Impact of W alloying on microstructure, mechanical property and corrosion resistance of face-centered cubic high entropy alloys: A review

Face-centered cubic (f.c.c.) high entropy alloys (HEAs) are attracting more and more attention owing to their excellent strength and ductility synergy, irradiation resistance, etc. However, the yield strength of f.c.c. HEAs is generally low, significantly limiting their practical applications. Recently, the alloying of W has been evidenced to be able to remarkably improve the mechanical properties of f.c.c. HEAs and is becoming a hot topic in the community of HEAs. To date, when W is introduced, multiple strengthening mechanisms, including solid-solution strengthening, precipitation strengthening (μphase,σphase, and b.c.c. phase), and grain-refinement strengthening, have been discovered to be activated or enhanced. Apart from mechanical properties, the addition of W improves corrosion resistance as W helps to form a dense WO_(3) film on the alloy surface. Until now, despite the extensive studies in the literature, there is no available review paper focusing on the W doping of the f.c.c. HEAs. In that context, the effects of W doping on f.c.c. HEAs were reviewed in this work from three aspects, i.e., microstructure,mechanical property, and corrosion resistance. We expect this work can advance the application of the W alloying strategy in the f.c.c. HEAs.

Progress and prospects of Mg-based amorphous alloys in azo dye wastewater treatment

Mg-based amorphous alloys exhibit efficient catalytic performance and excellent biocompatibility with a promising application probability,specifically in the field of azo dye wastewater degradation.However,the problems like difficulty in preparation and poor cycling stability need to be solved.At present,Mg-based amorphous alloys applied in wastewater degradation are available in powder and ribbon.The amorphous alloy powder fabricated by ball milling has a high specific surface area,and its reactivity is thousands of times better than that of gas atomized alloy powder.But the development is limited due to the high energy consumption,difficult and costly process of powder recycling.The single roller melt-spinning method is a new manufacturing process of amorphous alloy ribbon.Compared to amorphous powder,the specific surface area of amorphous ribbon is relatively lower,therefore,it is necessary to carry out surface modification to enhance it.Dealloying is a way that can form a pore structure on the surface of the amorphous alloys,increasing the specific surface area and providing more reactive sites,which all contribute to the catalytic performance.Exploring the optimal conditions for Mg-based amorphous alloys in wastewater degradation by adjusting amorphous alloy composition,choosing suitable method to preparation and surface modification,reducing cost,expanding the pH range will advance the steps to put Mg-based amorphous alloys in industrial environments into practice.

Reducing voltage hysteresis of metal oxide anodes to achieve high energy efficiency for Li-ion batteries

In the past two decades,a lot of high-capacity conversion-type metal oxides have been intensively studied as alternative anode materials for Li-ion batteries with higher energy density.Unfortunately,their large voltage hysteresis(0.8-1.2 V) within reversed conversion reactions results in huge round-trip inefficiencies and thus lower energy efficiency(50%-75%) in full cells than those with graphite anodes.This remains a long-term open question and has been the most serious drawback toward application of metal oxide anodes.Here we clarify the origins of voltage hysteresis in the typical SnO2anode and propose a universal strategy to minimize it.With the established in situ phosphating to generate metal phosphates during reversed conversion reactions in synergy with boosted reaction kinetics by the added P and Mo,the huge voltage hysteresis of 0.9 V in SnO_(2),SnO_(2)-Mo,and 0.6 V in SnO2-P anodes is minimized to 0.3 V in a ternary SnO_(2)-Mo-P(SOMP) composite,along with stable high capacity of 936 mA h g^(-1)after 800 cycles.The small voltage hysteresis can remain stable even the SOMP anode operated at high current rate of10 A g^(-1)and wide-range temperatures from 60 to 30℃,resulting in a high energy efficiency of88.5% in full cells.This effective strategy to minimize voltage hysteresis has also been demonstrated in Fe2O3,Co3O4-basded conversion-type anodes.This work provides important guidance to advance the high-capacity metal oxide anodes from laboratory to industrialization.

