Search

Additional file 1: Table S1. List of primers used in this paper. Figure S1. IPA facilitated the proliferation of irradiated HIEC-6 cells and MODE-K cells. Figure S2. Oral gavage of IPA ameliorates TBI-associated hematopoietic system injury. Figure S3. IPA administration improves GI tract function after total abdominal irradiation. Figure 4. IPA protects against radiation toxicity in mouse models without accelerating tumor growth. Figure 5. IPA treatment changes irradiation-shaped intestinal bacterial structure at day 6 after TAI. Figure 6. IPA preserves irradiation-shifted enteric bacterial composition at day 12 after TAI. Figure 7. Impact of antibiotics (ABX) and IPA on GI tract function after total abdominal irradiation. Figure 8. TAI changes the protein expression profile of small intestine. Figure 9. ACBP contributes to the protective function of IPA toward irradiation via PXR. Figure 10. ACBP or PXR inhibition blocked the protective function of IPA toward irradiation. Figure 11. Photographs of the lead shielding apparatus used in this study. The left photograph showed the lead shielding without lid, and the right photograph showed the lead shielding with lid

ZnO, as a wide-band gap semiconductor, has recently become a new research focus in the field of ultraviolet optoelectronic semiconductors. Laser molecular beam epitaxy (L-MBE) is quite useful for the unit cell layer-by-layer epitaxial growth of zinc oxide thin films from the sintered ceramic target. The ZnO ceramic target with high purity was ablated by KrF laser pulses in an ultra high vacuum to deposit ZnO thin film during the process of L-MBE. It is found that the deposition rate of ZnO thin film by L-MBE is much lower than that by conventional pulsed laser deposition (PLD). Based on the experimental phenomena in the ZnO thin film growth process and the thermal-controlling mechanism of the nanosecond (ns) pulsed laser ablation of ZnO ceramic target, the suggested effective ablating time during the pulse duration can explain the very low deposition rate of the ZnO film by L-MBE. The unique dynamic mechanism for growing ZnO thin film is analyzed. Both the high energy of the deposition species and the low growth rate of the film are really beneficial for the L-MBE growth of the ZnO thin film with high crystallinity at low temperature.

CdS/SiO2 nanowire arrays and CdS nanobelts were synthesized by thermal evaporation of CdS and CdO mixture powders, with highly selective etching occurring on the silicon substrate surfaces. Study of the growth mechanism of CdS/SiO2 nanowire arrays and the growth process of CdS nanobelts showed that the growth of CdS dendrites plays an important role in the formation of CdS/SiO2 nanowire arrays, and that the mechanism of CdS/SiO2 nanowire arrays growth was in good agreement with “self-assembling nanoelectrochemistry”. In the thermal evaporation process, an interaction between Si from silicon substrate and Cd took place.

Based on experimental observation and theoretical analysis, it explicates that light emission of a carbon nanotube-field emission display (CNT-FED) is mainly caused by electron bombardment on the phosphour if the level of vacuum ranges from 10 −4 to 5 Pa. In this case, light emission of the phosphour excited by ultraviolet (UV) light derived from gas discharge cannot be observed. If vacuum level is greater than 5 Pa, no emitted light is observed, since a large amount of gas ionisation reduces the electric potential difference between the cathode and the anode. To analyze collision between electron and gas under field emission conditions, a mathematical and physical model was built. Based on this model the number of electron–gas collisions is calculated. Calculations results indicate that the product of gas pressure and distance between the electrodes ( pd ) is a better parameter to characterize the effect of vacuum level for FED than gas pressure only. Calculations results also show that if the distance between the cathode and the anode is increased, it should be to improve the vacuum level to obtain the same effect.

To overcome the bulk acoustic wave (BAW), the triple transit signals and the discontinuous frequency band in the first generation surface acoustic wave's (FGSAW's) wavelet device, the full transfer multistrip coupler (MSC) is applied to implement wavelet device, and a novel structure of the second generation surface acoustic wave's (SGSAW's) wavelet device is proposed. In the SGSAW's wavelet device, the BAW is separated and eliminated in different acoustic propagating tracks, and the triple transit signal is suppressed. For arbitrary wavelet scale device, the center frequency is three times the radius of frequency band, which ensures that the frequency band of the SGSAW's wavelet device is continuous, and avoids losing signals caused by the discontinuation of frequency band. Experimental result confirms that the BAW suppression, ripples in band, receiving loss and insertion loss of the SGSAW's wavelet device are remarkably improved compared with those of the FGSAW's wavelet device.

