Abstract: The present disclosure provides a catalyst composition for ethylene oligomerization including an imino ferrous complex shown in Formula (I) as the main catalyst, an aluminum-containing cocatalyst, water, and an organic solvent: According to the present disclosure, a higher oligomerization activity can be obtained with the catalyst composition than with a catalyst composition system in the prior art which contains no water. Moreover, when the catalyst composition according to the present disclosure is used, a high selectivity of ?-olefins is obtainable. Besides, the catalyst composition according to the present disclosure can enable rapid initiation, stable operation, and good repeatability of the oligomerization reaction. According to the present disclosure, a high oligomerization activity can be obtained even at a rather low ratio of Al/Fe, or at a low reaction temperature.

Abstract: The present disclosure provides a catalyst composition for ethylene oligomerization including an imino ferrous complex shown in Formula (I) as the main catalyst, an aluminum-containing cocatalyst, water, and an organic solvent: According to the present disclosure, a higher oligomerization activity can be obtained with the catalyst composition than with a catalyst composition system in the prior art which contains no water. Moreover, when the catalyst composition according to the present disclosure is used, a high selectivity of ?-olefins is obtainable. Besides, the catalyst composition according to the present disclosure can enable rapid initiation, stable operation, and good repeatability of the oligomerization reaction. According to the present disclosure, a high oligomerization activity can be obtained even at a rather low ratio of Al/Fe, or at a low reaction temperature.

Abstract: A retinoscope for detecting eye ametropia and astigmatism axes is disclosed in the invention, which comprises an illuminating and imaging system comprising an illumination light source, a projecting mirror and a half transparent and half reflecting mirror arranged sequentially along the direction of propagation of the illumination light, the respective optical axes of the projecting mirror and half transparent and half reflecting mirror are collinear with each other, and the reflecting plane of the half transparent and half reflecting mirror is at an angle of 45° relative to the illumination optical axis, wherein a condensing lens column and a retinoscopy diaphragm are disposed sequentially along the illumination optical axis between the illumination light source and the projecting mirror, the optical axis of the condensing lens column is coincident with the illumination optical axis, and the plane of the retinoscopy diaphragm is perpendicular to the illumination optical axis.

Abstract: Provided are a process for preparing an N ortho acyl substituted nitrogen-containing heterocyclic compound and an aminal iron (II) complex thereof, and the use of the complexes obtained by the process in an olefin oligomerization catalyst. The N ortho acyl substituted nitrogen-containing heterocyclic compound in the present invention is for example 2-acyl-1,10-phenanthroline or 2,6-diacetyl pyridine as shown in formula b, and the N ortho acyl substituted nitrogen-containing heterocyclic compound in the present invention is produced by a reaction of a precursor thereof in a substituted or unsubstituted nitrobenzene. Preferably the precursor shown in formula I in the present invention is produced by 1,10-phenanthroline reacting with trialkyl aluminum, or a halogenoalkyl aluminum RnAlXm, or a substituted or unsubstituted benzyl lithium 2Li, followed by hydrolysis.

Abstract: The present invention provides a catalyst composition for the ethylene oligomerization, which comprises 2-imino-1,10-phenanthroline coordinated iron (II), cobalt (II) or nickel (II) chloride as main catalyst and triethylaluminum as cocatalyst. The present invention also provides a process for oligomerization of ethylene is provided, wherein a catalyst composition comprising 2-imino-1,10-phenanthroline coordinated iron (II), cobalt (II) or nickel (II) chloride as main catalyst and triethylaluminum as cocatalyst is used, and the molar ratio of aluminum in the cocatalyst to central metal in the main catalyst ranges from 30 to less than 200. According to the present invention, another process for oligomerization of ethylene is also provided, wherein a catalyst composition comprising 2-imino-1,10-phenanthroline coordinated iron (II), cobalt (II) or nickel (II) chloride as main catalyst and triethylaluminum as cocatalyst is used, and the temperature of ethylene oligomerization ranges from ?10 to 19° C.