Atomic decoration for improving the efficiency of field electron emission of carbon nanotubes

The field electron emission from the single-walled carbon nanotubes with their open ends terminated by -BH, -NH, and -O has been simulated. The apex-vacuum barrier and the emission current have been calculated. It has been found that -BH and -NH suppress the apex-vacuum barrier significantly and lead to higher emission current in contrast to the -O terminated structure in the same applied field. The calculated binding energy implies that the carbon nanotubes terminated with -BH and -NH are more stable than those saturated by oxygen atoms or by hydrogen atoms.Comment: 8 pages, 9 figures, LaTeX; content changed, typos corrected, references adde

Quantum Computing for MIMO Beam Selection Problem: Model and Optical Experimental Solution

Massive multiple-input multiple-output (MIMO) has gained widespread popularity in recent years due to its ability to increase data rates, improve signal quality, and provide better coverage in challenging environments. In this paper, we investigate the MIMO beam selection (MBS) problem, which is proven to be NP-hard and computationally intractable. To deal with this problem, quantum computing that can provide faster and more efficient solutions to large-scale combinatorial optimization is considered. MBS is formulated in a quadratic unbounded binary optimization form and solved with Coherent Ising Machine (CIM) physical machine. We compare the performance of our solution with two classic heuristics, simulated annealing and Tabu search. The results demonstrate an average performance improvement by a factor of 261.23 and 20.6, respectively, which shows that CIM-based solution performs significantly better in terms of selecting the optimal subset of beams. This work shows great promise for practical 5G operation and promotes the application of quantum computing in solving computationally hard problems in communication.Comment: Accepted by IEEE Globecom 202

A brief exploration of the physical properties of single living cells under dynamic loading conditions

Introduction:Single living cells exhibit both active biological functions and material-like mechanical behaviors. While extensive research has focused on static or quasi-static loading, the purely mechanical properties under high-rate impact remain underexplored. Investigating cell responses to dynamic loading can isolate rapid deformation characteristics, potentially clarifying how life activities modulate mechanical behavior.Methods:We developed a custom dynamic loading system to expose single adherent macrophage cells to transient compression–shear stresses in a controlled fluid environment. A Polymethyl Methacrylate chamber housed the cells, and impact pressures (156.48–3603.85 kPa) were measured in real time using a high-frequency sensor. High-speed imaging (up to 2×105 fps) captured cellular area changes, providing insight into global deformation. In total, 198 valid experiments were performed, and statistical tests confirmed that initial perimeter and area followed normal-like distributions suitable for theoretical analysis.Results:Cells demonstrated a two-stage expansion under shock loading. At lower pressures, cytoplasmic regions rapidly spread into the focal plane, producing significant increases in projected area. As pressure rose further, deformation rate decreased, reflecting the constraining influence of the nucleus. By analyzing the final-to-initial area ratios across various pressures and initial cell sizes, we derived an incomplete state equation akin to Tait-like or Birch–Murnaghan models, indicating an inflection point of maximum deformation rate.Discussion:These findings highlight that fast impact loading effectively minimizes confounding biological processes, revealing intrinsic mechanical responses. The proposed state equation captures cell behavior within milliseconds, offering a path to integrate dynamic results with slower, life-activity-driven adaptations, and laying groundwork for more comprehensive biomechanical models of living cells

Parsimonious monthly rainfall-runoff models for humid basins with different input requirements

The availability of data is a major problem for the widespread application of rainfall-runoff models. In order to assist the practicing hydrologists in the selection of suitable models, four levels of monthly water balance models are developed requiring different sets of input data. Essentially four types of models are considered according to the inputs necessary, which are respectively: precipitation and potential evapotranspiration; precipitation, temperature and humidity; precipitation and temperature; precipitation alone. The outputs from the models are monthly river flow and other water balance components. The models are examined on 91 small and medium sized basins, of which 85 are situated in Belgium and 6 in southern China, and they are capable of reproducing both the magnitude and timing of monthly and seasonal runoff, as well as changes in soil moisture conditions. Results are satisfactory and there are barely any differences between the model types, although the amount of information used is very different. Calibration is by automatic optimization without any subjective element. Application in forecasting and Monte Carlo simulation are exemplified. © 1995.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Sensitivity of monthly rainfall-runoff models to input errors and data length

Two problems are addressed which arise when using monthly water balance models as an aid to making decisions in water resources engineering: what is the influence of data errors on model performance, and what is the data length required in order to obtain reliable models? Two previously defined types of models are used: in PE type models the input series are precipitation and potential evapotranspiration; in P type models the only input is precipitation. The main conclusions are: (1) random errors in precipitation data, when great enough, affect model performance significantly; (2) systematic errors in precipitation data are less important for the estimation of river flow; and (3) a data length of 10 years is necessary and sufficient for a reliable calibration of monthly water balance models of humid basins. © 1994 Taylor and Francis Group, LLC.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Precipitation Pattern in the Western Himalayas revealed by Four Datasets

Abstract. Data scarcity is the biggest problem for scientific research related to hydrology and climate studies in the great Himalayas Region. High quality precipitation data are among the most difficult to obtain due to sparse network, cold climate and high heterogeneity in topography. This paper examines four different types of datasets, including interpolated gridded data based on ground observations (IMD, 1° × 1° and APHRODITE, 0.25° × 0.25°), reanalysis data (ERA-interim, 0.75° × 0.75°) and high resolution simulation by a regional climate model (WRF, 0.15° × 0.15°). In Northern India of the Western Himalayas, the four datasets show a similar spatial pattern and temporal variation during the period 1981–2007, though the absolute values vary significantly (497–819 mm/year) mainly due to the data source and the methods of data generation. The differences are particularly large in July and August at the windward slopes and the high elevation area. All the datasets show a wetter summer and drier winter during the period, though most of the trends in monthly precipitation are not significant. The comparison between two periods of 1981–1985 and 2003–2007 shows an increase in summer and a decrease in winter with large variations. Between the periods, the runoff is expected to increase which is likely to result in more and bigger floods in the downstream areas according to the IMD, APHRODITE and WRF datasets, whereas the ERA-interim dataset reveals a tendency toward longer low flow periods and more droughts. All the datasets can give a good overview of the precipitation, but because of coarse spatial resolution and small size of basins in this area, future work such as local correction is necessary for hydro-glacial modelling. </jats:p