Chelation-mediated in-situ formation of ultrathin cobalt(oxy)hydroxides on hematite photoanode towards enhanced photoelectrochemical water oxidation

In this work,a facile chelation-mediated route was developed to fabricate ultrathin cobalt(oxy)hydroxides(CoOOH)nanosheets on hematite photoanode(Fe_(2)O_(3)).The route contains two steps of the adsorption of[Co-EDTA]^(2-)species on Fe_(2)O_(3) nanorod array followed by the hydrolysis in alkaline solution.The resulting CoOOH/Fe_(2)O_(3) exhibits a remarkably improved photocurrent density of 2.10 mA cm^(-2) at 1.23 V vs.RHE,which is ca.2.8 times that of bare Fe_(2)O_(3).In addition,a negative shift of onset potential ca.200 mV is achieved.The structural characterizations reveal the chelate EDTA plays important roles that enhance the adsorption of Co species and the formation of contact between CoOOH and Fe_(2)O_(3).(Photo)electrochemical analysis suggests,besides providing active sites for water oxidation,CoOOH at large extent promotes the charge separation and the charge transfer via passivating surface states and suppressing charge recombination.It also found CoOOH possesses some oxygen vacancies,which could act as trapping centers for photogenerated holes and facilitate the charge separation.Intensity modulated photocurrent spectroscopy(IMPS)shows that,under low applied potential the water oxidation mainly occurs on CoOOH,while under high applied potential the water oxidation could occur on both CoOOH and Fe_(2)O_(3).The findings not only provide an efficient strategy for designing ultrathin(oxy)hydroxides on semiconductors for PEC applications but also put forward a new insight on the role of CoOOH during water oxidation.

Influence of the Thermal Barrier Coatings Design on the Oxidation Behavior

The properties of two different types of thermal barrier coatings （TBCs） were compared to improve the surface characteristics on high temperature components. These TBCs consisted of a duplex TBC and a five-layered functionally graded TBC. NiCrAIY bond coats were deposited on a number of Inconel-738LC specimens using high velocity oxy-fuel spraying （HVOF） technique. For duplex coating, a group of these specimens were coated with yttria stabilized zirconia （YSZ） using plasma spray technique. Functionally graded NiCrAIY/YSZ coatings were fabricated by plasma spray using co-injection of the two different powders in a single plasma torch. The amount of zirconia in functionally graded coatings were gradually increased from 30 to 100 vol. pct. Microstructural changes, thermally grown oxide （TGO） layer growth and damage initiation of the coatings were investigated as a function of isothermal oxidation test at 970℃. As a complementary test, the performance of the fabricated coatings by the optimum processing conditions was evaluated as a function of intense thermal cycling test at 1100℃. Also the strength of the adhesive coatings of the substrate was also measured. Microstructural characterization was analyzed by scanning electron microscopy （SEM） and optical microscopy whereas phase analysis and chemical composition changes of the coatings and oxides formed during the tests were studied by XRD （X-ray diffraction） and EDS （energy dispersive spectrometer）. The results showed that microstructure and compositions gradually varied in the functionally graded coatings. By comparison of duplex and functionally graded TBCs oxidation behavior （duplex failure after 1700 h and funcitionally graded TECs failure after 2000 h）, thermal shock test and adhesion strength of the coatings, the functionally graded TBC had better performance and more durability.

Gas-phase oxidation of NO at high pressure relevant to sour gas compression purification process for oxy-fuel combustion flue gas

