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A new variational Bayesian‐based adaptive distributed fusion unscented Kalman filter (ADFUKF‐VB) algorithm is proposed for the problem of state estimation in a distributed fusion target tracking system with unknown sensor measurement losses. First, the Bernoulli random variables are introduced as the judgement factors of the measurement losses in each local unscented Kalman filter (UKF) of the distributed fusion target tracking system, and the probability density function (PDF) of the measurement loss probability is modelled as a Beta distribution. Then, the variational Bayesian (VB) approach is used to infer the estimated variables in each local UKF. The measurement losses are judged according to the expectations of the Bernoulli random variables, and three ways are adopted to estimate the state vector based on the obtained judgement results. Finally, the covariance intersection (CI) fusion strategy is used to achieve the fusion of all local state estimates. The simulation results show that the proposed ADFUKF‐VB algorithm can accurately judge whether the measurement is lost and estimate the unknown measurement loss probability, moreover, effectively improve the accuracy of state estimation compared with the existing filtering algorithms with unknown measurement losses.

Efficient separation of carbohydrates and lignin, and converting them into valuable products are still major challenges for biorefinery commercialization. In this paper, organic acid-catalyzed hydrolysis of corn stalk was carried out as the first step of biorefinery. The hydrolysis behavior of lignocellulose from different tissues of corn stalk under different conditions (e.g., acid species and other process parameters) has been deeply analyzed. The results showed that the dissociation constants (pKa) were closely related to the hydrolysis of sugars, and oxalic acid had significant degradation ability on carbohydrates. Moreover, two robust models have been developed for monitoring the hydrolysis kinetics of carbohydrates in corn bark and pith. Lastly, the residue solids-driven activated carbon materials have also been developed for application in the fields of energy storage and environmental protection. This work provides a waste-free biorefinery reference for high-value utilization of corn stalk or other lignocellulose based on organic acid pretreatment.

Background Cone-shaped vena cava filters (VCFs) are widely used to treat venous thromboembolism. However, in the long term, the problem of occlusion persists even after the filter is deployed. A previous study hypothesized that the reverse deployment of a cone-shaped VCFs may prevent filter blockage. Methods To explore this hypothesis, a comparative study of the traditional and reverse deployments of VCFs was conducted using a computational fluid dynamics approach. The distribution of wall shear stress (WSS) and shear stress-related parameters were calculated to evaluate the differences in hemodynamic effects between both conditions. In the animal experiment, we reversely deployed a filter in the vena cava of a goat and analyzed the blood clot distribution in the filter. Results The numerical simulation showed that the reverse deployment of a VCF resulted in a slightly higher shear rate on the thrombus, and no reductions in the oscillating shear index (OSI) and relative residence time (RRT) on the vessel wall. Comparing the traditional method with the reversely deployed cases, the shear rate values is 16.49 and 16.48 1/s, respectively; the minimal OSI values are 0.01 and 0.04, respectively; in the vicinity of the VCF, the RRT values are both approximately 5 1/Pa; and the WSS is approximately 0.3 Pa for both cases. Therefore, the reverse deployment of cone-shaped filters is not advantageous when compared with the traditional method in terms of local hemodynamics. However, it is effective in capturing thrombi in the short term, as demonstrated via animal experiments. The reversely deployed cone-shaped filter captured the thrombi at its center in the experiments. Conclusions Thus, the reverse deployment of cone-shaped filters is not advantageous when compared with the traditional method in terms of local hemodynamics. Therefore, we would not suggest the reverse deployment of the cone-shaped filter in the vena cava to prevent a potentially fatal pulmonary embolism.

