期刊文献+
共找到684篇文章
< 1 2 35 >
每页显示 20 50 100
软开关高增益准YZ源DC-DC变换器
1
作者 李海滨 颜胥 +2 位作者 翁雨森 林佳奇 金涛 《中国电机工程学报》 EI CSCD 北大核心 2024年第11期4435-4445,I0022,共12页
针对新能源发电系统中所需要的高升压非隔离变换器升压能力不足问题,文中基于Y源变换器和准Z源变换器的优点,提出一种软开关高增益准YZ源DC-DC变换器。所提变换器不仅提高了升压能力,还能够有效吸收漏感产生的电压尖峰。除此之外,应用... 针对新能源发电系统中所需要的高升压非隔离变换器升压能力不足问题,文中基于Y源变换器和准Z源变换器的优点,提出一种软开关高增益准YZ源DC-DC变换器。所提变换器不仅提高了升压能力,还能够有效吸收漏感产生的电压尖峰。除此之外,应用同步整流技术,使得开关管和二极管工作在软开关条件,提升了转换效率。此外,所提变换器由于电源输入端连接的是单个电感,输入电流连续,电流纹波小。不仅如此,提出的变换器还具备开关管电压应力低、输入输出电压共地等优点。首先对所提变换器的工作模态和稳态进行分析;其次定量计算效率以及损耗分布;将所提变换器的性能与其他变换器进行对比,并明确设计要求;最后通过实验室制作的样机,验证所提变换器的有效性。 展开更多
关键词 高增益 软开关 y源变换器 准Z源变换器 dC-dC变换器
下载PDF
D-stability and disturbance attenuation properties fornetworked control systems: switched system approach 被引量:2
2
作者 Qiuxia Chen Andong Liu 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2016年第5期1108-1114,共7页
Both D-stability and finite L2-gain properties are studiedfor a class of uncertain discrete-time systems with timevaryingnetwork-induced delays. By using coordinate transformand delay partition, the D-stability and H... Both D-stability and finite L2-gain properties are studiedfor a class of uncertain discrete-time systems with timevaryingnetwork-induced delays. By using coordinate transformand delay partition, the D-stability and H∞ performance problemsfor such networked control systems (NCSs) are equivalentlytransferred into the corresponding problems for switching systemswith arbitrary switching. Then, a sufficient condition for the existenceof the robust D-stabilizing controllers is derived in termsof linear matrix inequality (LMI), and the design method is alsopresented for the state feedback controllers which guarantee thatall the closed-loop poles remain inside the specified disk D(α,r)and the desired disturbance attenuation level. Finally, an illustrativeexample is given to demonstrate the effectiveness of the proposedresults. 展开更多
关键词 d-STABILITy networked control system (NCS) H∞performance switching system.
下载PDF
Study the Effect of Thickness on the Performance of PM6:Y6 Organic Solar Using SCAPS Simulation
3
作者 Nagwa Ibrahim Mohammed Ibrahim Amnah Mohammed Elharbi Abdulrahman Albadri 《Advances in Materials Physics and Chemistry》 CAS 2024年第4期55-65,共11页
In this study, organic solar cells (OSCs) with an active layer, a blend of polymer of non-fullerene (NFA) Y6 as an acceptor, and donor PBDB-T-2F as donor were simulated through the one-dimensional solar capacitance si... In this study, organic solar cells (OSCs) with an active layer, a blend of polymer of non-fullerene (NFA) Y6 as an acceptor, and donor PBDB-T-2F as donor were simulated through the one-dimensional solar capacitance simulator (SCAPS-1D) software to examine the performance of this type of organic polymer thin-film solar cell by varying the thickness of the active layer. PFN-Br interfacial layer entrenched in OPV devices gives overall enhanced open-circuit voltage, short-circuit current density and fill factor thus improving device performance. PEDOT: PSS is an electro-conductive polymer solution that has been extensively utilized in solar cell devices as a hole transport layer (HTL) due to its strong hole affinity, good thermal and mechanical stability, high work function, and high transparency in the visible range. The structure of the organic solar cell is ITO/PEDOT: PSS/BTP-4F: PBDB-T-2F/PFN-Br/Ag. Firstly, the active layer thickness was optimized to 100 nm;after that, the active-layer thickness was varied up to 900 nm. The results of these simulations demonstrated that the active layer thickness improves efficiency significantly up to 500 nm, then it decreased with increasing the thickness of the active layer from 600 nm, also notice that the short circuit current and the fill factor decrease with increasing the active layer from 600 nm, while the open voltage circuit increased with increasing the thickness of the active layer. The optimum thickness is 500 nm. 展开更多
关键词 Organic Solar Cells PEdOT:PSS BTP-4F (y6) PBdB-T-2F (PM6) PFN-Br SCAPS 1d
下载PDF
Silicon-on-Insulator 1×2 Y-Junction Optical Switch Based on Waveguide-Vanishing Effect
4
作者 赵策洲 《High Technology Letters》 EI CAS 1997年第1期10-12,共3页
