飞秒激光以其超窄脉宽和超高光强等特性被广泛应用于各种金属材料的加工。本课题组采用波长为515 nm的绿光飞秒激光器对GH3230镍基高温合金进行刻蚀试验，研究了GH3230高温合金的绿光飞秒激光刻蚀阈值、刻蚀率和极限刻蚀深度。结果表明：相比于红外飞秒激光，绿光飞秒激光的刻蚀阈值明显降低，刻蚀率显著提高；与红外飞秒激光刻蚀类似，随着刻蚀次数增加，刻蚀深度增大，但当刻蚀次数增加到一定值后，刻蚀深度出现饱和现象；激光能量密度越高，极限刻蚀深度越大；改变扫描策略进行双道刻蚀时，通过增加刻缝宽度可以增大刻蚀深度；激光诱导等离子体是影响刻蚀深度的主要因素。

通过混沌相关光纤环衰荡传感系统实时监测氧化石墨烯沉积过程，并采用氧化石墨烯功能化锥形光纤作为传感元件对血红蛋白传感进行了实验研究。通过实时监测氧化石墨烯对锥形光纤功能化过程中衰荡时间的变化，分析了功能化过程中锥形光纤表面羟基化、硅烷化和氧化石墨烯沉积对光传输损耗的影响。通过扫描电子显微镜对氧化石墨烯功能化锥形光纤效果进行检测。研究了不同浓度的氧化石墨烯功能化锥形光纤作为传感元件时对血红蛋白传感灵敏度的影响，实验结果表明：与未功能化锥形光纤相比，使用氧化石墨烯功能化锥形光纤进行血红蛋白传感，灵敏度提高了一个数量级。在功能化过程中，氧化石墨烯浓度将影响功能化后锥形光纤的传感灵敏度，且随着浓度的增加传感灵敏度增强。该研究成果有望在生物传感领域得到应用。

针对浮法玻璃成形过程, 提出了锡槽入口段简化稳态多相模型, 并采用Ansys Fluent 2019 R3软件, 模拟研究了500 t/d锡槽入口段玻璃液的流动与成形过程, 分析了拉引量、玻璃液黏度对唇砖与八字砖区玻璃液流动与液层厚度分布的影响。结果表明, 拉引量过小或黏度过低时液层出现不连续, 拉引量过大或黏度过高时液层横向厚度均匀性变差, 案例锡槽实现浮法玻璃均匀稳定成形的工艺操作范围是拉引量400~550 t/d, 黏度400~600 Pa·s。

A method for detecting protein molecules based on the tilted fiber Bragg grating (TFBG) surface plasma resonance (SPR) is proposed to achieve the quick online real-time detection of trace amount of proteins. The detection principles of the TFBG-SPR protein molecular probe are analyzed, and its feasibility is demonstrated. The intermediary material between the protein molecules and the golden layer outside of the fiber gratings is cysteamine hydrochloride. When the concentration of the cysteamine hydrochloride solution is 2 M, the shift of the TFBG resonance peak is 2.23 nm, illustrating that the cysteamine hydrochloride modifies the gold film successfully. IgG antigen solution is poured on the surface of the cysteamine hydrochloride modifying the gold-deposited TFBG. Finally, antigen-antibody hybridization experiment is carried out with a 10 mg/mL antibody solution, and after two hours of hybridization the resonance peak of the TFBG shifts 5.1 nm, which validates the feasibility and effectiveness of the TFBG-SPR protein molecular probe.

This paper proposes an unprecedented systematic approach for real-time monitoring the temperature and flow of diesel engine by using embedded fiber Bragg grating (FBG). By virtue of FBG’s temperature effect, we design a novel sensitive FBG temperature sensing probe to measure the temperature of cylinder head and inlet flow of diesel engine. We also establish the corresponding software platform for intuitive data analysis. The experimental and complementary simulation results simultaneously demonstrate that the FBG-based optical fiber technique possesses extraordinary reproducibility and sensitivity, which makes it feasible to monitor the temperature and inlet flow of diesel engine. Our work can provide an effective way to evaluate the thermal load of cylinder head in diesel engine.

LDPC(低密度奇偶校验)码常见的编码方法常常无法将校验矩阵的围长和线性无关相统一, 对编译码复杂度和译码性能有一定影响。文章提出了一种低复杂度LDPC的构造方法, 通过构造分块矩阵A和B, 获得一个围长为10、列重为2、具有近似下三角形式的校验矩阵, 且矩阵各行之间线性无关。该码具有以下优点: 较高的围长能提升译码性能; 较低的列重使该码适合在部分响应信道传播; 近似下三角形式和线性无关的特性, 较好地降低了编译码的复杂度。采用Matlab软件的仿真结果表明, 在高斯白噪声信道、BP(置信传播)译码算法下, 该码比普通的10围长LDPC码具有更低的复杂度, 比普通的6围长LDPC码具有更好的译码性能。

In this paper, the response of fiber Bragg gratings (FBGs) subjected to the ultrasonic wave has been theoretically and experimentally investigated. Although FBG sensors have been widely used in the ultrasonic detection for practical structural health monitoring, the relationship between the grating length and ultrasonic frequency is not yet to be obtained. To address this problem, an ultrasound detection system based on FBGs is designed and the response sensitivity of different lengths gratings are detected. Experimental results indicate that the grating with 3 mm length has a higher sensitivity when detecting high frequency ultrasonic wave, and the amplitude can be up to 0.6 mV. The 10 mm length grating has better detection sensitivity for low frequency ultrasonic wave and the amplitude is 0.8 mV. The results of this analysis provide useful tools for high sensitivity ultrasound detection in damage detection systems.