The removal of NO from oxy-fuel combustion is typically incorporated in sour gas compression purification process. This process involves the oxidation of NO to NO2 at a high pressure of 1–3 MPa, followed by absorption of NO2 by water. In this pressure range, the NO conversion rates calculated using the existing kinetic constants are often higher than those obtained experimentally. This study aimed to achieve the regression of kinetic parameters of NO oxidation based on the existing experimental results and theoretical models.Based on three existing NO oxidation mechanisms, first, the expressions for NO conversion against residence time were derived. By minimizing the mean-square errors of NO conversion ratio, the optimum kinetic rate constants were obtained. Without considering the reverse reaction for NO oxidation, similar mean-square errors for NO conversion ratio were calculated. Considering the reverse reaction for NO oxidation based on the termolecular reaction mechanism, the minimum mean-square error for NO conversion ratio was obtained. Thus, the optimum NO oxidation rate in the pressure range 0.1–3 MPa can be expressed as follows:-d[NO]/dt=d[NO2]/dt=0.0026[NO]2[O2]-0.0034[NO2]2 Detailed elementary reactions for N2/NO/NO2/O2 system were established to simulate the NO oxidation rate. A sensitivity analysis showed that the critical elementary reaction is 2 NO + O2? 2 NO2. However, the simulated NO conversions at a high pressure of 10–30 bar are still higher than the experimental values and similar to those obtained from the models without considering the reverse reaction for NO oxidation.

miR-211 regulates the antioxidant function of lens epithelial cells affected by age-related cataracts

AIM： To investigate the effects and mechanism of miR-211 in mediating the antioxidant function of lens epithelial cells affected by age-related cataracts. METHODS： Real-time quantitative polymerase chain reaction （RT-qPCR） was used to detect miR-211 expression in the anterior lens capsules of healthy people, the anterior lens capsules of patients with age-related cataracts, and human epithelial cell line （SRA01/04） cells exposed to oxidative stress. A 2＇, 7＇-dichloro-fluorescein diacetate （DCFH-DA） probe was used to measure the levels of endogenous reactive oxygen species （ROS） in human lens epithelial cells （hLECs） exposed to 400 pmol/L H2O2 for lh. SRA01/04 cells were transfected with either miR-211 mimics, mimic controls, miR-211 inhibitors or inhibitor controls. After 72h, these cells were exposed to 400 IJmollL H2O2 for lh, then p53 and Bax mRNA expression were measured using RT-qPCR. p53 and Bax protein expression were also measured by Western blotting analysis. Finally, cell viability was assessed using an MTS assay. RESULTS： Compared to the control group, expression of miR-211 in the anterior lens capsules of age-related cataract patients and in SRA01/04 cells exposed to oxidative stress was significantly increased （P〈0.001）. Levels of endogenous ROS were significantly elevated in hLECs exposed to oxidative stress （P〈0.001）. Compared to the mimic control group, the hLECs in the miR-211 mimic group expressed significantly higher levels of p53 and Bax mRNA and protein while cell viability was significantly reduced （P〈0.001）. Conversely, p53 and Bax mRNA and protein expression were significantly reduced in the miR-211 inhibitor group as compared to the control group, while the cells in this group had much higher levels of call viability （P〈0.001）. CONCLUSION： miR-211 is upregulatsd in the anterior lens capsules of age-related cataract patients, miR-211 decreased the antioxidative stress capacity of lens epithelial cells by upregulating p53 and Bax, while inhibiting cell proliferation and repair. This finding suggests that miR-211 may play a key role in the development of age-related cataracts.

Effects of phosphate precursors on morphology and oxygen evolution reaction activity of NiFe(oxy)hydroxide on nickel foams

NiFe(oxy)hydroxides nanosheets were synthesized on nickel foams via co-precipitation and electrochemical activation. It is found that the phosphate precursors(Na_(3)PO_(4), Na_(2)HPO_(4)and NaH_(2)PO_(4)) have diverse effects on the morphology and thus the oxygen evolution reaction activity of the formed final catalysts. The resulting NiFe(oxy)hydroxides nanosheets prepared with Na_(2)HPO_(4)demonstrate a low overpotential of 205 m V to achieve a current density of 50 mA/cm^(2) with a Tafel slope down to 30 mV/dec in 1 mol/L KOH, and remain stable for 20 h during stability test.