The silicon-on-insulator(SOI) 1 × 2 Y-junction optical waveguide switch has been proposed and fabricated, which is based on the large cross-ction single--mode rib waveguide condition, the waveguide--vanishing eff... The silicon-on-insulator(SOI) 1 × 2 Y-junction optical waveguide switch has been proposed and fabricated, which is based on the large cross-ction single--mode rib waveguide condition, the waveguide--vanishing effect and the free-carrier plasma dispersion effect. The SOI switch utilizes silicon and silicon dioxide thermal bonding and back--polishing. The insertion loss and extinction ratio of the device are measured to be less than 4. 78 dB and 20. 8dB respectively at a wavelength of 1. 3pm and an injection current of 45mA. The response time is about 160us. 展开更多
关键词 SOI Integrated optics y JUNCTION Optical switch
下载PDF
农村留守老人的精神养老问题——以D市Y乡K村为例
5
作者 吴泽洋 《农村经济与科技》 2024年第18期224-226,257,共4页
伴随城镇化的不断推进,大量农村劳动力涌入城镇,农村“空心化”现象日趋严重。通过对贵州省D市Y乡K村10名留守老人进行访谈与观察,发现该群体在精神养老上较为匮乏,在自尊、情感、娱乐活动以及人际交往上的需求存在不足,其困境的成因是... 伴随城镇化的不断推进,大量农村劳动力涌入城镇,农村“空心化”现象日趋严重。通过对贵州省D市Y乡K村10名留守老人进行访谈与观察,发现该群体在精神养老上较为匮乏,在自尊、情感、娱乐活动以及人际交往上的需求存在不足,其困境的成因是经济、观念、社会等因素共同作用产生的。从社会工作的角度出发尝试运用社区工作的方法与理论,能够从多角度、多层次、多领域为服务对象提供服务,进而满足服务对象的需求。在提高农村留守老人的精神养老水平方面,社会工作具有独特的优势和作用,能够为解决这一社会问题提供有效思路与策略。 展开更多
关键词 农村 留守老人 精神养老 社会工作 dy乡K村
下载PDF
Resistive switching memory for high density storage and computing
6
作者 Xiao-Xin Xu Qing Luo +3 位作者 Tian-Cheng Gong Hang-Bing Lv Qi Liu Ming Liu 《Chinese Physics B》 SCIE EI CAS CSCD 2021年第5期26-51,共26页
The resistive random access memory(RRAM)has stimulated a variety of promising applications including programmable analog circuit,massive data storage,neuromorphic computing,etc.These new emerging applications have hug... The resistive random access memory(RRAM)has stimulated a variety of promising applications including programmable analog circuit,massive data storage,neuromorphic computing,etc.These new emerging applications have huge demands on high integration density and low power consumption.The cross-point configuration or passive array,which offers the smallest footprint of cell size and feasible capability of multi-layer stacking,has received broad attention from the research community.In such array,correct operation of reading and writing on a cell relies on effective elimination of the sneaking current coming from the neighboring cells.This target requires nonlinear I-V characteristics of the memory cell,which can be realized by either adding separate selector or developing implicit build-in nonlinear cells.The performance of a passive array largely depends on the cell nonlinearity,reliability,on/off ratio,line resistance,thermal coupling,etc.This article provides a comprehensive review on the progress achieved concerning 3D RRAM integration.First,the authors start with a brief overview of the associative problems in passive array and the category of 3D architectures.Next,the state of the arts on the development of various selector devices and self-selective cells are presented.Key parameters that influence the device nonlinearity and current density are outlined according to the corresponding working principles.Then,the reliability issues in 3D array are summarized in terms of uniformity,endurance,retention,and disturbance.Subsequently,scaling issue and thermal crosstalk in 3D memory array are thoroughly discussed,and applications of 3D RRAM beyond storage,such as neuromorphic computing and CMOL circuit are discussed later.Summary and outlooks are given in the final. 展开更多
关键词 resistive switching memory(RRAM) three-dimensional(3d)integration RELIABILITy COMPUTING
下载PDF
Application of 3D CAD Modeling in Designing 330 kV Outdoor Switch Yard Layout
7
作者 LiBochang Northwest Electric Power Design Institute (NWEPDI) 《Electricity》 1996年第3期46-47,共2页
The Development of 3D CAD technology presents a new effective tool in designing outdoor switch yard for power plant. A new layout pattern of 330 kV switch yard (SWYD) of aligned type was studied with this method. Some... The Development of 3D CAD technology presents a new effective tool in designing outdoor switch yard for power plant. A new layout pattern of 330 kV switch yard (SWYD) of aligned type was studied with this method. Some issues about computerized 3D modes applied in SWYD design are also discussed in this paper. 展开更多
关键词 3d modeling OUTdOOR switch yARd ALIGNEd layout CLEARANCE
下载PDF
Evaluating Pharmacological and Rehabilitation Strategies for Effective Management of Bipolar Disorder: A Comprehensive Clinical Study
8
作者 Rocco de Filippis Abdullah Al Foysal 《Advances in Bioscience and Biotechnology》 CAS 2024年第7期406-431,共26页