Four kinds of different post-treatment methods or conditions, including low residue adhesive tape treatment, high residue adhesive tape treatment, plasma exposure treatment and mechanical crushing and blowing treatment, were applied to screen-printed carbon nanotube (CNT) films to improve their field emission ability. The effects and results of these methods or conditions on field emission characteristics of printed CNT films were compared in some aspects such as I-V curves, luminescent images and annealing treatment and so on.

The carbon nanotubes (CNTs) film was fabricated successfully on 5 cm × 5 cm borosilicate glass substrate by using capacitive coupled radio frequency plasma-enhanced infrared thermal chemical vapor deposition equipment (CC-RF-PE-IT-CVD). The substrate temperature was 580 °C. Inborn Fe(OH) 3 sol was used as catalyst during the growth. Observation by scanning electron microscope indicated CNTs nearly uniformly distributed on the substrate. The measurement results of field emission characteristics at three stochastic-selective zones indicated that the turn-on field of electron emission for the sample was around 2.1 V μm −1 , and emission current density was larger than 400 μA cm −2 at 6 V μm −1 . Similar effective work function and field enhancement factor for the three different zones exhibited that the sample possesses good emission uniformity. Therefore, the cathode is suitable for FEDs.

Ionization gas sensors need to combine with chromatograph and mass spectrograph to separate gas mixture; this results in huge, bulky architecture, high power consumption and risky high-voltage operation. Here we proposed using two-sensor array composed of two carbon-nanotube film cathode gas sensors with different gaps and using multi-information fusion technology to directly and precisely identify the gas mixture at atmospheric pressure without separating the mixture. Two-sensor array with different gaps were used, and experiments were conducted to obtain the original patterns (OPs) of the two sensors, viz. the relationship between the breakdown voltages and the gas concentrations of the two-gas mixture. The interpolation technology was used to improve OPs, and the neural network technology was used to precisely identify the two components without separating the mixture. This novel method greatly improved the performance of the gas sensor, and can be used to identify n-gas mixture (n > 2) with n-sensor array.

This paper presents a novel method for predicting chaotic time series which is based on the support vector machines approach and it uses the mean-field theory for developing an easy and efficient learning procedure for the support vector machine. The proposed method approximates the distribution of the support vector machine parameters to a Gaussian process and uses the mean-field theory to estimate these parameters easily and select the weights of the mixture of kernels used in the support vector machine estimation more accurately and faster than traditional quadratic programming-based algorithms. Finally, relationships between the embedding dimension and the predicting performance of this method are discussed and the Mackey–Glass equation is applied to test this method. The stimulations show that the mean-field theory for support vector machine can predict chaotic time series accurately and even if the embedding dimension is unknown, the predicted results are still satisfactory. This result implies that the mean-field theory for support vector machine is a good tool for studying chaotic time series.

The principle of measuring the quenching-hardness for the machine elements is the Hall zero-magnetic flux type of principle (i.e. a closed-loop principle), and the formula of the steady-state error for the Hall zero-magnetic flux system is deduced, and the conclusion that the larger the amplifier amplification in the Hall zero-magnetic flux system, the smaller the steady-state error is reached.

A novel temperature-compensating structure for micromechanical bridge resonators has been developed in this paper. The temperature drift of resonance frequency is compensated by the output voltage of a Si/SiO2 bilayer cantilever temperature sensor, which is integrated in the same chip with the bridge resonator. The mechanism of this kind of temperature sensor resembles that of commercial bimetallic temperature sensors. The deformation of the cantilever measured by a Wheatstone bridge located at the clamped end changes with temperature due to the different thermal expansion coefficients of silicon and silicon dioxide. Both the bridge and the cantilever are of the same thickness and are fabricated simultaneously with the same materials and by an identical process flow. So there are few errors caused by the temperature difference between the temperature sensor and the resonator itself, which occurs during fast temperature changes.

Based on molecular dynamics (MD) simulation, the Young's moduli of carbon nanotubes are studied. The inter-atomic short-range interaction and long-range interaction of carbon nanotubes are represented by a second generation reactive empirical bond order (REBO) potential and Lennard–Jones (LJ) potential, respectively. The obtained potential expression is used to calculate the total potential energies of carbon nanotubes. Three types of single-walled carbon nanotubes (SWCNTs), armchair, zigzag and chiral tubules, are calculated, respectively. The computational results show that the Young's moduli of SWCNTs are in the range of 929.8±11.5 GPa. From the simulation, the Young's moduli of SWCNTs are weakly affected by the tube chirality and tube radius. The numeric results are in good agreement with the existing experimental results.

