期刊文献+
共找到29篇文章
< 1 2 >
每页显示 20 50 100
Tracking Performance of Electric Power Steering System Based on the Mixed H_2/H_∞ Strategy 被引量:10
1
作者 ZHAO Wanzhong SHI Guobiao +1 位作者 LIN Yi NIE Hong 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2011年第4期584-590,共7页
The tracking performance of motor current is an important factor that affects the assistance torque of electric power steering (EPS) system. Bad tracking performance will cause assistant torque delay, and make road ... The tracking performance of motor current is an important factor that affects the assistance torque of electric power steering (EPS) system. Bad tracking performance will cause assistant torque delay, and make road feeling bad, and is influenced by the input steering torque and system measuring noise. However the existing methods have some shortages on system's robust dynamic performance and robust stability. The mixed H2/H∞ strategy for recirculating ball-type EPS system in a pure electric bus is proposed, and vehicle dynamic model of the system is established. Due to the existence of system model uncertainty, disturbance signals, sensor noises and the demand of system dynamic performance, the indexes of robust performance and road feeling for drivers are defined as the appraisal control objectives. The H∞ method is introduced to design the H∞ controller, and the H2 method is applied to optimize the H∞ controller, thus the mixed H2/H∞ controller is designed. The response of EPS system to the motor current command with amplitude of 20 A, the road disturbance with amplitude of 500 N and the sensor random noise with the amplitude of 1 A is simulated. The simulation results show that the recirculating ball-type EPS system with the mixed H2/H∞ controller can attenuate the random noises and disturbances and track the boost curve well, so the mixed H2/H∞ controller can improve the system's robust performance and dynamic performance. For the purpose of verifying the performance of the designed control strategy, the motor current tracking performance ground tests are conducted with step response input of the steering wheel, double-lane steering test and lemniscate steering test, respectively. The tests show that the mixed H2/H∞ controller for the recirculating ball-type EPS system of pure electric bus is feasible. The designed controller can solve the robust performance and robust stability of the system, thus improve the tracking performance of the EPS system and provide satisfied road feeling for the drivers. 展开更多
关键词 recirculating ball-type electrical power steering (EPS) system tracking performance mixed h2/h
下载PDF
Hydrothermal Synthesis of H_3PW_(12)O_(40)/TiO_2 Nanometer Photocatalyst and Its Catalytic Performance for Methyl Orange 被引量:4
