In order to improve electrokinetic remediation efficiency of cadmium-contaminated soil,the effects of electric field intensity,remediation time and electrolyte on removal rate of total Cd in Cd-contaminated soil by el...In order to improve electrokinetic remediation efficiency of cadmium-contaminated soil,the effects of electric field intensity,remediation time and electrolyte on removal rate of total Cd in Cd-contaminated soil by electrokinetic remediation were studied through the preparation of Cd-contaminated soil and the construction of electrokinetic remediation equipment. The results showed that under the same condition,with the electric field intensity increasing from 2. 5 to 3 V/cm,the total Cd removal rate increased by 10. 62%,and with the increase of the electric field intensity from 3 to 3. 5 V/cm,the removal rate increased by 1. 87%;when the remediation time was prolonged from 72 to 96 h,the removal rate of total Cd increased by 6. 68%,and with the remediation time prolonged from 96 to120 h,the removal rate of total Cd increased by 8. 75%; and with the remediation time prolonged from 120 to 144 h,the removal rate of total Cd only increased by1. 07%. Compared with citric acid as the electrolyte,the acetic acid group improved the remediation efficiency by 12. 14% and the total energy consumption by62. 13%,while the hydrochloric acid group improved the remediation efficiency by 18. 04% and the total energy consumption by 187. 9%. Comprehensively from total Cd removal rate and energy consumption,the remediation effect was the best under the electric field intensity of 3 V/cm and the electrokinetic time of 120 h with acetic acid as the electrolyte,which achieved a total Cd removal rate of 41. 95%.展开更多
Various MnO2 structures have been extensively applied in catalysis. In this study,γ-MnO2,α-MnO2, and δ-MnO2 with corresponding rod, tube, and hierarchical architecture morphologies were prepared and applied for the...Various MnO2 structures have been extensively applied in catalysis. In this study,γ-MnO2,α-MnO2, and δ-MnO2 with corresponding rod, tube, and hierarchical architecture morphologies were prepared and applied for the catalytic oxidation of chlorobenzene (CB). The redox ability, H2O activation behavior, and acidity of MnO2 were analyzed using a range of techniques, including TPR, H2O-TPD, XPS, and pyridine-IR. The catalytic activities in CB oxidation were assessed;this revealed that γ-MnO2 exhibited the highest activity and best stability, owing to its enriched surface oxygen vacancies that functioned to activate O2 and H2O, and capture labile chlorine, which reacted with dissociated H2O to form HCl. All the MnO2 phases generated toxic polychlorinated by-products, including CHCl3, CCl4, C2HCl3, and C2Cl4, indicating the occurrence of electrophilic chlorination during CB oxidation. In particular, the dichlorobenzene detected in the effluents of α-MnO2 might generate unintended dioxins via a nucleophilic substitution reaction.展开更多
We incubated eggs of five Phrynocephalus species (P. albolineatus, P. axillaries, P. grumgrzimailoi, P. helioscopus and P. przewalskii) at three constant temperatures (24℃, 28℃ and 32℃) to examine differences i...We incubated eggs of five Phrynocephalus species (P. albolineatus, P. axillaries, P. grumgrzimailoi, P. helioscopus and P. przewalskii) at three constant temperatures (24℃, 28℃ and 32℃) to examine differences in incubation length and hatchling morphology among species and among temperature treatments. We combined data from this study with those reported previously for P. frontalis and P. versicolor to examine whether embryonic stage at laying is a causal factor for interspecific variation in incubation length, and whether the phylogenetic relationship inferred from hatchling morphology is consistent with the relationship based on mitochondrial DNA data. Mean values for incubation length differed among the five species studied herein and, in all these five species, incubation length decreased at a decreasing rate as temperature increased. In none of the five species did hatchling size (snout-vent length and body mass) and other morphological variables differ among the three temperature treatments. The seven oviparous Phrynocephalus lizards found in China differ from each other in hatchling morphology, and embryonic stage at laying is a causal factor of inter- and intra-specific variation in incubation length. The phylogenetic relationship inferred from hatchling morphology is not always consistent with the currently known relationship based on mitochondrial DNA data. Data from this study and those reported previously allow the conclusion that any Phrynocephalus species may have its unique position along the axis defined by hatchling morphology.展开更多
China experienced worsening ground-level ozone(O_(2)) pollution from 2013 to 2019. In this study, meteorological parameters, including surface temperature(T_(2)), solar radiation(SW), and wind speed(WS), were classifi...China experienced worsening ground-level ozone(O_(2)) pollution from 2013 to 2019. In this study, meteorological parameters, including surface temperature(T_(2)), solar radiation(SW), and wind speed(WS), were classified into two aspects,(1) Photochemical Reaction Condition(PRC = T_(2)× SW) and(2) Physical Dispersion Capacity(PDC = WS). In this way, a Meteorology Synthetic Index(MSI = PRC/PDC) was developed for the quantification of meteorology-induced ground-level O_(2)pollution. The positive linear relationship between the 90 th percentile of MDA8(maximum daily 8-h average) O_(2)concentration and MSI determined that the contribution of meteorological changes to ground-level O-3 varied on a latitudinal gradient, decreasing from ~40% in southern China to 10%–20% in northern China. Favorable photochemical reaction conditions were more important for ground-level O_(2)pollution. This study proposes a universally applicable index for fast diagnosis of meteorological roles in ground-level O_(2)variability, which enables the assessment of the observed effects of precursor emissions reductions that can be used for designing future control policies.展开更多
