Search

Dual nanopipettes with two channels have been receiving great attention due to the convenient experimental setup and multiple measuring channels in sensing applications at nanoscale, while the involved dynamic and asymmetrical ion transport processes have not been fully elucidated. In this paper, both experimental and simulation methods are used to investigate the dynamic mass transport processes inside dual nanopipettes with two well-separated channels. The results present that the ion transport resistance through the two channels (R12) is always the add-up of the individual ones (R13+ R23) with respect to the bulk solutions, at various ionic strengths and scan rates. A constant zero-current potential is obtained when loading an asymmetrical electrolyte concentration in the two channels, and the zero-potential current displays a good linear relationship with the bulk concentration outside the pipet. Besides revealing the dynamic and asymmetrical concentration polarization in the dual nanopipettes, these results would also further promote the better usage of dual nanopipettes in electrochemical sensing and imaging applications.

The diversified self-assembly in water is a versatile and significant phenomenon with far-reaching implications in materials science, medicine, biotechnology, and various other fields. Through subtle tailoring of the amphipathic molecular structures, two completely different self-assembly behaviors in water were obtained. The precursors M1-X(X = I–or Cl–) with rigid and shorter bridges between the hydrophobic core and the hydrophilic edge form 2D framework structures, while the precursor M2-Imolecule with flexible vinyl bridges gives 3D cube-like supramolecular cages. Notably, all of the single crystals of the assemblies were obtained. Single-crystal X-ray diffraction analysis provided unambiguous evidence of the 2D framework and cube-like structures.

Spray cooling is a practical solution for high heat flux heat dissipation problems. The spray cooling experiment was conducted with 50wt% ethylene glycol aqueous solution as the base liquid in this paper. The effects of the concentrations of copper nanoparticles, copper oxide nanoparticles, silica nanoparticles and surfactant Tween-20 on the heat transfer characteristics during spray cooling were investigated. The results showed that adding nanoparticles within a certain concentration range could enhance the effectiveness of spray cooling's heat transmission. Under the same conditions, adding copper nanoparticle has the best effect, followed by copper oxide nanoparticle, and silica nanoparticle has relatively poor effect. Among them, the heat transfer coefficient and heat flux of the nanofluid could be raised by 10.58% and 11.34% in comparison to the base liquid when the concentration of copper nanoparticles was 0.01wt%. As the concentration of nanoparticles rises higher, spray cooling's ability to transfer heat is hampered. Adding the surfactant Tween-20 could effectively improve the copper-water-ethylene glycol nanofluid's capacity for heat transmission. When the concentration is 3ppm, the heat transfer coefficient and heat flux of the nanofluid with Tween-20 were increased by 9.81% and 10.38% compared to the copper-water-ethylene glycol nanofluid.

Topographic undulations often have nonnegligible influence on frequency-domain airborne electromagnetic method (FAEM) exploration. To study this effect caused by complex topography, this article proposed a numerical simulation method based on the boundary element method (BEM) to calculate the 3-D topography EM field of frequency-domain magnetic dipole source with arbitrary inclination angle. First, according to the vector integral equations and boundary conditions of the EM field, the boundary integral equations are derived, which describes the coupled electric and magnetic fields that are integrated only for the 3-D surface. Then, the 3-D surface identified by the area of influence of the magnetic dipole source is used as the integration region (footprint) with unstructured triangular dissection, and the boundary integral equations are solved in this region using BEM. The EM field at the geometric center of gravity of each element on the surface is obtained by solving the dense linear equations using the conjugate gradients squared (CGS) method, and the influence of the 3-D topography on the magnetic field (secondary field) at the receiving coil can be calculated according to the magnetic field boundary integral equation in the upper half-space. The algorithm is then tested with synthetical models to validate its feasibility and evaluate its performance, where the response characteristics of the magnetic field with different model conditions are analyzed.

