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An Optimal DF Based method for Transient Stability Analysis

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Computers, materials & Continua 2022年第2期70卷 3449-3471页

作者： Z.A.Zaki Emad m.Ahmed Ziad m.Ali Imran Khan Department of Electrical Engineering College of EngineeringJouf UniversitySakaka2014Al-JoufSaudi Arabia Electrical Engineering Department College of EngineeringPrince Sattam bin Abdulaziz UniversityWadi Addawaser11991Saudi Arabia Electrical Engineering Department Aswan Faculty of EngineeringAswan UniversityAswan81542Egypt Department of Electrical Engineering University of Engineering and Technology PeshawarPakistan

The effect of energy on the natural environment has become increasingly severe as human consumption of fossil energy has *** capacity of the synchronous generators to keep working without losing synchronization when the system is exposed to severe faults such as short circuits is referred to as the power system’s transient *** the power system’s safe and stable operation and mechanism of action become more complicated,higher demands for accurate and rapid power system transient stability analysis are *** methods for analyzing transient stability are less accurate because they do not account formisclassification of unstable *** a result,this paper proposes a novel approach for analyzing transient *** key concept is to use deep forest(DF)and a neighborhood rough reduction approach *** the neighborhood rough sets,the original feature space is obtained by creating many optimal feature subsets at various granularity ***,by deploying the DF cascade structure,the mapping connection between the transient stability state and the features is *** weighted voting technique is used in the learning process to increase the classification accuracy of unstable *** contrasted to current methods,simulation results indicate that the proposed approach outperforms them.

关键词： Transient stability analysis power system cascade structure optimal power flow

Atom microscopy via Dual Resonant Superposition

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Communications in Theoretical Physics 2015年第12期64卷 741-746页

作者： m.S.Abdul Jabar Bakht Amin Bacha m.Jalaluddin Iftikhar Ahmad Department of Physics University of Malakand

An m-type Rb^(87) atomic system is proposed for one-dimensional atom microscopy under the condition of Electromagnetically Induced ***-localization of the atom in the absorption spectrum while its delocalization in the dispersion spectrum is observed due to the dual superposition effect of the resonant *** observed minimum uncertainty peaks will find important applications in Laser cooling,creating focused atom beams,atom nanolithography,and in measurement of the center-of-mass wave function of moving atoms.

关键词： atom microscopy resonant fields susceptibility

应用增强CT和CA19-9术前预测R0切除后胰腺导管腺癌病人的无病生存率

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国际医学放射学杂志 2024年第2期 251-251页

作者： D.F.Li Q.Peng L.Y.wang w.Cai m.Liang S.Y.Liu 朱婉秋

摘要目的探讨术前增强CT和CA19-9联合预测胰腺导管腺癌（PDAC）R0切除术后无病生存期（DFS）的价值。方法回顾性纳入138例接受根治性R0切除术的PDAC病人，

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Barrier height and ideality factor dependency on identically produced small Au/p-Si Schottky barrier diodes

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Journal of Semiconductors 2010年第7期31卷 16-21页

作者： m.A.Yeganeh S.H.Rahmatollahpur Faculty of Physics Baku State UniversityAcademic Zahid X■lilov ksi-23AZ 1148BakuAzerbaijan Departments of Physics Sharif University of Technology11365-9567TehranIran

Small high-quality Au/P-Si Schottky barrier diodes（SBDs） with an extremely low reverse leakage current using wet lithography were *** effective barrier heights（BHs） and ideality factors from current-voltage （Ⅰ-Ⅴ） characteristics were measured by a conducting probe atomic force microscope（C-AFm）.In spite of the identical preparation of the diodes there was a diode-to-diode variation in ideality factor and barrier height *** extrapolating the plots the built in potential of the Au /p-Si contact was obtained as V_（bi）=0.5425 V and the barrier height valueΦ_（b（c-V）） was calculated to beΦ_（B（C-V））=0.7145 V for Au/*** is found that for the diodes with diameters smaller than 100μm,the diode barrier height and ideality factor dependency to their diameters and correlation between the diode barrier height and its ideality factor are nonlinear,where similar to the earlier reported different metal semiconductor diodes in the literature,these parameters for the here manufactured diodes with diameters more than 100μm are also *** on the very obvious sub-nanometer C-AFm produced pictures the scientific evidence behind this controversy is also explained.

