There is diverse phosphorus (P) in eutrophicated waters, but it is considered as a crucial nutrient for cyanobacteria growth due to its easy precipitation as insoluble salts. To uncover the effects of complex P nutrients on the emission of volatile organic compounds (VOCs) from cyanobacteria and their toxic effects on other algae, the VOCs from Microcystis flos-aquae supplied with different types and amount of P nutrients were analyzed, and the effects of VOCs and their two main compounds on Chlamydomonas reinhardtii growth were investigated. When M. flos-aquae cells were supplied with K2HPO4, sodium pyrophosphate and sodium hexametaphosphate as the sole P source, 27, 23 and 29 compounds were found, respectively, including furans, sulfocompounds, terpenoids, benzenes, aldehydes, hydrocarbons and esters. With K2HPO4 as the sole P source, the VOC emission increased with reducing P amount, and the maximum emission was found under Non-P condition. In the treatments of M. flos-aquae VOCs under Non-P condition and two main terpenoids (eucalyptol and limonene) in the VOCs, remarkable decreases were found in C. reinhardtii cell growth, photosynthetic pigment content and photosynthetic abilities. Therefore, we deduce that multiple P nutrients in eutrophicated waters induce different VOC emissions from cyanobacteria, and P amount reduction caused by natural precipitation and algal massive growth results in more VOC emissions. These VOCs play toxic roles in cyanobacteria becoming dominant species, and eucalyptol and limonene are two toxic agents. 相似文献
A new type of Au/TiO2/reduced graphene oxide (RGO) nanocomposite was fabricated by the hydrothermal synthesis of TiO2 on graphene oxide followed by the photodeposition of Au nanoparticles. Transmission electron microscopy images showed that Au nanoparticles were loaded onto the surface of both TiO2 and RGO. Au/TiO2/RGO had a better photocatalytic activity than Au/ TiO2 for the degradation of phenol. Electrochemical measurements indicated that Au/TiO2/RGO had an improved charge transfer capability. Meanwhile, chemiluminescent analysis and electron spin resonance spectroscopy revealed that Au/TiO2/RGO displayed high production of hydrogen peroxide and hydroxyl radicals in the photocatalytic process. This high photocatalytic performance was achieved via the addition of RGO in Au/TiO2/RGO, where RGO served not only as a catalyst support to provide more sites for the deposition of Au nanoparticles but also as a collector to accept electrons from TiO2 to effectively reduce photogenerated charge recombination.
The antagonistic effects of supplementation of Zn and Se to the soil on vegetables were studied in this work. In the pot experiment, Se (Se4+) and Zn (Zn2+) were applied, respectively, to the soil, in which the Chinese cabbage (Brassica rapa) and the lettuce (Lactuca sativa L.) were planted. As a result, Se and Zn were enriched evidently in the two vegetables. The contents of Pb and Cd in the two vegetables were decreased markedly while contents of some healthy mineral elements, like Mn and Mg, were increased to some extent when Se and Zn were applied. The antagonism of Se and Zn against Pb and Cd in plants was suggested. The farmland experiment on the lettuce was conducted to explore further the effect of supplementation of Zn and Se under the actual field conditions. Result came out to be that the enrichment of Zn and Se restrained the accumulation of Pb and Cd in the lettuce remarkably, as well as enhanced the absorption of some other nutritional elements, like Fe, Mn, Cu, Ca and Mg. Therefore, application of Se and Zn was proved to be an effective and feasible method to improve trace elements nutrition in the vegetables. 相似文献
Objective: Crash test dummies are full-scale anthropomorphic test devices (ATDs) that simulate the dimensions, weight proportions, and articulation of the human body and are used to measure human injury potential in vehicle crashes. The Hybrid III dummy family, which is widely used currently, takes selected percentiles of anthropometry dimensions of U.S. adults as design references. The objective of this study was to assess the difference in anthropometry between Chinese adults and the currently used dummy.
Methods: Based on the Chinese National Physical Fitness Surveillance of the year 2000, 2005, 2010 and National Standard of China GB/T 10000–1988, a series of anthropometric parameters for Chinese adults were obtained, and data analysis was conducted between Chinese adults and ATDs that are currently used.
Results: The comparison revealed distinct anthropometric difference between ATDs and Chinese adults. Based on the latest data, median Chinese females were about 2.6% lower in stature and about 8.03% lower in body weight than the ATD design targets. Similarly, median Chinese males were about 3.48% shorter and weighed 11.89% less than the ATD design targets.
Conclusions: Although the anthropometric differences between Chinese adults and the Hybrid III ATD specifications were modest and growing smaller, it is advisable to take the differences in anthropometry between ATDs and Chinese adults into consideration when developing new vehicles in China to provide effective protection specifically for Chinese occupants. 相似文献
In this study, the size of tobacco rob (TR) particle was considered as a major factor in determining the mass loss in thermogravimetric analysis (TGA) and product yield and composition at different reactor temperatures in the fixed-bed reactor. The TGA results showed that the conversion rate increased and the activation energy (ranged from 53.29 to 58.25 kJ/mol) decreased with a decrease in particle size. The experiments demonstrated that fuel gas yield (from 0.76 to 0.82 Nm3/kg at 900 °C) increased with a decrease in particle size while char and tar yield decreased. Smaller particle sizes resulted in higher H2 (25.68%) and CO (27.36%) contents. Minimizing the size of raw materials is an alternative method to improve the gas quality of TR pyrolysis. The increase of gas yield was attributed to the decomposition of char and tar vapor as temperature increased. 相似文献