采用一种新型在线无损检测的试验方法———微型杯突试验法研究电站锅炉管道用 9Cr 1Mo V Nb N钢的强度和塑性。结果表明 :该试验方法与常规的单轴拉伸试验之间有很好的可比性 ,并且通过微型杯突试验的结果估算 9Cr 1Mo V Nb N钢的屈服...采用一种新型在线无损检测的试验方法———微型杯突试验法研究电站锅炉管道用 9Cr 1Mo V Nb N钢的强度和塑性。结果表明 :该试验方法与常规的单轴拉伸试验之间有很好的可比性 ,并且通过微型杯突试验的结果估算 9Cr 1Mo V Nb N钢的屈服强度与抗拉强度及伸长率 ,给出相应的经验公式。同时在采用微型杯突试验法估算 9Cr 1Mo V Nb N钢的塑性时 ,首次提出断裂挠度率的概念。展开更多
The objective of this study was to determine the effect of age and breed of cattle on carcass and meat characteristics in Ethiopia. A total of 39 (Arsi 11, Boran 14 and Harar 14) cattle breeds with age categories of &...The objective of this study was to determine the effect of age and breed of cattle on carcass and meat characteristics in Ethiopia. A total of 39 (Arsi 11, Boran 14 and Harar 14) cattle breeds with age categories of <3, 4 - 6, and 7 - 9 years were used for the study. The bulls were purchased from their respective production system of mixed crop livestock system (Arsi and Harar) and Ranch (Boran). Parameters such as live and carcass weight, meat yield percent, fat characteristics, and primal beef cuts were evaluated. Complete randomized design was used for the study. The live weight of bulls at <3, 4 - 6 and 7 - 9 years ranged 135 - 183, 167 - 181, and 155 - 433 kg, respectively. The carcass weight, dressing percentage, meat yield percent, forequarter, hindquarter, rib eye area, and fat thickness ranged 57 - 209.73 kg, 41.8% - 51.6%, 32% - 58%, 11.7 - 56.42 kg, 14.04 - 45.34 kg, 4.78 - 10.25 square inches and 0.18 - 0.38 inches, respectively. At an early age category (<3 years) meat yield percentage of Arsi, Boran and Harar breeds were 50.86, 30 and 18.72, respectively, and as age category shifted from one age category to the next Harar increased by 13× and Boran by 2.9× and Arsi decreased by -0.93×. The mean rib percentage of Arsi, Boran and Harar were in the range of 7.98 - 9.57, 8.62 - 10.44 and 7.08 - 8.83, respectively. Breed and age of bulls had significantly affected primal meat cuts. Meat yield was predicted from live and hot carcass weight with coefficient determination (R2) of 70.66% and 74.75%, respectively. From the study, it was concluded that age and breeds of cattle had significantly influence on carcass and meat characteristics. Therefore, to determine whether variations were due to genetic or environmental cause’s evaluation of the three breeds under similar feeding condition was recommended.展开更多
The plan of heat-treatment process for 2014Al alloy is designed using orthogonal method, the heat-treatment experiments are made and the mechanical properties are tested according to the designed plan. The effect of s...The plan of heat-treatment process for 2014Al alloy is designed using orthogonal method, the heat-treatment experiments are made and the mechanical properties are tested according to the designed plan. The effect of solid solution temperature, ageing temperature, ageing time on microscopic mechanism of the mechanical properties of the 2014Al alloy is studied using microscope, transmission electron microscope. The best heat treatment process of the 2014Al alloy is developed. The experimental results indicate that the strength σ<sub>b</sub>, yield stress σ<sub>0.2</sub>, percentage elongation δ of the alloy reach separately 490～500 MPa, 450～490 MPa, 10～12％ adopting the new heat treatment process. Compared with GB, the strength increases 20～30％, the percentage elongation increases 30～40％. The mechanism of the new heat-treatment process is also discussed.展开更多
文摘采用一种新型在线无损检测的试验方法———微型杯突试验法研究电站锅炉管道用 9Cr 1Mo V Nb N钢的强度和塑性。结果表明 :该试验方法与常规的单轴拉伸试验之间有很好的可比性 ,并且通过微型杯突试验的结果估算 9Cr 1Mo V Nb N钢的屈服强度与抗拉强度及伸长率 ,给出相应的经验公式。同时在采用微型杯突试验法估算 9Cr 1Mo V Nb N钢的塑性时 ,首次提出断裂挠度率的概念。
文摘The objective of this study was to determine the effect of age and breed of cattle on carcass and meat characteristics in Ethiopia. A total of 39 (Arsi 11, Boran 14 and Harar 14) cattle breeds with age categories of <3, 4 - 6, and 7 - 9 years were used for the study. The bulls were purchased from their respective production system of mixed crop livestock system (Arsi and Harar) and Ranch (Boran). Parameters such as live and carcass weight, meat yield percent, fat characteristics, and primal beef cuts were evaluated. Complete randomized design was used for the study. The live weight of bulls at <3, 4 - 6 and 7 - 9 years ranged 135 - 183, 167 - 181, and 155 - 433 kg, respectively. The carcass weight, dressing percentage, meat yield percent, forequarter, hindquarter, rib eye area, and fat thickness ranged 57 - 209.73 kg, 41.8% - 51.6%, 32% - 58%, 11.7 - 56.42 kg, 14.04 - 45.34 kg, 4.78 - 10.25 square inches and 0.18 - 0.38 inches, respectively. At an early age category (<3 years) meat yield percentage of Arsi, Boran and Harar breeds were 50.86, 30 and 18.72, respectively, and as age category shifted from one age category to the next Harar increased by 13× and Boran by 2.9× and Arsi decreased by -0.93×. The mean rib percentage of Arsi, Boran and Harar were in the range of 7.98 - 9.57, 8.62 - 10.44 and 7.08 - 8.83, respectively. Breed and age of bulls had significantly affected primal meat cuts. Meat yield was predicted from live and hot carcass weight with coefficient determination (R2) of 70.66% and 74.75%, respectively. From the study, it was concluded that age and breeds of cattle had significantly influence on carcass and meat characteristics. Therefore, to determine whether variations were due to genetic or environmental cause’s evaluation of the three breeds under similar feeding condition was recommended.
文摘The plan of heat-treatment process for 2014Al alloy is designed using orthogonal method, the heat-treatment experiments are made and the mechanical properties are tested according to the designed plan. The effect of solid solution temperature, ageing temperature, ageing time on microscopic mechanism of the mechanical properties of the 2014Al alloy is studied using microscope, transmission electron microscope. The best heat treatment process of the 2014Al alloy is developed. The experimental results indicate that the strength σ<sub>b</sub>, yield stress σ<sub>0.2</sub>, percentage elongation δ of the alloy reach separately 490～500 MPa, 450～490 MPa, 10～12％ adopting the new heat treatment process. Compared with GB, the strength increases 20～30％, the percentage elongation increases 30～40％. The mechanism of the new heat-treatment process is also discussed.
