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The issue of intercepting maneuvering targets at a specific time with multiple constraints is of great practical significance. To solve this problem, an impact time control guidance (ITCG) laws is proposed to intercept maneuvering targets with desired constraints. First, by introducing nonlinear virtual relative model, the newly defined virtual field-of-view (FOV) angle is represented as a polynomial function in range domain. Then, the relative trajectory length is analytically derived. By leveraging optimal error dynamics technique, the proposed guidance law in nonlinear virtual relative model can be deduced, which results in the combination of proportional navigation guidance (PNG) and an augmented biased feedback term. And the overall guidance command in inertial frame has the characteristic of terminal convergence. Furthermore, to fulfill virtual FOV limits, an auxiliary function is added into the biased term. Through the quantitative relation of realistic and virtual FOVs, missile’s FOV range analysis and constraint are realized. The characteristics of proposed guidance law is theoretically analyzed and extensive simulations are conducted to validate the guidance performance. Comparison studies indicate the advantages of proposed guidance law compared to preceding relevant work.

In this paper, a sliding-mode disturbance observer (SMDO)-based finite-time control scheme is proposed for a quadrotor under uncertainties and external disturbances. The SMDO is used to estimate and compensate the unknown time-varying disturbance with minor chattering and rapid convergence. However, a priori bounded uncertainty may impose a priori constraint on the system state before obtaining closed-loop stability. To address this issue, an adaptive SMDO (ASMDO) with a nested adaptive structure is further introduced. As for controller design, a fast nonsingular integral terminal sliding mode controller (FNITSMC) is proposed to ensure finite-time convergence and zero tracking error for the quadrotor attitude control. Finally, effectiveness of proposed method is verified through simulations and experiments. • ASMDO with a nested adaptive law can efficiently estimate unbounded disturbance. • FNITSMC generates continuous control signals and guarantees finite-time stability. • Effectiveness of the proposed method is verified by conducting flight experiments. [ABSTRACT FROM AUTHOR]

Despite recent progress in synthesis, self-assembly, and utility of low band gap lead chalcogenide nanoparticles (NPs) due to their intriguing optoelectronic characteristics, their compositional instability in ambient condition remains a great challenge for long-term practical applications. Herein, we report a unique strategy via capitalization on a set of starlike block copolymers as nanoreactors for in situ crafting of uniform lead chalcogenide NPs with readily tailored sizes, surface chemistry, near-infrared (NIR) optoelectronic properties, and more importantly, markedly enhanced stability against air exposure. The intimate and permanent tethering of the outer blocks of starlike block copolymers on the surface of lead chalcogenide NPs imparts their effective dispersion in both the solution and dry state. The diameter of the resulting NPs can be conveniently tuned by regulating the molecular weight (i.e., length) of the inner hydrophilic blocks of starlike block copolymers, manifesting the progressive red shift in the NIR absorption and emission as the diameter of the NPs increases. Most intriguingly, judiciously alternating the compositions and chain lengths of the outer blocks of the starlike block copolymers renders remarkably improved stability of lead chalcogenide NPs in ambient condition, representing no spectral change in both position and intensity for 30 days as compared to rapid and complete quenching of emission in 1 day in conventional small-molecular-ligand-capped counterparts. In principle, our starlike block copolymer nanoreactor strategy can be easily extended to synthesize functional NPs other than metal chalcogenides for investigation into their dimension-dependent physical properties and self-assembly as well as various applications.

Targeted delivery of molecular cargos to specific organelles is of paramount importance for developing precise and effective therapeutics and imaging probes. This work describes a disulfide-based delivery method in which mixed-charged nanoparticles traveling through the endolysosomal tract deliver noncovalently bound dye molecules selectively into mitochondria. This system comprises three elements: (1) The nanoparticles deliver their payloads by a kiss-and-go mechanism — that is, they drop off their dye cargos proximate to mitochondria but do not localize therein; (2) the dye molecules are by themselves nonspecific to any cellular structures but become so with the help of mixed-charge nanocarriers; and (3) the dye is engineered in such a way as to remain in mitochondria for a long time, up to days, allowing for observing dynamic remodeling of mitochondrial networks and long-term tracking of mitochondria even in dividing cells. The selectivity of delivery and long-lasting staining derive from the ability to engineer charge-imbalanced, mixed [+/−] on-particle monolayers and from the structural features of the cargo. Regarding the former, the balance of [+] and [−] ligands can be adjusted to limit cytotoxicity and control the number of dye molecules adsorbed onto the particles’ surfaces. Regarding the latter, comparative studies with multiple dye derivatives we synthesized rationalize the importance of polar groups, long alkyl chains, and disulfide moieties in the assembly of fluorescent nanoconstructs and long-lasting staining of mitochondria. Overall, this strategy could be useful for delivering hydrophilic and/or anionic small-molecule drugs difficult to target to mitochondria by classical approaches.

