Construction of Pd-doped RuO_(2) nanosheets for efficient and stable acidic water oxidation

RuO_(2) has been considered a potential alternative to commercial IrO_(2) for the oxygen evolution reaction(OER)due to its superior intrinsic activity.However,its inherent structure dissolution in acidic environments restricts its commercial applications.In this study,we report a novel Pd-doped ruthenium oxide(Pd–RuO_(2))nanosheet catalyst that exhibits improved activity and stability through a synergistic effect of Pd modulation of Ru electronic structure and the two-dimensional structure.The catalyst exhibits excellent performance,achieving an overpotential of only 204 mVat a current density of 10 mA cm^(-2).Impressively,after undergoing 8000 cycles of cyclic voltammetry testing,the overpotential merely decreased by 5 mV.The PEM electrolyzer with Pd0.08Ru0.92O_(2) as an anode catalyst survived an almost 130 h operation at 200 mA cm^(-2).To elucidate the underlying mechanisms responsible for the enhanced stability,we conducted an X-ray photoelectron spectroscopy(XPS)analysis,which reveals that the electron transfer from Pd to Ru effectively circumvents the over-oxidation of Ru,thus playing a crucial role in enhancing the catalyst's stability.Furthermore,density functional theory(DFT)calculations provide compelling evidence that the introduction of Pd into RuO_(2) effectively modulates electron correlations and facilitates the electron transfer from Pd to Ru,thereby preventing the overoxidation of Ru.Additionally,the application of the two-dimensional structure effectively inhibited the aggregation and growth of nanoparticles,further bolstering the structural integrity of the catalyst.

Simulation of the mixing process in a straight tube with sudden changed cross-section

In this work, we revised the expression of mixing intensity to describe the mixing output through a cross section in a flow system by considering heterogeneity of flow field, and carefully investigated the mixing process along a straight tube with expanding/contracting cross section by simulation method. The simulation results show that a sudden expansion of cross section has remarkable mixing intensification effect within a limited period(on the sub-second scale) or tube-length(on the millimeter scale), corresponding to the generation of considerable local vortices determined by both the flow capacity and the ratio of cross section change; a sudden contraction of cross section has instantaneous but weak mixing intensification effect; through introducing a local expansion structure with proper length, as the combination of sudden expansion and sudden contraction, their mixing intensification effects could be superposed. Besides, the rationality and importance are experimentally verified to explore the time profile of mixing intensity and carry out the vortex analysis by simulation for enhancing the selectivity of a complicated reaction system. These progresses may lead to more meaningful quantitative description of mixing process in a flow microreactor for some specific chemical processes.

Induction of apoptosis in purified animal and plant nuclei by Xenopus egg extracts

We have developed a cell-free system that can trigger the nuclei purified from mouse liver and suspensioncultured carrot cells to undergo apoptosis as defined by the formation of apoptotic bodies and nucleosomal DNA fragments. The effects of different divalent cations and cycloheximide on DNA cleavage in this system were assessed.The fact that nuclei of plant cells can be induced to undergo apoptosis in a cell-free animal system suggests that animals and plants share a common signal transduction pathway triggering in the initiation stage of apoptosis.

Effects on the mixing process of a coiled tube after a T-junction:Simulation and correlation

Simulations were performed to examine the effects of a coiled tube after a T-junction on the mixing and flow characteristics. A coiled tube was found to have two effects: inducing a radial flow and flattening the axial velocity distribution, which enhances and weakens the mixing, respectively. In the straight tube section connecting the Tjunction and coiled tube, the latter may dominate and cause the mixing to deteriorate. An experiment was performed with the Villermaux/Dushman method to verify the simulation results. Based on a mixing performance simulation with various fluid and geometric structure parameters, a dimensionless correlation was obtained that can be used to determine the mixing intensity along the coiled tube with a deviation of less than 1.5%.These results provide guidance for designing a coiled tube or optimizing the operating conditions to meet the mixing requirements of specific chemical processes.

