红外玻璃陶瓷的力学性能

在一定的温度和时间下对GeS2-Sb2S3-CsCl系红外玻璃进行微晶化处理,制备了新型的红外透明玻璃陶瓷.测定了微晶玻璃的力学性能和光学性能,研究了微晶化处理条件对微晶玻璃的力学性能和光学性能的影响.研究结果表明,玻璃基体中析出微晶晶体,使材料的断裂韧性和裂纹初始应力显著增大,但这种增大效应取决于析晶相的种类和晶体尺寸.为了保持微晶玻璃的红外透明性,析出的晶体尺寸应小于100nm.     

硫硒化镉微晶玻璃制备和非线性光学性质研究

具有明显量子尺寸效应和较大三阶非线性光学效应的CdSxSe1-x(O相似文献   

高非线性硫系玻璃的研究进展

综述了硫系玻璃的三阶和二阶光学非线性性质的研究情况,分别介绍了其当前的研究进展,讨论和分析了各自主要的理论模型,并提出了二者进一步的发展方向,即通过采用稀土掺杂的方法利用双光子共振增强效应提高硫系玻璃的非线性折射率n2,以及利用电场/温度场极化与玻璃表面微晶化相结合的方法来获得大的二阶非线性极化率χ(2).     

硫系锂离子导电玻璃及微晶玻璃的研究

硫系锂离子导电玻璃及微晶玻璃具有离子电导率高、成形简单、组成和性能在一定范围内连续可调、不可燃等特点,被视为实现全固态锂离子电池的理想电解质材料。综述了硫系锂离子导电玻璃及微晶玻璃的制备工艺、结构、导电性能以及在锂离子电池中的应用,最后指出了其发展趋势。     

Ge-Ga-S-AgCl硫卤微晶玻璃的二阶非线性光学效应

在275℃(Tg-40℃),将47.5GeS2-17.5Ga2S3-35AgCl硫卤玻璃保温6～48h后,获得了具有二阶非线性光学效应的硫卤微晶玻璃.X射线衍射(XRD)、可见一近红外透射光谱、扫描电子显微镜(SEM)测试结果表明,有AgGaGeS4微晶析出并均匀分布在整块微晶玻璃中.采用Maker条纹测试方法,研究了微晶玻璃中二次谐波产生(SHG)的效应,其产生的原因主要归结于微晶玻璃中析出的AgGaGeS4非线性光学晶体.获得的Maker条纹图形状是没有干涉条纹的圆形突起包络.当基频光入射角在0°左右时,二次谐波的强度出现最大值.最大的二次谐波相对强度值可达α-SiO2单晶的1/3.这种微晶玻璃极有希望应用于红外光谱区的光电调制领域.     

Bi2S3纳米晶掺杂钠硼硅玻璃的三阶非线性光学性质

利用溶胶-凝胶方法制备了1 wt%Bi2S3纳米晶掺杂钠硼硅玻璃.利用X射线粉末衍射仪(XRD),X射线光电子能谱(XPS),透射电子显微镜(TEM),X射线能量色散谱(EDX),扫描模式透射电子显微镜(STEM)以及高分辨透射电子显微镜(HRTEM)对Bi2S3纳米晶在钠硼硅玻璃中的形貌和微结构进行了表征,同时,利用飞秒Z扫描技术在波长为770 nm对该玻璃的三阶非线性光学性能进行了分析测试.结果表明,尺寸为10～30 nm的Bi2S3正交晶系纳米晶在钠硼硅玻璃中形成,该玻璃的三阶非线性光学折射率γ、三阶非线性吸收率β和三阶非线性极化率χ(3)分别为5.90×10-16 m2/W、7.35×10-9 m/W和4.55×10-18 m2/V2.其中,该玻璃的三阶非线性极化率值比未经掺杂的钠硼硅玻璃(χ(3)=1.09×10-22 m2/V2)高出4个数量级,这表明,随着Bi2S3纳米晶的引入,该玻璃的三阶非线性光学性能将得到显著的提高.     

SiO2-Al2O3-MgO-F系微晶玻璃的形变析晶

采用高温熔融法制备了SiO2 -Al2O3 -MgO-F系玻璃样品,应用X射线衍射(XRD)、扫描电子显微镜(SEM)研究了该微晶玻璃在自由形变时的析晶特征,得到了微晶玻璃自由形变析晶的规律.结果表明:在热处理过程中随着温度的升高,基础玻璃的黏度逐渐降低,可以在析晶前施加压力使之发生变形.在自由形变的前提下,微晶玻璃析出的晶体在垂直压力和平行压力方向上没有出现定向析晶.显微硬度测试结果也表明在微晶玻璃中没有明显的各向异性特征,不会带来材料性能在不同方向上的差异,为形状复杂、均质同性微晶陶瓷的制备提供了一个有效途径.     

