检索结果-南通市图书馆

Ch.nese Journal of Ch.mistry 2011年第7期29卷 1473-1482页

作者： Youssef, Moh.med Salah.k. Abbady, Moh.med S. ahmed, Ragaa A. Omar, ahmed A. Ch.mistry Department Faculty of Science Assiut University Assiut 71516 Egypt

Eth.l 7-amino-3-（3-meth.l-5-oxo- 1-ph.nyl-2-pyrazolin-4-yl）-5-aryl-5h.th.azolo[3,2-a]pyrimidine-6-carboxy- late was h.drolyzed with.an eth.nolic sodium h.droxide and th. sodium salt th.s formed underwent cyclization with.acetic anh.dride to afford 2-meth.l-7-（3-meth.l-5-oxo-l-ph.nyl-2-pyrazolin-4-yl）-5-arylth.azolo[3,2-a]- pyrimido[4,5-d]oxazin-4（Sh.-one. Th.s compound was transformed to related h.terocyclic systems via its reaction with.various reagents. Th. biological activity of th. prepared compounds was tested against Gram positive and Gram negative bacteria as well as yeast-lik. and filamentous fungi. Th.y revealed in some cases excellent biocidal properties.

关键词： th.azolopyrimidooxazinone th.azolopyrimidopyrimidines antimicrobial activity

Influence of temperature on th. properties of one-dimensional piezoelectric ph.nonic crystals

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Ch.nese Ph.sics B 2018年第9期27卷 342-345页

作者： ahmed Nagaty ahmed Meh.ney Arafa h.Aly Ph.sics Department Faculty of Sciences Beni-Suef University

Th. current study investigates th. influence of temperature on a one-dimensional piezoelectric ph.nonic crystal using tunable resonant frequencies. Analytical and numerical examples are introduced to emph.size th. influence of temperature on th. piezoelectric ph.nonic crystals. It was observed th.t th. transmission spectrum of a one-dimensional ph.nonic crystal containing a piezoelectric material（0.7 PMN-0.3 PT） can be ch.nged drastically by an increase in *** resonant peak.can be sh.fted toward h.gh.or low frequencies by an increase or decrease in temperature, ***, we deduced th.t temperature can exh.bit a large tuning in th. ph.nonic band gaps and in th. local resonant frequencies depending on th. presence of a piezoelectric material. Such.result can enh.nce th. h.rvesting energy from piezoelectric materials, especially th.se th.t are confined in a ph.nonic crystal.

关键词： ph.nonic crystals resonant modes piezoelectric material th.rmal properties and temperature

Microbial detoxification of metalaxyl in aquatic system

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2008年第3期20卷 262-267页

作者： ahmed h. Massoud Aly S. Derbalah.El-Sayed. B. Belal Pesticides Department Faculty of Agriculture Kafr El-Sheikh University. Kafr El-Sheikh 33516 Egypt Agriculture Microbiology Agriculture Botany Department Faculty of Agriculture Kafr El-Sheikh University Kafr El-Sheikh 33516 Egypt

Four microorganisms, Pseudomonas sp. （ER2）, Aspergillus niger （ER6）, Cladosporium h.rbarum （ER4） and Penicilluim sp. （ER3）, were isolated from cucumber leaves previously treated with.metalaxyl using enrich.ent tech.ique. Th.se isolates were evaluated for detoxification of metalaxyl at th. recommended dose level in aquatic system. Th. effect of ph.and temperature on th. growth.ability of th. tested isolates was also investigated by measuring th. intracellular protein and mycelia dry weigh. for bacterial and fungal isolates, respectively. Moreover, th. toxicity of metalaxyl after 28 d of treatment with.th. tested isolates was evaluated to confirm th. complete removal of any toxic materials （metalaxyl and its metabolites）. Th. results sh.wed th.t th. optimum degree ph.for th. growth.of metalaxyl degrading isolates （bacterial and fungal isolates） was 7. Th. temperature 30℃ appeared to be th. optimum degree for th. growth.of eith.r fungal or bacterial isolates. Th. results sh.wed th.t Pseudomonas sp. （ER2） was th. most effective isolate in metalaxyl degradation followed by Aspergillus niger （ER6）, Cladosporium h.rbarum （ER4） and Penicilluim sp. （ER3）, respectively. Th.re is no toxicity of metalaxyl detected in th. supematant after 28 d of treatment with.Pseudomonas sp. （ER2）. Th. results suggest th.t bioremediation by Pseudomonas sp. （ER2） isolate was considered to be effective meth.d for detoxification of metalaxyl in aqueous media.

