Qufu Normal University

Consensusability of multi-agent systems (MASs) is a fundamental problem in the MAS research area, since when starting to design a consensus protocol, one should know whether or not there exists such a protocol that has the ability to make the MAS involved consensus. This technical note is aimed at studying the joint impact of the agent dynamic structure and the communication topology on consensusability. For the MASs with fixed topology and agents described by linear time-invariant systems, a necessary condition of consensusability with respect to a set of admissible consensus protocols is given, which is shown, under some mild conditions, to be necessary and sufficient.

While catalysis is highly dependent on the electronic structure of the catalyst, the understanding of catalytic performance affected by electron spin regulation remains challenging and rare. Herein, we have developed a facile strategy to the manipulation of the cobalt spin state over covalent organic frameworks (COFs), COF-367-Co, by simply changing the oxidation state of Co centered in the porphyrin. Density functional theory (DFT) calculations together with experimental results confirm that CoII and CoIII are embedded in COF-367 with S = 1/2 and 0 spin ground states, respectively. Remarkably, photocatalytic CO2 reduction results indicate that COF-367-CoIII exhibits favorable activity and significantly enhanced selectivity to HCOOH, accordingly much reduced activity and selectivity to CO and CH4, in sharp contrast to COF-367-CoII. The results highlight that the spin-state transition of cobalt greatly regulates photocatalytic performance. Theoretical calculations further disclose that the presence of CoIII in COF-367-Co is preferable to the formation of HCOOH but detrimental to its further conversion, which clearly accounts for its distinctly different photocatalysis over COF-367-CoII. To the best of our knowledge, this is the first report on regulating photocatalysis by spin state manipulation in COFs.

As a non‐toxic species, Zn fulfills a multitude of biological roles, but its promoting effect on electrocatalysis has been rarely explored. Herein, the theoretic predications and experimental investigations that nonelectroactive Zn behaves as an effective promoter for CoP‐catalyzed hydrogen evolution reaction (HER) in both acidic and alkaline media is reported. Density function theory calculations reveal that Zn doing leads to more thermal‐neutral hydrogen adsorption free energy and thus enhanced HER activity for CoP catalyst. Electrochemical tests show that a Zn 0.08 Co 0.92 P nanowall array on titanium mesh (Zn 0.08 Co 0.92 P/TM) needs overpotentials of only 39 and 67 mV to drive a geometrical catalytic current of 10 mA cm ‐2 in 0.5 m H 2 SO 4 and 1.0 m KOH, respectively. This Zn 0.08 Co 0.92 P/TM is also superior in activity over CoP/TM for urea oxidation reaction (UOR), driving 115 mA cm ‐2 at 0.6 V in 1.0 m KOH with 0.5 m urea. The high HER and UOR activity of this bifunctional electrode enables a Zn 0.08 Co 0.92 P/TM‐based two‐electrode electrolyzer for energy‐saving hydrogen production, offering 10 mA cm ‐2 at a low voltage of 1.38 V with strong long‐term electrochemical stability.

The theoretically proposed graphene/single-walled carbon nanotube (G/SWCNT) hybrids by placing SWCNTs among graphene planes through covalent C-C bonding are expected to have extraordinary physical properties and promising engineering applications. However, the G/CNT hybrids that have been fabricated differ greatly from the proposed G/SWCNT hybrids because either the covalent C-C bonding is not well constructed or only multiwalled CNTs/carbon nanofibers rather than SWCNTs are available in the hybrids. Herein, a novel G/SWCNT hybrid was successfully fabricated by a facile catalytic growth on layered double hydroxide (LDH) at a high temperature over 950 °C. The thermally stable Fe nanoparticles and the uniform structure of the calcined LDH flakes are essential for the simultaneously catalytic deposition of SWCNTs and graphene. The SWCNTs and the CVD-grown graphene, as well as the robust connection between the SWCNTs and graphene, facilitated the construction of a high electrical conductive pathway. The internal spaces between the two stacked graphene layers and among SWCNTs offer room for sulfur storage. Therefore, the as obtained G/SWCNT-S cathode exhibited excellent performance in Li-S batteries with a capacity as high as 650 mAh g(-1) after 100 cycles even at a high current rate of 5 C. Such a novel G/SWCNT hybrid can serve not only as a prototype to shed light on the chemical principle of G/CNT synthesis but also as a platform for their further applications in the area of nanocomposites, heterogeneous catalysis, drug delivery, electrochemical energy storage, and so on.

