For treatment of common discontinuous tractions in 3 D elastic boundary element method,a simple and practical approach is proposed in this paper.The problem of the 1/r integral singularity and its treatment are discus...For treatment of common discontinuous tractions in 3 D elastic boundary element method,a simple and practical approach is proposed in this paper.The problem of the 1/r integral singularity and its treatment are discussed and analyzed as well.The numerical results show that the appprach in this paper is satisfactory.展开更多
Aiming at solving the problem of high global warming potential of R134 a,a new mixed refrigerant R13 I1/R152 a(molar fraction ratio of 35:65)with no ozone depletion potential and low global warming potential was propo...Aiming at solving the problem of high global warming potential of R134 a,a new mixed refrigerant R13 I1/R152 a(molar fraction ratio of 35:65)with no ozone depletion potential and low global warming potential was proposed as a substitute for R134 a in automotive air conditioning.The computational models for the thermodynamic properties of R13 I1/R152 a were established by using the PR(Peng-Robinson)equation of state combined with the vdW mixing rule.Based on these models,the cycle performance of this working fluid was calculated,which was also compared with that of R134 a and R1234 yf under the different operating conditions.The results show that R13 I1/R152 a is a near azeotropic refrigerant whose temperature glide is approximately 0,and the saturated vapor pressure curve of which is equivalent to that of R134 a.Moreover,compared to R134 a,R13 I1/R152 a has an average 5.7%improvement in coefficient of performance as well as similar volumetric cooling capacity.The average coefficient of performance and volumetric cooling capacity of R13 I1/R152 a are significantly higher than those of R1234 yf by 13.8%and12.0%,respectively.However,the average discharge temperature of R13 I1/R152 a is approximately13.3 K higher than that of R134 a,but it is also within reasonable limits.Hence,the application of the proposed refrigerant R13 I1/R152 a in automotive air conditioning system is technically feasible.展开更多
采用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳、双抗夹心酶联免疫吸附(enzyme-linked immunosorbent assay,ELISA)等方法,以Jug r 1含量为指标,对云南7个不同产地的泡核桃(Juglans sigillata)进行筛选,进一步利用硫酸铵分级沉淀、凝胶过滤层...采用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳、双抗夹心酶联免疫吸附(enzyme-linked immunosorbent assay,ELISA)等方法,以Jug r 1含量为指标,对云南7个不同产地的泡核桃(Juglans sigillata)进行筛选,进一步利用硫酸铵分级沉淀、凝胶过滤层析、液相色谱-串联质谱等手段制备Jug r 1并进行优化和鉴定,通过圆二色谱对Jug r 1的结构进行表征,最后采用双抗夹心ELISA法测定其含量。结果表明:保山隆阳产地核桃的总蛋白含量和Jug r 1含量均最高,用于后续实验;经优化得到Jug r 1的最佳硫酸铵分级沉淀分离区间为40%~80%,进一步对其进行凝胶过滤层析的最佳条件为上样质量浓度30 mg/mL、上样体积4 mL、洗脱流速1 mL/min;在此条件下纯化得到Jug r 1含量达19.90 mg/120 mg上样量,蛋白得率为16.58%;质谱分析表明该蛋白符合Jug r 1的典型特征;圆二色谱显示Jug r 1的二级结构以α-螺旋为主,多种构象共存;经“两步法”分离纯化后可获得蛋白纯度占总蛋白96%以上的Jug r 1。本结果可为深入研究Jug r 1提供科学基础,并为其他坚果致敏蛋白的分离纯化提供参考。展开更多
文摘For treatment of common discontinuous tractions in 3 D elastic boundary element method,a simple and practical approach is proposed in this paper.The problem of the 1/r integral singularity and its treatment are discussed and analyzed as well.The numerical results show that the appprach in this paper is satisfactory.
基金supported by the National Natural Science Foundation of China(22068024)。
文摘Aiming at solving the problem of high global warming potential of R134 a,a new mixed refrigerant R13 I1/R152 a(molar fraction ratio of 35:65)with no ozone depletion potential and low global warming potential was proposed as a substitute for R134 a in automotive air conditioning.The computational models for the thermodynamic properties of R13 I1/R152 a were established by using the PR(Peng-Robinson)equation of state combined with the vdW mixing rule.Based on these models,the cycle performance of this working fluid was calculated,which was also compared with that of R134 a and R1234 yf under the different operating conditions.The results show that R13 I1/R152 a is a near azeotropic refrigerant whose temperature glide is approximately 0,and the saturated vapor pressure curve of which is equivalent to that of R134 a.Moreover,compared to R134 a,R13 I1/R152 a has an average 5.7%improvement in coefficient of performance as well as similar volumetric cooling capacity.The average coefficient of performance and volumetric cooling capacity of R13 I1/R152 a are significantly higher than those of R1234 yf by 13.8%and12.0%,respectively.However,the average discharge temperature of R13 I1/R152 a is approximately13.3 K higher than that of R134 a,but it is also within reasonable limits.Hence,the application of the proposed refrigerant R13 I1/R152 a in automotive air conditioning system is technically feasible.
文摘采用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳、双抗夹心酶联免疫吸附(enzyme-linked immunosorbent assay,ELISA)等方法,以Jug r 1含量为指标,对云南7个不同产地的泡核桃(Juglans sigillata)进行筛选,进一步利用硫酸铵分级沉淀、凝胶过滤层析、液相色谱-串联质谱等手段制备Jug r 1并进行优化和鉴定,通过圆二色谱对Jug r 1的结构进行表征,最后采用双抗夹心ELISA法测定其含量。结果表明:保山隆阳产地核桃的总蛋白含量和Jug r 1含量均最高,用于后续实验;经优化得到Jug r 1的最佳硫酸铵分级沉淀分离区间为40%~80%,进一步对其进行凝胶过滤层析的最佳条件为上样质量浓度30 mg/mL、上样体积4 mL、洗脱流速1 mL/min;在此条件下纯化得到Jug r 1含量达19.90 mg/120 mg上样量,蛋白得率为16.58%;质谱分析表明该蛋白符合Jug r 1的典型特征;圆二色谱显示Jug r 1的二级结构以α-螺旋为主,多种构象共存;经“两步法”分离纯化后可获得蛋白纯度占总蛋白96%以上的Jug r 1。本结果可为深入研究Jug r 1提供科学基础,并为其他坚果致敏蛋白的分离纯化提供参考。