In order to effectively prevent the diffusion and pollution of highly concentrated PM2.5, the roadway full-section water curtain device has been developed in this paper. Based on our water spray experiments, a type II nozzle that was suitable for the water curtain device was selected. This roadway full-section water curtain device was optimized through a numerical simulation using Fluent software. The wind-droplet numerical simulation results showed that the water curtain device could achieve the optimal spray parameters. When the water pressure Pw was 7 MPa and the nozzle was inclined to the upwind side at θ = 15°, a high-quality spray field with the concentration greater than 10 g m−3 covered 93.1 % of the cross-sectional area of the entire roadway. The settlement of harmful particulates of PM2.5 in the air-return pathway of the Bailu Coal Mine’s 4307 coal mining face, using three roadway full-section water curtain devices, was then measured. The results showed that the ideal level of dust settlement can be achieved by consuming less water. It was also found that the settling rate of PM2.5 at the air-return pathway 200 m away from the coal mining face was as high as 95.7 %, indicating that the roadway full-section water curtain device had settled and controlled the PM2.5 in the roadway’s airflow effectively.

In this article, the effects of two-step annealing at the active layer (AL) and the completed device on the electrical properties and stability of amorphous In-Ga-Zn-O (a-IGZO) thin-film transistor (TFT) are studied. The subthreshold swing (SS) and stability of a-IGZO TFT devices are greatly improved, and the hump phenomenon under the negative bias illumination stability (NIBS) is particularly well suppressed when the TFT devices are treated with an optimum two-step annealing process (200 °C of preannealing and 300 °C of postannealing). Based on the analysis of the surface morphology, internal chemical state, and electrical properties of the IGZO thin film, an improvement of two-step annealing devices may be due to hydrogen filling the oxygen vacancies in the AL and well passivating the defects between insulating layer and AL. The result illustrates that two-step annealing is a promising method for IGZO TFT, which is not only beneficial to improve the stability of the device but also suppresses the hump phenomenon in NIBS.

High concentrated dust from coal mining is hazardous in that it seriously affects the health of the exposed miners and might also lead to explosion directly or indirectly. In order to effectively control the onsite dust density, we simulated the spray behavior of the dust-settling devices under various operational parameter combinations based on CFD numerical simulations in combination of the orthogonal experimental design. After a comprehensive evaluation, we obtained an optimal parameter combination from the multi-factor analysis and applied it to the working site. The results demonstrated that the concentration of total dust and respirable dust at every measurement point dropped below 80.4% and 81.9% respectively. The working condition was greatly improved and the dust explosion hazards were effectively under control. This study provides a new approach for the structural and parametric optimization of spray dust-settling devices. It yields reliable results using the CFD simulations combined with multi-index orthogonal experiments.

Biorefinery for the purpose of producing biofuels, chemicals, and materials has received much attention. Furfural alcohol (FOL) and levulinate ester (LE) are important biomass-derived platform chemicals, and they are produced from sugar-based furfural (FAL). Unfortunately, the two products are often obtained separately in different reaction systems, which is undesirable; furthermore, it is of significant practical interest to control their selectivity so that the desired product can be accumulated in high yields. Herein, we present an efficient method for the highly selective conversion of FAL to FOL or isopropyl levulinate (IPL) in a one pot system using isopropanol as the hydrogen source and ZrO2@SBA-15 as a bifunctional catalyst with both Lewis acid and Bronsted acid sites. Under optimized reaction conditions, high yields of FOL and IPL in up to 90.4% and 87.2%, respectively, were obtained. Based on the experimental results, a kinetic model describing the catalytic conversion of FAL into FOL and IPL process has been established, which has a good correlation (R2 > 0.92) between the measured and predicted data. The developed kinetics can provide an effective tool to monitor the process and tailor the process conditions to obtain the desired product.

In this paper, the indium gallium zinc oxide (IGZO) thin-film transistors (TFTs) with chitosan (CS) gate dielectric are prepared by the conventional photolithography technique on a pilot line. As-prepared devices on 200 × 200 mm substrate is very uniform, and have good performance of high on/off drain current ratio ~ 10−6, low subthreshold swing ~ 0.24, low-threshold voltage ~ 0.20 V and high-visible light transmittance > 90%. The glucose oxidase is drop-cased on the CS gate dielectric surfaces to make fully transparent CS-based IGZO TFTs with sensitivity to glucose. It is found that the current noticeably changes with increasing glucose concentrations. Herein, the glucose detection range from 0.5 to 30 mM covers the normal range of human blood glucose concentration. Moreover, the response time for glucose sensing is < 10 s, which is effective in detecting glucose. The results suggest that the CS-based IGZO TFTs can be used to detect glucose and provides a simple process to achieve low-cost- and larger-area fabrication of biosensors.

