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Effects of fencing on vegetation and soil restoration in a degraded alkaline grassland in northeast China

Journal of Arid Land 2014年第4期6卷 478-487页

作者： Qiang LI DaoWei ZHOU YingHua JIN MinLing WANG yantao song GuangDi LI Northeast Institute of Geography and Agroecology Chinese Academy of Sciences University of Chinese Academy of Sciences School of Geography Science Northeast Normal University Graham Centre for Agricultural Innovation New South Wales Department of Primary Industries and Charles Sturt University

In order to restore a degraded alkaline grassland, the local government implemented a large restoration project using fences in Changling county, Jilin province, China, in 2000. Grazing was excluded from the protected area, whereas the grazed area was continuously grazed at 8.5 dry sheep equivalent（DSE）/hm2. In the current research, soil and plant samples were taken from grazed and fenced areas to examine changes in vegetation and soil properties in 2005, 2006 and 2008. Results showed that vegetation characteristics and soil properties improved significantly in the fenced area compared with the grazed area. In the protected area the vegetation cover, height and above- and belowground biomass increased significantly. Soil pH, electrical conductivity and bulk density decreased significantly, but soil organic carbon and total nitrogen concentration increased greatly in the protected area. By comparing the vegetation and soil characteristics with pre-degraded grassland, we found that vegetation can recover 6 years after fencing, and soil pH can be restored 8 years after fencing. However, the restoration of soil organic carbon, total nitrogen and total phosphorus concentrations needed 16, 30 and 19 years, respectively. It is recommended that the stocking rate should be reduced to 1/3 of the current carrying capacity, or that a grazing regime of 1-year of grazing followed by a 2-year rest is adopted to sustain the current status of vegetation and soil resources. However, if N fertilizer is applied, the rest period could be shortened, depending on the rate of application.

关键词： vegetation and soil restoration fencing grazing alkaline soil semi arid region grassland degradation

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基于随机森林算法的羌塘草原NDVI时空格局及预测模型

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生态学杂志 2024年第6期43卷 1664-1673页

作者：李彩琳宋彦涛张靖乌云娜孙磊大连民族大学环境与资源学院辽宁大连116600 西藏农牧学院动物科学学院西藏林芝860000

为揭示羌塘草原2001—2020年植被时空变化格局及其影响因素,并预测气候变化条件下羌塘草原植被可能的变化趋势,本研究基于MODIS NDVI数据以及温度、降水和风速数据,探究了羌塘草原植被覆盖变化与气象因子的关系;利用随机森林、支持向量... 详细信息

为揭示羌塘草原2001—2020年植被时空变化格局及其影响因素,并预测气候变化条件下羌塘草原植被可能的变化趋势,本研究基于MODIS NDVI数据以及温度、降水和风速数据,探究了羌塘草原植被覆盖变化与气象因子的关系;利用随机森林、支持向量机和随机梯度下降回归3种机器学习算法建立NDVI预测模型,筛选模拟精度最优模型,进行多情景下植被变化模拟。结果表明:2001—2020年羌塘草原NDVI呈现轻微增加趋势,增长率为0.0003 a^(-1)。NDVI对温度的响应滞后3个月,降水滞后0~1个月,NDVI与风速呈负相关且无滞后。随机森林算法的模拟精度最高(Adjusted R2=0.958)。未来植被覆盖度整体提升的情景是增温1.0℃、降水增加25%、风速降低25%。研究结果有助于预警植被退化问题,为气候变化背景下该区域植被生态保护提供科学依据。

关键词：羌塘草原归一化植被指数随机森林多情景模拟

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基于对比学习的时间序列聚类方法

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计算机科学 2024年第2期51卷 63-72页

作者：杨博罗嘉琛宋艳涛吴宏涛彭甫镕山西大学大数据科学与产业研究院太原030006 山西大学计算机与信息技术学院太原030006 山西省交通科技研发有限公司太原030006

现有深度聚类方法严重依赖于复杂的特征提取网络和聚类算法,难以直观地定义时间序列的相似性。使用对比学习的方法可以从正负样本数据的角度定义时间序列的区间相似性,并对特征提取和聚类进行联合优化。基于对比学习的思想,提出了一种... 详细信息

现有深度聚类方法严重依赖于复杂的特征提取网络和聚类算法,难以直观地定义时间序列的相似性。使用对比学习的方法可以从正负样本数据的角度定义时间序列的区间相似性,并对特征提取和聚类进行联合优化。基于对比学习的思想,提出了一种不依赖于复杂表示网络的时间序列聚类模型。同时,为解决现有时间序列数据增强方法难以描述时间序列的变换不变性的问题,提出了一种基于时间序列形状特征的数据增强方法,在忽略数据时域特征情况下捕捉序列的相似性。模型通过设置不同的形状转换参数构造正负样本对,学习特征表示并投影到特征空间,在实例级对比和聚类级对比层面利用交叉熵损失最大化正样本对相似性,最小化负样本对相似性,实现了端到端的联合学习表示和聚类分配。在32个UCR中的数据集上进行了大量实验,结果表明该模型可以在不依赖于特定表示学习网络的情况下得到与现有方法相当或优于现有方法的聚类结果。

