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This experiment was conducted to assess the comparative effects of dietary antibiotics and oregano essential oil (OEO) addition on growth performance, antioxidant status and intestinal health of broilers. A total of 384 one-day-old broilers were randomly allocated to 4 treatments with 6 replicates of 16 broilers each. The 4 treatments were: an antibiotic-free control diet (control), control + 20 mg/kg colistin sulfate and 20 mg/kg virginiamycin (antibiotics), control + 200 mg/kg natural oregano essential oil (NOEO), and control + 200 mg/kg synthetic oregano essential oil (SOEO). The experiment lasted for 42 d. Results showed that birds fed with OEO had greater (P < 0.05) average daily gain (ADG) and lower (P < 0.05) feed conversion ratio (FCR) than those fed with control diet during d 1 to 21. Besides, birds fed with NOEO had the greatest (P < 0.05) ADG in the four groups during d 22 to 42. The serum oxidative stress parameters showed that OEO improved (P < 0.05) the activities of glutathione peroxidase (GSH-Px), superoxide dismutase (SOD) and glutathione reductase (GR) of birds on day 21 and the activity of total antioxidant capacity (T-AOC) of birds on d 42. Relative to control, NOEO increased (P < 0.05) the activity of T-AOC in jejunum and decreased (P < 0.05) the level of malondialdehyde (MDA) in serum and jejunum. Moreover, OEO supplementation increased (P < 0.05) the concentrations of sIgA in duodenum and jejunum, Lactobacillus and total anaerobes in cecum, as well as activities of trypsin, chymotrypsin, lipase and amylase in duodenum, but restrained (P < 0.05) the amount of Escherichia coli. The NOEO supplementation increased (P < 0.05) total anaerobes of broilers on d 42 and the villus height to crypt depth ratio (VH/CD) of ileum. These results suggest that OEO improved antioxidant status and intestinal health of broilers which contributed to the growth performance improvement of broilers. Dietary OEO supplementation can be a promising alternative to antibiotic growth promoters for improving poultry production.

Furrow diking is a type of conservation tillage practice that is widely used throughout the world and has been proved to be effective for preventing runoff and soil loss. However, it is not easy to maintain a stable conservation effect of furrow diking in various environments. Few studies have focused on the effects of rainfall and slope on the integrity and conservation efficiency of furrow diking. Therefore, simulated rainfall experiments were conducted with four rainfall intensities (30 mm/h, 60 mm/h, 90 mm/h and 120 mm/h) and three slopes (2, 4 and 8°) to study the effects of rainfall intensity and slope on soil and runoff production of furrow diking as well as its conservation efficiency. The conservation efficiencies were obtained by comparing furrow diking with up-down slope ridges. The result indicated that as rainfall intensity and slope increased, furrow diking dams may suffer from runoff overtopping resulting in damage and ultimate collapse. During this process, runoff and soil loss increased rapidly, severe rill erosion developed on dams resulting in the loss of the ability of furrow diking to store rainwater and sediment and obvious declines of water and soil conservation efficiencies. This paper established empirical equations to estimate the conservation efficiency of furrow diking under undamaged and damaged conditions. An empirical equation was also presented to estimate the critical rainfall and slope conditions that may cause overtopping, damage or collapse of dams in order to guide the implementation of furrow diking and predict its conservation efficiency.

Land-use and climate changes have impacts on hydrological processes for river basin. In this study, a multi-scenario ensemble streamflow forecast (MESF) method is developed for analyzing the streamflow variation under considering climate and land-use changes, through incorporating CA-Markov model, global climate model (GCM) and Soil and Water Assessment Tool (SWAT) model within a general framework. The advantages of MESF are as follows: (i) it can simultaneously assess the impacts of land-use and climate changes on streamflow; (ii) it can obtain the possible trend and the range of future streamflows through ensemble forecast under multiple scenarios; (iii) based on analysis of streamflow processes under extreme scenarios, it can examine the effects of key factors on streamflow. The MESF method is applied to the upper reaches of the Amu Darya River Basin in Central Asia. Totally 72 scenarios, under different land-use patterns, GCMs and Representative Concentration Pathways (RCPs), are analyzed. Ensemble forecast results reveal that (i) during 2021–2050, the average annual precipitation and the average annual temperature would both increase, but the mean annual streamflow would decrease; (ii) compared to the impact of land-use change, climate change has more obvious effects on the streamflow (with contribution of 78.8%–98.7%); (iii) among all factors of land-use change, glacier melting triggered by climate warming is the most prominent factor; (iv) the peak flow in one year would have a tendency to shift from summer to spring due to the rising temperature and the speeding up snow melt.

