A simple but applicable analytical model is presented to predict the lat- eral distribution of the depth-averaged velocity in meandering compound channels. The governing equation with curvilinear coordinates is derive...A simple but applicable analytical model is presented to predict the lat- eral distribution of the depth-averaged velocity in meandering compound channels. The governing equation with curvilinear coordinates is derived from the momentum equation and the flow continuity equation under the condition of quasi-uniform flow. A series of experiments are conducted in a large-scale meandering compound channel. Based on the experimental data, a magnitude analysis is carried out for the governing equation, and two lower-order shear stress terms are ignored. Four groups of experimental data from different sources are used to verify the predictive capability of this model, and good predictions are obtained. Finally, the determination of the velocity parameter and the limitation of this model are discussed.展开更多
To support the requirement analysis of the user interfaces and the auto generation of the final user interfaces, we should improve the traditional modeling method which centered on the system and the implementation, a...To support the requirement analysis of the user interfaces and the auto generation of the final user interfaces, we should improve the traditional modeling method which centered on the system and the implementation, and turn to use the modeling method which centered on the usage and the user. The compound use cases describe the system function from the user point of view. Based on the compound use cases, we can generate the final user interfaces.展开更多
The RNG κ-ε model considering the buoyancy effect, which is solved by the hybrid finite analytic method, is used to simulate the mixture of the horizontal round thermal buoyant jet in compound open channel flow. The...The RNG κ-ε model considering the buoyancy effect, which is solved by the hybrid finite analytic method, is used to simulate the mixture of the horizontal round thermal buoyant jet in compound open channel flow. The mixing features near the spout and flowing characteristic of the secondary currents are studied by numerical simulation. Meanwhile, （1） the distribution of the measured isovels for stream-wise velocity, （2） secondary currents, （3） the distribution of the measured isovels for temperature of typical cross-section near the spout, were obtained by the three-dimensional Micro ADV and the temperature measuring device. Compared with experimental data, the RNG κ-ε model based on buoyancy effect can preferably simulate the jet which performs the bifurcation phenomenon, jet reattachment （Conada effect） and beach secondary currents phenomenon with the effect of ambient flow, buoyancy, and secondary currents of compound section and so on.展开更多
Mathematical models of steady-state biofilteration are discussed. The theoretical results are much useful for the design of biofilters. This model is based on the system of non-linear reaction/diffusion equations cont...Mathematical models of steady-state biofilteration are discussed. The theoretical results are much useful for the design of biofilters. This model is based on the system of non-linear reaction/diffusion equations contains a non-linear term related to Monod kinetics, Andrews kinetics, interactive model from Monod kinetics and Andrews kinetics. Analytical expression of concentration of VOC (Volatile organic compounds) and oxygen are derived by solving the system of non-linear equations using Adomian decomposition method (ADM) method. Our analytical results are also compared with the simulation results. Satisfactory agreement is noted.展开更多
目的测算了解2023年南京市成年人健康期望寿命(healthy-adjusted life expectancy,HALE),评价人群健康水平并提供相应的指导依据。方法2023年通过南京市健康期望寿命专项调查获取健康状态资料,在南京市12个区采用多阶段分层整群随机抽...目的测算了解2023年南京市成年人健康期望寿命(healthy-adjusted life expectancy,HALE),评价人群健康水平并提供相应的指导依据。方法2023年通过南京市健康期望寿命专项调查获取健康状态资料,在南京市12个区采用多阶段分层整群随机抽样的方法,收集有效样本数18406例,结合南京市2023年人口和死亡数据,基于沙利文法和复合分层序数(compound hierarchical ordinal probit,CHOPIT)模型测算HALE。结果自报健康数据经CHOPIT模型校正后,南京市18岁以上居民的期望寿命(life expectancy,LE)和HALE结果分别为63.05和42.39岁,因伤残损失的健康期望寿命(expectation of lost healthy years,LHE)为20.66岁,LHE/LE为32.77%,随年龄增长,HALE损失占LE的百分比逐渐增大。各年龄组的LE女性高于男性,<85岁年龄组的HALE女性高于男性,≥85岁年龄组的HALE男性高于女性,各个年龄组的LHE和LHE/LE女性高于男性,年龄越大,男女性的LHE差距越小,LHE/LE越大。结论南京市HALE存在明显年龄、性别差异,应加强老年人的综合健康管理,对不同性别人群采取针对性的政策制定,进一步提高全人群HALE。展开更多
该文旨在研究不同包装方式对杏与玫瑰花酱复合果丹皮在贮藏过程中品质变化的影响,并通过品质变化规律预测其货架期。首先采用糖纸包装(candy paper packaging,CW)、真空包装(vacuum packaging,VP)、保鲜袋包装(storage bag packaging,W...该文旨在研究不同包装方式对杏与玫瑰花酱复合果丹皮在贮藏过程中品质变化的影响,并通过品质变化规律预测其货架期。首先采用糖纸包装(candy paper packaging,CW)、真空包装(vacuum packaging,VP)、保鲜袋包装(storage bag packaging,WPB)和铝箔袋包装(aluminum foil bag packaging,ABP)4种包装方式对复合果丹皮进行包装,并在常温下贮藏180 d测定其在贮藏期间品质指标的变化值,以水分含量、可溶性糖含量、硬度和菌落总数为表征指标建立化学动力学模型以预测复合果丹皮的货架期。结果表明,采用VP方式能有效延缓复合果丹皮中可溶性糖、维生素C、活性成分等营养成分的降解、抑制复合果丹皮在贮藏期间被微生物的污染。可溶性糖和菌落总数的变化规律符合零级动力学模型、水分含量与硬度的变化规律符合一级动力学模型,验证结果表明,VP方式下复合果丹皮以4种表征指标建立的预测模型准确度较高,预测值与实测值相对误差较小,Arrhenius方程具有较好的拟合性。因此,VP方式的应用将会为复合果丹皮的包装和贮藏提供理论基础。展开更多
基金Project supported by the National Natural Science Foundation of China(Nos.11171238,51279117,and 11072161)the Program for New Century Excellent Talents in University of China(No.NCET-13-0393)the National Science and Technology Ministry of China(No.2012BAB05B02)
文摘A simple but applicable analytical model is presented to predict the lat- eral distribution of the depth-averaged velocity in meandering compound channels. The governing equation with curvilinear coordinates is derived from the momentum equation and the flow continuity equation under the condition of quasi-uniform flow. A series of experiments are conducted in a large-scale meandering compound channel. Based on the experimental data, a magnitude analysis is carried out for the governing equation, and two lower-order shear stress terms are ignored. Four groups of experimental data from different sources are used to verify the predictive capability of this model, and good predictions are obtained. Finally, the determination of the velocity parameter and the limitation of this model are discussed.