In order to treat serious dust pollution problems in a fully mechanized mining face, computational fluid dynamics (CFD) was here used for numerical simulation. The atomization effects of the pressure swirling nozzles with three pore diameters of 1.6, 2.0, and 2.4 mm under the roadway airflow disturbance of 1.4 m/s and spray pressure of 1–8 MPa were simulated respectively. The results showed that the size of droplet had a power exponential relationship with the spray pressure. When the pressure exceeded 3 MPa, the change tended to be gentle; in presence of the spray pressure of 8 MPa, optimum atomization was achieved, over 90% of spray field droplets have particle sizes ranging from 20 to 100 μm, and the distribution of the size of droplet was more uniform. When the spray pressure reached 8 MPa and the diameter of nozzle pore was 2.4 mm, more than 70% of the target area's spray field concentration was above 0.04 kg/m2. After the field application by using a spray dust suppression device on the hydraulic support, the total dust and the respirable dust concentrations at the sampling points of the mining face significantly decreased, thus, the effect of dust control is obvious.

Oxidation of cellulosic fibers by the TEMPO system is highly efficient for obtaining micro/nano-sized fibrils. In this study, the dissolution degree related to the yield of products has been firstly and deeply investigated with treating bamboo pulps under various process conditions. Moreover, the dissolution behavior and mechanism for revealing the “phase transition” process of cellulosic fibers have been also studied. From the kinetic behavior results, it was found that the end dissolution degree of original pulps is almost fully controlled by the time-dependent TEMPO and especially NaOCl concentration. Meanwhile, the NaBr dosage and process temperature could also affect the dissolution rate. Based on the dissolution data, a two-stage dissolution kinetic model was firstly presented. According to the model, the difficulty of the dissolution process was evaluated.

The spraying dedusting technique using equipment that is mounted outside a roadheader is an important dust prevention measure in fully-mechanized excavation faces. In this study, ANSYS-FLUENT software was used for investigating the atomizing properties and the related variation rules of the nozzles with different orifice diameters (1.6 mm, 2.0 mm, 2.4 mm) under different spraying pressures from 1 MPa to 5.5 MPa. The conclusions are as follows: the relationship between the mean droplet size and spraying pressure can be fitted as a power function, as the spraying pressure increased, the variation of the droplet size tended to be small, and the uniformity degrees of the droplet size distribution reached the optimum level at a spraying pressure of 5 MPa. Under a spraying pressure of 5 MPa, the number of droplets in the target area increased greatly when a nozzle with an orifice diameter of 2.4 mm, the formed spray field exhibited the greatest spray concentration, which can wrap the cutting head effectively and provide the best performance with regard to dust suppression. Therefore, the use of a nozzle with an orifice diameter of 2.4 mm can achieve an optimal dust suppression performance under a spraying pressure of 5 MPa.

To determine the effect of air flowrate on pollutant dispersion pattern of coal dust particles at the fully mechanized mining face, the present study aims to reduce the dust concentration through adjusting the air flowrate parameter. Specifically, the CFD-DPM based numerical simulation is conducted to investigate the pollutant dispersion of coal dust particles subject to a variety of air flowrate parameters. Results indicate that the mean airflow velocity 90–230 m away from the air inlet corner on the leeward side is merely 12% of the airflow velocity at the air inlet; the high and low dust concentration boundaries associated with the footway's breathing zone and the transport coal route's breathing zone are 120 m and 150 m away from the advancing support on the leeward side, respectively; the dust concentration is relatively low when air flowrate stays between 2600 m3/min and 3000 m3/min, an increase of air flowrate leads to dust re-entrainment phenomenon, the maximum dust concentration in footway was higher at air flowrate of 2800 m3/min than at 2600 m3/min; field measurement is carried out by adjusting the air flowrate to 2600 m3/min, while measuring airflow velocity and dust concentration, the simulation results are accurate and effective.

