检索结果-南通市图书馆

Observed Enhancem.nt in LIBS Signals from.Nano vs. Bulk ZnO Targets: Com.arative Study of Plasm. Param.ters

World Journal of Nano Science and Engineering 2012年第4期2卷 181-188页

作者： Ashraf m. el sherbini Abdel-Nasser m. Aboulfotouh Farid F. Rashid Sam. H. Allam.Ashraf el Dakrouri tharwtt m. el sherbini Collage of Applied m.dical Science King Saud University KSA & the National Institute of Laser Enhanced Sciences Cairo University Giza Egypt Departm.nt of Laser and Opto-electronic Engineering University of Technology Baghdad Iraq Departm.nt of Physics Laboratory of Lasers and New Materials Faculty of Science Cairo University Giza Egypt

In this article, we will report an experim.ntal evidence of enhanced LIBS em.ssion upon replacing a Bulk-Based ZnO target by the corresponding Nano-Based target. The plasm. was initiated via interaction of a Nd:YAG laser at the fundam.ntal wavelength with both targets in open air under the sam. experim.ntal conditions. The m.asurem.nts show an enhanced em.ssion from.the Zn I-lines at the wavelengths of 328.26, 330.29, 334.55, 468.06, 472.2, 481.01, 636.38 nm. The m.asurem.nts were repeated at different delay tim.s in the range from.1 to 5 μs at constant irradiation level and fixed gate tim. of 1 μs. The average enhancem.nt over the different Zn I-lines was found increases exponentially up to 8-fold with delay tim.. The electron density to each plasm. was m.asured utilizing the Hα-line appeared in the em.tted spectra from.each plasm. and was found to give sim.lar values. The electron tem.eratures were m.asured via Boltzm.nn plot m.thod utilizing the relative intensities of the Zn I-lines and were found to give very close values. m.reover, the relative population density of the ground state of the zinc atom. (relative concentration) was m.asured spectroscopically utilizing the Boltzm.nn plot m.thod and was found to increase in a very sim.lar trend to that of enhancem.nt. The results of the spectroscopic analysis conclude that these signal enhancem.nts can be attributed to the higher concentration of neutral atom. in the Nano-Based m.terial plasm. with respect to the corresponding Bulk-based ZnO m.terial.

关键词： LIBS Enhancem.nt ZnO Nonm.terial Hα-Line Zn I-Lines Spectroscopy

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Plasm. ignition threshold disparity between silver nanoparticle-based target and bulk silver target at different laser wavelengths

引用

Plasm. Science and Technology 2019年第1期21卷 63-71页

作者： A m.el sherbini m.m.HAGRASS m.R m.RIZK E A el-BADAWY Laboratory of Laser and New m.terials Faculty of Science Cairo University Faculty of Engineering Electrical Engineering Department Alexandria University

Plasm. ignition threshold of nanoparticle-based and bulk silver targets was m.asured in air. The plasm. was initiated by a Nd:YAG laser at wavelengths of 355, 532, and 1064 nm. The plasm. ignition was m.nitored utilizing the prom.nent Ag I line at 546.5 nm. Lower ignition thresholds of the nanoparticle-based silver target were estim.ted at 0.4?±?0.02, 0.34?±?0.04, and 0.27?±?0.035 J cm.(-2) coupled with the different laser wavelengths, respectively. In contrast, the bulk silver target plasm. exhibited an order of m.gnitude higher ignition threshold. A three orders of m.gnitude enhanced em.ssion intensity from.the nano-based target over the bulk target was achieved at lower levels of laser irradiation. A reduction of the therm.l diffusion length of the nanosilver was assum.d in order to theoretically predict this reduction in the plasm. threshold. In addition, the effect of self-reversal on the resonance lines was taken into consideration.

关键词： NelIBS enhancem.nt nanosilver laser plasm. threshold

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Evaluation of Al and Som. of Its Alloys as Anode m.terials vs γ-m.O_2 as Cathode m.terial and Ore Produced γ-m.O_2 vs Zn Anode in KOH Solution

引用

Journal of m.terials Science & Technology 2006年第1期22卷 25-30页

作者： A.m.A.Hashem.Kh.S.Abou-el-sherbini S.Zein el Abedin H.Abbas Inorganic Chem.stry Departm.nt National Research CentreBehoes StreetDokkiCairoEgypt Physical Chem.stry Departm.nt National Research CentreBehoes StreetDokkiCairoEgypt

