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Movement of different strains in Drosophila melanogaster was continuously observed by using computer interfacing techniques and was analyzed by permutation entropy (PE) after exposure to toxic chemicals, toluene (0.1 mg/m³) and formaldehyde (0.01 mg/m³). The PE values based on one-dimensional time series position (vertical) data were variable according to internal constraint (i.e. strains) and accordingly increased in response to external constraint (i.e. chemicals) by reflecting diversity in movement patterns from both normal and intoxicated states. Cross-correlation function revealed temporal associations between the PE values and between the component movement patterns in different chemicals and strains through the period of intoxication. The entropy based on the order of position data could be a useful means for complexity measure in behavioral changes and for monitoring the impact of stressors in environment.

A number of measurements have been provided to detect formaldehyde in the atmosphere, but there are no clear unified standards in engine exhaust. Nowadays, formaldehyde, an unregulated emission from methanol engine, has been attracting increasing attention by researchers. This paper presents the detection techniques for formaldehyde emitted from the engines applied in recent market, introducing the approaches in terms of unregulated emission tests of formaldehyde, which involved gas chromatography, liquid chromatography, chromatography-mass spectrometry, chromatography-spectrum, Fourier infrared spectroscopy and spectrophotometry. The author also introduces the comparison regarding to the advantages of the existing detection techniques based on the principle, to compare with engine exhaust sampling method, the treatment in advance of detection, obtaining approaches accessing to the qualitative and quantitative analysis of chromatograms or spectra. The accuratest result obtained was chromatography though it cannot be used continuously. It also can be utilized to develop high requirements of emissions and other regulations. Fourier infrared spectroscopy has the advantage of continuous detection for a variety of unregulated emissions and can be applied to the bench in variable condition. However, its accuracy is not as good as chromatography. As the conclusion, a detection technique is chosen based on different requirements.

Formaldehyde is regarded as the major indoor air pollutant. Because of harmful effect on human health, its emission abatement is of significant practical interest. We report here excellent low-temperature catalytic performances of mesoporous MnO_x-CeO₂ catalysts in the process of formaldehyde oxidation. These MnO_x-CeO₂ catalysts were synthesized by a "nanocasting" method using SBA-15 as hard template. TEM images showed that the as-fabricated MnO_x-CeO₂ composites possess well-ordered mesoporous architectures. Results of catalytic tests revealed that mesoporous MnO_x-CeO₂ nanocomposites have excellent low-temperature catalytic activity for formaldehyde oxidation, the temperature for 100% formaldehyde conversion can be as low as 65°C over these noble-metal-free mesoporous catalysts. The excellent catalytic performance is attributed to their ordered mesoporous structures that expose abundant active sites to formaldehyde molecules.

We have theoretically studied the photodissociation spectroscopy of Ca⁺-formaldehyde complex using the TD-B2-PLYP method. The SDD pseudopotential and basis sets for Ca and 6-31++G (2df, 2pd) basis sets for C, H, and O atoms were employed in all calculations. In this way, we have reassigned the photodissociation spectroscopy of this complex. All experimentally observed spectral features can be well explained by our calculation. Besides the charge–dipole interaction, a strong molecule–orbital interaction also exists in the excited states and plays an important role in photoexcitation of the Ca⁺–CH₂O complex.

The equilibrium geometries of formaldehyde are optimized with B3LYP, B3PW91 and MP2 methods employing three basis sets 6-311++G(2d,2p), aug-cc-pVTZ and cc-pVTZ, respectively, which agree well with the corresponding experimental and previous theoretical data. The best optimized geometries are obtained at the theoretical level B3LYP/6-311++G(2d,2p) basis set. Basing on the calculated equilibrium geometries, the spectroscopic constants and anharmonic force field of H₂CO are investigated. The results show that DFT method is superior to MP2 method at the calculation of spectroscopic constants and force constants of H₂CO. The vibration–rotation interaction constants and fundamental vibrational wave numbers of H₂CO are firstly theoretically calculated. The Coriolis coupling constants, cubic force constants and most of quartic force constants are firstly theoretically predicted.

The porous Pd-loaded In₂O₃ hollow spheres were successfully prepared by simple one-step method with the template of carbon spheres. The effect of calcination temperatures on morphology, composition and gas sensing performance of the as-obtained products was discussed by a series of test methods. The sample calcined at 550^∘C showed uniform porous hollow spheres with an average diameter of 100nm. Gas-sensing results exhibited that the Pd-In₂O₃ hollow spheres-based sensor possessed excellent sensing properties to formaldehyde, which include high response value (33), low working temperature (180^∘C) and fast response and recovery time (12s and 22s). The enhanced HCHO-sensing properties of Pd-In₂O₃ composites were attributed to the special porous and hollow structure, abundant oxygen vacancies and the catalysis of palladium. Pd-loaded In₂O₃ hollow spheres had been proved to be an ideal material for detecting HCHO at a low working temperature.

A cataluminescence (CTL) based method for simultaneously identifying and determining formaldehyde (HCHO) and sulfur dioxide (SO₂) in air was proposed. The experimental conditions meeting the algebraic sum rule of the CTL intensities of HCHO and SO2 were sought. They are two analysis wavelengths of 460 nm and 580 nm, the surface temperature of sensing materials of 280°C and the flow rate of air of 130 mL/min. The limits of detection of this method were 0.08 mg/m³ for HCHO and 0.6 mg/m³ for SO₂. Common coexistence matters, such as acetaldehyde, ammonia, benzene, ethanol, hydrogen sulfide and carbon dioxide, did not disturb the determination.