Neogambogic acid is characterized by broad antitumor spectrum,good antitumor effect and low toxicity and side effects.This paper reviews the purification process,content determination and pharmacologic activity of neo...Neogambogic acid is characterized by broad antitumor spectrum,good antitumor effect and low toxicity and side effects.This paper reviews the purification process,content determination and pharmacologic activity of neogambogic acid,in order to provide a theoretical reference for the research and application of neogambogic acid.展开更多
This study reports an investigation into the degradation of 2,4-dichlorophenoxyacetic acid in bubble contactor column by O2/H2O2 process, which is widely used as a principal advanced oxidation process. The degradation...This study reports an investigation into the degradation of 2,4-dichlorophenoxyacetic acid in bubble contactor column by O2/H2O2 process, which is widely used as a principal advanced oxidation process. The degradation of 2,4-dichlorophenoxyacetic acid was studied under different H202/O3 molar ratio and pH value. Meanwhile, TOC removal was investigated both in distilled water and tap water. The influences of ozone transfer and consumed hydrogen peroxide were also discussed. The degradation products and oxidation intermediates were identified by GC-MS and LC-MS. A possible reaction mechanism was thus proposed.展开更多
In this study,advanced oxidation processes(AOPs) such as anodic oxidation(AO),UV/H_2O_2 and Fenton processes(FP) were investigated for the degradation of salicylic acid(SA) in lab-scale experiments.Boron-doped diamond...In this study,advanced oxidation processes(AOPs) such as anodic oxidation(AO),UV/H_2O_2 and Fenton processes(FP) were investigated for the degradation of salicylic acid(SA) in lab-scale experiments.Boron-doped diamond(BDD) film electrodes using Ta as substrates were employed for AO of SA.In the case of FP and UV/H_2O_2,most favorable experimental conditions were determined for each process and these were used for comparing with AO process.The study showed that the FP was the most effective process under aci...展开更多
High-concentration nitrite-containing wastewater that presents extreme toxicity to human health and organisms is difficult to be treated using traditional biological process. In this study, a novel microwave-enhanced ...High-concentration nitrite-containing wastewater that presents extreme toxicity to human health and organisms is difficult to be treated using traditional biological process. In this study, a novel microwave-enhanced chemical reduction process (MECRP) using sulfarninic acid (SA) was proposed as a new manner to treat such type of wastewater. Based on lab-scale experiments, it was shown that 75%-80% nitrite (NO2-) could be removed within time as short as 4 min under 50 W microwave irradiation in pH range 5-10 when molar ratio of SA to nitrite (SA/NO2-) was 0.8. Pilot-scale investigations demonstrated that MECRP was able to achieve nitrite and chemical oxygen demand (COD) removal with efficiency up to 80% and 20%, respectively under operating conditions of SA concentration 80 kg/m3, SA/NO2- ratio 0.8, microwave power 3.4 kW, and stirring time 3 min. Five-day biological oxygen demand (BODs)/COD value of treated effluent after MECRP was increased from 0.05 to 0.36 (by 620%), which clearly suggested a considerable improvement of biodegradability for subsequent biological treatment. This study provided a demonstration of using microwave irradiation to enhance reaction between SA and nitrite in a short time, in which nitrite in wastewater was completely converted into nitrogen gas without leaving any sludge and secondary pollutants.展开更多
Multi-objective optimization of a purified terephthalic acid (PTA) oxidation unit is carried out in this paper by using a process modei that has been proved to describe industrial process quite well. The modei is a se...Multi-objective optimization of a purified terephthalic acid (PTA) oxidation unit is carried out in this paper by using a process modei that has been proved to describe industrial process quite well. The modei is a semi-empirical structured into two series ideal continuously stirred tank reactor (CSTR) models. The optimal objectives include maximizing the yield or inlet rate and minimizing the concentration of 4-carboxy-benzaldhyde, which is the main undesirable intermediate product in the reaction process. The multi-objective optimization algorithra applied in this study is non-dominated sorting genetic algorithm Ⅱ (NSGA-Ⅱ). The performance of NSGA-Ⅱ is further illustrated by application to the title process.展开更多
Leaching kinetics of acid-soluble Cr(VI) in chromite ore processing residue (COPR) using hydrofluoric (HF) acid solution as a leaching agent was investigated for potential remediation of COPR with industrial was...Leaching kinetics of acid-soluble Cr(VI) in chromite ore processing residue (COPR) using hydrofluoric (HF) acid solution as a leaching agent was investigated for potential remediation of COPR with industrial waste water containing HF. The results show that HF can effectively destabilize the Cr(VI)-bearing minerals, resulting in the mobilization of Cr(VI) from COPR into the leachate. Particle size significantly influences the leaching of acid-soluble Cr(VI) from COPR, followed by leaching time, whereas the effects of HF concentration and leaching temperature are slight and the influence of stirring rate is negligible. The leaching process of acid-soluble Cr(VI) from COPR is controlled by the diffusion through the product layer. The apparent activation energy is 8.696 kJ/mol and the reaction orders with respect to HF concentration and particle size is 0.493 8 and -2.013 3, respectively.展开更多