Bipolar disorder presents significant challenges in clinical management, characterized by recurrent episodes of depression and mania often accompanied by impairment in functioning. This study investigates the efficacy... Bipolar disorder presents significant challenges in clinical management, characterized by recurrent episodes of depression and mania often accompanied by impairment in functioning. This study investigates the efficacy of pharmacological interventions and rehabilitation strategies to improve patient outcomes and quality of life. Utilizing a randomized controlled trial with multiple treatment arms, participants will receive pharmacotherapy, polypharmacotherapy, rehabilitation interventions, or combination treatments. Outcome measures will be assessed using standardized scales, including the Hamilton Depression Scale, Yale-Brown Obsessive Compulsive Scale (Y-BOCS), and Mania Scale. Preliminary data suggest improvements in symptom severity and functional outcomes with combination treatments. This research aims to inform clinical practice, guide treatment decisions, and ultimately enhance the quality of care for individuals living with bipolar disorder. Findings will be disseminated through peer-reviewed journals and scientific conferences to advance knowledge in this field. 展开更多
关键词 Bipolar disorder (Bd) Pharmacotherapy (PT) Rehabilitation Interventions (RI) Hamilton depression Scale (HAM-d) yale-Brown Obsessive Compulsive Scale (y-BOCS) Mania Scale (MS) Machine learning (ML) and Artificial Intelligence (AI).
下载PDF
Silicon-on-insulator 1×2 Y-junction Optical Switch Basedon Waveguide-vanishing Effect 被引量:1
9
作者 ZHAO Cezhou (Microelectron. Institute,Xidian University,Xi’an 710071,CHN) LIU Enke,LI Guozheng,LIU Yuliang (Depart.of Electron.Eng.,Xi’an Jiaotong University,Xi’an 710049,CHN) GUO Lin (Sichuan Institute of Solid State Circuits,Chongqing 630060,CH 《Semiconductor Photonics and Technology》 CAS 1997年第2期60-63,68,共5页
The silicon-on-insulator(SOI) 1×2 Y-junction optical waveguide switch has been proposed and fabricated,which is based on the large cross-section single-mode rib waveguide condition,the waveguide-vanishing effect ... The silicon-on-insulator(SOI) 1×2 Y-junction optical waveguide switch has been proposed and fabricated,which is based on the large cross-section single-mode rib waveguide condition,the waveguide-vanishing effect and the free-carrier plasma dispersion effect.In the switch,the SOI technique utilizes silicon and silicon dioxide thermal bonding and back-polishing.The insertion loss and extinction ratio of the device are measured to be less than 4.78 dB and 20.8 dB respectively at a wavelength of 1.3 μm and an injection current of 45 mA.Response time is about 160 ns. 展开更多
关键词 Integrated Optics OPTICAL switchs y JUNCTION SOI
全文增补中
A High-Performance Operational Amplifier for High-Speed High-Accuracy Switch-Capacitor Cells
10
作者 Qi Fan Ning Ning Qi Yu Da Chen 《Journal of Electronic Science and Technology of China》 2007年第4期366-369,共4页
A high-speed high-accuracy fully differenttial operational amplifier (op-amp) is realized based on no-Miller-capacitor feedforward (NMCF) compensation scheme. In order to achieve a good phase margin, the NMCF comp... A high-speed high-accuracy fully differenttial operational amplifier (op-amp) is realized based on no-Miller-capacitor feedforward (NMCF) compensation scheme. In order to achieve a good phase margin, the NMCF compensation scheme uses the positive phase shift of left-half-plane (LHP) zero caused by the feedforvvard path to counteract the negative phase shift of the non-dominant pole. Compared to traditional Miller compensation method, the op-amp obtains high gain and wide band synchronously without the pole-splitting effect while saves significant chip area due to the absence of the Miller capacitor. Simulated by the 0.35 μm CMOS RF technology, the result shows that the open-loop gain of the op-amp is 118 dB with the unity gain-bandwidth (UGBW) of 1 GHz, and the phase margin is 61°while the settling time is 5.8 ns when achieving 0.01% accuracy. The op-amp is especially suitable for the front-end sample/hold (S/H) cell and the multiplying D/A converter (MDAC) module of the high-speed high-resolution pipelined A/D converters (AVCs). 展开更多
关键词 Feedforward compensation op-amp pipelined A/d converter switch-capacitor.
