bluuebunny/crossref_metadata_2025_split huggingface dataset:
Doping-less tunnel field-effect transistors by compact Si drain frame/Si0.6Ge0.4-channel/Ge source
Authors: Lee Byoung-Seok , Kim Min-Won , Kim Ji-Hun , Yoo Sang-Dong , Shim Tae-Hun , Hong Jin-Pyo , Park Jea-Gun 
Published: April 2021

Tunnel field-effect transistors (TFETs) have attracted immense interest as a promising alternative to complementary metal–oxide semiconductors for low-power-consumption applications. However, conventional TFETs introduce both random dopant fluctuations and ambipolar current issues at negative gate voltages for sub-6-nm technology nodes. In this study, we address the performance of charge plasma-driven doping-less TFETs, including sub-3-nm thick compact drain (CD) geometry/SiGe-channel/Ge source layers for suitable bandgap engineering. An ultrathin CD frame and heteromaterials are adopted for use as channels/sources to improve the ambipolarity and ON-state features, respectively. Simulation demonstrates a clear reduction in the ambipolar current from 3.3 × 10−14 to 3.0 × 10−17 A at gate (VG)/drain (VD) voltages of −1.5/1.0 V and an enhancement in the ON-current from 2.0 × 10−5 to 8.6 × 10−5 A at VG = 1.5 and VD = 1.0 V, compared with conventional TFETs. In addition, diverse fabrication-friendly metals applicable to industry fieldwork sites are tested to determine how the metal work functions influence the outputs. The use of Ti/W/Ni as the drain/channel/source materials, respectively, yields an enhanced ambipolar current of 1.2 × 10−20 A and an ON-current of 3.9 × 10−5 A.
Molecular dynamics simulation on spreading of mixture nanodroplets on a smooth and homogeneous surface
Authors: Di Jiawei , Yang Zhen , Duan Yuanyuan 
Published: April 2021

The dynamic wetting of mixture droplets on the solid surface is important for various industrial technologies and applications, such as evaporation, microfluidics, surface self-cleaning, and power cycling. Due to the influence of different components, the dynamic wetting process of mixture droplets is quite different from that of pure fluids. Currently, the understanding of the spreading mechanism of mixture droplets is lacking. In this paper, molecular dynamics simulation is used to study the dynamic spreading process of ethanol/water and difluoromethane (R32)/2,3,3,3-tetrafluoroprop-1-ene (R1234yf) mixture droplets on a smooth and homogeneous surface. The droplets have different component mole fractions and various diameters of 9.4–12.8 nm. The influences of the component mole fraction on the spreading radius and dynamic contact angle are analyzed and compared with molecular kinetic theory. It is found that for the R32/R1234yf mixture droplets, the component mole fractions in the bulk and at the interface of the droplet are close and the dynamic spreading process is similar to that of pure fluids. However, for the ethanol/water mixture droplets, the mole fraction of ethanol is higher at the vapor–liquid and solid–liquid interfaces than in the bulk, and the spreading is faster than that of pure fluids. The mole fraction and the physical properties in the triple contact region are analyzed, and an improved prediction is proposed for the moving velocity of the triple contact line and the spreading process of the mixture droplet.
Study on the characteristics of elongation at break and tensile strength of photovoltaic insulating backsheets subjected to partial discharge degradation
Authors: Wang Qian , Sun Jinge , Li Tianhao , Xiao Peng 
Published: April 2021

As widely distributed vast reserves of emerging green energy, solar energy has gained widespread attention in recent years. Photovoltaic (PV) power generation is one of the most scientific ways to use solar energy. In PV systems, polyethylene terephthalate (PET) is the chief material of PV backsheets. It is well known that PV backsheets will encounter various challenges, among which partial discharge (PD) is one of these that cause deterioration in insulating and mechanical properties of PET. It has severely affected the service life of PV backsheets. In this paper, the PD characteristic of PET samples at different PD durations and temperatures was studied through phase-resolved PD patterns. In addition, the change mechanism of mechanical properties including elongation at break and tensile strength of PET after PD in 30, 60, and 120 min at 30 and 55 °C was also studied. It can be found that the insulating and mechanical properties of PET are reduced after PD degradation at different aging durations and temperatures. This study can provide a reference for the performance improvement of PV PET backsheets, which will also help to evaluate the service life of the PV module and PV power generation systems.
Growth of InAs0.32Sb0.68 on GaAs using a thin GaInSb buffer and strain superlattice layers
Authors: Tan Kian Hua , Loke Wan Khai , Wicaksono Satrio , Yoon Soon Fatt 
Published: April 2021

