This study will both compare and contrast the characteristics and roles of two pollutants: nitrogen dioxide and carbon monoxide. It will begin by tracing each gas’ negative contributions to the Earth’s spheres, as w...This study will both compare and contrast the characteristics and roles of two pollutants: nitrogen dioxide and carbon monoxide. It will begin by tracing each gas’ negative contributions to the Earth’s spheres, as well as relate any negative links that each plays concerning human activity, health, and interaction with the environment. It will include an in-depth analysis of what the proliferation of such toxic gases indicates about human production and causality, plus reflect on any current attempts being made to improve the effects of these pollutants on the environment. This examination will also inspect three NASA missions, i.e., MOPITT/Terra, AIRS/Aqua, and OMI/Aura, the aim of which, among many other tasks, is to detect pollutants within the Earth’s various spheres, as well as analyze weather anomalies, improve prediction methodology, and chronicle meteorological patterns for future study. It will also cover some of the goals, engineering breakthroughs, and in one case, the limitations, of these three satellite missions. Finally, it should be noted that in all stages of this discussion, the author’s main aim will be to focus on the positives that need to be implemented in order to improve the current situations that both anthropogenic and natural disasters have created for the planet.展开更多
This article investigates the responses of Brassica campestris seedlings to an acute level of nitrogen dioxide （NO2） exposure in a plant growth chamber, and examines whether pretreating plants with hydrogen peroxide...This article investigates the responses of Brassica campestris seedlings to an acute level of nitrogen dioxide （NO2） exposure in a plant growth chamber, and examines whether pretreating plants with hydrogen peroxide （H2O2） will alleviate NO2-caused injury. Twenty-eight-day-old B. campestris plants sprayed with 10 mmol L^-1 H2O2 aqueous solution （corresponding to approximate 1.0 mg H2O2 per single plant） were exposed to different concentrations of NO2 （0.25, 0.5, 1.0, and 2.0 μL L^-1, respectively） for 24 h under controlled environment. To measure the plant biomass, the plants were fumigated with the same NO2 concentrations as mentioned above for 7 h per day （8.00-15.00） for 7 days. As a control, charcoal filtered air alone was applied. Data were collected on plant biomass, total chlorophyll, photosynthetic rate, stomatal conductance, nitrate and nitrate reductase （NR）, antioxidative enzymes, ascorbate （ASA）, and malondialdehyde （MDA）, immediately after exposure. The results showed that exposure to a moderate dose of NO2 （e.g., 0.25 μL L^-1） had a favorable effect on plants, and the dry weight of the above-ground part increased, whereas the exposure to high NO2 concentrations （e.g., 0.5 μL L^-1 or higher） caused a reduction in the plant biomass and the total chlorophyll, when compared with the control. In addition, at 0.5 μL L^-1 or higher NO2 concentrations, prominent increases in the MDA level and superoxide dismutase （SOD） and NR activities were observed. Exposure to 1 μL L^-1 and higher NO2 resulted in necroses appearing on older leaves, and an increase in catalase （CAT） activity, decrease in ASA content, increased accumulation of NO3^-, and reduction in photosynthesis, when compared with the controls. No changes were detected in stomatal conductance under NO2 fumigation. The pretreatment with 10 mmol L^-1 H2O2 alleviated significantly NO2- caused biomass decrease and photosynthetic inhibition when compared with H2O2-untreated plants. Under NO2 fumigation, further induction in SOD and CAT activities occurred in H2O2 treated plants when compared with H2O2- untreated plants. The effect of NO2 on the ASA and MDA contents was also absent in H2O2-treated plants. However, the H2O2 treatment did not alter the nitrate content and NR activity in plants under NO2 fumigation. The H2O2 treatment caused a lower rate of stomatal conductance. Taken together, these data suggest that fumigation with an acute level of NO2 causes oxidative damage to B. campestris seedlings. The H2O2 pretreatment markedly protects plants against NO2 stress and this may be associated with inducible antioxidative level. NO2 fumigation contributes, at least in part, to the enhanced levels of nitrate in B. campestris leaves.展开更多
Stored peanuts often need treatments to control microbial infections as well as insects to maintain postharvest quality. Nitric oxide (NO) is a recently discovered fumigant for postharvest pest control. NO fumigation ...Stored peanuts often need treatments to control microbial infections as well as insects to maintain postharvest quality. Nitric oxide (NO) is a recently discovered fumigant for postharvest pest control. NO fumigation must be conducted under ultralow oxygen condition to preserve NO and always contains NO<sub>2</sub> due to NO reaction with oxygen and NO<sub>2</sub> has antimicrobial property. Therefore, NO fumigation has potential to control both pests and pathogens. In this study, we evaluated antimicrobial effects of NO<sub>2</sub> fumigation on unpasteurized unshelled peanuts. Peanuts were fumigated with 0.3%, 1.0%, and 3.0% NO<sub>2</sub> for three days at 25<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">˚</span></span></span>C by injecting NO gas into glass jars to react with O<sub>2</sub> in the atmosphere. After fumigation, wash-off microbial samples were collected from intact peanut samples and, then, cracked open peanut samples with non-selective tryptic soy broth medium. The wash-off samples were then diluted with both the non-selective medium and a fungal-selective potato dextrose broth medium and were tested on GreenLight<span style="white-space:nowrap;"><sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">™</span></span></sup></span> rapid enumeration test based on oxygen depletion on culture medium. All three NO<sub>2</sub> fumigation treatments showed significant antibacterial and antifungal effects on intact peanuts as well as on cracked peanuts with complete inhibition with 3.0% NO<sub>2</sub>. Fumigation did not have obvious effects on appearance of skinned peanut kernels. These results suggested that NO<sub>2</sub> fumigation has potential to control microbes on stored products, and NO fumigation with the combination of NO and NO<sub>2</sub> has potential to control both insects and microbes on stored products.展开更多
As a severe environmental pollutant, detection and quantitation of nitrogen dioxide (NO<sub>2</sub>) have been studied for centuries. In this review, recent progress of NO<sub>2</sub> analysis ...As a severe environmental pollutant, detection and quantitation of nitrogen dioxide (NO<sub>2</sub>) have been studied for centuries. In this review, recent progress of NO<sub>2</sub> analysis in the atmosphere will be summarized. Four major types of detection technologies, including traditional chemical detection, optical detection, solid-state field effect transistor detection, and other detection technology are covered. The standard method employed by the US EPA, which is based on luminol, is the most reliable and robust method that is used for fully validated monitoring. In the past two decades, accompanying the fast development of electrical engineering and integrated circuit, micro to nanoscale gas sensors have been gaining more and more attention. Application of novel materials including nano wires and graphene also leads to a new era of research and development of sensors.展开更多
