Y3Al5O12:Ce3+ (YAG:Ce3+) transparent ceramic phosphors (TCPs) are regarded as the most promising luminescent converter for laser‐driven (LD) lighting. High‐quality YAG:Ce3+ TCPs are still urgent for ...high efficiency LD lighting devices. YAG:Ce3+ TCPs in a vacuum ambience by using nano‐sized raw materials are prepared. Controlling defects by adding nano‐sized MgO and SiO2 simultaneously enables a high transmittance nearly 80%. After annealing in air furthermore, the luminous efficiency is enhanced greatly from 106 to 223 lm W−1, which is the best result reported now for LD lighting. These results demonstrate that the optimizing YAG:Ce3+ TCPs in a fitting strategy will brighten once again in the next‐generation LD lighting. Based on scanning electron microscopy (SEM) coupled with a cathodoluminescence system, defects and Ce3+ distributions in grains are identified directly for the first time.
Controlling defects by adding nano‐sized MgO and SiO2 enables a high transmittance of nearly 80%. After annealing in air, furthermore, the luminous efficiency is enhanced greatly from 106 to 223 lm W−1. These results demonstrate that the optimization of Y3Al5O12:Ce3+ transparent ceramic phosphors in a fitting strategy will brighten once again the next generation of laser‐driven lighting.
Tb3+-doped phosphors are widely used in fluorescent lamps and plasma display panels (PDP) due to the strong vacuum ultraviolet (VUV)/UV light absorption of Tb3+. Most of these phosphors are ...fluorides. The quantum efficiency (QE) of these phosphors is more than 90%; however, it is still too low. Theoretically, one VUV/UV photon can convert two visible photons or more by visible quantum cutting (QC), and the QE can reach 200% or more. Usually, the oxides have a higher QE than fluorides. In this work, we obtained a novel oxide phosphor Ba9Lu2Si6O24:Tb3+ (BLS:Tb3+). Under the 251 nm UV-light excitation, QC processes occur in BLS:Tb3+ via cross-relaxation energy transfers (CRET) between Tb3+ ions, leading to intense green emissions around 552 nm. Based on an indirect method, the ideal QE is calculated nearly to be 171%. When the UV light absorption and energy losses are considered, the practical QE is near 144% estimated by a direct method. This value is much higher than that of the commercial phosphors of 90%, indicating the promising application of BLS:Tb3+ for fluorescent lamps and PDP. The CRET processes were investigated according to the luminescence spectra and decay curves.
Based on core observations, the microheterogeneity, diagenetic features, diagenetic mineral compositions, and stable isotopes of cements in the calcareous interlayers in the Donghe sandstone were ...studied by polarizing microscopy, cathodoluminescence microscopy, X-ray diffractometry, isotope ratio mass spectrometry, and other techniques. By determining the proportions of cements of two phases by a statistical method and their clumped isotope values by an end-member method, the multiphase calcareous cementation was shown to be the major contributor to densification. Cluster isotopes revealed that the average formation temperatures of calcareous cements in phases II and III of cementation were 45–50°C and 80–90°C, indicating that they were products of the A and B phases during early diagenesis, respectively. According to the homogenization temperatures of coeval salt-water inclusions associated with hydrocarbon inclusions, which range from 100°C to 130°C, basin modeling revealed that the basin underwent mainly one stage of hydrocarbon charging during 8–5 Ma in the Miocene period. The cements of the two phases in the oil-free calcareous interlayers in the Donghe sandstone, which are the main controlling factor of the oil-water distribution in the reservoir at present, formed much earlier than the oil filling in the oil-bearing sandstone.
A series of emission color tunable Ce3+, Tb3+, and Eu3+ co-doped La2Si2O7 (LSO) phosphors have been prepared via a solid state reaction. The crystal structure, luminescence properties, and thermal ...stability of the phosphors were studied in this paper. There exists two kinds of energy transfer (ET) modes under UV excitation, namely, electric dipole-dipole interaction for Ce3+→Tb3+ and terbium bridge model Ce3+→(Tb3+)n→Eu3+ for LSO:Ce3+,Tb3+,Eu3+ system. The emitting color of the phosphors can be tuned from green to yellow and eventually to orange-red through the Ce3+→Tb3+→Eu3+ energy transfer. Although codoping Tb3+ and Eu3+ into La2Si2O7:Ce3+ leads to the reduction of thermal stability, it still remains 80% for LSO:0.05Ce3+,0.8 Tb3+,0.02Eu3+ at 150 °C when compared to that at room temperature. The absolute quantum yield (QY) increases from 71.04% (LSO:0.05Ce3+) to 95.60% (LSO:0.05Ce3+, 0.6 Tb3+), while those of LSO:0.05Ce3+,yTb3+,0.02Eu3+ samples remain more than 70%. These results indicate that the phosphors can be candidates for application in phosphor-converted white light-emitting diodes (pc-WLEDs).
