Showing papers by "Min Xu published in 2019"
TL;DR: Very different half-lives of ARGs and mobile genetic elements from farm manure and commercial manure were observed in both soils, and composting decreased abundance of most ARGs in manure, but increased the persistence of manure-introduced ARG in soil irrespective of fertilization history.
35 citations
TL;DR: This work presents the measurement of BC concentration from six lake sediments in the HTP to reconstruct historical BC deposition since the pre-industrial era and shows an increasing trend of BC concurrent with increased anthropogenic emission patterns after the commencement of the industrialization era during the 1950s.
Abstract: Black carbon (BC) is one of the major drivers of climate change, and its measurement in different environment is crucial for the better understanding of long-term trends in the Himalayan–Tibetan Plateau (HTP) as climate warming has intensified in the region. We present the measurement of BC concentration from six lake sediments in the HTP to reconstruct historical BC deposition since the pre-industrial era. Our results show an increasing trend of BC concurrent with increased anthropogenic emission patterns after the commencement of the industrialization era during the 1950s. Also, sedimentation rates and glacier melt strengthening influenced the total input of BC into the lake. Source identification, based on the char and soot composition of BC, suggests biomass-burning emissions as a major contributor to BC, which is further corroborated by open-fire occurrence events in the region. The increasing BC trend continues to recent years, indicating increasing BC emissions, mainly from South Asia.
35 citations
TL;DR: In this article, the authors proposed an effective and universal method to improve thermal-transport properties at the interface between multilayer graphene and water by grafting functionalized groups onto graphene.
Abstract: Highly efficient thermal transport between graphene and water is crucial in applications such as microscopic heat dissipation, solar steam generation, sea-water desalination, and thermally conductive composites. However, a practical approach for enhancing thermal transport across graphene–water interfaces is lacking. We propose an effective and universal method to improve thermal-transport properties at the interface between multilayer graphene and water by a factor of ∼4 by grafting functionalized groups onto graphene. The most improved interfacial thermal conductance was 121.0 ± 11.4 MW m−2 K−1. This design is compatible with industrial processes. We also undertook molecular-level analyses to unveil the underlying mechanism for heat-transport enhancement. This study could provide new approaches for engineering heat transport across two-dimensional materials and water interfaces.
18 citations
TL;DR: In this paper, the authors analyzed the impacts of climate change on the water budget for the upstream of the Shule River Basin on the northeast Tibetan Plateau, and suggested that the impact of warming will overcome the effect of precipitation increase on run-off in the study area.
Abstract: Glacial retreat and the thawing of permafrost due to climate warming have altered the hydrological cycle in cryospheric-dominated watersheds. In this study, we analysed the impacts of climate change on the water budget for the upstream of the Shule River Basin on the northeast Tibetan Plateau. The results showed that temperature and precipitation increased significantly during 1957–2010 in the study area. The hydrological cycle in the study area has intensified and accelerated under recent climate change. The average increasing rate of discharge in the upstream of the Shule River Basin was 7.9 × 10 6 m 3 /year during 1957–2010. As the mean annual glacier mass balance lost −62.4 mm/year, the impact of glacier discharge on river flow has increased, especially after the 2000s. The contribution of glacier melt to discharge was approximately 187.99 × 10 8 m 3 or 33.4% of the total discharge over the study period. The results suggested that the impact of warming overcome the effect of precipitation increase on run-off increase during the study period. The evapotranspiration (ET) increased during 1957–2010 with a rate of 13.4 mm/10 years. On the basis of water balance and the Gravity Recovery and Climate Experiment and the Global Land Data Assimilation System data, the total water storage change showed a decreasing trend, whereas groundwater increased dramatically after 2006. As permafrost has degraded under climate warming, surface water can infiltrate deep into the ground, thus changing both the watershed storage and the mechanisms of discharge generation. Both the change in terrestrial water storage and changes in groundwater have had a strong control on surface discharge in the upstream of the Shule River Basin. Future trends in run-off are forecasted based on climate scenarios. It is suggested that the impact of warming will overcome the effect of precipitation increase on run-off in the study area. Further studies such as this will improve understanding of water balance in cold high-elevation regions.
17 citations
TL;DR: The results show that nestedness of diatom communities can provide an additional metric for evaluating lake ecosystem health in this region and show that species turnover is typically the dominant component of β-diversity and that the influence of nestedness is generally low.
17 citations
TL;DR: It is confirmed that the responses of soil bacterial communities to the same biochar were specific to both soil type and bacterial phylum, especially those phyla present at low abundances.
Abstract: In this study, the responses of soil bacterial communities to biochar amendment in different soils were investigated. Biochar amendment had not significantly changed the bacterial richness and diversity in black soil, fluvo-aquic soil and red soil, but shifted all the soil bacterial community structures. Biochar amendment mainly increased the growth of low-abundance bacteria in fluvo-aquic soil and that of high-abundance bacteria in red soil. The most abundant bacterial phylum in black soil and fluvo-aquic soil, Proteobacteria, increased after biochar addition, while Chloroflexi, the most abundant phylum in red soil, decreased after biochar addition. Some bacterial phyla responded consistently to biochar amendment. However, many more bacterial phyla responded differently to biochar amendment in different soils, especially those phyla present at low abundances. Therefore, our study confirmed that the responses of soil bacterial communities to the same biochar were specific to both soil type and bacterial phylum.
15 citations
TL;DR: An effective agronomic strategy to reduce the bioavailability of polybrominated diphenyl ethers (PBDEs) in a soil used to grow high value vegetable crops shows promise as a practical method to support horticultural production systems, remediate soils, and help to ensure food safety.
