Tin diselenide (SnSe2) nanosheets as novel 2D layered materials have excellent optical properties with many promising application prospects, such as photoelectric detectors, nonlinear optics, ...infrared photoelectric devices, and ultrafast photonics. Among them, ultrafast photonics has attracted much attention due to its enormous advantages; for instance, extremely fast pulse, strong peak power, and narrow bandwidth. In this work, SnSe2 nanosheets are fabricated by using solvothermal treatment, and the characteristics of SnSe2 are systemically investigated. In addition, the solution of SnSe2 nanosheets is successfully prepared as a fiber‐based saturable absorber by utilizing the evanescent field effect, which can bear a high pump power. 31st‐order subpicosecond harmonic mode locking is generated in an Er‐doped fiber laser, corresponding to the maximum repetition rate of 257.3 MHz and pulse duration of 887 fs. The results show that SnSe2 can be used as an excellent nonlinear photonic device in many fields, such as frequency comb, lasers, photodetectors, etc.
Tin diselenide (SnSe2) nanosheets as novel 2D layered materials have excellent optical properties. SnSe2 nanosheets fabricated by using solvothermal treatment are successfully prepared as fiber‐based saturable absorbers by utilizing the evanescent field effect, which can bear a high pump power. 31st‐order subpicosecond harmonic mode‐locking is generated, corresponding to 257.3 MHz repetition rate.
Tin diselenide (SnSe2) nanosheets as novel 2D layered materials have excellent optical properties. In article number 1902811, Xiao‐Hui Li and co‐workers characterize SnSe2 nanosheets systemically and ...successfully apply SnSe2 nanosheets in an Er‐doped fiber laser to obtain 31th order subpicosecond harmonic mode‐locking, corresponding to a 257.3‐MHz repetition rate.
Tin diselenide (SnSe
) nanosheets as novel 2D layered materials have excellent optical properties with many promising application prospects, such as photoelectric detectors, nonlinear optics, ...infrared photoelectric devices, and ultrafast photonics. Among them, ultrafast photonics has attracted much attention due to its enormous advantages; for instance, extremely fast pulse, strong peak power, and narrow bandwidth. In this work, SnSe
nanosheets are fabricated by using solvothermal treatment, and the characteristics of SnSe
are systemically investigated. In addition, the solution of SnSe
nanosheets is successfully prepared as a fiber-based saturable absorber by utilizing the evanescent field effect, which can bear a high pump power. 31st-order subpicosecond harmonic mode locking is generated in an Er-doped fiber laser, corresponding to the maximum repetition rate of 257.3 MHz and pulse duration of 887 fs. The results show that SnSe
can be used as an excellent nonlinear photonic device in many fields, such as frequency comb, lasers, photodetectors, etc.
Branched selectivity in asymmetric allylic C−H alkylation is enabled by using 2‐acylimidazoles as nucleophiles in the presence of a chiral phosphoramidite‐palladium catalyst. A wide range of terminal ...alkenes, including 1,4‐dienes and allylarenes, are nicely tolerated and provide chiral 2‐acylimidazoles in moderate to high yields and with high levels of regio‐, and enantio‐, and E/Z‐selectivities. Mechanistic studies using density‐functional theory calculations suggest a nucleophile‐coordination‐enabled inner‐sphere attack mode for the enantioselective carbon–carbon bond‐forming event.
Branching out: Palladium‐chiral phosphoramidite catalysis is used for an unprecedented branched‐selective asymmetric allylic C−H alkylation by using 2‐acylimidazoles as model coordinating nucleophiles. Density‐functional theory calculations suggest an unusual inner‐sphere mechanism for the carbon–carbon bond‐forming process.
An asymmetric allylic C–H alkylation of allyl ethers has been established by chiral phosphoramidite-palladium catalysis, affording a wide variety of functionalized chiral 2-acylimidazoles in moderate ...to high yields and with high levels of enantioselectivity. Moreover, this protocol could be applied to a concise asymmetric synthesis of a tachykinin receptor antagonist.
New drug discovery is inseparable from the discovery of drug targets, and the vast majority of the known targets are proteins. At the same time, proteins are essential structural and functional ...elements of living cells necessary for the maintenance of all forms of life. Therefore, protein functions have become the focus of many pharmacological and biological studies. Traditional experimental techniques are no longer adequate for rapidly growing annotation of protein sequences, and approaches to protein function prediction using computational methods have emerged and flourished. A significant trend has been to use machine learning to achieve this goal. In this review, approaches to protein function prediction based on the sequence, structure, protein-protein interaction (PPI) networks, and fusion of multi-information sources are discussed. The current status of research on protein function prediction using machine learning is considered, and existing challenges and prominent breakthroughs are discussed to provide ideas and methods for future studies.
•The methods for protein function prediction in the last five years are summarized.•Discussing methods apply multi-algorithm combinations to predict protein function.•Methods based on multi-information source prediction are discussed.•Difficulties are pointed out and breakthrough developments are emphasized.
In the presence of chiral phosphoramidite ligand, a palladium-catalyzed asymmetric allylic C–H alkylation of 1,4-dienes with cyclic β-keto esters has been established to afford chiral ...α,α-disubstituted β-keto esters in good to excellent yields, with high levels of regioselectivity, E/Z selectivity, and enantioselectivity. 1,4-Dienes bearing a wide scope of functional groups, such as ketone, chloride, ester, and amide as well, have been nicely tolerated. In addition, preliminary application of this method enables a concise formal synthesis of (−)-tanikolide.
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