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Ca and Sr co-doping induced oxygen vacancies in 3DOM La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts for boosting low-temperature oxidative coupling of methane

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Journal of Energy Chemistry 2024年第4期91卷 331-344页

作者： Tongtong Wu Yuechang Wei Jing Xiong Yitao Yang Zhenpeng Wang dawei han Zhen Zhao Jian Liu State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China Key Laboratory of Optical Detection Technology for Oil and Gas China University of PetroleumBeijing 102249China

It is urgent to develop catalysts with application potential for oxidative coupling of methane(OCM)at relatively lower ***,three-dimensional ordered macro porous(3 DOM)La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)(A_(2)B_(2)O_(7)-type)catalysts with disordered defective cubic fluorite phased structure were successfully prepared by a colloidal crystal template method.3DOM structure promotes the accessibility of the gaseous reactants(O2and CH4)to the active *** co-doping of Ca and Sr ions in La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts improved the formation of oxygen vacancies,thereby leading to increased density of surface-active oxygen species(O_(2)^(-))for the activation of CH4and the formation of C2products(C2H6and C2H4).3DOM La_(2-x)Sr_(x)Ce_(2-y)CayO_(7-δ)catalysts exhibit high catalytic activity for OCM at low temperature.3DOM La1.7Sr0.3Ce1.7Ca0.3O7-δcatalyst with the highest density of O_(2)^(-)species exhibited the highest catalytic activity for low-temperature OCM,i.e.,its CH4conversion,selectivity and yield of C2products at 650℃are 32.2%,66.1%and 21.3%,*** mechanism was proposed that the increase in surface oxygen vacancies induced by the co-doping of Ca and Sr ions boosts the key step of C-H bond breaking and C-C bond coupling in catalyzing low-temperature *** is meaningful for the development of the low-temperature and high-efficient catalysts for OCM reaction in practical application.

关键词： 3DOM catalysts Ca ions Sr ions Low-temperature oxidative couplingof methane Oxygen vacancies O_(2)^(-) species

Effects on the local symptoms of subgenomic RNAs expressions and their translational products of Tobacco necrosis virus A Chinese isolate

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Chinese Science Bulletin 2008年第11期53卷 1682-1690页

作者： LI Jiang LI Min LI Cui GAO Yang LI dawei han ChengGui YU JiaLin State Key Laboratory of Agro-Biotechnology China Agricultural University Beijing 100094 China

Based on a full-length infectious cDNA clone, gene modifications of Tobacco necrosis virus A Chinese isolate (TNV-AC) were made by site-directed mutagenesis or nucleotide deletions for in vitro transcrip-tion of mutant viral RNAs. Mechanical inoculations of Chenopodium amaranticolor with in vitro tran-scripts, containing a single nucleic acid substitution at the presumed transcriptional start sites for the two subgenomic (sg) RNAs, showed that the sgRNA1 and sgRNA2 of TNV-AC were initiated at G2184 or G2460, respectively. Mutagenesis of the translational initiation-codons for the open-reading frame (ORF) P8 or P6 encoded by sgRNA1 indicated that each of the two genes was essential for formation of local lesions on C. amaranticolor leaves, perhaps by blocking virus cell-to-cell movement, but were not necessary for viral RNA replication in the protoplast of tobacco cell BY-2. Results of prokaryotic expression showed that the ORF coding for coat protein on TNV-AC sgRNA2 was initiatively translated by the first AUG codon at nucleotides 2612―2614. Site-directed mutation of translational start codons, and deletion of the entire coding region, showed that the intact TNV-AC coat protein was dispensable for establishment of TNV-AC infection in C. amaranticolor, otherwise the numbers of local lesions and the viral RNA accumulation level were reduced, or the time to symptom appearance significantly delayed. These results suggested that the nucleotide sequence around the translational start codon coding for TNV-AC coat protein gene may play an important role in the local symptoms. Aspects of the involve-ment of the coat protein in the TNV-AC life cycle were discussed.

关键词：烟草坏死病毒A RNAs 染色体基因表达

Al-F co-doping towards enhanced electrolyte-electrodes interface properties for halide and sulfide solid electrolytes

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Chinese Chemical Letters 2025年第1期36卷 610-617页

作者： han Yan Jingming Yao Zhangran Ye Qiaoquan Lin Ziqi Zhang Shulin Li dawei Song Zhenyu Wang Chuang Yu Long Zhang College of Physics and Energy Fujian Normal UniversityFuzhou 350117China Clean Nano Energy Center State Key Laboratory of Metastable Materials Science and TechnologyYanshan UniversityQinhuangdao 066004China Tianjin Key Laboratory for Photoelectric Materials and Devices School of Materials Science and EngineeringTianjin University of TechnologyTianjin 300384China Guilin Electrical Equipment Scientific Research Institute Co. Ltd.Guilin 541004China State Key Laboratory of Advanced Electromagnetic Engineering and Technology School of Electrical and Electronic EngineeringHuazhong University of Science and TechnologyWuhan 430000China

