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An efficient and versatile synthesis of alcohols via transfer hydrogenation from ketones with isopropanol, utilizing [Ni(6,6′‐(OH)2‐2,2′‐bpy)][Br2] under alkaline conditions, has been documented. It was noteworthy that many readily reducible or labile functional groups such as nitro, cyano, and halide, within the same molecular framework, did not undergo any change under the standard reaction conditions. Furthermore, the gram scale transfer hydrogenation reaction was successfully carried out with good yield using a common route with only a single purification by column chromatography. [ABSTRACT FROM AUTHOR]

As an essential component of the ventilation system of nuclear facilities, filters have significant filtration performance for the safety of the environment and personnel. The metal fiber filter has excellent temperature resistance and can still maintain good filtration performance under fire conditions. In the filter design process, it is usually necessary to fold the metal fibrous fabric into a pleated structure to increase the filtration area and improve performance. A numerical simulation method is carried out on the filtration performance of the metal fiber filter, and the complex stacking structure inside the metal fibrous fabric is simulated using the porous zone. It is developed by combining the flow resistance and particle collection efficiency calculation program based on the structural parameters of the fibrous fabric with FLUENT software. The accuracy of the developed simulation method is validated with experimental data. The filtration performance of metal fiber pleated filters is further studied by this method. The results indicate that the influence of the pleat geometries on the collection efficiency of filters can be ignored. Brownian diffusion and interception play a dominant role in the filtration process. As the filtration velocity increases, the Brownian diffusion effect of particles is suppressed, this is the main reason for the decrease in filtration efficiency. With the same geometries, the resistance of rectangular pleats is always smaller than that of triangular pleats. With the same geometries, rectangular pleats have more uniform flow distribution than triangular pleats. • The filtration performance of pleated metal fiber filters with large pleat ratios was studied. • The flow distribution characteristics of rectangular and triangular pleats were compared. • The impact of filtration mechanisms on the efficiency of high-efficiency filters was explored. [ABSTRACT FROM AUTHOR]

Fe3+ is a promising dopant for designing near‐infrared (NIR) phosphors due to its broadband emitting, non‐toxic, and inexpensive properties. However, the 4E (4D) and 4E + 4A1 (4G) levels of Fe3+ ions are independent of the crystal‐field parameter, and the spectral regulation has become a huge challenge. Herein, a broadband NIR‐emitting phosphor Ca2.5Hf2.5(Ga, Al)3O12: Fe3+ is successfully developed toward long‐wave ultraviolet (LWUV) light‐pumped NIR phosphor‐converted LED (pc‐LED). Significantly, the excited transition reverse of Ca2.5Hf2.5Ga3O12: Fe3+ can be realized by simply adjusting Fe3+ concentration, which results in the largely enhanced excitation around 410 nm and matches well with the commercial LWUV LED. Moreover, Ca2.5Hf2.5Ga3O12: Fe3+ can exhibit a broadband NIR emission centered at 770 nm with optimized doping content at 0.01 mol%, which are demonstrated to ascribe to Fe3+ occupying both octahedral Hf 4+ and tetrahedral Ga3+ sites. Further, a simple cation modulation strategy is proposed to successfully break the lattice symmetry around Fe3+ ions and largely enhance the NIR‐emission intensity to 200% as much as before. Finally, a NIR pc‐LED is fabricated by employing Ca2.5Hf2.5Ga3O12: Fe3+, Al3+ coating on a 410 nm LED chip, which shows great potential in non‐destructive inspection applications. [ABSTRACT FROM AUTHOR]

Fast optical modulation of nanoplasmonics is fundamental for on-chip integration of all-optical devices. Although various strategies have been proposed for dynamic modulation of surface plasmons, critical issues of device compatibility and extremely low efficiency in the visible spectrum hamper the application of optoplasmonic nanochips. Here we establish an optoplasmonic system based on Au@Cu2–xS hybrid core–shell nanoparticles. The optical excitation of hot electrons and their charge transfer to the semiconductor coating (Cu2–xS) lead to lowered electron density of Au, which results in the red shift of the localized surface plasmon resonance. The hot electrons can also transport through the Cu2–xS layer to the metal substrate, which increases the conductance of the nanogap. As such, the coupled gap plasmon blue-shifts with a magnitude of up to ∼15 nm, depending on the excitation power and the thickness of the coatings, which agrees with numerical simulations. All of this optoelectronic tuning process is highly reversible, controllable and fast with a modulated laser beam, which is highly compatible and sufficiently useful for on-chip integration of nanophotonic devices. [ABSTRACT FROM AUTHOR]