2
作者 FENG Chang-gen SHANG Hai-ru 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2012年第3期366-370,共5页
H3PW12O40/TiO2 nanometer photocatalyst was prepared by one step hydrothermal synthesis from H3PW12O40·nH20 and Ti(OBu)4, simultaneously realizing the load and modification of H3PW12O40. The catalyst was charact... H3PW12O40/TiO2 nanometer photocatalyst was prepared by one step hydrothermal synthesis from H3PW12O40·nH20 and Ti(OBu)4, simultaneously realizing the load and modification of H3PW12O40. The catalyst was characterized by Fourier transform infrared spectroscopy(FTIR), powder X-ray diffraction(XRD), nitrogen adsorp- tion-desorption analysis and scanning electron microscopy(SEM). The results show that the catalyst is Keggin struc- ture and crystallized in anatase structure, the diameter and specific area of the prepared catalyst are 3.8 nm and 177.9 m^2/g, respectively, and its dispersity is better. The photocatalytic properties were compared for TiO2H3PW12O40/TiO2 prepared by impregnation and H3PW12O40/TiO2 prepared by hydrothermal method with methyl orange as a probe. The effects of H3PW12O40 loadings, crystallization method, initial pH and concentration of dye solution on the degradation of methyl orange were investigated. 展开更多
关键词 h3PWt2O40/TiO2 hydrothermal synthesis Photocatalytic performance DEGRADATION Methyl orange
下载PDF
Effect of H_2S Flow Rate and Concentration on Performance of H_2S/Air Solid Oxide Fuel Cell 被引量:4
3
作者 钟理 张腾云 +3 位作者 陈建军 WEI Guolin LUO Jingli K.Chung 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2004年第2期306-309,共4页
A solid state H2S/air electrochemical cell having the configuration of H2S, (MoS2+NiS+Ag)/YSZ/Pt, air has been examined with different H2S flow rates and concentrations at atmospheric pressure and 750-850 ℃. Performa... A solid state H2S/air electrochemical cell having the configuration of H2S, (MoS2+NiS+Ag)/YSZ/Pt, air has been examined with different H2S flow rates and concentrations at atmospheric pressure and 750-850 ℃. Performance of the fuel cell was dependent on anode compartment H2S flow rate and concentration. The cell open-circuit voltage increased with increasing H2S flow rate. It was found that increasing both H2S flow rate and H2S concentration improved current-voltage and power density performance. This is resulted from improved gas diffusion in anode and increased concentration of anodic electroactive species. Operation at elevated H2S concentration improved the cell performance at a given gas flow rate. However, as low as 5% H2S in gas mixture can also be utilized as fuel feed to cells. Highest current and power densities, 17500mA·cm-2 and 200mW·cm-2, are obtained with pure H2S flow rate of 50ml·min-1 and air flow rate of 100ml·min-1 at 850℃. 展开更多
