Luminescent radicals have attracted extensive attention due to the unique emission properties from the doublet spin state.However,luminescent radicals are predominantly chloroarylmethyl radicals that emit light in the...Luminescent radicals have attracted extensive attention due to the unique emission properties from the doublet spin state.However,luminescent radicals are predominantly chloroarylmethyl radicals that emit light in the red and near-infrared spectral regions,and the blue emitting radicals remain scarcely reported.Herein,two novel boron-containing dioxoborocyclic blue-luminescent radicals were designed and synthesized by combining dioxoborocyclic radicals with thiophene units.They were characterized by single-crystal X-ray diffraction,UV-Vis spectroscopy,electron paramagnetic resonance(EPR)spectroscopy,and fluorescence spectroscopy in conjunction with theoretical calculations.Theoretical calculations demonstrate that both radicals 3a and 3b emit blue light from the anti-Kasha emission attributed to the effective suppression of IC pathways.Our work offers definitive proof that the boron-containing radical system functions as a highly efficient platform for expanding the diversity of short-wavelength emissive radicals.展开更多
Ambient ozone(O_(3))is generated through the reactions of nitrogen oxides and volatile organic compounds(VOCs)in sunlight,and the primary sources of RO_(x)radicals play a very important role in O_(3)photochemistry.How...Ambient ozone(O_(3))is generated through the reactions of nitrogen oxides and volatile organic compounds(VOCs)in sunlight,and the primary sources of RO_(x)radicals play a very important role in O_(3)photochemistry.However,as major precursors of RO_(x)radicals,the systematical evaluation of ClNO_(2),HCHO,and HONO impacts on O_(3)photochemistry remains limited.Here,we utilized the observations of ClNO_(2),HCHO,and HONO conducted in a coastal city of Southeast China during a photochemical O_(3)pollution episode,combined with model simulations to elucidate their impacts on RO_(x)radicals and atmospheric oxidation capacity(AOC),as well as O_(3)formation.Decreased concentrations of ClNO_(2)and HONO were observed after sunrise,while HCHO concentrations peaked in the daytime.HCHO photolysis contributed the largest(∼25%)to RO_(x)radical production around noon,while HONO photolysis(∼47%)dominated RO_(x)radical production in the morning and late afternoon,and VOCs consumed by Cl radical released via ClNO_(2)photolysis was more important(∼10%)in the early morning,similar to their effects on the AOC levels.The results of model simulations indicated that HCHO photolysis greatly enhanced the photochemical formation of O_(3),followed by HONO and ClNO_(2)photolysis.Except for reducing VOCs due to a VOC-limited regime,the impacts of HCHO photolysis as primary RO_(x)sources should be valued to inhibit the intensification of O_(3)pollution.Our study stressed the importance of primary RO_(x)sources for O_(3)photochemistry in coastal regions,provided new insights into elucidating the self-purifying effect of the atmospheric environment.展开更多
Preparing free-base porphyrinoid radicals that can function as coordination ligands is a challenging task.Here we report the synthesis of a stable,free-base benzocorrole(BC)radical containing only two inner NH protons...Preparing free-base porphyrinoid radicals that can function as coordination ligands is a challenging task.Here we report the synthesis of a stable,free-base benzocorrole(BC)radical containing only two inner NH protons via a retro-Diels-Alder conversion.The radical character of BC was fully supported by crystallographic analysis,spectroscopic evidence,and theoretical calculations.This neutral radical ligand allowed easy insertion of Zn(Ⅱ),Ga(Ⅲ),and Pd(Ⅱ)ions to produce radical complexes.All these radicals exhibited luminescence-on responses under weak reducing atmosphere,corresponding to the conversion to their aromatic anions.The red fluorescence was observed for BC and its Zn(Ⅱ)and Ga(Ⅲ)complexes,and the near-infrared phosphorescence(>900 nm)was detected for Pd(Ⅱ)complex at room temperature.Furthermore,Ga(Ⅲ)corrole exhibited a variation in fluorescence in response to axial coordination.Our findings provide a promising radical platform for coordination and developing novel functional materials with switchable spin and emission.展开更多
Six aryl-and pyridine-substituted nitronyl-nitroxide radicals were synthesized and characterized to investigate their optical anisotropic properties.Single-crystal X-ray diffraction analysis revealed molecular packing...Six aryl-and pyridine-substituted nitronyl-nitroxide radicals were synthesized and characterized to investigate their optical anisotropic properties.Single-crystal X-ray diffraction analysis revealed molecular packing organized by either halogen and hydrogen bonding or hydrogen bonding alone.Single-crystal electronic absorption spectra in the visible region of three studied radicals exhibit pronounced linear dichroism,while single crystals of other radicals do not demonstrate this property.Time-dependent DFT and ab initio calculations were employed to determine the transition dipole moment(TDM)vectors corresponding to the long-wavelength absorption bands.For all radicals,these vectors are found to be practically parallel to the O⋯O direction of the nitronyl-nitroxide chromophore.Correlation between the dichroic properties and crystal structure was established through comprehensive analysis of TDM vector orientations relative to the crystal surface.The strongest dichroic effect was observed in crystals where all projections of the TDM vectors onto the illuminated face are parallel to each other,while weaker or absent effects correspond to non-parallel arrangements.This study constitutes the first systematic investigation of linear dichroism in paramagnetic organic crystals,thereby establishing new avenues for developing multifunctional materials that respond to both optical and magnetic stimuli.展开更多
Harnessing bacteria for superoxide production in bioremediation holds immense promise,yet its practical application is hindered by slow production rates and the relatively weak redox potential of superoxide.This study...Harnessing bacteria for superoxide production in bioremediation holds immense promise,yet its practical application is hindered by slow production rates and the relatively weak redox potential of superoxide.This study delves into a cost-effective approach to amplify superoxide production using an Arthrobacter strain,a prevalent soil bacterial genus.Our research reveals that introducing a carbon source along with specific iron-binding ligands,including deferoxamine(DFO),diethylenetriamine pentaacetate(DTPA),citrate,and oxalate,robustly augments microbial superoxide generation.Moreover,our findings suggest that these iron-binding ligands play a pivotal role in converting superoxide into hydroxyl radicals by modulating the electron transfer rate between Fe(Ⅲ)/Fe(Ⅱ)and superoxide.Remarkably,among the tested ligands,only DTPA emerges as a potent promoter of this conversion process when complexed with Fe(Ⅲ).We identify an optimal Fe(Ⅲ)to DTPA ratio of approximately 1:1 for enhancing hydroxyl radical production within the Arthrobacter culture.This research underscores the efficacy of simultaneously introducing carbon sources and DTPA in facilitating superoxide production and its subsequent conversion to hydroxyl radicals,significantly elevating bioremediation performance.Furthermore,our study reveals that DTPA augments superoxide production in cultures of diverse soils,with various soil microorganisms beyond Arthrobacter identified as contributors to superoxide generation.This emphasizes the universal applicability of DTPA across multiple bacterial genera.In conclusion,our study introduces a promising methodology for enhancing microbial superoxide production and its conversion into hydroxyl radicals.These findings hold substantial implications for the deployment of microbial reactive oxygen species in bioremediation,offering innovative solutions for addressing environmental contamination challenges.展开更多
