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91.
Soljacic M Segev M Coskun T Christodoulides DN Vishwanath A 《Physical review letters》2000,84(3):467-470
We show that modulation instability can exist with partially spatially incoherent light beams in a noninstantaneous nonlinear environment. For such incoherent modulation instability to occur, the value of the nonlinearity has to exceed a threshold imposed by the degree of spatial coherence. 相似文献
92.
The present study aimed at the assessment of natural tritium radioactivity in groundwater, being used for domestic and irrigation
purposes in Varahi and Markandeya river basins. The study also intended to assess human health risk by estimating committed
effective dose due to groundwater ingestion in the study area, taking into consideration the obtained tritium activity concentrations
and annual water consumption. Tritium concentration of groundwater samples from the Varahi and Markandeya river basins were
determined by liquid scintillation counting and the results laid in the range of 1.95 ± 0.25 to 11.35 ± 0.44 TU and 1.49 ± 0.75
to 9.17 ± 1.13 TU in Varahi and Markandeya river basins, respectively. Majority of the samples from Varahi (46.67%) and Markandeya
(62.5%) river basins belong to modern water category aged between 5 and 10 years, while the remaining 53.33% and 37.5% of
the samples from Varahi and Markandeya river basins respectively belong to sub-modern water with modern recharge, significantly
influenced by precipitation and river inflowing/sea water intrusion. The effective committed dose for general public consumption
considering the highest concentration value of 0.02 μSv year−1, which is very negligible compared to EPA (0.04 mSv year−1), WHO (0.1 mSv year−1), ICRP (1.0 mSv year−1) and UNSCEAR (2.4 mSv year−1) recommended dose limits, should not mean any additional health risk for the population living nearby. 相似文献
93.
This study was carried out to investigate the anti-fertility and anti-venom activities of the extract of the stem bark of Butea monosperma by inhibiting hyaluronidase, which is a spreading factor and plays a role in fertilisation. Among ethanol, methanol and water extracts, the ethanol extract dose-dependently inhibited the ovine, mouse testicular and Vipera russelli snake venom hyaluronidase enzyme activities, with IC?? values 12.00?±?0.45, 49.40?±?1.58?μg and 125.42?±?2.82?μg?mL?1, respectively. In a zymogram assay, the extract showed differential inhibition towards hyaluronidase isoform preferentially with low-molecular weight isoforms. The V. russelli snake venom-induced hemorrhage was significantly reduced at 1:05 ratio of venom-to-extract in mouse. The high antioxidant activity and total phenolic content in the ethanolic extract strongly correlated with the hyaluronidase inhibition. The above results justify the traditional use of the stem bark of B. monosperma as a contraceptive and a strong antidote to snake venom. 相似文献
94.
Gunaji S. Bayes Sambhaji S. Raut Vishwanath R. Patil Rama S. Lokhande 《Journal of solution chemistry》2012,41(2):241-248
Diazepam (7-chloro-1,3-dihydro-1-methyl-5-phenyl-2H-1,4-benzodiazepin-2-one) is an important derivative of the 1,4-benzodiazepine
compound commercially distributed as Valium. The complex formation constants of diazepam with some light lanthanide(III) metal
ions have been studied by potentiometric measurements. All titrations were performed in 50–50% (volume/volume) ethanol–water
solvent mixtures at constant ionic strength (0.10 mol⋅dm−3). The ionic strength was maintained by using sodium perchlorate. The complex formation constants were determined at 25.00,
35.00 and 45.00 °C. With increasing temperature, a decrease was observed in the protonation constant (pK) of diazepam. 相似文献
95.
Systems near to quantum critical points show universal scaling in response to external probes. We consider whether this scaling is reflected in their out-of-equilibrium fluctuations. We study current noise in the metallic state at the z=1 quantum critical point between a superconductor and an insulator in two dimensions. Using a Boltzmann-Langevin approach within a 1/N expansion, we show that the current noise obeys a universal scaling form S_{j}=TPhi[T/T_{eff}(E)], with T_{eff} proportional, variantsqrt[E]. This treatment recovers Johnson noise in thermal equilibrium and S_{j} proportional, variantsqrt[E] at strong electric fields. The latter differs significantly from both the shot noise in conventional metals (diffusive Fermi liquids) and the free carrier result, due to strong correlations between the critical bosonic excitations. Current-noise measurements could therefore help clarify the physics of the destruction of superconductivity in thin film superconductors. 相似文献
96.
