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Radiation damage of 1Cr18Ni9Ti and Zr-Ti-Al alloys due to energetic particle irradiation

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Acta Metallurgica Sinica(English Letters) 2012年第1期25卷 29-39页

作者： Maosheng CHAI Wensheng lai Zhengcao LI Wei feng Department of Materials Science and Engineering Tsinghua UniversityBeijing 100084China

The radiation damage of 1Cr18Ni9Ti stainless steel and the Zr-Ti-Al alloy by 200 keV Xe＋ ions bombardment at the fluence ranging from 1×1014 to 8×1015 ions/cm2 has been investigated by conventional transmission electron microscope, X-ray diffraction line profile analysis （XRDLPA） and nanoindentation. XRDLPA shows that the order of magnitude of dislocation density in both materials remains almost unchanged up to the highest irradiation dose. Selected-area electron diffraction combined with bright and dark field image indicates that 1Cr18Ni9Ti is more easily damaged than the Zr-Ti-Al alloy. With increasing the ions fluence, the radiation damage became more severe in 1Cr18Ni9Ti, accompanied with phase transition and partial amorphization. The nano-hardness was found to increase rapidly with increasing ion fluence till the dose of 1×1015 ions/cm2, and then gradually saturate with dose. The enhancement of hardness in irradiated materials is due to irradiation-induced defects acting as barriers to dislocation motion.

关键词： Damage structure Zr-Ti-Al alloy 1Cr18Ni9Ti stainless steel XRD TEM Irradiation Depth profile

The Estimates for Sharp Maximal Functions of Multilinear Strongly Singular Integral Operators

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Acta Mathematica Sinica,English Series 2005年第6期21卷 1495-1508页

作者： jun feng LI Department of Mathematics Beijing Normal University Beijing 100875 P. R. China

In this paper, the author obtains that the multilinear operators of strongly singular integral operators and their dual operators are bounded from some L^p（R^n） to L^p（R^n） when the m-th order derivatives of A belong to L^p（R^n） for r large enough. By this result, the author gets the estimates for the Sharp maximal functions of the multilinear operators with the m-th order derivatives of A being Lipschitz functions. It follows that the multilinear operators are （L^p, L^p）-type operators for 1 〈 p 〈 ∞.

关键词： Multilinear operators Lipschitz functions L^p(R^n) Lipschitz

Fine decoration of carbon nanotubes with metal organic frameworks for enhanced performance in supercapacitance and oxygen reduction reaction

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Science Bulletin 2017年第16期62卷 1132-1141页

作者： Bin Tan Zhao-feng Wu Zai-lai Xie State Key Laboratory of Photocatalysis on Energy and Environment College of ChemistryFuzhou University State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of Sciences

Efficient electrode material is crucial for energy conversion from renewable sources such as solar electricity. We present a method for preparation of carbon nanotubes （CNTs） with zeolitic imidazolate frameworks （ZIFs, e.g., ZIF-8） via an in situ pyrolysis process. The resultant materials are completely new carbon composites with desirable hierarchical porosity and nitrogen-doped features. Electron microscopy images show that CNTs with small external diameters enable more uniform dispersion of ZlF-8-derived carbons, subsequently yielding a unique hierarchically porous structure. Such carbon shows superior activity in oxygen reduction reaction （ORR） and high performance of supercapacitance, making it a valu- able metal-flee electrode material and a competent alternative to the state-of-the-art Pt/C catalyst. The electrocatalytic performance of CNTs can be dramatically improved by the incorporation of ZIF-8-derived carbons, which is attributed to the combination of good conductivity, abundant accessible dopant species, as well as proper porosity. Our method offers a new avenue for constructing electrocatalysts by effective integration of ZlF-8-derived carbon and the CNTs skeleton.

关键词： Carbon nanotubes ZIF-8 derived carbons ORR activity Supercapacitance performance

High Temperature Seedless Synthesis of Au NRs Using BDAC/CTAB Co-surfactant

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Chinese Journal of Chemical Physics 2008年第5期21卷 476-480页

作者： Min Li lai Wei Xian Zhang Xue-feng Yu Department of Physics Key Laboratory of Acoustic and Photonic Materials and Devices of Ministry of Education Wuhan University Wuhan 430072 China

Au nanorods have been successfully synthesized at 90 ℃ by using hexadecyltrimethylammonium bromide （CTAB） and benzyldimethylammoniumchloride hydrate （BDAC） co-surfactant. At 90 ℃, the reaction time was less than 10 s, and the longitudinal surface plasmon absorption band could vary between 680 and 770 nm by adjusting the molar ratio of BDAC to CTAB from 2 to 0.5. At 90 ℃, nanorods with a longitudinal surface plasmon absorption peak of 770 nm can be obtained when the molar ratio of BDAC to CTAB was 3：2.

关键词： Au nanorod Hexdecyltrimethylammonium bromide Benzyldimethylammoniumchloride hydrate High temperature

Vision-based aerial image mosaicking algorithm with object detection

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Journal of Systems Engineering and Electronics 2022年第2期33卷 259-268页

作者： HAN jun LI Weixing feng Kai PAN feng School of Automation Beijing Institute of TechnologyBeijing 100081China

Aerial image sequence mosaicking is one of the chal-lenging research fields in computer *** obtain large-scale orthophoto maps with object detection information,we propose a vision-based image mosaicking algorithm without any extra location *** to object detection results,we define a complexity factor to describe the importance of each input ima-ge and dynamically optimize the feature extraction *** feature points extraction and matching processes are mainly guided by the speeded-up robust features(SURF)and the grid motion statistic(GMS)algorithm respectively.A robust refer-ence frame selection method is proposed to eliminate the trans-formation distortion by searching for the center area based on ***,the sparse Levenberg-Marquardt(LM)al-gorithm and the heavy occluded frames removal method are ap-plied to reduce accumulated errors and further improve the mo-saicking *** proposed algorithm is performed by using multithreading and graphics processing unit(GPU)accel-eration on several aerial image *** experiment results demonstrate that our algorithm outperforms most of the existing aerial image mosaicking methods in visual quality while guaranteeing a high calculation speed.

