油水井化学封窜堵漏新工艺

通过分析中原油田注水开发的两大问题，阐明了新型堵剂YLD-1的适应性，结合室内试验，重点分析了该堵剂的性能特点，深入探讨了封窜堵漏的选井原则和施工工艺，经过在文留油田的现场应用，展示了该技术良好的发展前景。     

Reaction kinetics study of asymmetric polymer-polymer interface

In this study, the reaction kinetics of asymmetric polymer-polymer interface was experimentally and theoretically studied. A new rheological method correlating the change of rheological property of reactive system with the conversion of the in situ formed copolymers was applied to study the reaction kinetics of PBT/epoxy reactive system. Then, the new method was proved to be useful by comparing its results with that obtained from the conventional endgroup determination method. Moreover, the conversion of PBT/epoxy reactive system from rheological method could be well fitted by the numerical analysis, from which the kinetic constant and the diffusion constant of epoxy in PBT could be determined simultaneously.     

Stochastic modeling of segregation in a motionless mixer

The mixing of particles with different characteristics is generally accompanied by segregation which prevents the particles from attaining the randomly mixed state. A discrete steady-state Markov chain model was employed to model the axial segregation of solid particles in a motionless mixer. Three systems containing particles of different sizes and/or densities were studied. One step transition probabilities of the model were experimentally determined. The model can predict the concentration profiles, the degrees of mixedness, and the equilibrium states of these particle systems blended by passing the particles through a motionless mixer. Experimental results are in good agreement with those predicted from the model.     

Optimal synthesis of process systems Necessary condition for optimal system and its use in synthesis of systems

The necessary condition for the optimal process system structure which includes both the optimal interconnection and optimal design of processing units is derived in terms of the structural parameters. The structural parameters are essentially splitting factors of process streams connecting processing units. The necessary condition requires the structural parameters and the design vectors to satisfy the weak maximum condition of the Hamiltonian type scalar functions. On the basis of the condition, a search method, evolutionary search for optimal structure (ESOS), for attaining the optimal structure starting from a simple structure is developed and its convergence is proved. An example of synthesizing a reactor-separator system illustrates its use.     

Multivariate statistical analysis of solids mixing

The applicability of multivariate statistics to the analysis of mixing processes and mixtures of multicomponent solid particles in a drum mixer has been successfully demonstrated. The applications include (1) test of sampling techniques, (2) test of the completely random state, (3) test of the completely segregated state, and (4) definition of a mixing index for a multicomponent mixture.     

Mechanical properties of (ethylene acrylate copolymer)‐modified polypropylene/TiO2 blends

An ethylene‐(methyl acrylate) (EMA) copolymer produced from a tubular reactor was found to be effective in toughening polypropylene, even at low concentrations. The addition of a small amount of TiO₂ pigment enhanced the EMA toughening effect. Microscopy and thermal analysis helped to reveal the possible EMA toughening mechanisms. The effects of two processing methods, dry blending and melt blending, on the mechanical properties of the formulation were also studied. J. VINYL ADDIT. TECHNOL., 13:65–70, 2007. © 2007 Society of Plastics Engineers.     

Seasonal evolution of the interannual variability of chlorophyll-a concentration and its forcing factors in the northwestern Pacific from 1998 to 2010

The northwestern Pacific Ocean is a complex region with significant biological spatial variations on a seasonal timescale. To investigate the joint variation patterns on both seasonal and interannual timescales, a season-reliant empirical orthogonal function (S-EOF) analysis was applied to seasonal mean chlorophyll-a concentration (chl-a) anomalies in the northwestern Pacific Ocean during the period 1998–2010. The first two dominant modes accounted for nearly 31% of the total interannual variance, with the second S-EOF mode (S-EOF2) lagging behind the first S-EOF mode (S-EOF1) by one year. S-EOF1 featured a strong variation pattern to the north of 30° N, with maximum chl-a in winter and minimum chl-a in summer. However, S-EOF2 indicated an opposite seasonally evolving pattern compared with S-EOF1, with chl-a increasing along the Kuroshio and extension current from boreal winter to autumn. Both these modes revealed significant relationships with climate-related indices. The two modes corresponded to the central Pacific (CP) La Niña developing episodes and the turnaround from eastern Pacific (EP) La Niña to CP El Niño, respectively. Both modes were associated with the cold phase of the Pacific Decadal Oscillation, which played an important role in prolonging the impact of the El Niño/Southern Oscillation on chl-a seasonal evolution from 1998 to 2010. In addition, we discuss the possible factors dominating chl-a seasonal variation, in terms of the subregions of the northwestern Pacific Ocean. In the subtropical northwestern Pacific Ocean (15° N – 30° N), the chl-a growth was primarily nutrient-limited, whereas in the mid-latitude northwestern Pacific Ocean (35° N – 50° N), the chl-a growth was mainly light-limited.     

Hydrogen evolution in alkaline solution on electrolytic nickel-cobalt and nickel-iron deposited with different bath compositions and current densities

Nickel-cobalt and nickel-iron electrodeposits were characterized as hydrogen electrodes in alkaline water electrolysis (6 mol/L KOH, 25°C). The nickel-based codeposits were fabricated with different bath compositions and at different current densities. The hydrogen evolution in water electrolysis on the nickel-based codeposits was apparently enhanced as compared with that on nickel. The improvement of the electrocatalytic behaviour of the hydrogen electrodes is attributed to their composition and an increase of their active surface, which are dependent on the electrodeposition conditions.     

广角摄像机在机器人视觉定位中的应用

为了保证广角摄像机在现代机器人视觉定位应用中的准确性,以广角摄像机像素坐标的反畸变过程为研究对象,提出一种在畸变对应表的基础上使用中心迭代法以及区域插值法确定物体实际位置的方法。通过实验证明了该方法能够测量物体的位置,其精度能够满足工业使用要求。