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能带论教学拓展:紧束缚模型的离散形式及应用 被引量:1
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作者 申庆徽 陈兵 《大学物理》 2023年第1期1-3,18,共4页
紧束缚模型的离散形式具有形式简洁且抓住物理本质等特点,成为科学研究工作中的重要表达形式.本文主要介绍紧束缚模型离散形式的推导过程,并以固体物理课程中两个常见模型为例进行了相应结果展示.本文的讨论一方面可以为固体物理课堂教... 紧束缚模型的离散形式具有形式简洁且抓住物理本质等特点,成为科学研究工作中的重要表达形式.本文主要介绍紧束缚模型离散形式的推导过程,并以固体物理课程中两个常见模型为例进行了相应结果展示.本文的讨论一方面可以为固体物理课堂教学提供进一步研讨的素材,另一方面还可帮助学生顺利从课本学习过渡到前沿研究. 展开更多
关键词 紧束缚模型 瓦尼尔表象 二次量子化
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Territorial Repartition and Ecological Importance of Wetlands in Moldova (Romania) 被引量:1
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作者 G. Romanescu C. Stoleriu C. Zaharia 《Journal of Environmental Science and Engineering》 2011年第11期1435-1444,共10页
The present paper is the first study conducted in Romania on the inventory of wetlands of a large surface of the country. The focus of this study is the Moldavian Plateau, located in the east of Romania. It is delimit... The present paper is the first study conducted in Romania on the inventory of wetlands of a large surface of the country. The focus of this study is the Moldavian Plateau, located in the east of Romania. It is delimitated by the Eastern Carpathians on the west, the Romanian Plain on the south, the Ukrainian border on the north and the Prut Valley (border with the Republic of Moldavia) on the east. Although the Moldavian Plateau is situated in the driest region of Romania, the majority of the wetlands and of the low discharge rivers is found in this region. The existence of numerous wetlands, respectively small ponds, is influenced by the human activities and the scarcity of water resources. The impermeable clayey substratum favored the occurrence and survival of a large number of wetlands. Most of them are found in the northern Moldavian Plain, and the fewest to the south, in the Covurlui Plateau. The most important wetlands are those developed along the two main rivers draining this territory: Prut and Siret. Unfortunately, Siret River floodplain has been in most of its part protected by means of flood prevention dikes. Consequently, many of the wetlands entered agricultural use. 展开更多
关键词 Aridization deep waters INVENTORY TYPOLOGY WETLANDS
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Constrained to the Oasienne Production and Strategies of a Sustainable Development (Case of the Oasis of El Mahassen, Southwestern of Tunisia)
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作者 A. Hammadi N. Khlif +1 位作者 T. Gallali M. M. Chalbaoui 《Journal of Agricultural Science and Technology》 2011年第4期476-480,共5页
In the absence of all industrial activity, the oasienne agriculture represents the only advantageous economic speculation of the region. However, the agricultural soils support largest constraints, which are the salin... In the absence of all industrial activity, the oasienne agriculture represents the only advantageous economic speculation of the region. However, the agricultural soils support largest constraints, which are the salinization, the hydromorphy, and the exaggerated division of the parcels by successive inheritance what can provoke a decline and a reduction of the productivity. The sampling and the analysis of the irrigation water shows a net rise of the waters salinity, of the order of 5.25 g/L. The topographic measures made during this work serve to detect zones favorable to the accumulation of the salt layers. The object of this note is to treat these constraints differently by means of an empiric survey, all trying to establish some adequate recommendations. 展开更多
关键词 OASIS SOILS SALINIZATION agriculture.
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(12)发明专利申请
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《乙醛醋酸化工》 2014年第3期29-35,25,共8页
(10)授权公开号CN 103080051 A(43)申请公布日2013.05.01(21)申请号201180042198.4(22)申请日2011.11.09(30)优先权数据13/094,661 2011.04.26 DS(85)PCT申请进入国家数据日2013.03.01(86)PCT申请的申请数据PCT/US2011/059917 2011.11.0... (10)授权公开号CN 103080051 A(43)申请公布日2013.05.01(21)申请号201180042198.4(22)申请日2011.11.09(30)优先权数据13/094,661 2011.04.26 DS(85)PCT申请进入国家数据日2013.03.01(86)PCT申请的申请数据PCT/US2011/059917 2011.11.09(87)PCT申请的公布数据WO2012/148462 EN 2012.11.01(71)申请人国际人造丝公司地址美国得克萨斯(72) 展开更多
关键词 甲醇合成 物料流 乙酸盐 约翰斯顿 申请日 瓦尼尔 发明专利 实施方案 甲醇装置 羰基化
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