Search

The major treatment for perforated peptic ulcers (PPU) is surgery, and several scoring systems have been reported to predict morbidity and mortality after surgery. However, it remains unclear which patient should receive nonoperative management instead of surgery. This study aimed to generate a scoring system for surgeons to identify patients with PPU who may be too weak to undergo surgery and without any survival benefit. We extracted the admission data of adult (≥ 18 years) patients with PPU disease from the NHIRD database. They were randomly divided into an 80% model derivation cohort and a 20% validation cohort. Multivariate analysis with a logistic regression model was applied to generate the scoring system, PPUMS. The scoring system was then applied to the validation group. The PPUMS score ranged from 0 to 8 points, composite with age ( 80: 3 points), and five comorbidities (congestive heart failure, severe liver disease, renal disease, history of malignancy, and obesity: 1 point each). In the derivation group, patients with PPUMS > 4 had a 45.9% in-hospital mortality rate and similar in-hospital mortality risk in the operation group [traditional laparotomy: odds ratio (OR) = 0.729, p = 0.320, laparoscopy: OR = 0.772, p = 0.697] and the non-operation group. In the validation group, patients with PPUMS > 4 points had a 36.9% mortality rate and similar mortality risk in the operation group (traditional laparotomy: OR = 0.353, p = 0.093, laparoscopy: no applicable) and non-operation group. PPUMS is a good predictor of mortality risk in patients with PPU and with various underlying diseases or comorbidities. Surgical management is suggested for patients with PPU with PPUMS ≤ 4 points because of lower mortality risk. However, in patients with PPUMS > 4 points, surgery may have limited benefit due to the high mortality rate compared to nonoperative treatment.

Esophagojejunostomy is a challenging step in laparoscopic gastrectomy. Although the overlap method is a safe and feasible approach for esophagojejunostomy, it has several technical limitations. We developed novel modifications for the overlap method to overcome these disadvantages. Forty-eight consecutive gastric cancer patients underwent totally laparoscopic total gastrectomy or laparoscopic proximal gastrectomy with double-tract reconstruction at our institution from January 2019 to April 2020 using the overlap method with the following modifications. The esophagus was initially rotated by 90° counterclockwise, followed by transection of two-thirds of the esophageal diameter. The unstapled esophagus was then transected with a harmonic ultrasonic scalpel to enable esophagostomy at the posterior side of the esophagus. A side-to-side esophagojejunostomy was then formed at the posterior side of the esophagus using an endoscopic linear stapler through the right lower trocar. The common entry hole was closed via hand sewing method using V-Loc suture. This procedure was termed “esophagus two-step-cut overlap method.” Only one patient suffered from esophagojejunal anastomotic leakage but subsequently recovered after conservative treatment. Patients did not experience anastomotic bleeding or stricture. Our modified overlap method provides satisfactory surgical outcomes and overcomes several technical limitations, such as entering the false lumen of the esophagus, unnecessary pollution caused by nasogastric tube, and unintended left crus stapling during anastomosis.

Background: Gastrointestinal stromal tumor (GIST) involving the esophagogastric junction (EGJ) is a relatively rare but thorny problem. It represents a dilemma between complete resection and impairment of quality of life (QOL) for loss of cardiac sphincter or even the whole stomach. Thus, emergence of function preserving gastrectomy is necessary and may provide partial solution to this hot potato. Here, we would like to introduce a method which successfully settle this matter through a clinical case. Case presentation: A 46-year-old male complaining of a progressive dysphagia. A huge GIST with 120mm in diameter was diagnosed by enhanced CT scan and pathological exam. Imatinib mesylate (IM) was initially prescribed, the tumor was shrank to a large extent while drug resistance emerged 6 months after therapy, leaving a mass approximately 90mm in diameter. We applied a method of vagus preserving proximal gastrectomy (VP-PG) and esophagogastrostomy with double-flap technique (DFT) for the patient. The operation was smooth and postoperative courses within a 12-months follow-up were uneventful. The patient had no digestive symptoms but slight leucopenia due to IM toxicity during this medication period. Conclusion: We consider that the application of VP-PG and DFT subsequent to neoadjuvant therapy with IM is likely to be an effective and feasible option for GISTs with EGJ involvement.