Boosting overall water splitting by incorporating sulfur into NiFe(oxy)hydroxide

Developing highly active and cost-effective electrocatalysts for enhancing the hydrogen evolution reaction(HER)and oxygen evolution reaction(OER)is a significant challenge for overall water splitting.Sulfur-incorporated nickel iron(oxy)hydroxide(S-NiFeOOH)nanosheets were directly grown on commercial nickel foam using a galvanic corrosion method and a hydrothermal method.The incorporation of sulfur into NiFeOOH enhanced the catalytic activity for the HER and OER in 1 M KOH electrolyte.The enhanced catalytic activity is attributed to the change in the local structure and chemical states due to the incorporation of sulfur.High performance for overall water splitting was achieved with an alkaline water electrolyzer.This was realized by employing S-NiFeOOH as a bifunctional electrocatalyst,thereby outperforming a water electrolyzer that requires the usage of precious metal electrocatalysts(i.e.,Pt/C as the HER electrocatalyst and IrO_(2) as the OER electrocatalyst).Moreover,when driven by a commercial silicon solar cell,an alkaline water electrolyzer that uses S-NiFeOOH as a bifunctional electrocatalyst generated hydrogen under natural illumination.This study shows that S-NiFeOOH is a promising candidate for a large-scale industrial implementation of hydrogen production for overall water splitting because of its low cost,high activity,and durability.In addition,the solar-driven water electrolyzer using S-NiFeOOH as a bifunctional electrocatalyst affords the opportunity for developing effective and feasible solar power systems in the future.

Spectrophotometric Assay for the Quantification of Plasma Ethanol Levels in Mice through Chromium-Ethanol Oxidation-Reduction Reaction

The quantification of blood/plasma ethanol concentration (BEC/PEC) is of great importance in experiments involving basic research, clinical studies, and bioethanol production. Traditional methods commonly used to measure BEC can be expensive and require high-cost equipment and qualified labor. The aim of this study was to develop a low-cost method that can be performed with simple infrastructure commonly available in research laboratories. For this, we developed a protocol to quantify PEC in mice, using the method of reduction of potassium dichromate by ethanol. However, this oxidation-reduction (redox) reaction is not specific to ethanol. Thus, the PEC was measured following a sequence of chemical reactions to eliminate the reductive interfering substances presented in the samples. Firstly, we evaluated the sensitivity of the dichromate reactive to ethanol and to different reducing substances found in the plasma, in order to determine which the main interfering substances are. Next, once the main interfering substances were determined in the dichromate reduction, plasma was assayed for PEC. First, mice received intraperitoneally (i.p.) saline (basal reading, 0% ethanol) or ethanol injections (0.5, 1, 2, 3, and 4 g/kg) and had their plasma collected. After plasma deproteinization and plasma glucose oxidation, it was mixed with the dichromate/acetic acid reactive, and then the products of the redox reaction were determined by the spectrophotometric method. Then, we determined the PEC with the same plasma samples using a commercial ethanol assay kit as a positive control. We found an excellent correlation between the administered ethanol doses and PECs in both the methods analyzed. The values of PEC found in the dichromate reaction method were similar to those obtained in the literature with the same ethanol doses, and to the commercial enzyme activity assay. Therefore, despite the need for a background reading, this method can be successfully applied to determine PEC using low-cost chemical reagents.

Effects of Electrolytes on the Oxidation of Carbon Fibres

Effects of electrolytes on the oxidation of carbon fibreswere investigated by ion chromatography and cyclic vol-tammogram measurement.The results indicate that theconcentration of nitrate ion decreases with increase oftreatment time,and the concentration of phosphate ionkeeps a constant in the process of electrochemical oxida-tion.Nitrate ions have more effective electrochemical ox-idation ability than other anions.The mechanism of elec-trochemical oxidation of carbon fibres was suggested.

