[Effects of irrigation and fertilizer levels on the distribution of water and salt in saline field and maize yield]. / 灌溉施肥水平对盐渍化农田水盐分布及玉米产量的影响.

Agriculture development in arid and semi-arid saline areas is seriously affected by water resources scarcity and excessive fertilization. Understanding the effects of different irrigation and fertilization levels on soil water and salt distribution and silage maize yield would provide scientific basis for determining appropriate irrigation and fertilization amount. The experiment was carried out in a saline field of the Datong Basin in 2015 and 2016. There were three irrigation levels, with the upper limit of soil moisture being controlled at 100% (W1), 90% (W2) and 80% (W3) of the field water capacity. Irrigation amount was calculated based on the average actual water content before irrigation of each treatment. There were four fertilization levels in 2015, 900 kg·hm-2 (F1), 750 kg·hm-2 (F2), 600 kg·hm-2(F3), and 450 kg·hm-2(F4), and three levels in 2016 (F1, F2, and F3). The total nutrient content of the slow-release compound fertilizer was 48%, with a 30:12:6 ratio of N:P2O5:K2O. Results showed that the surface conductivity of soil increased with the increases of fertilizer application levels. The effects of fertilization on soil salinity in 0-10 cm was significant. Compared with F1, the average EC of F2 in 0-10 cm was decreased by 25.6%-42.7% in 2015 and by 6.4%-7.7% in 2016, respectively. The water content in 20-80 cm decreased with the increases of fertilizer application levels. Compared with F1, the average soil water content in 20-80 cm soil layer of F2, F3, and F4 increased by 5.9%, 16.7% and 16.7% in 2015, and that of F2 and F3 increased by 13.3% and 16.7% in 2016, respectively. The yield of F1 and F2 was higher than that of F3 and F4, and W3 was lower than W1 and W2 in both years. There was no significant difference in yield between F1 and F2. Compared with W1, decrease in yield of W2 was less than 15%. Therefore, the application of compound fertilizer 600-750 kg·hm-2(nitrogen content 180-270 kg·hm-2), and irrigation levels W1 and W2 were suggested to ensure high yield of forage maize in saline soil in this area, without salt accumulation in root zone.

Synthesis and cytotoxic activity of novel tetrahydrobenzodifuran-imidazolium salt derivatives.

The synthesis of a series of novel 4-substituted 2,3,6,7-tetrahydrobenzo [1,2-b;4,5-b']difuran-1H-imidazolium salts is presented. The biological properties of the compounds were evaluated in vitro against a panel of human tumor cell lines. Results suggest that the 5,6-dimethyl-benzimidazole or 2-methyl-benzimidazole ring, and substitution of the imidazolyl-3-position with a 2-naphthylmethyl substituent or 2-naphthylacyl substituent, were important to the cytotoxic activity. Notably, 3-(2-Naphthylmethyl)-1-((2,3,6,7-tetrahydrobenzo[1,2-b;4,5-b']difuran-4-yl)methyl)-1H-5,6-dimethyl-benzimidazol-3-ium bromide (42) was found to be the most potent derivative against five human tumor cell lines with IC50 values of 1.06-4.34µM and more selective towards SMMC-7721, A549 and SW480 cell lines. 3-(2-Naphthylacyl)-1-((2,3,6,7-tetrahydrobenzo[1,2-b;4,5-b']difuran-4-yl)methyl)-1H-2-methyl-benzimidazol-3-ium bromide (37) showed higher selectivity to SMMC-7721 and MCF-7 cell lines with IC50 values 2.7-fold and 8.4-fold lower than DDP. Study regarding to the antitumor mechanism of action showed that compound 37 could induce cell cycle G1 phase arrest and apoptosis in SMMC-7721 cells.

[Calculation of spectroscopic properties of Tm:YVO4 crystals].

Sigma and pi polarized absorption spectra of Tm:YVO4 crystal have been measured at room temperature. Considering the difference of the sigma and pi polarized absorption spectra and the changing of the refractive index with different wavelengths, we calculate the intensity parameters of Tm3+ in crystal YVO4 which are omega 2 = 1.9416 x 10(-20) (cm2), omega 4 = 0.1568 x 10(-20) (cm2), omega 6 = 0.3963 x 10(-20) (cm2) by Judd-Ofelt theory. The spectra characteristic parameters, such as radiative transition rates, luminescence branching ratio, total radiative lifetime and integral cross-section are also calculated. The results show that the spontaneous rate of the transition 1D2-->3F4 is much higher than that of the transition 1D2 to other levels.