首页 | 官方网站   微博 | 高级检索  
相似文献
 共查询到19条相似文献,搜索用时 218 毫秒
1.
对被硅油污染的镜面进行了光谱测试,测得了硅油的红外吸收波段及吸收系数。实验证明吸收波段上的油膜透过率随着油膜厚度增加呈指数衰减。  相似文献   

2.
对小孔耦合输出的CO_2激光器,需要在小孔反射镜的后面贴一块能透过波长10.6微米的红外材料.NaCl晶体的透过率较好,但因其在空气中极潮解,所以影响使用.采用硅油作NaCl晶体保护膜,作为窗口使用能够承受较大的功率密度,且有良好的防潮作用;缺点是硅油易粘污灰尘,但由于涂膜方法简便,可克服这方面的不足.  相似文献   

3.
文中研究了不同种类硅油、不同金属氧化物导热填料及其颗粒直径大小分布、不同偶联剂种类等因素对导热硅脂产品的接触热阻、导热系数、界面厚度、粘度、耐渗油性等性能的影响。结果证明:二甲基硅油与球形氧化铝导热填料搭配使用可以获得更高的填料填充量,通过加入偶联剂可大大降低导热硅脂产品的粘度并提高导热硅脂的耐渗油性,而适中的导热填料颗粒大小分布以及较小的界面厚度可以得到高导热系数以及超低接触热阻的导热硅脂产品。  相似文献   

4.
皮秒激光加工具有峰值能量高、脉冲作用时间短等特点,是碳纤维复合材料(Carbon fiber reinforced polymer,CFRP)孔切割的重要手段。但是碳纤维和树脂基体的热物性存在较大差异,激光脉冲能量累积与传导行为,致使热损伤难以避免。本文提出一种CFRP硅油辅助皮秒激光制孔工艺,研究硅油对孔内部缺陷、热影响区(Heat affected Zone,HAZ)、孔圆度及锥度的影响。研究表明,与皮秒激光制孔相比,硅油辅助制孔质量显著提高:切口处无基体损伤,孔内壁面无裂纹,仍存在轻微的纤维裸露;孔表面HAZ减至41μm(重复频率200kHz、扫描速度1800mm/s);激光重复频率200kHz、扫描速度600mm/s时锥度减小1609。综上,硅油有助于调控CFRP激光制孔损伤:改善微观缺陷,抑制热影响区,降低锥度等。  相似文献   

5.
软模板的制作是紫外纳米压印中关键的技术,模版的分辨率直接决定了压印图形的最小分辨率。使用具有高度均匀、100nm级孔洞阵列结构的多孔氧化铝作为母版,使用基于液态浇铸的硅油稀释聚二甲基硅氧烷(硅油和聚二甲基硅氧烷的质量比为1:2)法制备出具有规则点阵结构的软模板。通过SEM和AFM表征发现,特征图形得到了有效转移,特征尺度保持在100nm左右。相对于传统的模板制备方法,此方法成本低、流程简单、适合大规模生产,是一种非常有前途的软模板制备方法。  相似文献   

6.
本文提出一种超声乳化针头对白内障碎片的实时跟踪技术,该技术可逐步实现将智能控制贯穿于整个白内障手术操作流程.智能超声乳化技术的关键因素在于:识别白内障和正常组织,识别白内障的颜色和硬度;实时跟踪乳化针头附近区域的白内障片段;根据实时结果自动控制乳化针头正确释放能量,避免损伤眼球.霍夫变换、k最近邻分类器和智能控制技术是本文提出的新超声乳化探针实时跟踪白内障片段方法的基础.实验结果分析表明,本新方法实现了超声乳化手术的智能化控制,并大幅提高了手术的安全性和效率.  相似文献   

7.
氧化锆陶瓷以其优异的力学性能和生物相容性被广泛用作牙科修复材料。通过表面改性工艺调控氧化锆陶瓷的表面润湿性,可以进一步拓展其在不同领域的应用。基于此,笔者提出了一种高效、低成本的激光加工+硅油修饰+热处理复合工艺,并采用该工艺制备了超疏水氧化锆陶瓷表面。首先通过纳秒激光加工在氧化锆陶瓷表面诱导出周期性多级微纳结构,而后利用硅油异丙醇混合溶液(硅油体积分数为0.4%)修饰+低温热处理来降低激光处理后氧化锆陶瓷的表面能,制备出了表面接触角高达153.8°具有超疏水特性的氧化锆陶瓷。加工前的氧化锆陶瓷的接触角为80.4°±2.1°,展现出亲水性;经纳秒激光加工后,液滴完全浸润表面,接触角变为0°,表面转变为超亲水表面。采用硅油异丙醇混合溶液修饰+低温热处理工艺实现了表面超亲水特性向超疏水特性的转变。超疏水氧化锆陶瓷在空气环境和胶带剥离实验中分别保持了优秀的稳定性和耐久性。通过改变激光的扫描速度及扫描间距可以精准调控液滴在材料表面的润湿性和黏附性。所提方法相较于传统激光加工方法提高了制备效率,降低了生产成本,有望扩展超疏水氧化锆陶瓷在医疗领域的应用。  相似文献   

