Combustion noise takes large proportion in diesel engine noise and the studies of its influence factors play an important role in noise reduction. Engine noise and cylinder pressure measurement experiments were carrie...Combustion noise takes large proportion in diesel engine noise and the studies of its influence factors play an important role in noise reduction. Engine noise and cylinder pressure measurement experiments were carried out. And the improved attenuation curves were obtained, by which the engine noise was predicted. The effect of fuel injection parameters in combustion noise was investigated during the combustion process. At last, the method combining single variable optimization and multivariate combination was introduced to online optimize the combustion noise. The results show that injection parameters can affect the cylinder pressure rise rate and heat release rate, and consequently affect the cylinder pressure load and pressure oscillation to influence the combustion noise. Among these parameters, main injection advance angle has the greatest influence on the combustion noise, while the pilot injection interval time takes the second place, and the pilot injection quantity is of minimal impact. After the optimal design of the combustion noise, the average sound pressure level of the engine is distinctly reduced by 1.0 d B(A) generally. Meanwhile, the power, emission and economy performances are ensured.展开更多
OBJECTIVE Danshen injection and Honghua injection,traditional Chinese medicine(TCM)injections,made from the extracts of Salvia miltiorrhiza Bge.and Carthamus tinctorius L.,have a potential to be developed into the use...OBJECTIVE Danshen injection and Honghua injection,traditional Chinese medicine(TCM)injections,made from the extracts of Salvia miltiorrhiza Bge.and Carthamus tinctorius L.,have a potential to be developed into the useful drugs for the.As the common TCM injections,Danshen injection is often combined with Honghua injection to treat cardiovascular disease.The purpose of this study was to investigate the pharmacokinetic parameters of Honghua injection combined with Danshen injection when they were coadministered intravenously in human and rats through the tail vein.METHODS Single and multiple doses of Danshen injection to study Danshen injection on Honghua injection pharmacokinetics parameters and single and multiple doses of Honghua injection to study Honghua injection on Danshen injection pharmacokinetics parameters.The plasma concentrations of hydroxysafflor A(HSYA)and tanshinol and salvianolic acid B were determined by the reliable high-performance liquid chromatography(HPLC)method.The concentrations of HSYA in urine of rats and human were also determined by HPLC method.DAS 2.1.1software was adopted for calculating the pharmacokinetic parameters.RESULTS The simultaneous intravenous Honghua injection and salvia miltiorrhiza injiection significantly altered the pharmacokinetic parameters of both injections when compared with the individual intravenous administration of each injection.The area under the concentration-timecurve(AUC)and maximum plasma concentration(Cmax)of HSYA and tanshinol and salvianolic acid B were significantly increased.The cumulative urine excretion of HSYA in human and rats during 24 h was decreased after two drugs were administered simultaneously by the intravenous.CONCLUSION Honghua injection and Danshen injection interact with each other following simultaneous intravenous and they have a synergistic action.This experiment has identified the pharmacokinetic parameters and provided a rationale for the clinical use of the drug combination.展开更多
In order to predict the powder flow law of the injection molding process of MgTiO3 ceramic parts with complex structures,a constitutive model and numerical simulation method for MgTiO3 ceramic injection molding were e...In order to predict the powder flow law of the injection molding process of MgTiO3 ceramic parts with complex structures,a constitutive model and numerical simulation method for MgTiO3 ceramic injection molding were established based on the Hunt method.The material parameters of MgTiO3 such as elastic modulus,Poisson ratio,glass transition temperature,thermal conductivity and specific heat capacity were measured.Based on the fitting curve and the material parameters measured,the cross-WLF viscosity model and P-V-T model required for MgTiO3 ceramic injection molding were optimized.Furthermore,the influence of process parameters on mold filling flow and distribution of parts defects was researched.It was found that the gate position,injection speed and melt temperature have greater influence on mold filling flow and the packing process has an obvious effect on parts’defects.On this basis,the MgTiO3 ceramic parts injection molding experiment verification was carried out.By comparing the experimental results with the simulated results,it is found that the deformation error is within 1.5%and the density error is within 1%.Therefore,this research provided theoretical guidance for the engineering application of MgTiO3 ceramic parts fabricated by injection molding.展开更多
