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祁连山北麓青海云杉林天然更新对土壤理化性质的响应

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中南林业科技大学学报 2024年第7期44卷 90-100页

作者：许尔文牛赟赵维俊敬文茂武秀荣赵晶忠马雪娥任小凤甘肃省祁连山水源涵养林研究院甘肃祁连山森林生态系统国家定位观测研究站甘肃张掖734000 淮阴师范学院江苏淮安223300

【目的】青海云杉是我国青藏高原东北边缘的特有树种,研究其天然更新对土壤物理性质的响应,从而为祁连山青海云杉次生林的恢复和管理及可持续利用提供基础理论依据。【方法】通过对分布在祁连山排露沟流域的青海云杉林设置海拔梯度固定... 详细信息

【目的】青海云杉是我国青藏高原东北边缘的特有树种,研究其天然更新对土壤物理性质的响应,从而为祁连山青海云杉次生林的恢复和管理及可持续利用提供基础理论依据。【方法】通过对分布在祁连山排露沟流域的青海云杉林设置海拔梯度固定样地,进行天然更新苗调查和土壤容重、水分、pH、有机碳、氮磷钾全量及其速效养分等理化性质的取样和测定,分析青海云杉林天然更新苗对土壤理化性质的响应。【结果】各海拔区段的青海云杉林更新指数从大到小依次为2 800~2 900 m(0.63)>2 700~2 800 m(0.58)>3 100~3 300 m(0.57)>2 900~3 100 m(0.56),其中更新状况最好的海拔区段是2 800~2 900 m。土壤质量含水量、有机碳、全氮、水解氮含量在海拔区段H_(1)和H_(2)处显著小于海拔区段H_(3)和H_(4)(P0.05),土壤全磷和速效磷含量在海拔区段H_(2)显著大于其他海拔区段(P0.05),速效磷在海拔区段H_(4)含量最小,海拔区段H_(1)和H_(3)速效磷差异性不显著(P<0.05)。相关性分析表明,海拔区段2 800~2 900 m的更新指数仅与土壤容重、全磷、速效磷呈显著正相关(P<0.05),更新指数与土壤理化性质之间相关系数绝对值的最大值主要集中在该海拔区段。更新指数与土壤剖面不同土层的质量含水量、有机碳、全氮、水解氮均呈显著负相关(P<0.05),与容重、全磷含量均呈显著正相关(P<0.05);与20~40 cm土层的速效磷呈显著正相关(P<0.05)。主成分分析表明,土壤有机碳、速效磷和全磷含量是影响青海云杉林天然更新的主要因子。【结论】祁连山青海云杉林天然更新与土壤理化性质之间的相互作用是密切的,特别是土壤中的有机碳累积和磷素养分的释放。

关键词：青海云杉林天然更新土壤理化性质祁连山排露沟流域

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祁连山自然保护区砂石料场植被多样性分析

防护林科技 2024年第3期 19-21,27页

作者：薛春许尔文赵维俊敬文茂安洁琼杨斌甘肃省祁连山水源涵养林研究院甘肃张掖734000 甘肃祁连山国家级自然保护区管护中心隆畅河自然保护站甘肃张掖734400

选择祁连山自然保护区4处典型砂石料场植被恢复地为研究对象,研究其植被恢复技术和林下草本植被的物种多样性。结果表明:砂石料场植被恢复技术主要是采坑回填、废弃渣堆平整、河道清淤、废弃建筑物拆除、排导堤修筑、围栏封育、覆土、... 详细信息

选择祁连山自然保护区4处典型砂石料场植被恢复地为研究对象,研究其植被恢复技术和林下草本植被的物种多样性。结果表明:砂石料场植被恢复技术主要是采坑回填、废弃渣堆平整、河道清淤、废弃建筑物拆除、排导堤修筑、围栏封育、覆土、种植单一的乔木或灌木以及草本植物种。林下植物以冷地早熟禾(Poa crymophila)和垂穗披碱草(Elymus nutans)占据优势地位,其他植物种处于劣势地位。林下植被Margalef物种丰富度指数、Simpson多样性指数、Shannon-Wiener多样性指数和Pielous均匀度指数均偏小,植物多样性维持在较低水平。建议继续加强祁连山自然保护区砂石料场植被恢复区的经营和管理。

