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排序方式: 共有229条查询结果,搜索用时 15 毫秒
41.
S. U. Haq R. Ali M. A. Kalyar M. Rafiq A. Nadeem M. A. Baig 《The European Physical Journal D - Atomic, Molecular, Optical and Plasma Physics》2008,46(1):1-8
A detailed study has been performed for estimating the orbital
energies, positions and shifts of the Lyman lines of C5+,
Al12+ and Ar17+ under strongly coupled plasma with a
view to understand such line positions and shifts obtained in
laser produced plasma experiments. The effect of strongly coupled
plasma has been treated within the Ion Sphere (IS) model. Both
non-relativistic and relativistic methods have been used for
estimating the spectral properties. Theoretical estimates with IS
model of the plasma are in conformity with the results of laser
plasma experiments on these highly stripped ions. The experimental
data for the systems have also been compared with the theoretical
estimates using Debye screening model of the plasma with spatial
confinements which gives additional restrictions to the wave
functions at finite boundaries. 相似文献
42.
Rajinder Singh Manesh Kumar Heena Khajuria Jigmet Ladol Haq Nawaz Sheikh 《Chemical Papers》2018,72(5):1181-1192
Nanocomposite of Fe3O4–nitrogen-doped graphene (Fe3O4–NG) was synthesized by single step hydrothermal method. The as-synthesized composite was characterised by various techniques such as powder X-ray diffraction, Fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, vibrating sample magnetometry and thermal analysis (TGA). The catalytic role of synthesized nanocomposite in visible light induced photodegradation of methyl orange (MO; acidic dye) and methylene blue (MB; basic dye) was explored. The role of Cu(II) ions on the photodegradation of the organic dyes was also monitored. Cu(II) ions enhance the photocatalytic activity of nanocomposite by capturing photoelectron, thereby quenching the recombination process of electron–hole pair in photocatalyst. 相似文献
43.
44.
Sabine Beuermann Muhammad Imran‐ul‐Haq 《Journal of polymer science. Part A, Polymer chemistry》2007,45(23):5626-5635
For the first time, stabilizer‐free vinylidene fluoride (VDF) homopolymerizations were carried out in homogenous phase with supercritical CO2 using the conventional initiator di‐tert butyl peroxide (DTBP). In‐line FT‐NIR spectroscopy showed that complete monomer conversion may be obtained. Molecular weights were determined via size‐exclusion chromatography and polymer endgroup analysis by 1H‐NMR spectroscopy. The number average molecular weights were below 104 g mol?1 and polydispersities ranged from 3.1 to 5.7 depending on DTBP and VDF concentration. For allowing isothermal reaction, high CO2 contents ranging from 61 to 83 wt % were used. The high‐temperature and high‐pressure conditions required for homogeneous polymerization did not alter the amount of defects in VDF chaining. Scanning electron microscopy indicated that regular stack‐type particles are obtained upon expansion of the homogeneous polymerization mixture. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5626–5635, 2007 相似文献
45.
Sirajul Haq Nadia Shahzad Muhammad Imran Shahzad Khaled Elmnasri Manel Ben Ali Alaa Baazeem Amor Hedfi Rimsha Ehsan 《Molecules (Basel, Switzerland)》2022,27(19)
Transmission electron microscopy (TEM), atomic force microscopy (AFM), X-ray diffraction (XRD), energy dispersive X-ray (EDX), scanning electron microscopy (SEM), diffuse reflectance spectroscopy (DRS), and Fourier transform infrared (FTIR) spectroscopy were applied to evaluate the tin dioxide nanoparticles (SnO2 NPs) amalgamated by the sol-gel process. XRD was used to examine the tetragonal-shaped crystallite with an average size of 26.95 (±1) nm, whereas the average particle size estimated from the TEM micrograph is 20.59 (±2) nm. A dose-dependent antifun3al activity was performed against two fungal species, and the activity was observed to be increased with an increase in the concentration of SnO2 NPs. The photocatalytic activity of SnO2 NPs in aqueous media was tested using Rhodamine 6G (Rh-6G) under solar light illumination. The Rh-6G was degraded at a rate of 0.96 × 10−2 min for a total of 94.18 percent in 350 min. 相似文献
46.
Sajid-ur- Rehman Faheem K. Butt Chuanbo Li Bakhtiar Ul Haq Zeeshan Tariq F. Aleem 《Frontiers of Physics》2018,13(3):137805
This study is focused on calculation of the electronic structure and optical properties of non-metal doped Sb2Se3 using the first-principles method. One and two N atoms are introduced to Sb and Se sites in a Sb2Se3 crystal. When one and two N atoms are introduced into the Sb2Se3 lattice at Sb sites, the electronic structure shows that the doping significantly modifies the bandgap of Sb2Se3 from 1.11 eV to 0.787 and 0.685 eV, respectively. When N atoms are introduced to Se sites, the material shows a metallic behavior. The static dielectric constants ε1(0) for Sb16Se24, Sb15N1Se24, Sb14N2Se24, Sb16Se23N1, and Sb16Se22N2 are 14.84, 15.54, 15.02, 18.9, and 39.29, respectively. The calculated values of the refractive index n(0) for Sb16Se24, Sb15N1Se24, Sb14N2Se24, Sb16Se23N1, and Sb16Se22N2 are 3.83, 3.92, 3.86, 4.33, and 6.21, respectively. The optical absorbance and optical conductivity curves of the crystal for N-doping at Sb sites show a significant redshift towards the short-wave infrared spectral region as compared to N-doping at Se sites. The modulation of the static refractive index and static dielectric constant is mainly dependent on the doping level. The optical properties and bandgap narrowing effect suggest that the N-doped Sb2Se3is a promising new semiconductor and can be a replacement for GaSb due to its very similar bandgap and low cost. 相似文献
47.
