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Early pregnancy loss (EPL) is the most common complication in assisted reproductive technology (ART). However, the precise causes for nearly 50% patients remain unexplained. In the current study, we aimed to discover the differentially expressed profiling of mRNAs and lncRNAs by RNA sequencing (RNA-seq). Human chorionic villi tissues were collected from patients with EPL and natural control (NC) group. RNA sequencing (RNA-seq) of these specimens was performed for transcriptome analysis. As a result, we identified a total of 141 mRNAs and 137 lncRNAs that were significantly differentially expressed between villi tissues from EPL and NC. Functional enrichment analyses indicated enrichment of differentially expressed genes involved in pathways were associated with growth hormone receptor binding, PI3K-Akt signaling pathway, Jak-STAT signaling pathway, transcriptional misregulation in cancer, metabolic pathways and Rap1 signaling pathway. Additionally, the co-expression networks (lncRNA–miRNA–mRNA) was constructed based on the correlation analysis between the differentially expressed RNAs.7 mRNAs and 6 lncRNAs were successfully technically validated with RT-PCR. In conclusion, our results suggest a direction for the further study of EPL-related mRNAs and lncRNAs and may ultimately assist in understanding the pathogenesis of EPL. [ABSTRACT FROM AUTHOR]

A novel AlGaN/GaN high-electron mobility transistor (HEMT) is put forward to promote its breakdown characteristics and anti-single-event transient (SET) effect. The features of the proposed device are a hybrid GaN/AlN buffer layer and a uniform-groove high-k passivation layer between the gate and drain electrodes (HGKB-HEMT). First, the uniform-groove high-k passivation layer not only reduces the peak electric field at the gate edges, but also modulates the electric field distribution between the gate and drain. Therefore, the breakdown voltage (BV) and the anti-SET effect show a great improvement. Second, the buffer leakage current was effectively reduced by the hybrid buffer layer, resulting in a further increase in the BV. The BV of the HGKB-HEMT reached 1672 V, which is 82.7% higher than the conventional GaN HEMT, and the peak drain current induced by the SET effect of the HGKB-HEMT decreased by 60.7% at VDS = 50 V. Moreover, the channel current of the HGKB-HEMT increased slightly and the on-state resistance decreased. [ABSTRACT FROM AUTHOR]

Understanding the heterogeneity of reservoirs is crucial for enhancing the efficiency of hydrocarbon exploration and development. The primary porosity of samples from modern braided river sands and outcrops of braided river sandstone was calculated using a model previously proposed by the authors. The characteristic parameters (Vx) for calculating primary porosity are closely related to the architectural–elemental configurations (AEC), and the AEC of braided river sand bodies (BRSD) has apparent effects on the distribution of the primary porosity heterogeneities. Analysis of our results has established a simple primary porosity heterogeneity model of BRSD. The center of braided river channel and mid-channel bars have excellent strong primary petrophysical properties with high primary porosity exceeding 38%. The contact areas between the braided river channel and channel bars exhibit relatively low primary porosities of less than 33%. The area between the center and edge of the braided bars and channels displays medium primary porosities. The nonlinear correlation in the Q–Q plot of the primary porosity and present porosity of samples from BRSD in the Ahe Formation is mainly caused by chemical diagenesis. The present porosity heterogeneity of BRSD in the Ahe Formation is less influenced by compaction and cementation, it predominantly arises from the differential of dissolution. Q–Q plots attempt to correlate the geological information from an individual sample with the heterogeneity of present porosity in BRSD. In addition, by utilizing Q–Q plots of the primary and current petrophysical properties of the sand body, the relative extent of heterogeneity modification caused by different diagenetic processes can be assessed. This assessment is crucial for modeling macroscopic models of physical properties during geological history periods. [ABSTRACT FROM AUTHOR]

In this paper, a novel AlGaN/GaN HEMT structure with a P-GaN buried layer in the buffer layer and a locally doped barrier layer under the gate (PN-HEMT) is proposed to enhance its resistance to single event transient (SET) effects while also overcoming the degradation of other characteristics. The device operation mechanism and characteristics are investigated by TCAD simulation. The results show that the peak electric field and impact ionization at the gate edges are reduced in the PN-HEMT due to the introduced P-GaN buried layer in the buffer layer. This leads to a decrease in the peak drain current (Ipeak) induced by the SET effect and an improvement in the breakdown voltage (BV). Additionally, the locally doped barrier layer provides extra electrons to the channel, resulting in higher saturated drain current (ID,sat) and maximum transconductance (gmax). The Ipeak of the PN-HEMT (1.37 A/mm) is 71.8% lower than that of the conventional AlGaN/GaN HEMT (C-HEMT) (4.85 A/mm) at 0.6 pC/µm. Simultaneously, ID,sat and BV are increased by 21.2% and 63.9%, respectively. Therefore, the PN-HEMT enhances the hardened SET effect of the device without sacrificing other key characteristics of the AlGaN/GaN HEMT. [ABSTRACT FROM AUTHOR]

BACKGROUND: Licorice extract is an important raw material for food additives and medicine. The quality of licorice extract is dictated by the drying process. The commonly used drying methods of licorice extract are not efficient in obtaining high‐quality products so alternative techniques need to be developed and researched. In this study, ultrasound‐assisted vacuum drying (UAVD) was first utilized to improve drying efficiency and produce a higher‐quality product. The changes in water mobility of licorice extract during drying were characterized using low‐field nuclear magnetic resonance. In addition, the effects of ultrasonic power on the drying dynamics, the contents of liquiritin and glycyrrhizic acid, the antioxidant capacity and the microstructure formation of licorice extract during the whole drying process were investigated. RESULTS: The drying times for licorice extract to reach equilibrium moisture content were reduced by 9.09–69.70% with UAVD at 40–200 W compared with that without ultrasonic treatment (0 W). Moreover, the proportions of bound water and semi‐bound water in fresh concentrate were 3.75% and 96.25%. It was also found that high ultrasonic power promoted the flow of water and the formation of porous structure in licorice extract, which led to the improvement of drying efficiency. The contents of liquiritin (2.444%) and glycyrrhizic acid (6.514%) were retained to a large degree in the dried product at an ultrasonic power of 80 W. The DPPH inhibition rate of UAVD samples with different ultrasonic powers ranged from 84.07 ± 0.46% to 90.65 ± 0.22%. CONCLUSION: UAVD has the advantages of high efficiency and low energy consumption, which may be an alternative technology for vacuum drying widely used in industry. © 2024 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