Recent Developments of Antimony-Based Anodes for Sodiumand Potassium-Ion Batteries

The development of sodium-ion(SIBs)and potassium-ion batteries(PIBs)has increased rapidly because of the abundant resources and cost-effectiveness of Na and K.Antimony(Sb)plays an important role in SIBs and PIBs because of its high theoretical capacity,proper working voltage,and low cost.However,Sb-based anodes have the drawbacks of large volume changes and weak charge transfer during the charge and discharge processes,thus leading to poor cycling and rapid capacity decay.To address such drawbacks,many strategies and a variety of Sb-based materials have been developed in recent years.This review systematically introduces the recent research progress of a variety of Sb-based anodes for SIBs and PIBs from the perspective of composition selection,preparation technologies,structural characteristics,and energy storage behaviors.Moreover,corresponding examples are presented to illustrate the advantages or disadvantages of these anodes.Finally,we summarize the challenges of the development of Sb-based materials for Na/K-ion batteries and propose potential research directions for their further development.

Adsorption and leaching of chalcopyrite by Sulfolobus metallicus YN24 cultured in the distinct energy sources

The chalcopyrite-adsorption characteristics and leaching properties of Sulfolobus metallicus（S. metallicus） YN24 were investigated in this study. The effects of zeta potentials of S. metallicus samples on chalcopyrite cultivated with distinct sources of energy were similar. Regardless of the energy source cultivated, all of the investigated S. metallicus samples adhered rapidly to the chalcopyrite surface, with an adhesion plateau being reached within 60 min. However, the mineral-cultured S. metallicus adsorbed more strongly onto chalcopyrite than the sulfur-cultured S. metallicus did. Furthermore, chalcopyrite-leaching tests suggested that the copper-leaching ability of the mineral-cultured S. metallicus was also greater than that of unadapted S. metallicus. Therefore, the results provide insights into the mechanism of mineral-surface adsorption of microorganisms that helps enhance the copper-leaching rate.

Arbitrary acoustic orbital angular momentum detection using dual-layer metasurfaces

Orbital angular momentum(OAM),with its unique physical properties and vast application prospects,has attracted widespread attention in various fields.Nonetheless,the development of valid and practical acoustic OAM detection methods continues to be a challenging endeavor.In this paper,we propose a novel construction method of dual-layer metasurfaces to achieve a doubleconversion process for the waveform reshaping and differentiated focusing of two-dimensional vortex sources with different OAMs.Specifically,by utilizing a concise formula,a one-to-one correspondence is established between the OAM of incident vortex waves and different imaging points.The fundamental principle of this special conversion relationship is rigorously constrained by the directional compensation of phase and the material parameters of dual-layer metasurfaces with different quadratic phase distributions.More importantly,the highly consistent results between numerical demonstrations and acoustic experiments further confirm the feasibility and effectiveness of the proposed OAM detection scheme.Our work provides a new perspective on the precise manipulation for the phase of vortex fields,holding potential applications in super-resolution imaging and the design of acoustic OAM-based devices.

Efficient conversion of acoustic vortex using extremely anisotropic metasurface

Vortex wave and plane wave,as two most fundamental forms of wave propagation,are widely applied in various research fields.However,there is currently a lack of basic mechanism to enable arbitrary conversion between them.In this paper,we propose a new paradigm of extremely anisotropic acoustic metasurface(AM)to achieve the efficient conversion from 2D vortex waves with arbitrary orbital angular momentum(OAM)to plane waves.The underlying physics of this conversion process is ensured by the symmetry shift of AM medium parameters and the directional compensation of phase.Moreover,this novel phenomenon is further verified by analytical calculations,numerical demonstrations,and acoustic experiments,and the deflection angle and direction of the converted plane waves are qualitatively and quantitatively confirmed by a simple formula.Our work provides new possibilities for arbitrary manipulation of acoustic vortex,and holds potential applications in acoustic communication and OAM-based devices.

Vortex localization and OAM selective conversion via cylindrical metagratings

Vortex waves with orbital angular momentum(OAM)are a highly active research topic in various fields.In this paper,we design and investigate cylindrical metagratings(CMs)with an even number of unit cells that can efficiently achieve vortex localization and specific OAM selective conversion.The multifunctional manipulation of vortex waves and the new OAM conservation law have further been confirmed through analytical calculations and numerical simulations.In addition,we qualitatively and quantitatively determine the OAM range for vortex localization and the OAM value of vortex selective conversion and also explore the stability for performance and potential applications of the designed structure.This work holds potential applications in particle manipulation and optical communication.

