Intelligent magnetic materials are capable of responding to environmental stimuli in an on/off manner. The photo- and thermal-responsive nanogel layer was surface-grafted onto several magnetic ...nanoparticles to prepare the magnetic imprinted nanoparticles (Fe
3
O
4
MIPs). The Fe
3
O
4
MIPs show dramatic temperature and light, dual-dependent rebinding and release characteristics for lysozyme. Above the volume phase transition temperature of the PNIPAAm, the imprinted protein (lysozyme) can be selectively separated from egg whites and the activity remained unchanged. By combining low temperature and UV irradiation, a more finely tuned release of the binding protein can be achieved. Time-dependent antibacterial activity was observed, and it was found that Fe
3
O
4
MIPs-loaded lysozyme almost completely suppressed the growth of
E. coli
with the continuous lysozyme release. More importantly, the Fe
3
O
4
MIPs could easily be separated by an external magnetic field and can be recycled. The photo- and thermal-responsive Fe
3
O
4
MIPs pave a new way for the development of an advanced, sustainable material for use in bioseparation, drug delivery, and antibacterial materials.
To solve the problem of large fluctuation and instability of photovoltaic power generation, a deep learning prediction model (TPA-TCN) based on temporal pattern attention mechanism (TPA) and temporal ...convolutional network (TCN) is proposed, and then applied to photovoltaic power generation. First of all, the k-means clustering algorithm is used to cluster historical data to obtain three typical weather types, and the model is trained by dividing test sets according to the clustering results. After TPA is introduced into the TCN model, which can capture the influence of each variable on the predicted series of the model, help the model pay better attention to the key features in the time series, improve the model’s ability to understand the data, and thus efficiently and accurately predict the short-term photovoltaic power. Combined with the measured data, the experiment results show that the TPA-TCN model has good generalization ability and high precision in different weather types.
Strong adaptive radar, such as cognitive radar (CNR), can perform various missions while ensuring its own security in electronic warfare, via detecting environments and changing the radar parameters ...in real time. Unfortunately, most of the current military countermeasures, such as jamming-based electronic countermeasures, have rarely been related to jamming for CNR. Since the behaviours of radar in the traditional design of the jammer-radar scenario are always static, it is easy to create a subjective or local optimal jamming effect. In order to dynamically analyse the execution process of a complete jamming radar mission, this work establishes an equivalent attack-defence game in which the radar is regarded as a defence decision agent, and the jammer is an attack decision agent. The attributes of the game's players, the rules of the game, and the conditions for the end of the game are set clearly by setting reasonable parameters. After searching for antagonism strategies by exhaustive method, it can be found that the survivability of the predictive cognitive jamming is much stronger than that of the normal jamming based on real-time sampling data of radars. This conclusion is demonstrated through a 1 ms simulation of the game process.
Here a dual-polarisation printed dipole antenna for spherical near-field measurements is proposed. The printed dipole employs double-layered structure to obtain low cross-polarisation and uses ...irregular patch to get wide bandwidth. Two such dipoles are cross arranged to form a dual-polarisation dipole antenna. Simulated results show that the bandwidth is over 72% when VSWR is less than 3, the cross-polarisation ratio is better than 30 dB, the port isolation between two dipoles is better than −26 dB, while good radiation performance is also obtained. All the results above prove that the crossed arrangement structure will not affect the performance of the printed dipole, and the strength of mutual coupling between probes can be neglected.
The development of intelligent polymeric materials to precisely control the catalytic sites of heterogeneous catalysts and enable highly efficient catalysis of a cascade reaction is of great ...significance. Here, the utilization of a polymer ionic liquid (PIL) containing two different anions facilitates the preparation of Ru–Pd catalysts with controllable phase transition temperatures and hydrophilic and hydrophobic surfaces. The combined multifunctionality, synergistic effects, micellar effects, aggregation effects, and temperature responsiveness of the nanocatalyst render it suitable for promoting selectively catalyzed Suzuki coupling and asymmetric transfer hydrogenation in water. Above the lower critical solution temperature (LCST) of the catalyst, it catalyzes only the coupling reaction with a high turnover number (TON) of up to 999.0. Below the LCST, the catalyst catalyzes only the asymmetric transfer hydrogenation with good catalytic activity and enantioselectivity. It is important that the catalyst can be simply and effectively recovered and recycled at least 10 times without significant loss of catalytic activity and enantioselectivity. This study also highlights the superiority of multifunctional heterogeneous catalysts based on PILs, which not only overcome limitations associated with low activity of heterogeneous catalysts but also realize selective reactions according to a temperature change, thereby improving the reactivity and enantioselectivity in multiple organic transformations.
