Asymptotic attenuation of a class of nonlinear systems with unknown sinusoidal disturbances

In this paper,nonlinear observers are incorporated into the adaptive control to synthesize controllers for a class of uncertain nonlinear systems with unknown sinusoidal disturbances which are presented in matched and unmatched forms.In addition to magnitudes and phases,frequencies of the sinusoidal disturbances need not be known as well,so long as the overall order is known.Nonlinear observers are constructed to eliminate the effect of unknown sinusoidal disturbances to improve the steady-state output tracking performance-asymptotic output tracking is achieved.The adaptation law is used to obtain the estimate of all unknown parameters.The presented disturbance decoupling algorithms can deal with matched and unmatched unknown sinusoidal disturbances.

State-of-the-art of biomass-derived carbon dots: Preparation, properties, and applications

Carbon dots (CDs) have attracted considerable attention as a new type of fluorescent carbon nanomaterial because of their excellent optical properties, biocompatibility, and high electrical conductivity. Research on CDs has been conducted for nearly two decades and has focused on numerous precursors, various synthesis conditions and properties and applications of CDs. Biomass is critical in the green development of CDs because of its low cost, environmental friendliness, and sustainable properties. This review focuses on the advantages and applications of biomass-derived CDs. In addition, the challenges of photobleaching, toxicity, and stability of biomass-based CDs are discussed in detail. Lastly, the prospects and challenges of biomass-derived CDs are highlighted.

Multiple virus sorting based on aptamer-modified microspheres in a TSAW device

Due to the overlapping epidemiology and clinical manifestations of flaviviruses,differential diagnosis of these viral diseases is complicated,and the results are unreliable.There is perpetual demand for a simplified,sensitive,rapid and inexpensive assay with less cross-reactivity.The ability to sort distinct virus particles from a mixture of biological samples is crucial for improving the sensitivity of diagnoses.Therefore,we developed a sorting system for the subsequent differential diagnosis of dengue and tick-borne encephalitis in the early stage.We employed aptamer-modified polystyrene(PS)microspheres with different diameters to specifically capture dengue virus(DENV)and tick-borne encephalitis virus(TBEV),and utilized a traveling surface acoustic wave(TSAW)device to accomplish microsphere sorting according to particle size.The captured viruses were then characterized by laser scanning confocal microscopy(LSCM),field emission scanning electron microscopy(FE-SEM)and reverse transcription-polymerase chain reaction(RT‒PCR).The characterization results indicated that the acoustic sorting process was effective and damage-free for subsequent analysis.Furthermore,the strategy can be utilized for sample pretreatment in the differential diagnosis of viral diseases.

Potential paleoceanographic application of cold-water bamboo coral in the South China Sea

Recent deep-diving expeditions in the South China Sea(SCS)discovered abundant indigenous cold-water corals[1].Cold-water corals,preferentially inhabiting the low-latitude intermediate and deep waters with hard substrates and a cool water temperature,have great potential to be applied in researches of the ocean interior by providing high-resolution records[2,3].

A hybrid guidance law of LOS acceleration feedback for missile against maneuvering targets

A quantised backstepping robust guidance law of three-dimension(3-D)space for compound control of reaction control jets and aerodynamic surfaces is proposed to attenuate the unknown target manoeuvre in this paper.The presented guidance law guarantees that the rates of line of sight converge to a residual circle centred at the origin whose radius is depended on the target manoeuvres,quantised length and guidance law gains.The simulations are given to illustrate the effectiveness of the proposed guidance law.