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Ma J.,Sichuan Agricultural University | Lei X.L.,Key Laboratory of Crop Ecophysiology and Farming System in Southwest China | Ma R.C.,Sichuan Agricultural University
Applied Mechanics and Materials | Year: 2013

In order to improve the seeding quality of paddy planter, some parts of rice seed-metering, such as sufficient regulator and delivery tube, were optimally designed, and field experiment was completed to optimize the structural and working parameters. Central composite design was employed to as design the experimental plan by means of the Design-Expert software (Version 7.0). The parameters of travel speed (A), sufficient regulator's angle (B) and length of delivery tube (C) were selected as influence factors, and seeding quality rate(y1), damage ratio of seeding(y2) and ratio of seeding holes(y3) were chosen as objective indexes. Regression models were established and analyzed based on Design-Expert and SAS software. The experiment results indicated that sufficient regulator improved quality of seeding and ratio of seeding holes especially with a few rice seeds in seed room. Under experimental conditions, the importance of each variable on y1, y2 and y3 was A>C>B, C>B>A and C>B>A and effects of the interaction of A and C on y1, the interaction of B and C on y2 and the interaction of A and C on y3 were significant by response surface analysis. By multiple objective programming, the optimal parameters were obtained as follow: travel speed of 2.8km/h, angle of sufficient regulator of 72° and delivery tube's length of 0.25m. This study has important significant to well improvement seeding quality of rice direct-seeding. © (2013) Trans Tech Publications, Switzerland. Source


Xiao R.L.,Sichuan Agricultural University | Xiao R.L.,Key Laboratory of Crop Ecophysiology and Farming System in Southwest China | Xiao L.L.,Chuzhou University
Advanced Materials Research | Year: 2014

At present the Maize picker has the large power consumption problem. The paper design a Maize picker device, the device is effective to reduce the power consumption of corn harvest machine work. By the virtual prototyping technology, completed the design of the overall structure of the Maize picker device. © (2014) Trans Tech Publications, Switzerland. Source


Shen S.,Sichuan Agricultural University | Chen D.,Yunnan Academy of Agricultural Sciences | Li X.,Sichuan Agricultural University | Li T.,Key Laboratory of Crop Ecophysiology and Farming System in Southwest China | And 3 more authors.
Carbohydrate Polymers | Year: 2014

Based on a single-factor test, a central composite design was used to optimize the extraction conditions of polysaccharides from leaves of Paris polyphylla Smith var. yunnanensis (Franch.) Hand.-Mazz. Three independent variables, including extraction temperature (C), ratio of water to raw material, and extraction time (h), which significantly affected the yield of polysaccharides, were investigated. The experimental data were fitted to a quadratic polynomial equation using multiple regression analysis and also examined using appropriate statistical methods. The optimum conditions were as follows: extraction temperature, 90.8 C; ratio of water to raw material, 21.3:1; and extraction time 4.8 h. Under these conditions, the experimental yield was 54.18%, which matched the predicted value well. Furthermore, the purified polysaccharide exerted strong antioxidant effects on DPPH, hydroxyl, and superoxide radicals in vitro. © 2014 Elsevier Ltd. Source


Shen S.,Sichuan Agricultural University | Cheng H.,Sichuan Agricultural University | Li X.,Sichuan Agricultural University | Li T.,Key Laboratory of Crop Ecophysiology and Farming System in Southwest China | And 3 more authors.
European Food Research and Technology | Year: 2014

Four purified polysaccharides (COP-H, COP-U, COP-E, and COP-A) were obtained from seed cake of Camellia oleifera Abel. by hot water extraction, ultrasonic-assisted extraction, enzyme extraction, and alkali extraction, respectively. Their structural characterizations were determined, and antioxidant activities were investigated. The results of FT-IR demonstrated that the characteristic absorption bands exhibited slight difference among four polysaccharides. HLPC analysis presented that the molecular weights were calculated to be 394, 297, 462, and 429 kDa for COP-H, COP-U, COP-E, and COP-A, respectively. GC-MS analysis showed that the monosaccharide compositions were identical to four polysaccharides, while the molecular ratios exhibited significant difference. Four polysaccharides showed antioxidant activities in a concentration-dependent manner. Among four polysaccharides, COP-E showed a higher scavenging activity on DPPH, hydroxyl radical, and superoxide anion radical. These findings suggest camellia seed cake polysaccharides have potential as a natural antioxidant. © 2014 Springer-Verlag Berlin Heidelberg. Source


Ma J.,Sichuan Agricultural University | Lei X.L.,Key Laboratory of Crop Ecophysiology and Farming System in Southwest China | Ma R.C.,Sichuan Agricultural University
Applied Mechanics and Materials | Year: 2014

In order to optimize the structure and technology parameters of rotary drying, mathematical models of effective residence time and mass of loading were established based on the motion of solid particles in rotary dryer. Uniform design was applied in experimental design with material of rapeseed. Four independent variables such as structural parameter (cylinder inclination angle) and operating parameters (the rotation speed of rotary dryer, solids feed speed and airflow speed) were investigated. Prediction models of effective residence time and mass of loading were established by using software DPS7.05 to optimize the experimental design. The experiment results showed that under experimental conditions, the effects of airflow speed, rotation speed, the interaction of rotation speed with airflow speed and the interaction of rotation speed with solids feed speed on effective residence time were significant. Rotation speed, airflow speed, the interaction of cylinder inclination angle with solids feed speed and the interaction of feed speed with airflow speed had significant influences on mass of loading. By optimizing with multiple objective programming, the optimal parameters were obtained as follow: cylinder inclination angle of 1.8°, rotation speed of rotary dryer of 4 r/min, solids feed speed of 2.5 kg/s and airflow speed of 2.4 m/s. The research has important significance to well improve structure and technology parameters of rotary drying technology in solids drying. © (2014) Trans Tech Publications, Switzerland. Source

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