咨询与建议

限定检索结果

文献类型

  • 91,237 篇 期刊文献
  • 5,253 篇 会议
  • 3,911 册 图书
  • 200 篇 学位论文
  • 16 篇 报纸
  • 2 篇 多媒体

馆藏范围

  • 98,898 篇 电子文献
  • 1,799 种 纸本馆藏

日期分布

学科分类号

  • 36,434 篇 工学
    • 7,255 篇 材料科学与工程(可...
    • 4,264 篇 化学工程与技术
    • 3,769 篇 生物医学工程(可授...
    • 2,639 篇 电子科学与技术(可...
    • 2,502 篇 机械工程
    • 2,188 篇 计算机科学与技术...
    • 1,902 篇 动力工程及工程热...
    • 1,729 篇 地质资源与地质工...
    • 1,455 篇 电气工程
    • 1,410 篇 仪器科学与技术
    • 1,314 篇 水利工程
    • 1,307 篇 力学(可授工学、理...
    • 1,272 篇 环境科学与工程(可...
  • 35,438 篇 医学
    • 29,369 篇 临床医学
    • 4,109 篇 医学技术(可授医学...
    • 2,978 篇 基础医学(可授医学...
    • 2,539 篇 中西医结合
    • 2,096 篇 公共卫生与预防医...
    • 1,536 篇 药学(可授医学、理...
  • 17,735 篇 理学
    • 3,258 篇 化学
    • 3,244 篇 物理学
    • 3,065 篇 数学
    • 2,428 篇 生物学
    • 1,853 篇 地质学
  • 8,409 篇 农学
    • 2,050 篇 作物学
    • 1,798 篇 畜牧学
    • 1,350 篇 农业资源与环境
  • 3,671 篇 管理学
    • 1,565 篇 管理科学与工程(可...
  • 2,550 篇 经济学
    • 2,228 篇 应用经济学
  • 2,035 篇 教育学
    • 1,456 篇 教育学
  • 1,474 篇 法学
  • 1,388 篇 文学
  • 578 篇 艺术学
  • 532 篇 历史学
  • 483 篇 哲学
  • 163 篇 军事学

主题

  • 974 篇 ct
  • 857 篇 mri
  • 589 篇 美国
  • 534 篇 病人
  • 518 篇 患者
  • 513 篇 and
  • 505 篇 of
  • 435 篇 mr
  • 406 篇 cancer
  • 296 篇 analysis
  • 249 篇 北美洲
  • 236 篇 治疗
  • 213 篇 disease
  • 194 篇 美利坚合众国
  • 184 篇 energy
  • 175 篇 water
  • 168 篇 诊断
  • 167 篇 model
  • 157 篇 儿童
  • 152 篇 treatment

机构

  • 167 篇 北京大学
  • 134 篇 同济医科大学附属...
  • 100 篇 清华大学
  • 86 篇 浙江大学
  • 74 篇 university of ch...
  • 71 篇 华中科技大学同济...
  • 68 篇 university of mi...
  • 67 篇 美国加州大学
  • 67 篇 institute for pa...
  • 67 篇 nikhef p.o.box 4...
  • 67 篇 fysikum stockhol...
  • 67 篇 michigan state u...
  • 66 篇 national researc...
  • 66 篇 institut fur the...
  • 66 篇 dept.of physics ...
  • 66 篇 compas group ins...
  • 65 篇 rudolf peierls c...
  • 63 篇 华中科技大学
  • 63 篇 nstitucio catala...
  • 61 篇 department of ph...

作者

  • 244 篇 叶鹏
  • 232 篇 m.k
  • 115 篇 刘莉
  • 110 篇 郭俊
  • 86 篇 m.white
  • 85 篇 h.murayama
  • 85 篇 j.d.jackson
  • 85 篇 g.d'ambrosio
  • 76 篇 朱国栋
  • 74 篇 唐光健
  • 60 篇 mohamed s. el na...
  • 49 篇 王铮
  • 49 篇 刘凯
  • 46 篇 余英豪
  • 46 篇 p.de jong
  • 41 篇 linda m.chung
  • 39 篇 郭战宏
  • 38 篇 graul a i
  • 37 篇 y.hatsukawa
  • 37 篇 崔荣