High-rate CH_(4)-to-C_(2)H_(6) photoconversion enabled by Au/ZnO porous nanosheets under oxygen-free system

Photocatalytic CH_(4) coupling into high-valued C_(2)H_(6) is highly attractive,whereas the photosynthetic rate,especially under oxygen-free system,is still unsatisfying.Here,we designed the negatively charged metal supported on metal oxide nanosheets to activate the inert C-H bond in CH_(4)and hence accelerate CH_(4) coupling performance.As an example,the synthetic Au/ZnO porous nanosheets exhibit the C_(2)H_(6) photosynthetic rate of 1,121.6μmol g^(-1)_(cat)h^(-1)and the CH_(4) conversion rate of 2,374.6μmol g^(-1)_(cat)h^(-1) under oxygen-free system,2 orders of magnitude higher than those of previously reported photocatalysts.By virtue of several in situ spectroscopic techniques,it is established that the generated Au^(δ-)and O^-species together polarized the C-H bond,while the Au^(δ-)and O^-species jointly stabilized the CH_(3) intermediates,which favored the coupling of CH_(3) intermediate to photosynthesize C_(2)H_(6) instead of overoxidation into CO_(x).Thus,the design of dual active species is beneficial for achieving high-efficient CH_(4)-to-C_(2)H_(6) photoconversion.

角布鲁斯特效应

The Brewster reflectionless effect stands out as one of the simplest yet pivotal discoveries in manipulating waves[1,2].Initial investigations were limited to isotropic materials,but later,thanks to the advent of metamaterials,the phenomenon was found to expand into anisotropic materials.An anomalous Brewster effect has been recently demonstrated in metamaterials with rotation angle,thus increasing the number of degrees of freedom[3].In materials without magnetic responses,the Brewster effect exclusively applies to transverse-magnetic(TM,or p-wave polarization)waves[4].

Robust asymmetric Cherenkov radiation in tilted anisotropic medium

Cherenkov radiation(CR)is available for a wide variety of terahertz(THz)radiation sources,but its efficiency is deeply affected by intrinsic losses.We find that if the tilted angle(α)of anisotropic material and radiation angle(θ)meet the condition ofθ+α=π/2,the intensity of radiation fields for the charged particle bunch(CPB)moving from left to right cannot be influenced by intrinsic losses,which means long-distance radiation can be achieved.Furthermore,we observe an asymmetric CR when the CPB moves from the opposite direction.In addition,we select natural van der Waals(vd W)materialα-MoO3as an example,further confirming that the radiation field can reach the far field and the asymmetric CR radiation can also be observed.These wonderful properties with long-distance radiation will extend the application of CR to a certain extent for future design and fabrication.

Prediction of Shanghai Stock Index Based on Investor Sentiment and CNN-LSTM Model

In view of the breakthrough progress of the depth learning method in image and other fields,this paper attempts to introduce the depth learning method into stock price forecasting to provide investors with reasonable investment suggestions.This paper proposes a stock prediction hybrid model named ISI-CNN-LSTM considering investor sentiment based on the combination of long short-term memory(LSTM) and convolutional neural network(CNN).The model adopts an end-to-end network structure,using LSTM to extract the temporal features in the data and CNN to mine the deep features in the data can effectively improve the prediction ability of the model by increasing investor sentiment in the network structure.The empirical part makes a comparative experimental analysis based on Shanghai stock index in China.By comparing the experimental prediction results and evaluation indicators,it verifies the prediction effectiveness and feasibility of ISI-CNN-LSTM network model.

Unusual selective reactivity of the rare-earth metal complexes bearing a ligand with multiple functionalities

Ligands play a key role in controlling activity of organometallic complexes so that development of new ligands to overcome the challenge is the main topic of modern chemistry.The first example of 1,1-hydride migratory insertion and intramolecular redox reaction has been realized in this work by applying a new ligand in rare-earth metal chemistry.The novel rare-earth metal complexes L^(Mes)RECH2TMS(THF)(RE=Y(1a),Dy(1b),Er(1c),Yb(1d),L^(Mes)=1-(3-(2,6-iPr_(2)C_(6)H_(3)N=CH)C8H4N)-CH_(2)CH_(2)-3-(2-CH2–4,6-Me_(2)C_(6)H_(2))-(N(CH)_(2)NC),THF=tetrahydrofuran)bearing a ligand with imino,indolyl,NHC(N-heterocyclic carbene)multiple functionalities were synthesized and characterized.Treatment of complexes 1 with silanes(PhSiH3or PhSiH2Me or PhSiD3)selectively produced the unprecedented 1,1-hydride(or deuterated H)migratory insertion of the indolyl moiety of the novel unsymmetrical dinuclear rare-earth metal complexes 2.The complex 2a reacts with Ph_(2)C=O to give the selective C=O double bond insertion to the RE–Co-methylene-Mesbond product 3a which further reacts with another Ph_(2)C=O(or DMAP,4-N,N-dimethylaminopyridine)affording the novelμ-η^(2):η^(3)-dianionic 3-iminoindolyl dinuclear rare-earth metal complex 4a.The latter is formed through an unusual intramolecular redox reaction(through electron migration from the 2-carbanion of the indolyl ring to the imino motif)resulting in the re-aromatization of the indolyl ring.