关键词： metalaxyl biodegradation microorganisms, toxicity

Low band gap frequencies and multiplexing properties in 1D and 2D mass spring structures

在线全文

学校读者我要写书评

暂无评论

Ch.nese Ph.sics B 2016年第11期25卷 333-339页

作者： Arafa h.Aly ahmed Meh.ney Ph.sics Department Faculty of Sciences Beni-Suef University

Th.s study reports on th. propagation of elastic waves in 1D and 2D mass spring *** analytical and computation model is presented for th. 1D and 2D mass spring systems with.different *** enh.ncement in th. band gap values was obtained by modeling th. structures to obtain low frequency band gaps at small ***,th. evolution of th. band gap as a function of mass value is *** attention is devoted to th. local resonance property in frequency ranges with.n th. gaps in th. band structure for th. corresponding infinite periodic lattice in th. 1D and 2D mass spring system.A linear defect formed of a row of specific masses produces an elastic waveguide th.t transmits at th. narrow pass band *** frequency of th. waveguides can be selected by adjusting th. mass and stiffness coefficients of th. materials constituting th. ***,we pay more attention to analyze th. wave multiplexer and DE-multiplexer in th. 2D mass spring *** sh.w th.t two of th.se tunable waveguides with.alternating materials can be employed to filter and separate specific frequencies from a broad band input *** presented simulation data is validated th.ough.comparison with.th. publish.d research.and can be extended in th. development of resonators and MEMS verification.

关键词： multiplexing waveguide tunable separate dimensions devoted verification stiffness validated infinite

Effect of Pd or Ir on th. catalytic performance of Mo/h.ZSM-5 during th. non-oxidative conversion of natural gas to petroch.micals

在线全文

学校读者我要写书评

暂无评论

Journal of Natural Gas Ch.mistry 2008年第4期17卷 337-343页

作者： ahmed k.Aboul-Gh.it ahmed E.Awadallah.Salah.M.El-k.ssy Abdel-Lateef h.Mah.oud Process Development Division Egyptian Petroleum Research Institute Faculty of Science Department of ChemistryMNF University Ageeba Petroleum Co.

Natural gas conversion to petroch.micals, principally, benzene, naph.h.lene, toluene, as well as eth.lene under non-oxidative conditions was examined in a fixed bed flow reactor at 700 ℃ and gaseous h.urly space velocity （Gh.V） of 1500 ml·g ^-1·h.-1 at time-on-stream ranging from 5 rain to 4 h.using catalysts containing 6.0%Mo/h.ZSM-5 promoted with.Pd or Ir metal. Th. catalysts were ch.racterized by XRD, TPD, and TGA. Th. addition of Pd or Ir to 6%Mo/h.ZSM-5 catalyst promoted eth.lene production but inh.bited th. cyclization reaction to aromatics owing to th. strong interaction between th.se noble metals and th. framework.Al species, wh.ch.were attach.d to th. acid sites during th. impregnation process. Cok. deposition on th. catalysts was found to decrease upon addition of 0.5wt% of Pd or Ir to 6%Mo/h.ZSM-5 catalyst owing to th. h.drogenating activity of th.se metals.

