检索结果-南通市图书馆

Design and research of RF system for 10 MeV compact cyclotron

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

Science China(Physics,Mechanics & Astronomy) 2011年第S2期54卷 225-230页

作者： Dong Li (1) TongNing Hu (2) KaiFeng Liu (1) Jun Yang (1) 1. College of Electrical and Electronic Engineering Huazhong University of Science and Technology Wuhan 430074 China2. Department of Electronics and Information Engineering Huazhong University of Science and Technology Wuhan 430074 China

A 10 MeV compact cyclotron (CYCHU-10) has been developing in Huazhong University of Science and Technology (HUST). The RF system includes a 10 kW RF power generator and a resonance cavity. There is no automatic frequency tuning equipment in the cavity due to space limitations, so the generator must search and track the cavity resonant frequency. AD9850 synthesizer is used to generate RF signal in the experimental prototype, and a fine sinusoidal waveform around 99 MHz is obtained with the method of picking up a special aliased signal from the synthesizer's output, and the output power level can be set by regulating the resistor connected to the Pin 'Rset'. The final stage amplifier based on tetrode operates in the grounded cathode configuration, and the schematic of the tetrode circuit is illustrated. The method of searching the resonant frequency is discussed in detail. For the sake of a compact and robust structure, the resonance cavity will adopt non-uniform characteristic impedance coaxial structure, and the magnet surface electroplated with copper will be used as dummy Dees. The precise shapes and dimensions of the cavity are designed and simulation results are carried out in this paper. The distributions of electromagnetic field are illustrated by means of numerical calculation analysis, and the wooden model test is preformed as well.

关键词： compact cyclotron RF system AD9850 tetrode resonance cavity

Tuning the Fermi level in Bi2Se3 bulk materials and transport devices

在线全文

学校读者我要写书评

暂无评论

Frontiers of physics 2012年第2期7卷 160-164页

作者： Zhi-yong Wang (1) Peng Wei (1) Jing Shi (1) Department of Physics & Astronomy University of California Riverside USA

Bi2Se3 has been predicted to be a three-dimensional （3D） topological insulator （TI） with Dirac fermions residing on the two-dimensional （2D） surface. Unique transport properties such as high carrier mobility due to the suppressed backscattering are expected for the Dirac fermions. In order to eliminate the contribution of the bulk carriers, therefore, to place the Fermi level in the band gap of Bi2Se3, we first introduce various amounts of Ca dopants into the crystal to realize the bulk insulating state. Then by avoiding uncontrolled heating and electron beam irradiation in the nanofabrication process, we maintain the insulating state in thin devices. By sweeping the gate voltage, we have observed a conductivity minimum that is expected for the Dirac fermions in the band gap of 3D TIs.

关键词： topological insulators Bi2Se3 transport properties nano-devices

Theoretical analysis of some problems in the measurement of beam divergence angle for EAST neutral beam injector

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

Science China(Physics,Mechanics & Astronomy) 2011年第S2期54卷 300-304页

作者： YongJian Xu (1) ChunDong Hu (1) 1. Institute of Plasma Physics Chinese Academy of Sciences Hefei 230031 China

Beam angular divergence is one of the indicators to evaluate the beam quality. Operating parameters of the beam extraction system could be adjusted to gain better beam quality following the measurement results, which will be helpful not only to study the transmission characteristics of the beam and the power distribution on the heat load components, but also to understand the real-time working condition of the ion source and beam extraction system. This study includes: (1) the theoretical analysis of beam extraction pulse duration for measurement of beam angular divergence; (2) the theoretical analysis of beam intensity distribution during beam transmission for Experimental Advanced Superconducting Tokomak (EAST) neutral beam injector. Those theoretical analyses could point the way to the measurement of beam divergence angle for EAST neutral beam injector.

关键词： neutral beam beam divergence angle beam intensity pulse duration

常染色体显性遗传性多囊肾患者妊娠后影响及治疗研究进展

在线全文

学校读者我要写书评

暂无评论

临床个性化医学 2024年第3期3卷 975-981页

作者：巩莎1 孟雪董辉辉徐璐魏明明李新建济宁医学院临床医学院山东济宁济宁医学院附属医院肾内科山东济宁济宁市兖州区人民医院肾内科山东济宁

常染色体显性遗传性多囊肾(ADPKD)是一种常见的肾脏遗传病,为单基因遗传,以双侧肾囊肿为特征,导致肾功能进行性下降。近年来基因检测技术和一些新药物的使用,使得ADPKD的管理取得了长足进步。但作为最常见的单基因遗传性肾病ADPKD患者... 详细信息

