In order to establish high-yield and high-efficient cultivation technology for ginger in the central region of Shandong Province, the effects of different manage-ment modes on yield of ginger, nutrient efficiency and ...In order to establish high-yield and high-efficient cultivation technology for ginger in the central region of Shandong Province, the effects of different manage-ment modes on yield of ginger, nutrient efficiency and soil nitrate were carried out by field experiment. Four management modes were farmer convention mode, high yield and high efficiency mode, super high yield mode and super high yield and high efficiency mode, in which farmer convention mode was local farmers ’ conven-tional cropping methods, the other three management modes were optimized combi-nations of al management measures under a certain goal of increasing yield and efficiency. The results were as fol ows: ginger yield and nitrogen fertilizer efficiency under such three optimized management measures combinations as high yield and high efficiency mode, super high yield mode and super high yield and high efficien-cy mode were al higher than these of farmer convention mode, moreover, com-pared with farmer convention mode, the yield increased by 11.85%, 25.75% and 23.34%, respectively, and nitrogen fertilizer efficiency increased by 47.94%, 11.24%and 33.14%, respectively. Thereinto, the yield under super high yield mode were the greatest,and nitrogen fertilizer efficiency under high yield and high efficiency mode was the highest.展开更多
A decision model to maximize the total profit of manufacturers in an imperfect production system is constructed.In this model the production reliability and the warranty length are jointly used as decision variables f...A decision model to maximize the total profit of manufacturers in an imperfect production system is constructed.In this model the production reliability and the warranty length are jointly used as decision variables for the case that products are sold with a warranty i.e. the demand is dependent on the warranty length and sale price.Also all the non-conforming quality defective items in the production process are refurbished to conform to quality ones at a cost. The existence and uniqueness of the optimal values of production reliability and the warranty length are proved by using the Euler-Lagrange method in analyzing the model.A numerical example is also provided to illustrate the effectiveness of the decision model.The sensitivity analysis of the key parameters of the optimal solution and objective value is presented in addition.展开更多
Chiral aromatic alcohols are the key chiral building block for many important enantiopure pharmaceu-ticals. In this work,we studied asymmetric reduction of prochiral aromatic ketone to produce the corresponding chiral...Chiral aromatic alcohols are the key chiral building block for many important enantiopure pharmaceu-ticals. In this work,we studied asymmetric reduction of prochiral aromatic ketone to produce the corresponding chiral alcohol using vegetables as the biocatalyst. Acetophenone was chosen as the model substrate. The results in-dicate that acetophenone can be reduced to the corresponding chiral alcohols with high enantioselectivity by the chosen vegetables,i.e. apple(Malus pumila),carrot(Daucus carota),cucumber(Cucumis sativus),onion(Allium cepa),potato(Soanum tuberosum),radish(Raphanus sativus),and sweet potato(Ipomoea batatas) . In the reaction,R-1-phenylethanol is produced with apple,sweet potato and potato as the catalyst,while S-1-phenylethanol is the product with the other vegetables as the catalyst. In term of the enantioselectivity and reaction yield,carrot(D. ca-rota) is the best catalyst for this reaction. Furthermore,the reaction characteristics were studied in detail using car-rot(D. carota) as the biocatalyst. The effects of various factors on the reaction were investigated and the optimal reaction conditions were determined. Under the optimal reaction conditions(reaction time 50 h,substrate concen-tration 20 mmol·L-1,reaction temperature 35 °C and pH 7),95% of e.e.(to S-1-phenylethanol) and 85% chemical yield can be obtained. This work extends the biocatalyst for the asymmetric reduction reaction of prochiral aromatic ketones,and provides a novel potential route to produce enantiopure aromatic alcohols.展开更多
