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This study conducts a numerical investigation of the self-propelled performance of a bio-inspired squid robot equipped with four rigid tentacles, exploring three sets of collaborative modes. Leveraging the open-source platform OpenFOAM, we develop a self-propulsion module incorporating the dynamic overset grid technique to manipulate the complex motion of rigid tentacles. The driving system of a single tentacle is simplified into a two-link mechanism, where the phase difference between the links effectively emulates the oscillatory pattern of fish-like locomotion. The interaction of four tentacles gives rise to three distinct driving modes: reverse, homologous, and interlace modes. The results indicate that the homologous mode follows the hydrodynamic characteristics of fish-like waves, the interlace mode can cause the robot to deviate from the initial path, and the reverse mode outperforms the other two modes, exhibiting a higher ultimate cruising speed. Regardless of the propulsion process, the cruising performance of the robot is significantly influenced by the maximum amplitude angle θmax. An increase in θmax also contributes to an elevation in the instantaneous longitudinal force coefficient CFx, with the most pronounced impact observed in the homologous mode. The disparity among the three modes is also evident in the periodic pressure variation and flow field evolution patterns. The vortex distribution during steady-state moments systematically reveals the collaborative effects among the tentacles in different modes on the self-propulsion performance. [ABSTRACT FROM AUTHOR]

Regional Integrated Energy Systems (RIESs) and Shared Energy Storage Systems (SESSs) have significant advantages in improving energy utilization efficiency. However, establishing a coordinated optimization strategy between RIESs and SESSs is an urgent problem to be solved. This paper constructs an operational framework for RIESs considering the participation of SESSs. It analyzes the game relationships between various entities based on the dual role of energy storage stations as both energy consumers and suppliers, and it establishes optimization models for each stakeholder. Finally, the improved Differential Evolution Algorithm (JADE) combined with the Gurobi solver is employed on the MATLAB 2021a platform to solve the cases, verifying that the proposed strategy can enhance the investment willingness of energy storage developers, balance the interests among the Integrated Energy Operator (IEO), Energy Storage Operator (ESO) and the user, and improve the overall economic efficiency of RIESs. [ABSTRACT FROM AUTHOR]

Chert is a sedimentary rock abundant and conspicuous throughout the geologic record. It serves as an essential geological archive and is vital for palaeogeographic reconstruction. The Chert Database Working Group is part of the OneSediment Working Groups of the Deep‐time Digital Earth (DDE) Big Science Program. To facilitate the sharing of chert information and promote chert research, we have compiled a summary of literature containing chert information worldwide and established the Global Chert Database (GCDB). The main body of the current database consists of seven data tables, each providing details on references, lithology, depositional age, geographic location, depositional environment and geochemical information for each sample. As of December 2023, the GCDB contains 8417 sample data from 617 pieces of literature, which can be downloaded from the ‘DDE Data Publish & Repository’. [ABSTRACT FROM AUTHOR]

One of the most essential tasks in probabilistic damage tolerance assessment is to describe the scatter in crack growth accurately. This study proposes a stochastic model of the crack growth rate, which calculates the critical parameters of a random distribution accurately by combining the Markov chain and data fitting algorithms. The proposed method is validated by the crack growth test data of Ni‐based superalloy GH4710Li at 550°C. The validation results show that the proposed method is a robust and efficient stochastic model for the crack growth rate. [ABSTRACT FROM AUTHOR]

The demand for low‐frequency microwave absorption materials is becoming more and more urgent. Novel shape anisotropy chain‐like CoNi is fabricated using polyvinylpyrrolidone as a shape‐directing agent via solvothermal method, which is then mixed with polydimethylsiloxane (PDMS) to prepare corresponding multifunctional chain‐like CoNi/PDMS composite films. Shape anisotropy and strong magnetic coupling effect of chain‐like CoNi enhance natural resonance and magnetic loss capability. The minimum reflection loss (RLmin) is −50.5 dB and low‐frequency effective absorption bandwidth (EAB) is 1.04 GHz (2.64–3.68 GHz) at 3.9 mm for chain‐like CoNi. The corresponding 18 vol% chain‐like CoNi/PDMS composite films present optimal low‐frequency microwave absorption performance with RLmin of −56.7 dB and low‐frequency EAB of 1.04 GHz (2.96–4.00 GHz) at 4.1 mm, which is far superior to 18 vol% spherical CoNi/PDMS composite films with RLmin of −9.5 dB. Meantime, the in‐plane and inter‐plane thermal conductivity coefficients of 18 vol% chain‐like CoNi/PDMS composite films are 2.05 and 0.61 W m−1 K−1, about 1.5 times higher than 18 vol% spherical CoNi/PDMS composite films (1.36 and 0.42 W m−1 K−1), also 220% and 190% higher than pure PDMS (0.64 and 0.21 W m−1 K−1). This composite films with low‐frequency microwave absorption and thermal conductivity can broaden applications in 5G communications and flexible electronics. [ABSTRACT FROM AUTHOR]

Three different hovering modes, namely, the caudal fin, pectoral fins, and multi fins, were utilized to achieve the standing-and-hovering behavior in robotic dolphins. A three-dimensional dolphin model, consisting of body, caudal fin, and symmetric pectoral fins, was used as the virtual swimmer to implement three hovering modes. A novel paddling motion was proposed, and a symmetric shape was designed of the pectoral fins. The hovering mechanisms of different modes were revealed, and the mapping relationships between different motion and performance parameters such as hovering height, efficiency, stability, and rapidity were established. The respective advantages of the three hovering modes were compared. The results showed that the caudal fin mode had the best hovering stability, while the pectoral fins mode had the best hovering rapidity. Moreover, it is worth noting that the multi fins mode had both the good hovering stability and rapidity. Therefore, the optimal hovering mode and motion parameters can be selected based on different expected objectives to achieve the best results. This study provides a new approach to break through the spatial barriers to movement of underwater robots and provides a solid hydrodynamic theoretical basis for the development of cross-medium robots with multiple hovering modes. [ABSTRACT FROM AUTHOR]

Object: Traumatic atlanto-occipital dislocation (AOD) is a relatively uncommon traumatic cervical spine injury characterized by disruption and instability of the atlanto-occipital joint. At many centers, management of pediatric AOD includes occipitocervical arthrodesis, but whether external immobilization without surgery is a viable treatment option for some pediatric patients is unknown. To answer this question, we analyzed our outcomes of pediatric AOD at the Hospital for Sick Children. Methods: We performed a retrospective chart review of all children with clinical and radiographic evidence of traumatic AOD. A total of 10 patients met criteria for traumatic AOD: 8 were treated with external immobilization alone and 2 were treated with occipitocervical arthrodesis. Results: Eight patients were treated exclusively with 3 months of halo immobilization. Two patients were treated with occipitocervical instrumentation and arthrodesis. No patient undergoing halo immobilization required subsequent operative fusion. Conclusion: Halo immobilization is a safe, viable, and definitive treatment option for the selected children with AOD. [ABSTRACT FROM AUTHOR]