There exists the most important REE-bearing phosphorite deposit in Southwest of China. Due to the fact that the REE are present in the form of ions in the lattices of collophanite or carbonatfluorapatite, the REE can ...There exists the most important REE-bearing phosphorite deposit in Southwest of China. Due to the fact that the REE are present in the form of ions in the lattices of collophanite or carbonatfluorapatite, the REE can be enriched in phosphate concentrate by flotation method. The phosphate concentrate is the main raw materials to produce phosphoric acid, therefore, it is significant to further investigate the distribution rule of REE in wet process. In this paper, the single leaching and recycled leaching technology were carried out to investigate the effect of various parameter conditions on distribution of REE in products. The REE compositions of products were analyzed by Inductively Coupled Plasma Emission Mass Spectrometry (ICP-MS) method. It was found that the acidic value of leaching liquor was the main effect factor on the distribution of REE in products. In single leaching stage, P2O5 concentration of leaching liquor slightly varied from 8% to about 10% when the excessive coefficient of sulphuric acid ranged from 1.03 to 1.05, and the distribution proportions of ∑REO in phosphoric acid solution was lower than 40%. However, in recycled leaching process(the condition similar to practical wet process), with an increase of P2O5 concentration as well as the acidic value of leaching liquor, the distribution proportions of ∑REO in phosphoric acid solution could be decreased to 2.56%. That is to say that under the condition similar to practical wet process, more than 90% of REE of phosphate concentrate became precipitation entering into the phosphogypsum product. This investigation will provide valid reference for reasonably recovering or reserving REE in wet-phosphoric acid process.展开更多
A new hydrometallurgical process based on the methanesulfonic acid system was proposed to extract the bismuth efficiently from by-products of lead smelting.The bismuth extraction process included electrorefining,oxida...A new hydrometallurgical process based on the methanesulfonic acid system was proposed to extract the bismuth efficiently from by-products of lead smelting.The bismuth extraction process included electrorefining,oxidation leaching,and electrodeposition.The optimum conditions of the bismuth extraction process were determined by a single-factor test.The bismuth plate with a purity of 99.8%was obtained under the optimum conditions.Cyclic voltammetry and linear sweep voltammetry were applied to investigating the cathode reaction mechanism of electrorefining.The results show that lead deposition,bismuth deposition,and hydrogen evolution occur at the cathode,and the reactions of metals deposition are irreversible and diffusion-controlled.In addition,decreasing the temperature and acidity can improve the purity of the cathodic product(lead powder)in the electrorefining process.展开更多
A devised beating process was applied, which enabled the formation of slurry consisting of uniformly dispersed fibrillated polylactic acid(PLA) fibers with bamboo fiber, and the polymer material was obtained by a co...A devised beating process was applied, which enabled the formation of slurry consisting of uniformly dispersed fibrillated polylactic acid(PLA) fibers with bamboo fiber, and the polymer material was obtained by a conventional papermaking process. Owing to the fast dewatering time, good repeatability and the facility to manufacture on a large scale, this process was used. It was revealed that the beaten PLA fiber was overall in machinery extrusion by the results of optical microscope and scanning electron microscope(SEM) observations. The improvement in the tensile index, burst index, tear index and other mechanical properties was considered as a key benefit as a result of adding bamboo fiber.展开更多
Hyaluronic acid (HA) is a high molecular weight glycosaminoglycan consisting of alternating D-glucuronic acid and N-acetylglueasamine and plays ex- tremely important roles in many biological processes. In this study...Hyaluronic acid (HA) is a high molecular weight glycosaminoglycan consisting of alternating D-glucuronic acid and N-acetylglueasamine and plays ex- tremely important roles in many biological processes. In this study, we optimized fermentation process for the production of HA by Streptococcus zooepidemicus ATCC35246, including fermentation broth composition and various fermentation parameters. The experimental results showed that the optimal fermentation broth composition was: glucose 45 g/L, yeast extract 10 g/L, tryptone 12 g/L, KH2PO4 2 g/L, K2HPO4 . 3H20 2 g/L, MgSO4 · 7H2O 2 g/L, and (NH4 )2SO4 0.4 g/L. The optimal parameters involved in fermentation was: liquid volume 20%, pH 6. 0, rotation speed 180 r/min, fermentation temperature 35 ℃, fermentation duration 18 h, CTAB concentration 25 mg/L. Under the optimized conditions, the yield of HA was 0. 305 g/L, which was dramatically improved by 43.87% compared to that of 0. 212 g/L before optimization.展开更多
Iodine-sulfur (IS) thermochemical water-splitting cycle is the most promising massive hydrogen production process. To avoid the undesirable side reactions between hydriodic acid(HI) and sulfuric acid (H2SO4), it...Iodine-sulfur (IS) thermochemical water-splitting cycle is the most promising massive hydrogen production process. To avoid the undesirable side reactions between hydriodic acid(HI) and sulfuric acid (H2SO4), it is necessary to purify the two phases formed by the Bunsen reaction. The purification process could be achieved by reverse reaction of the Bunsen reaction. In this study, the purification of the H2SO4 and HI Phases was studied. The purification proceeded in both batches and the continuous mode, the influences of operational parameters, including the reaction temperature, the flow rate of nitrogen gas, and the composition of the raw material solutions, on the purification effect, were investigated. Results showed that the purification of the H2SO4 phase was dominantly-affected by the reaction temperature, and iodine ion in the sulfuric acid phase could be removed completely when the temperature was above 130℃; although, the purification effect of the HI phase improved with increasing of both the flow rate of nitrogen gas and temperature.展开更多