Realizing Cd and Ag codoping in p-type Mg_(3)Sb_(2)toward high thermoelectric performance

Mg_(3)Sb_(2)has attracted intensive attention as a typical Zintl-type thermoelectric material.Despite the exceptional thermoelectric performance in n-type Mg_(3)Sb_(2),the dimensionless figure of merit(zT)of p-type Mg_(3)Sb_(2)remains lower than 1,which is mainly attributed to its inferior electrical properties.Herein,we synergistically optimize the thermoelectric properties of p-type Mg_(3)Sb_(2)materials via codoping of Cd and Ag,which were synthesized by high-energy ball milling combined with hot pressing.It is found that Cd doping not only increases the carrier mobility of p-type Mg_(3)Sb_(2),but also diminishes its thermal conductivity(κ_(tot)),with Mg_(2.85)Cd_(0.5)Sb_(2)achieving a lowκtot value of∼0.67 W m^(−1)K^(−1)at room temperature.Further Ag doping elevates the carrier concentration,so that the power factor is optimized over the entire temperature range.Eventually,a peak zT of∼0.75 at 773 K and an excellent average zT of∼0.41 over 300−773 K are obtained in Mg_(2.82)Ag_(0.03)Cd_(0.5)Sb_(2),which are∼240%and∼490%higher than those of pristine Mg_(3.4)Sb_(2),respectively.This study provides an effective pathway to synergistically improve the thermoelectric performance of p-type Mg_(3)Sb_(2)by codoping Cd and Ag,which is beneficial to the future applications of Mg_(3)Sb_(2)-based thermoelectric materials.

Halogen chlorine triggered oxygen vacancy-rich Ni(OH)_(2) with enhanced reaction kinetics for pseudocapacitive energy storage

Two-dimensional (2D)Ni(OH)_(2) nanosheets can theoretically expose their active sites of 100%.Whereas,their intrinsic easy accumulation and low conductivity lead to weak and unsustainable reaction kinetics.Herein,we propose a novel halogen chlorine-triggered electrochemical etching strategy to controllably manage the reaction kinetics of 2D Ni(OH)_(2) nanosheets(EE/Cl-Ni(OH)_(2)).It is found that halogen chlorine doping can adjust the interlamellar spacing flexibly and promote the lattice oxygen activation to achieve controlled construction of superficial oxygen defects at the adjustable voltage.The optimal EE/Cl-Ni(OH)_(2) electrode exhibits a high rate capability and excellent specific capacity of 206.9 mA h g^(-1) at 1 A g^(-1) in a three-electrode system,which is more than twice as high as the pristine Ni(OH)_(2).Furthermore,EE/Cl-Ni(OH)_(2) cathode and FeOOH@rGO anode are employed for developing an aqueous Ni-Fe battery with an excellent energy density of 83 W h kg^(-1),a high power density of 17051 W kg^(-1),and robust durability over 20,000 cycles.This strategy exploits a fresh channel for the ingenious fabrication of highefficiency and stable nickel-based deficiency materials for energy storage.

Regulating local coordination environment of Mg-Co single atom catalyst for improved direct methanol fuel cell cathode

Fuel cells operated with a reformate fuel such as methanol are promising power systems for portable electronic devices due to their high safety,high energy density and low pollutant emissions.However,several critical issues including methanol crossover effect,CO-tolerance electrode and efficient oxygen reduction electrocatalyst with low or non-platinum usage have to be addressed before the direct methanol fuel cells(DMFCs)become commercially available for industrial application.Here,we report a highly active and selective Mg-Co dualsite oxygen reduction reaction(ORR)single atom catalyst(SAC)with porous N-doped carbon as the substrate.The catalyst exhibits a commercial Pt/C-comparable half-wave potential of 0.806 V(versus the reversible hydrogen electrode)in acid media with good stability.Furthermore,practical DMFCs test achieves a peak power density of over 200 m W cm^(-2)that far exceeds that of commercial Pt/C counterpart(82 m W cm^(-2)).Particularly,the Mg-Co DMFC system runs over 10 h with negligible current loss under 10 M concentration methanol work condition.Experimental results and theoretical calculations reveal that the N atom coordinated by Mg and Co atom exhibits an unconventional d-band-ditto localized p-band and can promote the dissociation of the key intermediate*OOH into*O and*OH,which accounts for the near unity selective 4e-ORR reaction pathway and enhanced ORR activity.In contrast,the N atom in SAC–Co remains inert in the absorption and desorption of*OOH and*OH.This local coordination environment regulation strategy around active sites may promote rational design of high-performance and durable fuel cell cathode electrocatalysts.

In-situ cation-inserted MnO_(2) with selective accelerated intercalation of individual H^(+) or Zn^(2+) ions in aqueous zinc ion batteries

The recognized energy storage mechanism of neutral aqueous zinc-manganese batteries is the co-insertion/extrusion of H^(+) and Zn^(2+) ions.However,modulating the kinetics of a single H^(+) or Zn^(2+) ion is scarce,which can provide meaningful insights into the energy storage mechanism of Zn ion batteries.Herein,a distinctive doubly electric field in-situ induced cationic anchoring of two-dimensional layered MnO_(2) is successfully constructed to modulate the insertion/extrusion of a single H^(+) or Zn^(2+) ion.As a result,regulating the intercalation of different metal ions can precisely achieve the accelerated induction for the individual H^(+) or Zn^(2+) ions intercalation/deintercalation.Moreover,the introduction of metal ions stabilizes the lattice distortion and alleviates the irreparable structural collapse,leading to an increase in the H^(+)/Zn^(2+) storage sites,efficiently diminishing the stagnation of the ordered structure and creating the more open channels,which is conducive to facilitating the diffusion of ions.This work delivers some innovative insights into pre-embedding strategies,and also serves as a precious reference for the cathode development of advanced aqueous batteries.

