175 research outputs found
Pointwise approximation by Baskakov quasi-interpolants
AbstractRecently, the quasi-interpolants of some classical operators were introduced. Mache and Müller gave Baskakov quasi-interpolants and obtained approximation equivalence theorem with ωϕ2r(f,t)∞ In this paper, we extend the above result with modulus ωϕλ2r(f,t)∞ (0 ≤ λ ≤ 1) which unified classical modulus and Ditzian-Totik modulus
Combination of sonic wave velocity, density and electrical resistivity for joint estimation of gas-hydrate reservoir parameters and their uncertainties
Gas-hydrate saturation and porosity are the most crucial reservoir parameters for gas-hydrate resource assessment. Numerous academics have put forward elastic and electrical petrophysical models for calculating the saturation and porosity of gas-hydrate. However, owing to the limitations of a single petrophysical model, the estimation of gas-hydrate saturation and porosity using single elastic or electrical measurement data appears to be inconsistent and uncertain. In this study, the sonic wave velocity, density and resistivity well log data are combined with a Bayesian linear inversion method for the simultaneous estimation of gas-hydrate saturation and porosity. The sonic wave velocity, density and resistivity data of the Shenhu area in the South China Sea are used to estimate the gas-hydrate saturation and porosity. To validate the accuracy of this method, the estimation results are compared with the saturation obtained from pore water chemistry and porosity obtained from density logs. The well log data examples show that the joint estimation method not only provides a rapid estimation of the gas-hydrate reservoir parameters but also improves the accuracy of results and determines their uncertainty.Document Type: Original articleCited as: Zhang, X., Li, Q., Li, L., Fan, Q., Geng, J. Combination of sonic wave velocity, density and electrical resistivity for joint estimation of gas-hydrate reservoir parameters and their uncertainties. Advances in Geo-Energy Research, 2023, 10(2): 133-140. https://doi.org/10.46690/ager.2023.11.0
A method for considering a distributed spring constant for studying the flexural vibration of an Euler-beam with lightweight multistage local resonators
For the traditional locally resonant beams there always attached the one-stage local resonator and result that the lower band gap the heavier the scattering ring. In order to resolve this problem, the flexural vibration band gap in an Euler beam with periodically arranged lightweight multistage local resonators was theoretically investigated using the transfer matrix method based on discretization of lumped mass. The present method considered a distributed spring constant, which showed fast convergence with less computational requirements. A finite element method was then employed to calculate the frequency response function of a finite sample simultaneously, which demonstrated that the results calculated using the proposed method were closer to the simulation results than those obtained using the traditional transfer matrix method. The study found that, under the same additional mass, the lightweight multistage structure had much lower beginning frequency than one-stage structure, and the total width of the gaps was basically the same. In addition, a simplified model of the beginning frequency of gaps was proposed, and the effect of scattering density on the model precision was further explored numerically. The results show that the lower scattering density, the more important the role of the rubber mass and the higher precision of the simplified model
miR-155 Regulated Inflammation Response by the SOCS1-STAT3-PDCD4 Axis in Atherogenesis
Robust Representation Learning for Unified Online Top-K Recommendation
In large-scale industrial e-commerce, the efficiency of an online
recommendation system is crucial in delivering highly relevant item/content
advertising that caters to diverse business scenarios. However, most existing
studies focus solely on item advertising, neglecting the significance of
content advertising. This oversight results in inconsistencies within the
multi-entity structure and unfair retrieval. Furthermore, the challenge of
retrieving top-k advertisements from multi-entity advertisements across
different domains adds to the complexity. Recent research proves that
user-entity behaviors within different domains exhibit characteristics of
differentiation and homogeneity. Therefore, the multi-domain matching models
typically rely on the hybrid-experts framework with domain-invariant and
domain-specific representations. Unfortunately, most approaches primarily focus
on optimizing the combination mode of different experts, failing to address the
inherent difficulty in optimizing the expert modules themselves. The existence
of redundant information across different domains introduces interference and
competition among experts, while the distinct learning objectives of each
