首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
用于ICF靶的空心玻璃微球的干凝胶法制备   总被引:9,自引:13,他引:9       下载免费PDF全文
 为用干凝胶法制备用于ICF靶的空心玻璃微球(HGM),研究了载气组份、温度和压力对成球过程和HGM品质的影响,优化了制备工艺参数。结果表明:提高载气中氦气的含量,有利于增加干凝胶粒子的成球率和HGM的纵横比;适当提高载气中氩气的含量,有利于提高HGM的表面质量。降低载气压力可以提高HGM的纵横比;升高载气温度可以提高干凝胶粒子成球率和HGM品质。当载气中氦气的体积分数在50%~80%,载气压力在(0.75~1.00)×105 Pa,载气温度在1 500~1 650 ℃时,干凝胶粒子的成球率较高,HGM的球形度、同心度和表面光洁度较好。制备得到了直径100~500 μm、壁厚0.5~3.0 μm的HGM,其耐压强度、抗大气侵蚀性能和表面粗糙度等指标均满足ICF物理实验要求。  相似文献   

2.
为用干凝胶法制备用于ICF靶的空心玻璃微球(HGM),研究了载气组份、温度和压力对成球过程和HGM品质的影响,优化了制备工艺参数。结果表明:提高载气中氦气的含量,有利于增加干凝胶粒子的成球率和HGM的纵横比;适当提高载气中氩气的含量,有利于提高HGM的表面质量。降低载气压力可以提高HGM的纵横比;升高载气温度可以提高干凝胶粒子成球率和HGM品质。当载气中氦气的体积分数在50%~80%,载气压力在(0.75~1.00)×105 Pa,载气温度在1 500~1 650 ℃时,干凝胶粒子的成球率较高,HGM的球形度、同心度和表面光洁度较好。制备得到了直径100~500 μm、壁厚0.5~3.0 μm的HGM,其耐压强度、抗大气侵蚀性能和表面粗糙度等指标均满足ICF物理实验要求。  相似文献   

3.
为实现惯性约束聚变靶用空心玻璃微球直径、壁厚的可控,采用等离子体辉光放电聚合技术,以四甲基硅烷为掺杂气源,对化学气相沉积-氧化烧结法制备空心玻璃微球(HGM)这一制备方法进行了探索。实验结果表明:制备直径为400~600 m、壁厚为5~15 m的HGM,原子分数为5%是一个较合适的掺硅量,成功将微球直径和壁厚的收缩量控制在38%左右;玻璃化后样品中C含量明显降低,主要以CSi键合形式存在,而Si含量相对增加,主要以SiO键合形式存在;预充1.23106 Pa氘气的微球,96 h后球内剩余气压依然高达72.95%。  相似文献   

4.
为实现惯性约束聚变靶用空心玻璃微球直径、壁厚的可控,采用等离子体辉光放电聚合技术,以四甲基硅烷为掺杂气源,对化学气相沉积-氧化烧结法制备空心玻璃微球(HGM)这一制备方法进行了探索。实验结果表明:制备直径为400~600μm、壁厚为5~15μm的HGM,原子分数为5%是一个较合适的掺硅量,成功将微球直径和壁厚的收缩量控制在38%左右;玻璃化后样品中C含量明显降低,主要以C—Si键合形式存在,而Si含量相对增加,主要以Si—O键合形式存在;预充1.23×106 Pa氘气的微球,96h后球内剩余气压依然高达72.95%。  相似文献   

5.
 采用化学镀工艺在ICF聚苯乙烯靶丸表面包覆了一层磁性的Ni-P合金镀层,并分别用扫描电子显微镜、能谱仪、X射线衍射仪以及振动样品磁强计对其形貌、组成、结构和磁性能进行了表征。结果表明:通过化学镀工艺制备的Ni-P合金镀层厚度约为4 μm,且为非晶结构,并具有一定的磁性;该磁性ICF靶丸可望用来进行磁悬浮实验研究。最后,对聚苯乙烯靶丸表面磁性涂层的制备机理进行了讨论。  相似文献   

6.
高钾空心玻璃微球的制备   总被引:3,自引:0,他引:3       下载免费PDF全文
 以无机化合物为初始原料,选择合理的玻璃溶液配方和成球条件,用液滴法制备出直径200 μm,壁厚2 μm,K2O摩尔分数大于10 %的空心玻璃微球(HGM)。利用扫描电镜X射线能量色谱仪对玻璃球壳的组分进行了分析。结果表明,所制备的高钾空心玻璃微球各项技术指标能基本满足神光-Ⅱ物理实验的要求,微球球壳成份实测结果与理论计算结果吻合。  相似文献   

7.
为实现对干凝胶法空心玻璃微球(HGM)渗透性能的有效调控,研究了初始玻璃配方、载气成分、精炼温度、精炼区长度、HGM壁厚对HGM渗透性能的影响。结果表明:当精炼温度低于1400 ℃时,初始玻璃配方对HGM渗透性能有显著影响。但是,随着精炼温度的升高和精炼区长度的延长,液态玻璃中碱金属氧化物的挥发比例逐渐增大,由不同初始玻璃配方制备的HGM对氘气的渗透性能逐渐趋近于相同。随着载气中氦气体积分数的降低或HGM壁厚的增大,室温下HGM对氘气的渗透系数逐渐减小。  相似文献   