下载PDF
Y对AZ91D镁合金组织及力学性能的影响 被引量:25
11
作者 吴国华 李冠群 +4 位作者 樊昱 丁文江 朱燕萍 李波 王群 《特种铸造及有色合金》 CAS CSCD 北大核心 2006年第5期260-263,共4页
研究了稀土元素钇(Y)对AZ91D镁合金铸态及热处理态的组织和力学性能的影响。结果表明:Y会强烈地细化合金组织,并在合金中生成方块状的Al6Mn6Y相及杆状的Al2Y相。少量的Y能显著提高合金的力学性能,当Y含量(质量分数)达到1.5%时,合金得到... 研究了稀土元素钇(Y)对AZ91D镁合金铸态及热处理态的组织和力学性能的影响。结果表明:Y会强烈地细化合金组织,并在合金中生成方块状的Al6Mn6Y相及杆状的Al2Y相。少量的Y能显著提高合金的力学性能,当Y含量(质量分数)达到1.5%时,合金得到最佳的力学性能。另外,含Y的AZ91D合金固溶处理后硬度及抗拉强度皆高于原AZ91D合金,并且Y会推迟镁合金的时效过程,延长时效峰值的到来时间。 展开更多
关键词 AZ91d镁合金 y 显微组织 力学性能 热处理 硬度
下载PDF
柴胡皂苷d对SH-SY5Y细胞一氧化氮及JNK磷酸化水平的影响 被引量:3
12
作者 李妍 纪朋艳 +3 位作者 彭顺利 张巍 吕士杰 何哲 《中国医科大学学报》 CAS CSCD 北大核心 2013年第9期785-788,共4页
目的 初步探讨不同浓度的柴胡皂苷d(SSd)对SH-SY5Y细胞一氧化氮(NO)及JNK磷酸化水平的影响.方法 体外培养人神经母细胞瘤SH-SY5Y细胞,将SSd溶解于DMSO中,并分别以0~10μmol/LSSd作用于SH-SY5Y细胞48 h,NO试剂盒检测不同浓度的SSd对... 目的 初步探讨不同浓度的柴胡皂苷d(SSd)对SH-SY5Y细胞一氧化氮(NO)及JNK磷酸化水平的影响.方法 体外培养人神经母细胞瘤SH-SY5Y细胞,将SSd溶解于DMSO中,并分别以0~10μmol/LSSd作用于SH-SY5Y细胞48 h,NO试剂盒检测不同浓度的SSd对SH-SY5Y细胞培养基中NO含量的影响,Western blot法检测细胞中t-JNK、p-JNK蛋白表达水平的变化.结果 与对照组相比,4~10 μmol/L SSd作用48 h,细胞培养基中NO浓度明显减少,其中4μmol/L SSd组细胞培养液中NO含量最低(P<0.05);而与对照组相比,4~10 μmol/L SSd预处理的SH-SY5Y细胞中p-JNK/t-JNK蛋白表达量比值明显升高,且10 μmol/L SSd组比值最高(P<0.01).结论 一定浓度的SSd可引起SH-SY5Y细胞NO表达量减少和JNK蛋白磷酸化水平明显升高. 展开更多
关键词 一氧化氮 JNK 柴胡皂苷d SH-Sy5y细胞
下载PDF
柴胡皂苷d对人神经母细胞瘤SH-SY5Y细胞线粒体膜电位及细胞凋亡的影响 被引量:8
13
作者 李妍 赵东海 +3 位作者 张巍 罗军 朱文赫 吕士杰 《上海中医药杂志》 2016年第6期90-93,共4页
目的研究不同浓度的柴胡皂苷d(saikosaponin d,SSd)对人神经母细胞瘤SH-SY5Y细胞线粒体膜电位(mitochondrial transmembrane potential,△ψm)及凋亡水平的影响。方法体外常规培养SH-SY5Y细胞,将细胞置于分别含0-10μmol/L SSd的DME... 目的研究不同浓度的柴胡皂苷d(saikosaponin d,SSd)对人神经母细胞瘤SH-SY5Y细胞线粒体膜电位(mitochondrial transmembrane potential,△ψm)及凋亡水平的影响。方法体外常规培养SH-SY5Y细胞,将细胞置于分别含0-10μmol/L SSd的DMEM高糖培养基中,作用48 h;Rh123染色后流式细胞仪检测细胞线粒体膜电位变化,Tunel法、吖啶橙(AO)/溴化乙啶(EB)染色法检测细胞凋亡水平的变化。结果与对照组比较,8-10μmol/L SSd预处理的SH-SY5Y细胞TUNEL染色后凋亡指数明显升高(P〈0.01);AO/EB染色后可见明显的阳性细胞。此外,不同浓度的SSd作用后均可见SH-SY5Y细胞中Rh123荧光强度减弱,且细胞Rh123荧光强度降低有剂量依赖关系。结论一定浓度的SSd可引起SH-SY5Y细胞凋亡,其机制可能与影响线粒体膜电位有关。 展开更多
