Electrokinetic-mechanism of water and furfural oxidation on pulsed laser-interlaced Cu_(2)O and CoO on nickel foam

The electrocatalytic oxidation of biomass-derived furfural(FF)feedstocks into 2-furoic acid(FA)holds immense industrial potential in optics,cosmetics,polymers,and food.Herein,we fabricated Co O/Ni O/nickel foam(NF)and Cu_(2)O/Ni O/NF electrodes via in situ pulsed laser irradiation in liquids(PLIL)for the bifunctional electrocatalysis of oxygen evolution reaction(OER)and furfural oxidation reaction(FOR),respectively.Simultaneous oxidation of NF surface to NiO and deposition of CoO and/or Cu_(2)O on NF during PLIL offer distinct advantages for enhancing both the OER and FOR.CoO/NiO/NF electrocatalyst provides a consistently low overpotential of~359 m V(OER)at 10 m A/cm^(2),achieving the maximum FA yield(~16.37 m M)with 61.5%selectivity,79.5%carbon balance,and a remarkable Faradaic efficiency of~90.1%during 2 h of FOR at 1.43 V(vs.reversible hydrogen electrode).Mechanistic pathway via in situ electrochemical-Raman spectroscopy on CoO/NiO/NF reveals the involvement of phase transition intermediates(NiOOH and CoOOH)as surface-active centers during electrochemical oxidation.The carbonyl carbon in FF is attacked by hydroxyl groups to form unstable hydrates that subsequently undergo further oxidation to yield FA products.This method holds promise for large-scale applications,enabling simultaneous production of renewable building materials and fuel.

Pulsed laser interference patterning of transition-metal carbides for stable alkaline water electrolysis kinetics

We investigated the role of metal atomization and solvent decomposition into reductive species and carbon clusters in the phase formation of transition-metal carbides(TMCs;namely,Co_(3)C,Fe_(3)C,TiC,and MoC)by pulsed laser ablation of Co,Fe,Ti,and Mo metals in acetone.The interaction between carbon s-p-orbitals and metal d-orbitals causes a redistribution of valence structure through charge transfer,leading to the formation of surface defects as observed by X-ray photoelectron spectroscopy.These defects influence the evolved TMCs,making them effective for hydrogen and oxygen evolution reactions(HER and OER)in an alkaline medium.Co_(3)C with more oxygen affinity promoted CoO(OH)intermediates,and the electrochemical surface oxidation to Co_(3)O_(4)was captured via in situ/operando electrochemical Raman probes,increasing the number of active sites for OER activity.MoC with more d-vacancies exhibits strong hydrogen binding,promoting HER kinetics,whereas Fe_(3)C and TiC with more defect states to trap charge carriers may hinder both OER and HER activities.The results show that the assembled membrane-less electrolyzer with Co_(3)C∥Co_(3)C and MoC∥MoC electrodes requires~2.01 and 1.99 V,respectively,to deliver a 10 mA cm−2 with excellent electrochemical and structural stability.In addition,the ascertained pulsed laser synthesis mechanism and unit-cell packing relations will open up sustainable pathways for obtaining highly stable electrocatalysts for electrolyzers.

High temperature thermoelectric properties of highly c-axis oriented Bi_2Sr_2Co_2O_y thin films fabricated by pulsed laser deposition

High-temperature thermoelectric transport property measurements have been performed on the highly c-axis oriented Bi2Sr2Co20v thin films prepared by pulsed laser deposition on LaA1Oa （001）. Both the electric resistivity p and the seebeck coefficient S of the film exhibit an increasing trend with the temperature from 300 K-1000 K and reach up to 4.8 m. cm and 202 V/K at 980 K, resulting in a power factor of 0.85 mW/mK which are comparable to those of the single crystalline samples. A small polaron hopping conduction can be responsible for the conduction mechanism of the film at high temperature. The results demonstrate that the Bi2Sr2Co2Oy thin film has potential application has high temperature thin film thermoelectric devices,