关键词：时间序列聚类对比学习数据增强表示学习联合优化

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Effect of Autumn Cutting Date on Regrowth, Turning Green, Yield and Quality of <i>Leymus chinensis</i>Grassland in songnen Plain, Northeast China

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American Journal of Plant Sciences 2018年第2期9卷 185-195页

作者： yantao song &ensp Wuyunna Daowei Zhou College of Environment and Bioresources Dalian Minzu University Dalian China Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Changchun China

A field study was carried out to quantify the effects of different cutting time on Leymus chinensis population and community characteristic in songnen grassland of northeast China from August, 2006 to August, 2007. The treatment interval was ten days with the remaining stubble height of 5 cm from 15th August to 4th October in 2006. Results showed that the L. chinensis made up about 90% of the dry matter of aboveground biomass, and there were about ten species in the L. chinensis community in the 1 m × 1 m plot. The L. chinensis and Kalimeris integrifolia regrew rapidly after autumn cutting in 2016. In the second year, the coefficients of the community similarity were high between the different cutting time treatments. The density, height, aboveground biomass, stem/leaf ratio, and crude protein of L. chinensis were not significant at the turning green stage and harvesting stage, the companion species of L. chinensis community contained higher crude protein, but the crude protein of the plant community were not significant. Thus, considering the weather factor for haymaking, the harvest dates should be concentrated from the middle ten days of August to the first ten days in September.

关键词： Leymus chinensis Autumn Cutting Hay Yield Quality songnen Grass-land

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断桥铝合金门窗防渗漏构造技术研究与应用

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建设科技 2024年第3期 45-47,51页

作者：宋延涛石海明蒋利利武天杰北京城建北方众邦装饰工程有限公司北京101399

断桥隔热铝合金窗与传统的塑钢门窗、铝塑门窗相比具有良好的隔热性能和防风性能,在建筑行业的应用非常广泛。但仍存在框梃密封不严、排水阀倒灌、框扇组角位置开裂、窗扇角部胶条老化等问题,极易引发渗漏风险。本技术针对断桥铝合金门... 详细信息

断桥隔热铝合金窗与传统的塑钢门窗、铝塑门窗相比具有良好的隔热性能和防风性能,在建筑行业的应用非常广泛。但仍存在框梃密封不严、排水阀倒灌、框扇组角位置开裂、窗扇角部胶条老化等问题,极易引发渗漏风险。本技术针对断桥铝合金门窗密封工艺、窗框组合部位优化以及创新应用地漏式排水阀,有效改善门窗渗漏问题,具有一定推广价值。

关键词：高性能系统窗防渗漏注胶工艺

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施肥和刈割对呼伦贝尔草甸草原羊草叶绿素含量的影响

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大连民族大学学报 2024年第1期26卷 7-11页

作者：方乘风宋彦涛乌云娜徐鑫磊岳铁军倩娜大连民族大学环境与资源学院辽宁大连116605 赤峰市乡村振兴局内蒙古赤峰024000 内蒙古自治区国土空间规划院内蒙古呼和浩特0100110

施肥和刈割是草地管理的重要措施。以内蒙古呼伦贝尔草甸草原优势种羊草(Leymus Chinensis)为研究对象,分析施肥与不同刈割留茬高度对羊草叶片叶绿素含量的影响。结果表明:施肥显著增加羊草叶片叶绿素的含量,刈割对羊草叶片叶绿素含量... 详细信息

施肥和刈割是草地管理的重要措施。以内蒙古呼伦贝尔草甸草原优势种羊草(Leymus Chinensis)为研究对象,分析施肥与不同刈割留茬高度对羊草叶片叶绿素含量的影响。结果表明:施肥显著增加羊草叶片叶绿素的含量,刈割对羊草叶片叶绿素含量无显著性影响,施肥和刈割交互作用不显著;不同年际间羊草叶片叶绿素含量存在显著差异,留茬高度为9 cm和12 cm羊草叶片叶绿素含量变异最小,羊草叶片叶绿素含量与羊草地上生物量、相对生物量均无显著相关性。

关键词：留茬高度相对生物量变异系数草甸草原

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Asymmetrically ligated single atomic nickel sites for efficient hydrogen peroxide electrosynthesis

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Nano Research 2024年第3期17卷 1094-1100页

作者： Xusheng Cheng Jinwen Hu Wenzhe Shang Jingya Guo Cuncun Xin songlin Zhang Suchan song Wei Liu yantao Shi State Key laboratory of Fine Chemicals Frontier Science Center for Smart MaterialsSchool of ChemistryDalian University of TechnologyDalian 116024China

