RESUMEN
Soil salinization poses a great threat to sustainable land use and the limitation of greenhouse gas emissions. In this study, three saline alkali soils, saline soil[electrical conductivity (EC) 4.80 dS·m-1], high saline-alkaline soil (EC 2.60 dS·m-1), and low saline-alkaline soil (EC 0.74 dS·m-1) in the Hetao Irrigation District of Inner Mongolia were selected as research plots. Field experiments were conducted to study the uptake of methane (CH4) in the crop-growing season (April-October) for three years (2014-2016) using the static box method. There were significant differences in the soil CH4 uptake among the soil types in 2014 (F=18.0, P<0.001), 2015 (F=23.6, P<0.001), and 2016 (F=28.4, P<0.001). The uptake of CH4 by the soil decreases with increasing soil salinity. The accumulated CH4 uptake was 150.0 mg·m-2, 119.6 mg·m-2, and 99.9 mg·m-2 in the low saline-alkaline, high saline-alkaline, and saline soil in 2014, respectively. The cumulative uptake of CH4 was 27%, 28%, and 19% lower in the high saline-alkaline soil and 35%, 35%, and 53% lower in the saline soil than in the low saline-alkaline soil in 2014, 2015, and 2016, respectively. Redundancy analysis shows that the projection of the CH4 uptake flux and EC of saline-alkaline soil are in the positive direction, and in the opposite direction to the first principal component axis. The higher the soil EC, the lower the CH4 uptake flux. Soil EC was found to be the key factor controlling the uptakes of CH4, with a correlation coefficient (r) of -0.8809 (P<0.01, n=9).
RESUMEN
In the present paper, crude biodiesel prepared with sorbifolia oil as raw material by transesterification was purified by column chromatography, then the composition of biodiesel was analyzed by gas chromatography, FTIR, GC-MS and 1H NMR. Column chromatography can separate the crude biodiesel into two fractions: petroleum ether eluted fraction (A1) and methanol eluted fraction (A2). Petroleum ether eluted fraction was mainly biodiesel fraction, which was produced from sorbifolia oil by transesterification, including methyl linoleate, methyl cis-9-octadecenoate and so on; methanol eluted fraction was mainly glycerol fraction, which came from the side reaction of transesterification. The results show that the purity of refined biodiesel increased from 77.51% to 93.872, and the product recovery rate reached up to 91.04% after the purification by column chromatography. The results obtained by FTIR and 1H NMR further showed that the column chromatography can effectively improve the purity of biodiesel. This paper provides a basis for industrialization of purification of biodiesel.
Asunto(s)
Biocombustibles , Cromatografía de Gases , Cromatografía de Gases y Espectrometría de Masas , Glicerol , Metanol , Aceites de PlantasRESUMEN
The dehydration of bischofite is the key to the use of magnesium resource. Double salts or complex method is an important way to prepare anhydrous magnesium chloride. The crystals of bischofite and aniline hydrochloride were prepared through lowering the temperature of the mixture's aquatic solution slowly. The pyrolysis of aniline hydrochloride, bischofite and the crystals was qualitatively analyzed by TG-FTIR under 400 degrees C. We infered the reaction process through qualitative detection of escaping gas of each decomposition step. The Experimental results showed that there were three steps in the thermal decomposition of bischofite. In the first step, nearly four crystallized waters decomposed, while hydrolysis and decomposition took place together in the next two steps, but hydrolysis was the main reaction at the lower temperature (205-235 degrees C), and comparative decomposition was the main one at the higher temperature (235-287 degrees C). In the experimental temperature range, aniline hydrochloride didn't decompose. Water and aniline hydrochloride left the crystals at different temperature, and no hydrolysis reaction occurred. Anhydrous magnesium chloride can be prepared though this way.
