In recent years, great attention has been paid to the exploitation and use of biomass energy.Using bamboo as the raw material to produce energy and other chemicals is significantly important.A primary study was made o...In recent years, great attention has been paid to the exploitation and use of biomass energy.Using bamboo as the raw material to produce energy and other chemicals is significantly important.A primary study was made on the pubescens,one kind of bamboo distributed broadly in China with fast growth rate.The contents of cellulose, hemi-cellulose, and lignin in different parts of pubescens with different growth ages, as major components of the cell wall,were determined.The analysis procedures were as follows:firstly the substances other than the above mentioned three were removed chemically, then the hydrolyzed cellulose liquid was oxidized with excess oxidants,and at last titrated.Pubescens powder was packed into the quartz tube reactor, then was heated from room temperature to 300,350, 400, 450, 500, 550 ℃ and 600 ℃ respectively in flowing N 2.Pyrolysis was held at the final temperature for 10 h.The liquid products were analyzed with GC/MS.The main products in the liquid obtained were: acetic acid, 2,6-dimethoxy phenol, 2,3-dihydrobenzofuran,etc.The pyrolysis temperature exerted great effect on the composition of the liquid products.The distribution of the products could be regulated by controlling pyrolysis temperature.展开更多
Yuchisi Type is a local type of Dawenkou Culture, mainly distributing in Northern Anhui, Eastern Henan and Southwestern Shandong. The writer analyses the basic features of Yuchisi Type through the remains and antiques...Yuchisi Type is a local type of Dawenkou Culture, mainly distributing in Northern Anhui, Eastern Henan and Southwestern Shandong. The writer analyses the basic features of Yuchisi Type through the remains and antiques and concludes that Yuchisi is an independent type of Dawenkou, for it shares the same features with Dawenkou Culture but bears its own characteritics. Based on the chronology of the other types and C14date of Yuchisi Type, the writer regards that Yuchisi Type had been lasting from 3200 BC to 2400 BC. According to the stratigraphy and characteristics of relics, Yuchisi Type is classified into Early, Middle and Late periods, and their features and date also are discussed in the article.展开更多
化学交联聚乙烯醇的交联度显著影响其降失水剂的性能及应用,通过调节交联度可以使降失水剂达到所需的效果。本文选择戊二醛作为交联剂与聚乙烯醇反应,探究了反应温度、酸浓度、聚乙烯醇在共聚体系中的质量分数、戊二醛与聚乙烯醇摩尔比...化学交联聚乙烯醇的交联度显著影响其降失水剂的性能及应用,通过调节交联度可以使降失水剂达到所需的效果。本文选择戊二醛作为交联剂与聚乙烯醇反应,探究了反应温度、酸浓度、聚乙烯醇在共聚体系中的质量分数、戊二醛与聚乙烯醇摩尔比对聚乙烯醇交联度的影响。通过运用均匀设计方法,得出60℃、80℃、100℃的最佳交联度为1.29%、1.46%、1.29%,对应的最佳工艺条件为反应温度50℃,酸浓度0.96 mol·L^(-1),聚乙烯醇在共聚体系中的质量分数6%,戊二醛与聚乙烯醇摩尔比1.60/1.68。加有降失水剂的水泥浆的API滤失量均在50 m L以下,且流变性能良好。根据均匀设计方法得出结论,戊二醛与聚乙烯醇摩尔比对聚乙烯醇交联度的影响最大,应重点控制其数值以达到所需交联度。展开更多
The chemical compositions of two kinds of secondary biomass,auricularia residue and pleurotus ostreatus residue,were analyzed in comparison with their raw material.The pyrolysis of the three kinds of material was also...The chemical compositions of two kinds of secondary biomass,auricularia residue and pleurotus ostreatus residue,were analyzed in comparison with their raw material.The pyrolysis of the three kinds of material was also performed.Compared with the raw material,the cellulose,hemicellulose,lignin contents of both the mushroom residues decrease significantly,and the content of ash increases.The change of chemical components not only lessens the yield of bio-oil,but also alters the component of bio-oil.The uppermost composition in the bio-oil from the raw material is cyclobutanol,whereas acetic acid or 2,2,6,6-tetramethyl-4-piperdone is dominant in the bio-oil from Auricularia residue and pleurotus ostreatus residue respectively.The selectivity of 2,2,6,6-tetramethyl-4-piperdone and 4-methyl-3-penten-2-one in the bio-oil from pleurotus ostreatus residue reached 35.3 % and 33.1 %.展开更多