Using the achiral diazine ligands bearing two bidentate pyridylimino groups as sources of conformational chirality, five azido-bridged coordination polymers are prepared and characterized crystallographically and magnetically. The chirality of the molecular units is induced by the coordination of the diazine ligands in a twisted chiral conformation. The use of L(1) (1,4-bis(2-pyridyl)-1-amino-2,3-diaza-1,3-butadiene) and L(2) (1,4-bis(2-pyridyl)-1,4-diamino-2,3-diaza-1,3-butadiene) induces spontaneous resolution, yielding conglomerates of chiral compounds [Mn(3)(L(1))(2)(N(3))(6)](n) (1) and [Mn(2)(L(2))(2)(N(3))(3)](n)(ClO(4))(n).nH(2)O (2), respectively, where triangular (1) or double helical (2) chiral units are connected into homochiral one-dimensional (1D) chains via single end-to-end (EE) azido bridges. The chains are stacked via hydrogen bonds in a homochiral fashion to yield chiral crystals. When L(3) (2,5-bis(2-pyridyl)-3,4-diaza-2,4-hexadiene) is employed, a partial spontaneous resolution occurs, where binuclear chiral units are interlinked into fish-scale-like homochiral two-dimensional (2D) layers via single EE azido bridges. The layers are stacked in a heterochiral or homochiral fashion to yield simultaneously a racemic compound, [Mn(2)(L(3))(N(3))(4)](n) (3a), and a conglomerate, [Mn(2)(L(3))(N(3))(4)](n).nMeOH (3b). On the other hand, the ligand without amino and methyl substituents (L(4), 1,4-bis(2-pyridyl)-2,3-diaza-1,3-butadiene) does not induce spontaneous resolution. The resulting compound, [Mn(2)(L(4))(N(3))(4)](n) (4), consists of centrosymmetric 2D layers with alternating single diazine, single EE azido, and double end-on (EO) azido bridges, where the chirality is destroyed by the centrosymmetric double EO bridges. These compounds exhibit very different magnetic behaviors. In particular, 1 behaves as a metamagnet built of homometallic ferrimagnetic chains with a unique "fused-triangles" topology, 2 behaves as a 1D antiferromagnet with alternating antiferromagnetic interactions, 3a and 3b behave as spin-canted weak ferromagnets with different critical temperatures, and 4 also behaves as a spin-canted weak ferromagnet but exhibits two-step magnetic transitions.

The sodium storage mechanism of hard carbon, optimization strategies of electrochemical performance, and the scientific challenges towards the commercialization of sodium-ion batteries were systematically summarized and analyzed.

In this perspective, recent developments on palladium and nickel mediated chain walking olefin polymerization and copolymerization with polar functionalized comonomers are described. First, the chain walking polymerization mechanism is discussed followed by its implications in olefin polymerization and copolymerization. Then, recent advances in catalyst design are provided. Special attention is paid to the influence of ligand structures on the catalytic properties. Subsequently, the applications of these chain walking polymerization catalysts in the synthesis of functionalized hyperbranched polymers and copolymers are summarized. Finally, some recent developments and perspectives on very fast and very slow chain walking polymerization catalysts are discussed.

This paper is concerned with the event-triggered finite-time control problem for networked switched linear systems by using an asynchronous switching scheme. Not only the problem of finite-time boundedness, but also the problem of input-output finite-time stability is considered in this paper. Compared with the existing event-triggered results of the switched systems, a new type of event-triggered condition is proposed. Sufficient conditions are established to guarantee the event-based asynchronous closed-loop systems are both finite-time bounded and input-output finite-time stable. A set of event-triggered finite-time bounded and input-output finite-time stabilizing controllers are designed under the asynchronous control scheme. It is revealed that the triggered thresholds determine the number of sampling points transmitted to the controller, and the smaller triggered parameters indicate the less-sampled data needed to be transmitted to the controller under the event-triggered scheme. Finally, a boost converter circuit is applied to bring out the advantages of the proposed control scheme.

