激光防护材料的发展及研究现状

由于激光对人眼和光学系统有伤害,激光防护技术也因此产生.首先综述了各种激光防护技术,论述了各自的基本原理、国内外发展状况及特点,并重点讨论了激光防护玻璃的研究现状.     

新型微光探测器激光防护材料的研究

系统分析了微光夜视器的结构及其原理,并结合当前器件存在的激光致盲威胁,提出了增强系统安全的新措施。同时,系统地介绍了防激光滤光材料一些重要的性能参数以及滤光材料的组成、制备加工工艺。研究结果表明,新型的防激光材料能够有效地防护800nm,900nm以及10613nm等三个波长的激光,并且可见光透过率大于85％。     

激光防护镜材料的研究与发展

激光防护镜材料的发展背景1960年激光问世以来,激光在军事、科研、工农业和医学等领域的应用得到迅速地发展。数以万计的激光器或激光装置投入使用,由于激光是一种很强的光辐射,如果使用不当,可能对人产生危害。激光对人体的危害首先是眼睛。激光束射到眼睛时在视网膜上聚焦成小光斑。这种作用便产生了能量或功率的高度集中,这非常类似于放大镜对太阳光的聚焦作用。视网膜的曝光面积非常小,厚度极小的组织将吸收大部分能量,于     

激光隐身材料的研究现状及其发展趋势

在介绍激光隐身的基本原理的基础上,综述了目前国内外各种激光隐身材料的研究进展,较详细地介绍了纳米吸波材料、半导体化合物、光谱转换材料以及近红外线激光防护材料等吸收材料的主要特点和研究现状.在此基础上,介绍了激光与红外、雷达、毫米波的兼容隐身机理和研究现状,对其发展趋势进行了展望,并指出多频谱兼容隐身是未来隐身材料发展的...     

卫星激光防护技术研究

从３个方面探讨了卫星的激光防护技术。介绍了材料与光电传感器的抗激光攻击能力的试验评价方法;给出了卫星光电传感器的抗激光致盲薄膜的设计原理;阐述了结构材料的激光损伤机理并说明了结构材料的激光防护技术。     

激光辐照下的材料破坏和防护研究进展

简介了材料在激光辐照下的破坏和防护的研究进展,对激光作用下材料的破坏机理、破坏形式、影响因素和抗激光防护研究情况等进行了探讨。     

全息激光防护薄膜的研制

介绍了全息激光防护薄膜基本理论和设计方法。研制成功的全息激光防护薄膜，其光学性能测试表明：０．５３μｍ波长激光的光密度Ｄ达４．１１，防护角达１５°，具有良好的可见光透过率，且抗激光破坏能力强，可用于人眼和光电探测系统的激光防护。     

激光防护材料SmBO3的制备及其光学吸收特性

利用固相法制备了SmBO3粉体,讨论了煅烧温度对粉体合成及光学吸收特性的影响.结果表明:原料经800℃煅烧后,即可获得单相的三斜SmBO3,粉体呈不规则颗粒状,颗粒大小主要分布在500～600nm;1200℃煅烧后,三斜SmBO3完全转变为六方SmBO3,颗粒尺寸长大至1～2μm.反射率图谱表明,在1.05～1.15μm?长范围?两种晶?SmBO3粉体?光均存?较强的?收,并?在1.07μm波长附近反射率达最低值.红外图谱显示,三斜SmBO3在500～1400cm-1波数范围内,存在较为集中的吸收峰;六方SmBO3在944 cm-1(10.6μm波长)处的吸收峰宽化,并且吸收明显增强.因此SmBO3是一种能兼容1.06和10.6μm波长的激光防护吸收剂材料.     

基于激光熔覆技术的热防护材料选择

轻量化合金材料的耐高温、抗烧蚀性能较差,采用激光熔覆技术制作涂层的方法可提升其热防护性能。本文从热防护的机理出发,结合激光熔覆工艺对熔覆材料性能的要求,从现有的热防护材料和激光熔覆材料中筛选出几种可实现短时间、无冷却情况下基体热防护的熔覆材料,并对基于激光熔覆工艺的热防护材料的未来发展趋势进行了展望。     

激光隐身材料的研究新进展

针对当前激光制导武器的严重成胁，介绍了激光隐身的原理，综述了当前激光隐身技术的现状、激光隐身领域新材料与新技术研究动态，并展望了未来激光隐身发展的方向，为开展防激光制导打击的新材料和新技术研究提供参考。     

Photo-thermo-refractive glass co-doped with Nd as a new laser medium

Photo-thermo-refractive (PTR) glass demonstrates refractive index change after exposure to UV radiation followed by a thermal treatment that enables recording of high efficiency holographic optical elements. This work demonstrates feasibility of function of this material as a complex optical medium which posseses both photosensitive and luminescent properties and paves a way for creation of monolythic solid state lasers where resonator components can be holographically recorded inside of a laser medium. It was found, that incorporating of Nd³⁺ ions in PTR glass does not affect photosensitivity required for hologram recording. It was demonstrated that emission wavelength, spectral width, and cross section of Nd³⁺ luminescence in PTR glass are typical for silicate laser glasses and Nd-doped PTR glass can be considered as a promising laser medium for monolithic solid state lasers.     

