A novel technique was developed to remove impurities from crude lead by vacuum distillation.The thermodynamics on vacuum distillation refining process of crude lead was studied by means of saturated vapor pressure of ...A novel technique was developed to remove impurities from crude lead by vacuum distillation.The thermodynamics on vacuum distillation refining process of crude lead was studied by means of saturated vapor pressure of main components of crude lead,separation coefficients and vapor-liquid equilibrium composition of Pb-i(i stands for an impurity) system at different temperatures.The behaviors of impurities in the vacuum distillation refining process were investigated.The results show that the vacuum distillation should be taken to obtain lead from crude lead,in which Zn,As and partial Sb are volatilized at lower temperature of 923-1023 K.Lead is distilled from the residue containing Cu,Sn,Ag and Bi at higher temperature of 1323-1423 K,but the impurity Bi is also volatilized along with lead and cannot be separated from lead.展开更多
In this paper,Cassava dregs are an outgrowth produced during starchy production which uses cassava as raw material.It is usually dropped out or used as cheap feedstuff.In order to make the best use of cassava dregs,in...In this paper,Cassava dregs are an outgrowth produced during starchy production which uses cassava as raw material.It is usually dropped out or used as cheap feedstuff.In order to make the best use of cassava dregs,increase industrie'sbenefits and reduce castoff this study developed a new technique which used cassava dregs as raw material to produce distilled spirits based on cassava dregs characteristics.The technique adopt solid-ferment procedure.At first,the ferment is processed by solid-state distilling,and then rectification extra care refine-ment;at last the tequila was produced with characteristics of simple and elegant fragrance and mellow-tasting.展开更多
Three steam distillation devices (D-1, D-2 and D-4) or one simultaneous distillation (D-3, water-diethyl ether) as well as the process of CO2-SFE (Supercritical fluid extraction) were adopted in extraction of essentia...Three steam distillation devices (D-1, D-2 and D-4) or one simultaneous distillation (D-3, water-diethyl ether) as well as the process of CO2-SFE (Supercritical fluid extraction) were adopted in extraction of essential oils from Chinese-fir (Cunninghamia lancedata (Lamb) Hook.) and the chemical components of the extracted essential oil were analyzed by Gas chromatograph-MS analyses. The results showed that the essential oil could be almost extracted out within 2 hours and the device-3 had the highest extraction efficiency. The major chemical component of the oil was cedrol. The yield of the extracted essential oils from Chinese fir decreased gradually with the increase of the distillation time. The best condition for extraction by means of CO2-SFE is 100 kg·cm?2 in pressure and 40°C in temperature for. Keywords Chinese fir - Essential oil - Cedrol - Supercritical fluid extraction CLC number S781.4 Document code A Foundation item: This paper was support by the Key Foundation Research Project (G1999016001) of China and the Japan International Cooperation AgencyBiography: HUANG Luo-hua (1957-), male, Research associate, Research Institute of Wood Industry, Chinese Academy of forestry, Beijing 100091, P. R. ChinaResponsible editor: Song Funan展开更多
In this study, a reactive distillation column in which chemical reaction and separation occur simultaneously is applied for the synthesis of tert-amyl ethyl ether (TAEE) from ethanol (EtOH) and tert-amyl alcohol ...In this study, a reactive distillation column in which chemical reaction and separation occur simultaneously is applied for the synthesis of tert-amyl ethyl ether (TAEE) from ethanol (EtOH) and tert-amyl alcohol (TAA). Pervaporation, an efficient membrane separation technique, is integrated with the reactive distillation for enhancing the efficiency of TAEE production. A user-defined Fortran subroutine of a pervaporation unit is developed, allowing the design and simulation of the hybrid process of reactive distillation and pervaporation in Aspen Plus simulator. The performance of such a hybrid process is analyzed and the results indicate that the integration of the reactive distillation with the pervaporation increases the conversion of TAA and the purity of TAEE product, compared with the conventional reactive distillation.展开更多
Batch extractive distillation(BED)is a special method used in the distillation process by adding a solvent into the batch distillation column to alter the relative volatility of the components and improve the separati...Batch extractive distillation(BED)is a special method used in the distillation process by adding a solvent into the batch distillation column to alter the relative volatility of the components and improve the separation. A comprehensive design and simulation method is required due to the complexity of BED.In this study,a quasi-steady-state model for BED is proposed,the derivation and solution of the model are presented.This shortcut model can be used to simulate the composition and temperature of the reboiler,the top and other plates of the column in a batch extractive distillation operation.The calculated values are in good agreement with the experimental data.The results show that the quasi-steady-state model is a practical method because of some advantages such as high precision and fast calculation.展开更多
