Characterization of perylene in tropical environment : comparison of new and old fungus comb for identifying perylene precursor in Macrotermes gilvus termite nests of Peninsular Malaysia.

This is the first record on the distribution of perylene in new and old fungus combs of termite nest (Macrotermes gilvus) in order to determine perylene source in tropical environment. Twenty four samples of new and old fungus combs, inner and outer nest walls, fresh and decomposed bark, decomposed stem, soil, and soil-wood interface were collected in order to test of two hypotheses; i) Perylene is produced in the termite’s hindgut (M. gilvus) and ii) Perylene is present only in new fungus comb of M. gilvus termite nests. For one Station (Station A) the profile of perylene concentration was the following order: fungus comb > outer nest wall ≥ Soil-Wood interface ≥ decomposed stem ≥ decomposed bark ≥ Inner nest wall > Soil. For the other Station (i.e. B) the profile was new fungus comb > inner nest wall > old fungus comb ≥ outer nest wall ~ Soil. The perylene concentration was found up to 21-54 times higher in fungus comb as compare to the rest of the samples in Station A. whereas, the perylene concentration was 85-400 times higher in new fungus comb as compare to the remaining samples in Station B, this can be due to the production or accumulation of perylene in these nests. On the other hand, smaller termite nests (Stations C and E) no perylene was detected, due to the fact that the new fungus comb was not found in those nests. The results confirmed the following hypotheses; perylene occurs only in new fungus comb and may be attributed to the high concentrations of aromatic rings of lignin in new fungus comb

Vertical distribution and source identification of polycyclic aromatic hydrocarbons in anoxic sediment cores of Chini Lake, Malaysia: perylene as indicator of land plant-derived hydrocarbons.

Four anoxic sediment cores were collected from Chini Lake, Malaysia in order to investigate the variability of polycyclic aromatic hydrocarbon (PAH) and perylene concentrations. The study also determined significant differences of perylene concentrations in different sediment layers. Total PAH concentrations ranged from 248 to 8098 ng g−1 in the samples. Diagnostic PAH ratios such as methylphenanthrenes/phenanthrene (MP/P), phenanthrene/anthracene (P/A) and fluoranthene/(fluoranthene + pyrene) (Fl/(Fl + Py) revealed a dominance of pyrogenic influences and partial petrogenic inputs to the top sediment layers. Perylene concentrations were high in the top layers (12 cm). The average perylene concentrations accounted for 26–50% (0–12 cm) and 50–77% (12–36 cm) of pentacyclic-aromatic hydrocarbon isomers (PAI) present whereas it made up 10–34% (0–12 cm) and 46–66% (12–36 cm) of the total PAH. The average pyrene concentrations decreased with increasing depth and accounted for 62% (0–3 cm), 20–23% (3–12 cm) and 3–1.4% (12–36 cm) of perylene present. The results of hierarchical cluster analysis based on these ratios suggested different input sources for the top and bottom layers. It is concluded that the activity of termites on woody plants produced perylene which is supplied to the lake by run-off from the heavy and frequent rains in this Asian tropical climate. In addition, there was also in situ formation of perylene in the bottom layers due to diagenetic processes

Distribution of PAHs and n-alkanes in Klang River surface sediments, Malaysia

Surface sediment samples were collected from five locations at the downstream of Klang River in January 2007 to examine the spatial distribution, composition, and sources of 19 parent polycyclic aromatic hydrocarbons (PAHs) and aliphatic hydrocarbon (n-alkanes) using gas chromatography-mass spectrometry. The total concentrations of the 19 PAHs in the sediments were found to range from 1304 to 2187 ng g-1 sediment. Meanwhile, total concentrations of n-alkanes ranged from 17008 to 27116 μg g-1 sediment. The concentration of n-alkanes in the sediment was significantly correlated (r = 0.991, p = 0.001) with the content of sediment organic carbon. In this study, all the sediments exhibited phenanthrene/anthracene (PHE/ANT >15) fluoranthene/(fluorantene+pyrene) (FLT/FLT+PYR 1), combustion PAHs/total PAHs (CombPAH/∑19PAH <0.3), terrigenous/aquatic ratio for hydrocarbons greater than 23. The also data showed that petrogenic and natural inputs were predominant at all the locations investigated. Multiple sources of n-alkanes and PAHs in the river sediments were also explained by low carbon preference index (CPI) values, different ratios of diploptene/∑C23-C25 n-alkanes, poor correlation between diploptene and ∑C23-C25, average chain length (ACL) of 29.54 ± 0.09, correlation between CPI and ACL (r = 0.847, p= 0.035), and high ratio of naphthalene/total PAHs