Today, the time-to-market for plastic products ar e getting shorter, thus the lead-time for making the injection mould is decreasin g. There is potential in timesavings in the mould design stage because the design pro...Today, the time-to-market for plastic products ar e getting shorter, thus the lead-time for making the injection mould is decreasin g. There is potential in timesavings in the mould design stage because the design process that is repeatable for every mould design can be standardized. T he preliminary work of any final plastic injection mould design is to always pro vide an initial design of the mould assembly for product designers (customers) p rior to receiving the final product CAD data. Traditionally and even up till no w, this initial design is always created using 2D CAD packages. The information used for the initial design is based on the technical discussion checklist, in which most mould makers have their own standards. This checklist is also being used as a quotation since the most basic information of the mould in the particu lar project is being recorded in it. The basic information in this checklist in cludes the number of cavities, the type of mould base to be used, the moulding m achine to be used for the moulding, the type of gating system, the type of resin material used and its shrinkage value etc. Information on special requirements such as the number of sliders or lifters to be used is also listed in the check list. At this stage, there is still no information on the cooling and ejection design since they are greatly dependent on the final product CAD data. This res earch focuses on the methodology of providing the initial design in 3D solid bas ed on the technical discussion checklist, which takes the role of the overall st andard template since every sub-design has its own standard template. An examp le of a sub-design that has its own standard template is the cavity layout desi gn. The cavity layout for plastic injection moulds can be designed by controlli ng the geometrical parameters using a standardization template. The standardiza tion template for the cavity layout design consists of configurations for the po ssible layouts. Each configuration of the layout design has its own layout desi gn table of all the geometrical parameters. This standardization template is pr e-defined in the layout design level of the mould assembly design. This ensure s that the required configuration can be loaded into the mould assembly design v ery quickly without having the need to redesign the layout. This makes it usefu l for technical discussions between the product designers and mould designers pr ior to the manufacture of the mould. Changes can be made to the 3D cavity layou t design immediately during the discussions thus the savings in time and avo idance of miscommunications.展开更多
基金Project(2011BAE22B05)supported by the National Science and Technology Pillar Program during the 12th Five-year Plan of China
文摘Combustion noise takes large proportion in diesel engine noise and the studies of its influence factors play an important role in noise reduction. Engine noise and cylinder pressure measurement experiments were carried out. And the improved attenuation curves were obtained, by which the engine noise was predicted. The effect of fuel injection parameters in combustion noise was investigated during the combustion process. At last, the method combining single variable optimization and multivariate combination was introduced to online optimize the combustion noise. The results show that injection parameters can affect the cylinder pressure rise rate and heat release rate, and consequently affect the cylinder pressure load and pressure oscillation to influence the combustion noise. Among these parameters, main injection advance angle has the greatest influence on the combustion noise, while the pilot injection interval time takes the second place, and the pilot injection quantity is of minimal impact. After the optimal design of the combustion noise, the average sound pressure level of the engine is distinctly reduced by 1.0 d B(A) generally. Meanwhile, the power, emission and economy performances are ensured.
