Layer Pattern Research Articles

ParaX : Bandwidth-Efficient Instance Assignment for DL on Multi-NUMA Many-Core CPUs

Commercial clouds now heavily use CPUs in DL (deep learning) because there are large numbers of CPUs which would otherwise sit idle during off-peak periods. Following the trend, CPU vendors have not only released high-performance many-core CPUs but also developed efficient math kernel libraries. However, current DL platforms cannot scale well to a large number of CPU cores, making many-core CPUs inefficient in DL computation. We analyze the memory access patterns of various layers and identify the root cause of the low scalability, i.e., the per-layer barriers that are implicitly imposed by current platforms which assign one single instance (i.e., one batch of input data) to a CPU. The barriers cause severe memory bandwidth contention and CPU starvation in the access-intensive layers (like activation and BN). This paper presents a novel approach called ParaX, which boosts the performance of DL on multi-NUMA (non-uniform memory access) many-core CPUs by effectively alleviating bandwidth contention and CPU starvation. Our key idea is to assign one instance to each CPU core instead of to the entire CPU, so as to remove the per-layer barriers on the executions of the many cores. ParaX designs an ultralight scheduling policy which sufficiently overlaps the access-intensive layers with the compute-intensive ones to avoid contention, and proposes a NUMA-aware gradient server mechanism for training which leverages shared memory to substantially reduce the overhead of per-iteration parameter synchronization. We have implemented ParaX on MXNet. Extensive evaluation on a two-NUMA Intel 8280 CPU shows that ParaX significantly improves the training/inference throughput for all tested models (for image recognition and natural language processing) by <inline-formula><tex-math notation="LaTeX">$1.73\times \sim 2.93{\times}$</tex-math></inline-formula> .

The Role of Massive Ice and Exposed Headwall Properties on Retrogressive Thaw Slump Activity

AbstractRetrogressive Thaw Slumps (RTSs), a highly dynamic form of mass wasting, are accelerating geomorphic change across ice‐cored permafrost terrain, yet the main controls on their activity are poorly constrained. Questions over the spatial variability of environmentally sensitive massive ice bodies and a paucity of high‐spatial and temporal resolution topographic data have limited our ability to project their development and wider impacts. This research addresses these key problems by investigating RTS processes on Peninsula Point—a well‐studied site for intra‐sedimental massive ice in the Western Canadian Arctic. Utilizing high‐resolution topographic data from drone surveys in 2016, 2017 and 2018 we (a) measure the temporal and spatial variations in headwall properties and retreat rates, (b) determine the spatial pattern of subsurface layering using passive seismic monitoring and (c) combine these to analyze and contextualize the factors controlling headwall retreat (HWR) rates. We find that headwall properties, namely massive ice and overburden thickness, are significant controls over rates of HWR. Where persistent massive ice exposures are present inland of the headwall, regardless of thickness, and overburden thickness remains &lt;4 m, HWR is typically more than double that of other headwalls. Furthermore, a 3D site model was created by combining photogrammetric and passive seismic data, highlighting internal layering variability and demonstrating the limitations of extrapolations of internal layering based on headwall exposures. These results provide fresh insights into the in situ controls on HWR rates and new approaches to understanding their variability.

Atomically engineered cobaltite layers for robust ferromagnetism.

Emergent phenomena at heterointerfaces are directly associated with the bonding geometry of adjacent layers. Effective control of accessible parameters, such as the bond length and bonding angles, offers an elegant method to tailor competing energies of the electronic and magnetic ground states. In this study, we construct unit-thick syntactic layers of cobaltites within a strongly tilted octahedral matrix via atomically precise synthesis. The octahedral tilt patterns of adjacent layers propagate into cobaltites, leading to a continuation of octahedral tilting while maintaining substantial misfit tensile strain. These effects induce severe rumpling within an atomic plane of neighboring layers, further triggering the electronic reconstruction between the splitting orbitals. First-principles calculations reveal that the cobalt ions transit to a higher spin state level upon octahedral tilting, resulting in robust ferromagnetism in ultrathin cobaltites. This work demonstrates a design methodology for fine-tuning the lattice and spin degrees of freedom in correlated quantum heterostructures by exploiting epitaxial geometric engineering.

