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The development direction of advanced solid-state lasers is higher output power and better beam quality. Rare earth ion doped yttrium aluminum garnet transparent ceramics are preferred materials for solid-state laser gain media, but thermal effects during the pumping process deteriorate the beam quality and hinder further increase in output power. The heat generation and dissipation of laser ceramics with complex configurations are more uniform during the pumping process, which can significantly reduce thermal effects. Compared with traditional preparation methods, 3D printing is able to form more complex design structures, suppress thermal effects, and achieve integration and miniaturisation of multi-module devices, driving lasers towards a wider range of applications. In this paper, several traditional methods for the preparation of laser ceramics with complex configurations are introduced firstly, and the advantages and limitations are analyzed. Then, the research status and problems in 3D printing yttrium aluminum garnet-based laser ceramics are systematically reviewed. Common 3D printing methods include direct ink writing, stereolithography, digital light processing, material jet printing, two-photon polymerization and micro-continuous liquid interface printing. Among them, there are interlayer defects in the samples printed by stereolithography and digital light processing, resulting in severe scattering losses. Material jetting printing combined with dry pressing can be used to manufacture planar waveguides. Two-photon polymerization and micro-continuous liquid interface printing are suitable for the fabrication of highly complex structures at micrometer scales. Direct ink writing not only enables the fabrication of laser ceramics for the first time, but also has the most extensive relevant research and is still the most promising method for the preparation of laser ceramics with complex configuration. At the end of this paper, the current problems and research prospects of yttrium aluminum garnet-based laser ceramics prepared by 3D printing are summarized. [ABSTRACT FROM AUTHOR]

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The combination of up-conversion materials and photocatalysts can produce the effect of "redshifting" of absorption spectrum, which is of great significance for improving the degradation efficiency of photocatalysts. To improve the utilization of CdS in near-infrared light, the up-conversion luminescent material K3ScF6:Tm3+,Yb3+ with cryolite structure was synthesized by high-temperature solid-phase reaction method, and a new photocatalytic composite material K3ScF6:Tm3+,Yb3 + /CdS was prepared by combining it with CdS by high-energy ball milling method. The composition, structure and properties were systematically characterized by X-ray powder diffractometer ( XRD), field emission scanning electron microscopy ( SEM), fluorescence spectroscopy (PL) and UV-Vis diffuse reflection absorption spectroscopy. Simultaneously, the photodegradation efficiency and mechanism of K3 ScF6: Tm3 +, Yb3 + /CdS to rhodamine B ( RhB) were studied. The results show that the optimal mass composition ratio of K3ScF6:Tm3+,Yb3 + and CdS is 3. 6:1, and the introduction of up-conversion luminescent materials K3ScF6:Tm3+,Yb3 + synergistically promots the photocatalytic efficiency of CdS. The • OH and • O²- participated in the degradation of RhB, and • OH plays a major role. In addition, under the optimal recombination ratio, the degradation rate of K3ScF6:Tm3+, Yb3 + /CdS samples reaches 99. 9%, which is nearly 50 times higher than that of uncompounded CdS after 80 min. All results show that K3 ScF6: Tm3 +, Yb3 + /CdS photocatalytic composites has potential application value in the field of photocatalysis. [ABSTRACT FROM AUTHOR]

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Copyright of Natural Gas Geoscience is the property of Natural Gas Geoscience and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Geology & Exploration is the property of Geology & Exploration Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to obtain up-conversion luminescent materials with bright red emission, a series of Yb3+, Er3+, Mn2+- doped Gd2O3 microcrystals were prepared by simple chemical precipitation method, and their morphology, structure and luminescent properties were characterized. The results show that Gd2O3 :10%Yb3+, 1% Er3+ microcrystals exhibit a flower-like morphology, and the average diameter is 2. 28 μm. After calcination at high temperature, the sample presents a cubic Gd2O3 structure with good crystallinity, and Mn2+ doping does not affect the morphology and crystal phase of the product. Under 980 nm near-infrared light excitation, Gd2O3 : 10% Yb3+, 1% Er3+ microcrystals show orange-red luminescence, which corresponds to the 4F9/2→4I15/2 transition of Er3+. With the increase of Mn2+ doping concentration (molar fraction), the luminescence intensity of Gd2O3:10% Yb3+, 1% Er3+, x% Mn2+ microcrystals first increases and then decreases, and the luminescence color gradually turns to red, which is consistent with the CIE color coordinate. At the same time, the up-conversion luminescence mechanism and the possible energy transfer process of Gd2O3: 10% Yb3+, 1% Er3+, x% Mn2+ microcrystals were analyzed according to the relationship between luminescence intensity and excitation power. [ABSTRACT FROM AUTHOR]

