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鲁中山丘区地下水硝酸盐污染状况研究 被引量:6
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作者 谭志容 啜云香 +1 位作者 王新华 赵季初 《地下水》 2018年第5期59-61,66,共4页
地下水中硝酸盐污染是人们高度关注的问题,本文通过大量的水质测试分析资料,对位于鲁中山丘区的临朐县、沂源县、沂水县及莒县境内浅层地下水中硝酸盐污染状况进行了评价。评价结果显示,研究区浅层地下水中硝酸盐污染严重,硝酸盐含量(... 地下水中硝酸盐污染是人们高度关注的问题,本文通过大量的水质测试分析资料,对位于鲁中山丘区的临朐县、沂源县、沂水县及莒县境内浅层地下水中硝酸盐污染状况进行了评价。评价结果显示,研究区浅层地下水中硝酸盐污染严重,硝酸盐含量(以氮计)大于20 mg/L的Ⅳ、Ⅴ类水水样占总水样的35.17%,Ⅳ、Ⅴ类水分布面积约2 655 km^2,占研究区总面积的33%左右。地下水中硝酸盐污染多呈面状分布特征,农业生产中化肥、有机肥的施用是引起地下水中硝酸盐含量升高的主要原因。 展开更多
关键词 硝酸盐污染 地下水 水质测试分析 水质标准
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A Test Items Knowledge Library System for Adaptive Learning
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作者 Yi-Hsing Chang Rong-Jyue Fang 《Computer Technology and Application》 2013年第4期175-184,共10页
A test items knowledge library system of for adaptive learning is proposed in this paper. The first step is to carry out the quantity and quality analysis of the test items by using the Bloom's revised taxonomy and s... A test items knowledge library system of for adaptive learning is proposed in this paper. The first step is to carry out the quantity and quality analysis of the test items by using the Bloom's revised taxonomy and scale anchoring respectively to produce the characteristics for test items. A smoothing method of arbitrary anchoring revised from scale anchoring is first proposed to make tests more accurate in distinguishing test levels. In addition, raised three dimensional indicators based on the Bloom's revised taxonomy are adopted to validate test contents and therefore it concretely describes the examining function of items. The items obtained have the precise and concrete properties; an item knowledge library is therefore constructed combining teaching materials and items using the technologies of ontology and knowledge management. Finally, a knowledge library system of test items is established to achieve the purpose of adaptive learning for learners. 展开更多
关键词 Scale anchoring bloom's revised taxonomy test item knowledge library adaptive learning.
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