.Multi-gram preparation of pH-responsive DX MG colloidsomes by a scalable approach

Biodegradable pH-responsive hollow polymer particles have excellent potential for preparing high performance biomaterials. Recently, we reported that pH-responsive microgel-colloidosomes was prepared using microgel particles as the building blocks and macro-crosslinker [1]. Our method used covalent inter-linking of vinyl-functionalised microgel particles adsorbed to oil droplets to form shells of doubly crosslinked microgels (DX MGs). Unfortunately, this method is unsuitable for scale up. Here, we greatly expand and extend that work by investigating pH-responsive hollow particle systems based on poly(EA-co-MAA) (ethyl acrylate and methacrylic acid) using a scalable thermal crosslinking route (Scheme 1). The hollow polymer particles were crosslinked by covalent inter-linking of vinyl-functionalised microgel particles and gave micrometer-sized colloidosomes that were pH-responsive (Fig. 1). This is the first time we have obtained more than 1 g of pH-responsive DX MG colloidosomes. The properties of these microgel-colloidosomes dispersions imply they have good potential for future application as injectable gels for regenerative medicine. Further, the work indicates that the size of the colloidosomes can be controlled simply by preparation conditions. Please click Additional Files below to see the full abstract

Coherent FDA Receiver and Joint Range-Space-Time Processing

When a target is masked by mainlobe clutter with the same Doppler frequency, it is difficult for conventional airborne radars to determine whether a target is present in a given observation using regular space-time adaptive processing techniques. Different from phased-array and multiple-input multiple-output (MIMO) arrays, frequency diverse arrays (FDAs) employ frequency offsets across the array elements, delivering additional range-controllable degrees of freedom, potentially enabling suppression for this kind of clutter. However, the reception of coherent FDA systems employing small frequency offsets and achieving high transmit gain can be further improved. To this end, this work proposes an coherent airborne FDA radar receiver that explores the orthogonality of echo signals in the Doppler domain, allowing a joint space-time processing module to be deployed to separate the aliased returns. The resulting range-space-time adaptive processing allows for a preferable detection performance for coherent airborne FDA radars as compared to current alternative techniques.Comment: 11 pages, 9 figure

Time-Range FDA Beampattern Characteristics

Current literature show that frequency diverse arrays (FDAs) are able of producing range-angle-dependent and time-variant transmit beampatterns, but the resulting time and range dependencies and their characteristics are still not well understood. This paper examines the FDA transmission model and the model for the FDA array factor, considering their time-range relationship. We develop two novel FDA transmit beampatterns, both yielding the auto-scanning capability of the FDA transmit beams. The scan speed, scan volume, and initial mainlobe direction of the beams are also analyzed. In addition, the equivalent conditions for the FDA integral transmit beampattern and the multiple-input multiple-output (MIMO) beampattern are investigated. Various numerical simulations illustrate the auto-scanning property of the FDA beampattern and the proposed equivalent relationship with the MIMO beampattern, providing the basis for an improved understanding and design of the FDA transmit beampattern.Comment: 10 pages, 9 figure

Design of magnetic coupling of continuous wave of measurement while drilling

According to the special working environment of drilling proposed design parameters of distance sleeve; The Ansoft Maxwell software is used to optimize the magnetic coupling, and the optimized design process is illustrated with an example; The torque is studied under different rotation angles; The effects of magnetic steel thickness, magnet thickness and magnetic pole number on torque are studied respectively; With the development of the rare earth permanent magnet material, it is imperative to apply the no leakage magnetic coupling to petroleum drilling