Environment Barrier Coatings (EBCs) working in real service process meet not only environment of high-temperature water vapour, but also face of calcium and magnesium corrosion. In this paper, EBCs made by plasma spray with Yb2Si2O7 coatings were tested by thermal shock in a calcium/magnesium-included water vapour environment at 1 250 °C for 300 cycles. The results showed that there formed two-layer corrosion structures at the coating surface. The topmost layer sustained calcium corrosion, forming obvious multi-phase structure with large pores with phases of (Yb/Ca)2 Si2 O7, (Yb/Ca)2 SiO5 and (Ca/Yb)2 SiO4. The subsurface layer sustained both calcium and magnesium corrosion but mainly the magnesium corrosion, also forming multi phases (Yb/Mg/Ca)2SiO5 and (Mg/Ca/Yb)2SiO4 with relatively dense structure. Via analyses on surface morphology, cross section microstructure, micro-EDS composition and XRD phase structures, the chemical reaction mechanism of the EBC coatings was studied under the calcium/magnesium-included water-vapour thermal shock environment, and the failure mechanism of the coating was provided. [ABSTRACT FROM AUTHOR]

In recent years, rare-earth-doped up-conversion luminescent materials have received increasing attention in solar cells, industrial lighting, and medical fields. The current research is mainly to find new and efficient rare-earth up-conversion luminescent materials. For the study of luminescent materials, the choice of matrix is particularly important. Molybdate stands out from many matrixes due to its stable physical and chemical properties and low phonon energy. In this paper, molybdate is selected as the matrix material doped with rare earth ions. Tm and Yb ion-doped NaGd (MoO4)2 samples are prepared by hydrothermal method, and the change of the luminescence characteristics of NaGd (MoO4)2 phosphor is explored by changing the ion doping concentration. Through the analysis of its spectrum, it is found that under 980 nm laser irradiation, NaGd (MO4)2: Yb3+/Tm3+ has a blue emission peak at 477 nm and a red emission peak at 648 nm. When the doping mole fraction of fixed Yb3+ is 6% and the doping mole fraction of Tm3+ is changed to 0, 0. 5%, 1% and 2% respectively, it is found that with the increase of the doping mole fraction of Tm3+, the intensity of the emission peak at 477 nm first increases and then decreases. When the doping mole fraction of Tm3+ is 0. 5%, the luminous intensity of molybdate phosphor first increases and then decreases to the maximum. It has broad prospects in the application of multi-color lighting and light source devices. [ABSTRACT FROM AUTHOR]

Copyright of Experimental Technology & Management is the property of Experimental Technology & Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Piezoelectrics & Acoustooptics is the property of Piezoelectric & Acoustooptic and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

BACKGROUND: Mircobeam Lu-Hf isotopic analysis on minerals provides an important means to understand the microscopic process of magmatic activity and metamorphic reaction and to trace provenance of sediment, which greatly promotes the development of petrogeochemistry. Many methods were provided to obtain accurate and precise microbeam Lu - Hf isotopic data, and many mineral standards for microbeam Lu - Hf isotopic analysis were developed. OBJECTIVES: To review and understand the microbeam methods for Lu-Hf isotopic analysis. METHODS: Systematic compilations of published data of standards and discussion on the different methods for microbeam Lu-Hf isotopic analysis. RESULTS: The development history of microbeam Lu-Hf isotopic analysis in the past 30 years is reviewed, and the influence of 176Yb and 176Lu isobars, REE oxides, and Ta-rich matrices on the precision and accuracy of Hf isotope measurement is systematically evaluated as well as the different correction strategies and programs provided in previous studies. In addition, a comprehensive compilation of the different Yb and Lu isotopic compositions reported in references and the different methods of microbeam Lu-Hf isotopic analyses on various Hf-rich minerals such as zircon, baddeleyite, zirconolite, zirkelite, calzirtite, eudialyte, rutile, cassiterite, and columbite-group minerals is made. The micro-drill/ micro-saw sampling Lu-Hf isotopic analysis of Lu-rich minerals has played an important role in revealing the multi-stage orogenic process and the duration of mineral growth. The advent of laser ablation inductively coupled plasma triple quadrupole mass spectrometry (LA-ICP-Q-MS/ MS) has increased the spatial resolution of Lu-Hf single-spot/ isochron dating analysis of Lu-rich minerals to the micrometer scale. This method relies on the collision reaction of Hf and NH3 to realize the online separation of Hf from Lu, and achieves the purpose of synchronous measurement of 176Lu/ 177Hf and 176Hf/ 177Hf ratios, which is introduced in detail. CONCLUSIONS: The new generation of tandem multi-collector sector field mass spectrometer with collision/ reaction cell has high stability and sensitivity, which can be used to determine online separation of Hf from REEs, produce high-precision Hf isotope measurements for high Yb/ Hf or Ta-rich minerals under high spatial resolution conditions, and significantly improve the precision and accuracy of microbeam Lu -Hf isotopic analysis. This deserves extensive attention in the future. [ABSTRACT FROM AUTHOR]

