The most general contact in mechanical transmission is the elliptical one. In particular, a toroidal continuously variable transmission (CVT) has an elliptical shape in the contact area under the elastohydrodynamic lu...The most general contact in mechanical transmission is the elliptical one. In particular, a toroidal continuously variable transmission (CVT) has an elliptical shape in the contact area under the elastohydrodynamic lubrication regime, where the shearing of the fluid subjects to high contact stress and transmits the power. Many parameters affect the contact service performance of the half toroidal CVT, which include the properties of the contacting material (Young抯 modulus), operating parameters (input torque and maximum traction coefficient) and geometrical parameters (aspect cavity ratio, curvature ratio and half cone angle of the power roller). In this paper, the contacts between the input disk, the power roller and the output disk are formulated using the classical Hertzian contact theory. Based on the formulated equations, different system parameters, which affect the maximum Hertzian stresses, are compared. The comparative results will provide some observations of the relations between the maximum Hertzian stresses and transmission ratios in the form of graphs. These graphs give useful information for designer to know the maximum Hertzian stress during operation in such systems.展开更多
As environmental protection agencies enact new regulations for automotive fuel economy and emission, the toroidal continuously variable transmissions (CVTs) keep on contribute to the advent of system technologies for ...As environmental protection agencies enact new regulations for automotive fuel economy and emission, the toroidal continuously variable transmissions (CVTs) keep on contribute to the advent of system technologies for better fuel consumption of automobiles with internal combustion engines (ICE). Toroidal CVTs use infinitely adjustable drive ratios instead of stepped gears to achieve optimal performance. Toroidal CVTs are one of the earliest patents to the automotive world but their torque capacities and reliability have limitations in the past. New developments and implementations in the control strategies, and several key technologies have led to development of more robust toroidal CVTs, which enables more extensive automotive application of toroidal CTVs. This paper concerns with the current development, upcoming and progress set in the context of the past development and the traditional problems associated with toroidal CVTs.展开更多
The aim of this study was to explore the effects of bamboo vinegar powder on growth performance,diarrhea situation and mRNA expression levels of cytokines i.e., interleukin-10(IL-10), interleukin-22(IL-22), and interl...The aim of this study was to explore the effects of bamboo vinegar powder on growth performance,diarrhea situation and mRNA expression levels of cytokines i.e., interleukin-10(IL-10), interleukin-22(IL-22), and interleukin-25(IL-25) in immune organs of weaned piglets, and to accumulate theoretical data for the application of bamboo vinegar powder in weaned piglet production. Forty-five crossbred(Duroc × Landrace × Yorkshire, all male) weaned piglets with similar body weight(6.74 ± 0.17 kg) at 31 days of age were randomly assigned to 5 treatments with 3 replicates per treatment and 3 piglets in each replicate. The five treatments were as follows: CON(a basal diet), ANT(the basal diet + 0.12% antibiotics),BV1(the basal diet + 0.1% bamboo vinegar powder), BV5(the basal diet + 0.5% bamboo vinegar powder),BV10(the basal diet + 1.0% bamboo vinegar powder). This experiment lasted 35 days. The growth performance and diarrhea situation were recorded. The relative mRNA expression levels of IL-10, IL-22 and IL-25 in liver, spleen, duodenum and mesenteric lymph nodes were detected by real-time PCR. Feed:gain of BV5 was significantly lower than that of CON(P < 0.05). In comparison with CON, diarrhea rate and diarrhea index of BV1 and BV5 all tended to decrease(P < 0.1). Compared with CON, mRNA expression level of IL-10 in liver of ANT tended to be lower(P < 0.1) and these of BV1, BV5 and BV10 were significantly reduced(P < 0.05). The mRNA expression levels of IL-10 in duodenum of ANT, BV1, BV5 and BV10 were all lower than those of CON, of which BV10 had significantly decreased IL-10 mRNA expression in duodenum(P < 0.05). The mRNA expression levels of IL-22 in duodenum of ANT, BV1, BV5 and BV10 all tended to be inhibited compared with CON(P < 0.1). With the increase of bamboo vinegar powder dosage, mRNA expression levels of IL-25 in spleen and mesenteric lymph nodes of BV1, BV5 and BV10 tended to be up-regulated. Overall, bamboo vinegar powder could improve growth performance,and regulate mRNA expression levels of IL-10, IL展开更多
Ramie(Boehmeria nivea)is noted for the production of a large biomass that has a high protein content and is rich in antioxidants.It may thus serve as a high-quality forage material to replace alfalfa and improve the m...Ramie(Boehmeria nivea)is noted for the production of a large biomass that has a high protein content and is rich in antioxidants.It may thus serve as a high-quality forage material to replace alfalfa and improve the meat quality of farmed animals.In this study,we evaluated the carcass characteristics and meat quality of goats when 0,35%,75%,and 100%of dietary alfalfa was replaced with ramie.Crude protein content(linear,P<0.0001)and key muscle color values at 24 h after slaughter decreased with increasing ramie levels.The content of most individual amino acids,non-essential amino acids(NEAA),total amino acids(TAA),branched chain amino acids(BCAA),functional amino acids(FAA),and flavor amino acids(DAA)decreased(P<0.05)with increasing dietary ramie.The diet in which 35%of alfalfa was replaced with ramie yielded meat with the highest amino acid content,whereas the fatty acid profile was unaffected by the inclusion of ramie.These results indicate that ramie could be used as a potential dietary forage resource for goats,and that substituting 35%of alfalfa with ramie,which is equivalent to 126 g/kg DM content,would be optimal in terms of goat meat quality.展开更多
基金the Ford-NSFC Foundation of China (No. 50122151).
