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Reduced graphene oxide-supported CoP nanocrystals confined in porous nitrogen-doped carbon nanowire for highly enhanced lithium/sodium storage and hydrogen evolution reaction

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Nano Research 2019年第11期12卷 2872-2880页

作者： Xiaojun Zhao Dan Luo Yan Wang zhi-Hong liu Key Laboratory for Macromolecular Science of Shaanxi Province School of Chemistry and Chemical EngineeringShaanxi Normal UniversityXi’an710062China

Rational synthesis of a hierarchical porous architecture with highly active and consecutive conductive network is very critical to achieve the high-performance of nanomaterials in electrochemical energy conversion and *** propose here a hierarchical micro-/nanostructured hybrids constructed by the dual carbon shell nanowire host containing CoP nanocrystals of several nanometers,which generates Co-based metal-organic framework on graphene oxide nanosheets in situ and followed a direct phosphorization(CoP@NC/rGO).The dual carbon shell,consisting of Co-based metal-organic framework derived porous doped carbon(NC)and reduced graphene oxide(rGO),can not only impedes CoP nanocrystals from coalescing,and renders highly exposed the electrochemically accessible active sites,but also provides the multidimensional pathways for rapid electron and ion *** importantly,the covered dual carbon shell on CoP nanocrystals plays a role as a protective layer to impede the nanocrystals’*** virtue of compositional and structural advantages,the micro-/nanostructured CoP@NC/rGO hybrids manifest outstanding energy storage properties when evaluated as anodes for lithium/sodium ion ***,it also reveals highly efficient electrocatalytic performance for hydrogen evolution reaction in acid media with low Tafel slope,overpotential and robust durability.

关键词： micro-/nanostructured metal-organic framework CoP@NC/rGO lithium/sodium ion batteries hydrogen evolution reaction

Intelligent identification of landslides in loess areas based on the improved YOLO algorithm:a case study of loess landslides in Baoji City

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Journal of Mountain Science 2023年第11期20卷 3343-3359页

作者： liu Qing WU Ting-ting DENG Ya-hong liu zhi-heng School of Mechanical and Electrical Engineering Huainan Normal UniversityHuainan 232038China School of Geomatics Anhui University of Science and TechnologyHuainan 232001China School of Geology Engineering and Geomatics Chang’an UniversityXi’an 710064China School of Aerospace Science and Technology Xidian UniversityXi'an 710064China

Loess landslides are one of the geological hazards prevalent in mountainous areas of Loess Plateau,seriously threatening people's lives and property *** identification of landslides is a prerequisite for reducing the risk of landslide *** landslide interpretation methods often have the disadvantage of being laborious and difficult to use on a large scale compared with the recently developed deep learning-based landslide detection *** this study,we propose an improved deep learning model,landslide detectionyou only look once(LD-YOLO),based on the existing you only look once(YOLO)model for the intelligent identification of old and new landslides in loess ***,remote sensing images of landslides in Baoji City,Shaanxi Province,China are acquired from the Google Earth Engine *** landslide images of Baoji City(excluding Qianyang County)are used to establish a loess landslide dataset for training the *** landslide data of Qianyang County is used to verify the detection performance of the *** focal and efficient IoU(Focal-EIoU)loss function and efficient channel attention(ECA)mechanism are incorporated into the 7th version of YOLO(YOLOv7)model to construct the LD-YOLO model,which makes it more suitable for the landslide detection *** experiments yielded an improved LD-YOLO model with average precision of 92.05%,precision of 92.31%,recall of 90.28%,and F1-score of 91.28%for loess landslide *** landslides in Qianyang County were divided into two test sets,new landslides and old landslides,which were used to test the detection performance of LD-YOLO for both types of *** results show that LD-YOLO detects old landslides with a detection precision of 82.75%and a recall of 80%.When detecting new landslides,the detection precision is 94.29%and the recall is 91.67%.It indicates that our proposed LD-YOLO model has strong detection performance for both new and old landslides in loess areas

关键词： Loess landslide Deep learning Attention mechanism Data augmentation You only look once(YOLO)