脉冲CO_(2)激光结合牙周基础治疗对青春期龈炎前瞻性半口自身对照研究

目的基于半口自身对照研究观察脉冲CO_(2)激光结合牙周基础治疗对青春期龈炎的疗效。方法选择200例符合标准的青春期龈炎患者,采用左右半口自身对照研究,一侧行牙周基础治疗,为对照组;另一侧行脉冲CO_(2)激光结合牙周基础治疗,为治疗组。对比分析2组患者牙龈红肿、出血好转时间,治疗后7 d和6周时探诊深度(PD)>3 mm的位点数、探诊出血(BOP)阳性位点数、BOP百分率、牙龈指数(GI)、出血指数(BI)、菌斑指数(PLI)的变化以及龈沟液白细胞介素1β(IL-1β)、C-反应蛋白(CRP)、前列腺素E_(2)(PGE_(2))、肿瘤坏死因子-α(TNF-α)、白细胞介素-6(IL-6)水平的改变。结果治疗组牙龈红肿、出血好转时间均早于对照组(均P<0.05)。治疗后7 d和6周时,2组PD>3 mm的位点数、BOP阳性位点数和BOP百分率均降低(P<0.05),且治疗组较对照组更低(P<0.05)。治疗后7 d和6周时,2组PLI、GI、BI均降低(均P<0.05),且治疗组PLI、GI、BI均低于对照组(P<0.05)。治疗后6周时2组龈沟液IL-1β、CRP、PGE_(2)、TNF-α、IL-6水平均下降(均P<0.05),且治疗组低于对照组(均P<0.05)。结论相对于单纯牙周基础治疗,脉冲CO_(2)激光结合牙周基础治疗对青春期龈炎的临床疗效更佳,且能较快改善患者临床症状,降低局部炎性反应。

LD脉冲泵浦Er^(3+)/Yb^(3+):Lu_(2)Si_(2)O_(7)晶体百kHz激光器

目前1.5μm激光二极管(Laser Diode,LD)泵浦的铒镱共掺玻璃/晶体被动调Q微型激光器广泛应用于激光测距、激光雷达等领域。随着激光器输出重频的增加,玻璃面临突出的热效应问题,晶体的热导率是玻璃的10倍以上,有望能够实现比玻璃基质更高重频的激光输出。报道了一种通过LD脉冲端面泵浦Er^(3+)/Yb^(3+):Lu_(2)Si_(2)O_(7)晶体的百kHz人眼安全激光器。通过实验优化增益介质掺杂浓度和长度、泵浦光斑尺寸和调Q晶体初始透过率等实验参数,同时适当缩短脉宽,优化泵浦占空比,提高了输出重频的稳定性。最终获得了重频为100 kHz、单脉冲能量0.7μJ、脉冲宽度240 ns、光束质量M^(2)=1.61的1537 nm脉冲激光输出。实现了输出脉冲频率与泵浦的一致,保证了输出重频的稳定性,有效解决了输出重频具有随机性、不稳定、不可控等问题。

Improving pulsed laser weldability of duplex stainless steel to 5456 aluminum alloy via friction stir process reinforcing of aluminum by BNi-2 brazing alloy

Effects of laser pulse distance and reinforcing of 5456 aluminum alloy were investigated on laser weldability of Al alloy to duplex stainless steel (DSS) plates. The aluminum alloy plate was reinforced by nickel-base BNi-2 brazing powder via friction stir processing. The DSS plates were laser welded to the Al5456/BNi-2 composite and also to the Al5456 alloy plates. The welding zones were studied by scanning electron microscopy, X-ray diffractometry, micro-hardness and shear tests. The weld interface layer became thinner from 23 to 5 μm, as the laser pulse distance was increased from 0.2 to 0.5 mm. Reinforcing of the Al alloy modified the phases at interface layer from Al-Fe intermetallic compounds (IMCs) in the DSS/Al alloy weld, to Al-Ni-Fe IMCs in the DSS/Al composite one, since more nickel was injected in the weld pool by BNi-2 reinforcements. This led to a remarkable reduction in crack tendency of the welds and decreased the hardness of the interface layer from ~950 HV to ~600 HV. Shear strengths of the DSS/Al composite welds were significantly increased by ~150%, from 46 to 114 MPa, in comparison to the DSS/Al alloy ones.

