Since the production cost of biodiesel is now the main hurdle limiting their applicability in some areas, catalytic cracking reactions represent an alternative route to utilization of vegetable oils and animal fats. H...Since the production cost of biodiesel is now the main hurdle limiting their applicability in some areas, catalytic cracking reactions represent an alternative route to utilization of vegetable oils and animal fats. Hence, catalytic transformation of oils and fats was carried out in a laboratory-scale two-stage riser fluid catalytic cracking （TSRFCC） unit in this work. The results show that oils and fats can be used as FCC feed singly or co-feeding with vacuum gas oil （VGO）, which can give high yield （by mass）of liquefied petroleum gas （LPG）, C2-C4 oletms, tor example 45% LPG, 47% C2-C4 olefins, and 77.6% total liquid yield produced with palm oil cracking. Co-feeding with VGO gives a high yield of LPG （39.1%） and propylene （18.1%）. And oxygen element content is very low （about 0.5%） in liquid products, hence, oxygen is removed in the form of H2O, CO and CO2. At the same time, high concentration of aromatics （C7-C9 aromatics predominantly） in the gasoline fraction is obtained after TSRFCC reaction of palm oil, as a result of large amount of hydrogen-transfer, cyclization and aromatization reactions, Additionally, most of properties of produced gasoline and diesel oil fuel meet the requirements of national standards, containing little sulfur. So TSRFCC technology is thought to be an alternative processing technology leading to production of clean fuels and light olefins.展开更多
Firstly,this paper analyzes the cause of obstacles to continuous cropping of vegetables,and then introduces the soil ecological remediation technology used for overcoming obstacles to continuous cropping of vegetables...Firstly,this paper analyzes the cause of obstacles to continuous cropping of vegetables,and then introduces the soil ecological remediation technology used for overcoming obstacles to continuous cropping of vegetables. Finally,this paper analyzes the effect of applying soil ecological remediation technology in overcoming obstacles to continuous cropping of vegetables.展开更多
Based on the literature and experimental results, three kinds of soil amendments, namely rice biochar, hydroxyapatite and potassium dihydrogen phosphate(KH2PO4), and deeper ploughing were selected to evaluate the fiel...Based on the literature and experimental results, three kinds of soil amendments, namely rice biochar, hydroxyapatite and potassium dihydrogen phosphate(KH2PO4), and deeper ploughing were selected to evaluate the field application effect of soil amendments and agronomic measures on the remediation of Cd contamination in greenhouse vegetable fields. Cd-contaminated greenhouse screening was conducted from 2015 to 2017. In September 2017, comparative tests of eight treatments were performed, and a preferred test was performed in September 2018. The screening results of the contaminated areas indicated that the distribution of over-standard sites was uneven, and Cd content was significantly different. Over-standard rate of No.4 greenhouse was 83.33% and was the highest, and the average content of Cd in soil was 0.535 mg/kg. It was used as a comparative test greenhouse for eight treatments. No.1 greenhouse was selected as the preferred test greenhouse, with three over-standard plots having average Cd concentrations of 0.530, 0.568 and 0.792 mg/kg. The comparative test results showed that after 8 months of remediation, the content of available Cd in the treatment of hydroxyapatite+rice biochar+deeper ploughing(T6) was reduced by 32.55% compared with CK(the control) and 24.96% than 2 months of remediation. The content of available Cd using the treatment of potassium dihydrogen phosphate+rice biochar+deeper ploughing(T7) decreased by 47.88% compared with CK and 31.00% than 2 months of remediation. The preferred remediation test results showed that in the treatment of hydroxyapatite+rice biochar+deeper ploughing: the mean Cd content decreased from 0.489 to 0.372 mg/kg, reducing by 23.86%, and the mean did not exceed the standard. Compared with CK, the mean content of available Cd decreased by 10.71% after 8 months, and the lowest content of available Cd in three treatments was 0.133 mg/kg. In addition, the Cd content, bioconcentration factor(BCF) and translocation coefficient(TF) of bean aboveground plants were decreased by 15.86%, 23.68% and 25.77%, respectively when compared with CK. Rice biochar+hydroxyapatite +deeper ploughing is a favoured technology for the remediation of Cd-contaminated greenhouse vegetable fields.展开更多
Roof greening is crucial for improving urban eco-environment, showing benefits, ecological y or social y, but it is so hard for investors in terms of capitals or promotion. The research introduced sponge-type composit...Roof greening is crucial for improving urban eco-environment, showing benefits, ecological y or social y, but it is so hard for investors in terms of capitals or promotion. The research introduced sponge-type composite vegetation carpet techniques and constructionprocess, making a breakthrough in greening form and having formulated a new one.展开更多
The traditional computed tomography(CT)reconstruction methods are noisy,low resolution,poor contrast,and generally not suitable to detect the smaller flaws.Besides,the filter design is also difficult.The CT characteri...The traditional computed tomography(CT)reconstruction methods are noisy,low resolution,poor contrast,and generally not suitable to detect the smaller flaws.Besides,the filter design is also difficult.The CT characteristics reconstruction technology was brought forward to improve in these aspects,which is defined to directly reconstruct the characteristics of the projection for the best requirements not the overall image quality.The two-dimension(2D)and three-dimension(3D)CT characteristics reconstruction algorithm were firstly introduced,then by detailed analysis,experimental results and comparsion of parameters calculated,its advantages in keeping better high-frequency feature,better noise immunity,short time-consuming and easier design are verified.展开更多
基金the Major Research Plan of PetroChina Company Limited (07-03D-01-01-02-02)
文摘Since the production cost of biodiesel is now the main hurdle limiting their applicability in some areas, catalytic cracking reactions represent an alternative route to utilization of vegetable oils and animal fats. Hence, catalytic transformation of oils and fats was carried out in a laboratory-scale two-stage riser fluid catalytic cracking （TSRFCC） unit in this work. The results show that oils and fats can be used as FCC feed singly or co-feeding with vacuum gas oil （VGO）, which can give high yield （by mass）of liquefied petroleum gas （LPG）, C2-C4 oletms, tor example 45% LPG, 47% C2-C4 olefins, and 77.6% total liquid yield produced with palm oil cracking. Co-feeding with VGO gives a high yield of LPG （39.1%） and propylene （18.1%）. And oxygen element content is very low （about 0.5%） in liquid products, hence, oxygen is removed in the form of H2O, CO and CO2. At the same time, high concentration of aromatics （C7-C9 aromatics predominantly） in the gasoline fraction is obtained after TSRFCC reaction of palm oil, as a result of large amount of hydrogen-transfer, cyclization and aromatization reactions, Additionally, most of properties of produced gasoline and diesel oil fuel meet the requirements of national standards, containing little sulfur. So TSRFCC technology is thought to be an alternative processing technology leading to production of clean fuels and light olefins.