In this paper, a rapid and facile method of preparing metal-oxide semiconductor precursor solution using sonochemistry technology is proposed. Compared with the traditional method (water bath above 60 °C for several hours), the efficiency of preparing solution is improved, because sonochemical reaction is found to accelerate the dissolution of solutes and the agitation of solution. The color comparison and thermal gravimetric and differential scanning calorimetry of solution confirme the formation of W-doped zinc tin oxide (WZTO) precursor solution with good performance. The effects of sonochemical reactions on the film structure, surface morphology, optical properties and chemical composition of WZTO thin films are analyzed by atomic force microscopy, X-ray diffraction, UV visible spectrum and X-ray photoelectron spectroscopy. The results show that the film has a smooth surface, an amorphous structure, a high transmittance and more M–O bonding. Hence, a rapid process of preparing WZTO solution (sonochemical treatment for 10 min) and fabricate TFT with high electron mobility (2.7 cm2 V−1 s−1) is established, while the corresponding mobility of the traditional method is 1.2 cm2 V−1 s−1. The results show that the sonochemical reaction can improve the efficiency of preparing solution by 1800% and it is a fast and efficient method for preparing precursor solutions.

Aiming to effectively suppress excessively high dust concentration around the drums during coal cutting and the related dust particle dispersion issues at a fully-mechanized mining face, the present study employed experiments, numerical simulations, and field measurements to carry out an in-depth investigation of the dust suppression performance of an external spraying system. Firstly, the atomization characteristics of the nozzles with optimized macro-atomization performances were tested. According to the experimental results, hybrid nozzles with an orifice diameter of 2.0 mm and an X-shaped diversion core (type-B nozzles) delivered the best overall atomization performances at a spraying pressure of 8 MPa; in this case, the spraying angle and the effective spraying range were approximately 81.9° and 2.56 m, respectively. Next, numerical simulations were conducted to assess the dust suppression performances of an external spraying system, using ANSYS Fluent software. The results showed that, when the nozzles were installed at an inclination angle of 30° and operated at a spraying pressure of 8 MPa, the spray field formed could cover the whole dust-producing region around the drum. Meanwhile, the spray field near the coal cutter drum was not affected by airflow, which prevented dust particles being dispersed by the airflow, leading to a mitigation of pollution. Finally, field testing at the No. 30106 mining face of the Shiquan Coal Mine indicated that the mean overall dust suppression efficiency could reach up to 90.10%, i.e. the dust particles at this fully-mechanized mining face were effectively settled. To conclude, the dust pollution issues at a fully-mechanized mining face during the coal cutting process were adequately addressed by the measures investigated here.

Background Mucositis is an inflammatory response of mucosal epithelial cells to the cytotoxic effects of chemotherapy and radiation therapy. To assess the comparative efficacy of honey for patients with cancer undergoing chemo/radiotherapy-induced oral mucositis through a systematic review and network meta-analysis. Methods A network meta-analysis was used to identify evidence from relevant randomized controlled trials (RCTs). We searched PubMed, Embase, and the Cochrane Library for publications up to November 2017. The prespecified primary efficacy outcome was the treatment effect of moderate-severe oral mucositis with honey. We performed subgroup analyses and meta-regressions according to the age group, cancer type, mucositis cause, honey type, control arm and type of assessment scale. Moreover, secondary efficacy outcomes were treatment completed, onset time of mucositis, swallowing diary, fungal colonization, bacterial colonisation and analgesic use. And, we did standardize meta-analyses using the random-effects model, later completing the random-effects network meta-analyses by different treatment/control arms. Results A total of 17 RCTs were eligible (22 analyses), involving 1265 patients and 13 arms. Honey treatment arm significantly increased the therapeutic effect of chemo/radiotherapy-induced moderate-severe oral mucositis (0.25, 0.14–0.46); significant efficacy was observed in a large proportion of subgroups. The meta-regression may have identified the causes of heterogeneity as the honey type (P = 0.038). Therefore, we need to perform further comparisons of difference in honey types and controls by network meta-analysis, and the results from network meta-analysis revealed that pure natural honey was superior in therapeutic effect (0.05, 0.01–0.46). For secondary outcomes, significant effect was found in decreasing onset time of mucositis (0.41, 0.08–0.73), while no increase in adverse effects was observed. The study is registered with PROSPERO (CRD42017070873). Conclusions The adjuvant treatment honey is effective and safe for patients with cancer undergoing chemo/radiotherapy-induced oral mucositis, especially applied pure natural local honey can be invoked as a first-line adjuvant therapy agent.