关键词 柴胡皂苷d SH-Sy5y细胞 线粒体膜电位 凋亡
下载PDF
Y对AZ91D镁合金阻尼性能的影响 被引量:3
14
作者 马戎 董选普 +2 位作者 程鲁 张磊 樊自田 《铸造》 CAS CSCD 北大核心 2011年第3期283-286,共4页
通过DMA等手段研究了Y元素对AZ91D镁合金阻尼性能的影响,并通过扫描电镜、X射线衍射、透射电镜等手段研究了不同Y含量下AZ91D合金的显微组织,在此基础上分析了显微组织与阻尼性能的关系。结果显示:Y元素能明显细化AZ91D合金的组织,随着... 通过DMA等手段研究了Y元素对AZ91D镁合金阻尼性能的影响,并通过扫描电镜、X射线衍射、透射电镜等手段研究了不同Y含量下AZ91D合金的显微组织,在此基础上分析了显微组织与阻尼性能的关系。结果显示:Y元素能明显细化AZ91D合金的组织,随着Y含量的增加,β相逐渐变得细小、弥散,且合金中会出现弥散分布的Al2Y相,根据G-L位错模型理论,固溶在α-Mg基体中的Y原子对合金中的位错线构成弱钉扎,Al2Y等含Y合金相对合金中位错线构成强钉扎,且组织细化后合金中位错线相互缠结,导致AZ91D合金阻尼性能下降明显。 展开更多
关键词 AZ91d y合金化 阻尼性能 位错 G-L模型
下载PDF
稀土元素Y对AZ91D镁合金显微组织和力学性能的影响 被引量:8
15
作者 董方 刘月 +2 位作者 郭升乐 闫瑞军 武利平 《轻合金加工技术》 CAS 北大核心 2018年第5期62-66,共5页
试验研究了在AZ91D镁合金中添加不同质量分数的稀土元素Y(w(Y)=0.4%、0.8%、1.2%、1.6%、2.0%)对其组织和力学性能的影响。结果表明,添加适量的稀土元素Y能改善AZ91D镁合金的组织并提高其力学性能。当w(Y)=1.2%时,对AZ91D镁合金的晶粒... 试验研究了在AZ91D镁合金中添加不同质量分数的稀土元素Y(w(Y)=0.4%、0.8%、1.2%、1.6%、2.0%)对其组织和力学性能的影响。结果表明,添加适量的稀土元素Y能改善AZ91D镁合金的组织并提高其力学性能。当w(Y)=1.2%时,对AZ91D镁合金的晶粒细化作用效果最佳,此时,晶粒尺寸为46.15μm,相比未加入稀土元素Y的AZ91D镁合金细化幅度为27.85%。稀土元素Y的加入还能提高AZ91D镁合金的硬度、抗拉强度、伸长率等性能,当w(Y)=1.2%时,AZ91D镁合金的各项力学性能最佳:维氏硬度为99.7 HV,室温抗拉强度为299 N/mm^2,伸长率为9.5%;200℃的抗拉强度为161.75 N/mm^2,伸长率为5.8%。 展开更多
关键词 AZ91d镁合金 稀土元素y 金相组织 力学性能
下载PDF
相图计算在Mg-9Gd-3Y-0.6Zn-0.5Zr新型变形镁合金热处理工艺设计中的应用 被引量:11
16
作者 赵娟 李建平 +3 位作者 郭永春 杨忠 杨觉明 梁民宪 《铸造技术》 CAS 北大核心 2007年第4期531-534,共4页
本文以相图热力学计算为基础,计算了Mg-9Gd-3Y-0.6Zn-0.5Zr新型合金的垂直截面图,并结合扎克哈罗夫经验公式和合金的DSC曲线分析设计了该合金的热处理工艺,并用CMT5105A型电子万能试验机和显微硬度仪测试了该合金的力学性能。结果表明:... 本文以相图热力学计算为基础,计算了Mg-9Gd-3Y-0.6Zn-0.5Zr新型合金的垂直截面图,并结合扎克哈罗夫经验公式和合金的DSC曲线分析设计了该合金的热处理工艺,并用CMT5105A型电子万能试验机和显微硬度仪测试了该合金的力学性能。结果表明:在计算所得的Mg-9Gd-3Y-0.6Zn-0.5Zr相图指导下制定的热处理工艺是正确的;挤压态Mg-9Gd-3Y-0.6Zn-0.5Zr合金的最佳热处理工艺为:200℃时效63 h,抗拉强度σb为=430 MPa,比挤压态提高了30.9%。 展开更多