The chirality effect of individual single-walled carbon nanotube (SWCNT) on field emission characteristics is studied by using the dispersion relation of SWCNT derived from tight binding approximation. The characteristic of emission current versus applied electric field is investigated and the band structure influence on emission current is also analyzed. The results of numerical simulation indicate that the emission current increases with increasing applied electric field. For the same applied electric field and similar tube radius, the emission current increases in sequence with zigzag (semiconducting), chiral tube (semiconducting), chiral tube (metallic), armchair and zigzag (metallic).

The dependence of the resonance frequency of thermally excited microcantilever resonators on temperature has been reported by several papers. All these papers ignored the film grown or deposited on the surface of a cantilever and regarded the beam as a single layer one. As a result, there was difference between the theoretical model and experimental results. The paper proposes a bilayer beam model to calculate the dependence of resonance frequency on temperature. This novel model regard the film as another mechanical layer and takes the induced mass by the surrounding gas into account. The calculated results are in good agreement with experimental results.

At room temperature and ambient pressure we studied the H2 storage in carbon nanotubes (CNTs) and precisely measured the H2 storage capacity with a sensitive sensor. The results show that at ambient pressure the H2 storage by CNTs obtained from arc discharge is a slow process which generally takes 25 h or above and the H2 storage capacity is very low. The CNTs films on Si substrate has demonstrated a high H2 uptake performance at ambient pressure. Although the time for H2 storage is long, the CNTs films obtained from chemical vapor deposition has a H2 storage capacity of 8.0% and the CNTs films produced by catalytic decomposition has even higher H2 storage capacity than that.

The controllable growth processes of ZnO nanowires by evaporation of metal zinc with high purity and its luminescence properties have been investigated in detail. Firstly, the power of ZnO nanowires with high yield and homogeneous dimension was synthesized using the special quartz boat at 600°C. Then, the oriented ZnO nanowires with about 20nm diameter were synthesized by using a 90nm-thick layer of ZnO nanocrystals on the Si substrate as the seed layer. Both fabrication processes are repeatable and no catalysts are necessary. Finally, photoluminescence (PL) spectroscopy for ZnO nanowires using an He-Cd laser line of 325nm as the excitation source were measured at room temperature and both samples showed a sharp strong ultraviolet (UV) near-band edge emission. However, different UV peak positions (385nm for ZnO nanowire powder, 377nm for ZnO nanowire array) can be observed. The size confinement effect for excitons and carriers is proposed to explain the blue shift of the near-band edge emission with decreasing size and the native defects are responsible for the green emission.

In the study of electrostatic forces of semiconductor microstructures, especially in submicrometer or nanometer orders, it is valuable to analyse the influence of the space-charge layer at the surface of the microstructures. When the distance between microstructures is larger than 1 µm, the influence of space charge is a negligible factor and the metal approximation formula can be used. When the distance is reduced to the order of submicrometers or tens of nanometers, the error introduced by the metal approximation formula increases rapidly, dominated by the distance and the doping concentration. For the commonly used material n-type silicon, whose doping concentration is 1015 cm-3, when the distance is less than 450 nm, the error caused by the metal approximation formula is more than 10%. At this time, the metal approximation formula cannot be used and the influence of the space-charge layer must be taken into account.

The fabrication process of flat field emission display (FED) devices with excellent field emission properties was presented. The simple screen-printing process was performed to fabricate FED devices. Carbon nanotubes synthesized by DC arc discharge were mixed with conductive pastes and then screen-printed over the glass substrate. The basic structure of FED was of the triode type. The FED devices with this encapsulation process possess steady electron emission properties.

Carbon nanotubes (CNTs) on a glass substrate at a dramatic low temperature was obtained by a radio frequency plasma enhanced thermal chemical vapor deposition. Nickel film was heated and activated at 450 °C with 2400W rf plasma power, the deposition of the CNTs was performed for 60 minutes with 600W, 1500W and 2400W rf plasma power. The diameters of the CNTs obtained are from 8 to 40 nm and the lengths are about over 1.0 um. SEM micrographs show the lower synthesis plasma power can do better for the CNTs synthesis than the exorbitant rf plasma, the Raman spectra and Field emission properties proved this result. The field emission of the film shows the turn-on emission threshold field is 1.17V/um at an emission current density of 1 uA/cm. At this temperature, the glass did not exhibit deformation; electron emission sufficient for flat panel displays is an important progress in the integrated progress of glass sealed field emission displays.

As we know, the unsatisfactory field emission from the films by electrophoresis is resulted from the weak adhesion. The main aim of this paper is to improve the adhesion surrounding electrophoresis technologies. In addition, A simple controllable method is reported for the coating of ZnO nanowires with Ag nanoparticles and ZnO/Carbon nanotubes (CNT) composite.