In this work, we propose combining a low work function anode metal and junction barrier Schottky structure to simultaneously achieve low turn-on voltage (Von) and high breakdown voltage (BV), which alleviates the dilemma that high BV requires high Schottky barrier height (SBH) and high Von. Molybdenum (Mo) is used to serve as the anode metal to reduce the SBH and facilitate fast turn-on to achieve a low Von. To resolve the low SBH related low BV issue, a p-NiO/n-Ga2O3-based heterojunction structure is used to enhance β-Ga2O3 sidewall depletion during the reverse state to improve the BV. With such a design, a low Von = 0.64 V(@1A/cm2) and a high BV = 2.34 kV as well as a specific on-resistance (Ron,sp) of 5.3 mΩ cm2 are demonstrated on a 10 μm-drift layer with a doping concentration of 1.5 × 1016 cm−3. β-Ga2O3 JBS diodes with low Von = 0.64 V and a power figure of merit of 1.03 GW/cm2 show great potential for future high-voltage and high-efficiency power electronics. [ABSTRACT FROM AUTHOR]

We consider a class of Choquard problem set in \Omega which is a symmetric bounded smooth domain of \mathbb {R}^{N} (N\geq 3) with the upper critical exponent in the sense of the Hardy-Littlewood-Sobolev inequality. Assume that \Omega is invariant under the action of a group G of orthogonal transformations, up to some range which depends on the symmetries, we prove the existence of infinitely many nontrivial G-invariant solutions to this problem, one of them is positive and the rest are sign-changing. Moreover we show the gradient estimate of solutions is closely related to the best Hardy-Littlewood-Sobolev constant. The main results extend and complement the earlier works in the literature. [ABSTRACT FROM AUTHOR]

To clarify the residue behavior and possible dietary risk of abamectin in fresh corn, bitter melon, and Fritillaria, a method was developed for the simultaneous determination of abamectin residues in fresh corn, bitter melon, and Fritillaria by QuEChERS (quick, easy, cheap, effective, rugged, safe) ultra‐performance liquid chromatography–tandem mass spectrometry. The mean recovery of abamectin in fresh corn, bitter melon, and Fritillaria was 86.48%–107.80%, and the relative standard deviation was 2.07%–10.12%. The detection rates of abamectin residues in fresh corn, bitter melon, and Fritillaria were 62.50%, 87.50%, and 80.00%, respectively. The residues of abamectin in fresh corn, bitter melon, and Fritillaria were not more than 0.020, 0.019, and 0.087 mg/kg, respectively. Based on these results, dietary risk assessment showed that the risk content of abamectin residues in long‐ and short‐term dietary exposure for Chinese consumers was 61.57% and 0.41%–1.11%, respectively, indicating that abamectin in fresh corn, bitter melon, and Fritillaria in the market would not pose a significant risk to consumers. [ABSTRACT FROM AUTHOR]

Electronic nose (E-nose) combined with gas chromatography–mass spectrometry (GC-MS) was used to analyze the volatile components of silver wormwood from different habitats, and the antibacterial activity of essential oils was also studied, to provide a scientific basis for quality control of silver wormwood and rational utilization of their essential oils. In this study, the total content of essential oils in silver wormwood was determined by steam distillation; the volatile components were conducted in an overall analysis by E-nose combined with chemometrics; the volatile components were analyzed and identified by GC-MS; and two G-negative bacteria and one Gram-positive bacteria were used as test bacteria to determine the antibacterial activity of the essential oils from silver wormwood. The results showed that principal component analysis (PCA) and linear discriminant analysis (LDA) of E-nose could distinguish the essential oils of silver wormwood from different habitats, and the odor difference of essential oils was obvious. A total of 87 volatile components were identified by GC-MS, and there were significant differences in components and contents in silver wormwood from different habitats; PCA and hierarchical cluster analysis (HCA) could effectively distinguish silver wormwood from different habitats. The essential oils from silver wormwood from different habitats all had a certain inhibitory effect on Bacillus subtilis, Staphylococcus aureus, and Escherichia coli. Therefore, the combination of E-nose and GC-MS could quickly distinguish silver wormwood from different habitats and provide a reference for quality control, drug selection, and comprehensive utilization of silver wormwood. [ABSTRACT FROM AUTHOR]

The Ediacaran Dengying Formation fourth member in Central Sichuan Basin is the deep dolomite gas reservoir with the largest natural gas reserves in China, providing an excellent example for understanding the effect of hydrothermal silicification on deep dolomite reservoir quality. By integrating petrology, geochemistry and physical property measurement, this study aims to reveal the genesis of different quartz phase and their corresponding diagenetic events, and to discuss the temporal relationship of diagenetic events and their effects on the quality of deep dolomite reservoir in Dengying fourth member. Three phases of quartz cement are identified in Ediacaran Dengying Formation deep dolomite reservoirs of Central Sichuan Basin as follows: (1) first‐stage quartz filled in primary reservoir spaces, (2) second‐stage quartz mainly filled in secondary reservoir spaces, and (3) third‐stage quartz filled in secondary reservoir spaces with Mississippi Valley‐Type minerals. By analysing petrographic and temporal relationships between these fabrics, it is suggested that the first‐stage quartz precipitated during the syndiagenetic stage, the second‐stage quartz precipitated during middle diagenetic stage, and the third‐stage quartz precipitated during middle diagenetic stage as well. Silicification during syndiagenetic stage is characterized by replacement of cryptocrystalline quartz and cementation of first‐stage quartz within matrix dolomite (MD). After syndiagenetic silicification, the mineral composition of the MD changed from magnesium calcium carbonate to silica, and the later constructive diagenetic alterations were almost ineffective. The distribution of syndiagenetic silicification during syndiagenetic stage gradually decreases from the platform‐interior to the platform‐margin. The second‐stage and third‐stage quartz cements, derived from two‐stage hydrothermal silicification in the middle stage, are both destructive for reservoir preservation. This study, combined with coeval vapour–liquid inclusions Th data and thermal‐burial models, constrains the time of the second‐stage quartz to ca. 403–408 Ma, suggesting an hydrothermal silicification related to the Caledonian movement. The time of the third‐stage quartz cement is constrained to ca. 259.4 Ma, associated with Late Permian eruption of Emeishan flood basalts. [ABSTRACT FROM AUTHOR]

