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Responses of soil microbial communities to freeze–thaw cycles in a Chinese temperate forest

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Ecological Processes 2021年第1期10卷 903-920页

作者： Changpeng Sang Zongwei Xia lifei sun Hao sun Ping Jiang Chao Wang Edith Bai CAS Key Laboratory of Forest Ecology and Management Institute of Applied EcologyChinese Academy of SciencesShenyang 110016China. University of Chinese Academy of Sciences Beijing 100049China. Shandong Provincial Key Laboratory of Water and Soil Conservation and Environmental Protection College of Resources and EnvironmentLinyi UniversityLinyi 276000China. Key Laboratory of Geographical Processes and Ecological Security in Changbai Mountains Ministry of EducationSchool of Geographical SciencesNortheast Normal UniversityChangchun 130024China. Key Laboratory of Vegetation Ecology Ministry of EducationChangchun 130024China.

Background:Freeze–thaw events are common in boreal and temperate forest ecosystems and are increasingly infuenced by climate warming.Soil microorganisms play an important role in maintaining ecosystem stability,but their responses to freeze–thaw cycles(FTCs)are poorly understood.We conducted a feld freeze–thaw experiment in a natural Korean pine and broadleaf mixed forest in the Changbai Mountain Nature Reserve,China,to determine the dynamic responses of soil microbial communities to FTCs.Results:Bacteria were more sensitive than fungi to FTCs.Fungal biomass,diversity and community composition were not signifcantly afected by freeze–thaw regardless of the stage.Moderate initial freeze–thaw resulted in increased bacterial biomass,diversity,and copiotrophic taxa abundance.Subsequent FTCs reduced the bacterial biomass and diversity.Compared with the initial FTC,subsequent FTCs exerted an opposite efect on the direction of change in the composition and function of the bacterial community.Soil water content,dissolved organic carbon,ammonium nitrogen,and total dissolved phosphorus were important factors determining bacterial community diversity and composition during FTCs.Moreover,the functional potentials of the microbial community involved in C and N cycling were also afected by FTCs.Conclusions:Diferent stages of FTCs have diferent ecological efects on the soil environment and microbial activities.Soil FTCs changed the soil nutrients and water availability and then mainly infuenced bacterial community composition,diversity,and functional potentials,which may disturb C and N states in this temperate forest soil.This study also improves our understanding of microbial communities regulating their ecological functions in response to climate change.

关键词： Freeze–thaw cycle Microbial diversity Microbial community composition Soil resource availability Functional potential

Metallic and ferromagnetic MoS2 nanobelts with vertically aligned edges

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Nano Research 2015年第9期8卷 2946-2953页

作者： Guanchen Xu Xinsheng Wang Yupeng sun Xiao Chen Jingying Zheng lifei sun Liying Jiao Jinghong Li Department of Chemistry Tsinghua University Beijing 100084 China Key Laboratory of Colloid and Interface Chemistry Shandong University Jinan 250100 China

Edge effects are predicted to significantly impact the properties of low dimensional materials with layered structures. The synthesis of low dimensional materials with copious edges is desired for exploring the effects of edges on the band structure and properties of these materials. Here we developed an approach for synthesizing MoS2 nanobelts terminated with vertically aligned edges by sulfurizing hydrothermally synthesized MoO3 nanobelts in the gas phase through a kinetically driven process; we then investigated the electrical and magnetic properties of these metastable materials. These edge-terminated MoS2 nanobelts were found to be metallic and ferromagnetic, and thus dramatically different from the semiconducting and nonmagnetic two-dimensional （2D） and three-dimensional （3D） 2H-MoS2 materials. The transitions in electrical and magnetic properties elucidate the fact that edges can tune the properties of low dimensional materials. The unique structure and properties of this one-dimensional （1D） MoS2 material will enable its applications in electronics, spintronics, and catalysis.