BnWRI1 coordinates fatty acid biosynthesis and photosynthesis pathways during oil accumulation in rapeseed

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Journal of Integrative Plant Biology 2014年第6期56卷 582-593页

作者： Xue-Long Wu zhi-Hong liu Zhang-Hua Hu Rui-zhi Huang Institute of Virology and Biotechnology Zhejiang Academy of Agricultural Sciences Key Laboratory of Plant Metabolic Engineering of Zhejiang Province

Photosynthesis in“green”seeds, such as rapeseed, soybean, and Arabidopsis, plays a substantial role in the improved efficiency of oil accumulation. However, the molecular mecha-nism underpinning the coordinated expression of fatty acid （FA） biosynthesis-and photosynthesis-related genes in such develop-ing seeds remains to be elucidated. Here, we found that seed-specific overexpression of BnWRI1, a WRI1 homolog from rapeseed （Brassica napus cv. ZGY2）, results in enhanced chlorophyl content in developing seeds and increased oil content and seed mass in matured seeds. BnWRI1 was co-expressed with BnBCCP and BnCAB, two marker genes of FA biosynthesis and photosynthesis during seed development, respectively. Over-expression of BnWRI1 increased expression of both marker genes. Further, the nuclear-localized BnWRI1 protein was found to act as a transcription activator. It could bind to the GT1-element and/or GCC-box, which are widespread in the upstream regions of genes involved in FA biosynthesis and photosynthesis pathways. Accordingly, BnWRI1 could interact with promoters of BCCP2 and LHB1B2 in vivo. These results suggested that BnWRI1 may coordinate FA biosynthesis and photosynthesis pathways in developing seeds via directly stimulating expression of GT1-element and/or GCC-box containing genes.

关键词： BnWRI1 Brassica napus oil accumulation photosynthesis transcription factor

Exploring the sources of p-mode frequency shifts in the CoRoT target HD 49933

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Research in Astronomy and Astrophysics 2014年第6期14卷 683-692页

作者： zhi-E liu Shao-Lan Bi Wu-Ming Yang Tan-Da Li Kang liu zhi-Jia Tian zhi-Shuai Ge Jie Yu Department of Astronomy Beijing Normal University Key Laboratory of Solar Activity National Astronomical Observatories Chinese Academy of Science

Oscillations of the solar-like star HD 49933 have been thoroughly observed by CoRot. Two dozen frequency shifts, which are closely related to the change in magnetic activity, have been measured. To explore the effects of magnetic activity on frequency shifts, we calculate frequency shifts for the radial and l=1 p-modes of HD 49933 with the general variational method, which evaluates the shifts using a spa- tial integral of the product of a kernel and some sources. The theoretical frequency shifts reproduce the observation well. The magnitudes and positions of the sources are determined according to a χ2 criterion. We predict the source that contributes to both the l = 0 and l= 1 modes is located 0.48 - 0.62 Mm below the surface of the star. In addition, based on the assumption that A0 is proportional to the change in the MglI activity index △iMgⅡ, we obtain that the change in MgⅡ index between the minimum and maximum of the cycle during the period of HD 49933 is about 0.665. The magnitude of the frequency shifts compared to the Sun already demonstrates that HD 49933 is much more active than the Sun, which is further confirmed in this pa- per. Furthermore, our calculation of the frequency shifts for l = 1 modes indicates the variation of turbulent velocity in the stellar convective zone may be an important source for the l = 1 shifts.