A two-stage blade-packing rotating packed bed(TSBP-RPB) was designed and developed for the intensification of continuous distillation. The mass transfer parameters of the TSBP-RPB were investigated using a chemisorpti...A two-stage blade-packing rotating packed bed(TSBP-RPB) was designed and developed for the intensification of continuous distillation. The mass transfer parameters of the TSBP-RPB were investigated using a chemisorption system. Continuous distillation experiments were conducted in the TSBP-RPB by the methanol–water binary system. Experimental results showed that values of the effective interfacial area and liquid-side mass transfer coefficient of the TSBP-RPB were 93–337 m^2·m^(-3) and 0.05–0.19 cm·s^(-1), respectively. The height of equivalent theoretical plate(HETP) of the TSBP-RPB ranged from 1.9 to 10 cm. Moreover, the TSBP-RPB is easy to be manufactured, which shows great potential for the application of continuous distillation.展开更多
Peel essential oil of bergamot (Citrus bergamia Risso) growing in Tunisia was separated by hydrodistillation and obtained in a yield of 9.7%. The oil composition was investigated using GC and GC-MS with two columns ...Peel essential oil of bergamot (Citrus bergamia Risso) growing in Tunisia was separated by hydrodistillation and obtained in a yield of 9.7%. The oil composition was investigated using GC and GC-MS with two columns HP-I and HP-Innowax. Fifteen compounds accounting for 98.52% of the oil were identified. The oil was characterized by bigb content oflimonene (59.21%), linalool (9.51%) and linalyl acetate (16.83%).展开更多
For separating some specific four component mixtures into four products, the four-product dividing wall column(FPDWC) with two partition walls can provide the same utility consumption with the extended Petlyuk configu...For separating some specific four component mixtures into four products, the four-product dividing wall column(FPDWC) with two partition walls can provide the same utility consumption with the extended Petlyuk configuration, although with structure simplicity. However, the reluctance to implement this kind of four product dividing wall column industrially also consists in the two uncontrollable vapor splits associated with it. The vapor split ratios are set at the design stage and might not be the optimal value for changed feed composition, thus minimum energy consumption could not be ensured. In the present work, a sequential iterative optimization approach was initially employed to determine the parameters of cost-effective FPDWC. Then the effect of maintaining the vapor split ratios at their nominal value on the energy penalty was investigated for the FPDWC with two partition walls, in case of feed composition disturbance. The result shows that no more than + 2% above the optimal energy requirements could be ensured for 20% feed composition disturbances, which is encouraging for industrial implementation.展开更多
This study aimed to model the kinetic of hydro-distillation of Aquilaria malaccensis leaves oil in order to understand and optimize the extraction process. In addition, this study, for the first time, aimed to identif...This study aimed to model the kinetic of hydro-distillation of Aquilaria malaccensis leaves oil in order to understand and optimize the extraction process. In addition, this study, for the first time, aimed to identify the chemical compositions of the A. rnalaccensis leave-oil. By assessing both first-order kinetic model and the model of simultaneous washing and diffusion, the result indicated that the model of simultaneous washing and diffusion better describes the hydro-distillation mechanism of the essential oil from A. rnalaccensis leaves. The optimum time, solid to liquid ratio, and the heating power for extracting the highest amount of essential oil were found to be around 3 h, 1:10 (g. ml-1), and 300 W respectively. Yellow essential oil with a strong smell and a yield of 0.05 v/w was extracted by hydro-distillation Clevenger apparatus. Chemical compounds of the essential oil were analyzed using gas chromatography-mass spectroscopy (GC/MS), which resulted in identification of 42 compounds that constitute 93% of essential oil. Among the identified components, Pentadecanal (32.082%), 9-Octadecenal, (Z) (15.894%), and Tetradecanal (6.927%) were the major compounds. Considering the fact that all the identified major components possess pesticidal properties, A. malaccensis leaves can be regarded as a promising natural source for producing pesticides.展开更多