Reciprocal costimulatory molecules control the activation of mucosal type 3 innate lymphoid cells during engagement with B cells

Innate lymphoid cells(ILCs)are the counterpart of T helper cells in the innate immune system and share multiple phenotypes with T helper cells.Inducible T-cell costimulator(ICOS)is recognized on T cells and participates in T-cell activation and T and B-cell engagement in lymphoid tissues.However,the role of ICOS in ILC3s and ILC3-involved interactions with the immune microenvironment remains unclear.Here,we found that ICOS expression on human ILC3s was correlated with the activated state of ILC3s.ICOS costimulation enhanced the survival,proliferation,and capacity of ILC3s to produce cytokines(IL-22,IL-17A,IFN-γ,TNF,and GM-CSF).Via synergistic effects of ICOS and CD40 signaling,B cells promoted ILC3 functions,and ILC3-induced T-cellindependent B-cell IgA and IgM secretion primarily required CD40 signaling.Hence,ICOS is essential for the nonredundant role of ILC3s and their interaction with adjacent B cells.

Group 3 innate lymphoid cells: intestinal patrolling guardians bullied by T cells

Since the discovery of group 3 innate lymphoid cells(ILC3s),many studies have reported that,in addition to T cells,ILC3s also play an indispensable role in intestinal immune surveillance,host defense,and homeostasis[1].Although both ILC3s and T cells regulate intestinal inflammation through the secretion of interleukin(IL)-22,differences in the behaviors of these two cell types,especially the dynamic shift and mechanism of ILC3 regulation between normal and inflammatory states,remain unclear.A recent paper by Jarade et al.[2]published in Nature Immunology reported that intestinal ILC3s under basal conditions are immotile and arrested in the presence of T cells.Furthermore,the environmental T cells,the microbiota,and the chemokine CCL25 jointly shape ILC3 patrolling behavior and their effector function of maintaining intestinal barrier integrity via IL-22.These findings facilitate the study of ILC biodynamics and ILC immune regulation and the search for therapeutic strategies for gastrointestinal diseases.

Atomically Precise Pd Species Accelerating CO_(2) Hydrodeoxygenation into CH_(4) with 100%Selectivity

High-rate CO_(2)-to-CH_(4)photoreduction with high selectivity is highly attractive,which is a win-win strategy for mitigating the greenhouse effect and the energy crisis.However,the poor photocatalytic activity and low product selectivity hinder the practical application.To precisely tailor the product selectivity and realize high-rate CO_(2)photoreduction,we design atomically precise Pd species supported on In_(2)O_(3)nanosheets.Taking the synthetic 1.30Pd/In_(2)O_(3)nanosheets as an example,the aberration-correction high-angle annular dark-field scanning transmission electron microscopy image displayed the Pd species atomically dispersed on the In_(2)O_(3)nanosheets.Raman spectra and X-ray photoelectron spectra established that the strong interaction between the Pd species and the In_(2)O_(3)substrate drove electron transfer from In to Pd species,resulting in electron-enriched Pd sites for CO_(2)activation.Synchrotronradiation photoemission spectroscopy demonstrated that the Pd species can tailor the conduction band edge of In_(2)O_(3)nanosheets to match the CO_(2)-to-CH_(4)pathway,instead of the CO_(2)-to-CO pathway,which theoretically accounts for the high CH_(4)selectivity.Moreover,in situ X-ray photoelectron spectroscopy unveiled that the catalytically active sites had a change from In species to Pd species over the 1.30Pd/In_(2)O_(3)nanosheets.In situ FTIR and EPR spectra reveal the atomically precise Pd species with rich electrons prefer to adsorb the electrophilic protons for accelerating the*COOH intermediates hydrogenation into CH_(4).Consequently,the 1.30Pd/In_(2)O_(3)nanosheets reached CO_(2)-to-CH_(4)photoconversion with 100%selectivity and 81.2μmol g^(−1)h^(−1)productivity.

