Fifteen compounds were isolated from the processed seeds of Strychnos nux-vomica and were identified as follows：strychnine（1）,brucine（2）,pseudostrychnine（3）,pseudobrucine（4）,secoxyloganin（5）,caffeic acid（6...Fifteen compounds were isolated from the processed seeds of Strychnos nux-vomica and were identified as follows：strychnine（1）,brucine（2）,pseudostrychnine（3）,pseudobrucine（4）,secoxyloganin（5）,caffeic acid（6）,p-hydroxybenzoic acid（7）,p-hydroxyphenylacetic acid（8）,uvaol（9）,stigmasta-7,22,25-triene-3-ol（10）,lupeol（11）,11-oxo-α-amyrin palmitate（12）,catechol（13）,maltol（14）,adenosine（15）.Compounds 5-15 were isolated from genus Strychnos for the first time.展开更多
A modified seeded growth process of silica particles with a continuous addition of tetraethyl orthosilicate （TEOS） was presented to control the diameter of silica particles. The diameter of particles was monitored b...A modified seeded growth process of silica particles with a continuous addition of tetraethyl orthosilicate （TEOS） was presented to control the diameter of silica particles. The diameter of particles was monitored by dynamic light scattering to control the addition of TEOS. The increase in the diameter of the silica particles with time and the addition of TEOS was investigated. The diameter of silica seeds increased from 193 nm to 446 nm in 4 h. The final diameter of silica particles was tailored within the range of ±5 nm to the target diameter. Silica particles with diameter of 446 nm were synthesized and assembled into photonic crystals with a pseudo band gap centered at just 1000 nm. The feasibility and practicability of this modified seeded growth process was verified.展开更多
The development of a modified 206 alloy whose composition was optimized to minimize hot tearing during semi-solid forming was reported. The effect of varying silicon, copper and iron contents was investigated using a ...The development of a modified 206 alloy whose composition was optimized to minimize hot tearing during semi-solid forming was reported. The effect of varying silicon, copper and iron contents was investigated using a design of experiment (DOE) approach. Semi-solid slurries were prepared using the SEED process and injected into a high pressure die casting press. The hot tearing sensitivity results were reported for different alloy variants. The microstructure evolution during the semi-solid preparation was presented along with actual die cast components. The effects of silicon, copper and iron on mechanical properties in the T7 condition were also analyzed. Beyond the benefit of reducing hot tearing, it is shown that the tensile and fatigue properties remain compatible with the automotive industry requirements.展开更多
Some physical,frictional and thermal properties of Brachystegia eurycoma seed were studied at different moisture contents in order to explore the possibility of mechanizing the handling and processing techniques.Resul...Some physical,frictional and thermal properties of Brachystegia eurycoma seed were studied at different moisture contents in order to explore the possibility of mechanizing the handling and processing techniques.Results showed that the seed could be considered an oval disc in shape.In the moisture range of 2.79%to 27.13%(d.b.),the major,intermediate and minor axial dimensions increased with increase in moisture content from 2.29 mm to 2.45 mm,1.65 mm to 1.91 mm and 0.34 mm to 0.52 mm,respectively.In the above moisture range,one thousand seed weight,particle density,porosity,roundness,sphericity,surface area and angle of repose increased linearly from 0.901 kg to 1.252 kg,2270 kg/m^(3) to 2520 kg/m^(3),11.23%to 15.46%,35%to 47%,67%to 82%,7.67 cm^(2) to 8.48 cm^(2) and 16.8°to 29.2°respectively,while bulk density decreased from 745.4 kg/m^(3) to 613.6 kg/m^(3).Static coefficient of friction on different structural surfaces increased linearly with moisture content and had the highest values on galvanized steel sheet(0.445-0.639),and the lowest values on fiber glass(0.287-0.404).Kinetic coefficient of friction increased linearly with moisture content on different structural surfaces except on galvanized steel sheet where it decreased linearly with increase in moisture content in the above moisture range.It had the highest values on hessian bag material(0.266-0.389),and the lowest values on plywood with wood grains perpendicular to the direction of movement(0.204-0.271).Specific heat ranged from 1474 to 5992.7 J/kgK,and increased with increase in moisture content and temperature.Regression equations were used to express the relationships existing between the seed properties and moisture content.展开更多
To meet the requirement of“zero speed”for precision sowing,the instantaneous speed of seed falling into the seed bed should be equal to the opposite direction of the forward speed of the machine.Through analyzing th...To meet the requirement of“zero speed”for precision sowing,the instantaneous speed of seed falling into the seed bed should be equal to the opposite direction of the forward speed of the machine.Through analyzing the principle of seed guiding process,the main influencing factors affecting the contour curve of the seed tube were determined to plan the seed guiding path and realize zero speed seed delivery.With the help of EDEM simulation software,taking the inclination angle of seed tube end,operating speed of the metering disc,and machine’s forward speed as the experimental factors,a single-factor simulation test was conducted with the pass rate,replay rate,and missing seeding rate as experimental indexes.The results of the simulation test showed that the range of inclination angle of the seed tube end was 23°-40°,the range of machine forward speed was 5-9 km/h,and the range of operating speed of the metering disc was 15-40 r/min.The quadratic orthogonal rotation combination test method was carried out using the bench test,and a mathematical regression model was established between experimental factors and experimental indexes to determine the priority order of factors,and the best combination of factors.The test results showed that the pass rate was 93.25%,the replay rate was 2.97%and the missing seeding rate was 3.78%under the condition with the inclination angle of seed tube end of 32.28°,the forward speed of the machine of 6.89 km/h and the operating speed of the metering disc of 28.67 r/min,which can meet the requirements of relevant national standards.展开更多
基金Research Platform for Quality Standard of TCM and Information System Building(Grant No.2009ZX09308-04)National S&T Major Project-Created Major New Drugs Projects(Grant No.2009ZX09311-004)
文摘Fifteen compounds were isolated from the processed seeds of Strychnos nux-vomica and were identified as follows：strychnine（1）,brucine（2）,pseudostrychnine（3）,pseudobrucine（4）,secoxyloganin（5）,caffeic acid（6）,p-hydroxybenzoic acid（7）,p-hydroxyphenylacetic acid（8）,uvaol（9）,stigmasta-7,22,25-triene-3-ol（10）,lupeol（11）,11-oxo-α-amyrin palmitate（12）,catechol（13）,maltol（14）,adenosine（15）.Compounds 5-15 were isolated from genus Strychnos for the first time.