8.
激光等离子体相互作用(LPI)和瑞利-泰勒流体不稳定性(RTI)是影响间接驱动惯性约束聚变成功的两个主要不确定性因素。点火黑腔内环激光通道在靠近黑腔壁的区域是内环激光SRS背反产生与发展的主要区域。内环通道在该区域满足通道内外压力平衡和能量平衡条件。据此提出了间接驱动惯性约束聚变点火黑腔等离子体定标关系。结合描述靶丸内爆飞行阶段物理以及内爆性能的两个定标关系,提出了描述稳定性相对性能的指标。该指标可以指导点火靶设计,为LPI和RTI提供需要的裕量空间,是点火阈值因子(ITF)的补充。  相似文献   

9.
以碳酸钠为催化剂,乙醇为溶剂,间苯三酚 乙醛为反应前躯体,经溶胶 凝胶、交联老化、二氧化碳超临界干燥制备出间苯三酚-乙醛(PA)有机气凝胶。扫描电镜观察和N2吸附测试结果表明:气凝胶具有较高的比表面积,是一种连续nm级3维网络结构的多孔材料,其比表面积为1 210 m2/g,平均孔径为11 nm,与传统有机气凝胶相比,提高了比表面积,一定程度上实现有机气凝胶的扩孔。  相似文献   

10.
A colloidal solution of gold nanoparticles in deionized nanopure water was produced by laser ablation technique without the use of any chemical/surfactant. Spectral characterization and morphological studies of these nanoparticles were carried out by UV-Vis Spectroscopy and Scanning Electron Microscopy, respectively. A number of variables of the ablating laser pulse have been used to control the size of the fabricated nanoparticles. Excellent correlation between ablating laser pulse parameter and optical and morphological parameters of the gold colloids were obtained. The peak of the extinction spectra shows a monotonic blue shift for laser fluence of 410 J/cm2 and above. Below this the extinction peak remains fairly constant in wavelength. Blue shifts of the extinction spectra were also observed with increasing re-ablation time of previously ablated gold colloids. Possible explanations of all these observations are discussed.  相似文献   

11.
 采用油包水(W/O)的微乳液体系制备了粒度为20~100 nm的α Fe。对纳米Fe进行表面有机改性后分散到苯乙烯(St)单体中,得到分散均匀的Fe/St分散体系,用本体聚合的方法制备了纳米Fe/PS复合材料。利用XRD,TEM,FTIR,SEM及TG DSC分别研究了所得纳米Fe的性能、复合材料的结构、纳米Fe在PS中的分散情况以及掺杂量对纳米Fe/PS复合材料的热力学行为的影响。研究结果表明:增加纳米α-Fe的掺杂量能提高PS的降解率,降低降解温度,增大热分解的焓变。  相似文献   

12.
以改性聚苯乙烯微球为模板,采用化学镀法在聚苯乙烯微球表面包覆一层银,在四氢呋喃溶液中将聚苯乙烯微球溶解,得到中空Ag纳米球壳。采用扫描电镜、透射电镜和X射线衍射仪对样品进行了表征及分析,并用紫外可见分光光度计研究了粒子的光学性质。实验结果表明:运用此法成功地制备出中空Ag纳米球壳的内径为250 nm,壁厚约为15 nm,并且成功地使纳米粒子的紫外吸收光谱由600 nm红移至900 nm左右,实现了在可见光至近红外光区调节Ag纳米结构的吸收峰。  相似文献   

13.
中空Ag纳米球壳的制备及性能表征   总被引:6,自引:0,他引:6       下载免费PDF全文
 以改性聚苯乙烯微球为模板,采用化学镀法在聚苯乙烯微球表面包覆一层银,在四氢呋喃溶液中将聚苯乙烯微球溶解,得到中空Ag纳米球壳。采用扫描电镜、透射电镜和X射线衍射仪对样品进行了表征及分析,并用紫外可见分光光度计研究了粒子的光学性质。实验结果表明:运用此法成功地制备出中空Ag纳米球壳的内径为250 nm,壁厚约为15 nm,并且成功地使纳米粒子的紫外吸收光谱由600 nm红移至900 nm左右,实现了在可见光至近红外光区调节Ag纳米结构的吸收峰。  相似文献   

14.
Here, we report the fabrication of diamond-like carbon (DLC) thin films using pulsed laser deposition (PLD). PLD is a well-established technique for deposition of high-quality DLC thin films. Carbon tape target was ablated using a KrF (248 nm, 25 ns, 20 Hz) excimer laser to deposit DLC films on soap-coated substrates. A laser fluence between 8.5 and 14 J/cm2 and a target to substrate distance of 10 cm was used. These films were then released from substrates to obtain freestanding DLC thin foils. Foil thicknesses from 20 to 200 nm were deposited using this technique to obtain freestanding targets of up to 1-inch square area. Typically, 100-nm-thick freestanding DLC films were characterized using different techniques such as AFM, XPS, and nano-indentation. AFM was used to obtain the film surface roughness of 9 nm rms of the released film. XPS was utilized to obtain 74 % sp2, 23 % sp3, and 3 % C–O bond components. Nano-indentation was used to characterize the film hardness of 10 GPa and Young’s modulus of 110 GPa. Damage threshold properties of the DLC foils were studied (1,064 nm, 6 ns) and found to be 7 × 1010 W/cm2 peak intensity for our best ultrathin DLC foils.  相似文献   

