Direct Photocatalytic Methane Oxidation to Formaldehyde by N Doping Co-Decorated Mixed Crystal TiO2.

In this paper, N-doped TiO2 mixed crystals are prepared via direct calcination of TiN for highly selective oxidation of CH4 to HCHO at room temperature. The structures of the prepared TiO2 samples are characterized to be N-doped TiO2 of anatase and rutile mixed crystals. The crystal structures of TiO2 samples are determined by XRD spectra and Raman spectra, while N doping is demonstrated by TEM mapping, ONH inorganic element analysis, and high-resolution XPS results. Significantly, the production rate of HCHO is as high as 23.5 mmol·g-1·h-1 with a selectivity over 90%. Mechanism studies reveal that H2O is the main oxygen source and acts through the formation of ·OH. DFT calculations indicate that the construction of a mixed crystal structure and N-doping modification mainly act by increasing the adsorption capacity of H2O. An efficient photocatalyst was prepared by us to convert CH4 to HCHO with high yield and selectivity, greatly promoting the development of the photocatalytic CH4 conversion study.

Development of an on-site diagnostic LAMP assay for rapid differentiation of the invasive pest Phthorimaea absoluta (Meyrick) using insect tissues.

BACKGROUND: The tomato leafminer, Phthorimaea absoluta (Meyrick) (Lepidoptera: Gelechiidae), is a destructive invasive pest that originated in South America and has spread within China since 2017. A rapid method for on-site identification of P. absoluta is urgently needed for interception of this pest across China. RESULTS: We developed a loop-mediated isothermal amplification (LAMP) technique to differentiate P. absoluta from Liriomyza sativae, Chromatomyia horticola, and Phthorimaea operculella using extracted genomic DNA, which was then refined to create an on-site LAMP diagnostic method that can be performed under field conditions without the need for laboratory equipment. CONCLUSION: In the present research, we developed an on-site diagnostic method for rapid differentiation of P. absoluta from other insects with similar morphology or damage characteristics in China. © 2024 Society of Chemical Industry.

Temporal and spatial variations and influencing factors of gross primary productivity in Changbai Mountain Nature Reserve, China.

Changbai Mountain Nature Reserve (CNR) is a typical temperate forest ecosystem, and gross primary production (GPP) of which is closely related to topography and climate change. Research on the spatio-temporal variations and influencing factors of GPP in the CNR is of great significance for assessing growth status of vegetation and the quality of ecological environment. We calculated GPP in CNR using the vegetation photosynthesis model (VPM), and analyzed the influences of slope, altitude, temperature, precipitation, and total radiation. The results showed that the range of annual average GPP in CNR was 63-1706 g C·m-2·a-1 from 2000 to 2020 and that GPP decreased with the increases of altitude. Temperature played the most important role in driving the spatial varia-tion of GPP, with a significant positive correlation with GPP. During the study period, the overall annual GPP showed a significant increase trend in CNR, with an average annual increase of 13 g C·m-2·a-1. The areas with increase of annual GPP accounted for 79.9% of the total area, and the area proportion of annual GPP increase differed in each plant functional type. Annual precipitation was significantly negatively correlated with GPP in 43.2% of CNR, while annual mean temperature and annual total radiation were significantly positively correlated with GPP in 47.2% and 82.4% of CNR. GPP would increase continuously in CNR under the scenario of future global warming.

[Characteristics of climate change in Changbai Mountain ecological functional area, Northeast China.] / 长白山生态功能区气候变化特征.

We integrated the meteorological records from 36 national weather stations and CN05.1 gridded daily observation dataset to analyze the climate change characteristics of Changbai Mountain eco-functional area. Linear tendency estimation, Mann-Kendall mutation test, cumulative anomaly method and Morlet wavelet analysis were used to investigate the temporal and spatial variation of temperature (annual temperature, seasonal temperature, extreme temperature), moisture (annual precipitation, seasonal precipitation, relative humidity), radiation (sunshine duration, sunshine percentage) and wind speed from 1961 to 2016. The results showed that, during 1961-2016, the temperature of this area increased, the radiation and wind speed decreased, and the precipitation varied periodically. Specifically, winter temperature [0.45 ℃·(10 a)-1] and the lowest temperature [0.74 ℃·(10 a)-1] significantly increased. The mean annual wind speed significantly decreased [-0.21 m·s-1·(10 a)-1]. No abrupt climate change was observed. The annual precipitation days decreased considerably [-7.01 d·(10 a)-1], which was different from the climate change pattern of Northeast China. The annual precipitation trend coefficient of this area was 16.06 mm·(10 a)-1 , which could not be simply depicted by increase or decrease in trend. The precipitation change in this area was dominated by periodically patterns, and the period was 26 years and 3 years. Our results would be instructive to the regional ecological assessment, and the research on ecosystem responses to climate change and phenological changes.

[Natural science research in Changbai Mountain during 1956-2018:A review.] / é•¿ç™½å±±åœ°åŒºè‡ªç„¶ç§‘å­¦ç ”ç©¶ç»¼è¿°: 1956­2018.

We synthesized the scientific research carried out in Changbai Mountain from 1956 to 2018 by mapping knowledge domains and bibliometrics based on the literature from international database (WOS) and domestic databases (CNKI and CSCD). The results showed that natural science research in Changbai Mountain underwent three stages during 1956-2018, including embryo stage, growing stage, and rapid development stage. The natural research in Changbai Mountain could be divided into five fields, i.e., forest and ecological science, volcano and geology science, environmental change science, resource sciences and utilization, animal and microbial science, with a total of 20 main research directions. Since 2000, forest and ecological science, volcano and geological science, environmental change science dominated the natural science research in Changbai Mountain. The researches in recent 20 years mainly concentrated on the following seven disciplines: community ecology, forest management, soil ecology, ecosystem ecology, eco-climatology, forest responses to environmental change, and volcanic geology. International researches showed a trend of strong integration of different disciplines. We forecast that the natural science research in the Changbai Mountain would deepen its research in the next decade. Moreover, other fields such as old-growth forest and large-scale ecosystem carbon processes, forest-altitude-climate change, soil fauna and microorganisms, forest management and human activities, biodiversity, volcanic origin and eruption history, volcanic eruption dynamics and volcanic monitoring will emerge as the new research focus. Scale polarization, elements diversification, discipline crossing, and research deepening would be the future trend of natural science research in Changbai Mountain.