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Two-dimensional material MoS2 has excellent optical and electrical characteristics and a controllable energy band structure, leading to a high potential value for designing photodetectors. In this ...

To achieve high solar energy utilization efficiency, photothermal materials with broadband absorption of sunlight and high conversion efficiency are becoming a fast-growing research focus. Inspired by the forest structure with efficient sunlight utilization, we designed and fabricated a graphene film consisting of densely arranged porous graphene though laser scribing on polybenzoxazine resin (poly(Ph-ddm)). This hierarchical structure significantly reduced the light reflection of graphene as a 2D material. With a combination of advanced photothermal conversion properties of graphene, the 3D structured graphene film, named forest-like laser-induced graphene (forest-like LIG), was endowed with a very high light absorption of 99.0% over the whole wavelength range of sunlight as well as advanced light-to-heat conversion performance (reaching up to 87.7 °C within 30 s under the illumination of simulated sunlight and showing an equilibrium temperature of 90.7 ± 0.4 °C). As a further benefit of its superhydrophobicity, a photothermal actuator with quick actuated response and high motion velocity, as well as a solar-driven interfacial desalination membrane with durable salt-rejecting properties and high solar evaporation efficiencies, was demonstrated.

The total ionizing dose response of nanosheet gate-all-around metal-oxide-semiconductor field effect transistor (NS GAA MOSFET) fabricated on novel void-embedded silicon on insulator (VESOI) substrate was investigated in this work. Strong radiation tolerance with as small as 46.6mV threshold voltage shift and non-discernable increase of off-state current were observed even at a dose of 7Mrad(Si) X-ray irradiation. Both the experiment and simulation results reveal that the radiation tolerance of the MOSFET device can be inherently attributed to the GAA channel. Our work undoubtedly demonstrates that the NS GAA device on VESOI substrate has great potential for radiation-harden applications under heavy radiation environment.

Although laser-induced graphene (LIG) has great advantages in the cost and manufacturing process, it has been seldom reported in the field of electromagnetic interference (EMI) shielding due to its unobtrusive conductivity and the limitation of inherent substrates. In this work, polybenzoxazine is chosen as precursor to fabricate the LIG via a one-step defocused lasing process. As a result of favorable porous structures and high conductivity, the as-produced LIG exhibits the EMI shielding effectiveness up to 24.8 dB in X-band at the thickness of 68 μm. And the EMI shielding effectiveness of LIG/Fe3O4 composite is increased to 32.7 dB at a smaller thickness of 53 μm which is obtained by a solvent-free approach. When considering the thickness and lightweight properties, the absolute shielding effectiveness is also surpassing most of the other carbon-based shielding materials. More importantly, taking advantage of the difference in the thermal expansion coefficient of carbon material and polymeric substrate, we develop a rapid quench-peeling (RQP) strategy for the separation of LIG from polymeric substrate to obtain the free-standing LIG film. Moreover, the structures and properties of LIG are well preserved. The free-standing LIG films after peeling have wider adaptability in practical EMI shielding applications, and also opened up possibilities for use in other fields, such as Joule heating device.

A low voltage standing wave ratio (VSWR) broad bandwidth pillbox window with metamaterial is proposed for W-band traveling-wave tubes (TWTs) in this paper. The metamaterial structure is designed on a dielectric surface, which decreases the VSWR and broadens the bandwidth of the pillbox window. The cold-test results of the window with metamaterial are presented, which showed that the metamaterial pillbox window (MPW) achieves a bandwidth of 31.5 GHz with VSWR below 1.2, and a bandwidth of 18 GHz with VSWR below 1.1. The ghost mode and the power capacity of the window were also investigated. The results showed that the proposed metamaterial pillbox window is suitable for medium power TWTs. A Ka-band MPW was fabricated and the test results agreed well with the simulation results.

A novel method for manufacturing gate-all-around metal-oxide-semiconductor field effect transistor (GAA MOSFET) based on void embedded silicon on insulator (VESOI) substrate is demonstrated in this work. VESOI with embedded submicron void chambers has been designed to fabricate suspended silicon channels by a one-step lithography and dry etching process. GAA MOSFET built on VESOI substrate exhibits excellent characteristics with subthreshold swing (SS) about 63mV/dec, ON/OFF ratio of 1010, drain-induced barrier lowering (DIBL) less than 12mV/V and strong tolerance to back gate bias. This method shows significant advantages to fabricate suspended Si channels, and can be readily extended to other types of material systems for low-power and high-performance applications.

Strain-adjusting the band gap of MoS2 using patterned substrates to improve the photoelectric performance of MoS2 has gradually become a research hotspot in recent years. However, there are still difficulties in obtaining high-quality two-dimensional materials and preparing photodetectors on patterned substrates. To overcome this, a continuous multilayer MoS2 film was transferred to a patterned gallium nitride substrate (PGS) for the fabrication of photodetectors, and density functional theory calculations showed that the band gap of the MoS2 film increased and that the electron effective mass decreased due to the introduction of PGS. In addition, finite difference time domain simulation showed that the electric field in the MoS2 area on the PGS is enhanced compared with that on the flat gallium nitride substrate due to the enhanced light scattering effect of the PGS. The photoresponse of the MoS2/PGS photodetector at 460 nm was also enhanced, with Iph increasing by 5 times, R increasing by 2 times, NEP decreasing to 3.88 × 10-13 W/Hz1/2, and D* increasing to 5.6 × 108 Jones. Our research has important guiding significance in adjusting the band gap of MoS2 and enhancing the photoelectric performance of MoS2 photodetectors.

