为揭示冰封期氨氮（NH4+-N）在沉积物-水界面的迁移机制及内源性营养盐对全湖污染的贡献，于2018年2月初在乌梁素海湖区7个采样点采集了上覆水体与沉积物样品，得到了冰封期上覆水体与沉积物间隙水中的NH4+-N浓度，估算了沉积物-水界面NH4+-N的扩散通量.结果显示，上覆水体中NH4+-N浓度变化范围为0.55~1.60 mg/L，平均值为1.05 mg/L，0~5 cm表层沉积物间隙水中NH4+-N浓度是上覆水体中的10倍以上，其变化范围为6.64~18.63 mg/L，平均值为11.92 mg/L.估算沉积物间隙水NH4+-N向上覆水体的扩散通量为1.282~4.269 mg/（m2·d），表明在湖水冻结过程中，底泥沉积物接纳了大量的可溶性污染物成为内源污染源，会在冰封稳定期、融冰期和融冰后的一段时间内成为湖水的主要污染源.;Lake Ulansuhai is the largest lake in the Yellow River Basin with an area of 293 km2. The average air temperature is 7.3℃ and the winter is about six months with a cumulative negative accumulated temperature about 610-800℃·day. The lake water usually starts freezing in the early November and melting in the end of March or in the early April of the following year. The lake is completely sealed by ice in terms of ice-sealing period for about 100-130 days with an ice thickness of 0.63 m in average. To get better understanding in the migration mechanism of ammonia nitrogen at the water sediment interface and the impact of endogenous nutrients on the lake environment during the ice-sealing period, the water and sediment samples were collected at seven sampling sites in early February of 2018 in Lake Ulansuhai. The concentrations of ammonia nitrogen of the water samples were analyzed. The diffusion flux of ammonia nitrogen at the water sediment interface was estimated. The results showed that the concentrations of ammonia nitrogen in the water ranged from 0.55 mg/L to 1.60 mg/L with an average of 1.05 mg/L. The concentrations of ammonia nitrogen in the pore water of 0-5 cm surface sediments were one order of magnitude greater than that in overlying water which ranged from 6.64 mg/L to 18.63 mg/L with an average of 11.92 mg/L. The diffusion flux of ammonia from the sediments to the water was 1.282-4.269 mg/(m2·d). This indicated that a large number of soluble pollutants had been transported to the sediments during the process of freezing. It would be the one of the dominated source of water pollution to the lake environment in the period of ice stability, during the period of ice thawing, and in a period of time after ice thawing.
The natural frozen experiment on the water from Wuliangsuhai lake shows that the pollutants migrate from ice body to water body during the freezing process, which means that freezing process has a good purification effect on pollutants in water environment. The experiment also shows that the removal efficiency of pollutants rises at first and then decreases as the ice thickness increases. At 15cm thickness, the removal efficiency of total dissolved solids(TDS), ammonia nitrogen (NH 3 -N) and chemical oxygen demand (COD) can reach 81.20%, 86.80% and 86.60%.What is more, the removal efficiency is better as the frozen stage increase. The removal efficiency of TDS, NH 3 -N and COD is more than 92% through three stages frozen. Drawing inspiration from the natural frozen experiment and its mechanism of frozen concentration effect, a tentative idea that natural cool energy can be applied in the non-centralized water supply field was put forward and a reasonable technological process of freezing purification was designed, which can not only improve the quality of drinking water in rural area, but also can reduce the drinking water processing cost.
Calorie restriction (CR) and exercise training (EX) are two critical lifestyle interventions for the prevention and treatment of metabolic diseases, such as obesity and diabetes. Brown adipose tissue (BAT) and skeletal muscle are two important organs for the generation of heat. Here, we undertook detailed transcriptional profiling of these two thermogenic tissues from mice treated subjected to CR and/or EX. We found transcriptional reprogramming of BAT and skeletal muscle as a result of CR but little from EX. Consistent with this, CR induced alterations in the expression of genes encoding adipokines and myokines in BAT and skeletal muscle, respectively. Deconvolution analysis showed differences in the subpopulations of myogenic cells, mesothelial cells and endogenic cells in BAT and in the subpopulations of satellite cells, immune cells and endothelial cells in skeletal muscle as a result of CR or EX. NicheNet analysis, exploring potential inter-organ communication, indicated that BAT and skeletal muscle could mutually regulate their fatty acid metabolism and thermogenesis through ligands and receptors. These data comprise an extensive resource for the study of thermogenic tissue molecular responses to CR and/or EX in a healthy state.
Abstract This study analyzed the wintertime surface heat exchange for the Inner Mongolia reach of the Yellow River, China, based on the data from the nearby weather station at Wulateqianqi. In this analysis, the solar radiation is based on the observed data. Other components of the surface heat flux, that is, long‐wave radiation, and evaporative and conductive heat fluxes, are calculated. The relative importance of the contributions of long‐wave radiation, conductive, and evaporative heat fluxes are in descending order. The air temperature is the most important meteorological factor to the total heat flux. Although the wind speed influences evaporative and conductive heat fluxes, it has the least correlation with the total heat budget. The heat exchange coefficient for the linearized surface heat exchange equation is 21.87 W/(m 2 °C), which is comparable with published values in the regions of United States and Canada with similar latitudes.
To enhance the seismic performance of the recycled concrete deep flexural beam combination frame structure and increase the utilization rate of the square steel tube recycled concrete structure, on the basis of the previous research, starting from the structural level, the related seismic performance of the square steel tube recycled concrete column -recycled concrete deep flexural beam combination frame structure was studied in depth, so as to provide references for further theoretical research and application of square steel tube recycled concrete frame structure.Six sets of frames were designed and made for repeated low-cycle loading test, the failure process and failure form of the frame and the filled wall were observed, and the hysteretic curve, skeleton curve and strain changes at key parts of the specimens were obtained.In addition, the seismic performance of the specimen was analyzed in detail to study the influence of various parameters on the seismic performance of the structure.The results showed that the calculated values were in good agreement with the measured values, which can provide reference for the theoretical calculation of the structure.It was of great significance to conduct in-depth research on the new-type combination frame structure of square steel tube recycled concrete column -recycled concrete deep flexural beam, reveal its failure mechanism and seismic performance, and put forward reasonable structural measures, and this was an essential step for the promotion and application of square steel tube recycled concrete structure.
The slow-release inhibitors were prepared based on the technology of bio-inhibition on methanogens and slow-release.The process optimization on release of acetylene and Ca2+ was carried out,and it was found that when the ratio of calcium carbide to paraffin wax was 1:1 and the diameter of slow-release inhibitor was 10 mm,the release time was longer.Additionally,the inhibitor coated with cellulose acetate (CA) had better effect on slow-release.The ratio of release reached 28.42% after releasing 145 d with the content of rosin 20%.Empirical diffusion formula of Sinclair Peppas can describe the release process well.Moreover,a mechanism model was derived based on the Higuchi model and the diffusion coefficients were acquired.
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