The effect of laser, as a heat source, on a one-dimensional finite living tissue was stud- ied in this paper. The dual phase lagging （DPL） non-Fourier heat conduction model was used for thermal analysis. The thermal...The effect of laser, as a heat source, on a one-dimensional finite living tissue was stud- ied in this paper. The dual phase lagging （DPL） non-Fourier heat conduction model was used for thermal analysis. The thermal conductivity was assumed temperature- dependent, resulting in a nonlinear equation. The obtained equations were solved using the approximate-analytical Adomian decomposition method （ADM）. It was concluded that the nonlinear analysis was important in nomFourier heat conduction problems. Moreover, a good agreement between the present nonlinear model and experimental result was obtained.展开更多
Atom transfer radical copolymerization(ATRP) of styrene(St) and N cyclohexylmaleimide(NCMI) with the CuBr/bpy catalyst in anisole, initiated by 1 phenylethyl bromide(1 PEBr) or tetra (bromomethyl)benzene(TBMB), afford...Atom transfer radical copolymerization(ATRP) of styrene(St) and N cyclohexylmaleimide(NCMI) with the CuBr/bpy catalyst in anisole, initiated by 1 phenylethyl bromide(1 PEBr) or tetra (bromomethyl)benzene(TBMB), afforded well defined copolymer with predetermined molecular weights and low polydispersities, M w/ M n<1.5. Other monomer pairs such as methyl methacrylate(MMA)/NCMI, St/ N phenylmaleimide, MMA/ N phenylmaleimide were studied, too. The influences of several factors, such as temperature, solvent and monomer’s ratio on the copolymerization with the CuBr/bpy catalyst system were subsequently investigated. The apparent activation energy of St(MMA)and NCMI was deduced from the kinetics figure of different temperatures. Using TBMB as the initiator produced four armed star copolymer. The heat resistance of the resultant copolymer has been improved by increasing the NCMI. [WT5HZ]展开更多
Four armed star shaped copolymer of methyl methacrylate(MMA)/ N cyclohexylmaleimide(NCMI) with heat resistance was synthesized by atom transfer radical copolymerization with the CuBr/bpy catalyst in anisole, initiated...Four armed star shaped copolymer of methyl methacrylate(MMA)/ N cyclohexylmaleimide(NCMI) with heat resistance was synthesized by atom transfer radical copolymerization with the CuBr/bpy catalyst in anisole, initiated by tetra(bromomethyl)benzene. A linear plot of ln( 0/) versus reaction time was obtained by using anisole as solvent. In contrast, the use of cyclohexanone as solvent results in that the rate of copolymerization decreases as the reaction proceeds. Using anisole as the solvent in the copolymerization, the molecular weight of the resultant copolymer(measured by triple detection SEC) increased linearly with the increase of conversion, and the molecular weight distributions are narrow. The glass transition temperature of the resultant copolymer was higher than that of the pure PMMA. The synthesized four armed star copolymer was used as macroinitiator for the cationic polymerization of 2 methyl 2 oxazoline to yield star shaped poly(MMA co NCMI)/poly(2 methyl 2 oxazoline) block copolymers. The approximately linear increase of the molecular weight with the increase of reaction time and the low molecular weight distribution demonstrate a controlled chain extension reaction.展开更多
活立木茎干水分状况是植物生命状态的有效体现,其中茎干含水率(Stem water content,StWC)和液流密度(Sap flux density,SFD)是研究植物体内水分变化规律的重要参数。准确检测活立木茎干同一空间位置的含水率和液流密度可以更有效地分析...活立木茎干水分状况是植物生命状态的有效体现,其中茎干含水率(Stem water content,StWC)和液流密度(Sap flux density,SFD)是研究植物体内水分变化规律的重要参数。准确检测活立木茎干同一空间位置的含水率和液流密度可以更有效地分析2个参数的关系、评估植物生长状况。将基于驻波率(Standing wave ratio,SWR)原理的茎干水分检测方法和基于热比率法(Heat ratio method,HRM)原理的茎干液流检测方法结合,设计了活立木茎干含水率和液流复合参数检测传感器,复合传感器的含水率检测单元和液流检测单元复用一套三针式探针,可对活立木茎干同一位置的含水率和液流实时精准检测。含水率检测单元输出电压与介电常数(6~53.3范围内,对应茎干含水率为0~85%)具有良好的线性关系(决定系数R^(2)=0.9701),静态稳定性良好(长时间测试最大波动为0.6%全量程)。以杨树为研究对象,含水率检测单元与BD-IV型植物茎体水分传感器的对比实验结果一致(决定系数R^(2)=0.9800)。液流检测单元与ST1221型热扩散式液流计对比,二者检测的杨树液流密度具有显著的线性关系(决定系数R^(2)=0.8991),热扩散式液流计不能准确判断零液流条件而低估了液流密度,ST1221型液流计检测的平均值比本系统液流检测单元低1.1 cm/h,液流检测单元使用的热比率法可以准确检测低速液流。复合传感器对杨树茎干含水率和液流的长时间监测结果与前人研究一致且符合植物生理规律。茎干含水率和液流存在极显著的负相关性(Pearson相关系数为-0.7951)。展开更多
文摘The effect of laser, as a heat source, on a one-dimensional finite living tissue was stud- ied in this paper. The dual phase lagging （DPL） non-Fourier heat conduction model was used for thermal analysis. The thermal conductivity was assumed temperature- dependent, resulting in a nonlinear equation. The obtained equations were solved using the approximate-analytical Adomian decomposition method （ADM）. It was concluded that the nonlinear analysis was important in nomFourier heat conduction problems. Moreover, a good agreement between the present nonlinear model and experimental result was obtained.
