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排序方式: 共有235条查询结果,搜索用时 15 毫秒
51.
R. M. Godbole A. Grau G. Pancheri Y. N. Srivastava 《The European Physical Journal C - Particles and Fields》2009,63(1):69-85
In this paper we apply to the photoproduction total cross section a model we have proposed for purely hadronic processes and
which is based on QCD mini-jets and soft gluon re-summation. We compare the predictions of our model with the HERA data as
well as with other models. For cosmic rays, our model predicts substantially higher cross sections at TeV energies than models
based on factorization, but lower than models based on mini-jets alone, without soft gluons. We discuss the origin of this
difference. 相似文献
52.
An efficient synthesis of naturally occurring and biologically active furonaphthoquinones is described starting from suitably substituted dihydronaphthofuraps. 相似文献
53.
More Ganesh Vijay Hanumantha Rao Y. V. Kedar S. A. Gawande S. H. 《Journal of Thermal Analysis and Calorimetry》2022,147(12):7043-7062
Journal of Thermal Analysis and Calorimetry - Current environmental issues and depletion of natural petroleum resources demand alternative fuels for transportation. The present study deals with... 相似文献
54.
Nonstoichiometric (Cu2−xSe) and stoichiometric (CuSe, β-Cu2Se and Cu2Se) copper selenide hexagonal nanoplates have been synthesized using different general and convenient copper sources, e.g. copper chloride, copper sulphate, copper nitrate, copper acetate, elemental copper with elemental selenium, friendly ethylene glycol and hydrazine hydrate in a defined amount of water at 100 °C within 12 h adopting the solvothermal method. Phase analysis, purity and morphology of the product have been well studied by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray diffraction (EDAX) techniques. The structural and compositional analysis revealed that the products were of pure phase with corresponding atomic ratios. SEM, TEM and HRTEM analyses revealed that the nanoplates were in the range 200–450 nm and the as-prepared products were uniform and highly crystallized. The nanoplates consisted of {0 0 1} facets of top–bottom surfaces and {1 1 0} facets of the other six side surfaces. This new approach encompasses many advantages over the conventional solvothermal method in terms of product quality (better morphology control with high yield) and reaction conditions (lower temperatures). Copper selenide hexagonal nanoplates obtained by the described method could be potential building blocks to construct functional devices and solar cell. This work may open up a new rationale on designing the solution synthesis of nanostructures for materials possessing similar intrinsic crystal symmetry. On the basis of the carefully controlled experiments mentioned herein, a plausible formation mechanism of the hexagonal nanoplates was suggested and discussed. To the best of our knowledge, this is the first report on nonstoichiometric (Cu2−xSe) as well as stoichiometric (CuSe, β-Cu2Se and Cu2Se) copper selenide hexagonal nanoplates with such full control of morphologies and phases by this method under mild conditions. 相似文献
55.
Anna Celaya Anant P. Godbole Mandy Rae Schleifer 《Methodology and Computing in Applied Probability》2006,8(3):357-371
The classical Erdős–Ko–Rado (EKR) Theorem states that if we choose a family of subsets, each of size k, from a fixed set of size
, then the largest possible pairwise intersecting family has size
. We consider the probability that a randomly selected family of size t=t
n
has the EKR property (pairwise nonempty intersection) as n and k=k
n
tend to infinity, the latter at a specific rate. As t gets large, the EKR property is less likely to occur, while as t gets smaller, the EKR property is satisfied with high probability. We derive the threshold value for t using Janson’s inequality. Using the Stein–Chen method we show that the distribution of X
0, defined as the number of disjoint pairs of subsets in our family, can be approximated by a Poisson distribution. We extend
our results to yield similar conclusions for X
i
, the number of pairs of subsets that overlap in exactly i elements. Finally, we show that the joint distribution (X
0, X
1, ..., X
b
) can be approximated by a multidimensional Poisson vector with independent components.
相似文献
56.
K. Venugopal Chetty P. M. Mapara A. G. Godbole Rajendra Swarup 《Journal of Radioanalytical and Nuclear Chemistry》1997,223(1-2):193-198
Ion-exchange studies on uranium and plutonium using macroporous (MP) anion-exchange resins from an aqueous-organic solvent mixed media were carried out to develop a separation method. Out of the several water miscible organic solvents tried methanol and acetone were found to be best suited. Distribution data were obtained for U(VI) and Pu(IV) using three macroporous resins under various parameters. Based on these data, separation factors for Pu/U were calculated. Column experiments using Tulsion A-27(MP) were also carried out. The method has the advantage of loading plutonium from as low as 1M nitric acid in the presence of methanol or acetone and could be used satisfactorily for its recovery from solutions containing plutonium and uranium. 相似文献
57.