The objective of this study was to establish the thermal characteristics of the lauric acid (95% purity) as a latent heat storage material filled in the annulus of vertical concentric double pipe during its melting pr...The objective of this study was to establish the thermal characteristics of the lauric acid (95% purity) as a latent heat storage material filled in the annulus of vertical concentric double pipe during its melting process,The temperature data were used to determine the thermal characteristics,including the temporal temperature variations and the effects of the mass flow rate and the inlet temperature of the heat transfer fluid on the heat transfer coefficient and the heat charging fraction during the melting process,The results indicated that the time to reach to heat charging fraction of 1.0 could be altered by changing the mass flow rate and the inlet temperature of the heat transfer fluid.展开更多
[Objectives] To establish a method for determining the content of Laggera alata( D. Don) Sch. Bip. Ex Oliv. using caffeic acid the target component,and to compare the content of caffeic acid in the medicinal materials...[Objectives] To establish a method for determining the content of Laggera alata( D. Don) Sch. Bip. Ex Oliv. using caffeic acid the target component,and to compare the content of caffeic acid in the medicinal materials of L. alata in different production areas of Guangxi.[Methods]The content was determined by Inertsil~ODS-3 chromatographic column C_(18)( 4. 60 mm × 250 mm,5 μm,mobile phase: acetonitrile-0. 1% phosphoric acid( 22∶ 78),detection wavelength: 320 nm,flow rate: 1. 0 m L/min,column temperature: 30℃,and injection volume: 10 μL. [Results] The caffeic acid showed a good linear relationship in the range of injection volume of 0. 025 92-0. 259 2 μg( R =0. 999 5). The average recovery rate was 98. 33%( RSD = 1. 85%). L. alata in different production areas of Guangxi contained the caffeic acid,and there was a great difference in the caffeic acid. L. alata in Baise had the highest content of caffeic acid,while that in Guilin had the lowest content of caffeic acid. [Conclusions]This method can accurately determine the content of caffeic acid and is expected provide a scientific basis for the development and utilization of herbal medicine L. alata.展开更多
Adipic acid is an important petrochemical product,and its production process emits a high concentration of greenhouse gas N_2 O.This paper aims to provide quantitative references for relevant authorities to formulate ...Adipic acid is an important petrochemical product,and its production process emits a high concentration of greenhouse gas N_2 O.This paper aims to provide quantitative references for relevant authorities to formulate greenhouse gas control roadmaps.The forecasting method of this paper is consistent with the published national inventory in terms of caliber.Based on the N_2 O abatement technical parameters of adipic acid and the production trend,this paper combines the scenario analysis and provides a measurement of comprehensive N_2 O abatement effect of the entire industry in China.Four future scenarios are assumed.The baseline scenario(BAUS) is a frozen scenario.Three emission abatement scenarios(ANAS,SNAS,and ENAS) are assumed under different strength of abatement driving parameters.The results show that China's adipic acid production process can achieve increasingly significant N_2 O emission abatement effects.Compared to the baseline scenario,by 2030,the N_2 O emission abatements of the three emission abatement scenarios can reach 207-399 kt and the emission abatement ratios can reach 32.5%-62.6%.By 2050,the N_2 O emission abatements for the three emission abatement scenarios can reach 387-540 kt and the emission abatement ratios can reach 71.4%-99.6%.展开更多
This paper has reviewed that Omega 3 polyunsaturated fatty acids (PUFAs), as an essential fatty acids (EFAs), mainly come from fish oil of marine products, has positive effects on treatment and/or prevention of severa...This paper has reviewed that Omega 3 polyunsaturated fatty acids (PUFAs), as an essential fatty acids (EFAs), mainly come from fish oil of marine products, has positive effects on treatment and/or prevention of several diseases. In this review, the recent developments by 2019 in the field of enzymatic modification of oils rich in omega 3 PUFAs have summarized. Several different products, such as structured lipids with a variety of FA compositions, nutritional aspects, omega 3 PUFA concentrates and phospholipids,have discussed from the point of process technology as well as possible applications. Enhancing omega 3 PUFA content in diet involves a number of strategies aiming to modify the content of such FAs in fats and oils. Due to the mild reaction conditions used, especially the lipase specificity, the position as well as content of omega 3 PUFAs in lipid molecules being of importance from the point of bioavailability, enzymatic processing of omega 3 PUFA oil is safe, efficient and preferred over chemical treatments.展开更多
