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A fitted formula for calculation of three-section solenoids inductance
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作者 Ju Jinchuan Wu Dapeng Shu Ting 《强激光与粒子束》 EI CAS CSCD 北大核心 2016年第2期61-64,共4页
An algorithm for precisely calculating the inductance of a three-section solenoid is presented, which is based on summing the layer self-inductances and the mutual inductances. A theoretical model with ex plicit expre... An algorithm for precisely calculating the inductance of a three-section solenoid is presented, which is based on summing the layer self-inductances and the mutual inductances. A theoretical model with ex plicit expressions is firstly developed to calculate the self-inductance of a single layer, and then numerical calcu lation of the mutual inductance between two layers is introduced. Using the presented computation method, the inductance of a solenoid designed in the experiment is successfully calculated (4.30 mH), which has a difference of less than 1% from the experimental data. 展开更多
关键词 three-section SOLENOID SELF-inductance mutual inductance er microwavemagnetic field high pow
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Magnetic field-dependent inductance properties based on magnetorheological elastomer 被引量:2
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作者 JU Ben-xiang WANG Xiao-long 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第4期1075-1084,共10页
Magnetorheological(MR)materials are a class of smart material,whose the mechanical/rheological state can be controlled under a magnetic field.Magnetorheological materials are typically fluids,gels,or elastomers.In thi... Magnetorheological(MR)materials are a class of smart material,whose the mechanical/rheological state can be controlled under a magnetic field.Magnetorheological materials are typically fluids,gels,or elastomers.In this study,anisotropic and isotropic magneto-rheological elastomer(MRE)samples were fabricated using a silicone rubber matrix with carbonyl iron particles as filler particles.The magnetic field-dependent inductance properties of these samples were studied using inductors specially designed for the analysis.The effect of the filler particle content,fabrication conditions,and inductance properties were characterized using a self-built system in both constant and transient magnetic fields.These factors show a significant effect on the inductance properties of the MRE inductor under an applied magnetic field.The anisotropic MRE inductor was more sensitive than the inductor based on an isotropic MRE.Owing to the presence of a constant magnetic field,the inductance value of the MRE inductor decreased with an increase in the external magnetic field.An attempt in elucidation of the mechanism is reported here.This study may enable the MRE to be widely used in practical applications such as monitoring magnetic field or detecting the filler particle content inside MR materials. 展开更多
关键词 magnetorheological elastomer magnetorheological elastomer(MRE)inductor inductance constant magnetic field transient magnetic field
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Formation of mesophase microbeads from bulk mesophase pitch induced by fullerene