GeS_2-Ga_2S_3-AgCl玻璃的光学特性研究

采用熔融-淬冷法制备了摩尔组成为(100-x)(0.85GeS2-0.15Ga2S3)-xAgC l(x=0,5,10,15,20)硫卤玻璃,测试了样品的密度、转变温度、析晶温度、可见到中远红外透过光谱、吸收光谱以及折射率参数,根据Z-扫描测试原理用钛宝石飞秒激光器测试了样品的三阶非线性特性.利用经典的Tauc方程计算了样品光学带隙允许的直接跃迁、允许的间接跃迁及Urbach能量.讨论了玻璃的摩尔折射度、金属标准值、光学带隙、Urbach能量对玻璃样品折射率的影响.结果表明:该系统玻璃具有较宽光谱,从可见到中远红外透过区域(0.46~11.50)μm,可作为潜在的多光谱成像材料.随AgC l含量的增加,玻璃的折射率随着摩尔折射度增大而增大,金属标准值、光学带隙与Urbach能量有减小的趋势,而玻璃的三阶非线性性能得到明显提高.     

ZnO对碲铌基重金属氧化物玻璃的结构和光学性能的影响

TeO2 Nb2O5系统重金属氧化物玻璃是一种新型的重金属氧化物玻璃材料,具有优良的非线性光学性能。本文研究了ZnO对碲铌基玻璃的结构、非线性光学性能和光学透过率的影响,研究表明:碲铌基玻璃的非线性光学效应源于电子云畸变效应,掺杂少量ZnO有利于玻璃非线性光学性能的提高,增加ZnO至2.5%(质量分数)时用四波混频法测得的玻璃三阶非线性极化率χ(3)可达9.2×10-13esu,然后随ZnO含量增至10%(质量分数)时χ(3)减至6.0×10-13esu。ZnO含量在10%～15%(质量分数)时χ(3)则无明显变化。同时,加入15%(质量分数)的ZnO有利于玻璃透过率的提高。Raman光谱研究表明,掺入过多的ZnO(>5%(质量分数))时,网络间隙中的Nb5+可被Zn2+取代而进入网络,同时提供更多的桥氧,从而使玻璃网络中的[TeO4]4-基团向[TeO3]2-转化。     

非线性Ge-As-Se硫系光纤

平均配位数为2.45~2.50的Ge-As-Se硫系玻璃具有优异的红外透光性能、较高的三阶光学非线性和极低的光致折射率变化效应,是较理想的红外光学非线性材料。采用动态蒸馏技术制备了高纯GeAs-Se玻璃,采用棒管法拉制了芯包结构的光纤。光纤在2~8μm传输性能良好,背景损耗约1dB/m,杂质对应的峰值损耗约6dB/m。     

Ti－15－3合金管材的试制及组织性能研究

本文介绍了Ｔｉ－１５－３合金管材的加工工艺及工艺性能，研究了热处理条件对其性能的影响，并分析观察了不同状态下的组织特征。实验中还利用Ｘ射线衍射方法对Ｔｉ－１５－３合金管材的织构类型进行了确定。     

Synthesis of gold and silver nanoparticles by electron irradiation at 5-15 keV energy

Thin coatings (～10?μm) made from a mixture of polyvinyl alcohol (PVA) and HAuCl(4) or PVA and AgNO(3) on quartz plates were irradiated with 5-15?keV electrons, at room temperature. The electron energy was varied from coating to coating in the range of 5-15?keV, but electron fluence was kept constant at ～10(15)?e?cm(-2). Samples were characterized by the UV-vis, XRD, SEM and TEM techniques. The plasmon absorption peaks at ～511 and ～442?nm confirmed the formation of gold and silver nanoparticles in the respective electron-irradiated coatings. The XRD, SEM and TEM measurements reveal that the average size of the particles could be tailored in the range of 130-50?nm for gold and from 150-40?nm for silver by varying the electron energy in the range of 5-15?keV. These particles of gold and silver embedded in the polymer could also be separated by dissolving the coatings in distilled water.     

Thermoelectric properties of the n-type 85% Bi2 Te3-15% Bi2 Se3 alloys doped with Sbl3 and CuBr

The temperature dependence of the Hall mobility, Seebeck coefficient, electrical resistivity, thermal conductivity, and figure-of-merit of the SbI3 and CuBr-doped 85% Bi2Te3-15% Bi2Se3 single crystals have been characterized at temperatures ranging from 77 K to 600 K. The scattering parameter in 85% Bi2Te3-15% Bi2Se3 single crystal was determined as 0.1 from the temperature dependence of the carrier mobility. With increasing the amount of Sbl3 or CuBr doping, the Seebeck coefficient of 85% Bi2Te3-15% Bi2Se3 decreased and the temperature at which the Seebeck coefficient shows a maximum shifted to higher temperature. Compared to the Sbl3-doped specimens, the CuBr-doped single crystals exhibited higher (m* / m0)3/2 c, implying that CuBr is a more effective dopant to improve the material factor and thus the figure-of-merit of 85% Bi2Te3-15% Bi2Se3. The maximum figure-of-merit of 2.0 × 10–3/K and 2.2 × 10–3/K was obtained for 0.1 wt % Sbl3-doped specimen and 0.03 wt % CuBr-doped specimen, respectively.     

