Results 31 to 40 of about 11,737 (164)
Shuitu Baochi Xuebao, 2005 选择科尔沁沙地典型流动沙丘作为研究对象,分析了流动沙丘土壤水分的时空变化以及土壤水分特征常数的空间变化规律。结果表明,流动沙丘土壤水分受降雨的响应呈现出明显的时空变化特征;土壤容重、凋萎湿度和机械组成的空间变化,由于流动沙丘风蚀运动的复杂化而表现为无规律性;各部位土壤田间持水量和容重随深度具有显著的负相关关系。同时土壤水分特征常数的量化,可以为流动沙丘的综合整治、恢复和开发利用提供一定的理论支持。
刘新平 张铜会 赵哈林 赵学勇 移小勇
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Shuitu Baochi Xuebao, 2020 土壤侵蚀是现代地理环境条件下改变地貌景观的主要过程，也是引起土壤质量退化、沙漠化与石漠化的核心因素，与土壤、生态、水文等多个地表过程密切相关。虽然土壤侵蚀研究需要气候、地质、地貌、土壤、水文、生态等相关学科的基本知识，分析土壤侵蚀发生、发展过程的动力机制，但需要明确界定土壤侵蚀研究的时空尺度。土壤侵蚀与水土保持之间相互联系、相互促进。土壤侵蚀研究的时间尺度以次降雨、月、年为主，研究主题为次降雨侵蚀过程、土壤侵蚀季节变化与年际变化，时间尺度不宜超过100年。土壤侵蚀研究的空间尺度以小流域为主 ...
张光辉
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Submarine groundwater discharge in a subtropical bay and island traced by radium isotopes - Sansha bay and Dongshan island, Fujian [PDF]
, 2016 镭同位素来自母体钍的衰变，钍是强颗粒活性的元素，而其子体镭同位素却有一定的水溶性。223Ra、224Ra、226Ra、228Ra的半衰期分别为11.4天、3.6天、1600年和5.75年，这四种同位素的半衰期差异为近岸海域的水团混合和物质交换提供了重要的方法（Moore，1998）。其中，短半衰期的两种同位素能有效地示踪几天至几十天时间尺度的海洋学过程，而在这时间尺度内，长半衰期镭同位素的自身衰变可以忽略（Moore，1998;Moore，2000）。海底地下水排泄（SGD ...
陈利文
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Spatial-temporal Variation of Water Yield in Nanbei Panjiang River Basin Based on InVEST Model [PDF]
, 2023 [Objective] The temporal and spatial variation characteristics of water yield and differences in the water yield function for different land use types, soil types, and topography in the Nanbei Panjiang River basin were analyzed in order to provide a ...
Chen Quan +5 more
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Synthesizing Empirical Research on Learner Metacognition in Second Language Writing
International Journal of Applied Linguistics, EarlyView.ABSTRACT Despite considerable research interest in learner metacognition in second language (L2) writing, there is not yet a review that synthesizes the existing empirical findings and discusses their implications. To fill the void, this systematic review synthesized 39 empirical studies on learner metacognition in L2 writing and examined their salient
Chen Li, Icy Lee, Zhicheng Mao
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Dianci bileiqi, 2018 复合绝缘子状态评价指标数据变化具有时空特性。复合绝缘子评价指标权重值随时间变化且不同指标数据随时间变化程度不同,具有时间渐变性和时间敏感性的特点,而绝缘子所处空间环境差异影响专家对评价指标主观权重大小认知。依据复合绝缘子所处空间特点确定主观权重,克服复合绝缘子空间特性对权重的影响;以熵权法确定评价指标的客观权重,体现指标数据变化的时间渐变特性;以博弈模型组合主观权重和客观权重,以主观权重值弥补客观权重值无法体现时间敏感性的不足,兼顾复合绝缘子指标权重的时间和空间特性 ...
王勋, 张明瀚, 程宏波, 伦利
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Spatial analysis of urban economics in Guangdong Province [PDF]
, 2017 2013-2014 > Academic research: refereed > Publication in refereed journalVersion of ...
Jin, R, Shi, WZ
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Spatiotemporal Variations and Topographic Differentiation of Fractional Vegetation Cover in Changbai Mountain [PDF]
, 2023 [Objective] The dynamic changes of vegetation and its response relationship with topography in Changbai Mountain were explored in order to provide scientific support for ecological environmental protection and management in this mountainous area ...
Li Wen, Shi Song, Yang Ziyi, Yu Ran
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International Journal of Applied Linguistics, EarlyView.ABSTRACT This study examines how foreign language teachers’ beliefs about the medium of instruction and translanguaging evolve over time by revisiting three in‐service teachers twelve years after their initial interviews. Using a qualitative longitudinal design, the study traces how translanguaging was initially framed as pedagogically deficient but ...
Danping Wang
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The Concentration and Carbon Isotope Characteristics of Dissolved Inorganic Carbon in Jiulong River Tributaries and Estuary [PDF]
, 2015 碳是重要的生源要素，以各种形态贯穿生命全过程；碳循环是生态系统最重要的物质循环之一。本研究应用稳定同位素技术，以九龙江干流西溪、北溪和河口区域为研究对象，对西溪、北溪及九龙江河口区进行了一个水文年的季节性采样调查，分析了表层水体中溶解无机碳含量及其碳稳定同位素组成（δ13CDIC）、悬浮颗粒物有机碳氮含量及稳定同位素组成（δ13CPOC、δ15NPON），并结合其它相关的水体理化参数对九龙江干流至河口区水体溶解无机碳和颗粒有机碳及其碳稳定同位素的时空变化规律及环境控制因素进行了初步探讨，得出以下结论 ...
梁翠翠
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