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Effects of Irrigation with Well Water on Chemical Characteristics of a Weakly Alkaline Soil Used as Rice Field
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作者 GONG Zhen ping,ZHAO Yan zhong,ZU Wei, SUN Cong shu (Northeast Agricultural University Harbin Heilongjiang 150030 PRC) 《Journal of Northeast Agricultural University(English Edition)》 CAS 2002年第1期22-28,共7页
This paper discussed the effects of irrigation with well water on the salinity and pH of a weakly alkaline paddy soil in Fujin of Heilongjiang Province in the north-eastern part of China.It has been found that after s... This paper discussed the effects of irrigation with well water on the salinity and pH of a weakly alkaline paddy soil in Fujin of Heilongjiang Province in the north-eastern part of China.It has been found that after seven years the accumulation of total soluble salts did not occur and that the pH of 0~15 cm layer fell down from 7.92~8.30 to 6.76~7.45,and that the content of anion HCO - 3 and its proportion in the total soluble anions have fallen down.Conversion from paddy soil to upland restored the pH of soil,exchangeable sodium,ESR(exchangeable sodium ratio) to their original levels of upland fields respectively. 展开更多
关键词 weakly alkaline soil rice cultivation with well water total soluble salts PH
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Influence of Ethylene Glycol on the Formation of Calcium Phosphate Nanocrystals 被引量:2
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作者 Yi ZUO, Yubao LI, Jie WEI and Yonggang YANResearch Center for Nano-Biomaterials, Analytical and Testing Center, Sichuan University, Chengdu 610064, China 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2003年第6期628-630,共3页
A synthesis route of using calcium hydroxide Ca(OH)2 with ethylene glycol solvent and orthophosphoric acid (H3PO4) as reagents is described. Three ratios of ethylene glycol to distilled water 1:0, 1:1 and 0:1 are used... A synthesis route of using calcium hydroxide Ca(OH)2 with ethylene glycol solvent and orthophosphoric acid (H3PO4) as reagents is described. Three ratios of ethylene glycol to distilled water 1:0, 1:1 and 0:1 are used as diluting media for Ca(OH)2. Crystals of different morphology and composition are formed under weak alkaline circumstance at pH 7.0-8.0. Acicular calcium phosphate nanocrystals are prepared in pure ethylene glycol while rod-like calcium phosphate nanocrystals form in pure distilled water. The nanograde size of the former is smaller than that of the latter. Calcium-deficient apatite (CDAP) is obtained with a Ca/P molar ratio of 1.66. Therefore, it was deduced that the usage of ethylene glycol solvent could influence the formation of calcium phosphate crystal lattice. 展开更多
关键词 Acicular nanocrystals Calcium phosphate Ethylene glycol solvent weak alkaline circumstance
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A new weakly alkaline slurry for copper planarization at a reduced down pressure 被引量:1
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作者 陈蕊 康劲 +3 位作者 刘玉岭 王辰伟 蔡婷 李新 《Journal of Semiconductors》 EI CAS CSCD 2014年第2期151-154,共4页
This study reports a new weakly alkaline slurry for copper chemical mechanical planarization (CMP), it can achieve a high planarization efficiency at a reduced down pressure of 1.0 psi. The slurry is studied through... This study reports a new weakly alkaline slurry for copper chemical mechanical planarization (CMP), it can achieve a high planarization efficiency at a reduced down pressure of 1.0 psi. The slurry is studied through the polish rate, planarization, copper surface roughness and stability. The copper polishing experiment result shows that the polish rate can reach 10032 A/rain. From the multi-layers copper CMP test, a good result is obtained, that is a big step height (10870 A) that can be eliminated in just 35 s, and the copper root mean square surface roughness (sq) is very low (〈 1 rim). Apart from this, compared with the alkaline slurry researched before, it has a good progress on stability of copper polishing rate, stable for 12 h at least. All the results presented here are relevant for further developments in the area of copper CMP. 展开更多
关键词 planarization performance weakly alkaline slurry reduced down pressure copper CMP
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The stability of a novel weakly alkaline slurry of copper interconnection CMP for GLSI 被引量:2
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作者 Caihong Yao Chenwei Wang +4 位作者 Xinhuan Niu Yan Wang Shengjun Tian Zichao Jiang Yuling Liu 《Journal of Semiconductors》 EI CAS CSCD 2018年第2期78-85,共8页
Chemical mechanical polishing(CMP) is one of the important machining procedures of multilayered copper interconnection for GLSI, meanwhile polishing slurry is a critical factor for realizing the high polishing perfo... Chemical mechanical polishing(CMP) is one of the important machining procedures of multilayered copper interconnection for GLSI, meanwhile polishing slurry is a critical factor for realizing the high polishing performance such as high planarization efficiency, low surface roughness. The effect of slurry components such as abrasive(colloidal silica), complexing agent(glycine), inhibitor(BTA) and oxidizing agent(H_2O_2) on the stability of the novel weakly alkaline slurry of copper interconnection CMP for GLSI was investigated in this paper. First, the synergistic and competitive relationship of them in a peroxide-based weakly alkaline slurry during the copper CMP process was studied and the stability mechanism was put forward. Then 1 wt% colloidal silica, 2.5 wt% glycine,200 ppm BTA, 20 m L/L H_2O_2 had been selected as the appropriate concentration to prepare copper slurry, and using such slurry the copper blanket wafer was polished. From the variations of copper removal rate, root-mean square roughness(Sq) value with the setting time, it indicates that the working-life of the novel weakly alkaline slurry can reach more than 7 days, which satisfies the requirement of microelectronics further development. 展开更多
关键词 stability weakly alkaline slurry CMP copper interconnection
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