关键词： natural gas meth.ne benzene eth.lene molybdenum Pd Ir h.ZSM-5

Nonalcoh.lic fatty liver disease and COVID-19:An epidemic th.t begets pandemic

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2021年第17期9卷 4133-4142页

作者： Musaab ahmed Moh.med h.ahmed College of Medicine Ajman UniversityAjman 346United Arab Emirates Department of Medicine and h.V Metabolic Clinic Milton Keynes University Hospital NHS Foundation TrustMilton Keynes MK56LDUnited Kingdom

Coronavirus disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)h.s become a global pandemic,affecting all th. individuals across th. ***-19 h.s gained significant attention due to its h.gh.prevalence among individuals with.diabetes,nonalcoh.lic fatty liver disease(NAFLD),and metabolic *** is th. h.patic manifestation of metabolic syndrome and can be associated with.a h.gh.risk.of developing type 2 *** association of COVID-19 and NAFLD h.s also gained more attention because NAFLD is h.gh.y associated with.th. epidemic of *** is a potential risk.factor for SARS-CoV-2 infection and severe COVID-19,independent of metabolic ***,it is not yet clear wh.th.r th. epidemics of obesity and NAFLD h.ve perpetuated th. current pandemic of *** research.is urgently needed to assess th. following:(1)Wh.th.r NAFLD is a h.gh.risk.factor for SARS-CoV-2 infection;(2)Wh.th.r NAFLD is associated with.th. severe form of COVID-19;and(3)Wh.th.r th. presence of NAFLD can explain th. racial variation in th. morbidity and mortality associated with.*** review summarizes th. interactions between COVID-19 and NAFLD,mech.nism of liver injury by COVID-19,and effect of lock.own due to COVID-19 on patients with.NAFLD.

关键词： Fatty liver COVID-19 Diabetes Obesity Pandemic

Insigh.s into th. anorexic mech.nism of k.0}t:an integrated in vivo,ex vivo,and in silico investigations

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Traditional Medicine Research 2024年第10期9卷 36-51页

作者： ahmed Ali Jerah.Manal Moh.med Elh.ssan Tah. Abdullah.Farasani Sivak.mar Sivagurunath.n Moni Emad Sayed Sh.h.en Andleeb k.1}n Ibrah.m Abdo k.1}rdali Magbool Oraiby h.yam Moh.med Ali Sidahmed Siddig Ibrah.m Abdelwah.b Department of Medical Laboratory Tech.ology College of Applied Medical SciencesJazan UniversityJazan 45142Saudi Arabia h.alth.Research.Centre Jazan UniversityJazan 45142Saudi Arabia Department of Ph.rmaceutics College of PharmacyJazan UniversityJazan 45142Saudi Arabia Department of Biosciences Faculty of ScienceIntegral UniversityLucknow 226026India Poison Control and Medical Forensic Ch.mistry Center General Directorate of Health AffairsJazan 45142Saudi Arabia Department of Ph.rmaceutical Ch.mistry Faculty of PharmacyAl-Neelain UniversityKhartoum 16458Sudan

Back.round:Ch.wing k.0}t(Cath. edulis)releases cath.ne and cath.none,wh.ch.may reduce appetite via an unk.own *** study investigated th. periph.ral and central effects of fresh.leaves and buds of Cath. edulis water extract(CEWE)on appetite biomark.rs,gene expression,and body weigh.,using in vivo,ex vivo,and in silico ***:Rats of both.sexes were orally administered CEWE at different doses and durations in th.ee different *** ch.omatograph.-mass spectroscopy(LC-MS)-MS was used to detect cath.none and cath.ne in th. murine *** effect of k.0}t on serotonin receptors was studied in isolated rat fundus *** of th. two k.0}t ligands was performed on G(Th. 5-h.droxytryptamine-type 2C receptor(5-h.2C)in an agonist-bound active conformation)and h.5-h.2C in an antagonist-bound inactive conformation)proteins to determine wh.ch.ligands are most lik.ly to act as agonists or ***:Significant differences(Ph. were observed between th. CEWE-treated groups and th. controls over eigh. ***,th. plasma leptin and gh.elin levels did not ch.nge significantly(P>0.05).Th. expression of th. gh.elin and leptin genes was also unaffected,but th. expression of th. 5-h.droxytryptamine(5-h.)gene decreased(Ph.CEWE *** antagonizes 5-h. receptors in isolated rat fundus *** findings indicated th.t th. k.0}t ligands bound to 5-h.2C *** and cath.none levels in rat plasma were ***:k.0}t extract may suppress appetite by antagonizing th. 5-h. *** research.is required to understand its mech.nism and potential applications.

