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Isometric Extension Problem Between Strictly Convex Two-dimensional Normed Spaces
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作者 Guang Gui DING Jian Ze LI 《数学学报:英文版》 SCIE CSCD 2019年第4期513-518,共6页
In this paper, based on the smooth point of the unit ball and its support linear functional,we show two equivalent formulations of the isometric extension problem between the unit spheres of strictly convex two-dimens... In this paper, based on the smooth point of the unit ball and its support linear functional,we show two equivalent formulations of the isometric extension problem between the unit spheres of strictly convex two-dimensional normed spaces. We prove that these equivalent formulations have a positive answer in a special case. 展开更多
关键词 ISOMETRIC extension STRICTLY CONVEX unit SPHERE SMOOTH point ADDITIVE map
Copper-cobalt Bimetallic Oxides-doped Alumina Hollow Spheres: a Highly Efficient Catalyst for Epoxidation of Styrene
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作者 LI Baitao HUANG Jing WANG Xiujun 《高等学校化学研究:英文版》 SCIE CAS CSCD 2019年第1期125-132,共8页
Copper-cobalt bimetallic oxides-doped alumina hollow spheres(CuCo/AHS)were labricatcd through the sacrificial carbonaceous template strategy.The dependence of the physicochemical properties and morphologies of CuCo/AH... Copper-cobalt bimetallic oxides-doped alumina hollow spheres(CuCo/AHS)were labricatcd through the sacrificial carbonaceous template strategy.The dependence of the physicochemical properties and morphologies of CuCo/AHS on the composition of copper and cobalt in CuxCoy/AHS(x/y=9/1,7/3,5/5,and 3/7)was characterized bv means of X-ray powder diffraction,nitrogen physisorption,atomic adsorption spectroscopy,scanning electron microscopy,transmission electron microscopy and X-ray photoelectron spectroscopy.Among these catalysts, Cu7-Co3/AHS catalyst exhibited perfect hollow sphere structure,thin wall,and big pore size.The calcined catalysts were examined for the epoxidation of styrene with tert-butyl hydroperoxide as oxidant.Compared with the monometallic counterparts(Cu/AHS and Co/AHS)and other CuxCoy/AHS catalysts,Cu7Co3/AHS catalyst showed higher performance,yielding a styrene conversion of 64.6% with 93.0% selectivity toward styrene oxide.In addition,the strong interaction of Cu^2+or Co^2+ with AHS ensured good stability after four consecutive reactions. 展开更多
关键词 ALUMINA hollow sphere STYRENE EPOXIDATION CU-CO BIMETALLIC CATALYST STYRENE oxide
Axial acoustic radiation force on a fluid sphere between two impedance boundaries for Gaussian beam
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作者 臧雨宸 乔玉配 +1 位作者 刘杰惠 刘晓宙 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第3期230-237,共8页
The acoustic radiation force on a fluid sphere immersed in water between two boundaries given by a Gaussian beam is theoretically and numerically investigated in this work. Based on the finite series method, the Gauss... The acoustic radiation force on a fluid sphere immersed in water between two boundaries given by a Gaussian beam is theoretically and numerically investigated in this work. Based on the finite series method, the Gaussian beam is expressed in terms of Bessel function and a weighting parameter. The effects of the two boundaries concerned in our study is worked out by the image theory. This work also provides a reference when considering the effects of certain factors such as the radius of the sphere and the distance between the sphere and two boundaries. The contrast with the acoustic radiation force on a fluid sphere near only one boundary is also made in this paper. Our study can offer a theoretical basis for acoustics manipulation, acoustic sensors in the field of biomedical ultrasound and material science. 展开更多