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作者 CHEN Wen-sheng LIU Lan-tao +5 位作者 WANG Zheng DUAN Chun-feng ZHANG Xing-wei MA Zhao-kun CHEN Xiao-hong SONG Huai-he 《新型炭材料(中英文)》 SCIE EI CAS CSCD 北大核心 2024年第4期645-654,共10页
A transformation of naphthalene-based coalescenced mesophase pitch(NMP)to mesophase microbeads was achieved by heating a mixture of NMP and fullerene(C_(60)).This is different from the conventional process of the liqu... A transformation of naphthalene-based coalescenced mesophase pitch(NMP)to mesophase microbeads was achieved by heating a mixture of NMP and fullerene(C_(60)).This is different from the conventional process of the liquid-phase carbonization of isotropic pitch to the emergence of carbon microbeads in the matrix and finally their growth to form a 100%anisotropic bulk meso-phase,but rather a reverse transformation.The effects of C_(60) loading and reaction temperature on the morphological transformation of mesophase were investigated by polarizing optical and scanning electron microscopies.The physical changes in the NMP induced by C_(60) were characterized by thermogravimetric analysis,Fourier transform infrared spectroscopy,X-ray diffractometry and Raman spectroscopy.The results show that the coalesced NMP can be converted to a spherical type at 300-320℃ with the addition of 5%C_(60),and the size of the mesophase microbeads increases with increasing temperature.Furthermore,a model is established to ex-plain the unique induction effect of C_(60) in the transformation process.This work makes the morphological transformation of MP con-trollable,and provides a new idea for the understanding and research of mesophase pitch. 展开更多
关键词 Reversible transformation Fullerene induction mechanism Mesophase texture π-electron-induced effect Mesophase microbeads
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电阻电感RL积分/微分实验电路及仿真 被引量:11
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作者 吕伟锋 《实验技术与管理》 CAS 北大核心 2010年第1期83-85,共3页
分析了RL积分/微分电路实验的必要性,从理论上推导了RL积分/微分电路的原理和参数条件。采用Multisim8分析软件对实验电路进行了仿真,并得到了波形和相关的数据。仿真的波形表明,电路基础实验中设置RL积分/微分电路是可行的;数据表明,... 分析了RL积分/微分电路实验的必要性,从理论上推导了RL积分/微分电路的原理和参数条件。采用Multisim8分析软件对实验电路进行了仿真,并得到了波形和相关的数据。仿真的波形表明,电路基础实验中设置RL积分/微分电路是可行的;数据表明,理论的分析是可靠和正确的。 展开更多
关键词 RL(resistance and inductance)电路 积分/微分电路 仿真 MULTISIM软件
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封闭酸溶-ICP-MS分析超细地质样品的条件优化 被引量:6
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作者 何红蓼 孙德忠 《质谱学报》 EI CAS CSCD 2005年第z1期23-24,72,共3页
Using ultra-fine sample for determination 42 elements by pressurized acid digestion -ICP-MS, the mass of test portion can be reduced to 2 mg yet maintain the representation. And acid used for digestion could be reduce... Using ultra-fine sample for determination 42 elements by pressurized acid digestion -ICP-MS, the mass of test portion can be reduced to 2 mg yet maintain the representation. And acid used for digestion could be reduced to less than 0.5 mL, reaction time also largely reduced. 展开更多
关键词 inductively plasma mass SPECTROMETRY (ICP-MS) ultra-fine sample pressurized acid DIGESTION
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基于撬棒并联动态电阻的自适应双馈风力发电机低电压穿越 被引量:41
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作者 张曼 姜惠兰 《电工技术学报》 EI CSCD 北大核心 2014年第2期271-278,共8页
