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Seasonal variations in temperature sensitivity of soil respiration in a larch forest in the Northern Daxing’an Mountains in Northeast China

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Journal of Forestry Research 2022年第3期33卷 1061-1070页

作者： Lin Yang qiuliang zhang Zhongtao Ma Huijun Jin Xiaoli Chang Sergey S.Marchenko Valentin V.Spektor College of Forestry and Da Xing’anling Forest Ecosystem Research Station of Inner Mongolia Autonomous Region Inner Mongolia Agricultural UniversityHohhot010019People’s Republic of China Research-Station of Permafrost Geo-Environment Ministry of EducationInstitute of Cold Regions Science and Engineering and School of Civil EngineeringNortheast Forestry UniversityHarbin150040People’s Republic of China State Key Laboratory of Frozen Soils Engineering Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou730000People’s Republic of China Geophysical Institute University of Alaska FairbanksFairbanksAK99775USA Laboratory of General Geocryology Melnikov Permafrost InstituteSiberia BranchRussian Academy of SciencesYakutskRussia677010

Temperature sensitivity of respiration of forest soils is important for its responses to climate warming and for the accurate assessment of soil carbon budget. The sensitivity of temperature (T_(i)) to soil respiration rate (R_(s)), and Q_(10) defined by e^(10(lnRs−lna)/Ti) has been used extensively for indicating the sensitivity of soil respiration. The soil respiration under a larch (Larix gmelinii) forest in the northern Daxing’an Mountains, Northeast China was observed in situ from April to September, 2019 using the dynamic chamber method. Air temperatures (T_(air)), soil surface temperatures (T_(0cm)), soil temperatures at depths of 5 and 10 cm (T_(5cm) and T_(10cm), respectively), and soil-surface water vapor concentrations were monitored at the same time. The results show a significant monthly variability in soil respiration rate in the growing season (April–September). The Q_(10) at the surface and at depths of 5 and 10 cm was estimated at 5.6, 6.3, and 7.2, respectively. The Q_(10@10 cm) over the period of surface soil thawing (Q_(10@10 cm, thaw) = 36.89) were significantly higher than that of the growing season (Q_(10@10 cm, growth )= 3.82). Furthermore, the Rs in the early stage of near-surface soil thawing and in the middle of the growing season is more sensitive to changes in soil temperatures. Soil temperature is thus the dominant factor for season variations in soil respiration, but rainfall is the main controller for short-term fluctuations in respiration. Thus, the higher sensitivity of soil respiration to temperature (Q_(10)) is found in the middle part of the growing season. The monthly and seasonal Q_(10) values better reflect the responsiveness of soil respiration to changes in hydrometeorology and ground freeze-thaw processes. This study may help assess the stability of the soil carbon pool and strength of carbon fluxes in the larch forested permafrost regions in the northern Daxing’an Mountains.

关键词： Soil respiration Dynamic chamber method Ground thawing Major growth period Soil temperature

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Long-term mercury variations in tree rings of the permafrost forest,northeastern China

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Science China Earth Sciences 2022年第7期65卷 1328-1338页

作者： Huhu KANG Xiaohong LIU Junming GUO qiuliang zhang Yabo WANG Jie HUANG Guobao XU Guoju WU Wensen GE Shichang KANG State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China School of Geography and Tourism Shaanxi Normal UniversityXi'an 710119China University of Chinese Academy of Sciences Beijing 100049China Forest College Inner Mongolia Agricultural UniversityHohhot 010018China Key Laboratory of Tibetan Environment Changes and Land Surface Processes Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China CAS Center for Excellence in Tibetan Plateau Earth Sciences Chinese Academy of SciencesBeijing 100101China

Permafrost is a potential mercury(Hg)pool released by thawing,which can raise the risk of Hg pollution under global *** rings are useful archives of environment-specific Hg exposure over long *** determined Hg concentrations in tree rings of two dominant tree species(Larix gmelinii *** Pinus sylvestris ***)at permafrost sites in northeastern *** biweighted mean Hg concentrations ranged from 0.36 to 3.96 ng g^(-1) from 1840 to *** tree-ring width had no significant influence on the Hg *** Hg increased slightly before the 1970 s and peaked in the 1990 ***,the pine Hg concentration increased continuously until the 1930 s,decreased rapidly until the 1970 s,then rose to a peak in the late 1980 *** change of Hg concentrations in larch and pine revealed a time offset of 4 to 5 years,which implied possibly high mobility of Hg in pine tree *** Hg concentrations from 1920 to 1960 and subsequent decreases in isolated permafrost forests revealed the local geographical Hg cycling *** Hg concentrations and faster increases in larch suggest the role of additional winter Hg loading for the evergreen pine and species-specific differences in root absorption in response to melting *** results highlight possible geographical impacts on tree-ring Hg records,improve understanding of Hg cycles in permafrost forest,and suggest a need to sample additional species in a range of permafrost environments.

