State Key Laboratory of Biogeology and Environmental Geology

Kobresia (syn. Carex) pygmaea dominated pastures in the eastern Tibetan highlands are the world's largest pastoral alpine ecosystem forming a durable turf cover at 3000-6000 m a.s.l. Kobresia's resilience and competitiveness is based on dwarf habit, predominantly below-ground allocation of photo assimilates, mixture of seed production and clonal growth, and high genetic diversity. Kobresia growth is co-limited by livestock-mediated nutrient withdrawal and, in the drier parts of the plateau, low rainfall during the short and cold growing season. Overstocking has caused pasture degradation and soil deterioration over most parts of the Tibetan highlands and is the basis for this man-made ecosystem. Natural autocyclic processes of turf destruction and soil erosion are initiated through polygonal turf cover cracking, and accelerated by soil-dwelling endemic small mammals in the absence of predators. The major consequences of vegetation cover deterioration include the release of large amounts of C, earlier diurnal formation of clouds, and decreased surface temperatures. These effects decrease the recovery potential of Kobresia pastures and make them more vulnerable to anthropogenic pressure and climate change. Traditional migratory rangeland management was sustainable over millennia, and possibly still offers the best strategy to conserve and possibly increase C stocks in the Kobresia turf.

N values in the shallow aquitard exhibited a wide range from -1.8 to +9.4‰, owing to various sources. Two types of water in the shallow aquitard could be identified: (1) type-1 water with relatively longer residence time was similar to those in the aquifer where ammonium was mainly sourced from organic N mineralization; (2) type-2 water with shorter residence time was jointly affected by surface input, chemical attenuation and mineralization of organic N. The aquitard prevents prompt ammonium exchange between the surface and aquifer, and the shallower part of the aquitard provides a sufficient reaction time and an active reaction rate for ammonium removal.

Levoglucosan (LG) emitted from non-biomass burning (non-BB) sources has given rise to biased or even unreasonable source identification results when adopting LG as a distinct marker of biomass burning (BB). The estimation of LG emission and its spatiotemporal variation for various sources are the keys to reducing uncertainty. This study first developed a LG emission inventory for China from 25 sub-type sources belonging to eight categories, with a 3 km × 3 km spatial resolution and monthly distribution. The total LG emission in 2014 was 145.7 Gg. Domestic BB and open BB contributed 39.2 and 34.3% of the total emission. Non-BB sources, including municipal solid waste burning (9.7%), firework burning (9.6%), meat cooking (5.4%), domestic coal burning (1.5%), ritual item burning (0.2%), and industrial coal burning (0.1%), contributed to 26.5% of the total emission. LG emission varied spatially and temporally. Non-BB sources have a significant spatiotemporal impact on BB source contributions, even in high BB emission regions or in sowing, harvesting, and winter heating seasons. The local BB contributions have been substantially overestimated by 4.28-369% in previous studies, wherein LG was solely referred to as the BB source. By 2018, LG emission from BB might decrease to 63.9% of its total emission. This high-resolution LG emission inventory can be greatly useful for source identification studies in China. It also supports future research on the modeling of smoke aging and pollution control.

Highly efficient blue-green tunable emission from Ce³⁺/Eu²⁺ to Tb³⁺ and single-phase white emission from Ce³⁺, Mn²⁺-doped Ca₅(PO₄)₃Cl can be obtained by dipole–quadrupole energy transfers.

Linking groundwater quality to health will make the invisible groundwater visible, but there are knowledge gaps to understand the linkage which requires cross-disciplinary convergent research. The substances in groundwater that are critical to health can be classified into five types according to the sources and characteristics: geogenic substances, biogenic elements, anthropogenic contaminants, emerging contaminants, and pathogens. The most intriguing questions are related to quantitative assessment of human health and ecological risks of exposure to the critical substances via natural or induced artificial groundwater discharge: What is the list of critical substances released from discharging groundwater, and what are the pathways of the receptors' exposure to the critical substances? How to quantify the flux of critical substances during groundwater discharge? What procedures can we follow to assess human health and ecological risks of groundwater discharge? Answering these questions is fundamental for humans to deal with the challenges of water security and health risks related to groundwater quality. This perspective provides recent progresses, knowledge gaps, and future trends in understanding the linkage between groundwater quality and health.

