Search

At sub-3 nm nodes, the scaling of lateral devices represented by a fin field-effect transistor (FinFET) and gate-all-around field effect transistors (GAAFET) faces increasing technical challenges. At the same time, the development of vertical devices in the three-dimensional direction has excellent potential for scaling. However, existing vertical devices face two technical challenges: “self-alignment of gate and channel” and “precise gate length control”. A recrystallization-based vertical C-shaped-channel nanosheet field effect transistor (RC-VCNFET) was proposed, and related process modules were developed. The vertical nanosheet with an “exposed top” structure was successfully fabricated. Moreover, through physical characterization methods such as scanning electron microscopy (SEM), atomic force microscopy (AFM), conductive atomic force microscopy (C-AFM) and transmission electron microscopy (TEM), the influencing factors of the crystal structure of the vertical nanosheet were analyzed. This lays the foundation for fabricating high-performance and low-cost RC-VCNFETs devices in the future.

Transistor scaling has become increasingly difficult in the dynamic random access memory (DRAM). However, vertical devices will be good candidates for 4F2 DRAM cell transistors (F = pitch/2). Most vertical devices are facing some technical challenges. For example, the gate length cannot be precisely controlled, and the gate and the source/drain of the device cannot be aligned. Recrystallization-based vertical C-shaped-channel nanosheet field-effect transistors (RC-VCNFETs) were fabricated. The critical process modules of the RC-VCNFETs were developed as well. The RC-VCNFET with a self-aligned gate structure has excellent device performance, and its subthreshold swing (SS) is 62.91 mV/dec. Drain-induced barrier lowering (DIBL) is 6.16 mV/V.

Neodymium (Nd)- or yttrium (Y)- modified bulk Ni2P catalysts (Nd-Ni2P or Y-Ni2P) have been successfully prepared and their catalytic performance in benzofuran hydrodeoxygenation have been investigated. The as-prepared catalysts were characterised by X-ray diffraction, N2 adsorption–desorption, CO uptake and X-ray photoelectron spectroscopy. The addition of Nd or Y, especially Nd, can increase the surface area of the catalysts and promote the formation of smaller and more highly dispersed Ni2P particles. The Nd-Ni2P catalyst showed the highest benzofuran hydrodeoxygenation activity of 95.3% and the O-free products yield of 74.6%, which gives an increase of 25.3% and 35.4% when compared with that found for Ni2P.

Using Aspen Plus simulation software to simulate the hydrogen solubility of white oil raw materials, and calculate the de-aromatic hydrogen consumption. The liquid hydrogenation technology of white oil was studied by using 100mL uplink liquid hydrogenation evaluation device. The research results show that the ultraviolet absorbance of the liquid phase hydrogenation product is no more than 0.1, and saybolt color, copper plate corrosion, readily carbonizable substance can meet the quality requirements under the conditions of 230℃, 17 Mpa and LHSV 0.5 h-1. 2000 hours liquid phase hydrogenation test shows the stability of product quality which meets the food grade standard, and the liquid phase hydrogenation technology is feasible.

A novel n-type nanowire/nanosheet (NW/NS) vertical sandwich gate-all-around field-effect-transistor (nVSAFET) with self-aligned and replaced high-κ metal gates (HKMGs) is presented for the first time, aiming at a 3 nm technology node and beyond. The nVSAFETs were fabricated by an integration flow of Si/SiGe epitaxy, quasi-atomic layer etching (qALE) of SiGe selective to Si, formation of SiGe/Si core/shell NS/NW structure, building of nitride dummy gate, and replacement of the dummy gate. This fabrication method is complementary metal oxide semiconductor (CMOS)-compatible, simple, and reproducible, and NWs with a diameter of 17 nm and NSs with a thickness of 20 nm were obtained. Excellent control of short-channel-effects was presented. The device performance was also investigated and discussed. The proposed integration scheme has great potential for applications in chip manufacturing, especially with vertical channel devices.

With increasing of the intellectualized electronics devices, new kinds of flexible ferroelectric polymer materials with high dielectric constant attracted more and more attention in recent decades. Polyvinylidene fluoride (PVDF), as one of the most studied ferroelectric polymer materials, has been studied in many published works. Among these works, lots of efforts have been employed to promote the generation of β crystal phase. We here introduced a concise and effective way for large-scale fabrication of promising ferroelectric polymer films by doping a metal–organic framework (MOF) particles via costing process. Then effects of the addition of MOF on the ferroelectric, dielectric and mechanical properties of PVDF composite film were systematic researched. By comparing the results of XRD and FTIR, we found that the addition of MOF changed the α crystal phase of PVDF to β crystal phase which helped improve the ferroelectric and dielectric properties of PVDF composites. The new PVDF composite film, with very low addition (5wt.%) of MOF, possessed the highest remanent polarization (22μC/cm2 at 80MV/m and 1 Hz electric field), and the highest dielectric constant (21 at 10 Hz). The data of mechanical properties indicated that the fine dispersion of MOF maintained the flexibility of PVDF.