An effective pulse frequency modulation (PFM) control strategy compatible with the charge control is designed for Single Inductor Multiple Outputs (SIMO) DC-DC to deal with its unbalanced loads. Different from the traditional charge control strategy in PFM, it can function without buffer time that degrades the circuit efficiency. Simulation results show that the proposed PFM control strategy can steadily regulate the load-unbalance outputs, even in no load condition. Meanwhile, the PWM/PFM mode conversion can also be achieved.

In this study, an integrated CCA-RF-FA framework (abbreviated as CRFF) is developed for analyzing the streamflow variation in the mountainous watershed. CRFF incorporates cross-correlation analysis (CCA), random forest (RF), and factorial analysis (FA) within a general framework. CRFF can identify the time lag effect in the runoff mechanism (both rainfall and glacier/snow meltwater), tackle the problem of the simulation performance degradation caused by the time lag effect, as well as investigate the individual and interactive effects of meteorological and physical factors on runoff simulation. CRFF is applied to the Amu Darya River Basin (ADRB), a typical mountainous watershed in Central Asia. Bayesian neural network (BNN) and stepwise cluster analysis (SCA) are used for illustrating the advantage of RF in streamflow simulation. The main findings reveal that (i) compared with BNN and SCA, RF has the better simulation capacity; (ii) the time lag effect of heat conditions such as temperature (T) and shortwave radiation (SWR) is weak, with the lag time being less than 30 days; the time lag effect of the precipitation conditions such as snow precipitation rate (SPR) is strong, with a lag time ranging from 30 days to 90 days; (iii) in snow-melting, non-melting and entire periods, T has the dominant impact on the variation of the runoff in ADRB; (iv) the interaction of T and SWR has important effect on the streamflow; SPR can still considerably affect the runoff generation in non-melting period.

An integrated PCA-SCA-ANOVA framework (abbreviated as PSAF) is advanced to analyze the impacts of multiple factors on water-flow variation. PSAF incorporates techniques of principle component analysis (PCA), stepwise-cluster analysis (SCA), and analysis of variance (ANOVA) within a general framework. PSAF cannot only quantify the sensitivity of water flow to individual and interactive factors, but also simulate water flow effectively under different scenarios. A case study of the Aral Sea is conducted to demonstrate the effectiveness and practicability of PSAF. The Nash-Sutcliffe coefficients for calibration and validation are 0.96 and 0.84, respectively. Results reveal that the key impact factors that cause the variability of water flow from the Amu Darya into the Aral Sea are runoff in the upper reach (contributing 53%), agricultural water use (occupying 23%) and water storage in reservoirs (occupying 3%). Results also disclose that runoff in the upper reach and agricultural water use have obvious interaction; the high level of runoff in the upper reach can enhance the negative effects of agricultural water use on water flow. In the future, to recover the water flow from the Amu Darya into the Aral Sea to the level of that in the 1990s (about 8 km3), the decreasing rates of annual agricultural water use and water storage in reservoirs should be controlled at 1.0% and 0.5%, respectively. The findings are helpful for supporting water resources management and restoring the ecological environment of the Aral Sea.