语言

  • 59,145 篇 中文
  • 41,461 篇 英文
  • 2 篇 日文
  • 2 篇 其他
  • 1 篇 法文
检索条件"作者=a.m.el-Sayed"
100619 条 记 录,以下是1-10 订阅
排序:
electrical Conductivity and Sensitive Characteristics of Ag-Added BaTiO_3-CuO mixed Oxide for CO_2 Gas Sensing
收藏 引用
Journal of materials Science & Technology 2011年 第1期27卷 35-40页
作者: a.m.el-sayed F.m.Ismail S.m.Yakout Inorganic Chemistry Department National Research CentreTahrir StreetDokki P.C.12622 CairoEgypt
Carbon dioxide gas sensors based on BaTiO3-CuO composite with different concentrations of Ag addition(1,1.5 and 2 wt%) have been prepared by stander ceramic method and sintered at 500 and 700℃ for 5 *** conductivit... 详细信息
来源: 维普期刊数据库 维普期刊数据库 同方期刊数据库 同方期刊数据库 评论
Effects of Hyperfine and Dopant Cation Interactions on theDC-electrical Conductivity of mnZn Ferrites
收藏 引用
Journal of materials Science & Technology 1997年 第6期13卷 467-470页
作者: m.m.Abou Sekkina(Chem. Dept., Faculty of Science, Tanta University, Tanta, Egypt)a.m.el-sayed(Inorganic Chemistry Dept., National Research Centre, Dokki, Cairo, Egypt) Chem. Dept. Faculty of Science Tanta University Tanta Egypt Inorganic Chemistry Dept. National Research Centre Dokki Cairo Egypt
Samples of undoped, and CuO, CaO, Al2O3 as well as V2O5 doped mnZn ferrite were prepared using standard ceramic method. The X-ray diffraction results for the base and doped ferrite samples show a single phase with spi... 详细信息
来源: 维普期刊数据库 维普期刊数据库 同方期刊数据库 同方期刊数据库 评论
以棉籽粉作饵料蛋白源饲养尼罗罗非鱼(Oreochromis niloticus)的长期效果
收藏 引用
国外水产 1991年 第3期 20-23页
作者: a.m.el-sayed 邵力
本研究评价了用不同棉籽粉作铒料蛋白源饲养尼罗罗非鱼的长期效果.用带壳棉籽粉和去壳棉籽粉分别配制成等热值(475kcal总能量/100g饵料)的试验饵料(补充或不补充结晶体L-赖氨酸);粗蛋白含量约30%.用以鱼粉为主的饵料作对照.每一饵料组... 详细信息
来源: 维普期刊数据库 维普期刊数据库 同方期刊数据库 同方期刊数据库 评论
Classical taxonomy,molecular phylogeny and genetic analysis of the genus Exitianus Ball,1929(Hemiptera:Cicadellidae:Deltocephalinae)from Egypt
收藏 引用
Zoological Systematics 2024年 第2期49卷 143-157页
作者: Rabab m.el-Hady Ahmed F.el-sayed Survey&Taxonomy Department Plant Protection Research InstituteAgriculture Research CentreGizaEgypt microbial Genetics Department Biotechnology Research InstituteNational Research CentreGizaEgypt Egypt Center for Research and Regenerative medicine(ECRRm) CairoEgypt
Egyptian species of the leafhopper genus Exitianus Ball,1929,***(St?l,1855),***(Distant,1908),and *** Ross,1968 are ***,morphological descriptions,and a key for their identification are *** this study,we used molecula... 详细信息
来源: 维普期刊数据库 维普期刊数据库 同方期刊数据库 同方期刊数据库 评论
Urban electric Vehicle Charging Station Placement Optimization with Graylag Goose Optimization Voting Classifier
收藏 引用
Computers, materials & Continua 2024年 第7期80卷 1163-1177页
作者: Amel Ali Alhussan Doaa Sami Khafaga el-sayed m.el-kenawy marwa m.Eid Abdelhameed Ibrahim Department of Computer Sciences College of Computer and Information SciencesPrincess Nourah bint Abdulrahman UniversityP.O.Box 84428Riyadh11671Saudi Arabia Department of Communications and electronics Delta Higher Institute for Engineering and TechnologyMansoura35511Egypt Faculty of Artificial Intelligence Delta University for Science and TechnologyMansoura35712Egypt Computer Engineering and Control Systems Department Faculty of EngineeringMansoura UniversityMansoura35516Egypt
To reduce the negative effects that conventional modes of transportation have on the environment,researchers are working to increase the use of electric *** demand for environmentally friendly transportation may be ha... 详细信息
来源: 维普期刊数据库 维普期刊数据库 评论
Arrhythmia Detection by Using Chaos Theory with machine Learning Algorithms