Chiral two-dimensional (2D) perovskites offer numerous attractive features for optoelectronics owing to their soft, deformable lattices and a high degree of chemical tunability. While tremendous advances have been made in perovskite-based direct circularly polarized light (CPL) detection, the low circular polarization anisotropy factor and sensitivity of those photodetectors arising from large lattice distortion still limit practical applications. Herein, chiral 2D perovskite-based single-crystalline microwire arrays with enhanced circular dichroism (CD) absorption are fabricated with the synergy of the capillary-bridge-confined assembly method and chlorine-substituted phenethylamine (Cl-MBA). Compared with phenethylamine (MBA)-inserted perovskites, the smaller lattice distortion and increased halogen–halogen interaction within Cl–MBA-inserted perovskites strengthen lattice rigidity and weaken electron-phonon coupling to improve carrier transport and thermal stability, resulting in high-performance CPL photodetectors with an anisotropy factor of 0.25, responsivity exceeding 95.7±9.3 A W−1and detectivity exceeding (3.05±0.30)×1013Jones. This work opens a new perspective to modulate circular polarization sensitivity and will be helpful to realize promising implementations in quantum computation and communication.

Perovskite single crystals have emerged as attractive structures for integrated devices. However, due to uncontrolled crystallization, the versatile and scalable fabrication of arrays of perovskite single crystals with controllable morphology and location remains a great challenge. Here, we report a facile printing strategy to controllably fabricate perovskite single-crystal arrays with well-defined morphology and location. Through modulating perovskite precursor ion aggregation in microdroplets by controlling the temperature of substrates, perovskite single-crystal arrays with controlled morphologies are fabricated, which can be selectively integrated on silicon for high-performance-type tailored laser arrays. More importantly, integrated perovskite single-crystal microstructures are printed, showing an efficiently coupling property with well-maintained intrinsic characters of the original signals. This strategy enables fully inkjet-printed morphology-controllable perovskite single-crystal arrays and functional coupling-structure arrays, which offers new opportunities for integrated photonic and optoelectronic devices.

Chiral hybrid halide perovskites have attracted considerable attention in optoelectronics and spintronics owing to their unique optical, electric, and spin–orbit coupling (SOC) properties. In this article, with focus on the design scheme to increase the nonlinear optical (NLO) circular dichroism (CD) and spin selectivity effects by assembling chlorine-modified chiral R-/S-CLPEA [CLPEA = 1-(4-chlorophenyl)ethylamine] into bismuth-based perovskites, a pair of chiral hybrid perovskites (R-/S-CLPEA)4Bi2I10were synthesized and characterized experimentally. A large NLO CD effect and strong spin-dependent charge transport were confirmed by the experimental measurements. The unique chirality-induced spin textures were illustrated in the SOC band structures from first-principles simulations. The combined theoretical and experimental results demonstrate that it is the synergic effect of large chirality of CLPEA and strong SOC effect of the Bi2I10dimer that endows these perovskites with unique chiral spin textures, strong NLO CD effect, and remarkable spin-dependent charge transport properties, which are of importance for the functional design of chiral perovskites in nonlinear optics and spintronics.

The emergency logistics provider selection (ELPS) is an important part of emergency logistics management. In an increasingly complex and highly uncertain evaluation environment, how to effectively select emergency logistics providers has become a hot topic in the field of emergency logistics management. In this paper, by integrating the double hierarchy hesitant fuzzy linguistic term set (DHHFLTS), the normalized projection measure and the improved ELECTRE II method, a practical integrated decision support model is proposed to handle the ELPS problem. First, DHHFLTSs are utilized to represent the complex and uncertain linguistic evaluation information provided by decision makers (DMs) to provide subjective judgments. Meanwhile, a distance measure for DHHFLTSs based on the proposed normalized projection is proposed to reflect both the included angle and the distance between evaluation objects, and a weight-determining method based on the proposed distance measure and the maximizing deviation method is constructed. Then a new decision support framework of double hierarchy hesitant fuzzy linguistic ELECTRE II based on positive and negative ideal solutions is put forward, in which three kinds of preference relations of the concordance and discordance sets are set up to rank the alternatives more reasonably. Finally, a practical example of ELPS is presented to illustrate the effectiveness of the proposed method, and detailed comparative analysis with other representative methods is also conducted to demonstrate the advantages of the proposed method.

In this paper, two types of conjugated, triazine-based covalent organic frameworks (COFs) with different connected linkages (imine bond and sp2-carbon-CN bond) are presented. The insignificant difference in the linkages creates a remarkable difference in their performance in visible-light-driven hydrogen generation. The fully π-conjugated two-dimensional (2D) COF with sp2-carbon-CN linkages showed an external quantum efficiency of 13.48% at 450 nm, which is an unprecedented result for COF photocatalysts. In contrast, the imine-linked 2D COF displayed almost no photoactivity. Further photoelectrochemical and quantum chemical studies provide an in-depth understanding of the catalytic mechanism. This finding provides new insight into preparing high-performance organic photocatalysts for solar energy conversion.

