Ultrapulse超脉冲CO2激光治疗腋臭的疗效观察

目的 :探讨超脉冲CO2 激光治疗腋臭的临床疗效。方法 :本文应用超脉冲CO2 激光治疗 340例腋臭患者 ,二月后复诊判断疗效 ,未根治者重复治疗。结果 :超脉冲CO2 激光一次治愈 2 17例 ,占 6 3.82 % ,二次治愈 78例 ,占 2 2 .94 % ,余下例经第三次治愈 ,总有效率为 10 0 %。结论 :超脉冲CO2 激光治疗腋臭疗效显著 ,并发症少 ,是一种安全有效的治疗方法 ,值得临床推广使用     

超脉冲CO_2激光治疗鼾症68例报告

目的 :自 1998年 6月至 2 0 0 1年 6月 ,应用超脉冲 CO2 激光行下悬雍垂腭咽成形术 ,治疗鼾症 6 8例 ,术后随访 6～ 2 4个月 ,临床症状改善率达 76 %。结论 :本方法操作简单 ,安全可靠 ,疗效确切 ,术后并发症少     

超脉冲和连续式CO-2激光治疗腋臭疗效观察

目的:观察超脉冲和连续式CO2激光对腋臭的治疗效果。方法:超脉冲CO2激光治疗腋臭50例,并以CO2激光治疗作为对比。结果:超脉冲CO2激光治疗总有效率86%,CO2激光治疗总有效率80%。结论:两者治疗效果相当,但超脉冲CO2激光伤口愈合快,副作用小。     

超脉冲CO2激光治疗鼾症68例报告

目的自1998年6轮?001年6月,应用超脉冲CO2激光行下悬雍垂腭咽成形术,治疗鼾症68例,术后随访6～24个月,临床症状改善率达76%.结论本方法操作简单,安全可靠,疗效确切,术后并发症少.     

CO2激光治疗腋臭34例

我科1989年6月至1990年5月,用CO_2激光治疗腋臭31例,效果良好,治愈率为64.7％,有效率为97.1％,报告如下。 资料和方法 34例患者中,单侧2例,其余全为双侧。男性10例,女性24例;年龄16～46岁,平均23.5岁,其中>35岁4例,18～35岁28例,<18岁2例;病程1~+年～28年;34例中31例有家族遗传史,占91.7％。按备皮时臭味大小和距离,将患者分为轻、中、重三个程度。轻度:30cm内闻及臭味者6例;中度:30～100cm闻及臭味者21例;重度:100cm外闻     

CO2激光治疗痔疮445例临床分析

痔是临床上常见的多发病,它的发病率占肛直肠疾患的87.25％。其发病原因及处理方法迄今仍有争论。自1988年以来,我们采用CO_2激光治疗痔疮445例,疗效满意,现报告分析如下。     

CO2激光治疗乳头状瘤34例疗效分析

我科1990年5月至1992年7月采用CO_2激光治疗乳头状瘤34例,效果满意,报告如下: 资料和方法 34例均经病理及临床检查确诊。男性18例,女性16例。年龄19/(12)～59岁,平均37.27岁。病程1~+月～59年。部位分布:鼻前庭8例;外耳道5例;头面部8例;四肢部5例;腰背部4例;腹部2例;尿道口1例。     

CO2激光治疗宫颈息肉

自1987年11月至1989年11月,我们采用CO_2激光治疗宫颈息肉,收到了较好的效果,现报告如下: 一般资料 本组63例患者、工人28例,农民22例,干部13例,最小年龄23岁,最大年龄56岁,均为已婚妇女。     

超脉冲CO_2激光在经睑结膜整复眼术的临床应用

减少术中出血 ,提高经睑结膜整复眼袋的临床效果。方法　采用超脉冲CO2 激光 ,经下睑结膜整复眼袋 2 5 6例 ;结果　术中出血极少 ,全部病例均获满意效果。结论　用超脉冲CO2 激光在整复眼袋术中具有明显优势     

铜蒸气激光器激光上能级间粒子碰撞跃迁的实验研究

本实验利用铜蒸气激光器振荡—放大链,通过比较当黄绿光同时注入放大器时和仅以绿光或黄光注入放大器时所测得的绿光和黄光光脉冲的波形,观察到了在高气压下,粒子在激光上能级之间跃迁的现象,从而证实了这种碰撞跃迁的存在,并对其物理过程和机理做出了定性解释。     

Pulsed laser deposition of carbon films: Dependence of film properties on laser wavelength

We have grown thin carbon films by pulsed laser deposition and have investigated the extent to which the properties of such films, as well as the processes responsible for these properties, are laser wavelength dependent. Films were grown by ablating material from a graphite target onto room temperature Si(100) substrates with 1064 and 248 nm laser radiation. The films were analyzed byin situ electron energy loss spectroscopy and byex situ Raman spectroscopy. The results indicated that films grown with 1064 nm ablation were graphitic, while those grown with 248 nm radiation were diamond-like. We have also examined the mass and kinetic energy distributions of the particles ejected from graphite by the two laser wavelengths. The results indicated that irradiation of graphite with 1064 nm laser radiation results in the ejection of a series of carbon cluster ions C _n ⁺ (1 ≤ n ≤ 30) with mean kinetic energies less than 5 eV. Ablation of graphite with 248 nm radiation results in the ejection of primarily C ₂ ⁺ and C ₃ ⁺ with mean kinetic energies of 60 and 18 eV, respectively. These results suggest that large, low energy clusters produce graphitic films, while small, high energy clusters produce films of diamond-like carbon.     