Significant efforts have been devoted to developing immobilized chiral catalysts with high activity, selectivity, and stability. In this present study, a new heterogeneous proline catalyst system was ...prepared based on strong noncovalent interactions between polymer ionic liquid (PIL) and l-proline. First, pyridine PILs, which can complex with l-proline monomers through noncovalent interactions, were synthesized using reversible addition-fragmentation chain transfer (RAFT) polymerization. The polymer network-supported chiral catalysts were obtained following further free radical polymerization. Different structures were formed in response to different ratios of PIL and chiral monomer, as well as different PIL anions, in the reactions. The new formed layer structures and synergic effects of PIL resulted in heterogeneous catalysts with high catalytic activity and enantioselectivity, thus endowing them with better catalytic performance for the one-pot synthesis of heterocyclic compounds compared to homogeneous catalytic systems. These catalytic systems were able to be reused and recycled five times with no discernible loss in catalytic activity and enantioselectivity. l-Proline was efficiently loaded onto the polymer network simply based on supramolecular interactions, providing a novel method of synthesizing high performance supported catalysts for organic reactions.
The development of heterogeneous chiral metal catalysts which maintain efficiency and stability in the aqueous phase is significant for applications in many industries. On the basis of a series of ...polymer ionic liquids (PILs) that contain coexisting Cl– and NTf2− anions, the stable heterogeneous chiral Ru catalysts with controllable hydrophobic surface were successfully prepared. PIL-functionalized structure ensured that the catalysts could be well dispersed as micelles in a pure water medium, and enhance the adsorption of organic substrate, thereby significantly improving the reactivity in water. The catalyst successfully catalyzed the asymmetric hydrogenation transfer reaction of alkyl ketones in water with high activity and selectivity. Importantly, the catalyst can be easily and efficiently recovered and recycled at least nine times without significant loss of activity and enantioselectivity. This formation of a catalyst from PIL could provide an important approach to the design of environmentally friendly catalysts and the development of green reactions in the water.
Significant efforts have been devoted to developing immobilized chiral catalysts with high activity, selectivity, and stability. In this present study, a new heterogeneous proline catalyst system was ...prepared based on strong noncovalent interactions between polymer ionic liquid (PIL) and
l
-proline. First, pyridine PILs, which can complex with
l
-proline monomers through noncovalent interactions, were synthesized using reversible addition-fragmentation chain transfer (RAFT) polymerization. The polymer network-supported chiral catalysts were obtained following further free radical polymerization. Different structures were formed in response to different ratios of PIL and chiral monomer, as well as different PIL anions, in the reactions. The new formed layer structures and synergic effects of PIL resulted in heterogeneous catalysts with high catalytic activity and enantioselectivity, thus endowing them with better catalytic performance for the one-pot synthesis of heterocyclic compounds compared to homogeneous catalytic systems. These catalytic systems were able to be reused and recycled five times with no discernible loss in catalytic activity and enantioselectivity.
l
-Proline was efficiently loaded onto the polymer network simply based on supramolecular interactions, providing a novel method of synthesizing high performance supported catalysts for organic reactions.
Significant efforts have been devoted to developing immobilized chiral catalysts with high activity, selectivity, and stability.
Signal acquisition by GPS receiver is an important part both in navigation and positioning, thus reducing the complexities of signal acquisition and acquisition time is important. Since the grid of ...frequencies in joint code-frequency search algorithm is fixed, the amount of calculation is large in specific cases. Besides, under the condition that the receiver can obtain assistant information, the limited code-phase search algorithm has the problem of peak degradation, and the complexity is still high. Therefore, we propose an assisted GPS signal acquisition algorithm based on joint code-frequency search algorithm. The grid of frequency is modified and the code-phase search of the algorithm is realized in the time domain, the problems of the joint code-frequency search algorithm and the limited code-phase search algorithm is resolved. Simulation results show that the complexity of the proposed assisted GPS signal acquisition is reduced, moreover, the acquisition performance is improved as well.
Quadratic Lyapunov function based Algorithms (QLAs) for stochastic network optimization problems, which are cross-layer scheduling algorithms designed by Lyapunov optimization technique, have been ...widely used and studied. In this paper, we investigate the performance of using Lyapunov drift and perturbation in QLAs. By analyzing attraction points and utility performance of four variants of OQLA (Original QLA), we examine the rationality of OQLA for using the first-order part of an upper bound of Lyapunov drift of a function L_1. It is proved that either using the real Lyapunov function (L_2) of networks under QLA or using the entire expression of Lyapunov drift does not improve backlog-utility performance. The linear relationship between the attraction point of backlog and perturbation in the queue is found. Simulations verify the results above.
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