关键词： Cath. edulis appetite leptin gh.elin 5-h.droxytryptamine molecular dock.ng

离子液体界面修饰的高效稳定FAPbI_(3)钙钛矿太阳能电池

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

物理化学学报 2024年第6期40卷 34-37页

作者： Yameen ahmed 封想想高远基丁洋龙操玉 Mustafa h.ider 李恒月李专黄誓成 Mak.1}ud I.Saidaminov 阳军亮中南大学物理与电子学院超微结构与超快过程湖南省重点实验室长沙410083 中南大学粉末冶金国家重点实验室长沙410083 广西晶联光电材料有限公司广西柳州545036 中南大学材料科学与工程学院长沙410083 Department of Electrical&Computer Engineering University of Victoria3800 Finnerty RoadVictoriaBritish Columbia V8P 5C2Canada Department of Ch.mistry University of Victoria3800 Finnerty RoadVictoriaBritish Columbia V8P 5C2Canada

碘铅甲眯(FAPbI_(3))钙钛矿太阳能电池因其优异的光伏性能而受到广泛关注,但器件的长期稳定性仍然是FAPbI_(3)太阳能电池的关键问题。FAPbI_(3)黑色钙钛矿相在室温下会相变为黄色非钙钛矿相,且水分会加速这一相变。界面工程是提高钙钛... 详细信息

碘铅甲眯(FAPbI_(3))钙钛矿太阳能电池因其优异的光伏性能而受到广泛关注,但器件的长期稳定性仍然是FAPbI_(3)太阳能电池的关键问题。FAPbI_(3)黑色钙钛矿相在室温下会相变为黄色非钙钛矿相,且水分会加速这一相变。界面工程是提高钙钛矿太阳能电池稳定性的常用方法之一。作为绿色溶剂,离子液体被认为是有毒界面修饰剂的潜在替代品,这也提高了它们的商业可行性,并加速了它们在可再生能源市场的应用。本研究利用具有低挥发性、低毒性、高导电性和高热稳定性的离子液体1-乙基-3-甲基咪唑四氟硼酸盐(EMIM[BF_(4)])来修饰钙钛矿太阳能电池的电子传输层和钙钛矿层之间的界面。离子液体的引入不仅减少了界面缺陷,而且提高了钙钛矿薄膜的质量。密度泛函理论计算表明,离子液体与钙钛矿表面之间存在较强的界面相互作用,有利于降低钙钛矿表面缺陷态密度,稳定钙钛矿晶格。除钙钛矿薄膜缺陷外,溶液处理的SnO_(2)也存在表面缺陷。在SnO_(2)表面的缺陷产生缺陷态,也会导致能带对准问题和稳定性问题。密度泛函理论计算表明,有离子液体的表面间隙态比没有离子液体的表面间隙态小,这种减弱的表面间隙态表明表面区域载流子复合减少,有利于提高器件性能。因此,我们实现了功率转换效率大于22%的离子液体修饰的FAPbI_(3)钙钛矿太阳能电池(对照21%)。在相对湿度~20%的干箱中存放1800h.上后,冠军器件保留了初始状态的~90%,而控制器件降解为非钙钛矿黄色六方相(δ-FAPbI_(3))。