Considering the complexity of wireless sensor network (WSN) coverage problems, which include many variables and a large continuous search space, a WSN coverage optimization method based on an improved artificial bee colony (ABC) algorithm with teaching strategy is proposed in this paper. ABC, which is good at exploration but poor at exploitation, is improved by introducing a teaching strategy in teaching-learning-based optimization (TLBO) that has a rapid convergence but is easily trapped in a local optima. Thus, the proposed algorithm combines the advantages of ABC strong global search ability and TLBO rapid convergence. In addition, to retain the diversity and eliminate the parameter limit in ABC, a dynamic search update strategy is introduced instead of the scout bee phase of ABC. In addition to preliminary examinations with a number of benchmark functions, the performance of the algorithm is verified by solving a complicated wireless sensor network coverage problem. The simulation results verify that the proposed algorithm achieves better balance between global and local search compared with other state-of-the-art algorithms.

The further scientific applications of DMSP-OLS night-time light (NTL) imagery have been being limited by the accuracy, automation, and speed of radiometric intercalibration. In order to solve the aforementioned problems, this article is the first to propose a new least-median-of-squares (LMedS)-based power regression (LBPR) for automatically radiometric intercalibration and investigate the reasons for the optimal model of radiometric intercalibration, especially those based on the Taylor expansion and probability principle. NTL data in six regions all over the world, from 1994 and 1997 to 2007, were used as the test datasets. When the five kinds of LMedS-based radiometric intercalibration models (i.e., linear, quadratic, power, exponential, and logarithmic regression) are synthetically compared in absolute accuracy (adjusted RMSE) and running speed, it is concluded that the LBPR, which has the highest accuracy and preferable running speed, is recommended as the optimal method, which can also be used as a reference for other types of imagery preprocessing.

A solar-blind photodetector based on single crystal β-Ga2O3 thin film transferred on a SiC substrate with an Al2O3 buffer layer was prepared by a unique ion-cutting process. The structure and micro...

Molybdenum disulfide (MoS2) has substantial application prospects in the field of electronic devices. The fabrication of devices of excellent quality based on MoS2 films is an important research direction. In this study, based on the atomic layer deposition technique, large-area MoS2 films were grown, and top-gate MoS2-based field-effect transistor arrays were fabricated on four substrates (AlN, GaN, sapphire, and SiO2). It was found that the interface defects that were introduced by lattice mismatch and roughness of the growth substrate could cause an exponential (102) drop in mobility. Because of the small lattice mismatch and excellent surface quality, transistors on the AlN substrate have shown an enhanced mobility (10.45 cm2 V-1 s-1) compared to transistors on the other substrates. This study proves that the AlN substrate is a superior substrate for large-area and high-performance MoS2 film synthesis. This result can also be applied in higher-level microelectronic systems, such as in digital logic circuit design.

High-precision aspheric negative plastic lenses are widely used in optical systems owing to their excellent performance and ease of high-efficiency manufacturing. The imaging performance of the lens is difficult to control, because it is unable to perform optical measurements directly and is sensitive to manufacturing processing meanwhile. Generally, the imaging performance is guaranteed by a strict control of geometrical deviation, such as Peak-to-Valley (PV) and Root-Mean-Square (RMS). In this study, an optical ray-tracing algorithm with the measured geometrical deviation data is proposed to perform an imaging performance analysis correlated with geometrical deviation for the injection molded high-precision aspheric negative plastic lens. Taguchi experiments are applied to investigating the effect of processing parameters. The geometrical deviation of the convex surface is found to be an order of magnitude greater than that of the concave surface. The geometrical dimension of the concave surface is mainly determined by the machining precision of the mold cavity surface, whereas the convex surface dimension is mainly affected by the lens shrinkage. However, the imaging performance has a nonlinear correlation with the geometrical deviation. Modulation Transfer Function (MTF) and Spot Diagram are equivalently affected by the concave and convex geometrical deviations, and depend on the object field height. The effect of processing parameters on geometrical deviation and imaging performance is uncorrelated. Thus, the imaging performance should be simultaneously considered as a criterion as well as the geometrical deviation in the optimization of aspheric negative lens injection molding processing. The imaging performance prediction using an optical ray-tracing algorithm with the measured geometrical deviation data is instrumental to optimize the manufacturing processing.

Introduction Although several surgical methods have been introduced to treat mild-to-moderate blepharoptosis, including levator-based techniques such as Müller muscle–conjunctival resection, few complications and better functional and aesthetic outcomes remain elusive for plastic surgeons. Hence, this study aimed to provide a new technique (bridge technique) using the levator aponeurosis–Müller’s muscle flap to achieve optimal blepharoptosis correction for function and aesthetics among Asians. Methods From January 2019 to May 2020, this new technique was performed on 157 consecutive patients with mild-to-moderate blepharoptosis. Our technique was based on the anchor of the levator complex to the tarsus using mattress stitches and three-layer fixation, which provided a reliable motion transmitter for elevating the upper eyelid. The patients’ medical records and photographs were reviewed 12 months postoperatively to assess the margin reflex distance 1 (MRD1), incidence of complications, and aesthetic outcomes. Results The average preoperative and postoperative MRD1 measured 1.2 ± 0.31 mm and 3.7 ± 0.34 mm, respectively. A significant difference was observed between the preoperative and postoperative distance values (p

Presently, Gaussian noise removal is a very attractive research direction, because Gaussian noise can effectively simulate the real world noise when the real noise sources are complex and diverse. Existing traditional denoising methods have high complexity and low efficiency. Means of image Gaussian noise denoising will become more efficient with the development of deep learning. In this paper a novel deep learning model for Gaussian noise removal is proposed. The proposed method combines dilated convolution with skip connection of residual learning, which is trained by our proposed mixed loss function during back propagation. Not only compared with existing traditional methods, but also compared with representative deep learning methods, our proposed model has a better performance. In addition, our proposed model has less layers and training parameters than representative deep learning methods. Through several comparative experiments on test data sets, we can draw a conclusion that our proposed deep learning model can remove Gaussian noise more effectively than some state-of-art methods with quantitative and visual qualitative analyses.