In this note, we study consensus problems for continuous-time multi-agent systems in directed networks with dynamically changing topologies and nonuniform time-varying delays. We have analyzed consensus problems in the following three cases: 1) directed networks with dynamically changing topologies and nonuniform time-varying delays; 2) directed networks with intermittent communication and data packet dropout; and 3) finite-time consensus in directed networks with dynamically changing topologies and nonuniform time-varying delays. We propose a new approach based on a tree-type transformation to investigate consensus problems in all three cases. Some necessary and/ or sufficient conditions are established. Simulation results are also given to demonstrate the theoretical results.

Abiotic stresses such as drought and salinity are major environmental factors that limit crop yields. Unraveling the molecular mechanisms underlying abiotic stress resistance is crucial for improving crop performance and increasing productivity under adverse environmental conditions. Zinc finger proteins, comprising one of the largest transcription factor families, are known for their finger-like structure and their ability to bind Zn2+. Zinc finger proteins are categorized into nine subfamilies based on their conserved Cys and His motifs, including the Cys2/His2-type (C2H2), C3H, C3HC4, C2HC5, C4HC3, C2HC, C4, C6, and C8 subfamilies. Over the past two decades, much progress has been made in understanding the roles of C2H2 zinc finger proteins in plant growth, development, and stress signal transduction. In this review, we focus on recent progress in elucidating the structures, functions, and classifications of plant C2H2 zinc finger proteins and their roles in abiotic stress responses.

Abstract It is highly attractive, but still remains a huge challenge, to develop efficient non‐noble‐metal electrocatalysts for both the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) under neutral and alkaline conditions. In this paper, we report that CoP nanosheet arrays on carbon cloth (CoP NA/CC), derived from α‐Co(OH) 2 NA/CC, behaves as a three‐dimensional bifunctional water‐splitting catalyst electrode with high activity and durability in neutral and alkaline media. Such CoP NA/CC demands overpotentials of 145 and 52 mV to afford 10 mA cm −2 for the HER in 1.0 M phosphate buffer solution (PBS) and 1.0 M KOH, respectively, with much superior activity to α‐Co(OH) 2 NA/CC. It can be attributed to the more thermo‐neutral hydrogen adsorption free energy for CoP than α‐Co(OH) 2 , according to density functional theory calculations. This electrode also demonstrates superior OER activity over α‐Co(OH) 2 NA/CC and needs overpotentials of only 536 and 300 mV to drive 10 mA cm −2 at neutral and alkaline pH, respectively. The two‐electrode water electrolyzer using CoP NA/CC as both the cathode and anode shows a 2 mA cm −2 water‐splitting current at a cell voltage of 1.60 V in 1.0 M PBS and needs 1.65 V for 10 mA cm −2 under alkaline condition with excellent stability.

Ammonia (NH₃) is an activated nitrogen building block for the manufacture of modern fertilizers, plastics, fibers, explosives, <italic>etc.</italic>; however, its production is limited to the traditional Haber–Bosch process.

Abstract The ambient electrocatalytic N 2 reduction reaction (NRR) enabled by TiO 2 has attracted extensive recent attention. Previous studies suggest the formation of Ti 3+ in TiO 2 can significantly improve the NRR activity, but it still remains unclear what kinds of Ti 3+ are effective. Herein, it is demonstrated that mixed‐valent Cu acts as an effective dopant to modulate the oxygen vacancy (V O ) concentration and Ti 3+ formation, which markedly improves the electrocatalytic NRR performance. In 0.5 m LiClO 4 , this electrocatalyst attains a high Faradic efficiency of 21.99% and a large NH 3 yield of 21.31 µg h −1 mg cat. −1 at –0.55 V vs reversible hydrogen electrode, which even surpasses most reported Ti‐based NRR electrocatalysts. Using density function theory calculations, it is evidenced that mixed‐valent Cu ions modulate the TiO 2 (101) surface with multiple oxygen vacancies, which is beneficial for generating different Ti 3+ 3 d 1 defect states localized below the Fermi energy. N 2 activation and adsorption are effectively strengthened when Ti 3+ 3 d 1 defect states present the splitting of e g and t 2g orbitals, which can be modulated by its coordination structure. The synergistic roles of the three ion pairs formed by the V O defect, including Cu 1+ –Ti 4+ , Ti 3+ –Ti 4+ and Ti 3+ –Ti 3+ , are together responsible for the enhanced NRR performance.