[ Objective ] The research aimed to provide reference for the application of extracts from sweet potato leaves in anti-aging cosmetics. [ Method ] The extraction and storage conditions for free radicals scavenging sub...[ Objective ] The research aimed to provide reference for the application of extracts from sweet potato leaves in anti-aging cosmetics. [ Method ] The extraction and storage conditions for free radicals scavenging substances from sweet potato leaves were optimized by orthogonal test and the bioactive components in extracts were investigated by correlation analysis. [ Result] Sweet potato leaves contain the bioactive substances scavenging DPPH free radical and hydroxyl free radical. Extracting solvent species is the most important factor that influencing extraction yield. The optimal extraction and storage conditions are as following： water as solvent, pH 8.0 of extracting liquid, storage at 25 ℃. There is a good positive linear relationship between the content of total phenols in sweet potato leaves and corresponding scavenging rates against both the DPPH free radical and hydroxyl free radical. For the content of total flavones in sweet potato leaves, just a correlation with scavenging rate against hydroxyl free radical shown in test. [ Conclusion] The phenols in ex- tracts could effectively scavenge both the DPPH free radical and hydroxyl free radical, whereas the flavones in extracts can only function on the hydroxyl free radical.展开更多
[Objective] This study aimed to explore factors influencing the effects of theabrownin in Pu-erh tea on scavenging DPPH radicals. [Method] Taking Pu-erh tea as main research object, theabrownin in Pu-erh tea from tea ...[Objective] This study aimed to explore factors influencing the effects of theabrownin in Pu-erh tea on scavenging DPPH radicals. [Method] Taking Pu-erh tea as main research object, theabrownin in Pu-erh tea from tea piles with different times of mixture, stored for different years and processed by both the old and new techniques were extracted and isolated. And DPPH method was used to study the effects of theabrownin solution and tea liquor on scavenging radicals and their antioxidant activity. [Result] The result showed that the theabrownin content in Pu-erh tea from tea piles with one to four times of mixture revealed a first declining and subsequently rising trend. Under different pH conditions, the rates of DPPH radical scavenging of 1 mg/ml theabrownin solution made from tea piles with different times of mixture decreased gradually with the increase of pH, and all the rates were lower than that of the control vitamin C solution; the rates of DPPH radical scavenging of theabrownin from tea samples stored for different years and produced by different techniques dropped slowly within pH range 3.0-6.0; when pH was higher than 6.0, the rates of DPPH radical scavenging of theabrownin from tea samples produced by both new and traditional techniques in 2001 declined obviously, while the declining trend was not obvious in either the black tea or the Pu-erh tea produced by new technique in 2005. Under different theabrownin concentrations, the rates of DPPH radical scavenging of theabrownin solution made from tea piles with different times of mixture ascended as the concentration increased and the highest rate occurred in tea pile with four times of mixture, reaching up to 46.56%±0.88%; for tea samples stored for different years and produced by different techniques, the rates of DPPH radical scavenging of theabrownin rose gradually with the increase of the theabrownin concentration; the rate of radical scavenging of theabrownin in the black tea ascended obviously and that in Pu-erh tea was decreasing within the concentration range of 0.04 -0.06 mg/ml. At pH6.0, the DPPH radical scavenging ability of theabrownin in 0.1 mg/ml theabrownin solution and tea liquor containing 0.1mg/ml theabrownin from tea piles with different times of mixture ascended with the time of mixture; solution made from tea samples produced by different techniques in different years, the DPPH radical scavenging ability of theabrownin solution and tea liquor followed： Pu-erh tea produced by the new technique in 2001 ﹥ Pu-erh tea produced by the old technique in 2001﹥ Pu-erh tea produced by the new technique in 2005. And the DPPH radical scavenging ability of theabrownin in tea liquor containing 0.1 mg/ml theabrownin was higher than that in 0.1 mg/ml theabrownin Solution made from tea samples either with different times of mixture or produced by different techniques in different years. The above results indicated that many factor influenced the effects of theabrownin on eliminating DPPH radicals, including the time of fermentation, fermentation technique, years of storage, concentration and pH all had great influence on the effects of theabrownin on eliminating radicals. To ensure a good effect on scavenging radicals, it is better to prepare theabrownin at pH6.0 with concentration between 0.08 and 0.1 mg/ml for drinking. [Conclusion] Results of this study provide a basis for developing functional products of theabrownin from Pu-erh tea in the future.展开更多
The contamination of wastewater with organic pollutants and nitrogen compounds poses significant environmental challenges.The primary objective of wastewater treatment is the simultaneous denitrification and decarboni...The contamination of wastewater with organic pollutants and nitrogen compounds poses significant environmental challenges.The primary objective of wastewater treatment is the simultaneous denitrification and decarbonization of ammonia nitrogen and organics into harmless by-products.This study presents a novel method for the directional generation of chlorine radical species like·ClO and·Cl using electro-reactive membranes(EMs)known as RuO_(2)@PbO_(2)-M,which were fabricated using an electro-deposition coupled template approach.This method facilitates the rapid and efficient conversion of ammonia to nitrogen and concurrently reduces the chemical oxygen demand in the effluent.Our system achieved ultra-efficient simultaneous denitrification and decarbonization with minimal energy consumption in single-filtration mode,thereby eliminating the need for chemical precursors.We elucidate the formation pathway of·ClO and·Cl during the electrochemical oxidation process involving RuO_(2)@PbO_(2)-M,where·Cl generated from RuO_(2)reacts with·OH from PbO_(2)under hypochlorous acid conditions,thereby enhancing nitrogen and carbon removal.These findings highlight a novel electro-filtration and an innovative reactive membrane design for·ClO synthesis,which provides a new research framework for the concurrent removal of nitrogen and carbon,and offers a promising solution to enhance wastewater treatment efficiency.展开更多
