Hunting for sterile neutrino with collider signatures

We study the feasibility to observe sterile neutrino at the high energy colliders, using direct production channels $e^+e^-\to\bar{\nu}_e N,\ e^-\gamma \to NW^-$ and indirect production channels through heavy meson/baryon and Higgs decay. We thus cover a mass window that is between what can be studied in heavy hadron factories and high energy colliders. For $e^+e^-\to\bar{\nu}_e N$ channel, the sensitivity of active-sterile mixing $|U_{eN}|^2$ in the lower mass end (0.3$\sim 2$ GeV) could be $10^{-6}$ at the SuperKEKB under its operation with designed luminosity, the sensitivity for hundreds GeV region can be further extended to $10^{-7}$ at the CEPC and the ILC. We also explore the heavy sterile neutrino production through $e^-\gamma \to NW^-$ channel at the ep collider, the mixing $|U_{eN}|^2$ is estimated to reach a sensitivity of $10^{-4}$ at the LHeC if $m_N$ to be electroweak energy mass scale, which can shed light on sterile neutrino searching at this mass region. For heavy hadron decay, the lepton-number-violating process in $|\Delta L|=2$ decays of $\Lambda_c, \Xi_{c}, \Xi_{cc}$ and $\Lambda_b$ are explored via an intermediate on-shell Majorana neutrino in GeV scale. The branching fractions and the lower-limit on $|U_{\ell N}|^2$ versus $m_N$ are given. The $Higgs \to W\mu\mu\pi$ channel is also considered, which is sensitive at lower mass scale.Comment: 28 pages, 13 figure

Research and development talents training in China universities - based on the consideration of education management cost planning

Research and development (R&D) talents training are asymmetric in China universities and can be of great significance for economic and social sustainable development. For the purpose of making an in-depth analysis in the education management costs for R&D talents training, the belief rule-based (BRB) expert system with data increment and parameter learning is developed to achieve education management cost prediction for the first time. In empirical analysis, based on the BRB expert system, the past investments and future planning of education management costs are analyzed using real education management data from 2001 to 2019 in 31 Chinese provinces. Results show that: (1) the existing education management cost investments have a significant regional difference; (2) the BRB expert system has excellent accuracy over some existing cost-prediction models; and (3) without changing the current education management policy and education cost input scheme, the regional differences in China’s education management cost input always exist. In addition to the results, the present study is helpful for providing model supports and policy references for decision makers in making well-grounded plans of R&D talents training at universitie

Experimental research on dynamic characteristics of gas bearing-rotor with different radial clearances

The test rig of gas bearing-rotor system was established. The rotor was composed of turbine, compressor and four disks, it was supported by hydrostatic gas bearings. With this test rig, the dynamics of rotor bearing system with different bearing radial clearances were researched. Rotating speed of shaft could be higher with large bearing clearance, but speed soaring and low frequency oscillation occurred were dangerous to the shaft; with small bearing clearance, the speed soaring and low frequency oscillation could be eliminated and the dynamic characteristic was good, but rubbing deceleration was more likely to happen. Make a contrast of the dynamics with different radial clearances, it could be found that the dynamic characteristic of small radial clearance was good, but the threshold of safe amplitude was small, which limited the maximum speed

Experimental research on instability fault of high-speed aerostatic bearing-rotor system

The experimental research on high-speed aerostatic bearing-rotor system with one compressor, one turbine and coaxial four discs was developed. The gas bearing-rotor system stability under different bearing supply pressure plans was studied by experiments. The paper also presents fault features of gas film whip instability, power frequency rubbing and low frequency rubbing, which provides experimental data for gas bearing-rotor system stability study

Sensor Nodes Deployment Strategy for Monitoring Roadside Biomass Carbon Stocks of Tourism Destination: A Case of Wulong World Natural Heritage, China

Since the late 1978s, China has experienced one of the highest tourism growth rates in the world, which in turn has driven extensive land-use and land-cover change. The aim of this research is to develop a sensor nodes positioning strategy for detecting land use related dynamics of vegetation carbon stocks of Wulong world natural heritage. Based on the assessment of road networks’ influences on biomass carbon stocks, roadside biomass carbon stocks risk index was proposed as a sensor deployment strategy to identify the optimal positions of the sensors to detect the changes in vegetation carbon stocks. Forest and cropland around the lower levels of roads should be the most important region of sensor nodes deployment strategy. The results generated from this study have the ability to achieve optimal solution of spatial positioning problem with minimum number of sensors in biomass carbon monitoring sensor networks. This analysis appears to have great potential for a wide range of practical applications in tourism industry in China

Differential Evolution With a New Encoding Mechanism for Optimizing Wind Farm Layout

This paper presents a differential evolution algorithm with a new encoding mechanism for efficiently solving the optimal layout of the wind farm, with the aim of maximizing the power output. In the modeling of the wind farm, the wake effects among different wind turbines are considered and the Weibull distribution is employed to estimate the wind speed distribution. In the process of evolution, a new encoding mechanism for the locations of wind turbines is designed based on the characteristics of the wind farm layout. This encoding mechanism is the first attempt to treat the location of each wind turbine as an individual. As a result, the whole population represents a layout. Compared with the traditional encoding, the advantages of this encoding mechanism are twofold: 1) the dimension of the search space is reduced to two, and 2) a crucial parameter (i.e., the population size) is eliminated. In addition, differential evolution serves as the search engine and the caching technique is adopted to enhance the computational efficiency. The comparative analysis between the proposed method and seven other state-of-the-art methods is conducted based on two wind scenarios. The experimental results indicate that the proposed method is able to obtain the best overall performance, in terms of the power output and execution time