Study on Non-Limited Earth Pressures of Soilbag-Reinforced Retaining Structures with Surcharge Loads.

The earth pressure acting on soilbag-reinforced retaining structures subjected to surcharge loads under non-limited states is crucial for designing these structures. In this study, mode tests on soilbag-reinforced retaining walls were conducted to the earth pressure of the wall subjected to surcharge loads. The findings from these tests reveal a non-linear distribution of lateral earth pressure on the wall when subjected to surcharge loads in non-limited states, with an observed escalation in pressure corresponding to increased surcharge loads. Insights from the tests facilitated the development of a predictive method for estimating lateral pressure on soilbag-reinforced retaining walls under similar conditions, and its performance was fully validated by the model tests. Furthermore, the impact of the geometric dimensions and material properties of the soilbags on the earth pressure distribution was examined using the proposed method.

Efficient green upconversion luminescence in highly crystallized ultratransparent nano-glass ceramics containing isotropic KY3F10 nanocrystals.

Yb3+/Er3+ co-doped nano-glass ceramics (GCs) containing isotropic KY3F10 nanocrystals (NCs) are obtained from a simple ternary oxyfluoride glass by controlled crystallization. The nano-GCs thus obtained, albeit having very large crystallinity of ∼35%, are ultratransparent in the whole visible-light wavelength region of 300-700 nm. Remarkably enhanced green upconversion luminescence (UCL) of Er3+ (by 55 times) is observed in the nano-GCs as compared to the precursor glass. Absolute quantum efficiency of the green UCL reaches as high as 0.41±0.02% in the GCs under 10 W/cm2 power density. The UCL efficiency is comparable to that of the famous ZBLAN: Yb3+/Er3+ glass and GCs containing ß-NaYF4:Yb3+/Er3+ NCs, and nearly twice as large as that of GCs containing KYF4:Yb3+/Er3+ NCs under the same excitation conditions.

Full-color emissive carbon-dots targeting cell walls of onion for in situ imaging of heavy metal pollution.

Plant cell walls (CWs) with complex macromolecular structures can surround and protect cells from a variety of harsh environmental conditions such as pathogens, herbivores, and trace metals. Here, a novel strategy for in situ imaging of plant cell walls was developed to evaluate heavy metal pollution via thiolated full-color emissive carbon-dots (F-CDs) targeting Pb(ii)-adsorbed onion cell walls. The thiolated F-CDs with excellent optical properties from red light to blue light were synthesized through a facile electrochemical approach using new precursors of luminol and l-tryptophan and further modified with l-cysteine. Based on a strong covalent interaction of Pb(ii) and thiolated F-CDs, we achieved in situ fluorescence imaging for the Pb(ii) adsorbed on CWs, which showed enhanced red, blue and green multi-color fluorescence (FL) on CWs with increased Pb(ii)-ion content. In contrast, multi-color fluorescence on cytoplasm diminished, attributed to F-CDs targeting and accumulating on the cytoskeleton which thus limited F-CD diffusion into protoplasm. Therefore, in situ fluorescent images for CWs can demonstrate heavy metal contamination degrees in plant cells. This facile and undamaging protocol will be beneficial for investigating heavy metal migration into the protoplast and fast evaluation of food quality and safety.

Facile preparation of full-color emissive carbon dots and their applications in imaging of the adhesion of erythrocytes to endothelial cells.

Full-color emissive CDs (F-CDs) are synthesized by a green method, which avoids toxic reagents, harsh reaction conditions and multistep processes. The water-soluble, 6 ± 1 nm uniform-sized F-CDs exhibit tunable multicolor emission in gradient colors from blue to red. The emission wavelength and intensity of the fluorescence and the wavelength of the absorption peak can be tuned by controlling the concentration of the F-CD aqueous dispersions. The remarkable low cytotoxicity, good photostability and successful application in imaging of the adhesion of erythrocytes to endothelial cells demonstrate the great applicability of the F-CDs as multiplexed bioimaging reagents. The present research not only offers a facile, green, one-pot method for the preparation of F-CDs, but also presents a novel, experimentally convenient research mode for studying cellular functions and provides useful enlightenment for enlarging the application fields of CDs.