A high-performance filter is the key component in 5G communication. A surface acoustic wave (SAW) resonator fabricated on a piezoelectric thin film instead of piezoelectric bulk substrate can achie...

Background To evaluate the prognostic value of preoperative neutrophil lymphocyte ratio (NLR) and platelet lymphocyte ratio (PLR) in oral, pharyngeal, and lip cancer for survival and relapse. Methods Clinic-pathologic and hematological records were retrospectively retrieved. Patients completed follow-up period were included for survival and relapse analysis. Results The preoperative NLR value was a prognostic factor for both overall survival and relapse-free survival. The high NLR group demonstrated higher total relapse rate, higher local relapse rate, and higher relapse rate within 12 months. However, the preoperative PLR did not associate with survival or relapse. Conclusions The preoperative NLR, not PLR, is an independent prognostic indicator of survival. It also exhibits predictive value for relapse, particularly early relapse within 12 months. The preoperative NLR value might be recommended as a useful tool for predicting the outcomes and stratifying patients for different management strategies.

We present a novel T-shaped tunneling field-effect transistor (TFET) on Si-on-insulator (SOI). The asymmetric source-drain structure can effectively suppress the ambipolar switching. The on-current ( $\text{I}_{\mathrm{ on}}$ )/off-current ( $\text{I}_{\mathrm{ off}}$ ) ratio reaches very high value of $\sim 10^{8}$ at $\text{V}_{\mathrm{ ds}}= - 0.5$ V with a smaller tunneling junction width at the drain. The innovative T-shape design allows integration of both TFET and metal-oxide semiconductor field-effect transistors (MOSFET) operation modes in one structure. Both TFET and MOSFET operation modes are experimentally demonstrated in this device structure, which provide the implementation of the selector function with the single device.

In this paper, we make two contributions. The first is to propose a new keyframe extraction algorithm, which reduces the keyframe redundancy and reduces the motion sequence reconstruction error. Secondly, a new motion sequence reconstruction method is proposed, which further reduces the error of motion sequence reconstruction. Specifically, we treated the input motion sequence as curves, then the binomial fitting was extended to obtain the points where the slope changes dramatically in the vicinity. Then we took these points as inputs to obtain keyframes by density clustering. Finally, the motion curves were segmented by keyframes and the segmented curves were fitted by binomial formula again to obtain the binomial parameters for motion reconstruction. Experiments show that our methods outperform existing techniques, in terms of reconstruction error.

The creative integration of sp-hybridized carbon atoms into artificial carbon graphdiyne has led to graphdiyne with superior properties in terms of uniformly distributed pores, ambipolar carrier transport, natural bandgap, and broadband absorption. Consequently, graphdiyne, regarded as a promising carbon material, has garnered particular attention in light-matter interactions. Light-matter interactions play an important role in optical information technology and meet the increasing demand for various energy sources. Herein, the status and challenges in nonlinear photonic and optoelectronic applications of graphdiyne, which are still in the infancy stage, are summarized. Furthermore, the bottleneck and perspective of graphdiyne in these aspects are discussed. It is therefore anticipated that this review could promote the development of graphdiyne in photonic and optoelectronic fields.

Background Double eyelid blepharoplasty is the most popular cosmetic surgery among Asian populations. Although various surgical procedures have been reported, certain complications still arise, including asymmetry or the disappearance of the double eyelid crease, an unnatural double eyelid crease curve, and distinct scars. Objectives The aim of this study was to describe a new blepharoplasty technique intended to reduce the various complications and create dynamic, natural-looking double eyelids. Methods From September 2018 to June 2019, the new technique was performed on 92 Chinese patients. The core of our technique was to construct a reliable motion transmitter, the orbital septum-levator aponeurosis flap, which was sutured to the tarsus. The outcomes were assessed 6 months after the surgery by reviewing medical records and photographs to assess the aesthetic outcomes, the relapse rate, and the incidence of complications. Results In the aesthetic outcome assessment, 86 patients were graded as good and 4 were graded as fair; of the latter, 2 had uneven scars and 2 showed showed a slight asymmetry of the double eyelid curve in length or width. Two patients were graded as poor because of the disappearance of the double eyelid crease. The relapse rate was 2.2%. Two patients had temporary hematoma. Six patients had lagophthalmos that subsided within 30 days. No cases of infection or ptosis were observed. Conclusions The bridge technique is an effective method for creating dynamic, natural-looking double eyelids. However, the long-term outcome of this new surgical approach requires further study. Level of Evidence: 4

Keyframes extraction, a fundamental problem in video processing and analysis, has remained a challenge to date. In this paper, we introduce a novel method to effectively extract keyframes of a video. It consists of four steps. At first, we generate initial clips for the classified frames, based on consistent content within a clip. Using empirical evidence, we design an adaptive window length for the frame difference processing which outputs the initial keyframes then. We further remove the frames with meaningless information (e.g., black screen) in initial clips and initial keyframes. To achieve satisfactory keyframes, we finally map the current keyframes to the space of current clips and optimize the keyframes based on similarity. Extensive experiments show that our method outperforms to state-of-the-art keyframe extraction techniques with an average of \(96.84\%\) on precision and \(81.55\%\) on \(F_1\).