domain lead to varying optimization challenges among experts. To tackle these
issues, we propose robust representation learning for the unified online top-k
recommendation. Our approach constructs unified modeling in entity space to
ensure data fairness. The robust representation learning employs domain
adversarial learning and multi-view wasserstein distribution learning to learn
robust representations. Moreover, the proposed method balances conflicting
objectives through the homoscedastic uncertainty weights and orthogonality
constraints. Various experiments validate the effectiveness and rationality of
our proposed method, which has been successfully deployed online to serve real
business scenarios.Comment: 14 pages, 6 figures, submitted to ICD
Fast, multicolor photodetection with graphene-contacted p-GaSe/n-InSe van der Waals heterostructures
The integration of different two-dimensional materials within a multilayer van der Waals (vdW) heterostructure offers a promising technology for high performance opto-electronic devices such as photodetectors and light sources. Here we report on the fabrication and electronic properties of vdW heterojunction diodes composed of the direct band gap layered semiconductors InSe and GaSe and transparent monolayer graphene electrodes. We show that the type II band alignment between the two layered materials and their distinctive spectral response, combined with the short channel length and low electrical resistance of graphene electrodes, enable efficient generation and extraction of photoexcited carriers from the heterostructure even when no external voltage is applied. Our devices are fast ( ~ 1 μs), self-driven photodetectors with multicolor photoresponse ranging from the ultraviolet to the near-infrared and offer new routes to miniaturized optoelectronics beyond present semiconductor materials and technologies
A Modeling Study of Benthic Detritus Flux\u27s Impacts on Heterotrophic Processes in Lake Michigan
Effects of sediment resuspension-induced benthic detrital flux on the heterotrophic part of the microbial food web in Lake Michigan were examined using a three-dimensional (3-D) coupled biological and physical model. The model was driven by the realistic meteorological forcing observed in March 1999. Wind-induced surface wave dynamics were incorporated into the physical model to generate the bottom flux. The model-generated benthic detrital flux was assumed to be proportional to the difference between model-calculated and critical stresses at the bottom. The model results indicate that detrital flux at the bottom was a key factor causing a significant increase of phosphorus and detritus concentrations in the nearshore region of the springtime plume. Inside the plume the sediment-resuspended bottom detritus flux could directly enhance heterotrophic production, while outside the plume, detrital flux from river discharge might have a direct contribution to the high abundance of bacteria and microzooplankton in the nearshore region. Model-data comparison on cross-shore transects near Chicago, Gary, St. Joseph, and Racine suggests that other physical and biological processes may play a comparative role as the bottom detritus flux in terms of the spatial distribution of bacteria and microzoplankton. A more complete microbial food web model needs to be developed to simulate the heterotrophic process in southern Lake Michigan
A comprehensive review of circRNA: from purification and identification to disease marker potential
Circular RNA (circRNA) is an endogenous noncoding RNA with a covalently closed cyclic structure. Based on their components, circRNAs are divided into exonic circRNAs, intronic circRNAs, and exon-intron circRNAs. CircRNAs have well-conserved sequences and often have high stability due to their resistance to exonucleases. Depending on their sequence, circRNAs are involved in different biological functions, including microRNA sponge activity, modulation of alternative splicing or transcription, interaction with RNA-binding proteins, and rolling translation, and are a derivative of pseudogenes. CircRNAs are involved in the development of a variety of pathological conditions, such as cardiovascular diseases, diabetes, neurological diseases, and cancer. Emerging evidence has shown that circRNAs are likely to be new potential clinical diagnostic markers or treatments for many diseases. Here we describe circRNA research methods and biological functions, and discuss the potential relationship between circRNAs and disease progression
Validating DLL3-targeting CAR T in small cell lung cancer
View full abstracthttps://openworks.mdanderson.org/leading-edge/1022/thumbnail.jp
Competition between liquid crystallinity and block copolymer self-assembly in core-shell rod-coil block copolymers
