A Plant Biostimulant is any substance or microorganism applied to plants to enhance nutrition efficiency,abioticstress tolerance,and/or crop quality traits,regardless of its nutrient content.The application of Plant b...A Plant Biostimulant is any substance or microorganism applied to plants to enhance nutrition efficiency,abioticstress tolerance,and/or crop quality traits,regardless of its nutrient content.The application of Plant biostimulants(PBs)in production can reduce the application of traditional pesticides and chemical fertilizers and improvethe quality and yield of crops,which is conducive to the sustainable development of agriculture.An in-depthunderstanding of the mechanism and effect of various PBs is very important for how to apply PBs reasonablyand effectively in the practice of crop production.This paper summarizes the main classification of PBs;Thegrowth promotion mechanism of PBs was analyzed from four aspects:improving soil physical and chemical properties,enhancing crop nutrient absorption capacity,photosynthesis capacity,and abiotic stress tolerance;At thesame time,the effects of PBs application on seed germination,seedling vigor,crop yield,and quality were summarized;Finally,how to continue to explore and study the use and mechanism of PBs in the future is analyzedand prospected,to better guide the application of PBs in crop production in the future.展开更多
Fe_2O_3 nanorods and hexagonal nanoplates were synthesized and used as the promoters for Pt electrocatalysts toward the methanol oxidation reaction(MOR) in an alkaline electrolyte.The catalysts were characterized by...Fe_2O_3 nanorods and hexagonal nanoplates were synthesized and used as the promoters for Pt electrocatalysts toward the methanol oxidation reaction(MOR) in an alkaline electrolyte.The catalysts were characterized by scanning electron microscopy,transmission electron microscopy,X-ray diffraction,X-ray photoelectron spectroscopy,cyclic voltammetry and chronoamperometry.The results show that the presence of Fe_2O_3 in the electrocatalysts can promote the kinetic processes of MOR on Pt,and this promoting effect is related to the morphology of the Fe_2O_3 promoter.The catalyst with Fe_2O_3 nanorods as the promoter(Pt-Fe_2O_3/C-R) exhibits much higher catalytic activity and stability than that with Fe_2O_3 nanoplates as the promoter(Pt-Fe_2O_3/C-P).The mass activity and specific activity of Pt in a Pt-Fe_2O_3/C-R catalyst are 5.32 A/mgpt and 162.7 A/m^2_(Pt),respectively,which are approximately 1.67 and 2.04 times those of the Pt-Fe_2O_3/C-P catalyst,and 4.19 and 6.16 times those of a commercial PtRu/C catalyst,respectively.Synergistic effects between Fe_2O_3 and Pt and the high content of Pt oxides in the catalysts are responsible for the improvement.These findings contribute not only to our understanding of the MOR mechanism but also to the development of advanced electrocatalysts with high catalytic properties for direct methanol fuel cells.展开更多
Pt/Eu2O3-CeO2 materials with different Eu concentrations were prepared and applied to toluene destruction,and the remarkable promotion impact of EuOx on Pt/CeO2 can be observed.The characterization results reveal that...Pt/Eu2O3-CeO2 materials with different Eu concentrations were prepared and applied to toluene destruction,and the remarkable promotion impact of EuOx on Pt/CeO2 can be observed.The characterization results reveal that the presence of EuOx significantly enhances the redox property,lattice O concentration,and Ce3+ ratio of the Pt/CeO2 material,which facilitates the dispersion and activity of Pt active sites and thus accelerates the decomposition process of toluene.Among all catalysts,a sample with an Eu content of 2.5 at.%(Pt/EC-2.5)possesses the best catalytic activity with 0.09 vol% of toluene completely destructed at 200 ℃ under a relatively high GHSV of 50000 h^-1.The possible reaction pathway and mechanism of toluene combustion over Pt/Eu2O3-CeO2 samples are presented according to in-situ DRIFTS,which confirms that the toluene oxidation process obeys the Mars-van Krevelen mechanism with aldehydes and ketones as primary organic intermediates.展开更多
The effect of super absorbent polymer(SAP) on the formation of tetrahydrofuran(THF) hydrate was studied by the successional cooling method.It was found that THF solution samples with 0.004 wt% and 0.03 wt% of SAP ...The effect of super absorbent polymer(SAP) on the formation of tetrahydrofuran(THF) hydrate was studied by the successional cooling method.It was found that THF solution samples with 0.004 wt% and 0.03 wt% of SAP formed THF hydrate completely during the same cooling process.The corresponding induction time was 16-29 min,14-31 min,respectively,which was obviously shorter than that of THF solution samples without SAP(25-62 min).It indicated that SAP accelerated the formation of THF hydrate.At the same time,the pictures of hydrate formation with and without SAP had been compared.It was found that SAP did not change the morphology of the hydrate.Finally,the mechanism of SAP promoting effect on the formation of THF hydrate was suggested.展开更多