Non-covalent interactions between met- and leu-enkephalins and their antisense peptides were studied by electrospray ionization mass spectrometry. Mixtures of sense and antisense peptides gave both the corresponding homodimers and heterodimers. The relative abundance ratios of the heterodimer to that of the homodimer of the sense peptide and the relative stability constants of the heterodimers were compared with the corresponding values from mixtures of the sense peptides and a control peptide. The results show that there is a preferential interaction between the sense and antisense peptides compared with that between the sense and control peptides. 相似文献
48.
Magnetic phase evolution, crystallographic texture, microstructure and magnetic properties of Fe–28Cr–15Co–3.5Mo–1.8Ti alloy have been investigated by X-ray diffractometry, scanning transmission electron microscopy and magnetometry techniques as a function of processing conditions. Heat treatment conditions for obtaining optimum textural, microstructural and magnetic properties have been established by the experimentations. The Goss {110}〈001〉 and cube type {001}〈010〉 textures have been developed in an optimal treated Fe–28Cr–15Co–3.5Mo–1.8Ti magnets. The coercive force in Fe–28Cr–15Co–3.5Mo–1.8Ti magnets depends critically on the shape anisotropy of rod-like Fe Co Ti-rich α1 particles and remanence on the alignment and elongation of α1 particles parallel to applied magnetic field 〈100〉 directions. The optimum magnetic properties obtained in Fe–28Cr–15Co–3.5Mo–1.8Ti alloy are intrinsic coercive force, iHc, of 78.8 kA/m (990 Oe), remanence, Br of 1.12 T (11.2 kG) and energy product, (BH)max of 52.5 kJ/m3 (6.5 MGOe). The development of Fe–28Cr–15Co–3.5Mo–1.8Ti magnets as well as characterization of texture, microstructural and magnetic properties in the current study would be helpful in designing the new Fe–Cr–Co–Mo based magnets suitable for scientific and technological applications. 相似文献
49.
Zia Ul Haq Khan Arif Ullah Khan Dandan Kong Shafiullah Khan 《Natural product research》2015,29(10):933-938
The antibacterial and antifungal activities of three new pyrimidine derivatives, namely, 2,6-bis(4,6-dimethylpyrimidin-2-ylthio)benzene-1,4-diol (1),3,5-bis(4,6-dimethylpyrimidin-2-ylthio)-2-methylbenzene-1,4-diol (2) and 3,5-bis(4,6-dimethylpyrimidin-2-ylthio)-2-methoxybenzene-1,4-diol (3), synthesised by electrochemical method are presented here. The compounds were screened for their activities against Gram-positive and Gram-negative bacteria, Bacillus subtilis, Staphylococcusaureus, Escherichia coli and a pathogenic fungus Aspergillus niger. The results show that these compounds have significant activity against these bacteria and fungus. The minimum inhibitory concentration of compound 1 was determined as 62.5 μg/mL against B. subtilis, 125 μg/mL against E. coli and 250 μg/mL against S. aureus establishing its promising activities higher than susceptible ranges. 相似文献
50.
Developing imprinted polymer nanoparticles for the selective separation of antidiabetic drugs 下载免费PDF全文
Isma Haq Adnan Mujahid Adeel Afzal Naseer Iqbal Sadia Zafar Bajwa Tajamal Hussain Khurram Shehzad Hadia Ashraf 《Journal of separation science》2015,38(19):3469-3476
In this study, new molecularly imprinted polymer (MIP) nanoparticles are designed for selective recognition of different drugs used for the treatment of type 2 diabetes mellitus, i.e. sitagliptin (SG) and metformin (MF). The SG‐ and MF‐imprinted polymer nanoparticles are synthesized by free‐radical initiated polymerization of the functional monomers: methacrylic acid and methyl methacrylate; and the crosslinker: ethylene glycol dimethacrylate. The surface morphology of resultant MIP nanoparticles is studied by atomic force microscopy. Fourier transform infrared spectra of MIP nanoparticles suggest the presence of reversible, non‐covalent interactions between the template and the polymer. The effect of pH on the rebinding of antidiabetic drugs with SG‐ and MF‐imprinted polymers is investigated to determine the optimal experimental conditions. The molecular recognition characteristics of SG‐ and MF‐imprinted polymers for the respective drug targets are determined at low concentrations of SG (50–150 ppm) and MF (5–100 ppm). In both cases, the MIP nanoparticles exhibit higher binding response compared to non‐imprinted polymers. Furthermore, the MIPs demonstrate high selectivity with four fold higher responses toward imprinted drugs targets, respectively. Recycled MIP nanoparticles retain 90% of their drug‐binding efficiency, which makes them suitable for successive analyses with significantly preserved recognition features. 相似文献