Spatial distribution characteristics, risk assessment and management strategies of tailings ponds in China.

The tailings ponds (TPS) stemming from mineral resource exploitation are becoming a global challenge due to their high hazards and pollution to the surrounding area. However, previous studies on China's tailings ponds have either focused on a single or few areas, or the number of tailings ponds varies greatly. A systematic assessment of the number, distribution characteristics, potential risks and management strategies of the tailings pond in China is lacking.

Transcriptome-wide association analyses reveal the impact of regulatory variants on rice panicle architecture and causal gene regulatory networks.

Panicle architecture is a key determinant of rice grain yield and is mainly determined at the 1-2 mm young panicle stage. Here, we investigated the transcriptome of the 1-2 mm young panicles from 275 rice varieties and identified thousands of genes whose expression levels were associated with panicle traits. Multimodel association studies suggested that many small-effect genetic loci determine spikelet per panicle (SPP) by regulating the expression of genes associated with panicle traits.

[Main Chemical Components in Atmospheric Precipitation and Their Sources in Xi'an].

In order to understand the current status of main chemical components of atmospheric precipitation in Xi'an, the pH, electrical conductivity, mass concentration of water-soluble ions and heavy metals, wet deposition fluxes, and their sources in precipitation samples in urban and suburban areas of Xi'an in 2019 were studied. The results showed that the pH, conductivity, water-soluble ions, and heavy metals in precipitation in Xi'an in winter were higher than those in other seasons. The main water-soluble ions in precipitation were Ca, NH, SO, and NO, and the sum of these ions accounted for (88.

OsbHLH067, OsbHLH068, and OsbHLH069 redundantly regulate inflorescence axillary meristem formation in rice.

Rice axillary meristems (AMs) are essential to the formation of tillers and panicle branches in rice, and therefore play a determining role in rice yield. However, the regulation of inflorescence AM development in rice remains elusive. In this study, we identified no spikelet 1-Dominant (nsp1-D), a sparse spikelet mutant, with obvious reduction of panicle branches and spikelets.

Tracing fossil fuel CO by C in maize leaves in Guanzhong Basin of China.

Quantifying fossil fuel CO (CO) in the atmosphere provides a benchmark method to monitor anthropogenic carbon emissions. Radiocarbon (C) in atmospheric CO has been widely studied using the C in plants to document regional CO patterns. However, annual CO variations, reflecting spatial distributions based on plant samples, are still scarce.

Stable carbon isotopic characteristics of fossil fuels in China.

Good knowledge on the stable carbon isotopic composition (δC) of fossil fuels is critical for the estimation of atmospheric CO sources. Here, we complied a comprehensive δC database including 336 coal, 580 oil, and 1160 natural gas data based on the extensive literature search, and conducted field measurements in two megacities, to characterize the δC signatures of Chinese fossil fuels. Results show that coal exhibits a narrow range and the most enriched in δC signature, oil displays intermediate variations both in the distribution and value of δC.

The impact of COVID-19 lockdown on atmospheric CO in Xi'an, China.

Lockdown measures to control the spread of the novel coronavirus disease (COVID-19) sharply limited energy consumption and carbon emissions. The lockdown effect on carbon emissions has been studied by many researchers using statistical approaches. However, the lockdown effect on atmospheric carbon dioxide (CO) on an urban scale remains unclear.

Time series of atmospheric ΔCO recorded in tree rings from Northwest China (1957-2015).

Radiocarbon (C) is a unique and important tool for understanding carbon cycle in the nature, and its use can be significantly enhanced where reliable historical atmospheric ΔCO records can be established. In China, continuous atmospheric ΔCO records since the 1950s are scarce, a period when dramatic variations of ΔCO occurred caused by intensive human activities. In this research, ΔC of Qinghai spruce tree rings collected from Huangzhong (HZ) (36.

Fossil fuel CO traced by radiocarbon in fifteen Chinese cities.

China is an important fossil fuel CO (CO) emitter and the international community is thus concerned with quantifying reductions in Chinese carbon emissions in the recent past. Compared to traditional statistical method, radiocarbon (C) offers a different approach to quantify atmospheric CO derived from fossil fuel emissions. Here, we carry out a multi-year (2011-2016) CO tracing by C in Xi'an, and a three-year (2014-2016) CO tracing in 15 Chinese cities.

Determining diurnal fossil fuel CO and biological CO by ΔCO observation on certain summer and winter days at Chinese background sites.

Diurnal atmospheric ΔCO was measured on two consecutive days in summer and winter, 2016 at Shangdianzi, Lin'an and Luhuitou regional background sites, and at Waliguan global background site in China. The objectives of this study were to determine diurnal fossil fuel CO (CO) and biological CO (CO) concentrations and to ascertain the factors influencing them. Evident CO inputs (0-33.

C-AMS measurements in modern tree rings to trace local fossil fuel-derived CO in the greater Xi'an area, China.

Fossil fuel-derived CO (CO) time series are critical to understanding urban carbon emissions, and to devise strategies to mitigate emission reduction. Using tree ring C archives, we reconstruct an historical CO time series from 1991 to 2015 in the greater Xi'an region, China. CO concentrations from the urban sites reached 22.

Spatial variation of soil properties and carbon under different land use types on the Chinese Loess Plateau.

