Microorganisms capable of solubilizing and mineralizing phosphorus (P) pools in soils are considered vital in promoting P bioavallability. The study was conducted to screen and isolate inorganic P-solubilizing bacte...Microorganisms capable of solubilizing and mineralizing phosphorus (P) pools in soils are considered vital in promoting P bioavallability. The study was conducted to screen and isolate inorganic P-solubilizing bacteria (IPSB) and organic P-mineralizing bacteria (OPMB) in soils taken from subtropical flooded and temperate non-flooded soils, and to compare inorganic P-solubilizing and organic P-solubilizing abilities between IPSB and OPMB. Ten OPMB strains were isolated and identified as Bacillus cereus and Bacillus megaterium, and five IPSB strains as B. megaterium, Burkholderia caryophyUi, Pseudomonas cichorii, and Pseudomonas syringae. P-solubilizing and -mineralizing abilities of the strains were measured using the methods taking cellular P into account. The IPSB strains exhibited inorganic P-solubilizing abilities ranging between 25.4-41.7 μg P mL^-1 and organic P-mineralizing abilities between 8.2-17.8μg P mL^-1. Each of the OPMB strains also exhibited both solubilizing and mineralizing abilities varying from 4.4 to 26.5 μg P mL^-1 and from 13.8 to 62.8 μg P mL^-1, respectively. For both IPSB and OPMB strains, most of the P mineralized from the organic P source was incorporated into the bacterial cells as cellular P. A significantly negative linear correlation (P 〈 0.05) was found between culture pH and P solubilized from inorganic P by OPMB strains. The results suggested that P solubilization and mineralization could coexist in the same bacterial strain.展开更多
We have fabricated the white organic light-emitting devices (WOLEDs) based on 4,4' -bis(2,2 -diphenyl vinyl)-1,1' - biphenyl (DPVBi) and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene (rubrene)...We have fabricated the white organic light-emitting devices (WOLEDs) based on 4,4' -bis(2,2 -diphenyl vinyl)-1,1' - biphenyl (DPVBi) and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene (rubrene). The device structure is ITO/2T-NATA (20 nm)/NPBX (20 nm)/CBP: x%Ir(ppy)3:0.5% rubrene (8 nm)/NPBX (5 nm)/DPVBi (30 nm)/Alq(30 nm)/LiF(0.5 nm)/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris (2-phenylpyridine) iridium [Ir(ppy)3], acts as a yellow light-emitting layer, and N,N' -bis- (1-naphthyl)- N,N' -diphenyl -1, 1' -biphenyl-4,4' -diamine (NPBX) acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir (PPY)3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V.展开更多
Suspended particulate matter (SPM) collected in the Changjiang (Yangtze River) estuary in June 2006 was separated into five fractions via water elutriation: clay-very fme silt (〈8 μm), fine silt (8-16 μm),...Suspended particulate matter (SPM) collected in the Changjiang (Yangtze River) estuary in June 2006 was separated into five fractions via water elutriation: clay-very fme silt (〈8 μm), fine silt (8-16 μm), medium silt (16--32 μm), coarse silt (32~53 μm) and sand (〉63 μm). The SPM and fractionated particles were sequentially analyzed by a modified SEDEX sequential extraction method to obtain six species of phosphorus: exchangeable or loosely-sorbed P, organic P, Fe-bound P, authigenic P, detrital P and refractory P. The results indicated that all particulate phosphorus species except for detrital P were negatively correlated to particle size; a high detrital P content was found in coarse silt and very coarse silt. From the inside of the river mouth to the gate of the fiver mouth, organic P, Fe-bound P and refractory P in the suspended particles decreased and a higher amount of exchangeable P appeared around the gate of the fiver mouth. From the gate of the river mouth to the sea, exchangeable P and organic P in suspended panicles increased distinctly. The total particulate P flux into the estuary from the Changjiang River was about 45.45×10^8μmol/s during sampling. Of this, about 8.27×10^8μmol/s was associated with the "truly suspended" fraction. The bio-available particulate P flux was about 13.58×10^8μmol/s. Of this, about 4.24 ×10^8μmol/s w as transported by "truly suspended" particles.展开更多
A method for simultaneous determination of particulate inorganic phosphorus (PIP) and particulate organic phosphorus (POP) in seawater was improved. After using cellulose acetate membrane to filter the seawater sample...A method for simultaneous determination of particulate inorganic phosphorus (PIP) and particulate organic phosphorus (POP) in seawater was improved. After using cellulose acetate membrane to filter the seawater samples and washing the membrane with 1mol/L hydrochloric acid, PIP was extracted into hydrochloric acid phase and POP was left on the membrane. POP was oxygenated at 120℃, 0.12MPa with potassium persulphate. Phosphomolybdate blue spectrophotometry was used in the determination. The proper volume of seawater sample