In this study, a highly sensitive liquid electrode discharge atomic emission source was developed for the determination of Cd and Zn in aqueous solutions.

High levels of geogenic ammonium in groundwater is a highly neglected nitrogen pool in coastal aquatic systems. Although organic matter (OM) mineralization is known to significantly influence geogenic ammonium enrichment, the detailed mechanism underlying ammonium enrichment based on dissolved organic matter (DOM) characterization in coastal aquifer systems remains unclear. In this study, we characterized the optical and molecular signatures of DOM coupled with hydrogeochemistry and multiple isotopes (H/O/C/N) to elucidate in detail the mechanisms underlying the anomalously high ammonium in the coastal confined aquifer system of the Pearl River Delta, which exhibits the highest reported geogenic ammonium concentration in groundwater on the Earth. We identified three DOM fluorescent components, a marine humic-like component (C1) and two other humic-like components (C2 and C3). The autochthonous OM was first processed to the C1 component, which was further transformed to C2 and C3 components. In terms of molecular classes, the processing pathway from bacterial- or algal-derived OM to aliphatic compounds and highly unsaturated-low O compounds was identified, and highly unsaturated-low O compounds were accumulated as the main products. Compounds containing two or three N atoms were processed, and compounds with one N atom gradually accumulated, which was further degraded into CHO compounds. The ammonium (up to 179 mg/L as N) was gradually enriched due to the decomposition of CHO+3N to CHO+2N, CHO+1N, and CHO compounds. Owing to the longer residence time and less frequent fresh water flushing, the produced ammonium was retained in the aquifer as a "long-term result". The contrasting DOM characteristics, together with the differing depositional and hydrogeological conditions, give rise to the higher levels of geogenic ammonium in coastal confined aquifer systems compared with inland alluvial-lacustrine confined aquifer systems. To our knowledge, this is the first study to characterize DOM and its relationship with geogenic ammonium in coastal aquifer systems.

A synergetic effect of a mutual activation system enhancing the photo-oxidation and reduction ability of a C-BMO heterojunction.

Studies focusing on seasonal dynamics of microbial communities in terrestrial and marine environments are common; however, little is known about seasonal dynamics in high-temperature environments. Thus, our objective was to document the seasonal dynamics of both the physicochemical conditions and the microbial communities inhabiting hot springs in Tengchong County, Yunnan Province, China. The PhyloChip microarray detected 4882 operational taxonomic units (OTUs) within 79 bacterial phylum-level groups and 113 OTUs within 20 archaeal phylum-level groups, which are additional 54 bacterial phyla and 11 archaeal phyla to those that were previously described using pyrosequencing. Monsoon samples (June 2011) showed increased concentrations of potassium, total organic carbon, ammonium, calcium, sodium and total nitrogen, and decreased ferrous iron relative to the dry season (January 2011). At the same time, the highly ordered microbial communities present in January gave way to poorly ordered communities in June, characterized by higher richness of Bacteria, including microbes related to mesophiles. These seasonal changes in geochemistry and community structure are likely due to high rainfall influx during the monsoon season and indicate that seasonal dynamics occurs in high-temperature environments experiencing significant changes in seasonal recharge. Thus, geothermal environments are not isolated from the surrounding environment and seasonality affects microbial ecology.

