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Serving as the electrical to optical converter, the on-chip silicon light source is an indispensable component of silicon photonic technologies and has long been pursued. Here, we briefly review the history and recent progress of a few promising contenders for on-chip light sources in terms of operating wavelength, pump condition, power consumption, and fabrication process. Additionally, the performance of each contender is also assessed with respect to thermal stability, which is a crucial parameter to consider in complex optoelectronic integrated circuits (OEICs) and optical interconnections. Currently, III-V-based silicon (Si) lasers formed via bonding techniques demonstrate the best performance and display the best opportunity for commercial usage in the near future. However, in the long term, direct hetero-epitaxial growth of III–V materials on Si seems more promising for low-cost, high-yield fabrication. The demonstration of high-performance quantum dot (QD) lasers monolithically grown on Si strongly forecasts its feasibility and enormous potential for on-chip lasers. The superior temperature-insensitive characteristics of the QD laser promote this design in large-scale high-density OEICs. The Germanium (Ge)-on-Si laser is also competitive for large-scale monolithic integration in the future. Compared with a III-V-based Si laser, the biggest potential advantage of a Ge-on-Si laser lies in its material and processing compatibility with Si technology. Additionally, the versatility of Ge facilitates photon emission, modulation, and detection simultaneously with a simple process complexity and low cost. On-chip light sources: hybrid silicon lasers most promising sources Hybrid silicon lasers based on bonded III–V layers on silicon are currently the best contenders for on-chip lasers for silicon photonics. On-chip silicon light sources are highly desired for use as electrical-to-optical converters in silicon-based photonics. Zhiping Zhou and Bing Yin of Peking University in China and Jurgen Michel of Massachusetts Institute of Technology assess the three main contenders for such light sources: erbium-based light sources, germanium-on-silicon lasers and III-V-based silicon lasers. They consider operating wavelength, pumping conditions, power consumption, thermal stability and fabrication process. The scientists regard the power efficiencies of electrically pumped erbium-based lasers as being too low and the threshold currents of germanium lasers as being too high. They conclude that III–V quantum dot lasers monolithically grown on silicon show the most promise for realizing on-chip lasers.

Conventional electronic processors, which are the mainstream and almost invincible hardware for computation, are approaching their limits in both computational power and energy efficiency, especially in large-scale matrix computation. By combining electronic, photonic, and optoelectronic devices and circuits together, silicon-based optoelectronic matrix computation has been demonstrating great capabilities and feasibilities. Matrix computation is one of the few general-purpose computations that have the potential to exceed the computation performance of digital logic circuits in energy efficiency, computational power, and latency. Moreover, electronic processors also suffer from the tremendous energy consumption of the digital transceiver circuits during high-capacity data interconnections. We review the recent progress in photonic matrix computation, including matrix-vector multiplication, convolution, and multiply–accumulate operations in artificial neural networks, quantum information processing, combinatorial optimization, and compressed sensing, with particular attention paid to energy consumption. We also summarize the advantages of silicon-based optoelectronic matrix computation in data interconnections and photonic-electronic integration over conventional optical computing processors. Looking toward the future of silicon-based optoelectronic matrix computations, we believe that silicon-based optoelectronics is a promising and comprehensive platform for disruptively improving general-purpose matrix computation performance in the post-Moore’s law era.

We theoretically and experimentally demonstrate a significantly large modulation efficiency of a compact graphene modulator based on a silicon waveguide using the electro refractive effect of graphene. The modulation modes of electro-absorption and electro-refractive can be switched with different applied voltages. A high extinction ratio of 25 dB is achieved in the electro-absorption modulation mode with a driving voltage range of 0 V to 1 V. For electro-refractive modulation, the driving voltage ranges from 1 V to 3 V with a 185-pm spectrum shift. The modulation efficiency of 1.29 V · mm with a 40-μm interaction length is two orders of magnitude higher than that of the first reported graphene phase modulator. The realisation of phase and intensity modulation with graphene based on a silicon waveguide heralds its potential application in optical communication and optical interconnection systems.