Local multifractality in urban systems—the case study of housing prices in the greater Paris region

Even though the study of fractal and multifractal properties has now become an established approach for statistical urban data analysis, the accurate multifractal characterisation of smaller, district-scale spatial units is still a somewhat challenging task. The latter issue is key for understanding complex spatial correlations within urban regions while the methodological challenge can be mainly attributed to inhomogeneous data availability over their territories. We demonstrate how the approach proposed here for the multifractal analysis of irregular marked point processes is able to estimate local self-similarity and intermittency exponents in a satisfactory manner via combining methods from classical multifractal and geographical analysis. With the aim of emphasizing general applicability, we first introduce the procedure on synthetic data using a multifractal random field as mark superposed on two distinct spatial distributions. We go on to illustrate the methodology on the example of home prices in the greater Paris region, France. In the context of complex urban systems, our findings proclaim the need for separately tackling processes on the geolocation (support) and any attached value (mark, e.g. home prices) of geospatial data points in an attempt to fully describe the phenomenon under observation. In particular, the results are indicators of the strength of global and local spatial dependency in the housing price structure and how these build distinct layered patterns within and outside of the municipal boundary. The derived properties are of potential urban policy and strategic planning relevance for the timely identification of local vulnerabilities while they are also intended to be combinable with existing price indices in the regional economics context.

Simulation of Forced Convection Frost Formation in Microtubule Bundles at Ultra-Low Temperature

Hypersonic vehicles are an important area of research in the aerospace field today. One of the important issues is the power of the engine. In order to achieve large-span flight speeds, a more efficient approach is to use combined power systems. However, the problem of pre-cooler icing can occur in combined engine applications. The flow in the pre-cooler is extremely complex. Outside the tube is the high-temperature wet air entering from the engine intake, and the tube cooling is the ultra-low temperature cooling medium. Icing not only increases the heat exchange resistance of the pre-cooler during operation and affects the heat exchange performance of the pre-cooler, but also causes a large total pressure loss, resulting in a degradation of the engine performance. There is a lack of research on the icing law of the pre-cooler under different parameters. Therefore, it is necessary to conduct a corresponding numerical calculation study on pre-cooler icing and explore the influence of various influencing factors on icing. In this paper, a mathematical model of icing (frost) is established for the frosting phenomenon that may occur during the operation of the pre-cooler. Additionally, the principle of heat and mass transfer in the icing process is described by the mathematical model, and the influence of different parameters on the frosting parameters is explored by using the computational fluid dynamics (CFD) method. The law of tube bundle icing under different parameters was calculated, and the variation laws of frost layer morphology and wet air pressure drop were obtained. The laws of tube bundle icing under different parameters were calculated, and the changes in frost layer pattern and wet air pressure drop when each parameter was changed, which can provide guidance for the design and application of pre-coolers in the future.

Spatio‐temporal variation in deep soil water use patterns of overstorey and understorey layers in subtropical plantations predicts community assembly

Abstract Deep soil water utilization allows plants to cope with drought stress. However, little is known about the roles of the understorey layers in driving spatio‐temporal variations of deep soil water in forests and how the patterns of deep soil water use among life‐forms contribute to community assembly processes. We assessed the spatio‐temporal patterns and determinants of deep water utilization of tree, shrub and herb layers in subtropical coniferous plantations and investigated associations between deep water use parameters and dominance and richness of understorey vegetation. We found that the understorey layer had a higher reliance on deep soil water in the dry season, a larger seasonal plasticity of deep soil water uptake, but lower spatial variability in deep soil water utilization than the tree layer. We showed that greater reliance of the tree layer on deep soil water was associated with decreased shrub layer diversity, whereas greater reliance of the shrub layer on deep water was associated with increased herb layer diversity. Synthesis. Our results highlight the roles of understorey layers in driving the temporal dynamics of deep soil water in forests and improve our understanding of how deep soil water use patterns among life‐forms shape community assembly in forests.