In this study, an interval double-sided chance-constrained programming (abbreviated as IDCP) method is developed for dealing with uncertainties expressed as interval values and double-sided randomness in both left- and right-hand sides of constraints. The method is applied to planning urban eco-environmental management of Shenzhen (China), where various eco-environmental indicators are used for ensuring ecological security. Through solving the IDCP-based urban eco-environmental management (abbreviated as IDCP-UEM) model, solutions for land-use pattern, industrial structure, system benefit, and ecosystem service value under different probability levels (i.e. p level) have been generated. Then, the conversion of land use and its effect at small regional extent (abbreviated as CLUE-S) model is used for analyzing the spatial characteristic of land-use pattern, which can further optimize the results from the IDCP-UEM model through providing the spatial allocation of land resources. Results reveal that (i) uncertainties existed in the urban ecosystem have significant impacts on system benefit and land-use pattern; (ii) at the end of the planning horizon, the area of forest land would be raised and the expansion of construction land would slow down; (iii) industries of electronic information and machinery manufacturing should be developed because they contribute higher benefit and discharge relatively less pollutant than other industries; (iv) system benefit would be raised and pollutant emissions (e.g., chemical oxygen demand, ammonia nitrogen, and solid waste) would be mitigated over the planning horizon. The findings are helpful for decision makers to gain insights into tradeoffs between eco-environmental protection and urban-economic development.

Copula functions are widely used in multivariate hydrological risk assessment. Incorporation of uncertainty analysis within copula functions can improve the degree of reliability to risk inference. In this study, a Bayesian-copula-based frequency analysis (BCFA) method is developed for supporting multivariate hydrological risk assessment under uncertainty, through integrating copula functions and Markov Chain Monte Carlo (MCMC) into a general framework. BCFA is not only capable of identifying multivariate characteristics of hydrological extreme events, but also useful for assessing multiple uncertain parameters in their dependence structure. BCFA is applied to a real case of flood risk assessment in the Naryn River, a typical high-mountain watershed with high frequency snowmelt flood in Central Asia. Major findings can be summarized: (i) the uncertainty range of joint distribution is mainly influenced by the value of flood variable and the selection of copula function, where the uncertainty range would decreases along with flood variable value; (ii) in a same flood event, the probability of both flood duration and flood volume reaching extreme large values is highest, and the probability of either flood peak or flood duration exceeding a certain threshold is highest; (iii) high peak flows (large than 1828.4 m3/s) are usually accompanied with flood durations less than 24.4 day or flood volumes less than 17.6 × 103 m3·d/s. The findings are helpful for providing decision support of flood management and disaster prevention.

To evaluate the effects of splash erosion on crops, throughfall and splash detachment were measured in different crop-growth stages and rainfall intensities under corn and soybean cover. The relation between splash detachment under the crop canopy and leaf area index and throughfall intensity was analyzed. The characteristics of the spatial distribution of splash detachment under the crop canopy were discussed as well. The results indicated that, compared with bare soil, the average splash detachment rate under the canopy during corn growth was reduced from 77% to 43%, with an average of 68% approximately, while a soybean canopy can reduce the splash detachment rate from 77% to 48% with an average of 61% approximately during the growth stage. The splash erosion detachment rate increased significantly with increasing leaf area index and rainfall intensity. The throughfall was concentrated in the centers of rows as crop grows, and a sharp increase in the splash detachment rate was caused by concentrations of throughfall under the canopy, which resulted in uneven distribution of splash detachment. The spatial distributions of splash detachment depended on the spatial distributions of throughfall under the crop canopy. The change in throughfall intensity under the canopy was the main reason for the variation in splash detachment. The reduction of kinetic energy because of interception by the crop canopy contributed to a decrease in splash erosion. However, large raindrops formed at the tips and edges of leaves can generate substantial erosion, and this part of the splash may become the main portion of splash erosion under the canopy. These results indicated that continuous and concentrated raindrops impacted splash detachment and caused its uneven distribution under crop cover.

The aim of this study was to investigate the association between three common SNPs (-1082A/G, -819T/C, and -592A/C) in the interleukin 10 (IL-10) gene, and the development of coronary artery disease. Between January 2013 and December 2014, 272 patients with coronary artery disease and control subjects (each) were recruited for this study from the Huaihe Hospital of Henan University. The IL-10-1082A/G, -819T/C and -592A/C gene polymorphisms were analyzed using a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) assay. Logistic regression analyses revealed an association between the AA and GA+AA genotypes of IL-10-1082G/A and an elevated risk of coronary artery disease, compared to the GG genotype [adjusted odds ratio (OR) = 2.31 and 1.49; 95% confidence interval (CI) = 1.29-4.19 and 1.04-2.12, respectively]. The AG+GG genotype was associated with a moderately increased risk of coronary artery disease in smokers (adjusted OR = 2.74; 95% CI = 1.01-3.01). In conclusion, the AA and GA+AA genotypes of IL-10-1082G/A were associated with an elevated risk of coronary artery disease; the IL-10-1082G/A gene polymorphism also interacted with the tobacco smoking habits, contributing to the development of coronary artery disease.

