混合交通OD分布与随机平衡分配组合模型及算法

基于我国城市混合交通的特点,借助于Logit选择模型,建立了混合交通OD分布与随机平衡分配组合的数学规划模型,证明了模型最优解的等价性与唯一性,同时给出了算法和算例.     

还原温度对超细K－Co－Mo催化剂合成低碳醇性能的影响

 用溶胶－凝胶法合成了K－Co－Mo催化剂．样品经不同温度还原后，用于低碳醇的合成．XRD和HRTEM结果表明，样品是超细粒子，粒子尺寸为2～5nm．考察了催化剂的还原温度和反应条件对催化剂性能的影响．实验结果表明，还原温度对催化剂的活性有较大的影响，最佳还原温度为500℃．最佳反应温度范围为310～330℃．升高压力和空速可以提高醇的收率和选择性．在空速14400h－1，压力6．0MPa和温度310℃的条件下，醇的选择性为55．8％，收率为520．0g／（kg·h），MeOH／C2＋OH为0．27．催化剂稳定性良好，在200h的寿命实验中，活性基本不变．与文献中催化剂相比，超细K－Co－Mo催化剂对合成醇具有较高的活性和选择性，尤其是对C2＋OH的合成明显高于其他合成醇催化剂体系．     

Structural and magnetic investigations of the mixed-valence Fe(II,III) two-dimensional layer complex, [Fe2(II) Fe2(III)(HCOO)10(C6H7N)6]n.

The structure of the complex, [Fe2(II)Fe2(III)(HCOO)10(C6H7N6)n, (1) exhibits a neutral two-dimensional layer network of alternating iron(II) and iron(III) ions, bridged equatorially by formate groups. All iron atoms are octahedrally coordinated, with iron(III) coordinating axially to one gamma-picoline and one formate group, while the iron(II) centers interact axially with two gamma-picoline groups, above and below the layer plane. The complex crystallizes in the triclinic space group P1 at all studied temperatures [at 120 K, the cell dimensions are: a = 10.228(1), b = 12.071(1), c = 12.072(1) A, alpha = 89.801(2), beta = 71.149(2), gamma = 73.371(2) degrees]. An intralayer antiferromagnetic exchange interaction of J = -2.8 cm(-1) between iron(II) and iron(III) was observed in the magnetic studies. Decreasing the temperature to close to 20 K causes a magnetic-ordering phenomenon to occur and a low-temperature phase with a long-range antiferromagnetic spin orientation appears. The magnetic phase transition was confirmed by M?ssbauer spectroscopic studies at temperatures above and below the critical temperature. Structural information of 1 from synchrotron X-ray diffraction data collected at room temperature and 16 K suggests that the antiferromagnetic ordering is caused by an enhanced pi-pi interaction between chi-picoline groups from adjacent layers.     

Construction of solid-liquid phase diagrams in ternary systems by titration calorimetry

Titration calorimetry was used to construct the solid-liquid equilibrium line in ternary systems containing the solute and an aqueous mixed solvent by measuring the heat of dissolution of the solid solute during successive additions of the liquid solvent. The plot of cumulated heats versus the mole ratio, n_solvent/n_solute, yields two (almost) linear increases of different slopes. These two lines represent successively the enthalpy of dissolution then the enthalpy of dilution of the medium; their intersection gives the solubility and the enthalpy of dissolution of the solute. Phase diagrams have been established over the whole concentration range for o-anisaldehyde, 1,3,5-trimethoxybenzene and vanillin, in water + methanol, +ethanol, or +n-propanol at 303, 313 and 318 K.     

铜基催化剂的结构、物性及其对混合碳四选择加氢反应的催化性能

 用XRD，XPS，SEM和H2－TPR等手段研究了铜基负载型催化剂的结\r\n构和物性及其对混合碳四加氢脱炔的催化性能．结果表明，在负载铜催\r\n化剂中加入一定量的Co可提高催化剂的加氢脱炔活性，而Co含量较少时\r\n加入少量的Ce也能提高催化剂的活性和选择性．Cu和Co之间存在着相互\r\n协同作用，使得活性组分在催化剂表面偏析，CuO在催化剂表面呈非晶\r\n相分散状态，催化剂颗粒粒径变小，催化剂更容易被还原，从而改善了\r\n催化剂的催化性能．     

{[Gd(DMF)_3(DMSO)(H_2O)_3](μ-CN)[Fe(CN)_5]}·2H_2O的合成,结构表征和磁性(英文)

0IntroductionThefirstmolecule鄄basedmagnetswerereportedin1986[1].Duringthelasttwodecades,moreandmoreattentionhasbeenpaidtothesynthesisofmolecule鄄basedmagnets,especiallytoPrussianBlueanalogu鄄es[2].TheoldPrussianBlueanalogueshavebeenbroughtuptodateduetoth…     

Dealkylation ofpara-nitrophenyldimethyl thiophosphate in micellar and liquid-crystalline media of then-decylammonium chloride-n-decylamine-water system

The kinetics of decomposition of p-nitrophenyldimethyl thiophosphate (1) were investigated spectrophotometrically in the n-decylammonium chloride-n-decylamine-water system (DAC-DA-H₂O), in which micellar or lamellar liquid-crystalline phases are formed as a function of the concentration of components. It was shown that1 is dealkylated in both phases. An increase in the surface charge density of associates decreases the rate of dealkylation. The activation energy in the lamellar phase is significantly higher than in the micellar phase.A. E. Arbuzov Institute of Organic and Physical Chemistry, Kazan' Scientific Center, Russian Academy of Sciences, 420083 Kazan'. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 5, pp. 1042–1048, May, 1992.     

Selective Oxidation of Isobutene over CsFeCoBiMnMoOx Mixed Oxide Catalyst

Mixed oxide catalyst Cs0.1Fe2Co6BiMnMo12Ox was prepared by the coprecipitation method.Selective oxidation of isobutene was carried out in a fixed-bed reactor over Cs0.1Fe2Co6BiMnMo12Ox.The results showed that the catalyst had high catalytic activity. Under the optimum reaction conditions(n(i-C4):n(O2)=1:2-1:4, space velocity=180 h^-1, T=360℃), the yields of methacrolein and methacrylic acid can reach 80% and 8%, respectively. The total yield of liquid products (methacrolein, methacrylic acid and acetic acid) can reach about 90%.     

Effects of delayed linear electrical perturbation of the Belousov-Zhabotinsky reaction: a case of complex mixed mode oscillations in a batch reactor

Delayed feedbacks are quite common in many physical and biological systems and in particular many physiological systems. Delay can cause a stable system to become unstable and vice versa. One of the well-studied non-biological chemical oscillators is the Belousov-Zhabotinskii (BZ) reaction. This gives relaxation oscillations for a considerable period of time under batch conditions. This paper deals with the effect of perturbing the limit cycle oscillation of BZ reaction by employing a delayed electrical feedback to the system under batch conditions. The parameters chosen to study are external resistance and delay. For various resistances and delays the system was electrically perturbed and found to exhibit various complex mixed mode oscillations. The dynamic features are accounted for by the Oregonator model, with time delay incorporated in one of the variables. This revised version was published online in June 2006 with corrections to the Cover Date.