Morphogenesis of the uterine tube in the European shorthair cat in the prenatal and postnatal period: Light microscopy and three-dimensional reconstruction study

The study aimed to describe the morphogenesis of the domestic cat uterine tube, from the primordial tubal segment of the paramesonephric duct (TsPD) to the mature organ. The specific aims included identifying differences in the rate and way of development of the layers in the wall of the infundibulum, the ampulla, and the isthmus. In the study we conducted light microscopic (LM) observations of the uterine tube wall, and analysis of 3D models, which were used for the first time to visualize the arrangement of the paramesonephric duct and highlight the pattern of the developing mucosal folds. The results revealed the two stages in the prenatal development of the domestic cat uterine tube. The first stage lasts from day 26–44 p.c. (post-conception) and includes the growth of the TsPD. It starts with formation of the TsPD's epithelial tubule in the mesenchyme of the anterior part of the mesonephros. The tubule, surrounded by mesenchyme, elongates posteriorly, and the TsPD can be divided into three sections according to their location and diameter, i.e., anterior, middle, and posterior. The first stage ends with the histodifferentiation of the mesenchyme into loose connective tissue and mucosa formation. The second stage lasts from approximately day 45–63 p.c. and comprises the formation of the proper layers in the uterine tube wall. The pace and pattern of layers' development are specific to each section of the uterine tube, as tissues first differentiate in its anterior part and then continue posteriorly. The mucosal folds appear after day 44 p.c. in the infundibulum, and they become long and branched by the end of the prenatal period. Then, approximately day 48 p.c., the single mucosal folds appear in the ampulla, and at the end, i.e., about day 63 p.c., they become visible in the isthmus. The 3D models revealed the unique spiral-shaped arrangement of the mucosal folds in the ampulla. The tunica muscularis starts to develop ca day 48–51 p.c. in the anterior part of the uterine tube. On approximately day 55 p.c., the circular muscle layer can be distinguished in the ampulla, while in the isthmus, it develops just before birth. The postnatal development of the infundibulum includes the formation of the labyrinth-like system of mucosal folds, whereas in the ampulla and isthmus, branched mucosal folds and the second longitudinal muscle layer develop postnatally. At the end of the prenatal period, the differences in the wall thickness between the individual segments of the uterine tube reflect the proper proportions of the uterine tube wall in the mature female.

Differentiating benign from malignant gallbladder wall thickening in non-contrast MRI imaging: Preliminary study of a combined diagnostic indicator.

To synthetically evaluate the diagnostic accuracy of image features for differentiating benign from malignant gallbladder wall thickening disease with non-contrast MRI and establish the optimal diagnostic indicator. A total of 23 patients with wall thickening type gallbladder carcinoma and 61 patients with benign wall thickening disease were included. The diagnostic performance of six image features including the layered pattern on T2-weighted imaging (T2WI) and diffusion-weighted imaging (DWI) images, T2WI signal intensity, papillary growth, the apparent diffusion coefficient (ADC) value, and the lesion to liver parenchyma ratio (LLR) of gallbladder were evaluated and compared. The receiver operating characteristic (ROC) curve and binary logistic regression analysis were used to construct the optimally combined indicator. All six indicators showed high diagnostic accuracy. The layered pattern on DWI and LLR had the highest area under the curve (AUC) value (0.904), followed by the layered pattern on T2WI (0.883), T2WI signal intensity (0.859), ADC value (0.836), and papillary growth (0.796). There was no statistically significant difference in the AUC among indicators for pairwise comparisons. A combination of layered patterns on DWI and papillary growth was shown to be the optimal indicator by binary logistic regression analysis. The AUC value of the combination (0.972) was higher than the layered pattern on DWI (0.904) and papillary growth (0.796) (P < .001). Non-contrast MRI provides several reliable indicators for differentiating benign from malignant gallbladder thickening disease. The combination of layered patterns on DWI and papillary growth is the optimal indicator.

