温度是表征物理化学性质的最基本参数之一，精确的温度测量对于现代科学技术发展起着至关重要的作用。传统基于稀土离子热耦合能级对（TCLs）能量传递的荧光温度传感器因TCLs之间能量差的限制存在测温灵敏度低及信号区分困难等问题。为寻求更优的解决方案，本研究探索了氧空位缺陷发光在荧光温度传感器领域的应用前景。本文通过高温固相法合成了BaMgSiO₄陶瓷，由于在高温烧结过程中有少量Ba²⁺和Mg²⁺蒸发，陶瓷中会产生氧空位以保持材料电中性。这些氧空位所形成的缺陷能级在332 nm紫外光激发下，发射出372，400，527 nm三种波长的发射光。这三种发射光强度对温度有着不同的敏感性，使得其能够良好应用于荧光温度传感领域。其中，I₃₇₂和I₅₂₇组成的温度传感系统相对测温灵敏度在298 K时为2.90%·K^-1，高于传统TCLs荧光温度传感器的测温灵敏度，突破了TCLs温度传感器的灵敏度天花板。另外，由于372 nm和527 nm波长相差较大，使得BaMgSiO₄陶瓷有着室温下绿光发射到458 K高温下蓝光发射的显著变化，实现了温度监控可视化。因此，BaMgSiO₄陶瓷因其独特的氧空位缺陷发光特性，为开发荧光温度传感器提供了一种高精度和可视化的新选择，为荧光温度探测技术提供了一条新思路。

Mode-division multiplexers (MDMUXs) play a pivotal role in enabling the manipulation of an arbitrary optical state within few-mode fibers, offering extensive utility in the fields of mode-division multiplexing and structured optical field engineering. The exploration of MDMUXs employing cascaded resonant couplers has garnered significant attention owing to their scalability, exceptional integration capabilities, and the anticipated low insertion loss. In this work, we present the successful realization of high-quality orbital angular momentum MDMUX corresponding to topological charges 0, ±1, and ±2, achieved through the utilization of cascaded fused-biconical tapered couplers. Notably, the measured insertion losses at 1550 nm exhibit remarkable minimal values: 0.31, 0.10, and 0.64 dB, respectively. Furthermore, the 80% efficiency bandwidths exceed 106, 174, and 174 nm for these respective modes. The MDMUX is composed of precision-manufactured high-quality mode selective couplers (MSCs). Utilizing a proposed supermode propagation method based on mode composition analysis, we precisely describe the operational characteristics of MSCs. Building upon this comprehensive understanding, we embark on a pioneering analysis elucidating the influence of MSC cascading order on the performance of MDMUXs. Our theoretical investigation substantiates that when constructing MDMUXs, MSCs should adhere to a specific cascading sequence.

A Brillouin dynamic grating (BDG) can be used for distributed birefringence measurement in optical fibers, offering high sensitivity and spatial resolution for sensing applications. However, it is quite a challenge to simultaneously achieve dynamic measurements with both high accuracy and high spatial resolution. In this work, we propose a sensing mechanism to achieve distributed phase-matching measurement using a chirped pulse as a probe signal. In BDG reflection, the peak reflection corresponds to the highest four-wave mixing (FWM) conversion efficiency, and it requires the Brillouin frequency in the fast and slow axes to be equal, which is called the phase-matching condition. This condition changes at different fiber positions, which requires a range of frequency injection for the probe wave. The proposed method uses a chirped pulse as a probe wave to cover this frequency range associated with distributed birefringence inhomogeneity. This allows us to detect distributed phase matching for birefringence changes that are introduced by temperature and strain variations. Thanks to the single shot and direct time delay measurement capability, the acquisition rate in our system is only limited by the fiber length. Notably, unlike conventional BDG spectrum recovery-based systems, the spatial resolution here is determined by both the frequency chirping rate of the probe pulse and the birefringence profile of the fiber. In the experiments, an acquisition rate of 1 kHz (up to fiber length limits) and a spatial resolution of 10 cm using a 20 ns probe pulse width are achieved. The minimum detectable temperature and strain variation are 5.6 mK and 0.37 με along a 2 km long polarization-maintaining fiber (PMF).

考古发掘出土的风化骨质文物通常疏松多孔、力学强度低、质地脆弱, 易出现翘曲、开裂、酥粉化等现象,亟需探索脆弱骨质文物加固保护的新方法。本研究采用羟基磷灰石前驱材料氧化钙-磷酸氢钙的醇分散液渗入脆弱骨质内部, 再用蒸馏水渗入引发氧化钙与磷酸氢钙反应而生成羟基磷灰石连续相。该连续相能填充脆弱骨内部的孔隙和裂缝, 并通过桥连黏接而加固骨质。利用电镜、能谱、XRD、色差、质量、孔隙率、密度和断面强度等研究考察了悬浮分散液中氧化钙与磷酸氢钙的质量配比(1 : 1、1 : 3、1 : 4、1 : 5、1 : 6、1 : 7)和施加方式(刷涂、滴渗和浸泡)对加固效果的影响，结果表明, 悬浮分散液中氧化钙和磷酸氢钙的质量配比为1 : 3, 且施加方式为刷涂时, 加固处理效果最佳。经加固处理后, 脆弱骨的孔隙率下降了17.3%, 质量、密度和表面强度分别提高了38.39%、34.49%和16.32%, 且其色差∆E也小于3.0, 符合文物保护要求。本研究为脆弱骨质文物的加固保护提供了新的有效方法。

本文以油菜秸秆为原料，研究不同吸收剂量⁶⁰Co-γ辐照处理后样品中木质纤维素组分、降解产物种类和含量的变化，并对其酶解和分步糖化发酵特性进行评价。研究结果表明：随着吸收剂量的升高，油菜秸秆中纤维素、木聚糖和木质素含量降低，水溶性组分总量逐渐增加，水浸提液pH逐渐降低。降解产物中4种小分子脂肪酸总量随辐照吸收剂量的升高逐渐增加，1 000 kGy处理后达到最大值9.25 mg/g；9种小分子芳香类降解产物总量呈先增后降趋势，800 kGy时达到最大值0.22 mg/g。油菜秸秆酶解纤维素转化率和葡萄糖浓度随着吸收剂量的升高逐渐增加；随着底物浓度的增加，纤维素转化率逐渐降低，酶解液中葡萄糖浓度逐渐升高；15%底物浓度下800 kGy辐照处理油菜秸秆酶解纤维素转化率为57.55%，分步糖化发酵乙醇转化率低于10%。辐照结合水浸提处理显著提高油菜秸秆酶解发酵效率，水浸提后800 kGy辐照油菜秸秆在15%底物浓度酶解纤维素转化率和葡萄糖浓度分别为71.62%和40.38 mg/mL，分步发酵48 h后乙醇转化率达到64.00%，且发酵液中葡萄糖被全部消耗。