Current Issue : April-June Volume : 2025 Issue Number : 2 Articles : 5 Articles
The emission rate of atom-like photon sources can be significantly improved by coupling them to plasmonic resonant nanostructures. These arrangements function as nanoantennas, serving the dual purpose of enhancing light–matter interactions and decoupling the emitted photons. However, there is a contradiction between the requirements for these two tasks. A small resonator volume is necessary for maximizing interaction efficiency, while a large antenna mode volume is essential to achieve high emission directivity. In this work, we analyze a hybrid structure composed of a noble metal plasmonic resonant nanoparticle coupled to the atom-like emitter, which is designed to enhance the emission rate, alongside a corner reflector aimed at optimizing the angular distribution of the emitted photons. A comprehensive numerical study of silver and gold corner reflector nanoantennas, employing the finite difference time domain method, is presented. The results demonstrate that a well-designed corner reflector can significantly enhance photon emission directivity while also substantially boosting the emission rate....
A passive flow control method inspired by blowouts was employed to eliminate flow separation and reduce the losses associated with higher compressor loads. The flow characteristics of a dimple-shaped cascade were investigated by implementing bionic blowout dimples on a blade suction surface and the loss-generation mechanism was analyzed. First, the reliability of the numerical simulation was confirmed via experimental validation. Subsequently, biomimetic principles were applied to arrange dimples on the suction surface of cascade blades, and the effects of several blowouts were analyzed. The analysis revealed that vortices within the dimples induced external fluid into the dimples, thereby increasing the turbulent kinetic energy of the external fluid and improving wall-adjacent flow adherence. The bionic-blowout variant dimples created a ‘rolling bearing’ effect that reduced frictional losses and effectively controlled flow separation. Within a certain blowout range, the bionic blowout variant dimples significantly improved the flow characteristics. At a −6◦ angle of attack, the total pressure loss of the dimple-structured cascade decreased by 35.85%, and the pressure ratio increased by 2.35%. The bionic blowout-variant dimples on the blade suction surface exhibited a three-dimensional disturbance effect. The induced vortex structures regulated the boundary layer transition and suppressed the formation of laminar separation bubbles, thereby enhancing the flow conditions near the corner region....
Escherichia coli (E. coli) detection suffers from slow analysis time and high costs, along with the need for specificity. While state-of-the-art electrochemical biosensors are cost-efficient and easy to implement, their sensitivity and analysis time still require improvement. In this work, we present a paper-based electrochemical biosensor utilizing magnetic core-shell Fe2O3@CdSe/ZnS quantum dots (MQDs) to achieve fast detection, low cost, and high sensitivity. Using electrochemical impedance spectroscopy (EIS) as the detection technique, the biosensor achieved a limit of detection of 2.7 × 102 CFU/mL for E. coli bacteria across a concentration range of 102–108 CFU/mL, with a relative standard deviation (RSD) of 3.5781%. From an optical perspective, as E. coli concentration increased steadily from 104 to 107 CFU/mL, quantum dot fluorescence showed over 60% lifetime quenching. This hybrid biosensor thus provides rapid, highly sensitive E. coli detection with a fast analysis time of 30 min. This study, which combines the detection advantages of electrochemical and optical biosensor systems in a graphite-based paper sensor for the first time, has the potential to meet the needs of point-of-care applications. It is thought that future studies that will aim to examine the performance of the production-optimized, portable, graphite-based sensor system on real food samples, environmental samples, and especially medical clinical samples will be promising....
In our previous author’s works such properties of the phantom step as its length and curvature relative to the imaginary plane were considered. All these parameters were considered within clearly defined coordinates associated with the beginning and end of the step. Analytical and graphical models were obtained in this work, which are based on mathematical approaches to determining the spatiotemporal characteristics of the movement of objects taking into account the characteristics of phantom chains of bionic systems. Therefore, the application of the obtained models provides prospects for obtaining precise parameters of the movement of the final real technological object in the working space when performing complex kinematics of movements. At the same time, the dependences of the relationship between the volumes of technological abstract and their formed phantoms were investigated, which provide the opportunity to describe positive and negative technologies that are currently promising in modern production and the realities of the application of bionic automated equipment for various purposes. The results of our research can be used as a basis for obtaining new analytical models that determine the motion characteristics of dynamic abstract objects depending on the scope of application. This has the ultimate goal of being able to determine different types of motion of bionic objects, which is associated with automated systems in industry, medicine, implementation of technological processes, and scientific research. The prospects for further scientific research on this problem regarding the development of bionic automated systems, devices and objects are to continue the creation of analytical models of these objects with a view to their application in various areas and at different stages of the life cycle of technological objects, which improves production processes, as well as complex bionic systems for medical purposes....
With the acceleration of the world population growth, soil pollution is increasing, and the demand for food is increasing. It is urgent for modern agriculture to seek an accurate, efficient and environmental protection technology to improve plant growth. At present, agricultural fertilizers and plant growth regulators are still the main application methods. Compared with traditional methods, nanotechnology is expected to be more efficient, economical, and environmental friendly. Among them, nano selenium, graphene oxide, nano-TiO2 and carbon nanotubes have been widely used. Arabidopsis thaliana is considered to be one of the ideal materials for studying plant genetic engineering and crop genetic improvement because of its simple gene structure, short growth cycle and large seed quantity. Therefore, based on the biological characteristics and application value of Arabidopsis, this paper explores the growth promoting effect, stress resistance and mechanism of different nanomaterials on Arabidopsis, aiming to provide a theoretical basis for the application and promotion of plant growth of nanomaterials, and promote the application and development of nanotechnology in the agricultural field....
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