This paper reviews alternative market equilibrium models for policy analysis. The origin of spatial equilibrium models and their application to wood and wood-processing industries are described. Three mathematical pro...This paper reviews alternative market equilibrium models for policy analysis. The origin of spatial equilibrium models and their application to wood and wood-processing industries are described. Three mathematical programming models commonly applied to solve spatial problems - namely linear programming, non-linear programming and mixed complementary programming - are reviewed in terms of forms of objective functions and constraint equalities and inequalities. These programming are illustrated with numerical examples. Linear programming is only applied in transportation problems to solve quantities trans, ported between regions when quantities supplied and demanded in each region are already known. It is argued that linear programming can be applied in broader context to transportation problems where supply and demand quantities are unknown and are linear. In this context, linear programming is seen as a more convenient method for modelers because it has a simpler objective function and does not require as strict conditions, for instance the equal numbers of variables and equations required in mixed complementary programming. Finally, some critical insights are provided on the interpretation of optimal solutions generated by solving spatial equilibrium models.展开更多
Under study is the optimization problem of line structure (primarily railroad) routing. The improved mathematical models and algorithms of vertical alignment by set versions of the route plan are offered. The problem ...Under study is the optimization problem of line structure (primarily railroad) routing. The improved mathematical models and algorithms of vertical alignment by set versions of the route plan are offered. The problem is solved in some stages in interrelation with other design problems. The original algorithm of descent is given for solving the arising problem of nonlinear programming. Structural features of constraints are used and so it is not required to solve any systems of linear equations.展开更多
前期研究表明,在5 k Pa恒负压和35℃/65℃温度梯度和无添加剂的条件下,能以高达1 mm/h的沉积速度制备出表面光滑、近无沉积缺陷且多项性能优越的镍镀层。本实验则重点研究负压、温度梯度等条件参数对镍沉积层形貌、织构和性能的影响。...前期研究表明,在5 k Pa恒负压和35℃/65℃温度梯度和无添加剂的条件下,能以高达1 mm/h的沉积速度制备出表面光滑、近无沉积缺陷且多项性能优越的镍镀层。本实验则重点研究负压、温度梯度等条件参数对镍沉积层形貌、织构和性能的影响。研究结果显示:负压和温度梯度大小对沉积层的形貌、织构与硬度、耐腐蚀等性能都有一定程度的影响;只有在贴近阴极面的液层处于沸腾状态时才能获得良好的镍沉积层;增大温度梯度和(或)降低沉积槽气压都有利于细化晶粒、提高硬度和耐酸腐蚀性;温度梯度对镍沉积层的织构特征影响作用明显,但负压大小对镍层的择优取向几乎没有影响。镍沉积层上述形貌、织构与性能的变化主要归结于负压电沉积的沸腾驱动传质效应与真空脱气效应。展开更多
A nitrogen-containing ionic liquid was synthesized using an aromatic nitrogen-containing heterocyclic and an amino acid,and applied to the extractive desulfurization process to remove benzothiophene,dibenzothiophene,a...A nitrogen-containing ionic liquid was synthesized using an aromatic nitrogen-containing heterocyclic and an amino acid,and applied to the extractive desulfurization process to remove benzothiophene,dibenzothiophene,and 4,6-dimethyldibenzothiphene from a model fuel oil.Chemical characterizations and simulation using Gaussian 09 software confirmed the rationality of an ionic liquid structure.Classification of non-covalent interactions between the ionic liquid and the three sulfur-containing contaminants was studied by reduced density gradient analysis.The viscosity of the ionic liquid was adjusted by addition of polyethylene glycol.Under extraction conditions of the volume of ionic liquid to oil as 1:1 and temperature as room temperature,the desulfurization selectivity of ionic liquid followed the order of 4,6-dimethyldibenzothiphene(15 min)<benzothiophene(15 min)≈dibenzothiophene(10 min).Addition of p-xylene and cyclohexene to the fuel oil had little effect.The extractant remained stable and effective after multiple regeneration cycles.展开更多
()*￡-1 -(4-Fluorobenzylidene)^l-(4-ethylphenyl)thiosemicarbazone was synthesized via the reaction of 4-(4-ethylphenyl)thiosemicarbazide and 4-fluorobenzaldehyde. The title compound was characterized by FTIR, and 13C ...()*￡-1 -(4-Fluorobenzylidene)^l-(4-ethylphenyl)thiosemicarbazone was synthesized via the reaction of 4-(4-ethylphenyl)thiosemicarbazide and 4-fluorobenzaldehyde. The title compound was characterized by FTIR, and 13C NMR, mass spectrometry and elemental analysis techniques. Structural property of the title compound was displayed by the X-ray single crystal diffraction. The title compound crystallized in triclinic space group Pl witli a=0.6494(4) nm,a=0.7971(5) nm, c=1.5492( 10) nm,a=83.690( 11)°,β=84.185(10)。γ=84.348(11)。molecular formula Ci6H16FN3S,Mr=301.39,V=0.7868(9) nm^3, Z=2, Dc=1.272 g/cm……3,^000)=316,“=0.213 mm-1, 5=1.02, 7?=O.O513, and cw7[Z>2o(Z)]=0.1662. The intennolecular interactions in the crystal structure were explained using the Hirshfeld surface and their associated two-dimensional fingerprint plots. The title compound showed C-H-S(l-x,-y,-z) and NH(1-y,-z) intermolecular interactions, and formed the supramolecular self-assemblies through R2^2(12) and R2^2(8) ring motifs. Shape index and curvediiess were performed to further understand some unique weak interactions, for instance, the weakπ…π stacking contacts in molecular structure witli difierent characteristic regions. Besides, the reduced density gradient(RDG) function provided a real-space function for discussing non-covalent interactions within molecule, such as hydrogen bonds, weak van der Waals interactions and attractive or repulsive effects.展开更多
文摘This paper reviews alternative market equilibrium models for policy analysis. The origin of spatial equilibrium models and their application to wood and wood-processing industries are described. Three mathematical programming models commonly applied to solve spatial problems - namely linear programming, non-linear programming and mixed complementary programming - are reviewed in terms of forms of objective functions and constraint equalities and inequalities. These programming are illustrated with numerical examples. Linear programming is only applied in transportation problems to solve quantities trans, ported between regions when quantities supplied and demanded in each region are already known. It is argued that linear programming can be applied in broader context to transportation problems where supply and demand quantities are unknown and are linear. In this context, linear programming is seen as a more convenient method for modelers because it has a simpler objective function and does not require as strict conditions, for instance the equal numbers of variables and equations required in mixed complementary programming. Finally, some critical insights are provided on the interpretation of optimal solutions generated by solving spatial equilibrium models.