文摘In recent years, great attention has been paid to the exploitation and use of biomass energy.Using bamboo as the raw material to produce energy and other chemicals is significantly important.A primary study was made on the pubescens,one kind of bamboo distributed broadly in China with fast growth rate.The contents of cellulose, hemi-cellulose, and lignin in different parts of pubescens with different growth ages, as major components of the cell wall,were determined.The analysis procedures were as follows:firstly the substances other than the above mentioned three were removed chemically, then the hydrolyzed cellulose liquid was oxidized with excess oxidants,and at last titrated.Pubescens powder was packed into the quartz tube reactor, then was heated from room temperature to 300,350, 400, 450, 500, 550 ℃ and 600 ℃ respectively in flowing N 2.Pyrolysis was held at the final temperature for 10 h.The liquid products were analyzed with GC/MS.The main products in the liquid obtained were: acetic acid, 2,6-dimethoxy phenol, 2,3-dihydrobenzofuran,etc.The pyrolysis temperature exerted great effect on the composition of the liquid products.The distribution of the products could be regulated by controlling pyrolysis temperature.
文摘Yuchisi Type is a local type of Dawenkou Culture, mainly distributing in Northern Anhui, Eastern Henan and Southwestern Shandong. The writer analyses the basic features of Yuchisi Type through the remains and antiques and concludes that Yuchisi is an independent type of Dawenkou, for it shares the same features with Dawenkou Culture but bears its own characteritics. Based on the chronology of the other types and C14date of Yuchisi Type, the writer regards that Yuchisi Type had been lasting from 3200 BC to 2400 BC. According to the stratigraphy and characteristics of relics, Yuchisi Type is classified into Early, Middle and Late periods, and their features and date also are discussed in the article.
文摘化学交联聚乙烯醇的交联度显著影响其降失水剂的性能及应用,通过调节交联度可以使降失水剂达到所需的效果。本文选择戊二醛作为交联剂与聚乙烯醇反应,探究了反应温度、酸浓度、聚乙烯醇在共聚体系中的质量分数、戊二醛与聚乙烯醇摩尔比对聚乙烯醇交联度的影响。通过运用均匀设计方法,得出60℃、80℃、100℃的最佳交联度为1.29%、1.46%、1.29%,对应的最佳工艺条件为反应温度50℃,酸浓度0.96 mol·L^(-1),聚乙烯醇在共聚体系中的质量分数6%,戊二醛与聚乙烯醇摩尔比1.60/1.68。加有降失水剂的水泥浆的API滤失量均在50 m L以下,且流变性能良好。根据均匀设计方法得出结论,戊二醛与聚乙烯醇摩尔比对聚乙烯醇交联度的影响最大,应重点控制其数值以达到所需交联度。
文摘The chemical compositions of two kinds of secondary biomass,auricularia residue and pleurotus ostreatus residue,were analyzed in comparison with their raw material.The pyrolysis of the three kinds of material was also performed.Compared with the raw material,the cellulose,hemicellulose,lignin contents of both the mushroom residues decrease significantly,and the content of ash increases.The change of chemical components not only lessens the yield of bio-oil,but also alters the component of bio-oil.The uppermost composition in the bio-oil from the raw material is cyclobutanol,whereas acetic acid or 2,2,6,6-tetramethyl-4-piperdone is dominant in the bio-oil from Auricularia residue and pleurotus ostreatus residue respectively.The selectivity of 2,2,6,6-tetramethyl-4-piperdone and 4-methyl-3-penten-2-one in the bio-oil from pleurotus ostreatus residue reached 35.3 % and 33.1 %.
