haidar 《Plasma Chemistry and Plasma Processing》2009,29(4):307-319
Nanopowders of metals and metal oxides have been produced using an arc operated between a refractory rod anode and a hollow
cathode (J. Haidar in A method and apparatus for production of material vapour, Australian Patent No. 756273, 1999). the arc
attachment to the anode is through a small region of molten metal located at the tip of the rod anode. Heat from the arc evaporates
the molten metal and the vapour is passed through the arc plasma before condensing into sub-micron particles downstream of
the cathode. A precursor metal is continuously fed onto the tip of the anode to maintain the molten metal region and compensate
for losses of materials due to evaporation. The particle size of the produced powder depends on the pressure in the arc chamber
and for production of nanoparticles in the range below 100 nm we use a pressure of 100 torr. Aluminium has been used as a
precursor material, leading to production of aluminium metal nanopowders when the arc is operated in argon and to aluminium
oxide nanopowders for operation in air. For operation in air, the products are made of γ-Al2O3. 相似文献
36.
Zulqarnain Russell Cox Jawad Anwar Nasir Ahmad Khalid Khan 《Natural product research》2020,34(18):2642-2646
AbstractUsing a dual culture antagonism assay, Aspergillus niger exhibited 51.5?±?1.1% growth inhibition against Fusarium oxysporum f.sp. lycopersici, the wilt pathogen of tomato. For enhanced production of antifungal metabolites, nutrient optimization was performed and in vitro well-diffusion antifungal assays demonstrated that crude extract obtained from GPYB culture showed a maximum zone of inhibition (8.8?±?0.4?mm) against the wilt pathogen, which is corroborated by the comparative LCMS profiles of the extracts from all three media i.e. GPYB, YEB and PDB. Two known compounds, Asperazine (m/z 665 [M?+?H]+) and Nigerone (m/z 571 [M?+?H]+), were isolated from A. niger and their antifungal activity is reported here for the first time. In MIC experiments, Asperazine and Nigerone inhibited the pathogen at 60 and 80?µg·mL?1 respectively. Molecular docking studies of Nigerone and Asperazine with F. oxysporum tomatinase showed five and six binding interactions respectively. 相似文献
37.
Qishun Li Shahid Zaman Wanting Sun Jawad Alam 《International journal of quantum chemistry》2020,120(9):e26154
Let L n denote a linear pentagonal chain with 2n pentagons. The penta-graphene (penta-C), denoted by R n is the graph obtained from L n by identifying the opposite lateral edges in an ordered way, whereas the pentagonal Möbius ring is the graph obtained from the L n by identifying the opposite lateral edges in a reversed way. In this paper, through the decomposition theorem of the normalized Laplacian characteristic polynomial and the relationship between its roots and the coefficients, an explicit closed-form formula of the multiplicative degree-Kirchhoff index (resp. Kemeny's constant, the number of spanning trees) of R n is obtained. Furthermore, it is interesting to see that the multiplicative degree-Kirchhoff index of R n is approximately of its Gutman index. Based on our obtained results, all the corresponding results are obtained for . 相似文献
38.
39.
Brett D. Martin Jawad Naciri Martin H. Moore Daniel A. Lowy Michael A. Dinderman Erica C. Pehrsson Banahalli Ratna 《Electrochemistry communications》2009,11(1):169-173
We describe a nanoscale gating effect by an atypical tether-containing polythiophene, [poly(thiophene-3-carboxylic acid 2-(2-(2-(2-ethoxy-ethoxymethyl sulfonate)-ethoxy)-ethoxy)-amide], referred to as poly(TP-OEG-SO4). Cyclic voltammetry data permitted us to calculate liquid-phase ion diffusivities in the polymer as a function of its oxidation state. Diffusivities are more than 350 times higher in the oxidized state versus the reduced state. As a control, poly 3′,4′-dimethyl-[2,2′;5′,2″] terthiophene (DMPT) was synthesized and characterized. On comparing both polymers in the reduced state, we find diffusivities in poly(TP-OEG-SO4) to be more than 4500 times lower than in poly(DMPT). To explain this behavior, we propose a model that features a charge-balancing mechanism by the sulfonate tethers in poly(TP-OEG-SO4), which causes nanoporous regions around the polymer main chains to be opened and closed, leading to the large observed differences in diffusivities. These data suggest that the polymer poly(TP-OEG-SO4) is evidently able to act as a reversible “nanogate” with an open pore structure when oxidized, and a closed one when reduced. 相似文献
40.