Radon concentration in groundwater of Varahi and Markandeya river basins, Karnataka State, India 总被引:2,自引:0,他引:2
The present study presents an overview of the distribution of radon (222Rn) activity concentration in the groundwater samples and their annual effective dose exposure in the Varahi and Markandeya
command areas. Radon measurement was made using Durridge RAD-7 radon-in-air monitor, using RAD H2O technique with closed loop aeration concept. The measured 222Rn activities in 16 groundwater samples of Varahi command area ranged between 0.2 ± 0.4 and 10.1 ± 1.7 Bq L−1 with an average value of 2.07 ± 0.84 Bq L−1, well within the EPA’s maximum contaminant level (MCL) of 11.1 Bq L−1. In contrast, the recorded 222Rn activities in 14 groundwater samples of Markandeya command area found to vary from 2.21 ± 1.66 to 27.3 ± 0.787 Bq L−1 with an average value of 9.30 ± 1.45 Bq L−1. 21.4% of the samples (sample no. RMR5, RMR11 and RMR12) in the Markandeya command area exceeded the EPA’s MCL of 11.1 Bq L−1 and it was found that some samples in both the command areas were found to have radon values close to MCL value. The spatial
variation in the radon concentration in the Varahi and Markandeya command area were delineated by constructing the contour
map. The total annual effective dose resulting from radon in groundwater of both Varahi and Markandeya command areas were
significantly lower than the UNSCEAR and WHO recommended limit for members of the public of 1 mSv year−1. 相似文献
97.
Vinay Vishwanath Michael Sulyok Roman Labuda Wolfgang Bicker Rudolf Krska 《Analytical and bioanalytical chemistry》2009,395(5):1355-1372
This paper describes the application of a previously published multi-mycotoxin method for food and feed matrices based on
liquid chromatography/electrospray ionization-tandem mass spectrometry (HPLC/ESI-MS/MS) to the analysis of microbial metabolites
in indoor matrices. The range of investigated analytes has been extended by 99 fungal and bacterial metabolites to cover now
186 compounds overall. The method is based on a single extraction step using an acidified acetonitrile/water mixture (which
has been determined to be preferable to methanol and ethyl acetate) followed by analysis of the diluted crude extract. The
analytical signal of one third of the investigated analytes was reduced by more than 50% due to matrix effects in a spiked
extract of house dust, whereas the other investigated materials were less critical in that aspect. For determination of method
performance characteristics, a spiked reference material for house dust was chosen as a model sample for an extremely complex
matrix. With few exceptions, coefficients of variation of the whole procedure of <10% and limits of detection of <50 μg kg−1 were obtained. The apparent recoveries were below 50% for half of the investigated analytes due to incomplete extraction
and/or detection-related matrix effects. The application of the method to 14 samples from damp buildings revealed the presence
of 20 different analytes at concentrations of up to 130 mg kg−1. Most of these compounds have never been identified before in real-world samples, although they are known to be produced
by indoor-relevant fungi. This underlines the great value of the described method for the on-site determination of microbial
metabolites.
相似文献
98.
We study transport in Weyl semimetals with N isotropic Weyl nodes in the presence of Coulomb interactions or disorder at temperature T. In the interacting clean limit, we determine the conductivity σ(ω,T) by solving a quantum Boltzmann equation within a "leading log" approximation and find it to be proportional to T, up to logarithmic factors arising from the flow of couplings. In the noninteracting disordered case, we compute the Kubo conductivity and show that it behaves differently for ω < T and ω > T: in the former regime we recover a previous result, of a finite dc conductivity and a Drude width vanishing as NT(2); in the latter, we find that σ(ω,T) vanishes linearly with ω with a leading term as T → 0 equal to the clean, free-fermion result: σ(0)((N))(ω,T = 0) = Ne(2)/12h|ω|/v(F). We compare our results to transport data on Y(2)Ir(2)O(7) and comment on the possible relevance to recent experiments on Eu(2)Ir(2)O(7). 相似文献
99.