15.
合成了一种材料N,N′-二苯并咪唑-苝二酰亚胺(PV),经多次真空升华提纯,产率为68%,纯度达95%以上。利用傅里叶变换红外光谱(FTIR)、紫外/可见吸收光谱(UV/Vis)、元素分析、热失重分析(TG)对该产物的结构和性能进行了表征。结果表明:苝四甲酸二酐(PTCDA)与邻苯二胺反应,易转化成二苯并咪唑苝类衍生物。该PV材料在450~750 nm范围内有两个强的吸收峰,其初始热分解温度约为510 ℃,热稳定性较好。  相似文献   

16.
Several new materials and patterns are studied for the formation and etching of intraocular lenses (IOLs), in order to improve their optical properties, to reduce the diffractive aberrations and to decrease the incidence of posterior capsular opacification. The aim of this study is to investigate the use of UV (λ = 266 nm) laser pulses to ablate the intraocular lenses materials, and thus to provide an alternative to conventional surface shaping techniques for IOLs fabrication. Ablation experiments were conducted using various polymer substrates of hydrophobic acrylic IOLs and PMMA IOLs. We investigated the ablation efficiency and the morphology of the ablated area by imaging the surface modification with atomic force microscopy (AFM) and scanning electron microscopy (SEM). The morphological appearance of IOL samples reveals the effect of a photochemical and photothermal ablation mechanism.  相似文献   

17.
Pd/Ag alloy hollow spheres have been synthesized in ethylene glycol solution by the solvothermal method and have been characterized extensively. TEM results have revealed the formation of Pd/Ag hollow spheres. Moreover, HRTEM results confirmed the formation of Pd/Ag alloy spheres, where the lattice fringe spacing is 0.229 nm corresponding to the (111) plane of Pd/Ag alloy. SEM, XRD and UV–vis results have further suggested the formation of alloy hollow spheres. The preliminary results showed the reaction time may be an importance factor influencing the formation of Pd/Ag alloy hollow spheres.  相似文献   

18.
 采用脉冲激光沉积(PLD)方法在Si(100)衬底上制备了NaF薄膜。在激光重复频率2 Hz,能量密度3 J/cm2,本底真空度5×10-5 Pa的条件下,研究衬底温度对薄膜沉积速率及结构的影响。台阶仪分析表明:薄膜的沉积速率随衬底温度增加呈指数函数增加,算出NaF薄膜的反应激活能为48.67 kJ/mol。原子力显微镜分析表明:薄膜致密而光滑,均方根粗糙度为0.553 nm。扫描电镜截面微观形貌分析表明:薄膜呈现柱状结构。X射线衍射分析表明:NaF薄膜为面心立方晶体结构,并具有显著的择优取向;当衬底温度约为400 ℃时,平均晶粒尺寸最大(129.6 nm),晶格微应变最小(0.225%)。  相似文献   

19.
This paper describes the effect of doping on the composition, surface morphology and optical, structural and electrical properties of Al doped ZnO thin films by pulsed laser deposition. SEM analysis shows that the crystalline nature of the deposited films decreases with an increase of Al doping concentration from 1% to 6%. In the AFM analysis, the surface roughness of the deposited films increases by increasing the doping concentration of Al. Al doping strongly influences the optical properties of the ZnO thin films. Optical transmittance spectra show a very good transmittance in the visible region (450–700 nm). The calculated optical band gap was found to be in the range from 3.405 to 3.464 eV. Structural analysis confirms that the increases of Al concentration decrease the crystallinity of the ZnO films and the particle size decreases from 45.7±0.09 to 28.0±0.02 nm. In the Raman analysis, the active mode of Al(=1%) doped ZnO films were observed at 434.81 cm−1. The shifts of the active mode (E2)(E2) show the presence of tensile stress in the deposited films. The electrical properties of the deposited films showed that the values of the Hall mobility was in the range between 2.51 and 10.64 cm2/V s and the carrier concentration between 15.7 and 0.78×1017 and the resistivity values between 1.59 and 10.97 Ωcm, depending on the doping concentration.  相似文献   

20.
 合成了一种材料N,N′-二苯并咪唑-苝二酰亚胺(PV),经多次真空升华提纯,产率为68%,纯度达95%以上。利用傅里叶变换红外光谱(FTIR)、紫外/可见吸收光谱(UV/Vis)、元素分析、热失重分析(TG)对该产物的结构和性能进行了表征。结果表明:苝四甲酸二酐(PTCDA)与邻苯二胺反应,易转化成二苯并咪唑苝类衍生物。该PV材料在450~750 nm范围内有两个强的吸收峰,其初始热分解温度约为510 ℃,热稳定性较好。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号