关键词 fuel cell performance h2S/air fuel cell solid oxide fuel cell (SOFC)
下载PDF
Enhanced LMI Representations for H2 Performance of Polytopic Uncertain Systems: Continuous-time Case 被引量:1
4
作者 Ai-Guo Wu Guang-Ren Duan 《International Journal of Automation and computing》 EI 2006年第3期304-308,共5页
Based on two recent results, several new criteria of H2 performance for continuous-time linear systems are established by introducing two slack matrices. When used in robust analysis of systems with polytopic uncertai... Based on two recent results, several new criteria of H2 performance for continuous-time linear systems are established by introducing two slack matrices. When used in robust analysis of systems with polytopic uncertainties, they can reduce conservatism inherent in the earlier quadratic method and the established parameter-dependent Lyapunov function approach. Two numerical examples are included to illustrate the feasibility and advantage of the proposed representations. 展开更多
关键词 LMI representations h2 performance polytopic uncertainty continuous-time systems
下载PDF
Effects of ZnCl2/H2O/C2H5OH Treatment on the Filter Paper Performance 被引量:2
5
作者 Lele Cao Lisheng Tang +1 位作者 Qing Li Wenbo Liu 《Paper And Biomaterials》 2019年第3期15-22,共8页
Bleached softwood kraft pulp (BSKP) fibers were pretreated in a 5 mol/L NaOH aqueous solution at 35℃ for 90 min. The ZnCl2/H2O/ C2H5OH was used to treat the pretreated BSKP fibers, filter papers were then prepared. I... Bleached softwood kraft pulp (BSKP) fibers were pretreated in a 5 mol/L NaOH aqueous solution at 35℃ for 90 min. The ZnCl2/H2O/ C2H5OH was used to treat the pretreated BSKP fibers, filter papers were then prepared. In the course of processing, the effects of various molar ratios of ZnCl2/H2O/C2H5OH on the filter paper performance were evaluated. SEMEDX was conducted to analyze the physical configuration of the filter papers. Moreover, FT-IR and XPS were performed to further characterize the BSKP, the pretreated BSKP and the filter paper fibers. The results indicated that the fibers treated by ZnCl2/H2O/C2H5OH were swollen and exhibited slight fibrillation, leading to a looser fiber structure and therefore, enhanced filter paper performance. Air permeability increased from 161.7 L/(m2·s) to 1450.4 L/(m2·s) for the filter papers when the molar ratio of ZnCl2/H2O/C2H5OH was 1:14:1. The optimum molar ratio of ZnCl2/H2O/C2H5OH was found to be 1:14:1, and no significant effect of ZnCl2/H2O/C2H5OH on fibers’ functional groups was detected. These results showed that filtration performance of filter papers was improved when treated with the ZnCl2/H2O/C2H5OH solution. 展开更多
