Does ambient air quality standard contribute to green innovation of enterprises in China? Implications for environmental protection and public health.

In the post-COVID-19 era, environmental pollution has been a serious threat to public health. Enterprises are in urgent need of enhancing green technology innovation as the main source of pollutant emissions, and it is necessary for governments to support green innovation of enterprises to reduce pollutant emissions and promote public health. In this context, this paper investigates whether the Ambient Air Quality Standard (AAQS) implemented in 2012 in China contributes to green innovation of enterprises, to provide implications for environmental protection and public health. By using panel data of Chinese A-share listed companies from 2008 to 2020, this study adopts the difference-in-difference model to analyze the policy impact of environmental regulation on green innovation of enterprises and its internal mechanism. The results show that AAQS has significantly improved the green innovation of enterprises. Furthermore, AAQS affects the green innovation of enterprises by virtue of two mechanism paths: compliance cost effect and innovation offset effect. On the one hand, AAQS leads to an increase in production costs of enterprises, thus inhibiting green innovation activities of enterprises. On the other hand, AAQS encourages enterprises to increase R&D investment in green technology, thus enhancing their green innovation. In addition, the impact of AAQS on firms' green innovation has heterogeneous characteristics. Our findings not only enrich the studies of environmental regulation and green innovation of enterprises but also provide policymakers in China and other developing countries with implications for environmental protection and public health improvement.

Microstructures, physical and sustained antioxidant properties of hydroxypropyl methylcellulose based microporous photophobic films.

Hydroxypropyl methylcellulose (HPMC)/sodium citrate (SC)/lipid tea polyphenol (LTP) photophobic films with different pore sizes from micron scale to nanometer scale were prepared by regulating the SC content (1-7%). The microstructures, physical and sustained antioxidant properties of these films were studied by using wide angel X-ray diffraction, small angle X-ray scattering (SAXS), scanning electron microscope, whiteness meter, ultraviolet spectrophotometer, texture analyzer and peroxide value test. Composite films with higher SC content showed larger pore size and whiteness. With the increasing SC content, crystallinity first increased then decreased. The addition of SC decreased the Ds (surface fractal dimension) value, smoothness of the cross-section structure, tensile strength, elongation and modulus of composite films. HPMC/SC/LTP microporous films possessed control-release property in oil system, reflected by the lowest peroxide value of peanut oil enclosed in film with 3% SC during three weeks, meaning this film showed the best sustained antioxidant property.

Effect of hydroxypropyl methylcellulose molecular weight on supramolecular structures and properties of HPMC/sodium citrate photophobic films.

Photophobic (white) films were prepared by mixing hydroxypropyl methylcellulose (HPMC) of different molecular weights with sodium citrate (SC). Wide angle X-ray diffractometry, small angle X-ray scattering, scanning electron microscopy, dynamic mechanical analysis, whiteness determination and texture analysis were used to investigate the effect of HPMC molecular weight on the aggregation structures and properties of HPMC film. The crystalline integrity decreased with the increased molecular weight of HPMC for these HPMC/SC films. Similar crystallinity was observed for 6HPMC/SC and 15HPMC/SC, which was larger than that of 50HPMC/SC. All the three HPMC/SC film showed surface fractal structure with similar Ds. With the increasing molecular weight of HPMC, the HPMC/SC film showed honeycomb structures with smaller holes and more compact porous structure, Tg first increased and then decreased a little, the tensile strength and elongation increased with the increasing HPMC molecular weight. 50HPMC/SC films with the smallest pores showed the largest whiteness. A new Tg' peak was observed for HPMC/SC film.

Microstructures and properties of photophobic films composed of hydroxypropyl methylcellulose and different salts.

Monosodium phosphate (MP), sodium citrate (SC), sodium lactate (SL) and magnesium citrate (MC) can be blended with hydroxypropyl methylcellulose (HPMC) to make photophobic (white) films at lower drying temperatures. Small angle X-ray scattering (SAXS), wide angle X-ray diffraction (XRD), scanning electron microscopy (SEM), whiteness determination, dynamic mechanical analysis (DMA) and texture analysis were adopted to study the variation of microstructures and properties. These four kinds of HPMC/salt films showed decreased crystallinity and increased compactness and smoothness of the self-similar structures in larger scale ranges. HPMC/MP, HPMC/SC and HPMC/SL film showed coarser and porous morphologies, lower mechanical parameters and higher whiteness than pure HPMC film. HPMC/MC film showed smoother morphologies, higher tensile strength, elongation and whiteness than pure HPMC film. Porous structures and more compact self-similar structures might contribute to the photophobic property of these films, and relatively smooth morphology might dominate the increasing mechanical parameters of HPMC/MC film.

Multi-scale structures of cassava and potato starch fractions varying in granule size.

Large-, medium-, and small-sized granules were separated from cassava and potato starches. Fourier transform infrared spectroscopy, wide angle X-ray diffraction, small angle X-ray scattering, nuclear magnetic resonance and scanning electron microscope were used to investigate the supramolecular structures of cassava and potato starch fractions. The crystallinity of small-sized potato starch (SPS) was lower than that of its counterparts, while crystallinities of all cassava fractions were similar. The contents of lamellar structure of small-sized granules were the smallest, while those of their counterparts were similar. The lamellar repeat distance was similar for the starch fractions. Self-similar structure of SPS showed mass fractal with the lowest compactness, while that of small-sized corn starch showed surface fractal with the largest compactness. The NMR test revealed that SPS had the highest total double helix content, while its counterparts showed similar values. Moreover, a new 13C peak at 64 ppm was observed for SPS.

[Changes of regional environment quality pattern in China since 1986-2008].

For further study of regional differences and the pattern of changes in environmental quality in China since 1986-2008, we perform the principal component analysis, standard deviation, Mann-Kendall and cluster analysis on 18 environmental quality indexes in 28 provinces of China in this paper. Those indexes refer to pollutant emission, pollutants treatment capacities and pollutant emission of per unit land area, etc. The paper indicates that regional environmental quality in China has been increased slightly during this period. It can be divided into four stages: 1986-2000, 2000-2001, 2001-2005 and 2005-2008. The overall patterns of regional environmental quality is the West is higher than the East in general, while the environmental quality of the eastern part have been changed somewhat. For more details, the regional environmental quality in China in 1986 is composed of two parts, the eastern part and the western part, while in 2000 and 2001 the eastern part, the middle part and the western part appears as the overall pattern. For the year of 2005, the regional environmental quality in the western is higher than that of the eastern; meanwhile, the eastern can be divided into the northern part, the middle part and the southern part, and the environmental quality in northern part is better than that of the southern part, southern part is better than that of the middle part. This pattern hardly changed in 2008, except that the area with poor environment quality region had expanded. Pollutant emission of per unit land area played as a main factor; yet both the pollutant emission and the reuse of pollutants impacted the pattern specifically. In addition, the national macro policies, the regional policies, the regional economic and the industrial structure can be primary reason for the change of regional environmental quality pattern in China as well.