关键词： stars: individual (HD 49933) -- stars: evolution -- stars: oscillation --stars: modeling

Brightness and Lifetime Improved Light-Emitting Diodes from Sr-Doped Quasi-Two-Dimensional Perovskite Layers

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Tsinghua Science and Technology 2023年第1期28卷 131-140页

作者： Dan Chen Taoran liu Yuhua Zuo Chuanbo Li Jun Zheng zhi liu Baoyu liu Buwen Cheng State Key Laboratory on Integrated Optoelectronics Institute of SemiconductorChinese Academy of SciencesBeijing 100083China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China School of Science Minzu University of ChinaBeijing 100081China Beijing Advanced Innovation Center for Materials Genome Engineering Beijing Key Laboratory for SensorMOE Key Laboratory for Modern Measurement and Control Technologyand Beijing Information Science and Technology UniversityBeijing 100101China

Green Perovskite Light-Emitting Diodes(PeLEDs)have attracted wide attention for full spectrum ***,the inferior film morphology and luminescence property of quasi-two-dimensional(quasi-2D)perovskite layers limit the photoelectric property of the *** this paper,the effect of strontium(Sr)doped in quasi-2D perovskite layers is investigated to obtain a high-quality active *** morphologies and optical properties of Sr-doped quasi-2D perovskite films with different concentrations are *** the addition of strontium,more low-dimensional-layer perovskite phases(n D 2 and n D 3)appear in quasi-2D perovskite films,providing efficient intraband carrier funneling pathway and facilitating radiative *** photoluminescence(PL)peak intensity of optimized Sr-doped quasi-2D perovskite layers increases 50%compared with the non-strontium ***,green PeLEDs based on a Sr-doped quasi-2D perovskite layer reach a maximum luminance(Lmax)of 2943.77 cd/m^(2),which is three times of the control *** electroluminescence(EL)peaks of Maximum External Quantum Efficiency(MEQE)and Lmax of Sr-doped PeLEDs exhibite a slight shift,indicating the excellent stability and performance of Sr-doped *** optimized device can continuously operate for 360 s at MEQE driving voltage,resulting in a half-lifetime of60 s,which is 3-fold greater than that of the control PeLEDs.

关键词： Perovskite Light-Emitting Diodes(PeLED) Sr-doped brightness improved lifetime increased

Effect of Chloride Ion Concentrations on Luminescence Peak Blue Shift of Light-Emitting Diode Using Anti-Solvent Extraction of Quasi-Two-Dimensional Perovskite

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Tsinghua Science and Technology 2021年第4期26卷 496-504页

作者： Baoyu liu Xiaoping Zou Dan Chen Taoran liu Yuhua Zuo Jun Zheng zhi liu Buwen Cheng Beijing Advanced Innovation Center for Materials Genome Engineering Beijing Key Laboratory for SensorMOE Key Laboratory for Modern Measurement and Control TechnologyBeijing Information Science and Technology UniversityBeijing 100101China the State Key Laboratory on Integrated Optoelectronics Institute of SemiconductorChinese Academy of SciencesBeijing 100083China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

In recent years,Perovskite Light-Emitting Diodes(PeLEDs)have received considerable attention in ***,with the development of PeLEDs,commercial applications of full-color PeLED technology are largely limited by the progress of blue-emitting devices,due to the uncontrollably accurate composition,unstable properties,and low *** this article,we add Cesium chloride(CsCl)to the quasi-two-dimensional(quasi-2D)perovskite precursor solution and achieve the relatively blue shifts of PeLED emission peak by introducing chloride ions for photoluminescence(PL)and electroluminescence(EL).We also found that the introduction of chlorine ions can make quasi-2D perovskite films thinner with smoother surface of 0.408 *** is interesting that the EL peaks and intensities of PeLED are adjustable under different driving voltages in high concentration chlorine-added perovskite devices,and different processes of photo-excited,photo-quenched,and photo-excited occur sequentially with the increasing driving *** work provides a path for demonstrating full-color screens in the future.

关键词： Perovskite Light-Emitting Diodes(PeLEDs) quasi-two-dimensional(quasi-2D) chloride ions blue shifts

Development of RF windows for 650 MHz multibeam klystron

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Nuclear Science and Techniques 2023年第9期34卷 58-68页

作者： Sheng-Chang Wang Zu-Sheng Zhou zhi-Jun Lu zhi-Qing liu Shigeki Fukuda Yu liu Jing-Yi Li Wei-Ming Li National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230026China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Kunshan Guo Li Electronic Technology Co. Ltd.Kunshan 215300China High Energy Accelerator Research Organization KEK 1-1 OhoTsukubaIbaraki 305-0801Japan

Radio frequency windows are developed and evaluated for a 650 MHz continuous-wave multibeam ***-pillbox windows with alumina and beryllia disks are designed with an average RF power of CW 400 *** of a cold test and tuning procedures are *** final measured S11 curves under the required bandwidth are less than-32.0 and-26.9 dB for alumina and beryllia windows,*** windows are tested up to CW 143 kW for traveling waves and CW 110 kW for standing waves using a solid-state amplifier as an RF power *** simulations for windows and benchmark studies for the thermal analysis of ceramic disks are introduced.