关键词： Tree rings Mercury Long-term variations Larch Pine Geographic environment Permafrost forest

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城市轨道交通线网运营监控与应急指挥协同管控平台研究

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铁路计算机应用 2024年第6期33卷 89-92页

作者：王智慧孟宇坤蔡宇晶张秋亮王石生北京经纬信息技术有限公司北京100081 中国铁道科学研究院集团有限公司电子计算技术研究所北京100081

为满足城市轨道交通(简称:城轨)线网运营综合协调和调度指挥管理需求,研究线网运营监控与应急指挥协同管控平台(简称:管控平台)。设计了管控平台的架构,以及线网全景可视化监视及告警、线网智能运营管控、应急指挥协同管控、应急辅助决... 详细信息

为满足城市轨道交通(简称:城轨)线网运营综合协调和调度指挥管理需求,研究线网运营监控与应急指挥协同管控平台(简称:管控平台)。设计了管控平台的架构,以及线网全景可视化监视及告警、线网智能运营管控、应急指挥协同管控、应急辅助决策等功能。通过动态监控预警技术、指挥协同管控技术、线网运营效能提升技术、“站、线、网”运营仿真技术等关键技术,有效地解决运营过程中面临的综合运营监视预警、多单位/多层级协调管控、综合运营辅助决策困难等问题。该平台已在武汉地铁试点应用,应用结果表明,该平台可为轨道交通线网的统一运营协调与管控提供技术支持,为轨道交通线网提供应急处置辅助决策手段。

关键词：运营监视预警运营管控调度联动应急协同辅助决策

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Screening current in ultra-high-field non-insulated superconducting magnets

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Science China(Technological Sciences) 2024年第7期67卷 2255-2273页

作者： ZHOU BenZhe WANG Lei CHEN Yong WANG qiuliang WANG KangShuai zhang ZiLi LIU JianHua University of Chinese Academy of Sciences Beijing 100049China Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190China

Screening current is recognized as one of the critical elements limiting the progression of superconducting magnets toward achieving higher magnetic fields. Currently, most non-insulated(NI) superconducting magnets consider the magnet as insulated when addressing the issue of screening current. However, the bypass current in the NI magnet can modify the actual history of magnetization, so the screening current in NI magnet will be different from that in the insulated magnet. This paper presents a novel method based on the homogenized T-A formulation(T is the current vector potential, and A is the magnetic vector potential), which enables real-time simulation of both the bypass current behavior and the implications of screening current in NI superconducting magnets, even when these magnets contain tens of thousands of turns. We have developed a 32 T NI hybrid superconducting magnet and validated the effectiveness of this method through experiments. Employing this efficacious method,we conducted a comprehensive calculation of screening current in NI magnets, comparing them with insulated magnets in terms of screening current-induced stress(SCIS), screening current-induced field(SCIF), and losses. The results indicate that in the NI insert coils, the sequential excitation of background coils and insert coils induces a reverse screening current, resulting in slightly lower SCIF and SCIS compared to those in the insulated magnets. The method and results can contribute to the enhancement of magnet design and provide valuable insights for the development of ultra-high fields(UHF) NI magnets.

关键词： ultra-high-field superconducting magnet screening current REBCO coil NI coil stress loss

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Diversity and Biomass of Understory Plants in Larix gmelinii Forest under Different Reconstruction Methods

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Journal of Botanical Research 2019年第1期1卷 20-27页

作者： Jiayue Li qiuliang zhang Jing Wen Yulong Wei Inner Mongolia Agricultural University HohhotInner Mongolia Autonomous Region010018China

The effects of different management measures on the undergrowth diversity of Larix gmelinii forests were *** undergrowth vegetation of Xing'an Larch forest under seven different transformation methods was investigated in the Chaocha Forest Farm of the Genhe Forestry Bureau in the northern Daxinganling *** composition,structural characteristics,species diversity and biomass of seven different retrofitting methods and one control *** results showed that the species composition of Larix gmeliniii under 7 different transformation methods included 34 species of 30 genera and 21 families of shrubs,including 7 species,7 genera and 7 species of shrub layer,and 20 species,24 genera and 24 species of common species in the herb *** species with the largest proportion in the layer is bilberry,followed by Xing'an rhododendron,and the dominant species of herbaceous layer is quite *** terms of diversity index,the diversity index of Xing'an larch forest under local tending artificial promotion natural regeneration and transformation measures was low(P<0.05);the study showed that the best tending thinning intensity was between 30%and 40%,*** impact of the transformation method on the structure and diversity of understory vegetation in Larix gmelinii forest is not only related to the transformation,but also depends on the transformation measures taken.

