Topological insulators are materials that behave as insulators in the bulk and as conductors at the edge or surface due to the particular configuration of their bulk band dispersion. However, up to ...date possible practical applications of this band topology on materials' bulk properties have remained abstract. Here, we propose and experimentally demonstrate a topological bulk laser. We pattern semiconductor nanodisk arrays to form a photonic crystal cavity showing topological band inversion between its interior and cladding area. In-plane light waves are reflected at topological edges forming an effective cavity feedback for lasing. This band-inversion-induced reflection mechanism induces single-mode lasing with directional vertical emission. Our topological bulk laser works at room temperature and reaches the practical requirements in terms of cavity size, threshold, linewidth, side-mode suppression ratio and directionality for most practical applications according to Institute of Electrical and Electronics Engineers and other industry standards. We believe this bulk topological effect will have applications in near-field spectroscopy, solid-state lighting, free-space optical sensing and communication.
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FZAB, GEOZS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Conventional laser cavities require discontinuity of material property or disorder to localize a light field for feedback. Recently, an emerging class of materials, twisted van der Waals materials, ...have been explored for applications in electronics and photonics. Here we propose and develop magic-angle lasers, where the localization is realized in periodic twisted photonic graphene superlattices. We reveal that the confinement mechanism of magic-angle lasers does not rely on a full bandgap but on the mode coupling between two twisted layers of photonic graphene lattice. Without any fine-tuning in structure parameters, a simple twist can result in nanocavities with strong field confinement and a high quality factor. Furthermore, the emissions of magic-angle lasers allow direct imaging of the wavefunctions of magic-angle states. Our work provides a robust platform to construct high-quality nanocavities for nanolasers, nano light-emitting diodes, nonlinear optics and cavity quantum electrodynamics at the nanoscale.
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GEOZS, IJS, IMTLJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBMB, UL, UM, UPUK, ZAGLJ
Here, we report the first example of Ni‐catalyzed asymmetric hydrosilylation of 1,1‐disubstituted allenes with high level of regioselectivities and enantioselectivities. The key to achieve this ...stereoselective hydrosilylation reaction was the development of the SPSiOL‐derived bisphosphite ligands (SPSiPO). This protocol features broad substrate scope, excellent functional group, and heterocycle tolerance, thus provides a versatile method for the construction of enantioenriched tertiary allylsilanes in a straightforward and atom‐economic manner. DFT calculations were performed to reveal the reaction mechanism and the origins of the enantioselectivity.
With a newly developed SPSiOL‐base bisphosphite ligand (SPSiPO), Ni‐catalyzed asymmetric hydrosilylation of 1,1‐disubstituted allenes was realized for the first time, delivering the enantioenriched allylsilanes bearing a tertiary carbon stereocenter in high efficiency and 100 % atom‐economy with high chemo‐, regio‐ and enantioselectivities.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Spin-momentum locking is a direct consequence of bulk topological order and provides a basic concept to control a carrier's spin and charge flow for new exotic phenomena in condensed matter physics. ...However, up to date the research on spin-momentum locking solely focuses on its in-plane transport properties. Here, we report an emerging out-of-plane radiation feature of spin-momentum locking in a non-Hermitian topological photonic system and demonstrate a high performance topological vortex laser based on it. We find that the gain saturation effect lifts the degeneracy of the paired counterpropagating spin-momentum-locked edge modes enabling lasing from a single topological edge mode. The near-field spin and orbital angular momentum of the topological edge mode lasing has a one-to-one far-field radiation correspondence. The methodology of probing the near-field topology feature by far-field lasing emission can be used to study other exotic phenomena. The device can lead to applications in superresolution imaging, optical tweezers, free-space optical sensing, and communication.
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CMK, CTK, FMFMET, IJS, NUK, PNG, UL, UM
Organic hierarchical branch micro/nanostructures constituted by single crystals with inherent multichannel characteristics exhibit superior potential in regulating photon transmission for photonic ...circuits. However, organic branch micro/nanostructures with precise branch positions are extremely difficult to achieve due to the randomness of the nucleation process. Herein, by taking advantage of the dislocation stress field–impurity interaction that solute molecules deposit preferentially along the dislocation line, twinning deformation was introduced into microcrystals to induce oriented nucleation sites, and ultimately organic branch microstructures with controllable branch sites were fabricated. The growth mechanism of these controllable single crystals with an angle of 140° between trunk and branch is attributed to the low lattice mismatching ratio (η) of 4.8%. These as-prepared hierarchical branch single crystals with asymmetrical optical waveguide characteristics have been demonstrated as an optical logic gate with multiple input/out channels, which provides a route to command the nucleation sites and offers potential applications in the organic optoelectronics at the micro/nanoscale.