for simultaneously determining PIP and POP was 100-150ml, containing PIP≥0.27μg, POP≥0.69μg. Relative Standard Deviation (RSD) of the determination of PIP and POP was 5.8% and 4.3% respectively. This method was used to determine POP and PIP in the surface water of Huiquan Bay, Qingdao, China. PIP content there averaged at 69.0μg/L and POP at 3.3μg/L. PIP is the main form (>93%) of particulate phosphorus (PP). Maximum PIP coincided with flood tide, indicating that PIP mainly originated from disturbance of surface sediments. At the offshore area, maximum of PIP appeared at flood tide and minimum of PIP appeared at ebb-tide. The maximum of POP presented at about 10:00am, which suggests that POP is closely related to biological metabolism. The control factor of POP in seawater was concluded to be biological metabolization.展开更多
The Diels-Alder reaction of bis(diphenylphosphine oxide)butadiyne (BDPPOB) with spiro[2.4]hepta-4,6-diene affords the title compound, 2-(diphenylphosphine oxide)-3-(diphen- ylphosphine oxide ethynyl)spiro[bicyclo[2.2....The Diels-Alder reaction of bis(diphenylphosphine oxide)butadiyne (BDPPOB) with spiro[2.4]hepta-4,6-diene affords the title compound, 2-(diphenylphosphine oxide)-3-(diphen- ylphosphine oxide ethynyl)spiro[bicyclo[2.2.1] hepta-2,5-diene-7,1-cyclopropane] (DDSHC, C35H28O2P2, Mr = 542). Its crystal structure belongs to monoclinic system, space group P21/n with a =12.708(3), b = 14.666(4), c = 15.048(4) ? = 93.903(5) ? V = 2798.1(13) ?, Z = 4, Dc = 1.288g/cm3, F(000)=1136, (MoK? = 0.187mm-1, final R = 0.0626 and wR= 0.1422 for 4685 independent reflections with I > 2(I). Structural analyses reveal that the title compound is nonplanar and the dihedral angles between two phenyl rings around each phosphorus atom are 71.7(2) and 70.7(3)? respectively.展开更多
An incubation experiment was carried out in laboratory to study the effect of temperature, moisture, phosphorus, organic matter, cropping and previous elemental sulfur application on elemental sulfur oxidation in four...An incubation experiment was carried out in laboratory to study the effect of temperature, moisture, phosphorus, organic matter, cropping and previous elemental sulfur application on elemental sulfur oxidation in four selected soils, fluvo-aquic soil, black soil, yellow-brown soil and red soil. In all the soils tested, sulfur oxidation rate was influenced by temperature and the temperature coefficient (Q10) values at the range from 10 to 30 ℃ were 4.41, 4.05, 6.19 and 3.71 for the four soils, respectively. The rate of sulfur oxidation was parabolically related to soil Water content. The optimum moisture content for the maximum oxidation rate was different among soils. Phosphorus increased the oxidation rate of elemental sulfur by 57.7%, 33.1%, 21.7% and 26.4% for the above four soils, respectively, compared with the control (no phosphorus applied). Organic material of corn straw which was ground and passed through a 0.5-mm sieve also increased the oxidation rate of elemental sulfur in the four soils by 59.8%, 7.8%, 39.2% and 540.4%, respectively. Elemental sulfur which was applied previously to soils significantly enhanced the oxidation of elemental sulfur subsequently added and increased sulfur-oxidizing populations such as autotrophic elemental sulfur oxidizers with pH optimum 6.8, autotrophic thiosulfate oxidizers with pH optimum 6.8, heterotrophic thiosulfate oxidizers and heterotrophic sulfate producers. Cropping had little effect on elemental sulfur-oxidizing potentiality of soils.展开更多
Chlorpyrifos is a well known organophosphorus pesticide used worldwide. Microorganisms including bacteria, fungi and actinomycetes have been reported to be efficient degraders of chlorpyrifos. The present study was su...Chlorpyrifos is a well known organophosphorus pesticide used worldwide. Microorganisms including bacteria, fungi and actinomycetes have been reported to be efficient degraders of chlorpyrifos. The present study was successful in isolating a novel fungus that could degrade chlorpyrifos effectively upto 800 ppm concentration. Morphological and molecular characterization studies revealed the identity of the fungus as Isariafarinosa.展开更多
The title compound (C30H32NO4PGe), O,O-dimethyl-N-(β-triphenylgermanyl) propionyl-α-aminobenzylphosphonates was synthesized by a convenient method, and its crystal structure was determined by single-crystal X-ray di...The title compound (C30H32NO4PGe), O,O-dimethyl-N-(β-triphenylgermanyl) propionyl-α-aminobenzylphosphonates was synthesized by a convenient method, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal is triclinic, space group P-1 with parameters: a=9.7753(5), b=11.5773(5), c=13.5059(6) ?, α=104.185(1),β= 95.971(1), γ =96.727(1)°, V=1457.63(12) ?3, Z=2, Mr=574.13, Dc=1.308 g/cm3, λ=0.71073 ?, μ = 1.139mm-1, and F(000)=596. The structure was solved by direct methods. The structure was refined to R=0.0257, wR=0.0705 for 5080 observed reflections with I >2σ(I).The result of structure analysis indicates that atom Ge is sp3 hydridized because the arrangement of the four carbon atoms bonded to it is a distorted tetrahedron. The geometry of the three phenyl groups linking with the Ge atom looks like a propeller form.展开更多