脉冲激光沉积过程中TiO_(2)等离子体状态诊断及薄膜特性的研究

脉冲激光沉积技术由于具有较高的沉积速率和良好的兼容性,已广泛应用于各种纳米薄膜材料的制备.探究激光等离子体状态与沉积薄膜特性之间的关系,有助于进一步调控与优化脉冲激光技术对薄膜材料的沉积.本文将等离子体状态诊断与沉积薄膜性能相结合,讨论了不同脉冲激光能量下等离子体状态对沉积薄膜性能的影响.结果表明,低烧蚀能量下产生的等离子体更有助于获得质地更好,且与靶材晶相一致的优良薄膜材料.该结果也为探索和调控沉积过程提供参考.

Preparation of Ga_2O_3 thin film solar-blind photodetectors based on mixed-phase structure by pulsed laser deposition

Gallium oxide(Ga_2O_3) thin films were deposited on a-Al2O3(1120) substrates by pulsed laser deposition(PLD) with different oxygen pressures at 650?C. By reducing the oxygen pressure, mixed-phase Ga_2O_3 films with α and β phases can be obtained, and on the basis of this, mixed-phase Ga_2O_3 thin film solar-blind photodetectors(SBPDs) were prepared.Comparing the responsivities of the mixed-phase Ga_2O_3 SBPDs and the single β-Ga_2O_3 SBPDs at a bias voltage of 25 V,it is found that the former has a maximum responsivity of approximately 12 A/W, which is approximately two orders of magnitude larger than that of the latter. This result shows that the mixed-phase structure of Ga_2O_3 thin films can be used to prepare high-responsivity SBPDs. Moreover, the cause of this phenomenon was investigated, which will provide a feasible way to improve the responsivity of Ga_2O_3 thin film SBPDs.

ε-Fe_(2)O_(3)/FeO界面结构与相变机理研究

本文利用脉冲激光沉积技术在SrTiO_(3)(111)衬底上生长了ε-Fe_(2)O_(3)薄膜,并应用高分辨X射线衍射(HRXRD)、X射线光电子能谱(XPS)和透射电子显微镜(TEM)对薄膜的显微结构进行了系统表征。XRD和XPS的研究结果表明ε-Fe_(2)O_(3)(001)薄膜在SrTiO_(3)(111)衬底上外延生长,薄膜中Fe离子为+3价。TEM的结果表明,在TEM样品制备过程中,由于高能Ar离子束轰击,ε-Fe_(2)O_(3)/SrTiO_(3)界面上容易发生相变形成FeO。ε-Fe_(2)O_(3)/FeO/SrTiO_(3)的外延关系为ε-Fe_(2)O_(3)(001)[110]//FeO(111)[112]//SrTiO_(3)(111)[112]。基于ε-Fe_(2)O_(3)/FeO界面结构与取向关系,分析了离子束辐照诱导ε-Fe_(2)O_(3)→FeO相变的微观机制。

Study on Compound Electrodes for a Transverse Fast Pulse Discharge S_2 Laser

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超脉冲点阵CO_(2)激光联合小针刀皮下剥离治疗痤疮萎缩性瘢痕的美学效果观察

