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Mine sudden water is one of the most threatening geological hazards during mining production, so rapid and effective identification of sudden water sources is the key to prevent mine water damage. In this study, we analyzed the water chemistry of Panji Coal Mine aquifer and carried out the testing and analysis of strontium isotopes of water in the adjacent water rock, selected seven discriminatory indexes: 87Sr/86Sr, Ca2+, Na++K+, Mg2+, HCO3−, SO42−, Cl−, combined with principal component analysis and Fisher’s theory, principal component analysis and distance discriminatory theory, principal component analysis and BP Neural network, to establish the discriminatory models of mixed water sources based on strontium isotopes (Sr-F model, Sr-D model, Sr-B model), and use the models to discriminate unknown water samples. The results show that the Sr-B model based on strontium isotopes has the best discriminative effect, and its accuracy reaches 95%. Therefore, the identification model of water inrush sources based on principal component analysis and BP neural network can effectively improve the identification accuracy of water inrush sources, accurately identify water inrush sources in adjacent limestone aquifers, and provide guarantee for mine safety production.

Background and objective It is the main choice that neoadjust chemotherapy following surgery and induction chemotherapy following radiation therapy for locally advanced lung cancer. The aim of this study is to explore the selection of operation or synchronous radiotherapy and chemotherapy for stage III non small cell lung cancer (NSCLC) after induction chemotherapy. Methods After two cycles of induction chemotherapy, patients with stage III NSCLC were divided at random into synchronous radiotherapy and chemotherapy group or operation therapy group for therapy by the chemotherapy effect PR or CR, or estimated complete excision; and patients accepting complete excision operation continuously accepted two cycles of chemotherapy according to original proposal. Results Total 71 patients with stage III NSCLC entered therapy group after induction chemotherapy. Where, 37 patients accepted synchronous radiotherapy and chemotherapy, and 34 patients accepted operation. The 1-year, 2-year, and 3-year survival rate of synchronous radiotherapy and chemotherapy group was 78.4%, 40.5% and 23.4% respectively, while that of operation group was 81.1%, 39.5% and 35.1% respectively. The medium survival of the two groups was 18.0±2.4 and 23.0±1.6 respectively, and there was no statistical difference (P=0.23) in survival rate. The disease-free survival rate of synchronous radiotherapy and chemotherapy group and operation group was 14.0±1.7 months and 19.0±3.2 months respectively (P=0.044), and obviously, there was statistical difference. Conclusion After induction chemotherapy, patients with stage III NSCLC could select operation therapy and synchronous radiotherapy and chemotherapy. Where, synchronous radiotherapy and chemotherapy is relatively safe, but the adverse reaction can't be ignored. Operation therapy has higher risk and difficulty for induction chemotherapy, but has shown its superiority in disease-free survival. [ABSTRACT FROM AUTHOR]