We report on the growth of an InAs0.32Sb0.68 layer on (001) GaAs substrates. The lattice mismatch strain between the InAs0.32Sb0.68 layer and the GaAs substrate was accommodated using a thin 50–100 nm Ga0.35In0.65Sb buffer with interfacial misfit (IMF) dislocations. The epitaxial structures were characterized using transmission electron microscopy and x-ray diffraction analysis. The threading dislocation density in the InAs0.32Sb0.68 layer was reduced successfully to ∼1 × 108 cm−2 using the combination of a Ga0.35In0.65Sb IMF buffer and InSb/Ga0.35In0.65Sb superlattice layers. Compared to GaSb/GaAs and InSb/GaAs interfaces, a significantly higher threading dislocation density (&gt;1011 cm−2) was observed at the Ga0.35In0.65Sb/GaAs interface. Detailed analysis suggests that high threading dislocation density in the Ga0.35In0.65Sb IMF buffer could be due to the non-uniform microscopic distribution of indium and gallium atoms. This work is beneficial to the scientific community in the growth of the InAs0.32Sb0.68 material as it provides a novel approach to prepare a platform for the growth of the InAs0.32Sb0.68 material, which does not have a suitable lattice-matched substrate, on the widely available GaAs substrate.
Fundamentals of Recoupling and Decoupling Techniques in Solid State NMR
Authors: Chen Bo 
Published: April 2021

Fundamentals of Recoupling and Decoupling Techniques in Solid State NMR provides broad coverage from the fundamentals through updated recoupling and decoupling techniques. It details step by step derivations and teaches readers how solid state NMR with Magic Angle Spinning exploits the interplay between mechanical rotation and radio frequency (RF) pulses to actively switch on (recoupling) and off (decoupling) desired interactions.
This unique book offers:Coverage from the basic through advanced topics and incorporates step by step derivations and exercisesConceptual, experimental, and mathematical aspects of modern solidstate NMRDetailed instruction of tensor calculus and step-by-step derivation to help students learn magic angle spinning phase integration
This book is ideal for upper level undergraduate students majoring in physics or a related discipline and practicing physicists interested in learning more about this topic.
The Density Matrix and its Basic Applications in NMR
Authors: Chen Bo 
Published: April 2021

I hope we now established some qualitative physical concepts and pictures about the fundamentals of NMR after the first three chapters. This chapter will introduce the basics of quantitative analysis of NMR experiments by quantum mechanics. A good background in linear algebra will be very beneficial, even if you have no prior knowledge of quantum mechanics.
We will start our discussion with introduction of relevant quantum mechanical concepts and principles necessary for our NMR analysis, with emphasis on the density matrix method. Then density matrix will be applied to explain the concept of coherence, and why normally only -1 coherence is detected in our quadrature detection setup. As an example, the evolution of a system consisting of non-interacting spins will be derived under one of the most famous RF pulse sequences, the Hahn Echo, in the presence of isotropic chemical shift.
To account for interactions, we will demonstrate how to break down the dipolar interaction into different coherent components. Subsequently we will introduce the operator formalism, which is based on the density matrix method. The operator formalism will be applied to analyze some basic NMR pulse sequences, including the Stimulated Echo, Solid Echo and adiabatic demagnetization. In this process, the effects of nuclear interaction are manifested by their effect over the evolution of the spin system.
In this process, another important concept, the coherence transfer will be demonstrated. It is frequently exploited in various NMR pulse sequences, both in solution and ssNMR. To facilitate the analysis, the transformation into fictitious double and zero quantum space will be introduced. They will be employed to demonstrate the excitation and detection of double quantum coherence by a simple (π2)x−τ−(π2)x sequence. It shares the core principles as other advanced pulse sequences to be discussed in Chapter 6 and 7. To generalize our discussion, the Cogwheel phase cycling will be explained as the optimal strategy for coherence pathway selection. The fictitious spin operators will also be applied to analyze the mechanism of cross polarization (CP), one of the most frequently applied signal enhancement pulse sequence in ssNMR. We will end our discussion with the average Hamiltonian theory (AHT), which will be our main theoretical framework to analyze more complicated pulse sequences in subsequent chapters.
CLK1 reorganizes the splicing factor U1-70K for early spliceosomal protein assembly
Authors: Aubol Brandon E. , Wozniak Jacob M. , Fattet Laurent , Gonzalez David J. , Adams Joseph A. 
Published: April 2021