Organophosphate esters have become widely used as flame retardants since the phase out of polybrominated diphenyl ethers. Previously, we demonstrated that some organophosphate esters, such as tert -butylphenyl diphenyl phosphate (BPDP), were more detrimental to endochondral ossification in murine limb bud cultures than one of the major polybrominated diphenyl ethers that they replaced, 2,2′,4,4′-tetrabromodiphenyl ether. Here, we used a transcriptomic approach to elucidate the mechanism of action of BPDP in the developing limb. Limb buds collected from gestation day 13 CD1 mouse embryos were cultured for 3 or 24 h in the presence of vehicle, 1 μM, or 10 μM BPDP. RNA sequencing analyses revealed that exposure to 1 µM BPDP for 24 h increased the expression of 5 transcripts, including Ihh , and decreased 14 others, including Gli1 , Ptch1 , Ptch2 , and other targets of Hedgehog (Hh) signaling. Pathway analysis predicted the inhibition of Hh signaling. Attenuation of Hh signaling activity began earlier and reached a greater magnitude after exposure to 10 µM BPDP. Because this pathway is part of the regulatory network governing endochondral ossification, we used a known Hh agonist, purmorphamine, to determine the contribution of Hh signaling inhibition to the negative impact of BPDP on endochondral ossification. Cotreatment of limbs with purmorphamine rescued the detrimental morphological changes in the cartilage template induced by BPDP exposure though it did not restore the expression of key transcription factors, Runx2 and Sp7 , to control levels. These data highlight Hh signaling as a developmentally important pathway vulnerable to environmental chemical exposures. [ABSTRACT FROM AUTHOR]

Uncovering the underlying biophysical principles of emergent collective computational abilities, such as working memory, in neural circuits is one of the most essential concerns in modern neuroscience. Working memory system is often desired to be robust against noises. Such systems can be highly flexible for adapting environmental demands. How neural circuits reconfigure themselves according to the cognitive task requirement remains unclear. Previous studies explored the robustness and the flexibility in working memory by tracing individual dynamical trajectories in a limited time scale, where the accuracy of the results depends on the volume of the collected statistical data. Inspired by thermodynamics and statistical mechanics in physical systems, we developed a non-equilibrium landscape and flux framework for studying the neural network dynamics. Applying this approach to a biophysically based working memory model, we investigated how changes in the recurrent excitation mediated by slow NMDA receptors within a selective population and mutual inhibition mediated by GABAergic interneurons between populations affect the robustness against noises. This is realized through quantifying the underlying non-equilibrium potential landscape topography and the kinetics of state switching. We found that an optimal compromise for a working memory circuit between the robustness and the flexibility can be achieved through the emergence of an intermediate state between the working memory states. An optimal combination of both increased self-excitation and inhibition can enhance the flexibility to external signals without significantly reducing the robustness to the random fluctuations. Furthermore, we found that the enhanced performance in working memory is supported by larger energy consumption. Our approach can facilitate the design of new network structure for cognitive functions with the optimal balance between performance and cost. Our work also provides a new paradigm for exploring the underlying mechanisms of many cognitive functions based on non-equilibrium physics. Author summary: Working memory is often associated with stimulus-selective persistent activities in the prefrontal cortex. The nature of a memory storage system indicates that the persistent states should be robust to the noise. However, the brain is inherently noisy. Furthermore, sometimes tilting the balance in favor of the increased flexibility rather than the robustness is required according to the environmental conditions and behavioral task demands. This raises the question of what the precise mechanism is for the interplay between the robustness and flexibility in noisy working memory systems. Applying the non-equilibrium potential landscape and flux approach, we found that the network architecture plays a crucial role in determining the robustness against noises and the flexibility to external stimulus. In contrast to the conventional wisdom that there is a conflict between robustness and flexibility, we found that a combination of both increased self-excitation and mutual inhibition can enhance the flexibility to external signals without significantly reducing the robustness to the random fluctuations. The key element of the underlying mechanism for achieving good performance in working memory is the emergence of the new intermediate state. Furthermore, the good performance in working memory is supported by the larger energy expenditure. [ABSTRACT FROM AUTHOR]

The existence of cracks can significantly influence the electrical properties of rocks, and electrical exploration has been applied for the detection and characterization of cracks. However, the premise is the knowledge of the quantitative effects of cracks on the electrical properties of fractured rocks, and theoretical models have provided means to obtain such knowledge. In this work, we derive explicit theoretical models for the anisotropic electrical conductivity of transversely isotropic (TI) rocks with inclined and rotated cracks, as well as cracks with random orientation distribution. Based on the developed models, we study systematically and quantitatively the effects of the crack properties and distributions on the anisotropic electrical conductivity of cracked rocks. We show that for TI rocks with aligned cracks, the inclination angle of the cracks affects both the vertical and the horizontal electrical conductivities, whereas the rotation angle only influences the horizontal electrical conductivity, although both the two angles can lead to the global rotations of the principal axes of the electrical conductivity tensor. On the other hand, the conductivity of TI rocks containing randomly distributed cracks remains transversely isotropic. For both aligned and randomly distributed cracks, the increasing crack volume fraction can linearly increase the electrical conductivity of the effective rocks, and cracks with lower aspect ratio show more significant effects on the electrical conductivity. The knowledge of the effects of the cracks on the TI rocks obtained in this study can be applied for more accurate interpretation of the electrical exploration data to better characterize cracked formations. Key Points: We develop theoretical models for the electrical conductivity of transversely isotropic rocks with inclined cracks of varying orientationsThe effects of crack parameters and crack orientation distribution on the anisotropic electrical conductivity of cracked rocks are studiedThe models can be applied for more accurate interpretation of electrical exploration data to better characterize cracked formations [ABSTRACT FROM AUTHOR]

Squid products are becoming more and more popular with consumers because of their high yields and nutrition, including novel textures with desirable sensory properties. However, it has not been determined whether the cooking method has effects on the flavor of the squid. In this study, the aroma and volatile substances of squid samples from different cooking methods (boiled, steamed, sous vide) were determined and analyzed by headspace–gas chromatography–ion mobility spectrometry and differentiated by using, as well, an electronic nose and sensory evaluation. A total of 43 characteristic flavor compounds were identified. Based on the signal intensity of the identified violate compounds, we established a fingerprint of heat‐treated squid from different cooking methods. Due to the long‐term low‐temperature heating conditions under vacuum, the flavor of sous vide squid is different from steamed and boiled squid, and it has unique special flavor compounds. Different cooking methods can affect the aroma of squid, providing support for the industrial production of squid. [ABSTRACT FROM AUTHOR]

Summary: This article studies the drag‐tracking guidance design problem of entry vehicles with low lift‐to‐drag ratio. Taking issues of uncertainty and input saturation into account, we develop a reduced‐order observer‐based robust output feedback guidance law, making the drag‐tracking error converge near zero. Our study not only achieves robust drag‐tracking guidance against inherently existing uncertainty, but also removes the redundant drag estimation in the literature. The Monte Carlo simulation is done to illustrate the advantage of the developed method. [ABSTRACT FROM AUTHOR]