Highly selective and remotely communicable nitrogen dioxide(NO_(2))sensing may contribute to future Internet of Things in environmental monitoring.However,room-temperature NO_(2)sensing materials such as carbon materi...Highly selective and remotely communicable nitrogen dioxide(NO_(2))sensing may contribute to future Internet of Things in environmental monitoring.However,room-temperature NO_(2)sensing materials such as carbon materials is still less than satisfactory due to their insensitive interaction with target gas.Here,polyethylene imine functionalized three-dimensional(3D)carbon framework(PEI/C framework)has been developed for enhanced selective NO_(2)sensing,via combined template synthesis and subsequent doping.Typically,the 3D PEI/C framework is observed porous shape with irregular coating.Beneficially,the response of C framework to NO_(2)increases while those of interfering gases decrease after being functionalized with PEI.Remarkably,the sensor prototypes show a 100 ppb-concentration detection limit at room temperature.Theoretically,such excellent NO_(2)sensing is attributed to the large specific surface ratio of porous 3D PEI/C framework,in which PEI serves as an active layer for target NO_(2),while a passivated one for interfering gases.Practically,such PEI/C framework sensor prototype is simulated for NO_(2)sensing device and communicated with a smartphone,showing great potential in future intelligent environmental monitoring.展开更多
The defect engineering in graphene plays a significant role for the application of gas sensors. In this work, we proposed an efficient method to prepare ultrasensitive gas sensors based on the porous reduced graphene ...The defect engineering in graphene plays a significant role for the application of gas sensors. In this work, we proposed an efficient method to prepare ultrasensitive gas sensors based on the porous reduced graphene oxide(PRGO). Photo-Fenton etching was carried out on GO nanosheets in a controlled manner to enrich their vacancy defects. The resulting porous graphene oxide(PGO) was then drop-coated on interdigital electrodes and hydrothermal reduced at 180 °C. Controllable reduction was achieved by varying the water amount. The gas sensor based on PRGO-5 min-6h exhibited superior sensing and selective performance toward nitrogen dioxide(NO2), with an exceptional high sensitivity up to 12 ppm-1.The theoretical limit of detection is down to 0.66 ppb. The excellent performance could be mainly attributed to the typical vacancy defects of PRGO. Some residue carboxylic groups on the edges could also facilitate the adsorption of polar molecules. The process has a great potential for scalable fabrication of high-performance NO2gas sensors.展开更多
Few multicity studies have examined the acute effects of nitrogen dioxide(NO_(2))on respiratory disease(RD),especially its specific causes.This study aimed to investigate the associations between short-term exposure t...Few multicity studies have examined the acute effects of nitrogen dioxide(NO_(2))on respiratory disease(RD),especially its specific causes.This study aimed to investigate the associations between short-term exposure to NO_(2)and hospitalization of full-spectrum RDs in China.Hospitalization of 10 major categories and 40 cause-specific RDs were obtained from 20 provinces over the study period of 2013−2020.A time-stratified case-crossover study was conducted at the individual level to explore the associations between NO_(2)and RDs.NO_(2)was significantly associated with increased hospitalization of eight major RDs(acute upper respiratory infections,influenza and pneumonia,acute lower respiratory infections,upper respiratory tract diseases,chronic lower respiratory diseases,respiratory interstitium diseases,pleura diseases,and other respiratory diseases)and 18 specific causes of RDs,with the largest associations observed on lag 0−1 day.The effect estimates ranged from 0.75 to 4.09%per 10μg/m^(3)of NO_(2)exposure.The associations remained robust after controlling for copollutants.The concentration−response curves were mostly positive and linear.This nationwide study provides comprehensive information on the acute effects of NO_(2)on respiratory morbidity across the full spectrum,highlighting the need for caution with regard to this important traffic-related air pollutant in current pollution control programs.展开更多
Mineral dust is one of the major aerosols in the atmosphere.To assess its impact on trace atmospheric gases,in this work we present a laboratory study of the effect of temperature on the heterogeneous reaction of NO2 ...Mineral dust is one of the major aerosols in the atmosphere.To assess its impact on trace atmospheric gases,in this work we present a laboratory study of the effect of temperature on the heterogeneous reaction of NO2 on the surface of ambient Chinese dust over the temperature range from 258 to 313 K.The results suggest that nitrogen dioxide could mainly be adsorbed on these types of Chinese mineral dust reversibly with little temperature dependence.Similar to a previous study on NO2 uptake on mineral aerosols,the uptake coefficients are mainly on the order of 10^（-6） for the Chinese dust,when BET areas are taken into account.HONO was observed as a product,and its formation and decomposition on Chinese mineral dust during the uptake processes were also studied.The complete dataset from this study was compiled with previous literature determinations.Atmospheric implications of the heterogeneous reaction between NO2 and mineral dust are also discussed,in an effort to understand this important heterogeneous process.展开更多
Nitrogen dioxide（NO2） is one of the most common and harmful air pollutants. To analyze the response of plants to NO2 stress, we investigated the morphological change, reactive oxygen species（ROS） production and an...Nitrogen dioxide（NO2） is one of the most common and harmful air pollutants. To analyze the response of plants to NO2 stress, we investigated the morphological change, reactive oxygen species（ROS） production and antioxidant enzyme activity in Arabidopsis thaliana（Col-0） exposed to 1.7, 4, 8.5, and 18.8 mg/m3NO2. The results indicate that NO2 exposure affected plant growth and chlorophyll（Chl） content, and increased oxygen free radical（O2-）production rate in Arabidopsis shoots. Furthermore, NO2 elevated the levels of lipid peroxidation and protein oxidation, accompanied by the induction of antioxidant enzyme activities and change of ascorbate（As A） and glutathione（GSH） contents. Following this, we mimicked nitric acid mist under experimental conditions, and confirmed the antioxidant mechanism of the plant to the stress. Our results imply that NO2 and its acid mist caused pollution risk to plant systems. During the process, increased ROS acted as a signal to induce a defense response, and antioxidant status played an important role in plant protection against NO2/nitric acid mist-caused oxidative damage.展开更多