关键词： Plant diversity Technology of operation Biomass

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兴安落叶松生态系统CO_(2)浓度及其δ^(13)C动态对环境因子的响应

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林业科学 2023年第9期59卷 55-65页

作者：张欣张秋良孙守家王冰内蒙古大学生态与环境学院呼和浩特010021 内蒙古农业大学林学院呼和浩特010019 内蒙古大兴安岭森林生态系统国家野外科学观测研究站根河022350 中国林业科学研究院林业研究所北京100091

【目的】探明环境因子对兴安落叶松原始林生态系统CO_(2)浓度及其δ^(13)C动态的影响,深入理解生态系统的碳交换过程,为模拟和预测全球变化与生态系统之间的互馈机制以及科学评估寒温带森林生态系统碳汇能力提供参考。【方法】采用离轴... 详细信息

【目的】探明环境因子对兴安落叶松原始林生态系统CO_(2)浓度及其δ^(13)C动态的影响,深入理解生态系统的碳交换过程,为模拟和预测全球变化与生态系统之间的互馈机制以及科学评估寒温带森林生态系统碳汇能力提供参考。【方法】采用离轴积分腔输出光谱技术对兴安落叶松生态系统不同物候期、不同高度的CO_(2)浓度及其δ^(13)C进行连续高频观测,并分析环境因子与CO_(2)浓度变化的关系。【结果】1)兴安落叶松生态系统不同高度的CO_(2)浓度在生长季和日尺度上均呈单峰变化,峰值分别出现在展叶期(522.34μmol·mol^(-1))和凌晨(782.81μmol·mol^(-1)),谷值分别出现在落叶期(406.07μmol·mol^(-1))和中午(379.72μmol·mol^(-1));δ^(13)C变化趋势与CO_(2)浓度相反;2)CO_(2)浓度随垂直高度升高而减小,δ^(13)C随垂直高度升高而增大;不同高度的CO_(2)浓度及其δ^(13)C具有明显成层现象,夜间大气稳定性增加(理查逊数Ri≥0.083)会加剧冠层内外的差异;3)在0.5h尺度上,影响昼夜各高度CO_(2)浓度变化的主要因子为空气温度(T_(a))(0.714

关键词： CO_(2)浓度碳同位素环境因子兴安落叶松

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Irrigation and nitrogen fertiliser optimisation in protected vegetable fields of northern China:Achieving environmental and agronomic sustainability

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Journal of Integrative Agriculture 2024年第3期23卷 1022-1033页

作者： Bingqian Fan Yitao zhang Owen Fenton Karen Daly Jungai Li Hongyuan Wang Limei Zhai Xiaosheng Luo qiuliang Lei Shuxia Wu Hongbin Liu State Key Laboratory of Efficient Utilization of Arid and Semi-arid Arable Land in Northern China/Key Laboratory of Nonpoint Source Pollution Control Ministry of Agriculture and Rural Affairs/lnstitute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijing 100081China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China Teagasc Environmental Research CentreWexford Y35Ireland Institute of Plant Nutrition Resources and Environmental SciencesHenan Academy of Agricultural SciencesZhengzhou 450002China

Globally,sub-optimal use of nitrogen (N) fertiliser and elevated N irrigation groundwater have led to high leached nitrate (NO_(3)^(–)) losses from protected vegetable field *** fertiliser and irrigation management in different soil types is crucial to reduce future N loads from such *** present 4-year study examined leached N loads from lysimeter monitoring arrays set up across 18 protected vegetable system sites encompassing the dominant soil types of northern *** treatments applied at each field site were:1) a high N and high irrigation input treatment (HNHI);2) a low N but high irrigation input treatment (LNHI) and 3) a low N with low irrigation input treatment (LNLI).Results showed that the mean annual leached total nitrogen loads from the HNHI,LNHI and LNLI treatments were 325,294 and 257 kg N ha^(–1) in the fluvo-aquic soil,114,100 and 78 kg N ha^(–1) in the cinnamon soil and 79,68 and 57 kg N ha^(–1) in the black soil,*** N dissolved in irrigation water in the fluvo-aquic soil areas was 8.26-fold higher than in the cinnamon areas.A structural equation model showed that N fertiliser inputs and leaching water amounts explained 14.7 and 81.8%of the variation of leached N loads,***,reducing irrigation water by 21.5%decreased leached N loads by 20.9%,while reducing manure N and chemical N inputs by 22 and 25%decreased leached N loads by only 9.5%. This study highlights that protected vegetable fields dominated by fluvo-aquic soil need management to curtail leached N losses in northern China.