We report in situ doping of brushite on zinc manganese oxide(ZMO), fabricated by calcining a Mn(II) oxalate‐impregnated metal‐organic framework. The doping process was conducted in com‐bination with the photoca...We report in situ doping of brushite on zinc manganese oxide(ZMO), fabricated by calcining a Mn(II) oxalate‐impregnated metal‐organic framework. The doping process was conducted in com‐bination with the photocatalytic water oxidation reaction which was catalyzed by ZMO in neutral phosphate‐buffered aqueous solution containing [Ru(bpy)3]^2+‐Na2S2O8 and calcium(II) triflate salt, exhibiting greatly enhanced water oxidation performance with optimized turnover frequency of 0.18 mmol(O2) mol(Mn)^(–1) s^(–1). Different analytical techniques indicated that photodeposited calci‐um‐phosphate(CaP) acted as a co‐catalyst to promote the O2 evolution activity of ZMO. This system involved the use of manganese oxide and calcium ion, and the operation was conducted under am‐bient temperature and neutral conditions, thus, it efficiently mimicked the oxygen‐evolving complex in photosystem II.展开更多
This study aimed to characterize constituents of phosphorus (P) fractionation as wel as reciprocities among factors in sediments of a freshwater shal ow lake. [Method] Surface sediment was discretely sampled at 24 s...This study aimed to characterize constituents of phosphorus (P) fractionation as wel as reciprocities among factors in sediments of a freshwater shal ow lake. [Method] Surface sediment was discretely sampled at 24 sites through Van Veen grabs. Based on a modified sequential extraction scheme, P fractionation was determined as Fe/Al bound P (Fe/Al-P), Ca bound P (Ca-P), solute and re-ductive P (S/R-P) and organic P (OP). Curve estimation and Pearson product-mo-ment correlation were employed for statistical analysis. [Result] Total P (TP) content ranged from 443 to 774 mg/kg. Inorganic P (IP) was the major component of TP, of which Ca-P was dominated with an average of 51%±9.7%. Average contents of P fractionation were in the fol owing order: Ca-P(51%) 〉 OP(29%) 〉 S/R-P(8%) 〉Fe/Al-P(7%). The molar ratio of Fe to P was 11 - 20, close to the threshold value of P leaching. [Conclusion] In freshwater shal ow lakes, IP and Ca-P were prone to be relatively high, whereas Fe/Al-P was low compared with deep lakes. Occurrence of spatial y monotonic gradient indicated the primary causation of anthropogenic sources. Imminent sediment P liberation was also expected. Close associations a-mong TP, Fe/Al-P and Ca-P, implying that anthropogenic P was mainly bound to metals in particulates. Significant correlations of TOC and P fractionation highlighted endogenous mechanism and authigenic origin in sediments.展开更多
A series of amino organophosphorus imidazoles were designed and synthesized as a novel structural type of antimicrobial agents.Bioactive evaluation in vitro showed that compound 3f exhibited equipotent or superior ant...A series of amino organophosphorus imidazoles were designed and synthesized as a novel structural type of antimicrobial agents.Bioactive evaluation in vitro showed that compound 3f exhibited equipotent or superior anti-methicillin-resistant Staphylococcus aureus(anti-MRSA) and anti-S. cerevisiae efficiencies(minimal inhibitory concentration(MIC)=2 μg/mL) to clinical drugs,and the combinations with antibacterial or antifungal drugs enhanced the antimicrobial efficiency. Highly active molecule 3f showed low propensity for bacteria to develop resistance, and the preliminary action mechanism studies demonstrated that 3f was membrane-active, but had no significant intercalation towards MRSA DNA. The computational study on 3f reasonably explained its high antimicrobial activity. Experimental data revealed that ground-state 3f-HSA complexes were formed mainly through hydrophobic interactions and hydrogen bonds with a spontaneous process, and the non-radioactive energy transfer from HSA to 3f occurred beyond F鰎ster resonance energy transfer theory. The participation of metal ions in 3f-HSA supramolucular system could increase the concentration of free compound 3f, and shorten its storage time and half-life in the blood to improve the maximum antimicrobial efficacy.展开更多