文摘A modified seeded growth process of silica particles with a continuous addition of tetraethyl orthosilicate （TEOS） was presented to control the diameter of silica particles. The diameter of particles was monitored by dynamic light scattering to control the addition of TEOS. The increase in the diameter of the silica particles with time and the addition of TEOS was investigated. The diameter of silica seeds increased from 193 nm to 446 nm in 4 h. The final diameter of silica particles was tailored within the range of ±5 nm to the target diameter. Silica particles with diameter of 446 nm were synthesized and assembled into photonic crystals with a pseudo band gap centered at just 1000 nm. The feasibility and practicability of this modified seeded growth process was verified.
文摘The development of a modified 206 alloy whose composition was optimized to minimize hot tearing during semi-solid forming was reported. The effect of varying silicon, copper and iron contents was investigated using a design of experiment (DOE) approach. Semi-solid slurries were prepared using the SEED process and injected into a high pressure die casting press. The hot tearing sensitivity results were reported for different alloy variants. The microstructure evolution during the semi-solid preparation was presented along with actual die cast components. The effects of silicon, copper and iron on mechanical properties in the T7 condition were also analyzed. Beyond the benefit of reducing hot tearing, it is shown that the tensile and fatigue properties remain compatible with the automotive industry requirements.
文摘Some physical,frictional and thermal properties of Brachystegia eurycoma seed were studied at different moisture contents in order to explore the possibility of mechanizing the handling and processing techniques.Results showed that the seed could be considered an oval disc in shape.In the moisture range of 2.79%to 27.13%(d.b.),the major,intermediate and minor axial dimensions increased with increase in moisture content from 2.29 mm to 2.45 mm,1.65 mm to 1.91 mm and 0.34 mm to 0.52 mm,respectively.In the above moisture range,one thousand seed weight,particle density,porosity,roundness,sphericity,surface area and angle of repose increased linearly from 0.901 kg to 1.252 kg,2270 kg/m^(3) to 2520 kg/m^(3),11.23%to 15.46%,35%to 47%,67%to 82%,7.67 cm^(2) to 8.48 cm^(2) and 16.8°to 29.2°respectively,while bulk density decreased from 745.4 kg/m^(3) to 613.6 kg/m^(3).Static coefficient of friction on different structural surfaces increased linearly with moisture content and had the highest values on galvanized steel sheet(0.445-0.639),and the lowest values on fiber glass(0.287-0.404).Kinetic coefficient of friction increased linearly with moisture content on different structural surfaces except on galvanized steel sheet where it decreased linearly with increase in moisture content in the above moisture range.It had the highest values on hessian bag material(0.266-0.389),and the lowest values on plywood with wood grains perpendicular to the direction of movement(0.204-0.271).Specific heat ranged from 1474 to 5992.7 J/kgK,and increased with increase in moisture content and temperature.Regression equations were used to express the relationships existing between the seed properties and moisture content.
基金sponsored by the Natural Science Foundation of Shandong Province(Grant No.ZR202111230084)Qingdao Science and Technology Demonstration and Guidance Project(Grant No.2237xdny17nsh)+2 种基金Shandong Science and Technology SMEs Innovation Capacity Improvement Project(Grant No.2021TSGC 1428)Key R&D Plan of Shandong Province(Grant No.2019GNC106056)Key R&D Plan of Shandong Province(Grant No.2017NC212006)and Qingdao Minsheng Science and Technology Plan(Grant No.173352nsh).
文摘To meet the requirement of“zero speed”for precision sowing,the instantaneous speed of seed falling into the seed bed should be equal to the opposite direction of the forward speed of the machine.Through analyzing the principle of seed guiding process,the main influencing factors affecting the contour curve of the seed tube were determined to plan the seed guiding path and realize zero speed seed delivery.With the help of EDEM simulation software,taking the inclination angle of seed tube end,operating speed of the metering disc,and machine’s forward speed as the experimental factors,a single-factor simulation test was conducted with the pass rate,replay rate,and missing seeding rate as experimental indexes.The results of the simulation test showed that the range of inclination angle of the seed tube end was 23°-40°,the range of machine forward speed was 5-9 km/h,and the range of operating speed of the metering disc was 15-40 r/min.The quadratic orthogonal rotation combination test method was carried out using the bench test,and a mathematical regression model was established between experimental factors and experimental indexes to determine the priority order of factors,and the best combination of factors.The test results showed that the pass rate was 93.25%,the replay rate was 2.97%and the missing seeding rate was 3.78%under the condition with the inclination angle of seed tube end of 32.28°,the forward speed of the machine of 6.89 km/h and the operating speed of the metering disc of 28.67 r/min,which can meet the requirements of relevant national standards.
