Phosphorus‐substituted heterocycles represent an important class of organophosphorus compounds, which not only widely exist in biologically active pharmaceuticals, agrochemicals, but also have ...widespread applications in material science and organic synthesis as ligands for transition metal complexes. The synthesis of such compounds integrates the development of new synthetic methods and exploration of efficient catalytic systems, reflects the latest achievements in organic, transition metal, photo and even electrochemical catalysis, and facilitates the synthesis of sufficient quantities of related compounds as potential medicinal agents and biological probes in this area. Over the past few decades, two major synthetic strategies have been established toward phosphorus‐substituted heterocycles. This review summarizes the recent progress in this field and discusses the reaction mechanisms in detail. The advantages and limitations of each subdivisional tactic are presented, and the synthetic opportunities still open are outlined.
The Artificial Intelligence of Things (AIoT) connects everything with intelligence, while the increase in energy consumption generated by numerous electronic devices puts forward an impending demand ...on the power supply. Energy harvesting technology has emerged as a compelling innovation technology for the net zero emissions of the power supply for the AIoT. Although significant advances have been witnessed in energy harvesting, some issues such as poor electrical output, weak environmental adaptability, and low reliability are difficult to satisfactorily resolve. Mechanical intelligent energy harvesting can be defined as the system identifying the external excitation or its own state and reacting to it, rather than relying on electrical sensing elements or a central controller for certain adaptive or programmed functions. The adaptive and programmed functions exhibit great potential in solving the above‐mentioned issues that seriously restrict the development of the energy harvesting technology. Here, a generalized definition of mechanical intelligent energy harvesting is given critically and the design methodology is elaborated. The typical reported energy harvesting systems with the characteristics of mechanical intelligence are reviewed. The key research directions in mechanical intelligent energy harvesting are discussed. The mechanical intelligence is expected to revolutionize the development of the energy‐harvesting technology and pave the way for applications.
Mechanical intelligent energy harvesting (MIEH) can be defined as the system identifying excitation or its own state and reacting to it, rather than relying on electrical sensing elements or central controllers for certain adaptive or programmed functions. This review proposes a generalized definition and methodology of MIEH for the first time, reviewing state‐of‐the‐art research, and discussing directions for future developments.
To solve the financial risk problem of enterprise financing difficulties and large financing amounts in the era of big data, this paper constructs a financial risk assessment model and evaluates the ...indexes of enterprise financial risk by combining it with cloud accounting products. Firstly, we assign and determine the weights, use the evidence theory to develop the enterprise financial risk evaluation, and determine the weights of each risk evaluation index. Secondly, we set up a fuzzy evaluation language set, calculate the maximum value of the fuzzy rubric affiliation function for the risk indicators of state-owned enterprises under cloud accounting, pre-process the obtained data, determine the specific indicator weights with the help of fuzzy hierarchical analysis, and carry out consistency tests on them. Finally, the relative importance of each indicator is calculated among the model factors to obtain the overall risk score of cloud accounting enterprise finance. The experimental results show that the risk level measured according to the steps of the cloud accounting risk assessment system, the data confidentiality risk score is 76.14, the cloud accounting product risk is 85.96, the service risk is 72.88, and only one item is higher risk. This shows that the use of cloud accounting financial risk control measures can improve the quality of financial risk management of enterprises.
The application of semi‐quantum conception can provide unconditional secure communication for communicators without quantum capabilities. A semi‐quantum key distribution (SQKD) protocol based on ...four‐particle cluster states is put forward, which can achieve key distribution among one quantum party and two classical parties simultaneously. Furthermore, this protocol can be expanded to the χ‐party (χ>3) communication scheme. Compared with the existing multi‐party SQKD protocol, the proposed protocol and the extended one own more excellent time efficiency and qubit efficiency. The security of the proposed SQKD protocol under ideal circumstances is validated while the key rate under non‐ideal conditions is calculated.
The proposed semi‐quantum key distribution protocol with four‐particle cluster states can achieve key distribution among one quantum party and two classical parties simultaneously, which can be expanded to more than two classical communication parties. The proposed protocol owns great time efficiency and qubit efficiency, whose security under ideal circumstances and key rate under non‐ideal conditions are analyzed.