This study proposed a wearable device capable of recognizing six human daily activities (walking, walking upstairs, walking downstairs, sitting, standing, and lying) through a deep learning algorithm. Existing wearable devices are mainly watches or wristbands, and almost none are to be worn on the waist. Wearable devices in the forms of watches and wristbands are unfriendly to patients who are critically ill, such as patients undergoing dialysis. Patients undergoing dialysis have artificial blood vessels on their arm, and they cannot perform intense exercise. For this type of users, general hand wearable devices cannot correctly identify wearers' activities. Therefore, we proposed a waist wearable device and these types of daily life activities to assess their exercise. The hardware of the wearable device consisted of an inertial sensor, which included a microcontroller, a three-axis accelerometer, and a three-axis gyroscope. The activity recognition algorithm of the software used motion signals acquisition, signal normalization, and a feature learning method. The feature learning method was based on a 1D convolutional neural network that automatically performed feature extraction and classification from raw data. One part of the experimental data was from the dataset of the University of California (UCI), and the other part was recorded by this study. To capture the data recorded, the wearable inertial sensing device was attached to the waists of 21 experimental participants who performed six common movements in a laboratorial environment, and the subsequent records were collected to verify the validity of the proposed deep learning algorithm in relation to the inertial sensor of the wearable device. For the six common activities in the UCI dataset and the data recorded, the recognition rates in the training sample reached 98.93% and 97.19%, respectively, and the recognition rates in the testing sample were 95.99% and 93.77%, respectively.

A scaling law is demonstrated in the conductivity of gated two-dimensional (2D) materials with tunable concentrations of ionized impurity scatterers. Experimental data is shown to collapse onto a single 2D conductivity scaling (2DCS) curve when the mobility is scaled by r, the relative impurity-induced scattering, and the gate voltage is shifted by V s , a consequence of impurity-induced doping. This 2DCS analysis is demonstrated first in an encapsulated 2D black phosphorus multilayer at T = 100 K with charge trap densities programmed by a gate bias upon cooldown, and next in a Bi2Se3 2D monolayer at room temperature exposed to varying concentrations of gas adsorbates. The observed scaling can be explained using a conductivity model with screened ionized impurity scatterers. The slope of the r vs. V s plot defines a disorder-charge specific scattering rate Γ q = d r / d V s equivalent to a scattering strength per unit impurity charge density: Γ q > 0 indicates a preponderance of positively charged impurities with Γ q < 0 for negatively charged. This 2DCS analysis is expected to be applicable in arbitrary 2D materials systems with tunable impurity density, which will advance 2D materials characterization and improve performance of 2D sensors and transistors.

Esophagojejunostomy is a challenging step in laparoscopic gastrectomy. Although the overlap method is a safe and feasible approach for esophagojejunostomy, it has several technical limitations. We developed novel modifications for the overlap method to overcome these disadvantages.Forty-eight consecutive gastric cancer patients underwent totally laparoscopic total gastrectomy or laparoscopic proximal gastrectomy with double-tract reconstruction at our institution from January 2019 to April 2020 using the overlap method with the following modifications. The esophagus was initially rotated by 90° counterclockwise, followed by transection of two-thirds of the esophageal diameter. The unstapled esophagus was then transected with a harmonic ultrasonic scalpel to enable esophagostomy at the posterior side of the esophagus. A side-to-side esophagojejunostomy was then formed at the posterior side of the esophagus using an endoscopic linear stapler through the right lower trocar. The common entry hole was closed via hand sewing method using V-Loc suture. This procedure was termed "esophagus two-step-cut overlap method."Only one patient suffered from esophagojejunal anastomotic leakage but subsequently recovered after conservative treatment. Patients did not experience anastomotic bleeding or stricture.Our modified overlap method provides satisfactory surgical outcomes and overcomes several technical limitations, such as entering the false lumen of the esophagus, unnecessary pollution caused by nasogastric tube, and unintended left crus stapling during anastomosis.

From 2015, NSPO (National Space Organization) began to develop off-axis Korsch telescope system for next generation earth observation mission. The experimental Korsch telescope system is consist of five mirrors, including: (1) M1: 550mm diameter clear aperture concave primary mirror, (2) M2: Convex secondary mirror, (3) M3: Off-axis concave tertiary mirror with rectangular aperture, (4) FM1 & FM2: Two folding mirrors with rectangular aperture and flat surface. All the experimental mirrors are designed with lightweight structure and made of fused silica. Since early 2016, we collaborated with Taiwanese domestic company and manufactured all the mirrors for the experimental Korsch telescope. Moreover, we not only accomplished the assembly of M1 but also implemented the form error metrology technique to measure the surface error of M1 with high repeatability in 2017. Recently, in order to validate the structural and athermal design of opto-mechanical structures, several vibration tests and thermal experiments have been accomplished in 2018. The experimental data could not only help us to enhance the analysis accuracy of the finite element model but also benefit to our automated opto-mechanical design system. For next developed phase, the aspheric polishing and reflective coating will be achieved till 2021.

