595nm脉冲染料激光联合卤米松乳膏治疗甲银屑病的疗效观察

目的观察595nm脉冲染料激光(pulsed dye laser,PDL)联合卤米松乳膏治疗甲银屑病的临床疗效。方法入组15例10个指甲受累甲银屑病患者,随机选择指甲给予安慰剂、卤米松乳膏、PDL、PDL联合卤米松乳膏治疗。共治疗4次,每次术前及结束后1个月评估疗效。结果与治疗前相比,卤米松组、PDL组、联合治疗组治疗后指甲甲基及甲银屑病皮损面积严重度指数(NAPSI)评分均有不同程度的降低,联合组改善最为明显。结论PDL联合卤米松乳膏治疗甲银屑病安全有效,不良反应少,是治疗甲银屑病的理想方法之一。

Bioinspired superwetting surfaces for fog harvesting fabricated by picosecond laser direct ablation

Fog harvesting has been considered as a promising method for solving water crisis in underdeveloped regions.To mimic and optimize the alleged natural fog harvesting ability of the stenocara beetle,hybrid superhydrophobic(hydrophobic,superhydrophilic)/hydrophilic patterns are processed on stainless steel via picosecond laser direct writing.Basically,after laser processing,the surfaces of stainless steel change from hydrophilic to superhydrophilic.Then,after chemical and heat treatment,the superhydrophilic surfaces become superhydrophobic with ultra-low adhesion,and superhydrophobic(hydrophobic)with ultra-high adhesion,respectively.This work systematically examines the fog harvesting ability of picosecond laser treated surfaces(LTS),pristine surfaces(PS),laser and chemical treated surfaces(LCTS),laser and heat-treated surfaces(LHTS).Compared with the PS,the as-prepared surfaces enhanced the fog harvesting efficiency by 50%.This work provides a fast and simple method to fog collectors,which offer a great opportunity to develop water harvesters for real world applications.

Laser Induced Breakdown of Poly （Methyl Methacrylate （PMMA）） in Air

In the present work, Laser induced Breakdown spectroscopy technique is used to investigate the laser induced plasma of PMMA in air. The optical emission of PMMA plasma is found quite intense and dominated by vibrational band of CN molecules （violet band, B^2∑^＋ - X^2∑^＋） at 388.4 nm. The temporal response of the CN band emission is studied and found decay time 22 ns. The low decay time and small laser spot （34 × 32 μm^2） conf＇n-ms good thermal stability of PMMA. To get structural fingerprint of PMMA, Raman spectrum is recorded prior to the exposure to laser. Several sharp Raman peaks have been observed along with a very intense peak at 2,957 cm1 attributed to C-H stretching vibration. Post exposure Raman spectrum is also recorded to analyze the heating effect and re-deposition of ablated material.

Slicing-response model for ablation mass removal of polyformaldehyde irradiated by pulsed CO_2 laser in vacuum

The interaction between CO2 laser and polyformaldehyde(POM)is quite important in the research of laser irradiation effects and mechanisms.At this time,the accuracy of the existing mass-ablation models for POM irradiated by CO2 laser is poor compared with the experimental data.Based on the energy distribution deposited in the POM target,the active area excited by laser is divided into four slices,the ablation slice(the temperature-rising slice,the perturbation slice,and the undisturbed slice),and a slicing response model for the mass ablation of POM induced by pulsed CO2 laser irradiation in vacuum is developed.A formula is deduced to predict the ablated mass areal density from the model and is verified with data from several studies and our own experiments.The results show that our model fits the experimental data quite well before the shielding effect of ablation products becomes notable.The applicability of the model to other materials and the mass ablation in atmosphere are also briefly explored.

Photofragment translational spectroscopy at 304 nm from C-H symmetric stretch excited CH_3I [v_1 = 1]

The 304 nm photodissociation of the C-H symmetric stretch excited CH3I[v1=1,v2=0](v1 denotes the C-H symmetric stretch mode,and v2 denotes the umbrella mode)is studied with our simple photofragment translational spectrometer.An IR laser is used to excite the ground state CH3I[0,0]to the C-H symmetric stretch excited CH3I[1,0].With IR laser OFF and ON,the fractions of photofragments CH3(ν1,ν2)from the 304 nm photodissociation of CH3I[1,0]have been determined through the photofragment translational spectra(PTS)from measuring I and I*and also through the PTS from measuring CH3(0,0)(1,0)(0,1)and(1,1).The experimental results show that the C-H symmetric stretch vibration(v1=1)in parent molecules is about 66%retained in the photofragments in the I channel,but only 24%in the I*channel.The populations of photofragments CH3(0,2)and(0,3)are higher than CH3(0,0)and(0,1),showing strong inverted population both in I and I*channels.