基金The project supported by 2016-2018 Anhui University Research Platform Innovation Team
文摘OBJECTIVE Danshen injection and Honghua injection,traditional Chinese medicine(TCM)injections,made from the extracts of Salvia miltiorrhiza Bge.and Carthamus tinctorius L.,have a potential to be developed into the useful drugs for the.As the common TCM injections,Danshen injection is often combined with Honghua injection to treat cardiovascular disease.The purpose of this study was to investigate the pharmacokinetic parameters of Honghua injection combined with Danshen injection when they were coadministered intravenously in human and rats through the tail vein.METHODS Single and multiple doses of Danshen injection to study Danshen injection on Honghua injection pharmacokinetics parameters and single and multiple doses of Honghua injection to study Honghua injection on Danshen injection pharmacokinetics parameters.The plasma concentrations of hydroxysafflor A(HSYA)and tanshinol and salvianolic acid B were determined by the reliable high-performance liquid chromatography(HPLC)method.The concentrations of HSYA in urine of rats and human were also determined by HPLC method.DAS 2.1.1software was adopted for calculating the pharmacokinetic parameters.RESULTS The simultaneous intravenous Honghua injection and salvia miltiorrhiza injiection significantly altered the pharmacokinetic parameters of both injections when compared with the individual intravenous administration of each injection.The area under the concentration-timecurve(AUC)and maximum plasma concentration(Cmax)of HSYA and tanshinol and salvianolic acid B were significantly increased.The cumulative urine excretion of HSYA in human and rats during 24 h was decreased after two drugs were administered simultaneously by the intravenous.CONCLUSION Honghua injection and Danshen injection interact with each other following simultaneous intravenous and they have a synergistic action.This experiment has identified the pharmacokinetic parameters and provided a rationale for the clinical use of the drug combination.
基金Project(2018CFB439)supported by the Hubei Province Natural Science Foundation,China。
文摘In order to predict the powder flow law of the injection molding process of MgTiO3 ceramic parts with complex structures,a constitutive model and numerical simulation method for MgTiO3 ceramic injection molding were established based on the Hunt method.The material parameters of MgTiO3 such as elastic modulus,Poisson ratio,glass transition temperature,thermal conductivity and specific heat capacity were measured.Based on the fitting curve and the material parameters measured,the cross-WLF viscosity model and P-V-T model required for MgTiO3 ceramic injection molding were optimized.Furthermore,the influence of process parameters on mold filling flow and distribution of parts defects was researched.It was found that the gate position,injection speed and melt temperature have greater influence on mold filling flow and the packing process has an obvious effect on parts’defects.On this basis,the MgTiO3 ceramic parts injection molding experiment verification was carried out.By comparing the experimental results with the simulated results,it is found that the deformation error is within 1.5%and the density error is within 1%.Therefore,this research provided theoretical guidance for the engineering application of MgTiO3 ceramic parts fabricated by injection molding.
文摘Today, the time-to-market for plastic products ar e getting shorter, thus the lead-time for making the injection mould is decreasin g. There is potential in timesavings in the mould design stage because the design process that is repeatable for every mould design can be standardized. T he preliminary work of any final plastic injection mould design is to always pro vide an initial design of the mould assembly for product designers (customers) p rior to receiving the final product CAD data. Traditionally and even up till no w, this initial design is always created using 2D CAD packages. The information used for the initial design is based on the technical discussion checklist, in which most mould makers have their own standards. This checklist is also being used as a quotation since the most basic information of the mould in the particu lar project is being recorded in it. The basic information in this checklist in cludes the number of cavities, the type of mould base to be used, the moulding m achine to be used for the moulding, the type of gating system, the type of resin material used and its shrinkage value etc. Information on special requirements such as the number of sliders or lifters to be used is also listed in the check list. At this stage, there is still no information on the cooling and ejection design since they are greatly dependent on the final product CAD data. This res earch focuses on the methodology of providing the initial design in 3D solid bas ed on the technical discussion checklist, which takes the role of the overall st andard template since every sub-design has its own standard template. An examp le of a sub-design that has its own standard template is the cavity layout desi gn. The cavity layout for plastic injection moulds can be designed by controlli ng the geometrical parameters using a standardization template. The standardiza tion template for the cavity layout design consists of configurations for the po ssible layouts. Each configuration of the layout design has its own layout desi gn table of all the geometrical parameters. This standardization template is pr e-defined in the layout design level of the mould assembly design. This ensure s that the required configuration can be loaded into the mould assembly design v ery quickly without having the need to redesign the layout. This makes it usefu l for technical discussions between the product designers and mould designers pr ior to the manufacture of the mould. Changes can be made to the 3D cavity layou t design immediately during the discussions thus the savings in time and avo idance of miscommunications.