Bismuth based semiconductor photocatalysts are being generated as promising materials for photocatalysis. In this work, hydrothermal methods have been utilized to synthesize a bismuth oxyiodide semiconductor with deposited Bi nanodots (Bi-BiOI), which could create oxygen defects and accelerate photoinduced charge migration simultaneously. The resulting Bi-BiOI strongly demonstrates the high photocatalytic performance for bisphenol A and methylene blue degradation under visible light. 86% of BPA was degraded after an irradiation time of 4 hours. Electrospray ionization mass spectrometry was employed to detect the evolution of intermediates formed during the decomposition process of bisphenol A, and the following results suggested complete bisphenol A mineralization. Additionally, electron paramagnetic resonance results revealed the production of free radicals and the presence of oxygen vacancies. Furthermore, a distinctively increased photocurrent response and photoluminescence decay dynamics demonstrate that the interface between the Bi nanodots and BiOI semiconductor promotes the separation and migration of photoinduced electron-hole pairs. The lower valence band value (2.57 eV) of Bi-BiOI presented a higher oxidation potential, thus the production of hydroxyl radicals could be promoted considerably. Based on the experimental results, factors such as oxygen vacancies, effective charge migration, suppressed photoinduced electron-hole pair recombination and a high Bi-BiOI oxidation potential would result in advanced free radical production capacity, thereby enhancing the photocatalytic efficiency. The findings of our work will contribute to the fabrication of metal nanodot deposited semiconductor photocatalysts and pave the way for the utilization of advanced oxidation technology.

Novel K⁺ and cyano group decorated g-C₃N₄ hollow tubes were constructed <italic>via</italic> a facile one-step molten salt assisted strategy.

The Nanhua basin in South China hosts well-preserved middle–late Neoproterozoic sedimentary and volcanic rocks that are critical for studying the basin evolution, the breakup of the supercontinent Rodinia, the nature and dynamics of the “snowball” Earth and diversification of metazoans. Establishing a stratigraphic framework is crucial for better understanding the interactions between tectonic, paleoclimatic and biotic events recorded in the Nanhua basin, but existing stratigraphic correlations remain debated, particularly for pre-Ediacaran strata. Here we report new Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICPMS) U-Pb zircon ages from the middle and topmost Wuqiangxi Formation (the upper stratigraphic unit of the Banxi Group) in Siduping, Hunan Province, South China. Two samples show similar age distribution, with two major peaks at ca. 820 Ma and 780 Ma and one minor peak at ca. 910 Ma, suggesting that the Wuqiangxi sandstone was mainly sourced from Neoproterozoic rocks. Two major age peaks correspond to two phases of magmatic events associated with the rifting of the Nanhua basin, and the minor peak at ca. 910 Ma may correspond to the Shuangxiwu volcanic arc magmatism, which represents pre-collision/amalgamation subduction on the southeastern margin of the Yangtze Block. The youngest zircon group from the topmost Wuqiangxi Formation has a weighted mean age of 714.6 ± 5.2 Ma, which is likely close to the depositional age of the uppermost Banxi Group. This age, along with the ages reported from other sections, constrains that the Banxi Group was deposited between ca. 820 Ma and ca. 715 Ma. The age of 714.6 ± 5.2 Ma from the top of the Wuqiangxi Formation is indistinguishable with the SIMS U-Pb age of 715.9 ± 2.8 Ma from the upper Gongdong Formation in the Sibao village section of northern Guangxi, South China. It is also, within uncertainties, overlapped with two TIMS U-Pb ages from pre-Sturtian strata in Oman and Canada. These ages indicate that the Jiangkou (Sturtian) glaciation in South China started at ca. 715 Ma instead of ca. 780 Ma and support a globally synchronous initiation of the Sturtian glaciation at ca. 715 Ma.

Non-ionic surfactants (NISs) were used to improve the performance of dielectric barrier discharge plasma induced vapor generation (DBD plasma-CVG).

Paleotemperature proxy data form the cornerstone of paleoclimate research and are integral to understanding the evolution of the Earth system across the Phanerozoic Eon. Here, we present PhanSST, a database containing over 150,000 data points from five proxy systems that can be used to estimate past sea surface temperature. The geochemical data have a near-global spatial distribution and temporally span most of the Phanerozoic. Each proxy value is associated with consistent and queryable metadata fields, including information about the location, age, and taxonomy of the organism from which the data derive. To promote transparency and reproducibility, we include all available published data, regardless of interpreted preservation state or vital effects. However, we also provide expert-assigned diagenetic assessments, ecological and environmental flags, and other proxy-specific fields, which facilitate informed and responsible reuse of the database. The data are quality control checked and the foraminiferal taxonomy has been updated. PhanSST will serve as a valuable resource to the paleoclimate community and has myriad applications, including evolutionary, geochemical, diagenetic, and proxy calibration studies.