This paper discusses the findings of the first car MAX-DOAS（multi-axis differential optical absorption spectroscopy） field campaign（300 km long） along the National Highway-05（N5-Highway） of Pakistan conducted on...This paper discusses the findings of the first car MAX-DOAS（multi-axis differential optical absorption spectroscopy） field campaign（300 km long） along the National Highway-05（N5-Highway） of Pakistan conducted on 13 and 14 November, 2012. The main objective of the field campaign was to assess the spatial distribution of tropospheric nitrogen dioxide（NO_2）columns and corresponding concentrations along the N5-Highway from Islamabad to Lahore.Source identification of NO_2 revealed that the concentrations were higher within major cities along the highway. The highest NO_2 vertical column densities（NO_2VCDs） were found around two major cities of Rawalpindi and Lahore. This study also presents a comparison of NO_2 VCDs measured by the ozone monitoring instrument（OMI） and car MAX-DOAS observations. The comparison revealed similar spatial distribution of the NO_2 columns with both car MAX-DOAS and satellite observations, but the car MAX-DOAS observations show much more spatial details. Maximum NO_2 VCD retrieved from car MAX-DOAS observations was up to an order of magnitude larger than the OMI observations in urban areas.展开更多
Suspended particulates （TSP） and nitrogen dioxide （NO2） are known respiratory irritants linked to asthma aggravation. This pilot study was designed to investigate the role of these pollutants on the frequency of a...Suspended particulates （TSP） and nitrogen dioxide （NO2） are known respiratory irritants linked to asthma aggravation. This pilot study was designed to investigate the role of these pollutants on the frequency of asthmatic attack on two of the inhabitants of a household. The surveillance of TSP and NO2 in this household commenced a few hours later, after one of the occupants suffered an attack. The TSP load determination was done using a High Volume Gravimetric sampler and a light scattering method via a Haz-Dust 10 μm particulate monitor. Palmes Diffusion tubes for NO2 and a portable Crowcon Gasman toxic gas detector were utilized for NO2 screening. In the first day of monitoring in the living room, the in situ particulate sampler （Haz-Dust） recorded a mean TSP level of 26,000 μg·m^-3. A confirmatory test with the eight hour average Gravimetric sampler gave 25,833 μg·m^-3. With the use of the Gasman toxic gas detector for NO2, the NO2 concentration for the first few hours of sampling was lower than 188 μg·m^-3, the detection limit of this instrument. However, the exact NO2 concentrations for the 7 day monitoring after the attack were 27.50 μg·m^-3 （kitchen） and 12.03 μg·m^-3 （living room） as recorded by the Palmes diffusion tubes.展开更多
Nitrogen ion was implanted into the nano-TiO2 film surfaces by electron cyclotron resonance （ECR） plasma modification to improve the optical reactivity in visible-light region for nano-TiO2. Diagnosing the N2 plasma...Nitrogen ion was implanted into the nano-TiO2 film surfaces by electron cyclotron resonance （ECR） plasma modification to improve the optical reactivity in visible-light region for nano-TiO2. Diagnosing the N2 plasma by optical emission spectroscopy （OES） was applied to the process of plasma modification. X-ray photoelectron spectroscopy （XPS） was used for analysis of the binding of element after plasma modification. It is shown that the surface modification was caused by excitated N. The injecting of N2 and N＋ leads to the increase in the dissociative interstitial state N in the films. The doped N makes for TiO2-xNx appearing in the TiO2 films. TiO2-xNx forms the impurity energy state in the TiO2 energy band gap and reduces the energy band gap. This is the main reason leading to the red shift of absorption edge.展开更多
Oscillator strengths and cross sections of the valence-shell excitations in NO_(2)are of great significance in testing the theoretical calculations and monitoring the state of the ozone layer in the earth’s atmospher...Oscillator strengths and cross sections of the valence-shell excitations in NO_(2)are of great significance in testing the theoretical calculations and monitoring the state of the ozone layer in the earth’s atmosphere. In the present work, the generalized oscillator strengths of the valence-shell excitations in NO_(2)were obtained based on the fast electron scattering technique at an incident electron energy of 1.5 ke V and an energy resolution of about 70 me V. By extrapolating the generalized oscillator strengths to the limit of a zero squared momentum transfer, the optical oscillator strengths for the dipole-allowed transitions have been obtained, which provide an independent cross check to the previous experimental results. Based on the BE-scaling method, the corresponding integral cross sections have also been derived systematically from the excitation threshold to 5000 eV. The present dynamic parameters can provide the fundamental spectroscopic data of NO_(2)and have important applications in the studies of atmospheric science. The datasets presented in this paper, including the GOSs, OOSs and ICSs, are openly available at https://doi.org/10.57760/sciencedb.j00113.00156.展开更多
Real-time rapid detection of toxic gases at room temperature is particularly important for public health and environmental monitoring.Gas sensors based on conventional bulk materials often suffer from their poor surfa...Real-time rapid detection of toxic gases at room temperature is particularly important for public health and environmental monitoring.Gas sensors based on conventional bulk materials often suffer from their poor surface-sensitive sites,leading to a very low gas adsorption ability.Moreover,the charge transportation efficiency is usually inhibited by the low defect density of surface-sensitive area than that in the interior.In this work,a gas sensing structure model based on CuS quantum dots/Bi_(2)S_(3) nanosheets(CuS QDs/Bi_(2)S_(3) NSs)inspired by artificial neuron network is constructed.Simulation analysis by density functional calculation revealed that CuS QDs and Bi_(2)S_(3) NSs can be used as the main adsorption sites and charge transport pathways,respectively.Thus,the high-sensitivity sensing of NO_(2) can be realized by designing the artificial neuron-like sensor.The experimental results showed that the CuS QDs with a size of about 8 nm are highly adsorbable,which can enhance the NO_(2) sensitivity due to the rich sensitive sites and quantum size effect.The Bi_(2)S_(3) NSs can be used as a charge transfer network channel to achieve efficient charge collection and transmission.The neuron-like sensor that simulates biological smell shows a significantly enhanced response value(3.4),excellent responsiveness(18 s)and recovery rate(338 s),low theoretical detection limit of 78 ppb,and excellent selectivity for NO_(2).Furthermore,the developed wearable device can also realize the visual detection of NO2 through real-time signal changes.展开更多
The explosive spread of the 2019 novel coronavirus(COVID-19)provides a unique chance to rethink the relationship between human activity and air pollution.Though related studies have revealed substantial reductions in ...The explosive spread of the 2019 novel coronavirus(COVID-19)provides a unique chance to rethink the relationship between human activity and air pollution.Though related studies have revealed substantial reductions in primary emissions,obvious differences do exist in the responses of secondary pollutants,like ozone(0_(3))pollution.However,the regional disparities of O_(3)responses and their causes have still not been fully investigated.To better elucidate the interrelationship between anthropogenic emissions,chemical production,and meteorological conditions,O_(3)responses caused by lockdowns over different regions were comprehensively explored at a global scale.Observational signals of air-quality change were derived from multi-year surface measurements and satellite retrievals.With similar substantial drops in nitrogen dioxide(NO_(2)),ozone shows rising signals in most areas of both East Asia and Europe,even up to~14 ppb,while a non-negligible declining signal exists in North America,by about 2-4 ppb.Furthermore,the drivers behind the different O_(3)responses are discussed based on meteorological analysis and O_(3)sensitivity diagnosis.On the one hand,O_(3)responses to NO_(2)declines can be affected by the primary dependence on its precursors.On the other hand,it is also highly dependent on meteorological factors,especially temperature.Our study further highlights the great importance of taking into consideration both the regional disparities and synergistic effects of precursor reductions and meteorological influence for scientific mitigation of O_(3)pollution.展开更多
