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131.
Fiber-optic beam shaper based on multimode interference 总被引:1,自引:0,他引:1
A new method of fiber-optic based beam shaping is investigated both numerically and experimentally. A cylindrically symmetric method of lines (MoLs) is developed to simulate the device. The device is fabricated by fusion splicing a predetermined length of multimode fiber (MMF) to a single-mode fiber. The multimode interference (MMI) effects create ring-shaped field profiles at certain positions inside the MMF. The shaped beam can be used in medical applications requiring particular irradiation patterns. 相似文献
132.
Ziyat Hamid Elmzioui Souad Naciri Bennani Mohammed Houssaini Jamal Allaoui Safae Arhzaf Said 《Research on Chemical Intermediates》2021,47(6):2605-2627
Research on Chemical Intermediates - The objective of this work is to test the effectiveness of hydrotalcite as an adsorbent for the retention of nitrate and nitrite ions and to study the influence... 相似文献
133.
Majdoub Mohammed Essamlali Younes Amadine Othmane Ganetri Ikram Hafnaoui Anass Khouloud Mehdi Zahouily Mohamed 《Cellulose (London, England)》2021,28(12):7717-7734
Cellulose - A novel, environmentally friendly and simple method for chemical functionalization of microcrystalline cellulose (MCC) to produce organophilic cellulose nanocrystals (CNC-ODA) is herein... 相似文献
134.
135.
Mohammed S.H.?SuleimanEmail author Daniel P.?Joubert 《The European Physical Journal B - Condensed Matter and Complex Systems》2015,88(11):305
In the present work, the atomic and the electronic structures of Au3N, AuN and AuN2 are investigated using first-principles density-functional theory (DFT). We studied cohesive energy vs. volume data for a wide range of possible structures of these nitrides. Obtained data were fitted to a Birch-Murnaghan third-order equation of state (EOS) so as to identify the most likely candidates for the true crystal structure in this subset of the infinite parameter space, and to determine their equilibrium structural parameters. The analysis of the electronic properties was achieved by the calculations of the band structure and the total and partial density of states (DOS). Some possible pressure-induced structural phase transitions have been pointed out. Further, we carried out GW0 calculations within the random-phase approximation (RPA) to the dielectric tensor to investigate the optical spectra of the experimentally suggested modification: Au3N(D09). Obtained results are compared with experiment and with some available previous calculations. 相似文献
136.
Alam Perwez Siddiqui Nasir Ali Al-Rehaily Adnan J. Alajmi Mohamed Fahad Basudan Omar Ahmed Khan Tajdar Hussain 《平面色谱法杂志一现代薄层色谱法》2014,27(3):204-209
JPC – Journal of Planar Chromatography – Modern TLC - A simple, sensitive, and stability-indicating high-performance thinlayer chromatography (HPTLC)-densitometric method was developed... 相似文献
137.
Dongyi Liu Dr. Ahmed M. El-Zohry Maria Taddei Clemens Matt Laura Bussotti Dr. Zhijia Wang Prof. Jianzhang Zhao Prof. Omar F. Mohammed Prof. Mariangela Di Donato Prof. Stefan Weber 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(28):11688-11696
We prepared conceptually novel, fully rigid, spiro compact electron donor (Rhodamine B, lactam form, RB)/acceptor (naphthalimide; NI) orthogonal dyad to attain the long-lived triplet charge-transfer (3CT) state, based on the electron spin control using spin-orbit charge transfer intersystem crossing (SOCT-ISC). Transient absorption (TA) spectra indicate the first charge separation (CS) takes place within 2.5 ps, subsequent SOCT-ISC takes 8 ns to produce the 3NI* state. Then the slow secondary CS (125 ns) gives the long-lived 3CT state (0.94 μs in deaerated n-hexane) with high energy level (ca. 2.12 eV). The cascade photophysical processes of the dyad upon photoexcitation are summarized as 1NI*→1CT→3NI*→3CT. With time-resolved electron paramagnetic resonance (TREPR) spectra, an EEEAAA electron-spin polarization pattern was observed for the naphthalimide-localized triplet state. Our spiro compact dyad structure and the electron spin-control approach is different to previous methods for which invoking transition-metal coordination or chromophores with intrinsic ISC ability is mandatory. 相似文献
138.
