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91.
《Journal of power sources》2006,160(1):657-661
The cathode-active materials, layered Li[Ni0.333Co0.333Mn0.293Al0.04]O2−zFz (0 ≤ z ≤ 0.1), were synthesized from a sol–gel precursor at 900 °C in air. The influence of Al–F co-substitution on the structural and electrochemical properties of the as-prepared samples was characterized by X-ray diffraction (XRD), scanning electron microscope (SEM) and electrochemical experiments. The results showed that Li[Ni0.333Co0.333Mn0.293Al0.04]O2−zFz has a typical hexagonal structure with a single phase, the particle sizes of the samples tended to increase with increasing fluorine content. It has been found that Li[Ni0.333Co0.333Mn0.293Al0.04]O1.95F0.05 showed an improved cathodic behavior and discharge capacity retention compared to the undoped samples in the voltage range of 3.0–4.3 V. The electrodes prepared from Li[Ni0.333Co0.333Mn0.293Al0.04]O1.95F0.05 delivered an initial discharge capacity of 158 mAh−1 g and an initial coulombic efficiency is 91.3%, and the capacity retention at the 20th cycle was 94.9%. Though the F-doped samples had lower initial capacities, they showed better cycle performances compared with F-free samples. Therefore, this is a promising material for a lithium-ion battery. 相似文献
92.
《International Journal of Heat and Mass Transfer》2006,49(21-22):3831-3845
In lost foam casting of aluminum, pressure equilibrium between the liquid metal and the decomposing foam can produce a variety of different shapes for the metal flow front, ranging from convex to concave. In extreme cases, the flow front can become so strongly concave that small pieces of the foam pattern begin to break off inside the concave hollow of the flow front and become enveloped by the advancing liquid metal. When this happens, the entire mechanism of foam decomposition changes from steady ablation to a more chaotic motion in which the metal seems to “chew” its way through the pattern, creating large bubbles of vaporizing polymer liquid in its wake. These bubbles usually lead to undesirable anomalies in the final casting. In most cases, the nonlinear equations that govern the shape of the flow front depend on a single nondimensional number, which relates the onset of the engulfing motion to specific material, geometric, and process parameters. Numerical solutions to these equations are obtained for several special cases. These solutions help to explain a number of experimental observations that until now have been poorly understood. 相似文献
93.
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95.
With the aid of a double-tilt holder in a transmission electron microscope, a new method for a rapid and precise determination of the misorientations of a large number of subgrain or grain boundaries is given in this article. By use of the method, the continuous recrystallization can be rapidly and precisely evaluated when compared to the other conventional methods. 相似文献
96.
《Journal of the European Ceramic Society》2005,25(1):29-36
Crack opening displacement measurements on a sintered reaction-bonded Si3N4 ceramic obtained in bending tests with edge-V-notched specimens were evaluated. A procedure is proposed which allows a straight-forward evaluation of the experimental results in order to obtain the bridging stresses as a function of crack opening displacements. Bridging stresses up to 160 MPa were found acting over a distance of about 0.4 μm. In addition crack profile measurements were performed for Vickers indentation cracks which could approximately be described by use of the bridging relation obtained. 相似文献
97.
《Control Engineering Practice》2006,14(1):17-27
An anti-windup augmentation technique for active vibration isolation systems is considered in this paper and shown to lead to high-performance vibration isolation through simulations and experiments. First, the anti-windup construction is described and desirable properties of the augmented closed-loop system are illustrated. Then, the anti-windup technique is tested on a simulation example and finally shown to perform excellently on a commercial vibration isolation device: Newport Corporation's Elite 3TM active vibration isolation system which has been patented and is now commercialized with this architecture. Both simulation and experimental results confirm the effectiveness of the anti-windup scheme. 相似文献
98.
为深入了解木霉转化子的抗药性,对哈茨木霉及其转化子在PDA培养基上进行平板点植培养和小室培养,其菌体形态于40倍显镜镜下观察,结果显示,转化子的菌落形、菌丝形状、菌丝横隔间隔、孢子颜色、产孢数量均发生一定变化。对传代3年转化子抗药性的测定结果表明,哈茨木霉野生菌在多菌灵质量浓度度为1.0μg/mL时不能生长,而其转化子在多菌灵质量浓度高达1000.0μg/mL时仍能正常生长,说明此转化仍具抗药性且抗药性稳定。 相似文献
99.
100.
Effect of Traveling Magnetic Field on Mould-Filling Length of the A357 Melt during Casting THin Walled Plate 总被引:1,自引:0,他引:1
In order to improver the mould filling ability ,the method for production of thin-walled castings in the traveling magnetic field was applied,The relationship between magnetic field density and input voltage as well as distance was investigated,and the mould filling length of A357 melt has been studied,The electromagnetic forces applied on the melt were also analyzed,The result shows that the mould-filling length of the melt increase rapidly with the increase of magnetic flux density,The mould filling lengths in gypsum upper mould and magnetic material upper mould were compared from the standpoint of application,It demonstrated that the steel upper mould is superior to gypsum mould. 相似文献