The construction of tetrasubstituted carbon centers (especially chiral ones) represents one of the most challenging and demanding topics in the synthesis of natural products and related drugs. The ...development of isoindolinones with this feature appears to be of great importance, because 3,3‐disubstituted isoindolinones, which feature all kinds of tetrasubstituted carbon centers, also including spirocyclic and all‐carbon or heteroatom‐containing centers, show a wide spectrum of biological and pharmaceutical activities. Therefore, the synthetic methodologies for preparing these skeletons have received significant attention during the past decade. In general, these strategies can be classified into two major categories, namely the direct functionalization of parent isoindolinones and lactam‐ring‐formation‐involved reactions, depending on whether there is a lactam‐ring‐formation process or not during the production of the final 3,3‐disubstituted isoindolinone. Since the second strategy has been well reviewed, this review mainly summarizes the recent progress in the direct functionalization of parent isoindolinones to construct 3,3‐disubstituted isoindolinones via three subdivided strategies.
An emerging paradigm proposes a crucial role for lung resident mesenchymal stem cells (LR-MSCs) via a fibroblastic transdifferentiation event in the pathogenesis of idiopathic pulmonary fibrosis ...(IPF). Aberrant activation of Wnt/β-catenin signaling occurs in virtually all fibrotic lung diseases and is relevant to the differentiation of mesenchymal stem cells (MSCs). In vitro, by measuring the protein levels of several key components involved in Wnt/β-catenin signaling, we confirmed that this signaling pathway was activated in the myofibroblast differentiation of LR-MSCs. Targeted inhibition of Wnt/β-catenin signaling by a small molecule, ICG-001, dose-dependently impeded the proliferation and transforming growth factor-β1 (TGF-β1)-mediated fibrogenic actions of LR-MSCs. In vivo, ICG-001 exerted its lung protective effects after bleomycin treatment through blocking mesenchymal-myofibroblast transition, repressing matrix gene expression, and reducing cell apoptosis. Moreover, delayed administration of ICG-001 attenuated bleomycin-induced lung fibrosis, which may present a promising therapeutic strategy for intervention of IPF. Interestingly, these antifibrotic actions of ICG-001 are operated by a mechanism independent of any disruption of Smad activation. In conclusion, our study demonstrated that Wnt/β-catenin signaling may be an essential mechanism underlying the regulation of myofibroblast differentiation of LR-MSCs and their further participation in the development of pulmonary fibrosis.
Repetitive control (RC), which can achieve zero steady-state error tracking of any periodic signal with known integer period, offers active power filters (APFs) a promising accurate current control ...scheme to compensate the harmonic distortion caused by nonlinear loads. However, classical RC cannot exactly compensate periodic signals of variable frequency and would lead to significant performance degradation of APFs. In this paper, a fractional-order RC (FORC) strategy at a fixed sampling rate is proposed to deal with any periodic signal of variable frequency, where a Lagrange-interpolation-based fractional delay (FD) filter is used to approximate the factional delay items. The synthesis and analysis of FORC systems are also presented. The proposed FORC offers fast online tuning of the FD and the fast update of the coefficients, and then provides APFs with a simple but very accurate real-time frequency-adaptive control solution to the elimination of harmonic distortions under grid frequency variations. A case study on a single-phase shunt APF is conducted. Experimental results are provided to demonstrate the validity of the proposed FORC.
•A magnetically coupled two-degree-of-freedom harvester for rotation is proposed.•The electromechanical coupling model is developed and validated experimentally.•The harvester can generate high ...voltage at low rotating speeds.•The harvester can harvest vibration energy in multiple frequency bands.
Energy can be harvested from rotational motion for powering wireless autonomous electronic devices. The paper presents a magnetically coupled two-degree-of-freedom vibration energy harvester for rotary motion applications. The design consists of two inverted piezoelectric cantilever beams whose free ends point to the rotating shaft. The centrifugal force of the inverted cantilever beam is beneficial to producing large amplitude in a low speed range. The electromechanical coupling dynamical model is developed by the energy method from Hamilton’s principle and validated experimentally. The experimental results indicate that the presented harvester is suitable for low speed rotation and can harvest vibration energy in multiple frequency bands. The first and second resonant behaviors of voltage can be obtained at 420 r/min and 550 r/min, and the average output powers are 564μW and 535.3μW, respectively.
The stability of the grid-connected inverters adopted in distributed energy resources (DERs) highly depends on the characteristics of the grid impedance. Hence, various active damping methods and ...adaptive control algorithms have been proposed for the control of the grid inverters. Differently from those existing solutions, this paper proposes to use a smart transformer (ST) to shape the grid impedance to interact with the controllers of local inverters, aiming at improving the stability of the local controllers as well as the overall grid. A main advantage of this solution is that it offers a pervasive service to all the available DERs, reducing the cost and design effort of the local controllers. Three active damping methods are presented in this paper and the implementation issues in the ST LV-side voltage controller are given. Moreover, the design criteria of the active damping methods considering the control performance of ST and the stability requirements of local DERs are presented. Analysis and experiments are carried out to verify the effectiveness of the proposed solution.
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