• Hierarchical porosity in fibers and matrix influences mechanical behavior of porous composites. • Proposed a micromechanics-based model for porous composites under thermomechanical loading. • Use the hierarchical porosity to describe the damage evolution behaviors of the fibers and matrix. • Provide guidance for controlling the hierarchical porosity formation during the manufacturing. The manufacturing process often results in hierarchical microstructures of porous woven composites, with pores and cracks in the matrix and fibers ranging from nanometers to hundreds of micrometers. This research is devoted to the mechanical behavior of porous woven composites with hierarchical pores of very different sizes under thermomechanical loading. A micromechanics-based damage model is developed within the continuum damage mechanics (CDM) considering the contribution of hierarchical pores for capturing the thermomechanical behaviour of porous woven composites. The predicted results of the proposed model are compared with available experimental results as well as other analytical methods to verify its correctness. The main advantages of the proposed model, comparing to the existing counterparts, are that the contributions of hierarchical pores can be examined on the material macroscopic mechanical responses, and the capability in characterizing the damage behaviour of matrix and fibers. This work can provide theoretical guidance for controlling the formation of hierarchical porosity during the manufacturing process. [ABSTRACT FROM AUTHOR]

Mitochondrial Ca2+ uptake is mediated by an inner mitochondrial membrane protein called the mitochondrial calcium uniporter. In humans, the uniporter functions as a holocomplex consisting of MCU, EMRE, MICU1 and MICU2, among which MCU and EMRE form a subcomplex and function as the conductive channel while MICU1 and MICU2 are EF-hand proteins that regulate the channel activity in a Ca2+-dependent manner. Here, we present the EM structures of the human mitochondrial calcium uniporter holocomplex (uniplex) in the presence and absence of Ca2+, revealing distinct Ca2+ dependent assembly of the uniplex. Our structural observations suggest that Ca2+ changes the dimerization interaction between MICU1 and MICU2, which in turn determines how the MICU1-MICU2 subcomplex interacts with the MCU-EMRE channel and, consequently, changes the distribution of the uniplex assemblies between the blocked and unblocked states. [ABSTRACT FROM AUTHOR]

High‐carbon and high‐chromium alloy steels are prone to pitting and intergranular corrosion, which reduces corrosion resistance. The precipitation behavior of the carbides of high‐carbon and high‐chromium alloy steels is one of the main factors affecting pitting and intergranular corrosion of stainless steel. In this study, 5Cr15MoV stainless steel was heated to 1,200℃ and then cooled by cooling rates varying from 25 to 150°C/min. The precipitation behavior of grain boundary carbides of 5Cr15MoV steel at different cooling rates, and its effect on the corrosion resistance of materials was studied. The results show that the carbides of 5Cr15MoV steel mainly precipitate along the grain boundaries, which leads to the formation of chromium‐depleted zones near the grain boundaries and reduces resistance to intergranular corrosion. It has been found that a higher cooling rate shortens the width of the Cr‐depleted zone near the boundary from 0.871 to 0.569 μm, reduces the Cr‐concentration gradient near the grain boundary from 36.422% to 12.667%, and suppresses the nucleus growth rate of grain boundary carbides. As the cooling rate increases, the corrosion current density decreases from 13.29 to 2.42 μA/cm2. The corrosion rate is the lowest, while the cooling rate is 150°C/min. The corrosion rate decreases from 218.339 to 158.488 mm/a. The phenomenon of intergranular corrosion and pitting corrosion was found to be weakened; and thereby, it is shown that an intensive cooling rate can improve the corrosion resistance of 5Cr15MoV steel. [ABSTRACT FROM AUTHOR]

The genus Prunus contains many fruits used in the human diet, which exhibit a variety of different flavors. However, publications on the diversity of carotenoid profiles and sequestering structures in Prunus fruits are limited. In this study, carotenoids and their associated sequestering structures in mature fruits of four Prunus species, including peach [ Prunus persica (L.) Batschi], nectarine [ Prunus persica (L.) Batschi var. nucipersica], plum (Prunus salicina L.), and apricot (Prunus armeniaca L.) were investigated. HPLC-PAD analysis revealed that mature fruits all accumulated carotenoid esters, while their profiles and levels differed significantly. Transcription analysis suggested a positive correlation between carotenogenic genes and carotenoid profiles. Transmission electron microscopy (TEM) analysis revealed a common globular chromoplast in Prunus. However, the number and size of plastids and plastoglobules varied between species. Noticeably, the white-flesh Ruiguang 19 nectarine contained plastids similar to chromoplasts, except with smaller plastoglobules. In addition, it seemed like a lipid-dissolved β-carotene form in apricot fruits, which is more effectively absorbed by humans than the solid-crystalline form. Moreover, the lowest transcriptions of plastid-related genes were found in Friar plum, and GLK2 and OR genes were presumed to be associated with the largest chromoplasts observed in apricot. We investigated the correlations among carotenoid accumulation, plastid characteristics and gene transcription and found that chromoplast development is likely more important in determining carotenoid accumulation than carotenogenic transcription in Prunus fruits. This study presents the first report on the diversity of carotenoid sequestering structures in Prunus fruits and suggests some crucial genes associated with diversity. • Peach, apricot, and plum had a diversity in carotenogenesis in mature fruits. • Plastid characteristics were diverse in mature fruits of peach, apricot, and plum. • Plastid development is crucial for carotenoid accumulation in Prunus fruits. • Apricot fruits seemed likely to produce the lipid-dissolved β-carotene. [ABSTRACT FROM AUTHOR]

SrLa[Ga1−x(R0.5Ti0.5)x]O4 (R = Mg, Zn) ceramics were prepared by a standard solid state sintering method. The single‐phase ceramics with K2NiF4‐type layered perovskite structure and I4/mmm space group were obtained, indicating that SrLa(R0.5Ti0.5) and SrLaGaO4 can form the unlimited solid solutions. With increasing x for R = Mg and Zn, εr increases monotonously, the Qf value first increases and then decreases, while τf increases from a negative to a positive value. The optimized microwave dielectric properties were obtained as following: εr = 23.3, Qf = 89 400 GHz, τf = −0.8 ppm/°C for SrLa[Ga0.6(Mg0.5Ti0.5)0.4]O4 and εr = 23.3, Qf = 76 200 GHz, τf = 0.2 ppm/°C for SrLa[Ga0.7(Zn0.5Ti0.5)0.3]O4, indicating that the present solid solution ceramics are the promising candidates as microwave resonator materials for the telecommunication applications. [ABSTRACT FROM AUTHOR]