Organic phosphorescence materials with longlived triplet excitons that can highly generate active singlet oxygen(1O2) through the energy transfer with the molecular oxygen under photoexcitation, serve as highly effici...Organic phosphorescence materials with longlived triplet excitons that can highly generate active singlet oxygen(1O2) through the energy transfer with the molecular oxygen under photoexcitation, serve as highly efficient antibacterial agent. Herein, we report bright red-emissive organic phosphorescent nanoparticles(PNPs) based on a metal-free organic phosphor encapsulated with biocompatible block copolymers. The obtained PNPs with an ultra-small particle size of around 5 nm and a long emission lifetime of up to 167 μs showed effective 1O2 generation ability under visible light(410 nm) excitation in aqueous media, which can efficiently eradicate multi-drug resistant bacteria both in vitro and in vivo. This is the first demonstration of metal-free organic PNPs for photodynamic antimicrobial therapy, expanding the application scope of metal-free organic room temperature phosphorescent materials.展开更多
Continuous applications of organic and inorganic fertilizers can affect soil and food quality with respect to selenium (Se) concen- trations. A long-term (over 20 years) experimental field study, started in 1989, ...Continuous applications of organic and inorganic fertilizers can affect soil and food quality with respect to selenium (Se) concen- trations. A long-term (over 20 years) experimental field study, started in 1989, was conducted to investigate the changes in soil Se fractions and its uptake by crops, as affected by different fertilizer practices, in the North China Plain with an annual crop rotation of winter wheat and summer maize. The long-term experiment was arranged in a complete randomized block design consisting of 4 replications with 7 fertilizer treatments: 1) organic compost (OC), 2) half organic compost plus half N-P-K chemical fertilizers (OC + NPK), 3) N-P-K fertilizers (NPK), 4) N-P fertilizers (NP), 5) P-K fertilizers (PK), 6) N-K fertilizers (NK), and 7) an un-amended control. Soil samples from the surface (20 cm) were collected in 1989, 1994, 1999, 2004 and 2009 to characterize Se and other soil properties. In 2009, the average soil Se concentrations in the treatments (149 ± 8 beg kg-1) were higher than those in the soil samples collected in 1989 at the beginning of the experiment (112 4- 4 beg kg-1), and decreased in the order of OC 〉 OC + NPK 〉 NPK NP 〉 PK NK 〉 control. Sequential extraction showed the oxidizable fraction (50.06%± 3.94%) was the dominant form of Se in the soil, followed by the residual fraction (24.12% ± 2.89%), exchangeable fraction (15.09% ± 4.34%) and Fe-Mn oxides fraction (10.73%±4.04%). With an increase of soil K, the exchangeable Se concentrations in the soil increased. The Se concentrations in the soil tillage layer (0-20 cm) were mainly related to soil organic carbon (SOC), although different contributions came from atmospheric deposition, irrigation and fertilizers. With the accumulation of SOC, the uptakes of soil Se by two crops were inhibited. For the OC and OC + NPK treatments, Se concentrations in wheat grains were lower than the critical standard of Se in stable food (100 μg kg·1]. Additionallv. Se concentrations in grains were also decreased by the deficiencies of major soil nutrients, especially P.展开更多
Sandplain soils on the south coast of Western Australia have low inherent fertility, which is mainly due to poor nutrient retention caused by insufficient clay and organic colloidal material. Previous research has sho...Sandplain soils on the south coast of Western Australia have low inherent fertility, which is mainly due to poor nutrient retention caused by insufficient clay and organic colloidal material. Previous research has shown the benefits in nutrient levels and retention from adding clay to sandplain soils; however, there is almost no information on the addition of organic amendments. A field experiment was established at the Esperance Downs Research Station, Western Australian, in May 2010, to assess the effects of wheat straw(WS) and chicken manure(CM) biochars and compost with and without phosphorus(P) addition on soil properties and crop production over five growing seasons. The five seasons alternated between winter and summer crops. The CM and WS biochar and compost treatments significantly increased crop yields and P uptake in 3, 2 and 1 of the five seasons, respectively. The yield increases(P < 0.05) were no more than 8%. By the end of the third season, no differences in crop yields were found that could be attributed to the organic amendments. The addition of P increased crop yields in each winter cropping season. Phosphorus addition explained more than 30%of the variation in crop yields. Despite marginal P levels and summer drought conditions, arbuscular mycorrhizal root colonisation was not affected by the organic amendments. There were no significant interactions between the organic amendments and P addition in terms of crop yields, P uptake or P uptake efficiency. We conclude that much of the effect of the organic amendments was due to direct nutrient addition which dissipated over time.展开更多
基金the Scientific Research Foundation for the Returned Overseas Chinese Scholars, the Ministry of Education of the P.R. China.
