A sheep pangenome reveals the spectrum of structural variations and their effects on tail phenotypes

Structural variations (SVs) are a major contributor to genetic diversity and phenotypic variations, but their prevalence and functions in domestic animals are largely unexplored. Here we generated high-quality genome assemblies for 15 individuals from genetically diverse sheep breeds using Pacific Biosciences (PacBio) high-fidelity sequencing, discovering 130.3 Mb nonreference sequences, from which 588 genes were annotated. A total of 149,158 biallelic insertions/deletions, 6531 divergent alleles, and 14,707 multiallelic variations with precise breakpoints were discovered. The SV spectrum is characterized by an excess of derived insertions compared to deletions (94,422 vs. 33,571), suggesting recent active LINE expansions in sheep. Nearly half of the SVs display low to moderate linkage disequilibrium with surrounding single-nucleotide polymorphisms (SNPs) and most SVs cannot be tagged by SNP probes from the widely used ovine 50K SNP chip. We identified 865 population-stratified SVs including 122 SVs possibly derived in the domestication process among 690 individuals from sheep breeds worldwide. A novel 168-bp insertion in the 5' untranslated region (5' UTR) of HOXB13 is found at high frequency in long-tailed sheep. Further genome-wide association study and gene expression analyses suggest that this mutation is causative for the long-tail trait. In summary, we have developed a panel of high-quality de novo assemblies and present a catalog of structural variations in sheep. Our data capture abundant candidate functional variations that were previously unexplored and provide a fundamental resource for understanding trait biology in sheep

Comparative analysis of multi-energy complementary optimization schemes for regional integrated energy system considering wind power consumption

In order to select a more economical wind power consumption scheme for RIES （regional integrated energy system）， the electricity-gas multi-energy complementarity optimization models considering the reuse of waste heat from power to gas （P2G） reaction and the electric-thermal multi energy complementary optimization model of air source heat pump （ASHP） are established based on the principle of multi-energy complementarity. Taking account of the investment and maintenance cost of P2G and ASHP， the RIES multi-energy complementary economic dispatch model is established with the goal of minimizing the overall operating cost of the system. Constraints of energy supply and demand balance and various unit operation constraints are considered. The optimization software CPLEX is used to solve various models. The example calculation results show that the scheme considering the reuse of waste heat from P2G reaction can reduce the configuration capacity of P2G and increase the operation benefit of the system. On condition of the same consumption rate of wind power， the electric-thermal multi-energy complementary optimization model with ASHP is superior in economy and overall energy efficiency

Low Dynamic ON-Resistance in AlGaN/GaN-on-Si Power HEMTs Obtained by AlN Thin Film Passivation

An effective passivation technique for AlGaN/GaN-on-Si power HEMTs is presented. This technique features AlN ultra-thin film grown by plasma enhanced atomic layer deposition (PEALD). With low-surface-damage in situ remote plasma pretreatments prior to the AlN deposition, an atomically sharp PEALD-AlN/III-nitride interface as well as high-crystal-quality AlN film have been obtained. Effective current collapse suppression and dynamic ON-resistance reduction are demonstrated in the PEALD-AlN passivated AlGaN/GaN HEMTs under high drain bias switching conditions. An output power of 2.64 W/mm and a power added-efficiency of 33% are obtained at 2 GHz on the PEALD-AlN passivated HEMTs without the use of field-plate

1.4-kV AlGaN/GaN HEMTs on a GaN-on-SOI Platform

We demonstrate high-voltage depletion-mode and enhancement-mode (E-mode) AlGaN/GaN high-electron-mobility transistors (HEMTs) on a GaN-on-silicon-on-insulator (SOI) platform. The GaN-on-SOI wafer features GaN epilayers grown by metal-organic chemical vapor deposition on a p-type (111) Si SOI substrate with a p-type (100) Si handle wafer. Micro-Raman spectroscopy significantly reveals reduced stress in the GaN epilayers, which is a result expected from the compliant SOI substrate. E-mode HEMTs fabricated by fluorine plasma implantation technique deliver high ON/OFF current ratio (10(8)-10(9)), large breakdown voltage (1471 V with floating substrate), and low ON-resistance (3.92 m Omega . cm(2))