22q11.2 deletion is one of the strongest known genetic risk factors for schizophrenia. Recent whole-genome sequencing of schizophrenia cases and controls with this deletion provided an unprecedented opportunity to identify risk modifying genetic variants and investigate their contribution to the pathogenesis of schizophrenia in 22q11.2 deletion syndrome. Here, we apply a novel analytic framework that integrates gene network and phenotype data to investigate the aggregate effects of rare coding variants and identified modifier genes in this etiologically homogenous cohort (223 schizophrenia cases and 233 controls of European descent). Our analyses revealed significant additive genetic components of rare nonsynonymous variants in 110 modifier genes (adjusted P= 9.4E-04) that overall accounted for 4.6% of the variance in schizophrenia status in this cohort, of which 4.0% was independent of the common polygenic risk for schizophrenia. The modifier genes affected by rare coding variants were enriched with genes involved in synaptic function and developmental disorders. Spatiotemporal transcriptomic analyses identified an enrichment of coexpression between modifier and 22q11.2 genes in cortical brain regions from late infancy to young adulthood. Corresponding gene coexpression modules are enriched with brain-specific protein-protein interactions of SLC25A1, COMT, and PI4KAin the 22q11.2 deletion region. Overall, our study highlights the contribution of rare coding variants to the SCZ risk. They not only complement common variants in disease genetics but also pinpoint brain regions and developmental stages critical to the etiology of syndromic schizophrenia.

Two imine-based 2D covalent organic frameworks (COFs) with slight differences in their core structures are presented. The COF containing benzotrithiophene moieties with better planarity and π-conjugation (BTTh-TZ-COF) shows much better photocatalytic activity than the COF with trithienylbenzene cores (TThB-TZ-COF). Further photoelectrochemical study reveals the catalytic mechanism in more detail. Since other factors such as crystallinity, porosity, and optical bandgaps are equal, the different structures of the cores in the two similar COFs are the major contributors to the significantly different photocatalytic performance. The better electron delocalization of the planar trithiophene-based core and the enhanced D–A interactions between the triazine and trithiophene units in BTTh-TZ-COFcreate efficient charge separation and transfer, thus leading to superior photocatalytic hydrogen evolution activity. A new strategy for preparing high-performance organic photocatalysts for solar-energy conversion is revealed by this study.

To rapidly model the gravity field near elongated asteroids, an intelligent inversion method using Hopfield neural networks (HNNs) is proposed to estimate on-orbit simplified model parameters. First, based on a rotating mass dipole model, the gravitational field of asteroids is characterized using a few parameters. To solve all the parameters of this simplified model, a stepped parameter estimation model is constructed based on different gravity field models. Second, to overcome linearization difficulties caused by the coupling of the parameters to be estimated and the system state, a dynamic parameter linearization technique is proposed such that all terms except the parameter terms are known or available. Moreover, the Lyapunov function of the HNNs is matched to the problem of minimizing parameter estimation errors. Equilibrium values of the Lyapunov function are used as estimated values. The proposed method is applied to natural elongated asteroids 216 Kleopatra, 951 Gaspra, and 433 Eros. Simulation results indicate that this method can estimate the simplified model parameters rapidly, and that the estimated simplified model provides a good approximation of the gravity field of elongated asteroids.

A fully π-conjugated nitrogen-rich three-dimensional covalent organic framework (PYTRI-COF-2) containing both pyrazine and triazine units was prepared through a post-synthetic strategy. The imine linkages in the pre-prepared PYTRI-COF-1were converted into heterocyclic quinoline by the Povarov reaction. The obtained PYTRI-COF-2displayed high Li-ion storage capacity and excellent cycling stability when it was used as the lithium (Li)-ion battery electrode.

