ALBERT

Description: Crystal s tructures, characteristics, and preparations of 12CaO·7Al 2 O 3 family and CaO–Al 2 O 3 (C–A) system have been reviewed in detail with relevant thermodynamic parameters being assessed or recalculated. 12CaO·7Al 2 O 3 (shortened as C12A7) can form several derivatives of type C12A7:M n− or C12A7–M n− through replacing so-called “free oxygen ion” by many anions including OH − , H − , O − , , F − , Cl − , and e − in their cages, or being adopted by rare earth metals or alkaline earth metal oxides at cation sites (Ca 2+ or Al 3+ ). These doped C12A7 derivatives show unique material properties of transparent conduction, catalysis, and antibacterial with potential applications in fast ion conductors, optoelectronics, oxidants, and catalysts etc.

Description: Changes in spring vegetation phenology and production will presumably impact the velocity of greenup (Vgreenup, daily rate of changes in productivity during greenup period), yet little is currently known about the spatiotemporal patterns of global Vgreenup. Here, we define Vgreenup as the ratio of the amplitude of greenup to the duration of greenup, and derive global Vgreenup from 34‐year satellite leaf area index observations to study its spatiotemporal dynamics. The results suggest that combined effects of climate change and human land management have greatly accelerated global Vgreenup, with important implications for changes in terrestrial ecosystem functioning and global carbon cycling. Abstract Global warming and human land management have greatly influenced vegetation growth through both changes in spring phenology and photosynthetic primary production. This will presumably impact the velocity of vegetation greenup (Vgreenup, the daily rate of changes in vegetation productivity during greenup period), yet little is currently known about the spatio‐temporal patterns of Vgreenup of global vegetation. Here, we define Vgreenup as the ratio of the amplitude of greenup (Agreenup) to the duration of greenup (Dgreenup) and derive global Vgreenup from 34‐year satellite leaf area index (LAI) observations to study spatio‐temporal dynamics of Vgreenup at the global, hemispheric, and ecosystem scales. We find that 19.9% of the pixels analyzed (n = 1,175,453) experienced significant trends toward higher greenup rates by an average of 0.018 m2 m−2 day−1 for 1982–2015 as compared to 8.6% of pixels with significant negative trends (p 〈 0.05). Global distribution and dynamics of Vgreenup show high spatial heterogeneity and ecosystem‐specific patterns, which is primarily determined by the high spatial variation in Agreenup, while the temporal dynamics of Vgreenup are directly controlled by both changes in Dgreenup and Agreenup. Areas with the largest Vgreenup and largest positive trends are both observed in deciduous and mixed forests as compared to nonforest ecosystems showing both lower Vgreenup and trends. For nonforest ecosystems, human‐managed ecosystems (e.g., rangelands and rainfed croplands) exhibited higher Vgreenup and positive trends than those of natural counterparts, suggesting strong imprints of human land management on terrestrial ecosystem functioning. Globally, warming has accelerated Vgreenup in temperature‐constrained high latitude forest ecosystems and arctic regions, but decelerated Vgreenup in temperate and arid/semiarid areas. These results suggest that the combined effects of climate change and human land management have greatly accelerated global vegetation greenup, with important implications for changes in terrestrial ecosystem functioning and global carbon cycling.

Description: The effect of composite binder on the mechanical property of lightweight bubble alumina ceramics was studied. The ceramics were prepared using bubble alumina and α-Al 2 O 3 fines as raw materials, phosphoric acid (H 3 PO 4 ) and aluminum ammonium sulfate (NH 4 Al(SO 4 ) 2 ·12H 2 O) as binders. During sintering, most phosphoric acid react with aluminum ammonium sulfate and the rest react with bubble alumina and α-Al 2 O 3 fines, forming aluminum phosphate on the surface of the alumina particles, which effectively improves the sintering process. The mechanical property of the ceramic bonded by composite binder was greatly improved compared with that bonded by single binder