This paper describes superior candidate substrate material- aluminum nitride (AlN), for the cost-effective and high-performance requirements for aerospace mirrors. In fact, high specific stiffness and thermal stability are not only two major considerations to select ideal material but also machinability, dimensional stability, and cost. Silicon carbide shows the best figure of merits 12627, but it has extremely low remove rate and expensive raw material properties. Extremely low expansion ceramics such as Zerodur may be difficult to obtain in large quantities and its figure of merit is 1151. On the contrary, AlN has outstanding thermal conductivity (~170 W/m°C) and maintain high figure of merit 2222 without compromise. In our fabrication processes, the AlN substrate can be easily polished to 53±1nm Ra surface texture and 66.4±2nm RMS surface form. Its unique thermal stability, specific stiffness, and good figure of merits, associated with its easy machinability and low-cost raw materials, makes AlN an ideal selection for superior mirror substrate in the future space mirror optics.

In this paper, the FEM simulation package FLUX2D is utilized as a tool to design a proportional solenoid for the hydraulic proportional suspension damper. The hydraulic proportional suspension damper can be used in vehicle semi-active suspension system due to its adjustable output damping force. In addition, the proportional solenoid plays the most significant role to achieve such a variable output damping force. From previous literatures, three different structures of proportional solenoid will be discussed in this paper. The first one utilizes the stepped conical armature design. Its advantages include low cost, easy manufacturing. However, the limited available linear stroke as well as the poor linearity are its major faults. The second structure uses a special tube consisting of three metal rings that are welded together. Between two magnetic steel rings, there is a non-magnetic copper ring serving to guide the magnetic flux and to produce a linear force/stroke relation. Clearly, higher cost and complex manufacturing process are its major disadvantages. However, larger available linear stroke and good linearity are two promising advantages. In this paper, the third design of proportional solenoid is adopted. The construction of the proportional solenoid is divided into several parts. After assembling these parts together, a ring of air gap with a well-designed geometrical shape exists which can be used to replace the non-magnetic copper ring. Without the copper ring, the expensive and complex welding process can be omitted. Meanwhile, the large available linear stroke as well as good linearity are both preserved. Finally, an experimental test device for measuring the force/stroke relation of proportional solenoid is implemented in this study. It is observed that the simulation results agree quite well with the experimental results.

This network meta-analysis aimed to integrate the available direct and indirect evidence on regenerative injections—including 5% dextrose (D5W) and platelet-rich plasma (PRP)—for the treatment of carpal tunnel syndrome (CTS). Literature reports comparing D5W and PRP injections with non-surgical managements of CTS were systematically reviewed. The main outcome was the standardized mean difference (SMD) of the symptom severity and functional status scales of the Boston Carpal Tunnel Syndrome Questionnaire at three months after injections. Ranking probabilities of the SMD of each treatment were acquired by using simulation. Ten studies with 497 patients and comparing five treatments (D5W, PRP, splinting, corticosteroid, and normal saline) were included. The results of the simulation of rank probabilities showed that D5W injection was likely to be the best treatment, followed by PRP injection, in terms of clinical effectiveness in providing symptom relief. With respect to functional improvement, splinting ranked higher than PRP and D5W injections. Lastly, corticosteroid and saline injections were consistently ranked fourth and fifth in terms of therapeutic effects on symptom severity and functional status. D5W and PRP injections are more effective than splinting and corticosteroid or saline injection for relieving the symptoms of CTS. Compared with splinting, D5W and PRP injections do not provide better functional recovery. More studies investigating the long-term effectiveness of regenerative injections in CTS are needed in the future.

The main purpose of this paper is to develop an automatic print head alignment algorithm for a material jetting-based color 3D additive manufacturing system. This printing system has six print heads, respectively, filled with six different photocurable resin (C, M, Y, K, W) and support. Start of all, the printing system with initial parameters prints a standard platform, which is used to confirm whether the print head is aligned well or not. Next, a scanner is used to gain the printed image. An image processing algorithm is used to get the characteristic points of the capture image and calculate the compensation parameters, which will be imported to the printing system and make the system aligned well. This paper proposed an automatic smart print head alignment algorithm, which can be used on multiple print head based- 3D additive manufacturing system. Replacing of human alignment, this technology can save more time and reduce the error. It also can automatically work and oversee the system in real-time, which will improve the quality and the color performance of the printed products.