In this paper, a new approach using artificial neural network and genetic algorithm for the optimization of the thermally coupled distillation is presented. Mathematical model can be constructed with artificial neura...In this paper, a new approach using artificial neural network and genetic algorithm for the optimization of the thermally coupled distillation is presented. Mathematical model can be constructed with artificial neural network based on the simulation results with ASPEN PLUS. Modified genetic algorithm was used to optimize the model. With the proposed model and optimization arithmetic, mathematical model can be calculated, decision variables and target value can be reached automatically and quickly. A practical example is used to demonstrate the algorithm.展开更多
A novel operation of batch distillation-combination of varyingcolumn pressure and total reflux-total efflux is studiedexperimentally. In the operation, the product is accumulated at thetop of the column under total re...A novel operation of batch distillation-combination of varyingcolumn pressure and total reflux-total efflux is studiedexperimentally. In the operation, the product is accumulated at thetop of the column under total reflux and then drained off completely,and the column pressure is varying in the whole process. This processhas been industrialized successfully with large profits. Theconventional model of batch distillation is improved by this methodeffectively: the separation efficiency and the yield of product areincreased greatly, the operation time is shortened and the productioncost is cut down. Moreover, the amount of condensation water isdecreased and the over-high reboiler temperature is lowered.展开更多
Multivessel batch distillation(MVBD) is mainly used to separate mixtures with more than two components. In this article, a new operation mode with MVBD is proposed for separation of binary mixtures under total reflux....Multivessel batch distillation(MVBD) is mainly used to separate mixtures with more than two components. In this article, a new operation mode with MVBD is proposed for separation of binary mixtures under total reflux. A mathematic model is setup for the simulation. The proposed operation policy and the regular operation with constant reflux are compared theoretically and experimentally. The results show that the new operation mode has great advantages in time saving and operation flexibility. MVBD presents great potential for separation with high efficiency.展开更多
[Objective] The study aims to optimize the extracting technology conditions of essential oil from Elsholtzia densa Benth. [Method] Essential oil was extracted from E. densa Benth using steam distillation, and the effe...[Objective] The study aims to optimize the extracting technology conditions of essential oil from Elsholtzia densa Benth. [Method] Essential oil was extracted from E. densa Benth using steam distillation, and the effects of four extracting factors (grain size of the medicinal herb, ultrasonic time, soaking time and ratio of the material to liquid) on the yield of essential oil extracted from E. densa Benth were analyzed through the orthogonal test. [Result] The optimized extraction process of essential oil from E. densa Benth was as follows: grain size of the medicinal herb 50 mesh, ultrasonic time 12 min, being soaked in the water for 6 h, and ratio of the material to liquid 1∶16 g/ml. Under the conditions, the average extracting rate of the essential oil was 0.407%. [Conclusion] The optimized extraction process of essential oil from E. densa Benth was simple and practicable, and its extracting rate was higher.展开更多
The mercury-antimony-gold ore was subjected of the flotation. As a result of enrichment of ore, the mercury-antimony concentrate with the contents of 51.5% Sb, 3.55% Hg and 6 g/t Au was received. Vacuum distillation o...The mercury-antimony-gold ore was subjected of the flotation. As a result of enrichment of ore, the mercury-antimony concentrate with the contents of 51.5% Sb, 3.55% Hg and 6 g/t Au was received. Vacuum distillation of concentrate allocation in serial sublimates mercury and antimony was designed. The big amount gold passed to calcine after vacuum distillation. The gold in calcine roastin uo to 900 ℃was 30.6 e/t.展开更多
This work describes the separation and purification of lactic acid from diluted solution by HSPE (hybrid short path evaporation) and RD (reactive distillation) as coupled process. The results showed that it is pos...This work describes the separation and purification of lactic acid from diluted solution by HSPE (hybrid short path evaporation) and RD (reactive distillation) as coupled process. The results showed that it is possible to increase lactic acid concentration up to 4.7 times higher than the raw material concentration.展开更多