In spite of graphene and Ti 3 C 2 MXene sheets with various significant properties and function, the performance characteristics of their hybrid in organic coating have been rarely discussed. Herein, the Ti 3 C 2 /graphene hybrid (M-G) with wrapping structure was successfully prepared and as filler was added into epoxy coating (MG-EP). Their tribological performance against Al 2 O 3 and Si 3 N 4 balls under dry sliding and 3.5 wt % NaCl solution was evaluated in detail and the anti-wear mechanism was studied via surface/interface analysis techniques. Results show that the wrapping structure of M-G hybrid can obviously decrease the wear rate of composite coating by 81–88%, with pure epoxy coating as a comparison. Moreover, the composite coating can retain good anticorrosion properties in corrosive medium during friction test, because its integrity still hinders the diffusion of corrosive media. The improving performance of composite coating mainly depends on: (a) the excellent lubrication and thermal conductivity of graphene and Ti 3 C 2 ; (b) the synergistic effect of Ti 3 C 2 /graphene hybrid with wrapping structure; (c) the formation of protective film on the dual surface. The Ti 3 C 2 /graphene hybrid greatly enhances the tribological and anti-corrosive properties of organic coating, which provides a new thinking for the design and application of novel high-performance additive. Image 1 [ABSTRACT FROM AUTHOR]

The varied mechanisms of yttrium (Y) modifying a hypoeutectic Al–Si alloy under conditions of different cooling rates were investigated using solidification curves, scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), X-ray diffraction (XRD), transmission electron microscopy (TEM) equipped with energy dispersion X-ray detector (EDX) and high resolution transmission electron microscope (HRTEM). The results show that Y could modify the eutectic silicon of a hypoeutectic Al–Si alloy (A357), but the modification mechanism was different at variable cooling rates. At a low cooling rate, Y modified the eutectic silicon by introducing additional nucleation cores during the nucleation process. At a high cooling rate, Y modified the eutectic silicon by promoting the twin formation during its growth process. • The varied modification mechanism of yttrium (Y) on hypoeutectic Al–Si alloy at different cooling rates was investigated. • At low cooling rate, Y modified eutectic silicon through introducing more nucleation cores during its nucleation process. • At high cooling rate, Y modified eutectic silicon through promoting the formation of twins during its growth process. [ABSTRACT FROM AUTHOR]

• Few-layer Ti 3 C 2 nanosheets were parepared via etching and layering techniques from Ti 3 AlC 2 MAX phase. • Ti 3 C 2 nanosheets with perfect two-dimension layer structure have a series of performance characteristics. • Ti 3 C 2 nanosheets as corrosion inhibitor into epoxy resin provide excellent anticorrosion performance. • MXenes with good anticorrosion function mainly depend on the intrinsic properties with strong barrier effect. MXenes as novel two-dimensional (2D) materials, hold great promising for applications in many fields due to the layered-structure and performance characteristics. Here, few-layer Ti 3 C 2 nanosheets were successfully prepared by etching aluminum atoms layer of Ti 3 AlC 2 precursor along with layering technique. As-prepared Ti 3 C 2 nanosheets as a physical barrier in epoxy coating were evaluated on the anticorrosion performance via potentiodynamic polarization curve, electrochemical impedance spectroscopy (EIS) analysis, water absorption test in 3.5 wt. % NaCl aqueous solution and accelerated corrosion testing. The results demonstrate that the epoxy coatings with Ti 3 C 2 nanosheets are endowed with excellent corrosion resistance due to the intrinsic properties of 2D Ti 3 C 2 nanosheets and the formation of a barrier against corrosive medium. The findings will open a new perspective for 2D MXene materials' application as efficient anticorrosion additive. [ABSTRACT FROM AUTHOR]

A numerical method is utilized to investigate the converging angle effects on the flow structure and heat transfer of a pin fin wedge duct with dimples/protrusions. The studied converging angles are and The results show that a pin fin-dimple wedge duct with larger converging angle produces higher heat transfer enhancement due to flow acceleration, increase of the impingement region, and shrinkage of the flow recirculation region, but it is also accompanied with a much larger friction factor. A pin fin-protrusion wedge duct with larger converging angle yields higher heat transfer augmentation due to flow acceleration and more intense impingement on the protrusion but it is also associated with larger pressure penalty. [ABSTRACT FROM AUTHOR]

Objective: Invasive monitoring is sometimes necessary to guide resective surgery in epilepsy patients, but the ideal method is unknown. In this systematic review, we assess the association of postresection seizure freedom and adverse events in stereoelectroencephalography (SEEG) and subdural electrodes (SDE). Methods: We searched three electronic databases (MEDLINE, Embase, and CENTRAL [Cochrane Central Register of Controlled Trials]) from their inception to January 2018 with the keywords "electroencephalography," "intracranial grid," and "epilepsy." Studies that presented primary quantitative patient data for postresection seizure freedom with at least 1 year of follow‐up or complication rates of SEEG‐ or SDE‐monitored patients were included. Two trained investigators independently collected data from eligible studies. Weighted mean differences (WMDs) with 95% confidence interval (CIs) were used as a measure of the association of SEEG or SDE with seizure freedom and with adverse event outcomes. Results: Of 11 462 screened records, 48 studies met inclusion criteria. These studies reported on 1973 SEEG patients and 2036 SDE patients. Our systematic review revealed SEEG was associated with 61.0% and SDE was associated with 56.4% seizure freedom after resection (WMD = +5.8%, 95% CI = 4.7‐6.9%, P = .001). Furthermore, SEEG was associated with 4.8% and SDE was associated with 15.5% morbidity (WMD = −10.6%, 95% CI = −11.6 to −9.6%, P = .001). SEEG was associated with 0.2% mortality and SDE was associated with 0.4% mortality (WMD = −0.2%, 95% CI = −0.3 to −0.1%, P = .001). Significance: In this systematic review of SEEG and SDE invasive monitoring techniques, SEEG was associated with fewer surgical resections yet better seizure freedom outcomes in those undergoing resections. SEEG was also associated with lower mortality and morbidity than SDE. Clinical studies directly comparing these modalities are necessary to understand the relative rates of seizure freedom, morbidity, and mortality associated with these techniques. [ABSTRACT FROM AUTHOR]

When disadvantaged families seek to achieve upward social mobility, their most important breakthrough point is for their children to receive an education, and cultural capital is the most likely driving factor influencing educational attainment. In China, although the privileged classes have an advantage in terms of cultural capital, exhibiting a phenomenon of cultural reproduction, premium cultural capital does not display clear class divisions or exclusiveness, and students from disadvantaged families can compensate for their family's lack of cultural capital through important figures or other avenues. More importantly, the circumstances of disadvantage engender cultural capital characterized by disadvantage, greatly promoting the academic success of students from disadvantaged families. For "successful descendants" to emerge from humble families, impoverished families must not only actively compensate for their family's lack of cultural capital, but must also strive to produce the cultural capital particular to disadvantaged families; at the same time, the state and society must also provide multifaceted support. [ABSTRACT FROM AUTHOR]