A splice site mutation in the FvePHP gene is associated with leaf development and f lowering time in woodland strawberry

Leaves and f lowers are crucial for the growth and development of higher plants.In this study we identified a mutant with narrow leaf lets and early f lowering(nlef)in an ethyl methanesulfonate-mutagenized population of woodland strawberry(Fragaria vesca)and aimed to identify the candidate gene.Genetic analysis revealed that a single recessive gene,nlef,controlled the mutant phenotype.We found that FvH4_1g25470,which encodes a putative DNA polymeraseαwith a polymerase and histidinol phosphatase domain(PHP),might be the candidate gene,using bulked segregant analysis with whole-genome sequencing,molecular markers,and cloning analyses.A splice donor site mutation(C to T)at the 5-end of the second intron led to an erroneous splice event that reduced the expression level of the full-length transcript of FvePHP in mutant plants.FvePHP was localized in the nucleus and was highly expressed in leaves.Silencing of FvePHP using the virus-induced gene silencing method resulted in partial developmental defects in strawberry leaves.Overexpression of the FvePHP gene can largely restore the mutant phenotype.The expression levels of FveSEP1,FveSEP3,FveAP1,FveFUL,and FveFT were higher in the mutants than those in‘Yellow Wonder’plants,probably contributing to the early f lowering phenotype in mutant plants.Our results indicate that mutation in FvePHP is associated with multiple developmental pathways.These results aid in understanding the role of DNA polymerase in strawberry development.

3D printing of personalized polylactic acid scaffold laden with GelMA/autologous auricle cartilage to promote ear reconstruction

At present,the clinical reconstruction of the auricle usually adopts the strategy of taking autologous costal cartilage.This method has great trauma to patients,poor plasticity and inaccurate shaping.Three-dimensional(3D)printing technology has made a great breakthrough in the clinical application of orthopedic implants.This study explored the combination of 3D printing and tissue engineering to precisely reconstruct the auricle.First,a polylactic acid(PLA)polymer scaffold with a precisely customized patient appearance was fabricated,and then auricle cartilage fragments were loaded into the 3D-printed porous PLA scaffold to promote auricle reconstruction.In vitro,gelatin methacrylamide(GelMA)hydrogels loaded with different sizes of rabbit ear cartilage fragments were studied to assess the regenerative activity of various autologous cartilage fragments.In vivo,rat ear cartilage fragments were placed in an accurately designed porous PLA polymer ear scaffold to promote auricle reconstruction.The results indicated that the chondrocytes in the cartilage fragments could maintain the morphological phenotype in vitro.After three months of implantation observation,it was conducive to promoting the subsequent regeneration of cartilage in vivo.The autologous cartilage fragments combined with 3D printing technology show promising potential in auricle reconstruction.

Aging Resistance Evaluation of Aged Paper Reinforced with Different Nanocelluloses

Paper documents experience severe acidification and embrittlement.Nanocellulose is an excellent reinforcement material for paper documents owing to its compatibility and excellent mechanical strength.However,little research has been conducted on the aging resistance of nanocellulose-reinforced paper.In this study,six types of nanocelluloses were used to reinforce aged paper.The reinforcement and anti-aging performances were evaluated,and the anti-aging mechanism was further clarified.Nanocellulose with a high degree of polymerization can better enhance aged paper,and non-chemical nanocellulose also shows better anti-aging performance,such as nanocellulose prepared by mechanical or biological methods.However,nanocellulose prepared using chemical methods exhibits poor reinforcement and anti-aging performance.This is because it has a small particle size that is not beneficial for physical crosslinking with paper fibers.More importantly,the introduction of acidic or oxidizing groups on nanocellulose accelerates the acid hydrolysis and oxidation rate of paper fibers,especially nanocellulose prepared by 2,2,6,6-tetramethylpiperidine-1-oxyl oxidation,which should not be used to protect paper documents.

