[Analysis of 14 cases of melanosis caused by 1, 8-dinitronaphthalene and 1, 8-diaminonaphthalene].

14 workers in the 1, 8-diaminonaphthalene workshop of a chemical company in Nantong City had symptoms or signs of varying degrees of pruritus and pigmentation of the face, neck and waist. Pathological examination of skin biopsies showed hyperkeratosis, the basal cells were liquefied and denatured. Seven workers were eventually diagnosed with occupational melanosis. To explore the causes of occupational melanosis caused by exposure to 1, 8-dinitronaphthalene and 1, 8-diaminonaphthalene, and to provide reference for the prevention and treatment of occupational melanosis in the future, this paper reported 14 cases of melanosis in the skin of workers in chemical industry.

Effects of precursor solution composition on the performance and I-V hysteresis of perovskite solar cells based on CH3NH3PbI3-xClx.

Precursor solution of CH3NH3PbI3-xClx for perovskite solar cells was conventionally prepared by mixing PbCl2 and CH3NH3I with a mole ratio of 1:3 (PbCl2:CH3NH3I). While in the present study, CH3NH3PbI3-xClx-based solar cells were fabricated using the precursor solutions containing PbCl2 and CH3NH3I with the mole ratios of 1:3, 1.05:3, 1.1:3, and 1.15:3, respectively. The results display that the solar cells with the mole ratio of 1.1:3 present higher power conversion efficiency and less I-V hysteresis than those with the mole ratio of 1:3. Based on some investigations, it is concluded that the higher efficiency could be due to the smooth and pinhole free film formation, high optical absorption, suitable energy band gap, and the large electron transfer efficiency, and the less I-V hysteresis may be attributed to the small low frequency capacitance of the device.