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Sr2CrOsO6 has the highest magnetic transition temperature (725 K) among the double perovskite oxides. Ca2CrOsO6 was obtained by replacing Sr ions with smaller volume Ca ions, and the magnetic transition temperature was higher than room temperature. Further substitution of Cr ions by Mo ions with more delocalized d orbitals yielded Ca2MoOsO6. The electronic structures and magneto-optical Kerr effects of the double perovskite oxides Sr2CrOsO6, Ca2CrOsO6 and Ca2MoOsO6 have been systematically calculated by density functional theory. The electronic structures indicate that all three materials are semiconductors. The electronic structures of Sr2CrOsO6 and Ca2CrOsO6 are very similar, and the band gap of Ca2MoOsO6 is extremely small, only 0.10 eV. Observing the magneto-optical Kerr effect line, all three materials show significant magnetooptical Kerr effects in the range of infrared to visible spectrum. The maximum Kerr rotation angles of Sr2CrOsO6, Ca2CrOsO6 and Ca2MoOsO6 are 1.18°, 0.98° and 0.65°. The maximum Kerr rotation angle of the three materials is greater than 0.2°, which makes them to be ideal magneto-optical materials. The calculated results show that the inclusion of both 3d(4d) and 5d transition metal ions in the compound contributes to the significant magneto-optical Kerr effect. Analysis of the optical conductivity tensor shows that the peak of the magneto-optical Kerr line of three materials originates from the interband transition and is dominated by the imaginary part of the off-diagonal element of optical conductivity tensor. [ABSTRACT FROM AUTHOR]

In this study, the Cr2+ :CdSe and Fe2+ :CdSe crystals were successfully grown by the Mo-crucible sealed Bridgman method using a vacuum single-crystal furnace with two zones developed by ourselves, and the crystal size reaches φ51 mm x 110 mm. Cr2+ :CdSe and Fe2+ :CdSe crystals demonstrate obvious absorption in the bands of 1 400 ~ 2 400 nm and 2 500 ~5 200 nm, respectively. The transmittances of Cr2+/Fe2+ doped CdSe crystals are close to the transmittance limit of CdSe crystal (~70%) in the 7 ~ 15 μm band, and the converted absorption coefficient is about 0.005 cm-1. The Cr2+/Fe2+ : CdSe crystals grown by the Mo-crucible sealed Bridgman method have the advantages of the controllable doping concentration of transition metal ions, uniform doping and high crystal quality. The Cr2+/Fe2+ : CdSe crystals could be used as both midinfrared laser crystal and far-infrared nonlinear optical crystal material. [ABSTRACT FROM AUTHOR]

In general, ion-exchange adsorption and biological method have higher treatment efficiency for ammonia nitrogen in water, but the existence of salt makes the treatment efficiency of ion-exchange adsorption method decreased due to the competition of salt ions, and the salt also inhibits the activity of microorganisms, which makes the biological method s treatment efficiency decreased. Four transition metals (Co, Ni, Cu and Zn) were used to support montmorillonite, and four transition metal-based montmorillonite were obtained. Compared with montmorillonite, the ammonia-nitrogen removal performance of the four transition metal-based montmorillonite is greatly improved in the range of saline solution pH 9.0 - 11.5. The specific surface area test shows that the transition metal montmorillonite has larger inner space, and its specific surface area is also greatly improved. Moreover, compared with montmorillonite, the modification of transition metals makes the pore size of montmorillonite smaller, which is the exchange between Na+ with smaller ionic radius and transition metal ions with larger ionic radius in the montmorillonite layer. This conclusion is confirmed by energy spectrum analysis, that is, the relative content of Na decreases from 9.46% to 2.75% - 5.48% after the modification of montmorillonite by transition metal. X-ray diffraction analysis also confirmed this point, that is, compared with montmorillonite, NaCl at the characteristic peaks of 31.8°, 45.5°, 56.5° and 75.3°, the intensity of diffraction angles corresponding to the four transition metal-based montmorillonite weakened or even disappeared, indicating that the montmorillonite underwent iso-crystal replacement in the process of metal modification. In the layer, Na+ and other substances were successfully exchanged by Co2+, Ni2+, Cu2+, Zn2+. Scanning electron microscopy shows that the surface structure of montmorillonite is relatively compact, and the surface of transition metal-montmorillonite is porous and uneven, with obvious gullies. These microstructure make metal-montmorillonite have larger specific surface area and more adsorption sites. The four kinds of transition metal-montmorillonite showed a similar trend in the adsorption properties of ammonia nitrogen under the influence of different salt contents, that is, Cu-montmorillonite always maintained the best, which not only had the strongest coordination ability between Cu2+ ion and NH3 molecule, but also had the highest inner hydroxyl group and the largest inner layer spacing. According to the photoelectron spectroscopy analysis, the N1s of Cupric montmorillonite after the removal of ammonia nitrogen indicates that cupric montmorillonite forms a coordination covalent bond with ammonia nitrogen, and there are ion exchange and electrostatic attraction. The adsorption process is more consistent with the quasi-second-order kinetic model. The full spectrum shows that the N element of Cu-montmorillonite increases from 0 to 2.78% before and after removing ammonia nitrogen. [ABSTRACT FROM AUTHOR]