Generally,gaining fundamental insights into chain processes during the combustion of flame-retardant polymers relies on the qualitative and quantitative characterization of key chain carriers.However,polymer combustio...Generally,gaining fundamental insights into chain processes during the combustion of flame-retardant polymers relies on the qualitative and quantitative characterization of key chain carriers.However,polymer combustion processes based on conventional solid-fuel combustion strategies,due to the high coupling of pyrolysis,combustion,soot formation and oxidation,exhibit relatively high complexity and poor flame stability,and lead to a huge obstacle to the use of optical diagnostics.Herein,a spatial-confinement combustion strategy,which can produce a special staged flame with multi-jets secondary wave,is devised to provide a highly decoupled combustion environment.Glowing soot particles are therefore decoupled from main chemiluminescence region and confined to the flame tip to provide a well-controlled,opticalthin test environment for combustion diagnostic.Based on this strategy,a multi-nozzle-separation(MNS)burner is designed and fabricated,and the combustion processes associated with four model compounds,PVC,PS,PP/TBBA blends and PP/RP blends are investigated by spontaneous spectral diagnosis,and the chemiluminescence fingerprint of key diatomic/triatomic intermediates(such as OH,CH,C_(2),ClO,Br_(2),and PHO)are clearly observed.This encouraging result means that the strategy of spatial-confinement combustion we proposed shows promising prospect in many subjects associated with combustion chain regulation,such as efficient design of flame retardants.展开更多
Oxidative coupling of methane(OCM)is a catalytic partial oxidation process that directly converts methane into C_(2) products.For this high temperature reaction,understanding the radical behavior through experimental ...Oxidative coupling of methane(OCM)is a catalytic partial oxidation process that directly converts methane into C_(2) products.For this high temperature reaction,understanding the radical behavior through experimental investigation is important in correlating the catalytic activity and the products.In this work,a spatial resolution online mass spectrometry(MS)system was developed and applied to a Mn-Na_(2)WO_(4)/SiO_(2) catalyzed OCM system.In addition to the residue gas analysis,the system obtained the distribution information of the reactants and products in the reactor.At various setting temperatures,all species online MS signals were collected at different positions,mapping the reaction activity covering parameters including temperature,time and space.The distribution behavior of the catalytic activity,selectivity,and apparent activation energy were kinetically analyzed.Selectivity and additional carbon balance analysis strongly supported the radical coupling model of OCM and indicated that after the catalytic bed layer,there is a significant length in the reactor(>2 mm)filled with radicals.Based on the result,a designed new method by tuning the temperature field in the reactor was found effectively to improve the catalytic activity,especially the C_(2) yield from 702 to 773℃.展开更多
In this paper, we determine the Jacobson radicals and Brown-McCoy radicals of group rings of certain non-abelian groups and generalize some known results.
Objective To study the abnormal reactions of a series of free radicals and the oxidative damages induced by free radical abnormal reactions in the bodies of patients with chronic glomerulonephritis. Methods Eighty ...Objective To study the abnormal reactions of a series of free radicals and the oxidative damages induced by free radical abnormal reactions in the bodies of patients with chronic glomerulonephritis. Methods Eighty chronic glomerulonephritis patients (CGNP) and eighty healthy adult volunteers (HAV) were enrolled in a random control study, in which concentrations of nitric oxide (NO) in plasma, lipoperoxides (LPO) in plasma and in erythrocytes, and vitamin C (VC), vitamin E (VE) and beta-carotene (?CAR) in plasma as well as activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) in erythrocytes were determined with spectrophotometric assays. Results Compared with the average values of the above biochemical parameters in the HAV group, the average values of NO in plasma, and LPO in plasma and erythrocytes in the CGNP group were significantly increased (P = 0.0001), while those of VC, VE and -CAR in plasma as well as those of SOD, CAT and GPX in erythrocytes in the CGNP group were significantly decreased (P = 0.0001). Pearson product-moment correlation analysis showed that with increase of the concentration of blood creatinine as well as prolongation of the course of disease in the CGNP, the concentrations of NO in plasma, and LPO in plasma and erythrocytes in the CGNP increased gradually, while the concentrations of VC, VE and ?CAR in plasma as well as the activities of SOD, CAT and GPX in erythrocytes in the CGNP decreased gradually (P = 0.002454 0.000001). The relative risk ratio (RR) of the above biochemical parameters reflecting oxidative damages in the bodies of CGNP ranged from 6.061 to 72.429. The reliability coefficient (alpha) that the above biochemical parameters were used to reflect the oxidative damages of the CGNP was 0.8137, standardized item alpha = 0.9728, Hotelling抯 T-Squared = 1135680.191, F = 53274.6478, P = 0.000001. Conclusions The findings in this study show that in the bodies of CGNP a series of free radical chain reactions result in severe pathological aggravation and induce oxidative damages in their bodies. Therefore, suitable dose of antioxidants should be supplemented to them so as to alleviate oxidative damages in their bodies.展开更多
A crude polysaccharide was extracted from Physalis alkekengi L. fruit. HPLC was used for the component analysis of the polysaccharide. The results indicate that Physalis alkekengi L. polysaccharide（PAP） was composed...A crude polysaccharide was extracted from Physalis alkekengi L. fruit. HPLC was used for the component analysis of the polysaccharide. The results indicate that Physalis alkekengi L. polysaccharide（PAP） was composed of rhamnose, xylose, arabinose, galactose, and glucose. Free radicals scavenging activity of PAP was studied through 3 free radicals scavenging tests. PAP exhibited high scavenging effects on OH and DPPH radicals, and both the scavenging rates were about 80%. The scavenging rate of O2^- radical was about 22%.展开更多
The micron grade multi-metal oxide bismuth silicate （Bi 12 SiO 20,BSO） was prepared by the chemical solution decomposition technique.Photocatalytic degradation of pentachlorophenol （PCP） was investigated in the pr...The micron grade multi-metal oxide bismuth silicate （Bi 12 SiO 20,BSO） was prepared by the chemical solution decomposition technique.Photocatalytic degradation of pentachlorophenol （PCP） was investigated in the presence of BSO under xenon lamp irradiation.The reaction kinetics followed pseudo first-order and the degradation ratio achieved 99.1% after 120 min at an initial PCP concentration of 2.0 mg/L.The pH decreased from 6.2 to 4.6 and the dechlorination ratio was 68.4% after 120 min at an initial PCP concentration of 8.0 mg/L.The results of electron spin resonance showed that superoxide radical （O 2 · ） was largely responsible for the photocatalytic degradation of PCP.Interestingly,this result was different from that of previous photocatalytic reactions where valence band holes or hydroxyl radicals played the role of major oxidants.Some aromatic compounds and aliphatic carboxylic acids were determined by GC/MS as the reaction intermediates,which indicated that O 2 · can attack the bond between the carbon and chlorine atoms to form less chlorinated aromatic compounds.The aromatic compounds were further oxidized by O 2 · to generate aliphatic carboxylic acids which can be finally mineralized to CO 2 and H 2 O.展开更多
