检索结果-南通市图书馆

Investigation of Charge Transport in Percolating Network of PdCu Nanoclusters

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica sinica(English Letters) 2014年第1期27卷 156-160页

作者： A.I.Ayesh s.T.mahmoud N.Qamhieh Z.A.Karam Department of Physics United Arab Emirates University

Transport of charge carriers in percolating nanocluster devices based on bimetallic PdCu nanoclusters was investigated in this work. The device was fabricated by self-assembly of the nanoclusters between electrical electrodes inside an ultra-high vacuum compatible system. The average size of the produced nanoclusters was 7.3 nm, and the composition was Pdo.77Cuo.23. systematic in situ current-voltage measurements as a function of temperature were per- formed which provide a conductance-temperature profile. The results are explained in terms of the charge carriers＇ tunneling through small potential barriers at the junctions between nanoclusters. The results predict the size of the nanoclusters as well as the magnitude of the potential difference of the tunneling barriers. This investigation helps understanding the nature of the interface between the nanoclusters and the charge carrier transport within those devices to be utilized for optimizing gas sensing properties of PdCu nanocluster devices.

关键词： PdCu Bimetallic nanoclusters Nanocluster devices Inert-gas condensation Tunneling Charpe transvort

The rank of the 2-Class Group of some Fields with LargeDegree

在线全文

学校读者我要写书评

暂无评论

Algebra Colloquium 2022年第2期29卷 181-188页

作者： Mohamed mahmoud Chems-Eddin Department of Mathematics Faculty of Sciences Dhar El Mahraz Sidi Mohamed Ben Abdellah UniversityFezMorocco

Let n≥3 be an integer and d an odd square-free *** compute the rank of the 2-class group of some fields of the form L_(n,d)=Q(ζ_(2^(n)),√d)when all the prime divisors of d are congruent to±3(mod 8)or 9(mod 16).

关键词： cyclotomic Z_(2)-extension 2-rank 2-class group

Amino Acid Encryption Method Using Genetic Algorithm for Key Generation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2022年第1期70卷 123-134页

作者： Ahmed s.sakr M.Y.shams Amena mahmoud Mohammed Zidan Department of Information system Faculty of Computers and InformationMenofia UniversityEgypt Department of Machine learning and Information retrieval Faculty of Artificial IntelligenceKafrelsheikh UniversityEgypt Department of Computer science Faculty of Computers and InformationKafrelshiekh UniversityEgypt Hurghada Faculty of Computers and Artificial Intelligence South Valley UniversityEgypt

In this new information era,the transfer of data and information has become a very important *** data must be kept secured from unauthorized persons using *** science of cryptography depends not only on complex mathematical models but also on encryption *** acid encryption is a promising model for data *** this paper,we propose an amino acid encryption model with two encryption *** first key is generated randomly using the genetic *** second key is called the protein key which is generated from converting DNA to a protein ***,the protein message and the first key are used in the modified Playfair matrix to generate the cypher *** experimental results show that the proposed model survives against known attacks such as the Brute-force attack and the Ciphertext-only *** addition,the proposed model has been tested over different types of characters including white spaces and special characters,as all the data is encoded to 8-bit *** performance of the proposed model is compared with other models using encryption time and decryption *** model also balances all three principles in the CIA triad.

关键词： Cryptography amino acid genetic algorithm playfair deep learning DNA computing

Growth and Characterization of Pencil-Like ZnO Nanowires in the Presence of a Disturbance in Boundary Layer

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica sinica(English Letters) 2016年第6期29卷 595-600页

作者： A.Kamalianfar mahmoud Godarz Naseri Marzih Kamalianfar s.A.Halim K.P.Lim Department of Physics Faculty of Science Farhangian University Ministry of Education Fars Education Department of Physics Faculty of Science Malayer University Department of Physics Faculty of Science University Putra MalaysiaUPM