Description: Large uncertainties remain in the estimation of aerosol direct radiative effect (DRE) and forcing (DRF). In this work, using an aerosol-climate model with two- and four-stream radiation schemes, we show that the radiative transfer algorithms contribute to the uncertainties. Aerosol shortwave DREs and heating rate are underestimated significantly by the two-stream algorithm. For present-day conditions, the four-stream algorithms are found to enhance global annual mean aerosol shortwave DREs by more than 8% (14%) at the top of the atmosphere (TOA), 15% (18%) in the atmosphere, and 12% (15%) at the surface for all-sky (clear-sky) case. The regional-averaged relative differences in aerosol shortwave DREs between the two- and four-stream algorithms increase as latitude increases, exceeding 25% at the TOA and 30% at the surface in the high latitudes of the Southern Hemisphere. The DRE differences due to the four-stream algorithms are negative, except for the Arctic, Tibetan Plateau, Arabia, and Sahara, at the TOA, are positive in the atmosphere, and are negative at the surface, with the maximum exceeding 4.0 W m −2 . Increases in aerosol shortwave heating rates due to the four-stream algorithms are generally more than 10% and may even exceed 100%. Our results also show that the two-stream algorithm underestimates the DRFs due to anthropogenic aerosols. Significant underestimation appears in the middle latitudes of the Northern Hemisphere, with the maximum being close to the quantity of 0.6 W m −2 for clear-sky case. This study indicates that a multi-stream radiative transfer algorithm is necessary to reduce the uncertainties of aerosol DREs and DRFs estimated by global climate models.

Description: The effect of composite binder on the mechanical property of lightweight bubble alumina ceramics was studied. The ceramics were prepared using bubble alumina and α-Al 2 O 3 fines as raw materials, phosphoric acid (H 3 PO 4 ) and aluminum ammonium sulfate (NH 4 Al(SO 4 ) 2 ·12H 2 O) as binders. During sintering, most phosphoric acid react with aluminum ammonium sulfate and the rest react with bubble alumina and α-Al 2 O 3 fines, forming aluminum phosphate on the surface of the alumina particles, which effectively improves the sintering process. The mechanical property of the ceramic bonded by composite binder was greatly improved compared with that bonded by single binder

Description: Ribosomal protein S6 (rpS6) has long been regarded as one of the primary r-proteins that functions in the early stage of 40S subunit assembly, but its actual role is still obscure. The correct forming of 18S rRNA is a key step in the nuclear synthesis of 40S subunit. In this study, we demonstrate that rpS6 participates in the processing of 30S pre-rRNA to 18S rRNA only when its C-terminal five serines are phosphorylated, however, the process of entering the nucleus and then targeting the nucleolus does not dependent its phosphorylation. Remarkably, we also find that the aggregation of rpS6 at the nucleolus correlates to the phasing of cell cycle, beginning to concentrate in the nucleolus at later S phase and disaggregate at M phase. This article is protected by copyright. All rights reserved

Description: Abstract Fluorescence and absorption spectra at 530 nm (2H11/2→4I15/2), 560 nm (4S3/2→4I15/2), 660 nm (4F9/2→4I15/2), 980 nm (4I11/2→4I15/2), 1530 nm (4I13/2→4I15/2), and 2710 nm (4I11/2→4I13/2) of Er3+ in Gd3Ga5O12 single‐crystal codoped with Pr3+ have been measured. Judd‐Ofelt analysis yields the intensity parameters Ω2 = (0.68 ± 0.03) × 10−20 cm2, Ω4 = (0.60 ± 0.07) × 10−20 cm2, and Ω6 = (0.90 ± 0.17) × 10−20 cm2. A comparison with previously reported values of Er3+‐only doping case shows that Pr3+‐codoping causes slight change of both Ω2 and Ω4, while onefold increase of Ω6. From calculated radiative rates and measured fluorescence spectra, Er3+ emission cross‐section spectra were calibrated at first. Then, the absorption cross‐section spectra were calculated using McCumber relation. In parallel, the absorption cross‐section spectra were also obtained from the measured absorption spectrum, and compared with those obtained from the McCumber relation. The comparison shows that both methods give consistent result of absorption cross‐section spectrum. Further comparison with Er3+‐only doping case shows that Pr3+‐codoping causes considerable change of Er3+ cross‐section value. In spectrally mixing regions of Er3+ and Pr3+, Pr3+ emission affects little the determination of Er3+ emission cross‐section as Pr3+ fluorescence is much weaker than Er3+ fluorescence due to low Pr3+ concentration.

Description: Abstract With the increasing use of plastic products, the environmental pollution has become more and more serious, and it also prompts us to focus on the urgent problem: how do we deal with the waste plastic? This work develops a facile procedure to convert waste polyvinyl chloride (PVC) into tantalum carbide@carbon, via the chemical reaction of waste PVC, tantalum pentoxide, and metallic lithium in a stainless‐steel autoclave at 700°C. The structures, compositions, and morphologies of the as‐obtained products have been investigated by X‐ray diffraction pattern and electron microscopy. Furthermore, the effect of the reaction temperature on the composition and morphology of the as‐obtained products has been investigated. The possible formation mechanism of tantalum carbide has also been briefly discussed.