液下泵轴承部件的结构与设计

China’s Trade Flow Status of Agricultural Product and Influence Factors：Empirical Study Based on Gravity Model

介绍了适用于液下泵的几种轴承部件结构,分析了其结构特点,提出了适用于稀油润滑结构的离心式输油器进油端的压力计算方法。

Based on 1992-2009 panel data,firstly this paper describes china ’s agricultural products trade flow outline,main markets and trade products species,and then does empirical study on influence factors of trade flows by gravity model.The results show that factors of populations,economic scales,entry to WTO and APEC have positive influence,while the distance between trade partners,difference of per income and finance crises have adverse influence.Finally,according to empirical results by gravity model,this paper puts forward some suggestions on how to promote china’s agricultural product trade.