PubMed Health⌕ Search

Biomedical subjects

Jun-de Wang

Publications and source records attributed to Jun-de Wang.

At least 19 recordsLinked to original sources
PubMed2006

[The calibration of instrument response function during passive FTIR measurement].

In order to obtain infrared spectral radiance distribution of some infrared sources, such as spectral radiant flux density, spectral radiant intensity, spectral radiance and spectral irradiance, the instrument response function under different conditions must be known. In the present paper, the calibration of instrument response function during passive FTIR measurement has been discussed. The experimental results illustrate that under different experimental conditions, the instrument response function varies not only with the temperature of the blackbody but also with the signal amplitude received by the infrared instrument. So, during passive FTIR measurement, the temperature and the emission signal amplitude of the source must be observed carefully in order to get satisfactory instrument response function.

English Abstract↗
PubMed2006

[Automated recognition of VOCs using artificial neural networks].

Quantitative analysis of FTIR spectra, which are seriously overlapped in the spectral bands, was studied by artificial neural networks. The optimum network was chosen by a new criterion, i. e. the degree of approximation. After the network was established, two kinds of spectra were resolved. It was demonstrated that accurate results could be obtained when two components were both included. In addition, the unknown spectrum could be identified and quantified. It was showed that the artificial neural network has excellent non-linear ability of solution. Meanwhile, the method provides an efficient approach to the identification and quantification of the unknown samples.

English Abstract↗
PubMed2006

[Remote passive detection of flame temperature of solid propellant adulterating nanoparticles].

The flame temperature of three kinds of solid propellants was measured by passive remote sensing FTIR with the resolution of 1 cm(-1). These three kinds of solid propellants are adulterate nano-scale metal oxide particles, adulterate normal metal oxide particles, and propellant without any adulterations. The main components of the solid propellant are nitrocellulose and nitroglycerin. The metallic oxides, including 6 nm CuO, 56 nm Fe2O3, 16 nm NiO, and correspondingly the normal particles, were adulterated into the solid propellants respectively. The flame temperature was calculated through the fine structure of the emission fundamental band of H2O at 2.75 microm. The results of the flame temperature of the solid propellants adulterating nano-scale CuO, Fe2O3 and NiO are 3089, 3193 and 3183 K, respectively. The temperatures of the three kinds of solid propellants were compared, and it was shown that there is no obvious difference in the flame temperature among the three kinds of solid propellants.

English Abstract↗
PubMed2006

[Multi-component analysis of FTIR spectra of non-linear system using polynomial partial least squares method].

A non-linear algorithm, polynomial PLS was applied to the simultaneous analysis of OP-FTIR spectra of a five-component system whose FTIR spectra were seriously overlapped. The results were compared with the one obtained from PLS. PPLS yielded good performance, especially for the prediction of benzene and chloroform. RMSEP (root mean squared error of prediction) of benzene and chloroform in PPLS model were 0.043 and 0.087 and the corresponding values in PLS were 0.402 and 0.842, respectively. Meanwhile, variance was accounted by PPLS with fewer latent variables, which indicates the simplicity and robustness of the model. The successful application of PPLS to non-linear system was meaningful for the use of remote sensing FTIR in air monitoring.

English Abstract↗
PubMed2006

[A review on applications of infrared spectroscopy to the study of traditional Chinese medicine].

Infrared spectroscopy is well suited for the rapid and nondestructive identification and quantification of traditional Chinese medicine (TCM) for its high resolution, easy operation and strong specialization of absorbance bands. It is becoming an efficient methodology in the quality control of TCM. The present paper reviews the applications of infrared spectrometry in the qualitative and quantitative analysis of TCM, especially to the discrimination and effective content determination of traditional Chinese medicinal materials (including different parts of the same medicinal material, TCM from different geographical areas, easily confusing TCM, and true and false TCM) and Chinese patent medicine (such as TCM formula particles, injections, etc.). With the ceaseless rapid development and popularization of FTIR spectrometer and computer science, infrared spectrometry will greatly accelerate the process of TCM modernization and internationalization by all means.

Medicine, Chinese Traditional↗
PubMed2006

[Advanced development of remote sensing FTIR in air environment monitoring].

