Publications by authors named "Qinqin Du"

Background: is a member of the lactic acid bacterium group commonly found in many salt-fermented foods. Strains of isolated from high-salinity environments have been shown to tolerate salt stress to some extent. However, the specific responses and mechanisms of under salt stress are not fully understood.

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Climate changes and human activities have led to a rise of frequency and intensity of the global flash droughts, resulting in severe consequences for ecosystems, agriculture, and human societies. However, research dedicated to flash droughts in the dryland of western China is relatively limited, leaving their evolutionary characteristics and development processes of these phenomena unclear. To bridge this gap, this study analyzed the spatiotemporal characteristics of flash droughts in western China from 1981 to 2020, based on the standardized evapotranspiration stress index.

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The rapid development of the social economy has promoted a continuous increase in the intensity and scale of land use by humans, which has seriously affected the sustainable development of the region. It is important to understand the land use/cover change (LUCC) in the arid region and its future development trends and to make reasonable planning recommendations for the sustainable development of the ecological environment. This study validates the patch-generating land use simulation (PLUS) model in a typical arid region, the Shiyang River Basin (SRB), and analyzes the applicability of the model in arid regions.

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In recent years, heavy metal contamination of soils has been increasing, posing a major threat to food security, human health, and soil ecosystems. This study analyzed the spatial characteristics, contamination sources, risks of heavy metals by collecting topsoil samples from farmland in an oasis agricultural region in northwest China. The results found that soil heavy metals in farmland were at a moderate contamination level.

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During atmospheric precipitation, the evaporation of raindrops falling from the bottom of cloud layer to the ground and passing through unsaturated air, a process was called sub-cloud secondary evaporation, which will change the isotopic composition of precipitation. Using the hydrogen and oxygen stable isotope method to understand the temporal and spatial variation of secondary evaporation effect under clouds and its causes is important to understand regional water cycle process. Based on hourly meteorological data of 187 meteorological stations in Shaanxi-Gansu-Ningxia region from March 2018 to February 2019, the spatial and temporal variations of evaporation surplus ratio () and precipitation excess deuterium variation (Δ) were analyzed using the improved Ste-wart model, and the relationships between and meteorological elements and Δ were examined.

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To better understand the isotope variations on a short time scale, this study focused on a long-term rainfall event with light precipitation (June 26-27) and a short-term one with heavy precipitation (July 28) in Lanzhou City in the summer of 2019. Combined with HYSPLIT model, samples collected during a continuous precipitation event every 10 min and 30 min were analyzed to explore the characteristics and mechanism of stable hydrogen and oxygen isotopes in precipitation. The results indicate that the effect of sub-cloud secondary evaporation makes the slope of the sequential meteoric water line (SMWL) smaller at the beginning of the rainfall event.

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As plant species for riparian ecological restoration in northern China, Tamarix ramosissima and Salix matsudana play an important role in river protection, flood control, regional climate regulation, and landscape construction of riparian vegetation. Two sampling sites were selected in the riparian zones along the Lanzhou section of Yellow River, where plant xylems and potential water sources were collected. The direct comparison method, Bayesian mixture model MixSIAR and the proportional similarity index (PS index) were used to determine the proportions of water utilization for each potential water source and the relationship of two species in water utilization.

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Chlorine bleaching is still practiced by most of nonwood pulp and paper mills, resulting in a considerable amount of polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) formation and emission. In this study, the effects of primary chlorination conditions on the formation of PCDD/Fs from nonwood pulp bleaching with elemental chlorine were investigated. It was found that low-chlorinated PCDD/Fs were usually formed and then underwent further chlorination to form highly chlorinated PCDD/Fs with increasing chlorination time.

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Electrospray ionisation-mass spectrometry (ESI-MS) was applied to analyse the water-soluble extract of red ginseng (RG). Several new compounds were produced from the Maillard reaction during the steaming and drying process for preparing RG. Both the tandem electrospray ionisation (ESI-MS(n)) and Fourier transform ion cyclotron resonant mass spectrometric (FT-ICR-MS) data of these products proved that they were the initial Maillard reaction products (MRPs) of maltose with glutamic acid/aspartic acid, which were specific components in RG.

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Ginsenosides in the decoction of Radix Ginseng, Radix Ginseng with Flos Lonicerae, Radix Polygoni Multiflori or Radix Astragali have been investigated by high performance liquid chromatography (HPLC) and electrospray ionization mass spectrometric method (ESI-MS). Change of the content of ginsenosides was nonlinear in diverse combinative proportion of Radix Ginseng with Flos Lonicerae, while the stripping of ginsenosides was promoted by a small amount of Radix Polygoni Multiflori. In the combinative decoction of Radix Ginseng with Radix Astragali, ginsenosides contents were increased compared to single decoction of Radix Ginseng.

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