The cleaning process of removing oxides on the surface of copper alloy sheetswas investigated systematically. Through optimizing, a perfect process was selected that is fit forremoving oxides on the surface. By acid p...The cleaning process of removing oxides on the surface of copper alloy sheetswas investigated systematically. Through optimizing, a perfect process was selected that is fit forremoving oxides on the surface. By acid pickling, all kinds of copper oxides are removedcompletely, furthermore, no poisonous gases are given out and a smooth and clean surface of copperalloys is obtained. At present, the process is applied successfully in the copper-processingindustry.展开更多
We studied the decomposition of two haloacetic acids (HAAs),dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA),in water by single oxidants ozone (O3) and ultraviolet radiation (UV) and the advanced oxidation p...We studied the decomposition of two haloacetic acids (HAAs),dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA),in water by single oxidants ozone (O3) and ultraviolet radiation (UV) and the advanced oxidation processes (AOPs) constituted by the combinations of O3/UV,H2O2/UV,O3 /H2O2,and O3/H2O2/UV. The concentrations of HAAs were analyzed at specified time intervals to track their decomposition. Except for O3 and UV,the four combined oxidation processes remarkably enhance the decomposition of DCAA and TCAA owing to the generated very reactive hydroxyl radicals. The fastest decomposition process is O3/H2O2/UV,closely followed by O3/UV. DCAA is much easier to decompose than TCAA. The kinetics of HAA decomposition by O3/UV can be described well by a pseudo first-order reaction model under a constant initial dissolved O3 concentration and fixed UV radiation. Humic acids and HCO3-in the reaction system both decrease the decomposition rate constants for DCAA and TCAA. The amount of H2O2 accumulates in the presence of humic acids in the O3/UV process.展开更多
[Objectives]This paper aims to establish thin-layer identification and content determination method for Laggera alata(D.Don)Sch.Bip.ex Oliv.with chlorogenic acid as the index component and compare the content of chlor...[Objectives]This paper aims to establish thin-layer identification and content determination method for Laggera alata(D.Don)Sch.Bip.ex Oliv.with chlorogenic acid as the index component and compare the content of chlorogenic acid in L.alata from different places in Guangxi.[Methods]Silica gel GF254 thin-layer plate was used for identification under an ultraviolet lamp(365 nm),with butyl acetate-formic acid-water(V∶V∶V=7∶2.5∶2.5)as a developing agent.The content of chlorogenic acid was determined under the following chromatographic conditions:column,Inertsil ODS-3 C18 column(4.60 mm×250 mm,5μm);mobile phase,methanol-0.1%phosphoric acid(28∶72);detection wavelength,329 nm;flow rate,1.0 mL/min;column temperature,25℃;and injection volume,10μL.[Results]Chlorogenic acid can be detected by thin layer chromatography with clear spot and good specificity.Chlorogenic acid showed a good linear relationship in the injection amount range of 0.099-0.99μg(R^(2)=0.9999).The content of chlorogenic acid in L.alata varied greatly among the 10 different producing areas in Guangxi.L.alata produced in Dee Township,Longlin,Baise,Guangxi showed the highest chlorogenic acid content,and that produced in Shangsi County and Pingle County showed the lowest chlorogenic acid content.[Conclusions]This method can effectively identify L.alata and accurately determine the content of chlorogenic acid,thereby providing a scientific basis for the development and utilization of L.alata resources.展开更多
In this work, a procedure to simulate the MD (molecular distillation) process for lactic acid purification was developed. The simulation was carried out with the aid of the Aspen Plus Process Simulator. Flash vessel...In this work, a procedure to simulate the MD (molecular distillation) process for lactic acid purification was developed. The simulation was carried out with the aid of the Aspen Plus Process Simulator. Flash vessel was used to represent the MD process since the software does not present this unit operation. The simulation results with efficiency factors were in agreement with previously reported experimental data.展开更多
[Objectives]Taking chlorogenic acid as index component,TLC and content determination method of Laggerae Alatae Herba were established.[Methods]TLC identification used silica gel G thin-layer plate,and butyl acetate∶f...[Objectives]Taking chlorogenic acid as index component,TLC and content determination method of Laggerae Alatae Herba were established.[Methods]TLC identification used silica gel G thin-layer plate,and butyl acetate∶formic acid∶water(7∶2.5∶2.5)was taken as developing agent,and it was inspected under ultraviolet lamp(365 nm).The content was determined by chromatographic column Inertsil ODS-3 C_(18)(4.60 mm×250 mm,5μm).Mobile phase:methanol-0.1%phosphoric acid(28∶72);detection wavelength:329 nm;flow speed:1.0 mL/min;column temperature:25℃;injection volume:10μL.[Results]Chlorogenic acid can be detected by TLC,with clear spots and good specificity.When injection volume of chlorogenic acid was between 0.099 and 0.990μg(R^(2)=0.9999),there was good linear relationship.In low,medium and high sample adding groups of Laggerae Alatae Herba,average recovery rates of chlorogenic acids were 98.80%(RSD=2.09%),98.24%(RSD=1.96%)and 99.65%(RSD=2.15%).[Conclusions]The method could effectively identify medicinal material Laggerae Alatae Herba,and accurately measure the content of chlorogenic acid in Laggerae Alatae Herba,thereby providing a scientific basis for developing and using medicinal resources of Laggerae Alatae Herba.展开更多
基金Central Government Supports Local College Reform and Development Fund Talent Training Projects(2020GSP16)Heilongjiang Provincial Key Research and Development Plan Guidance Project(GZ20220039)Postgraduate Innovative Research Project of Heilongjiang Bayi Agricultural University(YJSCX2022-Y55).