In this paper, the low-cost screen printed method was adopted preparation uniform nano-SiC films on large areas of glass. The reunited nano-SiC was dispersed by ultrasonic before fabricating paste. After fabricating paste, the nano-SiC was further ultrasonic dispersed. The nano-SiC paste was screen printed on glass. Then nano-SiC films was sintered by the furnace controlled artificial intelligence, the anneal test was take to improve the field emission characteristics. The samples of nano-SiC film were micro-analyzed and tested the I-V characteristics. After above experiments and technics, the uniformity and stability of field emission characteristics for nano-SiC film was obtained.

As we know, the unsatisfactory field emission from the films by electrophoresis is resulted from the weak adhesion. The main aim of this paper is to improve the adhesion surrounding electrophoresis technologies. The technique we applied is referred to employ both organic binders and inorganic solution simultaneously. In addition, the influences of the applied voltage, inter-electrode distance and deposition time on the compound coatings were specifically investigated. The results of the experiments indicated that field emission current of the electrophoresis deposition film were remarkably enhanced compared with the traditional electrophoresis technology.

Based on the optically-induced capacitance change (OICC) effect of the metal-P/N-semiconductor-isolator-metal (MPNIM), a new type of photosensitive capacitor (PCS) has been developed. The dependence of the capacitance on the intensity and wavelength of light and on the temperature and the measuring have been studied. The C - V characteristics of the device have been studied as well.

The new composites of carbon nanotube with silicon dioxide (SiO/sub 2/) nanoparticle for FED cathode is studied. It has significantly improved emission current density property and stable emission characterization of cathode, because it has higher enhancement factor and less shield-effect by adjusting silicon nanoparticle content. The results indicated that when about 80 wt% CNT is optimum content, the current density at the electric field 2 V//spl mu/m is 56 mA/mm/sup 2/, the turn-on field of the CNTs cathode was about 0.71 V//spl mu/m. The fluctuation of emission current is less than 3% for three hours.

The field emission current as a function of the closed-end single-walled CNTs was investigated by using the tight-binding approximation including curvature effect. The discontinuous field emission electron energy distribution and multi-peaks electron emission were found.

ZnO nanowires with high quality and high yield can be obtained based on the simple thermal evaporation of metal zinc in situ at low temperature, which are repeatable. It's suggested that we can use the ZnO nanowires to develop nano-optoelectronics devices and sensors

amorphous silicon nanowire arrays have been successfully prepared by thermal evaporation under the electric field, the dependence of electric field on the growth of amorphous silicon nanowires is studied with the help of scanning electron microscope (SEM) , energy disperse X-ray spectroscopy (EDX) attached to SEM , transmission electron microscopy (TEM). The results show that silicon nanowires grown along straight line and paralleled to each other are located in the middle of two knots. The formation of Si nanowire arrays is controlled by the charged cluster model. And, we suggested that this method can be applied to synthesize other kinds of nanowire arrays.

An architecture for carbon nanotube field emission display based on screen-printing process is presented in this paper. Both the CNT film of cathode and phosphor layer of anode are prepared by screen-printing process. When the space of between cathode and gate electrode and between anode and gate electrode are 0.1 mm and 2.5 mm respectively, very good control ability of gate electrode can be achieved under below 25 V gate voltage and 750~770 V anode voltage

The effects of NH3 on the growth characteristics of carbon nanotubes (CNTs) were systematically investigated in plasma enhanced chemical vapor deposition (PECVD) with C2H2 as a carbon source. The well aligned CNTs were grown from the Ni nanoparticles by plasma-enhanced chemical vapor deposition (PECVD). CNT films were formed with uniform surface morphology instead of nanotube-features. High-resolution transmission electron microscopy revealed that nanotubes grow from the boot with high adhesive ability. The lowest suitable growth temperature is around 560degC. The threshold field is smaller than 2 v/mum, the current within linear extend is from 200 to 700 mA. The luminescence of the CNTs film is not uniform, which resulted from the reduction of field screening effect

To further disclose the emission mechanism and improve emission characteristics of carbon nanotubes (CNT) array films, some parameters affecting field emission characteristics were studied. The field-enhancement factor on the CNT's tip as a function of the CNT's radius r, height L, along with the inter-tube distance was simulated by self-developed CNTFENS2 software in terms of Laplace equation. The results of numerical simulation indicated that the height and radius of the CNT could affect the field emission of the CNT film. Another finding was that the inter-tube distance thus number density of CNT on the substrate could affect the field-enhancement greatly due to the screening effect of nearby CNT.

In this paper, we present optimization design of spacer configuration. An FEM analysis code ANSYS is used here for structural analysis.