The operating condition of ball screws is generally applied to ensure the ball screws with a high transmission efficiency and a high positioning accuracy. Aiming at the optimal operating condition of double-nut ball screws, a transmission efficiency model considering the kinematic analysis and lubrication status was proposed. Firstly, the distributions of the film bearing pressure, asperity bearing pressure, film thickness, and ratio of the asperity bearing pressure were determined based on the Reynolds equation. Subsequently, the transmission efficiency model was established by calculating the friction coefficient and friction torque of ball screws under various lubrication statuses and operating conditions. The optimal operating condition of double-nut ball screws can be determined by estimating the transmission efficiency and lubrication status to improve the manufacturing quality. Finally, a friction torque test based on the simulated model was designed and implemented on a self-designed bed for validation of the proposed model. The comparisons showed that the experimental friction torque was consistent with the simulated friction torque, which verified the effectiveness and correctness of the transmission efficiency model. Results showed that the optimal operating conditions of the entrainment velocity and axial working load could ensure high transmission efficiency and a good lubrication status, which are of great reference to the green processing and manufacturing fields.

Climate change is creating a new era of infectious disease crises, further exacerbated by extreme weather. However, the relationship between extreme weather and infectious disease remain unclear. Here, we provide a new quantitative study on the impact of cold wave on COVID‐19 as an example. We found that during cold waves, extreme cold temperatures coupled with rapid aerosol transport accelerated COVID‐19 outbreaks. It directly increased the number of COVID‐19 cases in Beijing by 28.1% in the winter of year 2022. More urgently, cold temperatures led to a higher risk of death during infectious disease outbreaks, with a 7.07% increase in confirmed deaths and a 16.61% increase in excess mortality. Our findings emphasize the urgent need to promote a synergistic policy for responding to infectious diseases during cold wave disasters in order to minimize the risk of death among the elderly and those with underlying diseases. The sudden drop in temperature and rapid spread of aerosols during cold waves resulted in a higher prevalence of infectious diseases. At the same time, low temperatures resulted in a higher risk of death due to infectious diseases and a variety of other factors during the epidemic. The rapid dispersion of aerosols during cold waves hastens the transmission of infectious diseasesLow temperatures contribute to higher risk of death during infectious disease outbreaks The rapid dispersion of aerosols during cold waves hastens the transmission of infectious diseases Low temperatures contribute to higher risk of death during infectious disease outbreaks

Halide double perovskites present a new branch for versatile optoelectronic devices because of their huge structural compatibility and environmental friendliness, whereas nonlinear optics (NLO) devices remain blank for this fascinating family. Simultaneously, the precise patterning of single-crystalline perovskite microwire arrays remains a challenge for the integration of NLO devices. Herein, we designed lead-free chiral 2D double perovskites with the nonsymmetrical structure presenting second-harmonic generation (SHG). Furthermore, perovskite single-crystalline arrays with regulated geometry, pure orientation, and high crystallinity are prepared using the capillary-bridge confined assembly technique. The efficient SHG originates from the asymmetric crystal structure and high crystallinity of the microwire arrays. Compared with their polycrystalline thin-film counterparts, linearly polarized SHG and a higher SHG conversion efficiency are demonstrated based on microwire arrays. The results not only expand the applications of lead-free double perovskites in the NLO-integrated fields but also provide a viable way for lead-free optoelectronic devices.

The isomerization of covalent organic frameworks(COFs) materials is still a mysterious and attractive topic. Diversified monomer structures are still urgently needed to explore the in-depth mechanism of isomerization in these special COFs. This work provides a new D2hmonomer for the construction of [D2h+C2] 2D COFs isomers. A new D2hmonomer adopted here was proven to tend to form a single pore framework structure.

An interlocked covalent organic molecular cage with a trigonal-prismatic structure based on anthracene units and imine bonds was synthesized by a template-free and one-pot reaction in a relatively good yield. By comparing the single-crystal structures of the interlocked cage and two additional monomeric cages as reference compounds, a cause of weak supramolecular interaction-induced synthesis was proposed; π···π interactions induce the triphenylbenzene units as the core and anthracenes as side parts close to each other, which provides a possibility of the preorganization for the formation of the interlocked structure.