Expression of the recombinant fusion protein CP15-23 of Cryptosporidium parvum and its protective test

The CP15 and CP23 surface proteins on the sporozoite of Cryptosporidium parvum are major protective antigens. The recombinant plasmid pET28-15-23 was constructed based on the plasmids pMD18-T-15 and pMD18-T-23 with two pairs of specific primers using DNA recombinant technique. In the primers, a synthetic linker sequence encoding a peptide (G-G-S) was designed. After identification, the recombinant plasmids were transformed to component cells of Escherichia coli BL21 (DE3). The positive strain containing the recombinant plasmid could express a specific fusion protein (CP15-23, MW approximately 25 kDa) induced by IPTG. The fusion protein could be recognized by the positive serum of mice infected with Cryptosporidium parvum oocysts specifically. The BALB/c mice were immunized with 80 microg of CP15-23 protein 4 times at 2 week intervals. The mice produced specific antibodies that responded to the lysate of Cryptosporidium parvum oocysts and could prevent Cryptosporidium parvum infection. The results indicated that the recombinant fusion protein CP15-23 would be used as a candidate antigen to prevent cryptosporidiosis.     

Cd2Nb2Te4O15: A Novel Pseudo-Aurivillius-Type Tellurite with Unprecedented Nonlinear Optical Properties and Excellent Stability

Oxides are emerging candidates for mid-infrared (mid-IR) nonlinear optical (NLO) materials. However, their intrinsically weak second harmonic generation (SHG) effects hinder their further development. A major design challenge is to increase the nonlinear coefficient while maintaining the broad mid-IR transmission and high laser-induced damage threshold (LIDT) of the oxides. In this study, it is reported on a polar NLO tellurite, Cd₂Nb₂Te₄O₁₅ (CNTO), featuring a pseudo-Aurivillius-type perovskite layered structure composed of three types of NLO active groups, including CdO₆ octahedra, NbO₆ octahedra, and TeO₄ seesaws. The uniform orientation of the distorted units induces a giant SHG response that is ≈31 times larger than that of KH₂PO₄, the largest value among all reported metal tellurites. Additionally, CNTO exhibits a large band gap (3.75 eV), a wide optical transparency window (0.33–14.5 µm), superior birefringence (0.12@ 546 nm), high LIDT (23 × AgGaS₂), and strong acid and alkali resistance, indicating its potential as a promising mid-IR NLO material.     

Component Evaporation of Ti-15-3 Melt during ISM Processing

How to control melt composition is the key for getting high quality alloy melt. The paper made the following efforts: (1) The activity coefficients in Ti-15-3 melt have been calculated. (2) Taking advantage of the activity coefficients, the evaporation losses of components in Ti-15-3 melt during ISM process have been studied. The calculated results show that there is a critical vacuum degree (about 1.33 Pa) during melting process.     

CsCl Effected Ultrafast Third-order Optical Nonlinearities of GeS_2-Sb_2S_3 Chalcogenide Glasses

A series of alkali halide doped chalcohalide glasses (100?x)(0.9GeS2-0.1Sb2S3)-xCsCl (x=5, 10, 15 and 20 mole fraction) were prepared. The absorption spectra and Raman scatting spectra of these glasses were measured. The optical band gaps Eopt were obtained from ultraviolet absorption edges. Z-scan technique was utilized to investigate the third-order nonlinear optical properties of GeS2-Sb2S3-CsCl glasses. The value of Eopt increases and the third-order optical nonlinearity decreases with increasing CsCl c...     

Absorption and emission cross sections of Er(3+) in Al(2)O(3) waveguides

Al(2)O(3) slab waveguide films were doped with erbium using ion implantation to a peak concentration of 1.5 at. %. Prism coupling measurements show absorption caused by (4)I (15/2) ?(4)I (13/2) intra-4f transitions in Er(3+) with a maximum at 1.530 mum of 8 dB/cm. The Er(3+) absorption cross section is determined as a function of wavelength. We used the McCumber theory to derive the emission cross section spectrum from the absorption results, which we then compared with the Er(3+) photoluminescence spectrum. The peak absorption and emission cross sections are found to be 6 x 10(-21) cm(-2). The results are used to predict the optical gain performance of an Er-doped Al(2)O(3) optical amplifier that operates around 1.5 mum.     

Fracture Mechanism Analysis of the Heat-Resistant Steel 15Kh2MFA(II) After Laser Shock-Wave Processing

The surface strengthening mechanisms of the 15Kh2MFA(II) heat-resistant steel are analyzed after the laser shock-wave treatment in the air and epoxy resin. The regularities are established in the formation of the ordered surface relief of the steel after treatment. The optical and digital analysis of the surface is performed which allows determining the size of irregularities, taking into account the stochastic and cyclic nature of their formation. The effect of treatment of the 15Kh2MFA(II) heat-resistant steel on the regularities of its static failure is established.