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The presence of stable U(V)-containing compounds is important for the study of radionuclides. However, pentavalent uranium is prone to disproportionation, thus U(V)-containing compounds are generally sensitive to air and water. Herein, a stable mixed-valent uranium (U(V)/U(VI))-based metal–organic framework was synthesized via an in situ hydrothermal method, which features a three-dimensional structure with 3-fold interpenetration. Moreover, it can be used as a dual-responsive fluorescence temperature sensor based on the fluorescence intensity and fluorescence lifetime in the cryogenic range of 77–197 K. The fluorescence enhancement at low temperature (77 K) is about 25 times higher that at room temperature, which is unparalleled in common fluorescent materials. The mechanism can be interpreted as the decrease of nonradiative decay with decreasing temperature. Overall, this finding is beneficial to further our understanding of actinides in this oxidation state and disclose their potential applications.

Uranium is one of the principal raw materials in the nuclear industry, but if released into the natural environment, it also poses latent health risks to mankind. Therefore, there is an urgent need to develop a strategy that can concurrently detect and adsorb uranium to realize the sustainable development of nuclear power and protect the environment. In this work, a fluorescent zinc-based metal-organic framework (HNU-50) was designed and synthesized for the effective detection and extraction of U(VI). The amide groups on N-pyridin-4-ylpyridine-4-carboxamide ligands and two uncoordinated carboxyl oxygen atoms on pyromellitic acid ligands in HNU-50 provide potential uranium-binding sites. Consequently, HNU-50 is competent of selectively and efficiently catching uranyl ions, achieving an optimum adsorption capacity of 632 mg/g. Additionally, the adsorption of U(VI) results in fluorescence quenching of HNU-50, thus allowing sensitive and selective detection of U(VI) by fluorescence change. Note that HNU-50 exhibits a considerably low detection limit of 1.2 × 10-8 M for U(VI) in aqueous solution, which is below the World Health Organization maximum pollution standards for potable water (6.3 × 10-8 M).

To tolerate the limited faults such as thrust decline or actuator jamming of launch vehicles, an adaptive fault-tolerant control method based on radial basis function neural network (RBFNN) is proposed in this paper. The method is based on a limited faults dynamics model, and the baseline controller is designed based on the pole placement, using RBFNN to online identify and compensate the fault parameters and uncertain disturbances in the model. Then an adaptive fault-tolerant control law is designed based on Lyapunov theory. The simulation results show that the proposed adaptive control method can effectively ensure the attitude stability as well as control accuracy under the limited faults of launch vehicles, compared with the traditional PD control method.

Open pNets are formal models that can express the behaviour of open systems, either synchronous, asynchronous, or heterogeneous. They are endowed with a symbolic operational semantics in terms of open automata, which allows us to check properties of such systems in a compositional manner. We present an algorithm computing these semantics, building predicates expressing the synchronisation conditions between the events of pNet sub-systems. Checking such predicates requires symbolic reasoning about first order logics and application-specific data. We use the Z3 SMT engine to check satisfiability of the predicates. We also propose and implement an optimised algorithm that performs part of the pruning on the fly, and show its correctness with respect to the original one. We illustrate the approach using two use-cases: the first one is a classical process-algebra operator for which we provide several encodings, and prove some basic properties. The second one is industry-oriented and based on the so-called “BIP architectures”, which have been used to specify the control software of a nanosatellite at the EPFL Space Engineering Center. We use pNets to encode a BIP architecture extended with explicit data, compute its semantics and discuss its properties, and then show how our algorithms scale up, using a composition of two such architectures.

Highly luminous lanthanide metal–organic gels (Ln-MOGs) can act as fluorescent probes for the detection of organic amines and can also be used to build white-light emitting materials based on the different luminescent properties of lanthanide ions. Here, we reported a Ln-MOG constructed with a 3,5-di(2′,4′-dicarboxylphenyl)benozoic acid (DPBA) ligand and Tb3+. Tb-MOG has an excellent fluorescence detection effect on organic amines including ethylenediamine, triethylamine, diisopropylamine and aniline in aqueous solution, and their detection limits reach a sub-ppm level. Considering the practicality, a Tb-MOG testing paper was prepared by a spin coating process, which can detect volatile organic amine vapors with good recyclability. Additionally, a single-phase white-light Tb0.84Eu0.16-MOG material was realized by in situ doping of Tb-MOG with Eu3+ and reasonably utilizing the blue emission of DPBA.