In recent years, dye wastewater caused serious effects on environmental ecology and human health. Thus, in the present study, hydroxylamine (HA) was used to improve the Fe3O4/H2O2process for removing the typical dye pollutant (tartrazine). Only 2.8% tartrazine could be removed in Fe3O4/H2O2system within 60 min at the reaction of 1 g/L Fe3O4, 1 mM H2O2, and pH 4 while 97.5% tartrazine could be removed within 20 min after adding 1 mM HA into the Fe3O4/H2O2system. Compared with Fe3O4/H2O2system, the removal rate for removing tartrazine in Fe3O4-HA/H2O2system could enhance more than 100 times. Electron paramagnetic resonance tests (EPR), radical quenching experiments and quantitative determination demonstrated that •OH was the major reactive species for removing tartrazine in Fe3O4-HA/H2O2system and •OH produced concentration in Fe3O4-HA/H2O2system was also much higher than that in Fe3O4/H2O2system. The key factors affecting tartrazine removal in Fe3O4-HA/H2O2system were also conducted. The optimal HA dosage, Fe3O4dosage, and H2O2dosage was 1 mM, 1 g/L and 1 mM. The optimal initial pH in Fe3O4-HA/H2O2system was 3, but compared with Fe3O4/H2O2system, the tatrazine removal efficiency could significantly improve under any initial pH condition. Fe3O4-HA/H2O2process had strong adaptability to inorganic ions and good applicability to different pollutants. Fe3O4-HA/H2O2process also exhibited good recycle ability for tartrazine removal. Overall, Fe3O4-HA/H2O2process is an effective and good practical applicability approach for dye wastewater treatment.

High-penetration renewable energy development causes transmission congestion in power system operation. Such transmission congestion in short period can be alleviated by energy storage configuration, instead of investing and expanding new transmission lines. This paper presents an optimal configuration method of energy storage for alleviating transmission congestion in renewable energy enrichment region. In order to obtain the characteristics of renewable energy outputs, a scenario generation technique for renewable energy outputs considering spatio-temporal correlation is first proposed. A Monte Carlo-based approach for evaluating the transmission congestion is proposed for identifying the potential locations of energy storage installation. Finally, an optimal configuration method of energy storage based on stochastic programming is proposed for alleviating transmission congestion. Numerical experiments are carried out on a modified IEEE-RTS 24-bus system and a practical 129-bus system. Numerical results show that energy storage can improve the flexibility of power system operation and the utilization of renewable energy generation. Especially, in the practical 129-bus system, the proposed method reduces renewable energy curtailment by 625.26 MWh and 444.43 MWh under fall and winter typical scenarios, respectively. And, investing some energy storage devices is more economical when the duration of transmission congestion is relatively short.

Structural health monitoring (SHM) is widely used to monitor and assess the condition and performance of engineering structures such as, buildings, bridges, dams, and tunnels. Owing to sensor defects, data acquisition errors, and environmental interference, abnormal data are often collected and stored in monitoring systems. The abnormal data in this study are essentially different from so-called “abnormal state data,” which result from structural physical damage or performance degradation. Abnormal data are totally related to the external interference rather than changes in the inherent structural features. However, abnormal data can significantly affect the performance assessment of engineering structures. It is imperative to detect and remove abnormal data from measurements to avoid misjudging structural performance in SHM. This paper summarizes abnormal data detection in the SHM field and discusses relevant challenges. Moreover, background knowledge regarding abnormal data detection is introduced. Abnormal data detection methods are then classified into statistical probability methods, predictive models, and computer vision methods. The advantages, disadvantages, and scope of each method are investigated. An example of detecting abnormal monitoring data for a cable-stayed bridge is introduced. In addition, the issues of existing studies are summarized, and future study interests are discussed.

Separation and purification of C8 aromatics is still a great challenge owing to their similar boiling point and molecular size. Herein, an aluminum-based metal–organic framework was synthesized to investigate the ability of discriminating C8 aromatics. Both the single-component and multicomponent experiments exhibited the preferential adsorption of o-xylene with the adsorption order of o-xylene > p-xylene > m-xylene > ethylbenzene. Especially, the separation selectivity of o-xylene over m-xylene can reach as high as 8.1, which exceeds the reported values using MOFs in the liquid phase. The results of the experiment in combination of calculations revealed that the interaction between polarity groups of frameworks and guests besides the stacking interaction among guest molecules is the main interaction. The cooperative effect of μ-OH groups and the aluminum-metal cluster can strengthen the electrostatic interactions for o-xylene. With the help of density function theory calculations, it is believed that the difference in binding affinities with the framework endows this MOF with excellent selective adsorption and separation of o-xylene from the C8 mixture.

