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71.
C Nasim 《Journal of Mathematical Analysis and Applications》1979,67(1):163-170
In this note we give a procedure for inverting the integral transform f(x) = ∫0∞k(xt) φ(t) dt, where the functions f(x) and k(x) are known and φ(x) is to be found. The inversion is accomplished in two steps: by first defining a transforming function, which is an integral, followed by the application of an infinite order differential operator. 相似文献
72.
Fasih A. Siddiqi M. Nasim Beg Poorna Prakash 《Journal of Electroanalytical Chemistry》1977,80(2):223-238
Thermodynamic effective fixed charge densities of cobalt tungstate and mercuric chromate parchment supported membranes were evaluated by a number of methods particularly those of Teorell-Meyer-Sievers [19]. Altug and Hair [23] and the most recent one of Kobatake et al. [24, 27] based on the thermodynamics of irreversible processes. The value of the permselectivity was also obtained for the two membranes based on Kobatake et al.'s procedure. Kobatake et al.' equation was used under two limiting conditions of concentration of electrolyte solution, namely (1) in the concentrated range, and (2) in the dilute range. The charge densities obtained under these conditions namely θc and θd were found to differ (θc=1/2θd), but it was interesting to note that θc values were more closer to those of the TMS values. The theoretical predictions for membrane potential using Kobatake et al.'s equation are borne out quite satisfactorily by our experimental results for both membranes. 相似文献
73.
Synthesis and Cytotoxic Activity of Some Novel Dihyrobenzo[h]pyrano[3,2‐c]chromene Derivatives
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Nasim Esmati Mahsa Foroughian Mina Saeedi Mohammad Mahdavi Mehdi Khoshneviszadeh Omidreza Firuzi Nader Tanideh Ramin Miri Najmeh Edraki Abbas Shafiee Alireza Foroumadi 《Journal of heterocyclic chemistry》2015,52(1):97-104
Three‐component reaction of 4‐hydroxy‐2H‐benzo[h]chromen‐2‐one, aromatic aldehydes, and malononitrile in the presence of 1,4‐diazabicyclo[2.2.2]octane (DABCO) in ethanol at room temperature affords good yields of novel dihyrobenzo[h]pyrano[3,2‐c]chromene derivatives. The synthesized compounds examined by MTT assays for cytotoxic activity in two human cancer cell lines (MOLT‐4, HL‐60). Most of the evaluated compounds showed low inhibitory activity against tumor cell line at micromolar concentrations. 相似文献
74.
Nasim Amiralian Pratheep K. Annamalai Christopher J. Garvey Edward Jiang Paul Memmott Darren J. Martin 《Cellulose (London, England)》2017,24(9):3753-3766
During the last two decades, work surrounding the preparation of a vast array of cellulose nanomaterials from both wood and non-wood based sources has steadily intensified. This study reports on the isolation of high aspect ratio nanocellulose from an arid grass source commonly called “spinifex”, Triodia pungens, via an optimised sulfuric acid hydrolysis protocol. The unique attributes of T. pungens have enabled pulping and bleaching under milder conditions than used in typically reported protocols, followed by relatively easy deconstruction into nanofibres with an unprecedentedly high aspect ratio. Hydrolysis of bleached T. pungens under these optimised processing conditions has yielded nanocellulose with a very high aspect ratio of 144 (average dimensions of 3.45 ± 1 nm × 497 ± 106 nm), a crystallinity of 73% and a production yield of 42%. Based on the spectroscopic and X-ray scattering analyses, an unusually high content of hemicellulose (42%) is correlated with both the ease of deconstruction and the retention of nanocellulose length. This high hemicellulose content also appears to give rise to a lower transverse stiffness than previously-reported values for wood sources. 相似文献
75.
We introduce the depth parameters of a finite semigroup, which measure how hard it is to produce an element in the minimum ideal when we consider generating sets satisfying some minimality conditions. We estimate such parameters for some families of finite semigroups, and we obtain an upper bound for wreath products and direct products of two finite (transformation) monoids. 相似文献
76.
Masoumeh Heydari Peyman Najafi Moghadam Amir Reza Fareghi Morteza Bahram Nasim Movagharnezhad 《先进技术聚合物》2015,26(3):250-254
Synthesis and characterization of polyaniline‐grafted poly(styrene‐alt‐maleic anhydride) (PANI‐g‐PSMA) was carried out to obtain conductive comb copolymers with highly improved processability. First, polyaniline (PANI) was prepared in nano‐scale by chemical synthesis under ultrasonic irradiation. Then the poly(styrene‐alt‐maleic anhydride) (PSMA) was synthesized by free radical polymerization. Moreover, the PANI was grafted on the PSMA backbone to prepare a comb‐like conductive copolymer for improving its processability as a new method. The products were characterized by Fourier transform infrared, ultraviolet–visible spectroscopy and X‐ray diffraction patterns. Morphology of the samples was also investigated by scanning electron microscopy images. Finally, the solubility and conductivity of the products were studied, and it resulted in high solubility of the products in water and other common organic solvents in comparison to the pure PANI. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
77.
