检索结果-南通市图书馆

Thermodynamic Simulation on the Change in Phase for Carburizing Process

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 2021年第7期68卷 1129-1145页

作者： Anh Tuan Hoang Xuan Phuong Nguyen Osamah ibrahim Khalaf Thi Xuan Tran Minh Quang Chau Thi Minh Hao dong duong Nam Nguyen Ho Chi Minh city University of Technology(HUTECH) HoVietnam Ho Chi Minh city University of Transport Ho Chi Minh cityVietnam Al-Nahrain University Al-Nahrain Nanorenewable Energy Research CenterBaghdadIraq Hanoi University of Science and Technology HanoiVietnam Industrial University of Ho Chi Minh City(IUH) Ho Chi Minh cityVietnam Vietnam Maritime University HaiphongVietnam

The type of technology used to strengthen the surface structure of machine parts,typically by carbon-permeation,has made a great contribution to the mechanical engineering industry because of its outstanding advantages in corrosion resistance and enhanced mechanical and physical ***,carbon permeation is considered as an optimal method of heat treatment through the diffusion of carbon atoms into the surface of alloy *** study presented research results on the thermodynamic calculation and simulation of the carbon permeability *** Fick’s law,the paper calculated the distribution of carbon concentration in the alloy steel after it is absorbed from the surface into the internal of the *** the SYSWELd software,an analysis was performed on the carbon permeability process to determine the distribution of carbon concentrations in 20CrMo steel that was then followed by a detailed analysis of the microstructure of the sample post the carburizing *** to the calculation results,the surface carbon content was 0.9%and steadily decreased into the *** 3 hours,the depth of the absorbent layer was measured at 0.5 mm for both the cylindrical and cubic *** analyzing the phase,the distribution of martensite phases such as ferrite/pearlite and residual austenite was also determined after the carburizing process.

关键词： Carburizing process 20CrMo steel thermodynamic analysis microstructure formation carbon concentration

Magnetic Resonance Imaging for Screening of Woman at High-Risk of Breast Cancer

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Advances in Breast Cancer Research 2014年第3期3卷 59-67页

作者： Reham G. Garout Howayda M. Ahmed Saddig d. Jastaniah ibrahim A. Awad department of diagnostic Radiology Faculty of Applied Medical Sciences King Abdulaziz University Jeddah KSA

MRI is an excellent option for detection of breast cancer for some selected groups, including those patients with a high probability to hit the disease. However, the high costs and low availability of the device have led to a decline in the application of imaging MRI. The aim of this study was to review usefulness of MRI as a new complementary way to detect breast cancer in routine annual checkup for women breasts of certain ages and breast mass. A cross-sectional descriptive MRI study was performed on 105 asymptomatic women with a mean age of 49 years. The study group with at least one risk factor of breast cancer were presenting for routine annual screening or follow up at King Abdulaziz University Hospital in Jeddah. It has been found that, 48 patients had biopsy, they were recommended by magnetic resonance imaging and only 14 had positive results, while magnetic resonance imaging suggested 16 and mammography had 62 positive results. Magnetic resonance imaging is not recommended for the average-risk or the general population either;it had been advised for screening the high-risk women of breast cancer. Sensitivity of magnetic resonance imaging has been found to be much higher than of mammography but specificity was generally lower. We propose that it is reasonable to consider MRI as a complement to mammography in screening patients who were at high risk for breast cancer because Magnetic Resonance Imaging can detect small foci that are occult in mammography but we don’t advise to check with the general population.

