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In recent years, in the construction process of closed-bridge side spans, construction has often been carried out in accordance with the construction sequence of, first, pouring the cast-in-place section, then preburying strong bone and pouring the closed section, and finally tensioning the closure steel bundle. However, the temperature change during the construction process of the conventional hinges leads to a large deformation of the hinges' strong bone, which disturbs the concrete of the hinged section, and, at the same time, its high stiffness means that the concrete of the hinged section will not be sufficiently precompressed, thus resulting in the loss of prestressing force. Therefore, it is necessary to study the one-time casting construction technology of the side-span's cast-in-place and closed sections. In this study, on the basis of introducing the conventional side-span joint-construction technology, the one-time pouring joint-construction technology was adjusted. In order to eliminate the sunlight temperature factor, which has a great influence on the process of joining, finite element analysis was used to further compare and analyze the changes in the internal force and the linearity of the structure under different joining methods. The results of this study show that, by adjusting the counterweight, the adverse effect of the disturbance of the main girder on the concrete at the joint end under the effect of sunshine temperature can be effectively controlled. Also, one-time joint construction is more reasonable for the internal force and deflection deformation of the structure compared with the conventional side-span joining method of a continuous rigid bridge, which is more favorable to the structure. The research methods and conclusions of this paper can provide a reference for the improvement of closed side-span one-time casting construction technology. [ABSTRACT FROM AUTHOR]

Structural aberrations (SA) have been shown to play an essential role in the occurrence and development of cancer. SAs are typically characterized by copy number alteration (CNA) dose and distortion length. Although sequencing techniques and analytical methods have facilitated the identification and cataloging of somatic CNAs, there are no effective methods to quantify SA considering the amplitude, location, and neighborhood of each nucleotide in each fragment. Therefore, a new SA index based on dynamic time warping is proposed. The SA index analysed 22448 samples of 35 types/subtypes of cancers. Most types had significant differences in SA levels ranging between 12p and 20q. This suggests that genes or inter-gene regions may warrant greater attention, as they can be used to distinguish between different types of cancers and become targets for specific treatments. SA indexes were then used to quantify the differences between cancers. Additionally, SA fingerprints were identified for every cancer type. Kidney chromophobe, adrenocortical carcinoma, and ovarian serous cystadenocarcinoma are the three severest types with structural aberrations caused by cancer, while thyroid carcinoma is the least. Our research provides new possibilities for the better utilization of chromosomal instability for further exploiting cancer aneuploidy, thus improving cancer therapy. [ABSTRACT FROM AUTHOR]

The effects of interface oxidation on the transport behavior of the 2-D electron gas (2DEG) in AlGaN/GaN heterostructures by plasma-enhanced-atomic-layer-deposited AlN (PEALD-AlN) passivation were investigated using temperature-dependent Hall-effect and X-ray photoelectron spectroscopy (XPS) characterizations. AlGaN/GaN heterostructure with a 4-nm-thick PEALD-AlN passivation exhibits good 2DEG transport behavior and stability at moderately high temperature (e.g., 275 °C). However, serious oxidation of the AlN/GaN (cap layer) interface occurs as the sample is heated up to 400 °C in low-pressure atmosphere, as verified by an increased Ga-O bond in Ga 3d core-level spectra. The oxidation leads to a significant reduction of 2.47 × 1012 cm-2 in the 2DEG density in the channel. A modified AlN passivation structure with Al2O3/AlN (10/4 nm) stack is shown to be able to effectively suppress the oxidation of the AlN/GaN interface, demonstrating an enhanced 2DEG density and high-temperature stability even when the sample is heated up to 500 °C. Based on XPS and 2DEG recovery experiments, it is suggested that acceptor-like deep levels have been generated in the near-surface region of AlGaN/GaN heterostructure because of the oxidation, and trapping of these deep levels results in significant depletion of the 2DEG in the channel. The effects of PEALD-AlN passivation on the strain in the AlGaN barrier of AlGaN/GaN heterostructures are also evaluated with high-resolution X-ray diffraction technique. [ABSTRACT FROM AUTHOR]

We report on the electrical and microstructural characterization of Au-free Ti/Al/Ti/TiN contacts for AlGaN/GaN heterostructures. Ultra-low Au-free ohmic contact has been obtained with contact resistance and specific contact resistivity as low as 0.21~\Omega \cdot \textmm and 1.16\times 10^-6 \Omega \cdot \,\,\textcm^2 , respectively. The ohmic alloy temperature is reduced as low as 550 °C by pre-ohmic recess of the AlGaN barrier and optimization of the thickness of bottom Ti layer. We found that interfacial layer formation of AlN between the ohmic metal and AlGaN surface is crucial to realize a low contact resistance with reduced low annealing temperature by a combination of electrical I – V characterization and high-resolution transmission electron microscopy analysis. Furthermore, we suggest a hypothesis that the bottom Ti layer plays a catalytic role for the Al–N reaction with optimized thickness. [ABSTRACT FROM PUBLISHER]