Objective To investigate whether photochemical smog emitted during the process of electric arc welding might cause oxidative stress and potential oxidative damage in the bodies of welding operators. Methods Seventy...Objective To investigate whether photochemical smog emitted during the process of electric arc welding might cause oxidative stress and potential oxidative damage in the bodies of welding operators. Methods Seventy electric arc welding operators (WOs) and 70 healthy volunteers (HVs) were enrolled in a randomized controlled study design, in which the levels of vitamin C (VC) and vitamin E (VE) in plasma as well as the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX), and the level of lipoperoxide (LPO) in erythrocytes were determined by spectrophotometry. Results Compared with the average values of the above experimental parameters in the HVs group, the average values of VC and VE in plasma as well as those of SOD, CAT and GPX in erythrocytes in the WOs group were significantly decreased (P<0.005-0.0001), while the average value of LPO in erythrocytes in the WOs group was significantly increased (P<0.0001). The findings from the partial correlation analysis on the controlling of age suggested that with a prolonged duration of exposure to photochemical smog the values of VC, VE, SOD, and GPX, except for CAT, in the WOs were decreased gradually (P<0.05-0.005), the value of LPO in the WOs was increased gradually (P<0.001), and that with the ozone dose increased in the air in each worksite VC, VE, SOD, CAT and GPX decreased (P<0.005-0.001), but LPO increased (P<0.001). The findings from the reliability analysis for the VC, VE, SOD, CAT, GPX, and LPO values which were used to reflect oxidative stress and potential oxidative damage in the WOs showed that the reliability coefficients?alpha (6 items) was 0.8021, P<0.0001, and that the standardized item alpha was 0.9577, P<0.0001. Conclusion Findings in the present study suggest that there exists an oxidative stress induced by long-term exposure to photochemical smog in the bodies of WOs, thereby causing potential oxidative and lipoperoxidative damages in their bodies.展开更多
The NO2 molecule adsorption on B12N12 nano-cage was investigated using density functional theory calculations in terms of adsorption energy, HOMO/LUMO energy gap （Eg） changes, charge transfer, structural deformation...The NO2 molecule adsorption on B12N12 nano-cage was investigated using density functional theory calculations in terms of adsorption energy, HOMO/LUMO energy gap （Eg） changes, charge transfer, structural deformation, etc. Furthermore, some aspects of stability and properties of B12N12 including calculation of binding electronic and Gibbs free energies, density of states, and molecular electrostatic potential surfaces are investigated. Three possible configurations for NO2 adsorption on the B12N12 nano-cage are energetically found. Interestingly, the results reveals that the Eg of B12N12 cluster is very sensitive to the pres- ence of NO2 molecules as its value reduces from 6.84 eV in free cluster to 3.23 eV in the most stable configuration of NO2/cluster complex. This phenomenon dramatically increases the electrical conductivity of the cluster, suggesting that the B12N12 nano-cluster may be potential sensor for NO2 gaseous molecule detection.展开更多
Chitosan membrane was modified by the selective oxidization of chitosan molecules on its surface with NO2 gas. FTIR spectra indicated there were plenty of –COOH and –COO- groups on the modified membrane surface. The...Chitosan membrane was modified by the selective oxidization of chitosan molecules on its surface with NO2 gas. FTIR spectra indicated there were plenty of –COOH and –COO- groups on the modified membrane surface. The SEM study showed the modified membrane surface was rough rather than smooth as chitosan membrane. All antithrombosis test, hemolysis test and blood cell morphology observation with SEM revealed that modified chitosan membranes have superior blood compatibility to chitosan.展开更多
A new efficient synthesis of p-nitrocalix[4]arene from calix[4]arene by using nitrogen dioxide is described. The compound is an useful intermediates for the introduction of other functional groups to obtain N containi...A new efficient synthesis of p-nitrocalix[4]arene from calix[4]arene by using nitrogen dioxide is described. The compound is an useful intermediates for the introduction of other functional groups to obtain N containing substituted calix[4]arene. The reaction mechanism is briefly discussed.展开更多
Directive(EU)2017/164 establishes a fourth list of indicative occupational exposure limit values(IOELVs)to protect workers from risks of exposure to hazardous chemicals.It states that in underground mining and tunnell...Directive(EU)2017/164 establishes a fourth list of indicative occupational exposure limit values(IOELVs)to protect workers from risks of exposure to hazardous chemicals.It states that in underground mining and tunnelling,Member States may benefit from a transitional period regarding IOELVs for nitrogen monoxide,nitrogen dioxide,and carbon monoxide,during which the existing established IOELVs may be applied.The European Advisory Committee on Health and Safety at Work questions the technical feasibility of the proposed IOELVs in underground mining(CO,NO and NO2)and tunnelling(NO and NO2).Challenges arise concerning the availability of measurement methodologies for compliance with proposed IOELVs(NO2)in underground mining and tunnelling environments.展开更多
文摘This study will both compare and contrast the characteristics and roles of two pollutants: nitrogen dioxide and carbon monoxide. It will begin by tracing each gas’ negative contributions to the Earth’s spheres, as well as relate any negative links that each plays concerning human activity, health, and interaction with the environment. It will include an in-depth analysis of what the proliferation of such toxic gases indicates about human production and causality, plus reflect on any current attempts being made to improve the effects of these pollutants on the environment. This examination will also inspect three NASA missions, i.e., MOPITT/Terra, AIRS/Aqua, and OMI/Aura, the aim of which, among many other tasks, is to detect pollutants within the Earth’s various spheres, as well as analyze weather anomalies, improve prediction methodology, and chronicle meteorological patterns for future study. It will also cover some of the goals, engineering breakthroughs, and in one case, the limitations, of these three satellite missions. Finally, it should be noted that in all stages of this discussion, the author’s main aim will be to focus on the positives that need to be implemented in order to improve the current situations that both anthropogenic and natural disasters have created for the planet.