Objective：To explore the nature of deficiency in spleen-yin syndrome,which could provide scientific theoretical support and practical guidance for clinical Traditional Chinese Medicine（TCM）syndrome differentiation ...Objective：To explore the nature of deficiency in spleen-yin syndrome,which could provide scientific theoretical support and practical guidance for clinical Traditional Chinese Medicine（TCM）syndrome differentiation based on biology,and had a strong clinical significance.Methods：Serum Cu and Zn were detected by atomic absorption spectrophotometer,serum vitamin E by high performance liquid chromatography,serum vitamin C by 2,4-Dinitrophenylhydrazine Colorimetry,total superoxide dismutase（SOD）and Cu and Zn- SOD by the xanthine oxidase method,and malondialdehyde（MDA）by the 2-thiobarbituric acid method（TBA）.Total antioxidant capacity was detected by a colorimetry kit.Amylase Activity was detected by an automatic biochemical analyzer.Lysozyme was detected by lysozyme detection plate,the diameter of bacteriolysis circle was measured and the corresponding content of lysozyme was obtained from a table of standard curve values.Results： No significant difference in total SOD and Cu,Zn-SOD was found between deficiency in spleen-yin group and normal group.However,such factors in deficiency in kidney-yin group were significantly lower than the other groups（P〈0.05）.The MDA content in both deficiency in spleen-yin group and deficiency in kidney-yin group were significantly higher than that of normal group（P〈0.05）,while the total antioxidant capacity was significantly lower than normal group（P〈0.05）.The vitamin E content in deficiency in kidney-yin group was significantly lower than that in the other two groups（P〈0.05）.No significant difference in the contents of vitamin C,Cu and Zn were observed in these groups.The Zn/Cu level in deficiency in kidney-yin group and the vitamin E level in deficiency in spleen-yin group decreased,but with no significant difference.Amylase activity in unit time in cases with deficiency in spleen-yin was lower than and had significant differences with that in normal cases,and higher than that in cases with deficiency in kidney-yin.The sectional velocity of saliva and the ratio of lysozyme in normal case group were significantly higher than other two groups,while deficiency in the spleen-yin group was significantly higher than the deficiency in kidney-yin group.Conclusion：All the results indicated that the objective pathological mechanism between the deficiency in spleen-yin and deficiency in kidney-yin was different.展开更多
Biochar as an emerging carbonaceous material has exhibited a great potential in environmental application for its perfect adsorption ability.However,there are abundant persistent free radicals(PFRs)in biochar,so the d...Biochar as an emerging carbonaceous material has exhibited a great potential in environmental application for its perfect adsorption ability.However,there are abundant persistent free radicals(PFRs)in biochar,so the direct and indirect PFRs-mediated removal of organic and inorganic contaminants by biochar was widely reported.In order to comprehend deeply the formation of PFRs in biochar and their interactions with contaminants,this paper reviews the formation mechanisms of PFRs in biochar and the PFRs-mediated environmental applications of biochar in recent years.Finally,future challenges in this field are also proposed.This review provides a more comprehensive understanding on the emerging applications of biochar from the viewpoint of the catalytic role of PFRs.展开更多
In this work,a high-efficiency photocatalytic BiOCl material with a visible light absorption range was successfully prepared by one-pot molecular self-assembly and particle recrystallization method at room temperature...In this work,a high-efficiency photocatalytic BiOCl material with a visible light absorption range was successfully prepared by one-pot molecular self-assembly and particle recrystallization method at room temperature.In the process of crystal growth,tartaric acid,as a structure control agent,gradually transforms the stacked two-dimensional nano-sheet-like BiOCl into a hierarchical structure composed of petallike nano-sheets through hydrogen bonding.Besides,the acid etching of organic carboxylic acid on the crystal surface increases the number of micropores and mesopores,thereby the reaction interface.The thiourea(TU)molecules adsorbed on the BiOCl surface with a strong electronic effect introduce oxygen vacancies(OVs)under the condition of low oxygen content.The synergistic effect of hierarchical structure and OVs reduces the recombination of photogenerated carriers,but absorbs more O_(2)and OH−to generate a large number of superoxide radicals(·O_(2)−)and hydroxyl radicals(·OH)effectively.The photocatalytic performance of the synthesized BiOCl material has been significantly improved,and it can effectively degrade 94.15%of rhodamine B(RhB)within 20 min.Furthermore,90.95%of tetracycline(TC),93.76%of ciprofloxacin(CIP),and 85.53%of methyl orange(MO)can be removed in 80 min.Therefore,our work provides an effective method for preparing BiOCl with visible light catalytic activity,which,of course,can be used to treat and repair actual environmental problems under mild conditions.展开更多
Hydroxyl radicals play the key role during electrochemical oxidation and photoelectrochemical oxidation. The production and effect of hydroxyl radicals on the interface between DSA anode and water was investigated by ...Hydroxyl radicals play the key role during electrochemical oxidation and photoelectrochemical oxidation. The production and effect of hydroxyl radicals on the interface between DSA anode and water was investigated by examining the quenching effect of iso-propanol on Orange II decolorization. We observed that with an increase in electrode potential from 4 to 12 V across electrodes at pH 7.0, the contribution percentage of hydroxyl radicals increased dramatically. More OH radicals were produced in acidic and alkaline conditions than at neutral conditions. At electrode potential of 4 V, the contribution percentage of hydroxyl radicals was obviously higher at near neutral pH conditions, while removal efficiency of Orange/I achieved was the lowest concurrently. Finally, for photocatalytic oxidation, electrochemical oxidation, and photoelectrochemical oxidation using the same DSA electrode, the effect of hydroxyl radicals proved to be dominant in photocatalytic oxidation but the contribution of hydroxyl radicals was not dominant in electrochemical oxidation, which implies the necessity of UV irradiation for electrochemical oxidation during water treatment.展开更多
The solution of the non-homogeneous Riemann boundary value problem with radicals (1. 2) together with its condition of solvability is obtained for arbitrary positive integersp andq, which generalizes the results for t...The solution of the non-homogeneous Riemann boundary value problem with radicals (1. 2) together with its condition of solvability is obtained for arbitrary positive integersp andq, which generalizes the results for the casep=q=2.展开更多
基金Project supported by the National Natural Science Foundation of China(No.22231005)the Strategic Priority Research Program of the Chinese Academy of Sciences(No.XDB0610000)。
文摘Luminescent radicals have attracted extensive attention due to the unique emission properties from the doublet spin state.However,luminescent radicals are predominantly chloroarylmethyl radicals that emit light in the red and near-infrared spectral regions,and the blue emitting radicals remain scarcely reported.Herein,two novel boron-containing dioxoborocyclic blue-luminescent radicals were designed and synthesized by combining dioxoborocyclic radicals with thiophene units.They were characterized by single-crystal X-ray diffraction,UV-Vis spectroscopy,electron paramagnetic resonance(EPR)spectroscopy,and fluorescence spectroscopy in conjunction with theoretical calculations.Theoretical calculations demonstrate that both radicals 3a and 3b emit blue light from the anti-Kasha emission attributed to the effective suppression of IC pathways.Our work offers definitive proof that the boron-containing radical system functions as a highly efficient platform for expanding the diversity of short-wavelength emissive radicals.