关键词： MoS2 two-dimensional (2D)atomic crystal,nanobelt,edge effect,metallic,ferromagnetic

Growth of single-walled carbon nanotubes from Ag15 cluster catalysts

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Science Bulletin 2016年第12期61卷 917-920页

作者： Dake Hu Xin He lifei sun Guanchen Xu Liying Jiao Liang Zhao The Key Laboratory of Organic Optoelectronics and Molecular Engineering Ministry of EducationDepartment of ChemistryTsinghua UniversityBeijing 100084China The Key Laboratory of Bioorganic Phosphorus Chemistry and Chemical Biology Ministry of EducationDepartment of ChemistryTsinghua UniversityBeijing 100084China

Chirality-specific growth of single-walled carbon nanotubes(SWNTs) remains a challenge for their practical applications in electronics. Here, we explored the surface growth of SWNTs by utilizing the atomic-precise silver cluster complex [Ag_(15){1,3,5–(C:C)_3–C_6H_3}_2(Py[8])_3–(CF_3SO_3)_3](CF_3SO_3)_6(Py[8] is abbreviation for octamethylazacalix[8]pyridine) as a catalyst precursor. The diameters of most acquired SWNTs distributed in the range of 1.2–1.4 nm, which is suitable for making high performance field-effect transistors. The high quality of the obtained SWNTs was evidenced by Raman spectroscopy and electrical measurements. Successful growth of high quality SWNTs in this study foresees that rational design of metal-organic complexes as growth catalysts can open up a new avenue for the controllable synthesis of SWNTs.

关键词：单壁碳纳米管催化剂前体表面生长簇合物金属有机配合物场效应晶体管 SWNTs 电子应用

Growth of large-area aligned pentagonal graphene domains on high-index copper surfaces

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Nano Research 2016年第7期9卷 2182-2189页

作者： Kailun Xia Vasilii I. Artyukhov lifei sun Jingying Zheng Liying Jiao Boris I. Yakobson Yingying Zhang Department of Chemistry Tsinghua University Beijing 100084 China Center for Nano and Micro Mechanics Tsinghua University Beijing 100084 China Department of Materials Science and Nano Engineering Rice University Houston TX 77005 USA

Single-crystal graphene domains grown by chemical vapor deposition （CVD） intrinsically tend to have a six-fold symmetry; however, several factors can influence the growth kinetics, which can in turn lead to the formation of graphene with different shapes. Here we report the growth of oriented large-area pentagonal single-crystal graphene domains on Cu foils by CVD. We found that high-index Cu planes contributed selectively to the formation of pentagonal graphene. Our results indicated that lattice steps present on the crystalline surface of the underlying Cu promoted graphene growth in the direction perpendicular to the steps and finally led to the disappearance of one of the edges forming a pentagon. In addition, hydrogen promoted the formation of pentagonal domains. This work provides new insights into the mechanism of graphene growth.

关键词： pentagonal graphene,copper foil,high index plane,chemical vapor deposition,large area

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人工智能与大数据技术在变配电系统中的应用

集成电路应用 2024年第1期41卷 260-261页

作者：孙立飞支昊国网沭阳县供电公司江苏223600

阐述变电系统的数字化技术特点,探讨变电站人工智能技术和大数据技术的应用,包括对变电站系统运营的巡视、变电站系统的运维操作、变电站系统运行的安全维护,分析大数据技术的应用成效。

关键词：人工智能大数据变配电系统

基于智能技术的变电运检现场安全管控系统设计与应用

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电子技术（上海） 2024年第1期53卷 236-237页

作者：支昊孙立飞国网沭阳县供电公司江苏223600

阐述变电站工程的安全状况,提出以人工智能为基础的变电运检现场安全管控措施,包括利用感知层捕捉信息,利用平台层有效采集与传输现场数据,利用应用层及时记录与控制现场违规操作。

关键词：变电运检人工智能现场作业安全管控系统

Laser emission from low-loss cladding waveguides in Pr:YLF by femtosecond laser helical inscription

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Chinese Optics Letters 2022年第12期20卷 43-49页