The seeds and sprouts of mung bean are very common cruise in Asia.Evidence showed that bioactive compounds in mung bean have emerged as an increasing scientific interest due to their role in the prevention of degenera...The seeds and sprouts of mung bean are very common cruise in Asia.Evidence showed that bioactive compounds in mung bean have emerged as an increasing scientific interest due to their role in the prevention of degenerative diseases.All data of in vitro,in vivo and clinical studies of mung bean and its impact on human health were collected from a library database and electronic search.Botanical,phytochemical and pharmacological information was gathered and orchestrated.Remarkable studies have been demonstrated,showing the enhancement of metabolites in mung bean during the sprouting process,which possesses various health benefiting bioactive compounds.These compounds have been frequently attributed to their antioxidant,anti-diabetic,antimicrobial,anti-hyperlipidemic and antihypertensive effect,anti-inflammatory,and anticancer,anti-tumor and anti-mutagenic properties.In this critical review,we aimed to study the insight of the nutritional compositions,phytochemistry,and healthpromoting effects of mung bean and its sprouts.The various curative potential of mung bean provides successive preclinical outcomes in the field of drug discovery and this review strongly recommends that mung bean is an excellent nutritive legume,which modulates or prevents chronic degenerative diseases.展开更多
A significant promotion effect of low-molecular hydroxyl compounds(LMHCs) was found in the nano-photoelectrocatalytic(NPEC) degradation of fulvic acid(FA),which is a typical kind of humic acid existing widely in natur...A significant promotion effect of low-molecular hydroxyl compounds(LMHCs) was found in the nano-photoelectrocatalytic(NPEC) degradation of fulvic acid(FA),which is a typical kind of humic acid existing widely in natural water bodies,and its influence mechanism was proposed.A TiO_2 nanotube arrays(TNAs) material is served as the photoanode.Methanol,ethanediol,and glycerol were chosen as the representative of LMHCs in this study.The adsorption performance of organics on the surface of TNAs was investigated by using the instantaneous photocurrent value.The adsorption constants of FA,methanol,ethanediol,and glycerol were 43.44,19.32,7.00,and 1.30,respectively,which indicates that FA has the strongest adsorption property.The degradation performance of these organics and their mixture were observed in a thin-layer reactor.It shows that FA could hardly achieve exhausted mineralization alone,while LMHCs could be easily oxidized completely in the same condition.The degradation degree of FA,which is added LMHCs,improves significantly and the best promotion effect is achieved by glycerol.The promotion effect of LMHCs in the degradation of FA could be contributed to the formation of a tremendous amount of hydroxyl radicals in the NPEC process.The hydroxyl radicals could facilitate the complete degradation of both FA and its intermediate products.Among the chosen LMHCs,glycerol molecule which has three hydroxyls could generate the most hydroxyl radicals and contribute the best effective promotion.This work provides a new way to promote the NPEC degradation of FA and a direction to remove humus from polluted water.展开更多
The effect of chloride ions on a monoclinic ZrO2-supported RuOx (RuOx/m-ZrO2) catalyst with a Ru surface density of 0.3 Ru/nm2 was studied in the selective oxidation of methanol to methyl formate (MF) at a low tem...The effect of chloride ions on a monoclinic ZrO2-supported RuOx (RuOx/m-ZrO2) catalyst with a Ru surface density of 0.3 Ru/nm2 was studied in the selective oxidation of methanol to methyl formate (MF) at a low temperature of 373 K. The m-ZrO2 support was Cl-free, and Cl- ions were introduced into the RuOx/m-ZrO2 catalyst by impregnation with zirconium oxychloride or ammonium chloride and subsequent thermal treatment in air at 673 K. The structures of these catalysts were characterized by X-ray diffraction, Raman and X-ray photoelectron spectroscopies. Their reducibility was probed by temperature-programmed reduction in H2. The RuOx domains were present as highly dispersed Rut42- structure on m-ZrO2 with similar reducibility for the RuOx/m-ZrO2 samples irrespective of modification with or without Cl ions. Introduction of appropriate amounts of zirconium oxychloride into RuOx/m-ZrO2 led to a remarkable increase in the methanol oxidation rate and MF selectivity, whereas introduction of ammonium chloride or zirconyl nitrate significantly inhibited the catalytic performance of RuOx/m-ZrO2. The promoting effect of Cl- ions derived from zirconium oxychloride can be tentatively attributed to their roles in facilitating the adsorption of methanol and desorption of MF product or its intermediates. This finding provides novel insights into the promoting effect of Cl- ions on oxides-based catalysts for selective oxidation reactions.展开更多
Tourmaline can promote the growth of microorganisms under the temperature less than 900 ℃ by experiment. However, this promotion effect will vanish at 900 ℃ as a result of denaturation. Through the XRD analysis the ...Tourmaline can promote the growth of microorganisms under the temperature less than 900 ℃ by experiment. However, this promotion effect will vanish at 900 ℃ as a result of denaturation. Through the XRD analysis the crystal form change can explain the vanishment of tourmaline’s biological promotion effect at high temperature. Therefore, tourmaline as a biological promoter was used to prepare a kind of biological promotive ceramsite with the surface area of 7.914 m2/g, pore volume of 0.1002 mg/L, superficial pH value of 7.8, Zeta potential of 25 mV, unit water absorption of 0.1365 g/g, biocompatibility of 0.023 A/g and SICE of 0.8456. The experimental results show that the biomass of biological promotive ceramsite is 3.58 times more than that of ordinary ceramsite, and the treatment effect of the biological promotive ceramsite is better than the ordinary ceramsite. These features of this new biological promotive ceramsite makes it a preferable biovector.展开更多