This article introduces cloud computing and discusses the author's experience "on the clouds." The author reviews cloud computing services and providers, then presents his experience of running multiple systems (e.g., integrated library systems, content management systems, and repository software). He evaluates costs, discusses advantages, and addresses some issues about cloud computing. Cloud computing fundamentally changes the ways institutions and companies manage their computing needs. Libraries can take advantage of cloud computing to start an IT project with low cost, to manage computing resources cost-effectively, and to explore new computing possibilities. [ABSTRACT FROM AUTHOR]

The fundamental challenge for microwave-absorbing honeycomb composites with grading coating thickness is the unsatisfactory absorption bandwidth. In this work, an effective equivalent permittivity prediction model was established based on the homogenization method, also both the result of calculations and simulation exhibit good consistency which indicates the validity of the model. Furthermore, in-depth analysis was done on the impact of structural factors like honeycomb height and coating thickness on single layer microwave absorption. Finally, both the microwave absorption properties and the electromagnetic response of grading honeycomb microwave absorbing composites were investigated which show a bright future in reducing electromagnetic wave irradiation and interference. The present work could provide a powerful theoretical basis for designing advanced grading honeycomb microwave absorbing composites. [ABSTRACT FROM AUTHOR]

In recent years, nano-drug delivery systems have made considerable progress in the direction of tumor treatment, but the low permeability of drugs has restricted the development of nano drugs. To solve this problem, we constructed a nano-drug delivery system with the dual effects of γ-glutamyltransferase (GGT) reaction and high nuclear targeting in tumor microenvironment to promote the deep penetration of drugs. Over-expression of GGT in tumor cells can specifically recognize γ-glutamyl substrate and release amino group from the hydrolysis reaction, which makes the whole system change from negative or neutral to positive charge system. The conjugated complex with positive charge rapidly endocytosis through electrostatic interaction, enhancing its permeability in tumor parenchyma. At the same time, the cell penetrating TAT contains a large amount of lysine, which can be identified by the nuclear pore complexes (NPCs) on the surface of the nuclear membrane, showing excellent nuclear localization function. The active DOX is released in the nucleus, which inhibits the mitosis of cancer cells and enhances the active transport ability of drugs in tumor cells. Therefore, this drug delivery system actively transports adriamycin into the tumor to achieve deep penetration of drugs through enzyme response and nuclear targeting, showing high anti-tumor activity and can be effectively applied to the treatment of liver cancer. [ABSTRACT FROM AUTHOR]

To protect the food contents from the exterior environmental stimulus and microbial contamination, herein, a photodynamic and photothermal synergistic antibacterial film (PP/GC film), as food packaging material, was synthesized by a solution-casting method. In brief, the film utilized gelatin‒carboxymethyl cellulose (GC) as the matrix for accommodating PCN@PDA nanoparticles (PPNPs), a porphyrin metal‒organic framework (PCN‒224) coating with a polydopamine layer. Various characterizations were implemented to demonstrate the successful formation of PPNPs, which simultaneously exhibited the methyl orange photodegradation ability and the photothermal conversion capability under 660 nm irradiation. The incorporation of 5% wt PPNPs significantly improved the mechanical properties, water barrier properties and UV shielding performance of the films. Notably, the PP/GC films had efficient antibacterial activity within short periods of irradiation time. Moreover, the as‒prepared films significantly improved the storage safety of pork, which can be a good development prospect in the food industry. • A novel PCN@PDA-loaded Gel-CMC composite film was successfully fabricated. • PCN@PDA endowed the film photodynamic and photothermal performance. • The PP/GC film eradicated more than 99% of E. coli and S. aureus within 15 min. • The PP/GC film improved tensile strength, water resistance and UV barrier properties. • The PP/GC film exhibited a promising application in pork preservation. [ABSTRACT FROM AUTHOR]

Blade rubbing faults cause detrimental impact on the operation of aeroengines. Most of the existing studies on blade rubbing in the shaft-disk-blade-casing (SDBC) system have overlooked the elastic deformation of the blade, while some only consider the whirl of the rotor, neglecting its spin. To address these limitations, this paper proposes a dynamic model with large rotation for the SDBC system. The model incorporates the spin and whirl of the rotor, enabling the realistic reproduction of multi-blade rubbing faults. To verify the accuracy of the SDBC model with large rotation and demonstrate its capability to effectively consider the rotational effects such as the centrifugal stiffening and gyroscopic effects, the natural characteristics and dynamic responses of the proposed model are compared with those obtained from reported research and experimental results. Furthermore, the effects of the rotating speed, contact stiffness, and blade number on the dynamic characteristics of the SDBC system with multi-blade rubbing are investigated. The results indicate that the phase angle between the rotor deflection and the unbalance excitation force increases with the increasing rotating speed, which significantly influences the rubbing penetration of each blade. The natural frequency of the SDBC system with rubbing constrain can be observed in the acceleration response of the casing and the torsional response of the shaft, and the frequency is related to the contact stiffness. Moreover, the vibration amplitude increases significantly with the product of the blade number under rubbing, and the rotating frequency approaches the natural frequency of the SDBC system. The proposed model can provide valuable insight for the fault diagnosis of rubbing in bladed rotating machinery. [ABSTRACT FROM AUTHOR]

The accuracy of wind speed prediction is crucial for the efficient operation and scheduling of power grids. In recent years, many wind speed prediction methods have been proposed, but the results have always been unsatisfactory, and the model accuracy in experimental testing has always been overestimated. This study focuses on the problem of information leakage caused by the decomposition of the test and general training sets in traditional wind speed prediction methods. Using the original model without decomposition as the standard and the mean average (PMAE) and mean squared (PMSE) errors as evaluation metrics, the overestimation degree of information leakage on the model accuracy was quantified. The results show that when the test set is decomposed together, the accuracy of the model is significantly overestimated. Specifically, the overestimation of PMAE ranges from 40% to 55%, and that of PMSE is from 65% to 85%. In addition, a singular spectrum analysis (SSA) – rolling decomposition (RD) – convolutional neural network (CNN) – bidirectional gated recurrent unit (BiGRU) – attention mechanism (AM) model based on the RD method was proposed. First, SSA was used to denoise the wind speed sequence, and then RD was performed on the original sequence to provide input vectors for the neural network model. Then, the CNN – BiGRU – AM hybrid neural network module predicted the wind speed sequence. Finally, to suppress the impact of boundary effects on the model accuracy, a time-series extension strategy based on neural networks was incorporated into the model. An example analysis indicates that the SSA – RD – CNN – BiGRU – AM model can avoid information leakage compared with other traditional models. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) semiconductors like molybdenum disulfide (MoS2) exhibit superior performance at nanometer-scale thickness compared to silicon. Notably, multilayers are more resistant to breakage during transfer and boast enhanced electrical properties over monolayers. In this study, we synthesized 4-in. multilayer MoS2 using a rapid thermal processing system through the ammonium tetrathiomolybdate precursor thermolysis. A 200 nm-scale space confinement on the sample surface was used to reduce sulfur loss during annealing and to facilitate vacancy healing by self-feeding sulfur atoms. Various characterizations confirmed good crystallinity, surface flatness, and continuity, including Raman spectroscopy, x-ray photoelectron spectroscopy, scanning transmission electron microscopy, and atomic force microscopy. Moreover, these samples showed a significant enhancement in electron mobility. Our approach benefits efficiency, scalability, and procedural simplicity, paving a promising path toward large-scale production of multilayer 2D semiconductors. [ABSTRACT FROM AUTHOR]