In this paper the problem of wave propagation over an adjoining-type of composite submerged poroelastic breakwater with different materials is investigated theoretically. A new analytical solution for describing the dynamic response of wave interaction with poroelastic structures is presented. A set of simultaneous equations is developed and numerically solved in order to produce a general solution for each region subject to matching boundary conditions. The present paper focuses on the changes of influence parameters such as different component widths of the composite breakwater, permeability coefficients, composite materials and configurations of breakwater on wave variations.

The aim of this study was to investigate the protective effect of necrostatin-1 on myocardial tissue of acute myocardial infarction (AMI) rats and to provide a basis for necrostatin-1 for the treatment of acute myocardial infarction. AMI rats (45) were established by ligating the anterior descending branch of the left coronary artery. The rats were randomly divided into the model group and necrostatin-1 low-dose and high-dose groups. The control group rats (15) underwent the sham operation. The rats in the necrostatin-1 low-dose and high-dose groups were injected with 1 and 4 mg/kg necrostatin-1, respectively, via the tail vein. The rats in the control and model groups were injected with isometric dimethyl sulfoxide, once daily, for 3 consecutive days. The levels of RIP1 and RIP3 mRNA and phosphorylated protein in the myocardial tissue of rats were detected by real time polymerase chain reaction and western blot. The myocardial infarct size was detected by tetrazolium chloride. Compared with that in the control group, the levels of RIP1 and RIP3 mRNA and phosphorylated protein significantly increased in the myocardial tissue of model group rats, necrostatin-1 low-dose group, and high-dose group. The levels of RIP1 and RIP3 mRNA and phosphorylated protein in the myocardial tissue of rats in the necrostatin-1 low-dose and high-dose groups decreased significantly compared with that in the model group (P < 0.05). The levels of RIP1 and RIP3 mRNA in the myocardium of the high-dose group rats were significantly lower than those of the low-dose group rats (P < 0.05). The myocardial infarct sizes significantly increased in model, low-dose, and high-dose group rats. The apoptotic level of myocardial cells significantly decreased in the low-dose group and high-dose group after treatment with necrostatin-1 but was still higher than that of the control group (P < 0.05). In conclusion, necrostatin-1 can inhibit myocardial tissue apoptosis and necrosis in acute myocardial infarct rats and has a protective effect on myocardial tissue.

Pentacene organic thin-film transistors (OTFTs) with fluorinated high-κ HfLaO as gate insulator were fabricated. The dielectrics were prepared by sputtering method and then annealed in N2 or NH3 at 400°C. Subsequently, the dielectrics were treated by fluorine plasma for different durations (100, 300, and 900 s). The N2 and NH3-annealed OTFTs with a 100-s plasma treatment achieve a carrier mobility of 0.62 and 0.66 cm2/V·s, respectively, which are higher than those of the OTFTs without plasma treatment (0.22 and 0.41 cm2/V·s). Moreover, the plasma-treated OTFTs realize better 1/f noise characteristics than those without plasma treatment. The improved performance is due to passivation of the dielectric surface by plasma-induced fluorine incorporation. However, for longer time (300 and 900 s) of plasma treatment, the performance of the OTFTs deteriorates in terms of carrier mobility and 1/f noise characteristics due to increased plasma-induced damage of the dielectric surface. The morphology of the pentacene film grown on the HfLaO gate insulator was characterized by SEM. It reveals that the pentacene film has larger grain size and smoother surface on the HfLaO dielectric (for both annealing gases) with 100-s plasma treatment than the others (0, 300, and 900 s). Finally, AFM characterization of the HfLaO film also confirms the damaging effect of excessive plasma treatment on the dielectric.