基金the National Natural Science Foundation of China （30570445） Natural Science Foundation of Liaoning Province, China （20021022）+1 种基金 Tackle Key Problem of Science and Technology, Education Department of Liaoning Province, China （2004D005）and Director Foundation of ExperimentalCentre, Shenyang Normal University, China （SY200406）.
文摘This article investigates the responses of Brassica campestris seedlings to an acute level of nitrogen dioxide （NO2） exposure in a plant growth chamber, and examines whether pretreating plants with hydrogen peroxide （H2O2） will alleviate NO2-caused injury. Twenty-eight-day-old B. campestris plants sprayed with 10 mmol L^-1 H2O2 aqueous solution （corresponding to approximate 1.0 mg H2O2 per single plant） were exposed to different concentrations of NO2 （0.25, 0.5, 1.0, and 2.0 μL L^-1, respectively） for 24 h under controlled environment. To measure the plant biomass, the plants were fumigated with the same NO2 concentrations as mentioned above for 7 h per day （8.00-15.00） for 7 days. As a control, charcoal filtered air alone was applied. Data were collected on plant biomass, total chlorophyll, photosynthetic rate, stomatal conductance, nitrate and nitrate reductase （NR）, antioxidative enzymes, ascorbate （ASA）, and malondialdehyde （MDA）, immediately after exposure. The results showed that exposure to a moderate dose of NO2 （e.g., 0.25 μL L^-1） had a favorable effect on plants, and the dry weight of the above-ground part increased, whereas the exposure to high NO2 concentrations （e.g., 0.5 μL L^-1 or higher） caused a reduction in the plant biomass and the total chlorophyll, when compared with the control. In addition, at 0.5 μL L^-1 or higher NO2 concentrations, prominent increases in the MDA level and superoxide dismutase （SOD） and NR activities were observed. Exposure to 1 μL L^-1 and higher NO2 resulted in necroses appearing on older leaves, and an increase in catalase （CAT） activity, decrease in ASA content, increased accumulation of NO3^-, and reduction in photosynthesis, when compared with the controls. No changes were detected in stomatal conductance under NO2 fumigation. The pretreatment with 10 mmol L^-1 H2O2 alleviated significantly NO2- caused biomass decrease and photosynthetic inhibition when compared with H2O2-untreated plants. Under NO2 fumigation, further induction in SOD and CAT activities occurred in H2O2 treated plants when compared with H2O2- untreated plants. The effect of NO2 on the ASA and MDA contents was also absent in H2O2-treated plants. However, the H2O2 treatment did not alter the nitrate content and NR activity in plants under NO2 fumigation. The H2O2 treatment caused a lower rate of stomatal conductance. Taken together, these data suggest that fumigation with an acute level of NO2 causes oxidative damage to B. campestris seedlings. The H2O2 pretreatment markedly protects plants against NO2 stress and this may be associated with inducible antioxidative level. NO2 fumigation contributes, at least in part, to the enhanced levels of nitrate in B. campestris leaves.
文摘Stored peanuts often need treatments to control microbial infections as well as insects to maintain postharvest quality. Nitric oxide (NO) is a recently discovered fumigant for postharvest pest control. NO fumigation must be conducted under ultralow oxygen condition to preserve NO and always contains NO<sub>2</sub> due to NO reaction with oxygen and NO<sub>2</sub> has antimicrobial property. Therefore, NO fumigation has potential to control both pests and pathogens. In this study, we evaluated antimicrobial effects of NO<sub>2</sub> fumigation on unpasteurized unshelled peanuts. Peanuts were fumigated with 0.3%, 1.0%, and 3.0% NO<sub>2</sub> for three days at 25<span style="white-space:nowrap;"><span style="white-space:nowrap;"><span style="white-space:nowrap;">˚</span></span></span>C by injecting NO gas into glass jars to react with O<sub>2</sub> in the atmosphere. After fumigation, wash-off microbial samples were collected from intact peanut samples and, then, cracked open peanut samples with non-selective tryptic soy broth medium. The wash-off samples were then diluted with both the non-selective medium and a fungal-selective potato dextrose broth medium and were tested on GreenLight<span style="white-space:nowrap;"><sup><span style="white-space:nowrap;"><span style="white-space:nowrap;">™</span></span></sup></span> rapid enumeration test based on oxygen depletion on culture medium. All three NO<sub>2</sub> fumigation treatments showed significant antibacterial and antifungal effects on intact peanuts as well as on cracked peanuts with complete inhibition with 3.0% NO<sub>2</sub>. Fumigation did not have obvious effects on appearance of skinned peanut kernels. These results suggested that NO<sub>2</sub> fumigation has potential to control microbes on stored products, and NO fumigation with the combination of NO and NO<sub>2</sub> has potential to control both insects and microbes on stored products.