With the development of modern cities, traffic congestion has become a problem affecting the travel, which makes urban rail transit develop rapidly. However, it is an era of mobile interconnection. Because urban rail transit takes full advantage of underground space and high-speed transportation, it is difficult to use the convenient and fast wireless network. In fact, it is found that the existing Wi-Fi construction of urban rail transit is not complete and cannot meet the needs of passengers. Improving Wi-Fi construction of urban rail transit has great economic value, and can further enhance the competitiveness of urban rail transit in urban public transport.

A nanofabrication method for the production of ultra-dense planar metallic nanowire arrays scalable to wafer-size is presented. The method is based on an efficient template deposition process to grow diverse metallic nanowire arrays with extreme regularity in only two steps. First, III–V semiconductor substrates are irradiated by a low-energy ion beam at an elevated temperature, forming a highly ordered nanogroove pattern by a “reverse epitaxy” process due to self-assembly of surface vacancies. Second, diverse metallic nanowire arrays (Au, Fe, Ni, Co, FeAl alloy) are fabricated on these III–V templates by deposition at a glancing incidence angle. This method allows for the fabrication of metallic nanowire arrays with periodicities down to 45 nm scaled up to wafer-size fabrication. As typical noble and magnetic metals, the Au and Fe nanowire arrays produced here exhibited large anisotropic optical and magnetic properties, respectively. The excitation of localized surface plasmon resonances (LSPRs) of the Au nanowire arrays resulted in a high electric field enhancement, which was used to detect phthalocyanine (CoPc) in surface-enhanced Raman scattering (SERS). Furthermore, the Fe nanowire arrays showed a very high in-plane magnetic anisotropy of approximately 412 mT, which may be the largest in-plane magnetic anisotropy field yet reported that is solely induced via shape anisotropy within the plane of a thin film.

The rapid detection and identification of specific subjects such as different types of pollutants, minerals or rare wood are of vital significance to industrial manufacture and scientific research. However, such works are quite challenging because of the extreme similarities in appearance or chemical composition of them. In this paper, a self-designed methodology is applied to detect and identify different remarkably similar objects rapidly and precisely. The methodology is based on laser-induced breakdown spectroscopy (LIBS), principal component analysis (PCA) and the newly designed double variance selecting method (DVSM). To specifically expound the theory and reliability of the methodology, four similar species of rosewood were taken as examples. In our study, LIBS was applied to detect the main elements in Dalbergia odorifera sample and heavy metal in polluted Pterocarpus erinaceus samples. Moreover, PCA was used to distinguish four species of rosewood (training set) and store the training data sets for further identification. In addition, the new self-designed method called DVSM was employed to select the characteristic lines efficiently to support PCA to complete the work. In the end, a new rosewood sample of the four species was regarded as the test set to test the methodology and a systematic method was designed to compare the training data sets with the testing data to complete the test of identification, from which we got the accurate results. All the results indicate that the self-designed methodology can detect and identify extremely similar objects like rosewood effectively.

Application of convolutional neural networks (CNNs) for image additive white Gaussian noise (AWGN) removal has attracted considerable attentions with the rapid development of deep learning in recent years. However, the work of image multiplicative speckle noise removal is rarely done. Moreover, most of the existing speckle noise removal algorithms are based on traditional methods with human priori knowledge, which means that the parameters of the algorithms need to be set manually. Nowadays, deep learning methods show clear advantages on image feature extraction. Multiplicative speckle noise is very common in real life images, especially in medical images. In this paper, a novel neural network structure is proposed to recover noisy images with speckle noise. Our proposed method mainly consists of three subnetworks. One network is rough clean image estimate subnetwork. Another is subnetwork of noise estimation. The last one is an information fusion network based on U-Net and several convolutional layers. Different from the existing speckle denoising model based on the statistics of images, the proposed network model can handle speckle denoising of different noise levels with an end-to-end trainable model. Extensive experimental results on several test datasets clearly demonstrate the superior performance of our proposed network over state-of-the-arts in terms of quantitative metrics and visual quality.

The abilities to fabricate wafer scale single crystalline oxide thin films on metallic substrates and to locally engineer their resistive switching characteristics not only contribute to the fundamental investigations of the resistive switching mechanism but also promote the practical applications of resistive switching devices. Here, wafer scale LiNbO3 (LNO) single crystalline thin films are fabricated on Pt/SiO2/LNO substrates by ion slicing with wafer bonding. The lattice strain of the LNO single crystalline thin films can be tuned by He implantation as indicated by XRD measurements. After He implantation, the LNO single crystalline thin films show self-rectifying filamentary resistive switching behaviors, which is interpreted by a model that the local conductive filaments only connect/disconnect with the bottom interface while the top interface maintains the Schottky contact. Thanks to the homogeneous distribution of defects in single crystalline thin films, highly reproducible and uniform self-rectifying resistive switching with large on/off ratio over four order of magnitude was achieved. Multilevel resistive switching can be obtained by varying the compliance current or by using different magnitude of writing voltage.