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Microvascular dysfunction caused by hyperglycemia leads to slow healing of diabetic wounds and significantly increases the risk of bacterial infection. The misuse of antibiotics can also lead to bacterial resistance, making the management of diabetic wounds more challenging. Thus, developing new antibacterial agents or strategies to overcome antibiotic resistance is highly pursued. Herein, novel supramolecular photothermal nanoparticles (MCC/CS NPs), assembled from mono-carboxyl corrole (MCC) and chitosan via hydrogen bonding and π-π stacking, are developed and used for treating bacterial wound infection. The MCC molecules possess good photothermal performance and the chitosan with inherent bioactivity can exert moderate antibacterial effects. The aggregation of MCC in MCC/CS NPs induced by chitosan-templated self-assembly further quenches molecular fluorescence and realizes an extraordinary photothermal conversion efficiency of 66.4%. Moreover, the highly positively charged MCC/CS NPs can selectively target bacteria via electrostatic interactions. Under near-infrared laser irradiation, the MCC/CS NPs achieve potent photothermal and inherent antimicrobial synergistic effects against Escherichia coli and methicillin-resistant Staphylococcus aureus (MRSA) in vitro. Furthermore, the bacteria-infected diabetic wound model confirms that the MCC/CS NPs can effectively kill drug-resistant bacteria, accelerate wound healing and angiogenesis, and show good biocompatibility, representing a novel and efficient photothermal antibacterial nanoplatform.

Multi-user panoramic video streaming demands 4∼6× bandwidth of a regular video with the same resolution, which poses a significant challenge on the wireless scheduling design to achieve desired performance. On the other hand, recent studies reveal that one can effectively predict the user’s Field-of-View (FoV) and thus simply deliver the corresponding portion instead of the entire scenes. Motivated by this important fact, we aim to employ autoregressive process for motion prediction and analytically characterize the user’s successful viewing probability as a function of the delivered portion. Then, we consider the problem of wireless scheduling design with the goal of maximizing application-level throughput (i.e., average rate for successfully viewing the desired content) and service regularity performance (i.e., how often each user gets successful views) subject to the minimum required service rate and wireless interference constraints. As such, we incorporate users’ successful viewing probabilities into our scheduling design and develop a scheduling algorithm that not only asymptotically achieves the optimal application-level throughput but also provides service regularity guarantees. Finally, we perform simulations to demonstrate the efficiency of our proposed algorithm using a real dataset of users’ head motion.

One important application of quantum process algebras is to formally verify quantum communication protocols. With a suitable notion of behavioural equivalence and a decision method, one can determine if an implementation of a protocol is consistent with its specification. Ground bisimulation is a convenient behavioural equivalence for quantum processes because of its associated coinduction proof technique. We exploit this technique to design and implement two on-the-fly algorithms for the strong and weak versions of ground bisimulation to check if two given processes in quantum CCS are equivalent. We then develop a tool that can verify interesting quantum protocols such as the BB84 quantum key distribution scheme.

Uranium is one of the main crude materials for nuclear reaction, but the total uranium content on land is far from meeting the long-term needs of nuclear energy for the human being. How to enrich uranium from seawater with high reserves but extremely low uranium concentration and a great quantity of competitive ions has become a key project. In this work, we report the synthesis of aminooxime functionalized ZIF-90 by grafting 4-aminobenzamidoxime, named ZIF-90-ABOA, which exhibits outstanding adsorption performance benefitting from the high chelating ability of amidoxime towards uranium. The maximum adsorption capacity of uranium is 353.4 mg g−1 from aqueous solution, which is much higher than the original ZIF-90. Additionally, the adsorption capacity can reach 2.8 mg g−1 in 7 days from natural seawater, proving the potential enrichment of uranium in real application.

The antibiotics are abused in recent years, leading to serious environment problem and health issues. Thus, selective and sensitive detection of antibiotics is a critical issue. In this work, a new metal-organic framework (HNU-52) was synthesized by solvothermal method, which can be used as the fluorescent sensor. Among five categories antibiotics, HNU-52 can effectively detect nitrofuran antibiotics with low detection limits of 9.2 × 10−7 M and 7.2 × 10−7 M for the nitrofurantoin and nitrofurazone, respectively. In addition, HNU-52 presents good selectivity, anti-interference and cyclicality for the detection of nitrofuran antibiotics. Especially, the quenching mechanism has been discussed in detail which can give a clear understanding for the following antibiotics detection.