Significance
Proteome size is greatly enhanced through alternative mRNA splicing, a process catalyzed by the macromolecular spliceosome. The initial step in spliceosome assembly involves the binding of U1 snRNP to the 5′ splice site in mRNA. SR proteins ensure the fidelity of this step by simultaneously binding to mRNA and U1-70K, a protein component of U1 snRNP. Although phosphorylation of U1-70K is required for coupling to the SR protein, the enzyme that catalyzes this modification and the activating mechanisms are unknown. Here, we show that the protein kinase CLK1 phosphorylates a specific serine in the splicing factor U1-70K, reorganizing its structure and relieving a repressor contact for integration into U1 snRNP and stable binding to the SR protein.
Emerging challenges of ozone impacts on asian plants: actions are needed to protect ecosystem health
Authors: Feng Zhaozhong , Agathokleous Evgenios , Yue Xu , Oksanen Elina , Paoletti Elena , Sase Hiroyuki , Gandin Anthony , Koike Takayoshi , Calatayud Vicent , Yuan Xiangyang , Liu Xuejun , De Marco Alessandra , Jolivet Yves , Kontunen-Soppela Sari , Hoshika Yasutomo , Saji Hikaru , Li Pin , Li Zhengzhen , Watanabe Makoto , Kobayashi Kazuhiko 
Published: April 2021

ABSTRACT

Context
: Ozone concentrations near the land surface are rising in Asia while they are declining or stagnating in Europe and North America. Ozone is the most widespread air pollutant negatively affecting vegetation, and its increased concentrations pose a major threat to food quality and production and other ecosystem services in Asia.
Method
: In this review, we provide an overview of scientific challenges in the impacts of ozone pollution on Asian vegetation, and synthesize the challenges toward mitigation of the impacts.
Result
: We argue that new policy initiatives need to seek both reduction of ozone levels and enhancement of plant tolerance to ozone to maintain food quality and ensure food supplies.
Conclusion
: The scientific advancements must be transferred to actions by two types of institutions: a) environmental agencies for reducing ozone levels and b) agricultural research institutions for enhancing plant tolerance to ozone. In connecting the scientific advancements with the institutional actions, scientists in Asian countries should play the key role taking advantages of interdisciplinary and international collaborations.
Spatiotemporal characteristics of atmospheric turbulence over China estimated using operational high-resolution soundings
Authors: Lv Yanmin , Guo Jianping , Li Jian , Cao Lijuan , Chen Tianmeng , Wang Ding , Chen Dandan , Han Yi , Guo Xiaoran , Xu Hui , Liu Lin , Solanki Raman , Huang Gang 
Published: April 2021