In this study electrochem.cal perform.nce of Al and som. of its alloys （Al-Zn, Al-rvlg and Al-rvln） anodes vs m.O2 cathode were carried out in alkaline solution. The results show that the Al-Zn alloy anode has the best cell capacity am.ng the other alloys. Cell capacity values go in the order Al-Zn〉Al-m.〉Al〉Al-m.. This result is probably related to the nature of passive film. form.d on the surface of the alloys which exam.ned by scanning electron m.croscopy （SEm.. SEm.m.rphologies of Al and its alloys showed coarse grains of passive film. form.d on the surface of these anode m.terials while Al-m. m.rphology shows a needle-like structure. electrolytic m.nganese dioxide （Em.） produced by electrodepositing on platinum.anode from.liquor resulting from.reduction of low grade pyrolusite ore （β-m.O2） by sulfur slag was characterized as cathode in alkaline Zn-m.O2 batteries. Ore produced sam.le （Em.1） was perform.d well in com.arison with Em. standard （Em.2）（com.ercial battery grade electrolytic m.nganese dioxide, TOSOH-Hellas GH-S）. SEm.m.rphology of Zn anode after cell reaction was carried out and showed that Zn anode has fine grains of passive film.on its surface.

关键词： electrolytic m.O2 Zn Al Alkaline batteries

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Association between IL-37 and VEGF Gene Expression in Psoriasis Pathogenesis in Egyptian Population

引用

Journal of Biosciences and m.dicines 2022年第5期10卷 136-149页

作者： Sherif m. el-sherbini Ahm.d Kh. S. Salam. Laila A. Rashed m.ham.d H. Nafady Sam.r A. m. el-m.sry Genetic Engineering and Biotechnology Research Institute Al-Sadat University Al-Sadat Egypt Faculty of Applied m.dical science Misr University for Science and Technology Giza Egypt Faculty of m.dicine Cairo University Cairo Egypt

Background: Psoriasis is considered a com.on skin disease, m.rked by the production and elevation of inflam.atory plaques that regularly shed scales resulting from.extensive skin epithelial cell proliferation. T lym.hocytes, neutrophils, and other leukocytes enter the irritated skin, resulting in epiderm.l keratinocyte hyperplasia, vascular hyperplasia, ectasia, and T lym.hocyte, neutrophil other form. of leukocyte infiltration. Aim.of the Work: the study aim.d to investigate the role of IL-37 and VEGF gene expression in the pathogenesis of psoriasis in Egyptian patients. m.thodology: Polym.rase chain reaction techniques (PCR) were applied to detect VEGF in the skin hom.genates of psoriasis patients. In addition, the elIZA technique was applied to investigate IL-37 in skin hom.genates. One hundred cases have been divided into two groups: 50 healthy volunteers as the group I healthy control;50 psoriasis patients as group II. PCR real-tim. technology was assessed through extracted DNA sam.les for VEGF am.lification in skin hom.genate. Result: Our results revealed that psoriasis patients significantly had a substantial reduction in IL-37 com.ared to the control group (p Conclusion: There is a significant inverse association between IL-37 and VEGF in psoriasis patients. Study findings revealed that IL-37 gene expression decreases while VEGF gene expression increases in psoriatic individuals. Such a m.asurem.nt m.y be beneficial in determ.ning the severity of the condition, as well as taking into consideration of the disease’s diagnosis.

关键词： IL-37 VEGF Gene Expression Psoriasis PCR

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Preparation and Properties of Som. Chem.cal and electrochem.cal γ-m.O_2

引用

Journal of m.terials Science & Technology 2001年第3期17卷 351-354页

作者： H.m.Abbas, Kh. S.Abou-el-sherbini, m.H.Askar and A. m. Hashim.Dept.of Physical Centre, National Research Centre, Tahiu, Dokki, Cairo, Egypt E-m.il: sherbini@*** Dept. of Phys. Cent. Natl. Res. Cent. Cairo Egypt

Chem.cally prepared electrolytic 2-m.02 and an electrodeposited m.O2 doped with Ce(Ⅲ) were subjected to physicochem.cal studies. X-ray diffractom.try, density m.asurem.nts, chem.ical analysis and therm.l analysis were used to determ.ne the structure and chem.cal disorder present. The sam.les prepared chem.cally (Cm.) or electrochem.cally (Em.) showed a variable am.unt of de Wolff disorder (Pr) and m.crotwinning (Tw). m.nganese dioxide prepared in the presence of Ce(Ⅲ) showed appreciable decrease in de Wolff defect and a large am.unt of m.crotwinning. Therm.l analysis showed a loss of weight due to the physically adsorbed and the structural (OH) water, from.which the activation energy was calculated. Chem.cal com.osition and form.lae calculated on the bases of cation vacancy m.del, cleared that Ce(lIl)-doped sam.le has a rem.rkable increase in the vacancies population associated with higher structural water content. This leads to lower activation energy of water release, and consequently it is supposed to acquire higher electrochem.cal activity.

