基于钙钛矿纳米晶体的复合材料微球发光特性的研究

为了拓展钙钛矿纳米晶体在激光领域的应用,利用低成本、易合成的溶剂-非溶剂法,将实验合成的CsPbBr₃纳米晶体封装或附着于高分子材料环烯烃聚合物（COP）以形成高稳定性的复合材料体系,进一步制备成微球,形成回音壁模式（WGM）谐振腔。借助于微球的WGM谐振腔,表面附着的纳米晶体的荧光会在微球内发生谐振,形成被动式的WGM谐振腔,形成激光,其阈值为28.5 μJ/cm²,品质因数Q为835。这种复合材料体系的微球为钙钛矿纳米晶体在高稳定性的激光器件、非线性系统及光动力学研究提供了一个有效平台。     

医用放射性核素的载体--磁性壳聚糖微球的制备

采用乳化交联法制备了可附载放射性核素的磁靶向药物载体--磁性壳聚糖微球,磁性微球中的纳米磁性Fe3O4粒子由FeSO4和FeCl3通过碱溶液的共沉淀法制备而得,借助SEM、IR及激光粒度仪等对微球的粒径、粒径分布和形貌进行了表征.结果表明在壳聚糖溶液质量分数为1.5%,Fe3O4与壳聚糖的质量比为1∶2,悬浮介质的搅拌速度为1 200r/min等条件下制得的磁性壳聚糖微球的粒径在(40±20)μm,且呈规则的球形,可满足放射性核素载体的基本要求.     

微球球度测量技术的研究进展

根据目前微球球度测量技术的原理,首先将其分为接触式测量和非接触式测量,其中非接触测量主要分为光学图像测量法和激光干涉测量法,就此对国内外微球球度测量技术进行了介绍和比较,并指出各种测量技术需要解决的问题。然后针对这些技术的局限性,如被测尺寸较大、测量精度不高、测量对象材料限制等,探讨了目前正在研究中的新型球度测量方法和技术。最后对微球球度测量方法和技术的研究及开发趋势进行了总结和展望。     

基于微球腔的回音壁模式激光的最小尺寸研究

回音壁模式(WGM)光学微球腔,因具有传播模式稳定闭合、光能量密度极高、结构简单、易于制备等特点,在微球激光的应用上受到广泛关注.不同物理尺寸的微球腔对应的模式特征也大不相同,这一特性被应用于光学传感器、非线性光学等领域.通过二维时域有限差分法(2D-FDTD)对二氧化硅微球进行理论模拟,分析了球腔在不同模式下的电场分...     

微球材料作为润滑添加剂的摩擦学性能研究——粒径分布的影响

以未处理空心微球材料为原料制备粒度分布均匀集中的空心微球材料,用硅烷偶联剂对其进行表面改性处理,使其具有良好的亲油性。用HQ-1环块试验机在高速低载荷和低速高载荷2种工况下,测定了所制备的空心微球材料作为500SN基础油添加剂的摩擦磨损性能。结果表明:经处理后的空心微球材料可以显著提高500SN基础油的抗磨减摩性能;经处理后的空心微球材料的抗磨减摩性能好于未处理空心微球材料,表明粒径分布对摩擦学性能有显著影响。     

异质微环谐振腔双稳态及全光存储器应用

提出了一种基于异质集成波导的微环谐振腔,对其双稳态现象进行了研究分析,并将其应用于全光存储功能的实现。异质集成波导具有超高的克尔非线性效应,不受热光效应和载流子响应的限制,在超快克尔非线性效应的支持下,该结构具有快速全光切换的能力。设计了一个高品质因子Q = 77565的微环谐振腔,用耦合模式理论模拟了其双稳态现象。在峰值功率为474 fJ,宽度为20 ps的脉冲激励下,该微环谐振腔很好地实现了全光存储功能,并通过波分复用的串联微环结构展示了波长可寻址的四位光存储器。研究了基于超高克尔非线性效应的双稳态现象,为实现超快切换速度提供了可能性,在光存储、光开关、人工智能研究等方面具有一定的参考价值。     

曲面上化学气相沉积的二维材料研究

过渡金属硫系化合物二维材料因其体积小、直接带隙发光等特点,可作为微纳光学结构的优异介质材料而受到广泛关注。通过转移法得到的二维材料微纳光学结构,如光学微腔、微纳传感器等,容易引起材料污染和破损,对结构的功能特性影响很大。通过化学气相沉积法（CVD）,将硒化钨直接沉积在6 μm直径的二氧化硅（SiO₂）微球上,对微球上的材料进行成分表征,证明在微球上生长出了二维材料硒化钨,且证明了通过化学气相沉积法在曲面上沉积二维材料是可行的。这种化学气相沉积法直接生长的二维材料微纳球腔,有望应用于高性能光学传感器和微纳光源器件中。     

微通道板对软X射线响应的实验研究

在X光成像望远镜中微通道板(MCP)作为焦平面上的成像接收器,探测天体的软X射线辐射图像。本文实验研究在软X射线波段MCP的成像性能以及与此有关的其他性能。作者没计了实验装置,测量了在碳K_a(4.47nm)线下微通道板——荧光屏组件的分辨率,与计算结果进行了比较。提出了一种用软X射线光电发射作为初电流测量MCP电流增益的新方法,具有可反复多次测量、重复性良好及测量方便等优点。测量了在两个波长下微通道板的量子效率及随X射线入射角的变化。     