Remote sensing FTIR(RS-FTIR) is one of the most important technologies in atmospheric pollutant monitoring. It has several prevailing advantages: (1) high resolution and high selectivity; (2) it requiring no sampling and no sample preprocessing; (3) capability of detecting several compounds simultaneously; (4) real time, long distance, and automatic monitoring. So it is extraordinarily appropriate for the quantitative and qualitative determination, and remote, real time, dynamic monitoring of air contaminant, especially the toxic volatile organic compounds (VOCs). The present paper reviews the research progress in remote sensing FTIR for air monitoring made by the Laboratory of Advanced Spectroscopy in recent years, including chemometrics, computed tomography, FTIR spectra interpretation, spatial distribution of air pollutant concentration and passive remote monitoring, etc. These research findings show that the rapid development and application of remote sensing FTIR accelerated the temporal and spatial extension of analytical chemistry, and it will by all means have wide prospects in atmospheric environmental monitoring.

English Abstract↗
PubMed2005

[Studies on spectral characteristics of solid propellant by remote sensing FTIR].

The infrared spectral characteristics of high-intensity IR solid propellant were measured in this paper using a Bruker EQUINOX55 remote sensing FTIR spectrometer. The emission spectra of the combustion flame were recorded in the range of 4700-1800 cm(-1) with a spectral resolution of 4 cm(-1). The combustion temperatures of solid propellant at the burning time of 0, 9, 18, 27 and 36 s calculated from the molecular rotation-vibration spectra were 1992.5, 1610.9, 2294.4, 2361.1 and 1916.9 K, respectively. Moreover, the spectral radiance distributions of the high IR flare material at different times were given, and the combustion product concentrations of HCl, HF, CO2 and CO were determined quantitatively. Results showed that remote sensing FTIR is a potential technology that can be applied to the measurement of IR spectral characteristics, especially to the identification of the IR objects, guidance and anti-guidance in the military, and the modification of the make-up of solid propellant.

Algorithms↗
PubMed2005

[Application and improvement of partial-least-squares in Fourier transform infrared spectroscopy].

Partial least squares(PLS) algorithm is an effective chemometric tool. It takes the advantages of multipal linear regression (MLR) and principal component regression (PCR), which makes Fourier transform infrared spectrometry (FTIR) more powerful and useful. Accompanied with increasing use of FTIR, the algorithm is modified and corrected under different circumstances. The applications of PLS to FTIR were mentioned. Improved algorithms were presented, such as moving windows PLS(MWPLS), robust PLS (RPLS), weighted PLS(WPLS), and non-linear PLS. Data pre-processing, selection of variable, noise elimination and non-linear model of PLS were introduced.

English Abstract↗
PubMed2005

[Advances in passive OP-FTIR].

As an OP-FTIR(Open Path FTIR) technology, passive OP-FTIR not only has the advantages of OP-FTIR, but also has the ability to collect data from any direction without prior background information. This technology allows mobile, fast, man-held and stand-off detection of hazardous chemical cloud.The present paper presents some developments of passive OP-FTIR, including high altitude atmospheric pollution detection, auto-detection of toxic cloud, hot gases detection (such as the determination of major combustion products in aircraft exhausts, remote sensing of smoke plumes, and remote sensing of volcano emissions), temperature and combustion products determination (including cloud temperature determination). The present paper also gives the application of passive OP-FTIR in the military. With the development of FTIR and computer science, more and more applications of OP-FTIR to environment supervision, aviation and space flight, engine exhausts, combustion and military will be fulfilled.

English Abstract↗
PubMed2003

[Error analysis of temperature measurement by Boltzmann plot in atomic emission spectroscopy for a high-density plasma produced by electrothermal capillary discharge].

The present paper analysed in detail the reasons for the errors found in the literature when Boltzmann plot was used for the temperature measurement of a high-density plasma produced by electrothermal capillary discharge. The reliability of experiment can reach as high as 98%-99.5% and the error is only +/- 6.5% when the spectroscopic parameters, such as transition probability A, statistical weight of upper level g, and the energy of upper level Ei, are selected correctly for the temperature measurement of a high-density plasma produced by electrothermal capillary discharge by Boltzmann plot in atomic emission spectroscopy.