A near-infrared methane detection system using a 1.654 μm wavelength-modulated diode laser

By adopting a distributed feedback laser(DFBL) centered at 1.654 μm, a near-infrared(NIR) methane(CH4) detection system based on tunable diode laser absorption spectroscopy(TDLAS) is experimentally demonstrated. A laser temperature control as well as wavelength modulation module is developed to control the laser's operation temperature. The laser's temperature fluctuation can be limited within the range of-0.02—0.02 °C, and the laser's emitting wavelength varies linearly with the temperature and injection current. An open reflective gas sensing probe is realized to double the absorption optical path length from 0.2 m to 0.4 m. Within the detection range of 0—0.01, gas detection experiments were conducted to derive the relation between harmonic amplitude and gas concentration. Based on the Allan deviation at an integral time of 1 s, the limit of detection(Lo D) is decided to be 2.952×10^(-5) with a path length of 0.4 m, indicating a minimum detectable column density of ~1.2×10^(-5) m. Compared with our previously reported NIR CH_4 detection system, this system exhibits some improvement in both optical and electrical structures, including the analogue temperature controller with less software consumption, simple and reliable open reflective sensing probe.

A novel strategy for improving upconversion luminescence of NaYF4：Yb, Er nanocrystals by coupling with hybrids of silver plasmon nanostructures and poly（methyl methacrylate） photonic crystals

The coupling of upconversion nanophosphors （UCNPs） with the surface plasmonic resonance （SPR） of noble metals is a promising way to improve luminescent efficiency of UCNPs; however, it is still a challenge to achieve stable, reproducible and effective upconversion luminescence （UCL） enhancement through such coupling. In this work, we present a novel strategy to improve UCL of NaYF4：ybB,Er3. UCNPs, by combining the near-field coupling of SPR of silver and the far-field coupling of poly（methyl methacrylate） （PMMA） opal photonic crystals （OPCs） with the UCNPs. In order to control the effective interaction distance between the UCNPs and the SPR, a porous silver film consisting of randomly distributed silver nanoparticles （NPs） （〉 100 nm） was prepared which demonstrated strong SPR over a broad wavelength range, and its coupling to the UCNPs was found to be much stronger than that of a dense film. In the far-field coupling of OPCs, the photonic stop band （PSB） of the PMMA OPCs was tuned to 980 nm, matching exactly the excitation light. By modulating the particle size of the UCNPs, and the direction and excitation power of the incident light, a maximum enhancement of 60-fold was observed, which is an important advance for metaMnduced UCL enhancement systems.

Synthesis and luminescent properties of ternary complex Eu(UVA)_3Phen in nano-TiO_2

By introducing 2-hydroxy-4-methoxy-benzophenone(UVA) and 1,10-phenanthroline(Phen) as the ligands, the ternary rare earth complex of Eu(UVA)3Phen is synthesized, and it is characterized by elemental analysis, mass spectra(MS) and infrared(IR) and ultraviolet(UV) spectroscopy. Results show that the Eu(III) in complex emits strong red luminescence when it is excited by UV light, and it has higher sensitized luminescent efficiency and longer lifetime. The organic-inorganic thin film of complex Eu(UVA)3Phen doped with nano-Ti O2 is prepared, and the nano-Ti O2 is used in the luminescence layer to change the luminescence property of Eu(UVA)3Phen. It is found that there is an efficient energy transfer process between ligands and metal ions. Moreover, in an indium tin oxide(ITO)/poly(N-vinylcar-bazole)(PVK)/Eu(UVA)3Phen/Al device, Eu3+ can be excited by intramolecular ligand-to-metal energy transfer process. The main peak of emission at 613 nm is attributed to 5D0→7F2 transition of the Eu3+, and this process results in the enhanced red emission.