39 research outputs found

    Impacts of groundwater depth on regional scale soil gleyization under changing climate in the Poyang Lake Basin, China

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    This manuscript version is made available under the CC-BY-NC-ND 4.0 license: http://creativecommons.org/licenses/by-nc-nd/4.0/ which permits use, distribution and reproduction in any medium, provided the original work is properly cited. This author accepted manuscript is made available following 24 month embargo from date of publication (November 2018) in accordance with the publisher’s archiving policyVarious natural and anthropogenic factors affect the formation of gleyed soil. It is a major challenge to identify the key hazard factors and evaluate the dynamic evolutionary process of soil gleyization at a regional scale under future climate change. This study addressed this complex challenge based on regional groundwater modelling for a typical agriculture region located in the Ganjiang River Delta (GRD) of Poyang Lake Basin, China. We first implemented in-situ soil sampling analysis and column experiments under different water depths to examine the statistical relationship between groundwater depth (GD) and gleyization indexes including active reducing substance, ferrous iron content, and redox potential. Subsequently, a three-dimensional groundwater flow numerical model for the GRD was established to evaluate the impacts of the historical average level and future climate change on vadose saturation and soil gleyization (averaged over 2016–2050) in the irrigated farmland. Three climate change scenarios associated with carbon dioxide emission (A1B, A2, and B1) were predicted by the ECHAM5 global circulation model published in IPCC Assessment Report (2007). The ECHAM5 outputs were applied to quantify the variation of groundwater level and to identify the potential maximum gleyed zones affected by the changes of meteorological and hydrological conditions. The results of this study indicate that GD is an indirect indicator for predicting the gradation of soil gleyization at the regional scale, and that the GRD will suffer considerable soil gleyization by 2050 due to fluctuations of the water table induced by future climate changes. Compared with the annually average condition, the climate scenario B1 will probably exacerbate soil gleyization with an 8.8% increase in total gleyed area in GRD. On average, the highly gleyed areas will increase in area by 29.7 km2, mainly on the riverside area, and the medium-slightly gleyed area will increase by 19.2 km2 in the middle region.This work was partially supported by the National Key R&D Program of China (No. 2016YFC0402800), the National Natural Science Foundation of China (Nos. 41772254, 41502226, and 41402198), and the Fundamental Research Funds for the Central Universities (No. 2018B18714). We are grateful to Jiangxi Institute of Survey and Design, who provides the detailed hydrogeological data of PLB for establishing three-dimensional groundwater flow model. Yun Yang gratefully acknowledges financial support from China Scholarship Council (CSC No. 201706715023) during the visit to National Centre for Groundwater Research and Training (NCGRT), Australia. Behzad Ataie-Ashtiani and Craig T. Simmons acknowledge support from the National Centre for Groundwater Research and Training, Australia

    Chemical synthesis of lactic acid from cellulose catalysed by lead(II) ions in water

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    该工作是博士生王炎良(实验)和王斌举(理论)以及邓卫平博士紧密合作的成果。The direct transformation of cellulose, which is the main component of lignocellulosic biomass, into building-block chemicals is the key to establishing biomass-based sustainable chemical processes. Only limited successes have been achieved for such transformations under mild conditions. Here we report the simple and efficient chemocatalytic conversion of cellulose in water in the presence of dilute lead(II) ions, into lactic acid, which is a high-value chemical used for the production of fine chemicals and biodegradable plastics. The lactic acid yield from microcrystalline cellulose and several lignocellulose-based raw biomasses is >60% at 463 K. Both theoretical and experimental studies suggest that lead(II) in combination with water catalyses a series of cascading steps for lactic acid formation, including the isomerization of glucose formed via the hydrolysis of cellulose into fructose, the selective cleavage of the C3–C4 bond of fructose to trioses and the selective conversion of trioses into lactic acid.该项研究工作得到国家自然科学基金委、科技部和教育部创新研究团队项目的资助

    A Stochastic Deterioration Process Based Approach for Micro Switches Remaining Useful Life Estimation

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    Real-time prediction of remaining useful life (RUL) is one of the most essential works in prognostics and health management (PHM) of the micro-switches. In this paper, a linear degradation model based on an inverse Kalman filter to imitate the stochastic deterioration process is proposed. First, Bayesian posterior estimation and expectation maximization (EM) algorithm are used to estimate the stochastic parameters. Second, an inverse Kalman filter is delivered to solve the errors in the initial parameters. In order to improve the accuracy of estimating nonlinear data, the strong tracking filtering (STF) method is used on the basis of Bayesian updating Third, the effectiveness of the proposed approach is validated on an experimental data relating to micro-switches for the rail vehicle. Additionally, it proposes another two methods for comparison to illustrate the effectiveness of the method with an inverse Kalman filter in this paper. In conclusion, a linear degradation model based on an inverse Kalman filter shall deal with errors in RUL estimation of the micro-switches excellently