Model simulation and in situ observations are often used to research water and carbon cycles in terrestrial ecosystems, but each of these methods has its own advantages and limitations. Combining these two methods cou...Model simulation and in situ observations are often used to research water and carbon cycles in terrestrial ecosystems, but each of these methods has its own advantages and limitations. Combining these two methods could improve the accuracy of quantifying the dynamics of the water and carbon fluxes of an ecosystem. Data assimilation is an effective means of integrating modeling with in situ observation. In this study, the ensemble Kalman filter(En KF) and the unscented Kalman filter(UKF) algorithms were used to assimilate remotely sensed leaf area index(LAI) data with the Biome-BGC model to simulate water and carbon fluxes at the Harvard Forest Environmental Monitoring Site(EMS) and the Dinghushan site. After MODIS LAI data from 2000–2004 were assimilated into the improved Biome-BGC model using the En KF algorithm at the Harvard Forest site, the R2 between the simulated and observed results for NEE and evapotranspiration increased by 7.8% and 4.7%, respectively. In addition, the sum of the absolute error(SAE) and the root mean square error(RMSE) of NEE decreased by an average of 21.9% and 26.3%, and the SAE and RMSE of evapotranspiration decreased by 24.5% and 25.5%, respectively. MODIS LAI data of 2003 were assimilated into the Biome-BGC model for the Dinghushan site, and the R2 values between the simulated and observed results for NEE and evapotranspiration were increased by 6.7% and 17.3%, respectively. In addition, the SAE values of NEE and ET were decreased by 11.3% and 30.7%, respectively, and the RMSE values of NEE and ET decreased by 10.1% and 30.9%, respectively. These results demonstrate that the accuracy of carbon and water flux simulations can be effectively improved when remotely sensed LAI data are properly integrated with ecosystem models through a data assimilation approach.展开更多
OBJECTIVE: To analyze the essential oils from flowers, leaves, stems, roots, and fruits of Chaihu(Radix Bupleuri Chinensis).METHODS: We extracted essential oils from different parts of Chaihu(Radix Bupleuri Chinensis)...OBJECTIVE: To analyze the essential oils from flowers, leaves, stems, roots, and fruits of Chaihu(Radix Bupleuri Chinensis).METHODS: We extracted essential oils from different parts of Chaihu(Radix Bupleuri Chinensis) using a steam distillation method. The essential oils were analyzed by gas chromatography-mass spectrometry(GC-MS). Data were collected in full scan mode(m/z 60-600). Volatile components were identified based on their retention indices and by comparing their mass spectra with those in the National Institute of Standards and Technology 2005 database assisted by tandem mass spectrometry information. The relative content of each constituent wasdetermined by area normalization.RESULTS: We identified 111 components, of which12 were common to all 5 parts, 30 were found only in roots, 14 were found only in flowers, 6 were found only in leaves, 4 were found only in stems,and 17 were found only in fruits.CONCLUSION: Our results show that the stems,flowers, leaves, and fruits of Chaihu(Radix Bupleuri Chinensis)contain a high concentration of essential oils, and that the exact composition of the essential oils differs among the plant parts. To develop new medicines and make full use of the Chaihu(Radix Bupleuri Chinensis)resource, it is important to characterize the essential oils from different parts of the plant. In future research, it will be important to determine the pharmacological effects of the various components and the essential oil mixtures.展开更多
基金Project (2012CB722803) supported by the National Basic Research Program of ChinaProject (U1202271) supported by the National Natural Science Foundation of China
文摘A novel technique was developed to remove impurities from crude lead by vacuum distillation.The thermodynamics on vacuum distillation refining process of crude lead was studied by means of saturated vapor pressure of main components of crude lead,separation coefficients and vapor-liquid equilibrium composition of Pb-i(i stands for an impurity) system at different temperatures.The behaviors of impurities in the vacuum distillation refining process were investigated.The results show that the vacuum distillation should be taken to obtain lead from crude lead,in which Zn,As and partial Sb are volatilized at lower temperature of 923-1023 K.Lead is distilled from the residue containing Cu,Sn,Ag and Bi at higher temperature of 1323-1423 K,but the impurity Bi is also volatilized along with lead and cannot be separated from lead.
文摘In this paper,Cassava dregs are an outgrowth produced during starchy production which uses cassava as raw material.It is usually dropped out or used as cheap feedstuff.In order to make the best use of cassava dregs,increase industrie'sbenefits and reduce castoff this study developed a new technique which used cassava dregs as raw material to produce distilled spirits based on cassava dregs characteristics.The technique adopt solid-ferment procedure.At first,the ferment is processed by solid-state distilling,and then rectification extra care refine-ment;at last the tequila was produced with characteristics of simple and elegant fragrance and mellow-tasting.
