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排序方式: 共有273条查询结果,搜索用时 386 毫秒
41.
Nano silica powders were synthesized from rice husk ash, the most silica-rich raw material, using alkaline extraction followed by acid precipitation. The phase transformation during sintering, the influence of sintering temperature and pH on the particle size and anti-reflective properties of nano silica were investigated. The results showed that the amorphous SiO2 sintered at 600°C were transformed to a cristobalite structures completely during the sintering process at 800°C and 1100°C. With the increasing sintering temperature and pH, the particle size distributions (d50) were increased respectively in the range of 62–84, 192–240, and 283–329?nm at sintering temperatures of 600°C, 800°C, and 1100°C. When the sintering temperatures were increased at 1100°C, 98.15% and 96.84% of transmittances were obtained respectively at the highest and lowest points of the anti-reflection band and could be used for anti-reflective applications. 相似文献
42.
Prakash Kasirajan Senthil Kumar Puvaneswaran Pandiaraj Sekar Karuthapandian Swaminathan 《Research on Chemical Intermediates》2019,45(3):1147-1167
Research on Chemical Intermediates - In the present study, we report novel graphitic carbon nitride (g-C3N4) nanosheets at different calcination temperatures viz 500 °C,... 相似文献
43.
Tamil Selvi Gopal Soon Kwan Jeong Tahani A. Alrebdi Saravanan Pandiaraj Abdullah Alodhayb Muthumareeswaran Muthuramamoorthy 《Materials Today Chemistry》2022
A recently discovered 2D transition titanium metal carbides also called as MXenes (Ti3C2Tx)-based nanocomposite was prepared with Cu2O through wet precipitation technique, and these materials were further developed as the electrode for sensing glucose by chronoamperometry technique. The prepared MXene-Cu2O (Ti3C2Tx-Cu2O) nanocomposite was characterized by XRD, FTIR, UV–Vis spectroscopy, FE-SEM, EDAX, and Raman spectroscopy. Morphological studies of the composites revealed that the micro-octahedral shape of Cu2O is distributed on the surface of MXene with size larger than bare Cu2O. Further, the prepared composite material was fabricated as a sensing probe, and the electrochemical activities were examined by cyclic voltammetric analysis (CV) and chronoamperometric (CA) methods. From the CV and CA investigation, the current response was higher for the composite than the bare material (Cu2O & MXene) in the presence of glucose. The amperometric investigation of MXene-Cu2O composite for the detection of glucose shows a broad linear range (0.01–30 mM) with a sensitivity of 11.061/μAmM cm?2 and a detection limit of 2.83 μM. Further, the fabricated sensor exhibits good selectivity with interfering species like NaCl, fructose, sucrose, urea, ascorbic acid, lactose, short response time, stability, good reproducibility, and compatibility with human serum sample. From the investigation, the prepared MXene-Cu2O composite is a good candidate for the direct detection of glucose molecules and is also well suitable for clinical diagnosis. 相似文献
44.
45.
R. Prakash K. Srinivasamoorthy S. Gopinath K. Saravanan F. Vinnarasi G. Ponnumani S. Chidambaram P. Anandhan 《Journal of Radioanalytical and Nuclear Chemistry》2018,317(1):25-36
Submarine groundwater discharge is the fresh groundwater discharge to sea that impacts the coastal regions. Radon (222Rn) isotope has been used to quantify SGD in coleroon river estuary, India. Continuous 222Rn analyses were attempted for 10 days in groundwater and pore water samples at three different locations. 222Rn in groundwater ranges between 35.0 and 222.0 Bq m?3 and in pore water between 14.0 and 150.0 Bq m?3 irrespective of locations. The radon mass balance estimated total SGD rate ranges between 2.37 and 7.47 m days?1. The SGD increases with distance from coast, influenced by tides and hydrological features. 相似文献
46.
Glycosyl‐Substituted Dicarboxylates as Detergents for the Extraction,Overstabilization, and Crystallization of Membrane Proteins 下载免费PDF全文
Dr. Kim‐Anh Nguyen Dr. Marine Peuchmaur Sandrine Magnard Dr. Romain Haudecoeur Dr. Cédric Boyère Saravanan Mounien Ikram Benammar Veronica Zampieri Dr. Sébastien Igonet Dr. Vincent Chaptal Dr. Anass Jawhari Prof. Ahcène Boumendjel Dr. Pierre Falson 《Angewandte Chemie (International ed. in English)》2018,57(11):2948-2952
To tackle the problems associated with membrane protein (MP) instability in detergent solutions, we designed a series of glycosyl‐substituted dicarboxylate detergents (DCODs) in which we optimized the polar head to clamp the membrane domain by including, on one side, two carboxyl groups that form salt bridges with basic residues abundant at the membrane–cytoplasm interface of MPs and, on the other side, a sugar to form hydrogen bonds. Upon extraction, the DCODs 8 b , 8 c , and 9 b preserved the ATPase function of BmrA, an ATP‐binding cassette pump, much more efficiently than reference or recently designed detergents. The DCODs 8 a , 8 b , 8 f , 9 a , and 9 b induced thermal shifts of 20 to 29 °C for BmrA and of 13 to 21 °C for the native version of the G‐protein‐coupled adenosine receptor A2AR. Compounds 8 f and 8 g improved the diffraction resolution of BmrA crystals from 6 to 4 Å. DCODs are therefore considered to be promising and powerful tools for the structural biology of MPs. 相似文献
47.
A novel unexpected anionic domino process involving n-BuLi-induced rearrangement of 3,3-bis(methylthio) or 3-methylthio-3-aryl/heteroaryl/alkyl-o-bromoarylacrylonitriles to o-cyanoarylacetylenes in synthetically useful yields has been reported. The scope and generality of the reaction has been examined, and a possible mechanism has been proposed. 相似文献
48.
A novel method for the synthesis of 1,3-enynes is described through oxidative cyclization of the semicarbazones of Michael adducts having potential nitrile functionality. Reaction of these 1,3-enynes with diaryl nitrones has yielded a diastereomeric mixture of highly substituted 2,3-dihydro-1H-pyrrole derivatives via a tandem regioselective addition with subsequent rearrangement. 相似文献
49.
G. Saravanan G. Jyothi Y. Suresh A. Annerao M. Ramakrishna M. Yogeshwar Reddy B. Ravibabu 《Chromatographia》2008,67(1-2):173-177
Levetiracetam is used in combination with other medications to treat certain types of seizures in people with epilepsy. Levetiracetam
is in a class of medications called anticonvulsants and it works by decreasing abnormal excitement in the brain. A chromatographic
separation was achieved on a YMC pack ODS AQ, 250 mm × 4.6 mm, 5 μm column using diluted phosphoric acid and acetonitrile
in the ratio 85:15 v/v. Forced degradation studies were performed on the levetiracetam drug substance. The drug substance was degraded to Imp-B
during acid and base hydrolysis. When the stress samples were assayed, the mass balance was matching. The sample solution
and mobile phase was found to be stable up to 48 h at 25 °C. The developed method was validated with respect to linearity,
accuracy, precision and robustness. 相似文献
50.
An integrable nonlinear Schrödinger (NLS) equation driven by spin polarized current governing the magnetization dynamics of a ferromagnetic nanowire is considered. The exact soliton solution of the NLS equation propagating along the direction of wire axis which is also the current direction along which nonuniform magnetization occurs is obtained through the application of exponential function method. The solution of the system admits a class of solitons such as kink and periodic solitons in the nanowire along the direction of the electric current. 相似文献