    Identification and Expression Profile of Chemosensory Receptor Genes in Aromia bungii (Faldermann) Antennal Transcriptome

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    The red-necked longicorn beetle, Aromia bungii (Faldermann) (Coleoptera: Cerambycidae), is a major destructive, wood-boring pest, which is widespread throughout the world. The sex pheromone of A. bungii was reported earlier; however, the chemosensory mechanism of the beetle remains almost unknown. In this study, 45 AbunORs, 6 AbunGRs and 2 AbunIRs were identified among 42,197 unigenes derived from the antennal transcriptome bioinformatic analysis of A. bungii adults. The sequence of putative Orco (AbunOR25) found in this study is highly conserved with the known Orcos from other Coleoptera species, and these Orco genes might be potentially used as target genes for the future development of novel and effective control strategies. Tissue expression analysis showed that 29 AbunOR genes were highly expressed in antennae, especially in the antennae of females, which was consistent with the idea that females might express more pheromone receptors for sensing pheromones, especially the sex pheromones produced by males. AbunOR5, 29, 31 and 37 were clustered with the pheromone receptors of the cerambycid Megacyllene caryae, suggesting that they might be putative pheromone receptors of A. bungii. All six AbunGRs were highly expressed in the mouthparts, indicating that these GRs may be involved in the taste perception process. Both AbunIRs were shown to be female-mouthparts-biased, suggesting that they might also be related to the tasting processes. Our study provides some basic information towards a deeper understanding of the chemosensing mechanism of A. bungii at a molecular level

    Identification of expressed resistance gene analogs (RGA) and development of RGA-SSR markers in tobacco

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    Tobacco is an important cash crop and an ideal experimental system for studies of plant-pathogen interactions. Identification of tobacco resistance (R) genes and resistance gene analogs (RGAs) is propitious to elucidate the underlying resistant mechanisms. In recent years, the public tobacco EST (expressed sequence tags) data set, which provides a rich source for identifying expressed RGAs, has enlarged substantially. In this study, 149606 Uni-ESTs were assembled from 412325 tobacco ESTs available in GenBank, scanned with 112 published plant R-genes protein sequences, and 1113 Nicotiana (tobacco) RGAs (NtRGAs) were identified. The majority of them comprised the common R-genes domains, such as NBS-LRR, LRR-PK, LRR, PK and Mlo, while we were unable to identify 109 RGAs using published domains of R-genes. Upon sequence alignment, 1079 NtRGAs were allocated on 712 loci within the Nicotiana benthamiana genome. A total of 78 simple sequence repeats (SSRs) were identified from 72 NtRGAs, and out of 64 newly designed primer pairs, 54 primer pairs generated clear bands upon PCR amplification using tobacco genomic DNA. Only nine primer pairs displayed polymorphism in 24 varieties of tobacco, with 2-4 alleles per locus (2.56 alleles on average), while 41 primer pairs were able to detect polymorphisms in six wild species of genus Nicotiana, with 2-4 alleles per locus (2.61 alleles on average)

    Complete genomic sequence and comparative analysis of the genome segments of sweet potato chlorotic stunt virus in China.

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    BACKGROUND:Sweet potato chlorotic stunt virus (family Closteroviridae, genus Crinivirus) features a large bipartite, single-stranded, positive-sense RNA genome. To date, only three complete genomic sequences of SPCSV can be accessed through GenBank. SPCSV was first detected from China in 2011, only partial genomic sequences have been determined in the country. No report on the complete genomic sequence and genome structure of Chinese SPCSV isolates or the genetic relation between isolates from China and other countries is available. METHODOLOGY/PRINCIPAL FINDINGS:The complete genomic sequences of five isolates from different areas in China were characterized. This study is the first to report the complete genome sequences of SPCSV from whitefly vectors. Genome structure analysis showed that isolates of WA and EA strains from China have the same coding protein as isolates Can181-9 and m2-47, respectively. Twenty cp genes and four RNA1 partial segments were sequenced and analyzed, and the nucleotide identities of complete genomic, cp, and RNA1 partial sequences were determined. Results indicated high conservation among strains and significant differences between WA and EA strains. Genetic analysis demonstrated that, except for isolates from Guangdong Province, SPCSVs from other areas belong to the WA strain. Genome organization analysis showed that the isolates in this study lack the p22 gene. CONCLUSIONS/SIGNIFICANCE:We presented the complete genome sequences of SPCSV in China. Comparison of nucleotide identities and genome structures between these isolates and previously reported isolates showed slight differences. The nucleotide identities of different SPCSV isolates showed high conservation among strains and significant differences between strains. All nine isolates in this study lacked p22 gene. WA strains were more extensively distributed than EA strains in China. These data provide important insights into the molecular variation and genomic structure of SPCSV in China as well as genetic relationships among isolates from China and other countries
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