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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.

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.

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.

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.

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.

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.