Gratings, one of the most important energy dispersive devices, are the fundamental building blocks for the majority of optical and optoelectronic systems. The grating period is the key parameter that limits the dispersion and resolution of the system. With the rapid development of large X-ray science facilities, gratings with periodicities below 50 nm are in urgent need for the development of ultrahigh-resolution X-ray spectroscopy. However, the wafer-scale fabrication of nanogratings through conventional patterning methods is difficult. Herein, we report a maskless and high-throughput method to generate wafer-scale, multilayer gratings with period in the sub-50 nm range. They are fabricated by a vacancy epitaxy process and coated with X-ray multilayers, which demonstrate extremely large angular dispersion at approximately 90 eV and 270 eV. The developed new method has great potential to produce ultrahigh line density multilayer gratings that can pave the way to cutting edge high-resolution spectroscopy and other X-ray applications., Fabrication of wafer-scale nanogratings for X-ray spectroscopy is difficult especially for very high line densities. The authors use vacancy epitaxy to fabricate sub-50-nm-periodicity gratings, coated with multilayers for efficient operation, for use in ultra-high resolution x-ray spectroscopy.

Strain engineering has been reported to improve the optical and electrical properties of two-dimensional materials, and the adjustable bandgap of MoS2 has great application value in strain engineering. In this work, to explore the influence of the Si3N4 stress liner on the MoS2 photodetector, plasma enhanced chemical vapor deposition was used to deposit a 5 nm Si3N4 film on the surface of the device to introduce strain. The simulation results show that there is tensile strain in the MoS2 area under a Si3N4 layer, which can decrease the bandgap and electron effective mass of MoS2. The measurement results of the device show that the Si3N4 stress liner devices exhibit a higher light response than the Al2O3/MoS2/sapphire photodetector (control devices) under 365 and 460 nm laser illuminations. The maximum photocurrent ( I p h) and responsivity (R) of the stress liner device under 365 nm illumination are 4.1 mA and 739.9 A/W, respectively, which are more than 30 times the corresponding value of the control device. Also, the maximum specific detectivity (D*) reached 2.5 × 1011 Jones, and the lowest noise equivalent power is 8.7 × 10−16 W/Hz1/2. Our work proved the feasibility of the Si3N4 stress liner to improve the performance of MoS2 photodetectors.

The introduction of patterned sapphire substrates (PSS) has been regarded as an effective method to improve the photoelectric performance of 2D layered materials in recent years. Molybdenum disulfide (MoS2 ), an intriguing transition metal 2D materials with splendid photoresponse owing to a direct-indirect bandgap transition at monolayer, shows promising optoelectronics applications. Here, a large-scale, continuous multilayer MoS2 film is prepared on a SiO2 /Si substrate and transferred to flat sapphire substrate and PSS, respectively. An enhanced dynamic distribution of local electric field and concentrated photon excitons across the interface between MoS2 and patterned sapphire substrates are revealed by the finite-difference time-domain simulation. The photoelectric performance of the MoS2 /PSS photodetector is improved under the three lasers of 365, 460, and 660 nm. Under the 365 nm laser, the photocurrent increased by 3 times, noise equivalent power (NEP) decreases to 1.77 × 10-14 W/Hz1/2 and specific detectivity (D*) increases to 1.2 × 1010 Jones. Meanwhile, the responsivity is increased by 7 times at 460 nm, and the response time of the MoS2 /PSS photodetector is also shortened under three wavelengths. The work demonstrates an effective method for enhancing the optical properties of photodetectors and enabling simultaneous detection of broad-spectrum emissions.

We present the experimental analysis of planar Si p-tunnel FETs (TFETs) fabricated on ultrathin body Silicon on Insulator (SOI) substrates by an optimized dopant implantation into silicide process. The average subthreshold swing of such planar TFETs reaches 75 mV/decade over four orders of magnitude of drain current. Emphasis is placed on the capacitance–voltage analysis of TFETs. In contrast to simulation predictions, we provide experimental evidence that the contribution of $C_{\mathrm {gs}}$ to the total gate capacitance increases at on-state, which in turn results in a decrease of the gate-to-drain capacitance $C_{\mathrm {gd}}$ . This beneficial effect could result in a reduction of the Miller capacitance effect in TFETs-based circuits.

An ion-sensitive field-effect transistor (ISFET) with improved sensing current and voltage sensitivity is realized by using a sSi/Si0.5Ge0.5/sSOI quantum-well (QW) heterostructure and an Al2O3 dielectric layer as sensing membrane coupling with the back-gate. The voltage sensitivity is much higher than the reference SOI ISFET, typically at low drain current due to the high hole mobility confined in the SiGe QW. A high voltage sensitivity 360mV/pH with a linearity of 99.89% was achieved for QW ISFET. The results of the planar QW ISFET show great potential for low cost, real-time monitoring of bio-chemicals due to its simplified process. Display Omitted sSi/Si0.5Ge0.5/sSOI (QW) ISFETs were fabricated and experimentally investigated for the first time.A high voltage sensitivity 360mV/pH with very good linearity has been achieved with QW ISFET.Compared with SOI devices, QW ISFETs show higher voltage sensitivity of small signals at smaller drain currents.