Nasim Hassani 《Molecular physics》2020,118(18)
DFT calculations are utilised to investigate the CO oxidation on the C20, BC19, and NC19 clusters. For CO oxidation over considered clusters, two continuous steps are proposed that in each step one CO2 molecule is released from clusters surface. The calculations demonstrate that in the case of the C20 cluster, the first step of CO oxidation takes place through the ER mechanism on two routes with a barrier height of 1.06?eV and 2.57?eV for the rate-limiting step. Also, in the cases of BC19 and NC19 clusters, both reaction paths occur via the ER mechanism. The activation energy of the first reaction step is about 0.53 and 0.46?eV, while it is negligible for the second step that is 0.04 and 0.18?eV for BC19 and NC19 clusters, respectively. Based on the present theoretical results, the catalytic activity of BC19 and NC19 clusters toward the CO oxidation is more than that of the C20 cluster. These results show that the BC19 and NC19 clusters can be recommended as an efficient and metal-free catalyst for CO oxidation at near ambient temperatures. Research Highlights
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CO oxidation over C20 fullerene has been investigated.
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The effect of N/B-doing on the CO oxidation reaction is also studied.
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The N/B-doping increases the catalytic activity of C20 fullerene.
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Boron/Nitrogen-doped C20 fullerene can be applied as an efficient catalyst for CO oxidation.
78.
Dr. Marco Deiana Dr. Karam Chand Dr. Jan Jamroskovic Dr. Ikenna Obi Dr. Erik Chorell Dr. Nasim Sabouri 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(2):906-912
The design of turn-on dyes with optical signals sensitive to the formation of supramolecular structures provides fascinating and underexplored opportunities for G-quadruplex (G4) DNA detection and characterization. Here, we show a new switching mechanism that relies on the recognition-driven disaggregation (on-signal) of an ultrabright coumarin-quinazoline conjugate. The synthesized probe selectively lights-up parallel G4 DNA structures via the disassembly of its supramolecular state, demonstrating outputs that are easily integrable into a label-free molecular logic system. Finally, our molecule preferentially stains the G4-rich nucleoli of cancer cells. 相似文献
79.
Nasim Babaknejad 《光谱学快报》2019,52(2):81-90
The interaction of enzymes with nanoparticles is important in the field of biotechnology and medicine. Due to the various uses of cadmium telluride nanoparticle in protein science, biotechnology and biophysical chemistry, drug delivery, and cellular imaging, study of this nanoparticle interaction with protein seems to be necessary. Therefore, the interaction between cadmium telluride semiconductor nanoparticle and bovine alkaline phosphatase, a clinical marker enzyme, were investigated by assaying kinetic parameters and fluorescence absorption, UV–vis absorption spectra, and circular dichroism spectroscopic techniques. Obtained results showed that cadmium telluride nanoparticle could quench the fluorescence signal of bovine alkaline phosphatase effectively with a static quenching mechanism. Moreover, the binding of cadmium telluride nanoparticle to the enzyme was spontaneous and van der Waals and hydrogen bonding forces played a key role in the complex stabilization. Circular dichroism spectra measurements indicated that cadmium telluride nanoparticle decreased α-helical content and increased the β-sheet structure of bovine alkaline phosphatase. These findings suggest that cadmium telluride nanoparticle changes the structure and activity of bovine alkaline phosphatase. 相似文献
80.
The suitability of Syrian Portland cement for disposal of solidified low-level radioactive waste was assessed by measuring the leaching rate of 134Cs. In ordinary cement concrete, a leaching rate of 1.309 × 10?3 g/cm2 per day was measured. Mixing this concrete with microsilica reduced significantly the leaching rate to 3.106 × 10?4 g/cm2 per day for 1% mixing, and to 9.645 × 10?5 g/cm2 per day for 3% mixing. It was also found that the application of a latex paint reduced these leaching rates by about 10%. These results, along with mechanical strength tests (under radiation exposure, high temperature, long water immersion and freeze–thaw cycling) indicate that Syrian Portland cement is suited for the disposal of low-level radioactive waste. 相似文献