血管紧张素转化酶(ACE)是一种含锌离子的羧二肽酶, 通过肾素-血管紧张素系统和激肽释放酶-激肽系统进行血压调节。 食源血管紧张素转化酶抑制肽(ACEIP)可抑制ACE的活性对高血压控制有利。 以鲣鱼蛋白分离出的ACE抑制肽Leu-Lys-Pro(LKP)为原料, 采用荧光光谱法、 紫外-可见光谱法、 圆二色谱法、 等温滴定量热法(ITC)以及分子对接技术研究了LKP对ACE的抑制机理。 荧光光谱结果表明, LKP能够有效猝灭ACE的内源荧光, 猝灭机制为静态猝灭, 两者结合可形成较稳定的复合物, ACE中色氨酸和酪氨酸残基所处的微环境疏水性减小, 导致极性增强。 紫外、 圆二色谱结果表明, LKP与ACE结合会导致ACE构象发生改变, ACE与LKP结合后二级结构比未结合时松散, 为紧密-松散-稍紧密的变化过程。 ITC测得LKP与ACE结合的焓变(ΔH)、 熵变(ΔS)、 化学计量比(n)以及结合常数(K_a)等热力学参数, 结果表明两者结合反应是由熵驱动的自发吸热过程, 结合力主要为疏水作用, 确定LKP与ACE相互作用的结合位点数约为1, 且随温度升高而增加。 LKP与ACE的结合常数K_a分别为2.2×10³, 0.9×10³和5.3×10³, 说明两者亲和力较小。 分子对接结果表明, ACE活性中心的S₁口袋的氨基酸残基Gln281, Lys511与LKP形成氢键相互作用, His353, His513与LKP具有疏水作用, LKP主要通过疏水作用与ACE结合, 氢键稳定蛋白空间结构。 该研究对了解ACE抑制肽与ACE的作用机制提供了一定的帮助, 为开发新的治疗高血压药物建立一定的理论基础。

表面增强拉曼光谱具有提高油中溶解糠醛原位检测极限的可行。本文在镀金膜的氧化铟锡玻璃表面吸附碳纳米管修饰的类花形银纳米颗粒作为SERS基底，并实现了不同浓度油中溶解糠醛高灵敏原位检测。研究表明，具有电磁增强效应的纳米银花与CNTs相结合而成的粗糙三维纳米结构所具有的结构间隙能有效增强拉曼信号，同时CNTs的大比表面积和强吸附能力促使基底表面形成更多的“热点”。对于变压器油中糠醛的检测下限可达7 mg/L，不同基底位置处的特征峰相对标准偏差为3.01%，本文所制备的基底具有较好的灵敏度、一致性，在原位检测变压器油中痕量老化特征物方面展现了巨大潜力。

量子通信光学地面站光学系统中，采用精、高精跟踪两个快速控制反射镜组成单检测模式闭环。为保证系统控制精度和稳定性，控制过程中必须考虑解耦。然而在目标信噪比较低情况下，难以实现精、高精跟踪回路的准确解耦。本文提出在精跟踪、高精跟踪内部增加位置传感器，一方面采用位置传感器闭环提高内环控制对象确定性，便于参数整定，另一方面，位置传感器偏差量反映了电视脱靶量的偏差，精跟踪采用修正位置传感器偏差量进行闭环从而避免了系统解耦。本文分析了基于该方法实现的复合轴控制结构的对象特性，控制系统设计方法及鲁棒性。理论和实验结果表明：目标特性较差的情况下，特别是滞后变化较大的情况下，本文提出的方法不需要进行解耦控制，具有更好的鲁棒性、更高的精度。

Two-photon excited fluorescence materials usually suffer from inefficient two-photon absorption (TPA) and nonradiative excited states. Here, upconversion fluorescence in an electron donor-acceptor (DA) exciplex doped with fluorescent emitters are systematically investigated. It has been found that the undoped DA exciplex exhibits enhancements of ～129% and ～365% in upconversion fluorescence compared to donor- and acceptor-only systems, respectively. Interestingly, photoluminescence quantum yields (PLQYs) up to ～98.65% were measured and immensely enhanced upconversion fluorescence was observed after doping various fluorescent emitters into the DA exciplex. Our results reveal the existence of two-photon excited energy harvesting in a thermally activated delayed fluorescence (TADF) DA exciplex doped with fluorescent emitters, via reverse intersystem crossing followed by rapid F?rster resonance energy transfer. Moreover, the additional gain mechanism related to intermolecular CT interaction that occurs at the TPA stage is found in the TADF DA exciplex system.

Precise and fast determination of position and orientation, which is normally achieved by distance and angle measurements, has broad applications in academia and industry. We propose a dynamic three-degree-of-freedom measurement technique based on dual-comb interferometry and a self-designed grating-corner-cube (GCC) combined sensor. Benefiting from its unique combination of diffraction and reflection characteristics, the absolute distance, pitch, and yaw of the GCC sensor can be determined simultaneously by resolving the phase spectra of the corresponding diffracted beams. We experimentally demonstrate that the method exhibits a ranging precision (Allan deviation) of 13.7 nm and an angular precision of 0.088 arcsec, alongside a 1 ms reaction time. The proposed technique is capable of precise and fast measurement of distances and two-dimensional angles over long stand-off distances. A system with such an overall performance may be potentially applied to space missions, including in tight formation-flying satellites, for spacecraft rendezvous and docking, and for antenna measurement as well as the precise manufacture of components including lithography machines and aircraft-manufacturing devices.

A fiber-optic sensor for the simultaneous measurement of strain and temperature is proposed and experimentally demonstrated based on Fabry–Pérot (FP) interference and the antiresonance (AR) mechanism. The sensor was implemented using a single-mode fiber (SMF)–hollow-core fiber–SMF structure. A temperature sensitivity of 21.11 pm/°C was achieved by tracing the troughs of the envelope caused by the AR mechanism, and a strain sensitivity of 2 pm/με was achieved by detecting the fine fringes caused by the FP cavity. The results indicate that the dual-parameter sensor is stable and reliable.