Land-use affects soil properties and soil carbon storage. Fully understanding land-use impacts on soil is essential to predicting effects on soils from climate change, and providing a scientific basis for soil management. Here, we measured soil properties, soil organic carbon (SOC), soil inorganic carbon (SIC) and total carbon (TC) from 202 samples from cropland, forestland, and grassland, to a depth of 500 cm on the Chinese Loess Plateau (CLP).

Simulations of summertime fossil fuel CO in the Guanzhong basin, China.

Recent studies on fossil fuel CO simulation associated with ΔCO measurements is quite limited, particularly in China. In this study, the fossil fuel CO recently added to the atmosphere (δCOff) over the Guanzhong basin, central China, during summer 2012 is simulated using a modified WRF-CHEM model constrained by measured CO mixing ratio and ΔCO. The model well captures the temporal variation of observed CO mixing ratio and ΔCO, and reasonably reproduces the distribution of observed ΔCO.

Emission characteristics of atmospheric carbon dioxide in Xi'an, China based on the measurements of CO concentration, △C and δC.

Given that cities contributed most of China's CO emissions, understanding the emission characteristics of urban atmospheric CO is critical for regulating CO emissions. Regular observations of atmospheric CO concentration, △C and δC values were performed at four different sites in Xi'an, China in 2016 to illustrate the temporal and spatial variations of CO emissions and recognize their sources and sinks in urban carbon cycles. We found seasonal variations in CO concentration and δC values, the peak to peak amplitude of which was 80.

Atmospheric fossil fuel CO traced by CO and air quality index pollutant observations in Beijing and Xiamen, China.

Radiocarbon (C) is the most accurate tracer available for quantifying atmospheric CO derived from fossil fuel (CO), but it is expensive and time-consuming to measure. Here, we used common hourly Air Quality Index (AQI) pollutants (AQI, PM, PM, and CO) to indirectly trace diurnal CO variations during certain days at the urban sites in Beijing and Xiamen, China, based on linear relationships between AQI pollutants and CO traced by C ([Formula: see text]) for semimonthly samples obtained in 2014. We validated these indirectly traced CO (CO) concentrations against [Formula: see text] concentrations traced by simultaneous diurnal CO observations.

ΔCO from dark respiration in plants and its impact on the estimation of atmospheric fossil fuel CO.

Radiocarbon (C) has been widely used for quantification of fossil fuel CO (CO) in the atmosphere and for ecosystem source partitioning studies. The strength of the technique lies in the intrinsic differences between the C signature of fossil fuels and other sources. In past studies, the C content of CO derived from plants has been equated with the C content of the atmosphere.

Observations of Atmospheric ΔCO at the Global and Regional Background Sites in China: Implication for Fossil Fuel CO Inputs.

Six months to more than one year of atmospheric ΔCO were measured in 2014-2015 at one global background site in Waliguan (WLG) and four regional background sites at Shangdianzi (SDZ), Lin'an (LAN), Longfengshan (LFS) and Luhuitou (LHT), China. The objectives of the study are to document the ΔCO levels at each site and to trace the variations in fossil fuel CO (CO) inputs at regional background sites. ΔCO at WLG varied from 7.

Atmospheric Fossil Fuel CO2 Traced by Δ(14)C in Beijing and Xiamen, China: Temporal Variations, Inland/Coastal Differences and Influencing Factors.

One year of atmospheric Δ(14)CO2 were observed in 2014 in the inland city of Beijing and coastal city of Xiamen, China, to trace temporal CO2ff variations and to determine the factors influencing them. The average CO2ff concentrations at the sampling sites in Beijing and Xiamen were 39.7 ± 36.

The spatial distribution of fossil fuel CO2 traced by Δ(14)C in the leaves of gingko (Ginkgo biloba L.) in Beijing City, China.

Atmospheric fossil fuel CO2 (CO2ff ) information is an important reference for local government to formulate energy-saving and emission reduction in China. The CO2ff spatial distribution in Beijing City was traced by Δ(14)C in the leaves of gingko (Ginkgo biloba L.) from late March to September in 2009.

New alpha-amino phenylalanine tetrazole ligand for immobilized metal affinity chromatography of proteins.

A new chelating compound has been developed for use in the immobilized metal affinity chromatographic (IMAC) separation of proteins. The bidentate ligand, alpha-amino phenylalanine tetrazole, 4, was synthesized via a five-step synthesis from N-fluorenylmethoxycarbonyl phenylalanine and then immobilized onto silica through the epoxide coupling procedure. The binding behavior of the resulting IMAC sorbent, following chelation with Zn2+ to a density of 183 micromol Zn2+ ions/g silica, was characterized by the retention of proteins in the pH range of 5.

Novel tetrazole-functionalized ion exchanger for weak cation-exchange chromatography of proteins.

A new type of weak cation exchanger, tetrazole-functionalized silica, was developed for bioseparation. It was prepared conveniently by modifying silica gel initially with gamma-glycidoxypropyltrimethoxysilane, then with 3-hydroxypropionitrile and finally with ammonium-catalyzed (3+2) azide-nitrile cycloaddition, which is an element of click chemistry. The prepared stationary phase was characterized and evaluated for its separation performance, protein retention behavior, loading capacity, protein recovery and chemical stability.