文摘Neogambogic acid is characterized by broad antitumor spectrum,good antitumor effect and low toxicity and side effects.This paper reviews the purification process,content determination and pharmacologic activity of neogambogic acid,in order to provide a theoretical reference for the research and application of neogambogic acid.
基金The National Natural Science Foundation of China (No. 50378028)
文摘This study reports an investigation into the degradation of 2,4-dichlorophenoxyacetic acid in bubble contactor column by O2/H2O2 process, which is widely used as a principal advanced oxidation process. The degradation of 2,4-dichlorophenoxyacetic acid was studied under different H202/O3 molar ratio and pH value. Meanwhile, TOC removal was investigated both in distilled water and tap water. The influences of ozone transfer and consumed hydrogen peroxide were also discussed. The degradation products and oxidation intermediates were identified by GC-MS and LC-MS. A possible reaction mechanism was thus proposed.
文摘In this study,advanced oxidation processes(AOPs) such as anodic oxidation(AO),UV/H_2O_2 and Fenton processes(FP) were investigated for the degradation of salicylic acid(SA) in lab-scale experiments.Boron-doped diamond(BDD) film electrodes using Ta as substrates were employed for AO of SA.In the case of FP and UV/H_2O_2,most favorable experimental conditions were determined for each process and these were used for comparing with AO process.The study showed that the FP was the most effective process under aci...
基金supported by the National Natural Science Foundation of China (No.50678045)
文摘High-concentration nitrite-containing wastewater that presents extreme toxicity to human health and organisms is difficult to be treated using traditional biological process. In this study, a novel microwave-enhanced chemical reduction process (MECRP) using sulfarninic acid (SA) was proposed as a new manner to treat such type of wastewater. Based on lab-scale experiments, it was shown that 75%-80% nitrite (NO2-) could be removed within time as short as 4 min under 50 W microwave irradiation in pH range 5-10 when molar ratio of SA to nitrite (SA/NO2-) was 0.8. Pilot-scale investigations demonstrated that MECRP was able to achieve nitrite and chemical oxygen demand (COD) removal with efficiency up to 80% and 20%, respectively under operating conditions of SA concentration 80 kg/m3, SA/NO2- ratio 0.8, microwave power 3.4 kW, and stirring time 3 min. Five-day biological oxygen demand (BODs)/COD value of treated effluent after MECRP was increased from 0.05 to 0.36 (by 620%), which clearly suggested a considerable improvement of biodegradability for subsequent biological treatment. This study provided a demonstration of using microwave irradiation to enhance reaction between SA and nitrite in a short time, in which nitrite in wastewater was completely converted into nitrogen gas without leaving any sludge and secondary pollutants.
基金National Key Technologies Research and Development Program in the 10th Five-year Phan(No.2001BA204B01)National Outstanding Youth Science Foundation of China(No.60025308)
文摘Multi-objective optimization of a purified terephthalic acid (PTA) oxidation unit is carried out in this paper by using a process modei that has been proved to describe industrial process quite well. The modei is a semi-empirical structured into two series ideal continuously stirred tank reactor (CSTR) models. The optimal objectives include maximizing the yield or inlet rate and minimizing the concentration of 4-carboxy-benzaldhyde, which is the main undesirable intermediate product in the reaction process. The multi-objective optimization algorithra applied in this study is non-dominated sorting genetic algorithm Ⅱ (NSGA-Ⅱ). The performance of NSGA-Ⅱ is further illustrated by application to the title process.
基金Project(2009FJ1009) supported by Major Program of Hunan Provincial Science and Technology, ChinaProject(2005CB6237) supported by the National Basic Research Program of China
文摘Leaching kinetics of acid-soluble Cr(VI) in chromite ore processing residue (COPR) using hydrofluoric (HF) acid solution as a leaching agent was investigated for potential remediation of COPR with industrial waste water containing HF. The results show that HF can effectively destabilize the Cr(VI)-bearing minerals, resulting in the mobilization of Cr(VI) from COPR into the leachate. Particle size significantly influences the leaching of acid-soluble Cr(VI) from COPR, followed by leaching time, whereas the effects of HF concentration and leaching temperature are slight and the influence of stirring rate is negligible. The leaching process of acid-soluble Cr(VI) from COPR is controlled by the diffusion through the product layer. The apparent activation energy is 8.696 kJ/mol and the reaction orders with respect to HF concentration and particle size is 0.493 8 and -2.013 3, respectively.
