Polarization management is very important for photonic integrated circuits (PICs) and their applications. Due to geometrical anisotropy and fabrication inaccuracies, the characteristics of the guided ...transverse‐electrical (TE) and transverse‐magnetic (TM) modes are generally different. Polarization‐dependent dispersion and polarization‐dependent loss are such manifestations in PICs. These issues become more severe in high index contrast structures such as nanophotonic waveguides made of silicon‐on‐insulator (SOI), which has been regarded as a good platform for optical interconnects because of the compatibility with CMOS processing. Recently, polarization division multiplexing (PDM) with coherent detection using silicon photonics has also attracted much attention. This trend further highlights the importance of polarization management in silicon PICs. The authors review their work on polarization management for silicon PICs using the polarization independence and polarization diversity methods. Polarization issues and solutions in PICs made of SOI nanowires and ridge waveguides are discussed.
Polarization management is very important for photonic integrated circuits (PICs) and their applications. Due to geometrical anisotropy and fabrication inaccuracies, the characteristics of the guided transverse‐electrical (TE) and transverse‐magnetic (TM) modes are generally different. Polarization‐dependent dispersion and polarization‐dependent loss are such manifestations in PICs. These issues become more severe in high index contrast structures such as nanophotonic waveguides made of silicon‐on‐insulator (SOI), which has been regarded as a good platform for optical interconnects because of the compatibility with CMOS processing. Recently, polarization division multiplexing (PDM) with coherent detection using silicon photonics has also attracted much attention. This trend further highlights the importance of polarization management in silicon PICs. The authors review their work on polarization management for silicon PICs using the polarization independence and polarization diversity methods. Polarization issues and solutions in PICs made of SOI nanowires and ridge waveguides are discussed.
Because the traditional multimode feasibility modeling analysis method of physical fitness training for long-distance runners has the problems of long modeling time and low modeling accuracy, a new ...multimode feasibility modeling analysis method for physical fitness training of long-distance runners is proposed. The improved LLE (local linear embedding) method is used to reduce the dimensionality of the training data for the physical fitness of long-distance runners. According to the processing results, the information theory is used to analyze the information content of the physical fitness training features of the long-distance runners, the information entropy of each feature is calculated, and the long-distance runners are extracted. Athlete’s physical fitness enhancement training characteristics, combined with quantitative regression analysis method to carry out the information regression analysis of the long-distance runners’ physical fitness training multimode statistical sequence, construct the feasibility evaluation model of the long-distance runners’ physical fitness training multimode and complete the feasibility of the long-distance runners’ physical fitness training multimode feasibility study Mode analysis. The simulation experiment results show that the proposed method has higher accuracy and shorter modeling time for multimode feasibility modeling of physical fitness training for long-distance runners.
Nanophotonics finds ever broadening applications requiring complex components with many parameters to be simultaneously designed. Recent methodologies employing optimization algorithms commonly focus ...on a single performance objective, provide isolated designs, and do not describe how the design parameters influence the device behaviour. Here we propose and demonstrate a machine-learning-based approach to map and characterize the multi-parameter design space of nanophotonic components. Pattern recognition is used to reveal the relationship between an initial sparse set of optimized designs through a significant reduction in the number of characterizing parameters. This defines a design sub-space of lower dimensionality that can be mapped faster by orders of magnitude than the original design space. The behavior for multiple performance criteria is visualized, revealing the interplay of the design parameters, highlighting performance and structural limitations, and inspiring new design ideas. This global perspective on high-dimensional design problems represents a major shift in modern nanophotonic design and provides a powerful tool to explore complexity in next-generation devices.
Endothelium (EC) is a key component of blood-brain barrier (BBB), and has an important position in the neurovascular unit. Its dysfunction and death after cerebral ischemic/reperfusion (I/R) injury ...not only promote evolution of neuroinflammation and brain edema, but also increase the risk of intracerebral hemorrhage of thrombolytic therapies. However, the mechanism and specific interventions of EC death after I/R injury are poorly understood. Here we showed that necroptosis was a mechanism underlying EC death, which promoted BBB breakdown after I/R injury. Treatment of rats with receptor interacting protein kinase 1 (RIPK1)-inhibitor, necrostatin-1 reduced endothelial necroptosis and BBB leakage. We furthermore showed that perivascular M1-like microglia-induced endothelial necroptosis leading to BBB disruption requires tumor necrosis factor-α (TNF-α) secreted by M1 type microglia and its receptor, TNF receptor 1 (TNFR1), on endothelium as the primary mediators of these effects. More importantly, anti-TNFα (infliximab, a potent clinically used drug) treatment significantly ameliorate endothelial necroptosis, BBB destruction and improve stroke outcomes. Our data identify a previously unexplored role for endothelial necroptosis in BBB disruption and suggest infliximab might serve as a potential drug for stroke therapy.
A photocatalytic formal 3+2 cycloaddition of 2H‐azirines with alkynes has been achieved under irradiation by visible light in the presence of organic dye photocatalysts. This transformation provides ...efficient access to highly functionalized pyrroles in good yields and has been applied to the synthesis of drug analogues. A primary trial of photocascade catalysis merging energy transfer and redox neutral reactions was shown to be successful.
