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991.
Xian Yang Yu Zhang Xuejie Zhang Jian Chen Haisen Huang Dongsheng Wang Xirong Chai Gening Xie Maxim S. Molokeev Haoran Zhang Yingliang Liu Bingfu Lei 《Journal of the American Ceramic Society》2020,103(3):1773-1781
The red emission with suitable peak wavelength and narrow band is acutely required for high color rendering index (CRI) white LEDs without at the cost of the luminous efficacy. Herein, the Li2Ca2Mg2Si2N6:Eu2+ red phosphor was prepared with facile solid-state method using Ca3N2, Mg3N2, Si3N4, Li3N, and Eu2O3 as the safety raw materials under atmospheric pressure for the first time, which shows red emission peaking at 638 nm with full width at half maximum (FWHM) of 62 nm under blue light irradiation and becomes the desired red phosphor to realize the balance between luminous efficacy and high CRI in white LEDs. The morphology, structure, luminescence properties, thermal quenching behavior, and chromaticity stability of the Li2Ca2Mg2Si2N6:Eu2+ phosphor are investigated in detail. Concentration quenching occurs when the Eu2+ content exceeds 1.0 mol%, whereas high-temperature photoluminescent measurements show a 32% drop from the room-temperature efficiency at 423 K. In view of the excellent luminescence performances of Li2Ca2Mg2Si2N6:Eu2+ phosphor, a white LEDs with CRI of 91 as a proof-of-concept experiment was fabricated by coating the title phosphor with Y3Al5O12:Ce3+ on a blue LED chip. In addition, the potential application of the title phosphor in plant growth LED device was also demonstrated. All the results indicate that Li2Ca2Mg2Si2N6:Eu2+ is a promising red-emitting phosphor for blue LED-based high CRI white LEDs and plant growth lighting sources. 相似文献
992.
Kacper Januchta Pengfei Liu Søren R. Hansen Theany To Morten M. Smedskjaer 《Journal of the American Ceramic Society》2020,103(3):1656-1665
Developing less brittle oxide glasses is a grand challenge in the field of glass science and technology, as it would pave the way toward new glass applications and limit the overall raw material usage and energy consumption. However, in order to achieve this goal, more insight into the correlation between the chemical composition and material properties is required. In this work, we focus on the mechanical properties of quaternary sodium aluminoborosilicate glasses, wherein systematic changes in glass chemistry yield different resistances to indentation crack initiation. We discuss the origin of the composition dependence of indentation cracking based on an evaluation of the deformation mechanism taking place during the indentation event. To this end, we use a simple metric, the extent of indent side length recovery upon annealing, to quantify the extent of reversible volume deformation. Finally, we also compare the compositional trend in crack initiation resistance to that in crack growth resistance (fracture toughness), showing no simple correlation among the two. 相似文献
993.
Ligang Xu Yaji Huang Jian Wang Changqi Liu Lingqin Liu Lei Zou Junfeng Yue Kuixu Chen 《加拿大化工杂志》2020,98(4):905-918
The presence of reducing atmospheres of the waterwall fireside in the boiler due to extensive use of low-NOx combustion mode caused severe high-temperature corrosion problems. In this study, high-temperature sulphur corrosion properties of two types of low alloyed waterwall steel (15CrMoG and 12Cr1MoVG) in two kinds of reducing-sulphidizing atmospheres were investigated by lab-scale experiments. The experimental atmospheres and temperature were simulated according to field measurements in the boiler of a thermal power plant. The experimental results showed that the reducing-sulphidizing atmosphere with CO was more corrosive, and the CO accelerated the corrosion of H2S and worsened the corrosion. The CO inhibited the formation of oxide scales, provided some corrosion resistance, and produced the intensely corrosive COS. The corrosivity of the alkali metal chlorides was limited in the reducing-sulphidizing atmosphere without CO, while the corrosion was strongly hindered in the reducing-sulphidizing atmosphere with CO. 相似文献
994.
In this study, the cost-effective graphite powder (GPd)-coated polyurethane (PGPd-PU) sponge hollow tube (PGPd-PUHT) was prepared for high-efficient continuous oil removal, the hydrophobicity-superoleophilicity PGPd-PU sponge was fabricated through a simple dip-coating method, which dipping PU sponge into GPd dispersion and drying, then coating polydimethylsiloxane (PDMS) on sponge skeleton, as-prepared sponge could selectively absorb a variety of oils up to 34 times of its own weight for dimethyl sulfoxide (DMSO). The PGPd-PUHT was prepared via wrapping PGPd-PU sponge on porous tubular support. The obtained PGPd-PUHT could continuously collect various types of oils from water surface with flux as high as 1.52 kL/m2h, and excellent separation efficiency (up to 97.7%) for toluene, as well as remarkable reusability. Moreover, a continuous floating oil collection device based on PGPd-PUHT was designed which showed excellent floating oil collection ability. In addition, our strategy possesses the advantages of low cost, simple preparation, highly efficient, and easily scale-up, showing a great potential for dealing with practical oil spill remediation. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48921. 相似文献
995.