A label-free, cost-effective fiber optic biosensor (FOB) using electrostatic self-assembly (ESA) technology is presented and experimentally demonstrated. The FOB was constructed by sandwiching a thin-core single-mode fiber (TCSMF) between two single-mode fibers (SMFs). Firstly, we simulated the refractive index (RI) sensitivity of this fiber structure, and validated it using different concentrations of glycerol solutions. Then the diallyldimethyl ammonium chloride (PDDA) and styrenesulfonate sodium salt (PSS) were employed as polyelectrolyte self-assembled multilayers (PSAMs) deposition for surface functionalization of the fiber. We selected biotin–streptavidin as a bioconjugate pair for testing the effectiveness of the biosensor, and achieved a streptavidin detection limit of 0.02 nM. The specificity was further verified by a comparison experiment conducted using bovine serum albumin (BSA) and gelatin. These results demonstrate the feasibility of this sensor for use in biological and chemical applications.

An ultra high voltage (UHV) ac and dc interconnection will become the foundation of China’s future smart grid. Due to the wide spread of interconnected regions, the distance between control stations will increase dramatically. Therefore, the communication system’s reliability and real-time performance will become increasingly crucial. However, failures of the communication system, such as interruptions, latency, and bit error, are inevitable. This paper uses the UHV grid security and stability defense system (SSDS) as an example to analyze its requirements for communication and the impact of communication failure on the system’s performance. The effect of communication latency on the power system’s stability is analyzed quantitatively and qualitatively. Based on this analysis, a framework of an UHV grid SSDS considering the risk of the communication system is proposed. A preliminary power system and communication system co-simulation tool is developed to perform a case study. The case study demonstrates that communication latency in the UHV grid changes the control strategy’s effectiveness due to a delay in executing the control strategy. Furthermore, communication latency will negatively affect the power grid’s stability.

Background: The study aims to evaluate the effectiveness and safety of acupuncture therapy for asymptomatic infection of COVID-19. Methods: The following electronic databases will be searched from December 2019 to December 2020: MEDLINE, PubMed, EMBASE, Web of Science, China National Knowledge Infrastructure (CNKI), Wan-fang database, Chinese Scientific Journal Database (VIP), Chinese Biomedical Literature Databases (CBM), and other databases. All published randomized controlled trials (RCTs) about this topic will be included. Two independent researchers will operate article retrieval, duplication removing, screening, quality evaluation, and data analyses by Review Manager (V.5.3.5). Meta-analyses, subgroup analysis, and/or descriptive analysis will be performed based on the included data conditions. Results: High-quality synthesis and/or descriptive analysis of current evidence will be provided from the time of negative nucleic acid detection for 2 consecutive times (not on the same day), cure rate, converting to clinical diagnosis rate, and side effects of acupuncture. Conclusion: This study will provide the evidence of whether acupuncture is an effective and safe intervention for asymptomatic infection of COVID-19. PROSPERO registration number: CRD 42020179729.

Layered tin disulfide (SnS2) nanosheets are gradually coming into people’s vision as an emerging two-dimensional material for the potential application majority in optoelectronic field. We investigate a sample of ultra-thin SnS2 nanosheets (∼5 nm) on SiO2/Si substrates and the photodetectors performance based on it with and without high-k ALD-Al2O3 stress liner. By means of temperature-dependent Raman spectroscopy, both a red-shift of Raman frequency from 313.1 cm−1 to 311.2 cm−1 as well as a reduction of the first order temperature coefficient from −0.01232 cm−1/K to −0.00895 cm−1/K are measured. For device, compared to SnS2 photodetector, Al2O3/SnS2 photodetector shows enhancement with 7-times light current, 10-times responsivity, 25%-off rising time and 70%-off falling time under 365 nm illumination. The phenomena can be rationalized by factors that the SnS2 sample suffers a tensile strain and passivation effect exerted by capped Al2O3 layer. Meanwhile, the first principle calculations assist the study from an angle of verification. The analogue stress treatment operated in this work improves the properties of SnS2 and enhances the performances of SnS2-based photodetectors, aiming at expanding the thin-film materials applications in optoelectronic devices.

BACKGROUND: The study aims to evaluate the effectiveness and safety of acupuncture therapy for coronavirus disease 2019. METHODS: The following electronic databases will be searched from December 2019 to December 2020: Medline, PubMed, EMBASE, Web of Science, China National Knowledge Infrastructure, Wan-fang database, Chinese Scientific Journal Database, Chinese Biomedical Literature Databases, and other databases. All published randomized controlled trials about this topic will be included. Two independent researchers will operate article retrieval, duplication removing, screening, quality evaluation, and data analyses by Review Manager (V.5.3.5). Meta-analyses, subgroup analysis, and/or descriptive analysis will be performed based on the included data conditions. RESULTS: High-quality synthesis and/or descriptive analysis of current evidence will be provided from mortality rate, cure rate, the time of negative nucleic acid detection for 2 consecutive times (not on the same day), improvement of chest CT scans, disappearance time of fever and cough, and side effects. CONCLUSION: This study will provide the evidence of whether acupuncture is an effective and safe intervention for coronavirus disease 2019 .PROSPERO registration number: CRD42020179298.

Strain regulation as an effective way to enhance the photoelectric properties of two-dimensional (2D) transition metal dichalcogenides has been widely employed to improve the performance of photovoltaic devices. In this work, tensile strain was introduced in multilayer MoS 2 grown on GaN by depositing 3 nm of Al 2 O 3 on the surface. The temperature-dependent Raman spectrum shows that the thermal stability of MoS 2 is improved by Al 2 O 3 . Theoretical simulations confirmed the existence of tensile strain on MoS 2 covered with Al 2 O 3 , and the bandgap and electron effective mass of six layers of MoS 2 decreased due to tensile strain, which resulted in an increase of electron mobility. Due to the tensile strain effect, the photodetector with the Al 2 O 3 stress liner achieved better performance under the illumination of 365 nm wavelength, including a higher responsivity of 24.6 A/W, photoconductive gain of 520, and external quantum efficiency of 8381%, which are more than twice the corresponding values of photodetectors without Al 2 O 3 . Our work provides an effective technical way for improving the performance of 2D material photodetectors.

