88 research outputs found
Dolfin: Diffusion Layout Transformers without Autoencoder
In this paper, we introduce a novel generative model, Diffusion Layout
Transformers without Autoencoder (Dolfin), which significantly improves the
modeling capability with reduced complexity compared to existing methods.
Dolfin employs a Transformer-based diffusion process to model layout
generation. In addition to an efficient bi-directional (non-causal joint)
sequence representation, we further propose an autoregressive diffusion model
(Dolfin-AR) that is especially adept at capturing rich semantic correlations
for the neighboring objects, such as alignment, size, and overlap. When
evaluated against standard generative layout benchmarks, Dolfin notably
improves performance across various metrics (fid, alignment, overlap, MaxIoU
and DocSim scores), enhancing transparency and interoperability in the process.
Moreover, Dolfin's applications extend beyond layout generation, making it
suitable for modeling geometric structures, such as line segments. Our
experiments present both qualitative and quantitative results to demonstrate
the advantages of Dolfin
Interfacial Properties of Monolayer and Bilayer MoS2 Contacts with Metals: Beyond the Energy Band Calculations
Although many prototype devices based on two-dimensional (2D) MoS2 have been
fabricated and wafer scale growth of 2D MoS2 has been realized, the fundamental
nature of 2D MoS2-metal contacts has not been well understood yet. We provide a
comprehensive ab initio study of the interfacial properties of a series of
monolayer (ML) and bilayer (BL) MoS2-metal contacts (metal = Sc, Ti, Ag, Pt,
Ni, and Au). A comparison between the calculated and observed Schottky barrier
heights (SBHs) suggests that many-electron effects are strongly suppressed in
channel 2D MoS2 due to a charge transfer. The extensively adopted energy band
calculation scheme fails to reproduce the observed SBHs in 2D MoS2-Sc
interface. By contrast, an ab initio quantum transport device simulation better
reproduces the observed SBH in the two types of contacts and highlights the
importance of a higher level theoretical approach beyond the energy band
calculation in the interface study. BL MoS2-metal contacts have a reduced SBH
than ML MoS2-metal contacts due to the interlayer coupling and thus have a
higher electron injection efficiency.Comment: 36 pages, 13 figures, 3 table
Does P-type Ohmic Contact Exist in WSe2-metal Interfaces?
Formation of low-resistance metal contacts is the biggest challenge that
masks the intrinsic exceptional electronic properties of 2D WSe2 devices. We
present the first comparative study of the interfacial properties between ML/BL
WSe2 and Sc, Al, Ag, Au, Pd, and Pt contacts by using ab initio energy band
calculations with inclusion of the spin-orbital coupling (SOC) effects and
quantum transport simulations. The interlayer coupling tends to reduce both the
electron and hole Schottky barrier heights (SBHs) and alters the polarity for
WSe2-Au contact, while the SOC chiefly reduces the hole SBH. In the absence of
the SOC, Pd contact has the smallest hole SBH with a value no less than 0.22
eV. Dramatically, Pt contact surpasses Pd contact and becomes p-type Ohmic or
quasi-Ohmic contact with inclusion of the SOC. Our study provides a theoretical
foundation for the selection of favorable metal electrodes in ML/BL WSe2
devices
The role played by ailanthone in inhibiting bone metastasis of breast cancer by regulating tumor-bone microenvironment through the RANKL-dependent pathway
Introduction: Bone metastasis of breast cancer (BC) is a process in which the disruption of the bone homeostatic microenvironment leads to an increase in osteoclast differentiation. Ailanthus altissima shows an inhibitory effect on osteoclast differentiation. Ailanthone (AIL) refers to a natural compound isolated from Ailanthus altissima, a Chinese herbal medicine, and has effective anti-tumor activity in numerous cell lines. Its impact on bone metastases for BC is yet unclear.Methods: We measured the effect of AIL on MDA-MB-231 cells by wound healing experiments, Transwell and colony formation experiment. Using the Tartrate-resistant Acid Phosphatase (TRAP) staining tests, filamentous (F-actin) staining and bone resorption test to detect the effect of AIL on the osteoclast cell differentiation of the Bone Marrow-derived Macrophages (BMMs), activated by the MDA-MB-231 cell Conditioned Medium (MDA-MB-231 CM) and the Receptor Activator of Nuclear factor-κB Ligand (RANKL),and to explore its possibility Mechanisms. In vivo experiments verified the effect of AIL