Search

In this study, we prepare topological insulator (TI) heterostructures (TI–TI) with a thickness of 25 nm and various interlayer distances, utilizing the laser molecular beam epitaxy (LMBE) system. Our characterization analysis revealed high-quality morphological features and distinct heterolayered structures. Moreover, we successfully isolated bulk-surface transport properties by employing the comprehensive physical property measurement system (PPMS) and terahertz time-domain spectroscopy (THz-TDS). Compared to the monolayer binary structures, the TI–TI heterostructures demonstrated enhancement of the bulk insulation and improvement of surface conductivity. Notably, various interlayer spacings played a pivotal role in modulating both the bulk-surface transport and topological surface states. TIs have emerged as an ideal medium for information transmission in quantum chips, terahertz optical devices, and low-energy spintronic devices. This research not only provides deeper theoretical insights but also holds significant implications for practical applications.

Age at menarche (AAM) is a sign of puberty of females. It is a heritable trait associated with various adult diseases. However, the genetic mechanism that determines AAM and links it to disease risk is poorly understood. Aiming to uncover the genetic basis for AAM, we conducted a joint association study in up to 438,089 women from 3 genome-wide association studies of European and East Asian ancestries. A series of bioinformatical analyses and causal inference were then followed to explore in-depth annotations at the associated loci and infer the causal relationship between AAM and other complex traits/diseases. This largest meta-analysis identified a total of 21 novel AAM associated loci at the genome wide significance level (P< 5.0  × 10−8), 4 of which were European ancestry-specific loci. Functional annotations prioritized 33 candidate genes at newly identified loci. Significant genetic correlations were observed between AAM and 67 complex traits. Further causal inference demonstrated the effects of AAM on 13 traits, including forced vital capacity (FVC), high blood pressure, age at first live birth, etc, indicating that earlier AAM causes lower FVC, worse lung function, hypertension and earlier age at first (last) live birth. Enrichment analysis identified 5 enriched tissues, including the hypothalamus middle, hypothalamo hypophyseal system, neurosecretory systems, hypothalamus and retina. Our findings may provide useful insights that elucidate the mechanisms determining AAM and the genetic interplay between AAM and some traits of women.

MBLS10A-200 magnesium-lithium (Mg-Li) alloy is a novel ultralight material, with the density, tensile strength and elongation rate of 1.5 g/cm3, 160 MPa and 60%, respectively. At present, the material is increasingly widely applied in structures with complex shapes of various fields such as aeronautics, astronautics and electronic engineering. At present, the industrial circle has put forward increasingly urgent demand for the welding technique of MBLS10A-200 alloy and the protection technology for corrosion resistance of the welded joints of the alloy. However, related research is rarely reported. Laser welding of MBLS10A-200 Mg-Li alloy with 5 mm in thickness was studied to further obtain the butt joint, with the elongation rate of about 54% and the same strength as base metal (BM). Moreover, the corrosion resistance of laser welded joint was detected by using electrochemistry method. During the experiment, it can be found that the corrosion resistance of metals in the welded seam zone (WSZ) was far higher than that of the BM. The corrosion current density of metals in WSZ was about 10-5A/cm2, which declined by two orders of magnitude compared with BMs which were about 10-7A/cm2and the charge transfer resistance of welded seam zone increased by 4.8 times compared with BMs.

In Part Ⅰ of this series, it can be found that the corrosion resistance of metals in the welded seam zone (WSZ) was far higher than that of the base metal (BM) of MBLS10A-200 Mg-Li alloy. Therefore, the feasibility of improving the corrosion resistance of MBLS10A-200 Mg-Li alloy through laser surface melting (LSM) was further explored. Meanwhile, laser shock peening (LSP) treatment was also used for contrast. The results showed that the surface melted zone with the corrosion resistance through LSM superior to that of metals in WSZ of MBLS10A-200 alloy through laser welding can be prepared by controlling heat input through increasing the scanning speed of laser beam, while LSP has limited impact on the electrochemical corrosion resistance of MBLS10A-200 alloy. The corrosion current density (Jcorr) of the samples subjected LSM declined by two orders of magnitude compared with the base metal (BM) while the charge transfer resistance increased by 17 times compared with BM. An analysis indicated that owing to the fast cooling rate during laser processing, the multi-phase microstructures (i.e. α phase, β phase and Li2MgAl) of BM were transformed into β single-phase microstructure in WSZ and surface melted zone. In this way, not only solid solution strengthening of the metals in WSZ was realized but also the micro-galvanic coupling generated due to the difference of electric potentials of multi-phase microstructures were reduced, thus improving the corrosion resistance of surface melted zone.

A much complicated structure, where GOA circuits were placed at the bottom side, was proposed for a 31‐inch AMOLED display. This structure contributed significantly to border reduction and reliability improvement. What's more, amorphous‐indium‐gallium‐zinc‐oxide (a‐IGZO) thin‐film‐transistors (TFTs) with top‐gate structure exhibited high performance and the GOA circuits could operate well.

Top‐gate typed amorphous‐indium‐gallium‐zinc‐oxide (a‐IGZO) thin‐film‐transistors (TFTs) and a technologically advanced transparent storage capacitance structure have been successfully employed in pixel circuits. The design procedure was systematically studied. Eventually, a 15‐inch gate‐driver‐on‐array (GOA) drived active matrix organic light‐emitting diode (AMOLED) display was demonstrated with a high resolution of 147 ppi.