This paper considers the problem of cooperative search for multiple stationary targets by multi-agent with limited sensing and communication capabilities. An integrated learning algorithm for cooperative search based on reinforcement learning is proposed. In particular, we consider a state containing local probability map and neighbouring agents map which provides the agent with information to plan routes and search collaboratively. In addition, a reward function consisting of target found reward, time consumption reward and guiding reward is designed to guide agents to explore and learn efficiently. To ensure the stability of training process, the policies of agents are frozen and shared periodically in a distributed training framework. The proposed method is tested under simulated scenarios compared with coverage control methods and random strategies. Multiple simulation results show considerable advantages.

Spintronic devices rely on the spin degree of freedom (DOF), and spin orbit coupling (SOC) is the key to manipulate spin DOF. Quasi-one-dimensional structures, possessing marked anisotropy gives more choice for the manipulation of the spin DOF since the concrete SOC form varies along with crystallographic directions. The anisotropy of the Dresselhaus SOC in cadmium selenide (CdSe) nanobelt and nanowire was studied by circular photogalvanic effect. It was demonstrated that the Dresselhaus SOC parameter is zero along the [0001] crystallographic direction, which suppresses the spin relaxation and increases the spin diffusion length, and thus is beneficial to the spin manipulation. To achieve a device structure with Rashba SOC presence and Dresselhaus SOC absence for manipulating the spin DOF, an ionic liquid gate was produced on a nanowire grown along the [0001] crystallographic direction, and the Rashba SOC was induced by gating, as expected.

We observed an anomalous linear photogalvanic effect (ALPGE) in undoped InGaAs/AlGaAs multiple quantum well and studied its wavelength dependence in details. This effect is believed to originate from the optical momentum alignment effect and the inhomogeneity of light intensity. We find that the spot location with the maximum ALPGE current is wavelength independent. And the normalized ALPGE current decreasing at smaller wavelengths is attributed to the sharp decrease of the momentum and energy relaxation time. The electrical measurement of the spectra dependence of ALPGE is highly sensitive proving to be an effective method for detecting the momentum anisotropy of photoinduced carriers and band coupling.

Dirac-like surface states on surfaces of topological insulators have a chiral spin structure with spin locked to momentum, which is interesting in physics and may also have important applications in spintronics. In this work, by measuring the tunable helicity-dependent photocurrent (HDP), we present an identification of the HDP from the Dirac-like surface states at room temperature. It turns out that the total HDP has two components, one from the Dirac-like surface states, and the other from the surface accumulation layer. These two components have opposite directions. The clear gate tuning of the electron density as well as the HDP signal indicates that the surface band bending and resulted surface accumulation are successfully modulated by the applied ionic liquid gate, which provides a promising way to the study of the Dirac-like surface states and also potential applications in spintronic devices.

We experimentally studied the magneto-photocurrents generated by direct interband transition in InAs/GaSb type II superlattice. By varying the magnetic field direction, we observed that an in-plane magnetic field induces a photocurrent linearly proportional to the magnetic field; however, a magnetic field tilted to the sample plane induces a photocurrent presenting quadratic magnetic field dependence. The magneto-photocurrents in both conditions are insensitive to the polarization state of the incident light. Theoretical models involving excitation, relaxation and Hall effect are utilized to explain the experimental results.

Virtual prototyping is introduced and the future development trends of Virtual Prototyping for Flight Control System are summarized. For analyzing redundancy Flight Control Computer Systems (FCCS) of Boeing, Airbus series and BUAA civil aircraft scheme, a VP testing platform for FCCS of civil aircraft is proposed. This platform is based on COTS products, modular components and user interactive interface. It can produce virtual prototypes of dissimilar redundancy FCCSs of Boeing 777, Airbus A340 and BUAA civil aircraft scheme. This platform is open and expandable, supporting concurrent multidisciplinary design.