两亲性纳米微球的制备及水润滑性能

水溶性纳米微球作为润滑添加剂成为润滑领域的重要发展方向。通过简单的无皂乳液聚合制备聚(苯乙烯-甲基丙烯酸3-磺酸丙酯钾盐)[P(St-co-SPMA)]两亲性纳米微球，通过改变聚合单体、微球浓度以及载荷，利用摩擦磨损试验机考察聚苯乙烯(PSt)和P(St-co-SPMA)2种纳米微球作为水润滑添加剂的摩擦学性能。结果表明：具有复合结构的两亲性纳米微球作为水润滑添加剂起到了非常优异的减摩抗磨性能，这是由于亲水单体的加入在微球表面形成水化层，避免了摩擦副之间的直接接触且保护了摩擦表面，有效改善了界面摩擦性能；2种纳米微球在高载荷下有着更为优异的减摩与抗磨性能，证明了纳米微球优异的承载能力。该研究为设计高效水润滑添加剂提供了新的思路，在生物润滑领域有着广阔的应用前景。     

磁性壳聚糖复合微球的制备及表征

采用磁性Fe_3O_4纳米颗粒为磁核,用反相悬浮聚合法制备了磁性壳聚糖复合微球,用激光粒度仪和透射电镜对磁性壳聚糖微球的尺寸和形貌进行分析,考察了壳聚糖浓度、乳化剂用量、交联剂浓度、搅拌速度等参数对壳聚糖成球的影响。结果表明:使用4 mL质量浓度为4 g·L~(-1)壳聚糖溶液、0.1 mL司本-80和0.1 mg磁性Fe_3O_4纳米颗粒,经超声分散1 h后,加入0.5 mL4%的戊二醛,在转速350 r·min~(-1)搅拌条件下,室温下反应2 h,可得到形貌光滑、粒径为0.5～2 μm的磁性壳聚糖复合微球,该壳聚糖复合微球具有较好的磁响应性能。     

一种基于高斯光束的平凹激光腔对准方法

给出了一种基于高斯光束的平凹激光腔对准方法。在高斯准直光束后加一透镜系统,恰当地调整准直高斯光束到某一种汇聚发散的状态。在这种状态下,可使由平凹腔凹面镜和平面镜反射回来的光斑直径大小相仿,解决了不加透镜系统时,两反射回来光斑直径相差很大,难于对准的问题,提高两光斑的对准精度。实验使用束腰为0.6 mm的氦氖光,其后加一优化好的透镜系统,在889 mm的距离下,对凹面镜曲率半径为50 mm的平凹腔进行对准。得到由凹面镜和平面镜反射回来的光斑直径分别为4.8 mm和5.1 mm,平凹腔的角度对准精度达到了3.18'。对准好的腔体在点亮LD后,均能出基模光斑。实验结果与理论分析相符,证明了该对准方法结构简单,执行方便。     

Super‐resolution optical microscopy based on scannable cantilever‐combined microsphere

We report an ingenious method of super‐resolution optical microscopy utilizing scannable cantilever‐combined microsphere. By scanning the microsphere over the sample surface in a cantilever‐combined microsphere‐sample contact state, super‐resolution images can be acquired at arbitrary sample regions through near‐field information collection by the microsphere. In addition, such a state can effectively reduce the possibility of breaking the cantilever and damaging the microsphere or sample surface. This work has developed a new method and technique of sub‐diffraction‐limit optical microscopy, and can be practically applied in various fields of micro/nanoscopy. Microsc. Res. Tech. 78:1128–1132, 2015. © 2015 Wiley Periodicals, Inc.     

ICF微球分离技术研究

在微球分离试验研究的基础上,根据微球自身特性以及在工作液体中的状态,分析了微球不易分离的原因,提出了一种直径筛选方法。该技术采用精密窄缝结构和脉冲水流驱动微球分散,并通过窄缝,达到对微球快速精确分离的目的。该技术具有操作简单、低强度、高效率等优点。试验结果表明此技术可行。本文对微球的挑选提供了一种新技术和新方案,从而满足微球挑选新工艺的要求,保证挑选出的微球的质量。     

一种激光束形参数简便测试方法

在以激光作为测试光源的高精度测试装置中,激光器实际输出的束形参数值与其标称值的偏离会直接传递并影响到后续测试结果的准确度。提出一种基于CCD的多点测试方法,此方法在不降低测量精度的条件下可实现激光束形参数的简便测试。在搭建的测试装置上实现了633nm He-Ne激光器束腰半径、远场发散角和M2质量因子的测量,可以方便地评价激光光束质量。将束形参数简便测试方法的结果与法国Phasics公司的SID4波前探测器的测量结果进行了比对,结果表明,激光束形参数简便测试方法不仅能用于激光束形参数的简便检测,而且具有较高的精度。     