关键词：祁连山自然保护区砂石料场植被恢复植被多样性

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祁连山祁丰矿区废弃矿山植被恢复调查分析

防护林科技 2024年第2期 57-60页

作者：许尔文赵维俊敬文茂王顺利张克海车宗伟甘肃省祁连山水源涵养林研究院甘肃张掖734000 甘肃祁连山国家级自然保护区管护中心祁丰自然保护站甘肃张掖735015

为了解祁连山祁丰矿区植被恢复情况,以期为该地区的废弃矿山植被恢复和重建提供理论依据,在该矿区选择包括石灰石矿、煤矿、铜矿、多金属矿、石英岩矿的5处典型废弃矿山为研究对象,通过设置植被样方并进行植被群落结构调查。结果表明:... 详细信息

为了解祁连山祁丰矿区植被恢复情况,以期为该地区的废弃矿山植被恢复和重建提供理论依据,在该矿区选择包括石灰石矿、煤矿、铜矿、多金属矿、石英岩矿的5处典型废弃矿山为研究对象,通过设置植被样方并进行植被群落结构调查。结果表明:废弃矿山的主要恢复措施为建筑物及废弃设施拆除、垃圾清理、渣堆整平、废弃探采坑洞的回填及刷坡整平、覆土、人工平土、植草绿化、纤丝石笼挡墙、道路翻耕、封育围栏等。从植被恢复效果看,土壤层较厚(蓄水能力强)的矿点及有灌溉条件的矿点,其植被恢复效果好;而土壤层较薄或无灌溉条件的矿点,其植被恢复效果差一些。因此,建议继续坚持人工修复和自然修复相结合,同时加强植被生态恢复后的后期管理,使矿山植被生态系统恢复进入良性循环。

关键词：祁连山祁丰矿区植被恢复植物多样性

Response of Grassland Biomass to Soil Moisture in the Arid Mountainous Area of the Qilian Mountains

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Journal of Landscape Research 2018年第1期10卷 77-82页

作者： WANG Shunli WANG Rongxin jing wenmao ZHAO Weijun NIU Yun MA Jian ZHU Hong Academy of Water Resources Conservation Forest of Qilian Mountains of Gansu Province Zhangye Gansu 734000 China Northwest Research Institute of Mining and Metallurgy Baiying Gansu 730900 China

The Pailugou watershed of the Qilian Mountains in the arid region of northeast China was selected for research to analyze the species, height, and biomass in typical mountain grassland with an altitude of 2,700–3,000 m and measure soil moisture, so as to explore the seasonal characteristics of grassland biomass as altitude increases and the relationship between grassland biomass and soil moisture. The results showed that:(1) with a mean value of 135.36 g/m^2, grassland aboveground biomass showed a unimodal distribution from rise to decline as altitude increased, and reached its maximum of 176.79 ± 28.37 g/m^2 at an altitude of 2,900 m; with a mean value of 946.13 g/m^2, grassland underground biomass showed an uptrend as altitude increased, and reached its maximum of 1,301.19 ± 68.24 g/m^2 at an altitude of 3,000 m;(2) the difference between aboveground biomass and underground biomass in the grassland at different altitudes was significant;(3) values of root shoot ratio of the arid mountain grassland varied between 4.14–11.95;(4) values of soil moisture content of the arid mountain grassland varied between 9.23%–31.31%;(5) there was a positive correlation between aboveground biomass and underground biomass and the mean soil moisture content(p < 0.05), with a correlation coefficient of 0.778 4 and 0.784 3 respectively, soil layers with different moisture content made different contributions to grassland biomass, and moisture content in the soil layer where over-60-cm root systems were located was of significance to grassland biomass.