There is no doubt that rare earth elements stand an important position among the essential elements of plant growth and it is long time since they are first used as plant growth promoters. Given their effects on micro...There is no doubt that rare earth elements stand an important position among the essential elements of plant growth and it is long time since they are first used as plant growth promoters. Given their effects on microstructure, most reports are focused on the toxicology rather than promotion. Using cucumis sativus L. (Jin Chun No.5) as experiment material, we try to find out the nutritional effects of low Y3+ concentrations on cucumber seedlings′ leaves. The present paper suggests that the rare earth elements act as micronutrients at low concentrations while they give rise to toxicity at high concentration. Benefits defeat toxicity with concentration ranging from 5 to 25 μmol·L-1. Through careful study, at the Y(NO3)3 concentration of 10 μmol·L-1 the content of chlorophyll as well as the activities of SOD, Cu-Zn SOD and the POD are the highest. It indicates 10 μmol·L-1 is the optimum concentration of yttrium for promoting the cucumber growth.展开更多
The adsorption of CO on Fe(110)with different coverages of tita- nia has been studied by AES,XPS,UPS.It is proposed that the adsorption sites of CO in this system are not only blocked by the deposited TiO_X,but also b...The adsorption of CO on Fe(110)with different coverages of tita- nia has been studied by AES,XPS,UPS.It is proposed that the adsorption sites of CO in this system are not only blocked by the deposited TiO_X,but also by the products of the dissociation of CO which is promoted by the deposited TiO_X.展开更多
Activated carbon (AC) supported silver catalysts were prepared by incipient wetness impregnation method and their catalytic performance for CO preferential oxidation (PROX) in excess H2 was evaluated. Ag/AC cataly...Activated carbon (AC) supported silver catalysts were prepared by incipient wetness impregnation method and their catalytic performance for CO preferential oxidation (PROX) in excess H2 was evaluated. Ag/AC catalysts, after reduction in H2 at low temperatures (≤200 ℃) following heat treatment in He at 200 ℃ (He200H200), exhibited the best catalytic properties. Temperature-programmed desorption (TPD), X-ray diffraction (XRD) and temperature-programmed reduction (TPR) results indicated that silver oxides were produced during heat treatment in He at 200 ℃ which were reduced to metal silver nanoparticles in H2 at low temperatures (≤200 ℃), simultaneously generating the adsorbed water/OH. CO conversion was enhanced 40% after water treatment following heat treatment in He at 600 ℃. These results imply that the metal silver nanoparticles are the active species and the adsorbed water/OH has noticeable promotion effects on CO oxidation. However, the promotion effect is still limited compared to gold catalysts under the similar conditions, which may be the reason of low selectivity to CO oxidation in PROX over silver catalysts. The reported Ag/AC-S-He catalyst after He200H200 treatment displayed similar PROX of CO reaction properties to Ag/SiO2. This means that Ag/AC catalyst is also an efficient low-temperature CO oxidation catalyst.展开更多
The effects of riboflavin deficiency and simultaneously nitrosodimethylamine (NDMA) given by gastric intubation on the hepatic glutathione (GSH) content were examined in rats. On different days of the experiment, hepa...The effects of riboflavin deficiency and simultaneously nitrosodimethylamine (NDMA) given by gastric intubation on the hepatic glutathione (GSH) content were examined in rats. On different days of the experiment, hepatic GSH content of the riboflavin deficient rats decreased to 55-61% of the control rats. When NDMA was given 6 mg kg by gastric intubation to riboflavin deficient rats, hepatic GSH content decreased markedly to 39-43% of the control rats. After supplying riboflavin, hepatie GSH content of the deficient rats recovered to the level of the control rats. These results suggest that alterations of rat hepatic GSH content during riboflavin deficiency may imply as one of the promoting effects of riboflavin deficiency on the carcinogenesis of nitrosamines.展开更多
Basicity of ZrO2 is enhanced by KF modification due to the reaction of KF with ZrO2 surface: KF+ ZrO2-> K2ZrF6 + KOH. After pretreated above 673K, KF/ZrO2 catalyst exhibited higher activity for 1-butene isomerizati...Basicity of ZrO2 is enhanced by KF modification due to the reaction of KF with ZrO2 surface: KF+ ZrO2-> K2ZrF6 + KOH. After pretreated above 673K, KF/ZrO2 catalyst exhibited higher activity for 1-butene isomerization at 273K than ZrO2. The amount of basic sites strongly adsorbing CO2 in the form of bicarbonate was also increased.展开更多
It was found for the first time that the compounds with only one functional group, such as pyridine, can show the promotion effect for the electrochemical reaction of cytochrome C at gold electrodes.