Emission of PAHs, NPAHs and OPAHs from residential honeycomb coal briquette combustion

Coal combustion is one of the most significant sources of air pollution in China. In this study, emission factors (EFs) of 15 polycyclic aromatic hydrocarbons (PAHs), 26 nitrated PAHs (NPAHs) and 6 oxygenated PAHs (OPAHs) were determined in five different coals with different geological maturity (vitrinite reflectance <i>R</i>_O = 0.77–1.88%) burned in the form of honeycomb briquettes. The total EFs ranged from 9.82 to 215 mg kg^–1 for PAHs, 0.14 to 1.88 mg kg^–1 for NPAHs and 4.47 to 20.8 mg kg^–1 for OPAHs. Measured EFs and gas-particle partitioning varied depending on the geological maturity. The lowest EFs were found in anthracite. The proportion of PAHs, NPAHs and OPAHs in gaseous phase increasing with increased geological maturity. The coal with higher geological maturity produced more 3-ring PAHs. On the basis of the statistical analysis for the residential sector of China in 2008, PAHs, NPAHs and OPAHs emitted from residential honeycomb coal briquettes were 4.36 Gg, 0.03 Gg and 0.47 Gg in 2007, respectively. By 2020, the emission would decrease to 2.18 Gg, 0.02 Gg and 0.24 Gg for PAHs, NPAHs and OPAHs due to the increasing usage of new energy resources. If only anthracite is used as the residential coal, 93% PAHs, 87% NPAHs and 71% OPAHs would be reduced in 2020

Measurement report: Molecular characteristics of cloud water in southern China and insights into aqueous-phase processes from Fourier transform ion cyclotron resonance mass spectrometry

Characterizing the molecular composition of cloud water could provide unique insights into aqueous chemistry. Field measurements were conducted at Mt. Tianjing in southern China in May, 2018. There are thousands of formulas (C$_{5-30}$H$_{4-55}$O$_{1-15}$N$_{0-2}$S$_{0-2}$) identified in cloud water by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS). CHON formulas (formulas containing C, H, O, and N elements; the same is true for CHO and CHOS) represent the dominant component (43.6 %–65.3 % of relative abundance), followed by CHO (13.8 %–52.1%). S-containing formulas constitute ∼5 %–20 % of all assigned formulas. Cloud water has a relative-abundance-weighted average O/C of 0.45–0.56, and the double bond equivalent of 5.10–5.70. Most of the formulas (>85 %) are assigned as aliphatic and olefinic species. No statistical difference in the oxidation state is observed between cloud water and interstitial PM$_{2.5}$. CHON with aromatic structures are abundant in cloud water, suggesting their enhanced in-cloud formation. Other organics in cloud water are mainly from biomass burning and oxidation of biogenic volatile organic compounds. The cloud water contains more abundant CHON and CHOS at night, which are primarily contributed by −N$_{2}$O$_{5}$ function and organosulfates, demonstrating the enhanced formation in dark aqueous or multi-phase reactions. While more abundant CHO is observed during the daytime, likely due to the photochemical oxidation and photolysis of N- or S-containing formulas. The results provide an improved understanding of the in-cloud aqueous-phase reactions

Device-independent verification of Einstein-Podolsky-Rosen steering

If the presence of entanglement could be certified in a device-independent (DI) way, it is likely to provide various quantum information processing tasks with unconditional security. Recently, it was shown that a DI protocol, combining measurement-device-independent techniques with self-testing, is able to verify all entangled states, however, it imposes demanding requirements on its practical implementation. Here, we present a less-demanding protocol based on Einstein-Podolsky-Rosen (EPR) steering, which is achievable with current technology. Particularly, we first establish a complete framework for DI verification of EPR steering and show that all steerable states can be verified. Then, we analyze the three-measurement setting case, allowing for imperfections of self-testing. Finally, a four-photon experiment is implemented to device-independently verify EPR steering and to further demonstrate that even Bell local states can be faithfully verified. Our findings pave the way for realistic applications of secure quantum information tasksComment: 6+8 pages; Comments are welcom

Impact of in-cloud aqueous processes on the chemical compositions and morphology of individual atmospheric aerosols