Keemun, Assam, Darjeeling and Ceylon black teas are honored as the world's four most famous black teas, and their excellent aroma qualities are well received by people around the world. In this study, aroma components in these four types of teas were analyzed by comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC × GC-TOFMS) and gas chromatography-olfactometry (GC-O) technologies. A total of 42 aroma-active compounds were ultimately identified, especially benzeneacetaldehyde, geraniol, (Z)-3-hexen-1-yl hexanoate, trans -β-ionone, cis -linalool oxide (pyranoid), hotrienol, and methyl salicylate presented the strongest aroma strengths with pleasant scents in all tested teas. The quantification results indicated that 19 compounds including (Z)-3-hexenol, 1-octen-3-ol, linalool, phenylethyl alcohol, hexanal, benzeneacetaldehyde, limonene, heptanoic acid, (Z)-3-hexen-1-ol, acetate, benzyl alcohol, trans -linalool oxide (furanoid), hotrienol, 1-octen-3-one, 2-nonanone, (E)-2-octenal, nonanal, β-myrcene, 2-pentylfuran, and methylpyrazine were identified as the key compounds with odor activity values (OAVs) higher than 1.0 in the world's four most famous black teas. Notably, the comparison of GC-O and OAV calculation results showed that methyl salicylate (Ceylon), (E)-2-octenal (Assam), benzeneacetaldehyde (Keemun) and linalool and trans -linalool oxide (furanoid) (Darjeeling) might be the most definitive odorants in the corresponding tea categories. Unlabelled Image • Key odorants in world's four most famous black teas were identified and quantified. • Methyl salicylate, 1-octen-3-ol, linalool etc. were key odorants of Ceylon teas. • (E)-2-Octenal, benzeneacetaldehyde, linalool etc. were key odorants of Assam teas. • Benzeneacetaldehyde, hotrienol, nonanal etc. were key odorants of Keemun teas. • Linalool, trans -linalool oxide (furanoid) etc. were key odorants of Darjeeling teas. [ABSTRACT FROM AUTHOR]

In this work, we investigated the deposition of AlN film on GaN substrate by using molecular dynamics (MD) simulations. The effects of GaN substrate surface, growth temperature, and injected N: Al flux ratio on the growth of AlN film were simulated and studied. Consequently, the deposited AlN film on the (0001) Ga-terminated GaN surface achieves better surface morphology and crystallinity than that on the (000-1) N-terminated GaN surface due to the different diffusion ability of Al and N adatoms on two GaN surfaces. Furthermore, with the increase of growth temperature, the surface morphology and crystallinity of AlN film were improved owing to the enhanced mobility of adatoms. At the optimised injected N: Al flux ratio of 1, comparatively good surface morphology and crystallinity of deposited AlN films were realised. This method lays a foundation for the follow-up real-time study of defects and stress evolution of AlN on GaN and can be applied to film growth of other materials. [ABSTRACT FROM AUTHOR]

Many gene expressions changed during the development of gastric cancer, and non-coding RNAs including microRNAs (miRNAs) have been found to regulate cancer progression by participating in the process of tumor cell growth, migration, invasion and apoptosis. Our previous study has identified 29 miRNAs that are highly expressed in gastric cancer stem cells. One of these miRNAs, miR-1915-3p, has shown great potential as a diagnostic and prognostic biomarker for the cancers in liver, colon and thyroid, as well as in immune and kidney diseases. Herein, we found that miR-1915-3p exhibited low expression level in differentiated gastric cancer cell lines and gastric cancer tissues. It was found that the miR-1915-3p inhibited the growth of gastric cancer cells and thus promoted cell apoptosis.We discovered that the expressions of miR-1915-3p were significantly correlated to the lymph node metastasis and overall survival of patients with gastric cancer. Further study showed that there was a negative correlation between miR-1915-3p and Bcl-2 (B cell lymphoma/leukemia-2) expression, suggesting that Bcl-2 was a target gene of miR-1915-3p. Hence, miR-1915-3p possibly contributes to the development and progression of gastric cancer by inhibiting the anti-apoptotic protein Bcl-2. The finding provides a potential therapeutic strategy for gastric cancer. [ABSTRACT FROM AUTHOR]

Phasing out the usage of polybrominated diphenyl ether (PBDE) flame retardants (FRs) in consumer products led to their widespread replacement with organophosphate ester (OPE) FRs, despite scarce safety data. PBDE exposures were associated with the suppression of endochondral ossification but little is known about the effects of OPEs on bones. Here, we used a novel ex vivo murine limb bud culture system to compare the effects of 2,2′,4,4′-tetrabromodiphenyl ether (BDE-47) with those of several OPEs. Gestation day 13 embryos were collected from transgenic CD1 mice expressing fluorescent markers for the major stages of endochondral ossification: COL2A1-ECFP (chondrogenesis), COL10A1-mCherry (early osteogenesis), and COL1A1-YFP (late osteogenesis). Limbs were excised and cultured for 6 days in the presence of vehicle, BDE-47, or an OPE FR: triphenyl phosphate (TPHP), tert -butylphenyl diphenyl phosphate (BPDP), tris(methylphenyl) phosphate (TMPP), or isopropylated triphenyl phosphate (IPPP). BDE-47 (50 μM) decreased the extent of chondrogenesis in the digits and COL1A1-YFP expression in the radius and ulna relative to control. In comparison, concentrations of ≥1 μM of all 4 OPEs limited chondrogenesis; osteogenesis (both COL10A1-mCherry and COL1A1-YFP fluorescence) was markedly inhibited at concentrations ≥3 μM. The expression of Sox9, the master regulator of chondrogenesis, was altered by BDE-47, TPHP, and BPDP. BDE-47 exposure had minimal impact on the expression of Runx2 and Sp7, which drive osteogenesis, whereas TPHP and BPDP both suppressed the expression of these transcription factors. These data suggest that OPE FRs may be more detrimental to bone formation than their brominated predecessors. [ABSTRACT FROM AUTHOR]

Summary of main observation and conclusion: In the present work, high quality γ‐Mo2N catalysts for ammonia decomposition were successfully synthesized via temperature programmed nitridation of α‐MoO3 nanobelts. The optimal conditions for the synthesis of MoO3 precursors were obtained by using the orthogonal experimental method. The MoO3 precursors and the corresponding fresh and used Mo2N catalysts were characterized by various characterization techniques, including transmission electron microscopy, X‐ray diffraction and N2 adsorption‐desorption. Furthermore, temperature‐ programmed desorption by N2 or NH3 and X‐ray photoelectron spectroscopy analysis were performed to better understand the chemical properties of Mo2N catalysts. The results revealed that Mo2N catalyst has good NH3 adsorption ability and facilitates the dissociation adsorption of N2. Moreover, the morphology and structure of Mo2N catalysts well maintained after the reaction. Therefore, among the three transition metal nitrides (Mo2N, W2N and VN) and some Mo‐based catalysts previously reported, Mo2N catalysts showed very high activity and stability. Nearly 94% conversion of NH3 could be reached at 550°C with the gas hourly space velocity of 22000 cm3∙gcat–1∙h–1 and no obvious deactivation was observed during a 72 h test. Mo2N nanobelts were synthesized by facile method, which exhibited very high activity and stability for ammonia decomposition reaction. [ABSTRACT FROM AUTHOR]