Diagnosis of coronary layered plaque by deep learning

Abstract Background/Introduction Healed coronary plaques, morphologically characterized by a layered pattern, are signatures of previous plaque disruption and healing. Recent optical coherence tomography (OCT) studies showed that layered plaque is associated with vascular vulnerability and rapid plaque progression. However, the diagnosis of layered plaque requires expertise in OCT image interpretation and is susceptible to interobserver variability. Purpose We aimed to develop a deep learning (DL) model for an accurate diagnosis of layered plaque. Methods We developed a Visual Transformer (ViT)-based DL model emulating the cardiologists who review consecutive OCT frames to make a diagnosis (Figure 1), and compared it to the standard convolutional neural network (CNN) model. We used 302,415 cross-sectional OCT images from 873 patients collected from 9 sites: 237,021 images from 581 patients for training and internal validation from 8 sites, and 65394 images from 292 patients collected from another site for external validation. Results Model performances were evaluated using the area under the receiver operating characteristics (AUC). In the five-fold cross validation, the ViT-based model showed better performance than the standard CNN-based model with AUC of 0.886 (95% confidence interval [CI], 0.882–0.891) compared with 0.797 (95% CI, 0.790–0.804). The ViT-based model also outperformed the standard CNN-based model in the external validation, with an AUC of 0.857 (95% CI, 0.849–0.864) compared to 0.806 (95% CI, 0.797–0.815) (Figure 2). Conclusion(s) The ViT-based DL model will help cardiologists to make an accurate diagnosis of layered plaque, which might help to stratify the risk of future adverse cardiac events. Funding Acknowledgement Type of funding sources: Private grant(s) and/or Sponsorship. Main funding source(s): Mrs. Gillian Gray through the Allan Gray Fellowship Fund in Cardiology

Fabrication of 3D microstructures for flexible pressure sensors based on direct-writing printing

Microstructure plays an important role in improving the performance of flexible sensors. Changing the shape of the dielectric layer microstructure is an effective countermeasure to promote the sensitivity of capacitive sensors. Nevertheless, traditional microstructure fabrication methods have high manufacturing costs, cumbersome manufacturing processes, and single structure manufacturing, which restrict the development of flexible sensors. In this work, electro-hydro-dynamic (EHD) printing method and aerosol jet (AJ) printing method were applied to fabricate 3D microstructures, in a manner of printing the same pattern in multiple layers. The height and morphology of 3D microstructures, under different printing parameters, were compared by changing the number of printing layers and printing speed. Additionally, the printing effects of the two printing methods were compared. The results demonstrated that various shapes and highly controllable 3D microstructures could be fabricated by both methods. The EHD printing method had higher manufacturing precision, whereas the AJ printing method had higher stacking efficiency. The height and morphology of 3D microstructures could be effectively controlled by changing the number of printed layers and the printing speed of the microstructures. It is indicated that the EHD printing method and the AJ printing method both have great potential in the fabrication of 3D microstructures and that both methods had their own advantages.

Investigating porosity structure effects on hydrothermal mineralization patterns within permeable horizontal layers of fluid-saturated rocks: Semi-analytical approach through generic models

The porosity structures of a permeable rock can have remarkable effects on pore-fluid flow within the rock. According to the modern mineralization theory, the mineralization pattern in a hydrothermal ore-forming system is strongly dependent on the pore-fluid flow velocity, so that different porosity structures of a permeable rock can affect significantly hydrothermal mineralization patterns within the permeable layers consisting of fluid-saturated porous rocks. This paper presents a semi-analytical approach, in which pore-fluid velocity is directly used as fundamental primary variables in the governing equations of the problem and the property matrices of finite elements are analytically evaluated in a purely mathematical manner, to ensure the high accuracy of the obtained pore-fluid velocity, which is involved in controlling mineralization patterns in hydrothermal ore-forming systems. After the proposed semi-analytical approach is verified through comparing the numerical solution with the analytical solution for a benchmark problem, it has been used to investigate how different porosity structures can affect the hydrothermal mineralization patterns within permeable horizontal layers consisting of fluid-saturated porous rocks through using a generic model, which can be viewed as the representation of a generalized and simplified geological model. Main outcomes of this study have demonstrated that: (1) the proposed semi-analytical approach can produce highly-accurate numerical solutions for solving coupled pore-fluid flow and heat transfer problems in fluid-saturated porous rocks with different porosity structures; (2) the different porosity structure within a permeable horizontal layer consisting of fluid-saturated porous rocks can have a significant effect on the hydrothermal mineralization pattern of the permeable horizontal layer; (3) layered pore-fluid vertical velocity focusing may take place within a permeable horizontal layer involving a heterogeneous porosity structure.