文摘Atom transfer radical copolymerization(ATRP) of styrene(St) and N cyclohexylmaleimide(NCMI) with the CuBr/bpy catalyst in anisole, initiated by 1 phenylethyl bromide(1 PEBr) or tetra (bromomethyl)benzene(TBMB), afforded well defined copolymer with predetermined molecular weights and low polydispersities, M w/ M n<1.5. Other monomer pairs such as methyl methacrylate(MMA)/NCMI, St/ N phenylmaleimide, MMA/ N phenylmaleimide were studied, too. The influences of several factors, such as temperature, solvent and monomer’s ratio on the copolymerization with the CuBr/bpy catalyst system were subsequently investigated. The apparent activation energy of St(MMA)and NCMI was deduced from the kinetics figure of different temperatures. Using TBMB as the initiator produced four armed star copolymer. The heat resistance of the resultant copolymer has been improved by increasing the NCMI. [WT5HZ]
文摘Four armed star shaped copolymer of methyl methacrylate(MMA)/ N cyclohexylmaleimide(NCMI) with heat resistance was synthesized by atom transfer radical copolymerization with the CuBr/bpy catalyst in anisole, initiated by tetra(bromomethyl)benzene. A linear plot of ln( 0/) versus reaction time was obtained by using anisole as solvent. In contrast, the use of cyclohexanone as solvent results in that the rate of copolymerization decreases as the reaction proceeds. Using anisole as the solvent in the copolymerization, the molecular weight of the resultant copolymer(measured by triple detection SEC) increased linearly with the increase of conversion, and the molecular weight distributions are narrow. The glass transition temperature of the resultant copolymer was higher than that of the pure PMMA. The synthesized four armed star copolymer was used as macroinitiator for the cationic polymerization of 2 methyl 2 oxazoline to yield star shaped poly(MMA co NCMI)/poly(2 methyl 2 oxazoline) block copolymers. The approximately linear increase of the molecular weight with the increase of reaction time and the low molecular weight distribution demonstrate a controlled chain extension reaction.
文摘活立木茎干水分状况是植物生命状态的有效体现,其中茎干含水率(Stem water content,StWC)和液流密度(Sap flux density,SFD)是研究植物体内水分变化规律的重要参数。准确检测活立木茎干同一空间位置的含水率和液流密度可以更有效地分析2个参数的关系、评估植物生长状况。将基于驻波率(Standing wave ratio,SWR)原理的茎干水分检测方法和基于热比率法(Heat ratio method,HRM)原理的茎干液流检测方法结合,设计了活立木茎干含水率和液流复合参数检测传感器,复合传感器的含水率检测单元和液流检测单元复用一套三针式探针,可对活立木茎干同一位置的含水率和液流实时精准检测。含水率检测单元输出电压与介电常数(6~53.3范围内,对应茎干含水率为0~85%)具有良好的线性关系(决定系数R^(2)=0.9701),静态稳定性良好(长时间测试最大波动为0.6%全量程)。以杨树为研究对象,含水率检测单元与BD-IV型植物茎体水分传感器的对比实验结果一致(决定系数R^(2)=0.9800)。液流检测单元与ST1221型热扩散式液流计对比,二者检测的杨树液流密度具有显著的线性关系(决定系数R^(2)=0.8991),热扩散式液流计不能准确判断零液流条件而低估了液流密度,ST1221型液流计检测的平均值比本系统液流检测单元低1.1 cm/h,液流检测单元使用的热比率法可以准确检测低速液流。复合传感器对杨树茎干含水率和液流的长时间监测结果与前人研究一致且符合植物生理规律。茎干含水率和液流存在极显著的负相关性(Pearson相关系数为-0.7951)。