A. G. Page S. V. Godbole Sandhya Deshkar Y. Babu B. D. Joshi 《Fresenius' Journal of Analytical Chemistry》1977,287(4-5):304-309
Summary An emission spectrographic method has been developed for the estimation of 22 metallic impurities in plutonium dioxide using carrier-distillation technique Silver chloride at 5% concentration in a charge of 100 mg has been used as the carrier. Mixed oxide standards containing 10% PuO2 have been used for the analysis of matching composition of plutonium samples. Precision and accuracy determinations of the synthetic samples indicate 7–16% deviation for most of the elements. The work described includes analysis of reference samples and matrix effect studies. The method is suitable for the chemical quality control analysis of plutonium oxide to be used for Fast Breeder Test Reactor (FBTR) fuel.
Spektralanalytische Bestimmung von metallischen Verunreinigungen in PuO2
Zusammenfassung Mit dem Verfahren der Trägerdestillation können 22 Elemente in Plutoniumdioxid spektralanalytisch erfaßt werden. Als Träger dient 5% Silberchlorid in je 100 mg. Mischoxid-Standards mit 10% PuO2 wurden verwendet. Bei der Untersuchung von Genauigkeit und Reproduzierbarkeit synthetischer Proben wurden für die meisten Elemente Abweichungen von 7–16% festgestellt. Matrixeinflüsse wurden ebenfalls untersucht sowie Analysenergebnisse für bestimmte Bezugsstandards mitgeteilt. Das Verfahren eignet sich für die Qualitätskontrolle von PuO2-Brennstoffen für schnelle Brutreaktoren.相似文献
58.
Analyzing the performance of a nanosatellite cluster-detector array receiver for laser communication
This work analyzes laser communication between a cluster of nanosatellites, which is a concentrated formation of small lightweight satellites and a ground station. The scenario under consideration is a cluster of nanosatellites communicating by means of a laser beam with a detector array receiver that is located on the earth's surface and equipped with a common optical system for all incoming beams. The beams are concentrated to spots over the detector plane by the receiver's optics. The detector array enables the ground station to communicate with a tight concentration of the nanosatellites, which reduces system complexity and cost. A critical parameter that determines the successful receipt and subsequent decoding of a transmitted signal for a given configuration is the angular separation between the satellites within the cluster. This separation must be retained to prevent critical overlapping of the spots on the detector's surface. The maximum allowable overlapping is calculated in terms of given bit-error rate. The spatial spreading of the beams, caused by scattering from aerosols in different layers of the atmosphere, is calculated for the case of single scattering. A stratified model of the atmosphere is used. Turbulence influences the beam width, especially for the case of short exposure, and is primarily caused by temperature changes, which result in fluctuations in the refractive index. In this research, a new approach is adopted for analyzing communication network performance through the atmosphere by applying optical-transfer function (OTF) concepts used in imaging and remote sensing. We evaluate the effectiveness of this new approach in applications where spatial spread between the users is very important. 相似文献
59.
Rohini M. Godbole Agnes Grau Rohit Hegde Giulia Pancheri Yogi Srivastava 《Pramana》2006,66(4):657-668
In this note, we summarize and compare various model predictions forpp total cross-section σ
tot
pp
, giving an estimate of the range of predictions for the total cross-section, σ
tot
pp
expected at the LHC. We concentrate on the results for σ
tot
pp
obtained in a particular QCD based model of the energy dependence of the total cross-section, including the effect of soft
gluon radiation. We obtain the range of predictions in this model by exploring the allowed range of model parameters. We further
give a handy parametrisation of these results which incidentally spans the range of various other available predictions at
the LHC as well 相似文献
60.
A. Belyaev I. A. Christidi A. De Roeck R. M. Godbole B. Mellado A. Nyffeler C. Petridou D. P. Roy 《Pramana》2009,72(1):229-237
We report on a plan to establish a ‘Dictionary of LHC Signatures’, an initiative that started at the WHEPP-X workshop in Chennai,
January 2008. This study aims at the strategy of distinguishing 3 classes of dark matter motivated scenarios such as R-parity conserved supersymmetry, little Higgs models with T-parity conservation and universal extra dimensions with KK-parity for generic cases of their realization in a wide range
of the model space. Discriminating signatures are tabulated and will need a further detailed analysis.
相似文献