Atomic transition-metal-nitrogen-carbon electrocatalysts hold great promise as alternatives to benchmark Pt in the oxygen reduction reaction.The pristine metal centers with quasi square-planar D_(4h) configuration,however,still suffer from unfavorable energetics and thereby strong activity/selectivity trade-off during the catalytic process.Here we present a ligand-field engineering of single-atom Ni-N-C catalysts to boost the sluggish kinetics via rationally constructing prototypical asymmetrically ligated Ni-N_(3)O_(1) sites.The as-obtained Ni-supported multi-walled carbon nanotubes with molten salt-treated(defined as Ni/CNS)catalyst delivered an excellent H_(2)O_(2) selectivity(>90%)within a wide potential window(0.2–0.7 V vs.reversible hydrogen electrode(RHE))and robust stability(for 10 h)in alkaline medium.Combined electron paramagnetic resonance and theoretical analysis rationalize this finding and demonstrate that the broken symmetry facilitates the electron transfer of a σ* to O–O orbital as compared to the Ni-N_(4) counterpart,playing an indispensable role in efficient O_(2) activation.

关键词： broken D4h single nickel sites oxygen reduction H_(2)O_(2)production

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Effects of vegetation height and density on soil temperature variations

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Chinese Science Bulletin 2013年第8期58卷 907-912页

作者： song yantao ZHOU DaoWei ZHANG HongXiang LI GuangDi JIN YingHua LI Qiang Institute of Grassland Science Northeast Normal University Key Laboratory of Vegetation Ecology Ministry of Education Northeast Institute of Geography and Agroecology Chinese Academy of Sciences Graham Centre for Agricultural Innovation (alliance between Industry&Investment NSW and Charles Sturt University) Wagga Wagga Agricultural Institute

Reduction in vegetation cover caused by human activities has a great impact on soil temperature. It is important to assess how soil temperature responds to reduction of vegetation height and density. In this paper we first report the trends of mean annual soil surface and air temperatures recorded at the meteorological stations near the Ecological Research Station for Grassland Farming (ERSGF) from 1961 to 2007, then we setup an experiment using reed (Phragmites australis) stalks with different heights and densities to simulate effects of different vegetation height and density on soil and air temperatures. The warming rates of the mean annual soil and air temperatures were 0.043 and 0.041C a 1 , respectively. Changes of soil temperature were characterized by both increased mean annual maximum and minimum soil temperatures. At the experimental site, mean daily temperature, mean daily maximum soil and air temperatures increased significantly. In contrast, mean daily minimum soil temperature increased significantly while mean daily minimum air temperature decreased significantly as the height and density of reed stalks reduced during the experimental period. Mean diurnal soil temperature ranges were smaller than mean diurnal air temperature ranges. These results highlight that the importance of vegetation cover on soil and air temperatures.

关键词：土壤温度植被高度密度空气温度气温记录植被覆盖实验场地温度范围

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The Developing Process of Western Political Conflict Theory

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学术界 2010年第12期 259-261页

作者： song yantao School of Public Administration University of International Business and Economics

There are a few scholars doing research of the history of western political conflict theory,whose field is almost blank.But there still exists a few explorations.In the ancient Greece,Plato already interpreted the conflict,but political conflict theory as an important part of modern conflict politics is formed in the modern democratic capitalist countries.Its essence is to demonstrate the rationality of the capitalist rule,and try to prove that the formed nonviolent conflict democratic countries will be permanent.In fact,the existence of nonviolence political conflicts still cannot solve the inherent contradictions of capitalism.The paper consists of three parts:the understanding of conflict in ancient Greek times;the initial formation of modem political conflict theory;the problems of western political conflict theory.

关键词： conflict politics Republic political conflict theory safety valve mechanism

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基于节点偏序关系的路由可用性框架研究

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计算机应用研究 2023年第4期40卷 1160-1164,1171页

作者：胡睿乾耿海军宋艳涛山西大学计算机与信息技术学院太原030006 山西大学大数据科学与产业研究院太原030006 山西大学自动化与软件学院太原030006

为了维护路由可用性,需要采取一定的路由保护策略来防止网络故障可能对网络造成的影响。因此,提出了一种基于节点偏序关系的路由可用性框架,该框架首先利用节点之间的偏序关系构造有向无环图,然后根据构造的有向无环图为每个节点计算备... 详细信息

为了维护路由可用性,需要采取一定的路由保护策略来防止网络故障可能对网络造成的影响。因此,提出了一种基于节点偏序关系的路由可用性框架,该框架首先利用节点之间的偏序关系构造有向无环图,然后根据构造的有向无环图为每个节点计算备份下一跳节点。在此框架基础上,根据节点之间的偏序关系提出了四种路由保护方法。实验结果表明,四种路由保护算法都拥有较高的故障保护率,能有效降低故障造成的网络中断,在真实拓扑中故障保护率可以到达89.76%,在模拟拓扑中故障保护率达到98.995%,几乎接近100%。

关键词：路由可用性网络延迟故障保护率备份节点路由保护

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