基金the Natural Science Foundation of Guizhou Province (QianKeHe J[2005]2098)
文摘There exists the most important REE-bearing phosphorite deposit in Southwest of China. Due to the fact that the REE are present in the form of ions in the lattices of collophanite or carbonatfluorapatite, the REE can be enriched in phosphate concentrate by flotation method. The phosphate concentrate is the main raw materials to produce phosphoric acid, therefore, it is significant to further investigate the distribution rule of REE in wet process. In this paper, the single leaching and recycled leaching technology were carried out to investigate the effect of various parameter conditions on distribution of REE in products. The REE compositions of products were analyzed by Inductively Coupled Plasma Emission Mass Spectrometry (ICP-MS) method. It was found that the acidic value of leaching liquor was the main effect factor on the distribution of REE in products. In single leaching stage, P2O5 concentration of leaching liquor slightly varied from 8% to about 10% when the excessive coefficient of sulphuric acid ranged from 1.03 to 1.05, and the distribution proportions of ∑REO in phosphoric acid solution was lower than 40%. However, in recycled leaching process(the condition similar to practical wet process), with an increase of P2O5 concentration as well as the acidic value of leaching liquor, the distribution proportions of ∑REO in phosphoric acid solution could be decreased to 2.56%. That is to say that under the condition similar to practical wet process, more than 90% of REE of phosphate concentrate became precipitation entering into the phosphogypsum product. This investigation will provide valid reference for reasonably recovering or reserving REE in wet-phosphoric acid process.
基金financial supports from the National Key Research and Development Program of China(No.2018YFC1900403)。
文摘A new hydrometallurgical process based on the methanesulfonic acid system was proposed to extract the bismuth efficiently from by-products of lead smelting.The bismuth extraction process included electrorefining,oxidation leaching,and electrodeposition.The optimum conditions of the bismuth extraction process were determined by a single-factor test.The bismuth plate with a purity of 99.8%was obtained under the optimum conditions.Cyclic voltammetry and linear sweep voltammetry were applied to investigating the cathode reaction mechanism of electrorefining.The results show that lead deposition,bismuth deposition,and hydrogen evolution occur at the cathode,and the reactions of metals deposition are irreversible and diffusion-controlled.In addition,decreasing the temperature and acidity can improve the purity of the cathodic product(lead powder)in the electrorefining process.
基金Funded by thethe National Key Technology R&D Program for the 12th Five-Year Plan(No.2013BAC01B03)the Fundamental Research Funds for the Central Universties(2014ZZ0062)
文摘A devised beating process was applied, which enabled the formation of slurry consisting of uniformly dispersed fibrillated polylactic acid(PLA) fibers with bamboo fiber, and the polymer material was obtained by a conventional papermaking process. Owing to the fast dewatering time, good repeatability and the facility to manufacture on a large scale, this process was used. It was revealed that the beaten PLA fiber was overall in machinery extrusion by the results of optical microscope and scanning electron microscope(SEM) observations. The improvement in the tensile index, burst index, tear index and other mechanical properties was considered as a key benefit as a result of adding bamboo fiber.
基金Supported by Scientific Research Fund of Sichuan University of Science&Engineering(2011RC12,2014KY02)Scientific Research Foundation of the Education Department of Sichuan Province(15ZA0222)+1 种基金Research Project of Liquor Making Biological Technology and Application of Key Laboratory of Sichuan Province(NJ2013-06)Sichuan Provincial Undergraduate Training Programs for Innovation and Entrepreneurship(201410622021)
文摘Hyaluronic acid (HA) is a high molecular weight glycosaminoglycan consisting of alternating D-glucuronic acid and N-acetylglueasamine and plays ex- tremely important roles in many biological processes. In this study, we optimized fermentation process for the production of HA by Streptococcus zooepidemicus ATCC35246, including fermentation broth composition and various fermentation parameters. The experimental results showed that the optimal fermentation broth composition was: glucose 45 g/L, yeast extract 10 g/L, tryptone 12 g/L, KH2PO4 2 g/L, K2HPO4 . 3H20 2 g/L, MgSO4 · 7H2O 2 g/L, and (NH4 )2SO4 0.4 g/L. The optimal parameters involved in fermentation was: liquid volume 20%, pH 6. 0, rotation speed 180 r/min, fermentation temperature 35 ℃, fermentation duration 18 h, CTAB concentration 25 mg/L. Under the optimized conditions, the yield of HA was 0. 305 g/L, which was dramatically improved by 43.87% compared to that of 0. 212 g/L before optimization.
基金Supported by the National Defense Fundamental Research Fund (A1420080145)
文摘Iodine-sulfur (IS) thermochemical water-splitting cycle is the most promising massive hydrogen production process. To avoid the undesirable side reactions between hydriodic acid(HI) and sulfuric acid (H2SO4), it is necessary to purify the two phases formed by the Bunsen reaction. The purification process could be achieved by reverse reaction of the Bunsen reaction. In this study, the purification of the H2SO4 and HI Phases was studied. The purification proceeded in both batches and the continuous mode, the influences of operational parameters, including the reaction temperature, the flow rate of nitrogen gas, and the composition of the raw material solutions, on the purification effect, were investigated. Results showed that the purification of the H2SO4 phase was dominantly-affected by the reaction temperature, and iodine ion in the sulfuric acid phase could be removed completely when the temperature was above 130℃; although, the purification effect of the HI phase improved with increasing of both the flow rate of nitrogen gas and temperature.