For the earth observation mission, there are some critical environmental requirements including low-light condition, fast moving objects, high scanning rate. In order to meet these requirements, the Time-Delay-and-Integration (TDI) technique is critical and essential for the sensor part to improve the Signal to Noise Ratio (SNR) performance. National space organization (NSPO) collaborates with National Chip Implementation Center (CIC) on the next generation image sensor. In order to increase SNR under the light-starved condition, a 32-stages digital-accumulator Time-Delay-and-Integration (TDI) CMOS image sensor is adapted to improve the image quality. Besides, it could successfully take several pictures under different TDI stages on a dynamic test bench. The experimental results verified that the 32-stage TDI CMOS image sensor could function well.

Large mirrors with lightweight structure, such as those used in the telescope system of astronomy or spaceborne applications, are susceptible to stress caused by fabrication process. Furthermore, both the residual stress and subsurface damage are critical for the lightweight tooling of glass materials. In order to figure out the stress distribution on glass substrate, the photoelastic method has been applied to not only the astronomical optics but also the industrial optics of semiconductor equipment. However, there are several influence factors in photoelasticity measurement, including the structure of mirror, fabrication process, and metrology technique. The above factors may affect to the retardation result of photoelasticity measurement and cause the error of stress calculation. Therefore, it is important to clarify the retardation difference contribution to the corresponding influence factors. In this study, we attempted to use photoelastic instrument to investigate the relationship between the photoelastic effect and stress of several kinds of lightweight mirrors. There are three different lightweight mirrors were adapted to the photoelasticity measurement, including: (1) GSO 12” Mirror with 12 inches diameter made by fused silica, (2) Primary Mirror (M1-B) of Formosat-5 with 450 mm diameter made by ZERODUR® , (3) Primary Mirror (M1) of Mircrosat with 380 mm diameter made by CLEARCERAM®-Z. The experimental results depict some obvious retardation differences caused by the certain influence factors and the details will be discussed below.

This article presents the opto-mechanical design of a primary mirror assembly of a ground-based telescope with optimization algorithm. The prototype of ground-based telescope – GSO RC16 with 16 inches diameter blank primary mirror had been manufactured in 2016. However, a telescope with a blank primary mirror is too heavy to carry on for the stargazer. Besides, deformations caused by temperature difference and gravity will do significant effect to the large aperture mirrors with high optical performance requirements. In order to reduce the weight and maintain the stiffness simultaneously, the lightweight design and mounting interface design are critical and important. There are four types of system architectures in this project, including (1) two types of lightweight mirror designs - honeycomb type segments and sector type segments; (2) two types of mounting interface designs - retainer type support and CFRP type support. The optimization results showed that (1) the lightweight ratio of the primary mirrors are greater than 70%; and (2) the PV value of the mirrors supported by optimal mounting interfaces with gravity effect as a tilt of about 45 degrees and ±20°C temperature difference effectively less than 1/4 λ.

The palette of two-dimensional materials has expanded beyond graphene in recent years to include the chalcogenides among other systems. However, there is a considerable paucity of methods for controlled synthesis of mono- and/or few-layer two-dimensional materials with desirable quality, reproducibility, and generality. Here we show a facile top-down synthesis approach for ultrathin layers of 2D materials down to monolayer. Our method is based on controlled evaporative thinning of initially large sheets, as deposited by vapor mass-transport. Rather than optimizing conditions for monolayer deposition, our approach makes use of selective evaporation of thick sheets to control the eventual thickness, down to a monolayer, a process which appears to be self-stopping. As a result, 2D sheets with high yield, high reproducibility, and excellent quality can be generated with large (10 μm) and thin (∼ 1-2 nm) dimensions. Evaporative thinning promises to greatly reduce the difficulty involved in isolating large, mono- and few-layers of 2D materials for subsequent studies.