The rise in wearable electronics has witnessed the advancement of self-healable wires, which are capable of recovering mechanical and electrical properties upon structural damage. However, their highly fluctuating electrical resistances in the range of hundreds to thousands of ohms under dynamic conditions such as bending, pressing, stretching and tremoring may seriously degrade the precision and continuity of the resulting electronic devices, thus severely hindering their wearable applications. Here, we report a new family of self-healable wires with high strengths and stable electrical conductivities under dynamic conditions, inspired by mechanical–electrical coupling of the myelinated axon in nature. Our self-healable wire based on mechanical–electrical coupling between the structural and conductive components has significantly improved the electrical stability under dynamic scenarios, enabling precise monitoring of human health status and daily activities, even in the case of limb tremors from simulated Parkinson's disease. Our mechanical–electrical coupling strategy opens a new avenue for the development of dynamically stable electrodes and devices toward real-world wearable applications.Self-healable wires with high strength and stable electrical conductivity under dynamic conditions have been developed based on a novel mechanical-electrical coupling effect, which show great potential for practical applications in highly dynamic scenarios.

The CRISPR/Cas9 system has been extensively used to engineer genetic loci for the generation of knockouts, insertions, and point mutations in animal models. However, many mutations that have been reported in animals are small insertions or deletions. This study used the CRISPR/Cas9 system to induce large DNA fragment deletions in MSTN viathree guide RNAs in sheep. This successfully achieved the precise gene editing of the ovine MSTNgene by injecting both Cas9 mRNA and sgRNAs into embryos at the one-cell stage. Of 10 edited animals, 3 animals (30%) exhibited large genomic fragment deletions (~5 kb). Furthermore, the body weights of these 3 animals were significantly different (P0>0.0001, P15=0.001, P30=0.005, P60=0.027) between lambs with large deletions and wildtype lambs. In addition, the edited lambs were also significantly different (P0>0.0001, P15>0.0001, P30=0.002, P60=0.011) compared with wildtype. These results suggest that the generated MSTNknockout sheep is a reliable and effective animal model for further study. Furthermore, this method is time- and labor-saving, and efficient for the creation of animal models for agriculture, biology, and medicine.

Powdery mildew (PM) is one of the most destructive diseases that threaten cucumber production globally. Efficient breeding of novel PM-resistant cultivars will require a robust understanding of the molecular mechanisms of cucumber resistance against PM. Using a genome-wide association study, we detected a locus significantly correlated with PM resistance in cucumber stem, pm-s5.1. A 1449-bp insertion in the CsMLO8coding region at the pm-s5.1locus resulted in enhanced stem PM resistance. Knockout mutants of CsMLO8and CsMLO11generated by CRISPR/Cas9 both showed improved PM resistance in the stem, hypocotyl, and leaves, and the double mutant mlo8mlo11displayed even stronger resistance. We found that reactive oxygen species (ROS) accumulation was higher in the stem of these mutants. Protein interaction assays suggested that CsMLO8 and CsMLO11 could physically interact with CsRbohD and CsCRK2, respectively. Further, we showed that CsMLO8 and CsCRK2 competitively interact with the C-terminus of CsRbohD to affect CsCRK2-CsRbohD module-mediated ROS production during PM defense. These findings provide new insights into the understanding of CsMLO proteins during PM defense responses.

The pursuit of ordered two-dimensional (2D) materials with customized properties has fueled extensive research. While many established fabrication methods rely on substrates, solution-based polymer self-assembly processes remain much unexplored. Here, by manipulating the delicate balance between dominating and competing forces, we demonstrate how polymer chains fold, self-adjust, and self-assemble into diverse ordered 2D nanostructures in solution guided by an energy landscape, especially highly ordered crystalline structures, which are of great challenge to realize by polymers. An alternating copolymer initially self-assembled into 2D planar flakes via a kinetic pathway, lacking crystallinity. Through thermal annealing, they overcame a local kinetic barrier, in situ transforming into 2D circular crystalline clusters. Furthermore, by facilely replacing alkenyl linkers with triazoles in the alternating copolymers, additional tunable competing interactions were introduced, enabling the system to take thermodynamically favored pathways from the beginning and form 2D crystalline spindles directly. Besides, both the systems exhibited reversible self-assembly behavior and remote-controllable merit under light irradiation, forming 2D crystalline structures including flowers and spindles, respectively, highlighting the systems’ responsiveness and versatility. This study offers diverse and facile strategies for constructing and fine-tuning tailorable nanostructures, suggesting promising applications in precision engineering and biomedical technologies.

