Results 31 to 40 of about 1,116,957 (194)

石羊河中游荒漠绿洲区土壤水分的分布特征

open access: yesShuitu Baochi Xuebao, 2007
通过田间实验,研究了不同土壤层颗粒组成、土壤水分的分布特征及不同土壤层间土壤水分的关联性。结果表明:(1)土壤颗粒组成决定了不同土壤层的持水性能,是导致土壤水的分布及运动方式发生变化,影响水分在土壤中滞留时间的根本原因,土壤层中的砂砾所占百分数越大,粘粒含量就越少,含水率就越小,壤土中的土壤水分滞留时间远大于砂质土壤。(2)试验区3m内土壤层可分为水分散失带、水分滞留带和水分过渡带,水分滞留带是土壤水分暂时贮存的重要土层,也是为植被提供深层土壤水分的直接来源,对植被的生长及农作物生产有重要的影响 ...
李王成   +4 more
doaj  

荒漠草原不同覆被类型土壤水分动态及其对降水的响应

open access: yesShuitu Baochi Xuebao, 2021
干旱、半干旱区植被恢复与重建对降雨具有高度的依赖性,降雨格局的任何细微变化对其生态系统均会产生影响。以宁夏盐池县荒漠草原3种主要覆被类型(浮沙地、天然草地和柠条林地)为研究对象,使用自动气象站、土壤水分仪连续监测2015—2017年降水量和土壤水分数据,分析了3种覆被类型0—250 cm土层的土壤水分动态及其对不同量级降水的响应。结果表明:浮沙地土壤水分从表层至深层为增长趋势,天然草地和柠条林地为增加—减少—增加趋势;水分季节变化分为土壤水分稳定期(12月至翌年2月)、土壤水分积累期(3—5月 ...
陈娟   +4 more
doaj  

Exploring legal‐ and health‐risk messaging to reduce demand for elephant skin

open access: yesConservation Biology, EarlyView.
Abstract Asian elephants (Elephas maximus) are poached for an illegal trade in their skins, which are used in traditional medicine in Africa and Asia. We explored whether messages about the legal and health risks of using elephant skin for medicinal purposes (stomach illness) could reduce such consumption.
Beilu Duan   +10 more
wiley   +1 more source

室内鱼类养殖水分压装置

open access: yes, 2006
本发明公开了一种室内鱼类养殖水分压装置,它主要包括储水箱、大出水管、分压水箱、小出水管、水族箱。大出水管分别与储水箱、分压水箱相连,小出水管分别与分压水箱、水族箱相连,小出水管固定在分压水箱的两侧下部。水箱的一侧箱壁下方由下向上固定着透明水位管,显示箱内水位;另一侧箱壁上方由上向下固定着溢水管,避免从储水箱的顶部溢出。本发明结构简单,加工施工方便,分解大出水管压力,能保证各小出水管出水压力和流量的均衡,成本低,节约了水资源 ...
朱晓鸣   +4 more
core  

黄土区人工林地水分供耗特点与林分生产力研究

open access: yesShuitu Baochi Xuebao, 1999
通过定位观测,分析了黄土区人工刺槐和油松林地供水与耗水关系、土壤水分动态及林木生长情况。结果表明人工刺槐和油松林4,5,6三个月林地土壤水分消耗大于供给,水分供耗矛盾突出,土壤贮水减少;雨季水分供给充足,土壤贮水增加;在干旱季节和年份,相同条件下,密度大的林分林地水分供耗矛盾突出,林地水分亏损严重;不同坡向,水分亏损量大小顺序为阳坡>半阳坡>阴坡;0~300 cm土层土壤水分调查显示,阳坡、半阳坡密度较大的中林林分林地土壤含水量较低,出现干化现象;从水分生产力来看,由于林地水分供应不足 ...
魏天兴 朱金兆
doaj  

Transitioning From L1 Medium of Instruction to L2 English Medium Instruction: The Role of Translanguaging in Contributing to EFL Students’ Language Learning Motivation

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT Research on English‐Medium‐Instruction (EMI) highlights inadequate support for students transitioning from L1‐medium‐instruction to EMI. To date, little research has focused on how L2 students’ adaptation to an EMI environment influences their L2 learning motivation (LLM).
Kevin W. H. Tai
wiley   +1 more source

气体分水排水器

open access: yes, 2005
本实用新型公开一种气体分水排水器,有分水器本体,在分水器本体的上端设有气体进口及气体出口,分水器本体的中部有离心分水滤芯,底部有排水口;在分水器本体的下端设有液位传感器,加设电磁阀与排水口相通,并通过控制单元与液位传感器电连接。本实用新型通过电磁阀的开启与关闭,完成系统的排水与阻气,在正常的系统压力下(0~1MPa)均可使用,适用压力范围宽;对气体的密封性好,不会产生气体泄露现象,节约气体,同时消除了由于泄露易燃易爆气体所带来的安全隐患 ...
回晓康   +6 more
core  

Motivation, Self‐Regulated R2W Strategy Use, and Their Relationship Patterns Among Different Writing Performance Groups

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT The study investigated how writing motivation and self‐regulated read‐to‐write (SRL‐R2W) strategy use was related to writing performance and how the relationship between motivation and SRL‐R2W strategy use varied among different writing performance groups.
Huixuan Zhou   +3 more
wiley   +1 more source

The Development and Validation of the Chinese Vocabulary Levels Test

open access: yesInternational Journal of Applied Linguistics, EarlyView.
ABSTRACT In response to the increasing need for effective Chinese vocabulary assessments, this study developed the Chinese Vocabulary Levels Test (CVLT), a test designed for intermediate‐level Chinese as a second or foreign language (CSL/FL) learners, based on the vocabulary lists (levels 4–6) from the Chinese Proficiency Grading Standards for ...
Shiwei Qi, Ailan Fu
wiley   +1 more source

FLOW CELL光譜分析方法應用於工廠水質監測之研究

open access: yes, 2014
水質分析資料為水質管理之重要依據,然 而以傳統人工水質分析方法監測工廠廢水,不 但耗時,且產生大量實驗廢液。光譜分析方法 應用於水質分析,已有相關文獻報導。水樣在 特定波長之光譜吸收值與水質參數之間,經由 多元線性迴歸分析,可得一良好關係。本研究 以Flow Cell方式進行水樣的紫外光掃描,首先建 立人工廢水化學需氧量與特定波長光譜吸收值 之間的線性關係,得一水質預測模式。進一步 再以兩家紙廠、一家染整廠之放流水為對象, 驗證模式的可行性。研究結果如下:(1)以Flow Cell ...
黃以棽; 許道平
core  

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