Unraveling the role of NiSnPH@OOH/CC perovskite hydroxide for efficient electrocatalytic oxidation of methanol to formate

The sluggish kinetics of oxygen evolution reaction(OER)is the key tailback for hydrogen production from the water electrolysis.Masking OER with thermodynamically auspicious methanol oxidation reaction(MOR)can significantly boost the H_(2) and value-added products production.However,it is currently challenging to achieve a synergistic manipulation of product selectivity and performance for MOR electrocatalyst.Herein,we report NiSnPH@OOH/CC(CC=carbon cloth)perovskite hydroxide nanosphere as an efficient MOR electrocatalyst with high activity,stability,and selectivity towards methanol oxidation to formate.A surface amorphous layer of defect rich NiOOH was generated in operando by selective Sn leaching with stable perovskite hydroxide bulk structure,which mitigates the oxidative power and optimizes the local coordination environment of the active NiOOH sites.In situ Raman combined with electrochemical studies further confirm the key active species,NiOOH,generated in operando enhance the MOR and blocking the over oxidation of methanol to CO_(2).As a result,NiSnPH@OOH/CC effectively masks the OER and attains>99%selectivity with 100%Faradic efficiency for methanol-to-formate.The results of this study show the advances of NiSnPH@OOH/CC as an efficient electrocatalyst for MOR and also suggest its potential applications for various small organic molecules oxidation.

A novel septenary high-entropy(oxy)hydroxide electrocatalyst for boosted oxygen evolution reaction

High-entropy materials(HEMs)have attracted extensive attention in the field of electrochemical catal-ysis due to their unique properties.However,the preparation of high-entropy catalysts typically relies on high-temperature,energy-intensive,and time-consuming synthesis methods due to their compositional complexity.In this study,a facile low-temperature electrochemical reconstruction approach is adopted to synthesize Ag-decorated septenary Co-Cu-Fe-Mo-Zn-Ag-Ru high-entropy(oxy)hydroxide electro-catalysts for oxygen evolution reaction(OER).By introducing Ag and Ru elements and implanting Ag nanoparticles to co-regulate the electronic structure of the catalysts,the as-prepared catalyst achieves remarkable OER performance with a low overpotential of 298 mV at 100 mA/cm^(2)and a small Tafel slope of 30.1 mV/dec in 1 mol/L KOH.This work offers a valuable strategy for developing high-performance high-entropy OER electrocatalysts.

Regulate electric double layer for one-step synthesize and modulate the morphology of(oxy)hydroxides

FeOOH have received considerable attention due to their natural abundance and cost-effectiveness.Despite the significant progress achieved,the one-step synthesis of integrated FeOOH is still a major challenge.Meanwhile,the current research on FeOOH catalyst still suffers from the unclear mechanism of controlling morphology.Here,density functional theory(DFT)calculations and X-ray photoelectron spectroscopy(XPS)demonstrated the strong electron-capturing and hydrogen absorption ability of Co in FeOOH,which further promotes the formation and stabilization of FeOOH.We used a one-step electrodeposition method to synthesize Co introduced FeOOH integrated electrocatalyst and propose to introduce ions with different valence states to regulate the morphology of FeOOH by precise modulation of electric double layer(EDL)composition and thickness.The prepared Co-FeOOH-K^(+)has a larger electrochemically active surface area(ECSA)(325 cm^(2))and turnover frequency(TOF)value(0.75 s^(-1)).In the electrochemical experiments of an alkaline anion exchange membrane electrolyzer,Co-FeOOH-K^(+)shows better oxygen evolution performance than commercial RuO_(2) under industrial production conditions and has good industrial application prospects.

Senescence-specific Alteration of Hydrogen Peroxide Levels in Arabidopsis thaliana and Oilseed Rape Spring Variety Brassica napus L.cv.Mozart

