Composite Foams of the Graphitic Carbon Nitride@Carbon Nanofibrils Conferred a Superamphiphilic Property and Reinforced Thermal Stability.

Herein, we demonstrated the preparation of novel three-dimensional (3D) superamphiphilic g-CN@carbon nanofibers foam (g-CN@CNFs) via a two-step approach: liquid nitrogen treatment-freeze-drying; the foams possessed good thermal stability. In this approach, melamine acted as a nitrogen source, and nanofibrillated cellulose (NFCs) functioned as a 3D skeleton. The thermal stability of the as-prepared g-CN@CNFs-3 foam was much higher than that of g-CN@CNFs-1, as indicated by thermogravimetric data, including an increase of the onset weight loss point () by 238.

Screen time among school-aged children of aged 6-14: a systematic review.

Background: Screen time refers to the time an individual spends using electronic or digital media devices such as televisions, smart phones, tablets or computers. The purpose of this study was to conduct systematic review to analyze the relevant studies on the length and use of screen time of school-aged children, in order to provide scientific basis for designing screen time interventions and perfecting the screen use guidelines for school-aged children.

Methods: Screen time related studies were searched on PubMed, EMBASE, Clinical Trials, Controlled Trials, The WHO International Clinical Trials Registry Platform, the Cochrane Central Register of Controlled Trials, CNKI, and Whipple Journal databases from January 1, 2016 to October 31, 2021.

Giant photon momentum locked THz emission in a centrosymmetric Dirac semimetal.

Strong second-order optical nonlinearities often require broken material centrosymmetry, thereby limiting the type and quality of materials used for nonlinear optical devices. Here, we report a giant and highly tunable terahertz (THz) emission from thin polycrystalline films of the centrosymmetric Dirac semimetal PtSe. Our PtSe THz emission is turned on at oblique incidence and locked to the photon momentum of the incident pump beam.

Magnetically tunable dual-band terahertz absorption based on guided-mode resonance.

We propose a magnetically tunable dual-band terahertz (THz) absorber by using an InAs substrate with a subwavelength zero-contrast germanium grating. The results demonstrate that the absorption peaks in this absorber can be dynamically tuned by changing the intensity and the rotation angle of the applied transverse magnetic field, which is achievable at a moderate order of magnitude of 0.1 Tesla.

Terahertz wave emission from the trigonal layered PtBi.

In this work, broadband terahertz (THz) wave emissions have been detected from the trigonal layered PtBi on the excitation of the femtosecond laser pulses. Such THz generation is found to arise from the dominated linear photogalvanic effect, which is further discovered to strongly depend on the unique electronic structures of PtBi. Furthermore, an effective nonlinear susceptibility of PtBi is also obtained and is nearly two orders of magnitude larger than that of the traditional nonlinear crystal for THz generation.

Tuning of Optical Behavior in Monolayer and Bilayer Molybdenum Disulfide Using Hydrostatic Pressure.

Researchers have shown great interest in two-dimensional crystals recently, because of their thickness-dependent electronic and optical properties. We have investigated the Raman and photoluminescence spectra of free-standing monolayer and bilayer MoS, as a function of pressure. As the enforcement of layer interaction, an electronic and a crystal phase transition were revealed at ∼6 GPa and ∼16 GPa, respectively, in bilayer MoS, while no phase transition in the monolayer is observed.

Comprehensively Analyzed Macrophage-Regulated Genes Indicate That PSMA2 Promotes Colorectal Cancer Progression.

Colorectal cancer (CRC) is the third most common cancer worldwide. Here, we identified tumor-associated macrophages (TAMs) as regulators of genes in CRC. In total, the expressions of 457 genes were dysregulated after TAM coculture; specifically, 344 genes were up-regulated, and 113 genes were down-regulated.

The loss of ZnO as the support for metal catalysts by H reduction.

The reduction of ZnO in a ZnO-supported catalyst to metallic zinc, the alloying of metallic zinc with a second metal and the evaporation of zinc species in a reductive atmosphere of hydrogen was investigated in this study. The results show that the reduction temperature was the determining factor for the transformation of zinc species. The complete removal of ZnO in a ZnO-supported catalyst can be achieved at 700 °C.

Poly(vinylidene chloride)-based carbon with ultrahigh microporosity and outstanding performance for CH4 and H2 storage and CO2 capture.

Poly(vinylidene chloride)-based carbon (PC) with ultrahigh microporisity was prepared by simple carbonization and KOH activation, exhibiting great potential to be superior CO2, CH4, and H2 adsorbent at high pressures. The CO2 uptake for pristine PC is highly up to 3.97 mmol/g at 25 °C and 1 bar while the activated PC exhibits a slightly lower uptake at 1 bar.