8 citations
TL;DR: In this paper, the triterpenoid acids were identified from E. japonica for the first time using extensive spectral methods, among which compounds 1, 2, and 4 were isolated.
Abstract: The leaves of Eriobotrya japonica (Thunb.) Lindl. (Rosaceae) were commonly recognized as a traditional Chinese medicine (TCM) to treat various skin diseases and diabetes mellitus. Phytochemical investigations on the leaves of E. japonica revealed their predominant secondary metabolites as triterpenoids including triterpenoid acids [1]. Our previous study showed that triterpenoid acids can decrease the excitability of cortical pyramidal neurons and acts in epilepsy [2]. In our ongoing search for novel and bioactive triterpenoid acids, a detail chemical investigation on the dried leaves of E. japonica was carried out. As a result, 13 triterpenoid acids were isolated and identified on the basis of extensive spectral methods, among which compounds 1, 2, and 4 were isolated from E. japonica for the first time. The air-dried and powdered leaves of E. japonica (10.0 kg) were extracted with MeOH (50 L × 3) under reflux conditions at 70°C, three hours each time. After removal of the organic solvent under reduced pressure, the extract (1.0 kg) was suspended in H2O (4 L), and then successively partitioned with petroleum ether, EtOAc, and n-BuOH. The n-BuOH fraction (100 g) was subjected to silica gel column chromatography (CC) (CHCl3–MeOH, 1:0–0:1) to afford four fractions, Frs.A–D. Fraction A (15 g) was subjected to CC over silica gel (petroleum ether–acetone, 10:1–1:9) and Sephadex LH-20 (MeOH) and then purified by semipreparative HPLC with a C18 column (MeOH–H2O, 1:1–1:0) to afford compounds 1 (17 mg), 2 (16 mg), 3 (40 mg), 4 (30 mg), 5 (200 mg), 6 (150 mg), 7 (100 mg), 8 (32 mg), 9 (20 mg), 10 (23 mg), 11 (25 mg), 12 (11 mg), and 13 (14 mg). 3β-O-cis-p-Coumaroyl-2α-hydroxy-12-ursen-28-oic Acid (1). C39H54O6, white amorphous powder. ESI-MS m/z 617 [M – H]–. 1H NMR (400 MHz, pyridine-d5, δ, ppm, J/Hz): 0.99 (3H, s, Me-23), 0.95 (3H, s, Me-24), 0.94 (3H, s, Me-25), 1.03 (3H, s, Me-26), 1.17 (3H, s, Me-27), 1.07 (3H, d, J = 6.4, Me-29), 1.03 (3H, d, J = 6.1, Me-30), 6.08 (1H, d, J = 12.0, H-2′), 6.92 (1H, d, J = 12.0, H-3′), 7.14 (2H, d, J = 8.0, H-9′, 5′), 8.13 (2H, d, J = 8.0, H-8′, 6′), 5.43 (1H, m, H-12), 5.20 (1H, m, H-3), 4.22 (1H, m, H-2) [3]. Jacoumaric Acid (2). C39H54O6, white amorphous powder. ESI-MS m/z 617 [M – H] –. 1H NMR (500 MHz, pyridine-d5, δ, ppm, J/Hz): 0.96 (3H, s, Me-23), 0.94 (3H, s, Me-24), 0.95 (3H, s, Me-25), 1.02 (3H, s, Me-26), 1.21 (3H, s, Me-27), 1.05 (3H, d, J = 6.5, Me-29), 1.03 (3H, d, J = 6.3, Me-30), 6.67 (1H, d, J = 16.0, H-2′), 7.99 (1H, d, J = 16.0, H-3′), 7.17 (2H, d, J = 8.5, H-9′, 5′), 7.55 (2H, d, J = 8.5, H-8′, 6′), 5.44 (1H, s, H-12), 5.25 (1H, m, H-3), 4.09 (1H, m, H-2) [3]. 3-O-trans-Feruloyl Euscaphic Acid (3). C40H56O8, white amorphous powder. ESI-MS m/z 663 [M – H] –. 1H NMR (400 MHz, pyridine-d5, δ, ppm, J/Hz): 0.92 (3H, s, Me-23), 0.78 (3H, s, Me-24), 0.93 (3H, s, Me-25), 0.86 (3H, s, Me-26), 1.27 (3H, s, Me-27), 1.19 (3H, s, Me-29), 0.98 (3H, d, J = 6.5, Me-30), 6.71 (1H, d, J = 15.8, H-2′), 8.00 (1H, d, J = 15.8, H-3′), 5.57 (1H, s, H-12), 5.25 (1H, m, H-3), 4.39 (1H, m, H-2) [4]. 2α,3α,19α,23-Tetrahydroxy-12-ursen-28-oic Acid (4). C30H48O6, white amorphous powder. ESI-MS m/z 503 [M – H]–. 1H NMR (600 MHz, pyridine-d5, δ, ppm, J/Hz): 1.05 (3H, s, Me-24), 0.88 (3H, s, Me-25), 1.11 (3H, s, Me-26), 1.68 (3H, s, Me-27), 1.40 (3H, s, Me-29), 1.13 (3H, d, J = 6.1, Me-30), 5.57 (1H, s, H-12), 4.32 (1H, m, H-2), 3.74 (1H, m, H-3), 3.07 (1H, m, H-18), 3.77 (1H, d, J = 10.8, H-23α), 3.94 (1H, d, J = 10.8, H-23β) [5].
3 citations