关键词： Mountain grassland Biomass Soil moisture Qilian Mountains

1965—2018年祁连山北麓及其附近地区气温与降水变化的时空格局

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高原气象 2022年第4期41卷 876-886页

作者：敬文茂任小凤赵维俊甘肃省祁连山水源涵养林研究院甘肃张掖734000 甘肃张掖生态科学研究院甘肃张掖734000 甘肃省祁连山生态环境研究中心甘肃兰州730000

基于祁连山北麓及其附近地区12个气象站点54年(1965-2018年)的气温和降水的监测数据,采用线性回归、Mann-Kendall趋势检验、Morlet小波变换法等分析方法,对其气温和降水的时间动态与空间格局进行了分析。研究表明:(1)多年平均气温、最... 详细信息

基于祁连山北麓及其附近地区12个气象站点54年(1965-2018年)的气温和降水的监测数据,采用线性回归、Mann-Kendall趋势检验、Morlet小波变换法等分析方法,对其气温和降水的时间动态与空间格局进行了分析。研究表明:(1)多年平均气温、最高气温与最低气温的变化趋势均为上升趋势,增幅分别为0.33℃·(10a)^(-1)、0.44℃·(10a)^(-1)和0.21℃·(10a)^(-1),气温在1998年发生显著突变;多年平均降水量、最大值呈波动上升的趋势,最小值呈下降趋势,变幅分别为4.28 mm·(10a)^(-1)、16.98 mm·(10a)^(-1)和-4.30 mm·(10a)^(-1),1971年和1994年降水量发生了由少到多的突变;气温和降水的季节性变化趋势相一致,均为持续上升,且以冬季显著上升为显著特征,二者的年代际演化在20世纪90年代呈现出持续上升的趋势。(2)气温和降水整体上表现出由东南向西北递减的趋势,形成了以张掖、高台为分界线,以东增温增湿速度较快,以西增温增湿速度较缓的空间格局,气候整体呈变暖变湿的趋势。(3)年平均气温在54年尺度内存在13年的强显著周期和6年、27年尺度变化周期;年均降水存在8年和20年的强显著周期和2年、27年的小尺度变化周期。

关键词：祁连山气温和降水时间序列空间格局

Ni-Cu bimetallic alloy anchored on nitrogen-doped carbon nanotubes for CO_(2)-to-CH_(4) electrochemical conversion

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Nano Research 2024年第8期17卷 6922-6930页

作者： jing Li Chuanyong jing Jin Wang School of Environment Beijing Key Laboratory of Aqueous Typical Pollutants Control and Water Quality SafeguardBeijing Jiaotong UniversityBeijing 100044China State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China Tangshan Research Institute Beijing Jiaotong UniversityTangshan 063000China

Electrocatalytic CO_(2) reduction to CH_(4) remains challenging due to multi-electron transfer and intermediates ***,we synthesized electrocatalysts by growing Ni-Cu alloy structure on nitrogen-doped carbon nanotubes(NixCuy-NCNT)for electrocatalytic CO_(2) reduction reaction(CO_(2)RR)via hydrothermal method followed by *** optimized Ni_(1)Cu_(1)-NCNT demonstrated a superior CO_(2)RR performance,achieving 99.7%FECH_(4)(FE=Faradaic efficiency)and 11.54 mA·cm^(−2) current density at−1.2 V *** hydrogen electrode(RHE),which outperformed single metal *** outstanding performance was due to the electrons transferred from Cu to Ni and Ni-Cu alloy shifted the d-band center toward the Fermi level,which was more conducive to the intermediate *** situ electrochemical attenuated total reflection(EC-ATR)and density functional theory(DFT)calculations revealed the appearance of *CHO intermediate and the pathway during the CO_(2)RR *** design of the bimetallic electrocatalyst in this study provides a new perspective for the highly selective reduction of CO_(2).