Sandstone is an important carrier of underground hydrocarbon and the geological sequestration of carbon dioxide. Primary porosity is an important parameter used to predict reservoir quality, and it is influenced by the grain shape, grain‐size distribution and grain packing texture. However, few studies have focused on deriving multivariate equations of the grain size, grain‐size distribution and grain packing texture to predict the primary porosity of sandstone. The natural sedimentary process of sandstones was designed and simulated using a discrete element method. The results confirmed that the primary porosity is influenced by roundness, flatness, elongation, grain‐size distribution and grain packing texture; of the attributes, the mean grain size contributes less to the primary porosity of sandstone. Based on 193 simulated sandstone samples with a one‐component grain packing texture, a mathematical model considering roundness, flatness, elongation, grain packing texture and grain‐size distribution was proposed. The maximum, mean absolute and root mean square errors were 0.71, 0.26 and 0.32, respectively. The correlation coefficient between the simulated results and mathematical predicted results was 0.94. Furthermore, the primary porosity was positively correlated with the kurtosis of the grain‐size distribution in sandstone with the same grain shape but different kurtosis. The primary porosity was found to be independent of the mean grain size and mainly affected by the grain packing texture. Moreover, the primary porosity prediction model for sandstones with different grain‐size distribution curves based on the grain packing texture, which was proposed by the author in a previous study, was verified, and the correlation coefficient between the simulated results and predicted results was >0.92. The new mathematical model proposed in this study is a useful supplement for key parameter acquisition in the previous primary porosity prediction model of sandstone with different grain‐size distribution curves and grain packing texture. A mathematical model considering roundness, flatness, elongation, grain packing texture and grain‐size distribution is of great significance for reservoir quality prediction and conducting a quantitative evaluation of the diagenesis. [ABSTRACT FROM AUTHOR]

Despite the discovery of high-producing natural gas reservoirs in the low-permeability dolomite-mottled limestone (DML) reservoir of the fourth Member (Ma4) of the Majiagou Formation in the Ordos Basin, the current understanding of the processes responsible for reservoir formation are still superficial, which extremely restricts the effectiveness of deep petroleum exploration and development in the basin. Therefore, this study analyzed the paragenesis process of the DML reservoir through systematic petrographic and geochemical measurements. The DML consists of burrows and matrix. The burrows are mainly filled with dolomite with a small amount of micrite, calcite cement, and solid bitumen. The matrix mainly consists of wakestone or mudstone. The DML has experienced multiple diagenetic events, including seepage-reflux dolomitization, compaction, calcite cement CaI cementation, micrite recrystallization, dissolution, hydrocarbon charging, calcite cement CaII cementation, and dolomite progressive recrystallization. Dolomitization is critical to the DML reservoir formation. The pore created by dolomitization is the hydrocarbon-migrated pathway and storage space. Due to the difference in Mg2+-rich fluid supply, the degree of dolomitization decreases from west to east, which causes the difference in diagenetic evolution of the western and eastern parts of the study area. The high dolomitization degree led to strong anti-compaction ability in the west, contrary to the east. Thus, the reservoir quality of the west is better than the east. [ABSTRACT FROM AUTHOR]

Calcite‐cemented concretions can reduce reservoir quality and form important low‐permeability baffles for fluid flow in sandstone hydrocarbon carrier beds/reservoirs. Understanding the origin and distribution patterns of concretions has important implications for characterizing reservoir heterogeneity and developing fields. The origin of calcite concretions in non‐marine sandstones lacking detrital carbonate to source the cement is poorly studied. The practical difficulty of obtaining the precipitation temperature of the concretions prevents the precise determination of the source of cement components, solute flux, pore water type and the geochemical microenvironments in which cement precipitated. Carbonate clumped isotope thermometry can give unique constraints to the temperature of concretionary cement precipitation. This study focused on outcrops of the Lower Cretaceous non‐marine Qingshuihe Formation in the Urho area, on the north‐western margin of the Junggar Basin (West China). Four depositional facies associations were recognized, corresponding to channel, mid‐channel bar, abandoned channel and overbank floodplain environments. Calcite concretions occur only in sandstones and include spherical, ellipsoidal and tabular forms. They are isolated and/or mutually aligned in layers that tend to be either at the top, base, or within channel and mid‐channel sand bodies. The clumped isotope temperatures for the concretionary calcite range from 31 to 45°C with a standard error of <3°C. The calcite has highly variable, low δ13C values ranging from −16.91 ± 0.01 to −2.93 ± 0.02‰ (Vienna Pee Dee Belemnite). The 13C‐depleted bicarbonate source was linked to biodegradation of migrated oils at shallow burial owing to tectonic uplift and erosion. Calcite δ18O values are very consistent and fall between −12.30 ± 0.04 to −9.79 ± 0.31‰ (Vienna Pee Dee Belemnite). Introduction of meteoric water was a dominant mechanism for the pronounced 18O‐depletion in the oxygen isotopes of pore water, along with water–rock interaction during alteration of volcaniclastic materials in sandstones. Meteoric groundwater flushed the Qingshuihe sandstones as confined aquifers down the regional palaeo‐slope, biodegrading the migrated oils and enabling a sufficient solute flux for precipitation of concretions. [ABSTRACT FROM AUTHOR]

New pollution elements introduced by the rapid development of modern industry and agriculture may pose a serious threat to the soil ecosystem. To explore the ecotoxicity and risk of these elements, we systematically studied the acute toxicity of 18 metal(loid)s toward lettuce using hydroponic experiments and quantitative relationships between element toxicity and ionic characteristics using ion-grouping and ligand-binding theory methods, thereby establishing a quantitative ion character-activity relationship (QICAR) model for predicting the phytotoxicity threshold of data-poor elements. The toxicity of 18 ions to lettuce differed by more than four orders of magnitude (0.05–804.44 μM). Correlation and linear regression analysis showed that the ionic characteristics significantly associated with this toxicity explained only 23.8–50.3% of the toxicity variation (R2Adj = 0.238–0.503, p < 0.05). Relationships between toxicity and ionic properties significantly improved after separating metal(loid) ions into soft and hard, with R2Adj of 0.793 and 0.784 (p < 0.05), respectively. Three ligand-binding parameters showed different predictive effects on lettuce metal(loid) toxicity. Compared with the binding constant of the biotic ligand model (log K) and the hard ligand scale (HLScale) (p > 0.05), the softness consensus scale (σCon) was significantly correlated with toxicity and provided the best prediction (R2Adj = 0.844, p < 0.001). We selected QICAR equations based on soft-hard ion classification and σCon methods to predict phytotoxicity of metal(loid)s, which can be used to derive ecotoxicity for data-poor metal(loid)s, providing preliminary assessment of their ecological risks. [ABSTRACT FROM AUTHOR]

Background: Human Adenovirus (HAdV) pneumonia is common in young children and infants. Overall, 7–8% of all viral respiratory illnesses among children for less than 5 years are induced by HAdVs. Unfortunately little is known about the role of monocyte count in the disease severity. Methods: Data were gathered from 595 children (age < 6 years) who were diagnosed with HAdV infection at the 1st People's Hospital (Changde City, China) between January 2019 and December 2019. There were 181 cases of severe adenovirus pneumonia. Results: The correlation between the patients' monocyte count and the severity of HAdV pneumonia was estimated by performing a multiple linear regression analysis. The results showed a negative association (OR: 0.53, 95% CI 0.31 to 0.89, P < 0.05). We further built Generalized Additive Models (GAMs) and demonstrated that the monocyte count had a non-linear association with severe HAdV pneumonia. The inflection point of monocyte count detected in the two-stage linear regression model was 1.5. On the left side of this point, the monocyte count was negatively interrelated (OR: 0.26, 95% CI 0.13 to 0.52, P < 0.001), while on the opposite side, there was a positive association (OR: 7.48, 95% CI 1.30 to 43.08, P < 0.05). Conclusions: Based on the results of this investigation, we established a link between monocyte count and the severity of HAdV pneumonia. Monocyte count is negatively associated with severe HAdV pneumonia. The inflection point of monocyte count detected in the two-stage linear regression model was 1.5 × 109/L. [ABSTRACT FROM AUTHOR]