All-solid-state Li batteries(ASSLBs)using solid electrolytes(SEs)have gained significant attention in recent years considering the safety issue and their high energy *** these advantages,the commercialization of ASSLBs still faces challenges regarding the electrolyte/electrodes interfaces and growth of Li *** doping is an effective and direct method to enhance the performance of ***,we report an Al-F co-doping strategy to improve the overall properties including ion conductivity,high voltage stability,and cathode and anode ***,the Al-F co-doping enables the formation of a thin Li-Al alloy layer and fluoride interphases,thereby constructing a relatively stable interface and promoting uniform Li *** similar merits of Al-F co-doping are also revealed in the Li-argyrodite *** assembled with these optimized electrolytes gain good electrochemical performance,demonstrating the universality of Al-F co-doping towards advanced SEs.

关键词： Solid electrolytes Li halides Li_(2)ZrCl_(6) Li argyrodites Fluorine doping

WSe_2负载掺氮三维石墨烯的制备及储锂性能

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复旦学报（自然科学版） 2017年第5期56卷 586-593页

作者：韩大伟江素华复旦大学材料科学系上海200433

近年来,过渡金属硫族化合物由于具有较高的理论比容量及特殊的层状结构,被认为有希望替代石墨作为下一代锂离子电池负极材料.作为典型的过渡金属硫族化合物,硒化钨(WSe_2)具有与石墨类似的二维层状结构,层间通过较弱的范德华力结合,方... 详细信息

近年来,过渡金属硫族化合物由于具有较高的理论比容量及特殊的层状结构,被认为有希望替代石墨作为下一代锂离子电池负极材料.作为典型的过渡金属硫族化合物,硒化钨(WSe_2)具有与石墨类似的二维层状结构,层间通过较弱的范德华力结合,方便锂离子嵌入和脱嵌.然而,在实际应用中,导电性差、循环过程中体积膨胀等问题制约了其进一步的发展.为了解决以上问题,本文经水热、退火等步骤,制备了将纳米棒状WSe_2锚定在掺氮三维石墨烯上的WSe_2@N-3DG复合材料.电化学测试表明,电流密度为2 A·g^(-1)时,复合材料循环500圈后放电比容量可以达到412 m Ah·g^(-1),在0.1,0.2,0.5,1和2 A·g^(-1)的电流密度下,WSe_2@N-3DG的放电比容量分别达到811,696,576,443和391 mAh·g^(-1),表现出优异的电化学性能.

关键词：硒化钨石墨烯氮掺杂锂离子电池负极

Mitochondrial DNA analysis of Bronze Age horses recovered from Chifeng region, Inner Mongolia, China

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Progress in Natural Science:Materials International 2007年第5期17卷 544-550页

作者： Cai dawei , han Lu , Xie Chengzhi , Li Shengnan , Zhou Hui and Zhu Hong (Ancient DNA Laboratory, Research Center for Chinese Frontier Archaeology of Jilin University, Changchun 130023, China College of Life Science, Jilin University, Changchun 130023, China) Ancient DNA Laboratory Research Center for Chinese Frontier Archaeology Jilin University Changchun 130023 China College of Life Science Jilin University Changchun 130023 China

In this study, mitochondrial DNA (mtDNA) analysis was carried out on 9 Bronze Age horses recovered from Dashanqian and Jinggouzi archaeological sites in Chifeng region, Inner Mongolia. China to explore the origin of Chinese domestic horses. Both mtDNA 16S rRNA gene and control region (D-loop) fragments of ancient horses were amplified and sequenced. The analysis of the highly conservative 16S rRNA gene sequences indicated that the burial environment of Chifeng region is suitable for the preservation of ancient DNA (aDNA). Combing 465 mtDNA D-loop sequences representing different breeds from East Asia, Central Asia, Near East and Europe, we constructed a phylogenetic network to investigate the relationship between ancient and modern horses. The phylogenetic network showed that the 9 horses were distributed into different modern horse clusters which were closely related to them representing a certain geographical distribution. Our results showed that the maternal genetic line of the ancient horses in Chifeng region was highly diversified, which contributed to the gene pool of modern domestic horses and suggested a complex origin of domestic horses in China.

关键词： origin of domestic horses ancient DNA mitochondrial DNA 16S rRNA gene phylogenetic network.