目的:观察超脉冲点阵CO_(2)激光联合小针刀皮下剥离治疗痤疮萎缩性瘢痕的美学效果。方法:回顾性分析河北省皮肤病防治院2021年6月-2022年12月收治的98例痤疮萎缩性瘢痕患者的临床资料,依照治疗方式的不同将其分为对照组(n=49)和观察组(n=49)。对照组使用切除缝合术治疗,观察组实施超脉冲点阵CO_(2)激光联合小针刀皮下剥离治疗。比较两组疗效、患者满意度以及治疗期间并发症发生率,对比两组瘢痕美学效果[瘢痕美容评估与评级量表(SCAR)]。结果:术后3个月,观察组疗效优于对照组(P<0.05);观察组患者满意程度明显优于对照组(P<0.05);观察组SCAR评分明显低于对照组(P<0.05)。治疗期间,两组并发症总发生率比较差异无统计学意义(P>0.05)。结论:超脉冲点阵CO_(2)激光联合小针刀皮下剥离治疗痤疮萎缩性瘢痕效果显著,能提高患者满意度和美学效果,且并发症发生较少,值得临床应用推广。

High stability and low noise laser-diode end-pumped Nd:YAG ceramic passively Q-switched laser at 1123 nm based on a Ti_(3)C_(2)T_(x)-PVA saturable absorber

We report a high repetition frequency, high power stability and low laser noise laser-diode(LD) end-pumped Nd: YAG ceramic passively Q-switched laser at 1123 nm based on a Ti_(3)C_(2)T_(x)-polyvinyl alcohol(PVA) film as a saturable absorber(SA). A Brewster polarizer(BP) and a birefringent crystal(BC) are incorporated to enable frequency selection and filtering for the passively Q-switched 1123 nm pulsed laser to improve the power stability and reduce the noise. When the pump power is 5.1 W, an average output power of 457.9 m W is obtained, corresponding to a repetition frequency of 1.09 MHz,a pulse width of 56 ns, a spectral line width of 0.65 nm, a power instability of ±0.92%, and a laser noise of 0.89%.The successful implementation of the “Ti_(3)C_(2)T_(x)-PVA film passively Q-switching” combined with “frequency selection and filtering of BP + BC” technology path provides a valuable reference for developing pulsed laser with high repetition frequency, high stability and low noise.

Microstructure,optical,and photoluminescence properties ofβ-Ga_(2)O_(3)films prepared by pulsed laser deposition under different oxygen partial pressures

Theβ-Ga_(2)O_(3)films are prepared on polished Al_(2)O_(3)(0001)substrates by pulsed laser deposition at different oxygen partial pressures.The influence of oxygen partial pressure on crystal structure,surface morphology,thickness,optical properties,and photoluminescence properties are studied by x-ray diffraction(XRD),atomic force microscope(AFM),scanning electron microscope(SEM),spectrophotometer,and spectrofluorometer.The results of x-ray diffraction and atomic force microscope indicate that with the decrease of oxygen pressure,the full width at half maximum(FWHM)and grain size increase.With the increase of oxygen pressure,the thickness of the films first increases and then decreases.The room-temperature UV-visible(UV-Vis)absorption spectra show that the bandgap of theβ-Ga_(2)O_(3)film increases from4.76 e V to 4.91 e V as oxygen pressure decreasing.Room temperature photoluminescence spectra reveal that the emission band can be divided into four Gaussian bands centered at about 310 nm(~4.0 e V),360 nm(~3.44 e V),445 nm(~2.79 e V),and 467 nm(~2.66 e V),respectively.In addition,the total photoluminescence intensity decreases with oxygen pressure increasing,and it is found that the two UV bands are related to self-trapped holes(STHs)at O1 sites and between two O2-s sites,respectively,and the two blue bands originate from V_(Ga)^(2-)at Ga1 tetrahedral sites.The photoluminescence mechanism of the films is also discussed.These results will lay a foundation for investigating the Ga_(2)O_(3)film-based electronic devices.

