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Aiming at the uncertainty of the concentration of the pollution gases and the spread of distribution in the process of shale gas development, the open optical path Fourier Transform infrared spectroscopy (FTIR) measurement system designed and built by ourselves is used to invert the concentration of pollution gases in the backflow, and the size of pollution source is calculated by the flow rate of backflow liquid and the size of pollution source. By combining with the field environment and establishing the reference coordinates, the Gaussian diffusion model is derived mathematically, and the non-point source diffusion model of pollution source is constructed and simulated. The result shows that the source intensity, distance, wind speed and atmospheric stability all affect gas concentration diffusion. The concentration of main pollution gas and the strength of non-point source are obtained by continuously measuring the backflow liquid for 80 h. The result shows that C3H8, C5H12, C3H6, CO and SO2 are the main pollution gases of the backflow liquid, and their maximum concentrations are 4.689 mg/m3, 25.494 mg/m3, 30.324 mg/m3, 0.656 mg/m3 and 4.620 mg/m3, respectively. The maximum strengths of non-point source are 1.9872 g/s, 10.9750 g/s, 12.8513 g/s, 0.2707 g/s and 1.9064 g/s, respectively. By combining the wind speed and daytime environmental conditions, the atmospheric stability is selected and the source strength is substituted into the non-point source diffusion model, the diffusion concentration of polluted gas is obtained, and the real-time monitoring of the concentration distribution of different polluted gases at different locations is realized. The traditional method is used to collect air samples in the field and determine them in the laboratory. It takes a long time and different sampling methods are affected by the preservation time of samples, etc., so there is a great difference between the measured values in the laboratory and the measured values in the field. The country has issued online monitoring standards for volatile organic compounds (VOCs), but most of them are for the determination of non-methane total hydrocarbon, which cannot realize in situ component analysis, and cannot implement the monitoring of VOC concentration distribution within the region. Compared with traditional measurement methods, the method of FTIR and non-point source diffusion model can not only realize the non-contact, long-distance, online measurement of pollution sources, but also set the dynamic factory boundary of the pollution area and determine the safe distribution area.

Under different ambient temperatures, the thermal aberration certainly affects the imaging quality of infrared multi-spectral camera. Therefore, an athermalized model of infrared multi-spectral cameras is established, and in this model the ambient infrared multispectral camera is equivalent to a separated dual-lens optical system. In the case of the fixed focal length, the influence of the back focal length on the change of the focal power of the front lens and back lens is analyzed. Now, the variation range of the front and rear lens interval is assumed to be restricted. When the back focal length is smaller than the focal length, the ratio of the absolute value of the focal power of the front lens to the absolute value of the focal power of the back lens decreases with the back focal length increasing. The material of the front lens and the back lens have a longer interval on the thermogram. When the back focal length is greater than the focal length, the scenario becomes exactly opposite. Combined with the judgment method of the positive value and negative value of the focal power on the thermogram, the selection range of materials is constrained by the positive value, negative value, and absolute value of focal power, thus realizing the rapid selection of the optical materials. This method is used to design an athermalized infrared multispectral camera with a waveband of 8–14 μm, a focal length of 50 mm, and an F number of 1.4 in a range from –40 ℃ to +60 ℃. Through the simulation analysis, the value of the athermalized infrared multispectral camera, at the Nyquist frequency of 30 lp/mm reaches 0.39, which is close to the diffraction limit; the root mean square radius of the diffuse spot is smaller than the Airy spot radius of 19.17 μm; the axial aberration is less than 0.02 mm, and the design results show that this method can make the long back-focus infrared optical system maintain stable imaging quality in a large temperature range. The SF6 gas is detected experimentally, and the experimental results demonstrate the excellent optical performance of the system.