关键词： electrocatalytic CO_(2) reduction Ni-Cu alloy nitrogen-doped carbon nanotube(NCNT) electrochemical attenuated total reflection(EC-ATR) density functional theory(DFT)calculations

An uncertainty investigation for liner impedance eduction methods

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Chinese Journal of Aeronautics 2024年第3期37卷 49-59页

作者： Weihao SHI Xiaodong jing School of Energy and Power Engineering Beihang UniversityBeijing 100191China

Impedance eduction methods have been developed for decades to meet the increasing need for high-quality impedance data in the design and optimization of acoustic *** this end,it is important to fully investigate the uncertainty problem,to which only limited attention has been devoted so *** paper considers the possibility of acoustically-induced structural vibration as a nonnegligible uncertainty or error source in impedance eduction *** the frequency moves away from the resonant frequency,with the increase in the value of cavity reactance,the acoustic particle velocity inside liner orifices possibly decreases to the extent comparable to the vibration velocity of liner facing ***,the acoustically-induced vibration,although generally being weak except at the inherent structural frequencies,may considerably affect the impedance eduction results near the anti-resonant frequency where the liner has poor *** demonstrate the effect of structural vibration,the vibration velocity of liner facing sheet is estimated from the experimentally educed admittance of the liner samples whose orifices are sealed with ***,a three-dimensional numerical model is set up,in which normal particle velocity is introduced over the solid portion of liner facing sheet to imitate structural vibration,rather than directly solving the acoustic-structural coupling *** shown by the results,the vibration of liner facing sheet,whose velocity is as small as estimated by the experiment,can result in anomalous deviation of the educed impedance from the impedance model near the anti-resonant *** trend that the anomalous deviation varies with frequency is numerically captured.

关键词： Impedance eduction Uncertainty analysis Acoustically-induced structural vibration Anti-resonant frequency Perforated liner

A review on numerical studies of airflow dynamics and particle deposition in human respiratory system Author links open overlay panel

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Particuology 2024年第8期91卷 351-377页

作者： Hao jing Xinguang Cui School of Aerospace Engineering Huazhong University of Science and TechnologyWuhan430074China

Accurate assessment and prediction of airflow dynamics and particle deposition in the human respiratory tract are essential for human health,involving inhaled drugs for treating various diseases and toxic particles that can cause *** intricate process involves complex multiphase flow with distinct respiratory *** fluid dynamics(CFD)acts as a bridge,overcoming the limitations of in vivo and in vitro experiments and providing a means to fully comprehend and reveal the fundamental mechanisms of respiratory flow and particle behavior on a microscopic *** paper provides a comprehensive overview and concise summary of recent advancements in the numerical simulation of airflow and particle deposition in the human respiratory ***,it summarizes the transition of respiratory tract models from segmented models to emerging physiological characteristic models and whole-lung airway models,and the latest developments on the effects of key factors such as geometric variations,respiratory patterns,and particle physical/chemical properties on respiratory flow and particle deposition.A notable focus of this review is on emerging physiological characteristics models and their associated complex airflow and particle dynamics inside *** paper concludes with recommendations for future research to further advance the development of this field.

关键词： Airflow dynamics Particle deposition Human respiratory system Numerical modeling

Robust adaptive radar beamforming based on iterative training sample selection using kurtosis of generalized inner product statistics

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Journal of Systems Engineering and Electronics 2024年第1期35卷 24-30页

作者： TIAN jing ZHANG Wei School of Information and Electronics Beijing Institute of TechnologyBeijing 100081China National Key Laboratory of Electromagnetic Space Security Chengdu 610036China

In engineering application,there is only one adaptive weights estimated by most of traditional early warning radars for adaptive interference suppression in a pulse reputation interval(PRI).Therefore,if the training samples used to calculate the weight vector does not contain the jamming,then the jamming cannot be removed by adaptive spatial *** the weight vector is constantly updated in the range dimension,the training data may contain target echo signals,resulting in signal cancellation *** cope with the situation that the training samples are contaminated by target signal,an iterative training sample selection method based on non-homogeneous detector(NHD)is proposed in this paper for updating the weight vector in entire range *** principle is presented,and the validity is proven by simulation results.

关键词： adaptive radar beamforming training sample selection non-homogeneous detector electronic jamming jamming suppression