A $\beta $ -Ga2O3 MOSFET is fabricated and its threshold voltage $({V}_{\mathrm{TH}})$ instability mechanisms are experimentally investigated under different gate-biased voltages and ambient temperatures. Under the condition of the positive bias stress (PBS) of ${V}_{\mathrm{GS}} = 4$ V for 1000 s at room temperature, the ${V}_{\mathrm{TH}}$ positive shift of 0.61 V is mainly caused by the electrons trapped by border traps in Al2O3. Combining the hysteresis with temperature-dependent performance analysis, the clockwise to anticlockwise hysteresis inversion at 125 °C is discovered in $\beta $ -Ga2O3 MOSFET for the first time, which is probably caused by the activation of deep-level acceptor-type interface states. The deep-level acceptor-type interface states with a fitting activation energy of 114 meV are found, and they also affect the ${V}_{\mathrm{TH}}$ instability at high temperature. With the stress of ${V}_{\mathrm{GS}} =4$ V at 125 °C for 1000 s, ${V}_{\mathrm{TH}}$ is increased by 0.9 V. Analyzing electrical parameters, such as ${V}_{\mathrm{TH}}$ , subthreshold slope (SS), and hysteresis width, can distinguish the quantitative contributions of interface states and border traps to ${V}_{\mathrm{TH}}$ instability under electrical stress and thermal stress (TS). This work reveals an important indication for investigating the ${V}_{\mathrm{TH}}$ instability of $\beta $ -Ga2O3 MOSFET in high-power applications. [ABSTRACT FROM AUTHOR]

Highlights: According to the design of the experiment (DoE), multivariate analysis models were used to optimize the critical process parameters combined with multi-objective optimization. Based on the optimized operating conditions, the MILT-HD method not only enhances the extraction efficiency from Amomi fructus but also reduces energy demands and CO2 emissions. Based on the density functional theoretical (DFT) and molecular dynamics (MD) simulations, the mechanisms for ionic liquids (ILs) to improve the extraction efficiency of essential oil was comprehensively revealed. In this paper, Amomi fructus (Latin) was used to explore the mechanism of ionic liquids (ILs) in improving the extraction efficiency of essential oils. Microwave assisted ionic liquid treatment followed by a hydro-distillation (MILT-HD) process for isolating Amomi fructus essential oil was optimized by multi-objective optimization. Under optimum operating conditions, the IL-assisted extraction method not only enhances extraction efficiency but also reduces energy demands and CO2 emissions. Since the hydrogen bond structure network of cellulose in the cell wall is an important reason for hindering diffusion of essential oils, the mechanism of ILs was explored by density functional theoretical (DFT) and molecular dynamics (MD) simulations. According to DFT calculations, ILs can facilitate the cleavage of cellulose chains and have strong non-covalent interactions with cellulose. Based on the MD simulations, the degree of destruction of the cellulose hydrogen bond structure was explored. According to the DFT and MD simulations, the ILs can significantly destroy cellulose structure, thereby promoting essential oil release from the plant. These results were confirmed by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). This work is conducive to better understand the MILT-HD process for isolating essential oil and comprehensively understand the mechanism of ILs in the extraction process. [ABSTRACT FROM AUTHOR]

A vertical GaN power MOSFET featuring an integrated fin-shaped non-junction diode (FDMOS) is proposed to improve reverse conduction and switching characteristics. Its static and dynamic characteristics are studied and analyzed by Sentaurus TCAD simulation. Compared with the conventional MOSFET (Con. MOS) with a body diode as a freewheeling diode (FWD), the FDMOS uses the integrated fin-shaped diode to reverse conduction, and thus, a low reverse turn-on voltage VON of 0.66 V is achieved, with a decreasing of 77.9%. Moreover, the Qrr of the FDMOS is reduced to 1.36 μC from 1.64 μC of the Con. MOS, without the minority carrier injection. The gate charge (QGD) of the FDMOS is significantly reduced because the fin structure reduces the gate area and transforms some part of CGD to CGS, and thus, a low switching loss is realized. The QGD, the turn-on loss (Eon) and the turn-off loss (Eoff) of the FDMOS are decreased by 56.8%, 33.8% and 53.8%, respectively, compared with those of the Con. MOS. In addition, the FDMOS is beneficial to reduce the parasitic inductance and the total chip area compared with the conventional method of using an externally connected Schottky diode as an FWD. [ABSTRACT FROM AUTHOR]

A novel double gates flip-structure enhancement-mode (E-mode) high electron mobility transistor with step field plate (DFF HEMT) is proposed. It features face-to-face double gates, including a top trench MIS gate with a step field plate and a bottom planar MIS gate, which is shorted together. In the on-state, the double gates not only can restore the 2DEG by the higher electric potential, but also can form the electron accumulation layers, and thus increase the saturation output current and reduce the on-resistance. The face-to-face double gates together deplete the 2DEG by using the work function difference to realize E-mode, instead of by etching the AlGaN layer under the gate for the conventional MIS gate E-mode HEMT. The double-gate structure not only avoids etch damage, but also maintains both high threshold voltage and low on-resistance. Meanwhile, the step gate field plate modulates E-field distribution to increase the BV. In order to easily fabricate, the trench gate with step field plate must be located on the top of device, forming the flip-structure. The flip-structure is also beneficial to decrease the leakage current in the substrate. The simulated Vth, BV and Id of the DFF HEMT are 0.8 V, 465 V and 494 mA/mm, respectively. The FOM of the DFF HEMT is 79.8% and 444.2% higher than those of the conventional MIS-FP HEMT and MIS HEMT. [ABSTRACT FROM AUTHOR]