The problem of detecting the biological aerosol at low elevation angle is analyzed and discussed by using MODTRAN model. First of all, the atmospheric model and profile of MODTRAN model are introduced for the biological aerosol detection by Fourier transform infrared (FTIR) spectroscopy. According to the passive detection of biological aerosol by FTIR spectroscopy, the radiation brightness difference L between the background and the target biological aerosol is calculated by using the radiative transfer theory and the simplest three-layer model. The signal value 2Lt under the actual circumstance is derived from the derivative of L combined with the noise equivalent spectral radiance value of the spectrometer. Finally, the detection limit of biological aerosol for each atmospheric mode is predicted with the passive remote sensing method. The limit concentration of detection for each atmospheric mode is different due to the differences in boundary layer temperature, transmittance, and background radiation brightness of atmospheric model, and it is also related to the absorption coefficient of biological aerosol. It is shown that the passive remote sensing of FTIR technology can detect the presence of the biological aerosol. Therefore, the detection of the biological aerosol is feasible. It presents a method of detecting the biological aerosol cloud under the actual circumstance.

Owing to space optical system working for a long time outside the field of view, where there is strong background radiation, and the fact that the point source transmittance (PST) is an important evaluation indicator for stray light suppression of this optical system, the development of stray light equipment for testing PST has received more and more attention. Though the development of PST testing system has been extensively studied, none of them elaborate on the calibration of the PST testing system. Besides, most of the PST testing systems are at a laboratory research stage, and the calibration of neither testing stability nor accuracy is recognized. Therefore, on the basis of the PST testing system established, one calibration lens is designed to calibrate the PST testing system. By comparing the measured PST values of the calibration lens with the analyzed values, the PST testing system can be evaluated. The calibration lens model is built to analyze PST values at different off-axis angles by using the ray tracing software Tracepro. We consider the accuracy of modeling, and on the basis of simplifying the structure design, we measure bidirectional reflectance distribution function (BRDF) values of the painted surface of the calibration lens, and then estimate values of lens surface from Harvey-Shack model and PSD theory by taking these property data into the model of simulation. Ultimately PST analyzed values of calibration lens can be obtained. Finally, by comparing the measured values of calibration lens, which are tested by using PST testing system, with the analyzed values, the calibration of the PST testing system is completed. In the PST testing process of calibration lens, by analyzing the data at different off-axis angles, the accuracy of repeated measurements and threshold of PST testing system can be obtained. At the same time, testing errors caused by the stability of light source, detector linearity, air scattering and structure of double cylindrical chamber are analyzed through the testing data. The data show that when double cylindrical chamber clean class is ISO7, the PST threshold of this equipment is 10-8, and the accuracy of repeated measurements is 7.9%. Taking into account the detection capability, the PST threshold of this equipment is 10-10 when environmental condition is better than ISO6.

The quantitative analysis based on Fourier transform infrared (FTIR) technology is affected by the temperature and pressure properties of gas and the H2O cross section, so the applications of FTIR technology to high-precision measurement area of the greenhouse gases and isotope ratio are restricted. Firstly, the methods of correcting the gas property sensitivities and H2O cross sensitivity are studied, then the standard gas measurements are corrected with these sensitivity correcting functions established through experimental study. The standard deviations of CO, CO2, N2O, CH4 and δ13CO2 are all improved after correcting the sensitivities, and reduced by 1.80-3.38 times. These studies are significant for the applications of FTIR technology to the high-precision measurement area of greenhouse gases and isotope ratio.

