Surface-potential-based compact model for the gate current of p-GaN Gate HEMTs

The gate leakage current of p-GaN gate HEMTs is modeled based on surface potential calculations. The model accurately describes the bias and temperature dependence of the gate leakage. Thermionic emission is the main mechanism of the gate current in forward bias operation while hopping transport component is the main mechanism of gate current in reverse bias operation. This newly developed gate current model was implemented in Verilog-A. A good agreement between the simulations and experimental data demonstrates the accuracy of the model

Proposal of a free-space-to-chip pipeline for transporting single atoms

A free-space-to-chip pipeline is proposed to efficiently transport single atoms from a magneto-optical trap to an on-chip evanescent field trap. Due to the reflection of the dipole laser on the chip surface, the conventional conveyor belt approach can only transport atoms close to the chip surface but with a distance of about one wavelength, which prevents efficient interaction between the atom and the on-chip waveguide devices. Here, based on a two-layer photonic chip architecture, a diffraction beam of the integrated grating with an incident angle of the Brewster angle is utilized to realize free-space-to-chip atom pipeline. Numerical simulation verified that the reflection of the dipole laser is suppressed and that the atoms can be brought to the chip surface with a distance of only 100nm. Therefore, the pipeline allows a smooth transport of atoms from free space to the evanescent field trap of waveguides and promises a reliable atom source for a hybrid photonic-atom chip.Comment: 8 pages, 7 figure

Effects of acidification on nitrification and associated nitrous oxide emission in estuarine and coastal waters

In the context of an increasing atmospheric carbon dioxide (CO2) level, acidification of estuarine and coastal waters is greatly exacerbated by land-derived nutrient inputs, coastal upwelling, and complex biogeochemical processes. A deeper understanding of how nitrifiers respond to intensifying acidification is thus crucial to predict the response of estuarine and coastal ecosystems and their contribution to global climate change. Here, we show that acidification can significantly decrease nitrification rate but stimulate generation of byproduct nitrous oxide (N2O) in estuarine and coastal waters. By varying CO2 concentration and pH independently, an expected beneficial effect of elevated CO2 on activity of nitrifiers (“CO2-fertilization” effect) is excluded under acidification. Metatranscriptome data further demonstrate that nitrifiers could significantly up-regulate gene expressions associated with intracellular pH homeostasis to cope with acidification stress. This study highlights the molecular underpinnings of acidification effects on nitrification and associated greenhouse gas N2O emission, and helps predict the response and evolution of estuarine and coastal ecosystems under climate change and human activities.publishedVersio

Genome editing reveals dmrt1 as an essential male sex-determining gene in Chinese tongue sole (Cynoglossus semilaevis)

Chinese tongue sole is a marine fish with ZW sex determination. Genome sequencing suggested that the Z-linked dmrt1 is a putative male determination gene, but direct genetic evidence is still lacking. Here we show that TALEN of dmrt1 efficiently induced mutations of this gene. The ZZ dmrt1 mutant fish developed ovary-like testis, and the spermatogenesis was disrupted. The female-related genes foxl2 and cyp19a1a were significantly increased in the gonad of the ZZ dmrt1 mutant. Conversely, the male-related genes Sox9a and Amh were significantly decreased. The dmrt1 deficient ZZ fish grew much faster than ZZ male control. Notably, we obtained an intersex ZW fish with a testis on one side and an ovary on the other side. This fish was chimeric for a dmrt1 mutation in the ovary, and wild-type dmrt1 in the testis. Our data provide the first functional evidence that dmrt1 is a male determining gene in tongue sole

Polynomial Convergence of Predictor-Corrector for SDLCP Based on the M-Z Family of Directions

We establishes the polynomial convergence of a new class of pathfollowing methods for semidefinite linear complementarity problems whose search directions belong to the class of directions introduced by Monteiro [6]. Namely, we show that the polynomial iteration-complexity bound of the well known algorithms for linear programming, namely the predictor-corrector algorithm of Mizuno and Ye, carry over to the context of SDLCP