关键词 稀土镁合金 相图计算 热处理工艺 Mg—Gd-y dSC
下载PDF
Preparation and performance of coating on rare-earth compounds-immersed magnesium alloy by micro-arc oxidation 被引量:5
17
作者 刘峰 李玉洁 +3 位作者 顾佳婧 严青松 罗强 蔡启舟 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第7期1647-1654,共8页
A composite ceramic coating containing Y2O3-ZrO2-MgO(YSZ-MgO) was prepared on AZ91D magnesium alloy,which was immersed in Y(NO3)3 aqueous solution as pretreatment,by micro-arc oxidation(MAO) process.The morpholo... A composite ceramic coating containing Y2O3-ZrO2-MgO(YSZ-MgO) was prepared on AZ91D magnesium alloy,which was immersed in Y(NO3)3 aqueous solution as pretreatment,by micro-arc oxidation(MAO) process.The morphology,elemental and phase compositions,corrosion behavior and thermal stability of the coatings were studied by SEM,EDX,XRD,electrochemical corrosion test,high temperature oxidation and thermal shock test.The results show that the coating mainly consists of ZrO2,Y2O3,MgO,Mg2SiO4,and MgF2.Among these compounds,Y2O3 accounts for 26.7% of(Y2O3 + ZrO2).The thickness of YSZ-MgO coating is smaller than that of ZrO2-MgO coating,but its compactness and surface roughness are better than those of ZrO2-MgO coating.YSZ-MgO coating has a good corrosion resistance,and its corrosion rate in 5% NaCl aqueous solution is lower than that of ZrO2-MgO and only about 8.5% of that of AZ91D magnesium alloy.After oxidation at 410 °C,the mass gain of AZ91D magnesium alloy presents a linear increase with the oxidation time.The YSZ-MgO coating and ZrO2-MgO coating can remarkably decrease the oxidation mass gain.The oxidation mass gain of YSZ-MgO coating is lower than that of ZrO2-MgO coating,especially during a long oxidation period.The thermal shock resistance of YSZ-MgO coating is superior to ZrO2-MgO coating. 展开更多