Standing wave solutions of the following Hartree system with nonlocal interaction and critical exponent are considered: - (a + b ∫ Ω | ∇ u | 2) Δ u = h (x) ∫ Ω | v (y) | 2 μ ∗ | x - y | μ d y | u | 2 μ ∗ - 2 u + f λ (x) | u | q - 2 u , i n Ω , - (a + b ∫ Ω | ∇ v | 2) Δ v = h (x) ∫ Ω | u (y) | 2 μ ∗ | x - y | μ d y | v | 2 μ ∗ - 2 v + g σ (x) | v | q - 2 v , i n Ω , u , v ≥ 0 , i n Ω , u , v = 0 , o n ∂ Ω , where 1 < q < 2 , 2 μ ∗ = 2 N - μ N - 2 is the upper critical exponent in the sense of the Hardy–Littlewood–Sobolev inequality. We study the effect of nonlocal interaction on the number of solutions in the case of general response function Ψ (x) = | x | - μ (0 < μ < N) , which possesses more information on the mutual interaction between the particles. When parameters pair (λ , σ) belongs to a certain subset of R 2 , we prove the existence, nonexistence and the limit behavior of the nonnegative vector solutions depending on parameters. In the special case of q = 2 , existence of nonnegative solution is also established. Our work extends and develops some recent results in the literature. [ABSTRACT FROM AUTHOR]

A novel snapback-free RC-LIGBT with integrated self-biased N-MOSFET is proposed and investigated by simulation. The device features an integrated self-biased N-MOSFET(ISM) on the anode active region. One side of the ISM is shorted to the P + anode electrode of RC-LIGBT and the other side is connected to the N + anode via a floating ohmic contact. The adaptively turn-on/off of the ISM contributes to improve the static and dynamic performance of the ISM RC-LIGBT. In the forward-state, due to the off-state of the ISM, the snapback could be effectively suppressed without requiring extra device area compared to the SSA (separated shorted anode) and STA (segmented trenches in the anode) LIGBTs. In the reverse conduction, the ISM is turned on and the parasitic NPN in the ISM is punched through, which provides a current path for the reverse current. Meanwhile, during the turn-off and reverse recovery states, the ISM turns on, providing a rapid electron extraction path. Thus, a superior tradeoff between the on-state voltage drop (Von) and turnoff loss (Eoff) as well as an improved reverse recovery characteristic can be obtained. Compared to the STA device, the proposed ISM RC-LIGBT reduces Eoff by 21.5% without snapback. Its reverse recovery charge is reduced by 53.7%/58.6% compared to that of the SSA LIGBT with Lb = 40/60 μm at the same Von. Due to the prominent static and dynamic characteristic, the power loss of ISM RC-LIGBT in a completed switching cycle is reduced. [ABSTRACT FROM AUTHOR]

In this Letter, we report on establishing high performance hysteresis-free and μs-switching depletion/enhancement-mode (D/E-mode) β-Ga2O3 heterojunction (HJ) field effect transistors (FETs) with the state-of-art power figure-of-merit (P-FOM). By optimizing the p-NiOx/n-Ga2O3 interface and n-Ga2O3 recess technology, a positive threshold voltage (VT) as well as a low subthreshold slope can be substantially achieved. The trade-off between the on-resistance (Ron,sp) and breakdown voltage (BV) is improved by incorporation of T-shaped NiOx, resulting in the Ron,sp of 6.24/13.75 mΩ cm2 and the breakdown voltage (BV) of 2145/1977 V for D/E-mode devices and yielding the P-FOM = BV2/Ron,sp to be 0.74/0.28 GW/cm2. To the best of all the authors' knowledge, those P-FOMs are the highest ones among all published lateral Ga2O3 FETs. Benefited from the high-quality interface, a negligible hysteresis of 4 mV and μs-switching can be essentially achieved, showing the great promise of Ga2O3 HJ-FETs for future high-power, high-efficiency, and high-speed power electronics. [ABSTRACT FROM AUTHOR]

Objective: To investigate the severity and risk factors of menopausal symptoms in the middle-aged women in Gansu Province of China.Methods: In this cross-sectional study, a total of 7319 women (aged 40-55 years) attended the health survey in Gansu Province in China were enrolled. Information on demographics, menopausal status, reproductive history, and history of chronic diseases was collected via a structured questionnaire. Severity of menopausal symptom was evaluated by the Modified Kupperman Menopausal Index. Ordinal logistic regression model was applied to explore its risk factors.Results: A total of 7319 participants were included in present study, among them, 3606 (49.27%) had moderate or severe menopausal symptom. Compared with premenopausal women, perimenopausal and postmenopausal women have a higher mKMI score. We observed that older age, higher BMI, non-married status, longer duration of menstruation (≥ 7 days), number of pregnancy (> 3 times), longer duration of breastfeeding (> 12 months), peri- or post-menopausal status, and menopause hormone therapy was positively associated with menopausal symptom score, while higher level of family income, educational and physical activity, and history of gynecological, breast or chronic disease were negatively associated with the score.Conclusions: Numerous factors were associated with the severity of menopausal symptom among the Chinese women. Because it was gradually increased with aging, more attention is warranted to manage the menopausal symptom. [ABSTRACT FROM AUTHOR]

The physical mechanism of threshold voltage (VTH) instability in AlGaN/GaN metal-insulator-semiconductor high electron mobility transistors (MIS-HEMTs) was identified via capacitance-mode deep-level transient spectroscopy characterization. MIS-HEMTs with low-pressure chemical vapor deposited (LPCVD) SiNx as the gate insulator feature two distinctive trap-emission transients. The initial transient corresponds to emission of states at the SiNx/AlGaN interface, and the extracted density of state exhibits an exponential decay distribution. The subsequent transient is revealed due to hybrid emission of the interface and bulk states from the LPCVD-SiNx gate insulator, which features an activation energy higher than 1.1 eV and a capture cross section that ranges between 1 × 10−11 and 1 × 10−10 cm2. The bulk states in the LPCVD-SiNx gate insulator become charged under high gate voltage overdrive, leading to severe VTH instability in GaN-based MIS-HEMTs. [ABSTRACT FROM AUTHOR]

A 600 V-rated insulated gate bipolar transistor (IGBT) with improved turn-on transient characteristics is proposed and investigated by simulation. The proposed IGBT features a built-in voltage-clamping structure. The floating ${p}$ -body adjacent to the trench gate is clamped at an appropriately high voltage before turn-on. This slows down the hole accumulation process in the floating p-body during turn-on transient, and thus the self-charging displacement current through the gate capacitance is reduced. The increasing rate for the gate voltage (dVGE/dt) is then reduced. As a result, the proposed IGBT achieves a 25% decrease in collector current ($I_C$) overshoot and 34% decrease in dIC/dt, when compared with the conventional IGBT with the same turn-on loss (EON), at IC = 250 A/cm2 under hard-switching. Its fabrication process is compatible with conventional trench IGBT. [ABSTRACT FROM AUTHOR]