关键词 BSKP fiber ZnCl2/h2O/C2h5Oh FILTRATION performance filter PAPERS
下载PDF
Experimental Evaluation of the Heat Output/Input and Coefficient of Performance Characteristics of a Chemical Heat Pump in the Periodic Operation of CaCl<sub>2</sub>Hydration
6
作者 Atsuhiro Ichinose Kazuki Kuwata +2 位作者 Takehiro Esaki Takayuki Matsuda Noriyuki Kobayashi 《Journal of Materials Science and Chemical Engineering》 2020年第11期33-42,共10页
We herein evaluate the use of a chemical heat pump (CHP) for upgrading waste heat. CaCl<sub>2</sub> was used in the system of CHP. We evaluated the heat storage and heat releasing of CHP, and confirmed the... We herein evaluate the use of a chemical heat pump (CHP) for upgrading waste heat. CaCl<sub>2</sub> was used in the system of CHP. We evaluated the heat storage and heat releasing of CHP, and confirmed the practicality from the experimental results. The reactor module employed was an aluminum plate-tube heat exchanger with corrugated fins, and the CaCl<sub>2</sub> powder was in the form of a packed bed. Heat storage operation and heat dissipation operation are performed at the same time and supplied to the heat demand destination. At this time, an environmental heat source can be used during the heat radiation operation, and the heat output can release more heat than the heat input during heat storage. The heat discharging and charging characteristics of the reactor module were evaluated experimentally. The coefficient of performance (COP) was calculated for the heat upgrading cycle, and the heat output in the system was determined. A COP of 1.42 and output of 650 W/L, based on the heat exchanger volume, were obtained using a 600 s change time for the heat pump. 展开更多
关键词 Chemical heat Pump CaCl2/h2O hydration Reaction heat Pump Cycle Coefficient of performance
下载PDF
Direct Z-scheme CdS-CdS Nanorod Arrays Photoanode: Synthesis,Characterization and Photoelectrochemical Performance
7
作者 Yi Fan Zhi-min Song +6 位作者 Jing-jing Dong Zhi-yu Wang Yue Yang Xiao-di Zhu Song Sun Chen Gao Jun Bao 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2019年第6期715-720,I0003,I0025-I0031,共14页
Direct Z-scheme CdO-CdS 1-dimensional nanorod arrays were constructed through a facile and simple hydrothermal process. The structure, morphology, photoelectrochemical properties and H2 evolution activity of this cata... Direct Z-scheme CdO-CdS 1-dimensional nanorod arrays were constructed through a facile and simple hydrothermal process. The structure, morphology, photoelectrochemical properties and H2 evolution activity of this catalyst were investigated systematically. The morphology of the obtained nanorod is a regular hexagonal