文摘The objective of this study was to establish the thermal characteristics of the lauric acid (95% purity) as a latent heat storage material filled in the annulus of vertical concentric double pipe during its melting process,The temperature data were used to determine the thermal characteristics,including the temporal temperature variations and the effects of the mass flow rate and the inlet temperature of the heat transfer fluid on the heat transfer coefficient and the heat charging fraction during the melting process,The results indicated that the time to reach to heat charging fraction of 1.0 could be altered by changing the mass flow rate and the inlet temperature of the heat transfer fluid.
基金Supported by Project of National Natural Science Foundation(81660701&81260673)Project of Guangxi Graduate Education Innovation(YJS201625)+2 种基金Natural Science Foundation Project of Guangxi(2016GXNSFAA380148&2014GXNSFAA118208)Program of Key Laboratory for Purification and Quality Analysis of TCM Extraction in Guangxi Universities(Gui Jiao Ke Yan[2014]No.6)Laboratory of Chemistry and Quality Analysis in the Third Level Laboratory for Research of TCM(Zhuang)of State Administration of Traditional Chinese Medicine(Guo Zhong Yi Yao Fa[200]No.21)
文摘[Objectives] To establish a method for determining the content of Laggera alata( D. Don) Sch. Bip. Ex Oliv. using caffeic acid the target component,and to compare the content of caffeic acid in the medicinal materials of L. alata in different production areas of Guangxi.[Methods]The content was determined by Inertsil~ODS-3 chromatographic column C_(18)( 4. 60 mm × 250 mm,5 μm,mobile phase: acetonitrile-0. 1% phosphoric acid( 22∶ 78),detection wavelength: 320 nm,flow rate: 1. 0 m L/min,column temperature: 30℃,and injection volume: 10 μL. [Results] The caffeic acid showed a good linear relationship in the range of injection volume of 0. 025 92-0. 259 2 μg( R =0. 999 5). The average recovery rate was 98. 33%( RSD = 1. 85%). L. alata in different production areas of Guangxi contained the caffeic acid,and there was a great difference in the caffeic acid. L. alata in Baise had the highest content of caffeic acid,while that in Guilin had the lowest content of caffeic acid. [Conclusions]This method can accurately determine the content of caffeic acid and is expected provide a scientific basis for the development and utilization of herbal medicine L. alata.
基金financial support by the Ministry of Science and Technology of China (Grant No.2018YFC1509006)the National Natural Science Foundation of China (Grant No.71874096)+1 种基金the Macao SAR Government Higher Education Fundthe Macao University of Science and Technology (Grant No.FRG-19-008-MSB)。
文摘Adipic acid is an important petrochemical product,and its production process emits a high concentration of greenhouse gas N_2 O.This paper aims to provide quantitative references for relevant authorities to formulate greenhouse gas control roadmaps.The forecasting method of this paper is consistent with the published national inventory in terms of caliber.Based on the N_2 O abatement technical parameters of adipic acid and the production trend,this paper combines the scenario analysis and provides a measurement of comprehensive N_2 O abatement effect of the entire industry in China.Four future scenarios are assumed.The baseline scenario(BAUS) is a frozen scenario.Three emission abatement scenarios(ANAS,SNAS,and ENAS) are assumed under different strength of abatement driving parameters.The results show that China's adipic acid production process can achieve increasingly significant N_2 O emission abatement effects.Compared to the baseline scenario,by 2030,the N_2 O emission abatements of the three emission abatement scenarios can reach 207-399 kt and the emission abatement ratios can reach 32.5%-62.6%.By 2050,the N_2 O emission abatements for the three emission abatement scenarios can reach 387-540 kt and the emission abatement ratios can reach 71.4%-99.6%.
文摘This paper has reviewed that Omega 3 polyunsaturated fatty acids (PUFAs), as an essential fatty acids (EFAs), mainly come from fish oil of marine products, has positive effects on treatment and/or prevention of several diseases. In this review, the recent developments by 2019 in the field of enzymatic modification of oils rich in omega 3 PUFAs have summarized. Several different products, such as structured lipids with a variety of FA compositions, nutritional aspects, omega 3 PUFA concentrates and phospholipids,have discussed from the point of process technology as well as possible applications. Enhancing omega 3 PUFA content in diet involves a number of strategies aiming to modify the content of such FAs in fats and oils. Due to the mild reaction conditions used, especially the lipase specificity, the position as well as content of omega 3 PUFAs in lipid molecules being of importance from the point of bioavailability, enzymatic processing of omega 3 PUFA oil is safe, efficient and preferred over chemical treatments.
文摘The cleaning process of removing oxides on the surface of copper alloy sheetswas investigated systematically. Through optimizing, a perfect process was selected that is fit forremoving oxides on the surface. By acid pickling, all kinds of copper oxides are removedcompletely, furthermore, no poisonous gases are given out and a smooth and clean surface of copperalloys is obtained. At present, the process is applied successfully in the copper-processingindustry.
基金Natural Science Foundation of Chongqing under Grant No. CSTC2008BB7299.