文摘As a severe environmental pollutant, detection and quantitation of nitrogen dioxide (NO<sub>2</sub>) have been studied for centuries. In this review, recent progress of NO<sub>2</sub> analysis in the atmosphere will be summarized. Four major types of detection technologies, including traditional chemical detection, optical detection, solid-state field effect transistor detection, and other detection technology are covered. The standard method employed by the US EPA, which is based on luminol, is the most reliable and robust method that is used for fully validated monitoring. In the past two decades, accompanying the fast development of electrical engineering and integrated circuit, micro to nanoscale gas sensors have been gaining more and more attention. Application of novel materials including nano wires and graphene also leads to a new era of research and development of sensors.
基金financially supported by the National Natural Science Foundation of China(No.52072184)Tianjin Research Innovation Project for Postgraduate Students(General Project,No.2022BKY035)。
文摘Highly selective and remotely communicable nitrogen dioxide(NO_(2))sensing may contribute to future Internet of Things in environmental monitoring.However,room-temperature NO_(2)sensing materials such as carbon materials is still less than satisfactory due to their insensitive interaction with target gas.Here,polyethylene imine functionalized three-dimensional(3D)carbon framework(PEI/C framework)has been developed for enhanced selective NO_(2)sensing,via combined template synthesis and subsequent doping.Typically,the 3D PEI/C framework is observed porous shape with irregular coating.Beneficially,the response of C framework to NO_(2)increases while those of interfering gases decrease after being functionalized with PEI.Remarkably,the sensor prototypes show a 100 ppb-concentration detection limit at room temperature.Theoretically,such excellent NO_(2)sensing is attributed to the large specific surface ratio of porous 3D PEI/C framework,in which PEI serves as an active layer for target NO_(2),while a passivated one for interfering gases.Practically,such PEI/C framework sensor prototype is simulated for NO_(2)sensing device and communicated with a smartphone,showing great potential in future intelligent environmental monitoring.
基金financially supported by National Natural Science Foundation of China (No. 52073302)。
文摘The defect engineering in graphene plays a significant role for the application of gas sensors. In this work, we proposed an efficient method to prepare ultrasensitive gas sensors based on the porous reduced graphene oxide(PRGO). Photo-Fenton etching was carried out on GO nanosheets in a controlled manner to enrich their vacancy defects. The resulting porous graphene oxide(PGO) was then drop-coated on interdigital electrodes and hydrothermal reduced at 180 °C. Controllable reduction was achieved by varying the water amount. The gas sensor based on PRGO-5 min-6h exhibited superior sensing and selective performance toward nitrogen dioxide(NO2), with an exceptional high sensitivity up to 12 ppm-1.The theoretical limit of detection is down to 0.66 ppb. The excellent performance could be mainly attributed to the typical vacancy defects of PRGO. Some residue carboxylic groups on the edges could also facilitate the adsorption of polar molecules. The process has a great potential for scalable fabrication of high-performance NO2gas sensors.
基金supported by the National Natural Science Foundation of China(Grant Nos.92043301,82103790)the Shanghai International Science and Technology Partnership Project(Grant No.21230780200).
文摘Few multicity studies have examined the acute effects of nitrogen dioxide(NO_(2))on respiratory disease(RD),especially its specific causes.This study aimed to investigate the associations between short-term exposure to NO_(2)and hospitalization of full-spectrum RDs in China.Hospitalization of 10 major categories and 40 cause-specific RDs were obtained from 20 provinces over the study period of 2013−2020.A time-stratified case-crossover study was conducted at the individual level to explore the associations between NO_(2)and RDs.NO_(2)was significantly associated with increased hospitalization of eight major RDs(acute upper respiratory infections,influenza and pneumonia,acute lower respiratory infections,upper respiratory tract diseases,chronic lower respiratory diseases,respiratory interstitium diseases,pleura diseases,and other respiratory diseases)and 18 specific causes of RDs,with the largest associations observed on lag 0−1 day.The effect estimates ranged from 0.75 to 4.09%per 10μg/m^(3)of NO_(2)exposure.The associations remained robust after controlling for copollutants.The concentration−response curves were mostly positive and linear.This nationwide study provides comprehensive information on the acute effects of NO_(2)on respiratory morbidity across the full spectrum,highlighting the need for caution with regard to this important traffic-related air pollutant in current pollution control programs.
基金supported by the National Basic Research Program (973) of Ministry of Science and Technology of China (No.2011CB403401)the National Natural Science Foundation of China (Nos.21190052,41173112,and 41475114)the Strategic Priority Research Program (B) of the Chinese Academy of Sciences (No.XDB05010400)
文摘Mineral dust is one of the major aerosols in the atmosphere.To assess its impact on trace atmospheric gases,in this work we present a laboratory study of the effect of temperature on the heterogeneous reaction of NO2 on the surface of ambient Chinese dust over the temperature range from 258 to 313 K.The results suggest that nitrogen dioxide could mainly be adsorbed on these types of Chinese mineral dust reversibly with little temperature dependence.Similar to a previous study on NO2 uptake on mineral aerosols,the uptake coefficients are mainly on the order of 10^（-6） for the Chinese dust,when BET areas are taken into account.HONO was observed as a product,and its formation and decomposition on Chinese mineral dust during the uptake processes were also studied.The complete dataset from this study was compiled with previous literature determinations.Atmospheric implications of the heterogeneous reaction between NO2 and mineral dust are also discussed,in an effort to understand this important heterogeneous process.