In order to improve the fluorescence properties of inorganic Y2O3 upconversion nanoparticles (UCNPs),and realize their in vivo imaging calibration simultaneously, Y2O3 : Yb3+, Er3+ @ Y2O3 : Yb3+ UCNPs with different shell thickness were prepared by co-precipitation and gradient synthesis. The morphology, structure and fluorescence properties of the samples were characterized by transmission electron microscopy (TEM) scanning, X-ray diffraction (XRD), up-conversion fluorescence (UCL) spectrum, and UCL lifetime. The results show that the small size of Y2O3 : Yb3+, Er3+ @ Y2O3: Yb3+ UCNPs core-shell particles were prepared by co-precipitation method, and the average particle size ranges from 25.57 nm to 26.24 nm. The synthesis process was optimized by adjusting the concentration of Yb3+ and water bath time, and the scheme of high emission intensity and long fluorescence life (80% Yb doping, 8 h water bath) was obtained. The fluorescence emission characteristics of high red-green ratio determine that red channel is more suitable for in vivo fluorescence calibration and detection in small animals. [ABSTRACT FROM AUTHOR]

Copyright of Asian Journals of Ecotoxicology is the property of Gai Kan Bian Wei Hui and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of the Chinese Society of Rare Earths is the property of Editorial Department of Journal of the Chinese Society of Rare Earths and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Natural Gas Geoscience is the property of Natural Gas Geoscience and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The eastern Yangtze Gorges area in Hubei belongs to the Upper Yangtze block of South China plate. The cherts from Ordovician Nanjinguan Formation limestone in this area are mostly developed as nodules and strips. Based on the detailed field geological survey, the petrography and geochemistry characteristics of these cherts were analysed, and the genesis and sedimentary environment were discussed. The results show that the main mineral compositions of cherts are quartz and chalcedony. C herts are poor in Mn and Fe. the ratios of Al/C A1 + Fe+Mn) range from 0. 27 to 0. 84 with an average of 0. 64. which is closer to that of the biogenic cherts. The ratio of Mno/ Tio2 is much less than 0. 5. indicating cherts in this area form in the shallow sea sedimentary environment near the edge of the land. The ratios of l h IJ range from 0. 02 to 0. 86 with an average of 0. 24. C herts have low REE content, the total REE content is (0. 67-27. 79)X 10-6. l he NASC'-normalized REE pattern shows a relatively gentle right-leaning trend. the 8('e ranges from 0. 97 to 1. 19 with an average of 1.11. and the average value of (La/Yb)N is 1. 31 . reflecting a bio-chemical origin rather than hydrothermal origin, and cherts form in a selling of continental margin. The carbon and oxygen isotope information of the host limestone of cherts in Nanjinguan Formation shows that the o1 ( ranges from -2. 37%r, to 2. 30%r. with an average of - 0.006 4%o. the 818 O ranges from -9. 04%o to - 6. 49%c with an average of -7.61 %c. The paleoenvironmental temperature varies from 4 C to 21 C. l he geochemistry characteristics of cherts in Nanjinguan Formation limestone indicate that cherts are biogenic origin and form in a warm and anoxic continental marginal tectonic sellings. [ABSTRACT FROM AUTHOR]

Hatu pluton in the southern margin of West Junggar invades into Early-Middle Devonian marine volcanic-sedimentary strata. The lithology of Hatu pluton is mainly composed of monzonitic granite, syenite granite and a small amount of alkali feldspar granite, which is an ideal object to study the tectonic setting of Late Carboniferous in West Junggar. The granites in Hatu pluton have high SiO2(72.06%-76.53%), Na2O+K2O(7.80%-8.57%)and Al2O3(12.55%-14.06%)contents, low CaO(0.20%-1.58%)and MgO(0.07%-0.42%)contents, with A/CNK(1.06-1.15)and A/NK(1.15-1.36)showing the characteristics of weakly peraluminous-strongly peraluminous granite. The granites have high total contents of REE((88.14-139.53)×10-6)and ratios of LREE/HREE((La/Yb)N is 3.04-6.50), and the chondrite-normalized REE pattern exhibits a typical right-dip “V” shape with a strong negative Eu anomaly, indicating that some plagioclases may be retained as a residue in the source area or there is the separation and crystallization of plagioclases. Meanwhile, the granites display significant enrichments of large ion lithophile elements(Rb, Th, U, K and Pb), relative enrichments of Zr and Hf, and depletions in Ba and Nb, especially Sr, Ti and P. The above characteristics demonstrate that Hatu pluton is a typical weakly peraluminous-strongly peraluminous A2-type granite. Combined with diagrams of major and trace elements, Hatu pluton in West Junggar is formed in a post-orogenic extension setting, and the petrogenesis is related to the juvenile crust that comprised both oceanic crust and island arc, which results from partial melting and fractionation under low pressure condition. [ABSTRACT FROM AUTHOR]