996.
刘春 《现代塑料加工应用》2020,(1):57-60
综述了一般3D打印技术的概念、产业及其发展。重点介绍了高聚物在3D打印材料中的应用。持续跟踪结果表明:一批新型高聚物的3D打印材料推向市场,一批国际知名化工公司也在积极介入3D打印业务。 相似文献
997.
Xia Liu Xuemei Pan Demian I. Njoku Kelechi J. Uwakwe Yugui Zheng 《Journal of Adhesion Science and Technology》2020,34(19):2047-2074
AbstractThe corrosion inhibition and adsorption behavior of glutamic acid (Glu), glutamine (Gln), and their cerium complexes: cerium glutamate (Ce(Glu)) and cerium glutamine (Ce(Gln)) on mild steel in 0.5?M HCl solutions were studied at 25 and 55?°C and concentration range of 25–200?ppm using potentiodynamic polarization (PDP) and electrochemical impedance spectroscopic (EIS) techniques. The inhibition efficiency was found to be dependent on the concentration and temperature of the system. The potentiodynamic polarization results suggest that the compounds act as mixed-type inhibitors with dominant cathodic inhibition. The mechanism of adsorption deduced from the variation of inhibition efficiency with temperature, as well as the activation parameters, suggest significant physisorption of the inhibitor molecules on the metal surface. The experimental data adhere to the Langmuir and El-Awady et al. kinetic adsorption models. The extent of inhibition was found to be Ce-Gln?>?Gln and Ce-Glu?>?Glu. The scanning electron microscope was employed for the morphological studies and the characteristic of the protective layer on the steel surface verified using UV-Vis spectroscopy and FTIR spectroscopy. Adsorption of the inhibitors on Fe (110) surface was evaluated theoretically. 相似文献
998.
999.
Lulu Wang Luyao Teng Xiaokang Zhang Xiaohua Liu Qianqian Lyu 《Journal of Adhesion Science and Technology》2020,34(17):1840-1852
AbstractThe formation of underwater adhesion is a complicated physiological process and many different types of enzymes are found to be essential apart from structural proteins. Previous studies have shown that various tyrosinases were present in marine adhesives, but little information is available about the over-expression and enzymatic characterization of these enzymes. Specifically, this study first identified four significantly up-regulated tyrosinases in the pedal disc of Haliplanella luciae by means of multi-omics technology, and made preliminary bioinformatics predictions. Sequence alignment showed that the Tyr1_Hl contained six conserved His residues that bind to copper ions, of which a tyrosinase with diphenolase activity named as Tyr1_HlΔ, was expressed in Escherichia coli BL21 (DE3) cells and purified by affinity chromatography. Enzymatic characterization showed that the activity of Tyr1_HlΔ was Cu2+ dependent and maximum catalytic activities were in 20?mM Tris–HCl (pH 8.0) at 37?°C. In summary, we identified novel tyrosinases in the pedal disks of sea anemone for the first time and the Tyr1_HlΔ was successfully recombinant expressed. Our study will provide basis for future exploration of bio-adhesion mechanism and design of bio-adhesives derived from sea anemones. 相似文献
1000.
为克服三乙醇胺早强剂对水泥抗折强度和后期强度的影响,合成了马来酸三乙醇胺酯,并通过背散射电子成像(BSE)和BET分析,研究了马来酸三乙醇胺酯对水泥水化程度、C-S-H含量和水泥水化28 d分形维数的影响。结果表明:马来酸三乙醇胺酯可促进水泥水化尤其是水泥中硅酸盐相的水化;复掺马来酸三乙醇胺酯和聚羧酸减水剂,可显著提高水泥水化产物中C-S-H的含量;三乙醇胺降低了水泥石28 d的分形维数,马来酸三乙醇胺酯单掺及与聚羧酸减水剂复掺则使水泥石28 d的分形维数提高。由此可见,马来酸三乙醇胺酯作为增强型水泥早强剂具有广阔的应用前景。 相似文献