关键词： MRI Mammogram Breast Cancer Women Breasts

Efficient Resource Allocation Algorithm in Uplink OFdM-Based Cognitive Radio Networks

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 2023年第5期75卷 3045-3064页

作者： Omar Abdulghafoor Musbah Shaat Ibraheem Shayea Ahmad Hamood abdelzahir abdelmaboud Ashraf Osman ibrahim Fadhil Mukhlif Herish Badal Norafida Ithnin Ali Khadim Lwas Electronic&Telecommunications Engineering department The American University of KurdistanDuhokKurdistan RegionIraq CTTC BarcelonaSpain Faculty of Electrical and Electronics Engineering Istanbul Technical UniversityIstanbulTurkey department of Information Systems King Khalid UniversityMuhayel AseerSaudi Arabia Faculty of Computing and Informatics University Malaysia SabahKota KinabaluMalaysia Information Assurance and Security Research Group(IASRG) School of ComputingFaculty of EngineeringUniversiti Teknologi MalaysiaJohorMalaysia R&d Ministry of Industry and MineralsBaghdadIraq

The computational complexity of resource allocation processes,in cognitive radio networks(CRNs),is a major issue to be ***,the complicated solution of the optimal algorithm for handling resource allocation in CRNs makes it unsuitable to adopt in real-world applications where both cognitive users,CRs,and primary users,PUs,exist in the identical geographical ***,this work offers a primarily price-based power algorithm to reduce computational complexity in uplink scenarioswhile limiting interference to PUs to allowable ***,this paper,compared to other frameworks proposed in the literature,proposes a two-step approach to reduce the complexity of the proposed mathematical *** the first step,the subcarriers are assigned to the users of the CRN,while the cost function includes a pricing scheme to provide better power control algorithm with improved reliability proposed in the second *** main contribution of this paper is to lessen the complexity of the proposed algorithm and to offer flexibility in controlling the interference produced to the users of the primary networks,which has been achieved by including a pricing function in the proposed cost ***,the performance of the proposed power and subcarrier algorithm is confirmed for orthogonal frequency-division multiplexing(OFdM).Simulation results prove that the performance of the proposed algorithm is better than other algorithms,albeit with a lesser complexity of O(NM)+O(Nlog(N)).

关键词： Cognitive radio resource allocation OFdM pricing

凹唇姜属(Boesenbergia ***)和山柰属(Kaempferia L.)(姜科)叶的解剖学(英文)

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

热带亚热带植物学报 2001年第1期9卷 49-54,T001,T002,T003,T004页

作者： Khatijah H. HUSSIN Halijah ibrahim d. Aminah H.A. ALI 廖景平刘念 School of Environmental and Resource Sciences Biodiversity and Conservation Section 中国科学院华南植物研究所广东广州510650

通过凹唇姜属（Ｂｏｅｓｅｎｂｅｒｇｉａｃｕｒｔｉｓｉｉ，Ｂ．Ｐｒａｉｎｉａｎａ，Ｂ．ｒｏｔｕｎｄａ和Ｂ．Ｐｌｉｃａｔａ和山柰属（Ｋａｅｍｐｆｅｒｉａ　ｐｕｌｃｈｒａ．Ｋ．ｇａｌａｎｇａ，Ｋｇｉｌｂｅｒｔｉ... 详细信息

通过凹唇姜属（Ｂｏｅｓｅｎｂｅｒｇｉａｃｕｒｔｉｓｉｉ，Ｂ．Ｐｒａｉｎｉａｎａ，Ｂ．ｒｏｔｕｎｄａ和Ｂ．Ｐｌｉｃａｔａ和山柰属（Ｋａｅｍｐｆｅｒｉａ　ｐｕｌｃｈｒａ．Ｋ．ｇａｌａｎｇａ，Ｋｇｉｌｂｅｒｔｉｉ，Ｋｒｏｔｕｎｄａ，Ｋｐａｒｖｉｆｌｏｒａ和Ｋａｎｇｕｓｔｉｆｏｌｉａ）种间叶解剖学变化的研究，寻找能用于鉴别种的解剖学特征。结果显示变化表现在气孔的类型、中脉的结构、叶缘和叶柄横切面轮廓、叶片的远轴面或近轴面下皮层和毛状体的出现或缺如。研究表明这些特征的联合对已研究的种的鉴别是有用的。

