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An organic–inorganic perovskite compound [(CH3)4P][Cd(SCN)3] (1) and its fluorine-substituted product [(CH3)3PCH2F][Cd(SCN)3] (2) exhibit ferroelastic phase transitions above room temperature. The very close van der Waals radii of H and F atoms ensure isomorphism of the crystal structures. However, the higher phase transition temperature, stronger ferroelastic spontaneous strain value and dielectric properties of 2 can possibly be explained by differences in the electronegativity between F and H atoms. [ABSTRACT FROM AUTHOR]

An organic–inorganic perovskite compound [(CH3)4P][Cd(SCN)3] (1) and its fluorine-substituted product [(CH3)3PCH2F][Cd(SCN)3] (2) exhibit ferroelastic phase transitions above room temperature. The very close van der Waals radii of H and F atoms ensure isomorphism of the crystal structures. However, the higher phase transition temperature, stronger ferroelastic spontaneous strain value and dielectric properties of 2 can possibly be explained by differences in the electronegativity between F and H atoms. [ABSTRACT FROM AUTHOR]

Reservoir sediment is an important sink for pollutants such as heavy metals. Under the changes in acid-base and redox conditions, there is a potential risk of heavy metals release into the water environment, which are transmitted through the food chain and threaten human health. Therefore, this study investigates the Qingliangshan Reservoir in the Meijiang River Basin, and conducts research concerning the contents and speciation of heavy metals in the sediments, potential ecological risks, and source apportionment. This study found that the content of heavy metals in the sediments of the reservoir area was in the order:Xitian tributary > dam front and reservoir center > Xintian-Baishui tributary. There is a large difference in the speciation of heavy metals in the sediments. Zn is mainly acid-soluble and in the residual state, Pb is mainly in an Fe/Mn oxide bound state, Cd is mainly in an acid-soluble state, and Cu, Ni, and Cr are in the residual state. Mainly, the percentage of bioavailable states are Cd(89%) > Pb(76%) > Zn(54%) > Cu(43%) > Ni(28%) > Cr(10%). The geoaccumulation index method shows that the pollution degree of heavy metal elements in reservoir sediments is in the order Cd > Pb > Zn > Cu > Cr > Ni, and the potential hazard ecological index method shows that the pollution degree of heavy metals is Cd > Pb > Cu > Ni > Zn > Cr. The potential ecological risk of Cd in the reservoir sediments is the largest, and the biological impact is greatest. Correlation analysis and principal component analysis results show that heavy metals Cu, Zn, Pb, and Cd in reservoir sediments are mainly from agricultural pollution, and Ni and Cr are mainly from natural background. Combined with the analysis of soil heavy metal content in the watershed, heavy metal pollution in the Qingliangshan Reservoir sediments originates from the effect of rainfall runoff and the use of agricultural chemical fertilizers before flooding in the upstream of the reservoir tributaries. There are significant spatial differences in heavy metal pollution in the sediments of the reservoir area. The Xintian-Baishui River recharge area is the least polluted, and it is closely related to the land use in the controlled watershed, which is mainly forest land, with fewer sources of pollution. The Xitian River replenishment area has the heaviest pollution. It controls many tea gardens and farmlands in the watershed, and the load of external fertilizer pollution is the largest. The pollution degree of heavy metals in front of the dam and the center of the reservoir area is between the two tributary replenishment areas, showing an obvious mixing effect.

In the last decade, hybrid materials have received widespread attention. In particular, hybrid lead halide perovskite-type semiconductors are very attractive owing to their great flexibility in band gap engineering. Here, by using precise molecular modifications, three one-dimensional perovskite-type semiconductor materials are designed and obtained: [Me 3 PCH 2 X][PbBr 3 ] (X=H, F, and Cl for compounds 1, 2, and 3, respectively). The introduction of a heavier halogen atom (F or Cl) to [Me 4 P] + increases the potential energy barrier required for the tumbling motion of the cation, hence achieving the transformation of the phase transition temperature from low temperature (192 K) to room temperature (285 K) and high temperature (402.3 K). Moreover, the optical band gaps reveal a broadening trend with 3.176 eV, 3.215 eV, and 3.376 eV along the H→F→Cl series, which is attributed to the formation of the structural distortion., (© 2020 Wiley-VCH GmbH.)

