232 research outputs found
Molecular Layer Deposition of Functional Thin Films for Advanced Lithographic Patterning
Photoresist materials comprise one of the main challenges faced by lithography to meet the requirements of electronic device size scaling. Here we report for the first time the use of molecular layer deposition (MLD) to produce photoresist materials with controllable placement of functional moieties. Polyurea resists films are deposited by MLD using urea coupling reactions between 1,4-phenylene diisocyanate (PDIC) and ethylenediamine (ED) or 2,2′-(propane-2,2-diylbis(oxy))diethanamine (PDDE) monomers in a layer-by-layer fashion with a linear growth rate, allowing acid-labile groups to be incorporated into the film at well-controlled positions. The films are deposited with stoichiometric compositions and have highly uniform surface morphology as investigated using atomic force microscopy. We show that acid treatment can cleave the backbone of the polyurea film at positions where the acid-labile groups are embedded. We further show that after soaking the polyurea film with photoacid generator (PAG), it acts as a photoresist material and we present several UV patterning demonstrations. This approach presents a new way to make molecularly designed resist films for lithography
Designing an Air-Stable Interphase on Lithium Metal Anode to Improve Cycling Performance
The application of rechargeable lithium metal batteries
is challenged
by intractable issues of uncontrollable Li dendrite growth that result
in poor cycle life and safety risks. In this work, an air-stable interphase
is developed to protect the lithium metal anode (LMA) via a facile
solution-based approach. The Ag-embedded fluoride-rich interphase
not only creates abundant lithiophilic sites for homogenizing Li nucleation
and growth but also resists severe air erosion to protect the LMA
beneath and enable decent cycling stability. As a result, the Ag–F-rich
interphase enables flat Li deposition on LMA, which is clearly observed
in the operando Li plating experiments. Paired with a LiFePO4 cathode (11.8 mg cm–2), the Ag–F-rich interphase-modified
LMA enables 300 stable cycles at 0.5 C, delivering a capacity retention
ratio as high as 91.4%. Even after being exposed to air for 1 h, the
modified LMA still runs smoothly for over 120 cycles with ignorable
capacity decay, exhibiting great air stability. This work proves the
concept of functionalizing the interphase on the LMA to enable good
cycling performance even under severe air erosion
Designing an Air-Stable Interphase on Lithium Metal Anode to Improve Cycling Performance
The application of rechargeable lithium metal batteries
is challenged
by intractable issues of uncontrollable Li dendrite growth that result
in poor cycle life and safety risks. In this work, an air-stable interphase
is developed to protect the lithium metal anode (LMA) via a facile
solution-based approach. The Ag-embedded fluoride-rich interphase
not only creates abundant lithiophilic sites for homogenizing Li nucleation
and growth but also resists severe air erosion to protect the LMA
beneath and enable decent cycling stability. As a result, the Ag–F-rich
interphase enables flat Li deposition on LMA, which is clearly observed
in the operando Li plating experiments. Paired with a LiFePO4 cathode (11.8 mg cm–2), the Ag–F-rich interphase-modified
LMA enables 300 stable cycles at 0.5 C, delivering a capacity retention
ratio as high as 91.4%. Even after being exposed to air for 1 h, the
modified LMA still runs smoothly for over 120 cycles with ignorable
capacity decay, exhibiting great air stability. This work proves the
concept of functionalizing the interphase on the LMA to enable good
cycling performance even under severe air erosion
Designing an Air-Stable Interphase on Lithium Metal Anode to Improve Cycling Performance
The application of rechargeable lithium metal batteries
is challenged
by intractable issues of uncontrollable Li dendrite growth that result
in poor cycle life and safety risks. In this work, an air-stable interphase
is developed to protect the lithium metal anode (LMA) via a facile
solution-based approach. The Ag-embedded fluoride-rich interphase
not only creates abundant lithiophilic sites for homogenizing Li nucleation
and growth but also resists severe air erosion to protect the LMA
beneath and enable decent cycling stability. As a result, the Ag–F-rich
interphase enables flat Li deposition on LMA, which is clearly observed
in the operando Li plating experiments. Paired with a LiFePO4 cathode (11.8 mg cm–2), the Ag–F-rich interphase-modified
LMA enables 300 stable cycles at 0.5 C, delivering a capacity retention
ratio as high as 91.4%. Even after being exposed to air for 1 h, the
modified LMA still runs smoothly for over 120 cycles with ignorable
capacity decay, exhibiting great air stability. This work proves the
concept of functionalizing the interphase on the LMA to enable good
cycling performance even under severe air erosion
DataSheet_1_Gene expression variations and allele-specific expression of two rice and their hybrid in caryopses at single-nucleus resolution.docx
