A device-level characterization approach to quantify the impacts of different random variation sources in FinFET technology

A simple device-level characterization approach to quantitatively evaluate the impacts of different random variation sources in FinFETs is proposed. The impacts of random dopant fluctuation are negligible for FinFETs with lightly doped channel, leaving metal gate granularity and line-edge roughness as the two major random variation sources. The variations of Vth induced by these two major categories are theoretically decomposed based on the distinction in physical mechanisms and their influences on different electrical characteristics. The effectiveness of the proposed method is confirmed through both TCAD simulations and experimental results. This letter can provide helpful guidelines for variation-aware technology development

Tetra­aqua­bis­[3-(pyridin-4-yl)benzoato-κN]manganese(II)

In the title compound, [Mn(C12H8NO2)2(H2O)4], the Mn2+ ion lies on a twofold rotation axis and has a distorted N2O4 octa­hedral coordination geometry formed by four water O atoms in the equatorial plane and two apical pyridyl N atoms. A three-dimensional network is formed in the crystal structure by multiple O—H⋯O hydrogen bonds between the coordin­ating water molecules and the free carboxylate groups

SAROTUP: Scanner and Reporter of Target-Unrelated Peptides

As epitope mimics, mimotopes have been widely utilized in the study of epitope prediction and the development of new diagnostics, therapeutics, and vaccines. Screening the random peptide libraries constructed with phage display or any other surface display technologies provides an efficient and convenient approach to acquire mimotopes. However, target-unrelated peptides creep into mimotopes from time to time through binding to contaminants or other components of the screening system. In this study, we present SAROTUP, a free web tool for scanning, reporting and excluding possible target-unrelated peptides from real mimotopes. Preliminary tests show that SAROTUP is efficient and capable of improving the accuracy of mimotope-based epitope mapping. It is also helpful for the development of mimotope-based diagnostics, therapeutics, and vaccines

Sources and formation of carbonaceous aerosols in Xi'an, China:Primary emissions and secondary formation constrained by radiocarbon

To investigate the sources and formation mechanisms of carbonaceous aerosols, a major contributor to severe particulate air pollution, radiocarbon (C-14) measurements were conducted on aerosols sampled from November 2015 to November 2016 in Xi'an, China. Based on the C-14 content in elemental carbon (EC), organic carbon (OC) and water-insoluble OC (WIOC), contributions of major sources to carbonaceous aerosols are estimated over a whole seasonal cycle: primary and secondary fossil sources, primary biomass burning, and other non-fossil carbon formed mainly from secondary processes. Primary fossil sources of EC were further sub-divided into coal and liquid fossil fuel combustion by complementing C-14 data with stable carbon isotopic signatures. The dominant EC source was liquid fossil fuel combustion (i.e., vehicle emissions), accounting for 64 % (median; 45 %-74 %, interquartile range) of EC in autumn, 60 % (41 %-72 %) in summer, 53 % (33 %-69 %) in spring and 46 % (29 %-59 %) in winter. An increased contribution from biomass burning to EC was observed in winter (similar to 28 %) compared to other seasons (warm period; similar to 15 %). In winter, coal combustion (similar to 25 %) and biomass burning equally contributed to EC, whereas in the warm period, coal combustion accounted for a larger fraction of EC than biomass burning. The relative contribution of fossil sources to OC was consistently lower than that to EC, with an annual average of 47 +/- 4 %. Non-fossil OC of secondary origin was an important contributor to total OC (35 +/- 4 %) and accounted for more than half of non-fossil OC (67 +/- 6 %) throughout the year. Secondary fossil OC (SOCfossil) concentrations were higher than primary fossil OC (POCfossil) concentrations in winter but lower than POCfossil in the warm period. Fossil WIOC and water-soluble OC (WSOC) have been widely used as proxies for POCfossil and SOCfossil, respectively. This assumption was evaluated by (1) comparing their mass concentrations with POCfossil and SOCfossil and (2) comparing ratios of fossil WIOC to fossil EC to typical primary OC-to-EC ratios from fossil sources including both coal combustion and vehicle emissions. The results suggest that fossil WIOC and fossil WSOC are probably a better approximation for primary and secondary fossil OC, respectively, than POCfossil and SOCfossil estimated using the EC tracer method