Modeling the Effects of Threading Dislocations on Current in AlGaN/GaN HEMT

The aim of this paper is to model the effects of threading dislocations on both gate and drain currents of AlGaN/GaN high electron mobility transistors (HEMTs). The fraction of filled traps increases with the threading dislocations, while the trapping effects cause a decrease in drain current and an increase in gate leakage current. To model the drain current drop, the two simplified RC subcircuits with diodes are proposed to capture the charge trapping/detrapping characteristics. The trap voltages Vg_trap and Vd_trap generated by RC networks are fed back into the model to capture the effects of traps on drain current. Considering acceptor-decorated dislocations, we present a novel Poole–Frenkel (PF) model to precisely describe the reverse leakage gate current, which plays a dominant role in the gate leakage current. The proposed model, which uses physical parameters only, is implemented in Verilog-A. It is in excellent agreement with the experimental data

Epidemiological study of HPV infection in 40,693 women in Putian: a population study based on screening for high-risk HPV infection

Abstract Background The infection rate of human papillomavirus (HPV) is high in the coastal regions of China. However, the infection rate among high-risk genotypes of women in Putian City is unknown. Therefore, this study aimed to analyse the epidemiology of high-risk HPV infection among women in Putian and provide a reference for the diagnosis, treatment and vaccination of cervical cancer in this region. Methods The data used were obtained from the Chinese government’s public health program (“Cervical and Breast Cancer Screening Project”). A total of 40,693 female cervical cell exfoliation samples screened for high-risk HPV at the Affiliated Hospital of Putian University from July 2020 to December 2021 were enrolled. DNA was extracted using a fully automatic extractor. Then, 14 high-risk genotypes of HPV were detected by polymerase chain reaction. The characteristics of HPV infection, distribution of high-risk genotypes, infection types and thinprep cytologic test (TCT) classification at different age groups were analysed. Results Among the 40,693 samples, 3899 were infected with HPV, with an infection rate of 9.6%. Accordingly, HPV infection rates gradually increased with age, and statistically significant differences were observed among age groups (χ 2  = 74.03, P < 0.01). The infection rates of high-risk HPV52, HPV58 and HPV16 were in the top three and increased with age. Single infection was dominant (84.7%), followed by double infections (12.7%). The cervical cytology of 3899 HPV-positive people can be classified into negative for intraepithelial lesion and malignancy (NILM, 88.0%), atypical squamous cells of undetermined significance (ASC-US, 6.6%), atypical squamous cells—cannot exclude high-grade squamous intraepithelial lesion (ASC-H, 1.4%), low-grade squamous intraepithelial lesion (LSIL, 3.2%) and high-grade squamous intraepithelial lesion (HSIL, 0.8%). HPV16 infection rate increased with increasing severity of cervical cytology (χ 2 trend  = 43.64, P < 0.01), whereas the infection rates of HPV52 (χ 2 trend  = 13.89, P < 0.01) and HPV58 (χ 2 trend  = 13.50, P < 0.01) showed opposite trends. Conclusion The infection rate of female HPV high-risk screening in this region was 9.6% and mainly involved single infections. In addition, HPV16, HPV52 and HPV58 were closely related to the severity of cervical cytology. Effective screening, vaccination and education are needed. The 9-valent vaccine will be effective in reducing cervical pre-invasive disease. It would also be reasonable to state that the rising trend in HPV infection and high grade cytology with age emphasises the need to target older women with screening. Vaccination of younger women (aged ≤ 25) will lay the foundation for better cancer outcomes in the future

Surface-potential-based compact modeling of p-GaN gate HEMTs

We propose a surface potential (SP)-based compact model of p-GaN gate high electron mobility transistors (HEMTs) which solves the Poisson equation. The model includes all possible charges in the GaN channel layer, including the unintended Mg doping density caused by out-diffusion. The SP equation and its analytical approximate solution provide a high degree of accuracy for the SP calculation, from which the closed-form I-V equations are derived. The proposed model uses physical parameters only and is implemented in Verilog-A code