Seeds are an indispensable part of the flowering plant life cycle and a critical determinant of agricultural production. Distinct differences in the anatomy and morphology of seeds separate monocots and dicots. Although some progress has been made with respect to understanding seed development in Arabidopsis, the transcriptomic features of monocotyledon seeds at the cellular level are much less understood. Since most important cereal crops, such as rice, maize, and wheat, are monocots, it is essential to study transcriptional differentiation and heterogeneity during seed development at a finer scale. Here, we present single-nucleus RNA sequencing (snRNA-seq) results of over three thousand nuclei from caryopses of the rice cultivars Nipponbare and 9311 and their intersubspecies F1 hybrid. A transcriptomics atlas that covers most of the cell types present during the early developmental stage of rice caryopses was successfully constructed. Additionally, novel specific marker genes were identified for each nuclear cluster in the rice caryopsis. Moreover, with a focus on rice endosperm, the differentiation trajectory of endosperm subclusters was reconstructed to reveal the developmental process. Allele-specific expression (ASE) profiling in endosperm revealed 345 genes with ASE (ASEGs). Further pairwise comparisons of the differentially expressed genes (DEGs) in each endosperm cluster among the three rice samples demonstrated transcriptional divergence. Our research reveals differentiation in rice caryopsis from the single-nucleus perspective and provides valuable resources to facilitate clarification of the molecular mechanism underlying caryopsis development in rice and other monocots.</p
DataSheet_2_Gene expression variations and allele-specific expression of two rice and their hybrid in caryopses at single-nucleus resolution.xlsx
Seeds are an indispensable part of the flowering plant life cycle and a critical determinant of agricultural production. Distinct differences in the anatomy and morphology of seeds separate monocots and dicots. Although some progress has been made with respect to understanding seed development in Arabidopsis, the transcriptomic features of monocotyledon seeds at the cellular level are much less understood. Since most important cereal crops, such as rice, maize, and wheat, are monocots, it is essential to study transcriptional differentiation and heterogeneity during seed development at a finer scale. Here, we present single-nucleus RNA sequencing (snRNA-seq) results of over three thousand nuclei from caryopses of the rice cultivars Nipponbare and 9311 and their intersubspecies F1 hybrid. A transcriptomics atlas that covers most of the cell types present during the early developmental stage of rice caryopses was successfully constructed. Additionally, novel specific marker genes were identified for each nuclear cluster in the rice caryopsis. Moreover, with a focus on rice endosperm, the differentiation trajectory of endosperm subclusters was reconstructed to reveal the developmental process. Allele-specific expression (ASE) profiling in endosperm revealed 345 genes with ASE (ASEGs). Further pairwise comparisons of the differentially expressed genes (DEGs) in each endosperm cluster among the three rice samples demonstrated transcriptional divergence. Our research reveals differentiation in rice caryopsis from the single-nucleus perspective and provides valuable resources to facilitate clarification of the molecular mechanism underlying caryopsis development in rice and other monocots.</p
Area Selective Molecular Layer Deposition of Polyurea Films
Patterned organic thin films with
submicrometer features are of
great importance in applications such as nanoelectronics and optoelectronics.
We present here a new approach for creating patterned organic films
using area selective molecular layer deposition (MLD). MLD is a technique
that allows for conformal deposition of nanoscale organic thin films
with exceptional control over vertical thickness and composition.
By expanding the technique to allow for area selective MLD, lateral
patterning of the film can be achieved. In this work, polyurea thin
films were deposited by alternating pulses of 1,4-phenylenediisocyanate
(PDIC) and ethylenediamine (ED) in a layer-by-layer fashion with a
linear growth rate of 5.3 Å/cycle. Studies were carried out to
determine whether self-assembled monolayer (SAM) formed from octadecyltrichlorosilane
(ODTS) could block MLD on silicon substrates. Results show that the
MLD process is impeded by the SAM. To test lateral patterning in MLD,
SAMs were patterned onto silicon substrates using two different approaches.
In one approach, SiO<sub>2</sub>-coated Si(100) substrates were patterned
with an ODTS SAM by soft lithography in a well-controlled environment.
In the second approach, patterned ODTS SAM was formed on H–Si/SiO<sub>2</sub> patterned wafers by employing the chemically selective adsorption
of ODTS on SiO<sub>2</sub> over H–Si. Auger electron spectroscopy
results revealed that the polyurea film is deposited predominantly
on the ODTS-free regions of both patterned substrates, indicating
sufficient blocking of MLD by the ODTS SAM layer to replicate the
pattern. The method we describe here offers a novel approach for fabricating
high quality, three-dimensional organic structures
LBM results for a system with a sound source in a Poiseuille flow profile.
<p>Figure (a) shows the horizontal velocity component. Figure (b) shows the density field. Figure (c) shows the excess sound level Δ<i>L</i> at receivers near the lower wall (at the same height as the source, i.e. two lattice spacings above the lower wall).</p
As Fig 13, but now for a system with halved lattice spacing.
<p>As <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0147206#pone.0147206.g013" target="_blank">Fig 13</a>, but now for a system with halved lattice spacing.</p
Results of an LBM calculation for a source and receivers at <i>y</i> = 250 and a porous medium below <i>y</i> = 200, showing the sound field at time 1600 (a) and the sound level as a function of distance (b).
<p>Results of an LBM calculation for a source and receivers at <i>y</i> = 250 and a porous medium below <i>y</i> = 200, showing the sound field at time 1600 (a) and the sound level as a function of distance (b).</p
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