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排序方式: 共有1009条查询结果,搜索用时 343 毫秒
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Non-standard fault models often require the application of two-pattern testing. A fully-automated approach for generating a multiple scan chain-based architecture is presented so that two-pattern test sets generated for the combinational core can be applied to the sequential circuit. Test time and area overhead constraints are considered. 相似文献
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通过对减振器结构设计的理论分析,建立了减振器的数学模型,同时通过设计的模拟装置对减振效果进行了实测,效果良好。 相似文献
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沈培强 《计算机光盘软件与应用》2012,(3):149-150,148
为了得到能更好应用于CAD系统的细分曲面造型方法,提出一种基于B-样条的对称非均匀细分算法,其中的思想和均匀Lane-Riesenfeld节点插入算法相似。基于B-样条的节点插入算法,以Blossoming为工具,计算出细分后的新控制顶点。细分后得到的极限曲面由张量积样条曲面组成,在奇异点达到2C连续。与传统的细分曲面算法相比,该细分曲面算法具有良好的局部支撑性,大大降低了算法的复杂度,而且该算法是对称的,不用考虑定向问题。 相似文献
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P ThomasD Billaud 《Electrochimica acta》2002,47(20):3303-3307
The electrochemical insertion of sodium ions into different types of hard carbons was achieved in electrolytes composed of ethylene carbonate as the solvent and NaClO4 as the salt. For all the materials studied the sodium uptake increases when the carbon highest heat treatment temperature (HTT) decreases. PAN-based carbon fibres appear to be suitable structures to allow significant sodium insertion. Thus, T650 ex-PAN fibres lead to a reversible capacity close to 209 mAh g−1. In that case, sodium insertion occurs in two main ways: one is the adsorption on the single graphene layers and the other is the concomitant insertion into the porosity that occurs below 0.1 V versus Na+/Na. This second mechanism, which is indicated by a low-voltage plateau on the electrochemical curves, allows significant insertion. The compared electrochemical study of two saccharose-coke samples corresponding to different regions of Dahn's classification underlines the importance of the carbon precursor and of the manufacture process. The reversible capacity is equal to 184 mAh g−1 for the sample heat treated at 800 °C which presents a high hydrogen content whereas it is close to 145 mAh g−1 for the one characterized by a HTT of about 1500 °C and a low hydrogen content. The best electrochemical performances are obtained for pyrolyzed cellulose carbons. Indeed, the reversible capacity is about 279 mAh g−1. Outgassing these carbons at 950 °C results in such a decrease of the reversible capacity down to 145 mAh g−1. That can be related either to the thermal elimination of heteroelements or to modifications of the pore size distribution. Consequently, the most suitable hard carbon material for anodic applications in rechargeable sodium-ion batteries should both present a high residual hydrogen content and a significant microporosity. 相似文献
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DXF是AutoCAD与其他软件进行数据交换的CAD通用图形文件格式。实现了一种DXF读取方式并自动生成数控加工代码。传统算法的读取结果无序,不适用于实际加工,针对这一问题根据提取结果及位置关系生成图元轮廓树,并利用最近邻插入算法对图元轮廓优化排序,得到全局优化的最短切割路径,并通过实例证实了算法的有效性,能满足实际自动编程数控系统的工作需要。 相似文献
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Hajime Arai Masayuki Tsuda Masahiko Hayashi Hideaki Ohtsuka Yoji Sakurai 《Electrochimica acta》2005,50(9):1821-1828
Several polymorphs of layered nickel dioxide were prepared by using the chemical insertion of alkaline ions into Li0.10NiO2. We used aqueous AOH (A = Li, Na, K) solutions as reducing agents. Sodium and potassium insertion resulted in hydrated layered compounds that can be classified as γ-NiOOH with high crystallinity, while lithium insertion occurred without hydration. We discuss the coordination environment around the A+ ions for these inserted compounds. The thermal behavior, analyzed using high temperature (HT) X-ray diffraction (XRD) and thermogravimetric (TG) measurements, indicated that heating the hydrate at 150 °C yielded its dehydrate. The electrode performance of the nickelate was studied in lithium cells. We discuss the effect of interlayer water on cell rechargeability and the similarity between these nickelate and hydrated manganese dioxide (birnessite). 相似文献
10.
New lithium nickel nitrides Li3−2xNixN (0.20 ≤ x ≤ 0.60) have been prepared and investigated as negative electrode in the 0.85/0.02 V potential window. These materials are prepared from a Ni/Li3N mixture at 700 °C under a nitrogen flow. Their structural characteristics as well as their electrochemical behaviour are investigated as a function of the nickel content. For the first time are reported here the electrochemical properties of a lithium intercalation compound based on a layered nitride structure. The Li3−2xNixN compounds can be reversibly reduced and oxidized around 0.5 V versus Li/Li+ leading to specific capacities in the range 120-160 mAh/g depending on the nickel content and the C rate. Due to a large number of lithium vacancies, the structural stability provides an excellent capacity retention of the specific capacity upon cycling. 相似文献