In this letter, the ultrafast reverse recovery β-Ga2O3 Schottky barrier diode (SBD) with improved breakdown voltage is proposed and investigated experimentally. It features the compound termination, consisting of air space field plate and thermal oxidation terminal. The compound termination not only reduces high-density interface states at the dielectric/Ga2O3 interface and the electron concentration in the oxidation terminal, but also modulates the electric-field distribution and suppresses the peak electric-field at the bottom of anode. Therefore, the reverse leakage current is suppressed as well as the reverse recovery and breakdown characteristics are improved effectively. The Ga2O3 SBDs with the diameter of 1000 μm obtain ultrashort reverse recovery time of 7.5 ns and ultralow reverse recovery charge of 1.0 nC at di/dt = 50 A/μs with its breakdown voltage up to 400 V, maintaining good rectification characteristics. The temperature-dependences of both forward conduction and reverse recovery characteristics are discussed in temperature range from 300 to 500 K. The results prove that the superior electronics performance of the β-Ga2O3 SBDs with good electronics thermal tolerance can overcome the low thermal conductivity of β-Ga2O3 to a certain extent. The fabricated β-Ga2O3 SBDs have great potential for high power and high-frequency applications. [ABSTRACT FROM AUTHOR]

The total organic carbon content (TOC) is a core indicator for shale gas reservoir evaluations. Machine learning-based models can quickly and accurately predict TOC, which is of great significance for the production of shale gas. Based on conventional logs, the measured TOC values, and other data of 9 typical wells in the Jiaoshiba area of the Sichuan Basin, this paper performed a Bayesian linear regression and applied a random forest machine learning model to predict TOC values of the shale from the Wufeng Formation and the lower part of the Longmaxi Formation. The results showed that the TOC value prediction accuracy was improved by more than 50% by using the well-trained machine learning models compared with the traditional Δ Log R method in an overmature and tight shale. Using the halving random search cross-validation method to optimize hyperparameters can greatly improve the speed of building the model. Furthermore, excluding the factors that affect the log value other than the TOC and taking the corrected data as input data for training could improve the prediction accuracy of the random forest model by approximately 5%. Data can be easily updated with machine learning models, which is of primary importance for improving the efficiency of shale gas exploration and development. [ABSTRACT FROM AUTHOR]

To achieve lower specific ON-resistance (${R}_{{ \mathrm{\scriptscriptstyle ON},\text {SP}}}$), a novel accumulation lateral double-diffused MOSFET (ALDMOS) characterized by a convex-shaped field plate (CFP) structure is proposed and investigated experimentally. The CFP structure above the ${N}$ -drift region consists of two diodes, with its contact regions embedding into the drain and source region. Hence, the proposed device could shrink the drift length and utilize the drift region effectively to sustain the same level of breakdown voltage in the OFF-state. Furthermore, the CFP structure enables to form a continuous electron accumulation layer at the drift surface in the ON-state. Consequently, the proposed CFP ALDMOS could obtain an ultralow ${R}_{{ \mathrm{\scriptscriptstyle ON},\text {SP}}}$ and achieve a better tradeoff relationship between BV and ${R}_{{ \mathrm{\scriptscriptstyle ON},\text {SP}}}$. The experimental results show that the CFP ALDMOS realizes a BV of 448 V and ${R}_{{ \mathrm{\scriptscriptstyle ON},\text {SP}}}$ of 16.9 $\text{m}\Omega \cdot $ cm2 with an extremely high figure of merit of 11.87 MW/cm2, decreasing ${R}_{{ \mathrm{\scriptscriptstyle ON},\text {SP}}}$ by 55.6% compared with theoretical triple-REduced SURface Field (RESURF) LDMOS at the same BV. [ABSTRACT FROM AUTHOR]

Wettability is an essential property of reservoirs that is of great importance for enhancing oil recovery (EOR) and oil migration. The wettability of reservoirs is generally believed to be strongly affected by mineral compositions but it is not always the case. An integrated study of petrography and wettability was carried out to determine the impact of chlorite minerals on the wettability of the sandstone reservoirs in the Upper Triassic Yanchang Formation. Chlorites are found to be commonly present in the reservoir sandstones as detrital grains, rim-shaped cements, and biotite-chloritized forms with the pore peripheries being largely coated by chlorite, which is the main mineral in direct contact with pores. At pore scale, the wetting state of chlorites can either be oil-wet or water-wet in the tight sandstone reservoirs depending on wettability alteration by oil charge. Chlorites in contact with pores occupy a large of proportions of oil-wet pore walls and are crucial for the formation of oil-wetting state of reservoir sandstones. At core scale, the contents of chlorites in direct contact with pores do not correlate well with the Amott-Harvey index due to other factors such as heterogeneity, oil-bearing degrees of samples. [ABSTRACT FROM AUTHOR]

Total organic carbon content (TOC) is an important parameter for shale gas resource evaluation. Among the existing TOC prediction methods, ΔlgR method is the most widely used. There are two main problems in this method: 1) assuming a linear relationship between ΔlgR and TOC; 2) manually determining the baseline and introducing human error. Due to the frequent alternating changes in the sedimentary environments of continental shale, the heterogeneity of it is strong. In this case, the relationship between well logs and TOC is complex and nonlinear, which leads to incorrect results for predicted TOC using ΔlgR method. The objective of this paper is to develop a new empirical method to determine the TOC of continental shale using support vector regression (SVR) based on grid search cross-validation. The optimized SVR method can fit the nonlinear relationships between log data and TOC well, and it is suitable for TOC estimation in strong heterogeneity case such as continental shale. Three hundred sixty-four measured TOC samples of Zhangjiatan shale and the corresponding GR, DEN, AC, U logs data were used to construct the SVR model. Compared with the ΔlgR method, the accuracy of the SVR model to calculate TOC is obviously higher. [ABSTRACT FROM AUTHOR]

A superjunction insulated gate bipolar transistor (SJ-IGBT) featuring a self-adaptive hole-extracting (SAHE) path is proposed and investigated by simulation. The SAHE path is formed by a narrow p-type mesa between the two trench gates. In the ON-state, the p-type mesa is depleted by the trench gates and the hole path is pinched off so as to maintain high injection efficiency, and thus a low ON-state voltage (VON) is achieved. During the turn-off period, the p-type mesa recovers into neutral region adaptively and then the hole-extracting path is opened, which helps decrease the turn-off loss (EOFF) and suppress the dynamic avalanche. Moreover, at the initial turn-on stage with the SAHE path opening, the P-pillar in the proposed device is shorted to the emitter electrode rather than floating, which suppresses the negative capacitance effect. Therefore, compared with the SJ-IGBT with floating P-pillar, the SAHE SJ-IGBT not only achieves better VON−EOFF tradeoff but also reduces the surge current by 23% at the turn-on stage and obtains better controllability on the turn-on dVCE/dt and dIC/dt characteristics, greatly decreasing the electromagnetic interference (EMI). [ABSTRACT FROM AUTHOR]