Nowadays, X-ray nanoprobe plays an important role in many research fields, ranging from materials science to geophysics and environmental science, to biophysics and protein crystallography. Refractive lenses, mirrors, and Laue lenses, can all focus X-rays into a spot with a size of less than 50 nm. To design a refractive lens at fixed wavelengths, absorption in the lens material can be significantly reduced by removing 2πup phase-shifting regions. This permits short focal length devices to be fabricated with small radii of curvatures at the lens apex. This feature allows one to obtain a high efficiency X-ray focusing. The reduced absorption loss also enables optics with a larger aperture, and hence improving the resolution for focusing. Since the single Kinoform lens can focus hard X-ray into a spot on a nanoscale efficiently, it has very important application prospect in X-ray nano-microscopy and nano-spectroscopy. We present a theoretical analysis of optical properties of the single Kinoform lens. Using Fermat's principle of least time, an exact solution of the single Kinoform lens figure is derived. The X-ray diffraction theory is reviewed. The complex amplitude transmittance function of the X-ray single Kinoform lens is derived. According to Fourier optics and optical diffraction theory, we set up the physical model of X-ray single Kinoform lens focusing. Employing this physical model, we study how the focusing performance of hard X-ray single Kinoform lens is influenced by the material, the photon energy, the number of steps and the vertex radius of curvature. We find that diamond single Kinoform lens can achieve a smaller focusing beam size with higher intensity gain than Al and Si single Kinoform lens. The single Kinoform lens designed at a certain photon energy can also focus other photon energies with different lateral beam sizes, axial beam sizes, intensity gains and focusing distances. The numbers of steps of a single Kinoform lens can be lessened with the thickness of step increasing, while the single Kinoform lens keeps good focusing performance. To improve the focusing performance further, reducing the vertex radius of curvature is proposed. Following these rules, a single Kinoform lens is optimally designed to focus 30 keV hard X-ray down to a lateral size of 14 nm (full-width at half-maximum, FWHM) and an axial size of 62 μm (FWHM) with an intensity gain of four orders of magnitude and transmittance of 30%.

In order to study the carrier transporting properties in organic semiconductors (OSCs), the samples of single layer structure ITO/NPB/Ag are prepared, and the corresponding admittance model in theory is built. Impedance samples of the structure under different DC bias voltages are obtained by small sinusoidal signal frequency test method. The particle swarm optimization (PSO) algorithm, in which fitness function includes both the real part and the imaginary part of OSC impedance, is used to identify the model parameter including dispersion coefficient M, α and charge-carrier transit time τdc. To validate the proposed method, an equivalent circuit model of the structure, whose time constant τc is identified by least squares method, is built. Two single-layer structures, whose NPB thickness values are respectively 1000 nm and 1200 nm, are tested. Test results show that the charge-carrier transit time τdc is proportional to the time constant τc and the two hole mobility μdc values both satisfy the famous Poole-Frenkel formula.

The magnetism, stabilities and phase transition of Ru in hcp, fcc, bct and bcc structures are investigated with detailed first-principles calculations based on density-functional theory and quasiharmonic lattice dynamics approximation. Magnetic ground states and stability ranges of various phases are obtained. Calculated results indicate that the non-magnetic (NM)-hcp structure is the most stable in the entire pressure range at zero temperature, and the structural transition cannot be induced by pressure alone. NM-fcc structure is a metastable phase of bulk Ru, while both the NM-bcc and ferromagnetic (FM)-bct structures are dynamically unstable. At high pressure and temperature, a transformation from NM-hcp to NM-fcc structure will occur. Finally, the pressure-temperature phase diagram of Ru is presented.

The concentration of carbon dioxide in the atmosphere has been increasing continuously. This is a big concern with respect to the environment and climate changes and so on. A kind of ground-based low-resolution remote sensing system and a real-time spectral inversion method are presented for the real-time remote sensing column concentration of carbon dioxide. Based on continuous observation of this system in Hefei, the total atmospheric transmittance is real-timely obtained from the solar absorption spectrum. The column concentrations of carbon dioxide and oxygen are inversed from total atmospheric transmittance by line-by-line nonlinear least squares spectral inversion algorithm. The column concentration of oxygen is used as internal standard function to obtain the column average volume mixing ratio of carbon dioxide in total dry air column, and the precision is better than 3%.The average volume mixing ratio of carbon dioxide in dry-air column, from 12: 00 to 15:00 on September 25, 2012, is compared with observation results by Japanese greenhouse-gases satellite over the site in this period, showing that the relative deviation is less than 1%. Obviously, it is an effective way to measure greenhouse gases concentration with high precision and accuracy.