Astaxanthin, a predominant carotenoid mainly distributed in aquatic animals, has been widely utilized as a food additive in modern aquaculture. Astaxanthin has many optical and geometric isomers. Investigating the accumulation characteristics of astaxanthin isomers with different functional characters in aquatic animals could provide a valuable reference for achieving the efficient utilization of astaxanthin in aquatic feeds. Many studies have provided information about the composition of astaxanthin isomers in aquatic animals, but lack a systematic analysis and summary. This review summarizes the available data on the distribution of astaxanthin isomers in fish and crustaceans, and compares the differences in isomer composition between aquatic animals and their dietary source, with an aim to investigate the conversion and accumulation mechanism. Aquatic animals convert dietary astaxanthin to body astaxanthin through the processes of absorption, transport, metabolism and deposition. Three optical isomers (3S,3′S, 3R,3′R and 3R,3′S) and the main geometric isomers (all-trans, 9-cis, 13-cis and 15-cis) of astaxanthin are distributed in aquatic animals. Accumulation of these astaxanthin isomers in aquatic animals is related to, but not completely dependent on, the isomer configuration of dietary astaxanthin, but rather is specific for various species and tissues. The differences of astaxanthin isomers between dietary source and body indicate the complexity of the conversion of astaxanthin in aquatic animals, and the possibility that there is a selective mechanism as well as isomerization of astaxanthin.

Ultrasonic sparse array which derived from phased array can control the aperture and overcome local area detection. It has simple configuration and has characteristics of large scanning range and high detection accuracy, which is one of the most promising applications of ultrasonic nondestructive testing technology. Scattering wave received by sparse array includes useful information of defects, such as location, shape and specific characteristics. However, scattering guided wave with multimode behavior will increasing complexity of scattering patterns. Methods using multi-mode signals are more adaptable than using single mode signals which generated by special transducer array. In order to utilize scattering coefficient matrix (SCM) method for defects identification, multi-mode separation technique is applied. This paper proposed a Multi-Objects Artificial Bee Colony (MOABC) method to separate modes and reconstruct SCM. First, sparse array signals are decomposed into different modes under a strategy of multi parameter objects optimization, which cannot achieved by means of traditional mode separation method only using symmetry for SCM. MOABC is then modified to improve boundary conditions of food source and enlarging changing elements of parameter vector for onlooker bees. Finally, mode separation is achieved and reconstructed mode is used to for new SCM. Sparse array guided wave is applied to homogeneous materials with through-hole defect. Both simulation and experiment results are discussed. Results show that MOABC algorithm can estimate characteristic parameters more accurate and more adaptable to reconstruct scattering coefficient matrix without symmetry.

High-energy ion slicing is promising to produce the free-standing GaN films with thickness in the range of 10–20 µm, which would promote the mass applications of GaN substrates. In this paper, bulk GaN was implanted by 1.6 MeV H ions with the mean projected range Rp of around 17 μm and the thermal evolution of the H-induced defects was investigated in detail. Due to the migration-coalescence mechanism, the H-induced point defects gather to form the initial cavity defects which grow up via the Ostwald ripening mechanism. The cavity defect distribution is determined by the distributions of the implanted hydrogen and the implantation-induced damages. The area ratio of cavity defects in the center damage band of the 1.6 MeV sample was around 3.4%. Annealing at higher temperature enhances the defect migration and recovery. Larger H ion fluence or higher annealing temperature is required to accomplish the exfoliation of a free-standing GaN thick film.

The artificial bee colony (ABC) algorithm is a relatively new optimization technique for simulating the honey bee swarms foraging behavior. Due to its simplicity and effectiveness, it has attracted much attention in recent years. However, ABC search equation is good at global search but poor at local search. Some different search equations are developed to tackle this problem, while there is no particular algorithm to substantially attain the best solution for all optimization problems. Therefore, we proposed an improved ABC with a new search equation, which incorporates the global search factor based on the optimization problem dimension and the local search factor based on the factor library (FL). Furthermore, aimed at preventing the algorithm from falling into local optima, dynamic search balance strategy is proposed and applied to replace the scout bee procedure in ABC. Thus, a hybrid, fast, and enhanced algorithm, HFEABC, is presented. In order to verify its effectiveness, some comprehensive tests among HFEABC and ABC and its variants are conducted on 21 basic benchmark functions and 20 complicated functions from CEC 2017. The experimental results show HFEABC offers better compatibility for different problems than ABC and some of its variants. The HFEABC performance is very competitive.

A high-κ/metal-gate (HKMG) last process for fabricating strained Si 0.5 Ge 0.5 quantum-well (QW) p-channel metal oxide semiconductor field effect transistors (p-MOSFETs) is presented. Because the HKMG was formed after the ion-implant doping activation process, the thermal budget issue could be mitigated. The transistor features good transfer and output characteristics with I on / I off ratio up to 10 6 and threshold voltage ( V T ) down to 0.1 V. The effective hole mobility of the SiGe QW transistor reaches 215 cm 2 /V s for strong inversion conditions, which is 2.74 times the SOI device’s hole mobility.