Atmospheric chemistry research has been growing rapidly in China in the last 25 years since the concept of the“air pollution complex”was first proposed by Professor Xiaoyan TANG in 1997.For papers published in 2021 ...Atmospheric chemistry research has been growing rapidly in China in the last 25 years since the concept of the“air pollution complex”was first proposed by Professor Xiaoyan TANG in 1997.For papers published in 2021 on air pollution(only papers included in the Web of Science Core Collection database were considered),more than 24000 papers were authored or co-authored by scientists working in China.In this paper,we review a limited number of representative and significant studies on atmospheric chemistry in China in the last few years,including studies on(1)sources and emission inventories,(2)atmospheric chemical processes,(3)interactions of air pollution with meteorology,weather and climate,(4)interactions between the biosphere and atmosphere,and(5)data assimilation.The intention was not to provide a complete review of all progress made in the last few years,but rather to serve as a starting point for learning more about atmospheric chemistry research in China.The advances reviewed in this paper have enabled a theoretical framework for the air pollution complex to be established,provided robust scientific support to highly successful air pollution control policies in China,and created great opportunities in education,training,and career development for many graduate students and young scientists.This paper further highlights that developing and low-income countries that are heavily affected by air pollution can benefit from these research advances,whilst at the same time acknowledging that many challenges and opportunities still remain in atmospheric chemistry research in China,to hopefully be addressed over the next few decades.展开更多
The title compound [Cu (ADC) (2, 2'-bipy)]n (ADC = C2 (COO)2^2.) was prepared and characterized by elemental analysis, IR spectroscopy, X-ray analysis, respectively. The analysis of the crystal structure reve...The title compound [Cu (ADC) (2, 2'-bipy)]n (ADC = C2 (COO)2^2.) was prepared and characterized by elemental analysis, IR spectroscopy, X-ray analysis, respectively. The analysis of the crystal structure reveals that the copper atom is five-coordinated with two nitrogen atoms of 2, 2'-bipy and three oxygen atoms of different acetylenedicarboxylate dianions. ADC as bridging ligands link the Cu (Ⅱ) ions, forming coordination polymer structure.展开更多
In order to improve the catalytic ozonation effect of resorcinol, the spinel CuFe_2O_4 was modified by doped CeO_2, and X-ray diffraction(XRD) and scanning electron microscopy(SEM) were used for characterization analy...In order to improve the catalytic ozonation effect of resorcinol, the spinel CuFe_2O_4 was modified by doped CeO_2, and X-ray diffraction(XRD) and scanning electron microscopy(SEM) were used for characterization analysis. The effects of composite catalyst CeO_2/CuFe_2O_4 dosage, ozone dosage, initial pH and reaction temperature on degradation were studied, and the stability of the catalyst was tested. The results showed that the composite effect of CeO_2/CuFe_2O_4 prepared by combustion method was good, and the catalyst presented a laminated structure, in which 30 wt% CeO_2/CuFe_2O_4 degradation effect was significant. The removal rate of resorcinol using CeO_2/CuFe_2O_4 composite catalyst was higher than that using ozone or CuFe_2O_4 separately by 41.8% and 11.9%, respectively. In a reaction with resorcinol concentration of 100 mg/L, the catalyst dosage of 1.0 g/L, the ozone dosage of 2.5 mg/(L·min), at pH=9, temperature of 20 ℃, for reaction time of 40 min, the resorcinol removal rate was 88.5%. The catalyst CeO_2/CuFe_2O_4 still showed good degradation effect after repeatedly using for 10 times, and the dissolution rate of metal ions was lower than that of CuFe_2O_4.展开更多
Qian Cao(Radix et Rhizoma Rubiae)is a perennial grass with red and yellow pigments in its roots.It has been used since ancient times for fabric dyeing and painting,and it’s the oldest red dye in both Europe and China...Qian Cao(Radix et Rhizoma Rubiae)is a perennial grass with red and yellow pigments in its roots.It has been used since ancient times for fabric dyeing and painting,and it’s the oldest red dye in both Europe and China.Xi Yang Qian(Rubia tirctorum L.)spread from the East to the West,while Zhong Guo Qian(Rubia cordifolia L.)spread from the West to the East.Both were integral in the development of Chinese and Western color cultures.Nowadays,although it is no longer commonly used in dyes and paints,Qian Cao is still used in clinical medicine as a medicinal herb.展开更多
1 The introduction of black walnut(Juglans nigra)from North America to Europe Black walnut is a Juglans tree native to the North America plains.It features a tall and dense canopy up to 20 or 30 m high.The timber is d...1 The introduction of black walnut(Juglans nigra)from North America to Europe Black walnut is a Juglans tree native to the North America plains.It features a tall and dense canopy up to 20 or 30 m high.The timber is dense and hard,making it suitable for woodworks.The natural dark color and beautiful grain are usually preserved in woodworks to reveal its unique chocolate hue.展开更多
BACKGROUND Emergency sepsis is a common and serious infectious disease,and its prognosis is influenced by a number of factors.AIM To analyse the factors influencing the prognosis of patients with emergency sepsis in o...BACKGROUND Emergency sepsis is a common and serious infectious disease,and its prognosis is influenced by a number of factors.AIM To analyse the factors influencing the prognosis of patients with emergency sepsis in order to provide a basis for individualised patient treatment and care.By retrospectively analysing the clinical data collected,we conducted a comprehensive analysis of factors such as age,gender,underlying disease,etiology and site of infection,inflammatory indicators,multi-organ failure,cardiovascular function,therapeutic measures,immune status and severity of infection.METHODS Data collection:Clinical data were collected from patients diagnosed with acute sepsis,including basic information,laboratory findings,medical history and treatment options.Variable selection:Variables associated with prognosis were selected,including age,gender,underlying disease,etiology and site of infection,inflammatory indicators,multi-organ failure,cardiovascular function,treatment measures,immune status and severity of infection.Data analysis:The data collected are analysed using appropriate statistical methods such as multiple regression analysis and survival analysis.The impact of each factor on prognosis was assessed according to prognostic indicators,such as survival,length of stay and complication rates.RESULTS Descriptive statistics:Descriptive statistics were performed on the data collected from the patients,including their basic characteristics and clinical presentation.CONCLUSION Type 2 diabetes mellitus were independent factors affecting the prognosis of patients with sepsis.展开更多