Two sound field separation techniques based on equivalent source method are proposed:one is based on the double-layer pressure measurements and the other is based on the single-layer pressure-velocity measurements. In this paper, a sound field separation technique based on equivalent source method but using the double-layer velocity measurements is proposed. First, the theoretical description of this technique is given, and then numerical simulations and experiments are conducted to demonstrate the validity of this technique. By comparison with the technique based on double-layer pressure measurements, the superiority of the proposed technique in separating particle velocity field is shown. And also, in the numerical simulations, the influences of the strength of disturbing source and the distance between two measurement planes on separation accuracy are investigated.

Infrared passive remote sensing allows remote monitoring and early warning of air pollution. The key to the quantitative resolution is to obtain the background radiation in application process. The existing methods (such as measuring the background and atmosphere radiance spectrum in the same condition or uptake) need in advance or at the same time to measure the background spectrum without target. So, they are difficult to satisfy the demand for rapid response in the practical application. According to the infrared radiation transmission model analysis and by studying the principle of measured spectrum in the 800-1200 cm-1 band containing the target, background and environmental radiation, we propose a real-time spectrum extraction algorithm that does not require to measure the background target feature. The method is applied to the developed polluting gas scanning imaging passive FTIR system. The remote sensing of SF6 is done. Concentration data and the data obtained by the method at the same condition are compared, and the results show that the correlation coefficient squared value reaches 0.99, indicating that the method is feasible, which can effectively improve the response speed of the system and the scope of application.

An instrument based on Fourier transform infrared spectrometer is developed, which is capable of simultaneously measuring carbon dioxide (CO2) and 13CO2 in a single air sample with higher precision. The temperature and pressure effect on the values of CO2 and 13CO2 are investigated. Both the standard gas and air sample gas are continuously measured using this method. Precision and accuracy are improved by comparing with the measurements of standard gas after correction using the law of temperature and pressure effect on the values of CO2 and 13CO2.

The incoherent sound field obtained by scanning measurement cannot be used directly for nearfield acoustic holography to reconstruct the sound field. And therefore, the incoherent sound field needs to be decomposed into fully coherent partial fields. In previous methods, the pressure is used as reference to obtain the partial fields. In this paper, the pressure gradient is used as the reference for the partial field decomposition. Because the pressure gradient decays faster than the pressure, the interaction of the pressure gradient between the incoherent sources is weaker than that of the pressure, which may improve the effect of the partial field decomposition. A numerical simulation and an experiment are conducted to test the feasibility of the method. And it is shown that the partial field decomposition method based on pressure gradient reference is robust and the decomposed results are better than those based on pressure references.

Hologram pressure extrapolation is a key process of Patch nearfield acoustic holography. In this paper, a pressure extrapolation method based on the weighted norm extrapolation is proposed, in which the auto-power spectrum of hologram pressure estimated by the measured data is used as a weighting function to build the weighted norm, and the hologram pressure extrapolation is realized by minimizing the weighted norm. Because both the spectrum shape and the bandwidth information about hologram pressure are utilized during the extrapolation, a more accurate extrapolated result can be achieved. The validity of the proposed method is proved by a numerical simulation and an experiment study. The simulation results show that the proposed method has obviously advantages in accurcy and computational efficiency compared with the classic wave number domain extrapolation method. Furthermore, the proposed method is used to extrapolate a pressure field generated by a camped steel plate in experiment and a satisfactory result is obtained.

Patch nearfield acoustic holography based on the distributed source boundary point method (DSBPM) is proposed to reduce an error of the reconstructed result obtained from the pressure measured on a small aperture. The extrapolated data on a larger holographic surface is obtained through the measured data on the small holographic surface using the DSBPM, then the extrapolated data is used to reconstruct sound source. The simulation results and the experimental results show that the method can provide a good reconstructed result under the condition of the small holographic aperture.