常染色体显性遗传性多囊肾(ADPKD)是一种常见的肾脏遗传病,为单基因遗传,以双侧肾囊肿为特征,导致肾功能进行性下降。近年来基因检测技术和一些新药物的使用,使得ADPKD的管理取得了长足进步。但作为最常见的单基因遗传性肾病ADPKD患者的发病年龄与育龄期妇女高度重合,母亲和婴儿的妊娠结局与普通人群不同,妊娠并发症的长期后果在ADPKD中也很常见。本文将对ADPKD患者妊娠后的影响、妊娠期间的多方面治疗与管理进行综述。Autosomal Dominant Polycystic Kidney Disease (ADPKD) is a prevalent genetic kidney disorder inherited through a single gene, characterized by bilateral renal cysts that lead to a progressive decline in renal function. Recent advancements in genetic testing technology and the introduction of novel medications have significantly improved the management of ADPKD. However, as the most prevalent monogenic inherited kidney disease, ADPKD patients often experience onset during childbearing age, leading to distinctive pregnancy outcomes for both mothers and infants compared to the general population. Additionally, long-term consequences of pregnancy complications are common in ADPKD. This review aims to outline the impact of pregnancy on ADPKD patients and explore multiple treatment and management strategies during pregnancy.

关键词：常染色体显性遗传性多囊肾病妊娠辅助生殖技术治疗与管理

Spark plasma and microwave sintering of Al6061 and Al2124 alloys

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

International Journal of Minerals,Metallurgy and Materials 2013年第2期20卷 152-159页

作者： Nouari Saheb1 Department of Mechanical Engineering King Fahd University of Petroleum & Minerals Center of Excellence in Nanotechnology King Fahd University of Petroleum & Minerals

Despite the importance of aluminum alloys as candidate materials for applications in aerospace and automotive industries, very little work has been published on spark plasma and microwave processing of aluminum alloys. In the present work, the possibility was explored to process A12124 and A16061 alloys by spark plasma and microwave sintering techniques, and the microstructures and properties were compared. The alloys were sintered for 20 rain at 400, 450, and 500℃. It is found that compared to microwave sintering, spark plasma sintering is an effective way to obtain homogenous, dense, and hard alloys. Fully dense （100%） A16061 and A12124 alloys were obtained by spark plasma sintering for 20 rain at 450 and 500℃, respectively. Maximum relative densities were achieved for A16061 （92.52%） and A12124 （93.52%） alloys by microwave sintering at 500℃for 20 min. The Vickers microhardness of spark plasma sintered samples increases with the increase of sintering temperature from 400 to 500℃, and reaches the values of Hv 70.16 and Hv 117.10 for A16061 and A12124 alloys, respectively. For microwave siutered samples, the microhardness increases with the increase of sintering temperature from 400 to 450℃, and then decreases with the further increase of sintering temperature to 500~C.

关键词： aluminum alloys spark plasma sintering microwave sintering microstructure hardness density

Effects of N-n-butyl Haloperidol Iodide on Myocardial Ischemia/ReperfusionInjury and Egr-1 Expression in Rat

在线全文

学校读者我要写书评

暂无评论

Acta Biochimica et Biophysica Sinica 2006年第6期38卷 435-441页

作者： Yan-Mei ZHANG~1,Gang-Gang SHI~(1*),Zhao TANG~1,Jin-Hong ZHENG~1,Wei-Qiu LI~2,Fu-Xiao GUO~1,and Qiang-Yong JIA~1~1 Department of Pharmacology and~2 Central Laboratory,Shantou University Medical College,Shantou 515041,China Department of Pharmacology Shantou University Medical CollegeShantou 515041 China Central Laboratory Shantou University Medical CollegeShantou 515041 China

We have previously shown that N-n-butyl haloperidol iodide (F) derived from haloperidolreduces ischemia/reperfusion-induced myocardial injury by blocking intracellular *** studytested the hypothesis that cardio-protection with F2 is associated with an attenuation in the expression ofearly growth response gene 1 (Egr-l).In an in vivo rat model of 60 rain coronary occlusion followed by180 rain of reperfusion,treatment with Fsignificantly reduced myocardial injury evidenced by the reductionin release of plasma creatine kinase,myocardial creatine kinase isoenzyme and lactate *** neonatal rat cardiomyocytes of hypoxia for 3 h and reoxygenation for 1 h,F2 treatment attenuatednecrotic and apoptotic cell death,as demonstrated by electron *** with cardio-protectionby F,the increased expression levels of Egr-l mRNA and protein were significantly reduced in myocardialtissue and cultured cardiomyocytes as detected by reverse transcription-polymerase chain reaction,immunohistochemistry and *** conclusion,these results suggest that the protectiveeffect of Fon ischemia/reperfusion-or hypoxia/reoxygenation-induced myocardial injury might be partlymediated by downregulating Egr-l expression.