In thousands of years from the Pre-Qin Dynasty to the Qing Dynasty,crimson represents sacredness and good fortune in several dynasties and is honored in the hierarchy of colors.Meanwhile,introduction to the exotic Mat...In thousands of years from the Pre-Qin Dynasty to the Qing Dynasty,crimson represents sacredness and good fortune in several dynasties and is honored in the hierarchy of colors.Meanwhile,introduction to the exotic Materia Medica for dyeing from the Silk Road trade greatly expands the dyeing category of red color.The exotic red dyestuff is eventually integrated into the red culture of the Central Plains through the localization process.Therefore,it becomes the color symbol on behalf of Chinese nation.展开更多
With the features of convenience and eco-friendly, the low-temperature solid-state reaction synthesis was successfully developed as a new approach to prepare quantum-sized ZnS nanocrystals. One major achievement is th...With the features of convenience and eco-friendly, the low-temperature solid-state reaction synthesis was successfully developed as a new approach to prepare quantum-sized ZnS nanocrystals. One major achievement is that the size and shape of ZnS nanocrystals can be tuned by adjusting the surfactant and its feed. The UV-Vis absorption spectra of quasispherical and one-dimensional quantum-sized ZnS nanocrystals all showed a blue-shift from the bulk counterpart, indicating large quantum confinement effects of ZnS nanocrystals. These ZnS nanocrystals all showed well-defined excitonic emission features. Contrastive studies on photoluminescence performances indicated that the bandedge emission experienced only the size-dependent quantum confinement effect, while the trap-state emission experienced the size- and shape-dependences. So we can design a purposeful synthesis route to ZnS nanocrystals with target luminescence emission performances.展开更多
In this paper, we study the inertial manifolds for a class of asymmetrically coupled generalized Higher-order Kirchhoff equations. Under appropriate assumptions, we firstly exist Hadamard’s graph transformation metho...In this paper, we study the inertial manifolds for a class of asymmetrically coupled generalized Higher-order Kirchhoff equations. Under appropriate assumptions, we firstly exist Hadamard’s graph transformation method to structure a graph norm of a Lipschitz continuous function, then we prove the existence of a family of inertial manifolds by showing that the spectral gap condition is true.展开更多
In this paper, we study the long-term dynamic behavior of a class of generalized high-order Kirchhoff-type coupled wave equations. Firstly, the existence of uniqueness global solution of this kind of equations in E<...In this paper, we study the long-term dynamic behavior of a class of generalized high-order Kirchhoff-type coupled wave equations. Firstly, the existence of uniqueness global solution of this kind of equations in E<sub>k</sub> space is proved by prior estimation and Galerkin method;Then, through using Rellich-Kondrachov compact embedding theorem, it is proved that the solution semigroup S(t) has the family of the global attractors A<sub>k</sub> in space E<sub>k</sub>;Finally, through linearization method, proves that the operator semigroup S(t) Frechet differentiable and the attenuation of linearization problem volume element. Furthermore, we can obtain the finite Hausdorff dimension and Fractal dimension of the family of the global attractors A<sub>k</sub>.展开更多
Introduction Human serum albumin(HSA)is a non-glycosylated,negatively charged,single-chain polypeptide composed of 585 amino acid residues with a relative molecular mass of 66.438 kD.It is synthesized by the liver at ...Introduction Human serum albumin(HSA)is a non-glycosylated,negatively charged,single-chain polypeptide composed of 585 amino acid residues with a relative molecular mass of 66.438 kD.It is synthesized by the liver at a rate of approximately 200 mg·kg^(-1)·day^(-1),with a half-life of 21 days,and subjected to catabolism in the muscles,liver,and kidneys at a rate of 4%per day.[1]Albumin,accounting for 60%of the total plasma protein,has various physiological functions,[2]such as maintaining 70%to 80%of effective plasma colloid osmotic pressure,coordinating vascular endothelial integrity,anti-oxidant and anti-inflammatory activities,maintaining the acidbase balance,and participating in the transport,distribution,and metabolism of a variety of endogenous and exogenous substances.展开更多
Background:Hirschsprung's disease (HSCR) is a congenital gut motility disorder of infants,and if left untreated,it is fatal to the affected infants.This study aimed to identify key microRNAs (miRNAs),signaling pat...Background:Hirschsprung's disease (HSCR) is a congenital gut motility disorder of infants,and if left untreated,it is fatal to the affected infants.This study aimed to identify key microRNAs (miRNAs),signaling pathways and genes involved in the pathogenesis of HSCR.Methods:The miRNA microarray dataset GSE77296 was downloaded.Nine colon tissue samples were available:six from HSCR patients and three matched control samples.Differentially expressed miRNAs (DEMs) were identified after data preprocessing.Target genes of the selected upregulated and downregulated DEMs were predicted.In addition,functional enrichment analyses for the selected DEMs and target genes were conducted.Finally,interaction networks between the DEMs and target genes were constructed.Results:A total of 162 DEMs (73 upregulated and 89 downregulated) were obtained.A total of 2511 DEM-target gene pairs for the 40 selected DEMs were identified,including 1645 pairs for the upregulated DEMs and 866 pairs for the downregulated DEMs.The upregulated DEM miR-141-3p and down-regulated DEM miR-30a-3p were identified as key miRNAs by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment and network analyses.Besides,KEGG pathway enrichment analysis revealed that pathways in cancer and the mitogen-activated protein kinase (MAPK) signaling pathway were key pathways.The key genes frizzled class receptor 3 (FZD3) and docking protein 6 (DOK6) were obtained through the DEM-target gene interaction networks.Conclusion:Two key miRNAs (miR-141-3p and miR-30a-3p),the MAPK signaling pathway and two key genes (FZD3 and DOK6) were implicated in the pathogenesis of HSCR.展开更多