基金The Key Foundation Research Project (G1999016001) of China and the Japan International Cooperation Agency
文摘Three steam distillation devices (D-1, D-2 and D-4) or one simultaneous distillation (D-3, water-diethyl ether) as well as the process of CO2-SFE (Supercritical fluid extraction) were adopted in extraction of essential oils from Chinese-fir (Cunninghamia lancedata (Lamb) Hook.) and the chemical components of the extracted essential oil were analyzed by Gas chromatograph-MS analyses. The results showed that the essential oil could be almost extracted out within 2 hours and the device-3 had the highest extraction efficiency. The major chemical component of the oil was cedrol. The yield of the extracted essential oils from Chinese fir decreased gradually with the increase of the distillation time. The best condition for extraction by means of CO2-SFE is 100 kg·cm?2 in pressure and 40°C in temperature for. Keywords Chinese fir - Essential oil - Cedrol - Supercritical fluid extraction CLC number S781.4 Document code A Foundation item: This paper was support by the Key Foundation Research Project (G1999016001) of China and the Japan International Cooperation AgencyBiography: HUANG Luo-hua (1957-), male, Research associate, Research Institute of Wood Industry, Chinese Academy of forestry, Beijing 100091, P. R. ChinaResponsible editor: Song Funan
文摘In this study, a reactive distillation column in which chemical reaction and separation occur simultaneously is applied for the synthesis of tert-amyl ethyl ether (TAEE) from ethanol (EtOH) and tert-amyl alcohol (TAA). Pervaporation, an efficient membrane separation technique, is integrated with the reactive distillation for enhancing the efficiency of TAEE production. A user-defined Fortran subroutine of a pervaporation unit is developed, allowing the design and simulation of the hybrid process of reactive distillation and pervaporation in Aspen Plus simulator. The performance of such a hybrid process is analyzed and the results indicate that the integration of the reactive distillation with the pervaporation increases the conversion of TAA and the purity of TAEE product, compared with the conventional reactive distillation.
基金Supported by the Natural Science Foundation of Hebei Province(B2006000018)
文摘Batch extractive distillation(BED)is a special method used in the distillation process by adding a solvent into the batch distillation column to alter the relative volatility of the components and improve the separation. A comprehensive design and simulation method is required due to the complexity of BED.In this study,a quasi-steady-state model for BED is proposed,the derivation and solution of the model are presented.This shortcut model can be used to simulate the composition and temperature of the reboiler,the top and other plates of the column in a batch extractive distillation operation.The calculated values are in good agreement with the experimental data.The results show that the quasi-steady-state model is a practical method because of some advantages such as high precision and fast calculation.
基金Supported by the Fundamental Research Funds for the Central Universities(ZY1403)the National Natural Science Foundation of China(No.21406008 and No.U1462127)
文摘A two-stage blade-packing rotating packed bed(TSBP-RPB) was designed and developed for the intensification of continuous distillation. The mass transfer parameters of the TSBP-RPB were investigated using a chemisorption system. Continuous distillation experiments were conducted in the TSBP-RPB by the methanol–water binary system. Experimental results showed that values of the effective interfacial area and liquid-side mass transfer coefficient of the TSBP-RPB were 93–337 m^2·m^(-3) and 0.05–0.19 cm·s^(-1), respectively. The height of equivalent theoretical plate(HETP) of the TSBP-RPB ranged from 1.9 to 10 cm. Moreover, the TSBP-RPB is easy to be manufactured, which shows great potential for the application of continuous distillation.
文摘Peel essential oil of bergamot (Citrus bergamia Risso) growing in Tunisia was separated by hydrodistillation and obtained in a yield of 9.7%. The oil composition was investigated using GC and GC-MS with two columns HP-I and HP-Innowax. Fifteen compounds accounting for 98.52% of the oil were identified. The oil was characterized by bigb content oflimonene (59.21%), linalool (9.51%) and linalyl acetate (16.83%).
