Owing to their almost similarities in size, shape, and chemical reactivity, effectively distinguishing deuteroxide (D 2 O) in water (H 2 O) remains an ongoing challenge, and the examples of a D 2 O probe are still quite scarce.Herein, since H 2 O can decrease the lifetime of a singlet oxygen as a vital intermediate and an H/D exchange in the luminescence process of porphyrins, we systematically investigated the enhanced ultraviolet−visible (UV−vis), photoluminescence (PL), and electrochemiluminescence (ECL) of watersoluble tetrakis(carboxphenyl)porphyrin (TCPP) in D 2 O. The findings showed that these luminescent properties had been greatly enhanced with the increase of the D 2 O fraction in water. Consequently, we first developed the highly facile methods of detecting D 2 O in H 2 O by the UV−vis, PL, and ECL of TCPP, respectively. Impressively, the ECL analysis exhibited a great superiority with a lower detection limit of 0.29 nM. The work not only achieves the challenging task of distinguishing between H 2 O and D 2 O but also provides a unique strategy to enhance the luminescent performance of porphyrin.

The apple peel (i.e., outermost tissue) plays a crucial role in protecting and preserving apple life, as well as in reducing fruit injury. Apple peels of the Danxia and Starkrimson varieties were compared for their tensile properties, shear properties, and tensile-property variations after 0, 14, and 28 days of storage at room temperature. Apple peel microstructures were observed and imaged using scanning electron microscopy. Cubic polynomials proved superior for quantifying the stress-strain non-linear relationship of peels. With increased storage period, tensile strength and fracture strain gradually decreased but elastic modulus increased. The mechanical indices of Starkrimson peels were greater than those of Danxia peels after the same storage period. Significant differences between cultivars were observed in terms of tensile strength, elastic modulus, and shear strength; significant storage differences also existed for both cultivars. Mechanical properties were closely related to peel microstructures. Strengths and weaknesses mainly depended on the number and width of microcracks on the cuticle, cuticle form, cell aspect radio, and space between cells. ARTICLE HISTORY

Abstract. Knowledge of the mechanical properties of apple peel, as the outermost tissue of the fruit, is crucial for the designing of apple harvesting machines. In this study, longitudinal and transverse tensile tests were conducted on peels from the shadow side and sunlit side of two apple cultivars (Starkrimson and Fuji) using an electronic universal testing machine, and tear tests and puncture tests were carried out on peels of both sides as well. The stress-strain curves and tear and puncture force-deformation curves of the peels were acquired and the tensile strength, elastic modulus, failure strain tear strength, puncture strength of the peels were measured. Also, scanning electron microscope images were made. The results showed that the maximum values of tensile strength, elastic modulus, fracture strain, tear strength, and puncture strength were 2.56 MPa, 24.00 MPa, 19.92%, 0.391 kN·m -1 , and 0.289 N·mm -2 , respectively. The tensile strength, elastic modulus, and puncture strength values for the Starkrimson peels were higher than those for the Fuji peels from the same side. Apple peel is an anisotropic heterogeneous material. The bearing capacity of the peel depends on the number and distribution of microcracks on the surface, and the size and shape of the epidermal cells. The organization and connections between the cells determine the strength of the connections between cells.

The atom fidelity is investigated in a system consisting of Mtwo-level atoms and M single-mode fields by use of complete quantum theory and numerical evaluation method. The influences of various system parameters on the evolution of atomic fidelity are studied. The results show that the atomic fidelity evolves in a Rabi oscillation manner. The oscillation frequency is mainly modulated by the coupling strength between atoms and light field, the atomic transition probabilities and the average photon numbers. Other factors hardly impact on the atomic fidelity. The present results may provide a useful approach to the maintenance of the atomic fidelity in the atom cavity field systems.

Using the complete quantum theory，the process of M two-level atoms interacting with M multi-mode light fields with intensity-dependent coupling is studied. It is found that quantum entanglement information can be transferred back and forth or be preserved between the cavity fields and atoms under certain time conditions. The entanglement states of the atoms or the cavities can be transferred when t=π/(2λ). The results are verified by numerically computing the entanglement degree. And it was shown that the entanglement states of the atoms or the cavities can be preserved when t=π/λ.