In this work, a comprehensive study of the bias temperature instability (BTI) degradation has been performed on SOI MOSFETs with various gate lengths (from 30 nm to 150 nm). For both nMOSFETs and pMOSFETs, the BTI degradation is alleviated when the gate length decreases. A new model was proposed to explain the observed gate length dependence of the BTI degradation. The decrease in the BTI degradation of MOSFETs with shorter gate length is caused by the decrease in normal electric field across the interface of Si-dielectric, which was concept-proofed by TCAD simulations.

Syringocystadenoma papilliferum (SCAP) is an uncommon benign adnexal tumor of the skin. It is frequently seen in association with other benign adnexal lesions, such as nevus sebaceous, apocrine nevus, tubular apocrine adenoma, apocrine hidrocystoma, apocrine cystadenoma, and clear cell syringoma. The unusual reported locations of SCAP include the head and neck, the buttock, the vulva, the scrotum, the pinna, the eyelid, the outer ear canal, the forehead, the back, the scalp, the thigh, the nipple, the axilla, and the postoperative scar. The occurrence of SCAP in the right lower abdomen is distinctly uncommon. Herein, we report an unusual case of a 41-year-old man with SCAP occurring in the right lower abdomen that did not develop malignancy, despite a long disease course and an absence of medical treatment. The clinical and histopathologic features and the differential diagnosis of SCAP are also discussed.

This paper presents an ultra thin body Si n-TFET which exploits a multi-finger gate layout and steep junction formed by dopant implantation into silicide (IIS) process. The sub-threshold slope (SS) reaches a minimum value of about 45 mV/dec, average SS of on /I off ratio (∼109) is achieved due to the successfully suppressed ambipolar behavior by the asymmetric source and drain design.

Virtual power plant(VPP) integrate distributed power, energy storage device and load, through reasonable control mode, the virtual power plant will have the same controllable external characteristics as the traditional power plant, such as maximum power generation capacity, minimum technical output, climbing rate, and frequency regulation characteristic etc. This paper presents a control strategy for the frequency modulation characteristics control of virtual power plant, which is suitable for the non-center control, by the pinning node of directly receiving the power grid dispatching instruction to convey information to all nodes in the virtual power plant, complete distributed pinning control, to meet the power grid scheduling requirements for the overall power adjustment. The numerical examples are verified by the electricity-communication interactive simulation platform, power simulation is done by MATLAB, and the communication simulation is done by OPNET, through COSIM interactive interface, interactive simulation platform will be able to simulate the impact of different communication architecture on frequency modulation control performance. The numerical examples show that the distributed pinning control strategy could effectively accomplish the task of frequency modulation control in virtual power plant, and make a beneficial exploration for virtual power plant engineering practice.

In smart grid, a strong communication network plays a very important role, which makes the power grid more controllable and observable. It is a very tough task to study the mutual impact between these two systems due to their different characteristics. This paper proposes a generic and systematic approach for quantitatively studying the impact of communication failures on power grid's measurement and control functions. And an example is used to illustrate how to apply the approach in studying the impact of communication failure on a stability control system.

Black phosphorus (BP) has emerged as a promising two-dimensional (2D) material for next generation transistor applications due to its superior carrier transport properties. Among other issues, achieving reduced subthreshold swing and enhanced hole mobility simultaneously remains a challenge which requires careful optimization of the BP/gate oxide interface. Here, we report the realization of high performance BP transistors integrated with HfO2 high-k gate dielectric using a low temperature CMOS process. The fabricated devices were shown to demonstrate a near ideal subthreshold swing (SS) of ~69 mV/dec and a room temperature hole mobility of exceeding >400 cm2/Vs. These figure-of-merits are benchmarked to be the best-of-its-kind, which outperform previously reported BP transistors realized on traditional SiO2 gate dielectric. X-ray photoelectron spectroscopy (XPS) analysis further reveals the evidence of a more chemically stable BP when formed on HfO2 high-k as opposed to SiO2, which gives rise to a better interface quality that accounts for the SS and hole mobility improvement. These results unveil the potential of black phosphorus as an emerging channel material for future nanoelectronic device applications.

A new low-profile planar eleven antenna is designed as a wideband MIMO antenna for micro-base stations in future wireless communication systems. The design criterion is to minimize both the reflection coefficient and the ratio of the required average received power over the threshold for 95% of the total probability of detection (PoD) in the Rich Isotropic Multipath (RIMP) and random Line-of-Sight (RLOS) scenarios of both one-bit stream and two-bit stream. The design is performed via optimization with a genetic algorithm.

FAS and its ligand FASL are crucial in apoptotic cell death. Loss of FAS and gain of aberrant FASL expression are common features of malignant transformation. This study was designed to investigate whether the functional polymorphisms of FAS -1377G/A (rs2234767) and FASL -844T/C (rs763110) affect the risk of developing breast cancer. Genotypes were analyzed by a polymerase chain reaction-restriction fragment length polymorphism assay in 436 breast cancer patients and 496 healthy controls. In this study, as compared to the wild-type homozygote and heterozygote, the distribution of the FAS -1377GG, GA and AA genotypes among breast cancer patients were significantly different from those among healthy controls (P=0.011), with the AA genotype being more prevalent among patients than the controls (P=0.003). Similarly, the frequencies of the FASL -844TT, TC and CC genotypes also significantly differed among breast cancer patients and healthy controls (P