关键词： agriculture water quality nitrate groundwater irrigation management

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Achievement of a high-performance 30-tesla metal-as-insulated user superconducting magnet

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Science China(Technological Sciences) 2024年第6期67卷 1974-1978页

作者： ZHOU BenZhe DAI YinMing zhang ZiLi LIU Hui WANG YaoHui WANG Lei WANG Hui CHEN ShunZhong WANG KangShuai CHEN Yong LIU JianHua WANG qiuliang Institute of Electrical Engineering Chinese Academy of Sciences University of Chinese Academy of Sciences

Strong magnetic fields can be used to manipulate the states of matter and induce unique ***,they enable a thorough investigation of the intrinsic properties of matter through the application of the nuclear magnetic resonance(NMR)*** versatile nature of strong magnetic fields facilitates the discovery of novel phenomena and patterns.

关键词： effect NMR versatile

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Effect of Magnetic Field Configuration on Stray-Crystal Formation with Different Platform Sizes during Directional Solidification of Single-Crystal Superalloy

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Acta Metallurgica Sinica(English Letters) 2024年第5期37卷 904-914页

作者： Keke Lu Congjiang zhang Xiaotan Yuan Hongbin Yu Weili Ren Biao Ding Haibiao Lu Yunbo Zhong Zuosheng Lei Hui Wang qiuliang Wang Peter KLiaw Xuezhi Qin Lanzhang Zhou State Key Laboratory of Advanced Special Steel Shanghai Key Laboratory of Advanced FerrometallurgyShanghai UniversityShanghai 200444China Institute of Electrical Engineering Chinese Academy of SciencesBeijing 100190China Department of Materials Science and Engineering The University of TennesseeKnoxvilleTN 37996USA Institute of Metal Research Chinese Academy of SciencesShenyang 110016China

The magnetic field is an effective means to control the solidification structure and the defects of metal and semiconductor *** work investigates the effects of Cusp magnetic field(CMF)and longitudinal magnetic field(LMF)on the stray-crystal formation in the platform regions during the directional solidification of single-crystal superalloy with the different cross section *** application of CMF reduces the formation of platform stray-crystal,while LMF increases its *** the platform size increases,the stray-crystal ratio increases regardless of whether the magnetic fields are applied or not,the effectiveness of CMF increases,while that of LMF *** reason that the effects of CMF and LMF on the platform stray-crystal formation could be attributed to the change of flow structure from the distribution characteristics of the thermoelectric magnetic force and the magnetic damping force near the liquid-solid interface.

关键词： Stray-crystal Magnetic field Single-crystal superalloy Cross section change Directional solidification

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大兴安岭兴安落叶松林下植被多样性及土壤养分季节分布特征

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水土保持学报 2015年第6期29卷 124-130页

作者：杨丽张秋良内蒙古农业大学林学院呼和浩特010019

研究了内蒙古大兴草类—兴安落叶松林(HLV)、杜香—兴安落叶松林(LLV)、藓类—兴安落叶松林(MLV)下植被多样性及土壤养分季节分布特征。结果表明:(1)3种林地植被丰富度指数、多样性指数、优势度指数、均匀性指数随着季节的变化呈先增加... 详细信息

研究了内蒙古大兴草类—兴安落叶松林(HLV)、杜香—兴安落叶松林(LLV)、藓类—兴安落叶松林(MLV)下植被多样性及土壤养分季节分布特征。结果表明:(1)3种林地植被丰富度指数、多样性指数、优势度指数、均匀性指数随着季节的变化呈先增加后降低趋势,以秋季最高;相同季节,3种林地植被丰富度指数、多样性指数、优势度指数、均匀性指数基本表现为HLV>LLV>MLV,局部有所波动。(2)3种林地土壤温度、土壤湿度和土壤电导率随着季节的变化呈先增加后降低趋势,土壤pH值随着季节的变化呈先降低后增加趋势。(3)3种林地土壤有机碳、全氮、全钾和土壤酶活性(纤维素酶、脲酶、酸性磷酸酶、蔗糖转化酶和过氧化氢酶)随着季节的变化呈先增加后降低趋势,在秋季达到最高,春季最低,土壤有机碳、全氮和全钾基本表现为HLV>LLV>MLV,局部有所波动,全磷没有明显的变化规律。(4)3种林地土壤养分和土壤酶活性均表现为腐殖层>沉淀层,其中土壤全磷在腐殖层和沉淀层没有显著差异(P>0.05)。(5)偏相关分析表明影响草类—兴安落叶松林(HLV)植被多样性的主要因子是土壤有机碳、酸性磷酸酶和转化酶;影响杜香—兴安落叶松林(LLV)植被多样性的主要因子是土壤pH值、有机碳、全氮、转化酶和过氧化氢酶;影响藓类—兴安落叶松林(MLV)植被多样性的主要因子是土壤有机碳、全氮和纤维素酶。(6)主成分分析表明土壤有机碳、全氮和过氧化氢酶是兴安落叶松林土壤养分的主要影响因子。

关键词：大兴安岭兴安落叶松植被多样性土壤养分季节分布

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