A polymer thin-film transistor (PTFT) based on poly(3-hexylthiophene) (P3HT) is fabricated by a spin-coating process and characterized. Its bias-stress-induced instability during operation is investigated as a function of time and temperature. For negative gate-bias stress, the carrier mobility remains unchanged, the off-state current decreases, and the threshold voltage shifts toward the negative direction. On the other hand, for negative drain-bias stress, the carrier mobility decreases slightly, the off-state current increases, and the threshold voltage shifts toward the positive direction. The threshold shifts under gate- and drain-bias stresses are observed to be logarithmically dependent on time, and the decay rate of the threshold-voltage shift is independent of temperature. The results suggest that the origin of the threshold-voltage shift upon negative gate-bias stress is predominantly associated with holes trapped within the gate dielectric or at the interface, while time-dependent charge trapping in the deep trap states and creation of defect states in the channel region are responsible for the drain-bias stress effect on the PTFT.

Pentacene organic thin-film transistors (OTFTs) with high-κ HfLaO as gate insulator were fabricated. HfLaO film was prepared by sputtering method. To improve the film quality, the dielectric was annealed in N2, NH3, or O2 at two temperatures, i.e., 200°C and 400°C, respectively. The I-V characteristics of the OTFTs and C-V characteristics of corresponding organic capacitors were measured. The OTFTs could operate at a low operating voltage of below 5 V, and the dielectric constant of the HfLaO film could be above ten. For all the annealing gases, the OTFTs annealed at 400°C achieved higher carrier mobility than their counterparts annealed at 200°C (with the one annealed in NH3 at 400°C showing the highest carrier mobility of 0.45 cm2/V · s), which could be supported by SEM images which indicate that pentacene tended to form larger grains on HfLaO annealed at 400°C than on that annealed at 200°C. The C-V measurement of the organic capacitors indicated that the localized charge density in the organic semiconductor/oxide was lower for the 400°C annealing than for the 200°C annealing. Furthermore, through the characterization of gate current leakage, HfLaO film annealed at 400°C achieved much smaller leakage than that annealed at 200°C. Since the maximum processing temperature of ITO glass substrates is around 400°C, this study shows that 400°C is suitable for the annealing of HfLaO film in high- performance OTFTs on glass substrate.

The influence of octadecyltrichlorosilane (OTS) surface modification of a gate dielectric on the electrical properties of polymer thin-film transistors based on poly(3-hexylthiophene) is investigated by using capacitance-voltage analysis. Results show that surface modification using OTS can effectively increase the field-effect mobility in the saturation region by almost two orders of magnitude to 2 × 102 cm2/V · s and improve the stability of the devices under gate-bias stress. Capacitance-voltage (C-V) analysis for the metal-polymer-oxide-silicon structures indicates that the frequency-dependent behavior of the C-V characteristics is related to the long relaxation time of the charge carriers in the polymer bulk rather than the trapping effect at the dielectric/ polymer interface, and the performance improvement of the de vices is attributed to a reduction of localized charges in the poly mer bulk.

Ordered mesoporous polymer/silica and carbon/silica nanocomposites have been successfully prepared with triblock copolymer Pluronic F127 using diblock copolymer poly(dimethylsiloxane)–poly(ethylene oxide) (PDMS–PEO) as co-template. The structure of resulting mesoporous materials has been characterized by small-angle X-ray scattering (SAXS), transmission electron microscopy (TEM), and nitrogen-sorption measurements. The framework composition is also studied by the combination of thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR), Raman spectra and wide-angle X-ray diffraction (WXRD). Experiments show that body-centered cubic (space group Im 3 ¯ m ) mesoporous polymer/silica and carbon/silica nanocomposite with large pore size have been obtained. The incorporation of PDMS–PEO can reduce the framework shrinkage and dramatically enlarges the pore sizes of the materials without evident effect on the BET surface areas. This simple one-pot route provides a pathway for large-scale convenient synthesis of polymer/silica and carbon/silica nanocomposites.