关键词：气孔叶柄中脉叶片叶缘凹唇姜属山柰属姜科植物解剖

Anti-trypanosomal effect of Peristrophe bicalyculata extract on Trypanosoma brucei brucei-infected rats

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

Asian Pacific Journal of Tropical Biomedicine 2013年第7期3卷 523-531页

作者： Abdulazeez Mansurah Abimbola ibrahim Abdulrazak Baba Edibo Zakari Yenusa Sidali Joseph Omanibe Idris Habeeb Oladimeji department of Biochemistry Faculty of Sciences Ahmadu Bello UniversityZaria Kaduna State Nigeria Embrapa Recursos Genética e Biotecnologia Laboratório de Transferência e Expresso de GenesPqEB W5 Asa Norte Brasilia-DF Brazil

Objective:To investigate thein vitroandin vivoeffect of whole plant extracts ofPeristrophe bicalyculataonTrypanosoma brucei brucei-infected ***:The experiment wasdivided into two phases:In the first phase,the anti-trypanosomal activity of the hot water,cold water,methanol and butanol extracts of the whole plant were determined by incubatingwithTrypanosoma brucei *** cold water extract was partially-purified and the anti-trypanosomal activity of the fractions *** the second phase,Trypanosoma brucei brucei-infected rats were treated with fraction 2c for nine *** cell volume(PCV),highdensity lipoprotein(HdL),low density lipoprotein(LdL),total cholesterol(TC),triacylglycerol(TAG),aspartate aminotransferase,alanine aminotransferases(ALT),alkaline phosphatase(ALP),total and direct bilirubin levels were determined at the end of the ***:Cold water extract immobilized 90%of the parasites after 60 min of incubation,and fraction 2ccompletely immobilized the parasites after 35 *** significantly increased PCV inTrypanosoma brucei brucei-infected *** TC,TAG,HdL and LdL levels of infected rats increasedsignificantly when rats were treated with the fraction,while elevated levels of total bilirubinand ALT also *** difference in urea,direct bilirubin and ALP was not significantwhen infected rats were compared to rats in other ***:The ability of the plantto ameliorate the infection-induced biochemical changes calls for detailed investigation of thepotentials of the plant for antitrypanosomiasis drug delivery.

关键词： Anti-trypanosomal activity Trypanosoma brucei brucei Peristrophe bicalyculata Lipoproteins

Hematopoietic Stem and Progenitor Cell(HSPC)Mobilization Responses to different Exercise Intensities in Young and Older Adults

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Science in Sport and Exercise 2020年第1期2卷 47-58页

作者： Joshua P.Nederveen Jeff Baker George ibrahim Victoria Ivankovic Michael E.Perciva Gianni Parise department of Kinesiology McMaster UniversityHamiltonON L8S 4L8Canada Child and Youth Mental Health Program McMaster University Medical CentreHamiltonON L8N 3Z5Canada

Introduction Hematopoietic stem and progenitor cells(HSPC)are responsible for the reconstitution of blood cells and thought to contribute to peripheral tissue *** acute exercise in young adults,HSPC are mobilized from their niche in bone marrow into circulation,however the kinetics of mobilization following exercise is not well understood in older *** the present study,we aimed to investigate how exercise intensity influences mobilization of specific subpopulations of HSPC,and how mobilization is affected by *** Healthy older men(OM;69.9±2.0 years)and young men(YM;21.5±0.8 years)performed three separate bouts of exercise on a cycle ergometer:70%of their peak work rate(WRpeak)until volitional fatigue,30%of their WRpeak work matched to the 70%WRpeak trial,and a high intensity interval training(HIIT)*** samples were collected before,immediately post,and 10,30,and 60 min *** blood cells,hematocrit,and mononuclear cells isolated by density gradient centrifugation were quantified using flow *** Mononuclear cells,Cd34+,Cd34+/Cd38+,Cd34+/Cd110+,Cd3+/Cd(16+56)+,Cd11c+/Cd123-,and Cd11c-/Cd123+cells per millilitre of blood increased immediately post-exercise,but predominately in the 70%WRpeak trial in both OM and *** Taken together,our evidence suggests that higher intensity exercise but also volume is necessary for the mobili-zation of ***,the pattern of mobilization was nearly identical in OM as compared to YM though to a lesser extent than their younger counterparts.

