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101.
Electron paramagnetic resonance and optical absorption spectra of radiation damage products of undoped and CrO42- doped ammonium alum are studied. On X-irradiation at room temperature several paramagnetic species like CrO43-, SO3? and O3? are formed in the doped crystals. In the undoped crystals SO3? and O3? are the major radiation damage products. 相似文献
102.
We derive the Bloch equations for a two-level system coupled to a spin bath of infinitely many two-level atoms to examine phase and energy relaxation of an optically excited system. We show that increasing temperature assists coherence. This is reflected in a number of anomalous features of relaxation of the system, e.g., decrease of integrated absorption coefficient with temperature, nonlinear variation of linewidth with incident power. We also predict that thermally induced coherence may result in anomalous narrowing of linewidth, reminiscent (but distinct) of "motional narrowing" of spectral line. The theoretical results are discussed in the light of absorption-emission experiments on single quantum dots. 相似文献
103.
Chidharth Krishnaraj Himanshu Sekhar Jena Florence Lecoeuvre Karen Leus Pascal Van Der Voort 《Molecules (Basel, Switzerland)》2021,26(12)
C2/C1 hydrocarbon separation is an important industrial process that relies on energy-intensive cryogenic distillation methods. The use of porous adsorbents to selectively separate these gases is a viable alternative. Highly stable covalent triazine frameworks (urea-CTFs) have been synthesized using 1,3-bis(4-cyanophenyl)urea. Urea-CTFs exhibited gas uptakes of C2H2 (3.86 mmol/g) and C2H4 (2.92 mmol/g) at 273 K and 1 bar and is selective over CH4. Breakthrough simulations show the potential of urea-CTFs for C2/C1 separation. 相似文献
104.
S. N. Bhadani Madhu Tiwari Archana Agrawal Chandra Sekhar Kavipurapu 《Mikrochimica acta》1994,117(1-2):15-22
A sensitive Spectrophotometric method for the determination of iron with tiron and a cationic surfactant, cetylpyridinium chloride, at pH 5.6 is reported. The complex is extracted into a chloroform-propan-2-ol (41) mixture and shows maximum absorbance at 520 nm. Beer's law is obeyed in the range 1–14 g/ml with an average molar absorptivity of 15800 l mol–1 cm–1. The molar ratio as determined by Job's method for Fe:tiron:CPC is 143. Interferences by various ions are examined. Zr, Ti and Mo interfere heavily. The method is applied for the determination of iron in Al-based and Cu-based alloys, using appropriate masking agents. 相似文献
105.
S. N. Bhadani Madhu Tewari Archana Agrawal K. Chandra Sekhar 《Analytical and bioanalytical chemistry》1994,349(6):478-481
A red, water-soluble complex of nickel with PAR can be extracted into chloroform with CTAB at pH 7.0. The system obeys Beer's law upto 0.5 μg/ml with a molar absorptivity of 45 200 L·mol?1·cm?1 at 540 nm. Job's method of continuous variations revealed that the composition of the extracting species is 1:2:2 for nickel:PAR:CTAB. Based on this extraction, a highly sensitive and selective spectrophotometric method for the determination of nickel in polymetallic sea-bed nodules and in steels, after prior separation of iron and manganese, was developed. The standard deviation was 0.04–0.127 μg for 5–25 μg of nickel. 相似文献
106.
The phase boundary of the binary liquid system CS2+CH3NO2 is studied over nearly six decades in reduced temperature 3×10−6<ε=(T
C−T)/T
C<2×10−1 and over the composition range 8-98 mole % of CS2. The critical parameters areT
C=335.132K andx
C=57.34 mole % of CS2. A single critical exponentβ=0.315±0.004 fits the observations over the entire range with no indication ofβ increasing to the classical value of 1/2 far away fromT
C. The diameter of the coexistence curve shows a rectilinear behaviour only far away fromT
C. NearT
C, the deviation ΔX from the rectilinear law seems to fit a curve of the form ΔX=fε7/8 exp (−gε
h), the derivative of which has a singularity like that of specific heat. An ambiguity in the analysis of the data in terms
of mole fractions and volume fractions is pointed out. It is also suggested that the curvature of the diameter may be much
weaker in a liquid-gas system and hence might have escaped detection. 相似文献
107.
Ratha Satyajit Vernekar Dnyanesh Sivaneri Kavin Jagadeesan Dinesh Rout Chandra Sekhar 《Journal of Solid State Electrochemistry》2017,21(6):1665-1674
Journal of Solid State Electrochemistry - In this work, we report the synthesis and electrode applications of iron-carbon nanohybrid particles prepared by carbonization of a nanocomposite of FeOOH... 相似文献
108.
Raveendran P. Saji Sekhar S. Joseph 《Journal of Thermal Analysis and Calorimetry》2019,136(1):381-388
Journal of Thermal Analysis and Calorimetry - Domestic refrigerator is one of the major energy-consuming appliances, and the enhancement of its energy efficiency plays a vital role in implementing... 相似文献
109.
Chandra Sekhar D. Venkata Rao D. V. Tejeswara Rao A. Lav Kumar U. Jha Anjali 《Russian Journal of General Chemistry》2019,89(4):770-779
Russian Journal of General Chemistry - A series of novel 5-phenyl-substituted 1,3,4-thiadiazole-2-amines were designed, synthesized, and screened for their antitumor and antitubercular activities.... 相似文献
110.