Polymer thin-film transistors (PTFTs) based on poly(2-methoxy-5-(2′-ethyl-hexyloxy)-1,4-phenylene vinylene) (MEH-PPV) semiconductor are fabricated by spin-coating process and characterized. In the experiments, solution preparation, deposition and device measurements are all performed in air for large-area applications. Hysteresis effect and gate-bias stress effect are observed for the devices at room temperature. The saturation current decreases and the threshold voltage shifts toward the negative direction upon gate-bias stress, but carrier mobility hardly changes. By using quasi-static C–V analysis for MOS capacitor structure, it can be deduced that the origin of threshold-voltage shift upon negative gate-bias stress is predominantly associated with hole trapping within the SiO2 gate dielectric near the SiO2/MEH-PPV interface due to hot-carrier emission.

Polymer thin-film transistors based on poly(2-methoxy-5-(2'-ethyl-hexyloxy)-1,4-phenylene vinylene) have been fabricated by spin-coating process and characterized. The electrical characteristics of the devices stored in dry air show obvious degradation with a smaller mobility due to oxygen effect, and lower threshold voltage. The devices present good optical response in low-light condition and optically induced memory effects, demonstrating their use as promising smart light-detection devices. Moreover, solution preparation, deposition and device measurements have been all performed in the air for the purpose of large-area applications.

The optical characteristics of barium–strontium titanate–niobate (Ba1−xSrxNbyTi1−yO3) thin-film resistor are investigated and the effects of annealing gas and annealing temperature on photoelectrical properties are studied. Experimental results show that Ba1−xSrxNbyTi1−yO3 thin films are highly sensitive not only to visible light, but also to ultraviolet light. As compared to N2-annealed devices, O2-annealed devices have higher photosensitivity and lower dark current. Moreover, the photosensitivity of the O2-annealed devices is reduced for higher annealing temperature. Based on scanning electron microscope (SEM) study and grain-boundary theory, it can be concluded that 400 °C in O2 is the optimal annealing condition, which can give a photosensitivity as high as 8400% to visible light and 5500% to ultraviolet light.

Barium strontium titanate (BST) thin-films deposited on a SiO2/Si substrate by argon ion-beam sputtering technique were annealed at 400, 500 and 600 °C in oxygen for 30 min, respectively, and were used to fabricate integrated parallel-plate capacitors by standard integrated-circuit technology. These capacitors can achieve tunability greater than 60% at an applied dc voltage of 2 V and a frequency of 100 kHz at room temperature. Considering tunability, loss factor and hysteresis effect, the BST thin-film annealed at 500 °C is superior for making tunable microwave integrated capacitors. The effects of annealing treatment in oxygen on the tuning properties of the thin-film capacitors are analyzed, and the results indicate that the tunability is strongly dependent on both oxygen vacancies and negatively charged oxygen, trapped at the grain boundary and/or at the electrode/dielectric interface.

Nb-doped Sr 0.98 La 0.02 TiO 3 thin-film resistor is fabricated on a SiO 2 /Si substrate by argon ion-beam sputtering technique. Photo- and thermal sensing characteristics of the thin-film resistor are investigated, and the results show that besides superior sensitivity to visible light, the thin-film resistor has good thermal sensitivity with negative temperature coefficient from room temperature to 200 °C, and a maximum value of −6.0%°C −1 at 30 °C. With increasing Nb concentration, the photoconductive gain of the thin-film resistor increases, while the temperature coefficient firstly decreases, and then increases. It is proposed that the effects of Nb on thermal sensitivity should be closely related to the grain-boundary defects and impurities of the film, while the effects of Nb on photo-sensing should be associated with the acceptor defects in the grain boundaries.

Strontium titanate–niobate (SrNb x Ti 1− x O 3 ) film deposited on SiO 2 /Si substrate by argon ion-beam sputtering technique is used to fabricate thin-film resistors by standard integrated-circuit technology. Effects of annealing conditions on their humidity-sensing characteristics were studied. Four cases were considered: 400 °C 20 min in N 2 ; 400 °C 20 min, 400 °C 4 h and 600 °C 4 h in O 2 . Experimental results showed that, as compared to the N 2 -annealed device, the O 2 -annealed devices have higher humidity sensitivity and faster response. Based on scanning electron microscope (SEM) study and adsorption-isotherm analysis, it can be concluded that oxygen annealing is helpful for grain growth, thus resulting in a higher porosity of the film. Among the four cases, 400 °C 4 h in O 2 is the best annealing condition, which gives rise to the highest porosity and an appropriate pore-volume distribution for improving the humidity sensitivity.