Significantly enhanced permittivity and energy density in dielectric composites with aligned BaTiO3 lamellar structures

A significant improvement of permittivity and energy density will enable the miniaturization of dielectric capacitors and promote integration for applications in electrical power and defense systems. In this work, lamellar composite architectures are fabricated from aligned barium titanate (BaTiO3) in an epoxy resin using the freeze casting method. Due to the continuous coupling effect originating from the interconnected and highly oriented BaTiO3 particles, these composites exhibit an extremely high permittivity (εr = 1408) at 1 kHz, which is the highest value achieved in BaTiO3/polymer composites reported so far and fits well to the parallel mode of the mixing rule. A finite element model is used to investigate the local electric field distributions in the BaTiO3 lamellae under the applied electric field parallel and perpendicular to the freezing direction, respectively. A high ratio value of discharge energy density per electric field, Udis/E, ∼0.033, is achieved due to a high electric displacement of D = 15.11 μC cm−2 and a discharge energy density of Udis = 19.6 × 10−2 J cm−3 is achieved at a low electric field (6 kV mm−1). This work provides an effective strategy of designing a ceramic–polymer composite to realize high permittivity and energy density of capacitors for modern electrical and electronic industries

Measurement report:Dual-carbon isotopic characterization of carbonaceous aerosol reveals different primary and secondary sources in Beijing and Xi'an during severe haze events

To mitigate haze pollution in China, a better understanding of the sources of carbonaceous aerosols is required due to the complexity in multiple emissions and atmospheric processes. Here we combined the analysis of radiocarbon and the stable isotope 13C to investigate the sources and formation of carbonaceous aerosols collected in two Chinese megacities (Beijing and Xi'an) during severe haze events of a "red alarm"level from December 2016 to January 2017. The haze periods with daily PM2:5 concentrations as high as ∼400 μgm-3 were compared to subsequent clean periods (i.e., PM2:5 less than median concentrations during the winter 2016/2017) with PM2:5 concentrations below 100 μgm-3 in Xi'an and below 20 μgm-3 in Beijing. In Xi'an, liquid fossil fuel combustion was the dominant source of elemental carbon (EC; 44 %-57 %), followed by biomass burning (25 %-29 %) and coal combustion (17 %-29 %). In Beijing, coal combustion contributed 45 %-61% of EC, and biomass burning (17 %-24 %) and liquid fossil fuel combustion (22 %-33 %) contributed less. Non-fossil sources contributed 51 %-56% of organic carbon (OC) in Xi'an, and fossil sources contributed 63 %-69% of OC in Beijing. Secondary OC (SOC) was largely contributed by non-fossil sources in Xi'an (56∼6 %) and by fossil sources in Beijing (75∼10 %), especially during haze periods. The fossil vs. non-fossil contributions to OC and EC did not change drastically during haze events in both Xi'an and Beijing. However, compared to clean periods, the contribution of coal combustion to EC during haze periods increased in Xi'an and decreased in Beijing. During clean periods, primary OC from biomass burning and fossil sources constituted ∼70% of OC in Xi'an and ∼53% of OC in Beijing. From clean to haze periods, the contribution of SOC to total OC increased in Xi'an but decreased in Beijing, suggesting that the contribution of secondary organic aerosol formation to increased OC during haze periods was more efficient in Xi'an than in Beijing. In Beijing, the high SOC fraction in total OC during clean periods was mainly due to an elevated contribution from non-fossil SOC. In Xi'an, a slight day-night difference was observed during the clean period with enhanced fossil contributions to OC and EC during the day. This day-night difference was negligible during severe haze periods, likely due to the enhanced accumulation of pollutants under stagnant weather conditions

