[Risk Assessment of Heavy Metal Contamination in Farmland Soil in Du'an Autonomous County of Guangxi Zhuang Autonomous Region, China].

For a comprehensive understanding of the pollution characteristics and ecological risk of heavy metals of farmland soil in Du'an Autonomous County of Guangxi Zhuang Autonomous Region, China, this study evaluated the cadmium (Cd), arsenic (As), nickel (Ni), zinc (Zn), chromium (Cr), antimony (Sb), copper (Cu) and lead ( Pb) pollution situation using the single factor index, the Nemerow pollution index and the Hakanson ecological risk index. The results showed that heavy-metal pollution of farmland soil in Du'an County was serious. 74.

Evaluation of Field Portable X-Ray Fluorescence Performance for the Analysis of Ni in Soil.

As a rapid, in-situ analysis method, Field portable X-ray fluorescence spectrometry (FP-XRF) can be widely applied in soil heavy metals analysis field. Whereas, some factors may affect FP-XRF performance and restrict the application. Studies have proved that FP-XRF has poorer performance when the concentration of target element is low, and soil moisture and particle size will affect FP-XRF performance.

Bioaccumulation, maternal transfer and elimination of polybrominated diphenyl ethers in wild frogs.

To investigate bioaccumulation, maternal transfer and elimination of polybrominated diphenyl ethers (PBDEs) in amphibians, we collected adult frogs (Rana limnocharis) from a rice field in an e-waste recycling site in China. We found that ∑PBDEs in the whole frogs and various tissues (brain, liver, testis and egg) ranged from 17.10 to 141.

[Effects of high temperature on leaf photosynthetic characteristics and photosystem II photochemical activity of kernel-used apricot].

In order to explore the photosynthetic adaption mechanisms of kernel-used apricot under high temperature stress, gas exchange technique and chlorophyll fluorescence transient technique (JIP-test) were adopted to study the leaf photosynthetic characteristics and photosystem II (PS II) photochemical activity of 4 year-old 'Chaoren' (Armeniaca vulgaris x sibirica) growing on Horqin sandy land at 25 degrees C, 30 degrees C, 40 degrees C, and 50 degrees C. Within a definite temperature range, and as the temperature increased, the 'Chaoren' could enhance its leaf photosynthetic pigments content and ratio to maintain the light absorption, transfer, and conversion, and thereby, to ensure the function of photosynthetic apparatus. However, when the temperature exceeded the physiological adjustment threshold of leaves, the chlorophyll began to be decomposed, net photosynthetic rate (Pn) declined obviously, and intercellular CO2 concentration (Ci) increased, indicating that the decline in photosynthesis was limited by mesophyll factor.

[Optimization of enzymatic extraction of effective constituents from fibrous roots of Salvia miltiorrhiza by central composite design and response surface method].

The fibrous roots are the residues of production of cut crude drug of Danshen (Salvia miltiorrhiza). Enzymatic pretreatment and ultrasonic extraction are beneficial to extract effective constituents from fibrous roots more effectively. The present research was to optimize the enzymatic parameters by the central composite design and response surface method.

[Microbial flora in Cerasus sachalinensis rhizosphere].

By using selected culture media, the microbes in Cerasus sachalinensis rhizosphere were isolated, identified and classified, with their community structure and dynamic changes at different growth stages of C. sachalinensis studied. The bacteria isolated were belonged to 15 genera, among which, Bacillus, Pseudomonas and Flavobacterium were the dominant ones.