8.
Nd:YAG激光对晶体透明皮质乳化的物理机理研究   总被引:2,自引:1,他引:1  
用Nd:YAG激光对未成熟期白内障进行晶体透明皮质乳化术36例。利用激光与组织相互作用的基本原理,讨论了手术中激光致使晶体透明皮质乳化的机理。提出激光等离子体冲击波对眼组织的机械效应和等离子体闪光对眼组织的光化学效应是导致晶体透明皮质组织蛋白变性和凝结的原因。  相似文献   

9.
目的:观察CO2激光用于犬裁耳术的效果.方法:采用CO2激光对31条犬进行了裁耳术.结果:犬CO2激光裁耳术操作简单、手术时间短、术中出血少,术后炎性反应轻微,术后恢复快.结论:将CO2激光应用于犬裁耳术中,手术效果好,术后恢复快,该方法明显优于传统的手术方法,值得在兽医临床推广.  相似文献   

10.
目的:探讨胆道镜对肝内胆管结石的治疗效果.方法:对2010年住院的57例肝内胆管结石患者的临床资料进行回顾性分析.比较32例胆道镜手术患者和25例常规手术患者的治疗效果、术后残石率和术后并发症有无差异.结果:胆道镜手术患者术后优良率为93.8%,术后残余结石发生率为15.6%,术后并发症发生率为3.1%;常规手术患者术...  相似文献   

11.
Superhydrophobic and superoleophilic polyester materials are successfully prepared by one‐step growth of silicone nanofilaments onto the textile via chemical vapor deposition of trichloromethylsilane. The successful growth of silicone nanofilaments is confirmed with scanning electron microscopy, energy‐dispersive X‐ray analysis, and investigation of the wetting behavior of water on the textile. Even microfibers deeply imbedded inside a woven material could be coated very well with the nanofilaments. The coated textile is water repellant and could only be wetted by liquids of low surface tension. The applications of the coated textile as a membrane for oil/water separation and as a bag for selective oil absorption from water are studied in detail. Owing to the superwetting properties and flexibility of the coated textile, excellent reusability, oil/water separation efficiency, and selective oil absorption capacity are observed, which make it very promising material, e.g., for practical oil absorption.  相似文献   

12.
Superwettable solid surfaces have attracted substantial research interest due to their outstanding performance. Various approaches have been developed for preparing superwettable surfaces via constructing a highly textured surface roughness and/or altering the surface free energy. Here, a facile dewetting strategy is proposed to produce multiple superwettabilities on copper hydroxide nanofiber arrays (Cu(OH)2‐NFAs) by controlling the localized state of low‐energy silicone oil. It is proposed that both the capillary forces along each nanofiber and the evaporation of the octane solvent contribute to the localization of the silicone oil in the NFAs. By varying the concentration of the silicone oil, its localized state changes from a scattered discontinuous distribution to a continuous thin/thick film, which leads to variations in the surface energy and surface roughness. Consequently, Cu(OH)2‐NFAs with superhydrophilicity, superhydrophobicity with both high and low adhesion, and super slippery properties are prepared. Notably, a very small amount of silicone oil can alter the surface wettability of the Cu(OH)2‐NFAs from superhydrophilic to superhydrophobic, which is attributable to the migration of silicone oil to the top of the nanofibers during the dewetting process. These results will provide new insights on the facile fabrication of functional surfaces with multiple superwettabilities.  相似文献   

13.
Highly elastic silicone foams, especially those with tunable properties and multifunctionality, are of great interest in numerous fields. However, the liquid nature of silicone precursors and the complicated foaming process hinder the realization of its three‐dimensional (3D) printability. Herein, a series of silicone foams with outstanding performance with regards to elasticity, wetting and sensing properties, multifunctionality, and tunability is generated by direct ink writing. Viscoelastic inks are achieved from direct dispersion of sodium chloride in a unique silicone precursor solution. The 3D‐architectured silicone rubber exhibits open‐celled trimodal porosity, which offers ultraelasticity with hyper compressibility/cycling endurance (near‐zero stress/strain loss under 90% compression or 1000 compression cycles), excellent stretchability (210% strain), and superhydrophobicity. The resulting foam is demonstrated to be multifunctional, such that it can work as an oil sorbent with super capacity (1320%) and customizable soft sensor after absorption of carbon nanotubes on the foam surface. The strategy enables tunability of mechanical strength, elasticity, stretchability, and absorbing capacity, while printing different materials together offers property gradients as an extra dimension of tunability. The first 3D printed silicone foam, which serves an important step toward its application expansion, is achieved.  相似文献   

