In nature, there are abundant products and rich plant species. Currently, the seeds used for sowing in agriculture are actually only a small part of many species in nature. In order to further tap the productive potential of crops and support the sustainable development of modern.......
Whether heap leaching requires ore crushing, depending on the structure of the ore, the primary state, that is disseminated metals and extent wrapped; secondly on the level of the main metal ore grade.
The urban sewage treatment market is becoming saturated, however, it is still challenging to really solve the problem of rural sewage. Professor Wang Hongchen, associate dean of the Renmin University of China's Environmental Science School, believes that the most serious prob.......
Plants have a dual impact on haze, on the one hand it can sink, block and adsorb particulate matter, on the other hand emit plant-derived VOCs, the second generation of PM2.5, the impact on the atmosphere is very complicated.
Into April, ushered in the northern .......
Abstract: The coal chemical industry has made an important contribution to the development of the national economy. However, the problem of coking wastewater pollution can not be ignored. The annual discharge of coal chemical coking wastewater in China is as high as several hundr.......
The elliptical cylinder gear is machined on the bed.
3. Calculate the actual indexing arc long center, there are two connecting holes to be drilled, the workpiece with =37 teeth through 2 pins, practical 20 teeth, 20 teeth on the indexing arc length = mZi丌X Through the above calc.......