Foliar application of sodium hydrosulfide(NaHS),a hydrogen sulfide(H2S) donor,can protect seedlings against heat stress in wheat(Triticum aestivum L.)

Temperature extremes represent an important limiting factor to plant growth and productivity. Low concentration of hydrogen sulfide （H2S） has been proven to function in physiological responses to various stresses. The present study evaluated the effect of foliar application of wheat seedlings with a H2S donor, sodium hydrosulfide （NariS）, on the response to acute heat stress. The results showed that pretreatment with NariS could promote heat tolerance of wheat seedlings in a dose-depen- dent manner. Again, it was verified that H2S, rather than other sulfur-containing components or sodion derived from NariS solution, should contribute to the positive role in promoting wheat seedlings against heat stress. To further study antioxidant mechanisms of NariS-induced heat tolerance, superoxide dismutase （SOD, EC 1.15.1.1 ）, catalase （CAT, EC 1.11.1.6） and ascorbate peroxidase （APX, EC 1.11.1.11 ） activities, and HzS, hydrogen peroxide （H2O2）, malonaldehyde （MDA）, and soluble sugar contents in wheat seedlings were determined. The results showed that, under heat stress, the activities of SOD, CAT, and APX, H2S, H2O2, MDA, and soluble sugar contents in NaHS-pretreated seedlings and its control all increased. Meanwhile, NaHS-pretreated seedlings showed higher antioxidant enzymes activities and gene expression levels as well as the H2S and soluble sugar levels, and lower H2O2, MDA contents induced by heat stress. While little effect was detected in antioxidant enzymes activities and soluble substances contents in pretreated wheat seedlings compared with its control under normal culture conditions （data not shown）. All of our results suggested that exogenous NariS could alleviate oxidative damage and improve heat tolerance by regulating the antioxidant system in wheat seedlings under heat stress.

Surface modification of up-conversion luminescence material Na[Y_(0.57)Yb_(0.39)Er_(0.04)]F_4 with hydrosulfide group

A new method was reported for surface modification of an up-conversion luminescence material with hydrosulfide group. The factors that may influence the surface modification,such as reaction time,amount of catalyzer and modifier,and reaction solvent,were investigated. The optimal conditions were that the reaction time,the quantity of the basic catalyzer,the quantity of modifier and the volume of reaction solvent were 40 min,1.0,1.0,and 40 mL,respectively. The results indicated that hydrosulfide group content modified on the surface of up-conversion luminescence material reached to 0.1430 mmol/g,and this modified up-conversion luminescence material could be widely used in the study of structure of protein and the property of microenvironment.

A nanoscale qualitative study on the role of sodium hydrosulfide in oxidized carrollite flotation

The surface species transformation of oxidized carrollite processing with NaHS and KBX was investigated.Flotation and contact angle tests indicate that the combination of NaHS and KBX takes a better flotation performance than adding NaHS or KBX alone.Thermodynamic analysis,X-ray photoelectron spectroscopy(XPS) and Fourier transform infrared(FTIR) results confirm the stronger chemisorption of KBX occurs on the oxidized carrollite surface with NaHS,which is beneficial to remove the cobalt oxides,thus contributing to the superior floatability.Interestingly,less elemental sulfur was observed on the carrollite surface as the interaction of NaHS and KBX than adding NaHS alone.It suggests that elemental sulfur is not the main contributor to the restored floatability of oxidized carrollite through sulfidisation.This study provided a new perspective to correlate the surface species with xanthate adsorption and oxidized carrollite flotation through determining the various intermediate products.

Origin of natural sulphur-bearing immiscible inclusions and H_2S in oolite gas reservoir, Eastern Sichuan

Based on results of microscopic observation and laser Raman analysis about fluid in- clusions, multiple special forms of immiscible inclusions that contain sulphur, liquid hydrocarbon, bi- tumen, etc. were discovered in samples collected from the H2S gas reservoir-containing carbonates in the Lower Triassic Feixianguan Formation in the Jinzhu-Luojia area, Kai County, Sichuan Province. Based on the lithology and burial history of the strata involved as well as measurement results of homogenization temperature of fluid inclusions, bitumen reflectivity, etc., it is concluded that the H2S in the gas reservoir resulted from the thermal reaction between hydrocarbons in reservoir and CaSO4 in the gypsum-bearing dolostone section at the high temperature (140℃―170℃) oil-cracked gas for- mation stage in Late Cretaceous. Thereafter, research on a great number of immiscible inclusions in the reservoir reveals that elemental sulphur resulted from oxidation of part of the earlier-formed H2S and further reaction between sulphates, hydrocarbons and H2S in geological fluids in H2S-bearing gas reservoir at a temperature of 86℃―89℃ and a pressure of 340×105Pa and during the regional uplift stage as characterized by temperature decrease and pressure decrease in Tertiary. Meanwhile, gyp- sum, anhydrite and calcite formed at this stage would trap particles like elemental sulphur and result in a variety of special forms of immiscible inclusions, and these inclusions would contain information concerning the complexity of the fluids in the reservoir and the origin of H2S and natural sulphur in the gas reservoir.