能量代谢工程促地衣芽胞杆菌DW2高效合成杆菌肽

杆菌肽是一种主要由芽胞杆菌产生的广谱性环肽类抗生素,目前广泛应用于兽药领域。能量代谢在微生物高效合成目的代谢产物中具有重要作用。文中以杆菌肽工业生产菌株地衣芽胞杆菌Bacillus licheniformis DW2为出发菌株,首先构建了呼吸链分支途径细胞色素bd泛醇氧化酶基因cydB缺失菌株,发现cydB缺失后杆菌肽效价和胞内ATP浓度相比于对照菌株分别提高了10.97%和22.96%。接着,证实了强化表达另外一条呼吸链分支途径--细胞色素aa3氧化酶基因qoxA能够提高杆菌肽合成水平,其杆菌肽效价和胞内ATP浓度相比于对照菌株分别提高了18.27%和34.00%。强化ADP合成供给也是促进胞内ATP积累的有效策略,结果表明强化表达腺苷激酶DcK和腺苷酸激酶AdK均可以提高杆菌肽效价和胞内ATP浓度,其中强化表达DcK效果较好,其杆菌肽效价相比对照提高16.78%。最后,通过组合代谢工程育种,在基因cydB缺失菌DW2ΔcydB基础上整合表达了qoxA和dck,得到工程菌株DW2-CQD(DW2ΔcydB::qoxA::dck),发酵结果表明,DW2-CQD杆菌肽效价达到954.25 U/mL,相比于对照菌株提高了21.66%,单位菌体杆菌肽效价为2.11 U/CFU,相比对照提高了11.05%。此外,DW2-CQD胞内ATP浓度为39.54 nmol/L,相比于对照提高了49.32%。结果证实能量代谢工程是提高杆菌肽发酵水平的有效策略,提供了一株具有工业化应用前景的杆菌肽生产菌株。

Recent advances in the role of toll-like receptors and TLR agonists in immunotherapy for human glioma

Gliomas are extremely aggressive brain tumors with a very poor prognosis. One of the more promising strat- egies for the treatment of human gliomas is targeted immunotherapy where antigens that are unique to the tumors are exploited to generate vaccines. The approach, however, is complicated by the fact that human gliomas escape immune surveillance by creating an immune suppressed microenvironment. In order to oppose the glioma imposed immune suppression, mol- ecules and pathways involved in immune cell matura- tion, expansion, and migration are under intensive clinical investigation as adjuvant therapy. Toll-like receptors （TLRs） mediate many of these functions in immune cell types, and TLR agonists, thus, are currently primary candidate molecules to be used as important adjuvants in a variety of cancers. In animal models for glioma, TLR agonists have exhibited antitumor proper- ties by facilitating antigen presentation and stimulating innate and adaptive immunity. In clinical trials, several TLR agonists have achieved survival benefit, and many more trials are recruiting or ongoing. However, a second complicating factor is that TLRs are also expressed on cancer cells where they can participate instead in a variety of tumor promoting activities including cell growth, proliferation, invasion, migration, and even stem cell maintenance. TLR agonists can, therefore, possibly play dual roles in tumor biology. Here, how TLRs and TLR agonists function in glioma biology and in anti-gli- oma therapies is summarized in an effort to provide acurrent picture of the sophisticated relationship of gli- oma with the immune system and the implications for immunotherapy.

Guards at the gate： physiological and pathological roles of tissue-resident innate lymphoid cells in the lung

The lung Is an Important open organ and the primary site of respiration. Many life.threatening diseases develop in the lung, e.g., pneumonia, asthma, chronic obstructive pulmonary diseases （COPDs）, pulmonary fibrosis, and lung cancer. In the lung, innate Immunity serves as the frontline in both anti-irritant response and anti-tumor defense and is also critical for mucosal homeostasis; thus, it plays an important role In containing these pul- monary diseases. Innate lymphoid cells （ILCs）, charac. terized by their strict tissue residence and distinct function in the mucosa, are attracting Increased atten. tion In innate Immunity. Upon sensing the danger slg- nals from damaged epithelium, ILCs activate, proliferate, and release numerous cytoklnes with specific local functions; they also participate in mucosal immune- surveillance, Immune-regulation, and homeostasis. However, when their functions become uncontrolled, ILCs can enhance pathological states and Induce dis- eases. In this review, we discuss the physiologicel and pathological functions of ILC subsets 1 to 3 in the lung, and how the pathogenic environment affects the func- tion and plasticity of ILCs.