Rambabu Sirgamalla Kurumanna Adem Sakram Boda Ashok Kommakula Suryam Neradi Shyam Perka Kiran Bojja Mohammed Arifuddin 《Journal of heterocyclic chemistry》2020,57(9):3375-3383
We report herein DABCO mediated one pot synthesis of 2-(3-benzyl-2, 6-dioxo-3,6-dihydropyrimidin-1[2H]-yl)-N-(4-(1,3-dioxo-1H-benzo[de]isoquinolin-2[3H]-yl) aryl) acetamides ( 4a-j ). The silent features of this new one pot synthesis include the shorter reaction time, high yields, simple workup, and simultaneous formation of N-Amide and N-benzyl bonds in the one pot. The newly synthesized compounds ( 4a-j ) were characterized by different spectral techniques such as IR, 1H-NMR, 13C-NMR, HRMS. All the synthesized compounds were evaluated for their anti-bacterial and anti-fungal activities. The anti-bacterial activities results reveal that the compounds 4a , 4g , 4i , and 4j are most active against S. aureus. In the case of B. subtilis the compounds 4a , 4i , and 4j are found to be most active. The compounds 4c , 4e , 4i , and 4j are most active against E. coli. In the case of P. aeruginosa 4a , 4i & 4j are found to be more active. On the other hand, the anti-fungal activity result shows that the compounds 4d , 4f , 4i , and 4j are more active against A. niger. The compounds 4a , 4d , 4i , and 4j are found to be more active against C. albicans. 相似文献
139.
Mounir A. A. Mohamed Omyma A. Abd Allah Adnan A. Bekhit Asmaa M. Kadry Ahmed M. M. El-Saghier 《Journal of heterocyclic chemistry》2020,57(6):2365-2378
New series of triazole derivatives coupled with amino acids 1a-h were obtained via multicomponent reaction of 2-hydroxy benzaldehyde or 2-hydroxy acetophenone with thiosemicarbazide and different amino acids. The obtained compounds were reacted with p-toluinesulfonyl chloride 2 to give the corresponding sulfonamides 3a-h . Compound 1b was allowed to react with different aromatic aldehydes or cyclic ketone under alkaline conditions to afford the expected imino compounds 4a-d and 6a-c , respectively. These compounds were allowed to react with ethyl glycolate to yield the expected thiazolidinone derivatives 5a-d or 7a-c , respectively. Structures of the newly synthesized compounds were found to be in accordance with their elemental analyses and spectral data. The obtained compounds exhibited very prominent in vitro and in vivo antihyperglycemic effect at a dose of 40 mg/kg body weight compared to the standard drug gliclazide and control. The antidiabetic effect was investigated using oral glucose tolerance test in normal and non-insulin-dependent diabetes mellitus (NIDDM) in STZ-rat model. Compounds 3a - h , 5b , 5c , 5d , 7a , 7b , and 7c showed significant activity in lowering blood glucose (more than 80%) compared to the NIDDM control. 相似文献
140.
Reda Mohammed Keshk 《Journal of heterocyclic chemistry》2020,57(9):3384-3393
Reaction of 3-cyano-4,6-dimethyl-2-pyridone with ethyl chloroacetate afforded ethyl 2-([3-cyano-4,6-dimethylpyridin-2-yl]oxy)acetate 2 and ethyl 2-(3-cyano-4,6-dimethyl-2-oxopyridin-1[2H]-yl)acetate 3 , the reaction product yield depend on the reaction condition (potassium carbonate concentration and reaction time). These compounds used as precursors to synthesize pyridine derivatives 4 , 6-10 , 15, 17-20 , furopyridines 5, 16 , pyrazolopyridine 12 , pyridopyrazolopyrimidines 14a,b . The structure of the newly synthesized compounds was confirmed by spectral data (IR, NMR, and mass spectra) and elemental analysis. 相似文献