prism with 100-200 nm in diameter. The calcination temperature and time were optimized carefully to achieve the highest photoelectrochemical performance. The as-fabricated hybrid system achieved a photocurrent density up to 6.5 mA/cm2 and H2 evolution rate of 240 μmol·cm-2·h-1 at 0 V vs. Ag/AgCl, which is about 2-fold higher than that of the bare CdS nanorod arrays. The PEC performance exceeds those previously reported similar systems. A direct Z-scheme photocatalytic mechanism was proposed based on the structure and photoelectrochemical performance characterization results, which can well explain the high separation efficiency of photoinduced carriers and the excellent redox ability. 展开更多
关键词 Direct Z-scheme CdO-CdS One-Dimensional nanorod arrays PEC performance h2 evolution rate
下载PDF
H_2和H_∞主动悬架统一的理论框架与比较 被引量:11
8
作者 陈虹 赵桂军 +1 位作者 孙鹏远 郭孔辉 《汽车工程》 EI CSCD 北大核心 2003年第1期1-6,共6页
以 2自由度 1/ 4车模型为例在鲁棒控制理论的统一框架下讨论H2 和H∞ 主动悬架的设计 ,并采用结构奇异值法和加权最坏RMS增益法对其鲁棒性能进行分析和比较。
关键词 主动悬架 h∞控制 频率加权 鲁棒性能 汽车 结构奇异值法 h2控制
下载PDF
差分进化改进微电网负荷频率混合H2/H∞鲁棒控制 被引量:14
9
作者 李洪跃 王锡淮 肖健梅 《电机与控制学报》 EI CSCD 北大核心 2019年第11期118-126,共9页
针对外部扰动及系统参数摄动引起微电网负荷频率波动问题,设计了混合H2/H∞鲁棒控制器对系统负荷频率进行控制。建立了包含电池的柴油发电机组二次频率控制模型,引入低通滤波器,使电池对系统高频扰动信号具有较好的抑制能力。以误差平... 针对外部扰动及系统参数摄动引起微电网负荷频率波动问题,设计了混合H2/H∞鲁棒控制器对系统负荷频率进行控制。建立了包含电池的柴油发电机组二次频率控制模型,引入低通滤波器,使电池对系统高频扰动信号具有较好的抑制能力。以误差平方的积分最小作为系统的目标函数,在综合H_2范数表征的系统性能和H∞范数表征的鲁棒性能下,设计具有多目标约束条件的混合H2/H∞鲁棒控制器。采用差分进化算法对控制器加权函数参数进行寻优,使控制器在满足约束条件下达到最优。仿真实验结果表明所提出方法在满足系统鲁棒性能的基础上,同时具备较好的控制输出,保证微电网频率在外部功率扰动和系统参数摄动情况下具有较好的动态性能。 展开更多
关键词 负荷频率控制 多目标优化 混合h_2/h_∞鲁棒控制 鲁棒性能 差分进化
下载PDF
H_2/H_∞混合优化问题综述 被引量:4
10
作者 张羽飞 冯汝鹏 王茂 《信息与控制》 CSCD 北大核心 2002年第5期430-436,共7页
H2 /H∞ 混合优化设计方法由于其可以使系统同时获得较好的鲁棒稳定性和鲁棒性能 ,一经提出 ,立即受到研究者的广泛关注 .本文综述了 H2 /H∞ 混合优化方法的产生、发展及其特点 ,概要介绍了 H2 /H∞ 优化理论研究的最新进展及实践应用... H2 /H∞ 混合优化设计方法由于其可以使系统同时获得较好的鲁棒稳定性和鲁棒性能 ,一经提出 ,立即受到研究者的广泛关注 .本文综述了 H2 /H∞ 混合优化方法的产生、发展及其特点 ,概要介绍了 H2 /H∞ 优化理论研究的最新进展及实践应用的主要结果 ,分析了 H2 /H∞ 混合优化理论在理论和实际应用中的发展方向 . 展开更多
关键词 鲁棒稳定性 鲁棒性能 最优控制理论 h2范数 h∞范数 h2/h∞混合优化
下载PDF
巡航导弹成像器稳定装置H_2/H_∞混合最优PID控制器设计 被引量:3
11
作者 张羽飞 冯汝鹏 《航天控制》 CSCD 北大核心 2003年第3期7-12,52,共7页
本文针对某巡航导弹成像器稳定装置同时在鲁棒稳定性和系统性能有着很高要求的特点 ,采用H2 /H∞ 混合优化的设计方法设计了H2 /H∞ 混合最优PID控制器。仿真和实验结果表明采用该设计方法设计的巡航导弹成像器稳定装置满足性能要求 ,... 本文针对某巡航导弹成像器稳定装置同时在鲁棒稳定性和系统性能有着很高要求的特点 ,采用H2 /H∞ 混合优化的设计方法设计了H2 /H∞ 混合最优PID控制器。仿真和实验结果表明采用该设计方法设计的巡航导弹成像器稳定装置满足性能要求 ,而且比采用H∞ 展开更多
关键词 巡航导弹 成像器稳定装置 鲁棒稳定性 混合控制 最优控制 PID控制器 设计
下载PDF
2-[2-(7H-二苯并[a,g]咔唑)-乙氧基]-乙基氯甲酸酯对脂肪胺类化合物的荧光标记及质谱鉴定 被引量:3
12
作者 闫涛 孙学军 +4 位作者 赵怀鑫 孙志伟 刘钦泽 索有瑞 尤进茂 《分析化学》 SCIE EI CAS CSCD 北大核心 2009年第6期788-794,共7页