Forest soil-plant-atmosphere continuum (SPAC) is an important continuous process of water cycle. In this study, we analyzed hydrogen and oxygen stable isotope compositions of the precipitation, atmospheric water vapor, soil water, branch water, and leaf water to explain the characteristics of the continuous process and the associated controlling factors in a subtropical evergreen broadleaved forest. The results showed that the regression equations between hydrogen and oxygen stable isotopes were δD P =7.97 δ 18 O P +12.68( R 2 =0.97) for precipitation, δD S =4.29 δ 18 O S -18.62( R 2 =0.81) for soil water, δD B =3.31 δ 18 O B -29.73( R 2 =0.49) for branch water and δD L =1.49 δ 18 O L -10.09( R 2 =0.81) for leaf water of Podocarpus nagi , δD V =3.89 δ 18 O V -51.29( R 2 =0.46) for atmospheric water vapor, respectively. In the process of water transport from precipitation to soil water to plant water, hydrogen and oxygen isotopes gradually enrich, while water vapor isotopes evaporated from soil and evaporated from plants were depleted. With the influence of precipitation and evaporation, soil water isotopes depleted with depth, and more enriched in the dry season than that in the rainy season. During the observation period, isotope content of branch water was slightly higher than that of soil water, indicating that water might be enriched by transpiration during the transportation process in plants. In the dry season, water isotope in branches of arbor plants was poorer than that of shrubs, indicating that arbor plants with deeper root distribution tended to use deep soil water. Because of the differences of leaf traits, transpiration rate and the response degree of environmental factors, the variation characteristics of water isotope composition in leaves of diffe-rent plants varied with the increases of leaf age. Environmental conditions in rainy season were more conducive to leaf transpiration, which made leaf water isotope enriched in rainy season than in dry season. The isotopic compositions in leaf water of Podocarpus nagi had a positive relationship with leaf water content (LWC), and a negative one with relative humidity, reflecting the water regulation function of plants in response to environmental changes.

An organic-inorganic perovskite compound [(CH 3 ) 4 P][Cd(SCN) 3 ] (1) and its fluorine-substituted product [(CH 3 ) 3 PCH 2 F][Cd(SCN) 3 ] (2) exhibit ferroelastic phase transitions above room temperature. The very close van der Waals radii of H and F atoms ensure isomorphism of the crystal structures. However, the higher phase transition temperature, stronger ferroelastic spontaneous strain value and dielectric properties of 2 can possibly be explained by differences in the electronegativity between F and H atoms.

In the present study,non-targeted metabolomics technique was used to screen potentially susceptibility biomarkers in patients with mild liver function abnormalities during long-term use of Chinese herbal compound. According to the inclusion and exclusion criteria,we collected 7 cases of patients with abnormal liver function during the period of complete taking Chinese herbal medicine( 60 days),and 18 cases of patients with normal liver function in re-examination from the reproductive medicine center in our hospital. Ultra performance liquid chromatography coupled with time-of-flight mass spectrometry( UPLC-Q-TOF/MS~E) technique combined with Progenesis QI software was used to analyze the differential biomarkers in serum of patients with wild liver function abnormalities and normal liver function. 11 potential biomarkers such as bilirubin,pantothenic acid,hippuric acid,sphingomyelin,palmitic acid,and oleic acid were tentatively identified. Metabolic disorders in patients with herbal-induced mild liver abnormality were mainly related to two pathways: pantothenic acid and coenzyme A biosynthesis and linoleic acid metabolism. It could provide a reference for the early warning of mild liver function abnormalities of patients that may be caused by long-term use of Chinese medicine compound in clinical application,and will lay a foundation for further understanding the endogenous substance changes in different levels of liver injury.