Traumatic injuries of peripheral nerves represent common casualties and their social impact is considerably high. Although peripheral nerves retain a good regeneration potential, the clinical outcome after nerve lesio...Traumatic injuries of peripheral nerves represent common casualties and their social impact is considerably high. Although peripheral nerves retain a good regeneration potential, the clinical outcome after nerve lesion is far from being satisfactory and functional recovery is almost never complete, especially in the case of large nerve defects, that result in loss or diminished sensitivity and/or motor activity of the innervated target organs. Therefore, to improve the outcome after nerve damage, or in peripheral neuropathies, there is a need for further research in nerve repair and regeneration to identify factors that promote axonal regrowth, remvelination and target reinnervation.展开更多
Recurrent oral ulcer is a painful oral mucosal disorder that affects 20%of the world’s population.The lack of a radical cure due to its unknown underlying cause calls for innovative symptomatic treatments.This work r...Recurrent oral ulcer is a painful oral mucosal disorder that affects 20%of the world’s population.The lack of a radical cure due to its unknown underlying cause calls for innovative symptomatic treatments.This work reports a hyaluronic acid-based dissolvablemicroneedle patch(ROUMNpatch,short for recurrent oral ulcer microneedle)loaded with dexamethasone acetate,vitamin C and tetracaine hydrochloride for the treatment of recurrent oral ulcers.The ROUMN patch shows enhancement in both the anti-inflammatory effect elicited by dexamethasone and the pro-proliferation effect of vitamin C.In vitro experiments show that ROUMN has a higher efficiency in suppressing lipopolysaccharide(LPS)-induced interleukin-6(IL-6)expression than dexamethasone alone.Cell proliferation and migrationwere also significantly promoted byROUMNcompared to vitamin C alone.The healing-promoting effect of ROUMN was also verified in vivo using an acetic acid-cauterized oral ulcer model in rats.ROUMN as a treatment accelerated the healing process of oral ulcers,shortening the total healing time to 5 days compared with the 7 days required by treatment using watermelon frost,a commonly used over-the-counter(OTC)drug for oral ulcers.The rapid dissolution of the hyaluronic acid-based microneedles and the superior healing-promoting effect of the drug combination could lead to a broad application prospect of the ROUMN patch in the treatment of recurrent oral ulcers.展开更多
A series of novel carbon nanofibers(CNFs)based Cu-ZrO2 catalysts were synthesized by deposition precipitation method.To investigate the influence of promoter,catalysts were loaded with 1,2,3 and 4 wt%ZnO and character...A series of novel carbon nanofibers(CNFs)based Cu-ZrO2 catalysts were synthesized by deposition precipitation method.To investigate the influence of promoter,catalysts were loaded with 1,2,3 and 4 wt%ZnO and characterized by ICP-OES,HRTEM,BET,N2O chemisorption,TPR,XPS and CO2-TPD techniques.The results revealed that physicochemical properties of the catalysts were strongly influenced by incorporation of ZnO to the parent catalyst.Copper surface area(SCu)and dispersion(DCu)were slightly decreased by incorporation of ZnO promoter.Nevertheless,SCuand DCuwere remarkably decreased when ZnO content was exceeded beyond 3 wt%.The catalytic performance was evaluated by using autoclave slurry reactor at a pressure and temperature of 30 bar and 180℃,respectively.The promotion of CuZrO2/CNFs catalyst with 3 wt%of ZnO enhanced methanol synthesis rate from 32 to 45 g kg^-1 h^-1.Notably,with the ZnO promotion the selectivity to methanol was enhanced to 92%compared to 78%of the un-promoted Cu-ZrO2/CNFs catalyst at the expense of a lowered CO2 conversion.In addition,the catalytic activity of this novel catalyst system for CO2 hydrogenation to methanol was compared with the recent literature data.展开更多
The surface functions produced by adding 14 rare earth oxides in Ni/γ Al 2O 3 system were determined by BET, gas chromatography, infrared spectroscopy, XRD, SEM, X ray electronic energy spectrum etc, and research...The surface functions produced by adding 14 rare earth oxides in Ni/γ Al 2O 3 system were determined by BET, gas chromatography, infrared spectroscopy, XRD, SEM, X ray electronic energy spectrum etc, and researched contrastively. The results show that the addition of rare earth oxides changes the property of catalyst surface. It is of benefit to increasing the number of active center of the catalyst and the surface acidity of the catalyst, decreasing the surface carbon deposit during the reaction. Moreover, the addition of rare earth oxides influences the electronic state of nickel atoms on the surface directly and produces electronic effect. The effect is different for each rare earth element.展开更多
基金the National Natural Science Foundation of China(No.32001984).