关键词 ACOUSTIC radiation force GAUSSIAN beam fluid SPHERE IMPEDANCE boundary
Rawls and Catholicism: Towards Reconciliation? 预览
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作者 Antonella Piccinin 《文化与宗教研究:英文版》 2019年第1期50-56,共7页
This paper takes up an ambivalence in Rawls’thought concerning the propriety of religious reason in public discourse.After a general introduction,the second paragraph gives a basic description of the two sides of thi... This paper takes up an ambivalence in Rawls’thought concerning the propriety of religious reason in public discourse.After a general introduction,the second paragraph gives a basic description of the two sides of this ambivalence.In the third paragraph,Joseph Ratzinger is introduced as a potential dialogue partner with Rawls,in as much as one side of Rawls’thought can be interpreted to be congenial to religious reasons that occur with his requirement for public reason.The aim of this paper is,eventually,to open the path towards a possible reconciliation between Rawls’positions and those of the Catholic tradition,as suggested by Joseph Ratzinger.Although some dialectical tensions remain,engaging the Ratzingerian idea of a“mutual correction”might result into a fruitful encounter of different views. 展开更多
关键词 PUBLIC reason religious reasons RELIGION in the PUBLIC sphere CATHOLIC social thought
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Controllable photon echo phase induced by modulated pulses and chirped beat detection
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作者 张显扬 张双根 +1 位作者 张化迪 马秀荣 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第2期247-251,共5页
In this paper, we propose a scheme for photon echo chirped detection process composed of additional modulation pulses to obtain controllable geometric phase. The geometric phases are observed and measured by a beat si... In this paper, we propose a scheme for photon echo chirped detection process composed of additional modulation pulses to obtain controllable geometric phase. The geometric phases are observed and measured by a beat signal between the photon echo field and the chirped field. The chirped detection model reveals that the period of the beat signal increases as the chirped rate and delay time increase. Additionally, a two-fold relationship between the modulation phase and the echo shift phase is obtained. The numerical simulations accord with the theoretical results obtained by the finite difference time domain(FDTD) method. 展开更多
关键词 geometric phase photon echo CHIRPED BEAT DETECTION BLOCH sphere
Water entry of decelerating spheres simulations using improved ISPH method 预览
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作者 Abdelraheem M.Aly Mitsuteru Asai 《水动力学研究与进展:英文版》 SCIE EI CSCD 2018年第6期1120-1133,共14页
In this paper, we simulated the vertical impact of spheres on a water surface using three-dimensional incompressible smoothed particle hydrodynamics (3-D ISPH) method. The sphere motion is taken to be a rigid body mot... In this paper, we simulated the vertical impact of spheres on a water surface using three-dimensional incompressible smoothed particle hydrodynamics (3-D ISPH) method. The sphere motion is taken to be a rigid body motion and it is modeled by ISPH method. The governing equations are discretized and solved numerically using ISPH method. A stabilized incompressible SPH method by relaxing the density invariance condition is adopted. Here, we computed the motions of a rigid body by direct integration of the fluid pressure at the position of each particle on the body surface. The equations of translational and rotational motion were integrated in time domain to update the position of the rigid body at each time step. In this study, we improved the boundary treatment between fluid and fixed solid boundary by using virtual marker technique. In addition, an improved algorithm based on the virtual marker technique for the boundary particles is proposed to treat the moving boundary of the rigid body motion. The force exerted on the moving rigid boundary particles by the surrounding particles, is calculated by the SPH approximation at the virtual marker points. The applicability and efficiency of the current ISPH method are tested by comparison with reference experimental results. 展开更多