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•La2Si2O7:Ce3+,Tb3+,Eu3+ has been prepared by a high-temperature solid state reaction.•The emitting color can be tuned from green to yellow and then to orange-red.•Ce3+→(Tb3+)n→Eu3+ bridge is responsible for the enhancement of Eu3+ emission.•The quantum efficiency of 0.05Ce3+,yTb3+,0.02Eu3+ codoped samples is more than 70%.•The phosphors exhibit good thermal stability.
This study aimed to quantitatively analyze the effects of neuromuscular training (NMT) on dynamic balance in healthy athletes through a systematic review and meta-analysis of randomized controlled ...trials.
Searches on six databases for randomized controlled trials examining the impact of NMT on athletes' balance ability. The search period extended from the inception of the database to March 16, 2024, languages are limited to Chinese and English. Review Manager 5.1 was used for literature quality assessment and data analysis. Stata 15.0 software was used for assessing publication bias, employing the clipping method, and conducting sensitivity analysis. The Grading of recommendations assessment development and evaluation (GRADE) was used to assess the certainty of evidence. Effect size (ES) was used to evaluate the impact effect of the results.
(1) Meta-analysis: A total of 7 papers met the inclusion criteria, and the meta-analysis indicated that NMT had a positive impact on the dynamic balance ability of the right (SMD = 0.74) and left (SMD = 0.70) lower limb of athletes, and a statistically significant difference was observed (p < 0.01). Subgroup analysis revealed that NMT did not have a positive effect (p > 0.05) on the right anterior (SMD = 0.35); However, it had a positive effect (p < 0.05) on the right posteromedial (SMD = 1.22), right posterolateral (SMD = 0.82), right composite score (SMD = 0.79), left anterior (SMD = 0.38), left posteromedial (SMD = 1.19), left posterolateral (SMD = 0.57) and left composite score (SMD = 0.86). (2) Reporting bias: Funnel plot indicated evidence of publication bias, but there was no significant asymmetry in the funnel plot after trimming and filling. The results were not reversed, indicating the robustness of the combined results. (3) Sensitivity analysis: The results of the sensitivity analysis suggest that the data in this meta-analysis are relatively stable and credible. (4) Grading the evidence: Based on GRADE scale the certainty of evidence from the included studies was determined to be moderate.
Neuromuscular training can enhance the dynamic balance ability of athletes on both the left and right sides. Therefore, neuromuscular training is an effective method for enhancing the unilateral dynamic balance ability of athletes.
Expanded emission spectra ranging from green to red are reported in Ca3Sc2Si3O12 (CSS):Ce3+,Mn2+ silicate garnets. Mn2+ may occupy Ca2+ site (Mn2+(I)) to generate a yellow emission band at 574nm or ...Sc3+ site (Mn2+(II)) with red emission band at 680nm. Efficient energy transfers from the green emitting Ce3+ to both Mn2+(I) and Mn2+(II) occur upon blue excitation into Ce3+. Concentration dependence of Mn2+ emission is analyzed based on Ce3+–Mn2+ energy transfer, steady state rate equations, and fluorescence lifetimes. Energy transfer efficiency (ηT) and rate (W) are calculated with values as high as 45% and 14.01×106s−1, respectively.
► Mn2+ can occupy Ca2+ site to generate a yellow emission band at 574nm in Ca3Sc2Si3O12 (CSS). ► Mn2+ can also occupy Sc3+ site to generate a red emission band at 680nm in CSS. ► Remarkable energy transfers (ETs) from Ce3+ to Mn2+ occur upon blue excitation into Ce3+ in CSS. ► Full color emissions are obtained based on Ce3+–Mn2+ ETs in CSS:Ce3+,Mn2+.
