Publications by authors named "Xiaohua Ma"

AlN-based bulk acoustic wave (BAW) filters have emerged as crucial components in 5G communication due to their high frequency, wide bandwidth, high power capacity, and compact size. This paper mainly reviews the basic principles and recent research advances of AlN-based BAW resonators, which are the backbone of BAW filters. We begin by summarizing the epitaxial growth of single-crystal, polycrystalline, and doped AlN films, with a focus on single-crystal AlN and ScAlN, which are currently the most popular.

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This paper presents a new small-signal model for double-channel (DC)-high-electron-mobility transistors, developed through an analysis of the unique coupling effects between channels in devices. Unlike conventional single-channel HEMTs, where electrons only transport laterally in the channel, DC-HEMTs exhibit additional vertical transport between the two channels along the material direction. This double-channel coupling effect significantly limits the applicability of traditional small-signal models to DC-HEMTs.

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The rigid V-shaped Tröger's base () unit has been proven efficacious in creating microporosity, making -based polyimides (PIs) exhibiting significant advantages in simultaneously increasing gas permeability and selectivity for the separation industry. However, -based PIs commonly display undesired mechanical performance due to the low molecular weight resulting from the evident steric hindrance and low reactivity of -containing diamines. Herein, a novel diamine-containing bisimide linkage () has been synthesized and then polymerized with paraformaldehyde via a moderate " polymerization" strategy to furnish polymers simultaneously, including imide linkages and units in the polymer main chains, namely, s.

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D-π conjugated coordination polymers (CCPs) are often widely used in photocatalysis and electrocatalysis due to their unique electronic conductivity and structural flexibility. However, it remains a challenge to overcome the self-degradation of d-π CCPs in thermal catalysis and to effectively utilize their excellent electron transfer properties. Here, we present a series of d-π CCPs derivative after calcination treatment.

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is a rare and endangered deciduous shrub originating from the Tertiary Period. Understanding its drought tolerance is crucial for conservation efforts and enhancing its resilience to environmental stress. This study aimed to assess the effects of varying levels of drought stress on the phenotype and physiological-biochemical characteristics of .

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In this paper, AlGaN/GaN high electron mobility transistors (HEMTs) with different thicknesses of unintentional doping GaN (UID-GaN) channels were compared and discussed. In order to discuss the effect of different thicknesses of the UID-GaN layer on iron-doped tails, both AlGaN/GaN HEMTs share the same 200 nm GaN buffer layer with an Fe-doped concentration of 8 × 10 cm. Due to the different thicknesses of the UID-GaN layer, the concentration of Fe trails reaching the two-dimensional electron gas (2DEG) varies.

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A 54-year-old man presented with a 1-month history of pain and numbness in the right lower limb. Lumbar spine MRI revealed bone metastases. 18F-FDG PET/CT showed a soft tissue mass with increased 18F-FDG uptake in the rectum, accompanied by multiple hypermetabolic lesions in the bilateral ribs, spine, pelvis, and upper right femur.

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The global quest for clean energy and sustainable processes makes advanced membrane extremely attractive for energy-intensive industrial gas separations. Here, we disclose a series of ultra-high-performance gas separation membranes (PIM-3D-TB) from novel network polymers of intrinsic microporosity (PIM) that combine the advantages of solution processible PIM and small pore size distribution (PSD) of porous organic polymers (POP), which was synthesized by in situ copolymerization of triptycene-2,6-diamine as linear part and triptycene-2,6,13(14)-triamine (TTA) as crosslinker. The resulting PIM-3D-TB membranes demonstrated outstanding separation properties that outperformed the latest trade-off lines for H/CH and O/N.

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In this work, we show a high-performance GaN-on-Si quasi-vertical PiN diode based on the combination of beveled sidewall and fluorine plasma treatment (BSFP) by an inductively coupled plasma (ICP) system. The leakage current and breakdown voltage of the diode are systematically studied. Due to the beveled sidewall treated by the fluorine plasma, the diodes achieve an excellent breakdown voltage (V) of 790 V and a low reverse leakage current.

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This study systematically investigates the effects of anode metals (Ti/Au and Ni/Au) with different work functions on the electrical and temperature characteristics of β-GaO-based Schottky barrier diodes (SBDs), junction barrier Schottky diodes (JBSDs) and P-N diodes (PNDs), utilizing Silvaco TCAD simulation software, device fabrication and comparative analysis. From the perspective of transport characteristics, it is observed that the SBD exhibits a lower turn-on voltage and a higher current density. Notably, the V of the Ti/Au anode SBD is merely 0.

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As a novel carbon-based material with two-dimensional (2D) characteristics, graphdiyne (GDY) shows great potential in constructing active catalytic sites due to its distinctive atomic configuration and sp/sp conjugated hybrid two-dimensional networks. In this study, the layered GDY was synthesized using the ball milling method, and ZnCdS/Graphdiyne/NiO (ZnCdS/GDY/NiO) composite was synthesized by in-situ composite and physical mixing method. The prepared ZnCdS/GDY/NiO has good photostability outstanding performance in photocatalytic hydrogen production.

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Ongoing coal-to-gas (CTG) largely cut down both coal consumption and associated PM. However, a knowledge gap still existed in CTG impacts on the other energy and organic pollutant emissions. Coupling on-site investigation with statistical yearbooks, we provided a more realistic energy evolutions before (BCTG), during (DCTG), and after (ACTG) the CTG for Hebei Province.

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African horse sickness (AHS) is an acute, fatal, contagious disease of animals of the family Equidae and is caused by infection with the African horse sickness virus (AHSV). Based on the outer capsid protein VP2, AHSV is classified into nine serotypes (AHSV-1 to -9) with little or no serological cross-reactivity between them. In 2020, AHS outbreaks caused by AHSV-1 were reported in Thailand and Malaysia, marking the first occurrences of AHS in Southeast Asia.