关键词： Exercise Hematopoietic stem cells Pmgenitor cells Aging F1ow cytometry

Sweet plasmonics： Sucrose macrocrystals of metal nanoparticles

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2015年第3期8卷 860-869页

作者： Talha Erdem Zeliha Soran-Erdem Pedro Ludwig Hernandez-Martinez Vijay Kumar Sharma Halil Akcali ibrahim Akcali Nikolai Gaponik Alexander Eychmeller Hilmi Volkan demir departments of Electrical and Electronics Engineering Physics UNAM-National Nanotechnology Research Center and Institute ot Materials Science and Nanotechnology Bilkent University Ankara 06800 Turkey School of Electrical and Electronic Engineering and School of Physical and Mathematical Sciences Nanyang Technological University Singapore 639798 Singapore Physical Chemistry TU Dresden Bergstrasse 66b D-O 1062 Dresden Germany

The realization of plasmonic structures generally necessitates expensive fabrication techniques, such as electron beam and focused ion beam lithography, allowing for the top-down fabrication of low-dimensional structures. Another approach to make plasmonic structures in a bottom-up fashion is colloidal synthesis, which is convenient for liquid-state applications or very thin solid films where aggregation problems are an important challenge. The architectures prepared using these methods are typically not robust enough for easy handling and convenient integration. Therefore, developing a new plasmonic robust platform having large-scale dimensions without adversely affecting the plasmonic features is in high demand. As a solution, here we present a new plasmonic composite structure consisting of gold nanoparticles （Au NPs） incorporated into sucrose macrocrystals on a large scale, while preserving the plasmonic nature of the Au NPs and providing robustness in handling at the same time. As a proof of concept demonstration, we present the fluorescence enhancement of green CdTe quantum dots （Qds） via plasmonic coupling with these Au NPs in the sucrose crystals. The obtained composite material exhibits centimeter scale dimensions and the resulting quantum efficiency （QE） is enhanced via the interplay between the Au NPs and CdTe Qds by 58% （from 24% to 38%）. Moreover, a shortening in the photoluminescence lifetime from 11.0 to 7.40 ns, which corresponds to a field enhancement factor of 2.4, is observed upon the introduction of Au NPs into the Qd incorporated macrocrystals. These results suggest that such ＂sweet＂ plasmonic crystals are promising for large-scale robust platforms to embed plasmonic nanoparticles.

关键词： plasmonics macrocrystals metal nanoparticles metal enhancedfluorescence colloidal quantum dots

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

研究和设计用于RF的MIMO天线

研究和设计用于RF的MIMO天线

作者： ibrahim Bouba 江苏大学

学位级别：硕士

过去二十多年以来,无线通信容量持续的增长需求已经将较低的射频(Radio Frequency,RF)频谱资源利用殆尽。因此,能够提供极宽带宽的更高频率的无线通信系统近来备受关注。由于频谱资源极其宝贵,因此现在运营商们正在更高的蜂窝频段上搭... 详细信息