关键词： image mosaicking object detection grid motion statistic(GMS) mapping

Flood management of Dongting Lake after operation of Three Gorges Dam

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Water Science and Engineering 2017年第4期10卷 303-310页

作者： Xi-jun lai Zi-ming Wang Key Laboratory of Watershed Geographic Sciences Nanjing Institute of Geography&LimnologyChinese Academy of Sciences(CAS)Nanjing 210008China Zhejiang Institute of Hydraulics and Estuary Hangzhou 310020Chin

Full operation of the Three Gorges Dam(TGD) reduces flood risk of the middle and lower parts of the Yangtze River Basin. However,Dongting Lake, which is located in the Yangtze River Basin, is still at high risk for potentially severe flooding in the future. The effects of the TGD on flood processes were investigated using a hydrodynamic model. The 1998 and 2010 flood events before and after the operation of the TGD, respectively, were analyzed. The numerical results show that the operation of the TGD changes flood processes, including the timing and magnitude of flood peaks in Dongting Lake. The TGD can effectively reduce the flood level in Dongting Lake, which is mainly caused by the flood water from the upper reach of the Yangtze River. This is not the case, however, for floods mainly induced by flood water from four main rivers in the catchment. In view of this, a comprehensive strategy for flood management in Dongting Lake is required. Non-engineering measures, such as warning systems and combined operation of the TGD and other reservoirs in the catchment, as well as traditional engineering measures, should be further improved. Meanwhile, a sustainable philosophy for flood control, including natural flood management and lake restoration, is recommended to reduce the flood risk.

关键词： Three Gorges Dam Flood control Water level Hydrodynamic model Dongting Lake

Genomic Analysis of Mitochondrial Carrier Genes in the Bombyx mori

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Journal of Integrative Agriculture 2012年第10期11卷 1707-1713页

作者： CAO jun SHI feng Institute of Life Science Jiangsu University Shandong Lvdu Bio-Technique Industry

This study is performed to investigate the mitochondrial carrier gene family in silkworm genome. In total, 30 genes are identified and claded into eight well-conserved groups. Gene duplication contributes to the expansion and complexity of this family. Diverse expression patterns suggest their functional differentiation. Analyses of the sitespecific profiles reveal critical amino acid residues for functional divergence. This study highlights the molecular evolution of the mitochondrial carrier gene family in silkworm and may provide a starting point for further experimental verification.

关键词： mitochondrial carrier gene phylogenetic analysis evolution silkworm

Design of a Low-Power 20Gb/s 1:4 Demultiplexer in 0.18μm CMOS

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Chinese Journal of Electronics 2015年第1期24卷 71-75页

作者： PAN Min feng jun Institute of RF & OE-ICs Southeast University School of Computer and Information Hefei University of Technology

A low-power multi-phase clock 20Gb/s1:4 Demultiplexer(DEMUX) without inductors is designed in 0.18μm Complementary metal oxide semiconductor(CMOS) process. The 1:4 DEMUX includes two 1:2DEMUX cells, one 1/2 frequency divider cell, some data and clock buffers. A dynamic CMOS logic latch is used in the 1:2 DEMUX cell and a single clock dynamic-loading latch is used in the 1/2 frequency divider cell. These two kinds of logical structures not only reduce power dissipation and area, but also have an output rail-to-rail level. The rail-to-rail level can offer high noise margin and implement seamless connection without logic level conversion in system integration. The test results show that when the data rate of the input pseudorandom is 20Gb/s and the sequence length is 231-1, this 1:4 DEMUX can work well at a supply voltage of 2V. The output swing is 450 m V with external 50 Ohm load and the die size is 0.475×0.475mm2. The chip power dissipation is 86 m W, when four pads connect with a four-channel oscillograph.

关键词： Demultiplexer Low power Dynamic CMOS logic latch Single clock dynamic-loading latch.

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基于学生个性的研究型大学实验室模式研究

电气电子教学学报 2009年第S2期31卷 127-130,134页

作者：段其昌林景栋何安国赖俊峰廖孝勇郭婷婷重庆大学罗克韦尔自动化实验室重庆400044

本课题针对传统实验教学内容单一,学生能力培养受限以及沿用计划性教学模式,学生只能被动记性学习等问题,着眼学生可开发的学习研究能力,提出一种基于学生个性的开放式实验教学模式,有针对性地研究探索在研究型大学实验室教学环节中,如... 详细信息

本课题针对传统实验教学内容单一,学生能力培养受限以及沿用计划性教学模式,学生只能被动记性学习等问题,着眼学生可开发的学习研究能力,提出一种基于学生个性的开放式实验教学模式,有针对性地研究探索在研究型大学实验室教学环节中,如何科学培养学生独立和协同进行科学研究和创新的能力,并使学生由被动学习转变为主动学习。通过实验教学在时间、空间、设备等方面的全面开放以及学生个体差异,在保证完成实践基本要求的基础上,采用不同层次的实验教学,给学生足够的自主选择空间,以充分发挥每个学生的主观能动性、想象力和创造力。

关键词：学生个性开放性创新性