Photo(chemistry) op: A photocatalytic formal 3+2 cycloaddition of 2H‐azirines with alkynes has been established under the irradiation of visible light in the presence of an organic dye. This transformation provides efficient access to highly functionalized pyrroles in good yields and has been applied to the formal synthesis of an inhibitor for HMG‐CoA reductase.
Aiming at the problems of low precision, long time, and poor effect of current remote real-time motion location methods, a long-distance real-time motion location method based on wireless network ...technology was proposed. Through the analysis of wireless network technology, the basic structure and positioning technology of wireless sensor networks are studied. In addition, this paper adopts the core matrix Isomap node location algorithm based on partial least squares (PLS). The distance of geodesic between long-distance running nodes is used to characterize the dissimilarity between nodes, and the sample contribution rate of the partial least squares method is used to find and eliminate the phenomenon of short circuits in long-distance running fields. High-dimensional feature interval is mapped by centroid transformation and kernel transformation. The experimental results show that the method can improve the positioning accuracy and shorten the positioning time effectively.
The water diversion project from the Luanhe River to Tianjin city has been a “lifeline” for the economic and social development of Tianjin city since the 1980s. The water quality of this project has ...received considerable attention due to the degradation of the river environment during the last decade. A comprehensive water quality index (WQI) was applied to provide a clear understanding of the water quality in the upper and middle streams of the Luanhe River. We utilized 12 water quality parameters from 85 sampling sites along the major tributaries in July 2017 (summer), October 2017 (autumn) and April 2018 (spring) respectively. The results showed that the WQI values ranged from 37.6 to 90.0, indicating “bad” to “excellent” water quality in the upper and middle streams of the Luanhe River. The seasonal variations in the WQI were significant and the relationship between land use and WQI also have certain seasonal characteristics, such as WQI of 85 sampling sites were significant negatively correlated with the proportion of cultivated land in summer, and with the proportion of built-up land in three sampling periods. The water quality pollutants, such as organic pollutants (permanganate index), nutrients (total phosphorus), total suspended solid, and chlorophyll-a were significantly influenced by the proportion of forest and grass land and the consumption of phosphate fertilizers in tributaries. The evident variation in the WQI was also found in the tributaries with higher proportions of cultivated land and built-up land. Overall, we think that agricultural and urban related activities are important factors affecting the water quality in this region. Water quality improvements should control the sewage in the urban area and the consumption of fertilizers, especially on the cultivated land along the riverside in the upper and middle streams of the Luanhe River.
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•Organic pollutants and nutrients were the main challenge in the Luanhe River.•Water quality affected by forest and grass land (%) and fertilizers in tributaries.•WQI was significant negatively correlated with cultivated land (%) in summer.•WQI was significant negatively correlated with built-up land (%).
Whole‐cell inorganic‐biohybrid systems, integrating inorganic photosensitizers with intact living cells, have shown great potential for solar hydrogen production. However, the typical whole cell ...biohybrid system often suffers from the sluggish kinetics of electron transfer in the transmembrane diffusion process, which severely restrict their photocatalytic activity. Here, a unique periplasmic photosensitized biohybrid system is constructed by translocating CuInS2/ZnS quantum dots (QDs) into the Shewanella oneidensis MR‐1 (SW) cells that express periplasmic hydrogenases. The photoexcitation and electron transfer processes of QDs photosensitizers occur simultaneously in the periplasm of SW cells, which reduces the distance for electron transport and avoids the extra energy loss involved in the transmembrane process. As expected, the photocatalytic H2 generation of the fabricated biohybrid system is 8.6 times higher than that of bare QDs under visible light irradiation. Moreover, the good viability and stability of this biohybrid system endow it with an excellent sustained hydrogen production within 45 h, representing the most stable biohybrid among the reported whole‐cell biohybrid H2 production systems. This work provides a novel insight into the construction of a robust whole‐cell biohybrid system for solar hydrogen production.
This work reports an intracellular quantum dots photosensitized biohybrid system for realizing an enhanced solar hydrogen production activity. Low toxicity and good biocompatibility of CuInS2/ZnS quantum dots (QDs), as well as the low damage of visible light to bacteria is helpful for increasing long‐term stability, which surpasses most reported whole cell biohybrid systems.
Here, N- and P-doped carbon–carbon nanotube CoP (NPC-CNTs-CoP) nanoparticles dodecahedra are achieved by multistep calcination of the Zn-doped zeolitic imidazolate framework ZIF-67 precursor ...(ZnCo-ZIF). In the structures, the presence of N and P atoms, abundant CNTs and the CoP nanoparticles can enhance electrochemical activity and promote the structural stability of materials. As the temperature increases, the Zn contents gradually reduce to zero, which provides more active sites for electrochemical testing. Furthermore, the high specific surface area and microporous behavior of NPC-CNTs-CoP-9 make it excellent in electrocatalytic testing. NPC-CNTs-CoP-9 shows a low overpotential of 224 mV at 10 mA·cm
−2
in 1.0 mol·L
−1
KOH solution. The strategy of zeolitic imidazole framework-derived transition metal phosphides will provide a new sight for developing energy conversion materials.
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