Background: Increasing number of studies have demonstrated certain patterns of microbial changes in gynecological diseases; however, the interaction between them remains unclear. To evaluate the consistency or specificity across multiple studies on different gynecological diseases and microbial alterations at different sites of the body (gut and genital tract), we conducted a systematic review and meta-analysis. Methods: We searched PubMed, Embase, Web of Science, and Cochrane Library up to December 5, 2022(PROSPERO: CRD42023400205). Eligible studies focused on gynecological diseases in adult women, applied next-generation sequencing on microbiome, and reported outcomes including alpha or beta diversity or relative abundance. The random-effects model on standardized mean difference (SMD) was conducted using the inverse-variance method for alpha diversity indices. Results: Of 3327 unique articles, 87 eligible studies were included. Significant decreases were found in gut microbiome of patients versus controls (observed species SMD=-0.35; 95%CI, -0.62 to -0.09; Shannon index SMD=-0.23; 95%CI, -0.40 to -0.06), whereas significant increases were observed in vaginal microbiome (Chao1 SMD = 1.15; 95%CI, 0.74 to 1.56; Shannon index SMD = 0.51; 95%CI, 0.16 to 0.86). Most studies of different diagnostic categories showed no significant differences in beta diversity. Disease specificity was observed, but almost all the changes were only replicated in three studies, except for the increased Aerococcus in bacterial vaginosis (BV). Patients with major gynecological diseases shared the enrichment of Prevotella and depletion of Lactobacillus, and an overlap in microbes was implied between BV, cervical intraepithelial neoplasia, and cervical cancer. Conclusions: These findings demonstrated an association between alterations in gut and genital microbiota and gynecological diseases. The most observed results were shared alterations across diseases rather than disease-specific alterations. Therefore, further investigation is required to identify specific biomarkers for diagnosis and treatment in the future. [ABSTRACT FROM AUTHOR]

• The minimum reflection loss of Co 9 S 8 -DETA at 4.2 GHz frequency reaches −41.6 dB and the effective absorption bandwidth is 4.1 GHz with a thickness of only 1.6 mm. • Co 9 S 8 -DETA organic-inorganic hybrid nanosheets were synthesized by a one-step simple hydrothermal method without further thermal treatment. • The enhanced EMW absorption property of Co 9 S 8 -DETA organic-inorganic hybrid materials expands the idea of EMW property control of EMW absorbing materials by adjusting the structural characteristics of organic-inorganic hybrid materials. Co 9 S 8 -DETA organic-inorganic hybrid materials synthesized by hydrothermal method show an enhanced electromagnetic wave (EMW) absorption performance because of its unique two-dimensional (2D) structure and EMW properties regulated by the interface structure. Using Co 9 S 8 -DETA as a precursor, the organic intercalation DETA can be removed by heat treatment to obtain inorganic Co 9 S 8. Compared with Co 9 S 8 inorganic, Co 9 S 8 -DETA hybrid material assembled in a paraffin matrix with 30 wt.% shows an excellent EMW absorption performance. The minimum reflection loss at 4.2 GHz frequency reaches -41.6 dB and the effective absorption bandwidth is 4.1 GHz with a thickness of only 1.6 mm. The enhanced EMW absorption property of Co 9 S 8 -DETA organic-inorganic hybrid materials expands the idea of EMW property control of EMW absorbing materials by adjusting the structural characteristics of organic-inorganic hybrid materials. [Display omitted] [ABSTRACT FROM AUTHOR]

Splines are widely used in aeronautic applications; however, misaligned splines often suffer contact stress concentration and fretting wear fatigue failure. Crowned modification is a useful way to relieve contact stress concentration and mitigate fretting wear for misaligned splines, but it is unclear how this method works. In this study, contact stresses for involute splines are calculated using finite elements and correlated to first-hand experimental results on fretting wear obtained using a dedicated test rig. Both contact stress distribution prediction and fretting wear measurement indicate that the crowned magnitude of splines should be selected according to the operating angular misalignment. ● A dedicated test rig for spline fretting wear is constructed. ● First-hand experimental results on spline fretting wear are presented. ● Spline contact stress predictions are implemented using finite elements. ● Optimum crowned magnitude depends on operating angular misalignment.A positive correlation exists between spline fretting wear and contact stress. [ABSTRACT FROM AUTHOR]

A series of rare-earth free far-red emitting phosphor NaYBa 4 W 2 O 12 : x Mn4+ (≤ x ≤ 0.75%, NYBW: Mn4+) is successfully synthesized for application in near-ultraviolet (n-UV) light pumped plant cultivation light-emitting diodes (LEDs). The phase purity, crystal structure, electronic structure and luminescent properties of NYBW: Mn4+ are investigated in detail. The results indicate that all NYBW: Mn4+ phosphors are well crystallized with a direct band gap of 3.86 eV. Broad excitation band can be found with dominant wavelengths at 365 and 520 nm, indicating NYBW: Mn4+ can be efficiently excited by commercial n-UV or green LED chip. Upon 360 nm excitation, NYBW: Mn4+ shows intense broad-band far-red emission centered at 696 nm, attributed to the 2E g →4A 2g transition of Mn4+. The optimal doping concentration of Mn4+ is determined to be 0.1% and the concentration quenching mechanism is the dipole-quadrupole interaction. The decay time decreases from 0.58 to 0.081 ms with Mn4+ concentration increasing from 0.025 to 0.75%. The temperature quenching behaviour of Mn4+ in NYBW is investigated, with a thermal activation energy estimated to be about 0.375 eV. Finally, a far-red emitting LED device is fabricated by coating NYBW: Mn4+ phosphor on a 365 nm n-UV LED chip. The above results guarantee that the as-prepared far-red emitting phosphor NYBW: Mn4+ has great potential for application in indoor plant cultivation LEDs. • Successful synthesis of a novel NYBW:Mn4+ perovskite phosphor. • Realization of rare-earth free far-red emission under UV excitation. • Investigation on the optical properties of NYBW:Mn4+ phosphor is conducted. • Potential far-red LED application for plant cultivation lighting is studied. [ABSTRACT FROM AUTHOR]