The heterogeneous loss of HO_(2)radicals onto ambient aerosols plays an important role in tropospheric chemistry.However,sparse investigation of the dominating parameters controlling the HO_(2)uptake coefficients onto...The heterogeneous loss of HO_(2)radicals onto ambient aerosols plays an important role in tropospheric chemistry.However,sparse investigation of the dominating parameters controlling the HO_(2)uptake coefficients onto ambient aerosols(γHO_(2))has largely hindered the application of the measuredγHO_(2)to the global spatial prediction.Here we induced an offine method using LFP-LIF technique to measure the kinetics of HO_(2)uptake onto ambient aerosols collected in summertime and wintertime in Yokohama city,a regional urban site near Tokyo,Japan.By controlling the dominating parameters which infuenceγHO_(2),we were able to investigate the detailed HO_(2)uptake mechanism.We characterized the chemical composition of the collected ambient aerosols,including organics,inorganics,transition metals ions,etc.and modeledγHO_(2)using different mechanisms.Results show thatγHO_(2)increased with the increase in RH,and the aerosol states(“dry”or wet/aqueous)have large effects onγHO_(2).With fixed RH and aerosol chemical composition,γHO_(2)was highly dependent on pH and inversely correlated with[HO_(2)]_0.By combing the measuredγHO_(2)values with the modeled ones,we found that both the HO_(2)self-reaction and transition metal-catalyzed reactions should be accounted for to yield a single parameterization to predictγHO_(2),and different chemical compositions may have collective effects onγHO_(2).Results may serve for extending theγHO_(2)values measured at one observation site to different environmental conditions,which will help us to achieve more accurate modeling results concerning secondary pollutant formation(i.e.,ozone).展开更多
In the troposphere, ozone is a harmful gas compound to both human health and vegetation. Ozone is produced from the reaction of NO_x(@NO + NO_2) and VOCs(volatile organic compounds) with light. Due to the highly nonli...In the troposphere, ozone is a harmful gas compound to both human health and vegetation. Ozone is produced from the reaction of NO_x(@NO + NO_2) and VOCs(volatile organic compounds) with light. Due to the highly nonlinear relationships between ozone and its precursors, proper ozone mitigation relies on the knowledge of chemical mechanisms. In this study, an observation-based method is used to simulate ozone formation and elucidate its controlling factors for a rural site on the North China Plain. The instantaneous ozone production rate is calculated utilizing a box model using the dataset obtained from the Wangdu campaign. First, the model was operated in a time-dependent mode to calculate the ozone production rate at each time stamp. The calculated ozone formation rate showed a diurnal average maximum value of 17 ppbv/h(1-h diurnal averaged). The contribution of individual peroxy radicals to ozone production was analyzed. In addition, the functional dependence of calculated P(O_3) reveals that ozone production was in a NO_x-limited regime during the campaign. Furthermore, the missing peroxy radical source will further extend NO_x-limited conditions to earlier in the day, making NO_xlimitation dominate more of a day than the current chemical model predicts. Finally, a multiple scenarios mode,also known as EKMA(empirical kinetic modeling approach), was used to simulate the response of P(O_3) to the imaginary change in precursor concentrations. We found that ozone production was in the NO_x-limited region. However, the use of NO_2 measured by the molybdenum converter and/or the absence of a peroxy radical source in the current chemical model could over-emphasize the VOC-limited effect on ozone production.展开更多
Regional ozone (O3) pollution has drawn increasing attention in China over the recent decade, but the contributions from urban pollution and biogenic emissions have not been clearly elucidated. To better understand ...Regional ozone (O3) pollution has drawn increasing attention in China over the recent decade, but the contributions from urban pollution and biogenic emissions have not been clearly elucidated. To better understand the formation of the regional O3 problem in the North China Plain (NCP), intensive field measurements of O3 and related parameters were conducted at a rural site downwind of Ji'nan, the capital city of Shandong province, in the summer of 2013. Markedly severe 03 pollution was recorded, with the 03 mixing ratios exceeding the Chinese national ambient air quality standard on 28 days (a frequency of 78%) and with a maximum hourly value of 198 ppbv. Extensive regional transport of well-processed urban plumes to the site was identified. An observation-constrained chemical box model was deployed to evaluate in situ photochemical O3 production on two episodes. The results show that the in situ formation accounted for approximately 46% of the observed O3 accumulation, while the remainder (54%) was contributed by regional transport of the O3-laden urban plumes. The in situ ozone production was in a mixed controlled regime that reducing either NOx or VOCs would lead to a reduction of ozone formation. Biogenic VOCs played an important role in the local ozone formation. This study demonstrates the significant mixed effects of both anthropogenic pollution from urban zones and biogenic emission in rural areas on the regional 03 pollution in the NCP region, and may have general applicability in facilitating the understanding of the formation of secondary pollution over China.展开更多
Volatile organic compounds (VOCs) play important roles in the atmosphere via three main pathways: photochemical ozone formation, secondary organic aerosol production, and direct toxicity to humans. Fewstudies have ...Volatile organic compounds (VOCs) play important roles in the atmosphere via three main pathways: photochemical ozone formation, secondary organic aerosol production, and direct toxicity to humans. Fewstudies have integrated these effect, s to prioritize control measures for VOC.s sources. In this study,we developed a multi-effects evaluation methodology based on updated emission inventories and source profiles, by combining the ozone formation potential (OFP), secondary organic aerosol potential (SOAP), and VOC toxicity data. We derived species-specific emission inventories for 152 sources. The OFPs, SOAPs, and toxicity of each source were estimated, the contribution and sharing of source to each of these adverse effects were calculated. Weightings were given to the three adverse effects by expert scoring, and then the integrated effect was determined. Taking 2012 as the base year,solvent use and industrial process were found to be the most important anthropogenic sources, accounting for 24.2% and 23.1% of the integrated effect, respectively, followed by biomass burning, transportation, and fossil fuel combustion, each had a similar contribution ranging from 16.7% to 18.6%. The top five industrial sources, including plastic products, rubber products, chemical fiberproducts, the chemical industry, and oil refining, accounted for nearly 70.0% of industrial emissions. Beijing, Chongqing, Shanghai, Jiangsu, and Guangdong were the five provinces contributing the largest integrated effects. For the VOC species from emissions showed the largest contributions were styrene, toluene, ethylene, benzene, and m/p-xylene.展开更多