Solid-state nanopores are considered an attractive basis for single-molecule DNA sequencing. At present, one obstacle to be overcome is the improvement of their temporal resolution, with the DNA molecules remaining in the sensing volume of the nanopore for a long period of time. Here, we used a composite system of a concentration gradient of LiCl in solution and a nanofiber mesh to slow the DNA perforation speed. Compared to different alkali metal solutions with the same concentration, LiCl can extend the dwell time to 20 ms, five times longer than NaCl and KCl. Moreover, as the concentration gradient increases, the dwell time can be tuned from dozens of milliseconds to more than 100 ms. When we introduce a nanofiber mesh layer on top of the pore in the asymmetric solution, the DNA molecules get retarded by 162–185 μ s/nt, which is three orders of magnitude slower than the bare nanopore. At the same time, because the molecule absorption region becomes larger at the pore vicinity, the higher molecule capture rate improves the detection efficiency. [ABSTRACT FROM AUTHOR]

High operating temperature of solar cell in high concentrating photovoltaic system reduces its electrical power efficiency and lifetime. Therefore, it is urgent to find an efficient cooling method to manage the temperature of solar cells. In this paper, we presented a structure and established a three-dimensional numerical model of flared heat sink to investigate the performance with different structural parameters. The simulation results reveal that the thermal resistance gradually decreases and tends to be constant as the increase in non-dimensional fin length. In addition, the thermal resistance of flared fin heat sink decreases with the increase in fin number to a certain value and then increases. The value of thermal resistance is minimum when the fin number of flared fin heat sink reaches to 13. [ABSTRACT FROM AUTHOR]

Background and aims: Studies on the aboveground growth and traits of plants suggest that plants exhibit faster growth with greater plasticity in leaf traits to adapt to changing environments. However, our knowledge of belowground growth and trait responses and associated root foraging strategies, under competition remains limited.Methods: Using an understory species-addition experiment, we investigated the responses of function-based root (absorptive fine roots [AFRs] vs. transport fine roots [TFRs]) growth, mycorrhizal association, and order-based root traits (morphological, architectural, and chemical traits) of Pinus massoniana (native species) and Pinus elliottii (exotic species), which are the dominant coniferous tree species in subtropical China.Results: Higher understory-species diversity increased the biomass of AFRs, but not TFRs and total fine roots (AFRs plus TFRs) of both species. Higher diversity increased the biomass ratio of the AFRs and TFRs of P. elliottii, indicating a tradeoff in plant carbon investment between the two functional root modules for P. elliottii. Higher diversity increased the total root length of P. massoniana, but did not affect that of P. elliottii. Increased species diversity decreased the ectomycorrhizal colonization rate of P. massoniana, but increased that of P. elliottii. Increased species diversity altered the branching-related traits (increased branching ratio and intensity), but did not affect the morphological (diameter, specific root length, and root tissue density) or chemical traits across the root orders of either species.Conclusions: Our findings indicate that P. elliottii employed dual root foraging strategies (growth and mycorrhizal strategies) and had a cost-benefit tradeoff between AFR and TFR construction. In comparison, P. massoniana only accelerated root growth under competition. These results facilitate a better understanding of the root foraging strategies of plants and the rapid adaptation of exotic species in novel environments. [ABSTRACT FROM AUTHOR]

HHLA2 is a newly identified member of the B7 immune checkpoint family, but its function and crosstalk with immune cells is not fully understood. To gain insights into the HHLA2 expression profile and to determine the clinical significance and function of HHLA2 in pancreatic cancer, we performed immunohistochemistry (IHC) analyses on tissue microarrays (TMAs) of pancreatic ductal adenocarcinoma (PDAC, n = 92) with matched peritumoral tissues as well as in cohorts of precancerous lesions: pancreatic intraepithelial neoplasia (PanIN) and intraductal papillary mucinous neoplasm (IPMN). We found that HHLA2 was rarely detected in normal acinar, islet, and ductal cells but widely expressed from early pancreatic precancerous lesions to invasive PDAC. The overall HHLA2 positivity was 95% (19/20) in low grade PanIN and 70.73% (29/41) in IPMN. HHLA2 expression was detected in 77.17% (71/92) of the PDAC cases and was significantly associated with better prognosis in this cohort. Our findings suggest that HHLA2 may behave as a costimulatory ligand in pancreatic cancer, which differs from other B7 family members that are largely characterized as checkpoint inhibitors. Further investigation of the HHLA2 signaling pathway and its receptors is warranted by our data and may lead to novel therapeutic interventions. [ABSTRACT FROM AUTHOR]

With the development of urbanization, road congestion has become increasingly serious, and an important cause is the traffic accidents. In this article, we aim to predict the duration of traffic accidents given a set of historical records and the feature of the new accident, which can be collected from the vehicle sensors, in order to help guide the congestion and restore the road. Existing work on predicting the duration of accidents seldom consider the imbalance of samples, the interaction of attributes, and the cost-sensitive problem sufficiently. Therefore, in this article, we propose a two-level model, which consists of a cost-sensitive Bayesian network and a weighted K-nearest neighbor model, to predict the duration of accidents. After data preprocessing and variance analysis on the traffic accident data of Xiamen City in 2015, the model uses some important discrete attributes for classification, and then utilizes the remaining attributes for K-nearest neighbor regression prediction. The experiment results show that our proposed approach to predicting the duration of accidents achieves higher accuracy compared with classical models. [ABSTRACT FROM AUTHOR]

A nonlinear dynamic model of a one-dimensional photonic crystal nanocavity resonator is presented. It considers the internal tensile stress and the geometric characteristics of a photonic crystal with rectangular (and circular) holes. The solution of the dynamic model shows that the internal tensile stress can suppress the hardening and softening behaviors of the resonator. However, the stress can reduce the amplitude, which is not conducive to an improvement of the sensitivity of the sensor. It is demonstrated that with an optimized beam length, the normalized frequency drift of the beam can be stabilized within 1% when the optical power increases from 2 mW to 6 mW. When the hole size of the resonator beam is close to the beam width, its increase can lead to a sharp rise of the resonant frequency and the promotion of hardening behavior. Moreover, the increase in the optical power initially leads to the softening behavior of the resonator followed by an intensification of the hardening behavior. These theoretical and numerical results are helpful in understanding the intrinsic mechanism of the nonlinear response of an optomechanical resonator, with the objective of avoiding the nonlinear phenomena by optimizing key parameters. [ABSTRACT FROM AUTHOR]