Most of recent research on layered chalcogenides is understandably focused on single atomic layers. However, it is unclear if single-layer units are the most ideal structures for enhanced gas-solid interactions. To probe this issue further, we have prepared large-area MoS2 sheets ranging from single to multiple layers on 300 nm SiO2/Si substrates using the micromechanical exfoliation method. The thickness and layering of the sheets were identified by optical microscope, invoking recently reported specific optical color contrast, and further confirmed by AFM and Raman spectroscopy. The MoS2 transistors with different thicknesses were assessed for gas-sensing performances with exposure to NO2, NH3, and humidity in different conditions such as gate bias and light irradiation. The results show that, compared to the single-layer counterpart, transistors of few MoS2 layers exhibit excellent sensitivity, recovery, and ability to be manipulated by gate bias and green light. Further, our ab initio DFT calculations on single-layer and bilayer MoS2 show that the charge transfer is the reason for the decrease in resistance in the presence of applied field.

Field emission studies are reported for the first time on layered MoS₂ sheets at the base pressure of ∼1 × 10⁻⁸ mbar. The turn-on field required to draw a field emission current density of 10 μA/cm² is found to be 3.5 V/μm for MoS₂ sheets. The turn-on values are found to be significantly lower than the reported MoS₂ nanoflowers, graphene, and carbon nanotube-based field emitters due to the high field enhancement factor (∼1138) associated with nanometric sharp edges of MoS₂ sheet emitter surface. The emission current-time plots show good stability over a period of 3 h. Owing to the low turn-on field and planar (sheetlike) structure, the MoS₂ could be utilized for future vacuum microelectronics/nanoelectronic and flat panel display applications.

Oxidative etching of graphene flakes was observed to initiate from edges and the occasional defect sites in the basal plane, leading to reduced lateral size and a small number of etch pits. In contrast, etching of highly defective graphene oxide and its reduced form resulted in rapid homogeneous fracturing of the sheets into smaller pieces. On the basis of these observations, a slow and more controllable etching route was designed to produce nanoporous reduced graphene oxide sheets by hydrothermal steaming at 200 °C. The degree of etching and the concomitant porosity can be conveniently tuned by etching time. In contrast to nonporous reduced graphene oxide annealed at the same temperature, the steamed nanoporous graphene oxide exhibited nearly 2 orders of magnitude increase in the sensitivity and improved recovery time when used as chemiresistor sensor platform for NO(2) detection. The results underscore the efficacy of the highly distributed nanoporous network in the low temperature steam etched GO.

In this paper, a design of dual-layer Blu-ray recordable (DL BD-R) disc without silver or silver alloy semi-reflective layer is introduced. Five potential dielectric reflector materials, including the AlN, BN, Nb2O5, TiO2 and ZnS-SiO2 are evaluated and tested to compensate the reflectivity of layer 1 after removing the metallic semi-reflective layer. With the help of optical simulation software, reflectivity in both layers could be optimized by fine tuning thickness of each material and the recording performance was examined in each condition. Furthermore, a simplified layer 1 stack was proposed and evaluated. The disc with only Nb2O5 layer as semi-reflector in layer 1 can achieve the desired performance of 6× recording speed and provide the benefit of better mass production from the simplified practical film structure point of view.

This paper addresses a novel competitive facility location problem about a firm that intends to enter an existing decentralized supply chain comprised of three tiers of players with competition: manufacturers, retailers and consumers. It first proposes a variational inequality for the supply chain network equilibrium model with production capacity constraints, and then employs the logarithmic-quadratic proximal prediction–correction method as a solution algorithm. Based on this model, this paper develops a generic mathematical program with equilibrium constraints for the competitive facility location problem, which can simultaneously determine facility locations of the entering firm and the production levels of these facilities so as to optimize an objective. Subsequently, a hybrid genetic algorithm that incorporates with the logarithmic-quadratic proximal prediction–correction method is developed for solving the proposed mathematical program with an equilibrium constraint. Finally, this paper carries out some numerical examples to evaluate proposed models and solution algorithms.

This paper is concerned with the supply chain network equilibrium models proposed by Nagurney et al. [Nagurney, A., Dong, J., Zhang, D., 2002. A supply chain network equilibrium model. Transportation Research 38E, 281–303] and Dong et al. [Dong, J., Zhang, D., Nagurney, A., 2004. A supply chain network equilibrium model with random demands. European Journal of Operational Research 156, 194–212]. It demonstrates that these models possess the unconstrained continuously differentiable minimization formulations, whose any stationary point is the solution of the corresponding model. Accordingly, not only is the Quasi-Newton algorithm capable of finding a solution of the model, but also it can overcome the difficulty experienced by the modified projection method in choosing an appropriate predetermined step size. In addition, 11 benchmark examples are employed to show the advantage of the unconstrained minimization formulation.