文摘Microorganisms capable of solubilizing and mineralizing phosphorus (P) pools in soils are considered vital in promoting P bioavallability. The study was conducted to screen and isolate inorganic P-solubilizing bacteria (IPSB) and organic P-mineralizing bacteria (OPMB) in soils taken from subtropical flooded and temperate non-flooded soils, and to compare inorganic P-solubilizing and organic P-solubilizing abilities between IPSB and OPMB. Ten OPMB strains were isolated and identified as Bacillus cereus and Bacillus megaterium, and five IPSB strains as B. megaterium, Burkholderia caryophyUi, Pseudomonas cichorii, and Pseudomonas syringae. P-solubilizing and -mineralizing abilities of the strains were measured using the methods taking cellular P into account. The IPSB strains exhibited inorganic P-solubilizing abilities ranging between 25.4-41.7 μg P mL^-1 and organic P-mineralizing abilities between 8.2-17.8μg P mL^-1. Each of the OPMB strains also exhibited both solubilizing and mineralizing abilities varying from 4.4 to 26.5 μg P mL^-1 and from 13.8 to 62.8 μg P mL^-1, respectively. For both IPSB and OPMB strains, most of the P mineralized from the organic P source was incorporated into the bacterial cells as cellular P. A significantly negative linear correlation (P 〈 0.05) was found between culture pH and P solubilized from inorganic P by OPMB strains. The results suggested that P solubilization and mineralization could coexist in the same bacterial strain.
基金the Ministry of Science and Technol- ogy of Jilin under Grant No. 20050523the Grant for the Scien- tific Research from the educational office of Jilin (Project No.25, [2003]+2 种基金 54, [2004])the Grant from the department of Science and Technology of Siping [Project No.2005007 2006008]
文摘We have fabricated the white organic light-emitting devices (WOLEDs) based on 4,4' -bis(2,2 -diphenyl vinyl)-1,1' - biphenyl (DPVBi) and phosphorescence sensitized 5,6,11,12,-tetraphenylnaphthacene (rubrene). The device structure is ITO/2T-NATA (20 nm)/NPBX (20 nm)/CBP: x%Ir(ppy)3:0.5% rubrene (8 nm)/NPBX (5 nm)/DPVBi (30 nm)/Alq(30 nm)/LiF(0.5 nm)/A1. In the devices, DPVBi acts as a blue light-emitting layer, the rubrene is sensitized by a phosphorescent material, fac tris (2-phenylpyridine) iridium [Ir(ppy)3], acts as a yellow light-emitting layer, and N,N' -bis- (1-naphthyl)- N,N' -diphenyl -1, 1' -biphenyl-4,4' -diamine (NPBX) acts as a hole transporting and exciton blocker layer, respectively. When the concentration of Ir (PPY)3 is 6wt%, the maximum luminance is 24960 cd/m^2 at an applied voltage of 15 V, and the maximum luminous efficiency is 5.17 cd/A at an applied voltage of 8 V.
基金Supported by the National Natural Science Foundation of China (Nos.40976044,40920164004 and 30490232)the National Basic Research Program of China (973 Program) (Nos.2002CB12405 and 2005CB422305)
文摘Suspended particulate matter (SPM) collected in the Changjiang (Yangtze River) estuary in June 2006 was separated into five fractions via water elutriation: clay-very fme silt (〈8 μm), fine silt (8-16 μm), medium silt (16--32 μm), coarse silt (32~53 μm) and sand (〉63 μm). The SPM and fractionated particles were sequentially analyzed by a modified SEDEX sequential extraction method to obtain six species of phosphorus: exchangeable or loosely-sorbed P, organic P, Fe-bound P, authigenic P, detrital P and refractory P. The results indicated that all particulate phosphorus species except for detrital P were negatively correlated to particle size; a high detrital P content was found in coarse silt and very coarse silt. From the inside of the river mouth to the gate of the fiver mouth, organic P, Fe-bound P and refractory P in the suspended particles decreased and a higher amount of exchangeable P appeared around the gate of the fiver mouth. From the gate of the river mouth to the sea, exchangeable P and organic P in suspended panicles increased distinctly. The total particulate P flux into the estuary from the Changjiang River was about 45.45×10^8μmol/s during sampling. Of this, about 8.27×10^8μmol/s was associated with the "truly suspended" fraction. The bio-available particulate P flux was about 13.58×10^8μmol/s. Of this, about 4.24 ×10^8μmol/s w as transported by "truly suspended" particles.
