Publications by authors named "Guo Zichen"

Indoor semivolatile organic compounds (SVOCs) pose a substantial threat to human health. However, identifying the sources of these emissions has been challenging owing to the scarcity of convenient and practical on-site methodologies. Herein, a novel method for source screening was proposed using aluminum silicate sampling strips to adsorb SVOCs from the surface air of indoor materials.

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In order to investigate the impact of environmental conditions on the distribution and migration of Sr in the Longji terrace environment, the activity concentrations of Sr and Cs were determined. The activity concentration ranges of Sr and Cs in surface soil were 0.15-1.

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Recently, phthalate exposure has become a major public health concern. However, gaps still remain in our understanding of phthalate profile characteristics, source screening, and gas-phase estimation. This study measured phthalate concentrations in dust and window films in 101 dormitories at 13 universities in Beijing, China, from October to December 2019.

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To investigate the spatial distribution and source of plutonium isotopes in the Beibu Gulf, surface sediments were collected and analyzed using sector field inductively coupled plasma mass spectrometry (SF-ICP-MS). The activities of Pu in surface sediments ranged from 0.012 to 0.

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The spatial and vertical distribution of Pu and Cs in the sediments of the Yellow River Delta was studied to evaluate the deposition dynamics in the Yellow River estuary from 1960s. The activity of Pu and Cs in sediment core ranged from 0.001 to 0.

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Alzheimer's disease (AD) is an age-related neurodegenerative disorder (NDD). In the central nervous system (CNS), immune cells like microglia could reprogram intracellular metabolism to alter or exert cellular immune functions in response to environmental stimuli. In AD, microglia could be activated and differentiated into pro-inflammatory or anti-inflammatory phenotypes, and these differences in cellular phenotypes resulted in variance in cellular energy metabolism.

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The evaluation of the pentafluorocyclopropyl group as a chemotype in crop protection and medicinal chemistry has been hampered in the past by the lack of suitable methodologies that enable the practical incorporation of this moiety into advanced synthetic intermediates. Herein, we report the gram-scale synthesis of an unprecedented sulfonium salt, 5-(pentafluorocyclopropyl)dibenzothiophenium triflate, and its use as a versatile reagent for the photoinduced C-H pentafluorocyclopropylation of a broad series of non-previously functionalized (hetero)arenes through a radical mediated mechanism. The scope and potential benefits of the protocol developed are further demonstrated by the late-stage introduction of the pentafluorocyclopropyl unit into biologically relevant molecules and widely used pharmaceuticals.

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Freestanding electrodes with high energy density and cycle stability have attracted attention on the development of lithium-sulfur (Li-S) batteries. However, both severe shuttle effect and sluggish conversion kinetics hinder their practical applications. Herein, we employed the electrospinning and subsequent nitridation processes to prepare a necklace-like structure of CuCoN nanoparticles anchored on N-doped carbon nanofibers (CuCoN/NC) as freestanding sulfur host for Li-S batteries.

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A grating lobe-free silicon optical phased array with large field of view is demonstrated. Antennas with periodically bending modulation are spaced at half wavelength or less. The experimental results show that the crosstalk between adjacent waveguides is negligible at 1550 nm wavelength.

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Radionuclides in environmental ecosystems have ecotoxicity and health impact on human and environment, so radioactive contamination has always been one of the global concerns. This study mainly focused on the radioactivity of mosses collected from the Leye Tiankeng Group in Guangxi. The activities of Pu measured by SF-ICP-MS and Cs measured by HPGe in moss and soil samples are as follows: 0-2.

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Intensive and frequent climate change events (e.g., droughts or extreme weather) significantly affect vulnerable water-limited ecosystems.

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Article Synopsis
  • A new method for synthesizing BINOL-derived cationic phosphonites is introduced.
  • These phosphonites serve as ancillary ligands in gold (Au) catalysis, enabling the creation of complex 1-(aryl)benzo[5]carbohelicenes with specific regio- and enantioselectivity.
  • The process highlights the significance of these ligands in enhancing the reactivity of Au centers, allowing for optimized reactions that yield high quantities of enantioselective products.
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Previous studies proposed various hypotheses to the formation of the mega-dunes and water recharge of the lakes in the Badain Jaran Desert but left the coexistence of lake-dune pattern unsolved. This research found that the local circulation, generated from the differences of thermodynamic properties and the unique landscape settings between lakes and mega-dunes, can be applied to interpret the pattern.

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