基金Supported by National Science Foundation of China(41641032)
文摘In order to improve electrokinetic remediation efficiency of cadmium-contaminated soil,the effects of electric field intensity,remediation time and electrolyte on removal rate of total Cd in Cd-contaminated soil by electrokinetic remediation were studied through the preparation of Cd-contaminated soil and the construction of electrokinetic remediation equipment. The results showed that under the same condition,with the electric field intensity increasing from 2. 5 to 3 V/cm,the total Cd removal rate increased by 10. 62%,and with the increase of the electric field intensity from 3 to 3. 5 V/cm,the removal rate increased by 1. 87%;when the remediation time was prolonged from 72 to 96 h,the removal rate of total Cd increased by 6. 68%,and with the remediation time prolonged from 96 to120 h,the removal rate of total Cd increased by 8. 75%; and with the remediation time prolonged from 120 to 144 h,the removal rate of total Cd only increased by1. 07%. Compared with citric acid as the electrolyte,the acetic acid group improved the remediation efficiency by 12. 14% and the total energy consumption by62. 13%,while the hydrochloric acid group improved the remediation efficiency by 18. 04% and the total energy consumption by 187. 9%. Comprehensively from total Cd removal rate and energy consumption,the remediation effect was the best under the electric field intensity of 3 V/cm and the electrokinetic time of 120 h with acetic acid as the electrolyte,which achieved a total Cd removal rate of 41. 95%.
基金supported by the Outstanding Youth Project of Zhejiang Natural Science Foundation(LR19E080004)the National Natural Science Foundation of China(51478418)~~
文摘Various MnO2 structures have been extensively applied in catalysis. In this study,γ-MnO2,α-MnO2, and δ-MnO2 with corresponding rod, tube, and hierarchical architecture morphologies were prepared and applied for the catalytic oxidation of chlorobenzene (CB). The redox ability, H2O activation behavior, and acidity of MnO2 were analyzed using a range of techniques, including TPR, H2O-TPD, XPS, and pyridine-IR. The catalytic activities in CB oxidation were assessed;this revealed that γ-MnO2 exhibited the highest activity and best stability, owing to its enriched surface oxygen vacancies that functioned to activate O2 and H2O, and capture labile chlorine, which reacted with dissociated H2O to form HCl. All the MnO2 phases generated toxic polychlorinated by-products, including CHCl3, CCl4, C2HCl3, and C2Cl4, indicating the occurrence of electrophilic chlorination during CB oxidation. In particular, the dichlorobenzene detected in the effluents of α-MnO2 might generate unintended dioxins via a nucleophilic substitution reaction.
基金supported by grants from the National Natural Science Foundation of China (31071910 and 31200282)Priority Academic Program Development of Jiangsu Higher Education Institutions and High Academic Talent Foundation of Nanjing Forestry University (GXL201306)
文摘We incubated eggs of five Phrynocephalus species (P. albolineatus, P. axillaries, P. grumgrzimailoi, P. helioscopus and P. przewalskii) at three constant temperatures (24℃, 28℃ and 32℃) to examine differences in incubation length and hatchling morphology among species and among temperature treatments. We combined data from this study with those reported previously for P. frontalis and P. versicolor to examine whether embryonic stage at laying is a causal factor for interspecific variation in incubation length, and whether the phylogenetic relationship inferred from hatchling morphology is consistent with the relationship based on mitochondrial DNA data. Mean values for incubation length differed among the five species studied herein and, in all these five species, incubation length decreased at a decreasing rate as temperature increased. In none of the five species did hatchling size (snout-vent length and body mass) and other morphological variables differ among the three temperature treatments. The seven oviparous Phrynocephalus lizards found in China differ from each other in hatchling morphology, and embryonic stage at laying is a causal factor of inter- and intra-specific variation in incubation length. The phylogenetic relationship inferred from hatchling morphology is not always consistent with the currently known relationship based on mitochondrial DNA data. Data from this study and those reported previously allow the conclusion that any Phrynocephalus species may have its unique position along the axis defined by hatchling morphology.
基金supported by the National Key Research and Development Plan(Grant No.2017YFC0210105)the second Tibetan Plateau Scientific Expedition and Research Program(Grant No.2019QZKK0604)+7 种基金the National Natural Science Foundation of China(Grant Nos.41905086,41905107,42077205,and 41425020)the Special Fund Project for Science and Technology Innovation Strategy of Guangdong Province(Grant No.2019B121205004)the China Postdoctoral Science Foundation(Grant No.2020M683174)the Air Quip(High-resolution Air Quality Information for Policy)Project funded by the Research Council of Norwaythe Collaborative Innovation Center of Climate ChangeJiangsu ProvinceChinathe high-performance computing platform of Jinan University。
文摘China experienced worsening ground-level ozone(O_(2)) pollution from 2013 to 2019. In this study, meteorological parameters, including surface temperature(T_(2)), solar radiation(SW), and wind speed(WS), were classified into two aspects,(1) Photochemical Reaction Condition(PRC = T_(2)× SW) and(2) Physical Dispersion Capacity(PDC = WS). In this way, a Meteorology Synthetic Index(MSI = PRC/PDC) was developed for the quantification of meteorology-induced ground-level O_(2)pollution. The positive linear relationship between the 90 th percentile of MDA8(maximum daily 8-h average) O_(2)concentration and MSI determined that the contribution of meteorological changes to ground-level O-3 varied on a latitudinal gradient, decreasing from ~40% in southern China to 10%–20% in northern China. Favorable photochemical reaction conditions were more important for ground-level O_(2)pollution. This study proposes a universally applicable index for fast diagnosis of meteorological roles in ground-level O_(2)variability, which enables the assessment of the observed effects of precursor emissions reductions that can be used for designing future control policies.
