一款新设计发动机的动力学计算分析

以一款新设计发动机为例,详细叙述了针对该机的动力学计算过程,为进一步研究该发动机的平衡打下了基础。计算出的曲柄销理论磨损图,表示了曲柄销的磨损趋势,为结构设计提供了理论依据。     

Mixed convective peristaltic flow of Eyring‐Prandtl fluid with chemical reaction and variable electrical conductivity in a tapered asymmetric channel

The influence of inconstant electrical conductivity and chemical reaction on the peristaltic motion of non‐Newtonian Eyring‐Prandtl fluid inside a tapered asymmetric channel is investigated. The system is concerned by a uniform external magnetic field. The heat and mass transfer are considered. The problem is controlled mathematically by a system of nonlinear partial differential equations which describe the velocity, temperature, and nanoparticle concentration of the fluid. By means of long wavelength and low Reynolds numbers, our system is simplified. It is explained by using the multi‐step differential transform method as a semi‐analytical technique. The distributions of velocity, temperature, nanoparticle concentration, as well as pressure gradient and pressure rise are obtained as a function of the physical parameters of the problem. The effects of these parameters on these distributions are deliberated numerically and illustrated graphically through a set of figures. The results indicate that the parameters play a significant role in controlling the velocity, temperature, nanoparticle concentration, pressure gradient, and pressure rise.     

丹皮酚缩水合肼席夫碱化合物的合成及量化计算研究

以丹皮酚和水合肼为原料合成席夫碱化合物,对产物进行表征;使用Hyperchem7、0程序,用半经验方法对标题化合物进行了量化计算研究。     

统计知识在企业经营活动分析中的运用

灵活运用统计计算方法、统计图表、统计分析方法对企业生产经营目标计划完成情况进行分析,分析查找影响目标计划完成主要原因。     

Design,optimization and controllability of an alternative process based on extractive distillation for an ethane–carbon dioxide mixture

Alternative configurations based on cryogenic extractive distillation were proposed and simulated by using Aspen Plus 7.0^® coupled to a multi-objective stochastic optimization procedure (differential evolution, DE). The evaluation of the performances of the proposed configurations was focused on the ethane–carbon dioxide azeotrope separation considering different liquefied hydrocarbon fractions as entrainers. The design alternatives were compared to the conventional chemical absorption system.The proposed sequences were simultaneously Pareto optimized by minimizing the total annual cost (TAC) and maximizing the acid gas removal. Complementary studies regarding the theoretical control properties, the thermodynamic efficiency and the greenhouse gases generation were conducted for several representative operating conditions obtained from the Pareto optimized fronts. The proposed cryogenic extractive distillation sequences realized the higher carbon dioxide removal together with the lower TAC compared to the conventional chemical absorption system.     

给水加氧技术在节能降耗上的应用

通过对广东红海湾发电有限公司2#机组的给水加氧技术应用前后的各种参数对比,结果表明,给水加氧技术在节能降耗方面的空间比较大,值得推广。     

Optimal design of catalytic distillation columns: A case study on synthesis of TAEE

The design of catalytic distillation (CD) columns is a challenging task because of the superposition of chemical reaction and distillation in one apparatus. In this work, a method to design a cost-optimal CD column for chemical systems with large number of components and chemical reactions is presented. The method is based on the following steps: (1) estimation of the number of theoretical stages and catalyst volume by the decomposition of the CD column into a sequence of chemical reactors and non-reactive distillation columns, (2) estimation of the column diameter and operating conditions using an equilibrium stage model, and (3) design of the column applying an optimisation algorithm and using a rigorous non-equilibrium stage model to represent the CD process. The method is applied to determine the optimal column configuration and operating conditions for the synthesis of tert-amyl ethyl ether from ethanol and isoamylenes. Eight components and four chemical reactions were selected to represent the chemical system in the simulations.     

Is the analysis of molecular electronic structure of corrosion inhibitors sufficient to predict the trend of their inhibition performance

The often used approach in the corrosion inhibition studies employing quantum chemical calculations that relies on the correlation between molecular electronic structure parameters and inhibition effectiveness is critically examined. It is shown that the inhibition performance of three selected triazole-based corrosion inhibitors for copper - 3-amino-1,2,4-triazole (ATA), benzotriazole (BTAH), and 1-hydroxybenzotriazole (BTAOH) - cannot be explained on this basis in a sound manner. As the effectiveness of inhibitors is due to several phenomena, the outcome depends on the interplay between them and although molecular electronic parameters may provide many necessary elements, the involved effects can be estimated only approximately which may not always suffice. This supports the proposition that in general molecular electronic properties cannot be directly related to inhibition effectiveness - the actual relation is more involved - thus emphasizing the importance of a rigorous modeling of the inhibitor-surface interaction in the corrosion inhibition studies.     

Towards Automated Binding Affinity Prediction Using an Iterative Linear Interaction Energy Approach

Binding affinity prediction of potential drugs to target and off-target proteins is an essential asset in drug development. These predictions require the calculation of binding free energies. In such calculations, it is a major challenge to properly account for both the dynamic nature of the protein and the possible variety of ligand-binding orientations, while keeping computational costs tractable. Recently, an iterative Linear Interaction Energy (LIE) approach was introduced, in which results from multiple simulations of a protein-ligand complex are combined into a single binding free energy using a Boltzmann weighting-based scheme. This method was shown to reach experimental accuracy for flexible proteins while retaining the computational efficiency of the general LIE approach. Here, we show that the iterative LIE approach can be used to predict binding affinities in an automated way. A workflow was designed using preselected protein conformations, automated ligand docking and clustering, and a (semi-)automated molecular dynamics simulation setup. We show that using this workflow, binding affinities of aryloxypropanolamines to the malleable Cytochrome P450 2D6 enzyme can be predicted without a priori knowledge of dominant protein-ligand conformations. In addition, we provide an outlook for an approach to assess the quality of the LIE predictions, based on simulation outcomes only.     

Alloy design of a cost-effective and castable heat-resistant iron alloy

A new heat-resistant Fe-based cast alloy has been designed making the best use of the CALPHAD method. The objective was to replace the material for precision cast products made from Ni-based superalloys with improved Fe-based alloys originally developed for lower temperature applications.The key to the design is to balance the amount of strengthening ${\gamma }^{\prime }$- Ni₃(Ti,Al) precipitates and brittle $\sigma$ phase, and to simultaneously decrease as-cast microsegregation. Contours of the equal phase fraction were calculated over the isothermal diagrams of the Fe–Ni–Cr–Ti–Al–Nb system, and provided useful guidelines for compositional modifications. The microsegregation was also evaluated by Scheil-type simulation in order to reduce micropores caused by oxidation of the solidifying front.The developed cast Fe-based alloy showed desirable strength at the envisioned service temperatures and filled the open range of heat resistance between Ni-based superalloys and the original alloy.