Amorphous carbon nanodot arrays were successfully prepared through filtered cathodic arc plasma (FCAP) technique, and via a special widen process, the negative effect of the anion impurities distributed in the anodic aluminum oxide (AAO) template was avoided during carbon ions deposition. The morphology of the samples was studied by a field emission scanning electron microscopy (FESEM). The AAO template prepared by multi-steps combining anodization process and pore-widening process has special pore openings. The nanodot arrays are uniformly distributed and in good agreement with the AAO pore arrays. The diameter of the as-prepared nanodot is about 100 nm, and the density was estimated to be 1010 cm-2. Field emission properties of the nanodot arrays were investigated and a low threshold field of 37 V/mm at 10 mA/cm2 was obtained.

By the wave superposition approach a method of enhancing the spatial resolution of the nearfield acoustic holography is proposed. According to wave superposition approach, the source strengths of fictitious sources placed on the fictitious surface which is near the hologram surface are obtained by measuring the hologram pressure signal, then these fictitious sources are used to realize the interpolation of acoustic pressure, finally, the reconstruction can be done by the interpolated hologram pressure. By this method the spatial resolution of the reconstructed image can be improved, the measurement workload is reduced, and the measurement process is simplified. The parameters affecting the interpolated result are reasonably chosen by numerical simulations and the availability of this method is proved by numerical simulations and experimental resuets.

In the conventional nearfield acoustic holography （NAH）, only the pressure or particle velocity is used as the input quantity, and it cannot separate the waves from the two sides of the hologram surface. Therefore, all sources are assumed to be on one side of the hologram surface, i.e. the sound field is assumed to be free. This assumption limits the practical applications of NAH. In the NAH using pressure and particle velocity measurements, both pressure and particle velocity are used as the input quantities. By establishing and solving the coupling relationship on the hologram surface between the waves from the two sides of the hologram surface, the waves from the two sides can be separated. On the basis of the previous studies on sound field separation techniques and based on the Euler formula and the finite difference approximation technique, a new theoretical formula of NAH using pressure and particle velocity measurements is given, and then an experiment is performed to validate the method.

The sound field separation technique based on single surface measurement is investigated in this paper. A modified separation formula based on the spatial Fourier transform is presented to overcome the inherent singularity of the current single surface separation technique. However due to the wraparound error associated with fast Fourier transform （FFT）, the accuracy of separation technique based on FFT is not satisfactory and a novel separation method based on the statistically optimized nearfield acoustic holography is proposed to improve the separation. The simulations as well as experiments carried out with the p-u intensity probe produced by Microflown demonstrate the validity of the proposed modified formula and the effectiveness of the new separation method.

A new patch nearfield acoustic holography (PNAH) based on wave superposition approach is proposed in this paper. In the method, the sound field is extrapolated by superposing wave fields produced by a number of fictitious sources placed inside the radiator, and then the FFT is used for reconstructing the normal velocity or the field on and near the radiator. This method has higher computational accuracy and efficiency than other PNAH techniques, and is very easy for applications. In order to prove its validity, the method was used in the experiment to reconstruct the normal velocity of a clamped point-driven steel plate, and satisfactory results were obtained.

We have investigated the surface damage induced by visible laser in LiNbO3:Fe. The laser damage tracks (glide lines and microcracks) and microdomains are produced at +c side of the periphery of light-illuminated regions. These microdomains arise at laser damage tracks and at cylindrical grooves on the surface of sample. We also found that these damage defects in LN:Fe can be decorated by space-charges due to photovoltaic effect and they are directly observable between crossed polarizers. Role of the cavity field, the electrostatic repulsive force at the doma-in boundary and self-enhanced diffraction light induced by physical imperfection on laser-induced surface damage are discussed.

Following our previous work [1], the influence of photo-induced refractive index change on Raman spectra of LiNbO3 crystals doped with 0.07% Fe has been further studied. Anomalous phenomenon appeared in x(zx)z and y(zy)z geometry. This can be explained as the result of interaction between the polarization electrical field of extraordinary phonon and the strong space charge field forming after photo-induced refractive index change in the crystals.