Abstract
Large-scale in situ observations are sorely lacking, leading to poor understanding of nationwide atmospheric turbulence over China. Nevertheless, high-resolution soundings have become available starting in 2011, providing a unique opportunity to investigate turbulence across China. Here, we calculated the mean turbulence dissipation rate (ϵ) from radiosonde measurements across China for the period 2011–2018 using Thorpe analysis. The atmospheric layers that had stronger turbulence indicated by larger ϵ generally came with larger Thorpe length but with smaller Brunt–Väisälä frequency. Overall, the clear-air ϵ in the free atmosphere exhibited large spatial variability with a ‘south-high north-low’ pattern. Large clear-air ϵ values were observed in both the lower stratosphere (LS) and upper troposphere (UT), especially over the Tibetan Plateau (TP) and its neighboring regions with complex terrain likely due to large-amplitude mountain waves. Particularly, less frequent but more intense clear-air turbulence was observed in both lower troposphere (LT) and UT over the TP, while more frequent, less intense clear-air turbulence was found in northern China. The all-sky turbulence considering the moist-saturation effects was much stronger in the troposphere, notably in southern China where convective clouds and precipitation oftentimes dominated. In the vertical direction, the altitude of peak clear-air ϵ in the troposphere was found to decrease poleward, broadly consistent with the meridional gradient of tropopause height in the Northern Hemisphere. A double-peak mode stood out for the profiles of clear-air ϵ at midlatitudes to the north of 30° N in winter: one peak was at altitudes of 15–18 km, and another at altitudes of 5–8 km. The strong shear instabilities around the westerly jet stream could account for the vertical bimodal structures. The seasonality of ϵ was also pronounced, reaching maxima in summer and minima in winter. Our results may help understand and avoid clear-air turbulence, as related to aviation safety among other issues.
Effect of copper ions concentration on the particle size of alginate-stabilized Cu2O-Cu nanocolloids and its antibacterial activity against rice bacterial leaf blight (Xanthomonas oryzae pv. oryzae)
Authors: Ngoc Doan Thi Bich , Bui Duy Du , Tuan Le Nghiem Anh , Thach Bui Dinh , Tho Tran Phuoc , Van Phu Dang 
Published: April 2021

Abstract
In this study, nano Cu2O-Cu/alginate was synthesised by the chemical reduction of tetra-amminecopper (II) ion complexes soluble using hydrazine as a reducing agent and alginate as a stabiliser. The influence of various copper ion concentrations on particle size and morphology of produced nano Cu2O-Cu/alginate was investigated. The transmission electron microscopy (TEM) analysis and X-ray diffraction (XRD) measurement revealed that the synthesised nano Cu2O-Cu/alginate was mostly composed of Cu2O-Cu in the form of a Cu2O@Cu core–shell structure with particle sizes of 4.2, 5.3, and 8.4 nm for 60, 80, and 100 mM of copper ion initial concentrations, respectively. The obtained nano Cu2O-Cu/alginate exhibited high antibacterial activity against Xanthomonas oryzae pv. Oryzae (Xanthomonas OO). The results showed that the nano Cu2O-Cu/alginate containing 30 mg.l−1 of copper ions completely inhibited the growth of Xanthomonas OO bacteria, which are responsible for the rice leaf blight disease. Nano Cu2O-Cu/alginate materials can be used as a fungicide to replace toxic agro-chemicals and potentially applied to the development of sustainable agricultural production.
Kant on the Aesthetic Ideas of Beautiful Nature
Authors: Reiter Aviv 
Published: April 2021

Abstract
For Kant the definitive end of art is the expression of aesthetic ideas that are sensible counterparts of rational ideas. But there is another type of aesthetic idea: ‘Beauty (whether it be beauty of nature or of art) can in general be called the expression of aesthetic ideas: only in beautiful nature the mere reflection on a given intuition, without a concept of what the object ought to be, is sufficient for arousing and communicating the idea of which that object is considered as the expression.’ What are these aesthetic ideas? I argue that Kant is drawing on the idealist conception of art, associated with Vasari, Bellori and Winckelmann, as presenting idealized spatial forms characteristic of natural kinds. He incorporates this conception into his analysis of the beauty of nature and adds that we have non-conceptual access to it. These idealized forms he names aesthetic normal ideas of natural species.
Snowball Sampling Study Design for Serosurveys Early in Disease Outbreaks
Authors: Kennedy-Shaffer Lee , Qiu Xueting , Hanage William P 
Published: April 2021