基金Supported by Open Research Project of State Key Laboratory of Chemical Engineering(SKL-ChE-16B06)Yangtze Scholars and Innovative Research Team in Chinese University(IRT-17R81)
文摘For separating some specific four component mixtures into four products, the four-product dividing wall column(FPDWC) with two partition walls can provide the same utility consumption with the extended Petlyuk configuration, although with structure simplicity. However, the reluctance to implement this kind of four product dividing wall column industrially also consists in the two uncontrollable vapor splits associated with it. The vapor split ratios are set at the design stage and might not be the optimal value for changed feed composition, thus minimum energy consumption could not be ensured. In the present work, a sequential iterative optimization approach was initially employed to determine the parameters of cost-effective FPDWC. Then the effect of maintaining the vapor split ratios at their nominal value on the energy penalty was investigated for the FPDWC with two partition walls, in case of feed composition disturbance. The result shows that no more than + 2% above the optimal energy requirements could be ensured for 20% feed composition disturbances, which is encouraging for industrial implementation.
文摘This study aimed to model the kinetic of hydro-distillation of Aquilaria malaccensis leaves oil in order to understand and optimize the extraction process. In addition, this study, for the first time, aimed to identify the chemical compositions of the A. rnalaccensis leave-oil. By assessing both first-order kinetic model and the model of simultaneous washing and diffusion, the result indicated that the model of simultaneous washing and diffusion better describes the hydro-distillation mechanism of the essential oil from A. rnalaccensis leaves. The optimum time, solid to liquid ratio, and the heating power for extracting the highest amount of essential oil were found to be around 3 h, 1:10 (g. ml-1), and 300 W respectively. Yellow essential oil with a strong smell and a yield of 0.05 v/w was extracted by hydro-distillation Clevenger apparatus. Chemical compounds of the essential oil were analyzed using gas chromatography-mass spectroscopy (GC/MS), which resulted in identification of 42 compounds that constitute 93% of essential oil. Among the identified components, Pentadecanal (32.082%), 9-Octadecenal, (Z) (15.894%), and Tetradecanal (6.927%) were the major compounds. Considering the fact that all the identified major components possess pesticidal properties, A. malaccensis leaves can be regarded as a promising natural source for producing pesticides.
文摘In this paper, a new approach using artificial neural network and genetic algorithm for the optimization of the thermally coupled distillation is presented. Mathematical model can be constructed with artificial neural network based on the simulation results with ASPEN PLUS. Modified genetic algorithm was used to optimize the model. With the proposed model and optimization arithmetic, mathematical model can be calculated, decision variables and target value can be reached automatically and quickly. A practical example is used to demonstrate the algorithm.
文摘A novel operation of batch distillation-combination of varyingcolumn pressure and total reflux-total efflux is studiedexperimentally. In the operation, the product is accumulated at thetop of the column under total reflux and then drained off completely,and the column pressure is varying in the whole process. This processhas been industrialized successfully with large profits. Theconventional model of batch distillation is improved by this methodeffectively: the separation efficiency and the yield of product areincreased greatly, the operation time is shortened and the productioncost is cut down. Moreover, the amount of condensation water isdecreased and the over-high reboiler temperature is lowered.
文摘Multivessel batch distillation(MVBD) is mainly used to separate mixtures with more than two components. In this article, a new operation mode with MVBD is proposed for separation of binary mixtures under total reflux. A mathematic model is setup for the simulation. The proposed operation policy and the regular operation with constant reflux are compared theoretically and experimentally. The results show that the new operation mode has great advantages in time saving and operation flexibility. MVBD presents great potential for separation with high efficiency.
基金Supported by the Open Lab Project and Innovative Entrepreneurial Project of Institute of Chemical Engineering,Northwest University for NationalitiesFundamental Research Funds for the Central Universities( ZYZ2011063)
文摘[Objective] The study aims to optimize the extracting technology conditions of essential oil from Elsholtzia densa Benth. [Method] Essential oil was extracted from E. densa Benth using steam distillation, and the effects of four extracting factors (grain size of the medicinal herb, ultrasonic time, soaking time and ratio of the material to liquid) on the yield of essential oil extracted from E. densa Benth were analyzed through the orthogonal test. [Result] The optimized extraction process of essential oil from E. densa Benth was as follows: grain size of the medicinal herb 50 mesh, ultrasonic time 12 min, being soaked in the water for 6 h, and ratio of the material to liquid 1∶16 g/ml. Under the conditions, the average extracting rate of the essential oil was 0.407%. [Conclusion] The optimized extraction process of essential oil from E. densa Benth was simple and practicable, and its extracting rate was higher.