文摘Under study is the optimization problem of line structure (primarily railroad) routing. The improved mathematical models and algorithms of vertical alignment by set versions of the route plan are offered. The problem is solved in some stages in interrelation with other design problems. The original algorithm of descent is given for solving the arising problem of nonlinear programming. Structural features of constraints are used and so it is not required to solve any systems of linear equations.
基金National Natural Science Foundation of China(51175152)Program for Science and Technology Innovation Talents in Universities of Henan Province(2012HASTIT012)
文摘前期研究表明,在5 k Pa恒负压和35℃/65℃温度梯度和无添加剂的条件下,能以高达1 mm/h的沉积速度制备出表面光滑、近无沉积缺陷且多项性能优越的镍镀层。本实验则重点研究负压、温度梯度等条件参数对镍沉积层形貌、织构和性能的影响。研究结果显示:负压和温度梯度大小对沉积层的形貌、织构与硬度、耐腐蚀等性能都有一定程度的影响;只有在贴近阴极面的液层处于沸腾状态时才能获得良好的镍沉积层;增大温度梯度和(或)降低沉积槽气压都有利于细化晶粒、提高硬度和耐酸腐蚀性;温度梯度对镍沉积层的织构特征影响作用明显,但负压大小对镍层的择优取向几乎没有影响。镍沉积层上述形貌、织构与性能的变化主要归结于负压电沉积的沸腾驱动传质效应与真空脱气效应。
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.22125802,22078010 and U1862113)the Big Science Project from BUCT(Grant No.XK180301).
文摘A nitrogen-containing ionic liquid was synthesized using an aromatic nitrogen-containing heterocyclic and an amino acid,and applied to the extractive desulfurization process to remove benzothiophene,dibenzothiophene,and 4,6-dimethyldibenzothiphene from a model fuel oil.Chemical characterizations and simulation using Gaussian 09 software confirmed the rationality of an ionic liquid structure.Classification of non-covalent interactions between the ionic liquid and the three sulfur-containing contaminants was studied by reduced density gradient analysis.The viscosity of the ionic liquid was adjusted by addition of polyethylene glycol.Under extraction conditions of the volume of ionic liquid to oil as 1:1 and temperature as room temperature,the desulfurization selectivity of ionic liquid followed the order of 4,6-dimethyldibenzothiphene(15 min)<benzothiophene(15 min)≈dibenzothiophene(10 min).Addition of p-xylene and cyclohexene to the fuel oil had little effect.The extractant remained stable and effective after multiple regeneration cycles.
文摘()*￡-1 -(4-Fluorobenzylidene)^l-(4-ethylphenyl)thiosemicarbazone was synthesized via the reaction of 4-(4-ethylphenyl)thiosemicarbazide and 4-fluorobenzaldehyde. The title compound was characterized by FTIR, and 13C NMR, mass spectrometry and elemental analysis techniques. Structural property of the title compound was displayed by the X-ray single crystal diffraction. The title compound crystallized in triclinic space group Pl witli a=0.6494(4) nm,a=0.7971(5) nm, c=1.5492( 10) nm,a=83.690( 11)°,β=84.185(10)。γ=84.348(11)。molecular formula Ci6H16FN3S,Mr=301.39,V=0.7868(9) nm^3, Z=2, Dc=1.272 g/cm……3,^000)=316,“=0.213 mm-1, 5=1.02, 7?=O.O513, and cw7[Z>2o(Z)]=0.1662. The intennolecular interactions in the crystal structure were explained using the Hirshfeld surface and their associated two-dimensional fingerprint plots. The title compound showed C-H-S(l-x,-y,-z) and NH(1-y,-z) intermolecular interactions, and formed the supramolecular self-assemblies through R2^2(12) and R2^2(8) ring motifs. Shape index and curvediiess were performed to further understand some unique weak interactions, for instance, the weakπ…π stacking contacts in molecular structure witli difierent characteristic regions. Besides, the reduced density gradient(RDG) function provided a real-space function for discussing non-covalent interactions within molecule, such as hydrogen bonds, weak van der Waals interactions and attractive or repulsive effects.