基金funded by the National Natural Science Foundation of China(Grant No.91844000)。
文摘Atmospheric chemistry research has been growing rapidly in China in the last 25 years since the concept of the“air pollution complex”was first proposed by Professor Xiaoyan TANG in 1997.For papers published in 2021 on air pollution(only papers included in the Web of Science Core Collection database were considered),more than 24000 papers were authored or co-authored by scientists working in China.In this paper,we review a limited number of representative and significant studies on atmospheric chemistry in China in the last few years,including studies on(1)sources and emission inventories,(2)atmospheric chemical processes,(3)interactions of air pollution with meteorology,weather and climate,(4)interactions between the biosphere and atmosphere,and(5)data assimilation.The intention was not to provide a complete review of all progress made in the last few years,but rather to serve as a starting point for learning more about atmospheric chemistry research in China.The advances reviewed in this paper have enabled a theoretical framework for the air pollution complex to be established,provided robust scientific support to highly successful air pollution control policies in China,and created great opportunities in education,training,and career development for many graduate students and young scientists.This paper further highlights that developing and low-income countries that are heavily affected by air pollution can benefit from these research advances,whilst at the same time acknowledging that many challenges and opportunities still remain in atmospheric chemistry research in China,to hopefully be addressed over the next few decades.
文摘The title compound [Cu (ADC) (2, 2'-bipy)]n (ADC = C2 (COO)2^2.) was prepared and characterized by elemental analysis, IR spectroscopy, X-ray analysis, respectively. The analysis of the crystal structure reveals that the copper atom is five-coordinated with two nitrogen atoms of 2, 2'-bipy and three oxygen atoms of different acetylenedicarboxylate dianions. ADC as bridging ligands link the Cu (Ⅱ) ions, forming coordination polymer structure.
基金Supported by the National Natural Science Foundation of China(41772240)
文摘In order to improve the catalytic ozonation effect of resorcinol, the spinel CuFe_2O_4 was modified by doped CeO_2, and X-ray diffraction(XRD) and scanning electron microscopy(SEM) were used for characterization analysis. The effects of composite catalyst CeO_2/CuFe_2O_4 dosage, ozone dosage, initial pH and reaction temperature on degradation were studied, and the stability of the catalyst was tested. The results showed that the composite effect of CeO_2/CuFe_2O_4 prepared by combustion method was good, and the catalyst presented a laminated structure, in which 30 wt% CeO_2/CuFe_2O_4 degradation effect was significant. The removal rate of resorcinol using CeO_2/CuFe_2O_4 composite catalyst was higher than that using ozone or CuFe_2O_4 separately by 41.8% and 11.9%, respectively. In a reaction with resorcinol concentration of 100 mg/L, the catalyst dosage of 1.0 g/L, the ozone dosage of 2.5 mg/(L·min), at pH=9, temperature of 20 ℃, for reaction time of 40 min, the resorcinol removal rate was 88.5%. The catalyst CeO_2/CuFe_2O_4 still showed good degradation effect after repeatedly using for 10 times, and the dissolution rate of metal ions was lower than that of CuFe_2O_4.
基金This study was financed by the grant from the National Social Science Fund of China(No.18BG126).
文摘Qian Cao(Radix et Rhizoma Rubiae)is a perennial grass with red and yellow pigments in its roots.It has been used since ancient times for fabric dyeing and painting,and it’s the oldest red dye in both Europe and China.Xi Yang Qian(Rubia tirctorum L.)spread from the East to the West,while Zhong Guo Qian(Rubia cordifolia L.)spread from the West to the East.Both were integral in the development of Chinese and Western color cultures.Nowadays,although it is no longer commonly used in dyes and paints,Qian Cao is still used in clinical medicine as a medicinal herb.
基金financed by the grant from the National Social Science Fund of China(No.18BG126)。
文摘1 The introduction of black walnut(Juglans nigra)from North America to Europe Black walnut is a Juglans tree native to the North America plains.It features a tall and dense canopy up to 20 or 30 m high.The timber is dense and hard,making it suitable for woodworks.The natural dark color and beautiful grain are usually preserved in woodworks to reveal its unique chocolate hue.
文摘BACKGROUND Emergency sepsis is a common and serious infectious disease,and its prognosis is influenced by a number of factors.AIM To analyse the factors influencing the prognosis of patients with emergency sepsis in order to provide a basis for individualised patient treatment and care.By retrospectively analysing the clinical data collected,we conducted a comprehensive analysis of factors such as age,gender,underlying disease,etiology and site of infection,inflammatory indicators,multi-organ failure,cardiovascular function,therapeutic measures,immune status and severity of infection.METHODS Data collection:Clinical data were collected from patients diagnosed with acute sepsis,including basic information,laboratory findings,medical history and treatment options.Variable selection:Variables associated with prognosis were selected,including age,gender,underlying disease,etiology and site of infection,inflammatory indicators,multi-organ failure,cardiovascular function,treatment measures,immune status and severity of infection.Data analysis:The data collected are analysed using appropriate statistical methods such as multiple regression analysis and survival analysis.The impact of each factor on prognosis was assessed according to prognostic indicators,such as survival,length of stay and complication rates.RESULTS Descriptive statistics:Descriptive statistics were performed on the data collected from the patients,including their basic characteristics and clinical presentation.CONCLUSION Type 2 diabetes mellitus were independent factors affecting the prognosis of patients with sepsis.