基金supported by the National Natural Science Foun-dation of China(No.U22A20578)the guiding project of seizing the commanding heights of“self-purifying city”(No.IUE-CERAE-202402)+3 种基金the Science and Technology Department of Fujian Province(No.2022L3025)the National Key Research and Development Program(No.2022YFC3700304)the STS Plan Supporting Project of the Chinese Academy of Sciences in Fujian Province(No.2023T3013)Xiamen Atmospheric Environment Observation and Research Station of Fujian Province.
文摘Ambient ozone(O_(3))is generated through the reactions of nitrogen oxides and volatile organic compounds(VOCs)in sunlight,and the primary sources of RO_(x)radicals play a very important role in O_(3)photochemistry.However,as major precursors of RO_(x)radicals,the systematical evaluation of ClNO_(2),HCHO,and HONO impacts on O_(3)photochemistry remains limited.Here,we utilized the observations of ClNO_(2),HCHO,and HONO conducted in a coastal city of Southeast China during a photochemical O_(3)pollution episode,combined with model simulations to elucidate their impacts on RO_(x)radicals and atmospheric oxidation capacity(AOC),as well as O_(3)formation.Decreased concentrations of ClNO_(2)and HONO were observed after sunrise,while HCHO concentrations peaked in the daytime.HCHO photolysis contributed the largest(∼25%)to RO_(x)radical production around noon,while HONO photolysis(∼47%)dominated RO_(x)radical production in the morning and late afternoon,and VOCs consumed by Cl radical released via ClNO_(2)photolysis was more important(∼10%)in the early morning,similar to their effects on the AOC levels.The results of model simulations indicated that HCHO photolysis greatly enhanced the photochemical formation of O_(3),followed by HONO and ClNO_(2)photolysis.Except for reducing VOCs due to a VOC-limited regime,the impacts of HCHO photolysis as primary RO_(x)sources should be valued to inhibit the intensification of O_(3)pollution.Our study stressed the importance of primary RO_(x)sources for O_(3)photochemistry in coastal regions,provided new insights into elucidating the self-purifying effect of the atmospheric environment.
基金supported by the National Natural Science Foundation of China(Nos.22271140,22071103,and 22371118)。
文摘Preparing free-base porphyrinoid radicals that can function as coordination ligands is a challenging task.Here we report the synthesis of a stable,free-base benzocorrole(BC)radical containing only two inner NH protons via a retro-Diels-Alder conversion.The radical character of BC was fully supported by crystallographic analysis,spectroscopic evidence,and theoretical calculations.This neutral radical ligand allowed easy insertion of Zn(Ⅱ),Ga(Ⅲ),and Pd(Ⅱ)ions to produce radical complexes.All these radicals exhibited luminescence-on responses under weak reducing atmosphere,corresponding to the conversion to their aromatic anions.The red fluorescence was observed for BC and its Zn(Ⅱ)and Ga(Ⅲ)complexes,and the near-infrared phosphorescence(>900 nm)was detected for Pd(Ⅱ)complex at room temperature.Furthermore,Ga(Ⅲ)corrole exhibited a variation in fluorescence in response to axial coordination.Our findings provide a promising radical platform for coordination and developing novel functional materials with switchable spin and emission.
基金supported by the Russian Science Foundation(No.24-73-10026)https://rscf.ru/en/project/24-73-10026/Investigation of dichroic properties was supported by Ministry of Science and Higher Education of the Russian Federation(No.075-03-2024-118/1)+2 种基金The computational part of this work was supported by the Ministry of Science and Higher Education of the Russian Federation(No.AAAA-A21-121011390040-4)SCXRD experiments were supported by the Ministry of Science and Higher Education of the Russian Federation(No.125021302132-4)The measurement of the solid state electronic absorption spectra was supported by the Ministry of Science and Higher Education of the Russian Federation(No.AAAAA-A21-1210112290043-3).
文摘Six aryl-and pyridine-substituted nitronyl-nitroxide radicals were synthesized and characterized to investigate their optical anisotropic properties.Single-crystal X-ray diffraction analysis revealed molecular packing organized by either halogen and hydrogen bonding or hydrogen bonding alone.Single-crystal electronic absorption spectra in the visible region of three studied radicals exhibit pronounced linear dichroism,while single crystals of other radicals do not demonstrate this property.Time-dependent DFT and ab initio calculations were employed to determine the transition dipole moment(TDM)vectors corresponding to the long-wavelength absorption bands.For all radicals,these vectors are found to be practically parallel to the O⋯O direction of the nitronyl-nitroxide chromophore.Correlation between the dichroic properties and crystal structure was established through comprehensive analysis of TDM vector orientations relative to the crystal surface.The strongest dichroic effect was observed in crystals where all projections of the TDM vectors onto the illuminated face are parallel to each other,while weaker or absent effects correspond to non-parallel arrangements.This study constitutes the first systematic investigation of linear dichroism in paramagnetic organic crystals,thereby establishing new avenues for developing multifunctional materials that respond to both optical and magnetic stimuli.
基金supported by the National Natural Science Foundation of China(Nos.52170156,52250056,and 52293443)the Shenzhen Science and Technology Program(No.KQTD20190929172630447).