文摘A Plant Biostimulant is any substance or microorganism applied to plants to enhance nutrition efficiency,abioticstress tolerance,and/or crop quality traits,regardless of its nutrient content.The application of Plant biostimulants(PBs)in production can reduce the application of traditional pesticides and chemical fertilizers and improvethe quality and yield of crops,which is conducive to the sustainable development of agriculture.An in-depthunderstanding of the mechanism and effect of various PBs is very important for how to apply PBs reasonablyand effectively in the practice of crop production.This paper summarizes the main classification of PBs;Thegrowth promotion mechanism of PBs was analyzed from four aspects:improving soil physical and chemical properties,enhancing crop nutrient absorption capacity,photosynthesis capacity,and abiotic stress tolerance;At thesame time,the effects of PBs application on seed germination,seedling vigor,crop yield,and quality were summarized;Finally,how to continue to explore and study the use and mechanism of PBs in the future is analyzedand prospected,to better guide the application of PBs in crop production in the future.
基金supported by the National Natural Science Foundation of China(21403125,21403124)the Scientific Research Foundation for the Outstanding Young Scientist of Shandong Province(BS2011NJ009)~~
文摘Fe_2O_3 nanorods and hexagonal nanoplates were synthesized and used as the promoters for Pt electrocatalysts toward the methanol oxidation reaction(MOR) in an alkaline electrolyte.The catalysts were characterized by scanning electron microscopy,transmission electron microscopy,X-ray diffraction,X-ray photoelectron spectroscopy,cyclic voltammetry and chronoamperometry.The results show that the presence of Fe_2O_3 in the electrocatalysts can promote the kinetic processes of MOR on Pt,and this promoting effect is related to the morphology of the Fe_2O_3 promoter.The catalyst with Fe_2O_3 nanorods as the promoter(Pt-Fe_2O_3/C-R) exhibits much higher catalytic activity and stability than that with Fe_2O_3 nanoplates as the promoter(Pt-Fe_2O_3/C-P).The mass activity and specific activity of Pt in a Pt-Fe_2O_3/C-R catalyst are 5.32 A/mgpt and 162.7 A/m^2_(Pt),respectively,which are approximately 1.67 and 2.04 times those of the Pt-Fe_2O_3/C-P catalyst,and 4.19 and 6.16 times those of a commercial PtRu/C catalyst,respectively.Synergistic effects between Fe_2O_3 and Pt and the high content of Pt oxides in the catalysts are responsible for the improvement.These findings contribute not only to our understanding of the MOR mechanism but also to the development of advanced electrocatalysts with high catalytic properties for direct methanol fuel cells.
基金financially supported by the National Key R&D Program of China (2016YFC0204201)the National Natural Science Foundation of China (21677114, 21477095, 21876139)the Fundamental Research Funds for the Central Universities (xjj2017170)~~
文摘Pt/Eu2O3-CeO2 materials with different Eu concentrations were prepared and applied to toluene destruction,and the remarkable promotion impact of EuOx on Pt/CeO2 can be observed.The characterization results reveal that the presence of EuOx significantly enhances the redox property,lattice O concentration,and Ce3+ ratio of the Pt/CeO2 material,which facilitates the dispersion and activity of Pt active sites and thus accelerates the decomposition process of toluene.Among all catalysts,a sample with an Eu content of 2.5 at.%(Pt/EC-2.5)possesses the best catalytic activity with 0.09 vol% of toluene completely destructed at 200 ℃ under a relatively high GHSV of 50000 h^-1.The possible reaction pathway and mechanism of toluene combustion over Pt/Eu2O3-CeO2 samples are presented according to in-situ DRIFTS,which confirms that the toluene oxidation process obeys the Mars-van Krevelen mechanism with aldehydes and ketones as primary organic intermediates.
文摘The effect of super absorbent polymer(SAP) on the formation of tetrahydrofuran(THF) hydrate was studied by the successional cooling method.It was found that THF solution samples with 0.004 wt% and 0.03 wt% of SAP formed THF hydrate completely during the same cooling process.The corresponding induction time was 16-29 min,14-31 min,respectively,which was obviously shorter than that of THF solution samples without SAP(25-62 min).It indicated that SAP accelerated the formation of THF hydrate.At the same time,the pictures of hydrate formation with and without SAP had been compared.It was found that SAP did not change the morphology of the hydrate.Finally,the mechanism of SAP promoting effect on the formation of THF hydrate was suggested.