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嵌入式智能涡街流量计的设计与实现

计算机测量与控制 2013年第8期21卷 2327-2329页

作者：韩大伟熊欣河南工程学院电气信息工程系河南郑州451191 河南工程学院软件学院河南郑州450053

为了提高涡街流量计对低流量的测量精度,利用热敏电阻电桥检测涡街分离频率,通过对涡街信号进行预处理电路放大后,再分别以190Hz为界限对高低频信号设置不同的增益进行处理,避免了信号失真;经整形电路变成脉冲信号后,送给嵌入式处理器LP... 详细信息

为了提高涡街流量计对低流量的测量精度,利用热敏电阻电桥检测涡街分离频率,通过对涡街信号进行预处理电路放大后,再分别以190Hz为界限对高低频信号设置不同的增益进行处理,避免了信号失真;经整形电路变成脉冲信号后,送给嵌入式处理器LPC2129的ADC接口进行运算、分析和显示,并通过CAN总线自动将流量数据发送至上位机进行处理、监测和存储;通过实验表明,该智能涡街流量计不仅具有良好的线性,还能够实现小于1m/s的风速测量,大大提高了涡街流量计的测量下限和精度。

关键词：热敏电阻电桥涡街流量计放大电路线性

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内孔焊技术在WSA装置蒸汽发生器的应用

化工设备与管道 2023年第2期60卷 1-5页

作者：胡涛韩大伟北京航化节能环保科技有限公司北京100176

WSA装置中蒸汽发生器中常出现管板与换热管焊接泄漏问题,针对常见的换热管和管板焊接技术进行了对比分析,最后采用内孔焊技术。结合设备的具体特征,对内孔焊技术进行了描述,并对采用内孔焊结构后管板的受力状况进行了数值分析及对比,作... 详细信息

WSA装置中蒸汽发生器中常出现管板与换热管焊接泄漏问题,针对常见的换热管和管板焊接技术进行了对比分析,最后采用内孔焊技术。结合设备的具体特征,对内孔焊技术进行了描述,并对采用内孔焊结构后管板的受力状况进行了数值分析及对比,作为换热管和管板焊接技术的改进和优化。优化后的结构可为今后WSA装置蒸汽发生器的换热管和管板焊接提供技术指导。

关键词：内孔焊 WSA装置蒸汽发生器数值分析

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舰船噪声环境下改进语音信号增强算法

西安电子科技大学学报 2016年第5期43卷 133-138页

作者：李大卫杨日杰韩建辉海军航空工程学院电子信息工程系山东烟台264001

谱减法广泛应用于语音增强,但在舰船噪声环境下,噪声的复杂多样性给谱减法中信号的语音段与噪声段的正确检测带来极大的困难,影响了谱减法的效果,为此,笔者在分析信号频谱特性的基础上,首先通过分帧信号相邻帧间频谱的相似性测度对信号... 详细信息

谱减法广泛应用于语音增强,但在舰船噪声环境下,噪声的复杂多样性给谱减法中信号的语音段与噪声段的正确检测带来极大的困难,影响了谱减法的效果,为此,笔者在分析信号频谱特性的基础上,首先通过分帧信号相邻帧间频谱的相似性测度对信号段粗判断,再利用帧间偏移方法进行精确判断,实现语音段与背景噪声段的精确辨别,进而利用谱减法实现舰船噪声环境下语音信号的增强.经过大量实测数据的验证,改进的谱减法能够适应多种类型舰船噪声环境下的语音增强,对语音段的判别准确度达到96%,对背景噪声的判别准确度达98%.与传统谱减法及其他相关改进算法相比,在低信噪比强背景噪声下,文中改进谱减法仍能取得稳定的语音增强效果.

关键词：语音增强谱减法频谱相似性语音段检测帧间偏移

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FOK判断与可接近信息之间的关系

心理学报 2001年第4期33卷 320-327页

作者：沈大为韩凯北京大学心理系北京100871

通过三个实验 ,用语义联想集大小不同的中文单字词研究了靶项目联想集的大小与FOK判断等级和准确性的关系。实验一通过两种不同联想集大小的靶子 ,比较外显的、提取出的信息和内隐的、语义网络中固有的被激活信息量对FOK判断等级和FOK... 详细信息

通过三个实验 ,用语义联想集大小不同的中文单字词研究了靶项目联想集的大小与FOK判断等级和准确性的关系。实验一通过两种不同联想集大小的靶子 ,比较外显的、提取出的信息和内隐的、语义网络中固有的被激活信息量对FOK判断等级和FOK判断准确性是否有不同的影响。实验二和实验三通过不同的靶子呈现时间和学习遍数 ,比较不同的识记强度对不同大小联想集的靶子的FOK判断等级和FOK判断准确性的影响。实验结果表明 :FOK判断等级随外显的、提取出的信息总量的增多而增高 ,随内隐的、语义网络中固有的被激活信息量的增多而降低。FOK判断准确性随靶子本身的激活强度的增强而增高 ,随内隐的、语义网络中固有的被激活信息的激活强度的增强而降低。

关键词： FOK判断 FOK判断等级 FOK判断准确性靶项目联想集