Pulsed laser deposition of titanium nitride and diamond-like carbon films on polymers

We have investigated the deposition of titanium nitride (TiN) and diamond-like carbon (DLC ) films on polymethylmethacrylate (PMMA) substrates using pulsed laser deposition (PLD) technique. The TiN and diamond-like films were deposited by laser ablation (KrF excimer laser λ = 248 nm, pulse duration τ～25 × 10^?9 s, energy density ～2?15J/cm²) of TiN and graphite targets, respectively, at room temperature. These films were characterized by transmission electron microscopy, scanning electron microscopy, x-ray diffraction, Auger electron spectroscopy, UV-visible absorption spectroscopy, and Raman spectroscopy. The TiN films were smooth and found to be polycrystalline with average grain size of 120Å. The diamond-like carbon films were amorphous with a characteristic Raman peak at 1550 cm^?1. The TiN films are highly adherent to the polymer substrates as compare to DLC films. The adhesion strength of DLC films on polymers was increased by interposing thin TiN layer (200Å) on polymers byin-situ pulsed laser deposition. The DLC films were found to be amorphous with good adhesion to TiN/PMMA substrates.     

Recent progress on nanostructured bimetallic electrocatalysts for water splitting and electroreduction of carbon dioxide

The exploitation of renewable energy as well as the elimination of the harmful impact of excessive carbon emission are worldwide concerns for sustainable development of the ecological environment on earth. To address that, the technologies regarding energy conversion systems, such as water splitting and electroreduction of carbon dioxide, have attracted significant attention for a few decades. Yet, to date, the production of green fuels and/or high energy density chemicals like hydrogen, methane, and ethanol, are still suffering from many drawbacks including high energy consumption, low selectivity, and sluggish reaction rate. In this regard, nanostructured bimetallic materials that is capable of taking the full benefits of the coupling effects between different elements/components with structure modification in nanoscale are considered as a promising strategy for high-performance electrocatalysts. Herein, this review aims to outline the important progress of these nanostructured bimetallic electrocatalysts. It starts with the introduction of some important fundamental background knowledge about the reaction mechanism to understand how these reactions happen. Subsequently, we summarize the most recent progress regarding how the nanostructured bimetallic electrocatalysts manipulate the activity and selectivity of catalytic reactions in the order of bimetallic alloying effect, interface/substrate effect of bi-component electrocatalyst, and nanostructuring effect.     

碳纳米管被动锁模光纤激光器的研究进展

单壁碳纳米管(SWCNTs)作为被动锁模材料具有许多优点:恢复时间快(＜1 ps)、饱和光强低、制各处理容易、成本低、工作光谱范围宽、化学稳定性好、与光纤兼容等,在超快激光器方面引起了人们的极大兴趣,并成功应用于固体、波导和光纤被动锁模激光器.本文对被动锁模超短脉冲光纤激光器的研究进展进行了综述,特别是对以单壁碳纳米管...     

激光表面处理1.6%C超高碳钢的组织与性能

为了研究激光处理后超高碳钢表面组织及性能的变化,采用2kW连续横流CO2激光器对超高碳钢(C的质量分数为0.016)进行了激光处理,采用扫描电镜观察组织和显微硬度计测量深度方向显微硬度值的方法,进行了理论分析和实验验证,取得了沿深度方向的组织照片和硬度分布曲线。结果表明,激光处理层分为熔凝层、过热层和相变硬化层。熔凝层可观察到胞状树枝晶和离异共晶;相变硬化层组织细小,显微硬度(高达750HV～905HV)高于其它层,是典型的激光淬火组织。随激光功率增大(1000W～1200W),熔凝层中胞状树枝晶和离异共晶增多并细化,马氏体数量减少,各层的宽度、深度均增大,显微硬度降低。这一结果对细化超高碳钢组织和改善其性能是有帮助的。     

45~#钢激光铬钼合金层性能的研究

本文对45~#钢表面激光铬、钼合金化前后各项性能进行了分析比较。结果表明,激光铬钼合金化可使45~#钢表面耐磨性提高1～2倍,也可使45~#钢表面的抗高温氧化性和耐酸腐蚀性有较大程度的改善。     

基于激光热弹效应的碳纤维增强树脂复合材料缺陷检测机理研究北大核心CSCD

碳纤维增强树脂基复合材料(carbon fiber reinforced resin polymer, CFRP)在周期载荷作用下产生的基体裂纹、纤维断裂等微损伤的累积会严重影响CFRP的力学性能,微损伤尺寸较小且位置分散,传统的无损检测方法难以准确识别。激光超声检测技术具有非接触、检测速度快、测量范围广等优点,特别是结合激光的远距离激励和大角度入射的优势,在大尺寸、曲面形式结构材料的损伤检测方面有巨大的潜力。本文基于激光热弹效应,在分析激光作用到CFRP后的温度、应力和位移场分布的基础上,对CFRP内部超声波的产生过程和传播特性进行了系统研究。并通过对CFRP中不同处存在缺陷时的超声波回波信号的分析比较,得到缺陷位置与回波信号特性之间的对应关系,从而实现从回波信号特征反演出CFRP中缺陷位置的关键信息。     

激光参数对激光激发超声信号的影响分析

研究了激光参数对激光激发超声信号的影响.研究中首先理论分析激光激发超声过程中,激光参数对激发超声信号的影响.同时,设计并搭建一种激光激发超声的实验装置,实验验证理论分析结果.该实验装置应用脉冲激光配合光衰减结构对被测目标激发产生超声波,通过超声探头实现激光超声信号的探测.实验中以铝板为检测对象,对激光脉冲能量和照射光斑大小对激发超声信号的影响进行实验分析.通过理论分析及实验验证,可得出照射光斑直径与激光能量会直接影响入射激光功率密度,从而影响激发超声的幅度.