Boguorize area is located in the central part of Bangonghu-Nujiang suture zone, the northern margin of Gangdese belt, Tibet. At present, the closure time of Bangonghu-Nujiang ocean basin is controversial. The A-type granite outcropped in Boguorize area intrudes into the first member of Woronggou Formation in the form of rock stocks, and its lithology is mid-fine-grained biotite granite porphyry. The rock is characterized by high SiO2(the contents are 70. 61 %-74.94%), K2 (4. 96%-7. 48%), lean Al2O3 ( 11. 90%13. 79%), high ratio of FeOT/MgO (7. 47-25. 88), and low TiO2(0. 16%-0. 25%), which belongs to weak aluminum-quasi-aluminum alkaline series (A/CNK is 0. 90-1. 12, A/NK is 1. 10-1. 34). The total contents of REE are (179. 80-370. 29) X 10 h, (La/Yb)N is 5. 36-8. 70, and Eu anomaly is 0. 28-0. 61. The chondrite-normalized REE pattern is right-leaning seagull type, which belongs to typical aluminous A-type granite. On the primitive mantle-normalized trace element spider diagram, the large ion lithophile elements and high field strength elements (Rb, Th, U, K, Zr and Hf) are obviously enriched.while Ba, Sr, Nb, Ta and Ti are obviously depleted. The higher contents of Zr, Nb, Ce and Y, and the higher ratios of Y/Nb, Yb/Ta and Ce/Nb indicate that the A-type granite is A2type. The combination research of petrography, geochemistry and regional geological data shows that the A-type granite in Boguorize area forms in the extension of the lithosphere after the collision. It is the product of the lower crust displacing, which causes the asthenosphere material upwelling and heats the metamorphic mudstone in the upper crust, and make the metamorphic mudstone occur partially melt and undergo a certain degree of separation crystallization. The LA-ICP-MS zircon U-Pb age of A-type granite is (110. 8 + 1. 3)Ma, indicating that it is formed in late Early Cretaceous. It is estimated that Bangonghu-Nujiang ocean basin is closed at least in late Early Cretaceous. [ABSTRACT FROM AUTHOR]

The Zhuxiling W-polymetallic deposit in the southern Anhui is located at the eastern margin of Jiangnan paleocontinent, the rock closely associated with the mineralization is the granodiorite. The petrographic, mineralogical and petrogeochemical studies on the granodiorite were carried out. The results show that the granodiorite has moderate contents of SiO2(64.67%-67.33%), Al2O3(15.26%-16.26%)and MgO(1.09%-1.37%), the ratio of K2O/Na2O is higher than 1.1 with the A/CNK ratio of 1.00-1.04, indicating that the granodiorite belongs to high-K cal-alkaline series and weakly peraluminous series; the granodiorite shows enrichment of Rb, K, and depletion of Nb, Ta, Zr and Ti, the total contents of REE are(90.40-166.94)×10-6 with the ratios of LREE/HREE(7.15-15.16)and(La/Yb)N(11.60-37.32), the chondrite-normalized REE pattern displays a characteristic listric-shaped REE profile; the whole-rock zircon saturation thermometer and the chemical composition of biotites in the granodiorite indicate that the diagenetic temperatures range from 720 ℃ to 780 ℃, and the diagenetic pressures range from 73 to 169 MPa with corresponding emplacement depth varying from 2.75 to 6.39 km, and the calculated oxygen fugacity varies from -17.52 to -10.09. Collectively, the granodiorite belongs to I-type granitic rock, which is formed in the moderate-high temperature, water-rich and oxidized environment, and it is likely related to the previously proposed EW-trending slab-window that caused by the rupture of the subduction of paleo-Pacific plate [ABSTRACT FROM AUTHOR]

Hydroxyapatite was extensively used to repair osteoshortage recently. To improve its bondibility and X-ray obstructibility, we added ytterbium oxide of different proportions in the synthetic process of hydroxyapatite. Ytterbium oxide is characterized by high activity and X-ray obstructibility. A cheap biomaterial with good biocompatibility and high X-ray obstructibility has been got in this way.