We consider the following Choquard equation {−(a+ε ∫Ω|∇u|2)Δu = (∫Ω|u(y)|2∗μ/|x−y|μ dy)|u|2∗μ−2 u+λƒ(x)|u|q−2u in Ω,u=0 on ∂Ω, where λ is a real parameter, 2∗μ = 2N−μ/N−2(0 < μ < N) is the critical exponent in the sense of the Hardy-Littlewood-Sobolev inequality. Under some suitable assumptions on λ,μ, via the constrained minimizer method and concentration compactness principle, we prove that this system has multiple of solutions, and one of which is a positive ground state solution. Moreover, by using an abstract result due to K.-C Chang, we admit infinitely many pairs of distinct solutions. In addition, we prove the nonexistence result by Pohožaev identity when λ < 0. The main results extend and complement the earlier works in the literature. [ABSTRACT FROM AUTHOR]

The Lower Jurassic Ahe Formation is an important exploration target for deep clastic reservoirs in the eastern Kuqa Depression. The Ahe Formation sandstones show heterogeneous porosity and permeability petrophysical properties. These properties have been poorly understood, limiting forecast of petroleum accumulations and making it difficult to develop the reservoirs. Based on cores, thin sections, SEM, and fluid inclusions, this study examined sandstone composition and texture and diagenetic heterogeneity at the core scale. The aim was to understand the influence of variations in detrital composition and texture on diagenetic and reservoir quality evolution. The Ahe Formation sandstones are dominantly fine- to coarse-grained litharenites, with minor feldspathic litharenites. In fining-up sand beds, detrital grain size determines the degree of mechanical compaction and, consequently, the abundance of porosity through ductile grains and muddy matrix. Local complete calcite cementation is a noticeable exception to this general trend. Three sandstone petrofacies have been defined based on texture and framework composition, detrital matrix, diagenesis, and pore types: (1) ductile-lean sandstone, (2) ductile-rich sandstone, and (3) tightly calcite-cemented sandstone. Different petrofacies experienced contrasting diagenetic and porosity evolution pathways. Ductile-lean sandstones underwent lower degree of compaction relative to ductile-rich sandstones during the eodiagenesis stage, and extensive grain dissolution occurred. The petrofacies remained relatively porous and permeable before early oil arrival. With continued burial, the porosity and permeability in the sandstones were further reduced by cementation. The petrofacies still had moderate porosity and permeability and were substantially charged when late petroleum migrated into the reservoirs. Thus, ductile-lean sandstones constitute effective reservoir rocks in deep reservoirs. By translating petrofacies to signatures of well logs, the effective properties of the reservoir rocks can be forecasted at the well scale. [ABSTRACT FROM AUTHOR]

This study evaluated the relationships between parity and the age at menopause and menopausal syndrome among Chinese women in Gansu. A total of 7236 women aged 40 to 55 years met study eligibility criteria. The modified Kupperman Menopausal Index scale was used to assess the severity of menopausal syndrome. Cox regression was applied to estimate hazard ratio and 95% confidence interval, and logistic regression was performed to calculate odds ratio and confidence interval. The mean age at menopause was 47.91 ± 3.31 years. There is no relationship between parity and age at menopause. Women with nulliparity or multiparity seemed to have higher risks of moderate and severe menopausal syndrome. The potential beneficial effects of one or two births on menopausal syndrome were also observed by applying the multivariable logistic regression analysis, particularly in urogenital symptoms. Women with nulliparity and multiparity appeared to be at the higher risks of menopause syndrome. [ABSTRACT FROM AUTHOR]

Oil-water relative permeability curves are the basis of oil field development. In recent years, the calculation of oil-water relative permeability in sandstone reservoirs by resistivity logging data has received much attention from researchers. This article first analyzed the existing mathematical models of the relationship between relative permeability and resistivity and found that most of them are based on Archie formula, which assumes the reservoir is clean sandstone. However, in view of the fact that sandstone reservoir is commonly mixed with shale contents, this research, based on the dual water conductivity model, Poiseuille's equation, Darcy's law, and capillary bundle model, derived a mathematical model (DW relative permeability model) for shaly sandstone reservoir, which calculates the oil-water relative permeability with resistivity. To test and verify the DW relative permeability model, we designed and assembled a multifunctional core displacement apparatus. The experiment of core oil-water relative permeability and resistivity was designed to prove the effectiveness of the DW relative permeability model in shaly sandstone reservoirs. The results show that the modified Li model can well express the transformational relation between resistivity and relative permeability in sandstone reservoir with low clay content. Compared with the modified Li model and the Pairoys model, the DW relative permeability model is more helpful to collect better results of relative permeability in shaly sand. These findings will play a significant role in the calculation of oil-water relative permeability in reservoirs based on resistivity logging data and will provide important data and theory support to the shaly sandstone reservoir characterized oil field development. [ABSTRACT FROM AUTHOR]

An AlGaN/GaN Schottky barrier diode (SBD) with double-heterojunction is theoretically and experimentally investigated on the GaN/AlGaN/GaN/Si-sub. The two-dimensional hole gas (2DHG) and electron gas (2DEG) are formed at the GaN-top/AlGaN and AlGaN/GaN interface, respectively. At the off-state, the 2DEH and 2DHG are partially depleted and then completely disappear. There remain the fixed positive and negative polarization charges, forming the polarization junction. Therefore, a flat electric field in the drift region and a high breakdown voltage (BV) are obtained. Moreover, the anode is recessed to reduce turn-on voltage (VON). The low-damage ICP etching process results in the improved Schottky contacts, and a low leakgae current and a low VON is obtained. The fabricated SBD exhibits a BV of 1109 V with anode-to-cathode distance (LAC) of 11 μm. The fabricated SBDs achieve a low VON of 0.68 V with good uniformity, a high on/off current ratio ∼ 1010 at room temperature, a low specific on-resistance (RON,SP) of 1.17 mΩ cm2, and a high Baliga's figure-of-merit (FOM) of 1051 MW/cm2. [ABSTRACT FROM AUTHOR]

In this paper, we study the quasilinear Schrödinger equation involving concave and convex nonlinearities. When the pair of parameters belongs to a certain subset of ℝ 2 , we establish the existence of a nontrivial mountain pass-type solution and infinitely many negative energy solutions by using some new techniques and dual fountain theorem. Recent results from the literature are improved and extended. [ABSTRACT FROM AUTHOR]