Background This study examined the relationship between maternal preeclampsia (PE) and gut microbiota colonization in preterm infants and analyzed the effects of prenatal Bifidobacterium supplementation. Methods This observational study included 45 preterm infants categorized according to their mothers’ exposure status during pregnancy. Group A (healthy controls, n  = 15) included infants born to healthy mothers who received no supplementation; Group B (PE+Bifidobacterium, n  = 15) included infants whose mothers had PE and received Bifidobacterium supplementation as part of routine clinical management; and Group C (PE only, n  = 15) included infants born to mothers with PE who did not receive Bifidobacterium supplementation. All enrolled infants were followed from birth for subsequent analyses. The initial postnatal fecal samples of the infants were collected and analyzed using 16S rRNA gene sequencing. Microbial diversity within the intestinal microbiota was evaluated using alpha diversity (within-sample) and beta diversity (between-sample) analyses. To identify taxon-specific differences among groups, we performed linear discriminant analysis effect size and differential abundance analysis, with statistical significance set at p  < 0.05. The functional potential of the gut microbiota was inferred based on Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways via the PICRUSt2 algorithm. Results Alpha diversity analysis revealed significantly greater microbial diversity in the fecal microbiota of preterm infants born to healthy mothers (Group A) than in those delivered by mothers with PE, regardless of prenatal Bifidobacterium exposure. Taxonomic profiling revealed distinct microbial community structures across groups: Group A exhibited significant enrichment of Bacteroides at all taxonomic levels, along with an elevated abundance of Clostridium at the class and order levels. Group B showed a markedly greater relative abundance of Actinobacteria at the phylum level and Rothia at the genus level, whereas Group C was dominated by Proteobacteria (phylum level) and Streptococcus (genus level). All intergroup differences were statistically significant following Benjamini‒Hochberg correction (q < 0.05). A functional analysis of the gut microbiota revealed 53 KEGG pathways with significant overall group differences ( p  < 0.05), among which 23 pathways were significantly different in at least two groups (q < 0.05). Notably, the activity of the LPS biosynthesis pathway was significantly upregulated in Group C compared with Group A (q = 0.001). Although LPS biosynthesis activity was reduced in Group B relative to Group C (q = 0.018), it remained elevated compared to Group A (q = 0.001), suggesting incomplete mitigation of endotoxin risk. Additionally, glycolytic activity was significantly impaired in Group C relative to Group A (q = 0.003) but was partially restored in Group B compared to Group C (q = 0.022). Conclusions Maternal PE impaired early-life gut microbiota establishment in preterm infants, manifesting in reduced microbial diversity, enrichment of pathogenic Proteobacteria and Streptococcus, and consequent functional dysbiosis characterized by elevated endotoxin biosynthesis potential and compromised energy metabolism. Although prenatal supplementation with Bifidobacterium partially restored the microbial compositional balance, promoting beneficial bacteria, reducing LPS synthesis activity, and partially improving glycolytic function, it failed to fully reverse endotoxin-related risks, indicating the need to develop more effective microbiota-targeted strategies to comprehensively optimize metabolic and immune homeostasis.

Herein, a novel strategy for sensitive determination of uranium in natural water was proposed using electropolymerization of Nile blue modified glassy carbon electrode (PNB/GCE) and differential pulse adsorptive stripping voltammetry (DPAdSV). The preparation of modified electrodes, electrolyte, reproducibility, and substance interferences was studied. The PNB/GCE were characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and DPAdSV. The DPAdSV peak current was proportional to the concentration of uranium in the range of 0.30–100 μg·L−1 with the detection limit of 0.19 μg·L−1 and R2 = 0.997. Finally, the PNB/GCE was successfully applied to determination of uranium in natural water samples.

Understanding the strain-induced crystallization (SIC) mechanism of natural rubber (NR) is a prerequisite for comprehending the reinforcement mechanism of NR and for designing new high-performance rubber materials. With the help of new technologies that have enabled more accurate experimental measurement of the microstructure and the use of molecular simulations that can be applied to probe structural changes during stretching in real time, some interesting results have been found. For instance, even at high strains, a very large fraction of the unoriented amorphous phase still remains in the stretched sample with homogeneous or heterogeneous networks. In addition, the onset strain of SIC in peroxide-cured NR decreases with an increasing crosslinking density, while sulfur-cured NR is independent of the crosslinking density, which cannot be explained by conventional theories. The presence of nanofillers, entanglements, non-rubber components and pseudoend-linked networks also results in abnormal phenomena of SIC. Both experimental measurements and molecular simulations were applied to probe the strain-induced crystallization (SIC) of natural rubber in real time, and some interesting results have been found. A very large fraction of unoriented amorphous phase remains, even at high strains. The onset strain of SIC in peroxide-cured NR decreases with increasing crosslinking density, while that in sulfur-cured NR is independent of crosslinking density. This difference may be caused by different network structures. Nanofillers, entanglements, non-rubber components and pseudoend-linked networks also result in abnormal SIC phenomena.

With the rapid development of artificial intelligence, the electronic system has fallen short of providing the needed computation speed. It is believed that silicon-based optoelectronic computation may be a solution, where Mach–Zehnder interferometer (MZI)-based matrix computation is the key due to its advantages of simple implementation and easy integration on a silicon wafer, but one of the concerns is the precision of the MZI method in the actual computation. This paper will identify the main hardware error sources of MZI-based matrix computation, summarize the available hardware error correction methods from the perspective of the entire MZI meshes and a single MZI device, and propose a new architecture that will largely improve the precision of MZI-based matrix computation without increasing the size of the MZI’s mesh, which may lead to a fast and accurate optoelectronic computing system.

Due to their benefits in interior thermal comfort, energy saving, and noise reduction, radiant cooling systems have received wide attention. Radiant cooling systems can be viewed as a part of buildings’ maintenance structure and a component of cooling systems, depending on their construction. This article reviews studies on heat exchange in rooms utilizing radiant cooling systems, including research on conduction in radiant system structures, system cooling loads, cooling capacity, heat transfer coefficients of cooling surfaces, buildings’ thermal performance, and radiant system control strategy, with the goal of maximizing the benefits of energy conservation. Few studies have examined how radiant cooling systems interact with the indoor environment; instead, earlier research has focused on the thermal performance of radiant cooling systems themselves. Although several investigations have noted variations between the operating dynamics of radiant systems and conventional air conditioning systems, the cause has not yet been identified and quantified. According to heat transfer theory, the authors suggest that additional research on the performance of radiant systems should consider the thermal properties of inactive surfaces and that buildings’ thermal inertia should be used to coordinate radiant system operation.