Although male testosterone levels are thought to be linked with the mating system, ecological and social factors complicate the big picture of the function of testosterone in wild nonhuman primates. We examined testosterone correlates with rank and copulatory behavior in male Tibetan macaques (Macaca thibetana) at Mt. Huangshan, China. A total of 426 fecal samples and approximately 453h of behavioral data were collected on five adult males from October 2005 to September 2006. Copulatory behaviors were significantly different between high and low ranking males in the mating season, but not during the non-mating season. No significant correlation between testosterone levels and a male's David's score indicated that testosterone was independent of social rank. Also, copulatory behaviors were positively correlated with fecal testosterone levels in both seasons, regardless of social rank. The present study represents a preliminary assessment of the relationship between testosterone level, rank, and copulatory behavior in a wild environment. The results enrich the picture of testosterone, rank, and copulatory relationships in non-human primates, and may also provide insight into what mechanisms link physiological factors to male reproductive success in natural circumstances.
Hematite is composed of iron and oxygen elements, and the iron–oxygen spatial distribution would affect directly its photoelectrochemical (PEC) performance. However, less work has focused on the effect of iron–oxygen composition on the characteristic of charge transport and interfacial reaction. Here, we investigated the charge transfer and interface reaction of two typical iron–oxygen compositions of hematite prepared from the precursors of Fe and FeOOH in which different iron–oxygen ratios were obtained. X-ray photoelectron spectroscopy etching confirms that different precursors do cause differences in spatial elemental composition after thermal treatment. For Fe precursors, oxygen deficiency in the bulk is responsible for its lower bulk efficiency, whereas the defect-free surface results in a high surface separation efficiency and a low interfacial reaction catalysis rate. The FeOOH precursor forms an oxygen-rich surface and, therefore, introduces a large number of surface hole traps. Excessive traps significantly hinder surface charge separation and transport but favor surface electrocatalytic kinetics. Our work provides a perspective on the relationship between the semiconductor electrode performance and its structure and provides effective guidance for further optimization.
The coefficient of performance (COP), the volumetric refrigeration capacity and the pressure ratio of refrigeration cycle were studied in a refrigeration-type compressed-air dryer using environmentally friendly refrigerants R410A and R407C and compared with those using R22. Study indicates that under the working condition of a refrigeration-type compressed-air dryer, COP using R410A is 3% higher than that using R407C, the volumetric refrigeration capacity using R410A is 50 percentage points higher than that using R407C and the pressure ratio of R410A is 10% less than that of R407C. COP using R410A equals 96% of that using R22 and the volumetric refrigerating capacity equals 147% of that using R22. COP using R407C is equal to 93% of that using R22 and the volumetric refrigerating capacity is equal to 97% of that using R22. R410A is a more appropriate alternative to R22 than R407C in a refrigeration-type compressed-air dryer.
In order to notably improve the mechanical properties and durability of low-grade cement-based material, superfine silica fume was used to modify the cement-based composite based on special perfomance and effects of nano powder. The mechanical performance and durability were investigated.Then the phase compositions,microstructure and morphologies of as-received cement-based composite were studied by X-ray Diffractometer、TGA-DTA and SEM. The results show that： the best formula of raw materials is 1:1:0.025:0.015, and hydration can be accelerated and increasing of hydration products is observed after modification. In the hardened cement matrix, microstructure is very compacted and C-S-H gel forms densed structure, so the structure defect is notably reduced. This means that both strength and durability of cement-based composite are notably improved by the addition of superfine silica fume.
A significant promotion effect of low-molecular hydroxyl compounds (LMHCs) was found in the nano-photoelectrocatalytic (NPEC) degradation of fulvic acid (FA), which is a typical kind of humic acid existing widely in natural water bodies, and its influence mechanism was proposed. A TiO2 nanotube arrays (TNAs) material is served as the photoanode. Methanol, ethanediol, and glycerol were chosen as the representative of LMHCs in this study. The adsorption performance of organics on the surface of TNAs was investigated by using the instantaneous photocurrent value. The adsorption constants of FA, methanol, ethanediol, and glycerol were 43.44, 19.32, 7.00, and 1.30, respectively, which indicates that FA has the strongest adsorption property. The degradation performance of these organics and their mixture were observed in a thin-layer reactor. It shows that FA could hardly achieve exhausted mineralization alone, while LMHCs could be easily oxidized completely in the same condition. The degradation degree of FA, which is added LMHCs, improves significantly and the best promotion effect is achieved by glycerol. The promotion effect of LMHCs in the degradation of FA could be contributed to the formation of a tremendous amount of hydroxyl radicals in the NPEC process. The hydroxyl radicals could facilitate the complete degradation of both FA and its intermediate products. Among the chosen LMHCs, glycerol molecule which has three hydroxyls could generate the most hydroxyl radicals and contribute the best effective promotion. This work provides a new way to promote the NPEC degradation of FA and a direction to remove humus from polluted water.
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