Microstructure and micromechanical properties evolution pattern of metamorphic layer subjected to turning process of carbon steel

Turning process results in microstructure alteration and forms a metamorphic layer beneath the machined surface, which influence micromechanical properties. The metamorphic layer induced by turning was divided into severe deformation layer (SDL) and moderate deformation layer (MDL) through grain size distribution, and the microstructure was observed and characterized by electron backscattered diffraction (EBSD) and transmission electron microscope (TEM). The model to predict the depth of SDL (hSDL) based on dynamic recrystallization and specific shear energy (US) in the cutting process was established, and the results showed that ΔUS had a linear relationship with hSDL (R2 = 0.8799). The micromechanical properties of SDL, MDL, and bulk material were characterized by micro-hardness and micropillar compression tests. The increment of micro-hardness in SDL (increased by 66.4 % on the bulk material) is mainly due to the Hall-Petch effect caused by nanocrystals formed through dynamic recrystallization, and the micro-hardness in MDL (increased by 24.1 % on the bulk material) is affected by the superposition of the Hall-Petch effect and Taylor strengthening caused by the gradient distribution of grain size and dislocation density. The yield stress (σy) obtained from the micropillar compression test decreased successively in SDL, MDL, and bulk material (from 1072 MPa to 604 MPa). The influence mechanism of the critical resolved shear stress (τCRSS) and Schmidt factor (SF) on SDL, MDL, and bulk material were illustrated.

Regulation of Nodal signaling propagation by receptor interactions and positive feedback

During vertebrate embryogenesis, the germ layers are patterned by secreted Nodal signals. In the classical model, Nodals elicit signaling by binding to a complex comprising Type I/II Activin receptors (Acvr) and the co-receptor Tdgf1. However, it is currently unclear whether receptor binding can also affect the distribution of Nodals themselves through the embryo, and it is unknown which of the putative Acvr paralogs mediate Nodal signaling in zebrafish. Here, we characterize three Type I (Acvr1) and four Type II (Acvr2) homologs and show that - except for Acvr1c - all receptor-encoding transcripts are maternally deposited and present during zebrafish embryogenesis. We generated mutants and used them together with combinatorial morpholino knockdown and CRISPR F0 knockout (KO) approaches to assess compound loss-of-function phenotypes. We discovered that the Acvr2 homologs function partly redundantly and partially independently of Nodal to pattern the early zebrafish embryo, whereas the Type I receptors Acvr1b-a and Acvr1b-b redundantly act as major mediators of Nodal signaling. By combining quantitative analyses with expression manipulations, we found that feedback-regulated Type I receptors and co-receptors can directly influence the diffusion and distribution of Nodals, providing a mechanism for the spatial restriction of Nodal signaling during germ layer patterning.

Analysis of Heat Transfer of Mono and Hybrid Nanofluid Flow between Two Parallel Plates in a Darcy Porous Medium with Thermal Radiation and Heat Generation/Absorption

In the last two decades, academicians have concentrated on the nanofluid squeezing flow between parallel plates. The increasing energy demands and their applications have seen the focus shifted to the hybrid nanofluid flows, but so much is still left to be investigated. This analysis is executed to explore the symmetry of the MHD squeezing nanofluid (MoS2/H2O) flow and the hybrid nanofluid (MoS2–SiO2/H2O–C2H6O2) flow between the parallel plates and their heat transport property. The heat transport phenomenon is analyzed with the magnetic field, thermal radiation, heat source/sink, suction/injection effect, and porous medium. In the present model, the plate situated above is in the movement towards the lower plate, and the latter is stretching with a linear velocity. The prevailing PDEs depicting the modeled problem with the aforementioned effects are transformed via similarity transformations and solved via the “bvp4c” function, which is an inbuilt function in MATLAB software. The control of the factors on the fields of velocity and temperature, heat transfer rate, velocity boundary layer patterns, and streamlines is investigated. The solution profiles are visually shown and explained. Furthermore, the Nusselt number at the bottom plate is larger for the (MoS2–SiO2/H2O–C2H6O2) hybrid nanofluid than for the (MoS2/H2O) nanofluid flow. In the presence of suction/injection, the streamlines appear to be denser. In addition, the magnetic field has a thinning consequence on the velocity boundary layer region. The results of this study apply to several thermal systems, engineering, and industrial processes, which utilize nanofluid and hybrid nanofluid for cooling and heating processes.