文摘We studied the decomposition of two haloacetic acids (HAAs),dichloroacetic acid (DCAA) and trichloroacetic acid (TCAA),in water by single oxidants ozone (O3) and ultraviolet radiation (UV) and the advanced oxidation processes (AOPs) constituted by the combinations of O3/UV,H2O2/UV,O3 /H2O2,and O3/H2O2/UV. The concentrations of HAAs were analyzed at specified time intervals to track their decomposition. Except for O3 and UV,the four combined oxidation processes remarkably enhance the decomposition of DCAA and TCAA owing to the generated very reactive hydroxyl radicals. The fastest decomposition process is O3/H2O2/UV,closely followed by O3/UV. DCAA is much easier to decompose than TCAA. The kinetics of HAA decomposition by O3/UV can be described well by a pseudo first-order reaction model under a constant initial dissolved O3 concentration and fixed UV radiation. Humic acids and HCO3-in the reaction system both decrease the decomposition rate constants for DCAA and TCAA. The amount of H2O2 accumulates in the presence of humic acids in the O3/UV process.
基金Basic Research Ability Enhancement Project for Young and Middle-aged Teachers in Colleges and Universities of Guangxi in 2019(No.2019KY0341)National Traditional Chinese Medicine Special Technology Inheritance Talent Training Project 2016+1 种基金Open Project of Guangxi Zhuang Yao Pharmaceutical Engineering Technology Research Center(No.KJT1900105)Youth Foundation of Guangxi University of Chinese Medicine(No.2019QN036).
文摘[Objectives]This paper aims to establish thin-layer identification and content determination method for Laggera alata(D.Don)Sch.Bip.ex Oliv.with chlorogenic acid as the index component and compare the content of chlorogenic acid in L.alata from different places in Guangxi.[Methods]Silica gel GF254 thin-layer plate was used for identification under an ultraviolet lamp(365 nm),with butyl acetate-formic acid-water(V∶V∶V=7∶2.5∶2.5)as a developing agent.The content of chlorogenic acid was determined under the following chromatographic conditions:column,Inertsil ODS-3 C18 column(4.60 mm×250 mm,5μm);mobile phase,methanol-0.1%phosphoric acid(28∶72);detection wavelength,329 nm;flow rate,1.0 mL/min;column temperature,25℃;and injection volume,10μL.[Results]Chlorogenic acid can be detected by thin layer chromatography with clear spot and good specificity.Chlorogenic acid showed a good linear relationship in the injection amount range of 0.099-0.99μg(R^(2)=0.9999).The content of chlorogenic acid in L.alata varied greatly among the 10 different producing areas in Guangxi.L.alata produced in Dee Township,Longlin,Baise,Guangxi showed the highest chlorogenic acid content,and that produced in Shangsi County and Pingle County showed the lowest chlorogenic acid content.[Conclusions]This method can effectively identify L.alata and accurately determine the content of chlorogenic acid,thereby providing a scientific basis for the development and utilization of L.alata resources.
文摘In this work, a procedure to simulate the MD (molecular distillation) process for lactic acid purification was developed. The simulation was carried out with the aid of the Aspen Plus Process Simulator. Flash vessel was used to represent the MD process since the software does not present this unit operation. The simulation results with efficiency factors were in agreement with previously reported experimental data.
基金Supported by Key R&D Projects of Guangxi Science and Technology Department (GUIKE AB21196057)Basic Scientific Research Ability Improvement Project of Young and Middle-aged Teachers in Guangxi Universities and Colleges in 2019 (2019KY0341)+1 种基金Open Project of Guangxi Zhuang Yao Medicine Key Laboratory (GXZYKF2020A-08)Zhuang Pharmacy,a Key Discipline of Traditional Chinese Medicine (Ethnic Pharmacy) in the"12^th Five-year" Plan of the State Administration of Traditional Chinese Medicine
文摘[Objectives]Taking chlorogenic acid as index component,TLC and content determination method of Laggerae Alatae Herba were established.[Methods]TLC identification used silica gel G thin-layer plate,and butyl acetate∶formic acid∶water(7∶2.5∶2.5)was taken as developing agent,and it was inspected under ultraviolet lamp(365 nm).The content was determined by chromatographic column Inertsil ODS-3 C_(18)(4.60 mm×250 mm,5μm).Mobile phase:methanol-0.1%phosphoric acid(28∶72);detection wavelength:329 nm;flow speed:1.0 mL/min;column temperature:25℃;injection volume:10μL.[Results]Chlorogenic acid can be detected by TLC,with clear spots and good specificity.When injection volume of chlorogenic acid was between 0.099 and 0.990μg(R^(2)=0.9999),there was good linear relationship.In low,medium and high sample adding groups of Laggerae Alatae Herba,average recovery rates of chlorogenic acids were 98.80%(RSD=2.09%),98.24%(RSD=1.96%)and 99.65%(RSD=2.15%).[Conclusions]The method could effectively identify medicinal material Laggerae Alatae Herba,and accurately measure the content of chlorogenic acid in Laggerae Alatae Herba,thereby providing a scientific basis for developing and using medicinal resources of Laggerae Alatae Herba.