In order to analyze the signaling function of hydrogen peroxide （H202） production in senescence in more detail, we manipulated intracellular H202 levels in Arabidopsis thaliala （L.） Heynh by using the hydrogen- peroxide-sensitive part of the Escherichia coil transcription regulator OxyR, which was directed to the cytoplasm as well as into the peroxisomes. H202 levels were lowered and senescence was delayed in both transgenic lines, but OxyR was found to be more effective in the cytoplasm. To transfer this knowledge to crop plants, we analyzed oilseed rape plants Brassica napus L. cv. Mozart for H20~ and its scavenging enzymes catalase （CAT） and ascorbate peroxidase （APX） during leaf and plant development. H202 levels were found to increase during bolting and flowering time, but no increase could be observed in the very late stages of senescence. With increasing H202 levels, CAT and APX activities declined, so it is likely that similar mechanisms are used in oilseed rape and Arabidopsis to control H202 levels. Under elevated CO2 conditions, oilseed rape senescence was accelerated and coincided with an earlier increase in H202 levels, indicating that H202 may be one of the signals to inducing senescence in a broader range of Brassicaceae.

微管蛋白聚合抑制剂OXi8006的合成新方法

2-(3'-羟基-4'-甲氧基苯基)-3-(3",4",5"-三甲氧基苯甲酰基)-6-甲氧基吲哚(OXi8006)能够有效抑制微管蛋白聚合,而表现出良好抗癌活性.目前报道的OXi8006全合成路线较长、总收率低,且反应条件苛刻.为了更高效地合成该化合物,从而为进一步的活性和构效关系研究提供原料.以廉价易得的异香兰素为起始原料,先合成芳基乙炔,再与3,4,5-三甲氧基苯甲醛通过亲核加成、氧化反应获得二芳基炔酮、二芳基炔酮再与邻碘代苯胺通过杂迈克尔加成和分子内Heck反应构建出OXi8006的主体结构——2-芳基-3-芳酰基取代吲哚,从而缩短了合成路线,并使总收率提高到20%.

Effects of acupuncture at Shu,Yuan,and Mu acupoints on blood se-rum uric acid and xanthine oxidase levels in a rat model of gout and hyperuricemia

OBJECTIVE: To investigate the effects of needling the Shu, Yuan, and Mu acupoints on serum uric acid(SUA), xanthine oxidase(XOD), and alkaline phosphatase(ALP) levels and the kidney index in a rat model of gout and hyperuricemia.METHODS: Fifty rats were randomly divided into five groups: blank, model, Shu-acupoint, Yuan-acupoint, and Mu-acupoint groups. A rat model of hyperuricemia was developed by intragastric administration of adenine and ethambutol. This experiment last for 90 d in total. Treatment groups underwent 3 courses of acupuncture. Each course involved a total of 10 interventions(one intervention every second day) with each intervention lasting15 min. There was a break for 10 d between courses. SUA and ALP were analyzed using an automatic biochemical analyzer and XOD was analyzed using immunofluorescence.RESULTS: Compared with the blank group, SUA and XOD levels in the model group were significantly higher and the renal index significantly improved. Compared with the model group, SUA and XOD levels in the three treatment groups decreased and the renal index significantly improved.When the three treatment groups were compared,the Mu-acupoint group showed the greatest decreases in SUA and XOD levels, followed by the Yuan-acupoint group. There was no significant difference in kidney index among the three treatment groups. There was no significant difference in ALP levels among the groups.CONCLUSION: The three treatments showed significantly reduced SUA and XOD levels compared with the control groups, possibly suggesting reduced renal damage.

Study of the Transient Reactive Pd(Ⅳ) Intermediate in the Pd(OAc)2-Catalyzed Oxidative Coupling Reaction System by Electrospray Ionization Tandem Mass Spectrometry

Pd-catalyzed oxidative coupling reaction was of great importance in the aromatic C--H activation and the for-mation of new C-O and C--C bonds. Sanford has pioneered practical, directed C-H activation reactions em-ploying Pd（OAc）2 as catalyst since 2004. However, until now, the speculated reactive Pd（Ⅳ） transient intermedi-ates in these reactions have not been isolated or directly detected from reaction solution. Electrospray ionization tandem mass spectrometry （ESI-MS/MS） was used to intercept and characterize the reactive Pd（Ⅳ） transient inter-mediates in the solutions of Pd（OAc）2-catalyzed oxidative coupling reactions. In this study, the Pd（IV） transient in-termediates were detected from the solution of Pd（OAc）2-catalyzed oxidative coupling reactions by ESI-MS and the MS/MS of the intercepted Pd（IV） transient intermediate in reaction system was the same with the synthesized au-thentic Pd（Ⅳ） complex. Our ESI-MS（/MS） studies confirmed the presence of Pd（Ⅳ） reaction transient intermedi-ates. Most interestingly, the MS/MS of Pd（Ⅳ） transient intermediates showed the reductive elimination reactivity to Pd（Ⅱ） complexes with new C-O bond formation into product in gas phase, which was consistent with the proposed reactivity of the Pd（Ⅳ） transient intermediates in solution.