收藏 引用
Computers, materials & Continua 2024年 第6期79卷 3855-3875页
作者: maie Aboghazalah Passent el-kafrawy Abdelmoty m.Ahmed Rasha elnemr Belgacem Bouallegue Ayman el-sayed math and Computer Science Department Faculty of ScienceMenoufia UniversityShebin El-komEgypt College of Engineering Computer Science DepartmentEffat UniversityJeddahKingdom of Saudi Arabia Department of Computer Engineering College of Computer ScienceKing Khalid UniversityAbha61421Saudi Arabia Computer Science and Engineering Department Faculty of Electronic EngineeringMenoufia UniversityShebin El-komEgypt Climate Change Information Center and Expert Systems Agriculture Research CenterGizaEgypt
Heart monitoring improves life ***(ECGs or EKGs)detect heart *** learning algorithms can create a few ECG diagnosis processing *** first method uses raw ECG and time-series *** second method classifies the ECG by pati... 详细信息
来源: 维普期刊数据库 维普期刊数据库 评论
Wood By-Products as UV Protection:A Consequence Review
收藏 引用
Journal of Renewable materials 2024年 第4期12卷 699-720页
作者: Naglaa Salem elsayed mohamed Hasanin Samir Kamel Cellulose and Paper Department National Research CentreCairo12622Egypt
In recent decades,the ozone layer has suffered considerable damage,increasing the entry of ultraviolet(UV)light into the atmosphere and reaching the earth’s surface,negatively affecting ***,researchers aimed to solve... 详细信息
来源: 维普期刊数据库 维普期刊数据库 评论
Enhanced heavy and extra heavy oil recovery:Current status and new trends
收藏 引用
Petroleum 2024年 第3期10卷 399-410页
作者: sayed Gomaa Khalaf G.Salem A.N.el-hoshoudy mining and Petroleum Engineering Department Faculty of EngineeringAl-Azhar UniversityEgypt Department of Reservoir Engineering South Valley Egyptian Petroleum Holding Company(GANOPE)CairoEgypt PVT Lab-Production Department Egyptian Petroleum Research Institute(EPRI)Cairo 11727Egypt PVT-Service Center Egyptian Petroleum Research Institute(EPRI)Cairo 11727Egypt
Due to the increased demand for energy resources these days,especially due to the Russian-Ukrainian war,the focus of the major countries is turning strongly towards improving oil production,especially heavy and extra ... 详细信息
来源: 维普期刊数据库 维普期刊数据库 评论
Effectiveness of biofertilizers foliar application on yield and quality traits of flax(Linum usitatissimum L.)
收藏 引用
Oil Crop Science 2024年 第2期9卷 91-101页
作者: Saied el sayed A.B.Bakry O.A.Nofal m.A.Abo Horish Plant Nutrition Department National Research Centre33 El-Behouth St12622DokkiCairoEgypt Field Crops Department National Research Centre33 El-Behouth St12622DokkiCairoEgypt
Flax is considered to be one of the most significant dual-purpose crops for oil and fiber production in Egypt and *** have a substantial impact on various metabolic processes,including increased photo-synthesis,endoge... 详细信息
来源: 维普期刊数据库 维普期刊数据库 同方期刊数据库 同方期刊数据库 评论
The combined effects of farm yard manure and boron application on growth,and oil quality of Canola grown under newly reclaimed soils
收藏 引用
Oil Crop Science 2024年 第1期9卷 53-59页
作者: Farid Hellal Saied el sayed Amany Abdel mohsen Ramadan Doaa m.Abobasha Plant Nutrition Department National Research Centre33 El-Behouth St12622DokkiCairoEgypt Botany Department National Research Centre33 El-Behouth St12622DokkiCairoEgypt
Two field experiments were conducted during the main seasons of 2021/2022 at the Research and Production Station of National Research Centre in Egypt to investigate the effects of farmyard manure(FYm)and boron on Cano... 详细信息
来源: 维普期刊数据库 维普期刊数据库 同方期刊数据库 同方期刊数据库 评论