Aiming at addressing serious pollution in the No. 30106 fully mechanized coal mining face of Shiquan Coal Mine during coal cutting process, the spraying device between hydraulic supports was improved through the combination of experimental analysis, numerical simulation, and field measurement, and a novel wind-assisted centralized spraying dedusting device was developed. The newly developed device could make the formed spraying field more concentrated on the dust-producing source around the coal shearer’s drum, and thus significantly enhanced the spraying performance. According to numerical simulation results, the spraying performance reached the optimum at a hydraulic pressure of 8 MPa for the spraying device and an air pressure of 1 MPa for the pneumatic motor; under these optimal conditions, the droplet concentration in the spraying field around the coal cutter drum was as high as 24.85 g/m3, and the formed high-concentration spraying field could basically cover the whole section in the spraying field from coal wall to the support pillar. Field measured results revealed that, at a hydraulic pressure of 8 MPa and an air pressure of 1 MPa, the dust suppression rate around coal cutter driver reached up to 87.96%, suggesting that the developed wind-assisted centralized spraying dedusting device had remarkable dust suppression performance and could effectively improve the operating environment in the fully mechanized mining face.

Data Clustering algorithms are essential techniques to pattern recognition. While many clustering algorithms have been proposed, none of them could gain a desirable result on various pattern recognition problems. In this paper, an adaptive clustering ensemble algorithm based on stability feature selection and spectral clustering for data clustering is proposed. The paper chooses strong features by stability feature selection, aiming to improve the quality of clustering. LIMBO is then applied on dataset to engender ensemble instances via calculating the similarity of ensemble members, a proximity matrix could be formed. The cluster ensemble problem is then formalized as a combinatorial spectral clustering problem. Empirical studies on several benchmarks from UC Irvine Machine Learning Repository shows the favorites of the proposed algorithm compares to its competitors, and the promising results yields new inspiration of cluster ensemble and spectral clustering.

To improve the dust removal efficiency of external spray negative-pressure mist-curtain dust suppression devices, a multi-factor orthogonal experiment was designed and a numerical simulation was carried out for these types of devices. According to changes in the measurement factor values in the simulation results, the main factors affecting the negative-pressure suction effect of the device were obtained through analysis and ranked in the order: Nozzle installation position > Angle of the conical cover > Length of the conical cover; the significant analysis results were FA

In order to solve the problem of severe dust pollution in a tunnel during continuous mining effectively, this study used the external spraying method around a continuous miner and determined the optimal parameter settings via an experimental analysis, numerical simulation and field measurement. According to the experimental results, the optimal nozzle was firstly determined as a round-mouth nozzle with an X-type diversion core with a caliber of 2.4 mm (hereinafter the X-2.4 mm nozzle). Next, the numerical simulation results confirmed that the cutting head can be fully wrapped when the nozzle was installed at an outward inclination angle of 15°. At a spray pressure of 7 MPa, the formed spray field was almost unaffected by the airflow and could cover the dust-producing region fully, thereby achieving an effective dust settling process. Finally, the proposed external spraying technique was applied to the No.104 continuous mining face of the Jinjitan Coal Mine, Shanxi, China. Under optimal spraying conditions, the dust-suppression efficiency in the continuous mining face exceeded 90%, and the concentrations of respiratory dust at the tail of the scraper and at the driver’s operating position were 6.2 mg/m3 and 10.1 mg/m3 respectively. Therefore, the proposed solution can solve the problem of dust pollution in a tunnel effectively.

