Sensitivity improvement of aluminum-based far-ultraviolet nearly guided-wave surface plasmon resonance sensor

An aluminum (Al) based nearly guided-wave surface plasmon resonance (NGWSPR) sensor is investigated in the far-ultraviolet (FUV) region. By simultaneously optimizing the thickness of Al and dielectric films, the sensitivity of the optimized Al-based FUV-NGWSPR sensor increases from 183°/RIU to 309°/RIU, and its figure of merit rises from 26.47 RIU^-1 to 32.59 RIU^-1 when the refractive index of dielectric increases from 2 to 5. Compared with a traditional FUV-SPR sensor without dielectric, the optimized FUV-NGWSPR sensor can realize simultaneous improvement of sensitivity and figure of merit. In addition, the FUV-NGWSPR sensor with realistic materials (diamond, Ta₂O₅, and GaN) is also investigated, and 137.84%, 52.70%, and 41.89% sensitivity improvements are achieved respectively. This work proposes a method for performance improvement of FUV-SPR sensors by exciting nearly guided-wave, and could be helpful for the high-performance SPR sensor in the short-wavelength region.     

Sentinel-2卫星的多光谱轻量级船舶目标检测算法

近年来深度卷积神经网络在可见光船舶检测方面取得了显著的进展，然而，大多数相关研究是通过改进大型的网络结构来提高检测性能，因此加大了对更高计算机性能的需求。此外，可见光图像难以在云、雾、海杂波、黑夜等复杂场景检测到船舶。针对以上问题，提出了一种融合红（red, R）、绿（green, G）、蓝（blue, B）和近红外（NIR）4个波段光谱信息的由粗到精细的轻量型船舶检测算法。与现有的方法中根据光谱特性利用水体检测算法提取水体区域不同之处是该算法是利用改进的水体检测算法来提取船舶候选区域。为获取更准确的候选区域，对船舶、厚云、薄云、平静海面、杂波海面5种场景中4个波段的像素值进行了统计分析，选取近红外大于阈值作为辅助判断，并以其中心点获取候选区域32×32大小的切片，并对切片进行非极大值抑制，由此获得了船舶粗检测结果。随后构建了轻量级LSGFNet网络对船舶候选区域切片进行精细识别。构建的网络融合了1×1卷积提取的波谱特征与3×3的提取几何特征，为防止光谱特征与几何特征的信息在融合时“信息不流通”，在LSGFNet网络中引入了ShuffleNet中的通道打乱机制，并减小了模型结构，与典型的轻量级网络相比具有更好的效果且模型较小。最后，利用Sentinel-2卫星多光谱10 m分辨率数据构建了512×512大小的1 120组数据进行粗检测，以及32×32大小的6 014组数据进行精细网络训练，其中候选区域粗提取的查全率为98.99%，精细识别网络精确度为96.04%，不同场景下的平均精确度为92.98%。实验表明该算法在抑制云层、海浪杂波等干扰的复杂背景下具有较高的检测效率，且训练时间短、计算机性能需求低。     

Molecular and colloidal self-assembly at the oil–water interface

Self-assembly is a versatile bottom-up approach for fabricating novel supramolecular materials with well-defined nano- or micro-structures associated with functionalities. The oil-water interface provides an ideal venue for molecular and colloidal self-assembly. This paper gives an overview of various self-assembled materials, including nanoparticles, polymers, proteins, and lipids, at the oil-water interface. Focus has been given to fundamental principles and strategies for engineering the self-assembly process, such as control of pH, ionic strength and use of external fields, to achieve complex soft materials with desired functionalities, such as nanoparticle surfactants, structured liquids, and proteinosomes. It has been shown that self-assembly at the oil-water interface holds great promise for developing well-structured complex materials useful for many research and industrial applications.     

Non-Hermitian electronics multipods of electromagnetically induced transparency (EIT) and absorption (EIA)

Optical and Quantum Electronics - In the past few decades, the academic research and industrial synergy is dramatically accelerating to conceptualize high data rate services. The congestion in the...     

The complexation of insulin with sodium N‐[8‐(2‐hydroxybenzoyl)amino]‐caprylate for enhanced oral delivery: Effects of concentration,ratio, and pH

Permeation enhancers (PEs), such as N-[8-(2-hydroxybenzoyl)amino]-caprylate (SNAC), have been reported to improve the oral absorption of various macromolecules. However, the bioavailabilities of these formulations are quite low and variable due to the influences of enzymes, pH and other gastrointestinal barriers. In this study, we revealed that SNAC could interact with insulin to form tight complexes in a specific concentration (insulin ≥ 40 µg/mL)-, ratio (SNAC/insulin ≥ 20:1)- and pH (≥ 6.8)-dependent manner, thus contributing to a significantly high efficacy of oral insulin delivery. Specifically, absorption mechanism studies revealed that the SNAC/insulin complexes were internalized into the cells by passive diffusion and remained intact when transported in the cytosol. Furthermore, the complexes accelerated the exocytosis of insulin to the basolateral side, thereby enhancing its intestinal mucosal permeability. Eudragit^? S100-entrapped SNAC/insulin microspheres were then prepared and exhibited an apparent permeability coefficient (P_app) that was 6.6-fold higher than that of the insulin solution. In diabetic rats, hypoglycemic activity was sustained for more than 10 h after the microspheres were loaded into enteric-coated capsules. Further pharmacokinetic studies revealed an approximately 6.3% oral bioavailability in both the fasted and fed states, indicating a negligible food effect. Collectively, this study provides insight into the interaction between PEs and payloads and presents an SNAC-based oral insulin delivery system that has high oral bioavailability and patient-friendly medication guidance.     

新型含吡啶基团二羧酸配体的合成及单晶培养

以1，4-二溴-2，5-二甲基苯和4-吡啶硼酸为原料，经两步合成了一种新颖的含吡啶基团的二羧酸配体。通过核磁共振氢谱及傅里叶变换红外光谱对配体结构进行表征，通过热重分析对配体的热稳定性进行了测试；通过溶剂热法对配体的单晶进行培养，并考察反应温度、时间、pH和溶剂等条件对单晶培养的影响。结果表明：在反应温度为80 ℃，反应时间为12 h、溶剂为蒸馏水、溶液pH=5的条件下可获得高质量单晶。该配体为单斜晶系，属于C2/c空间群，结构中含有4个氧原子和2个氮原子，可为金属离子的配位提供足够的位点，有望应用于配合物的设计或催化、吸附和医药载体等行业。     

环加成反应、环合反应、电环化反应与环化反应的区别*

环加成反应、环合反应、电环化反应与环化反应都是合成有机环状化合物的成环反应,它们描述的反应类型完全不同。但是,它们却经常被误用或者混用。阐述了这4类反应的区别,希望能够从教学上明确这4类反应,从源头为将来的有机化学工作者建立起准确的概念。     

Integrability and multisoliton solutions of the reverse space and/or time nonlocal Fokas–Lenells equation

Nonlinear Dynamics - This paper studies reverse space and/or time nonlocal Fokas–Lenells (FL) equation, which describes the propagation of nonlinear light pulses in monomode optical fibers...     

Adsorption of Th(IV) from aqueous solution by the graphene oxide nanoribbons/chitosan composite material

Journal of Radioanalytical and Nuclear Chemistry - In order to reduce the potential toxicity to the environment after treatment of radioactive waste water, an eco-friendly graphene oxide...