Room temperature phosphorescence (RTP) materials with long persistent luminescence (LPL) have raised particular attention among researchers for their potential uses in chemical sensing, optical ...recording devices, biological imaging, and security systems applications, due to the long‐lived triplet states. In this study, one‐pot method of reaction of appropriate ratio of crown ether ligand (15‐Crown‐5) and metallic salts (CdX2) is utilized to yield three metal halide‐based complexes (namely 15‐5‐CdCl2, 15‐5‐CdBr2, and 15‐5‐CdI2). In solid state, three complexes exhibit nearly standard white light emission with CIE coordinates of (0.28, 0.32), (0.31, 0.39), (0.30, 0.34) at room temperature under UV radiation of 340 nm. Meanwhile, they display the excitation‐dependent room temperature phosphorescence from blue/cyan to green/yellow, especially, 15‐5‐CdCl2 and 15‐5‐CdBr2 exhibit color‐tunable and visible LPL with time‐resolved luminescence lifetime as high as 1–2 s. Single‐crystal X‐ray diffraction analysis and theoretical calculations reveal that the bright LPL of 15‐5‐CdCl2 and 15‐5‐CdBr2 arise from the crown ether ligand and aggregation state induced by halogen‐bond. The thus obtained LPL provides potentials in lighting and displaying devices, optical recording devices, security systems and so on.
A macrocyclic molecule 15‐crown‐5 with CdX2 was hydrothermally constructed into metal‐organic linker, which was built into 2D metal‐organic frameworks with metal halide chains that play an external heavy atom effect to achieve long persistent luminescence at room temperature. Near white light emission is achieved in a single component, moreover adjustable phosphorescence is realized with longest visual time of 1‐2 s at ambient conditions.
Summary
This article presents a two‐layered framework to investigate the output synchronization problem in nonhomogeneous agent systems in the presence of periodic energy‐limited denial‐of‐service ...(DoS) attacks with an event‐triggered control strategy. Under the developed framework, the proposed controller for different agents is composed of a dynamic compensator and a regulator, where the dynamic compensator on the first layer can copy the dynamics of the leader node. DoS attacks with a periodic (partially known) attack strategy are based on a time sequence and interrupt the data exchange over a shard network consisting of the leader node and dynamic compensators in the first layer. An event‐triggered control protocol is proposed to reduce the update frequency of the controller, and it also ensures that the output of every dynamic compensator can track the output of the leader node without occurring “Zeno phenomenon.” Based on the output regulator theory, the regulator for every agent can guarantee that all nonhomogeneous agents can converge to the trajectory of every dynamic compensator in the bottom layer. Finally, a simulation example is demonstrated to verify the new design method developed.
For decreasing communication load and overcoming network constrains, such as the limited bandwidth and data loss in multi-agent networks, this paper integrates the two control strategies to ...investigate the bounded consensus problem of multi-agent systems (MASs) with external disturbance on the basis of an undirected graph, namely, the quantized control and the event-triggered control. In the existence of the external disturbance, two types of the high-gain control laws with the uniform quantized relative state measurements for the bounded consensus problem of MASs are first discussed, respectively. Then, in order to save the limited network resources in a multi-agent network, the event-triggered quantized communication protocols are designed based on the first case to obtain the bounded consensus in multi-agent systems. Moreover, it is shown that "Zeno behavior" phenomenon can be excluded under the two event-triggered quantized control mechanisms, and the boundness of the relative state error can be adjusted by selecting the different parameters. Finally, two examples are shown to validate the feasibility and efficiency of our theoretical analysis.
This paper analyzes the fission information dissemination mode from the digital information media mode of the film and television media industry. Using the correlation algorithm to analyze the ...influence of TV drama ratings and broadcasting accounted for and selecting cluster analysis to explore the relationship between TV drama broadcasting and TV type and rating. Take the ratings as the dependent variable, set the independent variables, establish the multivariate statistical model, and use SPSS software to calculate factor analysis of TV drama ratings. By combining user opinions, optimize the heterogeneous graph neural network film and television communication model based on attribute information. Test the MAE value and effect of the propagation algorithm proposed in this paper using the real Movies Lens dataset. When N=5, the recall, precision and
of this paper’s algorithm are 0.295, 0.751, and 0.425, respectively. The difference of the three metrics with the resource diffusion algorithm based on the three-step graph is 0.25, 0.634, and 0.36. When N=50, the difference of the three metrics between this paper’s algorithm and the social diffusion algorithm based on labels is 0.197, 0.071, and 0.101.