In Vitro Degradation and In Vivo Skin sensitisation study of Hernia Mesh - Sterilized Partially Absorbable Tissue Separating Dual Layered Surgical Mesh

As hernia mesh implants are used to reinforce the abdominal wall, several complications can occur, such as hernia recurrence, abdominal pain, seroma formation and infection, depending on their biocompatibility. The polymer coated knitted mesh is used to repair hernias by providing a flexible scaffold. The objective of this study was to assess skin sensitisation potential of polar and non-polar extract and In Vitro degradation and In Vivo skin sensitisation pattern for polymer coated knitted mesh. The guinea pig maximization test (GPMT) is usually performed with one moderately irritant induction dose of the allergen and gives a qualitative assessment hazard identification of the allergenicity of the chemical. The apparent morphological change, weight, and strength loss rate of the mesh all showed the degrading impact. The degradation of polymer coated knitted mesh is performed to check polymer layer pattern after implantation.

Soil Layers Impact Lithocarpus Soil Microbial Composition in the Ailao Mountains Subtropical Forest, Yunnan, China

Plant litter decomposition is a complex, long-term process. The decomposition of litterfall is a major process influencing nutrient balance in forest soil. The soil microbiome is exceptionally diverse and is an essential regulator of litter decomposition. However, the microbiome composition and the interaction with litterfall and soil remain poorly understood. In this study, we examined the bacterial and fungal community composition of Lithocarpus across soil samples from different sampling seasons. Our results displayed that the microbiome assembly along the soil layer is influenced predominantly by the soil layer rather than by the sampling season. We identified that the soil layer strongly affected network complexity and that bacterial and fungal microbiomes displayed different patterns in different soil layers. Furthermore, source tracking and community composition analysis indicated that there are significantly different between soil and litter. Moreover, our results demonstrate that few dominant taxa (2% and 4% of bacterial and fungal phylotypes) dominated in the different soil layers. Hydnodontaceae was identified as the most important biomarker taxa for humic fragmented litter fungal microbiome and Nigrospora and Archaeorhizomycetaceae for organic soil and the organic mineral soil layer, and the phylum of Acidobacteria for the bacteria microbiome. Our work provides comprehensive evidence of significant microbiome differences between soil layers and has important implications for further studying soil microbiome ecosystem functions.

Gastric lymphangioma: a case report and review of literature

BackgroundGastric lymphangioma is one of the highly rare benign tumors characterized by multilocular or unilocular lymphatic spaces. Herein, we report a case of lymphangioma in the gastric antrum.Case presentationA 77-year-old male patient who had been experiencing epigastric discomfort for a year was presented to our hospital. A gastric subepithelial lesion was diagnosed by upper endoscopy and was entirely excised via diatal subtotal gastrectomy. Endoscopic ultrasonography revealed an echoless homogenous echo pattern in the third wall layer. A lymphangioma was diagnosed by pathologic investigation of the resected specimen. The PubMed, Embase and Web of Science databases were reviewed for literature in English while using the keywords of “gastric lymphangioma” or “lymphangioma of stomach” or “gastric lymphatic cyst” or “lymphatic cyst of stomach” and the results were discussed.ConclusionGastric lymphangioma is a rarely occurring submucosal tumor that should be considered when diagnosing subepithelial lesions in the stomach.

Adhesion Forces of Shale Oil Droplet on Mica Surface with Different Roughness: An Experimental Investigation Using Atomic Force Microscopy

