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32篇 您的检索式:作者名="Defeng Qi"
    题名 作者 年代 出处 被引量
1Atomic Fe-Zn dual-metal sites for high-efficiency pH-universal oxygen reduction catalysis显示文摘An effective electrocatalyst being highly active in all pH range for oxygen reduction reaction(ORR)is crucial for energy conversion and storage devices.However,most of the high-efficiency ORR catalysis was reported in alkaline conditions.Herein,we demonstrated the preparation of atomically dispersed Fe-Zn pairs anchored on porous N-doped carbon frameworks(Fe-Zn-SA/NC),which works efficiently as ORR catalyst in the whole pH range.It achieves high half-wave potentials of 0.78,0.85 and 0.72 V in 0.1 M HClO4,0.1 M KOH and 0.1 M phosphate buffer saline(PBS)solutions,respectively,as well as respectable stability.The performances are even comparable to Pt/C.Furthermore,when assembled into a Zn-air battery,the high power density of 167.2 mWcm−2 and 120 h durability reveal the feasibility of Fe-Zn-SA/NC in real energy-related devices.Theoretical calculations demonstrate that the superior catalytic activity of Fe-Zn-SA/NC can be contributed to the lower energy barriers of ORR at the Fe-Zn-N6 centers.This work demonstrates the potential of Fe-Zn pairs as alternatives to the Pt catalysts for efficient catalytic ORR and provides new insights of dual-atom catalysts for other energy conversion related catalytic reactions.Jie Xu Shuhua Lai Defeng Qi Min Hu Xianyun Peng Yifan Liu Wei Liu Guangzhi Hu Heng Xu Fan Li Chao Li Jia He Longchao Zhuo Jiaqiang Sun Yuan Qiu Shusheng Zhang Jun Luo Xijun Liu 2021Nano Research2021,14,5:6
2Raman micro-spectrometry as a technique for investigating heterogeneous reactions on individual atmospheric particles显示文摘Investigating the heterogeneous reaction on individual atmospheric particles is important because it approximates actual atmospheric conditions and can aid in reducing artifacts in elucidating real mechanisms and processes,and determining real kinetic parameters of the atmosphere relevance.This study developed a Raman microspectrometry method to investigate heterogeneous reactions on individual particles.The method was applied to the reaction of NO2 with individual CaCO3 particles.It was demonstrated that Raman microspectrometry can obtain information on both chemical composition and microscopic morphology at the same time,as well as information on chemical characteristics,such as the phase,which is useful for studying reaction processes.Raman spectra of individual particles deposited on a substrate showed no interference by morphological resonance,which is helpful for obtaining high-quality spectra.Moreover,Raman microspectrometry was compared with other methods for investigating heterogeneous reactions on individual particles and was found to have several advantageous characteristics.ZHAO DeFeng,ZHU Tong,CHEN Qi,LIU YingJun & ZHANG ZeFeng State Key Joint Laboratory of Environmental Simulation and Pollution Control College of Environmental Sciences and Engineering,Peking University,Beijing 100871,China 2011Science China Chemistry2011,54,1:5
3Age assignment and geological significance of the “Budate Group” in the Hailar Basin显示文摘Age and nature of the Budate Group in the Hailar Basin are of great significance in studying the evolution of the Hailar Basin and the Xing'an-Mongolian Orogenic Belt(XMOB).Zircon U-Pb ages of eight volcanic rocks from the Budate Group and two basement granites in the Hailar Basin were reported in this study.The dating results indicated that the formation of these volcanic rocks was consistent with the emplacement of Late Paleozoic basement granite in age(356-290 Ma),i.e.,Early Carboniferous to Early Permian rather than Early Mesozoic.Combined with regional geology,it was concluded that the Budate Group is the component of the basement of the Hailar Basin,and these volcanic rocks were formed at an active continental margin,which is related to the closure of the Hegen Mountains suture zone.The captured Neoproterozoic zircons(814-873 Ma) were probably derived from the Neoproterozoic basement materials in the Ergun Block,implying the close genetic relationships between the Ergun Block(including the Hailar Basin) and the Siberian Block.MENG Qi'An WAN ChuanBiao ZHU DeFeng ZHANG YanLong GE WenChun WU FuYuan 2013Science China Earth Sciences2013,56,6:4
4High-efficiency electrocatalytic NO reduction to NH_(3) by nanoporous VN显示文摘Electrocatalytic NO reduction reaction to generate NH_(3)under ambient conditions offers an attractive alternative to the energy-extensive Haber-Bosch route;however,the challenge still lies in the development of cost-effective and high-performance electrocatalysts.Herein,nanoporous VN film is first designed as a highly selective and stable electrocatalyst for catalyzing reduction of NO to NH_(3)with a maximal Faradaic efficiency of 85%and a peak yield rate of 1.05×10^(-7)mol·cm^(-2)·s^(-1)(corresponding to 5,140.8mg·h^(-1)·mg_(cat).^(-1))at-0.6 V vs.reversible hydrogen electrode in acid medium.Meanwhile,this catalyst maintains an excellent activity with negligible current density and NH_(3)yield rate decays over 40 h.Moreover,as a proof-of-concept of Zn-NO battery,it delivers a high power density of 2.0 mW·cm^(-2)and a large NH_(3)yield rate of 0.22×10^(-7)mol·cm^(-2)·s^(-1)(corresponding to 1,077.1mg·h^(-1)·mg_(cat).^(-1)),both of which are comparable to the best-reported results.Theoretical analyses confirm that the VN surface favors the activation and hydrogenation of NO by suppressing the hydrogen evolution.This work highlights that the electrochemical NO reduction is an eco-friendly and energy-efficient strategy to produce NH_(3).Defeng Qi Fang Lv Tianran Wei Mengmeng Jin Ge Meng Shusheng Zhang Qian Liu Wenxian Liu Dui Ma Mohamed SHamdy Jun Luo Xijun Liu 2022Nano Research Energy2022,1,2:2