关键词： N-n-butyl haloperidol iodide ischemia/reperfusion injury early growth response gene-1 myocardium cardiomyocyte

Inhibition of the α-mannosidase Man2c1 gene expression enhances adhesion of Jurkat cells

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Cell Research 2006年第7期16卷 622-631页

作者： Li Qu~(1,*) Ji Yu Ju~(1,*) Shuang Ling Chen~1 Yan Shi~1 Zhi Guang Xiang~1 Yi Qun Zhou~1 Yun Tian~1 Yin Liu~1 Li Ping Zhu~1 ~1Department of Immunology,Institute of Basic Medical Sciences,Chinese Academy of Medical Sciences and Peking Union Medical College,Beijing 100005,China Department of Immunology Institute of Basic Medical Sciences Chinese Academy of Medical Sciences and Peking Union Medical College Beijing China

Protein N-glycosylation plays very important roles in immunity and α-mannosidase is one of the key enzymes in *** paper reports that inhibition of α-mannosidase Man2cl gene expression enhances adhesion of JurkatT *** comparison to the controls with normal expression of the enzyme,Jurkat cells with the inhibition of Man2clgene expression（AS cell）formed larger aggregates in culture,indicating an enhancement of adhesion between the *** differential display analysis discovered up-regulation of several adhesion molecule genes in the AS *** the pivotal role played by CD54-LFA-1 interaction in immune cell interaction,this study focused on the contributionof enhanced expression of CD54 and LFA-1 to the enhanced adhesion of AS Jurkat *** facts,including increasedbinding of AS cells to ICAM-1-Fc,Mg2+activation of the binding of AS cells to ICAM-1-Fc and enhanced aggregationof AS cells,together with the inhibiting effect of a blocking CD 11a mAb on the binding to ICAM-1-Fc and aggregationof the cells demonstrate an important contribution of enhanced CD54-LFA-1 interaction to increased adhesion betweenAS *** enhanced CD54-LFA-1 interaction also resulted in increased adhesion between AS Jurkat T cells and RajiB *** addition,AS cells showed cytoskeletal *** data imply a biological significance of MAN2C1in T-cell functioning.

关键词： Man2cl Jurkat T cell adhesion CD54-LFA-1 cytoskeleton

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

科学流言榜

百科知识 2024年第14期 33-36页

作者： 1.新华社 2.北京协和医院新华社北京协和医院

“每月科学流言榜”由北京市科学技术协会、北京市网信办、首都互联网协会指导，北京科技记者编辑协会、北京地区网站联合辟谣平台共同发布，得到中国科普作家协会科技传播专业委员会、中国晚报科学编辑记者学会、上海科技传播协会、北...

“每月科学流言榜”由北京市科学技术协会、北京市网信办、首都互联网协会指导，北京科技记者编辑协会、北京地区网站联合辟谣平台共同发布，得到中国科普作家协会科技传播专业委员会、中国晚报科学编辑记者学会、上海科技传播协会、北京市科学技术情报研究所的支持。

关键词：

以“千万工程”为指引打造“青农飞地”引育新农人助力乡村振兴

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

中国共青团 2024年第7期 62-65页

作者： 1.团金华市委 2.团婺城区委团金华市委团婺城区委

习近平总书记在义乌李祖村考察调研时指出“乡村振兴为年轻人提供了展现才华的用武之地,希望更多的年轻人为乡村振兴发挥积极作用”。为深入学习贯彻习近平总书记关于实施乡村振兴战略的重要论述,共青团金华市委以“千万工程”为指引,... 详细信息

习近平总书记在义乌李祖村考察调研时指出“乡村振兴为年轻人提供了展现才华的用武之地,希望更多的年轻人为乡村振兴发挥积极作用”。为深入学习贯彻习近平总书记关于实施乡村振兴战略的重要论述,共青团金华市委以“千万工程”为指引,着力破解青年投身农创“不愿回、留不下、干不好”三个痛点、难点问题,率先在婺城区探索建设“青农飞地”省级共富试点,旨在建立政府主导、多方协同、市场化运作的青年农创枢纽平台,推动城乡之间各类创业资源和要素高效流通。

关键词：乡村振兴创业资源共富婺城区新农人飞地多方协同市场化运作