In order to investigate the effect of rock surface roughness on the occurrence state of shale oil, muscovite mica was firstly characterized by performing atomic force microscopy (AFM). Two-dimensional (2D) images and the three-dimensional (3D) structure of the mica surface were obtained. Wettability of the micas was measured according to the sessile drop method using shale oil, collected from a lacustrine shale oil well drilling through the Yanchang Formation, Ordos Basin. Then, the adhesion forces between shale oil and mica surface with a different roughness were finely measured using AFM mounted with the shale oil modified probe tips. The adhesion force curves at the approaching and retract modes were obtained. The results show that the average roughness value of the mica samples was about 1 nm, while the maximum height was up to 4 nm. The contact angle between shale oil and mica ranged from 128.73° to 145.81°, and increased with increasing surface roughness, which can be described by the Wenzel model. The adhesion force between shale oil and mica also increased with an increasing contact area. Shale oil can fill the deep valleys on the rough surface of rocks and then form microscopic storage for oil droplets. The maximum adhesion force, reached at a distance of about 5–10 nm between shale oil droplets and micas, was between 14 and 30 nN. The adhesion force disappeared when the distance was larger than 40 nm. These indicate that shale oil in pores with a diameter of less than 10 nm was tightly adsorbed, and formed a layered accumulation pattern. Additional energy is needed to decrease the disjoining pressure and then separate shale oil from these tight pores. Shale oil is freely movable at pores with pore diameters of larger than 40 nm. This work provides a new insight about the interaction between shale oil and rock, and helps to understand the occurrence mechanism of shale oil.

Fabrication of a Multilayer X-Band Band-Pass Metasurface Using Liquid Metal

Fabrication of a physically flexible multi-layer metasurface composed of gallium-based liquid metal encapsulated in polydimethylsiloxane (PDMS) is reported. The second-order bandpass frequency selective surface (FSS) operating in the X-band is comprised of two modified Jerusalem cross resonator layers separated by an aperture layer. The multi-layer spatial filter has a total thickness of 4.81 mm ( <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\lambda _{0}$ </tex-math></inline-formula> /7.5). An inverse image mold of the FSS layer patterns is fabricated in silicon, and FSS patterned PDMS is replicated from the silicon mold. The FSS patterned PDMS is spray coated with liquid metal to fabricate a massive array of discrete conductor patterns in PDMS and subsequent encapsulation by an additional layer of PDMS. Multiple versions of the m <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$\times $ </tex-math></inline-formula> n metasurfaces have been fabricated and have been repeatedly tested for their bendability, stretchability, twistability, and foldability. The fabricated metasurface in a waveguide environment demonstrated a band-pass center frequency at 8.33 GHz which agreed well with the simulated frequency at 8.31 GHz.

Three Proton‐Conductors Based on Keggin‐Type Polyoxometalates Well‐Arranged in the Networks of Dinuclear‐Cu(II)‐Mixed‐Organic‐Ligand Clusters

AbstractThree proton‐conductors, [Cu(5‐H2L)(IN)(H2O)]2H2[SiW12O40] ⋅ 2CH3CN ⋅ 2.5H2O (1), [Cu(4‐HL)(HIN)(H2O)]2H2[SiW12O40] ⋅ 7H2O (2) and [Cu(4‐HL)(HIN)(CH3CN)]2[HIN]2H4[PMo12O40]2 ⋅ 2CH3CN ⋅ 12H2O (3) (where 5‐H2L/4‐H2L is 5,5’/4,4’‐bis(hydroxymethyl)‐2,2’‐bipyridine and HIN is isonicotinic acid), were synthesized at room temperature. Interestingly, three dinuclear‐Cu(II)‐mixed‐organic‐ligand clusters, [Cu(5‐H2L)(IN)(H2O)]22+ cluster for 1, [Cu(4‐HL)(HIN)(H2O)]22+ for 2 and [Cu(4‐HL)(HIN)(CH3CN)]22+ for 3, are in situ synthesized under the coexistence of Keggin‐type polyoxometalates. More interestingly, in 1–3, the global Keggin‐type anions are well‐arranged in the hydrogen‐bonding networks of double‐Cu(II)‐mixed‐organic‐ligand clusters to give different spatial arrangement patterns. The [SiW12O40]4− anions in 1 display two dimensional layer pattern. The [SiW12O40]4− anions in 2 act as single bidentate O,O bridge ligands. The [PMo12O40]3− anions in 3 form the pair pattern. The AC impedance measurement results reveal 3 gives a high conductivity value over 10−3∼10−2 S ⋅ cm−1 in a wide temperature range from 25 to 100 °C under a wide relative humidity range from 35 to 98 %, while 1 and 2 give a middle conductivity value over 10−5∼10−4 S ⋅ cm−1 under the same conditions.