Lithiation-exfoliation produces single to few-layered MoS2 and WS2 sheets dispersible in water. However, the process transforms them from the pristine semiconducting 2H phase to a distorted metallic phase. Recovery of the semiconducting properties typically involves heating of the chemically exfoliated sheets at elevated temperatures. Therefore, it has been largely limited to sheets deposited on solid substrates. Here, we report the dispersion of chemically exfoliated MoS2 sheets in high boiling point organic solvents enabled by surface functionalization and the controllable recovery of their semiconducting properties directly in solution. This process connects the scalability of chemical exfoliation with the simplicity of solution processing, ultimately enabling a facile method for tuning the metal to semiconductor transitions of MoS2 and WS2 within a liquid medium.

Gastric cancer is the second cause of death from cancer worldwide and its prevalence and mortality rates are still very high in developed countries. Interleukin-10 (IL10) is a pleiotropic cytokine produced by macrophages which can suppress and stimulate the immune response in tumorigenesis signaling. However, the contribution of IL10 genomic variants to gastric cancer is still largely unknown. In the present study, we aimed at investigating the role of IL10 genotypes in gastric cancer risk. The promoter single nucleotide polymorphisms on IL10, A-1082G (rs1800896), T-819C (rs3021097) and A-592C (rs1800872), were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method among 716 Taiwanese people (358 patients gastric cancer and 358 cancer-free controls). The results showed that there was a significant difference between the patient and control groups in the genotypic frequency distribution of IL10 A-1082G genotypes (p=0.0004). In addition, those carrying the G allele were found to have a higher risk for gastric cancer compared with those with the A allele (p=3.19×10(-5)). Furthermore, personal cigarrete smoking habits enhanced the gastric cancer risk for those IL10 A-1082G AG and GG carriers. In conclusion, AG and GG genotype at IL10 A-1082G, together with smoking, synergistically contribute to individual susceptibility for gastric cancer in Taiwan.

The concentrated local electric field on a substrate surface is very helpful to enhance the signal for surface-enhanced Raman scattering (SERS) and surface plasmon resonance (SPR) techniques. In this research, the metallic nano-cylinder, the nano-hole, and nano-annular aperture structures on the glass have been simulated by the finite difference time domain method (FDTD) first to understand the localized surface plasmon resonance (LSP) of them. The simulations for different inner diameters, outer diameters and thickness of the gold film have been done and the better dimension and film thickness which can induce the largest electric field concentration have been chosen. We coated 2 nm and 5 nm thick chromium(Cr), and 50nm and 60nm thick gold(Au) films on SF2 glass substrate, respectively. The different nanoannular aperture structures were successfully patterned on them by using focus ion beam (FIB) to etching gold film surface. Using the OB Morph measurement to observe the structure caused by the SPR shifted. The transmission spectrometer has been adapted to measurement the substrate to observe the spectrum of them. Different concentrations of sodium chloride(NaCl) solutions also have been measured on the different substrates, and the shift of the transmission light wave peak was detected.

Field emission studies are reported for the first time on layered MoS₂ sheets at the base pressure of ∼1 × 10⁻⁸ mbar. The turn-on field required to draw a field emission current density of 10 μA/cm² is found to be 3.5 V/μm for MoS₂ sheets. The turn-on values are found to be significantly lower than the reported MoS₂ nanoflowers, graphene, and carbon nanotube-based field emitters due to the high field enhancement factor (∼1138) associated with nanometric sharp edges of MoS₂ sheet emitter surface. The emission current-time plots show good stability over a period of 3 h. Owing to the low turn-on field and planar (sheetlike) structure, the MoS₂ could be utilized for future vacuum microelectronics/nanoelectronic and flat panel display applications.

The authors have synthesized InN quantum dots by ion implantation into a Si (100) substrate followed by a postannealing process. X-ray photoemission spectroscopy data verified the formation of In–N bonding in both as-implanted and postannealed samples. Diffraction patterns from transmission electron microscopy (TEM) confirm that the dots are of cubic crystal (zinc-blende phase) with no presence of wurtzite InN. The silicon matrix provides a constraint for the formation of the InN cubic metastable phase. However, dislocations were revealed by high resolution TEM at the interfaces between the dots and the silicon. In addition, the authors found that as the annealing temperature or time increases, dot size increases and dot density decreases. Furthermore, they demonstrate that the main emission energy of zinc-blende InN dots is about 0.736eV.

not Available.