on bone destruction in breast cancer bone metastasis model mice.Results:In vitro, AIL significantly decrease the proliferation, migration and infiltration abilities of MDA-MB-231 cells at a safe concentration, and also reduced the expression of genes and proteins involved in osteoclast formation in MDA-MB-231 cells. Osteoclast cell differentiation of the BMMs, activated by MDA-MB-231 CM and RANKL, were suppressed by AIL in the concentration-dependent manner. Additionally, it inhibits osteoclast-specific gene and protein expression. It was noted that AIL inhibited the expression of the osteoclast differentiation-related cytokines RANKL and interleukin-1β (IL-1β) that were secreted by the MDA-MB-231 cells after upregulating the Forkhead box protein 3 (FOXP3) expression. Furthermore, AIL also inhibits the expression of the Mitogen-Activated Protein Kinase (MAPK), Phosphoinositide 3-kinase (PI3K)/protein kinase B (AKT), and Nuclear factor-κB Ligand (NF-κB) signaling pathways, which then suppresses the MDA-MB-231CM-induced development of Osteoclasts.Conclusion: Our study shows that AIL blocks osteoclast differentiation in the bone metastasis microenvironment by inhibiting cytokines secreted by BC cells, which may be a potential agent for the treatment of BC and its secondary bone metastasis
Graphdiyne-metal contacts and graphdiyne transistors
Graphdiyne is prepared on metal surface, and making devices out of it also
inevitably involves contact with metals. Using density functional theory with
dispersion correction, we systematically studied for the first time the
interfacial properties of graphdiyne contacting with a series of metals (Al,
Ag, Cu, Au, Ir, Pt, Ni, and Pd). Graphdiyne is in an n-type Ohmic or
quasi-Ohmic contact with Al, Ag, and Cu, while it is in a Schottky contact with
Au (at source/drain interface), Pd, Pt, Ni, and Ir (at source/drain-channel
interface), with high Schottky barrier heights of 0.39, 0.21 (n-type), 0.30,
0.41, and 0.45 (p-type) eV, respectively. A graphdiyne field effect transistor
(FET) with Al electrodes is simulated by using quantum transport calculations.
This device exhibits an on-off ratio up to 104 and a very large on-state
current of 1.3 * 104 mA/mm in a 10 nm channel length. Thus, a new prospect is
opened up for graphdiyne in high performance nanoscale devices.Comment: 27 pages, 9 figure
Diameter effect on the heat transfer of supercritical hydrocarbon fuel in horizontal tubes under turbulent conditions
This document is the Accepted Manuscript version of the following article: Zeyuan Cheng, Zhi Tao, Jianqin Zhu, and Hongwei Wu, ‘Diameter effect on the heat transfer of supercritical hydrocarbon fuel in horizontal tubes under turbulent conditions’, Applied Thermal Engineering, Vol. 134: 39-53, April 2018. Under embargo until 31 January 2019. The final, definitive version is available online at: https://doi.org/10.1016/j.applthermaleng.2018.01.105This article presented a numerical investigation of supercritical heat transfer of the hydrocarbon fuel in a series of horizontal tubes with different diameters. The Reynolds averaging equations of mass, momentum and energy with the LS low-Reynolds number turbulence model have been solved using the pressure-based segregated solver based on the finite volume method. For the purpose of comparison, a four-species surrogate model and a ten-species surrogate model of the aviation kerosene RP-3 (Rocket Propellant 3) were tested against the published experimental data. In the current study, the tube diameter varied from 2 mm to 10 mm and the pressure was 3 MPa with heat flux to mass flux ratios ranging from 0.25 to 0.71 kJ/kg. It was found that the buoyancy has significant effect on the wall temperature non-uniformity in the horizontal tube. With the increase of the diameter, the buoyancy effect enhances and the thermal-induced acceleration effect reduces. The buoyancy effect makes wall temperature at the top and bottom generatrices of the horizontal tube increase and decrease, respectively. Due to the coupled effect of the buoyancy and thermal-induced acceleration caused by the significant change of the properties, as the diameter increases, the heat transfer deteriorates dramatically at the top generatrix but remains almost unchanged at the bottom generatrix at high heat flux to mass flux ratio. Heat transfer enhancement is observed at low heat flux to mass flux ratio when the tube diameter is less than 6 mm. Moreover, the safety analysis has been performed in order to optimally design the supercritical cooling system.Peer reviewe
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