Effective regulation mechanisms of Fe-Ni(oxy)hydroxide:Ni-rich heteroatomic bonding(Ni–O–Fe–O–Ni)is essential

Although Fe-Ni combination performs well in transition metal-based oxygen evolution reaction(OER)electrocatalysts,there are lack of clear and general regulations mechanism to fully play the synergistic catalytic effect.Here,we made the utmost of the interaction of Fe–Ni heteroatomic pair to obtain a highly active Fe-Ni(oxy)hydroxide catalytic layer on iron foam(IF)and nickel foam(NF)by in-situ electrochemical deposition and rapid surface reconstruction,which only required 327 and 351 mV overpotential to provide a large current of 1,000 mA·cm^(−2),respectively.The results confirm that the moderate Ni-rich heteroatomic bonding(Ni–O–Fe–O–Ni)formed by adjusting the Ni/Fe ratio on the catalyst surface is important to offer predominant OER performance.Fe is a key component that enhances OER activity of Ni(O)OH,but Fe-rich structural surface formed by Fe–O–Ni–O–Fe bonding is not ideal.Finally,the remarkable oxygen evolution performance of the prepared Ni2Fe(O)OH/IF and FeNi2(O)OH/NF can be chalked up to the optimized electronic structure of Fe–Ni heteroatomic bonding,the efficient gas spillover,the fast electron transport,and nanosheet clusters morphology.In summary,our work suggests a comprehensive regulation mechanism for the construction of efficient Fe-Ni(oxy)hydroxide catalytic layer on inexpensive,stable,and self-supporting metallic material surface.

Review on research and application of mesoporous transitional metal oxides in water treatment

This paper reviews the application of meso- porous transitional metal oxides in water treatment on basis of the catalysis and adsorption. Mesoporous transitional metal oxides are characterized by their intrinsic features, such as a high surface area, a highly ordered array of unidimensional pores with a very narrow pore size distribution, and highly dispersed active sites. Finally, the suggestions of further study on application are proposed.

Preparation and characteristics of TEMPO-oxidized cellulose nanofibrils from bamboo pulp and their oxygen-barrier application in PLA films

Bleached bamboo kraft pulp was pretreated by 2,2,6,6-tetramethylpiperidine-l-oxy radical （TEMPO）- mediated oxidation using a TEMPO/NaBr/NaC10 system at pH = 10 in water to facilitate mechanical disintegration into TEMPO-oxidized cellulose nanofibrils （TO-CNs）. A series of TO-CNs with different carboxylate contents were obtained by varying amounts of added NaC10. An increase in carboxylate contents results in aqueous TO-CN dispersions with higher yield, zeta potential values, and optical transparency. When carboxylate groups are introduced, the DPv value of the TO-CNs remarkably decreases and then levels off. And the presence of hemicellulose in the pulp is favorable to TEMPO oxidization. After the oxidization, the native cellulose I crystalline structure and crystal size of bamboo pulp are almost maintained. TEM micrographs revealed that the degree of nanofibrillation is directly proportional to the carboxylate contents. With increasing carboxylate con- tents, the free-standing TO-CN films becomes more transparent and mechanically stronger. The oxygen permeability of PLA films drastically decreases from 355 for neat PLA to 8.4 mL-1 m a. d-1 after coating a thin layer of TO-CN with a carboxylate content of 1.8 mmol.g1. Therefore, inexpensive and abundant bamboo pulp would be a promising starting material to isolate cellulose nanfibrils for oxygen-barrier applications.