文摘A method for simultaneous determination of particulate inorganic phosphorus (PIP) and particulate organic phosphorus (POP) in seawater was improved. After using cellulose acetate membrane to filter the seawater samples and washing the membrane with 1mol/L hydrochloric acid, PIP was extracted into hydrochloric acid phase and POP was left on the membrane. POP was oxygenated at 120℃, 0.12MPa with potassium persulphate. Phosphomolybdate blue spectrophotometry was used in the determination. The proper volume of seawater sample for simultaneously determining PIP and POP was 100-150ml, containing PIP≥0.27μg, POP≥0.69μg. Relative Standard Deviation (RSD) of the determination of PIP and POP was 5.8% and 4.3% respectively. This method was used to determine POP and PIP in the surface water of Huiquan Bay, Qingdao, China. PIP content there averaged at 69.0μg/L and POP at 3.3μg/L. PIP is the main form (>93%) of particulate phosphorus (PP). Maximum PIP coincided with flood tide, indicating that PIP mainly originated from disturbance of surface sediments. At the offshore area, maximum of PIP appeared at flood tide and minimum of PIP appeared at ebb-tide. The maximum of POP presented at about 10:00am, which suggests that POP is closely related to biological metabolism. The control factor of POP in seawater was concluded to be biological metabolization.
基金This work was supported by the NNSFC (No. 29832030 and 20072018)
文摘The Diels-Alder reaction of bis(diphenylphosphine oxide)butadiyne (BDPPOB) with spiro[2.4]hepta-4,6-diene affords the title compound, 2-(diphenylphosphine oxide)-3-(diphen- ylphosphine oxide ethynyl)spiro[bicyclo[2.2.1] hepta-2,5-diene-7,1-cyclopropane] (DDSHC, C35H28O2P2, Mr = 542). Its crystal structure belongs to monoclinic system, space group P21/n with a =12.708(3), b = 14.666(4), c = 15.048(4) ? = 93.903(5) ? V = 2798.1(13) ?, Z = 4, Dc = 1.288g/cm3, F(000)=1136, (MoK? = 0.187mm-1, final R = 0.0626 and wR= 0.1422 for 4685 independent reflections with I > 2(I). Structural analyses reveal that the title compound is nonplanar and the dihedral angles between two phenyl rings around each phosphorus atom are 71.7(2) and 70.7(3)? respectively.
文摘An incubation experiment was carried out in laboratory to study the effect of temperature, moisture, phosphorus, organic matter, cropping and previous elemental sulfur application on elemental sulfur oxidation in four selected soils, fluvo-aquic soil, black soil, yellow-brown soil and red soil. In all the soils tested, sulfur oxidation rate was influenced by temperature and the temperature coefficient (Q10) values at the range from 10 to 30 ℃ were 4.41, 4.05, 6.19 and 3.71 for the four soils, respectively. The rate of sulfur oxidation was parabolically related to soil Water content. The optimum moisture content for the maximum oxidation rate was different among soils. Phosphorus increased the oxidation rate of elemental sulfur by 57.7%, 33.1%, 21.7% and 26.4% for the above four soils, respectively, compared with the control (no phosphorus applied). Organic material of corn straw which was ground and passed through a 0.5-mm sieve also increased the oxidation rate of elemental sulfur in the four soils by 59.8%, 7.8%, 39.2% and 540.4%, respectively. Elemental sulfur which was applied previously to soils significantly enhanced the oxidation of elemental sulfur subsequently added and increased sulfur-oxidizing populations such as autotrophic elemental sulfur oxidizers with pH optimum 6.8, autotrophic thiosulfate oxidizers with pH optimum 6.8, heterotrophic thiosulfate oxidizers and heterotrophic sulfate producers. Cropping had little effect on elemental sulfur-oxidizing potentiality of soils.
文摘Chlorpyrifos is a well known organophosphorus pesticide used worldwide. Microorganisms including bacteria, fungi and actinomycetes have been reported to be efficient degraders of chlorpyrifos. The present study was successful in isolating a novel fungus that could degrade chlorpyrifos effectively upto 800 ppm concentration. Morphological and molecular characterization studies revealed the identity of the fungus as Isariafarinosa.