文摘The most general contact in mechanical transmission is the elliptical one. In particular, a toroidal continuously variable transmission (CVT) has an elliptical shape in the contact area under the elastohydrodynamic lubrication regime, where the shearing of the fluid subjects to high contact stress and transmits the power. Many parameters affect the contact service performance of the half toroidal CVT, which include the properties of the contacting material (Young抯 modulus), operating parameters (input torque and maximum traction coefficient) and geometrical parameters (aspect cavity ratio, curvature ratio and half cone angle of the power roller). In this paper, the contacts between the input disk, the power roller and the output disk are formulated using the classical Hertzian contact theory. Based on the formulated equations, different system parameters, which affect the maximum Hertzian stresses, are compared. The comparative results will provide some observations of the relations between the maximum Hertzian stresses and transmission ratios in the form of graphs. These graphs give useful information for designer to know the maximum Hertzian stress during operation in such systems.
基金the Ford-NSFC Foundation of China (No. 50122151).
文摘As environmental protection agencies enact new regulations for automotive fuel economy and emission, the toroidal continuously variable transmissions (CVTs) keep on contribute to the advent of system technologies for better fuel consumption of automobiles with internal combustion engines (ICE). Toroidal CVTs use infinitely adjustable drive ratios instead of stepped gears to achieve optimal performance. Toroidal CVTs are one of the earliest patents to the automotive world but their torque capacities and reliability have limitations in the past. New developments and implementations in the control strategies, and several key technologies have led to development of more robust toroidal CVTs, which enables more extensive automotive application of toroidal CTVs. This paper concerns with the current development, upcoming and progress set in the context of the past development and the traditional problems associated with toroidal CVTs.
基金supported by Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)Key Research and Development Projects (Modern Agriculture) of Jiangsu Province (BE2015329)Northern Jiangsu Science and Technology Development Plan (BN2015064)
文摘The aim of this study was to explore the effects of bamboo vinegar powder on growth performance,diarrhea situation and mRNA expression levels of cytokines i.e., interleukin-10(IL-10), interleukin-22(IL-22), and interleukin-25(IL-25) in immune organs of weaned piglets, and to accumulate theoretical data for the application of bamboo vinegar powder in weaned piglet production. Forty-five crossbred(Duroc × Landrace × Yorkshire, all male) weaned piglets with similar body weight(6.74 ± 0.17 kg) at 31 days of age were randomly assigned to 5 treatments with 3 replicates per treatment and 3 piglets in each replicate. The five treatments were as follows: CON(a basal diet), ANT(the basal diet + 0.12% antibiotics),BV1(the basal diet + 0.1% bamboo vinegar powder), BV5(the basal diet + 0.5% bamboo vinegar powder),BV10(the basal diet + 1.0% bamboo vinegar powder). This experiment lasted 35 days. The growth performance and diarrhea situation were recorded. The relative mRNA expression levels of IL-10, IL-22 and IL-25 in liver, spleen, duodenum and mesenteric lymph nodes were detected by real-time PCR. Feed:gain of BV5 was significantly lower than that of CON(P < 0.05). In comparison with CON, diarrhea rate and diarrhea index of BV1 and BV5 all tended to decrease(P < 0.1). Compared with CON, mRNA expression level of IL-10 in liver of ANT tended to be lower(P < 0.1) and these of BV1, BV5 and BV10 were significantly reduced(P < 0.05). The mRNA expression levels of IL-10 in duodenum of ANT, BV1, BV5 and BV10 were all lower than those of CON, of which BV10 had significantly decreased IL-10 mRNA expression in duodenum(P < 0.05). The mRNA expression levels of IL-22 in duodenum of ANT, BV1, BV5 and BV10 all tended to be inhibited compared with CON(P < 0.1). With the increase of bamboo vinegar powder dosage, mRNA expression levels of IL-25 in spleen and mesenteric lymph nodes of BV1, BV5 and BV10 tended to be up-regulated. Overall, bamboo vinegar powder could improve growth performance,and regulate mRNA expression levels of IL-10, IL
基金financially supported by the National Key Research and Development Program of China(No.2018YFD0501604,2018YFD0501900)China Special Fund for Agro-Scientific Research in the Public Interest(No.201303144)+2 种基金the National Natural Science Foundation of China(No.31501988)Hunan Provincial Major Scientific and Technological Special Project(No.2017NK1020)Key Research and Development Program of Hunan Province(No.2016NK2171)
文摘Ramie(Boehmeria nivea)is noted for the production of a large biomass that has a high protein content and is rich in antioxidants.It may thus serve as a high-quality forage material to replace alfalfa and improve the meat quality of farmed animals.In this study,we evaluated the carcass characteristics and meat quality of goats when 0,35%,75%,and 100%of dietary alfalfa was replaced with ramie.Crude protein content(linear,P<0.0001)and key muscle color values at 24 h after slaughter decreased with increasing ramie levels.The content of most individual amino acids,non-essential amino acids(NEAA),total amino acids(TAA),branched chain amino acids(BCAA),functional amino acids(FAA),and flavor amino acids(DAA)decreased(P<0.05)with increasing dietary ramie.The diet in which 35%of alfalfa was replaced with ramie yielded meat with the highest amino acid content,whereas the fatty acid profile was unaffected by the inclusion of ramie.These results indicate that ramie could be used as a potential dietary forage resource for goats,and that substituting 35%of alfalfa with ramie,which is equivalent to 126 g/kg DM content,would be optimal in terms of goat meat quality.