AIM: To compare efficacy of proton pump inhibitors (PPIs) with H2-receptor antagonists (H2RA$) plus pro- kinetics (Proks) for dysmotility-like symptoms in func- tional dyspepsia (FD). METHODS: Subjects were ...AIM: To compare efficacy of proton pump inhibitors (PPIs) with H2-receptor antagonists (H2RA$) plus pro- kinetics (Proks) for dysmotility-like symptoms in func- tional dyspepsia (FD). METHODS: Subjects were randomized to receive openlabel treatment with either rabeprazole 10 mg od (n = 57) or famotidine 10 mg bid plus mosapride 5 mg tid (n = 57) for 4 wk. The primary efficacy endpoint was change (%) from baseline in total dysmotility-like dyspepsia symptom score. The secondary efficacy endpoint was patient satisfaction with treatment. RESULTS: The improvement in dysmotility-like dyspep- sia symptom score on day 28 was significantly greater in the rabeprazole group (22.5% ± 29.2% of baseline) than the famotidine + mosapride group (53.2%±58.6% of baseline, P 〈 0.0001). The superior benefit of rabeprazole treatment after 28 d was consistent regardless of Helicobacter pylori status. Significantly more subjects in the rabeprazole group were satisfied or very satisfied with treatment on day 28 than in the famotidine + mosapride group (87.7% vs 59.6%, P = 0.0012). Rabeprazole therapy was the only significant predictor of treatment response (P 〈 0.0001), defined as a total symptom score improvement ≥ 50%. CONCLUSION: PPI monotherapy improves dysmotil- ity-like symptoms significantly better than H2RAs plus Proks, and should be the treatment of first choice for Japanese FD.展开更多
Abstract Production planning under uncertainty is considered as one of the most important problems in plant-wide optimization. In this article, first, a stochastic programming model with uniform distribution assumptio...Abstract Production planning under uncertainty is considered as one of the most important problems in plant-wide optimization. In this article, first, a stochastic programming model with uniform distribution assumption is developed for refinery production planning under demand uncertainty, and then a hybrid programming model incorporating the linear programming model with the stochastic programming one by a weight factor is proposed. Subsequently, piecewise linear approximation functions are derived and applied to solve the hybrid programming model-under uniform distribution assumption. Case studies show that the linear approximation algorithm is effective to solve.the hybrid programming model, along with an error≤0.5% when the deviatiorgmean≤20%. The simulation results indicate that the hybrid programming model with an appropriate weight factor (0.1-0.2) can effectively improve the optimal operational strategies under demand uncertainty, achieving higher profit than the linear programming model and the stochastic programming one with about 1.3% and 0.4% enhancement, respectavely.展开更多
In order to effectively diagnose the infeasible linear programming (LP) model of production planning in refinery, the article proposed three stages strategy based on constraints’ classification and infeasibility anal...In order to effectively diagnose the infeasible linear programming (LP) model of production planning in refinery, the article proposed three stages strategy based on constraints’ classification and infeasibility analysis. Generally, infeasibility sources involve structural inconsistencies and data errors, and the data errors are further classified intoⅠ, Ⅱ and Ⅲ. The three stages strategy are: (1) Check data when they are inputted to detect data error Ⅰ and repair them; (2) Inspect data whether they are accorded with material balance before solving the LP model to identify data error Ⅱ and repair them; (3) Find irreducible inconsistent system of infeasible LP model and give diagnosis information priority-ranked to recognize data error Ⅲ and structural inconsistencies. These stages could be automatically executed by computer, and the approach has been applied to diagnose the infeasible model well in our graphic I/O petro-chemical industry modeling system.展开更多
Genetic modifi cation is useful for improving the nutritional qualities of cyanobacteria. To increase the total unsaturated fatty acid content, along with the ratio of ω-3/ω-6 fatty acids, genetic engineering can be...Genetic modifi cation is useful for improving the nutritional qualities of cyanobacteria. To increase the total unsaturated fatty acid content, along with the ratio of ω-3/ω-6 fatty acids, genetic engineering can be used to modify fatty acid metabolism. S ynechococcus sp. PCC7002, a fast-growing cyanobacterium, does not contain a Δ6 desaturase gene and is therefore unable to synthesize γ-linolenic acid(GLA) and stearidonic acid(SDA), which are important in human health. In this work, we constructed recombinant vectors Syd6 D, Syd15 D and Syd6Dd15 D to express the Δ15 desaturase and Δ6 desaturase genes from Synechocystis PCC6803 in Synechococcus sp. PCC7002, with the aim of expressing polyunsaturated fatty acids. Overexpression of the Δ15 desaturase gene in S ynechococcus resulted in 5.4 times greater accumulation of α-linolenic acid compared with the wild-type while Δ6 desaturase gene expression produced both GLA and SDA. Co-expression of the two genes resulted in low-level accumulation of GLA but much larger amounts of SDA, accounting for as much to 11.64% of the total fatty acid content.展开更多