文摘The title compound (C30H32NO4PGe), O,O-dimethyl-N-(β-triphenylgermanyl) propionyl-α-aminobenzylphosphonates was synthesized by a convenient method, and its crystal structure was determined by single-crystal X-ray diffraction. The crystal is triclinic, space group P-1 with parameters: a=9.7753(5), b=11.5773(5), c=13.5059(6) ?, α=104.185(1),β= 95.971(1), γ =96.727(1)°, V=1457.63(12) ?3, Z=2, Mr=574.13, Dc=1.308 g/cm3, λ=0.71073 ?, μ = 1.139mm-1, and F(000)=596. The structure was solved by direct methods. The structure was refined to R=0.0257, wR=0.0705 for 5080 observed reflections with I >2σ(I).The result of structure analysis indicates that atom Ge is sp3 hydridized because the arrangement of the four carbon atoms bonded to it is a distorted tetrahedron. The geometry of the three phenyl groups linking with the Ge atom looks like a propeller form.
文摘We report in situ doping of brushite on zinc manganese oxide(ZMO), fabricated by calcining a Mn(II) oxalate‐impregnated metal‐organic framework. The doping process was conducted in com‐bination with the photocatalytic water oxidation reaction which was catalyzed by ZMO in neutral phosphate‐buffered aqueous solution containing [Ru(bpy)3]^2+‐Na2S2O8 and calcium(II) triflate salt, exhibiting greatly enhanced water oxidation performance with optimized turnover frequency of 0.18 mmol(O2) mol(Mn)^(–1) s^(–1). Different analytical techniques indicated that photodeposited calci‐um‐phosphate(CaP) acted as a co‐catalyst to promote the O2 evolution activity of ZMO. This system involved the use of manganese oxide and calcium ion, and the operation was conducted under am‐bient temperature and neutral conditions, thus, it efficiently mimicked the oxygen‐evolving complex in photosystem II.
基金Supported by the National Natural Science Foundation of China(grant No.41171384,41271414 and 41301529)
文摘This study aimed to characterize constituents of phosphorus (P) fractionation as wel as reciprocities among factors in sediments of a freshwater shal ow lake. [Method] Surface sediment was discretely sampled at 24 sites through Van Veen grabs. Based on a modified sequential extraction scheme, P fractionation was determined as Fe/Al bound P (Fe/Al-P), Ca bound P (Ca-P), solute and re-ductive P (S/R-P) and organic P (OP). Curve estimation and Pearson product-mo-ment correlation were employed for statistical analysis. [Result] Total P (TP) content ranged from 443 to 774 mg/kg. Inorganic P (IP) was the major component of TP, of which Ca-P was dominated with an average of 51%±9.7%. Average contents of P fractionation were in the fol owing order: Ca-P(51%) 〉 OP(29%) 〉 S/R-P(8%) 〉Fe/Al-P(7%). The molar ratio of Fe to P was 11 - 20, close to the threshold value of P leaching. [Conclusion] In freshwater shal ow lakes, IP and Ca-P were prone to be relatively high, whereas Fe/Al-P was low compared with deep lakes. Occurrence of spatial y monotonic gradient indicated the primary causation of anthropogenic sources. Imminent sediment P liberation was also expected. Close associations a-mong TP, Fe/Al-P and Ca-P, implying that anthropogenic P was mainly bound to metals in particulates. Significant correlations of TOC and P fractionation highlighted endogenous mechanism and authigenic origin in sediments.
基金supported by the National Natural Science Foundation of China(21672173,21372186)Research Fund for International Young Scientists from International(Regional)Cooperation and Exchange Program(81350110523)+1 种基金Chongqing Special Foundation for Postdoctoral Research Proposal(Xm2014127,Xm2016039)Fundamental Research Funds for the Central Universities(XDJK2016E059)
文摘A series of amino organophosphorus imidazoles were designed and synthesized as a novel structural type of antimicrobial agents.Bioactive evaluation in vitro showed that compound 3f exhibited equipotent or superior anti-methicillin-resistant Staphylococcus aureus(anti-MRSA) and anti-S. cerevisiae efficiencies(minimal inhibitory concentration(MIC)=2 μg/mL) to clinical drugs,and the combinations with antibacterial or antifungal drugs enhanced the antimicrobial efficiency. Highly active molecule 3f showed low propensity for bacteria to develop resistance, and the preliminary action mechanism studies demonstrated that 3f was membrane-active, but had no significant intercalation towards MRSA DNA. The computational study on 3f reasonably explained its high antimicrobial activity. Experimental data revealed that ground-state 3f-HSA complexes were formed mainly through hydrophobic interactions and hydrogen bonds with a spontaneous process, and the non-radioactive energy transfer from HSA to 3f occurred beyond F鰎ster resonance energy transfer theory. The participation of metal ions in 3f-HSA supramolucular system could increase the concentration of free compound 3f, and shorten its storage time and half-life in the blood to improve the maximum antimicrobial efficacy.