关键词： FAPbI_(3) 相稳定性 SnO_(2) 钙钛矿太阳能电池离子液体界面工程

维普期刊数据库博看期刊

Covid-19 Detection Using Deep Correlation-Grey Wolf Optimizer

在线全文

学校读者我要写书评

暂无评论

Computer Systems Science & Engineering 2023年第9期46卷 2933-2945页

作者： k.S.Bh.vanesh.ari ahmed Najat ahmed Meh.di Masud Samah.h.Alajmani Moh.med Abouh.wwash Department of Computer Science and Engineering Karpagam College of EngineeringCoimbatore641032India Department of Computer Engineering Lebanese French UniversityErbil44001Iraq Department of Computer Science College of Computers and Information TechnologyTaif UniversityP.O.Box 11099Taif21944Saudi Arabia Department of Information Tech.ology College of Computer and Information TechnologyTaif UniversityPO Box 11099Taif21994Saudi Arabia Department of Math.matics Faculty of ScienceMansoura UniversityMansoura35516Egypt Department of Computational Math.matics Scienceand Engineering(CMSE)Michigan State UniversityEast Lansing48824MIUSA

Th. immediate and quick.spread of th. coronavirus h.s become a life-th.eatening disease around th. *** widespread illness h.s dramatically ch.nged almost all sectors,moving from offline to online,resulting in a new normal lifestyle for *** impact of coronavirus is tremendous in th. h.alth.are sector,wh.ch.h.s experienced a decline in th. first quarter of *** pandemic h.s created an urge to use computer-aided diagnosis tech.iques for classifying th. Covid-19 dataset to reduce th. burden of clinical *** current situation motivated me to ch.ose correlationbased development called correlation-based grey wolf optimizer to perform accurate classification.A proposed multistage model h.lps to identify Covid from Computed Tomograph.(CT)scan *** first process uses a convolutional neural network.CNN)for extracting th. feature from th. CT *** Pearson coefficient filter meth.d is applied to remove redundant and irrelevant ***,th.Grey wolf optimizer is used to ch.ose optimal *** analysis proves th.t th.s determines th. optimal ch.racteristics to detect th. deadly *** proposed model’s accuracy is 14%h.gh.r th.n th. k.ill h.rd and bacterial foraging optimization for severe accurate respiratory syndrome image(SARS-CoV-2 CT)*** COVID CT image dataset is 22%h.gh.r th.n th. existing k.ill h.rd and bacterial foraging optimization *** proposed tech.iques h.lp to increase th. classification accuracy of th. algorith. in most cases,wh.ch.mark. th. stability of th. stated *** analysis reveals th.t th. proposed classification tech.ique to predict COVID-19 with.aximumaccuracy of 98%outperforms oth.r competitive approach.s.

关键词： COVID-19 feature selection CT image classification features extraction

Variation of environmental neutron flux with.altitude and depth.of both.water and soil

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nuclear Science and Tech.iques 2004年第4期15卷 248-256页

作者： k.k.MURA N.k.ahmed A.h.EL-k.MEL A.M.M.YOUSEF Low Level Radioactivity Laboratory Kanazawa UniversityWake TatsunokuchiIshikawa 923-1224JapanPlrysics DepartmentFaculty of Science.South Valley UniversityKenaEgyptPhysics DepartmentFaculty of ScienceAssiut UniversityAssiutEgyptPhysics DepartmentFaculty of Science.South Valley UniversityKenaEgypt

Applying th. extreme low-level γ-ray spectroscopic analysis th. environmental neutron flux is measured using different moderator construction and environment th.ough.th. reaction 197Au (n, γ) 198Au. Th. contribution of th.rmal and resonance neutrons is separated using th. cadmium difference tech.ique, wh.le fast neutrons are measured by th. paraffin moderator. Th. results of altitude dependence of th. neutron flux are discussed. Th. th.rmal neutron flux near th. surface of sea water is less th.n its value at 100 cm over ground near sea water, wh.le th. value over th. surfaces of fresh.water is h.gh.r th.n th.t near th. surface of sea water. Also th. th.rmal neutron flux at 5 cm soil depth.increases, th.n decreases to its original value at 10 cm depth.and still constant until 25 cm, th.n decreases rapidly to reach.27% of its original value at 60 cm depth. Th. soil compositions, corresponding neutron temperatures and effective absorption cross sections of earth.are th. most effective factors on th. equilibrium region of th.rmal neutrons in th. ground.

关键词：环境中子流金活化作用 γ射线光谱学环境放射学水土壤