(Al)GaN recess-free normally OFF technology is developed for fabrication of high-yield lateral GaN-based power devices. The recess-free process is achieved by an ultrathin-barrier (UTB) AlGaN/GaN heterostructure that features a natural pinched-off 2-D electron gas channel. The top–down manufacturing technique overcomes the challenges in etching of AlGaN barrier with well-controlled depth and uniformity, which is especially attractive for fabrication of normally OFF GaN-based high-electron-mobility transistors (HEMTs) and metal–insulator–semiconductor HEMTs (MIS-HEMTs) on large-size Si substrate. With SiNx passivation grown by low-pressure chemical-vapor deposition, on-resistance of the UTB-AlGaN/GaN-based power devices can be significantly reduced. High-uniformity low-hysteresis normally OFF HEMTs and Al2O3/AlGaN/GaN MIS-HEMTs are successfully demonstrated on the UTB AlGaN/GaN-on-Si platform. It is also a compelling technology platform for manufacturing high-performance GaN-based lateral power diodes, and normally OFF p-(Al)GaN heterojunction field-effect transistors. [ABSTRACT FROM PUBLISHER]

Ultra-thin-barrier (UTB) AlGaN/GaN heterostructure is utilized for fabrication of normally-OFF GaN metal–insulator–semiconductor high-electron-mobility transistors (MIS-HEMTs). The sheet resistance of 2-D electron gas in the UTB Al0.22Ga0.78N(5-nm)/GaN heterostructure is effectively reduced by SiNx passivation grown by low-pressure chemical vapor deposition, from 2570 to 334~\Omega /□. The fabricated Al2O3/AlGaN/GaN MIS-HEMTs exhibit normally-OFF behavior with good V_{\mathrm {TH}} uniformity and low V_{\mathrm {TH}} -hysteresis. 20 mm-gate-width power devices featuring a low R\sc {\mathrm{ on}} of 0.75~\Omega ( \textI\mathrm {D,MAX} =6.5 A) are also demonstrated on the platform. [ABSTRACT FROM PUBLISHER]

Low-current-collapse normally OFF GaN-on-Si MIS high-electron-mobility transistors (MIS-HEMTs) are fabricated with low-pressure chemical-vapor-deposited SiNx (LPCVD-SiNx) passivation and high-temperature low-damage gate-recess technique. The high-thermal-stability LPCVD-SiNx enables a passivation-prior-to-ohmic process strategy and effectively suppresses deep states at the passivation/HEMT interface. The fabricated MIS-HEMTs feature a high VTH of +0.85 V at the drain current of 1 $\mu $ A/mm and a remarkable ON/OFF current ratio of 1010 while reduced dynamic ON-resistance as compared to plasma-enhanced chemical-vapor-deposited SiO2 passivation. High field-effect channel mobility of 180 cm ^{2}/ \text{V} \cdot \text{s} is achieved, leading to a high maximum drain current density of 663 mA/mm. [ABSTRACT FROM AUTHOR]

Abstract: Seasonal changes in water quality were measured in samples taken at various distances from shallow water across mudflat to mangroves during flood period and from mangroves across mudflat to shallow water during ebb period in a subtropical mangrove estuary (Zhangjiang Estuary, Fujian, China). The TN (total dissolved nitrogen), TP (total dissolved phosphorus), COD (chemical oxygen demand), and DOC (dissolved organic carbon) contents during the flood period were significantly higher than those during the ebb period. In contrast, the opposite was true for the POC (particulate organic carbon) content and transparency. The mangroves at Zhangjiang Estuary may trap nutrients at rates of 90.5gN/m2/yr, 2.2g TP/m2/yr, and 13.7g C/m2/yr in the form of DOC, and export POC at a rate of 81.8g/m2/yr. Our results support the hypothesis that the maintenance of estuarine water quality by mangroves occurs during flood periods. [ABSTRACT FROM AUTHOR]

In this letter, we report high-performance enhancement-mode (E-mode) Al2O3/AlGaN/GaN metal–insulator–semiconductor high-electron-mobility transistors (MIS-HEMTs) fabricated with high-temperature low-damage gate recess technique. The high-temperature gate recess is implemented by increasing the substrate temperature to 180 °C to enhance the desorption of chlorine-based etching residues during the dry etching of AlGaN barrier. High-crystal-quality Al2O3 gate dielectric was grown by atomic-layer deposition using O3 as the oxygen source to suppress hydrogen-induced weak bonds. The fabricated E-mode MIS-HEMTs exhibit a threshold voltage of 1.6 V, a pulsed drive current of 1.13 A/mm, and very low OFF-state standby power of 6.8 \times 10^\mathrm -8 W/mm at V\mathrm {GS} =0 V and V\mathrm {DS} =30 V. At 4 GHz and in pulse-mode operation, the output power density and power-added efficiency were measured to be 5.76 W/mm and 57%, both of which are the highest for GaN-based E-mode MIS-HEMTs reported to date. [ABSTRACT FROM AUTHOR]