当电网故障引起电压跌落时,为防止大装机容量风电场的风机脱网,双馈风力发电机(DFIG)多采用Crowbar电路来实现低电压穿越(LVRT)。传统Crowbar电路采用固定阻值的电阻,很难兼顾对转子电流和直流母线电压的抑制以及对Crowbar的投入工作时... 当电网故障引起电压跌落时,为防止大装机容量风电场的风机脱网,双馈风力发电机(DFIG)多采用Crowbar电路来实现低电压穿越(LVRT)。传统Crowbar电路采用固定阻值的电阻,很难兼顾对转子电流和直流母线电压的抑制以及对Crowbar的投入工作时间的控制。针对传统Crowbar的不足提出了一种基于Crowbar并联动态电阻的双馈风力发电机低电压穿越方案,制定了该方案的自适应控制策略以及其阻值的整定方法。仿真分析不同跌落深度下所提方案的LVRT特性,并与改变IGBT的导通脉宽的变电阻Crowbar方案进行了比较,结果表明带并联动态电阻Crowbar方案的LVRT效果较好,不仅兼顾了对转子过电流和直流母线过电压的抑制,而且在电压深度跌落时可缩短Crowbar的投入时间,有利于系统电压的恢复。 展开更多
关键词 撬棒 并联动态电阻(PDR) 自适应控制 低电压穿越 双馈风力发电机(DFIG) parallel dynamic resistor(PDR) low voltage ride-through (LVRT) DOUBLY-FED induction generator(DFIG)
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ICP-MS法分析过氧化氢、硝酸、硫酸中的金属杂质 被引量:4
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作者 黄曜 黄郁芳 《质谱学报》 EI CAS CSCD 2005年第z1期15-16,共2页
Inductively coupled plasma mass spectrometry (ICP-MS) was used to detect trace metal impurities in reagents such as H2O2, HNO3and H2SO4. The limit of detection to metal elements can be down to 2-20 ng/L in H2O2 and HN... Inductively coupled plasma mass spectrometry (ICP-MS) was used to detect trace metal impurities in reagents such as H2O2, HNO3and H2SO4. The limit of detection to metal elements can be down to 2-20 ng/L in H2O2 and HNO3 and 0.1-1.0 ng/L in H2SO4. 展开更多
关键词 inductively coupled plasma mass SPECTROMETRY (ICP-MS) metal IMPURITIES REAGENTS
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电网电压跌落下双馈风力发电机组暂态性能的比较分析 被引量:14
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作者 李辉 叶仁杰 +2 位作者 韩力 王荷生 Chen Z 《太阳能学报》 EI CAS CSCD 北大核心 2010年第6期775-781,共7页
为了较全面地研究不同运行工况下并网双馈风力发电机组的暂态运行性能,该文基于双馈发电机电磁暂态模型,采用等效集中质量法,建立了考虑风力机和发电机之间传动轴扭转柔性的风力机两个质量块等效模型。在此基础上,基于定子电压定向的矢... 为了较全面地研究不同运行工况下并网双馈风力发电机组的暂态运行性能,该文基于双馈发电机电磁暂态模型,采用等效集中质量法,建立了考虑风力机和发电机之间传动轴扭转柔性的风力机两个质量块等效模型。在此基础上,基于定子电压定向的矢量控制策略,对风电机组在不同风力机输出转矩、不同电网电压跌落和不同故障持续时间下分别进行了暂态运行性能的仿真,并对风力机不同质量块等效模型的结果进行比较。结果表明,双馈风力发电机组暂态性能与风力机传动链柔性、电压跌落程度和故障持续时间等密切相关。 展开更多
关键词 电网 电压跌落 双馈发电机 风力发电机组 暂态性能 比较分析 DIP GRID WIND TURBINE DOUBLY FED INDUCTION GENERATOR ANALYSIS 风力机 运行性能 等效模型 持续时间 质量块 矢量控制策略 定子电压定向 电磁暂态模型 集中质量法
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电感耦合等离子体质谱法(ICP-MS)测定运动员食品中铅、砷、镉、铜 被引量:1
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作者 刘丽萍 毛红 +2 位作者 张妮娜 张勐 沙博玉 《质谱学报》 EI CAS CSCD 2005年第z1期11-12,共2页
Inductively coupled plasma mass spectrometry (ICP-MS) was applied to determine copper, arsenic, cadmium, lead in athletic food using Sc, Ge, In, Bi as an internal standard. The linear correlation factor for four eleme... Inductively coupled plasma mass spectrometry (ICP-MS) was applied to determine copper, arsenic, cadmium, lead in athletic food using Sc, Ge, In, Bi as an internal standard. The linear correlation factor for four elements are higher than 0.999. Recoveries of spiked samples are in the range of 85.5%-115.5% and precision was fine, RSD is lower than 5.0%. And these are close agreement with the reference values in three standard reference materials of GBW08503, NBS1568, GBW08571. It indicates that the method is simple, rapid, sensitive and accurate, which can meet the demand for copper, arsenic, cadmium, lead analysis in athletic food. 展开更多
关键词 copper ARSENIC CADMIUM lead inductively coupled plasma mass SPECTROMETRY athletic FOOD
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多接收电感耦合等离子体质谱法测量痕量钚同位素 被引量:1
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作者 张继龙 王同兴 +3 位作者 李力力 常志远 赵永刚 刘俊岭 《质谱学报》 EI CAS CSCD 2005年第z1期81-82,共2页