基金supported by the National Key R&D Program of China (2018YFC1105402 and 2017YFA0207202)the National Natural Science Foundation of China (21975120, 21875104, 51673095 and 21875189)+3 种基金the National Basic Research Program of China (973 Program, 2015CB932200)the Natural Science Fund for Distinguished Young Scholars of Jiangsu Province (BK20180037)the Natural Science Fund for Colleges and Universities of Jiangsu Province (17KJB430020)the Key R&D Program of Jiangsu Province (BE2017740)
文摘Organic phosphorescence materials with longlived triplet excitons that can highly generate active singlet oxygen(1O2) through the energy transfer with the molecular oxygen under photoexcitation, serve as highly efficient antibacterial agent. Herein, we report bright red-emissive organic phosphorescent nanoparticles(PNPs) based on a metal-free organic phosphor encapsulated with biocompatible block copolymers. The obtained PNPs with an ultra-small particle size of around 5 nm and a long emission lifetime of up to 167 μs showed effective 1O2 generation ability under visible light(410 nm) excitation in aqueous media, which can efficiently eradicate multi-drug resistant bacteria both in vitro and in vivo. This is the first demonstration of metal-free organic PNPs for photodynamic antimicrobial therapy, expanding the application scope of metal-free organic room temperature phosphorescent materials.
基金supported by the National Basic Research Program (973 Program) of China (No.2011CB100506)the China Agriculture Research System-Wheat (No.CARS-03-02A)the Knowledge Innovation Program of Chinese Academy of Sciences (No.KSCX2-EW-N-08)
文摘Continuous applications of organic and inorganic fertilizers can affect soil and food quality with respect to selenium (Se) concen- trations. A long-term (over 20 years) experimental field study, started in 1989, was conducted to investigate the changes in soil Se fractions and its uptake by crops, as affected by different fertilizer practices, in the North China Plain with an annual crop rotation of winter wheat and summer maize. The long-term experiment was arranged in a complete randomized block design consisting of 4 replications with 7 fertilizer treatments: 1) organic compost (OC), 2) half organic compost plus half N-P-K chemical fertilizers (OC + NPK), 3) N-P-K fertilizers (NPK), 4) N-P fertilizers (NP), 5) P-K fertilizers (PK), 6) N-K fertilizers (NK), and 7) an un-amended control. Soil samples from the surface (20 cm) were collected in 1989, 1994, 1999, 2004 and 2009 to characterize Se and other soil properties. In 2009, the average soil Se concentrations in the treatments (149 ± 8 beg kg-1) were higher than those in the soil samples collected in 1989 at the beginning of the experiment (112 4- 4 beg kg-1), and decreased in the order of OC 〉 OC + NPK 〉 NPK NP 〉 PK NK 〉 control. Sequential extraction showed the oxidizable fraction (50.06%± 3.94%) was the dominant form of Se in the soil, followed by the residual fraction (24.12% ± 2.89%), exchangeable fraction (15.09% ± 4.34%) and Fe-Mn oxides fraction (10.73%±4.04%). With an increase of soil K, the exchangeable Se concentrations in the soil increased. The Se concentrations in the soil tillage layer (0-20 cm) were mainly related to soil organic carbon (SOC), although different contributions came from atmospheric deposition, irrigation and fertilizers. With the accumulation of SOC, the uptakes of soil Se by two crops were inhibited. For the OC and OC + NPK treatments, Se concentrations in wheat grains were lower than the critical standard of Se in stable food (100 μg kg·1]. Additionallv. Se concentrations in grains were also decreased by the deficiencies of major soil nutrients, especially P.
基金supported by the Australian Centre for International Agricultural Research (ACIAR) Project (No.SMCN 2007/109)
文摘Sandplain soils on the south coast of Western Australia have low inherent fertility, which is mainly due to poor nutrient retention caused by insufficient clay and organic colloidal material. Previous research has shown the benefits in nutrient levels and retention from adding clay to sandplain soils; however, there is almost no information on the addition of organic amendments. A field experiment was established at the Esperance Downs Research Station, Western Australian, in May 2010, to assess the effects of wheat straw(WS) and chicken manure(CM) biochars and compost with and without phosphorus(P) addition on soil properties and crop production over five growing seasons. The five seasons alternated between winter and summer crops. The CM and WS biochar and compost treatments significantly increased crop yields and P uptake in 3, 2 and 1 of the five seasons, respectively. The yield increases(P < 0.05) were no more than 8%. By the end of the third season, no differences in crop yields were found that could be attributed to the organic amendments. The addition of P increased crop yields in each winter cropping season. Phosphorus addition explained more than 30%of the variation in crop yields. Despite marginal P levels and summer drought conditions, arbuscular mycorrhizal root colonisation was not affected by the organic amendments. There were no significant interactions between the organic amendments and P addition in terms of crop yields, P uptake or P uptake efficiency. We conclude that much of the effect of the organic amendments was due to direct nutrient addition which dissipated over time.