关键词 INCOMPRESSIBLE smoothed particle HYDRODYNAMICS (ISPH) free surface flow SPHERE RIGID body water ENTRY
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2010上海世博会台湾馆钢结构施工技术 预览
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作者 郑荧锋 《山西建筑》 2018年第32期99-101,共3页
以2010上海世博会台湾馆为案例,针对工程施工场地小、工期短、吊装精确度高、现场焊接量大、对焊缝质量要求高等问题,分析阐述了合理安排构件进场顺序,科学组织现场工序搭接,合理布设测控网,并严格按照焊接工艺要求实施焊接等施工技术,... 以2010上海世博会台湾馆为案例,针对工程施工场地小、工期短、吊装精确度高、现场焊接量大、对焊缝质量要求高等问题,分析阐述了合理安排构件进场顺序,科学组织现场工序搭接,合理布设测控网,并严格按照焊接工艺要求实施焊接等施工技术,为类似工程的施工技术提供一定的参考。 展开更多
关键词 台湾馆 球体 球体罩 天灯馆 圆管柱
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中东液化石油气球罐水喷雾灭火系统设计 预览
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作者 梅欢 连广宇 《油气田地面工程》 2018年第3期47-49,共3页
国内石油天然气资源日趋枯竭,石油工程公司需要走出国门,开展更多的海外工程项目。采用美国消防设计规范,满足当地消防局要求,将同等类型大小的液化石油气储罐水喷雾灭火系统进行模块化的设计与施工,成为消防设计的当务之急。在中东某... 国内石油天然气资源日趋枯竭,石油工程公司需要走出国门,开展更多的海外工程项目。采用美国消防设计规范,满足当地消防局要求,将同等类型大小的液化石油气储罐水喷雾灭火系统进行模块化的设计与施工,成为消防设计的当务之急。在中东某石油终端二期工程液化石油气球罐水喷雾灭火系统的设计过程中,在球罐的水雾喷头布置和喷头喷射强度与喷射时间上,国家标准与美国标准存在很大的差异,美国标准采用10.2L/(min·m2)的喷射强度,但喷射时间只有1小时。中东项目二期工程消防水喷雾系统设计的完成为该地区同等大小液化石油气球罐水喷雾灭火系统设计提供了参考。 展开更多
关键词 中东地区 液化石油气 球罐 水喷雾灭火系统 美国消防规范
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超声点聚焦探头在球体中的声束发散与聚焦 预览
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作者 濮海明 王哲 康宜华 《中国机械工程》 CSCD 北大核心 2018年第11期1268-1273,共6页
探究了点聚焦探头焦点相对于球体在不同位置时的声束传播路径,讨论了进入工件内部的超声波束的聚焦与发散情况;分析计算出点聚焦探头在球体内实际焦距的表达公式,得到实际焦距与水层厚度等参数之间的关系;利用有限元分析软件建立点聚焦... 探究了点聚焦探头焦点相对于球体在不同位置时的声束传播路径,讨论了进入工件内部的超声波束的聚焦与发散情况;分析计算出点聚焦探头在球体内实际焦距的表达公式,得到实际焦距与水层厚度等参数之间的关系;利用有限元分析软件建立点聚焦探头在球体内焦距变化的瞬态仿真模型,仿真结果与理论公式计算得到的结果基本一致;最后,通过实际焦距表达式确定了检测不同半径钢球的点聚焦探头的选型和水层厚度,实验现象验证了结果的可靠性。 展开更多
关键词 点聚焦探头 球体 焦距 声束路径
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用数列求和的方法计算匀质刚体的转动惯量 预览
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作者 傅美欢 《南京工业职业技术学院学报》 2018年第2期33-35,共3页
把规则刚体分成多个质元,根据转动惯量的定义公式,用等幂数列求和的方法进行计算,再用极限方法求出刚体的转动惯量。这种方法加深了学生对转动惯量概念的理解,使学生对转动惯量的计算方法有了更深的认识。
关键词 转动惯量 数列求和 细棒 圆柱体 球体
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基于MATLAB的磁性体磁场正演模拟研究 预览
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作者 廖一鹏 《当代化工研究》 2018年第8期103-104,共2页
本文主要是利用MATLAB软件对磁性体的磁场进行正演模拟,了解磁性体的-般分布规律以及影响磁性体磁场的主要因素( 如物性 参数、走向等),掌握磁性体磁场正演的计算方法,为后续更为复杂的研究奠定-定的基础.
关键词 球体 磁场 正演模拟
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Zirconia Hollow Spheres and Their Application 预览
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作者 GAO Qianyu WU Aijun +1 位作者 WANG Qi YIN Hongji 《中国耐火材料:英文版》 CAS 2018年第4期26-30,共5页
Zirconia hollow sphere products are ultra-high temperature energy saving lightweight insulating refractories in zirconia system. They not only have the same refractoriness as zirconia products,but also have the advant... Zirconia hollow sphere products are ultra-high temperature energy saving lightweight insulating refractories in zirconia system. They not only have the same refractoriness as zirconia products,but also have the advantages of low bulk density and excellent thermal insulation properties. Their thermal conductivity is 0. 3-0. 4 W·m-1·K-1 only 1/2 of that of the ordinary zirconia products. They are special refractories which can be used steadily up to 2 400 ℃ in oxidation,reduction and vacuum atmospheres. Zirconia hollow sphere products are the best lining refractories for various ultra-high temperature kilns and furnaces of tungsten and molybdenum metal products processing,artificial crystals,and quartz industrial production. 展开更多