基金supported by the National Natural Science Foundation of China (Nos.21477070, 21377076)the Specialized Research Fund for the Doctoral Program of Higher Education (SRFDP) (Nos.20121401110003, 20131401110005)+2 种基金the Project for Science and Technology Development of Shanxi Province (No.20120313009-2)the Research Project supported by the Shanxi Scholarship Council of China (No.2012-009)the Program for the Top Young and Middle aged Innovative Talents of Higher Learning Institutions of Shanxi (TYMIT, No.20120201)
文摘Nitrogen dioxide（NO2） is one of the most common and harmful air pollutants. To analyze the response of plants to NO2 stress, we investigated the morphological change, reactive oxygen species（ROS） production and antioxidant enzyme activity in Arabidopsis thaliana（Col-0） exposed to 1.7, 4, 8.5, and 18.8 mg/m3NO2. The results indicate that NO2 exposure affected plant growth and chlorophyll（Chl） content, and increased oxygen free radical（O2-）production rate in Arabidopsis shoots. Furthermore, NO2 elevated the levels of lipid peroxidation and protein oxidation, accompanied by the induction of antioxidant enzyme activities and change of ascorbate（As A） and glutathione（GSH） contents. Following this, we mimicked nitric acid mist under experimental conditions, and confirmed the antioxidant mechanism of the plant to the stress. Our results imply that NO2 and its acid mist caused pollution risk to plant systems. During the process, increased ROS acted as a signal to induce a defense response, and antioxidant status played an important role in plant protection against NO2/nitric acid mist-caused oxidative damage.
基金financial support as Master thesis research fund to conduct this study
文摘This paper discusses the findings of the first car MAX-DOAS（multi-axis differential optical absorption spectroscopy） field campaign（300 km long） along the National Highway-05（N5-Highway） of Pakistan conducted on 13 and 14 November, 2012. The main objective of the field campaign was to assess the spatial distribution of tropospheric nitrogen dioxide（NO_2）columns and corresponding concentrations along the N5-Highway from Islamabad to Lahore.Source identification of NO_2 revealed that the concentrations were higher within major cities along the highway. The highest NO_2 vertical column densities（NO_2VCDs） were found around two major cities of Rawalpindi and Lahore. This study also presents a comparison of NO_2 VCDs measured by the ozone monitoring instrument（OMI） and car MAX-DOAS observations. The comparison revealed similar spatial distribution of the NO_2 columns with both car MAX-DOAS and satellite observations, but the car MAX-DOAS observations show much more spatial details. Maximum NO_2 VCD retrieved from car MAX-DOAS observations was up to an order of magnitude larger than the OMI observations in urban areas.
文摘Suspended particulates （TSP） and nitrogen dioxide （NO2） are known respiratory irritants linked to asthma aggravation. This pilot study was designed to investigate the role of these pollutants on the frequency of asthmatic attack on two of the inhabitants of a household. The surveillance of TSP and NO2 in this household commenced a few hours later, after one of the occupants suffered an attack. The TSP load determination was done using a High Volume Gravimetric sampler and a light scattering method via a Haz-Dust 10 μm particulate monitor. Palmes Diffusion tubes for NO2 and a portable Crowcon Gasman toxic gas detector were utilized for NO2 screening. In the first day of monitoring in the living room, the in situ particulate sampler （Haz-Dust） recorded a mean TSP level of 26,000 μg·m^-3. A confirmatory test with the eight hour average Gravimetric sampler gave 25,833 μg·m^-3. With the use of the Gasman toxic gas detector for NO2, the NO2 concentration for the first few hours of sampling was lower than 188 μg·m^-3, the detection limit of this instrument. However, the exact NO2 concentrations for the 7 day monitoring after the attack were 27.50 μg·m^-3 （kitchen） and 12.03 μg·m^-3 （living room） as recorded by the Palmes diffusion tubes.
基金the Guangdong Provincial Natural Science Foundation under grant No. 031502.
文摘Nitrogen ion was implanted into the nano-TiO2 film surfaces by electron cyclotron resonance （ECR） plasma modification to improve the optical reactivity in visible-light region for nano-TiO2. Diagnosing the N2 plasma by optical emission spectroscopy （OES） was applied to the process of plasma modification. X-ray photoelectron spectroscopy （XPS） was used for analysis of the binding of element after plasma modification. It is shown that the surface modification was caused by excitated N. The injecting of N2 and N＋ leads to the increase in the dissociative interstitial state N in the films. The doped N makes for TiO2-xNx appearing in the TiO2 films. TiO2-xNx forms the impurity energy state in the TiO2 energy band gap and reduces the energy band gap. This is the main reason leading to the red shift of absorption edge.
基金Project supported by the National Key Research and Development Program of China (Grant No. 2022YFA1602500)the National Natural Science Foundation of China (Grant Nos. 12334010 and U1932207)。
文摘Oscillator strengths and cross sections of the valence-shell excitations in NO_(2)are of great significance in testing the theoretical calculations and monitoring the state of the ozone layer in the earth’s atmosphere. In the present work, the generalized oscillator strengths of the valence-shell excitations in NO_(2)were obtained based on the fast electron scattering technique at an incident electron energy of 1.5 ke V and an energy resolution of about 70 me V. By extrapolating the generalized oscillator strengths to the limit of a zero squared momentum transfer, the optical oscillator strengths for the dipole-allowed transitions have been obtained, which provide an independent cross check to the previous experimental results. Based on the BE-scaling method, the corresponding integral cross sections have also been derived systematically from the excitation threshold to 5000 eV. The present dynamic parameters can provide the fundamental spectroscopic data of NO_(2)and have important applications in the studies of atmospheric science. The datasets presented in this paper, including the GOSs, OOSs and ICSs, are openly available at https://doi.org/10.57760/sciencedb.j00113.00156.
基金supported by the National Natural Science Foundation of China(61971284)the Oceanic Interdisciplinary Program of Shanghai Jiao Tong University(SL2020ZD203 and SL2020MS031)+2 种基金Scientific Research Fund of Second Institute of Oceanography,Ministry of Natural Resources of P.R.China(SL2003)Shanghai Sailing Program(21YF1421400)Startup Fund for Youngman Research at Shanghai Jiao Tong University.