The damage was noted during the usage of the pipe system which was made out of austenite steel 316L on the assembly line for the production of urea. In order to find out the cause of such damage, the samples of pipes ...The damage was noted during the usage of the pipe system which was made out of austenite steel 316L on the assembly line for the production of urea. In order to find out the cause of such damage, the samples of pipes were taken at the places where the most damage took place. Samples were taken in the form of film, sediment and/or sludge from inner and the outer surface of the pipes. As well as each pieces of pipes were further cut into 10 mm x 10 mm plates. The prepared samples were studied using X-ray diffraction, X-ray emission spectrometry, scanning electron microscope and microanalysis as well as a light microscope. The results implicate microstructural changes within the inner wall of the pipe which was caused by intercrystalline corrosion. Such corrosion in the investigated samples of sediment and/or sludge appeared due to the damage of the protective film during the aggressive phases,展开更多
Improving the production of methane, while maintaining a significant level of process stability, is the main challenge in the anaerobic digestion process. Recently, microbial electrolysis cell(MEC) has become a promis...Improving the production of methane, while maintaining a significant level of process stability, is the main challenge in the anaerobic digestion process. Recently, microbial electrolysis cell(MEC) has become a promising method for CO_2 reduction produced during anaerobic digestion(AD) and leads to minimize the cost of biogas upgrading technology. In this study, the MEC-AD coupled reactor was used to generate and utilize the endogenous hydrogen by employing biocompatible electrodeposited cobalt-phosphate as catalysts to improve the performance of stainless steel mesh and carbon cloth electrodes. In addition, the modified version of ADM1 model(ADM1 da) was used to simulate the process. The result indicated that the MEC-AD coupled reactor can improve the CH_4 yield and production rate significantly. The CH_4 yield was enhanced with an average of 48% higher than the control. The CH_4 production rate was also increased 1.65 times due to the utilization of endogenous hydrogen.The specific yield, flow rate, content of CH_4, and p H value were the variables that the model was best at predicting(with indexes of agreement: 0.960/0.941, 0.682/0.696, 0.881/0.865, and 0.764/0.743) of the process with SSmeshes 80/SS-meshes 200, respectively. Employing the catalyzed SS mesh cathode, in the MEC-AD coupled reactor, could be an effective approach to generate and facilitate the utilization of endogenous hydrogen in anaerobic digestion of CH_4 production technology, which is a promising and feasible method to scale up to the industrial level.展开更多
To develop an effective process for titanium powders production, a calciothermic reduction process of pigment titanium dioxide (w(TiO2)〉98%), based on the preform reduction process (PRP), was investigated by me...To develop an effective process for titanium powders production, a calciothermic reduction process of pigment titanium dioxide (w(TiO2)〉98%), based on the preform reduction process (PRP), was investigated by means of XRD, SEM and EDS. In this process, the mixture of TiO2 powder and CaC12 was pressed into pieces as feed preform and was reduced by calcium vapor. Titanium powders was recovered after leaching from the reduced preform with hydrochloric acid and deionized water. The results indicate when the mass ratio of CaC12 to TiO2 is about 1:4 and at a constant temperature of 1 273 K for 6 h in vacuum furnace, titanium powders with 99.55% purity by EDS analysis and irregular shape (8-15 μm in particle size) are obtained.展开更多