The Lower Cretaceous (Baxigai and Bashijiqike Formations) of the northern Tarim basin contains over 1000 m of siliciclastic fluvial-deltaic deposits and is of great significance for oil and gas ...exploration. Based on integrated cores, outcrops, well-logs, and seismic data, the sequence stratigraphy, depositional architecture and sedimentary infilling process from a shallow lake basin to a braided fluvial-dominated basin, as well as their controlling factors, were documented. Four major depositional facies, including lacustrine and braided-river delta in Baxigai Formation, braided river, and sheetflood, sand-bed river in Bashijiqike Formation, were identified based on the analysis of lithofacies and facies associations. Four third-order sequences（SQ1 in Baxigai Formation, SQ2-4 in Bashijiqike Formation）bounded by regional unconformities are recognized in the deposits. SQ1 consisting of deltaic deposits can be classified into Lowstand (LST) + Transgression (TST) and Highstand (HST) systems tracts based on recognition of regressive-transgressive cycle. The third-order sequences in Bashijiqike Formation consisting of fluvial deposits can be divided into Low and High Accommodation Systems Tracts （LAST and HAST） according to the degree of channel amalgamation. Sheetflood, sand-bed river deposits developed in LAST, and is characterized by highly amalgamated channels; the HAST is dominated by braided-river and floodplain deposits, with a higher floodplain ratio and more isolated channels. The tectonic uplifts at the early deposition of Bashijiqike Formation caused the overcompensation of sediments, and thus the depositional system shifted from deltaic to fluvial. The unconformity at the base of the Bashijiqike Formation was attributed to tectonic uplifts occurred in the study area. The cycle of arid to semi-arid paleoclimate led to the periodic changes from sheetflood, sand-bed river in LAST to braided-river in HAST of Bashijiqike Formation. The delta front sandstones comprise the potential favorable reservoirs in the study area.
•Four 3rd-order sequences are recognized in braided fluvial and lacustrine deposits of Lower Cretaceous in Tarim Basin.•Depositional architectures of braided river, sheetflood, sand-bed river and braided fluvial deltaic systems are documented.•Deposition and evolution from deltaic to braided fluvial systems were constrained by climatic change and tectonism.•Sand bodies of braided delta front deposits are favorable exploration targets.
Targeting the capsid protein of hepatitis B virus (HBV) and thus interrupting normal capsid formation have been an attractive approach to block the replication of HBV viruses. We carried out ...multidimensional structural optimizations based on the heteroaryldihydropyrimidine (HAP) analogue Bay41-4109 (1) and identified a novel series of HBV capsid inhibitors that demonstrated promising cellular selectivity indexes, metabolic stabilities, and in vitro safety profiles. Herein we disclose the design, synthesis, structure–activity relationship (SAR), cocrystal structure in complex with HBV capsid proteins and in vivo pharmacological study of the 4-methyl HAP analogues. In particular, the (2S,4S)-4,4-difluoroproline substituted analogue 34a demonstrated high oral bioavailability and liver exposure and achieved over 2 log viral load reduction in a hydrodynamic injected (HDI) HBV mouse model.
Yellow-emitting persistent phosphor Gd3Al2Ga3O12:Ce3+ (GAGG:Ce3+) was synthesized by two-step solid-state reactions. The phase evolution, luminescence, persistent luminescence, and thermal ...stabilities of GAGG:Ce3+ sintered in an O2 atmosphere and annealed in a CO reducing atmosphere at different temperatures were investigated. Comparing with the samples sintered only in O2, the samples annealed in CO show higher luminescence and afterglow and better thermal stability. Under 445 nm excitation, the luminescence and afterglow of GAGG:Ce3+ are similar with each other, displaying a broad yellow emission with a peak around 545 nm. By optimizing the sintering process, the internal quantum efficiency can reach as high as 71.3%. The time τ80 is about 15 ms, which is much longer than 0.4 ms required for alternating current (AC)-LEDs. These results indicate the promising application of the GAGG:Ce3+ persistent phosphor for reducing flicker from AC-LEDs.
•The luminescence intensity of GAGG:Ce3+ is improved by a two-step reaction.•The internal quantum efficiency reaches as high as 71.3%.•The persistent intensity and time of GAGG:Ce3+ are enhanced as well.
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