基金Supported by Independent Agricultural Innovation Foundation in Jiangsu Province(CX151044)
文摘Firstly,this paper analyzes the cause of obstacles to continuous cropping of vegetables,and then introduces the soil ecological remediation technology used for overcoming obstacles to continuous cropping of vegetables. Finally,this paper analyzes the effect of applying soil ecological remediation technology in overcoming obstacles to continuous cropping of vegetables.
基金Supported by the Beijing-Tianjin-Hebei Collaborative Innovation Community Construction Project (19244010D)Technology Model and Application of Biological Obstacle Reduction and Healthy Soil Cultivation in Wheat and Corn Cropping Area of North China (2022YFD1901300)+1 种基金the National Key R&D Program of China (2016YFD0801003)the Talent Training Project in Hebei Province (A201803030)。
文摘Based on the literature and experimental results, three kinds of soil amendments, namely rice biochar, hydroxyapatite and potassium dihydrogen phosphate(KH2PO4), and deeper ploughing were selected to evaluate the field application effect of soil amendments and agronomic measures on the remediation of Cd contamination in greenhouse vegetable fields. Cd-contaminated greenhouse screening was conducted from 2015 to 2017. In September 2017, comparative tests of eight treatments were performed, and a preferred test was performed in September 2018. The screening results of the contaminated areas indicated that the distribution of over-standard sites was uneven, and Cd content was significantly different. Over-standard rate of No.4 greenhouse was 83.33% and was the highest, and the average content of Cd in soil was 0.535 mg/kg. It was used as a comparative test greenhouse for eight treatments. No.1 greenhouse was selected as the preferred test greenhouse, with three over-standard plots having average Cd concentrations of 0.530, 0.568 and 0.792 mg/kg. The comparative test results showed that after 8 months of remediation, the content of available Cd in the treatment of hydroxyapatite+rice biochar+deeper ploughing(T6) was reduced by 32.55% compared with CK(the control) and 24.96% than 2 months of remediation. The content of available Cd using the treatment of potassium dihydrogen phosphate+rice biochar+deeper ploughing(T7) decreased by 47.88% compared with CK and 31.00% than 2 months of remediation. The preferred remediation test results showed that in the treatment of hydroxyapatite+rice biochar+deeper ploughing: the mean Cd content decreased from 0.489 to 0.372 mg/kg, reducing by 23.86%, and the mean did not exceed the standard. Compared with CK, the mean content of available Cd decreased by 10.71% after 8 months, and the lowest content of available Cd in three treatments was 0.133 mg/kg. In addition, the Cd content, bioconcentration factor(BCF) and translocation coefficient(TF) of bean aboveground plants were decreased by 15.86%, 23.68% and 25.77%, respectively when compared with CK. Rice biochar+hydroxyapatite +deeper ploughing is a favoured technology for the remediation of Cd-contaminated greenhouse vegetable fields.
基金Supported by Guangdong Province Soft Science Research Program(2014B090903015)Guangdong Province Science&Technology Cooperation Program([2015]162)~~
文摘Roof greening is crucial for improving urban eco-environment, showing benefits, ecological y or social y, but it is so hard for investors in terms of capitals or promotion. The research introduced sponge-type composite vegetation carpet techniques and constructionprocess, making a breakthrough in greening form and having formulated a new one.
基金National Natural Science Foundation of China(No.61471325)
文摘The traditional computed tomography(CT)reconstruction methods are noisy,low resolution,poor contrast,and generally not suitable to detect the smaller flaws.Besides,the filter design is also difficult.The CT characteristics reconstruction technology was brought forward to improve in these aspects,which is defined to directly reconstruct the characteristics of the projection for the best requirements not the overall image quality.The two-dimension(2D)and three-dimension(3D)CT characteristics reconstruction algorithm were firstly introduced,then by detailed analysis,experimental results and comparsion of parameters calculated,its advantages in keeping better high-frequency feature,better noise immunity,short time-consuming and easier design are verified.