调Q 532 nm激光联合超脉冲CO_(2)激光治疗面部脂溢性角化病的疗效及对患者生活质量的影响

目的:探讨调Q 532 nm激光联合超脉冲CO_(2)激光治疗面部脂溢性角化病患者的临床效果。方法:采用单中心临床试验研究方法,选取2019年6月30日-2022年12月31日在笔者医院接受治疗的186例面部脂溢性角化病患者进行随机分组,其中联合组93例患者采用调Q 532 nm激光联合超脉冲CO_(2)激光治疗,对照组93例患者采用超脉冲CO_(2)激光治疗,对比两组患者治疗前后的临床疗效、皮肤病生活质量指数(Dermatology Life Quality Index,DLQI)评分、并发症的发生情况。结果:联合组疗效优于对照组(P<0.05);治疗后,两组衣物选择评分、患者的日常活动评分、症状与躯体感受评分、心理感受程度评分方面及DLQI总分均低于治疗前(均P<0.05),且联合组改善均优于对照组(均P<0.05)。两组并发症率比较,差异无统计学意义(P>0.05)。结论:调Q 532 nm激光联合超脉冲CO_(2)激光治疗面部脂溢性角化病患者较单纯采用超脉冲CO_(2)激光治疗具有更好的效果,能更有效地改善患者的生存质量。

Quantum Path Selection and Isolated-Attosecond-Pulse Generation of H2+ with an Intense Laser Pulse and a Static Field

We theoretically investigate the high-order-harmonic generation from the H2^＋ molecular ion exposed to the combi- nation of an intense trapezoidal laser and a static field. The results show that the harmonic spectrum is obviously extended and the short quantum path is selected to contribute to the spectrum, because the corresponding long path is seriously suppressed. Then the combined Coulomb and laser field potentials and the time-dependent electron wave packet distributions are applied to illustrate the physical mechanism of high-order harmonic gen- eration. Finally, by adjusting the intensity of the static field and superposing a properly selected range of the HHG spectrum, a 90-as isolated attosecond pulse is straightforwardly obtained.

超脉冲CO_(2)激光联合马来酸噻吗洛尔在婴幼儿体表血管瘤的应用

目的观察婴幼儿体表血管瘤治疗中超脉冲CO_(2)激光联合马来酸噻吗洛尔滴眼液外敷的疗效。方法回顾性选取2020年7月至2022年2月江西省妇幼保健院医学美容科收治的体表血管瘤患儿共90例,联合组30例接受超脉冲CO_(2)激光联合马来酸噻吗洛尔治疗,激光组30例接受超脉冲CO_(2)激光治疗,药物组30例接受马来酸噻吗洛尔滴眼液外敷治疗;对比三组的临床疗效。结果治疗后6个月,联合组治愈率高于激光组及药物组,差异有统计学意义(P<0.05);联合组治疗疗程较激光组及药物组缩短,差异有统计学意义(P<0.05)。结论体表血管瘤患儿接受超脉冲CO_(2)激光联合马来酸噻吗洛尔治疗可提高疗效,缩短疗程。

Highly Defective Dark TiO_(2) Modified with Pt: Effects of Precursor Nature and Preparation Method on Photocatalytic Properties

The study focused on the modification with platinum of dark defective titania obtained via pulsed laser ablation. Both the method of Pt introduction and the nature of the Pt precursor were varied. All samples exhibited similar phase compositions, specific surface areas, and Pt contents. High-resolution transmission electron microscopy coupled with pulsed CO adsorption revealed increased dispersity when photoreduction and the hydroxonitrate complex (Me _(4) N) _(2) [Pt _(2) (OH) _(2) (NO _(3) ) _(8) ] were used. The sample featured a high content of single-atom species and subnano-sized Pt clusters. The X-ray photoelectron spectroscopy results showed that the photoreduction method facilitated the appearance of a larger number of Pt ^(2+) states, which appeared owing to the strong metal-support interaction (SMSI) eff ect of the transfer of electron density from the electron-saturated defects on the TiO _(2) surface to Pt ^(4+) . In the hydrogen evolution reaction, samples with a significant fraction of the Pt ^(2+) ionic component, capable of generating short-lived Pt^(0) single-atom sites under irradiation due to the SMSI eff ect, exhibited the highest photocatalytic activity. The 0.5Pt(C)/TiO_(2) -Ph sample exhibited the highest hydrogen yield with a quantum efficiency of 0.53, retaining its activity even after 8 h of operation.