Vertical Leakage/Breakdown Mechanisms in AlGaN/GaN-on-Si Devices

Vertical leakage/breakdown mechanisms in AlGaN/GaN high-electron-mobility transistors grown on low-resistivity p-type (111) Si substrate are studied by temperature-dependent current-voltage (I-V) measurements. It is found that the top-to-substrate vertical breakdown voltage (BV) is dominated by the space-charge-limited current conduction involving both acceptor and donor traps in the GaN buffer/transition layer. From the temperature-dependent transient backgating measurements, the acceptor level at E-V + 543 meV and the donor level at E-C-616 meV were identified

Investigation of ON-State Breakdown Mechanism in AlGaN/GaN HEMTs with AlGaN Back Barrier

The temperature-dependent ON-state breakdown BVON loci of AlGaN/GaN high-electron-mobility transistors (HEMTs) with an AlGaN back barrier were investigated using the gate current extraction technique. The impact ionization of acceptor-like traps was revealed to be responsible for the ON-state breakdown in HEMTs as a 2D electron gas (2DEG) channel is marginally turned on. The characteristic electric field Ei of impact ionization was extracted, exhibiting a U-shaped temperature dependence from 40 to −30 ∘C, with minimum Ei occurring at −10 ∘C. The impurity scattering effect of acceptor-like traps in AlGaN/GaN heterostructures is suggested to be responsible for the negative temperature dependence of BVON and Ei below −10 ∘C

Investigation of ON-State Breakdown Mechanism in AlGaN/GaN HEMTs with AlGaN Back Barrier

The temperature-dependent ON-state breakdown BVON loci of AlGaN/GaN high-electron-mobility transistors (HEMTs) with an AlGaN back barrier were investigated using the gate current extraction technique. The impact ionization of acceptor-like traps was revealed to be responsible for the ON-state breakdown in HEMTs as a 2D electron gas (2DEG) channel is marginally turned on. The characteristic electric field Ei of impact ionization was extracted, exhibiting a U-shaped temperature dependence from 40 to −30 ∘C, with minimum Ei occurring at −10 ∘C. The impurity scattering effect of acceptor-like traps in AlGaN/GaN heterostructures is suggested to be responsible for the negative temperature dependence of BVON and Ei below −10 ∘C

A High-Voltage Low-Standby-Power Startup Circuit Using Monolithically Integrated E/D-Mode AlGaN/GaN MIS-HEMTs

We experimentally demonstrate a high-voltage low-standby power startup circuit for powering up the off-line switched-mode power supply (SMPS) during the startup period by exploiting monolithically integrated enhancement/depletion-mode metal-insulator-semiconductor high electron mobility transistors (E/D-mode MIS-HEMTs) fabricated on a GaN-on-Si power device platform. The E/D-mode MIS-HEMTs exhibit a threshold voltage of +1.2 and -11 V, respectively. The high-voltage D-mode device used in the demonstration features an OFF-state breakdown voltage of 640 V and a safe operating area with a thermal limitation of 11.6 W/mm, whereas the low-voltage E-mode device features a source-gate breakdown voltage of 98 V, satisfying the requirement of the startup circuit. The functionality of the startup circuit is successfully achieved with an input voltage range 10-200 V and a startup current of 1.08 mA

Effective Passivation of AlGaN/GaN HEMTs by ALD-Grown AlN Thin Film

An effective passivation technique for AlGaN/GaN high-electron-mobility transistors (HEMTs) is presented. This technique features an AlN thin film grown by plasma-enhanced atomic layer deposition (PEALD). With in situ remote plasma pretreatments prior to the AlN deposition, an atomically sharp interface between ALD-AlN and III-nitride has been obtained. Significant current collapse suppression and dynamic ON-resistance reduction are demonstrated in the ALD-AlN-passivated AlGaN/GaN HEMTs under high-drain-bias switching conditions