关键词： Schottky barrier diodes conducting probe-atomic force microscope barrier height and ideality factor

Antioxidative effect of fullerenol on goat epididymal spermatozoa

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Asian Journal of Andrology 2002年第2期4卷 149-152页

作者： m.Arulmurugan BinduGangadharan 等 SchoolofLifeSciences PondicherryUniversityPondicherry605014India

OBJECTIVE:To evaluate the effect of fullerenol on the antioxidant system of goat epididymal sperm.;mETHODS:Fresh epididymides of adult goats were obtained from local slaughter houses and sperm were collected by chopping the epididymis in modified Ringer's phosphate solution (RPS medium). After several washings the sperm samples were equally dispersed in RPS medium and incubated with fullerenol (1, 10 and 100 micromol) and FeSO(4)/ascorbate (40/200 micromol) with or without fullerenol (1, 10 and 100 micromol) for 3 h at 32 degree C. After incubation, an aliquot of sperm samples were homogenized and centrifuged and the supernatant used for biochemical studies.;RESULTS:In FeSO(4)/ascorbate-incubated samples, the activities of antioxidant enzymes, superoxide dismutase, glutathione peroxidase and glutathione reductase, were decreased while lipid peroxidation increased as compared to the control sperm samples. In fullerenol-incubated sperm samples, the activities of superoxide dismutase, glutathione peroxidase and glutathione reductase were increased while lipid peroxidation was decreased in a dose-dependent manner. Co-incubation of sperm with fullerenol (1,10 and 100 micromol) and FeSO(4)/ascorbate (40/200 micromol) increased the activities of antioxidant enzymes and prevented the iron-induced elevation of lipid peroxidation in a dose-dependent manner.;CONCLUSIONS:Fullerenol reduces iron-induced oxidative stress in epididymal sperm of goat by increasing the activities of antioxidant enzymes and decreasing lipid peroxidation.

关键词： Antioxidant enzymes Fullerenol Goat Iron Lipid peroxidation Oxidative stress Spermatozoa

Isolation, Biochemical Characterization and DNA Identification of Yogurt Starters <i>Streptococcus thermophilus</i>&<i>Lactobacillus delbrueckii ssp. bulgaricus</i>in Gaza Strip

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Advances in microbiology 2018年第12期8卷 1005-1020页

作者： Kamal E.m.El Kahlout Ismail m.El Quqa mahmoud w.El Hindi Tarek A.El Bashiti Department of Biology&Biotechnology Islamic UniversityGazaPalestine

Background: milk is a healthy human nutrient, which is fermented to yogurt by lactic acid bacteria, mainly Streptococcus salivarius ssp, thermophilus and Lactobacillus. delbrueckii ssp. bulgaricus. This study aimed to isolate thermophilic starter bacteria from homemade yogurt made in Gaza Strip. The study sought to define both the biochemical and molecular characteristics of the isolated bacteria. Results: Three of the isolates were identified as Streptococcus thermophiles while two isolates were recognized as Lactobacillus delbrueckii ssp. bulgaricus. All five identified isolates showed worthy acidification capacity. Based on these characters, strains were applied for making yogurt either as single pure cultures or as mixed cultures. when using mixed cultures from S. thermophiles and L. bulgaricus, all tested combinations showed positive results. Conclusion: Isolated strains showed remarkable biotechnological characters. The isolates are expected to stimulate and improve quality of the yogurt when they are used as mixed starter cultures.

关键词： Thermophilic Lactic Acid Phonotypic Genotypic Yogurt

Assessment of Deformation of Shear Localized Chip in High Speed machining

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厦门大学学报（自然科学版） 2002年第S1期41卷 11-12页

作者： T C LEE w S LAU S K CHAN Industrial System Engineering Department Hong Kong Polytechnic UniversityHong Kong Institute of Vocational EducationGolden Tech Machinery Ltd. Hong Kong China Hong Kong China Hong Kong China