Increasing demand for hydrogen energy has boosted the exploration of inexpensive and effective catalysts. Transition metal phosphides (TMPs) have been proven as excellent catalysts for the hydrogen evolution reaction (HER). Very recently, the search for TMP-based catalysts has being mainly directed at enhanced electrocatalytic performance. Hence, a concluded guideline for enhancing HER activity is highly desired. In this mini review, we briefly summarize the most recent and instructive developments in the design of TMP-based catalysts with enhanced electrocatalysis for hydrogen evolution from composition and structure engineering strategies. These strategies and perspectives are also meaningful for designing other inexpensive and high-performance catalysts.

This review summarizes recent advances in and future prospects of iron-based phosphides as electrocatalysts for the hydrogen evolution reaction, providing an in-depth understanding of two important aspects to boost catalytic performances.

This paper discusses the inseparability of culture and language, presents three new metaphors relating to culture and language, and explores cultural content in specific language items through a survey of word associations. The survey was designed for native Chinese speakers (NCS) in Chinese, as well as for native English speakers (NES) in English (see Appendix). The words and expressions associated by NCS convey Chinese culture, and those associated by NES convey English culture. The intimate relationship between language and culture is strikingly illustrated by the survey, which confirms the view that language and culture cannot exist without each other.

A simple and sensitive fluorescent assay for detecting alkaline phosphatase (ALP) based on the inner filter effect (IFE) has been proven, which is conceptually different from the previously reported ALP fluorescent assays. In this sensing platform, N-doped carbon dots (CDs) with a high quantum yield of 49% were prepared by one-pot synthesis and were directly used as a fluorophore in IFE. p-Nitrophenylphosphate (PNPP) was employed to act as an ALP substrate, and its enzyme catalytic product (p-nitrophenol (PNP)) was capable of functioning as a powerful absorber in IFE to influence the excitation of fluorophore (CDs). When in the presence of ALP, PNPP was transformed into PNP and induced the absorption band transition from 310 to 405 nm, which resulted in the complementary overlap between the absorption of PNP and the excitation of CDs. Because of the competitive absorption, the excitation of CDs was significantly weakened, resulting in the quenching of CDs. The present IFE-based sensing strategy showed a good linear relationship from 0.01 to 25 U/L (R(2) = 0.996) and provided an exciting detection limit of 0.001 U/L (signal-to-noise ratio of 3). The proposed sensing approach was successfully applied to ALP sensing in serum samples, ALP inhibitor investigation and phosphatase cell imaging. The presented IFE-based CDs fluorescence sensing strategy gives new insight on the development of the facile and sensitive optical probe for enzyme activity assay because the surface modification or the linking between the receptor and the fluorophore is no longer required.

We present the synthesis and multifunctional utilization of core-shell Fe3O4 polydopamine nanoparticles (Fe3O4@PDA NPs) to serve as the enabling platform for a range of applications including responsive drug delivery, recyclable catalyst support, and adsorbent. Magnetite Fe3O4 NPs formed in a one-pot process by the hydrothermal approach were coated with a polydopamine shell layer of ~20 nm in thickness. The as prepared Fe3O4@PDA NPs were used for the controlled drug release in a pH-sensitive manner via reversible bonding between catechol and boronic acid groups of PDA and the anticancer drug bortezomib (BTZ), respectively. The facile deposition of Au NPs atop Fe3O4@PDA NPs was achieved by utilizing PDA as both the reducing agent and the coupling agent. The nanocatalysts exhibited high catalytic performance for the reduction of o-nitrophenol. Furthermore, the recovery and reuse of the catalyst was demonstrated 10 times without any detectible loss in activity. Finally, the PDA layers were converted into carbon to obtain Fe3O4@C and used as an adsorbent for the removal of Rhodamine B from an aqueous solution. The synergistic combination of unique features of PDA and magnetic nanoparticles establishes these core-shell NPs as a versatile platform for multiple applications.

A Zn-doped Ni₃S₂nanosheet array on Ni foam (Zn-Ni₃S₂/NF) acts as a high-performance and durable electrocatalyst for the oxygen evolution reaction in 1.0 M KOH, driving a catalytic current density of 100 mA cm⁻²at an overpotential of 330 mV, 90 mV less than that for Ni₃S₂/NF.

Ni₂P nanoflake arrays on carbon cloth act as an efficient and durable catalyst electrode for the urea oxidation reaction (UOR) and hydrogen evolution reaction (HER). Its two-electrode alkaline electrolyzer needs 1.35 V for 50 mA cm⁻², which is 0.58 V less than that required for pure water splitting.