文摘Harnessing bacteria for superoxide production in bioremediation holds immense promise,yet its practical application is hindered by slow production rates and the relatively weak redox potential of superoxide.This study delves into a cost-effective approach to amplify superoxide production using an Arthrobacter strain,a prevalent soil bacterial genus.Our research reveals that introducing a carbon source along with specific iron-binding ligands,including deferoxamine(DFO),diethylenetriamine pentaacetate(DTPA),citrate,and oxalate,robustly augments microbial superoxide generation.Moreover,our findings suggest that these iron-binding ligands play a pivotal role in converting superoxide into hydroxyl radicals by modulating the electron transfer rate between Fe(Ⅲ)/Fe(Ⅱ)and superoxide.Remarkably,among the tested ligands,only DTPA emerges as a potent promoter of this conversion process when complexed with Fe(Ⅲ).We identify an optimal Fe(Ⅲ)to DTPA ratio of approximately 1:1 for enhancing hydroxyl radical production within the Arthrobacter culture.This research underscores the efficacy of simultaneously introducing carbon sources and DTPA in facilitating superoxide production and its subsequent conversion to hydroxyl radicals,significantly elevating bioremediation performance.Furthermore,our study reveals that DTPA augments superoxide production in cultures of diverse soils,with various soil microorganisms beyond Arthrobacter identified as contributors to superoxide generation.This emphasizes the universal applicability of DTPA across multiple bacterial genera.In conclusion,our study introduces a promising methodology for enhancing microbial superoxide production and its conversion into hydroxyl radicals.These findings hold substantial implications for the deployment of microbial reactive oxygen species in bioremediation,offering innovative solutions for addressing environmental contamination challenges.
基金Scientific Research Program of Beijing Municipal Commission of Education (KM200710011007)~~
文摘[ Objective ] The research aimed to provide reference for the application of extracts from sweet potato leaves in anti-aging cosmetics. [ Method ] The extraction and storage conditions for free radicals scavenging substances from sweet potato leaves were optimized by orthogonal test and the bioactive components in extracts were investigated by correlation analysis. [ Result] Sweet potato leaves contain the bioactive substances scavenging DPPH free radical and hydroxyl free radical. Extracting solvent species is the most important factor that influencing extraction yield. The optimal extraction and storage conditions are as following： water as solvent, pH 8.0 of extracting liquid, storage at 25 ℃. There is a good positive linear relationship between the content of total phenols in sweet potato leaves and corresponding scavenging rates against both the DPPH free radical and hydroxyl free radical. For the content of total flavones in sweet potato leaves, just a correlation with scavenging rate against hydroxyl free radical shown in test. [ Conclusion] The phenols in ex- tracts could effectively scavenge both the DPPH free radical and hydroxyl free radical, whereas the flavones in extracts can only function on the hydroxyl free radical.
基金Supported by the National Natural Science Foundation of China(3076015230960241)Key Fund of Yunnan Province(2009CC005)~~
文摘[Objective] This study aimed to explore factors influencing the effects of theabrownin in Pu-erh tea on scavenging DPPH radicals. [Method] Taking Pu-erh tea as main research object, theabrownin in Pu-erh tea from tea piles with different times of mixture, stored for different years and processed by both the old and new techniques were extracted and isolated. And DPPH method was used to study the effects of theabrownin solution and tea liquor on scavenging radicals and their antioxidant activity. [Result] The result showed that the theabrownin content in Pu-erh tea from tea piles with one to four times of mixture revealed a first declining and subsequently rising trend. Under different pH conditions, the rates of DPPH radical scavenging of 1 mg/ml theabrownin solution made from tea piles with different times of mixture decreased gradually with the increase of pH, and all the rates were lower than that of the control vitamin C solution; the rates of DPPH radical scavenging of theabrownin from tea samples stored for different years and produced by different techniques dropped slowly within pH range 3.0-6.0; when pH was higher than 6.0, the rates of DPPH radical scavenging of theabrownin from tea samples produced by both new and traditional techniques in 2001 declined obviously, while the declining trend was not obvious in either the black tea or the Pu-erh tea produced by new technique in 2005. Under different theabrownin concentrations, the rates of DPPH radical scavenging of theabrownin solution made from tea piles with different times of mixture ascended as the concentration increased and the highest rate occurred in tea pile with four times of mixture, reaching up to 46.56%±0.88%; for tea samples stored for different years and produced by different techniques, the rates of DPPH radical scavenging of theabrownin rose gradually with the increase of the theabrownin concentration; the rate of radical scavenging of theabrownin in the black tea ascended obviously and that in Pu-erh tea was decreasing within the concentration range of 0.04 -0.06 mg/ml. At pH6.0, the DPPH radical scavenging ability of theabrownin in 0.1 mg/ml theabrownin solution and tea liquor containing 0.1mg/ml theabrownin from tea piles with different times of mixture ascended with the time of mixture; solution made from tea samples produced by different techniques in different years, the DPPH radical scavenging ability of theabrownin solution and tea liquor followed： Pu-erh tea produced by the new technique in 2001 ﹥ Pu-erh tea produced by the old technique in 2001﹥ Pu-erh tea produced by the new technique in 2005. And the DPPH radical scavenging ability of theabrownin in tea liquor containing 0.1 mg/ml theabrownin was higher than that in 0.1 mg/ml theabrownin Solution made from tea samples either with different times of mixture or produced by different techniques in different years. The above results indicated that many factor influenced the effects of theabrownin on eliminating DPPH radicals, including the time of fermentation, fermentation technique, years of storage, concentration and pH all had great influence on the effects of theabrownin on eliminating radicals. To ensure a good effect on scavenging radicals, it is better to prepare theabrownin at pH6.0 with concentration between 0.08 and 0.1 mg/ml for drinking. [Conclusion] Results of this study provide a basis for developing functional products of theabrownin from Pu-erh tea in the future.
基金supported by the National Natural Science Foundation of China(52270043)the National Key Research and Development Program of China(2023YFE0113800 and 2024YFC3715000)the Natural Science Foundation of Beijing Municipality(8242030).
文摘The contamination of wastewater with organic pollutants and nitrogen compounds poses significant environmental challenges.The primary objective of wastewater treatment is the simultaneous denitrification and decarbonization of ammonia nitrogen and organics into harmless by-products.This study presents a novel method for the directional generation of chlorine radical species like·ClO and·Cl using electro-reactive membranes(EMs)known as RuO_(2)@PbO_(2)-M,which were fabricated using an electro-deposition coupled template approach.This method facilitates the rapid and efficient conversion of ammonia to nitrogen and concurrently reduces the chemical oxygen demand in the effluent.Our system achieved ultra-efficient simultaneous denitrification and decarbonization with minimal energy consumption in single-filtration mode,thereby eliminating the need for chemical precursors.We elucidate the formation pathway of·ClO and·Cl during the electrochemical oxidation process involving RuO_(2)@PbO_(2)-M,where·Cl generated from RuO_(2)reacts with·OH from PbO_(2)under hypochlorous acid conditions,thereby enhancing nitrogen and carbon removal.These findings highlight a novel electro-filtration and an innovative reactive membrane design for·ClO synthesis,which provides a new research framework for the concurrent removal of nitrogen and carbon,and offers a promising solution to enhance wastewater treatment efficiency.
