Purpose To investigate the influence of vehicle operation speed, curve geometry parameters and rail profile on wheel–rail creepage in high-speed railway curves propose a multi-parameter coordinated optimization strategy to reduce contact fatigue damage. Design/methodology/approach Taking small-radius as research object, field measurements were conducted obtain track profiles. A coupled vehicle-track dynamics model was established. Multiple numerical experiments designed using Latin Hypercube...

Purpose The purpose of this paper is to compare the combustion characteristics, including pressure, heat release rate (HRR), coefficient variation (COV) indicated mean effective pressure (IMEP), flame development period and duration, aviation kerosene fuel, namely, rocket propellant 3 (RP-3), gasoline on a two-stoke spark ignition engine. Design/methodology/approach This an experimental investigation using bench test reflect performance two-stroke unmanned aerial vehicle (UAV) engine RP-3...

Purpose The purpose of this paper is to investigate the knock combustion characteristics, including pressure, heat release rate (HRR) and intensity aviation kerosene fuel, that is, Rocket Propellant 3 (RP-3), on a port-injected two-stoke spark ignition (SI) engine. Design/methodology/approach Experimental investigation using bench test statistical analysis data reflect characteristics two-stroke SI unmanned aerial vehicle (UAV) engine RP-3 fuel. Findings Under full load condition 4,000 rpm,...

A doubly salient brushless high voltage DC power system, that is composed of a 12/8 pole exciting-magnetic (EMDS) generator and diode bridge rectifier, was developed. The performance, including no-load characteristic, regulating characteristic efficiency, are tested analyzed in 30 kW prototype generator. test results show the proposed EMDS offers advantage efficiency over wide range, automatic regulator based on nonlinear PI combined with bang-bang control designed. digital implemented DSP...

Advanced drug carriers for the controlled release of chemotherapeutics in treatment malignant tumors have drawn significant notice recent years. In current study, microspheres (MPs) loaded with docetaxel (DTX) were prepared using polylactic-co-glycolic acid copolymer (PLGA). The double emulsion solvent evaporation method is simple to perform, and results high encapsulation efficiency. Electron micrographs MPs showed that controlling shear rate can effectively control size MPs. At present,...

Purpose The purpose of this paper is to summarize the status and characteristics rail technology high-speed railway in China, point out development direction railway. Design/methodology/approach This study reviews evolution standards comparing their chemical composition, mechanical attributes geometric specifications with EN standards. It delves into production technology, shifts key performance indicators quality rails. analysis further examines interplay between wheels rails,...

Ag-doped BaTiO3 nanocomposite films have been synthesized on MgO substrates by excimer laser deposition. X-ray diffraction was used to characterize the structure and crystallinity of films. The Ag chemical band concentrations in composite were determined photoelectron spectroscopy. optical absorption measured range 300 800 nm peaks due surface plasmon resonance particles observed. z-scan results showed that exhibited large nonlinearities signs nonlinear absorption, β, refractive index, n2,...

An integrated fully differential ultra-wideband CMOS receiver for 3.1–4.8 GHz MB-OFDM systems is presented. A gain controllable low noise amplifier and a merged quadrature mixer are as the RF front-end. Five order Gm-C type pass filters VGAs also both I Q IF paths in receiver. The ESD protected chip fabricated Jazz 0.18 μm process achieves maximum total voltage of 65 dB, an AGC range 45 dB with about 6 dB/step, averaged figure 6.4 to 8.8 over 3 bands in-band IIP3 −5.1 dBm. occupies 2.3 mm2...

As a typical rapid-development seaport area in coastal cities, such as Caofeidian, the study on spatiotemporal changes of urban land use and its surrounding rural areas is valuable significant reference to future planning policies similar China or other countries. Based satellite images, this research processes images different years for summarizing vegetation, areas, water Caofeidian suburbs. This aims summarize experience city process sustainable development by analyzing dynamic trends...

The distribution, yield and sample information data of Pinus massoniana was obtained by document literature investigation. Based on from 12 provinces including 414 plots environment factors in China,the distribution regionalization P. predicted using Maxent spatial analysis function ArcGIS. results showed that the northernmost 33.5 degrees north latitude, it mainly distributed southeast China. plant age, height, per other growth index plots, combined vegetation form data, carried out SPSS...

Abstract According to the International Drilling HSE (Health, Safety, and Environment) management standards advanced experience as well hazard techniques, CNOOC (China National Offshore Oil Corporation) constantly improves objectives of offshore drilling platforms, organizations operating specification in compliance with its particular operation development features, aim in-place effective measures. During more than 30 years' operations, has already learned summarized a set project systems,...

The deviation Maintenance is an examination activity including measurement of the trolley wire angle, height to rail, and adjust on catenary system or Overhead Contact Systems (OCS). All maintenance activities are carried out along railway lines handled directly by workers. Implementation this very rich full risks, because all work still done manually In research we will create a prototype automatic adjustment equipment using Arduino uno microcontroller some supporting sensors such as...

In this work, using the formula for hyperfine splittings, we first calculate mass of bottomonium member axial-vector multiplet (11P1). Then, masses mesons Bc1,(ss and K1B are extracted in Regge phenomenology. After that, estimate nonet mixing angle K1A - K1B. We suggest restudying h1(1380) near 1478 MeV searching Bc1(1P) 6774 MeV. The predictions may be useful discovery unobserved doubly heavy meson Bc1 understanding (11P1) mixing.

This paper designed an operational amplifier based on TSMC 0.35um CMOS process. Using folded cascode and the two class AB output structure. Hspice 2004 software for circuit simulation. Simulation results show that has high gain low static power consumption. More than 96 dB open loop gain, bandwidth up to 127 M, phase margin is 63.4 degrees, CMRR 131.5 dB, supply rejection ratio of 78 dB.

Scientific and technological innovation are inseparable from the creativity of scientific talents. As potential talents, adolescents always been concerned about their creative ability. Qualitative interview research quantitative questionnaire combined to study personality adolescents. Data was collected middle school students in Beijing. Based on whether they received a reward adolescents' science technology contest or not, data divided into two groups: high group(HCG) common group(CG)....