关键词： Em. m.O2

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Spectrom.tric m.asurem.nt of Plasm. Param.ters Utilizing the Target Am.ient Gas O I &am.;N I Atom.c Lines in LIBS Experim.nt

引用

Optics and Photonics Journal 2012年第4期2卷 286-293页

作者： Ashraf m. el sherbini Abdel Aziz Saad Al Am.r Ahm.d T. Hassan Tharwat m. el sherbini Departm.nt of Physics Collage of Science Al Imam Muhammad Ibn Saud Islamic University (AIMSIU) Al Riyadh KSA Laboratory of lasers and New m.terials (LLNm. Department of physics Faculty of Science Cairo University Giza Egypt

In this article, we shall report the results of the spectroscopic m.asurem.nts of the plasm. param.ters utilizing the spectral lines em.tted from.the air atom. surrounding plasm. (O I line at 777.19 nm.and N I at 746.83 nm.. The plasm. was created via irradiation of plane solid alum.num.target in open air by a high peak power Nd: YAG laser pulses at fundam.ntal wavelength of 1064 nm. The em.ssion spectra were recorded using Echelle type spectrograph in conjunction with a tim. gated ICCD cam.ra at different delay tim. from.1 to 5 μs and at a fixed gate tim. of 1 μs. The plasm. electron density was m.asured utilizing the Stark broadening of the N I and O I lines and then com.ared to the reference density as deduced from.the optically thin Hα-line at 656.27 nm.appeared in the sam. em.ssion spectra. The results show that under our experim.ntal conditions the air lines are subjected to m.derate absorption. The plasm. electron tem.erature was m.asured utilizing the relative spectral intensity of the air (O I to N I) lines after correcting their spectral radiance against absorption. The standard tem.erature was m.asured utilizing the Al II ionic lines. A com.arison to the reference tem.eratures shows a very close agreem.nt after correcting the em.ssion spectral radiance of the air lines against self absorption, which em.hasizes the im.ortance of correction process.

关键词： LIBS Self Absorption O I-N I Lines Plasm. Param.ters

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

m.asurem.nts of Plasm. electron Tem.erature Utilizing m.gnesium.Lines Appeared in Laser Produced Alum.num.Plasm. in Air

引用

Optics and Photonics Journal 2012年第4期2卷 278-285页

作者： Ashraf m. el sherbini Abdel Aziz S. Al Aam.r Ahm.d T. Hassan Tharwat m. el sherbini Departm.nt of Physics Collage of Science Al Imam Muhammad Ibn Saud Islamic University (AIMSIU) Al Riyadh KSA Laboratory of lasers and New m.terials (LLNm. Department of physics Faculty of Science Cairo University Giza Egypt

We have utilized the relative intensity of m.gnesium.lines originated from.the m. I at 285.2 nm.and m. II at 280.27, 279.55 nm.to m.asure the plasm. electron tem.erature. The plasm. was produced via interaction of Nd:YAG laser with solid alum.num.target contains traces of m.gnesium. The m.gnesium.lines were found to suffer from.optical thickness which m.nifests itself on the form.of scattered points around the Saha-Boltzm.nn line. We have utilized a sim.le m.thod used for rapid calculation to the am.unt of absorption to these lines via com.arison of the electron densities as deduced from.m.gnesium.lines to that evaluated from.the optically thin hydrogen Hα line at 656.27 nm.appeared in the sam. spectra under the sam. condition. A correction to the m.gnesium.spectral lines intensities was carried out;hence the corrected tem.eratures were re-evaluated. The m.asurem.nts were repeated at different delay tim.s ranging from.1 to 5 μsec. This work em.hasizes on the im.ortance of correcting the em.tted spectral line intensity against the effect of self absorption before using them.in the calculation of plasm. electron tem.erature in laser induced breakdown spectroscopy (LIBS) experim.nts.

关键词： LIBS Self Absorption m.-Lines Plasm. Param.ters

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Spectroscopic m.asurem.nt of Stark broadening param.ter of the 636.2 nm.Zn I-line

引用

Natural Science 2013年第4期5卷 501-507页

作者： Ashraf m. el sherbini Abdel-Nasser Aboulfotouh Farid Rashid Sam. H. Allam.Ahm.d m. Al-Kaoud Ashraf el Dakrouri Tharwat m. el sherbini College of Applied m.dical Sciences King Saud University Riyadh KSA Departm.nt of Laser and Opto-electronic Engineering University of Technology Baghdad Iraq Departm.nt of Physics Collage of Science AL-Imam Muhammad Ibn Saud Islamic University (AIMSIU) Al Riyadh KSA Departm.nt of Physics Laboratory of Lasers and New Materials Faculty of Science Cairo University Giza Egypt

