According to the situation that polymer flooding and micro-gel flooding have been completed in Shuanghe North II4-5 Block of Henan oilfield, a viewpoint that combination flooding including polymer flooding and polymer/surfactant compound flooding as well as micro-gel flooding enhances oil recovery is put forward.

The flow properties, fractional flow and profile modification effect of polymer solution and micro-gel system were tested, and combination flooding of polymer slug with micro-gel slug were experimented in parallel super-long core and heterogeneous inter-layer models.

By using hardware circuit,the combined driving logic was fulfilled,thus reduce the work of software,make the hardware easily debug and adjust to generate needed waveforms.

3-layer combination casing strength analysis and calculation;

Progress of combination photocatalytic oxidation in wastewater treatment;

A new injection profile combination logging tool and its application;

Resolving Problems of Permutations and Combinations with Generation Function;

Analysis on Applied Effects of Different Forage Combinations Used in Rabbit Production;

By crossing 8 hybrid rice sterile lines with 12 early hybrid rice restorer lines(cultivars) through incomplete diallel cross(NC Ⅱ)desig n,96 combinations of early hybrid rice were obtained.

Theoretic Mode and Positive Analysis of Technological Innovation Portfolio;

This paper presents the modern portfolio theory and related math model, modifies the benefit and risk function from oil production plant portfolio model: the net present value instead of yield rate is as the measurement of yield function; the absolute deviation instead of variance is as the measurement of risk function.

The modern investment portfolio theory and its evolvement model which are based on β value are introduced.