This paper presents the method for the performance calibration of AACMM (articulated arm coordinate measuring machines) according to ASME B89.4.22 Standard. The growing use of this class of measurement equipment has...This paper presents the method for the performance calibration of AACMM (articulated arm coordinate measuring machines) according to ASME B89.4.22 Standard. The growing use of this class of measurement equipment has been accompanied by an absence of authorized laboratories to provide calibration certificates for its performance. Due to ASME B89.4.22 and VD12617-9 are nowadays the unique standards in the field of AACMM verification, IK4 Tekniker has compared both of them in order to develop internal test procedures to yield reliable performance calibration results. As a result, IK4 Tekniker has been recognized by the Spanish Accreditation Body (ENAC) in the field of AACMM calibration. Internal test procedures and uncertainty evaluation analysis have been developed as well as ENAC certificated reference test equipments have been acquired to ensure a suitable AACMM calibration process.展开更多
Pickling sludge generated during the neutralization of pickling wastewater with calcium hydroxide in stainless steel pickling process was characterized using X-ray fluorescence spectrometry, X-ray diffractometry, scan...Pickling sludge generated during the neutralization of pickling wastewater with calcium hydroxide in stainless steel pickling process was characterized using X-ray fluorescence spectrometry, X-ray diffractometry, scanning electron microscopy, thermogravimetry and differential scanning calorimetry, etc. The major compositions of pickling sludge are CaF2, CaSO4, Me(OH), (M: Fe, Cr, Ni), and the content of CaF2 is high in the sludge. The melting point of pickling sludge is about 1350℃ and the viscosity is about 0.14 Pa.s at 1450 ℃, which are comparatively lower than those of normal refining slag. After heat treatment, the contents of sulfur and fluorine in the pickling sludge were reduced, confirming the thermal decomposition of sulfate in the sludge. Fluorine in the sludge is reduced by the gaseous SiF4 and A1F3 generated through the reactions of CaF2 with SiO2 and Al2O3. The preliminary results from the reduction test indicate that the sulfur content in the steel is not affected by the presence of sulfur in the sludge. The recovery of nickel is about 40%, and the chromium content changes marginally due to the protective atmosphere under the reduction condition of chromic oxide. The pickling sludge is a potential auxiliary material for the production of stainless steel.展开更多
The effects of temperature, light intensity, salinity, and initial pH on the growth and fatty acid composition of Pinguiococcus pyrenoidosus 2078 were studied for eicosapentaenoic acid (EPA) production potential. The ...The effects of temperature, light intensity, salinity, and initial pH on the growth and fatty acid composition of Pinguiococcus pyrenoidosus 2078 were studied for eicosapentaenoic acid (EPA) production potential. The fatty acid composition was assayed by gas chromatography-mass spectrometry, which indicated that the main fatty acids were C14:0, C16:0 and EPA. The highest EPA percentage 20.83% of total fatty acids was obtained at 20℃ with the temperature being set at 20, 24, and 28℃. Under different salinities and light intensities, the highest percentages of total polyunsaturated fatty acids (PUFAs) and EPA were 17.82% and 31.37% of total fatty acids, respectively, which were achieved at salinity 30 and 100μmol photon m-2s-1 illumination. The highest percentages of total PUFAs and EPA were 38.75% and 23.13% of total fatty acids, respectively, which were reached at an initial pH of 6 with the test range being from 5.0 to 9.0.展开更多
Mortierella alpina has been considered as the most effective producer of arachidonic acid(ARA)-rich oil. It was found that several methods could improve the percentage of ARA in total lipids successfully, as they acti...Mortierella alpina has been considered as the most effective producer of arachidonic acid(ARA)-rich oil. It was found that several methods could improve the percentage of ARA in total lipids successfully, as they activated the desaturation system on the endoplasmic reticulum. Additionally, in M. alpina the ARA exists in several forms, such as triacylglycerol(TAG), and diacylglycerol(DAG). These forms are caused by different acyltransferases and they determine the nutrient value of the microbial oil. However, few works revealed detailed fatty acid distribution among lipid classes, which to some extent impeded the accurate regulation in ARA accumulation. Herein, this paper gives information on the accumulation process of main lipid classes and the changes of fatty acid composition in these lipids during ARA accumulation period in M. alpina. The result demonstrates that TAG was the dominant component of the total lipids, and it is the main form for ARA storage. The ARA enrichment stage occurred during 168–192 h when the amount of total lipids maintained steady. Further analysis indicated that the newly formed ARA-TAG might come from the incorporation and modi fication of saturated and monounsaturated fatty acids in other lipid classes. This work could be helpful for further optimization of ARA-rich TAG production.展开更多