基金The work was jointly supported by two grants(Project code:UIC 201624 and UIC 201714)from Beijing Normal University-Hong Kong Baptist University United International College,Zhuhai,Guangdong,China.
文摘The seeds and sprouts of mung bean are very common cruise in Asia.Evidence showed that bioactive compounds in mung bean have emerged as an increasing scientific interest due to their role in the prevention of degenerative diseases.All data of in vitro,in vivo and clinical studies of mung bean and its impact on human health were collected from a library database and electronic search.Botanical,phytochemical and pharmacological information was gathered and orchestrated.Remarkable studies have been demonstrated,showing the enhancement of metabolites in mung bean during the sprouting process,which possesses various health benefiting bioactive compounds.These compounds have been frequently attributed to their antioxidant,anti-diabetic,antimicrobial,anti-hyperlipidemic and antihypertensive effect,anti-inflammatory,and anticancer,anti-tumor and anti-mutagenic properties.In this critical review,we aimed to study the insight of the nutritional compositions,phytochemistry,and healthpromoting effects of mung bean and its sprouts.The various curative potential of mung bean provides successive preclinical outcomes in the field of drug discovery and this review strongly recommends that mung bean is an excellent nutritive legume,which modulates or prevents chronic degenerative diseases.
基金the National High Technology Research and Development Program of China(Grant No.2009AA063003)the National Nature Science Foundation of China(Grant No.20677039) for financial support
文摘A significant promotion effect of low-molecular hydroxyl compounds(LMHCs) was found in the nano-photoelectrocatalytic(NPEC) degradation of fulvic acid(FA),which is a typical kind of humic acid existing widely in natural water bodies,and its influence mechanism was proposed.A TiO_2 nanotube arrays(TNAs) material is served as the photoanode.Methanol,ethanediol,and glycerol were chosen as the representative of LMHCs in this study.The adsorption performance of organics on the surface of TNAs was investigated by using the instantaneous photocurrent value.The adsorption constants of FA,methanol,ethanediol,and glycerol were 43.44,19.32,7.00,and 1.30,respectively,which indicates that FA has the strongest adsorption property.The degradation performance of these organics and their mixture were observed in a thin-layer reactor.It shows that FA could hardly achieve exhausted mineralization alone,while LMHCs could be easily oxidized completely in the same condition.The degradation degree of FA,which is added LMHCs,improves significantly and the best promotion effect is achieved by glycerol.The promotion effect of LMHCs in the degradation of FA could be contributed to the formation of a tremendous amount of hydroxyl radicals in the NPEC process.The hydroxyl radicals could facilitate the complete degradation of both FA and its intermediate products.Among the chosen LMHCs,glycerol molecule which has three hydroxyls could generate the most hydroxyl radicals and contribute the best effective promotion.This work provides a new way to promote the NPEC degradation of FA and a direction to remove humus from polluted water.
基金supported by the National Natural Science Foundation of China(20825310 and 20973011)National Basic Research Project of China (2011CB201400 and 2011CB808700)
文摘The effect of chloride ions on a monoclinic ZrO2-supported RuOx (RuOx/m-ZrO2) catalyst with a Ru surface density of 0.3 Ru/nm2 was studied in the selective oxidation of methanol to methyl formate (MF) at a low temperature of 373 K. The m-ZrO2 support was Cl-free, and Cl- ions were introduced into the RuOx/m-ZrO2 catalyst by impregnation with zirconium oxychloride or ammonium chloride and subsequent thermal treatment in air at 673 K. The structures of these catalysts were characterized by X-ray diffraction, Raman and X-ray photoelectron spectroscopies. Their reducibility was probed by temperature-programmed reduction in H2. The RuOx domains were present as highly dispersed Rut42- structure on m-ZrO2 with similar reducibility for the RuOx/m-ZrO2 samples irrespective of modification with or without Cl ions. Introduction of appropriate amounts of zirconium oxychloride into RuOx/m-ZrO2 led to a remarkable increase in the methanol oxidation rate and MF selectivity, whereas introduction of ammonium chloride or zirconyl nitrate significantly inhibited the catalytic performance of RuOx/m-ZrO2. The promoting effect of Cl- ions derived from zirconium oxychloride can be tentatively attributed to their roles in facilitating the adsorption of methanol and desorption of MF product or its intermediates. This finding provides novel insights into the promoting effect of Cl- ions on oxides-based catalysts for selective oxidation reactions.