关键词 ZIRCONIA HOLLOW SPHERE high temperature resistance THERMAL INSULATION APPLICATION
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BP神经网络学习效率研究 预览
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作者 李卉 孙伟 《价值工程》 2018年第12期183-186,共4页
为了对BP神经网络学习效率进行研究,利用一个特定的半球面方程案例,对隐层单元数、传递函数、测试集样本点数这三个变量对BP网络学习效率影响程度进行分析。通过3次实验,实验一只改变一个变量、实验二同时改变两个变量,实验三同时改变... 为了对BP神经网络学习效率进行研究,利用一个特定的半球面方程案例,对隐层单元数、传递函数、测试集样本点数这三个变量对BP网络学习效率影响程度进行分析。通过3次实验,实验一只改变一个变量、实验二同时改变两个变量,实验三同时改变三个变量来比较实验的运行时间,实验误差,记录实验结果,并进行了实验分析,得出BP神经网络学习效率最佳时的参数取值。结果表明当隐层单元数为8、传递函数为tansig、测试集样本点数为16时,BP神经网络学习效率最佳。 展开更多
关键词 BP神经网络 球面 效率分析
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Preparation optimization of multilayer-structured SnO2-Sb-Ce/Ti electrode for efficient electrocatalytic oxidation of tetracycline in water
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作者 Kun Yang Yuyu Liu +1 位作者 Jiawen Liu Jinli Qiao 《中国化学工程学报:英文版》 SCIE EI CAS CSCD 2018年第12期2622-2627,共6页
In this study, electrodeposition and thermal decomposition were alternatively used for the fabrication of a series of novel multilayer-structured SnO2–Sb–Ce/Ti(SSCT) electrodes, and their physiochemical and electroc... In this study, electrodeposition and thermal decomposition were alternatively used for the fabrication of a series of novel multilayer-structured SnO2–Sb–Ce/Ti(SSCT) electrodes, and their physiochemical and electrochemical properties were investigated for electrochemical oxidation of tetracycline(TC) in aqueous medium.Experimentally, after the SnO2–Sb–Ce(SSC) composite was electrodeposited for 120 s on the titanium substrate in aqueous solution, the outer thermal coatings composed of SSC were synthesized by a hydrothermal method.Both influences of electrodeposition time(Ted) and thermal decomposition time(Ttd) were investigated to obtain the optimum preparation. It was found that when increasing Tedto a certain extent a longer lifetime of electrode can be achieved, which was attributed to a more solid interlayer structure. A notable SSCTTed,Ttdelectrode,i.e., SSCT3,10, which was prepared through three times of 120 s’ electrodeposition(Ted= 3) and ten times of thermal decomposition(Ttd= 10) obtained the highest oxygen evolution potential 3.141 V vs. SCE. In this selected electrode, when 10 mg·L-1 initial TC concentration was added to this wastewater, the highest color removal efficiency and mineralization rate of TC were 72.4% and 41.6%, respectively, with an applied electricity density of 20 m A·cm-2 and treatment time of 1 h. These results presented here demonstrate that the combined application of electrodeposition and thermal decomposition is effective in realization of enhanced electrocatalytic oxidation activity. 展开更多
关键词 MULTILAYER STRUCTURED electrode Nano-hollow SPHERE ANTIBIOTICS Electro-oxidation
Approximate ballistics formulas for spherical pellets in free flight 预览
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作者 E.J. Allen 《Defence Technology(防务技术)》 CAS CSCD 2018年第1期1-11,共11页
The ballistics equations for spherical pellets in free flight are simplified through appropriate scaling of the pellet velocity and pellet distance. Two different drag coefficient curves are averaged to yield a single... The ballistics equations for spherical pellets in free flight are simplified through appropriate scaling of the pellet velocity and pellet distance. Two different drag coefficient curves are averaged to yield a single curve applicable to shot pellets and round balls. The resulting S-shaped drag coefficient curve is approximated by three straight-line segments. The scaled ballistics equations are then solved exactly and