Comparison on Morphological and Optical Properties of TiO_(2) Thin Films Grown by Single-Pulse and Multi-Pulse Laser Ablation

TiO2 thin films were prepared on glass substrates using the PLD (Pulsed Laser Deposition) technique. In order to carry out the ablation process, a Nd:YAG laser was used emitting in 1064 nm wavelength at 10 Hz repetition rate, set up for operating in both single-pulse and multi-pulse regimes. A comparison of the deposition rate, the optical and morphological properties of the layers obtained from both ablation regimes was made, which showed that the multi-pulsed ablation produced layers with a higher surface quality and better optical properties.

Pulse Laser Deposition of HfO_(2)Nanoporous-Like Structure,Physical Properties for Device Fabrication

The pulsed laser deposition(PLD)technology was used to effectively create conductive nano and micro hafnium oxide with great purity and transparency for(HfO_(2))nanofilms.In many optoelectronics devices and their applications,the presence of a high dielectric substance like a nano HfO2,between the metal contacts and the substrates was critical.We used the Pulsed Laser Deposition method to fabricate an Al/HfO_(2)/p-Si Schottky barrier diode where the nanostructured HfO2 films as an intermediate layer and varied substrate temperatures.The optical result reveals a high degree of transparency(93%).The optical bandgap of deposited HfO2 films was observed to vary between 4.9 and 5.3 eV,with a value of roughly 5.3 eV at the optimal preparation condition.The morphology of the surface shows a high homogeneous nano structure with the average values of the roughness about(0.3 nm).With regard to substrate temperature,the produced factor ideality for fabricated diode was determined to be lowering and the associated values of the barrier height rose based on I-Vcharacterization.With regard to substrate temperature,the produced factor ideality for fabricated diode was determined to be lowering and the associated values of the barrier height rose based on I-V characterization.The diode manufactured at 600℃,in particular,had a higher ideality factor value(n=3.2).

超脉冲CO_(2)点阵激光配合果酸应用于痤疮瘢痕患者中的疗效及对其ECCA评分的改善

目的:探讨超脉冲CO_(2)点阵激光配合果酸应用于痤疮瘢痕患者中的疗效及对痤疮瘢痕权重评分(Echelle d’evaluation clinique des cicatrices d’acne,ECCA)的改善情况。方法:选取2021年6月—2022年6月国药葛洲坝中心医院接收的痤疮瘢痕患者86例,按随机数字表法分为两组,对照组43例予以超脉冲CO_(2)点阵激光治疗,观察组43例予以超脉冲CO_(2)点阵激光配合果酸治疗,对比两组的临床疗效、五级整体改善量表(global aesthetic improvement scale,GAIS)评分、ECCA评分、患者满意度及不良反应发生情况。结果:观察组总有效率为95.35%,高于对照组的81.40%,差异有统计学意义(P<0.05);观察组治疗后的GAIS与ECCA评分均优于对照组,差异均有统计学意义(P<0.05);观察组患者满意度为95.35%,高于对照组的78.07%,差异有统计学意义(P<0.05);观察组不良反应发生率为9.30%,与对照组的6.98%比较,差异无统计学意义(P>0.05)。结论:超脉冲CO_(2)点阵激光配合果酸应用于痤疮瘢痕患者治疗中可进一步提升效果,并有效改善ECCA评分,提高患者满意度,且安全性理想。