基金Funded by the Major Sqpecial Technological Programmes Concerning Water Pollution Control and Management(No. 2008ZX07317-02)
文摘Tourmaline can promote the growth of microorganisms under the temperature less than 900 ℃ by experiment. However, this promotion effect will vanish at 900 ℃ as a result of denaturation. Through the XRD analysis the crystal form change can explain the vanishment of tourmaline’s biological promotion effect at high temperature. Therefore, tourmaline as a biological promoter was used to prepare a kind of biological promotive ceramsite with the surface area of 7.914 m2/g, pore volume of 0.1002 mg/L, superficial pH value of 7.8, Zeta potential of 25 mV, unit water absorption of 0.1365 g/g, biocompatibility of 0.023 A/g and SICE of 0.8456. The experimental results show that the biomass of biological promotive ceramsite is 3.58 times more than that of ordinary ceramsite, and the treatment effect of the biological promotive ceramsite is better than the ordinary ceramsite. These features of this new biological promotive ceramsite makes it a preferable biovector.
基金Project supported by Scientific Grant of TianJin Normal University (1CHS02B)Special Grant of the President of TianJin Normal University
文摘There is no doubt that rare earth elements stand an important position among the essential elements of plant growth and it is long time since they are first used as plant growth promoters. Given their effects on microstructure, most reports are focused on the toxicology rather than promotion. Using cucumis sativus L. (Jin Chun No.5) as experiment material, we try to find out the nutritional effects of low Y3+ concentrations on cucumber seedlings′ leaves. The present paper suggests that the rare earth elements act as micronutrients at low concentrations while they give rise to toxicity at high concentration. Benefits defeat toxicity with concentration ranging from 5 to 25 μmol·L-1. Through careful study, at the Y(NO3)3 concentration of 10 μmol·L-1 the content of chlorophyll as well as the activities of SOD, Cu-Zn SOD and the POD are the highest. It indicates 10 μmol·L-1 is the optimum concentration of yttrium for promoting the cucumber growth.
文摘The adsorption of CO on Fe(110)with different coverages of tita- nia has been studied by AES,XPS,UPS.It is proposed that the adsorption sites of CO in this system are not only blocked by the deposited TiO_X,but also by the products of the dissociation of CO which is promoted by the deposited TiO_X.
基金supported by the National Natural Science Foundation of China (No. 21207039)the Natural Science Foundation of Guangdong Province, China (Grant No. S2011010000737)+2 种基金the Doctoral Fund of Ministry of Education of China (20110172120017)the Fundamental Research Funds for the Central Universities (Grant No. 2011zm 0048)the Key Laboratory of Renewable Energy and Gas Hydrate, Chinese Academy of Sciences (No. Y007K1)
文摘Activated carbon (AC) supported silver catalysts were prepared by incipient wetness impregnation method and their catalytic performance for CO preferential oxidation (PROX) in excess H2 was evaluated. Ag/AC catalysts, after reduction in H2 at low temperatures (≤200 ℃) following heat treatment in He at 200 ℃ (He200H200), exhibited the best catalytic properties. Temperature-programmed desorption (TPD), X-ray diffraction (XRD) and temperature-programmed reduction (TPR) results indicated that silver oxides were produced during heat treatment in He at 200 ℃ which were reduced to metal silver nanoparticles in H2 at low temperatures (≤200 ℃), simultaneously generating the adsorbed water/OH. CO conversion was enhanced 40% after water treatment following heat treatment in He at 600 ℃. These results imply that the metal silver nanoparticles are the active species and the adsorbed water/OH has noticeable promotion effects on CO oxidation. However, the promotion effect is still limited compared to gold catalysts under the similar conditions, which may be the reason of low selectivity to CO oxidation in PROX over silver catalysts. The reported Ag/AC-S-He catalyst after He200H200 treatment displayed similar PROX of CO reaction properties to Ag/SiO2. This means that Ag/AC catalyst is also an efficient low-temperature CO oxidation catalyst.
文摘The effects of riboflavin deficiency and simultaneously nitrosodimethylamine (NDMA) given by gastric intubation on the hepatic glutathione (GSH) content were examined in rats. On different days of the experiment, hepatic GSH content of the riboflavin deficient rats decreased to 55-61% of the control rats. When NDMA was given 6 mg kg by gastric intubation to riboflavin deficient rats, hepatic GSH content decreased markedly to 39-43% of the control rats. After supplying riboflavin, hepatie GSH content of the deficient rats recovered to the level of the control rats. These results suggest that alterations of rat hepatic GSH content during riboflavin deficiency may imply as one of the promoting effects of riboflavin deficiency on the carcinogenesis of nitrosamines.
文摘Basicity of ZrO2 is enhanced by KF modification due to the reaction of KF with ZrO2 surface: KF+ ZrO2-> K2ZrF6 + KOH. After pretreated above 673K, KF/ZrO2 catalyst exhibited higher activity for 1-butene isomerization at 273K than ZrO2. The amount of basic sites strongly adsorbing CO2 in the form of bicarbonate was also increased.
