On the mean value of some new sequences

The main purpose of this paper is using the elementary and analytic methods to study the mean value properties of the Smarandache repetitional sequence, and give two asymptotic formulas for it

Development And Applications Of Gold-Silica Nanohybrids For Bioanalysis

In the first project, both non-spherical and spherical silica nanomateirals with hollow interiors were synthesized by a one-step soft-templating method. By simply changing the applied solvent from ethanol to 1-propanol, or 1-pentanol, three different shapes of nanomaterials, including nanosphere, nanowire, and nanotadpole, could be obtained, respectively. The effects of other factors on morphology were also systematically studied to propose a growth mechanism. It was found that the PVP-water droplet was the crucial factor on the formation of hollow interiors. Without the addition of PVP, only solid silica nanomaterials, such as solid nanoparticles, nanorods, and nanowires, were synthesized. This developed method showed excellent reproducibility and great potential for a large-scale synthesis. In the second project, a novel nanocomposite contained a spherical gold nanoparticle core, a silica spacer and a fluorescent dye layer in the silica matrix was designed to study the metal-enhanced fluorescence phenomenon. It was found that the size of gold nanoparticles cores and the distances between cores and fluorescent dyes had significant effects on the emitted fluorescence intensity. An enhancement factor of 9.2 was obtained when the nanocomposite contained a 13.7 ± 1.3 nm gold nanoparticle core and a 36.6 ± 4.4 nm silica spacer. In the third project, an ultrasensitive protein assay was developed by using silica nanorods decorated with gold nanoparticles (AuNPs-SiNPs) as labelsin a lateral flow platform. A large number of AuNPs on one single SiNR provided visualized dark purple color that was much darker than the pure AuNPs solution. Therefore, the detection limit was lowered 50 times compared to the traditional AuNP-based lateral flow assay. Under optimal conditions, a linear range of 0.05 - 2 ng/mL with a detection limit of 0.01 ng/mL was obtained. The lateral flow bioassay based on these composite nanomaterials thus offered an ultrasensitive method for rapid detection of trace amount of proteins and has a potential application for point-of-care screening in clinical diagnostics and biomedical research. In the fourth project, a new hyperthermia agent, Au-silica nanowire nanohybrid (Au-SiNW nanohybrid)was synthesized and applied in the photothermal therapy. Due to its strong NIR absorption ability, the Au-SiNW nanohybrid can generate significant amount of heat upon NIR irradiation and induced thermal cell death. By incubating the nanohybrids with cancer cells and irradiating with NIR laser, cancer cells were successfully killed, indicating their potential as promising hyperthermia agents

Characteristics of Supraglacial Channels and Drainage Networks on Antarctic Ice Shelves

Supraglacial channels that flow on ice shelves can store and transport large volumes of meltwater to various locations (e.g., moulins, lakes, crevasses) during the melt season, so they play an important role in glacial hydrology and ice shelf stability. However, the current understanding of supraglacial channels is limited, especially the underlying processes and the controls on their development and variability. This study uses multiple remotely sensed data including satellite imagery and Digital Elevation Models (DEMs) to measure supraglacial channels in Antarctica. Five contrasting ice shelves around the margin of the Antarctic Ice Sheet are chosen as the study sites – Bach, Nansen, Nivlisen, Riiser-Larsen and Roi Baudouin ice shelves. Supraglacial lakes and channels are mapped by automatic delineation method during the melt season in 2020 and 2022, and key fluvial metrics are calculated, e.g., number, length, width, depth, sinuosity, bifurcation ratio, orientation, slopes and drainage density. Extensive supraglacial lakes and channels were observed on all five Antarctic ice shelves during the peak of the melt season and most were interconnected to form a total of 119 channel networks at different scales. The results demonstrate that: (ⅰ) supraglacial channel networks often occurred in areas with low elevations and near grounding lines, (ⅱ) supraglacial channel networks on different ice shelves exhibited different drainage patterns and hydromorphic characteristics, (ⅲ) the surface topography and structural glaciology of ice shelves affected the distribution of the supraglacial channel network. Future work could focus on long-term observation of supraglacial channels and exploring the applicability of terrestrial river-related research methods (e.g., hydrological modelling) to supraglacial channels

Equilibrium Phase Behavior and Maximally Random Jammed State of Truncated Tetrahedra

Systems of hard nonspherical particles exhibit a variety of stable phases with different degrees of translational and orientational order, including isotropic liquid, solid crystal, rotator and a variety of liquid crystal phases. In this paper, we employ a Monte Carlo implementation of the adaptive-shrinking-cell (ASC) numerical scheme and free-energy calculations to ascertain with high precision the equilibrium phase behavior of systems of congruent Archimedean truncated tetrahedra over the entire range of possible densities up to the maximal nearly space-filling density. In particular, we find that the system undergoes two first-order phase transitions as the density increases: first a liquid-solid transition and then a solid-solid transition. The isotropic liquid phase coexists with the Conway-Torquato (CT) crystal phase at intermediate densities. At higher densities, we find that the CT phase undergoes another first-order phase transition to one associated with the densest-known crystal. We find no evidence for stable rotator (or plastic) or nematic phases. We also generate the maximally random jammed (MRJ) packings of truncated tetrahedra, which may be regarded to be the glassy end state of a rapid compression of the liquid. We find that such MRJ packings are hyperuniform with an average packing fraction of 0.770, which is considerably larger than the corresponding value for identical spheres (about 0.64). We conclude with some simple observations concerning what types of phase transitions might be expected in general hard-particle systems based on the particle shape and which would be good glass formers

Concavity of the meson Regge trajectories

It is illustrated by the fitted Regge trajectories for a large majority of mesons that both the radial and orbital Regge trajectories for mesons prefer being concave. The concavity of the meson Regge trajectories is model-independent. If the convex Regge trajectories or the Regge trajectories having the inflection points do not exist, the concavity can act as a criterion to choose a newly observed meson or to assign a particle to the unwell-established state. The curvature of the meson Regge trajectories can be taken as a guide in constructing models. The appropriate models should yield the spectra which can produce the concave Regge trajectories according to the concavity of the meson Regge trajectories. If the large majority of the meson Regge trajectories are concave while a few meson Regge trajectories are convex which neither have been confirmed nor have been completely excluded at present, many existing models should be corrected or even be reconstructed, which will lead to the further understanding of the meson dynamics.Comment: 12 pages, 2 figures, 3 tables. Matches the published version in PL