The isotopic analysis of 232Pu plutonium in 5×10-12 g/g samples using a multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) is described. IRMM-290b and uranium (UTB750) were used to correct th... The isotopic analysis of 232Pu plutonium in 5×10-12 g/g samples using a multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) is described. IRMM-290b and uranium (UTB750) were used to correct the metrical data, and the analytical precision is about 0.5%. 展开更多
关键词 multicollector inductively coupled plasma mass SPECTROMETRY (MC-ICP-MS) PU ISOTOPE ABUNDANCE
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Pt-Os同位素系统定年方法研究 被引量:1
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作者 杜安道 杨刚 +2 位作者 屈文俊 陈江峰 杨胜洪 《质谱学报》 EI CAS CSCD 2005年第z1期57-58,共2页
Six massive ores in the Jinchuan deposit were dated by Re-Os technique. The Os concentrations and isotopic ratios were determined by N-TIMS, while Re and Pt concentrations were determined by ICP-MS. The samples gave a... Six massive ores in the Jinchuan deposit were dated by Re-Os technique. The Os concentrations and isotopic ratios were determined by N-TIMS, while Re and Pt concentrations were determined by ICP-MS. The samples gave an isochron age of (852±25) Ma with an initial 187Os/188Os ratio of 0.255 ± 0.014. A 7-point Pt-Os isochrone gives an age of (870±38) Ma with an initial 186Os/188Os ratio of 0.119 84±0.000 27. 展开更多
关键词 Pt-Os ISOTOPE system NEGATIVE thermal ion MASS SPECTROMETRY (N-TIMS) inductively coupled plasma MASS SPECTROMETRY (ICP-MS)
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样品粒度对封闭酸溶-ICP-MS分析性能的影响 被引量:2
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作者 孙德忠 何红蓼 《质谱学报》 EI CAS CSCD 2005年第z1期21-22,共2页
To improve precision of analytical results of pressurized acid digestion-ICP-MS, the first step is to improve the homogeneity by reducing the particle size of sample. Using of ultra-fine sample (-500 mesh) can reduce ... To improve precision of analytical results of pressurized acid digestion-ICP-MS, the first step is to improve the homogeneity by reducing the particle size of sample. Using of ultra-fine sample (-500 mesh) can reduce the mass of the sample and the acid. The satisfactory precision is achieved at 2 mg sampling mass. 展开更多
关键词 pressurized acid DIGESTION inductively plasma mass spectrometry(ICP-MS) ultra-fine SAMPLE
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ICP-AES法测定煤中硫含量的不确定性评定 被引量:1
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作者 陈菊 李靖 《安徽农业科学》 CAS 2014年第26期8974-8975,9060,共3页
[目的]为准确表示煤炭中硫含量奠定基础。[方法]应用电感耦合等离子体发射光谱仪(ICP-AES),对煤中的硫含量进行测定,同时对测量结果的不确定度进行评价。[结果]获得各个不同来源的不确定度,并且计算合成标准不确定度,对测定结果给出合... [目的]为准确表示煤炭中硫含量奠定基础。[方法]应用电感耦合等离子体发射光谱仪(ICP-AES),对煤中的硫含量进行测定,同时对测量结果的不确定度进行评价。[结果]获得各个不同来源的不确定度,并且计算合成标准不确定度,对测定结果给出合理的波动范围。[结论]评价结果对测定方法有效性的判定与优化以及煤燃烧过程中的污染控制具有重要意义。 展开更多
关键词 电感耦合等离子体发射光谱仪(ICP-AES) 硫含量 测定 不确定度 Inductively coupled plasma ATOMIC emission SPECTROMETRY (ICP-AES)
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ICP-MS测定硼矿区饮用水和尿样中的硼及多种元素
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作者 杨红霞 李冰 《质谱学报》 EI CAS CSCD 2005年第z1期17-18,共2页