文摘In thousands of years from the Pre-Qin Dynasty to the Qing Dynasty,crimson represents sacredness and good fortune in several dynasties and is honored in the hierarchy of colors.Meanwhile,introduction to the exotic Materia Medica for dyeing from the Silk Road trade greatly expands the dyeing category of red color.The exotic red dyestuff is eventually integrated into the red culture of the Central Plains through the localization process.Therefore,it becomes the color symbol on behalf of Chinese nation.
文摘With the features of convenience and eco-friendly, the low-temperature solid-state reaction synthesis was successfully developed as a new approach to prepare quantum-sized ZnS nanocrystals. One major achievement is that the size and shape of ZnS nanocrystals can be tuned by adjusting the surfactant and its feed. The UV-Vis absorption spectra of quasispherical and one-dimensional quantum-sized ZnS nanocrystals all showed a blue-shift from the bulk counterpart, indicating large quantum confinement effects of ZnS nanocrystals. These ZnS nanocrystals all showed well-defined excitonic emission features. Contrastive studies on photoluminescence performances indicated that the bandedge emission experienced only the size-dependent quantum confinement effect, while the trap-state emission experienced the size- and shape-dependences. So we can design a purposeful synthesis route to ZnS nanocrystals with target luminescence emission performances.
文摘In this paper, we study the inertial manifolds for a class of asymmetrically coupled generalized Higher-order Kirchhoff equations. Under appropriate assumptions, we firstly exist Hadamard’s graph transformation method to structure a graph norm of a Lipschitz continuous function, then we prove the existence of a family of inertial manifolds by showing that the spectral gap condition is true.
文摘In this paper, we study the long-term dynamic behavior of a class of generalized high-order Kirchhoff-type coupled wave equations. Firstly, the existence of uniqueness global solution of this kind of equations in E<sub>k</sub> space is proved by prior estimation and Galerkin method;Then, through using Rellich-Kondrachov compact embedding theorem, it is proved that the solution semigroup S(t) has the family of the global attractors A<sub>k</sub> in space E<sub>k</sub>;Finally, through linearization method, proves that the operator semigroup S(t) Frechet differentiable and the attenuation of linearization problem volume element. Furthermore, we can obtain the finite Hausdorff dimension and Fractal dimension of the family of the global attractors A<sub>k</sub>.
基金the Wisdom Medical Research Project of Shanghai Municipal Health Commission(No.2018ZHYL0227)the Shanghai Science and Technology Commission(No.20DZ2200500).
文摘Introduction Human serum albumin(HSA)is a non-glycosylated,negatively charged,single-chain polypeptide composed of 585 amino acid residues with a relative molecular mass of 66.438 kD.It is synthesized by the liver at a rate of approximately 200 mg·kg^(-1)·day^(-1),with a half-life of 21 days,and subjected to catabolism in the muscles,liver,and kidneys at a rate of 4%per day.[1]Albumin,accounting for 60%of the total plasma protein,has various physiological functions,[2]such as maintaining 70%to 80%of effective plasma colloid osmotic pressure,coordinating vascular endothelial integrity,anti-oxidant and anti-inflammatory activities,maintaining the acidbase balance,and participating in the transport,distribution,and metabolism of a variety of endogenous and exogenous substances.
文摘Background:Hirschsprung's disease (HSCR) is a congenital gut motility disorder of infants,and if left untreated,it is fatal to the affected infants.This study aimed to identify key microRNAs (miRNAs),signaling pathways and genes involved in the pathogenesis of HSCR.Methods:The miRNA microarray dataset GSE77296 was downloaded.Nine colon tissue samples were available:six from HSCR patients and three matched control samples.Differentially expressed miRNAs (DEMs) were identified after data preprocessing.Target genes of the selected upregulated and downregulated DEMs were predicted.In addition,functional enrichment analyses for the selected DEMs and target genes were conducted.Finally,interaction networks between the DEMs and target genes were constructed.Results:A total of 162 DEMs (73 upregulated and 89 downregulated) were obtained.A total of 2511 DEM-target gene pairs for the 40 selected DEMs were identified,including 1645 pairs for the upregulated DEMs and 866 pairs for the downregulated DEMs.The upregulated DEM miR-141-3p and down-regulated DEM miR-30a-3p were identified as key miRNAs by Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment and network analyses.Besides,KEGG pathway enrichment analysis revealed that pathways in cancer and the mitogen-activated protein kinase (MAPK) signaling pathway were key pathways.The key genes frizzled class receptor 3 (FZD3) and docking protein 6 (DOK6) were obtained through the DEM-target gene interaction networks.Conclusion:Two key miRNAs (miR-141-3p and miR-30a-3p),the MAPK signaling pathway and two key genes (FZD3 and DOK6) were implicated in the pathogenesis of HSCR.
基金supported by the Key-Area Research and Development Program of Guangdong Province (No.2020B1111360003)the Japan Society for the Promotion of Science (JSPS,No.16H06305)the Natural Science Foundation of Guangdong Province (No.2020A1515110526)。
文摘The heterogeneous loss of HO_(2)radicals onto ambient aerosols plays an important role in tropospheric chemistry.However,sparse investigation of the dominating parameters controlling the HO_(2)uptake coefficients onto ambient aerosols(γHO_(2))has largely hindered the application of the measuredγHO_(2)to the global spatial prediction.Here we induced an offine method using LFP-LIF technique to measure the kinetics of HO_(2)uptake onto ambient aerosols collected in summertime and wintertime in Yokohama city,a regional urban site near Tokyo,Japan.By controlling the dominating parameters which infuenceγHO_(2),we were able to investigate the detailed HO_(2)uptake mechanism.We characterized the chemical composition of the collected ambient aerosols,including organics,inorganics,transition metals ions,etc.and modeledγHO_(2)using different mechanisms.Results show thatγHO_(2)increased with the increase in RH,and the aerosol states(“dry”or wet/aqueous)have large effects onγHO_(2).With fixed RH and aerosol chemical composition,γHO_(2)was highly dependent on pH and inversely correlated with[HO_(2)]_0.By combing the measuredγHO_(2)values with the modeled ones,we found that both the HO_(2)self-reaction and transition metal-catalyzed reactions should be accounted for to yield a single parameterization to predictγHO_(2),and different chemical compositions may have collective effects onγHO_(2).Results may serve for extending theγHO_(2)values measured at one observation site to different environmental conditions,which will help us to achieve more accurate modeling results concerning secondary pollutant formation(i.e.,ozone).