Distribution and sources of solvent extractable organic compounds in PM_(2.5) during 2007 Chinese Spring Festival in Beijing

The solvent extractable organic compounds (SEOC), including n-alkanes, polycylic aromatic hydrocarbons, fatty acids, anddicarboxylic acids in PM2.5 during the 2007 Chinese Spring Festival in Beijing, were measured via gas chromatography-massspectrometry for determining the characteristics and sources of these organic pollutants. The concentrations of total n-alkanes, PAHs,and organic acids before Chinese Spring Festival Eve (1025.5, 95.9, and 543.3 ng/m3, respectively) were higher than those after (536.6,58.9, and 331.8 ng/m3, respectively). n-Aalkanes and PAHs had much higher concentration in nighttime than those in daytime becauseof high relative humidity and low wind speed during the night. Combustion of coal and exhaust emission were major sources of n-alkanes. It could be concluded by the characteristic ratios that the primary source of PAHs in fine particles was the combustion of coal,but the combustion of gasoline was in the next place. The ratios of C18:0/C16 indicated the contribution of vehicular emissions to thefatty acids. Dicarboxylic and aromatic acids were abundant in daytime than in nighttime because these acids were secondary organicacid and the photochemical degradation of aromatic hydrocarbons was the main source.

Improving mechanical properties of Mg-Al-Zn alloy sheets through accumulative roll-bonding

Experiments were conducted to evaluate the potential for improving the mechanical properties of Mg-Al-Zn alloy at room temperature by subjecting to accumulative roll-bonding(ARB).It is shown that ARB may be applied successfully to Mg-Al-Zn alloy at elevated temperatures and it leads to grain refinement and significant improvements in the ductility.The strength of the as-rolled Mg-Al-Zn alloy sheet after ARB processing is slightly decreased and basal texture is weakened by ARB processing.

Microstructural and tribological behavior of TiAlN/MoS_2-Ti coatings

A TiAlN/MoS2-Ti coating was developed to improve the tribological characteristics of a single TiAlN coating. The MoS2-Ti layer was deposited by a DC magnetron sputtering system on the hard TiAlN coated SKD-11 steel substrate. The titanium content in the MoS2-Ti layer was 11.3 at.% determined by EPMA. The surface morphology was observed by FE-SEM. The TiAlN layer exhibited excellent adhesion and hardness. However, the deposition of an MoS2-Ti layer on the TiAlN led to a significant improvement in tribological properties without affecting the adhesion to the substrate. The MoS2-Ti layer significantly decreased the friction coefficient of the TiAlN coating, and the drop was 48% after MoS2-Ti deposition. Also, the MoS2-Ti layer remarkably decreased the wear rate of the TiAlN coating.

Photoluminescence properties of LaF_3:Eu^(3+) nanoparticles prepared by refluxing method

The europium-doped LaF3 nanoparticles were prepared by refluxing method in glycerol/water mixture and characterized with X-ray diffraction(XRD), field emission scanning electron microscopy(FE-SEM), UV-vis diffuse reflectance spectrum, and photoluminescence spectra.The results of XRD indicated that the obtained LaF3:Eu3+ nanoparticles were well crystallized with a hexagonal structure.The FE-SEM image illustrated that the LaF3:Eu3+ nanoparticles were spherical with an average size around 30 nm.Under irradiation of UV light, the emission spectrum of LaF3:Eu3+ nanoparticles exhibited the characteristic line emissions arising from the 5D0→7FJ(J=1, 2, 3, 4) transitions of the Eu3+ ions, with the dominating emission centered at 590 nm.In addition, the emissions from the 5D1 level could be clearly observed due to the low phonon energies(-350 cm?1) of LaF3 matrix.The optimum doping concentration for LaF3:Eu3+ nanoparticles was determined to be 20mol.%.

Al(III) speciation distribution and transformation in high concentration PACl solutions

Effects of Al(III) concentration and pH on the speciation of Al(III) in polyaluminum chloride (PACl) solutions especially on the Al13 fraction were investigated. A series of PACl samples were prepared over the range of Al(III) concentration from 0.01 to 2.0 mol/L with the B (OH/Al ratio) value from 1.0 to 2.5 by forced hydrolysis of AlCl3. The samples were characterized by ferron assay, pH and 27Al NMR. It was shown that the Al(III) concentration had a dramatic effect on the hydrolysis processes and the species distribution of PACl was in relate to the decrease of pH. The fraction of Al species, Alb (or Al13) decreased and Alc increased with increase of total Al(III) concentration. Under the condition of Al(III) 2.0 mol/L, B = 2.5, the pH value was 2.73 and no Al13 could be detected. During diluting and aging, the species distribution evolved. The Al13 could then be detected again and the amounts increased with time. If the diluted samples were concentrated by freeze dry at -35℃ or heating at 80℃, the pH value and Al13 content would decrease with the increased concentration. It demonstrated that the key factor for formation of Al13 in concentrated PACl was pH value.

