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1.
J Environ Sci (China) ; 123: 430-445, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36522004

RESUMO

Because of the recent growth in ground-level ozone and increased emission of volatile organic compounds (VOCs), VOC emission control has become a major concern in China. In response, emission caps to control VOC have been stipulated in recent policies, but few of them were constrained by the co-control target of PM2.5 and ozone, and discussed the factor that influence the emission cap formulation. Herein, we proposed a framework for quantification of VOC emission caps constrained by targets for PM2.5 and ozone via a new response surface modeling (RSM) technique, achieving 50% computational cost savings of the quantification. In the Pearl River Delta (PRD) region, the VOC emission caps constrained by air quality targets varied greatly with the NOx emission reduction level. If control measures in the surrounding areas of the PRD region were not considered, there could be two feasible strategies for VOC emission caps to meet air quality targets (160 µg/m3 for the maximum 8-hr-average 90th-percentile (MDA8-90%) ozone and 25 µg/m3 for the annual average of PM2.5): a moderate VOC emission cap with <20% NOx emission reductions or a notable VOC emission cap with >60% NOx emission reductions. If the ozone concentration target were reduced to 155 µg/m3, deep NOx emission reductions is the only feasible ozone control measure in PRD. Optimization of seasonal VOC emission caps based on the Monte Carlo simulation could allow us to gain higher ozone benefits or greater VOC emission reductions. If VOC emissions were further reduced in autumn, MDA8-90% ozone could be lowered by 0.3-1.5 µg/m3, equaling the ozone benefits of 10% VOC emission reduction measures. The method for VOC emission cap quantification and optimization proposed in this study could provide scientific guidance for coordinated control of regional PM2.5 and O3 pollution in China.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Ozônio , Compostos Orgânicos Voláteis , Compostos Orgânicos Voláteis/análise , Poluentes Atmosféricos/análise , Monitoramento Ambiental/métodos , Poluição do Ar/prevenção & controle , Ozônio/análise , China , Material Particulado/análise
2.
Int J Biol Macromol ; 257(Pt 2): 128820, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38103671

RESUMO

Eucommia ulmoides seed essential oil (EUSO) is a natural plant oil rich in various nutrients, which has been widely used due to its unique medicinal effects. However, it is prone to oxidation and rancidity under many adverse environmental influences. Nanoencapsulation technology can protect and slow down the loss of its biological activity. In this study, chitosan nanoparticles (CSNPs) loaded with EUSO were prepared by emulsification and ionic gel technology. EUSO-CSNPs were characterized by Fourier transform infrared (FTIR) spectroscopy, Thermogravimetric analysis (TGA) and X-ray diffraction (XRD). The results confirmed the success of EUSO encapsulation and the encapsulation rate ranged from 36.95 % to 67.80 %. Nanoparticle size analyzer, Scanning electron microscope (SEM) and Transmission electron microscopy (TEM) showed that CSNPs were spherical particles with a range of 200.6-276.0 nm. The results of in vitro release study indicated that the release of EUSO was phased, and EUSO-CSNPS had certain sustained-release properties. Furthermore, EUSO-CSNPs had higher antioxidant and antibacterial abilities than pure EUSO and chitosan, which was verified through free radical scavenging experiments and bacteria biofilm experiments, respectively. This technology can enhance the medicinal value of EUSO in biomedical and other fields, and will provide support for in vivo research of EUSO-CSNPs in the future.


Assuntos
Quitosana , Eucommiaceae , Nanopartículas , Óleos Voláteis , Óleos Voláteis/química , Antioxidantes/farmacologia , Antioxidantes/análise , Quitosana/química , Eucommiaceae/química , Antibacterianos/farmacologia , Antibacterianos/análise , Nanopartículas/química , Sementes/química , Espectroscopia de Infravermelho com Transformada de Fourier , Tamanho da Partícula
3.
Front Psychol ; 13: 892348, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35756271

RESUMO

This study aims to explore the impact mechanism of the new dimension of entrepreneurship on the innovation performance of enterprises in the context of digital transformation. The relationship between entrepreneurship and enterprise innovation performance is studied in Beijing, Shanghai, Guangzhou, Shenzhen, and other high-tech enterprises represented by innovative companies. Firstly, the correlation hypothesis between variables is proposed through the induction and summary of relevant data and academic achievements. Statistical data is collected by means of a questionnaire survey. The content of the questionnaire includes three dimensions: 1. collective innovation, risk-taking, and integrity; 2. the survival performance and growth performance of new ventures; 3. basic information about the enterprise, such as the size, age, type, and classification of different Internet and the location. Statistical Product and Service Solutions (SPSS) and Advanced Mortar System (AMOS) statistical software are used to carry out statistical and correlation analyses of the valid questionnaires. Finally, the proposed hypothesis is verified through regression analysis. To sum up, the main conclusions are: the correlation coefficients between innovative spirit, adventurous spirit, integrity, and enterprise survival performance are 0.401, 0.426, and 0.393, respectively, which are positive correlations. The correlation coefficients between innovative spirit, adventurous spirit, integrity, and enterprise survival performance are 0.434, 0.367, and 0.536, respectively, and there is a significant and positive correlation. It shows that entrepreneurship and its three dimensions have a significant positive impact on enterprise entrepreneurial performance. The research examines the logical relationship and influence mechanism between the entrepreneurial spirit of entrepreneurs and the innovation performance of enterprises, which has a certain guiding role in the management practice of innovative enterprises in China.

4.
Sci Total Environ ; 456-457: 127-36, 2013 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-23584189

RESUMO

Industrial sector-based VOC source profiles are reported for the Pearl River Delta (PRD) region, China, based source samples (stack emissions and fugitive emissions) analyzed from sources operating under normal conditions. The industrial sectors considered are printing (letterpress, offset and gravure printing processes), wood furniture coating, shoemaking, paint manufacturing and metal surface coating. More than 250 VOC species were detected following US EPA methods TO-14 and TO-15. The results indicated that benzene and toluene were the major species associated with letterpress printing, while ethyl acetate and isopropyl alcohol were the most abundant compounds of other two printing processes. Acetone and 2-butanone were the major species observed in the shoemaking sector. The source profile patterns were found to be similar for the paint manufacturing, wood furniture coating, and metal surface coating sectors, with aromatics being the most abundant group and oxygenated VOCs (OVOCs) as the second largest contributor in the profiles. While OVOCs were one of the most significant VOC groups detected in these five industrial sectors in the PRD region, they have not been reported in most other source profile studies. Such comparisons with other studies show that there are differences in source profiles for different regions or countries, indicating the importance of developing local source profiles.


Assuntos
Poluentes Ocupacionais do Ar/análise , Monitoramento Ambiental/métodos , Indústrias , Compostos Orgânicos Voláteis/análise , China , Indústrias/normas , Rios
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