关键词： RF window High-power test MBK

Cobalt and manganese stress in the microalga Pavlova viridis (Prymnesiophyceae):Effects on lipid peroxidation and antioxidant enzymes

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Journal of Environmental Sciences 2007年第11期19卷 1330-1335页

作者： LI Mei ZHU Qin HU Chang-wei CHEN Li liu zhi-li KONG zhi-ming National Key Laboratory of Pollution Control and Resource Reuse of China School of the Environment Nanjing University Nanjing 210093 China School of Life Science Nanjing University Nanjing 210093 China

Pollution of marine environment has become an issue of major concern in recent years. Serious environmental pollution by heavy metals results from their increasing utilization in industrial processes and because most heavy metals are transported into the marine environment and accumulated without decomposition. The aim of the present study is to investigate the effects on growth, pigments, lipid peroxidation, and some antioxidant enzyme activities of marine microalga Pavlova viridis, in response to elevated concentrations of cobalt （Co） and manganese （Mn）, especially with regard to the involvement of antioxidative defences against heavy metal-induced oxidative stress. In response to Co^2＋, lipid peroxidation was enhanced compared to the control, as an indication of the oxidative damage caused by metal concentration assayed in the microalgal cells but not Mn^2＋. Exposure of Pavlova viridis to the two metals caused changes in enzyme activities in a different manner, depending on the metal assayed： after Co^2＋ treatments, total superoxide dismutase （SOD） activity was irregular, although it was not significantly affected by Mn^2＋ exposure. Co^2＋ and Mn^2＋ stimulated the activities of catalase （CAT） and glutathione （GSH）, whereas, glutathione peroxidase （GPX） showed a remarkable increase in activity in response to Co^2＋ treatments and decreased gradually with Mn^2＋ concentration, up to 50 μmol/L, and then rose very rapidly, reaching to about 38.98% at 200 μmol/L Mn^2＋. These results suggest that an activation of some antioxidant enzymes was enhanced, to counteract the oxidative stress induced by the two metals at higher concentration.

关键词： antioxidant enzymes cobalt manganese malondialdehyde (MDA) Pavlova viridis

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铁基氧化物团簇催化CO还原NO反应模拟

原子与分子物理学报 2025年第6期42卷 22-30页

作者：刘众元孔繁宇陈琳梁五洲刘志兵高义斌国网山西省电力公司电力科学研究院太原030001 太原理工大学太原030024

固定床实验表明,在深度欠氧的条件下,铁基氧化物对CO还原NO的反应具有催化作用.为进一步理解脱销催化反应机理,本文利用量化软件Gaussian模拟了铁及其三种不同价态氧化物团簇:Fe_(2)团簇、Fe_(2)O_(2)团簇、Fe_(2)O_(3)团簇催化CO还原N... 详细信息

固定床实验表明,在深度欠氧的条件下,铁基氧化物对CO还原NO的反应具有催化作用.为进一步理解脱销催化反应机理,本文利用量化软件Gaussian模拟了铁及其三种不同价态氧化物团簇:Fe_(2)团簇、Fe_(2)O_(2)团簇、Fe_(2)O_(3)团簇催化CO还原NO的反应路径,为进一步改进脱硝反应提供理论基础.本文分析了反应过程的各阶段能量壁垒,三种团簇中最容易发生催化反应的团簇为Fe_(2),整个反应过程中的决速步为NO在Fe_(2)团簇上的解离吸附过程.

关键词：铁团簇脱硝模拟反应机理

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