利用新型荧光标记试剂2-[2-(7H-二苯并[a,g]咔唑-乙氧基)-乙基氯甲酸酯作为柱前衍生化试剂,在Eclipse XDB-C8反相色谱柱上,采用梯度洗脱,实现了12种脂肪胺类化合物完全基线分离。检测最佳激发和发射波长分别为300和400 nm。通过荧光检... 利用新型荧光标记试剂2-[2-(7H-二苯并[a,g]咔唑-乙氧基)-乙基氯甲酸酯作为柱前衍生化试剂,在Eclipse XDB-C8反相色谱柱上,采用梯度洗脱,实现了12种脂肪胺类化合物完全基线分离。检测最佳激发和发射波长分别为300和400 nm。通过荧光检测及离子阱大气压化学电离源(APCI Source)正离子模式实现了在线的柱后质谱鉴定。对土壤中脂肪胺类化合物的测定快速、准确,具有良好的重现性。荧光定量检测的回归系数大于0.9991;检出限为10.1~0.3 fmol。 展开更多
关键词 液相色谱-质谱 荧光标记 柱前衍生 脂肪胺
下载PDF
2-D系统H∞输出反馈迭代学习控制器设计 被引量:2
13
作者 刘丛志 王铃燕 +2 位作者 刘伟群 马卢平 任冰禹 《计算机应用》 CSCD 北大核心 2016年第A02期112-115,142,共5页
针对2-D线性离散系统设计迭代学习控制器。首先,给出描述参考轨迹、初始状态、外界干扰等迭代变化参数的高阶内模。然后,聚合这些高阶内模得到增广的高阶内模并构造一种新的迭代学习控制器。针对非零边界条件和干扰的2-D Roesser模型,利... 针对2-D线性离散系统设计迭代学习控制器。首先,给出描述参考轨迹、初始状态、外界干扰等迭代变化参数的高阶内模。然后,聚合这些高阶内模得到增广的高阶内模并构造一种新的迭代学习控制器。针对非零边界条件和干扰的2-D Roesser模型,利用2-D分析方法提出其渐近稳定性。建立了适用于零边界条件和非零边界条件的迭代学习控制律设计准则以实现完美跟踪和2-D H∞性能,并提出了基于高阶内模的H∞输出反馈迭代学习控制器。针对控制器的求解问题,提出了两种不同的解法。最后,对一个初始温度、外界干扰迭代变化的化学反应过程的数值计算,表明了所提出的2-D控制器设计方法的有效性。 展开更多
关键词 线性离散系统 迭代学习控制 高阶内模 迭代变化 2-D h∞性能
下载PDF
3H-1,2-二氢-2-(4-甲基苯胺基)甲基-1-吡咯里嗪酮在家兔体内主要代谢产物的研究 被引量:5
14
作者 钟大放 顾景凯 +1 位作者 陈仁弟 罗旭 《药学学报》 CSCD 北大核心 1996年第11期855-860,共6页
用高效液相色谱法对家兔单剂量ig750mg新抗炎镇痛剂3H-1,2二氢-2-(4-甲基苯胺基)-甲基-1-吡咯里嗪酮(Z-47)后尿中的代谢物进行了分离、检测。根据代谢物的色谱行为及与Z-47结构有关的其它药物的代谢... 用高效液相色谱法对家兔单剂量ig750mg新抗炎镇痛剂3H-1,2二氢-2-(4-甲基苯胺基)-甲基-1-吡咯里嗪酮(Z-47)后尿中的代谢物进行了分离、检测。根据代谢物的色谱行为及与Z-47结构有关的其它药物的代谢途径,推测Z-47羧基衍生物[4-(3H-1,2-二氢-1-吡咯里嗪酮-2-甲基胺基)苯甲酸]是一可能的代谢产物,遂用化学方法合成了该衍生物。利用色谱保留值、紫外双波长吸收比值等对代谢物和标准品进行比较,并对尿样的酶水解产物进行色谱分析,证实Z-47羧基衍生物及其酯型β-D-葡糖苷酸结合物是Z-47在家兔体内的主要代谢产物。 展开更多
关键词 吡咯里嗪酮 合成 甲基苯胺基 消炎镇痛药
下载PDF
扇型极点区域与H_2性能约束下不确定系统的参数摄动界
15
作者 赵克友 《青岛大学学报(自然科学版)》 CAS 1998年第1期57-63,共7页
考虑在扇型极点区域及H2范数同时约束下线性连续时间不确定系统的参数最大摄动区域,系统由状态空间模型描述且非线性依赖摄动参量.本文将给出参量的最大摄动区间的计算公式(对单参数情况),和最大摄动圆盘的算法(对两参数情况)... 考虑在扇型极点区域及H2范数同时约束下线性连续时间不确定系统的参数最大摄动区域,系统由状态空间模型描述且非线性依赖摄动参量.本文将给出参量的最大摄动区间的计算公式(对单参数情况),和最大摄动圆盘的算法(对两参数情况),且指出极点分布鲁棒性与H2性能鲁棒性在哲理上的相似性. 展开更多
关键词 极点分布 h2性能 鲁棒性 非线性摄动 不确定系统
下载PDF
汽车主动悬架H2/H∞多目标优化控制 被引量:3
16
作者 段建民 黄小龙 《西华大学学报(自然科学版)》 CAS 2019年第5期30-35,共6页
为协调主动悬架各项相互冲突的性能,采用基于H2/H∞混合控制进行约束优化,解决半车电液主动悬架系统多目标优化控制问题。选择路面扰动到悬架质量垂直加速度和俯仰角加速的闭环传递函数的H2范数为平顺性指标,路面扰动到悬架动行程、主... 为协调主动悬架各项相互冲突的性能,采用基于H2/H∞混合控制进行约束优化,解决半车电液主动悬架系统多目标优化控制问题。选择路面扰动到悬架质量垂直加速度和俯仰角加速的闭环传递函数的H2范数为平顺性指标,路面扰动到悬架动行程、主动控制力和轮胎动位移的闭环传递函数的H∞范数为操纵稳定性指标,选择合理的γ1值,最终求出全状态最优控制律。仿真中假设平整路面上有一个包块,作为路面扰动脉冲输入,将该控制方案与半车被动悬架的时域仿真结果进行对比。结果表明该方案较好地解决了舒适性与操纵稳定性指标之间的矛盾。 展开更多
关键词 半车主动悬架 性能约束 多目标优化 状态反馈控制 h2/h∞混合控制
下载PDF
Robust H_2 control for uncertain sampled-data systems
17
作者 Xie Weinan Ma Guangcheng Wang Changhong 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2009年第1期172-177,共6页