The application of inductively coupled plasma mass spectrometry (ICP-MS) for determination of boron in water and urine samples was described. The detect limit (3σ) was 0.057 μg/L. The precision of the method was les... The application of inductively coupled plasma mass spectrometry (ICP-MS) for determination of boron in water and urine samples was described. The detect limit (3σ) was 0.057 μg/L. The precision of the method was less than 2%. Multi-elements including Cr, Cu, Cd, Ba, Sr, Mn, Co, Tl, Li, Pb, Ca, Fe, K, Na, Mg, P, Si and Zn could be measured simultaneously. The method was successfully used in practice. 展开更多
关键词 inductively coupled plasma mass SPECTROMETRY (ICP-MS) BORON water URINE
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电感耦合等离子体磁质谱法测定无尘产品中痕量氯
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作者 聂玲清 纪红玲 《质谱学报》 EI CAS CSCD 2005年第z1期35-36,共2页
A method of analysis trace element chloride in cleaning products by Inductively Coupled Plasma-Mass Sepctrometry (ICPMS) was studied. It has good precision (RSD<5%). The LOD is 0.06 μg/L (n=7). The recovery is 93.... A method of analysis trace element chloride in cleaning products by Inductively Coupled Plasma-Mass Sepctrometry (ICPMS) was studied. It has good precision (RSD<5%). The LOD is 0.06 μg/L (n=7). The recovery is 93.7%-110.0%. 展开更多
关键词 inductively coupled plasma-mass SPECTROMETRY (ICPMS) cleaning product TRACE CHLORIDE
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基于逆磁致伸缩的索力传感器原理与影响因素研究
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作者 姜建山 陈伟民 +3 位作者 黄尚廉 廖昌荣 章鹏 Jian-shan Wei-min Shang-lian Chang-rong 《计量学报》 CSCD 北大核心 2009年第6期-,共5页
基于逆磁致伸缩效应,建立钢缆索索力传感器理论模型,分析了施加在缆索材料上的力信号(外力和应变)与磁信号(磁感应强度、磁场强度)之间的耦合关系.针对一种环式结构的索力传感器,对索力测量原理做了详细推导,可通过检测感应线圈的感应... 基于逆磁致伸缩效应,建立钢缆索索力传感器理论模型,分析了施加在缆索材料上的力信号(外力和应变)与磁信号(磁感应强度、磁场强度)之间的耦合关系.针对一种环式结构的索力传感器,对索力测量原理做了详细推导,可通过检测感应线圈的感应电压反映材料所受外力.传感器输出感应电压与空气间隙尺寸、外部激励磁场下的材料磁导率、激励磁场变化、加载外力变化等因素有关,重点分析了激励磁场变化和外力变化对传感器输出的影响.当外力是缓变力,可通过检测感应积分电压求得外力;当外力是交变力,直接通过感应电压求得外力;最后通过对磁场变化和外力变化影响分别进行了仿真,结果与理论分析基本一致,表明所建立的索力传感器理论模型可行. Abstract: Based on Villari-effect, the theoretic mdel d the cable tension sensor is presented. The relationship between mechanical parameters such as stress, strain and electromagnetic parameters like magnetic field and magnetic induction field are discussed. One loop-shaped stinulative structure of cable tension sensor based on Villari--effect is proposed and cable tension sensor principle is deeply analysed. By measuring inductive voltage in inductive loops, cable tension stress may be measured. Sensor output may be determined by air clearance, magnetic permeability, magnetic field, stress and inductive loops denseness. The sensor output effects resulting from magnetic field and stress ate analysed respectively. When stress changes tardigradely, the cable tension stress may be measured by measuring inductive integral voltage. When stress changes expeditiously, the cable tension stress may be measured by measuring inductive voltage. Sensor sensibility may be determined by stress frequency, inductive loops denseness, magnetic field and nagnetic permeability. In addition, the sensor output effects from magnetic changing and stress changing have been analysed with emulational methods. The results indicate that sensor theory model is feasible. 展开更多
关键词 逆磁致伸缩效应 力传感器 影响因素研究 Based CABLE Tension Influencing Factors CABLE tension tension stress MAGNETIC field 外力 激励磁场 感应电压 磁场变化 mechanical parameters MAGNETIC induction 索力 理论模型 CHANGING changes 分析
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用电感耦合等离子体质谱法测定中草药中的重金属元素 被引量:14