The composition, morphology, and mixing structure of individual cloud residues (RES) and interstitial particles (INT) at a mountaintop site were investigated. Eight types of particles were identified, including sulfate-rich (S-rich), S-organic matter (OM), aged soot, aged mineral dust, aged fly ash, aged metal, refractory, and aged refractory mixture. A shift of dominant particle types from S-rich (29 %) and aged soot (27 %) in the INT to aged refractory mixture (23 %) and S-OM (22 %) in the RES is observed. In particular, particles with organic shells are enriched in the RES (27 %) relative to the INT (12 %). Our results highlight that the formation of more oxidized organic matter in the cloud contributes to the existence of organic shells after cloud processing. The fractal dimension (D$_{f}$), a morphologic parameter to represent the branching degree of particles, for soot particles in the RES (1.82 ± 0.12) is lower than that in the INT (2.11 ± 0.09), which indicates that in-cloud processes may result in less compact soot. This research emphasizes the role of in-cloud processes in the chemistry and microphysical properties of individual particles. Given that organic coatings may determine the particle hygroscopicity, activation ability, and heterogeneous chemical reactivity, the increase of OM-shelled particles upon in-cloud processes should have considerable implications

Stability of SARS-CoV-2 in cold-chain transportation environments and the efficacy of disinfection measures

BackgroundLow temperature is conducive to the survival of COVID-19. Some studies suggest that cold-chain environment may prolong the survival of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and increase the risk of transmission. However, the effect of cold-chain environmental factors and packaging materials on SARS-CoV-2 stability remains unclear.MethodsThis study aimed to reveal cold-chain environmental factors that preserve the stability of SARS-CoV-2 and further explore effective disinfection measures for SARS-CoV-2 in the cold-chain environment. The decay rate of SARS-CoV-2 pseudovirus in the cold-chain environment, on various types of packaging material surfaces, i.e., polyethylene plastic, stainless steel, Teflon and cardboard, and in frozen seawater was investigated. The influence of visible light (wavelength 450 nm-780 nm) and airflow on the stability of SARS-CoV-2 pseudovirus at -18°C was subsequently assessed.ResultsExperimental data show that SARS-CoV-2 pseudovirus decayed more rapidly on porous cardboard surfaces than on nonporous surfaces, including polyethylene (PE) plastic, stainless steel, and Teflon. Compared with that at 25°C, the decay rate of SARS-CoV-2 pseudovirus was significantly lower at low temperatures. Seawater preserved viral stability both at -18°C and with repeated freeze−thaw cycles compared with that in deionized water. Visible light from light-emitting diode (LED) illumination and airflow at -18°C reduced SARS-CoV-2 pseudovirus stability.ConclusionOur studies indicate that temperature and seawater in the cold chain are risk factors for SARS-CoV-2 transmission, and LED visible light irradiation and increased airflow may be used as disinfection measures for SARS-CoV-2 in the cold-chain environment

The role of confucius institutes in Chinese Education in Russia (based on the example of confucius institute of the humanitarian institute, Novosibirsk state university)

With the increase of Sino-Russian cooperation in various fields, interest in Chinese is growing in Russia, which highlights the role of Confucius Institute to meet demand. Confucius Institute is a non-profit educational organization jointly established by China and other countries. Each of the 22 Confucius Institutes and classrooms in Russia present its distinctive feature and work hard in helping the Russian people learn Chinese, understand Chinese culture and enhance the humanist exchange between China and Russia. Chinese education is the most important task of the institutes. Using Confucius Institute of Novosibirsk State University as an example, this paper introduces works done by the institute from three aspects. Firstly, it contributes to Chinese education in the university. Secondly, it meets local residents’ needs to learn Chinese. Thirdly, it broadens the scope of regional cooperation and trains local Chinese teachers. With the support of Xinjiang University in China, the Confucius Institute at Novosibirsk State University has cooperated with many higher and secondary education institutions in Russia to expand international cooperation in Chinese education. The effective work of Confucius Institute at Novosibirsk State University has proved that it has played an active role in Chinese education. Against the backdrop of the COVID-19 pandemic, all Confucius Institutes and classrooms in Russia have continued operating by taking advantage of online teaching and learning and explored the route of development characterized with “Internet + Chinese”. The authors believe that Confucius Institutes will keep on contributing to the Chinese education in Russia with the joint efforts of both parties