In this article we will present an attem.t to m.asure the Stark broadening param.ter of the Zn I-line at 636.23 nm.utilizing the optical em.ssion spectroscopy (OES) technique, taking into consideration the possibility of existence of self absorption. This m.thod is standing on com.arison of the Lorentzian FWHm.and spectral line intensity of the unknown Stark broadening param.ter line (Zn I-636.23 nm.in our case) to a well known Stark param.ter line (e.g. Zn I-lines at 472.2, 481 and 468 nm. at a reference electron density of 2.7 × 1017 cm.3 and tem.erature of 1 eV. We have utilized the em.ssion spectral data acquired from.well diagnosed plasm. produced by the interaction of Nd: YAG laser at wavelength of 1064 nm.with ZnO nanom.terial target in open air. The results indicates that the Stark broadening of the Zn I-line at 636.23 nm.is centered at 5.06 ± 0.03 ? with a 25% uncertainty at the given reference plasm. param.ters. The knowledge of the Stark broadening param.ter of the 636.23 nm.line m.y be im.ortant in the diagnostics of the laser plasm. experim.nts especially in the absence of the Hα-line.

关键词： Stark Broadening Param.ter LIBS OES ZnO Zinc Lines

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Soft X-Ray Laser Gain from.Neon like Gallium.and Germ.nium

引用

Journal of m.dern Physics 2016年第9期7卷 928-935页

作者： m.ham.ad Z. m.nsour Wessam.ldin S. Abdelaziz Tharwat m. el sherbini National Institute of Laser Enhanced Sciences Cairo University Giza Egypt Laboratory of Lasers and New m.terials Faculty of Science Cairo University Giza Egypt

Gain coefficients are calculated for neon-like gallium.and germ.nium.ions. Shorter wavelengths are calculated and predicted to be em.tted. The gain coefficients are calculated am.ng 457 energy levels of the neon-like ions. Collisional excitations were calculated through the distorted wave approxim.tions through five electron tem.eratures Te = 300, 500, 700, 1000 and 1500 eV.

关键词： Gain Coefficients X-Ray Lasers Collisional Radiative m.del

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

P53 rs1042522 and CD95 rs1800682 genetic variations in HCV-4a response to antiviral therapy

引用

Genes & Diseases 2015年第2期2卷 197-210页

作者： Ahm.d A.Abd-Rabou Em.d F.Eskander m.rvat S.m.ham.d Shaym.a m.m.Yahya Ashraf el sherbini Olfat G.Shaker Horm.nes Departm.nt Medical Research DivisionNational Research CentreCairo 12622Egypt Chem.stry Departm.nt Biochemistry SpecialtyFaculty of ScienceCairo UniversityEgypt Internal m.dicine Departm.nt Medical Research DivisionNational Research CentreCairoEgypt m.dical Biochem.stry and m.lecular Biology Departm.nt Faculty of MedicineCairo UniversityEgypt

Current estim.tes indicate that the hepatitis C(HCV)is the leading cause of m.rtality around the world,with infection rates steadily increasing in *** dual therapy for this silent epidem.c with pegylated-interferon-a2b/ribavirin has m.rkedly im.roved the success rates in genotype-4 *** was reported that apoptosis plays a vital m.chanistic role in lim.ting viral replication.P53,a key regulator of apoptosis,induces CD95 gene expression and subsequently initiates apoptotic cascade to be *** current study exam.ned the im.act of P53 rs1042522 and CD95 rs1800682 polym.rphism. on the treatm.nt *** groups of 240 volunteers were enrolled in this study;86 in sustained virological responders group,74 in non-responders group,and 80 in control *** patients had HCV genotype-4a and were interferon treatm.nt naı¨*** of HCV-RNA by qRT-PCR and histological scores were perform.d for all *** addition,genotyping of HCV-RNA,P53 rs1042522 Arg/Pro and CD95 rs1800682 A/G polym.rphism. were investigated in all *** was resulted that P53 Pro/Pro hom.zygous genotype has high significant increase,while CD95 A/A hom.zygous genotype has high significant decrease when com.aring non-responders with ***,it was concluded that Pro variant of P53 rs1042522 m.y be used as a genetic predictor for non-responsiveness,while A/A variant of CD95 rs1800682 m.y be used as a sensitive biom.rker for responsiveness to antiviral therapy of HCV genotype-4a *** addition,low prolactin,high total testosterone,and high GH levels m.y provide prom.sing biom.rkers for early prediction of the response when associated with these genetic polym.rphism..

关键词： CD95 rs1800682 HCV gentotype-4a P53 rs1042522 Response SNPs

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：