文摘To support the requirement analysis of the user interfaces and the auto generation of the final user interfaces, we should improve the traditional modeling method which centered on the system and the implementation, and turn to use the modeling method which centered on the usage and the user. The compound use cases describe the system function from the user point of view. Based on the compound use cases, we can generate the final user interfaces.
基金Project supported by the National Natural Science Foundation of China (Nos.50479038 and 50679061)the Open Foundation of State Key Laboratory of Coastal and Offshore Engineering,Dalian University of Technology (No.LP0601)
文摘The RNG κ-ε model considering the buoyancy effect, which is solved by the hybrid finite analytic method, is used to simulate the mixture of the horizontal round thermal buoyant jet in compound open channel flow. The mixing features near the spout and flowing characteristic of the secondary currents are studied by numerical simulation. Meanwhile, （1） the distribution of the measured isovels for stream-wise velocity, （2） secondary currents, （3） the distribution of the measured isovels for temperature of typical cross-section near the spout, were obtained by the three-dimensional Micro ADV and the temperature measuring device. Compared with experimental data, the RNG κ-ε model based on buoyancy effect can preferably simulate the jet which performs the bifurcation phenomenon, jet reattachment （Conada effect） and beach secondary currents phenomenon with the effect of ambient flow, buoyancy, and secondary currents of compound section and so on.
文摘Mathematical models of steady-state biofilteration are discussed. The theoretical results are much useful for the design of biofilters. This model is based on the system of non-linear reaction/diffusion equations contains a non-linear term related to Monod kinetics, Andrews kinetics, interactive model from Monod kinetics and Andrews kinetics. Analytical expression of concentration of VOC (Volatile organic compounds) and oxygen are derived by solving the system of non-linear equations using Adomian decomposition method (ADM) method. Our analytical results are also compared with the simulation results. Satisfactory agreement is noted.
文摘目的测算了解2023年南京市成年人健康期望寿命(healthy-adjusted life expectancy,HALE),评价人群健康水平并提供相应的指导依据。方法2023年通过南京市健康期望寿命专项调查获取健康状态资料,在南京市12个区采用多阶段分层整群随机抽样的方法,收集有效样本数18406例,结合南京市2023年人口和死亡数据,基于沙利文法和复合分层序数(compound hierarchical ordinal probit,CHOPIT)模型测算HALE。结果自报健康数据经CHOPIT模型校正后,南京市18岁以上居民的期望寿命(life expectancy,LE)和HALE结果分别为63.05和42.39岁,因伤残损失的健康期望寿命(expectation of lost healthy years,LHE)为20.66岁,LHE/LE为32.77%,随年龄增长,HALE损失占LE的百分比逐渐增大。各年龄组的LE女性高于男性,<85岁年龄组的HALE女性高于男性,≥85岁年龄组的HALE男性高于女性,各个年龄组的LHE和LHE/LE女性高于男性,年龄越大,男女性的LHE差距越小,LHE/LE越大。结论南京市HALE存在明显年龄、性别差异,应加强老年人的综合健康管理,对不同性别人群采取针对性的政策制定,进一步提高全人群HALE。
文摘该文旨在研究不同包装方式对杏与玫瑰花酱复合果丹皮在贮藏过程中品质变化的影响,并通过品质变化规律预测其货架期。首先采用糖纸包装(candy paper packaging,CW)、真空包装(vacuum packaging,VP)、保鲜袋包装(storage bag packaging,WPB)和铝箔袋包装(aluminum foil bag packaging,ABP)4种包装方式对复合果丹皮进行包装,并在常温下贮藏180 d测定其在贮藏期间品质指标的变化值,以水分含量、可溶性糖含量、硬度和菌落总数为表征指标建立化学动力学模型以预测复合果丹皮的货架期。结果表明,采用VP方式能有效延缓复合果丹皮中可溶性糖、维生素C、活性成分等营养成分的降解、抑制复合果丹皮在贮藏期间被微生物的污染。可溶性糖和菌落总数的变化规律符合零级动力学模型、水分含量与硬度的变化规律符合一级动力学模型,验证结果表明,VP方式下复合果丹皮以4种表征指标建立的预测模型准确度较高,预测值与实测值相对误差较小,Arrhenius方程具有较好的拟合性。因此,VP方式的应用将会为复合果丹皮的包装和贮藏提供理论基础。