过去二十多年以来,无线通信容量持续的增长需求已经将较低的射频(Radio Frequency,RF)频谱资源利用殆尽。因此,能够提供极宽带宽的更高频率的无线通信系统近来备受关注。由于频谱资源极其宝贵,因此现在运营商们正在更高的蜂窝频段上搭建新的无线通信系统。最常测试和最近部署的频段是n78(3500 MHz),也被称为5G 3.5 GHz频段或5G C频段。一方面,由于蜂窝频谱的低频段已经被3G和4G网络使用,所以部署处于高频段且具有可用性的n78频段势在必行。另一方面,由于高频率特有的传播特性,n78频段的覆盖范围和通信连接性存在天然的局限性,但通过MIMO等无线技术可以在一定程度上改善这种局限性。为了解决无线系统中的覆盖范围和连接问题,寻找可行的天线结构是关键的一步。通信系统工程师们一直在努力研究低成本、轻量级、低剖面的天线,使其在宽频谱上具有高端性能。这种技术发展趋势使得微带贴片天线设计受到了极大的关注。本论文研究了贴片天线增益及带宽的增强。研究内容主要被分为以下两个部分:第一,设计了一款高增益贴片阵列,克服了微带线不连续性的影响。提出了采用并联馈电网络的单层矩形贴片阵列的设计及实现方法。2x4微带贴片天线阵列采用罗杰斯RT/duroid 5880作为基材,高度为1.575mm,介电常数为2.2,损耗角正切为0.0009。为了验证模拟结果,制作了贴片天线单元和八单元阵列的实物。测试结果表明,该天线阵列实现了16.2 d B的峰值增益和19°的3 d B波束宽度。分析结果表明,采用该天线阵列可以很大程度上提高天线性能。该天线阵列的10 d B带宽为3400-3520 MHz,适用于n78频段的5G接入点应用。第二,研究和设计了带有改进接地短截线的UWB-MIMO天线。这项研究旨在解决贴片天线的带宽限制问题,并为此设计了一款UWB贴片天线。然后,将所提出的结构用于一个二单元MIMO天线系统并进行性能分析。天线单元可以描述为矩形微带天线的一个变体。设计的天线由两个蚀刻在1.6 mm高的FR4介质基板上几何形状相同的辐射单元组成。介质基板的相对介电常数为4.4。每个贴片单元分别用50Ω的微带线馈电。在尺寸方面,MIMO天线的尺寸缩小为20 mm×32 mm,工作频段为4.4-10.7 GHz。该MIMO系统可用于高速率传输和短程通信设备,例如无线个人局域网。

关键词： 5G MIMO UWB 微带不连续贴片天线

Real Time Ultrasound Elastography for the differentiation of Benign and Malignant Thyroid Nodules

同方学位论文库评论

在线全文

同方学位论文库

学校读者我要写书评

暂无评论

Open Journal of Medical Imaging 2014年第1期4卷 38-47页

作者： Hamad Elniel H. Eltyib ibrahim A. Awad Naglaa M. Elsayed Saddig d. Jastaniah department of diagnostic Radiology Faculty of Applied Medical Sciences King Abdulaziz UniversityJeddah KSA

The purpose of this study was to evaluate the predictive value of real-time ultrasound elastography (RUE) in differentiating benign from malignant thyroid nodules, with fine needle aspiration cytology analysis as the reference standard. A total of 78 consecutive patients with thyroid nodules who were selected for fine needle aspiration biopsies were examined in this prospective study. 78 nodules in these patients were examined by conventional ultrasound, and ultrasound elastography. The final diagnosis was obtained from cytological findings. Tissue stiffness on ultrasound elastography was scored from 1 (low stiffness over the entire nodule) to 5 (high stiffness over the entire nodule and surrounding tissue). On real-time ultrasound elastography, 47 of 62 benign nodules (76%) had a score of 1 or 2, whereas 15 of 16 malignant nodules had a score of 3 to 5, with sensitivity of 93.7%, specificity of 90%, a positive predictive value of 71%, and a negative predictive value of 98%. Real-time ultrasound elastography is a promising imaging technique that is useful in the differential diagnosis of thyroid cancer. Utilization of ultrasound elastography could reduce the rate of thyroid biopsies because of its high elasticity being highly associated with benign cytology.

关键词： Elastography Real-Time Thyroid Nodules Ultrasound Malignant