As the cutting speed goes higher, the mechanism of chip deformation will be changed significantly, i.e., continuous chip in low cutting speed will shift to serrated chip with shear localization. For the shear localized chip, the parameters used to assess the chip deformation for continuous chip, such as shorten coefficient ξ, shear angle φ and shear strain ε, can not describe the chip deformation correctly or comprehensively. This paper deals with the assessment of chip deformation of shear localization. There are two deformation regions in shear localized chip, one is the chip segment body with relative smaller plastic deformation, another one is the boundary between segments with shear localization, so called shear band. Considering the two distinct deformation regions, two parameters are used to define their deformation respectively. According to the analysis of chip formation process, the equations have been deduced to calculate the shear strains of shear band ε, shear strain of chip segment ε 1 and shear rate so that the shear localized chip deformation can be assessed correctly and comprehensively. By use of this assessment, the chip deformation in machining selenium treated stainless steel (STSS) and common stainless steel at various cutting conditions is investigated. The experiment results obtained by the machining of stainless steel prove that: (1) the shear strain and strain rate increase with the increasing of cutting speed; (2) the shear strain in shear band can be over 10 when cutting speed exceeding 200 m/min for both types of stainless steel, and it is much higher than the strain of chip segment. The difference will be enlarged as the cutting speed increasing; (3) As the comparison, the shear strain for the STSS is a little lower than that for JIS304; (4) The stain rate is extremely high (= 2.5×10 5 1/s ). In range of cutting speed less than 180 m/min, the strain rate for STSS is lower than that for JIS304. However, when the cutting speed is higher t

关键词： chip deformation shear localization high speed machining

Compositional Effect of ZrO_2 Nanofillers on a PVDF-co-HFP Based Polymer Electrolyte System for Solid State Zinc Batteries

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Chinese Journal of Polymer Science 2016年第3期34卷 332-343页

作者： m.Johnsi S.Austin Suthanthiraraj Department of Energy University of MadrasGuindy Campus

Composite polymer electrolytes（CPEs） comprising poly（vinilydene fluoride-hexafluoro propylene）, PVDF-coHFP and zinc triflate, Zn（CF3SO3）2 with varying concentrations of ZrO_2 nanofillers were prepared by solution casting technique with N,N-dimethyl formamide（DmF） as the common solvent. The polymer electrolyte specimen with the particular composition 75 wt% PVDF-co-HFP： 25 wt% Zn Tf ＋ 7 wt% Zr O2 showed the highest conductivity of 4.6 × 10-4 S/cm at 298 K as confirmed from impedance measurements and favored by the rich amorphous phase of the CPE revealed from room temperature X-ray diffraction analysis（XRD）. The electrical conductivity relaxation time and its distribution within the materials have been evaluated from the electric modulus m 2 and impedance Z＂ data which showed the occurrence of non-Debye type of relaxation phenomenon. The changes in the surface morphology of the CPEs were examined using scanning electron microscopy（SEm）. The electrochemical stability window of CPE is found to be 2.6 V with a thermal stability up to 300 °C. An electrochemical cell has been fabricated based on Zn/mnO_2 electrode couple under a constant load of 1 mΩ and its discharge characteristics have been evaluated.

关键词： Nanocomposites Dielectric properties Thermal stability Electrochemical stability Batteries

Proper Teleparallel Homothetic Vector Fields in General Cylindrically Symmetric Space-Times in Teleparallel Theory of Gravitation Using Diagonal Tetrads

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Communications in Theoretical Physics 2017年第11期67卷 611-616页

作者： Ghulam Shabbir masoom Ali Shahani m.Amer Qureshi F.m.mahomed Faculty of Engineering Sciences GIK Institute of Engineering Sciences and Technology School of mathematics University of the Witwatersrand

In this paper we consider the most general form of non-static cylindrically symmetric space-times in order to study proper teleparallel homothetic vector fields using the direct integration technique and diagonal tetrads. This study also covers static cylindrically symmetric, Bianchi type I, non-static and static plane symmetric space-times as well. Here, we will only discuss the cases which do not fall in the category of static cylindrically symmetric, Bianchi type I, non-static and static plane symmetric space-times. From the above study we show that very special classes of the above space-times yield 6, 7 and 8 teleparallel homothetic vector fields with non-zero torsion.

关键词： proper teleparallcl homothetic vector field weitzenbck geometry Torsion