基金Supported by Agro-research Projects in Public Interest "Study and Development of Key Technology of Scallion,Ginger and Garlic Industry"(200903018)the Project of Shandong Science and Technology Development Plan(2013GGC02022)~~
文摘In order to establish high-yield and high-efficient cultivation technology for ginger in the central region of Shandong Province, the effects of different manage-ment modes on yield of ginger, nutrient efficiency and soil nitrate were carried out by field experiment. Four management modes were farmer convention mode, high yield and high efficiency mode, super high yield mode and super high yield and high efficiency mode, in which farmer convention mode was local farmers ’ conven-tional cropping methods, the other three management modes were optimized combi-nations of al management measures under a certain goal of increasing yield and efficiency. The results were as fol ows: ginger yield and nitrogen fertilizer efficiency under such three optimized management measures combinations as high yield and high efficiency mode, super high yield mode and super high yield and high efficien-cy mode were al higher than these of farmer convention mode, moreover, com-pared with farmer convention mode, the yield increased by 11.85%, 25.75% and 23.34%, respectively, and nitrogen fertilizer efficiency increased by 47.94%, 11.24%and 33.14%, respectively. Thereinto, the yield under super high yield mode were the greatest,and nitrogen fertilizer efficiency under high yield and high efficiency mode was the highest.
基金The National Natural Science Foundation of China(No.71171049)the Scientific Innovation Research of College Graduates in Jiangsu Province(No.CXLX13-097)
文摘A decision model to maximize the total profit of manufacturers in an imperfect production system is constructed.In this model the production reliability and the warranty length are jointly used as decision variables for the case that products are sold with a warranty i.e. the demand is dependent on the warranty length and sale price.Also all the non-conforming quality defective items in the production process are refurbished to conform to quality ones at a cost. The existence and uniqueness of the optimal values of production reliability and the warranty length are proved by using the Euler-Lagrange method in analyzing the model.A numerical example is also provided to illustrate the effectiveness of the decision model.The sensitivity analysis of the key parameters of the optimal solution and objective value is presented in addition.
基金Supported by the Natural Science Foundation of Hubei Province(2008CDB354) Wuhan Youth Scientist Dawn Foundation(200750731288)
文摘Chiral aromatic alcohols are the key chiral building block for many important enantiopure pharmaceu-ticals. In this work,we studied asymmetric reduction of prochiral aromatic ketone to produce the corresponding chiral alcohol using vegetables as the biocatalyst. Acetophenone was chosen as the model substrate. The results in-dicate that acetophenone can be reduced to the corresponding chiral alcohols with high enantioselectivity by the chosen vegetables,i.e. apple(Malus pumila),carrot(Daucus carota),cucumber(Cucumis sativus),onion(Allium cepa),potato(Soanum tuberosum),radish(Raphanus sativus),and sweet potato(Ipomoea batatas) . In the reaction,R-1-phenylethanol is produced with apple,sweet potato and potato as the catalyst,while S-1-phenylethanol is the product with the other vegetables as the catalyst. In term of the enantioselectivity and reaction yield,carrot(D. ca-rota) is the best catalyst for this reaction. Furthermore,the reaction characteristics were studied in detail using car-rot(D. carota) as the biocatalyst. The effects of various factors on the reaction were investigated and the optimal reaction conditions were determined. Under the optimal reaction conditions(reaction time 50 h,substrate concen-tration 20 mmol·L-1,reaction temperature 35 °C and pH 7),95% of e.e.(to S-1-phenylethanol) and 85% chemical yield can be obtained. This work extends the biocatalyst for the asymmetric reduction reaction of prochiral aromatic ketones,and provides a novel potential route to produce enantiopure aromatic alcohols.