文摘The mercury-antimony-gold ore was subjected of the flotation. As a result of enrichment of ore, the mercury-antimony concentrate with the contents of 51.5% Sb, 3.55% Hg and 6 g/t Au was received. Vacuum distillation of concentrate allocation in serial sublimates mercury and antimony was designed. The big amount gold passed to calcine after vacuum distillation. The gold in calcine roastin uo to 900 ℃was 30.6 e/t.
文摘This work describes the separation and purification of lactic acid from diluted solution by HSPE (hybrid short path evaporation) and RD (reactive distillation) as coupled process. The results showed that it is possible to increase lactic acid concentration up to 4.7 times higher than the raw material concentration.
基金supported by the National Natural Science Foundation of China(Grant Nos.41301451&41471349)the Fundamental Research Funds for the Central Universities(Grant No.QN2013074)China’s Qian-Ren Program
文摘Model simulation and in situ observations are often used to research water and carbon cycles in terrestrial ecosystems, but each of these methods has its own advantages and limitations. Combining these two methods could improve the accuracy of quantifying the dynamics of the water and carbon fluxes of an ecosystem. Data assimilation is an effective means of integrating modeling with in situ observation. In this study, the ensemble Kalman filter(En KF) and the unscented Kalman filter(UKF) algorithms were used to assimilate remotely sensed leaf area index(LAI) data with the Biome-BGC model to simulate water and carbon fluxes at the Harvard Forest Environmental Monitoring Site(EMS) and the Dinghushan site. After MODIS LAI data from 2000–2004 were assimilated into the improved Biome-BGC model using the En KF algorithm at the Harvard Forest site, the R2 between the simulated and observed results for NEE and evapotranspiration increased by 7.8% and 4.7%, respectively. In addition, the sum of the absolute error(SAE) and the root mean square error(RMSE) of NEE decreased by an average of 21.9% and 26.3%, and the SAE and RMSE of evapotranspiration decreased by 24.5% and 25.5%, respectively. MODIS LAI data of 2003 were assimilated into the Biome-BGC model for the Dinghushan site, and the R2 values between the simulated and observed results for NEE and evapotranspiration were increased by 6.7% and 17.3%, respectively. In addition, the SAE values of NEE and ET were decreased by 11.3% and 30.7%, respectively, and the RMSE values of NEE and ET decreased by 10.1% and 30.9%, respectively. These results demonstrate that the accuracy of carbon and water flux simulations can be effectively improved when remotely sensed LAI data are properly integrated with ecosystem models through a data assimilation approach.
基金Breeding Research Project of Chinese Medical Herbs in Sichuan Province:Study on the breeding of new Chaihu variety and cultivation and the related techniques(No.2011NZ0098-12-11)China Spark Program in 2010(No.2010GA810056)
文摘OBJECTIVE: To analyze the essential oils from flowers, leaves, stems, roots, and fruits of Chaihu(Radix Bupleuri Chinensis).METHODS: We extracted essential oils from different parts of Chaihu(Radix Bupleuri Chinensis) using a steam distillation method. The essential oils were analyzed by gas chromatography-mass spectrometry(GC-MS). Data were collected in full scan mode(m/z 60-600). Volatile components were identified based on their retention indices and by comparing their mass spectra with those in the National Institute of Standards and Technology 2005 database assisted by tandem mass spectrometry information. The relative content of each constituent wasdetermined by area normalization.RESULTS: We identified 111 components, of which12 were common to all 5 parts, 30 were found only in roots, 14 were found only in flowers, 6 were found only in leaves, 4 were found only in stems,and 17 were found only in fruits.CONCLUSION: Our results show that the stems,flowers, leaves, and fruits of Chaihu(Radix Bupleuri Chinensis)contain a high concentration of essential oils, and that the exact composition of the essential oils differs among the plant parts. To develop new medicines and make full use of the Chaihu(Radix Bupleuri Chinensis)resource, it is important to characterize the essential oils from different parts of the plant. In future research, it will be important to determine the pharmacological effects of the various components and the essential oil mixtures.