RESUMEN

Lithium niobate (LiNbO3) is emerging as an appealing candidate for integrated optical applications with enhanced complexity, owing to its inherent abundant optoelectronic properties. To compensate for the inability of LiNbO3 to generate indistinguishable single photons, the evanescent coupling heterointerface constructed between III-V compound semiconductors (e.g., InP) and LiNbO3 through plasma activation provides a feasible solution for balancing the integration efficiency and interfacial stability while achieving sub-50 nm alignment accuracy between devices, thus offering ultracompact on-chip light sources for classical optoelectronics and quantum optics. However, a challenge remains in the formation of the InP/LiNbO3 platform due to the huge mismatch in the coefficient of thermal expansion. Here, we demonstrate the InP/LiNbO3 covalent heterointerface using an asymmetric plasma activation strategy. Different plasmas are used for the activation of InP and LiNbO3 specifically, balancing the enhancement of surface functional group density with the avoidance of defect generation effectively. More importantly, combined with surface comprehensive characterizations and interface performance, we determine that the introduction of ammonia solution enables the surface hydroxyl groups to be "effective" as LiNbO3 surface relaxation increases the chance of -OH groups' contact. Therefore, a robust covalent bond network is established across the InP/LiNbO3 interface at 80 °C with an enhanced bonding strength of 9.7 MPa. Moreover, a hybrid quantum photonic chip based on the InP/LiNbO3 platform is designed to compute the coupling efficiency and the impact of misalignment on it, demonstrating the potential of extending the platform to hybrid integrated quantum systems.

RESUMEN

Cobalt-Tetraamide-Phthalocyanine (CoTaPc) immobilized onto magnetic Fe3O4 chitosan microspheres (Fe3O4/CTO) was synthesized via a simple immersion method, which is an efficient catalyst for the oxidation of cyclic ketones to lactones with O2/benzaldehyde as the oxidant. The CoTaPc-Fe3O4/CTO catalyst was applied for the first time in the Baeyer-Villiger (B-V) oxidation reaction. Characterization results obtained from X-ray diffraction, UV-vis, Fourier transform infrared, and scanning electron microscopy showed that the combination of CoTaPc and magnetic Fe3O4/CTO microspheres was achieved. The catalyst could be easily separated from the reaction system with an external magnet and reused several times without the remarkable loss of activity. In addition, a possible radical mechanism for the B-V oxidation in this catalytic system is proposed and verified by controlled experiments.

RESUMEN

Ultraviolet (UV) disinfection is an early discovered technology that is currently and widely used for water treatment and food hygiene treatment. A newly emerging technology of UV disinfection, that is, UV light-emitting diodes (UV-LEDs), has aroused considerable research attention. UV-LEDs feature numerous advantages compared with traditional UV mercury vapor lamps and are expected to replace traditional UV lamps. Researchers currently perform studies to obtain data and develop methods for UV-LED water treatment systems. This article analyzes the latest research status and discusses the types of inactivation factors, such as the wavelength selectivity of UV light source, control of UV dose, effect of inactivation rate constant (K) (cm2/mJ), working mode of water sample, external auxiliary system, and UV sensitivity of pathogenic bacteria in water. The wavelengths of approximately 260 and 280 nm normally feature strong inactivation characteristics. When compared with the approximately 260 nm wavelength chip, the around 280 nm wavelength chip proves to be a better choice as its higher wavelength light power can result in faster disinfection capacity of bacteria. UV dose can also be used as the reference value for disinfection of drinking water, whereas the inactivation rate constant (K) (cm2/mJ) varies with different microorganism internal structures. Changing the working mode or adding an auxiliary system can also enhance the inactivation effect in water treatment system settings. In addition, we can compare the inactivation capacities of several pathogens as follows: ΦX174 > Escherichia coli > T type bacteriophage >Bacillus subtilis > MS2 or Qß > human adenovirus. The in-depth investigation and discussion of inactivation factors and the mechanism of action in UV-LEDs water treatment systems will establish a more efficient UV-LED disinfection method in the future, provide a guiding direction, and promote the standardization and normalization of pathogen inactivation mechanism in UV-LED water treatment systems.

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RESUMEN

Changes in the elasticity modulus of an epoxy molding compound (EMC), an electronic packaging polymer, under high-temperature air storage conditions, are discussed in this study. The elasticity modulus of EMC had two different compositions (different filling contents) under different temperatures (175, 200, and 225 °C) and aging times (100, 500, and 1500 h), which were analyzed by using dynamic mechanic analysis technology. The results revealed that the elasticity modulus increased in the thermal aging process, with an increase in the temperature and the aging time. The increments of the glassy and rubbery states were similar. However, the growing rate was significantly different, and the growth of the rubbery state was significantly higher than that of the glassy state. The filling content influenced the degree of aging of the materials significantly. At a low filling content, long-term aging under high temperatures completely changed the material structure, and the mechanical properties of the polymer were reduced.

RESUMEN

Triphenylphosphine oxide (TPPO) and oxalyl chloride ((COCl)2) are used as novel and high-efficiency coupling reagents for the esterification of alcohols with carboxylic acids via the TPPO/(COCl)2 system at room temperature for 1 h. The reaction represents the first TPPO-promoted esterification under mild and neutral conditions with excellent yields. Furthermore, we proposed a plausible mechanism with the help of 31P NMR spectroscopy.