文摘Real-time rapid detection of toxic gases at room temperature is particularly important for public health and environmental monitoring.Gas sensors based on conventional bulk materials often suffer from their poor surface-sensitive sites,leading to a very low gas adsorption ability.Moreover,the charge transportation efficiency is usually inhibited by the low defect density of surface-sensitive area than that in the interior.In this work,a gas sensing structure model based on CuS quantum dots/Bi_(2)S_(3) nanosheets(CuS QDs/Bi_(2)S_(3) NSs)inspired by artificial neuron network is constructed.Simulation analysis by density functional calculation revealed that CuS QDs and Bi_(2)S_(3) NSs can be used as the main adsorption sites and charge transport pathways,respectively.Thus,the high-sensitivity sensing of NO_(2) can be realized by designing the artificial neuron-like sensor.The experimental results showed that the CuS QDs with a size of about 8 nm are highly adsorbable,which can enhance the NO_(2) sensitivity due to the rich sensitive sites and quantum size effect.The Bi_(2)S_(3) NSs can be used as a charge transfer network channel to achieve efficient charge collection and transmission.The neuron-like sensor that simulates biological smell shows a significantly enhanced response value(3.4),excellent responsiveness(18 s)and recovery rate(338 s),low theoretical detection limit of 78 ppb,and excellent selectivity for NO_(2).Furthermore,the developed wearable device can also realize the visual detection of NO2 through real-time signal changes.
基金This research was supported by the National Natural Science Foundation of China[grant numbers 91744311 and 41922038]the International Cooperation project of Jiangsu Provincial Science and Technology Agency[grant number BZ2017066].
文摘The explosive spread of the 2019 novel coronavirus(COVID-19)provides a unique chance to rethink the relationship between human activity and air pollution.Though related studies have revealed substantial reductions in primary emissions,obvious differences do exist in the responses of secondary pollutants,like ozone(0_(3))pollution.However,the regional disparities of O_(3)responses and their causes have still not been fully investigated.To better elucidate the interrelationship between anthropogenic emissions,chemical production,and meteorological conditions,O_(3)responses caused by lockdowns over different regions were comprehensively explored at a global scale.Observational signals of air-quality change were derived from multi-year surface measurements and satellite retrievals.With similar substantial drops in nitrogen dioxide(NO_(2)),ozone shows rising signals in most areas of both East Asia and Europe,even up to~14 ppb,while a non-negligible declining signal exists in North America,by about 2-4 ppb.Furthermore,the drivers behind the different O_(3)responses are discussed based on meteorological analysis and O_(3)sensitivity diagnosis.On the one hand,O_(3)responses to NO_(2)declines can be affected by the primary dependence on its precursors.On the other hand,it is also highly dependent on meteorological factors,especially temperature.Our study further highlights the great importance of taking into consideration both the regional disparities and synergistic effects of precursor reductions and meteorological influence for scientific mitigation of O_(3)pollution.
文摘Objective To investigate whether photochemical smog emitted during the process of electric arc welding might cause oxidative stress and potential oxidative damage in the bodies of welding operators. Methods Seventy electric arc welding operators (WOs) and 70 healthy volunteers (HVs) were enrolled in a randomized controlled study design, in which the levels of vitamin C (VC) and vitamin E (VE) in plasma as well as the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX), and the level of lipoperoxide (LPO) in erythrocytes were determined by spectrophotometry. Results Compared with the average values of the above experimental parameters in the HVs group, the average values of VC and VE in plasma as well as those of SOD, CAT and GPX in erythrocytes in the WOs group were significantly decreased (P<0.005-0.0001), while the average value of LPO in erythrocytes in the WOs group was significantly increased (P<0.0001). The findings from the partial correlation analysis on the controlling of age suggested that with a prolonged duration of exposure to photochemical smog the values of VC, VE, SOD, and GPX, except for CAT, in the WOs were decreased gradually (P<0.05-0.005), the value of LPO in the WOs was increased gradually (P<0.001), and that with the ozone dose increased in the air in each worksite VC, VE, SOD, CAT and GPX decreased (P<0.005-0.001), but LPO increased (P<0.001). The findings from the reliability analysis for the VC, VE, SOD, CAT, GPX, and LPO values which were used to reflect oxidative stress and potential oxidative damage in the WOs showed that the reliability coefficients?alpha (6 items) was 0.8021, P<0.0001, and that the standardized item alpha was 0.9577, P<0.0001. Conclusion Findings in the present study suggest that there exists an oxidative stress induced by long-term exposure to photochemical smog in the bodies of WOs, thereby causing potential oxidative and lipoperoxidative damages in their bodies.
文摘The NO2 molecule adsorption on B12N12 nano-cage was investigated using density functional theory calculations in terms of adsorption energy, HOMO/LUMO energy gap （Eg） changes, charge transfer, structural deformation, etc. Furthermore, some aspects of stability and properties of B12N12 including calculation of binding electronic and Gibbs free energies, density of states, and molecular electrostatic potential surfaces are investigated. Three possible configurations for NO2 adsorption on the B12N12 nano-cage are energetically found. Interestingly, the results reveals that the Eg of B12N12 cluster is very sensitive to the pres- ence of NO2 molecules as its value reduces from 6.84 eV in free cluster to 3.23 eV in the most stable configuration of NO2/cluster complex. This phenomenon dramatically increases the electrical conductivity of the cluster, suggesting that the B12N12 nano-cluster may be potential sensor for NO2 gaseous molecule detection.
基金Financial support for this work from Natural Science Foundation of Hebei Province(No.B2004000402).
文摘Chitosan membrane was modified by the selective oxidization of chitosan molecules on its surface with NO2 gas. FTIR spectra indicated there were plenty of –COOH and –COO- groups on the modified membrane surface. The SEM study showed the modified membrane surface was rough rather than smooth as chitosan membrane. All antithrombosis test, hemolysis test and blood cell morphology observation with SEM revealed that modified chitosan membranes have superior blood compatibility to chitosan.
文摘A new efficient synthesis of p-nitrocalix[4]arene from calix[4]arene by using nitrogen dioxide is described. The compound is an useful intermediates for the introduction of other functional groups to obtain N containing substituted calix[4]arene. The reaction mechanism is briefly discussed.
文摘Directive(EU)2017/164 establishes a fourth list of indicative occupational exposure limit values(IOELVs)to protect workers from risks of exposure to hazardous chemicals.It states that in underground mining and tunnelling,Member States may benefit from a transitional period regarding IOELVs for nitrogen monoxide,nitrogen dioxide,and carbon monoxide,during which the existing established IOELVs may be applied.The European Advisory Committee on Health and Safety at Work questions the technical feasibility of the proposed IOELVs in underground mining(CO,NO and NO2)and tunnelling(NO and NO2).Challenges arise concerning the availability of measurement methodologies for compliance with proposed IOELVs(NO2)in underground mining and tunnelling environments.