Aimed at effectively controlling coal dust pollution in the mining face of a coal mine, this study first conducted a theoretical analysis and then combined a spraying experiment and a numerical simulation to perform an in-depth examination of the atomizing characteristics and dust suppression performance of a coal cutter external spraying device. Based on the experimental spraying results, the optimal nozzle was determined to be a pressure round-mouth nozzle with an X-shaped core. The characteristics of the spray fields from nozzles of different calibers (1.6, 2.0 and 2.4 mm) at different spraying pressures (2, 4, 6 and 8 MPa) were then analyzed. It was found that the droplet concentration in the spray field increased with increasing spraying pressure and nozzle caliber. The droplet diameter was mainly dependent on the spraying pressure and varied more slowly with increased spraying pressure. At a spraying pressure of 8 MPa, the spray field formed could achieve effective dust suppression; specifically, the droplet concentration in the spray field was mostly more than 15 g/m3, and the droplet size was mainly distributed in the range of 30-100 μm. When using a 2.4 mm caliber nozzle, the dust concentration measured around the coal cutter operator was reduced to 87.21 mg/m3 under a spraying pressure of 8 MPa, suggesting adequate dust suppression.

Aluminum electrolytic capacitors are widely used in the converter systems of wind turbines. Though vital the capacitors are they are the “weak link” in wind turbines. Accurately predicting its remaining useful life is of great importance. However, traditional estimation methods are only applicable to the static operating conditions. This paper proposed an estimation method by introducing the virtual lifetime instead of the actual operating time to predict the equivalent series resistance (ESR) as well as remaining useful life of capacitor. Compared with measured ESR values, the model is reasonable for complicated operating conditions and is of practical significance in the prediction of capacitor's remaining useful life.

The effects of Si doping on the structural properties of a high-quality AlN layer grown on a trench-patterned AlN/sapphire by metalorganic vapor phase epitaxy (MOVPE) were systematically studied. With a high Si doping concentration, void formation became much slower than that in undoped AlN film. This phenomenon was attributed to the anti-surfactant effect of Si in the growth process. Moreover, as the Si doping concentration increased, compressive stress was significantly relaxed in Si-doped AlN films. A high Si doping concentration of 1×1018 cm−3 was successfully achieved for AlN grown at 1500 °C.