5A new look at smoothing Newton methods for nonlinear complementarity problems and box constrained variational inequalities显示文摘Liqun Qi Defeng Sun Guanglu Zhou 2000Mathematical Programming2000,,1:1
6A new look at smoot- hing Newton methods for nonlinear complementarity prob- lems and box constrained variational inequalities显示文摘Qi Liqun Sun Defeng Zhou Guanglu 2000Mathe- matical Programming2000,87,:1
7A nonsmooth version of Newton's method 显示文摘Qi Liqun Sun Defeng 1997Mathematical Programming1997,58,:1
8On NCP-Function 显示文摘SUN DEFENG QI LIQUN 1999Computational Optiomization and Applications1999,13,:1
9A new look at smoothing Newton methods for nonlinear complementarity problems and box constrained variational inequalities显示文摘Liqun Qi Defeng Sun Guanglu Zhou 2000Mathematical Programming2000,,1:1
10A new look at smoothing Newton methods for nonlinear complementarity problems and box constrained variational inequalities显示文摘Liqun Qi Defeng Sun Guanglu Zhou 2000Mathematical Programming2000,,1:1
11Global and superlinear convergence of the smoothing Newton method and its application to general box constrained variational inequalities 显示文摘Chen X Qi Liqun Sun Defeng 1998Mathematics of Computation1998,67,:1
12Fabrication of large-area uniform carbon nanotube foams as near-critical-density targets for laser–plasma experiments显示文摘Carbon nanotube foams(CNFs)have been successfully used as near-critical-density targets in the laser-driven acceleration of high-energy ions and electrons.Here we report the recent advances in the fabrication technique of such targets.With the further developed floating catalyst chemical vapor deposition(FCCVD)method,large-area(>25 cm^(2))and highly uniform CNFs are successfully deposited on nanometer-thin metal or plastic foils as double-layer targets.The density and thickness of the CNF can be controlled in the range of 1−13 mg/cm^(3)and 10−200µm,respectively,by varying the synthesis parameters.The dependence of the target properties on the synthesis parameters and the details of the target characterization methods are presented for the first time.Pengjie Wang Guijun Qi Zhuo Pan Defeng Kong Yinren Shou Jianbo Liu Zhengxuan Cao Zhusong Mei Shirui Xu Zhipeng Liu Shiyou Chen Ying Gao Jiarui Zhao Wenjun Ma 2021High Power Laser Science and Engineering2021,9,2:1
13A new look at smoothing Newton methods for nonlinear complementarity problems and box constrained variational inequalities 显示文摘Qi Liqun Sun Defeng Zhou Guanglu 2000Mathematical Programming2000,87,1:1
14On NCP-Functions显示文摘Defeng Sun Liqun Qi 1999Computational Optimization and Applications (-)1999,,1:1
15A new look at smoothing Newton methods for nonlinear complementarity problems and box constrained variational inequalities显示文摘Liqun Qi Defeng Sun Guanglu Zhou 0,,:1
16Provenance System Analysis of the Nantun Formation of the Huhehu Sag in Hailar Basin显示文摘Huhehu Sag is a new battlefield for the future oil and gas exploration in the Hailar Basin.At present,exploration of this area stays at a low level and the understanding of the provenance system of the Nantun Formation is comparatively weak.So,to carry out the detailed depiction of the provenance system in the study area is significant for the sedimentary system reconstruction,for the prediction of reservoir distribution and favorable areas.Based on comprehensive analysis of paleogeomorphy,light-heavy mineral and seismic reflection features,sandstone thickness and sandstone percentage,this paper analyzes in detail the provenance system of the Nantun Formation in Huhehu Sag from various angles and levels.It shows that provenances of the Huhehu Sag mainly originated from the eastern Xilinbeier Salient and western Bayan Mountain Uplift.The provenances surrounding the lake basin converged to the center of the basin,among which,the steep slope belt and the gentle slope belt are the main provenances,and the southern uplift is a secondary one.The distribution framework of the provenance fundamentally determines the distribution rules of the depositional system and its sand body developing during the Nantun period.LI Junhui MENG Qi'an LU Shuangfang ZHU Defeng WU Haibo LIU He ZHANG Dazhi 2012Acta Geologica Sinica(English Edition)2012,86,1:1
17A new look at smoothing Newton methods for nonlinear complementarity problems and box constrained variational inequalities显示文摘Liqun Qi Defeng Sun Guanglu Zhou 2000Mathematical Programming2000,,1:1
18A feasible semismooth asymptotically Newton method for mixed complementarity problems显示文摘Sun Defeng Womersley R S Qi Houdou 0,,02:1
19On NCP-Functions显示文摘 Qi Liqun 2000Computational Optimization and Applications2000,121,:1
20A new Iook at smoothing Newton methods for nonlinear complementarity problems and box constrained variational inequalities 显示文摘Qi Liqun Sun Defeng Zhou Guanglu 2000Mathematical Programming2000,87,:1
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