Core-shell type of architecture revealed the subtle competition between liquid-crystalline ordering and block copolymer (BCP) self-assembly in a rod-coil BCP system. Block copolymer (BCP) self-assembly offers a simple and controllable means to obtain nanostructures with typical orders on the scale of 5-100 nm. 1 Liquid crystals (LCs) are one class of soft materials that undergo self-organization at 1-10 nm. 2 Incorporating LCs as one of the blocks in a BCP results in LCBCPs that possess both structural hierarchy and functionality. 3 One unique type of LCBCP is the rodcoil BCP (RCBCP), in which one block adopts a rigid rod-like conformation. 4 Several factors affect the thermodynamic behavior of these systems, including c (Flory-Huggins parameter), N (degree of polymerization), f (volume fraction of each block), the order parameter of the macromolecular mesogen, and the area per junction of the rod (A rod ) and the coil (A coil ). 4 Novel self-assembling behaviors with complex phase structures different from the coil-coil systems have been observed. 4 In general, at symmetric volume fractions, lamellar morphology is prevalent. At asymmetric volume fractions, morphologies with highly curved interfaces such as sphere (S) or gyroid (G) have only been observed in low molecular mass rod-coil systems. 4c,5 As the molecular weight of the rod increases, the rigid rod becomes incompatible with the curved inter-material dividing surface (IMDS) dictated by S or G phases; there thus exists competition between liquid crystallinity of the rods and BCP self-assembly. Most of the reported work showed that liquid crystallinity dominated the phase behavior and the S or G phase was often degenerated into structures with planar IMDS such as zig-zag, arrow-head, mushroom, perforated lamellae, etc. 4a-d This is because the interaction between the rods is relatively strong and LC ordering dominates the ordering process. Thus, we hypothesize that in a RCBCP system with relatively weak LC interactions, BCP self-assembly could dominate the overall phase structure. In order to test this hypothesis, we designed a core-shell RCBCP using mesogen-jacketed LC polymers (MJLCP). Side-attaching LC mesogens directly along the polymer backbone leads to MJLCP systems within which the strong interactions between the mesogens and backbone force the backbone to adopt an extended chain conformation and the polymer chains arrange in the form of macromolecular columns. 6 Further linking MJLCPs with coil chains leads to MJ-RCBCPs. Compared to other types of rod-forming macromolecules such as polypeptides, 7 LC/conjugated oligomers, 8 and poly(hexyl isocyanate) (PHIC) and it derivatives, 4a using MJLCP as the rod to form RCBCP is advantageous because the length, diameter and the surface chemistry of the macromolecular rods can be readily controlled. 9 The molecular weight of the rod dictates the rod length, and the mesogen structure determines the rod diameter and surface chemistry. By using relatively long soft tails in the molecular design, a core-shell rod can be obtained with an aromatic core and an aliphatic shell. (Scheme 1a). Herein we report that, in this system, the shell decouples the strong rod-rod interactions and influences the competition between liquid crystallinity of the rods and BCP self-assembly, which in turn, leads to a variety of new hierarchical structures. The unique role of the shell in the RCBCP structure formation is two fold: first, in the symmetric BCPs, both BCP self-assembly and LC ordering dictate planar IMDS. In this case, the shell enhances the LC ordering and novel columnar-hexagonalin-lamellar (F H -in-L) hierarchical nanostructure was observed. Second, in the asymmetric BCPs, since BCP self-assembly and LC ordering dictate different types of IMDS (curved vs. planar), the shell decreased rod-rod interaction and BCP self-assembly became the dominant factor. Consequently, LC symmetry breaks (from F H to F N ) to compromise with the stronger BCP self-assembly process. Poly[styrene-block-{3,5-bis[(4 0 -((4 00 -tetradecanoylbenzoyl)oxy)benzoyl)oxy]styrene}] (PS-b-PTBOS) where the mesogen is a bent-core LC (BCLC), was chosen as the model RCBCP system (Scheme 1b, see ESI † for the detailed experimental procedure). 9 BCLCs exhibit unique phase structures and possess excellent electro-optical properties. 10 In the present case, the five-ring mesogen ensures a rigid core of the rod with a relatively large diameter while the 14-C tails of the mesogen render a relatively thick ''shell''. A series of BCPs have been synthesized using atomic transfer radical polymerization, representing the symmetric, PS-rich and PTBOS-rich BCPs. On the basis of differential scanning calorimetry and polarized light microscopy experiments, all these samples show LC behavior with the isotropization temperature of 240 C (see ESI †). Small-angle X-ray scattering and wide-angle X-ray diffraction (SAXS, WAXD) experiments were conducted on the sheared BCP samples, and Scheme 1c shows the shear geometry consisting of the flow direction (FD), constraint direction (CD), and load direction (LD). For the symmetric BCPS, (i.e. PS 202 -b-PTBOS 35 f PTBOS 0.58)
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