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IJS, KILJ, NUK, PNG, UL, UM
Herein, we have employed linear-response time dependent density functional theory (LR-TDDFT)-based nonadiabatic dynamics simulations to investigate the ultrafast charge transfer in a nonfullerene ...all-small-molecule donor-acceptor (D-A) system formed by a porphyrin small-molecule donor ZnP and a recently developed nonfullerene small-molecule acceptor 6TIC, during which the optimally tuned range-separated hybrid (OT-RSH) functional was adopted. In combination with static electronic structure calculations, several important conclusions were drawn. Firstly, the ZnP and 6TIC are more likely combined together non-covalently in parallel rather than in perpendicular to form ZnP-6TIC due to the much larger adsorption energies,
i.e.
−44.6 kcal mol
−1
vs.
−25.2 kcal mol
−1
. Secondly, the excited state properties obtained by OT-RSH functionals seem more consistent with the experimental results compared to their untuned versions. Specifically, the energy of the lowest charge transfer (CT) state was predicted to be smaller than the lowest lying local excitation (LE) states using the OT-RSH functional-based LR-TDDFT calculations, which is beneficial for the charge transfer process that might be crucial for the high power conversion efficiency (PCE) achieved experimentally. In contrast, the untuned RS functionals all predict higher CT state energies, which is contradictory to the high PCE obtained in the experiment. Moreover, strong hybridization upon excitation between these states was revealed, which might be one of the reasons responsible for the high PCE observed in the experiment. Finally, ultrafast excited state relaxation can be completed within 500 fs due to the small energy gaps and the strong nonadiabatic couplings between these states, which is accompanied by ultrafast photoinduced electron transfer from ZnP to 6TIC and photoinduced hole transfer the other way around. The efficient charge transfer processes and the involvement of two charge generation channels might be another cause resulting in the excellent photovoltaic performance of ZnP-6TIC based OSCs. Our present work not only provides solid evidence for elucidating the underlying mechanism observed in previous experiments, but also suggests that the combination of OT-RSH functionals and LR-TDDFT-based nonadiabatic dynamics simulations might be a powerful tool for investigating the excited state dynamics of organic D-A systems, which is crucial for the theoretical design of novel OSCs with better performances in the future.
The combination of nonadiabatic dynamics simulation and optimally tuned range-separated functional might be a powerful tool for elucidating the ultrafast charge transfer in nonfullerene all-small-molecule organic solar cells.
The hot deformation behavior and microstructure evolution of a recently developed 2Cr12Ni4Mo3VNbN martensitic stainless steel are examined through hot compression tests conducted within the ...temperature range of 900–1200 °C and the strain rate range of 0.01–10 s−1. The constitutive equation and processing maps corresponding to hot deformation are established. The activation energy for hot deformation of 2Cr12Ni4Mo3VNbN steel is determined to be ≈457491.77 J mol−1. Simultaneously, the microstructure evolution during hot deformation is studied. Based on the processing maps and microstructure evolution analysis, it is concluded that the optimal windows for hot processing are within the temperature range of 1106–1150 °C and the strain rate range of 0.01–2.7 s−1, as well as at 1200 °C within the strain rate range of 1–2.7 s−1, exhibiting a power dissipation efficiency of 0.32. As the temperature increases and the strain rate decreases, the degree of dynamic recrystallization escalates.
2Cr12Ni4Mo3VNbN steel is a newly developed martensitic stainless steel used for last‐stage large blades of steam turbine. Herein, the hot deformation behavior and microstructure evolution of 2Cr12Ni4Mo3VNbN steel are investigated for the first time. Constitutive equations and hot‐processing maps of 2Cr12Ni4Mo3VNbN steel are established. Combined processing maps and microstructure evolution, the optimum windows of hot processing are obtained.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Water transport is vital for the durability of ultra-high performance concrete (UHPC) in engineering, but its absorption behavior requires further comprehension. This study investigates the impact of ...silica fume (SF) and metakaolin (MK) on water absorption in UHPC matrix with a high volume of limestone powder (LS) under two curing temperatures, and the variation in water transport with pore size obtained by low field nuclear magnetic resonance (LF-NMR). Relations between cumulative water absorption with other properties were discussed, and the pore size distribution (PSD) measured by Mercury intrusion porosimetry (MIP) was compared with that determined by LF-NMR. Results showed that MK outperformed SF in reducing water absorption in UHPC matrix, containing 30% LS under steam curing due to the synergistic effect between MK and LS. The incorporation of LS greatly affected the water absorption process of UHPC matrix. In samples without LS, capillary and gel pores absorbed water rapidly within the first 6 h and slowly from 6 h to 48 h simultaneously. However, in samples with 30% LS, gel pore water decreased during water absorption process due to the coarsening of gel pores. MK was able to suppress gel pore deterioration caused by the addition of a large amount of LS. Compared with PSD measured by MIP, NMR performed better in detecting micropores (<10 nm).