RESUMEN
OBJECTIVE: Shen Yan Ling Tablet is an innovative compound of traditional Chinese medicine, scientifically prepared with Tripterygium wilfordii, Radix Astragali, and others, with precise efficacy on renal diseases and reduced adverse effects of Tripterygium wilfordii. Based on the Guiding Principles for New Drug Toxicity Research Before Clinical Application, we investigated the long-term toxicity of Shen Yan Ling Tablet and its effect on the reproductive function in rats. METHODS: According to the clinical therapeutic dose and the results of the acute toxicity test of Shen Yan Ling Tablet, we equally divided 80 rats (males and females half-and-half) into a low-dose (1.25 g/kg body wt), a medium-dose (2.50 g/kg body wt), a high-dose (5.00 g/kg body wt) and a control group. After a 3-month medication, we conducted standardized long-term toxicity tests and observed the effects of Shen Yan Ling on the serum sexual hormones and epididymal sperm count. RESULTS: After 3 months of treatment with Shen Yan Ling, no death occurred, the general status remained unchanged, and the parameters of blood cytology and biochemistry fluctuated within the normal range, without any significant changes (P > 0.05). Some blood parameters, RBC, WBC, HGB, AST and TBIL, showed statistic changes (P < 0.05), but with no clinical significance. There were no significant differences in the mass coefficients of the main organs between the medication and control groups. The high-dose group exhibited slight hepatic and pulmonary pathological changes and significantly reduced sperm counts in the epididymis, but no significant changes in serum sexual hormones (P < 0.05). CONCLUSION: Three-month medication of Shen Yan Ling at 1.25 - 5.00 g/kg produced no significant accumulated toxicity on rats, but it had a negative effect on their reproductive function at a higher dose of > or = 5.00 g/kg.
Asunto(s)
Epidídimo/efectos de los fármacos , Extractos Vegetales/toxicidad , Pruebas de Toxicidad Aguda , Tripterygium , Animales , Medicamentos Herbarios Chinos/toxicidad , Femenino , Masculino , Nefritis/tratamiento farmacológico , Tamaño de los Órganos , Fitoterapia , Ratas , Ratas Sprague-Dawley , Espermatozoides/efectos de los fármacos , ComprimidosRESUMEN
Radiolysis of aqueous solution of thiocyanate by 60Co gamma-rays was studied. In condition of pH = 1 and pH = 3,25 mg/L SCN- was decomposed under the dose of 6 kGy, with decomposition rate of 98.11% (pH = 1) and 95.97% (pH = 3) respectively. 25 mg/L SCN- (pH = 7) was decomposed under the dose of 9 kGy and the decomposition rate is 99.33%. In the alkaline condition, pH = 10 and pH = 12, the dose of 18 kGy was need, and the decomposition rate is 99.64% and 99.93% respectively. High SCN- concentration means that more radiation dose is need. From the comparison of before radiolysis and after radiolysis's TOC (total organic carbon) and TN (total nitrogen) of SCN- solution, little TOC and TN was removed. The determination of SO4(2-) and NO3- concentration indicated that sulfur element was removed and converted to SO4(2-), and nitrogen element rarely converted to NO3-, but converted to other forms of nitrogen.
Asunto(s)
Rayos gamma , Tiocianatos/química , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/química , Fotólisis , Tiocianatos/aislamiento & purificación , Contaminantes Químicos del Agua/aislamiento & purificaciónRESUMEN
We studied the 60Co gamma-ray radiolysis of thiocyanate aqueous solutions in the presence of free radical scavengers, determination of cyanide of radiated thiocyanate solutions, degradation of cyanide and thiocyanate complicated system and cyanide, thiocyanate and copper (I) cyanide complicated system. The presence of NaHCO3 and n-butanol made the degradation efficiency of thiocyanate decreased, in the radiation procession of thiocyanate, cyanide was produced; and the possible reaction equation is SCN(-) + 8*OH-->SO4(2-) + CN(-) +4H2O, in the cyanide and thiocyanate system, the thiocyanate degradation rate can obtained 30%, free cyanide degradation was little effected by coexistence of thiocyanate; and due to strong complex ability of copper (I), the main form of copper (I) cyanide is Cu(CN)3(2-), the total cyanide of the system can't be degraded completely and degradation rate is about 80%.