Two-dimensional inorganic semiconductor materials have aroused tremendous research interest and found their potential in resolving the present urgent global issues, such as cancer therapy and fresh water shortage. Particularly, the near-infrared (NIR) photothermal conversion efficiency is a significant parameter in photothermal therapy. However, lack of an effective improvement strategy and their relatively low NIR phothermal conversion efficiency would restrict their wide and further application. Here, this work reports that enhanced NIR photothermal conversion is achieved in topological Bi2Se3nanosheets by introducing a lanthanide dopant. Specifically, lanthanide Pr-doped Bi2Se3nanosheets possess a photothermal conversion efficiency of 49.5%, which is higher than those of undoped Bi2Se3nanosheets (31.0%) and numerous reported photothermal materials. The electronic structure of Pr-doped Bi2Se3nanosheets was also analyzed by first-principles simulation. Furthermore, an interfacial evaporation system based on the developed nanosheets has been established, demonstrating a superior solar–thermal conversion efficiency of 91.5% and a water evaporation rate of 1.669 kg m–2h–1under 1 sun irradiation. The present work would provide new insights for the increase in the efficiency of photothermal materials.

Two charge-transfer single crystals induced by donor-acceptor interactions were obtained. The presence of different solvent molecules led to 1D (linear) or 2D self-assembly modes. More interestingly, the 2D organic framework, a layer-by-layer 2D organic framework single crystal, showed a stronger charge-transfer effect than the 1D cocrystal.

Schizophrenia occurs in about one in four individuals with 22q11.2 deletion syndrome (22q11.2DS). The aim of this International Brain and Behavior 22q11.2DS Consortium (IBBC) study was to identify genetic factors that contribute to schizophrenia, in addition to the ~20-fold increased risk conveyed by the 22q11.2 deletion. Using whole-genome sequencing data from 519 unrelated individuals with 22q11.2DS, we conducted genome-wide comparisons of common and rare variants between those with schizophrenia and those with no psychotic disorder at age ≥25 years. Available microarray data enabled direct comparison of polygenic risk for schizophrenia between 22q11.2DS and independent population samples with no 22q11.2 deletion, with and without schizophrenia (total n= 35,182). Polygenic risk for schizophrenia within 22q11.2DS was significantly greater for those with schizophrenia (padj= 6.73 × 10−6). Novel reciprocal case–control comparisons between the 22q11.2DS and population-based cohorts showed that polygenic risk score was significantly greater in individuals with psychotic illness, regardless of the presence of the 22q11.2 deletion. Within the 22q11.2DS cohort, results of gene-set analyses showed some support for rare variants affecting synaptic genes. No common or rare variants within the 22q11.2 deletion region were significantly associated with schizophrenia. These findings suggest that in addition to the deletion conferring a greatly increased risk to schizophrenia, the risk is higher when the 22q11.2 deletion and common polygenic risk factors that contribute to schizophrenia in the general population are both present.

Structural engineering in multiple scales permits the integration of exotic properties into a single material, which boosts the development of ultracompact multifunctional devices. Layered perovskites are capable of cross-linking efficient carrier transport originating from few-layer perovskite frameworks with extended functionalities contributed by designable bulky organic cations and nanostructures, thus providing a platform for multiscale material engineering. Herein, high-performance Stokes-parameter photodetectors for arbitrary polarized light detection are realized on the basis of solution-processed chiral-perovskite nanowire arrays. The chiral ammonium cations intercalated between the perovskite layers are responsive to circularly polarized light with a maximum anisotropy factor of 0.15, while the strictly aligned nanowires with the anisotropic dielectric function result in a large polarized ratio of 1.6 to linearly polarized light. Single crystallinity and pure crystallographic orientation permit efficient in-plane carrier transport along the nanowires, yielding a responsivity of 47.1 A W–1and a detectivity of 1.24 × 1013Jones. By synergy of linear- and circular-polarization response with high optoelectronic performance for providing sufficient photocurrent contrasts, Stokes-parameter photodetection is demonstrated on these nanowires. Our Stokes-parameter photodetectors with a small footprint and high performances present promising applications toward polarization imaging.