Comparative study of Sm^(3+) ions doped phosphate based oxide and oxy-fluoride glasses for solid state lighting applications

The physical and luminescent properties of Sm^(3+)-doped oxide and oxy-fluoride phosphate glasses were investigated. The glass samples with chemical composition of 69 P_2 O_5-10 BaO-10 ZnO-10 Gd_2 O_3-1 Sm_2 O_3 and 69 P_2 O_5-10 BaO-10 ZnO-10 GdF_3-1 Sm_2 O_3 were prepared by conventional melt quenching technique. The prepared glass samples were characterized with density, molar volume, refractive index,FTIR, UV-Vis-NIR, photo luminesce nce, radio luminescence, decay time profile and CIE diagram. The density and refractive index of the oxide glass have higher values as compared to the oxy-fluoride glass.The FTIR spectra show the reduction of O-H group in oxy-fluoride glass. The characteristic peaks of Sm^(3+)are observed at 360,372,402,438,419,473,944,1077,1227,1373,1474,1529 and 1585 nm in UV-VIS-NIR spectra. These peaks are related respectively to the transitions from ground state ~6 H_(5/2) to ~4 D_(3/2), ~6 P_(7/2),6 P3/2, ~4 I_(11/2), ~6 F_(11/2), ~6 F_(9/2), ~6 F_(7/2),~6 F_(5/2),~6 F_(3/2), ~6 H_(15/2) and ~6 F_(1/2) excited states. From photoluminescence and radio-luminesce nce it is observed that the oxy-fluoride glass samples show better emission intensity than the oxide glass. The Judd-Ofelt theory(J-0 theory) was used to find J-O intensity Ω_λ(λ = 2,4 and 6)parameters and radiative properties such as transition probability, stimulated emission cross section and branching ratios for titled glasses. The trend observed in the J-O parameters is Ω_4 >Ω_2 >Ω_6. The transition probability,emission cross section and branching ratio have the highest values for the ~4 G_(5/2)→~6 H_(7/2)transition. The CIE coordinates of the prepared glass samples are positioned in the orange region and the CCT value is 3776.105 for oxide and oxyfluoride glass. The oxy-fluoride glass has shorter decay time as compared to the oxide glass and it is recorded to be 1.62 and 1.32 ms for oxide and oxy-fluoride respectively. According to the results obtained in this work, it is obvious that these glass samples can be good candidate materials for producing cool orange light.

基于替代电镀硬铬的WC增强金属复合涂层疲劳性能的研究现状

传统电镀硬铬涂层存在网纹裂纹缺陷、抗疲劳性能不足以及环境污染严重等问题,针对新一代航空工业急需新技术替代传统电镀硬铬这一迫切需求,研发新型的耐磨耐蚀涂层体系及其先进环保的再制造技术迫在眉睫。根据先进涂层技术的发展情况,研发出了基于高温熔化-凝固技术的物理气相沉积、超音速火焰喷涂以及激光熔覆技术,这在绿色制备航空工业用耐磨耐蚀涂层上表现出了一定的应用前景,并表现出了比传统电镀硬铬更长的疲劳寿命,但其仍存在内应力过高而开裂、粉末氧化或相变导致疲劳性能下降等一系列关键问题。近年来,冷喷涂涂层技术作为先进环保的新技术,凭借其低温固态沉积特性在制备金属基复合涂层上展现出了显著的冶金优势,其中冷喷涂涂层的残余压应力有助于提高零件的疲劳性能。此外,从起落架防护涂层沉积到其修复再制造环节,冷喷涂技术均可参与其中。因此,作为固态沉积工艺的冷喷涂,其在替代传统电镀铬的新型涂层制备工艺方面具有显著的应用潜力,未来的研究将集中于优化冷喷涂涂层材料和工艺上,以进一步提高其力学性能和疲劳性能。