The strong demand for high-efficiency light-emitting diodes in the deep-ultraviolet region and for sensors has led to renewed interest in the growth of high-quality AlN. However, the growth of high-quality AlN is extremely difficult owing to the low surface migration rate of Al adatoms. In this study, the effects of the carrier gas ratio and growth temperature on the growth rate of AlN are examined with the aim of optimizing the growth conditions of high-temperature AlN. AlN epilayers were grown on sapphire substrates by metal-organic vapor phase epitaxy (MOVPE) at a growth temperature of 1430 °C with a medium-temperature AlN layer grown at 1100 °C. A combination of H2 and N2 was used as the carrier gas in the growth of AlN, and the ratio of H2 to N2 in the carrier gas was changed to examine its effect on the growth of AlN. Under all growth conditions, crack-free and smooth surfaces at the atomic level with an extremely small tilt were obtained. The growth rate decreased with increasing growth temperature and ratio of H2 in the carrier gas. This suggests that the high temperature and the H2 carrier gas inhibit the adsorption of atoms. Also, with increasing ratio of N2 in the carrier gas, the radius of curvature of the AlN layer increased and the compressive strain decreased. The reduction of compressive strain and increase in curvature of the AlN layer were due to an increase in the number of dislocations. (© 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The growth condition of AlN buffer layer has been studied in order to fabricate a high-quality AlN layer on a sapphire substrate. The growth of high-quality AlN is extremely difficult due to the weak surface migration of Al adatoms. Therefore we have focused on the AlN buffer layer, and examined the growth condition while controlling the thickness and growth temperature. The crystalline quality of the AlN layer grown on an AlN buffer layer at a growth temperature of 1250 °C was improved, and the full width at half-maximum (FWHM) value of the X-ray rocking curve (XRC) obtained for (0002) and (10-10) diffractions were 138 and 464 arcsec, respectively. Moreover, AlOxN1-x was formed when the AlN buffer layer was grown at a high temperature (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The paper proposes a complete energy harvesting solution integrated with a low-loss AC/DC rectifier and a high efficiency low dropout regulator (LDO) optimized for micro piezoelectric energy harvester. The AC/DC module converts AC into DC and then supplies power for the following LDO circuit module, through which the whole chip can obtain a stable 3.3V output voltage. A dynamic compensation mechanism is presented to improve the loop stability of LDO, which is easier to achieve high phase margin than traditional compensation strategy. The simulation results of LDO indicate that the typical dropout is 0.4mV with 1mA load current and 61mV with 150mA load current respectively, and the typical voltage line regulation error is 0.025%/V. In addition, the typical load regulation error was 0.00018%. The results demonstrate that the proposed chip meets the requirements of power supply for wireless sensor node (WSN).

The aim of the study is to utilize electrical impedance tomography (EIT) to guide positive end-expiratory pressure (PEEP) and to optimize oxygenation in patients undergoing laparoscopic abdominal surgery. Fifty patients were randomly assigned to the control (C) group and the EIT (E) group (n = 25 each). We set the fraction of inspired oxygen (FiO2) at 0.30. The PEEP was titrated and increased in a 2-cm H2O stepwise manner, from 6 to 14 cm H2O. Hemodynamic variables, respiratory mechanics, EIT images, analysis of blood gas, and regional cerebral oxygen saturation were recorded. The postoperative pulmonary complications within the first 5 days were also observed. We chose 10 cm H2O and 8 cm H2O as the “ideal” PEEP for the C and the E groups, respectively. EIT-guided PEEP titration led to a more dorsal shift of ventilation. The PaO2/FiO2 ratio in the E group was superior to that in the C group in the pneumoperitoneum period, though the difference was not significant (330 ± 10 vs 305.56 ± 4 mm Hg; P = 0.09). The C group patients experienced 8.7% postoperative pulmonary complications versus 5.3% among the E group patients (relative risk 1.27, 95% confidence interval 0.31–5.3, P = 0.75). Electrical impedance tomography represents a new promising technique that could enable anesthesiologists to assess regional ventilation of the lungs and optimize global oxygenation for patients undergoing laparoscopic abdominal surgery.

The growth conditions and interface microstructure of AlN on sapphire grown using a nucleation layer (NL) have been studied. The AlN layer with NL-AlN grown at 1100 °C exhibits a smooth surface morphology. The epilayer has a small amount of tilting but the twisting is large. For the AlN layer with NL-AlN grown at 1250 °C, the twisting is reduced, but the surface is rough owing to the mixing of crystallographic polarity. The origins of AlN inversion domains are discussed by considering the microstructures observed by transmission electron microscopy (TEM), with the ultimate aim of growing a high-quality AlN layer.

High-crystalline-quality epitaxial films of wurtzite AlN were grown by metalorganic vapor phase epitaxy (MOVPE) and hydride vapor phase epitaxy (HVPE). The lattice strain of the films was analyzed by high-resolution X-ray diffraction and the E2 (high)-phonon frequency was observed by Raman scattering. Data analysis for wide ranges of lattice strains and phonon-peak shifts yielded a precise biaxial stress coefficient of this phonon mode, -4.04±0.3 cm-1/GPa. Furthermore, the deformation potential constant was accurately determined from the biaxial stress coefficient.