mathematical models

mathematical models的基本解释

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[经] 数学模型

与mathematical models相关的网络例句 [注：此内容来源于网络，仅供参考]

Four classes of partition models , empirical models , functional equilibrium models , optimal control models , and source-sink models were reviewed in this paper. The empirical models were widely used with minimal mechanistic assumptions. The function equilibrium models were successful in the simulation of the rootPcanopy ratio at the periods of the vegetative growth , but were poor to simulate portioning among other organs. The optimal control models were suitable for the modeling under the equilibrium state. The source2sink models were the most powerful and mechanistically based models capable of simulating dynamic photoassimilates partitioning between any organs of the plants.

对于同化物分配模型按照经验模型，目的性模型，源汇关系模型进行了总结归纳，分析指出：经验性模型应用最多但机理性差；功能平衡模型在模拟营养生长阶段同化物在条与根之间的分配很成功，但应用于其它器官之间很困难；最优化模型适于模拟平衡态下同化物的分配；源汇关系模型机理性最强，可模拟任何器官间的同化物分配，应用范围最广泛。

Density Functional Theory method was used to optimize the geometries of 209 PCDE molecules, 209 PBDE molecules and 75 PCDD molecules at the B3LYP/6-31G* level. Using computed structural parameters as theoretical descriptors, the forward stepwise multiple regression technique was adopted to obtain QSPR models of environmental partition properties for these POPs by using GQSARF 2.0 and SPSS12.0 for windows programs. The obtained QSPR models are as follows:(1) QSPR models for predicting subcooled liquid vapor pressure, n-octanol/water partition coefficients lgK_(ow and subcooled liquid water solubilities -lgS_(w,l of PCDEs, of which correlative coefficients (R~2) are 0.988, 0.958 and 0.959 and the root-mean-square-error of estimation are 0.134, 0.116 and 0.327 respectively.(2) QSPR models of lgPL and n-octanol/air partition coefficients lgK_(oa for PBDEs, which both contain three structural parameters. The values of R2 for the two models are both 0.997 while the values of RMSEE are 0.073 and 0.062 respectively.(3) QSPR models of lgKow and–lgS_ for PCDEs, which both have one variable (mean molecular polarizability,α). The values of R~2 for the two models are 0.978 and 0.866 and the values of RMSEE are 0.300 and 0.270 respectively.(4) The molecular structures of 24 substituted naphthaline compounds were optimized using Hartree-Fock and DFT methods at four different levels and the same means was used to obtain four three-parameter (EHOMO, q~+ andα) QSPR models of lgK_. The model at the HF/6-311G** level is the best one of which R2 is 0.9662 and RMSEE is 0.380.(5) QSPR study for environmental partition properties of PCDEs was also performed using position of Cl substitution method in which simple parameters of substitution position were taken as descriptors. The multiple linear regression was performed with GQSARF 2.0 and SSPS 12.0 for windows programs to obtain QSPR models of lgP_L, lgK_ and–lgS_ for PCDEs of which R~2 are 0.991, 0.983 and 0.965 and RMSEE are 0.311, 0.100 and 0.300 respectively.

采用密度泛函理论方法在B3LYP/6-31G*水平上对PCDEs、PBDEs和PCDDs的分子结构进行了全优化计算，以计算得到的量子化学参数作为理论描述符，采用GQSARF 2.0和SPSS 12.0 for windows统计程序进行正向逐步回归分析，建立了这些POPs的环境分配性质的QSPR模型：(1) PCDEs的过冷液体蒸汽压、正辛醇/水分配系数lgK_(ow和水溶解度-lgS_(w，l的QSPR模型，这3个QSPR模型的相关系数(R2)分别为0.988、0.958和0.959，估计的均方根误差分别为0.134、0.116和0.327；(2) PBDEs的lgPL和正辛醇/空气分配系数lgK_(oa的QSPR模型，这两个模型都包含三个分子结构参数，其R~2都为0.997，RSMEE分别为0.073和0.062；(3) PCDDs类化合物的lgK_和-lgS_w的QSPR模型，两个模型都只含一个变量，其R~2分别为0.978和0.866，RSMEE分别为0.300和0.270；(4)采用Hartree-Fock和DFT方法，在4种不同水平上优化计算了24个取代萘系列化合物的分子结构，采用上述同样的方法分别建立了四种水平上的三变量lgK_模型，通过比较得到，在HF/6-311G**水平计算得到的模型最好，R为0.966，RSMEE为0.380；(5)同时，采用氯原子取代位置方法对PCDEs的环境分配性质进行QSPR研究，建立了PCDEs的lgPL、lgK_和-lgS_的QSPR模型，其R~2分别为0.991、0.983和0.965，RSMEE分别为0.110、0.100和0.300。

On the base of reviewing the development of NSP models, some deficiencies of existent models are analysed and listed as follows: most models can be applied only to very small watershed; mechanism models involve too many parameters which can not be calibrated properly by limited data; amoung practical models, empirical models are much more common than mechanism models; most models are focus on the conservative soluble pollutants rather than non-conservative and particulate pollutants; almost all models rely highly on the measured data, and there are fewer studies about the load estimation for ungauged areas.

本文在评述非点源污染模型研究进展的基础上，分析了现有模型的不足，主要有：大多数模型只能适应于很小的流域面积；机理类模型参数过多，率定困难，应用效果不理想；实用模型中，经验类模型多，机理类模型少；对保守性的液态污染物研究得较多，对非保守性和固态污染物研究得较少；各类模型均高度依赖于实测资料，无资料地区的模型或预测方法研究得很少。

与mathematical models相关的网络解释 [注：此内容来源于网络，仅供参考]

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