A light-erosion method for high-pressure dust-gas-plasma flows generation

A light-erosion method for generating high-pressure dust-gas-plasma flows during ultraviolet (λ = 213 nm) laser ablation of a polymeric matrix ((C₂F₄) _n ) containing dust particles (thin-wall borosilicate glass microspheres with a ∼15- to 80-μm diameter d) is described. The carrying-out of the dust particles by ionized vapors of the substance of the target matrix, their space-time localization in the gas-plasma flow in a period Δτ ∼ 15–75 μs after the laser exposure up to the further spatial separation of the vaporized substance of the target matrix and the dust particle cloud is recorded by laser interferometry and shadow photography methods. The importance of certain selection of the matrix-dust system for realizing the light-erosion method for generating dust-gas-plasma flows, in particular laser exposure conditions, is shown. When condensed media with a low ionization potential (Al, Ce) are used as a dust component, the proposed method for generating heterogeneous gas-plasma flows can be efficient for their further heating by coherent radiation.     

Characterization of whispering gallery mode slow light in microspheres

A slow-light system composed by a microsphere resonator and a section of bitapered fiber is characterized theoretically in this article. Theoretical analysis and numerical simulation on the input and output characteristics and the transmittivity of the microsphere resonator were carried out. The directional coupling theory was used to analyze the input/output characteristics of single microsphere resonator and parameters in the overcoupling state, including the relationships between the effective phase shift, transmittivity, effective time delay, light velocity, and the speed of light. The coupling coefficient distance was studied by theoretical analysis and numerical simulation. The theoretical analysis and simulation optimization of the slow-light gyroscope were carried out to obtain the optimized radius of microsphere resonator and distance between microsphere resonator and bitapered fiber. Through theoretical investigation and mathematical simulation, transmission characteristics and time delay mathematical expressions of the microsphere resonator were obtained. Theoretical analysis and simulation of the fiber optic gyroscope sensitivity showed that slow-light improved the accuracy of the interferometric fiber optic gyroscope.     

金属薄膜边缘诱导改变谐振激光模式实验

为研究在不同方向移动的金属薄膜边缘的干扰情况下谐振激光模式的改变现象,调节定制的氦氖激光谐振腔产生高阶高斯光束,用金属薄膜边缘进行干扰,并用CCD相机对光束的演变过程进行详细记录。随着金属薄膜边缘沿X和Y正方向上位移的增加,出射的激光模式由高阶向低阶模式演化,然后变成基模,变弱直到消失。原始激光模式的阶数越高,它的演化模式光斑形状越丰富。当用金属薄膜上方边缘向Y轴正向缓慢移动进行干扰时,激光模式的演化规则是最后趋于沿X轴的分裂模式;当用金属薄膜的左侧边缘向X轴正向缓慢移动进行干扰时,激光模式的演化规则最后趋于沿Y轴的分裂模式。     

A piezoelectric resonator for optical power measurement with radiation beam quality retaining

A method for measuring the power of laser radiation in a wide range of wavelengths is introduced. The method is based on weak heating of an optically transparent piezoelectric resonator through which laser radiation is transmitted. After passing through such a resonator, the beam quality of laser radiation remains unchanged and the optical power can be utilized in laser technologies.     

基于微波谐振器的谷物湿度检测系统

设计和研制一种能连续测量谷物湿度的微波检测系统.提出利用微波谐振器的干扰特性测量谷物的湿度,并设计专用于谷物湿度检测的中心开通孔的微波谐振器.当谷物颗粒通过微波谐振器的中孔时,其质量和湿度都令谐振器的谐振频率产生偏移和功率衰减,谷物的质量和湿度两者所引起的谐振频率偏移和微波功率衰减是相对独立的,在同一湿度下谷物的质量仅仅与微波功率的衰减量有关.因此在得到谐振频率的偏移量和微波功率的衰减量后,就可以计算谷物的湿度.在大量试验的基础上,对试验数据进行模糊聚类,从而对微波谐振器的频偏和功率衰减特性进行建模,据此设计并研制了谷物湿度的微波连续检测系统.试验调试表明:该检测系统适宜于谷物的连续湿度检测,检测精度达到92%以上.     

Fretting fatigue life estimations based on fretting mechanisms

Generally the fretting fatigue S-N curve has two regions: one is the high cycle (low stress) region and the second is the low cycle (high stress) region. In a previous paper we introduced the fretting fatigue life estimation methods in high cycle region by considering the wear process; with this estimation method the fretting fatigue limit can be estimated to be the crack initiation limit at the contact edge. In this paper we estimate the low cycle fretting fatigue life based on a new critical distance theory, modified for a high stress region using ultimate tensile strength σ_B and fracture toughness K_IC. The critical distance for estimating low cycle fretting fatigue strength was calculated by interpolation of the critical distance on the fretting fatigue limit (estimated from σ_w0 and ΔK_th) with critical distance on static strength (estimated from σ_B and K_IC). By unifying this low cycle fretting fatigue life estimation method with the high cycle fretting fatigue life estimation method, which was presented in the previous paper, we can estimate the total fretting life easily. And to confirm the availability of this estimation method we perform the fretting fatigue test using Ni-Mo-V steel.