基金supported by the National Natural Science Foundation of China(No.51827803)the Fundamental Research Funds for the Central Universities,111 Center(No.B20001)Institutional Research Fund from Sichuan University(No.2021SCUNL201).
文摘Generally,gaining fundamental insights into chain processes during the combustion of flame-retardant polymers relies on the qualitative and quantitative characterization of key chain carriers.However,polymer combustion processes based on conventional solid-fuel combustion strategies,due to the high coupling of pyrolysis,combustion,soot formation and oxidation,exhibit relatively high complexity and poor flame stability,and lead to a huge obstacle to the use of optical diagnostics.Herein,a spatial-confinement combustion strategy,which can produce a special staged flame with multi-jets secondary wave,is devised to provide a highly decoupled combustion environment.Glowing soot particles are therefore decoupled from main chemiluminescence region and confined to the flame tip to provide a well-controlled,opticalthin test environment for combustion diagnostic.Based on this strategy,a multi-nozzle-separation(MNS)burner is designed and fabricated,and the combustion processes associated with four model compounds,PVC,PS,PP/TBBA blends and PP/RP blends are investigated by spontaneous spectral diagnosis,and the chemiluminescence fingerprint of key diatomic/triatomic intermediates(such as OH,CH,C_(2),ClO,Br_(2),and PHO)are clearly observed.This encouraging result means that the strategy of spatial-confinement combustion we proposed shows promising prospect in many subjects associated with combustion chain regulation,such as efficient design of flame retardants.
文摘Oxidative coupling of methane(OCM)is a catalytic partial oxidation process that directly converts methane into C_(2) products.For this high temperature reaction,understanding the radical behavior through experimental investigation is important in correlating the catalytic activity and the products.In this work,a spatial resolution online mass spectrometry(MS)system was developed and applied to a Mn-Na_(2)WO_(4)/SiO_(2) catalyzed OCM system.In addition to the residue gas analysis,the system obtained the distribution information of the reactants and products in the reactor.At various setting temperatures,all species online MS signals were collected at different positions,mapping the reaction activity covering parameters including temperature,time and space.The distribution behavior of the catalytic activity,selectivity,and apparent activation energy were kinetically analyzed.Selectivity and additional carbon balance analysis strongly supported the radical coupling model of OCM and indicated that after the catalytic bed layer,there is a significant length in the reactor(>2 mm)filled with radicals.Based on the result,a designed new method by tuning the temperature field in the reactor was found effectively to improve the catalytic activity,especially the C_(2) yield from 702 to 773℃.
文摘In this paper, we determine the Jacobson radicals and Brown-McCoy radicals of group rings of certain non-abelian groups and generalize some known results.
文摘Objective To study the abnormal reactions of a series of free radicals and the oxidative damages induced by free radical abnormal reactions in the bodies of patients with chronic glomerulonephritis. Methods Eighty chronic glomerulonephritis patients (CGNP) and eighty healthy adult volunteers (HAV) were enrolled in a random control study, in which concentrations of nitric oxide (NO) in plasma, lipoperoxides (LPO) in plasma and in erythrocytes, and vitamin C (VC), vitamin E (VE) and beta-carotene (?CAR) in plasma as well as activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPX) in erythrocytes were determined with spectrophotometric assays. Results Compared with the average values of the above biochemical parameters in the HAV group, the average values of NO in plasma, and LPO in plasma and erythrocytes in the CGNP group were significantly increased (P = 0.0001), while those of VC, VE and -CAR in plasma as well as those of SOD, CAT and GPX in erythrocytes in the CGNP group were significantly decreased (P = 0.0001). Pearson product-moment correlation analysis showed that with increase of the concentration of blood creatinine as well as prolongation of the course of disease in the CGNP, the concentrations of NO in plasma, and LPO in plasma and erythrocytes in the CGNP increased gradually, while the concentrations of VC, VE and ?CAR in plasma as well as the activities of SOD, CAT and GPX in erythrocytes in the CGNP decreased gradually (P = 0.002454 0.000001). The relative risk ratio (RR) of the above biochemical parameters reflecting oxidative damages in the bodies of CGNP ranged from 6.061 to 72.429. The reliability coefficient (alpha) that the above biochemical parameters were used to reflect the oxidative damages of the CGNP was 0.8137, standardized item alpha = 0.9728, Hotelling抯 T-Squared = 1135680.191, F = 53274.6478, P = 0.000001. Conclusions The findings in this study show that in the bodies of CGNP a series of free radical chain reactions result in severe pathological aggravation and induce oxidative damages in their bodies. Therefore, suitable dose of antioxidants should be supplemented to them so as to alleviate oxidative damages in their bodies.
基金Supported by the Science and Technique Foundation of Jilin Province, China(No20020503-2)
文摘A crude polysaccharide was extracted from Physalis alkekengi L. fruit. HPLC was used for the component analysis of the polysaccharide. The results indicate that Physalis alkekengi L. polysaccharide（PAP） was composed of rhamnose, xylose, arabinose, galactose, and glucose. Free radicals scavenging activity of PAP was studied through 3 free radicals scavenging tests. PAP exhibited high scavenging effects on OH and DPPH radicals, and both the scavenging rates were about 80%. The scavenging rate of O2^- radical was about 22%.
基金supported by the National Natural Science Foundation of China(No.21077010)the Na-tional Key Technology R&D Program of China(No.2008BAC32B06-3)+1 种基金the National High Technology Research and Development Program (863) of China(No.2009AA05Z306)the Program for Changjiang Schol-ars and Innovative Research Team in University(No.IRT0809)
文摘The micron grade multi-metal oxide bismuth silicate （Bi 12 SiO 20,BSO） was prepared by the chemical solution decomposition technique.Photocatalytic degradation of pentachlorophenol （PCP） was investigated in the presence of BSO under xenon lamp irradiation.The reaction kinetics followed pseudo first-order and the degradation ratio achieved 99.1% after 120 min at an initial PCP concentration of 2.0 mg/L.The pH decreased from 6.2 to 4.6 and the dechlorination ratio was 68.4% after 120 min at an initial PCP concentration of 8.0 mg/L.The results of electron spin resonance showed that superoxide radical （O 2 · ） was largely responsible for the photocatalytic degradation of PCP.Interestingly,this result was different from that of previous photocatalytic reactions where valence band holes or hydroxyl radicals played the role of major oxidants.Some aromatic compounds and aliphatic carboxylic acids were determined by GC/MS as the reaction intermediates,which indicated that O 2 · can attack the bond between the carbon and chlorine atoms to form less chlorinated aromatic compounds.The aromatic compounds were further oxidized by O 2 · to generate aliphatic carboxylic acids which can be finally mineralized to CO 2 and H 2 O.