A new approach is proposed for robust H2 problem of uncertain sampled-data systems. Through introducing a free variable, a new Lyapunov asymptotical stability criterion with less conservativeness is established. Based... A new approach is proposed for robust H2 problem of uncertain sampled-data systems. Through introducing a free variable, a new Lyapunov asymptotical stability criterion with less conservativeness is established. Based on this criterion, some sufficient conditions on two classes of robust H2 problems for uncertain sampled-data control systems axe presented through a set of coupled linear matrix inequalities. Finally, the less conservatism and potential of the developed results are illustrated via a numerical example. 展开更多
关键词 sampled-data systems h2 performance uncertain systems LMI optimization.
下载PDF
具有执行器饱和特性和未知扰动的时变时滞系统鲁棒预测控制
18
作者 何超群 蔡宏斌 胡小龙 《南京理工大学学报》 CAS CSCD 北大核心 2024年第3期318-327,共10页
针对具有执行器饱和特性和未知扰动的时变时滞离散系统,提出一种混合H 2/H∞指标的鲁棒模型预测控制方法。首先,用凸组合方法对执行器饱和特性进行变换,很大程度上降低了处理执行器饱和特性的复杂度,并且构造了依赖时变时滞上下界的Lyap... 针对具有执行器饱和特性和未知扰动的时变时滞离散系统,提出一种混合H 2/H∞指标的鲁棒模型预测控制方法。首先,用凸组合方法对执行器饱和特性进行变换,很大程度上降低了处理执行器饱和特性的复杂度,并且构造了依赖时变时滞上下界的Lyapunov-Krasovskii泛函。其次,通过Lyapunov稳定性理论,研究了混合H 2/H∞鲁棒模型预测控制在范数有界意义下的扰动抑制问题,得到了混合H 2/H∞鲁棒模型预测控制器存在的充分条件。最后,进行仿真对比,结果表明提出的方法具有很强的鲁棒性和良好的应用价值。 展开更多
关键词 执行器饱和 时变时滞 扰动抑制 h 2/h∞性能指标 鲁棒模型预测控制
下载PDF
以α型氢氧化物前驱体制备LiNi_(0.8)Co_(0.15)Al_(0.05)O_2及其电化学性能 被引量:17
19
作者 陈勃涛 《无机化学学报》 SCIE CAS CSCD 北大核心 2010年第2期190-196,共7页
本文采用球形Al/Co部分取代α型Ni(OH)2为前驱体成功制备了锂离子电池正极材料LiNi0.8Co0.15Al0.05O2。首先采用氢氧化钠与碳酸钠为沉淀剂合成出Al/Co部分取代α型Ni(OH)2,然后将之与LiOH·H2O混合,最后在氧气气氛中不同温度下热处... 本文采用球形Al/Co部分取代α型Ni(OH)2为前驱体成功制备了锂离子电池正极材料LiNi0.8Co0.15Al0.05O2。首先采用氢氧化钠与碳酸钠为沉淀剂合成出Al/Co部分取代α型Ni(OH)2,然后将之与LiOH·H2O混合,最后在氧气气氛中不同温度下热处理8h,即可得到球形LiNi0.8Co0.15Al0.05O2材料。X射线衍射结果表明,LiNi0.8Co0.15Al0.05O2材料为α-NaFeO2相。扫描电镜结果表明,材料颗粒形貌为球形。热重分析结果表明合成LiNi0.8Co0.15Al0.05O2的主反应温度在700~750℃之间。振实密度测试结果表明,750℃下制备的LiNi0.8Co0.15Al0.05O2材料可达2.2g·cm-3。恒流充放电结果表明,该材料在0.5mA·cm-2电流密度下,在3.0~4.3V间的首次充电容量可达210.3mAh·g-1,首次放电容量为179.7mAh·g-1,充放电效率为85.4%。与采用以β-Ni0.85Co0.15(OH)2为前驱体合成的LiNi0.85Co0.15O2和Al掺杂的LiNi0.8Co0.15Al0.05O2相比,尽管其首次放电容量与放电效率都有所降低,但循环性能有所提高,50周期后容量仍为初始容量的89.5%。研究表明,以球形Al/Co部分取代α型Ni(OH)2作为前驱体为球形氧化镍钴铝锂材料的制备提供了一条新的途径。 展开更多
关键词 锂离子电池 LiNi0.8Co0.15Al0.05O2正极材料 球形α型氢氧化物 前驱体 电化学性能
下载PDF
HPLC-MS测定奥美沙坦酯中有关基因毒性杂质 被引量:2
20
作者 栾保磊 徐新军 +2 位作者 梁桂挺 游孟梦 刘国柱 《中国药科大学学报》 CAS CSCD 北大核心 2019年第3期325-329,共5页
建立一种直接测定奥美沙坦酯中基因毒性杂质5-(4′-溴甲基联苯-2-基)四氮唑和5-(4′-二溴甲基联苯-2-基)四氮唑的液相色谱-质谱联用方法。采用色谱柱AgilentZorbaxEclipsePlusC18(250mm×4.6mm,5μm),以0.1%甲酸水溶液-乙腈为流动相... 建立一种直接测定奥美沙坦酯中基因毒性杂质5-(4′-溴甲基联苯-2-基)四氮唑和5-(4′-二溴甲基联苯-2-基)四氮唑的液相色谱-质谱联用方法。采用色谱柱AgilentZorbaxEclipsePlusC18(250mm×4.6mm,5μm),以0.1%甲酸水溶液-乙腈为流动相;在电喷雾正离子模式下,对m/z315和m/z395离子进行选择性监测。5-(4′-溴甲基联苯-2-基)四氮唑和5-(4′-二溴甲基联苯-2-基)四氮唑的质量浓度分别在0.0094~0.5610μg/mL和0.0182~0.5475μg/mL范围内与峰面积呈良好线性关系;定量限分别为9.35和18.25ng/mL;检测限分别为3.12和6.08ng/mL;平均回收率分别为96.5%(n=9,RSD=4.8%)和98.0%(n=9,RSD=5.1%)。本法操作简便、专属性好、准确度高,可用于奥美沙坦酯中基因毒性杂质5-(4′-溴甲基联苯-2-基)四氮唑和5-(4′-二溴甲基联苯-2-基)四氮唑的检测。 展开更多
关键词 奥美沙坦酯 液相色谱-质谱联用 基因毒性杂质 5-(4′-溴甲基联苯-2-基)四氮唑 5-(4′-二溴甲基联苯-2-基)四氮唑
下载PDF
上一页 1 2 下一页 到第
使用帮助 返回顶部