Pencil-like zinc oxide（ZnO） nanowire was synthesized on si（111） substrate through a simple vapor phase method using a mixture of zinc oxide and graphite as the source material. The source inside a quartz tube created a Zn-rich vapor that facilitated the formation and growth of ZnO nanowires. Field emission scanning electron microscopic studies indicated that pencil-like ZnO nanowires had a size of the range from 50 to 150 nm in diameter and several microns in length. X-ray diffraction was used to investigate the crystal structure of ZnO nanowires. raman scattering and photoluminescence were applied to characterize the optical properties of the pencils. The growth mechanism of the nanopencils was discussed based on the growth conditions.

关键词： Zinc oxide Nanowires Vapor-phase transport Pencil-like

Computerized Detection of Limbal stem Cell Deficiency from Digital Cornea Images

在线全文

学校读者我要写书评

暂无评论

Computer systems science & Engineering 2022年第2期40卷 805-821页

作者： Hanan A.Hosni mahmoud Doaa s.Khafga Amal H.Alharbi Department of Computer sciences College of Computer and Information SciencesPrincess Nourah Bint Abdulrahman UniversityRiyadh11047KSA

Limbal stem Cell Deficiency(LsCD)is an eye disease that can cause corneal opacity and *** its advanced stage it can lead to a degree of visual *** involves the changing in the semispherical shape of the cornea to a drooping shape to downwards *** is hard to be diagnosed at early *** color and texture of the cornea surface can provide significant information about the cornea affected by *** such as shape and texture are very crucial to differentiate normal from LsCD *** several medical approaches exist,most of them requires complicated procedure and medical ***,in this paper,we pursued the development of a LsCD detection technique(LDT)utilizing image processing *** diagnosis of LsCD is very crucial for physicians to arrange for effective *** the proposed technique,we developed a method for LsCD detection utilizing frontal eye images.A dataset of 280 eye images of frontal and lateral LsCD and normal patients were used in this ***,the cornea region of both frontal and lateral images is segmented,and the geometric features are extracted through the automated active contour model and the spline *** the texture features are extracted using the feature selection *** experimental results exhibited that the combined features of the geometric and texture will exhibit accuracy of 95.95%,sensitivity of 97.91% and specificity of 94.05% with the random forest classifier of n=*** a result,this research developed a Limbal stem cell deficiency detection system utilizing features’fusion using image processing techniques for frontal and lateral digital images of the eyes.

关键词： Feature extraction corneal opacity geometric features computerized detection image processing

Combinatorial therapies for spinal cord injury repair

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Neural regeneration research 2025年第5期20卷 1293-1308页

作者： Carla s.sousa Andreia Monteiro António J.salgado Nuno A.silva Life and Health sciences research Institute(ICVs) School of MedicineUniversity of MinhoCampus de Gualtar-gualtarBragaPortugal ICVs/3B’s Associate Lab PT Government Associated LabCampus de Gualtar-gualtarBragaPortugal

spinal cord injuries have profound detrimental effects on individuals, regardless of whether they are caused by trauma or non-traumatic events. The compromised regeneration of the spinal cord is primarily attributed to damaged neurons, inhibitory molecules, dysfunctional immune response, and glial scarring. Unfortunately, currently, there are no effective treatments available that can fully repair the spinal cord and improve functional outcomes. Nevertheless, numerous pre-clinical approaches have been studied for spinal cord injury recovery, including using biomaterials, cells, drugs, or technological-based strategies. Combinatorial treatments, which target various aspects of spinal cord injury pathophysiology, have been extensively tested in the last decade. These approaches aim to synergistically enhance repair processes by addressing various obstacles faced during spinal cord regeneration. Thus, this review intends to provide scientists and clinicians with an overview of pre-clinical combinatorial approaches that have been developed toward the solution of spinal cord regeneration as well as update the current knowledge about spinal cord injury pathophysiology with an emphasis on the current clinical management.