In this paper, a novel ultralow on-state voltage-drop (VON) and high current capability SOI lateral insulated gate bipolar transistor (LIGBT) is proposed and investigated by simulation. The proposed device features a folded t rench gate (FTG) and a s tep thickness (ST) drift region filled with insulator, named FTS LIGBT. The FTG is employed to increase the channel density and modulate the current distribution, achieving high current capability and reducing the VON. The stepped insulator in drift region acts as the barrier to suppresses holes from being extracted by cathode and enhances the conductivity modulation, thus further contributes to an ultralow VON in the on-state. Meanwhile, the drift region with varied thickness approximates the effect of variation of lateral doping (VLD) technique to optimize the electric-field distribution, and then maintains high breakdown voltage (BV). Additionally, the T-shaped P+ cathode region improves hole collection efficiency and vertical channels provide a low-resistance for hole current, and thus improves the latch-up immunity and short-circuit capability. Compared with the conventional LIGBT at the same turn-off loss (EOFF), the VON of the FTS LIGBT is reduced by 23% and 38% at the current density of 100 A cm−2 and 200 A cm−2, respectively; The EOFF is reduced by 53% at the current density of 100 A cm−2 at the same VON. The FTS exhibits high saturation current capability (751 A cm−2), which is 2.5 times as that of the conventional LIGBT. [ABSTRACT FROM AUTHOR]

The cover image is based on the Research Article Effects of ultrasonic power on drying kinetics and product quality of licorice extract during ultrasound‐assisted vacuum drying by Xuecheng Wang et al., https://doi.org/10.1002/jsfa.13283. [ABSTRACT FROM AUTHOR]

A novel Lateral Double-Diffused MOSFET (LDMOSFET) with ultra-low resistance is investigated by experiments. The proposed LDMOSFET features an extended gate field plate consisting of two back-to-back diodes. In the ON state, the electron accumulation layer is formed below the gate field plate and greatly reduces the resistance of the drift region. In the OFF state, the field plate assists in depleting the drift region and modulates the electric field distribution of the drift region, which ensures high breakdown voltage (BV). The key fabrication process steps for the proposed device are given. The fabricated prototype device shows specific on-resistance (${R} _{{\text {on},\text {sp}}}$) of 70 $\text{m}\Omega \cdot $ cm2 and BV of 680 V, which is superior performance for reported 600 V-rated lateral devices. The ${R} _{{\text {on},\text {sp}}}$ of the proposed LDMOSFET is decreased by 50% compared with the LDMOSFET without accumulation effect. [ABSTRACT FROM AUTHOR]

There is considerable interest in quantum dots incorporated in nanowires for nanolasers and quantum emitters. In this letter, we demonstrate single InAsP quantum dots embedded in InP nanowires grown by metalorganic vapor-phase epitaxy. Despite the abrupt change of growth conditions at the interface, InAsP quantum dots can be grown in pure wurtzite InP nanowires. We develop a model and analyze the effects of the thickness of InAsP quantum dots and the composition of As on the formation of dislocations. Furthermore, the InAsP/InP quantum dot nanowires show bright photoluminescence up to room temperature without any surface passivation. The emission from the quantum dots could be well tuned by adjusting the dot size either vertically or laterally. The study demonstrates the potential of this material system for optoelectronic applications. [ABSTRACT FROM AUTHOR]

A novel high voltage ultra-thin silicon on insulator (SOI) lateral double diffused metal oxide semiconductor field effect transistor (LDMOS) with a sectional linearly doped drift region is proposed and experimentally realized in this letter. The new device features a sectional linear doping (SLD) in a $0.17~ {\mu }\text{m}$ SOI layer with a source field plate covering the full drift region. Low specific on-resistance ${R} _{\text {on,sp}}$ is obtained by increasing the local doping concentration of the high resistance region. An analytical model is developed to provide the design guidance for the thin SOI devices with the field plate. The experimental results of the SOI SLD-LDMOS demonstrate that the new device shows a high breakdown voltage ${V} _{\text {B}}$ of 960 V with a superior figure of merit (FOM $= {V} _{\text {B}}{^{\text {2}}} / {R} _{\text {on,sp}}$) of 5.98 MW/cm2 when comparing with other reported thin SOI devices. Good agreements are observed between the model and the experimental results. [ABSTRACT FROM AUTHOR]

In this paper, we present a lateral injection enhanced insulated gate bipolar transistor (LIEGT) and investigate its mechanism. The LIEGT features a recessed trench at the cathode side of the drift region formed by LOCal oxidation of silicon (LOCOS) process. The recessed trench suppresses holes being extracted and enhances the electron injection, thus contributing to a very low loss in the ON-state. The ON-state voltage (${V}_{ \mathrm{\scriptscriptstyle ON}}$) of the LIEGT is reduced by 24% at the current density of 200 A/cm2 and the saturation current is 40% higher than that of the conventional lateral insulated gate bipolar transistor (LIGBT). The LIEGT exhibits an improved tradeoff between ${V}_{ \mathrm{\scriptscriptstyle ON}}$ and turnoff loss (${E}_{ \mathrm{\scriptscriptstyle OFF}}$). For the same ${V}_{ \mathrm{\scriptscriptstyle ON}}$ , the ${E}_{ \mathrm{\scriptscriptstyle OFF}}$ is decreased by 38% compared with that of the conventional LIGBT. [ABSTRACT FROM AUTHOR]

A novel 600-V snapback-free and low-loss shorted-anode (SA) silicon on insulator lateral insulated gate bipolar transistor (LIGBT) with self-adaptive resistance (SAR) in anode is proposed and investigated by simulation, named SAR LIGBT. The device is characterized by dual anode trenches which are filled with p-type polysilicon and surrounded by oxide, and the dual trenches are shorted with the anode electrode, separated by the low-doped N− region and N+ anode region. At low anode voltage ($V_{A}$), the N− region is fully depleted by p-type polysilicon, serving as a large resistance to hinder electrons flowing into the N+ anode; at high VA, an electron accumulation layer is formed along the anode trenches to provide a low-resistance path for electron current. Consequently, N− region makes the distributed resistances at the anode side (${R}_{\text {SA}}$) act as a SAR. It not only eliminates the snapback effect but also reduces on-state voltage drop (${V}_{ \mathrm{\scriptscriptstyle ON}}$) and turn-off energy loss (${E}_{ \mathrm{\scriptscriptstyle OFF}}$). Therefore, SAR LIGBT achieves a better tradeoff between $V_{ \mathrm{\scriptscriptstyle ON}}$ and ${E}_{ \mathrm{\scriptscriptstyle OFF}}$. At the same ${V}_{ \mathrm{\scriptscriptstyle ON}}$ , the SAR LIGBT reduces the ${E}_{ \mathrm{\scriptscriptstyle OFF}}$ by 20.6%, 28.1%, and 30.5% compared with those of multisegment anode, segmented trenches in the anode, and SA-NPN LIGBTs, respectively. Moreover, the SAR LIGBT exhibits the lowest ${V}_{ \mathrm{\scriptscriptstyle ON}}$ of 1.71 V and the shortest switching time of 93 ns at $J_{A} = {100}$ A/cm2. In addition, the SAR LIGBT achieves snapback-free with smaller cell pitch than that of separated SA LIGBT. [ABSTRACT FROM AUTHOR]