文摘AIM: To compare efficacy of proton pump inhibitors (PPIs) with H2-receptor antagonists (H2RA$) plus pro- kinetics (Proks) for dysmotility-like symptoms in func- tional dyspepsia (FD). METHODS: Subjects were randomized to receive openlabel treatment with either rabeprazole 10 mg od (n = 57) or famotidine 10 mg bid plus mosapride 5 mg tid (n = 57) for 4 wk. The primary efficacy endpoint was change (%) from baseline in total dysmotility-like dyspepsia symptom score. The secondary efficacy endpoint was patient satisfaction with treatment. RESULTS: The improvement in dysmotility-like dyspep- sia symptom score on day 28 was significantly greater in the rabeprazole group (22.5% ± 29.2% of baseline) than the famotidine + mosapride group (53.2%±58.6% of baseline, P 〈 0.0001). The superior benefit of rabeprazole treatment after 28 d was consistent regardless of Helicobacter pylori status. Significantly more subjects in the rabeprazole group were satisfied or very satisfied with treatment on day 28 than in the famotidine + mosapride group (87.7% vs 59.6%, P = 0.0012). Rabeprazole therapy was the only significant predictor of treatment response (P 〈 0.0001), defined as a total symptom score improvement ≥ 50%. CONCLUSION: PPI monotherapy improves dysmotil- ity-like symptoms significantly better than H2RAs plus Proks, and should be the treatment of first choice for Japanese FD.
基金the Specialized Research Fund for Doctoral Program of Higher Education of China(20060003087)
文摘Abstract Production planning under uncertainty is considered as one of the most important problems in plant-wide optimization. In this article, first, a stochastic programming model with uniform distribution assumption is developed for refinery production planning under demand uncertainty, and then a hybrid programming model incorporating the linear programming model with the stochastic programming one by a weight factor is proposed. Subsequently, piecewise linear approximation functions are derived and applied to solve the hybrid programming model-under uniform distribution assumption. Case studies show that the linear approximation algorithm is effective to solve.the hybrid programming model, along with an error≤0.5% when the deviatiorgmean≤20%. The simulation results indicate that the hybrid programming model with an appropriate weight factor (0.1-0.2) can effectively improve the optimal operational strategies under demand uncertainty, achieving higher profit than the linear programming model and the stochastic programming one with about 1.3% and 0.4% enhancement, respectavely.
文摘In order to effectively diagnose the infeasible linear programming (LP) model of production planning in refinery, the article proposed three stages strategy based on constraints’ classification and infeasibility analysis. Generally, infeasibility sources involve structural inconsistencies and data errors, and the data errors are further classified intoⅠ, Ⅱ and Ⅲ. The three stages strategy are: (1) Check data when they are inputted to detect data error Ⅰ and repair them; (2) Inspect data whether they are accorded with material balance before solving the LP model to identify data error Ⅱ and repair them; (3) Find irreducible inconsistent system of infeasible LP model and give diagnosis information priority-ranked to recognize data error Ⅲ and structural inconsistencies. These stages could be automatically executed by computer, and the approach has been applied to diagnose the infeasible model well in our graphic I/O petro-chemical industry modeling system.
基金Supported by the International S&T Cooperation Program of China(No.2012DFA30450)the National Natural Science Foundation of China(No.30871541)+1 种基金the Taishan Scholar Foundation of Shandong Province(No.tshw20091014)the Innovation Program of the University Institutes of Jinan,Shandong Province(No.201004044)
文摘Genetic modifi cation is useful for improving the nutritional qualities of cyanobacteria. To increase the total unsaturated fatty acid content, along with the ratio of ω-3/ω-6 fatty acids, genetic engineering can be used to modify fatty acid metabolism. S ynechococcus sp. PCC7002, a fast-growing cyanobacterium, does not contain a Δ6 desaturase gene and is therefore unable to synthesize γ-linolenic acid(GLA) and stearidonic acid(SDA), which are important in human health. In this work, we constructed recombinant vectors Syd6 D, Syd15 D and Syd6Dd15 D to express the Δ15 desaturase and Δ6 desaturase genes from Synechocystis PCC6803 in Synechococcus sp. PCC7002, with the aim of expressing polyunsaturated fatty acids. Overexpression of the Δ15 desaturase gene in S ynechococcus resulted in 5.4 times greater accumulation of α-linolenic acid compared with the wild-type while Δ6 desaturase gene expression produced both GLA and SDA. Co-expression of the two genes resulted in low-level accumulation of GLA but much larger amounts of SDA, accounting for as much to 11.64% of the total fatty acid content.