Dielectric materials have been regarded as an emerging field for dielectric energy storage in the last few decades. To improve the dispersion of high-dielectric-constant fillers in polymer, many methods of surface modification and core-shell structure have been reported focusing on the forming of shell. Here we introduce a soluble ferroelectric [Hdabco]ClO4 (TEDA.C, dabco = diazabicyclo[2.2.2]octane) into polyvinyl alcohol (PVA) matrix via solution mixing to create a ferroelectric TEDA.C crystal core by the hydrogen bonding between PVA and TDEA.C. We studied the effects of PVA's chain structure on the interfacial interactions between the two components, the crystalline phase of TEDA.C, and the dielectric, ferroelectric, and physical properties of composites by employing three PVAs of different hydrolysis degree. High hydrolysis degree promoted the homogeneous distribution and fine miscibility of TEDA.C in PVA matrix, but also impeded the hydrogen bond movement of TEDA.C, which resulted in the disordered paraelectric phase of ordered-disordered-type ferroelectric. Comparing the dielectric, ferroelectric and physical properties of three PVA systems provides further insights about the hydrolysis degree of PVA benefitting the interfacial interaction and interfacial effects, leading to a potential facile and powerful tool for tuning the properties of PVA composites.

A novel and simple method to synthesize supported Ni2P/Na(x)-MCM-41 catalysts (where x is the mass fraction of Na-to-MCM-41 in terms of percentage) at a lower reduction temperature by incorporation of Na was described. The catalysts were characterized by H2 temperature-programmed reduction (H2-TPR), X-ray diffraction (XRD), N2 adsorption–desorption, CO uptake, X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM). The effect of Na on the structure of catalysts and catalytic properties for the dibenzothiophene (DBT) hydrodesulfurization (HDS) was investigated, which confirmed that a suitable amount of Na can promote highly dispersed Ni2P particles. The Na preferentially interacts with phosphate to generate the sodium phosphate and therefore suppresses the formation of stronger P–O–P bonds, which enables the phosphide catalyst to be easily formed at a lower reduction temperature. Compared with conventional phosphate (973–1273 K), the reduction temperature of Ni2P/Na(x)-MCM-41 catalyst was relatively low (773 K). The Ni2P/Na(x)-MCM-41 catalyst with x = 1.0 showed the maximum DBT conversion of 91.6%, which is higher than that of Ni2P/M41 without Na (80.3%).

Highly active MCM-41-supported nickel phosphide catalysts for hydrodesulfurization (HDS) were synthesized by surface modification, in which the surface of supported Ni2P catalysts were directly modified at different temperatures by air instead of being passivated by an O2/N2 mixture. In addition, the prepared catalysts need not be activated under high temperature in H2 flow prior to the HDS reaction as in the conventional method. X-ray diffraction, X-ray photoelectron spectroscopy, N2-adsorption specific surface area measurements, CO chemisorption and transmission electron microscope were used to characterize the resulting catalysts. The effect of modification temperature on HDS performance of the catalysts was investigated. The results showed that the surface modification could promote the formation of smaller and more uniform Ni2P particles and the exposure of more Ni atoms. The modification method is simple and energy-saving, and the catalyst modified by air at 150 °C presents a dibenzothipohene conversion of 95.4%, which is 6.8% higher than that of a catalyst passivated by O2/N2 mixture followed by high-temperature and H2 pretreatments.

A novel method for preparing Ni2P/C-x (x = preparation temperature, °C) catalysts in a flowing N2 atmosphere by decomposition of hypophosphites was proposed, and the effect of preparation temperature on the hydrodeoxygenation performance of the catalysts was further investigated. X-ray diffraction (XRD), N2-adsorption specific surface area measurements, CO uptake, and X-ray photoelectron spectroscopy (XPS) were applied. The performances of the Ni2P/C-x catalysts prepared at different preparation temperatures were tested in the benzofuran hydrodeoxygenation (BF HDO) reaction. The diffraction peaks related to Ni2P can be seen when x ≧ 400 °C. With increasing x, the Ni2P crystallite size and CO uptake amount of the Ni2P/C-x catalysts increased, and the amount of phosphorous decreased. The BF conversion and yield of total O-free products over the Ni2P/C-x catalysts increased with increasing preparation temperature. The Ni2P/C-550 catalyst showed a BF HDO conversion of 91.6% and a yield of total O-free products of 70.2% under the reaction conditions of 300 °C, 3.0 MPa, a H2/oil ratio of 500 (V/V), and a weight hourly space velocity (WHSV) of 4.0 h−1.

An artificial neural network (ANN) is a parallel, distributed processing system consisting of a large number of interconnected neurons. At present, artificial neural networks have been widely used in signal processing, automation, control systems, image recognition and many other fields. Usually, the realization of neural networks is based on software. However, because the software implementation method cannot achieve real-time calculation in many cases, the hardware implementation method can reflect the inherent parallel processing characteristics of neural networks. This paper proposes an ANN neural network field programmable neuron array based on the design of reusable ANN artificial neural network IP core. It not only can save a lot of hardware resources and improve processing speed, but also has a rapid development cycle and good reconfigurability and other advantages.

Patent data shows that mobile power supplies are in urgent need of new technology solutions. Aiming at the demand and problems of mobile power, this paper proposes a safe, reliable and high-power solar mobile power supply design. The use of a folding solar panel can provide power for portable devices such as mobile phones, and has practical value. This design can improve the charging quality of mobile electronic devices.

With the vigorous development of new energy technologies, the scale of the electric vehicle market continues to grow, and the number of electric vehicles has risen sharply. The problem that comes with it is that a large number of decommissioned power batteries are in urgent need of treatment. The power battery that has been retired from the whole vehicle still has objective capacity and large utilization value. Finding a suitable way to use the ladder is a commonly accepted treatment method. The communication base station backup power supply has a huge demand for energy storage batteries, which is in line with the characteristics of large-scale use of the battery by the ladder, and has become one of the main application fields of the battery. In view of the characteristics of the base station backup power system, this paper proposes a design scheme for the low-cost transformation of the decommissioned stepped power battery before use in the communication base station backup power system.