关键词 AZ91d magnesium alloy micro-arc oxidation(MAO) y2O3-ZrO2-MgO composite coating corrosion behavior thermal stability
下载PDF
x-y平面3D打印的交叉耦合矢量控制研究 被引量:2
18
作者 魏代海 邓开发 +1 位作者 吴承刚 高丽萍 《包装工程》 CAS CSCD 北大核心 2014年第11期118-121,127,共5页
目的研究3D打印机下x-y平台的双轴矢量控制精度。方法介绍永磁电机的数学模型,同时对系统的轮廓误差进行描述,对变增益交叉耦合矢量控制算法进行分析。在Matlab/Simulink软件中对两轴变增益交叉耦合矢量控制进行仿真并分析。结果变增益... 目的研究3D打印机下x-y平台的双轴矢量控制精度。方法介绍永磁电机的数学模型,同时对系统的轮廓误差进行描述,对变增益交叉耦合矢量控制算法进行分析。在Matlab/Simulink软件中对两轴变增益交叉耦合矢量控制进行仿真并分析。结果变增益交叉耦合矢量控制算法能将轮廓误差控制在0.01 mm之内。结论通过变增益交叉耦合算法,提高了系统的鲁棒性,并且减小了系统的轮廓误差。 展开更多
关键词 x—y平面 3d打印 交叉耦合矢量控制 仿真
下载PDF
Y/>/D平衡变压器带单相负载的Matlab仿真分析 被引量:3
19
作者 田文君 陈小强 田铭兴 《兰州交通大学学报》 CAS 2010年第4期32-35,共4页
通过分析Y/>/D平衡变压器的电压电流关系,得到了负序电流和两相侧电流之间的关系;根据移相原理,分析了Y/>/D平衡变压器带单相纯阻性负载时电感、电容和负载的匹配关系,以及负载变化对不平衡度的影响.基于Matlab建立了Y/>/D平... 通过分析Y/>/D平衡变压器的电压电流关系,得到了负序电流和两相侧电流之间的关系;根据移相原理,分析了Y/>/D平衡变压器带单相纯阻性负载时电感、电容和负载的匹配关系,以及负载变化对不平衡度的影响.基于Matlab建立了Y/>/D平衡变压器的仿真模型,并由此建立了Y/>/D平衡变压器带纯阻性负载供电系统的仿真模型.通过正常工况、开路和短路故障工况,以及空载合闸过程的仿真分析,证明了Y/>/D平衡变压器的仿真模型的正确性和可行性. 展开更多
关键词 y/>/d平衡变压器 不平衡度 单相负载 MATLAB仿真
下载PDF
柴胡皂苷d对SH-SY5Y细胞ERK蛋白表达及凋亡的影响 被引量:1
20
作者 李妍 纪朋艳 +2 位作者 张巍 彭顺利 吕士杰 《中国医科大学学报》 CAS CSCD 北大核心 2013年第12期1091-1094,共4页
目的初步研究不同浓度的柴胡皂苷d(SSd)对SH—SY5Y细胞ERK蛋白磷酸化及细胞凋亡水平的影响。方法体外常规培养人神经母细胞瘤SH-SY5Y细胞,将SSd溶解于含0.3%DMSO的DEAM高糖培养基q-,分别以0~10μmol/LSSd作用于SH—SY5Y细胞48h... 目的初步研究不同浓度的柴胡皂苷d(SSd)对SH—SY5Y细胞ERK蛋白磷酸化及细胞凋亡水平的影响。方法体外常规培养人神经母细胞瘤SH-SY5Y细胞,将SSd溶解于含0.3%DMSO的DEAM高糖培养基q-,分别以0~10μmol/LSSd作用于SH—SY5Y细胞48h,之后用Westernblot法检测不同浓度的SSd对SH—SY5Y细胞t-ERK1/2及p-ERK1/2蛋白表达量的影响,并通过Hoechst33342染色及流式细胞仪检测细胞凋亡水平的变化。结果与对照组相比,8~10μmol/LSSd作用48h,SH—SY5Y细胞中ERKl/2蛋白磷酸化水平明显降低;而与对照组相比,8—10btmol/LSSd预处理的SH—SY5Y细胞凋亡细胞数明显增加,且随着SSd浓度的增加,凋亡细胞数也相应增多。结论一定浓度的SSd可引起SH—SY5Y细胞凋亡率的上升,其机制可能与抑制ERK蛋白磷酸化表达有关。 展开更多
关键词 ERK1 2 凋亡 柴胡皂苷d SH—Sy5y细胞
下载PDF
上一页 1 2 35 下一页 到第
使用帮助 返回顶部