文摘The damage was noted during the usage of the pipe system which was made out of austenite steel 316L on the assembly line for the production of urea. In order to find out the cause of such damage, the samples of pipes were taken at the places where the most damage took place. Samples were taken in the form of film, sediment and/or sludge from inner and the outer surface of the pipes. As well as each pieces of pipes were further cut into 10 mm x 10 mm plates. The prepared samples were studied using X-ray diffraction, X-ray emission spectrometry, scanning electron microscope and microanalysis as well as a light microscope. The results implicate microstructural changes within the inner wall of the pipe which was caused by intercrystalline corrosion. Such corrosion in the investigated samples of sediment and/or sludge appeared due to the damage of the protective film during the aggressive phases,
基金Supported by the State Key Development Program for Basic Research of China(2013CB733501)the National Natural Science Foundation of China(21476106)+1 种基金the Natural Science Foundation of Jiangsu Province(BK20130062)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)(PPZY2015A044)
文摘Improving the production of methane, while maintaining a significant level of process stability, is the main challenge in the anaerobic digestion process. Recently, microbial electrolysis cell(MEC) has become a promising method for CO_2 reduction produced during anaerobic digestion(AD) and leads to minimize the cost of biogas upgrading technology. In this study, the MEC-AD coupled reactor was used to generate and utilize the endogenous hydrogen by employing biocompatible electrodeposited cobalt-phosphate as catalysts to improve the performance of stainless steel mesh and carbon cloth electrodes. In addition, the modified version of ADM1 model(ADM1 da) was used to simulate the process. The result indicated that the MEC-AD coupled reactor can improve the CH_4 yield and production rate significantly. The CH_4 yield was enhanced with an average of 48% higher than the control. The CH_4 production rate was also increased 1.65 times due to the utilization of endogenous hydrogen.The specific yield, flow rate, content of CH_4, and p H value were the variables that the model was best at predicting(with indexes of agreement: 0.960/0.941, 0.682/0.696, 0.881/0.865, and 0.764/0.743) of the process with SSmeshes 80/SS-meshes 200, respectively. Employing the catalyzed SS mesh cathode, in the MEC-AD coupled reactor, could be an effective approach to generate and facilitate the utilization of endogenous hydrogen in anaerobic digestion of CH_4 production technology, which is a promising and feasible method to scale up to the industrial level.
基金Project(51004058) supported by the National Natural Science Foundation of ChinaProject(2011FB039) supported by the Natural Science Foundation of Yunnan Province,China
文摘To develop an effective process for titanium powders production, a calciothermic reduction process of pigment titanium dioxide (w(TiO2)〉98%), based on the preform reduction process (PRP), was investigated by means of XRD, SEM and EDS. In this process, the mixture of TiO2 powder and CaC12 was pressed into pieces as feed preform and was reduced by calcium vapor. Titanium powders was recovered after leaching from the reduced preform with hydrochloric acid and deionized water. The results indicate when the mass ratio of CaC12 to TiO2 is about 1:4 and at a constant temperature of 1 273 K for 6 h in vacuum furnace, titanium powders with 99.55% purity by EDS analysis and irregular shape (8-15 μm in particle size) are obtained.
文摘This paper presents the method for the performance calibration of AACMM (articulated arm coordinate measuring machines) according to ASME B89.4.22 Standard. The growing use of this class of measurement equipment has been accompanied by an absence of authorized laboratories to provide calibration certificates for its performance. Due to ASME B89.4.22 and VD12617-9 are nowadays the unique standards in the field of AACMM verification, IK4 Tekniker has compared both of them in order to develop internal test procedures to yield reliable performance calibration results. As a result, IK4 Tekniker has been recognized by the Spanish Accreditation Body (ENAC) in the field of AACMM calibration. Internal test procedures and uncertainty evaluation analysis have been developed as well as ENAC certificated reference test equipments have been acquired to ensure a suitable AACMM calibration process.