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作者 缪恩铭 张艳红 +3 位作者 王森 施红林 陈章玉 杨光宇 《分析测试学报》 CAS CSCD 北大核心 2007年第z1期184-186,共3页
In this paper,the determination of six heavy metal ions (arsenic,lead,cadmium,chromium,mercury and nickel) in the Chinese Herb by inductively coupled plasma-mass spectrometry (ICP-MS) was studied.The samples were dige... In this paper,the determination of six heavy metal ions (arsenic,lead,cadmium,chromium,mercury and nickel) in the Chinese Herb by inductively coupled plasma-mass spectrometry (ICP-MS) was studied.The samples were digested by nitric acid and hydrogen peroxide in a microwave oven.The Sc,Y,In,Bi were added as internal standards to eliminate the matrix interferences.The results show that most of the relative standard deviations of these trace elements were below 3.5%,the standard recoveries of these elements were in the range of 91%-107%,and the detection limits were in the range of 0.001-0.006 μg·L-1. This method is accurate,rapid,convenience,and can be applied to the determination of arsenic,lead,cadmium,chromium,mercury and nickel in Chinese Herb with good results. 展开更多
关键词 Chinese Herb Heavy metal element Inductively coupled plasma-mass spectrometry
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全功率笼型异步风电系统低电压穿越控制策略 被引量:2
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作者 苏小晴 王毅 张志恒 《电测与仪表》 北大核心 2014年第4期23-28,共6页
随着风电装机容量不断扩大对风电场的低电压穿越能力提出了更为严格的要求,而传统的笼型异步发电机组本身并不具备低电压穿越能力。本文针对全功率变流器的笼型异步风电机组,在深入研究该机组的运行特性和控制策略的基础上,分析了电网... 随着风电装机容量不断扩大对风电场的低电压穿越能力提出了更为严格的要求,而传统的笼型异步发电机组本身并不具备低电压穿越能力。本文针对全功率变流器的笼型异步风电机组,在深入研究该机组的运行特性和控制策略的基础上,分析了电网电压跌落过程中引起全功率变流器直流侧电压波动的原因,提出了一种基于功率跟踪优化和网侧无功优先输出的控制策略。在电网电压跌落时,该控制策略根据网侧变流器的功率变化切换功率跟踪曲线以减少发电机的有功输出,抑制直流侧过电压。同时,根据国网公司并网技术规范要求,电网无功电流以及电网电压的跌落深度时迅速向电网提供无功,提升电网电压。仿真结果表明该控制策略可以有效抑制直流侧电压的波动,提高了笼型异步风电机组的低电压穿越能力。 展开更多
关键词 风力发电 笼型异步风力发电机 全功率变流器 低电压穿越 SQUIRREL CAGE INDUCTION generator(SCIG)
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雪纳瑞犬下颌组合性牙瘤病例 被引量:1
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作者 乔雁超 黄山 +1 位作者 陈思 金艺鹏 《中国兽医杂志》 CAS 北大核心 2015年第12期76-77,I0003,共3页
牙源性肿瘤在小动物临床中极为少见[1],一般发生于幼龄动物。牙源性肿瘤分为牙源性上皮细胞瘤和牙源性间质细胞瘤,二者混合发生的病例较为多见,包括猫诱导性牙源性肿瘤(feline inductive odontogenic tumor)、复合性牙瘤(complex ond... 牙源性肿瘤在小动物临床中极为少见[1],一般发生于幼龄动物。牙源性肿瘤分为牙源性上皮细胞瘤和牙源性间质细胞瘤,二者混合发生的病例较为多见,包括猫诱导性牙源性肿瘤(feline inductive odontogenic tumor)、复合性牙瘤(complex ondontoma)、组合性牙瘤(compound odontoma)、成釉细胞纤维瘤(ameloblastic fibroma)和成釉细胞纤维性牙瘤(ameloblastic fibro-odontoma,AFO)。 展开更多
关键词 组合性牙瘤 牙源性肿瘤 成釉细胞纤维瘤 上皮细胞瘤 动物临床 雪纳瑞 间质细胞瘤 复合性 幼龄动物 INDUCTIVE
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电感耦合等离子体质谱测定大气铅污染物
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作者 郑永红 于水 +3 位作者 赵法 宋占军 刘丽萍 郭志英 《分析测试学报》 CAS CSCD 北大核心 2007年第z1期191-192,共2页
Inductively coupled plasma mass spectrometry(ICP-MS) was used to determine the concentration of Pb in atmospheric particulate samples,and the enrichment factor was calculated.The causes of the results were also discus... Inductively coupled plasma mass spectrometry(ICP-MS) was used to determine the concentration of Pb in atmospheric particulate samples,and the enrichment factor was calculated.The causes of the results were also discussed. 展开更多
关键词 Inductively coupled plasma mass spectrometry(ICP-MS) Microwave digestion Enrichment factor
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