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Our study was performed to elucidate how SOCS‐1/3 silencing suppresses renal interstitial fibrosis (RIF) by alleviating renal tubular damage in rat models affected by hydronephrosis. Male Wistar rats ...were randomly selected to establish hydronephrosis rat model, after which all rats were classified into normal, model, negative control (NC), siRNA‐SOCS‐1, siRNA‐SOCS‐3, and siRNA‐SOCS‐1 + siRNA‐SOCS‐3 groups. The levels of urine protein, serum creatinine (Scr), and blood urea nitrogen (BUN) were detected. ELISA was performed to determine levels of cystatin (CysC), β2‐microglobulin (β2‐MG), interleukin (IL)‐6, and tumor necrosis factor (TNF)‐α. RT‐qPCR and Western blotting were used for mRNA and protein expressions of SOCS‐1, SOCS‐3, α‐smooth muscle actin (α‐SMA), and transforming Growth Factor (TGF)‐β1. Compared with the normal group, the levels of Scr, BUN, urine protein, NAG, CysC, β2‐MG, IL‐6, and TNF‐α were increased in other groups, as well as elevated mRNA and protein expressions of SOCS‐1, SOCS‐3, α‐SMA, and TGF‐β1. The siRNA‐SOCS‐1, siRNA‐SOCS‐3, and siRNA‐SOCS‐1 + siRNA‐SOCS‐3 groups were found with decreased levels of Scr, BUN, urine protein, NAG, CysC, β2‐MG, IL‐6, and TNF‐α, as well as mRNA and protein expressions of SOCS‐1, SOCS‐3, α‐SMA, and TGF‐β1, including positive rates of SOCS‐1 and SOCS‐3 proteins in comparison with the model and NC groups. In comparison with the siRNA‐SOCS‐1 and siRNA‐SOCS‐3 groups, the siRNA‐SOCS‐1 + siRNA‐SOCS‐3 group exhibited decreased levels of Scr, BUN, urine protein, NAG, CysC, β2‐MG, IL‐6, and TNF‐α. Our study demonstrated that silencing of SOCS‐1/3 may suppress RIF by alleviating the renal tubular damage in rat models affected by hydronephrosis.
Our study demonstrated that silencing of SOCS‐1/3 may suppress RIF by alleviating the renal tubular damage in rat models affected by hydronephrosis.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
As one of the main gynecological cancers, ovarian cancer (OC) has an unfavourable outcomes owing to its high recurrence and metastasis rate. Our previous studies have revealed that LINC01296 ...functions as an oncogene in OC, but the underlying mechanism has not been explored. The aim of this paper was to further investigate that how LINC01296 plays a role in OC. Through online software prediction, miR-29c-3p has been discriminated as the target miRNA of LINC01296 for further research, and subsequent luciferase assay confirmed bioinformatics prediction. Then the data obtained from the two databases (GSE119055 and GSE83693) were analyzed by GEO2R for differential gene analysis. The results indicated that the miR-29c-3p was lowly expressed in OC tissues than that in normal ovarian tissues, and its expression in recurrent OC tissues was lower than that in primary OC tissues. Simultaneously, Kaplan-Meier survival analysis illustrated that the lower expression of miR-29c-3p was interrelated to unfavourable outcomes of OC. Further, the qRT-PCR data revealed that the miR-29c-3p expression in OC cell lines (SKOV-3 and OVCAR-3) was markedly declined than that in normal control cells (IOSE80). Subsequently, the functional experiments, such as CCK8, colony formation and Transwell assays, prompted that inhibition of miR-29c-3p can obviously increase the proliferation, invasion and migration of OVCAR3 and SKOV3 cells compared with control group, while downregulation of LINC01296 showed an opposite result. It is worth noting that downregulation of LINC01296 can reverse the effect of miR-29c-3p suppression on OC cells. Finally, we detected the changes of EMT-related proteins by western blot experiment, and reached a similar conclusion that knockdown of LINC01296 reversed the EMT caused by miR-29c-3p inhibition. In sum up, the cancer-promoting function of LINC01296 was achieved by regulating the expression of miR-29c-3p, and LINC01296/miR-29c-3p axis mediates the mechanical regulation of EMT in OC cells, hoping to provide the novel biomarkers and possibilities for OC therapy.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
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