基金Project(2010JM7010)supported by the Natural Science Foundation of Shaanxi Province,ChinaProject supported by the Scientific Research Foundation for the Returned Overseas Chinese Scholars,Ministry of Education,ChinaProject supported by the Technology Foundation for Selected Overseas Chinese Scholars,Department of Human Resources and Social Security of Shaanxi Province,China
文摘Pickling sludge generated during the neutralization of pickling wastewater with calcium hydroxide in stainless steel pickling process was characterized using X-ray fluorescence spectrometry, X-ray diffractometry, scanning electron microscopy, thermogravimetry and differential scanning calorimetry, etc. The major compositions of pickling sludge are CaF2, CaSO4, Me(OH), (M: Fe, Cr, Ni), and the content of CaF2 is high in the sludge. The melting point of pickling sludge is about 1350℃ and the viscosity is about 0.14 Pa.s at 1450 ℃, which are comparatively lower than those of normal refining slag. After heat treatment, the contents of sulfur and fluorine in the pickling sludge were reduced, confirming the thermal decomposition of sulfate in the sludge. Fluorine in the sludge is reduced by the gaseous SiF4 and A1F3 generated through the reactions of CaF2 with SiO2 and Al2O3. The preliminary results from the reduction test indicate that the sulfur content in the steel is not affected by the presence of sulfur in the sludge. The recovery of nickel is about 40%, and the chromium content changes marginally due to the protective atmosphere under the reduction condition of chromic oxide. The pickling sludge is a potential auxiliary material for the production of stainless steel.
基金supported by the Scientific Research Foundation of Ji’nan University (No. 50624068)the Fundamental Research Funds for the Central Universities (No. 11609318)the Project of Science and Technology Development Plan, Science and Technology Bureau of Hengyang (2010KJ25)
文摘The effects of temperature, light intensity, salinity, and initial pH on the growth and fatty acid composition of Pinguiococcus pyrenoidosus 2078 were studied for eicosapentaenoic acid (EPA) production potential. The fatty acid composition was assayed by gas chromatography-mass spectrometry, which indicated that the main fatty acids were C14:0, C16:0 and EPA. The highest EPA percentage 20.83% of total fatty acids was obtained at 20℃ with the temperature being set at 20, 24, and 28℃. Under different salinities and light intensities, the highest percentages of total polyunsaturated fatty acids (PUFAs) and EPA were 17.82% and 31.37% of total fatty acids, respectively, which were achieved at salinity 30 and 100μmol photon m-2s-1 illumination. The highest percentages of total PUFAs and EPA were 38.75% and 23.13% of total fatty acids, respectively, which were reached at an initial pH of 6 with the test range being from 5.0 to 9.0.
基金Supported by the National Science Foundation for Distinguished Young Scholars of China(21225626)the National Basic Research Program of China(2011CBA00800)+3 种基金the National Natural Science Foundation of China(21376002,21476111)the Natural Science Foundation of Jiangsu Province(BK20131405)the National High-Tech R&D Program of China(2014AA021703)the Priority Academic Program Development of Jiangsu Higher Education Institutions
文摘Mortierella alpina has been considered as the most effective producer of arachidonic acid(ARA)-rich oil. It was found that several methods could improve the percentage of ARA in total lipids successfully, as they activated the desaturation system on the endoplasmic reticulum. Additionally, in M. alpina the ARA exists in several forms, such as triacylglycerol(TAG), and diacylglycerol(DAG). These forms are caused by different acyltransferases and they determine the nutrient value of the microbial oil. However, few works revealed detailed fatty acid distribution among lipid classes, which to some extent impeded the accurate regulation in ARA accumulation. Herein, this paper gives information on the accumulation process of main lipid classes and the changes of fatty acid composition in these lipids during ARA accumulation period in M. alpina. The result demonstrates that TAG was the dominant component of the total lipids, and it is the main form for ARA storage. The ARA enrichment stage occurred during 168–192 h when the amount of total lipids maintained steady. Further analysis indicated that the newly formed ARA-TAG might come from the incorporation and modi fication of saturated and monounsaturated fatty acids in other lipid classes. This work could be helpful for further optimization of ARA-rich TAG production.