Determination of Pesticide Residue Cartap Using a Sensitive Fluorescent Probe

The insecticide cartap(CP) is non-fluorescent in aqueous solutions.This property makes its determination through direct fluorescent method difficult.In acidic medium and at room temperature,palmatine(PAL) can react with cucurbit[7]uril(CB[7]) to form stable complexes,and the fluorescence intensity of the complex is greatly enhanced.Significant quenching of the fluorescence intensity of the CB[7]-PAL complex was observed with the addition of cartap.Based on the significant quenching of the supramolecular complex fluorescence intensity,a new spectrofluorimetric method with high sensitivity and selectivity was developed to determine cartap in aqueous solution.The fluorescence quenching values(F) showed good linear relationship with cartap concentrations from 0.009 to 2.4 μg mL-1 with a detection limit 0.0029 μg mL-1.The proposed method had been successfully applied to the determination of cartap residues in grain and vegetable with recoveries of 87.4-103%.In addition,the association constants of the complexes formed between the host and the guest were determined.The competing reaction and the supramolecular interaction mechanisms between the cartap and PAL as they fight for occupancy of the CB[7] cavity were studied using spectrofluorimetry,1H NMR and molecular modeling calculations.

Study on the inclusion interactions of berberine hydrochloride and cucurbit[7] by spectrofluorimetry

在 berberine 水疗院氯化物(BRH ) 和葫芦之间的包括相互作用[7 ](CB [7 ]) 被 spectrofluorimetry 学习了。结果显示出那 CB [7 ] 和到形式的 BRH 的相互作用有 9.57 × 的一个协会常数的稳定的包括建筑群； 10 4 L/mol 和建筑群的荧光紧张自己比学习的药的高在 17 次被提高。在包括建筑群基于 BRH 的荧光紧张的重要改进，有高敏感和选择的一个 spetrofluorimetric 方法在水的答案为 BRH 的决心被开发。方法的线性范围是 3.2 –； 2 ×；有 1.1 ng/mL 的察觉限制的 10 3 ng/mL。建议过程能成功地被用于与令人满意的结果在药品的剂量形式，刺的人的血浆和尿仍然是的 BRH 的决心。

Cumene Liquid Oxidation to Cumene Hydroperoxide over CuO Nanoparticle with Molecular Oxygen under Mild Condition

CuO nanoparticle 经由湿化学方法被综合并且被 X 光检查描绘衍射(XRD ) ，氮吸附解吸附作用，和扫描电子显微镜学(SEM ) 。有分子的氧的 cumene 的催化氧化在 CuO nanoparticle 上被学习。催化剂作为与常规方法， CuO/Al2O3，或同类的铜催化剂在可比较的反应条件下面准备的 CuO 相比显示出显著地更高的活动。用在为 7 h 的 358 K 的 0.25 g CuO nanoparticle 催化剂和 0.1 摩尔 cumene 的 cumene 变换， cumene 水疗院过氧化物(CHP ) 收益，和选择分别地是 44.2% ， 41.2% 和 93.2% 。催化剂能被再循环。在 6 个再循环的实验以后，催化活动的损失都没被观察。

Ni-mediated Liquid Phase Reduction of Carbonyl Compounds in the Presence of Atmospheric Hydrogen

An efficient reduction system of benzaldehyde with hydrogen under ambient pressure was developed using facile NiO catalyst. The non-aromatic solvents such as cyclohexane, tetrahydrofuran (THF) and n-hexane, and the addi-tive with strong basicity e.g. KOH, were necessary for smooth conversion of the substrate. That the catalyst can be recov-ered and reused for nine times without loss of catalytic activity indicates that this catalyst is a recyclable one for benzal-dehyde reduction.

Comparison of Compositions and Structural Characterizations of Synthetic Nano-hydroxyapatite and Mineral Phase from Porcine Femoral Bone

In the paper, nano-hydroxyapatite was synthesized by hydrothermal treatment. The crystal morphology and compositions of the synthetic HA were investigated using TEM, IR, XRD and XPS techniques and were compared with those of porcine femoral bone apatite. The results showed that the synthetic HA is nanometer rod crystal similar to the bone apatite, and the average crystal sizes calculated by Scherrer equation for the four samples (HA dried at 80℃, unburned bone apatite, HA calcined at 750℃ and bone apatite calcined at 750℃) are 20.6, 21.7, 22.5 and 27.6nm, respectively. Moreover, the essential compositions for the synthetic HA and bone apatite are almost the same.