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排序方式: 共有2748条查询结果,搜索用时 281 毫秒
1.
Rongrong Li Hongjie Peng Qingping Wu Xuejun Zhou Jiang He Hangjia Shen Minghui Yang Chilin Li 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2020,132(29):12227-12236
Herein, we propose the construction of a sandwich-structured host filled with continuous 2D catalysis–conduction interfaces. This MoN-C-MoN trilayer architecture causes the strong conformal adsorption of S/Li2Sx and its high-efficiency conversion on the two-sided nitride polar surfaces, which are supplied with high-flux electron transfer from the buried carbon interlayer. The 3D self-assembly of these 2D sandwich structures further reinforces the interconnection of conductive and catalytic networks. The maximized exposure of adsorptive/catalytic planes endows the MoN-C@S electrode with excellent cycling stability and high rate performance even under high S loading and low host surface area. The high conductivity of this trilayer texture does not compromise the capacity retention after the S content is increased. Such a job-synergistic mode between catalytic and conductive functions guarantees the homogeneous deposition of S/Li2Sx, and avoids thick and devitalized accumulation (electrode passivation) even after high-rate and long-term cycling. 相似文献
2.
Consider the following nonparametric model: \(Y_{ni}=g(x_{ni})+ \varepsilon _{ni},1\le i\le n,\) where \(x_{ni}\in {\mathbb {A}}\) are the nonrandom design points and \({\mathbb {A}}\) is a compact set of \({\mathbb {R}}^{m}\) for some \(m\ge 1\), \(g(\cdot )\) is a real valued function defined on \({\mathbb {A}}\), and \(\varepsilon _{n1},\ldots ,\varepsilon _{nn}\) are \(\rho ^{-}\)-mixing random errors with zero mean and finite variance. We obtain the Berry–Esseen bounds of the weighted estimator of \(g(\cdot )\). The rate can achieve nearly \(O(n^{-1/4})\) when the moment condition is appropriate. Moreover, we carry out some simulations to verify the validity of our results.
相似文献3.
催化动力学光度法测定水中痕量铁 总被引:4,自引:0,他引:4
本文研究了ph5.0的HAc-NaAc介质中,痕量铁催化过氧化氢氧化紫脲酸的褪色反应,建立了催化动力学光度法测定痕量铁的新方法,方法的线性范围0-0.40,0.40-2.0μg/25mL,检出限为8×10^-11g/mL,用于水样中痕量铁的测定,结果满意。 相似文献
4.
J. KANG 《Journal of sound and vibration》2002,258(5):793-813
A radiosity-based theoretical/computer model has been developed to study the fundamental characteristics of the sound fields in urban streets resulting from diffusely reflecting boundaries, and to investigate the effectiveness of architectural changes and urban design options on noise reduction. Comparison between the theoretical prediction and the measurement in a scale model of an urban street shows very good agreement. Computations using the model in hypothetical rectangular streets demonstrate that though the boundaries are diffusely reflective, the sound attenuation along the length is significant, typically at 20-30 dB/100 m. The sound distribution in a cross-section is generally even unless the cross-section is very close to the source. In terms of the effectiveness of architectural changes and urban design options, it has been shown that over 2-4 dB extra attenuation can be obtained either by increasing boundary absorption evenly or by adding absorbent patches on the façades or the ground. Reducing building height has a similar effect. A gap between buildings can provide about 2-3 dB extra sound attenuation, especially in the vicinity of the gap. The effectiveness of air absorption on increasing sound attenuation along the length could be 3-9 dB at high frequencies. If a treatment is effective with a single source, it is also effective with multiple sources. In addition, it has been demonstrated that if the façades in a street are diffusely reflective, the sound field of the street does not change significantly whether the ground is diffusely or geometrically reflective. 相似文献
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6.
WANG Mingwei LI Bo FENG Kun RAO Jun KANG Zihua LI Xiujuan LILi WANG Minghong FAN Mingjie 《核工业西南物理研究院年报(英文版)》2004,(1):77-79
in order to study non-indutive plasma current production, the lower hybrid current drive(LHCD) experiment on the HL-2A tokamak is carried out. Simultaneously a microcomputer has been used to control the whole LHCD system. During the experiment this year, we can monitor and protect the LHCD system by use of the microcomputer control system, which will imediately switch off the microwave power to be launched into the tokamak if the plasma is disrupted. All this ensure that the microwave is injected into the equipment correctly. 相似文献
7.
一类非线性单调型方程的区域分裂法 总被引:1,自引:0,他引:1
本文考虑了一类非线性单调问题的加性Schwgrz交替法和异步平行算法,并得到了在能量模意义下的收敛性结果,最后还讨论了格式的有限元离散。 相似文献
8.
ICP-AES测定饮用水源中的Cu、Mn、Pb、Cd、Zn 总被引:7,自引:2,他引:5
用ICP-AES法同时测定饮用水源中的Cu、Mn、Pb、Cd、Zn等重金属元素,具有基体效应小、测量范围宽等优点。检出限为0.2-4.0μg/L,回收率为91.5%-103.9%,相对标准偏差为0.29%-1.5%,测定密码样与实际样品,结果令人满意。 相似文献
9.
KANG Zihua WANG Mingwei QIAN Jiamei RAO Jun LI Xiujuan ZHENG Tieliu WANG Xuehua 《核工业西南物理研究院年报(英文版)》2004,(1):73-76
Lower hybrid wave (LHW), electro cyclotron (EC) and neutral beam injection (NBI) etc. are the important methods of auxiliary heating. They would be devoted to the HL-2A tokamak step by step. In order to satisfy the debug of each system and the need of the experiment, the system should be equipped with high voltage pulse power (HVPP) according to the requirement. 相似文献
10.