R-process beta-decay neutrino flux from binary neutron star merger and collapsar

This study investigates the antineutrinos production by $\beta$-decay of $r$-process nuclei in two astrophysical sites that are capable of producing gamma-ray bursts (GRBs): binary neutron star mergers (BNSMs) and collapsars, which are promising sites for heavy element nucleosynthesis. We employ a simplified method to compute the $\beta$-decay $\bar\nu_e$ energy spectrum and consider two representative thermodynamic trajectories for $r$-process simulations, each with four sets of $Y_e$ distribution. The time evolution of the $\bar\nu_e$ spectrum is derived for both the dynamical ejecta and the disk wind for BNSMs and collapsar outflow, based on approximated mass outflow rates. Our results show that the $\bar\nu_e$ has an average energy of approximately 3 to 9~MeV, with a high energy tail of up to 20 MeV. The $\bar\nu_e$ flux evolution is primarily determined by the outflow duration, and can thus remain large for $\mathcal{O}(10)$~s and $\mathcal{O}(100)$~s for BNSMs and collapsars, respectively. For a single merger or collapsar at 40~Mpc, the $\bar\nu_e$ flux is $\mathcal{O}(10-100)$~cm$^{-2}$~s$^{-1}$, indicating a possible detection horizon up to $0.1-1$~Mpc for Hyper-kamiokande. We also estimate their contributions to the diffuse $\bar\nu_e$ background. Our results suggest that although the flux from BNSMs is roughly 4--5 orders of magnitude lower than that from the regular core-collapse supernovae, those from collapsars can possibly contribute a non-negligible fraction to the total diffuse $\bar\nu_e$ flux at energy $\lesssim 1$~MeV, with a large uncertainty depending on the unknown rate of collapsars capable of hosting the $r$-process.Comment: 13 pages, 7 figure

MimoDB 2.0: a mimotope database and beyond

Mimotopes are peptides with affinities to given targets. They are readily obtained through biopanning against combinatorial peptide libraries constructed by phage display and other display technologies such as mRNA display, ribosome display, bacterial display and yeast display. Mimotopes have been used to infer the protein interaction sites and networks; they are also ideal candidates for developing new diagnostics, therapeutics and vaccines. However, such valuable peptides are not collected in the central data resources such as UniProt and NCBI GenPept due to their ‘unnatural’ short sequences. The MimoDB database is an information portal to biopanning results of random libraries. In version 2.0, it has 15 633 peptides collected from 849 papers and grouped into 1818 sets. Besides the core data on panning experiments and their results, broad background information on target, template, library and structure is included. An accompanied benchmark has also been compiled for bioinformaticians to develop and evaluate their new models, algorithms and programs. In addition, the MimoDB database provides tools for simple and advanced searches, structure visualization, BLAST and alignment view on the fly. The experimental biologists can easily use the database as a virtual control to exclude possible target-unrelated peptides. The MimoDB database is freely available at http://immunet.cn/mimodb

Recent progress on RF orbital angular momentum antennas

In the last five years or so, there has been a great interest in RF OAM to address the contradiction between the lack of wireless spectrum resources and the continually growing demands of the bandwidth. Recent developments and technological advancements in antenna design, material science, and integrated circuits have enabled miniaturized, multiple modes, tunable in radio frequency (RF) orbital angular momentum (OAM) antenna designs. From conventional methods such as spiral phase plate and reflector antenna to antenna array and metasurface, the working principle and structures are introduced. To improve the performance of RF OAM antennas, several innovative physical concepts have been explored for the designs of RF OAM antenna designs. In this paper, we present an up-to-date survey on the development of RF OAM antenna technologies. Open issues and development trends are explored as a source of inspiration towards the future better outcome of RF OAM antenna designs