关键词： electric stimulation neural tissue regeneration neuroprotection polytherapy spinal cord injury

Predicting Maximum Lifespan Limits at Mean Menopausal Age

在线全文

学校读者我要写书评

暂无评论

Journal of Mathematical research with Applications 2025年第1期 133-142页

作者： M.sUMATHI s.ANTONY CArLA Department of Mathematics N.M.S.S.Vellaichamy Nadar College research scholar (Part-time) Madurai Kamaraj University

The age at which a woman enters natural menopause has also been associated to death from any cause. Menopause is a natural component of aging that happens between the ages of 45 and 55, with the average menopausal age being 51. Previous research has revealed the age at which women reach menopause, but there is no evidence to support the link between menopause and longevity. We made a study in assessing the limits of maximum lifespan at menopausal age in our previous article. In this paper, we aim to predict the maximum lifespan of women at mean menopausal age.

关键词：

Middle East respiratory syndrome coronavirus： a comprehensive review

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Frontiers of Medicine 2016年第2期10卷 120-136页

作者： mahmoud M. shehata Mokhtar r. Gomaa Mohamed A. Ali Ghazi Kayali Center of scientific Excellence for Influenza Viruses National Research Centre Giza Egypt Department of Infectious Diseases St. Jude Children's Research Hospital Memphis TN 38105 USA

The Middle East respiratory syndrome eoronavirus was first identified in 2012 and has since then remained uncontrolled. Cases have been mostly reported in the Middle East, however travel-associated cases and outbreaks have also occurred. Nosocomial and zoonotic transmission of the virus appear to he the most important routes. The infection is severe and highly fatal thus necessitating rapid and efficacious interventions. Here, we performed a comprehensive review of published literature and summarized the epidemiology of the virus. In addition, we summarized the virological aspects of the infection and reviewed the animal models used as well as vaccination and antiviral tested against it.

关键词： MErs coronavirus review

Degradation of direct azo dye by Cucurbita pepo free and immobilized peroxidase

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental sciences 2013年第6期25卷 1235-1244页

作者： Nabila Boucherit mahmoud Abouseoud Lydia Adour Université Mouloud Mammeri Laboratoire de Biomatériaux et de Phénomènes deTransports Université Dr.Yahia Fares Laboratoire de Biomatériaux et de Phénomènes de Transports Université Dr.Yahia Fares Laboratoire de Génie de la réaction Faculté de Génie Mécanique et Génie des ProcédésUniversité Houari Boumediene Laboratoire des Biotechnologies Environnementales et Génie des Procédés

Enzymatic decolourization of the azo dye, Direct Yellow （DY 106） by Cucurbita pepo （courgette） peroxidase （CP） is a complex process, which is greatly affected by pH, temperature, enzyme activity and the concentrations of H202 and dye. Courgette peroxidase was extracted and its performance was evaluated by using the free-CP （FCP） and immobilized-CP （ICP） forms in the decolourization of DY106. Immobilization of peroxidase in calcium alginate beads was performed according to a strategy aiming to minimize enzyme leakage and keep its activity at a maximum value by optimizing sodium alginate content, enzyme loading and calcium chloride concentration. The initial conditions ~it which the highest DY106 decolourization yield was obtained were found at pH 2, temperature 20~C, H202 dose 1 mmol/L （FCP） and 100 mmol/L （ICP）. The highest decolourization rates were obtained for dye concentrations 50 mg/L （FCP） and 80 mg/L （ICP）. Under optimal conditions, the FCP was able to decolorize more than 87% of the dye within 2 min. While with ICP, the decolourization yield was 75% within 15 rain. The decolourization and removal of DY106 was proved by UV-Vis analysis. Fourier transform infrared （FF-Ir） spectroscopy analysis was also performed on DY106 and enzymatic treatment precipitated byproduct.

关键词： Cucurbita pepo peroxidase immobilization decolourization azo dye