This study was aimed at the relationship model between LMX and work performance. Hypotheses mode was set up, and Chinese edition of LMX scale, team cohesion scale and team performance evaluation scale were used in this paper. 342 survey questionnaires were sent and 231 valid accounting for 67% of the total were received, the samples came from many industries, such as finance, energy, scientific research, IT and telecommunications, representing the state-owned, joint ventures, and private enterprises. Then, multiply stepwise regression, intermediary effect and regulatory effect analysis are used. Through those studies, we found that LMX had significantly positive effects on work performance and the team type and team cohesion affected the relationship between LMX and work performance as regulation variable and intermediary variable respectively. The follows also be found that in order to achieve performance targets, managers should strengthen exchange and communication with staff, care for members' feeling and special needs, show their care and support and build harmony subordinate relationship to promote team cohesion and work performance with good LMX.

This article introduces a mine production management system based on the Internet of Things and Virtual Technology. The system is digitization and automation which has following functions, mineral resources and reserves dynamic management, personnel positioning management, escape routes design, mining production plan and optimize the management and production scheduling management.

With the increasing demand for deep space exploration, technology of space signal coverage gradually becomes a important research domain in deep space communications. A signal coverage mathematic model was given focused on the characteristics of deep space communications environment especially in celestial body blocking case. An approximation algorithm which used volume measurement in multiple integral is proposed. The approximation algorithm obtained a space covering nodes set based on iteration process in polynomial time0(nm).