基金The project is supported by National Natural Science Foundation of China
文摘It was found for the first time that the compounds with only one functional group, such as pyridine, can show the promotion effect for the electrochemical reaction of cytochrome C at gold electrodes.
基金funding from the European Community’s Seventh Framework Programme(FP7-HEALTH-2011)under grant agreement No.278612(BIOHYBRID),from MIUR and from Compagnia di San Paolo(MOVAG)
文摘Traumatic injuries of peripheral nerves represent common casualties and their social impact is considerably high. Although peripheral nerves retain a good regeneration potential, the clinical outcome after nerve lesion is far from being satisfactory and functional recovery is almost never complete, especially in the case of large nerve defects, that result in loss or diminished sensitivity and/or motor activity of the innervated target organs. Therefore, to improve the outcome after nerve damage, or in peripheral neuropathies, there is a need for further research in nerve repair and regeneration to identify factors that promote axonal regrowth, remvelination and target reinnervation.
基金the National Natural Science Foundation of China(Nos.62003023,32071407,52073138,52003018 and 52003019)Beijing Natural Science Foundation(No.7212204)Beijing Advanced Innovation Center for Biomedical Engineering and Beihang University.
文摘Recurrent oral ulcer is a painful oral mucosal disorder that affects 20%of the world’s population.The lack of a radical cure due to its unknown underlying cause calls for innovative symptomatic treatments.This work reports a hyaluronic acid-based dissolvablemicroneedle patch(ROUMNpatch,short for recurrent oral ulcer microneedle)loaded with dexamethasone acetate,vitamin C and tetracaine hydrochloride for the treatment of recurrent oral ulcers.The ROUMN patch shows enhancement in both the anti-inflammatory effect elicited by dexamethasone and the pro-proliferation effect of vitamin C.In vitro experiments show that ROUMN has a higher efficiency in suppressing lipopolysaccharide(LPS)-induced interleukin-6(IL-6)expression than dexamethasone alone.Cell proliferation and migrationwere also significantly promoted byROUMNcompared to vitamin C alone.The healing-promoting effect of ROUMN was also verified in vivo using an acetic acid-cauterized oral ulcer model in rats.ROUMN as a treatment accelerated the healing process of oral ulcers,shortening the total healing time to 5 days compared with the 7 days required by treatment using watermelon frost,a commonly used over-the-counter(OTC)drug for oral ulcers.The rapid dissolution of the hyaluronic acid-based microneedles and the superior healing-promoting effect of the drug combination could lead to a broad application prospect of the ROUMN patch in the treatment of recurrent oral ulcers.
基金the Ministry of Higher Education Malaysia for providing financial support to this work via FRGS No:FRGS/1/2011/SG/UTP/02/13Universiti Teknologi PETRONAS
文摘A series of novel carbon nanofibers(CNFs)based Cu-ZrO2 catalysts were synthesized by deposition precipitation method.To investigate the influence of promoter,catalysts were loaded with 1,2,3 and 4 wt%ZnO and characterized by ICP-OES,HRTEM,BET,N2O chemisorption,TPR,XPS and CO2-TPD techniques.The results revealed that physicochemical properties of the catalysts were strongly influenced by incorporation of ZnO to the parent catalyst.Copper surface area(SCu)and dispersion(DCu)were slightly decreased by incorporation of ZnO promoter.Nevertheless,SCuand DCuwere remarkably decreased when ZnO content was exceeded beyond 3 wt%.The catalytic performance was evaluated by using autoclave slurry reactor at a pressure and temperature of 30 bar and 180℃,respectively.The promotion of CuZrO2/CNFs catalyst with 3 wt%of ZnO enhanced methanol synthesis rate from 32 to 45 g kg^-1 h^-1.Notably,with the ZnO promotion the selectivity to methanol was enhanced to 92%compared to 78%of the un-promoted Cu-ZrO2/CNFs catalyst at the expense of a lowered CO2 conversion.In addition,the catalytic activity of this novel catalyst system for CO2 hydrogenation to methanol was compared with the recent literature data.
文摘The surface functions produced by adding 14 rare earth oxides in Ni/γ Al 2O 3 system were determined by BET, gas chromatography, infrared spectroscopy, XRD, SEM, X ray electronic energy spectrum etc, and researched contrastively. The results show that the addition of rare earth oxides changes the property of catalyst surface. It is of benefit to increasing the number of active center of the catalyst and the surface acidity of the catalyst, decreasing the surface carbon deposit during the reaction. Moreover, the addition of rare earth oxides influences the electronic state of nickel atoms on the surface directly and produces electronic effect. The effect is different for each rare earth element.