The basic reviewed the research status of different types of metal catalysts, such as transition metal ions, zero-valent metals and bimetals, activated PMS/PDS for the degradation of bisphenol A(BPA), and also discussed the degradation mechanism of BPA removal by bimetallic catalyst. These include synergy between bimetals, and the important role of oxygen vacancies and surface hydroxyl radical. The paper analyzed the influencing factors in the activation process, water matrix conditions, reusability and stability of the catalyst. The paper looks forward to the future research on the degradation of bisphenol A by metal catalysts. [ABSTRACT FROM AUTHOR]

With the continuous development of smart materials, multiple-responsive viologen coordination polymers are expected to be applied in engineering fields such as materials science and biology, and have aroused extensive interest. In order to obtain such compounds, a carboxybenzyl viologen ligand, 1, 1'-bis(4- carboxybenzyl) -4, 4'-bipyridine dichloride (H2BpybcCl2) is used as the functional ligand to react with the transition metal ions Ni2+ (1), Mn2+ (2) and Co2+ (3) to form three isostructural two-dimensional (2D) coordination polymers {[M2 (Bpybc) (3H2O)6]·(OH) 4·nH2O}n. Due to the existence of viologen radicals, the three compounds exhibited photochromic behaviors under UV light irradiation. Upon heating, the three compounds also showed obvious color changes due to d-d transitions in the coordination field caused by dehydration. [ABSTRACT FROM AUTHOR]

As a new type of smart material, color-changing materials have great application potential in the fields of optical storage information and optical devices. The viologen ligand 1,1'-bis(4-carboxybenzyl)-4,4'-bipyridine dichloride (H2 BpybcCl2 ) with a flexible skeleton is used as a functional ligand, and the transition metal ion Mn2+ and Cd2+ self-assembled to synthesize two isostructural coordination polymers [Mn(Bpybc)Cl2·H2O]n (1) and [Cd(Bpybc)Cl2 ·4H2O]n (2) . X-ray single crystal diffraction showed that the two compounds had a one-dimensional chain structure. Viologen free radicals were generated by light-induced electron transfer under the irradiation of ultraviolet light, and both compounds showed obvious photochromic behavior. [ABSTRACT FROM AUTHOR]

MoS2 and Ni-MoS2 photocatalytic materials were prepared by hydrothermal method. Using XRD, SEM, UV-Vis, XPS etc. to characterize the morphology, crystal structure, composition and properties of the prepared photocatalytic materials were studied. A 300 W xenon lamp was used as a light source to simulate sunlight irradiating the sample, and the photocatalytic performance of the prepared material to degrade tetracycline was tested. The results showed that the photocatalytic performance of 3% Ni-MoS2 was the best, and the degradation rate of tetracycline after 90 min of reaction was 67.1%. The increase in photocatalytic activity is due to the decrease of the band gap of MoS2 due to the doping of nickel transition metal ions, thereby increasing the utilization rate of visible light and effectively inhibits the recombination of photogenerated carriers. [ABSTRACT FROM AUTHOR]

Seven advanced oxidation processes based on sulfate radical activation of persulfate are reviewed, including electrochemical activation, transition metal ion activation, thermal activation, and photoactivation, and the research progress of this technology at home and abroad. The reaction mechanism of the advanced oxidation process based on sulfate radicals is summarized, and the effects of temperature, initial pH, persulfate concentration and degrading agent concentration on the degradation effect of this technology are analyzed. Advanced oxidation processes based on sulfate radicals have promising applications, but the technology still have limitation. This paper also points out that in the future, it is necessary to increase the sewage purification experiments based on sulfate radicals in the real environment. To establish a theoretical system for selecting activation methods, types of oxidants, and determining the ratio of oxidants to pollutants. To develop low-cost and recontamination -free activation methods. These measures promote the development and application of this technology in the degradation of actual sewage. [ABSTRACT FROM AUTHOR]

BACKGROUND: Varus-type osteoarthritis is often accompanied by obvious medial meniscus lesions. However, the underlying mechanism of its occurrence is yet unclear. OBJECTIVE: To explore the molecular mechanism of medial meniscus lesions secondary to varus knees. METHODS: The anterior cruciate ligament and lateral collateral ligament of the right rear limbs of seven Wuzhishan minipigs were resected to establish a varus knee model (experimental side), while the left hind legs were subjected to sham operation (control side). Medial meniscus samples were taken for a gene chip analysis at 26 weeks after modeling. An ethic approval was obtained from the Medical Ethics Committee of Hainan General Hospital with an approval No. Med- Eth-Re[2020]5 on December 5, 2017. RESULTS AND CONCLUSION: The samples in the two groups showed significant differences in the gene expression. A total of 893 differentially expressed genes were found, in which 537 were upregulated and 356 were downregulated. The significantly affected biological processes included sex determination, interstitial morphogenesis, and regulation of nitric oxide biosynthetic process. The significantly affected cellular components included intrinsic component of membrane, integral component of plasma membrane, endoplasmic reticulum membrane, and epinuclear membrane-endoplasmic reticulum network. The significantly affected molecular functions included transition metal ion binding and iron ion binding. The significantly affected pathways included type II diabetes mellitus, inflammatory mediator regulation of TRP channels, and AMPK signaling pathway. These findings suggest significant changes in gene expression of varus knee meniscus, and these differentially expressed genes may reveal the mechanism of medial meniscus lesions secondary to varus knee, providing a potential target for its treatment and early diagnosis. [ABSTRACT FROM AUTHOR]