In this letter, we investigated the spin polarized photocurrents excited by mid-infrared radiation and near-infrared radiation, respectively, in InAs/GaSb type II superlattices with different kinds of interfaces. By periodically varying the polarization state of the radiation, we analyzed Rashba-type and Dresselhaus-type spin polarized photocurrents, which present different features depending on the interface types and excitation conditions. Under mid-infrared excitation, the ratio of Rashba-type and Dresselhaus-type spin polarized photocurrents of the superlattice with InSb-like interface is obviously larger than that of the superlattice with GaAs-like interface, the ratio of the superlattice with alternate interface is in the middle. Whereas under near-infrared excitation, the ratios of the three superlattices are nearly the same. Further researches reveal the synactic effects of interface dependent strain and asymmetric interface potential on the spin splitting. Besides, the polarized Raman spectroscopies of these structures were also analyzed.

The spin polarization under low electric fields ( ≤300 V/cm) at low temperatures has been studied in undoped InGaAs/AlGaAs multiple quantum well. The spin polarization was created by optical spin orientation using circularly polarized light and the inverse spin-Hall effect was employed to measure the spin polarization current. We observed an obvious spin depolarization especially at lower temperatures (80–120 K). We ascribed the spin depolarization of the photoinduced electrons to the heating effect from the low electric fields (the low field regime 50–300 V/cm). This spin depolarization due to the heating effect is sensitive to temperature and electric field, suggesting a wide range of potential applications and devices.

We have measured the in-plane optical anisotropy (IPOA) of (110) ZnO (a-plane) on (102) sapphire (r-plane) by reflectance difference spectroscopy (RDS) at room temperature. Giant IPOA has been observed between the light polarized direction parallel and perpendicular to the c axis of ZnO, since the symmetry of a-plane is C2v. A sharp resonance has been observed near the fundamental band gap, which is induced by the polarization-depend band gap shift. The sharp line shape is attributed to the exciton transition. The spectra fitting and differential spectra indicate the polarization-depend band energies. The giant IPOA is possible enhanced by anisotropy strain along and perpendicular to the c axis in the a-plane.

The photocurrent spectra of the inter-band photoinduced anomalous Hall effect (PAHE) in insulating GaAs/AlGaAs quantum wells have been observed at room temperature. The PAHE current changes linearly with the varied longitudinal electric fields. The anomalous Hall conductivity corresponding to excitonic state 1HH-1E (the first valence subband of heavy hole to the first conduction) has the same sign with that of excitonic state 1LH-1E (the first valence subband of light hole to the first conduction), while under uniaxial strain along the ⟨110⟩ axes, they have different signs. The PAHE current of 1HH-1E decreases linearly, but that of 1LH-1E increases linearly with shear strain. The linearly dependence of the PAHE current on uniaxial strain along the ⟨110⟩ axes suggests that the dominant mechanism is intrinsic, which has not yet been confirmed in our previous work [Yu et al., Appl. Phys. Lett. 100, 142109 (2012)].

The (001)-oriented P-I-N InGaAs/GaAs quantum wells (QWs) are studied by means of helicity dependent spin photocurrent. We have observed an unexpected circular dichroism effect along [001] direction in the QWs without an applied magnetic field. The circular polarization rate can be linearly tuned by the applied DC current flowing along [001] direction, and its value is enhanced more than one order in an InGaAs/GaAs vertical-cavity surface-emitting laser with distributed Bragg reflectors than that in a common InGaAs/GaAs QWs. This experiment indicates a type of spin-splitting in (001)-grown P-I-N InGaAs/GaAs quantum wells induced by space inversion asymmetry introduced by residual strain which is previously overlooked.

The spin diffusion and drift at different excitation wavelengths and different temperatures have been studied in undoped InGaAs/AlGaAs multiple quantum well (MQW). The spin polarization was created by optical spin orientation using circularly polarized light, and the reciprocal spin Hall effect was employed to measure the spin polarization current. We measured the ratio of the spin diffusion coefficient to the mobility of spin-polarized carriers. From the wavelength dependence of the ratio, we found that the spin diffusion and drift of holes became as important as electrons in this undoped MQW, and the ratio for light holes was much smaller than that for heavy holes at room temperature. From the temperature dependence of the ratio, the correction factors for the common Einstein relationship for spin-polarized electrons and heavy holes were firstly obtained to be 93 and 286, respectively.