Abstract
Serological surveys can provide evidence of cases that were not previously detected, depict the spectrum of disease severity, and estimate the proportion of asymptomatic infections. To capture these parameters, survey sample sizes may need to be very large, especially when the overall infection rate is still low. Therefore, we propose the use of “snowball sampling” to enrich serological surveys by testing contacts of infected persons identified in the early stages of an outbreak. For future emerging pandemics, this observational study sampling design can answer many key questions, such as estimation of the asymptomatic proportion of all infected cases, the probability of a given clinical presentation for a seropositive individual, or the association between characteristics of either the host or the infection and seropositivity among contacts of index individuals. We provide examples, in the context of the coronavirus disease 2019 (COVID-19) pandemic, of studies and analysis methods that use a snowball sample and perform a simulation study that demonstrates scenarios where snowball sampling can answer these questions more efficiently than other sampling schemes. We hope such study designs can be applied to provide valuable information to slow the present pandemic as it enters its next stage and in early stages of future pandemics.
MG-BERT: leveraging unsupervised atomic representation learning for molecular property prediction
Authors: Zhang Xiao-Chen , Wu Cheng-Kun , Yang Zhi-Jiang , Wu Zhen-Xing , Yi Jia-Cai , Hsieh Chang-Yu , Hou Ting-Jun , Cao Dong-Sheng 
Published: April 2021

Abstract
Motivation: Accurate and efficient prediction of molecular properties is one of the fundamental issues in drug design and discovery pipelines. Traditional feature engineering-based approaches require extensive expertise in the feature design and selection process. With the development of artificial intelligence (AI) technologies, data-driven methods exhibit unparalleled advantages over the feature engineering-based methods in various domains. Nevertheless, when applied to molecular property prediction, AI models usually suffer from the scarcity of labeled data and show poor generalization ability.
Results: In this study, we proposed molecular graph BERT (MG-BERT), which integrates the local message passing mechanism of graph neural networks (GNNs) into the powerful BERT model to facilitate learning from molecular graphs. Furthermore, an effective self-supervised learning strategy named masked atoms prediction was proposed to pretrain the MG-BERT model on a large amount of unlabeled data to mine context information in molecules. We found the MG-BERT model can generate context-sensitive atomic representations after pretraining and transfer the learned knowledge to the prediction of a variety of molecular properties. The experimental results show that the pretrained MG-BERT model with a little extra fine-tuning can consistently outperform the state-of-the-art methods on all 11 ADMET datasets. Moreover, the MG-BERT model leverages attention mechanisms to focus on atomic features essential to the target property, providing excellent interpretability for the trained model. The MG-BERT model does not require any hand-crafted feature as input and is more reliable due to its excellent interpretability, providing a novel framework to develop state-of-the-art models for a wide range of drug discovery tasks.
Topographic variability of the normal circle of Willis anatomy on a paediatric population
Authors: Zrafi Wael , Veres Cristina , Dangouloff-Ros Volodia , Boddaert Nathalie , Haddy Nadia , Journy Neige , Allodji Rodrigue , Alabdoaburas Mohamad Mohamad , Diallo Ibrahima , de Vathaire Florent 
Published: April 2021

Abstract
Long-term sequelae are major limitations of radiation therapy use, especially for childhood brain tumour. Circle of Willis irradiation strongly increases the long-term risk of stroke, but to establish dose-response relationship, anticipating long-term effects of new techniques, requires to perform accurate and reproducible dosimetric estimations in large cohorts of patients having received radiotherapy decades ago. For the accuracy of retrospective dose reconstruction, the topographic variability of the Circle of Willis arteries is crucial. In order to improve retrospective dosimetric studies and dose-volume estimates to the typical Circle of Willis arteries, we aim to study the inter-individual topographic variability of these structures. Thirty-eight time of flight MRI sequences of children aged 2–17 years in both genders were investigated. A region growth algorithm was used for the segmentation of the cerebral arteries. A rigid registration in a common skull was performed following the anatomy of skull base foramina. The Posterior clinoid processes of the sella turcica were used as reference landmark (R0), and 5 key landmarks were chosen in each segmented Circle of Willis, then distances between the 5 landmarks and R0 were calculated for each of the 38 subjects. The distance between R0 and each landmark of the Circle of Willis followed a normal distribution, the average values ranging from 13.6 to 17.0 mm, and the standard deviations ranged from 2.6 to 3.0 mm, i.e. less than a fifth of the average value. The perimeter of the Circle of Willis was longer in older subjects, this increase being isotropic. Our study shows a remarkably low topographic variability of the typical Circle of Willis. An important result, allowing reliable anthropomorphic phantoms-based retrospective estimations of the radiation doses delivered to these arterial structures during radiotherapy treatment.