High-performance hysteresis-free perovskite transistors through anion engineering

Despite the impressive development of metal halide perovskites in diverse optoelectronics, progress on high-performance transistors employing state-of-the-art perovskite channels has been limited owing to ion migration and large organic spacer isolation. Herein, we report high-performance and hysteresis-free p-channel perovskite thin-film transistors (TFTs) based on methylammonium tin iodide (MASnI3) and rationalise the effects of halide (I/Br/Cl) anion engineering on crystallinity enhancement and vacancy suppression, realising a high hole mobility of 20 cm2 V−1 s−1, current on/off ratio exceeding 107, and threshold voltage of 0 V with high operational stability and reproducibility. We reveal ion migration has a negligible contribution to the hysteresis of Sn-based perovskite TFTs; instead, minority carrier trapping is the primary cause. Finally, we integrate the perovskite TFTs with commercialised n-channel indium gallium zinc oxide TFTs on a single chip to construct high-gain complementary inverters, facilitating the development of halide perovskite semiconductors for printable electronics and circuits.

Observational appearances of a f(R) global monopole black hole illuminated by various accretions

In this paper, we explore three simple models of accretions on a global monopole black hole in f(R) theory, and numerically study the corresponding observational appearances as seen by an observer located at the asymptotic infinity and the certain region out of black hole. For the thin-disk accretion, the results here show that the brighter lensing ring and the darker photon ring that around black hole shadow, always make a small contribution and a negligible contribution to total observed intensity respectively. While, the direct emission of disk contributes a dominant part, and the size of shadow always depends on the disk’s location. For the static and infalling spherical accretions, it turns out that the radiuses of the shadows and photon spheres are always same for both accretions, which implies that the boundary of shadow represents the signature of the spacetime geometry in this case. However, we also find that the brightness of shadow in infalling accretion is darker than that in static case since the Doppler effect is taken into account. In addition, the effect of the global monopole parameter $$\eta $$ η and f(R) parameter $$\psi _0$$ ψ 0 on observational appearances of black hole are clearly emphasized throughout of this paper. Finally, we conclude that black hole shadows and the related rings with some different observable features can be used for us to distinguish black holes from different gravity theories and set the upper limits to the f(R) parameter $$\psi _0$$ ψ 0 .

Differentially expressed genes reflect disease-induced rather than disease-causing changes in the transcriptome

Comparing transcript levels between healthy and diseased individuals allows the identification of differentially expressed genes, which may be causes, consequences or mere correlates of the disease under scrutiny. We propose a method to decompose the observational correlation between gene expression and phenotypes driven by confounders, forward- and reverse causal effects. The bi-directional causal effects between gene expression and complex traits are obtained by Mendelian Randomization integrating summary-level data from GWAS and whole-blood eQTLs. Applying this approach to complex traits reveals that forward effects have negligible contribution. For example, BMI- and triglycerides-gene expression correlation coefficients robustly correlate with trait-to-expression causal effects (rBMI = 0.11, PBMI = 2.0 × 10−51 and rTG = 0.13, PTG = 1.1 × 10−68), but not detectably with expression-to-trait effects. Our results demonstrate that studies comparing the transcriptome of diseased and healthy subjects are more prone to reveal disease-induced gene expression changes rather than disease causing ones.

Physical constraints derived from FCNC in the 3-3-1-1 model

We investigate several phenomena related to FCNCs in the $$\text {3-3-1-1}$$ 3-3-1-1 model. The sources of FCNCs at the tree-level from both the gauge and Higgs sectors are clarified. Experiments on the oscillation of mesons most stringently constrain the tree-level FCNCs. The lower bound on the new physics scale is imposed more tightly than in the previous, $$\text {M}_{\text {new}}>12 $$ M new > 12 TeV. Under this bound, the tree-level FCNCs make a negligible contribution to the $$\text {Br}(B_s \rightarrow \mu ^+ \mu ^-)$$ Br ( B s → μ + μ - ) , $$\text {Br}(B \rightarrow K^{*} \mu ^+ \mu ^-)$$ Br ( B → K ∗ μ + μ - ) and $$\text {Br}(B^{+}\rightarrow K^{+}\mu ^{+}\mu ^{-})$$ Br ( B + → K + μ + μ - ) . The branching ratio of radiative decay $$b \rightarrow s \gamma $$ b → s γ is enhanced by the ratio $$\frac{v}{u}$$ v u via diagrams with the charged Higgs mediation. In contrast, the charged currents of new gauge bosons significantly contribute to the decay process $$\mu \rightarrow e \gamma $$ μ → e γ .

LNG producers will aim to cut their carbon footprint

Significance The companies use carbon offsets in a bid to sustain demand in the face of rising concern about methane emissions, evolving sustainability criteria, the adoption of carbon net-zero targets and a decline in public sector funding for LNG supply chain infrastructure. They are also seeking to reduce the greenhouse gas (GHG) impact of their operations. Impacts Downstream LNG infrastructure projects will find it more difficult to raise public and private finance. Carbon-neutral LNG deliveries will make a negligible contribution to limiting climate change. The adoption of carbon capture and storage to cut emissions from LNG liquefaction will offer insights for other sectors.

Measuring the Casimir Forces with an Adhered Cantilever: Analysis of Roughness and Background Effects

Technological progress has made possible precise measurements of the Casimir forces at distances less than 100 nm. It has enabled stronger constraints on the non-Newtonian forces at short separations and improved control of micromechanical devices. Experimental information on the forces below 30 nm is sparse and not precise due to pull-in instability and surface roughness. Recently, a method of adhered cantilever was proposed to measure the forces at small distances, which does not suffer from the pull-in instability. Deviation of the cantilever from a classic shape carries information on the forces acting nearby the adhered end. We calculate the force between a flat cantilever and rough Au plate and demonstrate that the effect of roughness dominates when the bodies approach the contact. Short-distance repulsion operating at the contact is included in the analysis. Deviations from the classic shape due to residual stress, inhomogeneous thickness of the cantilever, and finite compliance of the substrate are analysed. It is found that a realistic residual stress gives a negligible contribution to the shape, while the finite compliance and inhomogeneous thickness give measurable contributions that have to be subtracted from the raw data.

Decomposing the admixture statistic, D, suggests a negligible contribution due to archaic introgression into humans

It is widely accepted that non-African humans carry a few percent of Neanderthal DNA due to historical inter-breeding. However, methods used to infer a legacy all assume that mutation rate is constant and that back-mutations can be ignored. Here I decompose the widely used admixture statistic, D, in a way that allows the overall signal to be apportioned to different classes of contributing site. I explore three main characteristics: whether the putative Neanderthal allele is likely derived or ancestral; whether an allele is fixed in one of the two human populations; and the type of mutation that created the polymorphism, defined by the base that mutated and immediately flanking bases. The entire signal used to infer introgression can be attributed to a subset of sites where the putative Neanderthal base is common in Africans and fixed in non-Africans. Moreover, the four triplets containing highly mutable CpG motifs alone contribute 29%. In contrast, sites expected to dominate the signal if introgression has occurred, where the putative Neanderthal allele is absent from Africa and rare outside Africa, contribute negligibly. Together, these observations show that D does not capture a signal due to introgression but instead they support an alternative model in which a higher mutation rate in Africa drives increased divergence from the ancestral state.