Yesterday, Jufei Optoelectronics, Weiwei, Ruifeng Optoelectronics, Hongli Zhihui, Guanghao, Sanxiong Aurora, Lianjian Optoelectronics, Zhouming Technology, Lehman Technology, Infineon and other 10 LED listed companies disclosed 2018 The first quarter results forecast, in which the four companie…

The principle of maintenance during valve operation is as follows:

1 Keep the outside of the valve and the active part clean and protect the integrity of the valve paint. The surface of the valve, the trapezoidal thread on the stem and stem nut, the sliding portion of the stem n…

With the rapid development of the economy, cities are gradually growing. While these high-rise buildings have risen, the issue of high-level fire safety has also attracted everyone's attention. What are the points of attention for the acceptance of high-rise fire smoke extraction systems?…

“To me, this is the right choice.” In September 2017, we selected the liberation tractor vehicle of FAW Qingdao and the Weichai WP10H series engine. Zhang Lei, a user of Shandong Weifang, again proved his enthusiasm for the W…

Jaw crusher

The jaw crusher is mainly used for medium-sized crushing of various ores and bulk materials, and can crush materials with compressive strength of not more than 320Mpa, which …

1 External environment analysis

(1) security issues into safe production of coal mine is an eternal theme, but must ensure safety in production inputs, lack of investment is difficult to ensure safety in production, pla…

1 Composition of mine reserves

1.1 Mineral reserves (geological reserves)

The mineral reserves held by the production mines consist of mineral reserves and production of ore. Mineral reserves (commonly referred to as geological reserves) are geological exploration, infrastru…

In general, power quality problems in the power grid are mainly caused by various disturbances in the power grid. It covers a wide range of things, both short-term and short-term, as well as long-term or long-term: both amplitude and frequency issues. However, on t…