English Abstract↗
PubMed2003

[Combustion temperature measurement of solid propellant and the effect of organic compound on combustion temperature].

The FTIR emission spectra in the spectral range of 4,500-300 cm-1 for the solid propellants were measured by a remote sensing FTIR system. The P-branch of fine structure of HCl fundamental band lying at 3.46 microns was used for precise combustion temperature measurement of the solid propellant. The effect of the organic compound in the solid propellant on the combustion temperature was discussed.

English Abstract↗
PubMed2003

[Real time diagnostics of instantaneous temperature of combustion and explosion process by modern spectroscopy].

The combustion temperature is one of the important parameters to express flame combustion and explosion characteristics. It will effectively guide the design and manufacture of new model explosives, industrial explosive materials, and weapons. The recent developments and applications of real time diagnostics of instantaneous temperature of combustion and explosion processes by modern spectroscopic methods, such as atomic absorption-emission method, atomic emission two-line spectroscopy, atomic emission multiline spectroscopy, molecular rotation-vibration spectroscopy, coherent anti-stokes Raman scattering (CARS) and plane laser-induced fluorescence (PLIF), were reviewed in this paper. The maximum time resolution of atomic absorption-emission method is 25 microseconds. The time resolution of atomic emission two-line spectroscopy can reach 0.1 microsecond. These two methods can completely suit the need of real time and instantaneous temperature diagnostics of violent explosion and flame combustion. Other methods will also provide new effective research methods for the processes and characteristics of combustion, flame and explosion.

English Abstract↗
PubMed2002

[Simple preparation and evaluations of amide-octyl-bonded phase].

A simple preparation process of amide-octyl-bonded phase (AOBP) is described. In the process aminopropyltriethoxysilane first reacted with octanoyl chloride and then the obtained intermediate was bonded onto porous silica. Characterization of prepared packing was carried out with elemental analysis, solid-state nuclear magnetic resonance (13C-NMR) and Fourier transform infrared (FTIR) spectroscopy. Chromatographic evaluations were carried out by testing with a mixture including acidic, basic and neutral organic compounds using methanol-water as binary mobile phase. The results show that the stationary phase has excellent chromatographic properties and resistance to hydrolysis between pH 2.5-7.5. It can be used for the efficient separation of basic compounds.

1-Octanol↗
PubMed2002

[Reconstruction algorithms of computed tomography of remote sensing FTIR].

Reconstruction algorithms of computed tomography-remote sensing fourier transform infrared spectroscopy plays a key role in fast and cost-effective acquirement of gas concentration distribution. Ideally, a reconstruction algorithm can be used to obtain good reconstruction maps only by limited number of measurements and non-symmetric ray configurations, even in the presence of instrument noise, measurement error, poor beam geometry, and variations in the contaminant spatial distribution. Several conventional reconstruction algorithms used to reconstruct two-dimensional concentration maps of the vapor contaminants by remote sensing FTIR, such as ART, MART, SIRT and SBFM, have been reviewed in this paper. Comparing to ART, MART has the advantages of iterative speed and iterative precision, while SIRT overcomes the problem of illegibility and SBFM can reduce the noise sharply.

Air Pollutants↗
PubMed2002

[Calibration of EQUINOX55 remote sensing FTIR emission system].

In order to obtain the infrared spectral radiance distribution of the emission spectrum or the concentration of the gases, the calibration of FTIR emission system is necessary for obtaining an instrument response function of the system. This paper gives the effect of the temperature of the standard blackbody for calibration of EQUINOX55 remote sensing FTIR emission system on the instrument response function. The result illustrates that the values of the instrument response functions increase as the blackbody temperature increased, and tends to a limit.

Calibration↗
PubMed2002

[Remote sensing FTIR and computed tomography for air pollution].

Gas concentration mapping with computed tomography-remote sensing fourier transform infrared spectroscopy demonstrates that this system and reconstruction method can be directly applied in many environmental and industrial settings. This development of reconstruction algorithm can greatly broaden the application of CT to obtain rapid reconstruction of ambient air pollution data.

Air Pollutants↗