基金supported from the research projects of the Environmental Public Welfare Industry in China (201509001,201409005)the National Science and Technology Support Program of China (2014BAC21B01)+2 种基金the Strategic Priority Research Program of the Chinese Academy of Sciences (XDB05010500)the Special Fund of State Key Joint Laboratory of Environment Simulation and Pollution Control (18K03ESPCP)the EU-project AMIS (Fate and Impact of Atmospheric Pollutants,PIRSES-GA-2011295132)
文摘In the troposphere, ozone is a harmful gas compound to both human health and vegetation. Ozone is produced from the reaction of NO_x(@NO + NO_2) and VOCs(volatile organic compounds) with light. Due to the highly nonlinear relationships between ozone and its precursors, proper ozone mitigation relies on the knowledge of chemical mechanisms. In this study, an observation-based method is used to simulate ozone formation and elucidate its controlling factors for a rural site on the North China Plain. The instantaneous ozone production rate is calculated utilizing a box model using the dataset obtained from the Wangdu campaign. First, the model was operated in a time-dependent mode to calculate the ozone production rate at each time stamp. The calculated ozone formation rate showed a diurnal average maximum value of 17 ppbv/h(1-h diurnal averaged). The contribution of individual peroxy radicals to ozone production was analyzed. In addition, the functional dependence of calculated P(O_3) reveals that ozone production was in a NO_x-limited regime during the campaign. Furthermore, the missing peroxy radical source will further extend NO_x-limited conditions to earlier in the day, making NO_xlimitation dominate more of a day than the current chemical model predicts. Finally, a multiple scenarios mode,also known as EKMA(empirical kinetic modeling approach), was used to simulate the response of P(O_3) to the imaginary change in precursor concentrations. We found that ozone production was in the NO_x-limited region. However, the use of NO_2 measured by the molybdenum converter and/or the absence of a peroxy radical source in the current chemical model could over-emphasize the VOC-limited effect on ozone production.
基金funded by the Taishan Scholar Grand (No. ts20120552)the National Natural Science Foundation of China (No. 41375126)+2 种基金supported by the National Natural Science Foundation of China (No. 41675118)the Qilu Youth Talent Programme of Shandong Universitythe Jiangsu Collaborative Innovation Center for Climate Change
文摘Regional ozone (O3) pollution has drawn increasing attention in China over the recent decade, but the contributions from urban pollution and biogenic emissions have not been clearly elucidated. To better understand the formation of the regional O3 problem in the North China Plain (NCP), intensive field measurements of O3 and related parameters were conducted at a rural site downwind of Ji'nan, the capital city of Shandong province, in the summer of 2013. Markedly severe 03 pollution was recorded, with the 03 mixing ratios exceeding the Chinese national ambient air quality standard on 28 days (a frequency of 78%) and with a maximum hourly value of 198 ppbv. Extensive regional transport of well-processed urban plumes to the site was identified. An observation-constrained chemical box model was deployed to evaluate in situ photochemical O3 production on two episodes. The results show that the in situ formation accounted for approximately 46% of the observed O3 accumulation, while the remainder (54%) was contributed by regional transport of the O3-laden urban plumes. The in situ ozone production was in a mixed controlled regime that reducing either NOx or VOCs would lead to a reduction of ozone formation. Biogenic VOCs played an important role in the local ozone formation. This study demonstrates the significant mixed effects of both anthropogenic pollution from urban zones and biogenic emission in rural areas on the regional 03 pollution in the NCP region, and may have general applicability in facilitating the understanding of the formation of secondary pollution over China.
基金This study was funded by the Natural Science Foundation for Outstanding Young Scholars (Grant No. 41125018) and Natural Science Foundation Key Project (Grant No. 41330635). The fimding source was involved in the data collection of this paper.
文摘Volatile organic compounds (VOCs) play important roles in the atmosphere via three main pathways: photochemical ozone formation, secondary organic aerosol production, and direct toxicity to humans. Fewstudies have integrated these effect, s to prioritize control measures for VOC.s sources. In this study,we developed a multi-effects evaluation methodology based on updated emission inventories and source profiles, by combining the ozone formation potential (OFP), secondary organic aerosol potential (SOAP), and VOC toxicity data. We derived species-specific emission inventories for 152 sources. The OFPs, SOAPs, and toxicity of each source were estimated, the contribution and sharing of source to each of these adverse effects were calculated. Weightings were given to the three adverse effects by expert scoring, and then the integrated effect was determined. Taking 2012 as the base year,solvent use and industrial process were found to be the most important anthropogenic sources, accounting for 24.2% and 23.1% of the integrated effect, respectively, followed by biomass burning, transportation, and fossil fuel combustion, each had a similar contribution ranging from 16.7% to 18.6%. The top five industrial sources, including plastic products, rubber products, chemical fiberproducts, the chemical industry, and oil refining, accounted for nearly 70.0% of industrial emissions. Beijing, Chongqing, Shanghai, Jiangsu, and Guangdong were the five provinces contributing the largest integrated effects. For the VOC species from emissions showed the largest contributions were styrene, toluene, ethylene, benzene, and m/p-xylene.