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61.
G. Barreau A. Sicre F. Caïtucoli M. Asghar T.P. Doan B. Leroux G. Martinez T. Benfoughal 《Nuclear Physics A》1985,432(2):411-420
Fragment-mass and kinetic-energy distribution measurements for 252Cf(sf) have been extended to the far-out asymmetric low-yield fission region of MH = 190 compared with the existing data that go up to MH ≈ 168. The mass yield Y(m) shows a shoulder for MH ≈ 163 and an important enhancement for MH ? 176. The 〈EK〉(m), σEK(m) and, to a lesser extent, Y(m) distributions show strong and correlated amplitude fluctuations for MH ? 170. These data indicate strong and rapid changes in deformation of the nascent fragments and the coexistence of more than one deformed-shell stabilized scission configuration for the same mass splits. These structures and those present in the relatively high-yield regions are discussed in terms of the static macro-microscopic potential-energy calculations. 相似文献
62.
We give characterizations of different classes of ordered semigroups by using intuitionistic fuzzy ideals. We prove that an
ordered semigroup is regular if and only if every intuitionistic fuzzy left (respectively, right) ideal of S is idempotent. We also prove that an ordered semigroup S is intraregular if and only if every intuitionistic fuzzy two-sided ideal of S is idempotent. We give further characterizations of regular and intra-regular ordered semigroups in terms of intuitionistic
fuzzy left (respectively, right) ideals. In conclusion of this paper we prove that an ordered semigroup S is left weakly regular if and only if every intuitionistic fuzzy left ideal of S is idempotent. 相似文献
63.
The Weibull distribution is widely used in applications such as reliability and lifetime studies. Although this distribution has three parameters, for simplicity, literature pertaining to Weibull parameter estimation relaxes one of its parameters in order to estimate the other two. When the three-parameter Weibull distribution is of interest, the estimation procedure is complicated. For example, the likelihood function for a three-parameter Weibull distribution is hard to maximize. In this paper, a Cross Entropy (CE) method is developed in the context of maximum likelihood estimation (MLE) of a three-parameter Weibull distribution. Performing a simulation study, a comparative analysis between the newly developed method and two existing methods is conducted. The results show the proposed method has better performance in terms of accuracy, precision and run time for different parameter settings and sample sizes. 相似文献
64.
Asghar Anam Raman Abdul Aziz Abdul Daud Wan Mohd Ashri Wan Ramalingam Anantharaj Zain Sharifuddin Bin Md 《Research on Chemical Intermediates》2019,45(6):3311-3327
Research on Chemical Intermediates - Hydrogen peroxide (H2O2) is commercially produced by catalytic oxidation of anthrahydroquinone, which is energy-intensive. Electrochemical production of... 相似文献
65.
Summary The diffraction of a spherical acoustic wave from the juncture of pressure release (soft) and locally reacting (absorbing)
half-planes in a fluid moving at subsonic velocity is examined. This consideration is important because the point sources
are regarded as better substitutes for real sources than line sources/plane waves. The integral representation of the field
is obtained using integral transforms and the Wiener-Hopf technique. The factorization of the kernel function in the Wiener-Hopf
functional equation is accomplished. The analytic solution of the integrals is obtained by employing asymptotic methods and
the far field is presented. The effect of the Mach number is shown explicitly on the diffracted field. 相似文献
66.
A Photoferroelectric Perovskite‐Type Organometallic Halide with Exceptional Anisotropy of Bulk Photovoltaic Effects 下载免费PDF全文
Dr. Zhihua Sun Dr. Xitao Liu Tariq Khan Chengmin Ji Muhammad Adnan Asghar Dr. Sangen Zhao Dr. Lina Li Prof. Maochun Hong Prof. Junhua Luo 《Angewandte Chemie (International ed. in English)》2016,55(22):6545-6550
Perovskite‐type ferroelectrics composed of organometallic halides are emerging as a promising alternative to conventional photovoltaic devices because of their unique photovoltaic effects (PVEs). A new layered perovskite‐type photoferroelectric, bis(cyclohexylaminium) tetrabromo lead ( 1 ), is presented. The material exhibits an exceptional anisotropy of bulk PVEs. Upon photoexcitation, superior photovoltaic behaviors are created along its inorganic layers, which are composed of corner‐sharing PbBr6 octahedra. Semiconducting activity with remarkable photoconductivity is achieved in the vertical direction, showing sizeable on/off current ratios (>104), which compete with the most active photovoltaic material CH3NH3PbI3. In 1 the temperature‐dependence of photovoltage coincides fairly well with that of polarization, confirming the dominant role of ferroelectricity in such highly anisotropic PVEs. This finding sheds light on bulk PVEs in ferroelectric materials, and promotes their application in optoelectronic devices. 相似文献
67.