作者：任莹莹崔泽孟孙丽菲王超刘洪亮蔡阳健 Shandong Provincial Engineering and Technical Center of Light Manipulations and Shandong Provincial Key Laboratory of Optics and Photonic Device School of Physics and ElectronicsShandong Normal UniversityJinan 250358China Key Laboratory of Optical Information Science and Technology Ministry of EducationInstitute of Modern OpticsNankai UniversityTianjin 300071China School of Physical Science and Technology Soochow UniversitySuzhou 215006China

Depressed cladding waveguides are fabricated in Pr:LiYF_(4)(YLF)crystal by femtosecond laser inscription following a helical scheme.With the optimized parameters,the propagation loss of the waveguide is around 0.12 dB/cm for multimode guiding.Under optical pumping with InGaN laser diodes at 444 nm,efficient waveguide lasers in the orange around604 nm(π-polarized)are achieved with minimum lasing threshold of 119.8 mW,maximum slope efficiency of 16.6%,and maximum output power of 120.6 mW.Benefiting from their optimized performances,the waveguides produced in this work are promising for applications as compact orange laser sources.

关键词： femtosecond laser helical inscription Pr:YLF crystal optical waveguide laser

基于能量分段与平稳小波变换的运动心电图特征波检测算法研究

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生物医学工程学杂志 2021年第6期38卷 1181-1192页

作者：刘近贞孙利飞熊慧梁美玲天津工业大学控制科学与工程学院天津300387 天津工业大学天津市电气装备智能控制重点实验室天津300387 北京兆易创新科技股份有限公司北京100088

心电图(ECG)的特征波检测是心血管疾病分析与心率变异性分析的基础,为解决运动状态下ECG信号特征波检测准确率低、实时性差的问题,本文提出了一种基于分段能量与平稳小波变换(SWT)的运动ECG信号特征波检测算法。首先,分段计算ECG信号的... 详细信息

心电图(ECG)的特征波检测是心血管疾病分析与心率变异性分析的基础,为解决运动状态下ECG信号特征波检测准确率低、实时性差的问题,本文提出了一种基于分段能量与平稳小波变换(SWT)的运动ECG信号特征波检测算法。首先,分段计算ECG信号的能量,使用移动平均获得能量阈值后,得到能量候选波以检测QRS波;其次,将QRS幅值置零,利用SWT的第五分量定位P波和T波。实验结果表明,同其它算法相比,本文算法对不同运动状态下的QRS波检测的准确率高,且对1条30 min的ECG信号记录进行QRS波检测仅需0.22 s,实时性也有明显提高。在QRS波检测的基础上,对P波和T波检测的准确率均高于95%,从而表明该方法能够提高运动ECG信号特征波检测的效率,为运动状态下ECG信号的实时分类和心血管疾病的实时诊断提供一种新方法。

关键词：运动心电信号 QRS波检测能量分段平稳小波变换

中国共产党的爱国主义教育:历史传承、主要成就及经验启示

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辽宁行政学院学报 2024年第2期 56-62页

作者：刘丽霏孙希云沈阳农业大学辽宁沈阳110866

爱国主义是中华民族的民族心、民族魂,是中华民族最宝贵的精神财富。爱国主义教育是中华民族的优良传统,更是中国共产党思想政治教育的永恒主题。新中国成立以来,党在带领全国各族人民进行革命、建设和改革实践中,始终高度重视发挥爱国... 详细信息

爱国主义是中华民族的民族心、民族魂,是中华民族最宝贵的精神财富。爱国主义教育是中华民族的优良传统,更是中国共产党思想政治教育的永恒主题。新中国成立以来,党在带领全国各族人民进行革命、建设和改革实践中,始终高度重视发挥爱国主义教育固本培元、凝心铸魂的作用,作出一系列重要部署,有力推动爱国主义教育的规范发展,取得了一系列成就,积累了宝贵的经验。进入新时代,准确把握中国共产党爱国主义教育的历史传承、主要成就及经验启示,对深入推进新时代爱国主义教育实践具有重要意义。

关键词：中国共产党爱国主义教育爱国主义精神历史传承

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