金属材料水导激光加工实验研究

金属材料的激光加工目前正向着低表面粗糙度、小热影响区及大深径比结构的趋势发展。新近发展了一种基于激光-水射流耦合原理的水导激光加工技术,本文阐述了水导激光加工技术的基本原理及其相对于传统激光加工方法的优势,基于激光-水射流耦合原理构建了一套水导激光加工设备,对多种金属材料进行了水导激光加工实验。利用超景深显微镜对加工工件表面进行了观测与分析,发现两种金属材料加工得到的盲孔边缘规则圆滑,切槽的边缘平直无毛刺,没有热影响区。实验结果说明对金属材料的水导激光精密加工具有可行性且有重要的应用价值。     

一种新双光子吸收材料PSPI的性能研究

合成了一种染料反式-4-[对 -(吡啶咯烷基 )苯乙烯基 ]-N-甲基吡啶盐碘 (PSPI).实验研究了这种新化合物的双光子吸收 ,双光子吸收引起的频率上转换发射,双光子泵浦的上转换超辐射性质 . 化合物在 1064 nm处具有中等大小的双光子吸收截面σ=5.7× 10-48cm4·s/photon,但具有很高的超辐射效率 . 当泵浦能量为2.02mJ时总的转换效率高达 16.8% .     

金属粉末激光快速成形的工艺及材料成形性

对比了3类金属粉末激光快速成形工艺:选区激光烧结;选区激光重熔,或称选区激光熔覆;以及直接激光沉积,或称激光净成形.提出了其分类依据是金属粉末与激光的作用机制,以及由此导致的金属粉末激光成形机理.综述了上述3类激光快速成形工艺的成形原理、成形材料及工艺优劣,分析了"球化"效应、翘曲变形、以及裂纹等对金属粉末激光成形性的影响规律及相应解决措施.     

新型聚酯材料状态方程的研究

聚酯材料在航空航天领域有着较广泛的应用,其高压力学性能的研究逐渐受到人们的关注。针对一种新型聚酯材料通过轻气炮(LGG)实验开展其冲击压缩力学性能研究。采用非对称碰撞直接测量法测量并计算激波速度(D)与波后质点速度(u)的D-u型Hugoniot曲线,并由此推导出P-η型Hugoniot曲线。建立了该材料的Murnagham状态方程,求得了相应的材料参数。并对新型聚酯材料的Murnagham状态方程和P-η型Hugoniot状态方程进行了比较和分析。     

Study on mechanical properties of a new type micro/nano metal material based on bacteria shape

The functional groups and mechanical properties of Nocadia, a kind of bacteria with submicrometer in diameter and 3-10 microm in length, before and after metallization are determined by fourier transform infrared spectroscopy (FT-IR) and nanoindentation technology. The group -COOH exists on surface of Nocadia and the function groups of Nocadia decreases due to metallization. The elastic modulus of metallized Nocadia, Nocadia and resin is 42.583 GPa, 9.501 GPa and 5.723 GPa, respectively, and the hardness is 1.940 GPa, 0.265 GPa and 0.301 GPa, respectively. There is a great improvement of 5 times in elastic modulus and 9 times in hardness compared with bare Nocadia.     

Effects of material combination on laser beam drilling of a metal foil using a cover plate

This research investigated the microdrilling characteristics of metal foils depending on the materials of the cover plates and metal foils in the cover plate-laser beam machining (c-LBM) process, which is a method to achieve better quality in metal foil machining with a given piece of equipment. Laser beam drilling using a nanosecond pulsed laser was carried out on 10-µm-thick stainless steel 304 (STS304), nickel, and copper foils with 100-µm-thick cover plates of each material. Consequently, STS304 was found to be an effective cover plate material for reducing the hole diameter and spatter deposition on metal foils. Compared to the results without using a cover plate, the average hole diameter and the area of spatter deposition decreased by up to 77% and 96%, respectively, by using the STS304 cover plate. Meanwhile, the thermal deformation of the STS304 and nickel foils was prevented by using a cover plate, while the copper foil was barely deformed even without a cover plate. Lastly, it was remarkable that the copper foil was drilled with approximately 67% lower pulse energy than the effective minimum pulse energy required to drill it by using the STS304 cover plate, resulting in a smaller hole with little spatter.     

Study on microwave absorption properties of metal-containing foam glass

Materials with the properties of electromagnetic (EM) wave absorption are attractive topics. In this work, we report that EM wave absorption composites, consisting of foam glass, zinc and zinc oxide, were prepared by sintering mixture of foam glass raw material and zinc powder. Microwave reflection loss of composite was calculated based on the permittivity in the range of 8.2-12.4 GHz. The results show that zinc-containing foam glass absorbs efficiently microwaves. The sample with zinc filler to foam glass mass ratio of 3/18 had a reflection loss below −10 dB in the range of 11.3-12.4 GHz, and the minimum reflectivity was −15.6 dB at both 12.0 and 12.4 GHz. Microwave absorption performances of specimens can be controlled by changing the ratio between zinc powder and foam glass mass. The detailed mechanism of the control was investigated through X-ray diffraction (XRD) analysis and scanning electrical microscopy (SEM) observations.     

Study of the heat-transfer characteristics of a thermally protective composite material

Results are presented from a theoretical-experimental study of the thermal conductivity of a thermally protective composite for different models of heat transfer.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 49, No. 6, pp. 989–994, December, 1985.