A dual‐gate amorphous indium‐gallium‐zinc‐oxide (a‐IGZO) thin‐film transistor (TFT) has been proposed and designed in this work. Based on this specific structure, a technologically advanced external Vth compensation system, where Vth can be controllable by an external DC signal source, has been developed for gate driver on array (GOA). Subsequently, the working mode of this circuit was introduced. Moreover, detailed simulation has been performed to study the appropriate process window. Finally, the proposed GOA circuit exhibited stable high‐voltage output pulse, meanwhile, the lifetime showed an significant improvement with the utilization of the external Vth compensation system. It should be also mentioned that a wide pulse of 3.6ms has been obtained to sense Vth of driving TFTs in pixel circuits.

STM32F103 microprocessor as the core, this paper introduces the research design scheme of power acquisition in the smart grid. This design can realize real-time acquisition and analysis of power, has the characteristics of high precision and little error. The power acquisition design program is also used in the chip ATT7022, simplify the design of the circuit. Chip ATT7022 collected can be voltage, current reactive power and power factor and other parameters were calculated. The microprocessor STM32F103 mainly analyze the calculation of the data. If the data is not correct, the microprocessor STM32F103 then control circuit is revised accordingly. Practice shows that the intelligent power acquisition system meet the requirements of the smart grid.

For the implementation of digital multimedia communication, an efficient, reliable, deterministic transmission system plays a vital role. Quadrature amplitude modulation (QAM) is commonly used in digital communication systems. We focuses on simulation and analysis of M-level QAM by using MATLAB in this paper.

Presents the working principle of Integrated PLL chip Si4133, this paper presents the implementation of a 375MHz local oscillator for a super heterodyne transmitter/receiver by using Si4133.Using programming method to set the divider register Internal chip. In addition, this paper discuss the methods for decreases the phase noise. Debugging circuit using ICCAVR software , and show the debugging results. Facts show that the phase noise and spurious of the frequency synthesizer is low, and it is practical.

This paper mainly analyzes a type of wireless sensor network MAC protocol based on probability function detection with random multi-access protocol to ensure a higher systemic throughput and stability by using channel load equilibrium. By using the average cycle method, we get the mean waiting time of information packet, the formulas of performance index of the systemic throughput, and the life cycle of node through mathematical derivation strictly. At last, gives the simulation results.

Cellulose acetate (CA), a hydrophilic membrane material, was selected to prepare ultrafiltration membrane for the aim of achieving high-performance membranes with respect to flux and rejection characteristics. In order to prepare membranes with improved properties, blending of cellulose acetates with different degrees of substititution(DS) has been attempted. In this study, polymeric blend ultrafiltration membranes based on cellulose acetate with different DS were prepared by phase inversion technique. Scanning electron microscopy (SEM), atomic force microscopy (AFM), and contact angle are used to understand the influence of DS on the properties of modified membranes. The blend membranes prepared were subjected to the separation of egg albumin (EA). The separation and permeate flux efficiencies of the blend membranes were discussed.

Fe3O4 ferrite nanoparticles used for preparation of PE composite have been prepared by chemical co-precipitation method and modified by different methods. And the nanoFe3O4/LDPE composite materials with different mass percentage concentration of 0.25 to 1 percent were prepared by melt blending. The relationship of permittivity and dissipation factors dependence of frequency were investigated by Broadband Dielectric Spectrometer made by novo-control company. Through these measurements we got the conclusion that both the doping of Fe3O4 and magnetization have effect on permittivity and dissipation factors, and the effect relates to the doping methods and quality percentage content.

Efficient preparation of high-quality topological insulator nanofilms (TINFs) in large scale is demanding. Using a home-built pulsed laser enhanced molecular epitaxy system (PLEES), we efficiently fabricate TINFs with prefect stoichiometry using Bi2Te3TINFs as an example. Instead of utilizing multiple beam source furnaces to provide essential elements, hybrid targets containing both pure Bi2Te3and Te targets are applied in a single epitaxial chamber. Moreover, diffraction pattern of growing Bi2Te3TINFs are monitored in live by a high-energy electron diffractometer, allowing fast optimization of growth conditions. Scanning electron microscopy and atomic force microscopy demonstrate that the surface morphology of the prepared Bi2Te3nanofilms with a thickness of 70 nm are flat and dense, and energy-dispersive X-ray spectroscopy analysis suggests that the ratio of Bi to Te elements is 2:3. The grazing incidence X-ray diffractometer reveals that the X-ray diffraction peaks of the synthesized nanofilm matches those of the Bi2Te3standard PDF card. The prepared nanofilm exhibits a weak anti-localization effect at low magnetic fields characterized by physical property measurement system, confirming its unique electrical transporting properties. This work demonstrates that using hybrid targets with optimized growth parameters enable PLEES to efficiently grow high-quality stoichiometric TINFs on a large scale.

A unique Penicilliumisolate from Chinese soil with terverticillate penicilli and ellipsoidal to cylindrical smooth-walled conidia, produces, in addition to the common metabolite ergosterol, copious amounts of an unknown peach-red pigment and the following secondary metabolites: griseofulvin, dechlorogriseofulvin, lichexanthone, roquefortine C, roquefortine D, chrysogine, 2-pyrovoylaminobenzamide, 2-acetyl-quinazolin-4(3H)-one. This isolate, CBS 111235, is described as Penicillium persicinumsp. nov., which belongs to subgenus Penicilliumsection Chrysogenabut is morphologically similar to P. italicum.On the basis of the production of secondary metabolites it resembles P. griseofulvumand P. coprophilum. Sequence data using part of the β-tubulin gene showed that it is phylogenetically related to P. chrysogenumand P. aethiopicumin section Chrysogenawith which it shares both secondary metabolites and ability to grow at 37 °C.