Binding and fluorescence study on interaction of human serum albumin (HSA) with cetylpyridinium chloride (CPC) 总被引:1,自引:0,他引:1
Human serum albumin (HSA) is frequently used in biophysical and biochemical studies since it has a well-known primary structure and it has been associated with the binding of many different categories of small molecules. In the present study, results are presented for the binding of cetylpyridinium chloride (CPC) with HSA at various pH and 25 degrees C, as monitored using ion selective membrane electrodes and fluorescence spectroscopy of intrinsic tryptophan. The obtained binding isotherms were analyzed on basis of binding capacity concept and Hill plot in order to determine the Hill parameters of binding sets. The system behaved as a system with two sets of binding sites in all studied situations. The results represent a positive cooperative behavior and the essential role of hydrophobic interactions in both binding sets. The intrinsic binding affinity of second binding set have a similar values and trends at acidic and neutral pHs, that represents the similar unfolded structure at these pHs. CPC quenched the fluorescence arising from Trp group incorporated to HSA. A biphasic behavior was observed in quenching process that confirmed the results of binding study correspond to the existence of two binding sets. The similarity of unfolded structure in acidic and neutral pH was also confirmed by fluorescence study. The quenching of HSA fluorescence takes place with a Stern-Volmer constant of 0.643 x 10(4), 1.23 x 10(4) and 7.40 x 10(4) at pH 3.5, 6.8 and 9.5, respectively. The Stern-Volmer behavior observed at low molar ratio of [CPC]/[HSA] (about 6), that represents the occurrence of conformational changes after this molar ratio. Comparing, the K(SV) values and binding parameters indicate that the binding is dominated by hydrophobic effects and, in minor degree, by electrostatic interactions. 相似文献
68.
Tasawar Hayat S. Asghar B. Asghar 《International Journal of Infrared and Millimeter Waves》1999,20(6):1169-1194
The spherical wave scattering response by a perfectly conducting open–ended waveguide in a biisotropic medium is obtained. Interestingly, the vector diffraction problem is reduced to the scattering of a single scalar field, this scalar field being the normal component of either a left–handed or a right–handed Beltrami field. Here, we explicitly consider the scattering of the left–handed field component, that of the other scalar field being analogously tractable. The solution is constructed with the aid of the Wiener–Hopf technique. 相似文献
69.
70.
H. M. Noor ul Huda Khan Asghar Yi Tan Shuang Shi Dachuan Jiang Shiqiang Qin Jiao Liao Shutao Wen Wei Dong Yao Liu 《Applied Physics A: Materials Science & Processing》2014,115(3):753-757
Small amounts of multicrystalline silicon were melted in an electron beam furnace in different experimental conditions in order to investigate the oxygen evaporation behavior during the electron beam melting (EBM) process. The oxygen content level before and after EBM was determined by secondary ion mass spectroscopy. The oxygen content was reduced from 6.177 to 1.629 ppmw when silicon was melted completely at 15 kW with removal efficiency up to 73.6 %. After that, it decreased continually to <0.0517 ppmw when the refining time exceeded 600 s with a removal efficiency of more than 99.08 %. During the melting process, the evaporation rate of silicon is 1.10 × 10?5 kg/s. The loss of silicon could be reduced up to 1.7 % during oxygen removal process to a desirable figure, indicating EBM is an effective method to remove oxygen from silicon and decrease the loss of silicon. 相似文献