14.
Liquids with low surface tension, such as petroleum, serve as the source of power for development of modern industry. Spontaneous and directional transportation of oily liquids in aqueous environment has drawn wide attentions owing to its scientific significance and practical prospect in marine petroleum exploitation and oil spill cleanup. Persistent effort has been made to the directional transportation of oil droplets under specific assistance. However, the spontaneous oriented movement of oil, especially the air/water two‐phase oil delivery is still identified as a big challenge. Here, a bioinspired superoleophobic pump has been fabricated through the assembly of a superoleophobic mesh and an oil column. Depending on the directional releases of surface energy, oil droplets can be continuously collected and pumped to centimeters high without additional driving forces. The antigravity oil delivery system can realize continuous oil flow under water, even the air/water two‐phase oil transportation. This work demonstrates a new mode of liquid transportation without external energy and should open a new way to design novel fluid delivery systems to realize diverse liquid transport.  相似文献   

15.
In order to avoid the distortion dangers to the colon, caused by spiral-type capsule robot, a Low Torsional Torque Capsule Robot (LTTCR) is developed, capable of non-contact steering swimming motion in a tortuous pipe, filled with silicone oil. Due to the non-contact and suspension state of motion, the robot is isolated from the colon and inner pipe wall, achieving low torsional effect on the intestines. Based on the coupling principle of magnetic field, a spatial magnetic torque model is derived, while a method for detecting the critical coupling magnetic torque, in tortuous environment, is proposed. The fluid resistance torque in straight and tortuous pipes is studied, deriving the scope of stable steering. Simulation and experimental results have shown that higher commutation and slip angles are beneficial to robot steering, and the swimming speed of LTTCR is higher and the twist impact on the colon, during the steering process, is lower. The LTTCR has a promising prospect in non-invasive examination applications in the sectors of diagnosis and treatment, inside the human body.  相似文献   

16.
硅树脂凝胶在铁路信号产品灌封中的工艺研究   总被引:2,自引:2,他引:0  
介绍硅树脂凝胶和环氧树脂等灌封材料的特点,比较它们的优缺点;指出各种灌封材料对印制电路板组件(PCBA)性能的影响;详细说明在铁路信号产品生产中应用双组份硅树脂凝胶灌封印制电路板组件的关键工艺,包含了PCBA表面清洁、凝胶温度控制、配方管理和控制、抽真空消除凝胶中的气泡、凝胶的灌封有效期管理、固化过程管理等;比较并选择各个关键工艺过程的实施方案,特别提出灌封有效期管理的新观点,并进行了实践和总结.  相似文献   

17.
丁宝  齐维贵  朱学莉 《电子学报》2004,32(10):1742-1745
基于油田多数抽油机轻载运行的现状,提出抽油机"间歇启停"运行的节能控制方案,考虑采油为一复杂过程,选择模糊神经网络(FNN)预报方法给予实现.为了实现这一方案,首先介绍了T-S模糊神经网络的结构,结合抽油过程的特点和研究的需要,对其进行了简化和改进;然后运用采油现场的样本信息和专家知识对FNN进行训练;最后给出了实用的抽油机节能FNN预报算法,将该算法应用在智能抽油机控制器中,取得了满意的节能效果.  相似文献   

18.
Controlling liquid adhesion is a fundamental issue in many applications for special wettable surfaces. Compared to superhydrophobic surfaces of different water adhesion, superoleophobic surfaces of controllable oil adhesion are much more practical, as it leads to non‐wetting for both water and oil. However, previously the investigation for oil adhesion ability on superoleophobic surfaces in oil/air/solid system has been extremely rare. In this work, we describe a convenient approach to fabricate superoleophobic surfaces through perfluorothiolate reaction on Cu(OH)2 nanostructure surfaces and investigate their possible application in oil droplet transportation. The prepared surfaces exhibit controllable oil adhesive force depending on surface nanostructures or external preloads on the oil droplet. A model of the penetrating Cassie state is used to help analyze the unique phenomena on oil adhesion. Moreover, we provide a proof of demonstrate of oil transportation for application in oil‐based microreactors via our surfaces. Our results give a useful attempt in understanding the fabrication principle of preparing superoleophobic surfaces with controllable oil adhesion.  相似文献   

19.
Organic getters are used to reduce the amount of reactive hydrogen in applications such as nuclear plants and transuranic waste. The present study examines the performance of getter loaded silicone elastomers in reducing reactive hydrogen gas from the gas phase and their capability of being 3D printed using direct ink writing techniques. The samples are placed in closed vessels and exposed to hydrogen atmosphere at pressures of 580 torr and 750 mtorr and at a temperature of 25 °C. The hydrogen consumption is measured as a function of time and normalized to getter concentration in the polymer. The performance of the getter‐loaded silicone elastomer containing 1,4‐bis[phenylethynyl]benzene (DEB) as the organic getter and Pd/C catalyst (ratio of 3:1 DEB to catalyst) decreases with increasing the resin's curing temperature. Chemical analysis suggests that DEB reacts with the silicone resin at high temperatures. In addition, it is demonstrated that the increased surface area of 3D printed composites results in improved getter performance.  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-23

京公网安备 11010802026262号