Preparation of N-doped carbon dots based on starch and their application in white LED

N-doped carbon dots (CDs) were synthesized simply and economically by a one-step hydrothermal method using starch as a carbon source and ethylenediamine (EDA) as a nitrogen dopant. The prepared CDs possess the properties of excitation-wavelength dependence and emit blue fluorescence under the excitation wavelength of 365 nm. CDs/starch composite was prepared to achieve the solid-state emission of CDs and their application in light emitting diode (LED) as fluorescent materials. White LED, with CIE coordinates of (0.33, 0.37) and correlated color temperature of 5462 K, was obtained by combining CDs/starch and ultraviolet LED light source, indicating that starch-based CDs have the promising potential in the field of optoelectronic devicesPeer reviewe

Facilitating dynamic web service composition with fine-granularity context management

Context is an important factor for the success of dynamic service composition. Although many contextbased AI or workflow approaches have been proposed to support dynamic service composition, there is still an unaddressed issue of the support of fine-granularity context management. In this paper, we propose a granularity-based context model together with an approach to supporting the intelligent context-aware service composing problem. The corresponding case study is provided to show the validity of our approach.<br /

Numerical analysis of vibration-isolating effect of vibration-isolating slot under buried pipe subjected to millisecond blasting

Research on vibration-isolating effects of vibration-isolating slot on buried pipe can be done by numerical method, without being disturbed by external environmental factors. It has measured data without relatively high experiment cost and analyzed the influence of some key parameters according to the results of numerical simulation. The results show that the vibration speed of the pipeline with vibration-isolating slot tends to have a larger decrease than those without vibration-isolating slot. What’s more, the homogeneous explosive charge is discrepant in different working conditions, but the vibration-isolating ratio is similar in the vibration-isolating slot with same structure parameter. The millisecond blasting is hardly affected by total explosive charge. But the blasting seismic intensity is influenced by explosive charge in each stage directly

Experimental and numerical simulation study of perforation effect of steel pipes subject to the impact loadings of ASC and LSC jets

The perforation effect of steel pipes subjected to the circular-shaped charge (ASC) and linear-shaped charge (LSC) jet were studied by experimental research, and the explicit nonlinear dynamic finite element computer code LS-DYNA was adapted to study the nonlinear responses of the steel pipes, which subjected to the impact of the two different jets, using Lagrangian-Eulerian coupling method. The deformation process and the stress of the steel pipes were described and analyzed, and the simulation results are in good agreement with the experiment data. The studies indicated that under the impact of ASC jet, the steel pipe got a circular incision and a deformation process of local perforation, flocculent shear lip forming and axial shock. Under the impact of LSC jet, the steel pipe got a ship-type incision and a deformation process of coupling of local perforation and dent, whole bending and radial shock. The formation of flocculent shear lip attributes to the radial stress concentration. Under the impact of LSC jet, the whole bending leads to the axial stretch and tearing of the cut tip, and there is a bigger radial plastic deformation area than the damage effect for the impact of ASC jet

Multi-Level Data-Driven Battery Management: From Internal Sensing to Big Data Utilization

Battery management system (BMS) is essential for the safety and longevity of lithium-ion battery (LIB) utilization. With the rapid development of new sensing techniques, artificial intelligence and the availability of huge amounts of battery operational data, data-driven battery management has attracted ever-widening attention as a promising solution. This review article overviews the recent progress and future trend of data-driven battery management from a multi-level perspective. The widely-explored data-driven methods relying on routine measurements of current, voltage, and surface temperature are reviewed first. Within a deeper understanding and at the microscopic level, emerging management strategies with multi-dimensional battery data assisted by new sensing techniques have been reviewed. Enabled by the fast growth of big data technologies and platforms, the efficient use of battery big data for enhanced battery management is further overviewed. This belongs to the upper and the macroscopic level of the data-driven BMS framework. With this endeavor, we aim to motivate new insights into the future development of next-generation data-driven battery management

NFC Secure Payment and Verification Scheme with CS E-Ticket

As one of the most important techniques in IoT, NFC (Near Field Communication) is more interesting than ever. NFC is a short-range, high-frequency communication technology well suited for electronic tickets, micropayment, and access control function, which is widely used in the financial industry, traffic transport, road ban control, and other fields. However, NFC is becoming increasingly popular in the relevant field, but its secure problems, such as man-in-the-middle-attack and brute force attack, have hindered its further development. To address the security problems and specific application scenarios, we propose a NFC mobile electronic ticket secure payment and verification scheme in the paper. The proposed scheme uses a CS E-Ticket and offline session key generation and distribution technology to prevent major attacks and increase the security of NFC. As a result, the proposed scheme can not only be a good alternative to mobile e-ticket system but also be used in many NFC fields. Furthermore, compared with other existing schemes, the proposed scheme provides a higher security

The following performance between particle and fluid medium inside hydrocyclone with double vortex finders

In this paper, we used numerical simulations to study the effect of size, density and concentration of particles on the relative motion between two phases in a cyclone separator with double vortex finders, which is different than a traditional separator that has only one overflow pipe