Xie Y.,Nanjing Forestry University |
Tao G.,Tongcheng Teachers College |
Chen Q.,CAS Kunming Institute of Botany |
Tian X.,Nanjing Forestry University
Water, Air, & Soil Pollution | Year: 2014
Effects of perchlorate stress on the growth and physiological characteristics of rice (Oryza sativa L.) were studied in controlled water culture experiments. Perchlorate stress resulted in varied patterns of biomass allocation to O. sativa organs (roots, stems, and leaves). When stressed with higher perchlorate concentrations, the proportion of root biomass was higher, stem biomass was invariant, while leaf biomass was lower. Coefficients of variation in biomass of different organs followed the order leaf > stem > root, indicating that leaf growth has a higher sensitivity to perchlorate. Compared to the control, the chlorophyll and protein content of leaves and root vigor were lower, whereas malondialdehyde (MDA) content and catalase (CAT) activity were higher and related to perchlorate concentration and duration of stress. Superoxide dismutase (SOD) activity was initially high and then decreased markedly during the experiment, while peroxidase (POX) activity in perchlorate-treated rice was always higher than the POX activity of the control. POX was the most sensitive antioxidant enzyme to perchlorate stress. Correlation analysis showed a positive correlation between SOD activity and the fresh weight of the whole plant, and negative correlation with MDA content. The results suggest that perchlorate could induce oxidative stress and oxidative damage may be the main cause of physiological damage and growth inhibition in rice plants under perchlorate stress. © 2014 Springer International Publishing Switzerland.
Liu Y.,Shenzhen University |
Huang H.,Tongcheng Teachers College |
Lin X.,Shenzhen University
Key Engineering Materials | Year: 2013
TiO2 thin films were prepared on quartz glasses by pulsed laser deposition (PLD) using a KrF laser excimer. The crystalline structure was characterized by X-ray diffraction, and the optical properties of the films were investigated using spectroscopic ellipsometry and UV-vis spectra respectively. The effects of the PLD conditions, including substrate temperature and O 2 pressure on the crystalline structure and the optical properties of the films were investigated. The results indicated that there are a suitable substrate temperature and an O2 pressure which is favorable for the synthesis of anatase-type TiO2. © (2013) Trans Tech Publications, Switzerland.
Zhan F.,Zhejiang Normal University |
Zhan F.,Tongcheng Teachers College |
Yang D.,Zhejiang Normal University
Shengtai Xuebao/ Acta Ecologica Sinica | Year: 2012
According to the rate of living theory of aging, the longevity of living organisms should be negatively correlated with body metabolic rate. For the organisms having the same body size, the metabolic rate is usually greater in favorable habitats than in poor-quality sites, as demonstrated in many previous studies. Therefore, it is expected that organisms would live longer in environments with low-resource availability than in their counterparts. Specifically, we hypothesize that plant branches or twigs would live shorter in sun-lit microhabitats than in shaded or partial-shaded ones. This hypothesis is consistent with the recently established leaf and wood economic spectrums, in which leaf longevity is positively associated with leaf mass per area but negatively with leaf nitrogen content and photosynthetic capacity that often characterize favorable sites. A similar hypothesis has also been interspecifically tested to be true at whole-individual level of tree species, where long-lived species are often associated with low respiration rates. In order to test the above hypothesis, we in this study examined the effects of light level on branch longevity and on the relationship between crown shape and the longevity for an evergreen species (Osmanthus fragrans) and a deciduous species (Metasequoia glyptostroboides) in Nanjing, southeast China. We measured plant size (height and diameter at breast height), crown depth (i. e. vertical crown length) that was obtained by plant height minus under branch height, crown profile that was calculated as the ratio of crown depth to crown width, and relative crown width that was defined as the ratio of crown width to plant height; we also determined the longevity of shed branches by bud scales for plants (with similar size) grown in different light conditions (under full sun light/unshaded, partial shaded, fully shaded). In both species, branch longevity was found to be significantly greater for plants living in the fully-shaded environments than for those grown in open sites; the longevity increased with increasing shading level, consistent with the theoretical prediction. Crown depth and crown profile increased, but relative crown width decreased with increasing shading level in both species, i. e. shading tended to result in narrow and deep plant crowns. In addition, branch longevity was positively correlated with crown depth and crown profile but negatively with relative crown width in both species, and branch longevity was positively related to relative crown depth in O. fragrans, not in M. glyptostroboides. The possible underlying mechanism is that shading might have increased the level of apical dominance but decreased the self-shading level of crown interior (as reflected by increased crown profile and decreased crown width), which potentially led to low metabolic rates. These results collectively suggest that the morphological responses of plant crowns to light may largely account for the variation in branch longevity under different shading levels. However, the current study did not address the importance of life form to plant metabolic rates and organism longevity despite two different species being investigated. Future studies need to examine branch biomass allocation, leaf photosynthetic capacity and respiration rates to fully understand the relationship between branch longevity and habitat quality for species differing in life forms.
Kai X.-M.,Anhui Normal University |
Fang H.-W.,Tongcheng Teachers College |
Lei Y.-F.,Basic Course Instruction of Anqing Technician Institute
Yejin Fenxi/Metallurgical Analysis | Year: 2016
The buffer solution is an important teaching content in inorganic chemistry and analytical chemistry. The calculation formula of buffer capacity of two buffer solutions composed of triptotic weak acids was deduced, and the additivity of buffer capacity was discovered. The buffer capacity of 0.10 mol/L citric acid-0.10 mol/L phosphoric acid and Clark-Lubs buffer solution (0.20 mol/L phthalic acid-0.20 mol/L phosphoric acid-0.20 mol/L boric acid) under different pH conditions was calculated by Excel. The changing curve of buffer capacity against pH was graphically displayed. The buffer range of buffer solutions above was intuitively shown. The results indicated that the citric acid-phosphoric acid buffer solution had good buffer effect at pH<8, while Clark-Lubs buffer solution exhibited good buffer effect at pH<10. © 2016, CISRI Boyuan Publishing Co., Ltd. All right reserved.
Kai X.-M.,Anqing Teachers College |
Kai X.-M.,Anhui Tongcheng Mingsheng Complex Packing Co. |
Fang H.-W.,Tongcheng Teachers College |
Hao S.-L.,Anqing Teachers College |
And 3 more authors.
Yejin Fenxi/Metallurgical Analysis | Year: 2013
The content of aluminum in aluminizing plastic film was determined by chrome azurol S spectrophotometry. Then, the thickness of aluminizing layer was calculated according to the density of aluminum and the mass of aluminizing layer on unit area of plastic film. The coloring reaction between aluminum and chrome azurol S (CAS) was studied. the results showed that aluminum could react with CAS to form a complex in buffer solution at pH 5.5.The maximum absorption wavelength of the complex was 610 nm. The apparent molar absorptivity was ε=3.89×104 L·mol-1·cm-1. Under the optimal conditions, the mass concentration of aluminum in range of 0.004-0.20 μg/mL was linear to the absorbance. The detection limit for aluminum was 0.004μg/mL. The recovery test of aluminizing plastic film sample was performed. The recovery rates of aluminum were between 97% and 102%. The proposed method was applied to the determination of aluminizing thickness on plastic film, with relative standard deviation (RSD, n=6) less than 3%.