Estimating scene depth from a single image can be widely applied to understand 3D environments due to the easy access of the images captured by consumer-level cameras. Previous works exploit conditional random fields (CRFs) to estimate image depth, where neighboring pixels (superpixels) with similar appearances are constrained to share the same depth. However, the depth may vary significantly in the slanted surface, thus leading to severe estimation errors. In order to eliminate those errors, we propose a superpixel-based normal guided scale invariant deep convolutional field by encouraging the neighboring superpixels with similar appearance to lie on the same 3D plane of the scene. In doing so, a depth-normal multitask CNN is introduced to produce the superpixel-wise depth and surface normal predictions simultaneously. To correct the errors of the roughly estimated superpiexl-wise depth, we develop a normal guided scale invariant CRF (NGSI-CRF). NGSI-CRF consists of a scale invariant unary potential that is able to measure the relative depth between superpixels as well as the absolute depth of superpixels, and a normal guided pairwise potential that constrains spatial relationships between superpixels in accordance with the 3D layout of the scene. In other words, the normal guided pairwise potential is designed to smooth the depth prediction without deteriorating the 3D structure of the depth prediction. The superpixel-wise depth maps estimated by NGSI-CRF will be fed into a pixel-wise refinement module to produce a smooth fine-grained depth prediction. Furthermore, we derive a closed-form solution for the maximum a posteriori (MAP) inference of NGSI-CRF. Thus, our proposed network can be efficiently trained in an end-to-end manner. We conduct our experiments on various datasets, such as NYU-D2, KITTI, and Make 3D. As demonstrated in the experimental results, our method achieves superior performance in both indoor and outdoor scenes. [ABSTRACT FROM AUTHOR]

A numerical method is employed to study effects of convergence angle and dimple shape on flow structure and heat transfer under a rotating frame. The investigated convergence angles are 0.0°, 6.3°, and 12.7°. The dimple shapes are circular, streamwise-elliptical, and spanwise-elliptical. The rotation number ranges from 0.0 to 0.4. Computed flow structures and heat transfer are compared. Higher rotation number generates better heat transfer in the dimple-pin wedge duct. The rotation direction also affects the flow structure and heat transfer. The spanwise-elliptical dimple shape shows best heat transfer augmentation as it generates the strongest vortex structure and turbulent kinetic energy in the dimples. Larger convergence angles exhibit larger Nusselt numbers and better heat transfer enhancement. Effects of the Coriolis force are considered as this force has favorable effects on enhancing the heat transfer on the surface it acts on. [ABSTRACT FROM AUTHOR]

Abstract In this paper, an underwater vibration model is developed to depict the dynamic characteristic of V-shaped beams for both small and finite amplitude vibrations by considering the fluid–structure interactions between the complicated geometry and viscous fluids. The gap to width ratio in beam's cross-section is introduced to describe the geometry of the V-shaped beam. For small amplitude vibrations, a complex hydrodynamic function in terms of the gap to width ratio and the frequency parameter is presented to characterize the fluid–structure interactions according to the 2-D fluid dynamics simulations. Besides, a 3-D numerical simulation is performed to verify the proposed computational approach and hydrodynamic function in the 2-D analysis. As the vibration amplitude increases, the 2-D fluid dynamics simulations are further conducted to investigate the effects of amplitude parameter on the flow physics. Therefore, a revised hydrodynamic function governed by the interplay of the frequency parameter, the gap to width ratio and the amplitude parameter is presented to model the hydrodynamic force for finite vibration amplitude accounting for nonlinear damping effects. Moreover, the experimental verifications on both small and finite amplitude vibrations of several V-shaped beams with different geometrical sizes are carried out. It illustrates that the presented model is capable of capturing the nonlinear damping phenomenon occurred at finite oscillation amplitudes and is generally able to predict the underwater vibrations of V-shaped beams with both small and finite amplitude. [ABSTRACT FROM AUTHOR]

• Potassium oleate (PO) can inhibit corrosion of copper (Cu) and cobalt (Co). • A small amount of PO can increase the removal rate of Co. • PO can work in synergy with fatty alcohol polyoxy ethylene ether. As the feature size of integrated circuit drops down to 20–14 nm, cobalt (Co) is used as the barrier layer material for multilayer copper (Cu) wiring. The chemical mechanical polishing (CMP) process of Cu film has developed from a combined rough polishing and fine polishing to a one-step polishing, which needs to stop on the Co barrier layer. So the removal rate (RR) of Co should approach zero to meet the requirement of higher RR selection ratio of Cu and Co. Inhibitors in the Cu film slurry play an important role for controlling the RR during CMP process. In this paper, the anionic surfactant potassium oleate (PO) was selected as a key corrosion inhibitor in Cu film CMP to enhance the RR selection ratio of Cu and Co. The complexation and corrosion inhibition mechanisms between PO and Cu or Co were revealed by electrochemical measurements, X-ray photoelectron spectroscopy and scanning electron microscopy measurements. It was found that the rapid complexation of a small amount of PO with Co2+ could increase the Co RR. However, with a higher concentration of PO, the effective catalysis caused the conversion of cobaltous hydroxide to tricobalt tetraoxide, and thus resulted in a lower Co RR. With the addition of the nonionic surfactant called fatty alcohol polyoxy ethylene ether (JFCE), the morphology of the PO aggregates changes to spherical, which weakened the inhibiting effect of PO on Cu RR, and thus a higher Cu RR and RR selection ratio of Cu and Co was achieved. The synergistic action mechanism of PO and JFCE on Cu and Co surfaces was analyzed systematically. The present work provides an idea that surfactants are excellent candidates for metal inhibitors. [ABSTRACT FROM AUTHOR]

• Porous biochar from waste bamboo is used for electromagnetic wave absorption. • Porous structure improves electromagnetic wave absorption performance. • The good hydrophobicity of porous biochar helps in practical applications. The rational use of agroforestry waste and the development of highly efficient electromagnetic wave absorbing materials have attracted a lot of attention. Carbon based electromagnetic wave absorbing materials derived from agroforestry waste have the advantages of low density, stable physicochemical properties, and therefore they became a research hotspot. However, the good conductivity, high permittivity of pure carbon materials are prone to electromagnetic mismatch, which limits their further applications. In this paper, a series of 2D biochar-based flakes with different pore sizes were prepared by pyrolysis of cellulose from bamboo wood, followed by chemical etching, using waste bamboo as an example. The increase of the etching time directly affected the pore size of the material, which affected its dielectric properties. It was shown that the pores of biochar-based flakes (PGC-6) with macroporous structure obtained by 6 h of etching provided an ideal impedance match an enhanced polarization effect, which made it an excellent electromagnetic wave absorber. The lowest RL value of PGC-6 is −15.8 dB, while the absorption bandwidth achieves 3.8 GHz at 1.70 mm. This study provides a viable pathway for the reuse of agroforestry waste. [ABSTRACT FROM AUTHOR]