Pentacene organic thin-film transistors (OTFTs) with HfLaO high-κ gate dielectric were fabricated. The dielectric was prepared by a sputtering method and then annealed in N2, NH3, O2, or NO at 400 °C. The carrier mobility of the NH3-annealed OTFT could reach 0.59 cm2/V · s, which is higher than those of the other three devices. Moreover, the NH3-annealed OTFT obtained the smallest subthreshold swing of 0.26 V/dec among them. Furthermore, 1/f noise measurement indicated that the NH3-annealed OTFT achieved the smallest 1/f noise. All these should be attributed to the improved interface between the gate dielectric and the organic semiconductor associated with the passivation effects of the NH3 annealing on the dielectric surface.

Pentacene OTFTs with HfLaO or HfO 2 as gate dielectric were fabricated. The dielectrics were prepared by sputtering method and then annealed in NH 3 at 400 oC. The k value for the HfLaO and HfO 2 films amounted to 12.3 and 11.8 respectively. Both of the OTFTs could operate with a supply voltage of -5 V. The mobility of the OTFT with HfLaO gate dielectric was 0.688 cm2/Vs, which was much higher than that of the OTFT with HfO 2 gate dielectric. Moreover, the HfLaO-based OTFT obtained smaller sub-threshold swing, larger drive current and larger on/off current ratio than the HfO 2 -baesd OTFT. The superior performance of the HfLaO-based OTFT is due to its better interfacial characteristics between the dielectric and the organic semiconductor. SEM images revealed that the pentacene film on HfLaO was more uniform and its grains were larger. C-V measurement indicated that Au-pentacene-HfLaO-Si structure displayed less hysteresis than Au-pentacene-HfO 2 -Si structure.

OTFTs with P3HT as organic semiconductor and HfTiO as gate dielectric have been studied in this work. The HfTiO dielectric film was prepared by RF sputtering of Hf and DC sputtering of Ti at room temperature. Subsequently, the dielectric film was annealed in an NH 3 or N 2 ambient at 200 °C. Then a layer of OTS was deposited by spin-coating method to improve the surface characteristics of the gate dielectric. Afterwards, P3HT was deposited by spin-coating method. The OTFTs were characterized by I-V measurement and 1/f noise measurement. The OTFT with gate dielectric annealed in NH 3 displays higher carrier mobility, smaller threshold voltage, smaller sub-threshold swing, and lower 1/f noise level than the OTFT annealed in N 2 . Moreover, the HfTiO dielectric film annealed in NH 3 shows higher dielectric constant. In summary, HfTiO film annealed in NH 3 at low temperature is a promising candidate to act as the gate dielectric of high-quality low-voltage OTFTs.

Polymer thin-film transistors (PTFTs) based on MEH-PPV semiconductor are fabricated by spin-coating process and characterized. Gate-bias and drain-bias stress effects at room temperature are observed in the devices. The saturation current decreases and the threshold voltage shifts toward negative direction upon the gate-bias stress. However, the saturation current increases and the threshold voltage shifts toward positive direction upon the drain-bias stress. For variable bias stress conditions, carrier mobility is almost unchanged. The results suggest that the origin of threshold-voltage shift upon negative gate-bias stress is predominantly associated with holes trapped within the SiO2 gate dielectric or at the SiO2/Si interface due to hot-carrier emission under high gate-bias stress, while time-dependent charge trapping into the deep trap states in the channel region is responsible for the drain-bias stress effect in the PTFTs.

Barium strontium titanate (Ba/sub 1-x/Sr/sub x/TiO/sub 3/) thin-film resistor is fabricated on a SiO/sub 2//Si substrate by argon ion-beam sputtering technique. Thermal sensitivity characteristics of the resistor are investigated, and the results show that the thin-film resistor has good thermal sensitivity with negative temperature coefficient. Moreover, the effects of annealing condition on thermal sensing properties of the resistor are studied.