Major depressive disorder (MDD) is a debilitating psychiatric illness. However, there is currently no objective laboratory-based diagnostic tests for this disorder. Although, perturbations in ...multiple neurotransmitter systems have been implicated in MDD, the biochemical changes underlying the disorder remain unclear, and a comprehensive global evaluation of neurotransmitters in MDD has not yet been performed. Here, using a GC-MS coupled with LC-MS/MS-based targeted metabolomics approach, we simultaneously quantified the levels of 19 plasma metabolites involved in GABAergic, catecholaminergic, and serotonergic neurotransmitter systems in 50 first-episode, antidepressant drug-naïve MDD subjects and 50 healthy controls to identify potential metabolite biomarkers for MDD (training set). Moreover, an independent sample cohort comprising 49 MDD patients, 30 bipolar disorder (BD) patients and 40 healthy controls (testing set) was further used to validate diagnostic generalizability and specificity of these candidate biomarkers. Among the 19 plasma neurotransmitter metabolites examined, nine were significantly changed in MDD subjects. These metabolites were mainly involved in GABAergic, catecholaminergic and serotonergic systems. The GABAergic and catecholaminergic had better diagnostic value than serotonergic pathway. A panel of four candidate plasma metabolite biomarkers (GABA, dopamine, tyramine, kynurenine) could distinguish MDD subjects from health controls with an AUC of 0.968 and 0.953 in the training and testing set, respectively. Furthermore, this panel distinguished MDD subjects from BD subjects with high accuracy. This study is the first to globally evaluate multiple neurotransmitters in MDD plasma. The altered plasma neurotransmitter metabolite profile has potential differential diagnostic value for MDD.
In this article, a distributed observer- and event-based practical consensus control for networked systems subject to adaptive nonlinear couplings is investigated. Considering that the node's state ...is not always measurable and the finite communication bandwidth exists in engineering systems, two distributed adaptive event-triggered control protocols subject to nonlinear couplings are proposed under observer-based dynamic output feedback. Then, distributed dynamic event-triggered control policies corresponding to two abovementioned adaptive controllers are proposed, respectively. The proposed nonlinear coupled event-triggered control schemes not only overcome continuous communication among nodes, but also relax the requirement of relying on global information for achieving a distributed practical consensus. Finally, the theoretical analysis is verified through a team of practical networked ground vehicles implemented through MATLAB/Simulink and robot operating systems environment.
Privacy and security are the most important issues to the popularity of cloud computing service. In recent years, there are many research schemes of cloud computing privacy protection based on access ...control, attribute-based encryption (ABE), trust and reputation, but they are scattered and lack unified logic. In this paper, we systematically review and analyze relevant research achievements. First, we discuss the architecture, concepts and several shortcomings of cloud computing, and propose a framework of privacy protection; second, we discuss and analyze basic ABE, KP-ABE (key policy attribute-based encryption), CP-ABE (ciphertext policy attribute-based encryption), access structure, revocation mechanism, multi-authority, fine-grained, trace mechanism, proxy re-encryption (PRE), hierarchical encryption, searchable encryption (SE), trust, reputation, extension of tradition access control and hierarchical key; third, we propose the research challenge and future direction of the privacy protection in the cloud computing; finally, we point out corresponding privacy protection laws to make up for the technical deficiencies.
The Illiquidity of Corporate Bonds BAO, JACK; PAN, JUN; WANG, JIANG
The Journal of finance (New York),
June 2011, Letnik:
66, Številka:
3
Journal Article
Recenzirano
Odprti dostop
This paper examines the illiquidity of corporate bonds and its asset-pricing implications. Using transactions data from 2003 to 2009, we show that the illiquidity in corporate bonds is substantial, ...significantly greater than what can be explained by bid-ask spreads. We establish a strong link between bond illiquidity and bond prices. In aggregate, changes in market-level illiquidity explain a substantial part of the time variation in yield spreads of high-rated (AAA through A) bonds, overshadowing the credit risk component. In the cross-section, the bond-level illiquidity measure explains individual bond yield spreads with large economic significance.
In this article, an adaptive nonsingular terminal sliding-mode (ANTSM) method is proposed for the motion tracking control of a bilateral teleoperation system. Efforts in this article seek to improve ...the position tracking performance of nonlinear systems subject to time-varying network delays, parametric uncertainties, and unknown external disturbances and frictions. Another issue addressed in this article is the common delay-induced phase shift of tracking profiles in many control methods, which is greatly reduced by introducing a novel mixed type of feedback signals in the ANTSM control design. Furthermore, the proposed adaptive control design with two online-estimated compensatory bounds removes the requirement of exact knowledge of network delays and disturbance bounds as a prior. In the master side, a force predictor is used to estimate the current environmental force for the reference signal generator. Therefore, the direct transmission of force signals is avoided. By comparing with the existing model-based and model-free methods, numerical simulation results with six-degree-of-freedom manipulators illustrate the merits of the developed robust and adaptive controllers. Experimental results with two Phantom Omni devices are also provided to demonstrate the effectiveness and the significant performance improvements of the proposed controllers.
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