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In order to improve the off-state and breakdown characteristics of double-channel GaN HEMTs, an ultra-thin barrier layer was chosen as the second barrier layer. The strongly polarized and ultra-thin AlN sub-barrier and the InAlN sub-barrier are great candidates. In this article, the two epitaxial structures, AlGaN/GaN/AlN/GaN (sub-AlN) HEMTs and AlGaN/GaN/InAlN/GaN (sub-InAlN) HEMTs, were compared to select a more suitable sub-barrier layer.

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Immunoassays have been widely used for the determination of various analytes in the fields of disease diagnosis, food safety, and environmental monitoring. Dual-signal immunoassays are now advanced and integrated detection technologies with excellent self-correction and self-validation capabilities. In this work, we summarize the recent advances in the development of optical and electrochemical dual-signal immunoassays, including colorimetric, fluorescence, surface-enhanced Raman spectroscopy (SERS), electrochemical, electrochemiluminescence, and photoelectrochemical methods.

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Article Synopsis
  • - Membrane technology has grown significantly in gas separation over the past two decades, favored for its energy efficiency, compact design, continuous operation, and eco-friendly benefits.
  • - New materials, specifically ladder polymers of intrinsic microporosity (PIM) and polyimides (PIM-PI), have been developed with extremely small pores (<20 Å) that enhance gas permeation performance.
  • - The study highlights the creation of plasticization-resistant PIM-based membranes with high selectivity for gases, showcasing the effective use of hydroxyl- and carboxyl-functionalized blends that enable superior separation capabilities through strong hydrogen bonding networks.
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Article Synopsis
  • * The research involved irradiating Cascode GaN power devices with Ge and Bi ions to explore the effects of electrical stress, LET values, and gate voltages on SEE.
  • * Findings indicate that pre-stressing the device causes electron de-trapping and defects that increase charge collection, while higher LET values lead to more electron-hole pair generation, influencing drain leakage current and device reliability under radiation.
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Carbon molecular sieve (CMS) membranes have emerged as attractive gas membranes due to their tunable pore structure and consequently high gas separation performances. In particular, polyimides (PIs) have been considered as promising CMS precursors because of their tunable structure, superior gas separation performance, and excellent thermal and mechanical strength. In the present work, polyphosphoric acid (PPA) was employed as both cross-linker and porogen, it created pores within the PI polymeric matrix, while it also effectively acting as a cross-linker to regulate the ultramicropores of the CMS membranes, thus simultaneously improving both permeability and selectivity of the CMS membranes.

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Maedi-visna virus (MVV) and caprine arthritis encephalitis virus (CAEV) are members of a group of genetically highly homologous lentiviruses collectively referred to as small ruminant lentiviruses (SRLVs). SRLVs can infect sheep, goats and other small ruminants, causing multisystemic disease with progressive and persistent inflammatory changes, severely reducing animal productivity and impeding animal trade. The capsid protein of SRLVs, p28, is highly conserved among strains and is a commonly used marker for the detection of SRLVs.

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is the queen of the vines, being an ornamental plant with high economic value. Waterlogging stress reduces the ornamental value of the plant and limits its application. Melatonin plays an important role in plant resistance to abiotic stresses.

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Epigenetic mechanisms such as DNA methylation and hydroxymethylation play a significant role in depression. This research has shown that Ten-eleven translocation 2 (Tet2) deficiency prompts depression-like behaviors, but Tet2's transcriptional regulation remains unclear. In the study, bioinformatics is used to identify nuclear receptor subfamily 2 group E member 3 (Nr2e3) as a potential Tet2 regulator.

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Recently, the solar-driven interfacial evaporation desalination has attracted more and more attentions due to the advantages of low cost, zero energy consumption, and high water purification rate, etc. One of the bottlenecks of this emerging technique lies in a lack of simple and low-cost ways to construct three-dimensional (3D) hierarchical microstructures for photothermal membranes. To this end, a two-step strategy is carried out by combining surface functionalization with substrate engineering.

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Separating helium (He) and hydrogen (H), two gases that are extremely similar in molecular size and condensation properties, presents a formidable challenge in the helium industry. The development of membranes capable of precisely differentiating between these gases is crucial for achieving large-scale, energy-efficient He/H separation. However, the limited selectivity of current membranes has hindered their practical application.

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Cisplatin-based chemotherapy is the current standard care for lung cancer patients; however, drug resistance frequently develops during treatment, thereby limiting therapeutic efficacy.The molecular mechanisms underlying cisplatin resistance remain elusive. In this study, we conducted an analysis of microarray data from the Gene Expression Omnibus (GEO) database under the accession numbers GSE21656, which encompassed expression profiling of cisplatin-resistant H460 (DDP-H460)and the parental cells (H460).

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Synopsis of recent research by authors named "Xiaohua Ma"

  • - Xiaohua Ma's recent research primarily focuses on advancing semiconductor technologies, particularly GaN-based HEMTs (High Electron Mobility Transistors) and their applications, demonstrating improvements in device characteristics through novel barrier layers and passivation techniques to enhance performance in high-frequency and high-power applications.
  • - Another significant area of investigation involves the development of innovative materials and methods in membrane technologies for gas separations, including the creation of functionalized polymers and carbon-based membranes aimed at enhancing permeability and selectivity while reducing energy costs in various industrial applications.
  • - Additionally, Ma's work encompasses the exploration of biosensing technologies, particularly the integration of boronic acid and metal ion interactions for targeted molecular recognition, showcasing advancements in analytical methods with implications for disease diagnosis and environmental monitoring.

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