Asunto(s)
Rayos gamma , Tiocianatos/efectos de la radiación , Eliminación de Residuos Líquidos/métodos , Contaminantes Químicos del Agua/efectos de la radiación , Purificación del Agua/métodos , Radioisótopos de CobaltoRESUMEN
Sugarcane bagasse hemicellulose hydrolysates, pretreated by either over-liming or electrodialysis and, supplemented with nutrient materials, were fermented to ethanol using Pachysolen tannophilus DW06. Compared with detoxification by over-liming, detoxification by electrodialysis decreased the loss of sugar and increased the acetic acid removal, leading to better fermentability. A batch culture with electrodialytically pretreated hydrolysate as substrate was developed giving 21 g ethanol l(-1) with a yield of 0.35 g g(-1) sugar and productivity of 0.59 g l(-1) h(-1).
Asunto(s)
Celulosa/metabolismo , Etanol/metabolismo , Fermentación , Polisacáridos/metabolismo , Saccharomycetales/metabolismo , Saccharum/metabolismo , Hidrólisis , Factores de TiempoRESUMEN
Broth containing 152 g glycerol l(-1) from Candida krusei culture was converted to 1,3-propanediol by Klebsiella pneumoniae. Residual glucose in the broth promoted growth of K. pneumoniae while acetate was inhibitory. After desalination treatment of glycerol broth by electrodialysis, the acetate in the broth was removed. A fed-batch culture with electrodialytically pretreated broth as substrate was developed giving 53 g 1,3-propanediol l(-1) with a yield of 0.41 g g(-1) glycerol and a productivity of 0.94 g l(-1) h(-1).
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Biotecnología/métodos , Glicerol/química , Klebsiella pneumoniae/metabolismo , Glicoles de Propileno/metabolismo , Reactores Biológicos , Candida/metabolismo , Cromatografía , Electroquímica/métodos , Filtración , Glicerol/metabolismo , Membranas/química , Glicoles de Propileno/química , Factores de TiempoRESUMEN
Quaternary ammonium salt has strong affinity with gold in cyanide solutions, but it is not readily stripped. Stripping with acidic thiourea solutions and air sparging shows promise. There are some reports on the process of thiourea stripping, but little about its mechanism. In this paper, the stripping mechanism of N263/sulphuric thiourea/alkaline cyanide gold solution is studied by EXAFS. According to the experiments, sulphuric acid, thiourea and gold-thiourea complex can be extracted by N263 as a neutral molecule, and the stripping process can be described as following: (1) Sulphuric acid and thiourea are extracted by N263; (2) In organic phase, gold-cyanide complex is converted to gold-thiourea complex, which exists as Au[SC(NH2)2]2HSO4, and CN- forms HCN with acid at the same time; (3) HCN is removed by air sparging, and Au[SC(NH2)2]2HSO4 is distributed between organic phase and liquor phase, most of which transfers to liquor phase and is stripped.
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Oro/aislamiento & purificación , Compuestos de Amonio Cuaternario/química , Tiras Reactivas/química , Tiourea/química , Aminas , Cianatos/química , Cianuros/química , Electroquímica , Monitoreo del Ambiente , Oro/química , Concentración de Iones de Hidrógeno , Nanopartículas del Metal/química , Nanotecnología , Soluciones Farmacéuticas , Soluciones/química , Ácidos Sulfúricos/químicaRESUMEN
The concentrations of gold in thiourea and sulfuric acid solutions using gold standard solutions in diluent royal water were determined by AAS. The linear range was 0.2-12 x 10(-6), and RSD < 5%. This method simplifies the analysis of gold in thiourea and sulfuric acid solution. Thiourea declines the absorbency of gold while sulfuric acid plays a contrary role. The determined value were satisfactor after being modified by the blank curve.