文摘Objective：To explore the nature of deficiency in spleen-yin syndrome,which could provide scientific theoretical support and practical guidance for clinical Traditional Chinese Medicine（TCM）syndrome differentiation based on biology,and had a strong clinical significance.Methods：Serum Cu and Zn were detected by atomic absorption spectrophotometer,serum vitamin E by high performance liquid chromatography,serum vitamin C by 2,4-Dinitrophenylhydrazine Colorimetry,total superoxide dismutase（SOD）and Cu and Zn- SOD by the xanthine oxidase method,and malondialdehyde（MDA）by the 2-thiobarbituric acid method（TBA）.Total antioxidant capacity was detected by a colorimetry kit.Amylase Activity was detected by an automatic biochemical analyzer.Lysozyme was detected by lysozyme detection plate,the diameter of bacteriolysis circle was measured and the corresponding content of lysozyme was obtained from a table of standard curve values.Results： No significant difference in total SOD and Cu,Zn-SOD was found between deficiency in spleen-yin group and normal group.However,such factors in deficiency in kidney-yin group were significantly lower than the other groups（P〈0.05）.The MDA content in both deficiency in spleen-yin group and deficiency in kidney-yin group were significantly higher than that of normal group（P〈0.05）,while the total antioxidant capacity was significantly lower than normal group（P〈0.05）.The vitamin E content in deficiency in kidney-yin group was significantly lower than that in the other two groups（P〈0.05）.No significant difference in the contents of vitamin C,Cu and Zn were observed in these groups.The Zn/Cu level in deficiency in kidney-yin group and the vitamin E level in deficiency in spleen-yin group decreased,but with no significant difference.Amylase activity in unit time in cases with deficiency in spleen-yin was lower than and had significant differences with that in normal cases,and higher than that in cases with deficiency in kidney-yin.The sectional velocity of saliva and the ratio of lysozyme in normal case group were significantly higher than other two groups,while deficiency in the spleen-yin group was significantly higher than the deficiency in kidney-yin group.Conclusion：All the results indicated that the objective pathological mechanism between the deficiency in spleen-yin and deficiency in kidney-yin was different.
基金supported by the National Natural Science Foundation of China(No.52000013)the Scientific Research Foundation of Hunan Provincial Education Department,China(No.18B415,18B406 and 18A378)+1 种基金the Natural Science Foundation of Hunan Province,China(No.2020JJ4643)the training program for Excellent Yong Innovators of Changsha(No.kq1802022)。
文摘Biochar as an emerging carbonaceous material has exhibited a great potential in environmental application for its perfect adsorption ability.However,there are abundant persistent free radicals(PFRs)in biochar,so the direct and indirect PFRs-mediated removal of organic and inorganic contaminants by biochar was widely reported.In order to comprehend deeply the formation of PFRs in biochar and their interactions with contaminants,this paper reviews the formation mechanisms of PFRs in biochar and the PFRs-mediated environmental applications of biochar in recent years.Finally,future challenges in this field are also proposed.This review provides a more comprehensive understanding on the emerging applications of biochar from the viewpoint of the catalytic role of PFRs.
基金financially supported by the National Natural Science Foundation of China (No. 51602281)the China Postdoctoral Science Foundation (No. 2017M621832)+3 种基金the Science and Technology Innovation Cultivation Fund project of Yangzhou University (No. 2019CXJ092)the project of national local joint engineering laboratory to functional adsorption material technology for the environmental protection, Soochow University (No. SDGC2124)Yangzhou University High-end Talent Support Programthe “Qinglan Project” of Jiangsu Universities
文摘In this work,a high-efficiency photocatalytic BiOCl material with a visible light absorption range was successfully prepared by one-pot molecular self-assembly and particle recrystallization method at room temperature.In the process of crystal growth,tartaric acid,as a structure control agent,gradually transforms the stacked two-dimensional nano-sheet-like BiOCl into a hierarchical structure composed of petallike nano-sheets through hydrogen bonding.Besides,the acid etching of organic carboxylic acid on the crystal surface increases the number of micropores and mesopores,thereby the reaction interface.The thiourea(TU)molecules adsorbed on the BiOCl surface with a strong electronic effect introduce oxygen vacancies(OVs)under the condition of low oxygen content.The synergistic effect of hierarchical structure and OVs reduces the recombination of photogenerated carriers,but absorbs more O_(2)and OH−to generate a large number of superoxide radicals(·O_(2)−)and hydroxyl radicals(·OH)effectively.The photocatalytic performance of the synthesized BiOCl material has been significantly improved,and it can effectively degrade 94.15%of rhodamine B(RhB)within 20 min.Furthermore,90.95%of tetracycline(TC),93.76%of ciprofloxacin(CIP),and 85.53%of methyl orange(MO)can be removed in 80 min.Therefore,our work provides an effective method for preparing BiOCl with visible light catalytic activity,which,of course,can be used to treat and repair actual environmental problems under mild conditions.
基金supported by the National Natural Science Foundation of China (No. 50708037)the Starting Fund for Talents of North China University of Water Conservancy and Electric Power
文摘Hydroxyl radicals play the key role during electrochemical oxidation and photoelectrochemical oxidation. The production and effect of hydroxyl radicals on the interface between DSA anode and water was investigated by examining the quenching effect of iso-propanol on Orange II decolorization. We observed that with an increase in electrode potential from 4 to 12 V across electrodes at pH 7.0, the contribution percentage of hydroxyl radicals increased dramatically. More OH radicals were produced in acidic and alkaline conditions than at neutral conditions. At electrode potential of 4 V, the contribution percentage of hydroxyl radicals was obviously higher at near neutral pH conditions, while removal efficiency of Orange/I achieved was the lowest concurrently. Finally, for photocatalytic oxidation, electrochemical oxidation, and photoelectrochemical oxidation using the same DSA electrode, the effect of hydroxyl radicals proved to be dominant in photocatalytic oxidation but the contribution of hydroxyl radicals was not dominant in electrochemical oxidation, which implies the necessity of UV irradiation for electrochemical oxidation during water treatment.
文摘The solution of the non-homogeneous Riemann boundary value problem with radicals (1. 2) together with its condition of solvability is obtained for arbitrary positive integersp andq, which generalizes the results for the casep=q=2.