simple formulas are found for the velocity and flight time with respect to trajectory distance. The formulas are applicable to spherical shot pellets and round balls of any composition under any atmospheric conditions. The formulas are amenable to quick and easy computation and may also serve as an aid in understanding and comparing black-box ballistics calculators. For shotshell ballistics, an important assumption in the present investigation is that the pellets are moving as single, free spheres and not as a dense cloud or in a shot column, in particular, the pellets are not interacting during flight. Therefore, the ormulas are most appropriate for singleround balls, for large shot sizes, and for pellets of small shot size fired from open chokes. The formulas are clear and accessible, and can be implemented by military or law enforcement personnel as well as hunters and shooters. This work differs from previous investigations in that accurate ballistics formulas are derived for spherical projectiles of shotguns and muzzleloaders using realistic drag coefficients. 展开更多
关键词 BALLISTICS SPHERE Drag SHOTGUN Muzzleloader Nondimensionalization
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基于高性能云数据挖掘的算法研究 预览
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作者 昂朝群 胡炜 胡冉 《计算机与数字工程》 2017年第9期1724-1730,共7页
论文设计并实现了一种可以用于存档、分析、和挖掘大型分布式数据集的高性能云。文中定义云为一种可以提供互联网资源与(或)服务的基础设施。存储云提供存储服务,计算云则提供计算服务。高性能且能保持这些服务自身的有效性和效率不变... 论文设计并实现了一种可以用于存档、分析、和挖掘大型分布式数据集的高性能云。文中定义云为一种可以提供互联网资源与(或)服务的基础设施。存储云提供存储服务,计算云则提供计算服务。高性能且能保持这些服务自身的有效性和效率不变,自然很合理地被预期作为实现大规模数据挖掘的中间步骤。论文提出了一种使用Sector/Sphere框架和关联规则的云数据挖掘方法,同时给出了由Sphere计算云和关联规则支持的编程范例。 展开更多
关键词 SPHERE SECTOR 数据挖掘 云计算 高性能云
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在用球罐球壳板表面裂纹的处理
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作者 孙建平 《中国化工装备》 CAS 2017年第6期32-35,共4页
本文主要介绍了在用球罐定期检验时,球壳板表面裂纹的发现、对裂纹的分析以及消缺处理,并对球罐的安全使用进行了评估。
关键词 球罐球壳板 表面裂纹 处理
光明轻烃储库混合轻烃球罐消防水炮能力分析及改进建议 预览
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作者 王舟 《油气田地面工程》 2017年第12期9-10,共2页
光明储库混合轻烃球罐区两座轻烃球罐面临着消防失控的风险,存在安全隐患.从光明轻烃储库改造以后设置的混合轻烃罐区附近消防设施的平面布局、消防能力和大庆地区的主导风向等要素出发,对消防系统的主要参数进行了实际测试与分析,并以... 光明储库混合轻烃球罐区两座轻烃球罐面临着消防失控的风险,存在安全隐患.从光明轻烃储库改造以后设置的混合轻烃罐区附近消防设施的平面布局、消防能力和大庆地区的主导风向等要素出发,对消防系统的主要参数进行了实际测试与分析,并以国家行业标准规范作为判断依据,提出了相应的改进措施,即针对消防水炮喷头流量不足的问题对现有6座消防水炮的喷头进行更换,将流量为25 L/s的消防水炮炮头全部换成流量为30 L/s的炮头;对现有消防水炮进行均匀布局,以解决消防水炮不能对轻烃球罐全覆盖的问题,从而提高轻烃储库的消防能力. 展开更多
关键词 轻烃储库 球罐 消防水炮 水炮流量 布局
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矩阵代数收敛至球面与非交换度量几何
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作者 龙波涛 吴畏 《数学学报》 CSCD 北大核心 2017年第1期133-148,共16页
介绍了Rieffel定义的紧致量子度量空间与量子Gromov-Hausdorff距离和近来Latremoliere定义的量子Gromov-Hausdorff邻距,分别讨论了矩阵代数如何在这两种量子距离下收敛至球面.
关键词 紧致量子度量空间 量子Gromov—Hausdorff距离 量子Gromov-Hausdorff邻距 矩阵代数 球面
Porous CoF2 Spheres Synthesized by a One-Pot Solvothermal Method as High Capacity Cathode Materials for Lithium-Ion Batteries
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作者 Qun Guan Jianli Cheng +1 位作者 Xiaodong Li Bin Wang 《中国化学:英文版》 SCIE CAS CSCD 2017年第1期48-54,共7页
直到现在,有用作高能力阴极材料的 CoF <sub>2</sub> 范围的稀罕报告。此处,多孔的 CoF <sub>2</sub> 范围为解放作为阴极材料被综合并且学习。当氟的符号采购原料,多孔的 CoF <sub>2</sub> 范... 直到现在,有用作高能力阴极材料的 CoF <sub>2</sub> 范围的稀罕报告。此处,多孔的 CoF <sub>2</sub> 范围为解放作为阴极材料被综合并且学习。当氟的符号采购原料,多孔的 CoF <sub>2</sub> 范围被一个灵巧的一个壶 solvothermal 方法用一只保险箱和便宜的铵氟化物综合。合成的性质能避免使用腐蚀剂氟的符号来源和另外的高温度的热处理。结构,形态学和在不同反应时间和 solvothermal 温度获得的样品的电气化学的性能被调查。结果证明为 20 &thinsp;h 在 200 &thinsp;&deg;C 获得的 CoF <sub>2</sub> 范围显示出更好电气化学的表演,包括一个高起始的分泌物能力,好能力保留和高 Coulombic 效率。它能交付 537.8 mA&bull;h&bull;g <sup>&minus;1</sup> 的一个高起始的分泌物能力并且在为锂离子电池用作阴极材料的 30 个周期以后把 127.4 mA&bull;h&bull;g 作为 <sup>&minus;1</sup> 。好电气化学的表演可以被归因于好 crystallinity,多孔的结构和相对中间的范围尺寸。 展开更多
关键词 多孔结构 锂离子电池 正极材料 高容量 合成 水热法 电化学性能 溶剂热法
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