We leveraged the potential of high χ-low Nblock copolymer (BCP), namely, poly[2-(perfluorobutyl) ethyl methacrylate]-block-poly(2-vinylpyridine) (P2PFBEMA-b-P2VP), and demonstrated its utility in next-generation nanomanufacturing. By combining molecular dynamics simulations with experiments, the χ value was calculated to be as high as 0.4 (at 150 °C), surpassing similar structures. Highly ordered features suitable for application were observed, ranging in periods from 19.0 nm down to 12.1 nm, with feature sizes as small as 6 nm. Transmission electron microscopy images of the BCP solutions indicated that preformed micelles in the solution facilitated the self-assembly process of the thin film. In addition, the vertical or parallel orientation of the cylindrical structure was determined by manipulating the solvent, substrate, and annealing conditions. Finally, guided by a wide topographical template, nearly defect-free directed self-assembly (DSA) lines with a resolution of 8 nm were achieved, highlighting its potential practical application in DSA lithography technology.

Porous and flexible actuating materials are important for the development of smart systems. We report here a facile method to prepare scalable, flexible actuating porous membranes based on a poly(ionic liquid)-modified tissue paper. The targeted membrane property profile was based on synergy of the gradient porous structure of a poly(ionic liquid) network and flexibility of a tissue paper. The gradient porous structure was built through an ammonia-triggered electrostatic complexation of a poly(ionic liquid) with poly(acrylic acid), which were previously impregnated inside the tissue paper. As a result, these porous membranes undergo deformation by bending in response to organic solvents in the vapor or liquid phase and can recover their shape in air, which demonstrates their ability to serve as solvent sensors. Besides, they show enhanced mechanical properties due to the introduction of mechanically flexible tissue paper that allows the membranes to be designed as new responsive textiles and contractile actuators.

We report the synthesis and crystal structures of four dinuclear dysprosium(III) complexes with the general formula (Dy2L2xY2) (1–4) based on the association of various flexible benzothiazolyl ligands and β-diketonate ligands [(Dy2L2xZ2) (x= 1, 3 with Z = 1,3-diphenyl-1,3-propanedionate (dphac); x= 2, 4 with Z = hexafluoroacetylacetonate (hfac)]. While these complexes share similar dinuclear cores, magnetic investigations, in line with theoretical calculations, reveal a zero-field slow relaxation of the magnetization for all complexes, albeit different relaxation dynamics. Although the Dy3+single-ion anisotropy is mainly driving the relaxation, the observed intramolecular ferromagnetic interactions shortcut the quantum tunneling of the magnetization.

With the rapid development of China's construction industry, the production of construction waste has become a growth trend.Construction of waste treatment is urgently needed in the old main building demolition materials,crushed bricks and earth accounts for more than 90%.[1]Studies show that the root cause of a large number construction waste is that the awareness of the value of construction waste recycling still unclear.

This paper gave the definition of fuzzy (completely) regular subring ,generalized fuzzy (completely) regular subring , fuzzy (completely) regular subring and some properties of them .Baesd on the idea of generalized fuzzy subring,we obtain the equivalent connection between them and discuss some algebraic properties of them .Finally,we give the properties of homomorphic image and homomorphic preimage of fuzzy (completely) regular subring

Development efforts at Oxford Superconducting Technology (OST) have recently been aimed at manufacturing long length round wires with improvement of transport properties for high field magnet applications. Recently, significant improvements in the JE and Jc performance have been achieved by optimizing the starting precursor composition, the deformation processes, and the heat treatments. The highest JE of 1580 A/mm2 (Jc of 6140 A/mm2) at 4.2 K, 0 T, JE of 420 A/mm2 at 4.2 K, 31 T and JE of 312 A/mm2 at 20 K, 2 T were obtained in 0.81 mm wire with the optimized condition. In addition, significant progress on braided insulation has been made for enabling a robust procedure for wind-and-react Bi-2212 solenoid coils. Ic and generated field have been measured in a series of such coils of increasing dimensions. In this paper the progress on the development of Bi-2212 round wires and coils will be reported.

The article reports on the impact of the arrest of Meng Wanzhou, chief financial officer of Chinese technology company Huawei. It mentions the difficulties Huawei faces in its global expansion plans, its involvement in the trade dispute with the U.S., and negotiations to resolve the issue.