A sensitive assay for detection of HIV-1 p24 antigen by ICP-MS was developed using a streptavidin–biotin system and Au nanoparticles based immunoassay.

Continuous cropping often leads to an unbalanced soil microbial community, which in turn negatively affects soil functions. However, systematic research of how these effects impact the bacterial composition, microbial functional traits, and soil metabolites is lacking. In the present study, the rhizosphere soil samples of Tibetan barley continuously monocropped for 2 (CCY02), 5 (CCY05), and 10 (CCY10) years were collected. By utilizing 16S high-throughput sequencing, untargeted metabolomes, and quantitative microbial element cycling smart chips, we examined the bacterial community structure, soil metabolites, and bacterial functional gene abundances, respectively. We found that bacterial richness (based on Chao1 and Phylogenetic Diversity [PD] indices) was significantly higher in CCY02 and CCY10 than in CCY05. As per principal component analysis (PCA), samples from the continuous monocropping year tended to share more similar species compositions and soil metabolites, and exhibited distinct patterns over time. The results of the Procrustes analysis indicated that alterations in the soil metabolic profiles and bacterial functional genes after long-term continuous cropping were mainly mediated by soil microbial communities ( P &lt; 0.05). Moreover, 14 genera mainly contributed to the sample dissimilarities. Of these, five genera were identified as the dominant shared taxa, including Blastococcus , Nocardioides , Sphingomonas , Bacillus , and Solirubrobacter . The continuous cropping of Tibetan barley significantly increased the abundances of genes related to C-degradation ( F = 9.25, P = 0.01) and P-cycling ( F = 5.35, P = 0.03). N-cycling significantly negatively correlated with bacterial diversity ( r = − 0.71, P = 0.01). The co-occurrence network analysis revealed that nine hub genera correlated with most of the functional genes and a hub taxon, Desulfuromonadales, mainly co-occurred with the metabolites via both negative and positive correlations. Collectively, our findings indicated that continuous cropping significantly altered the bacterial community structure, functioning of rhizosphere soils, and soil metabolites, thereby providing a comprehensive understanding of the effects of the long-term continuous cropping of Tibetan barley.

The effect of the DS ratio is evaluated and a correction approach is proposed to improve the accuracy and robustness of the proposed DS Cd isotope analysis.

An Fe(<sc>ii</sc>)-based metal organic framework, α-ferrous oxalate dihydrate (α-FOD), with remarkable n-type semiconductor characteristics has been successfully prepared for use as a bifunctional catalyst in both photocatalysis and Fenton oxidation.

Nonmarine strata of Cretaceous age are well developed in North China.Their chronostratigraphic division and correlation with marine successions are a matter of intense debate in Cretaceous research.Lower Cretaceous strata have been well studied in northern Hebei and western Liaoning provinces,and the Upper Cretaceous is well developed in the Songliao area.These provide the reference sections to establish terrestrial Cretaceous stages in China.Correlation with the international geological time scale shows that the Jurassic-Cretaceous boundary is possibly placed in the upper Tuchengzi Formation,the Upper-Lower Cretaceous boundary is at the base of Quantou Formation,and the top Cretaceous boundary is in the upper part of the second member of the Mingshui Formation.Based on the distribution of nonmarine Cretaceous strata in the North China,the terrestrial Cretaceous chronostratigraphy can be subdivided into,in ascending order,the Jibeian,Jeholian and Liaoxian stages of Lower Cretaceous,and the Nonganian,Songhuajiangian,and Suihuanian stages of Upper Cretaceous.The bottom age of these stages is estimated at 145.5Ma,130Ma,119Ma,99.6Ma,86.1Ma,and 79.1Ma,respectively.

A low power (∼10 W), miniaturized atmospheric pressure glow discharge (APGD) source was coupled with a hydride generation (HG) system for sensitive determination of antimony in water samples with atomic emission spectrometry (AES).