Separation and identification of an abundant trigalloylglucose from special tea genetic resources

Galloylglucoses can extensively and intensively interact with proteins and possess many biological activities and exhibit optimal health benefits.A novel galloylglucose had been observed and separated from fresh shoots of some special tea genetic resources,and was characterized as a trigalloylglucose isomer with mass parent ion[M-H]−at m/z 635.10 and daughter ions at m/z 483.08,465.08,313.02 and 168.98 and with UV absorbance peaks at 221 nm and 278 nm after being measured with UPLC-DAD-MS/MS.The trigalloylglucose was highly purified by semipreparative chromatography and identified as 1,4,6-tri-O-galloyl-β-glucopyranose(1,4,6-TGG)by 1H-NMR,13C-NMR,H1-H1 COSY and HMQC.Antioxidant capacity of the 1,4,6-TGG was 2.68−5.77μmol TEAC/μmol,and significantly higher(42.7%−419.4%)than that of ascorbic acid,but similar to another well-known powerful antioxidant epigallocatechin gallate in tea,indicating that 1,4,6-TGG could,in the future,be applied in the development of functional foods and pharmaceuticals.

Comprehensive power-supply planning for active distribution system considering cooling,heating and power load balance

An active distribution system power-supply planning model considering cooling,heating and power load balance is proposed in this paper.A regional energy service company is assumed to be in charge of the investment and operation for the system in the model.The expansion of substations,building up distributed combined cooling,heating and power(CCHP),gas heating boiler(GHB)and air conditioner(AC)are included as investment planning options.In terms of operation,the load scenarios are divided into heating,cooling and transition periods.Also,the extreme load scene is included to assure the power supply reliability of the system.Numerical results demonstrate the effectiveness of the proposed model and illustrate the economic benefits of applying distributed CCHP in regional power supply on investment and operation.

Analysis of multi-center topological domain states in BiFeO_(3)nanodot arrays

High-density ferroelectric BiFeO_(3)(BFO)nanodot arrays were developed through template-assisted tailoring of epitaxial thin films.By combining piezoresponse force microscopy(PFM)and Kelvin probe force microscopy(KPFM)imaging techniques,we found that oxygen vacancies in nanodot arrays can be transported in the presence of an electric field.Besides triple-center domains,quadruple-center domains with different vertical polarizations were also identified.This was confirmed by combining the measurements of the domain switching and polarization vector distribution.The competition between the accumulation of mobile charges,such as oxygen vacancies,on the interface and the geometric constraints of nanodots led to the formation of these topological domain states.These abnormal multi-center topological defect states pave the way for improving the storage density of ferroelectric memory devices.

对固体废物征收环境保护税的国际经验借鉴

对固体废物征收环境保护税,是促进固体废物污染防治的重要经济调节手段。我国目前开征的环境保护税在固体废物税目、税率设置以及计税依据等方面,还有待进一步完善。本文通过借鉴国际上典型国家对固体废物征税的税收制度,结合我国国情及环境保护税制度,提出对我国固体废物征收环境保护税的建议。

Uncertainties in stormwater runoff data collection from a small urban catchment, Southeast China

Monitoring data are often used to identify stormwater runoff characteristics and in stormwater runoff modelling without consideration of their inherent uncertainties. Integrated with discrete sample analysis and error propagation analysis, this study attempted to quantify the uncertainties of discrete chemical oxygen demand （COD）, total suspended solids （TSS） concentration, stormwater flowrate, stormwater event volumes, COD event mean concentration （EMC）, and COD event loads in terms of flow measurement, sample collection, storage and laboratory analysis. The results showed that the uncertainties due to sample collection, storage and laboratory analysis of COD from stormwater runoff are 13.99%, 19.48% and 12.28%. Meanwhile, flow measurement uncertainty was 12.82%, and the sample collection uncertainty of TSS from stormwater runoff was 31.63%. Based on the law of propagation of uncertainties, the uncertainties regarding event flow volume, COD EMC and COD event loads were quantified as 7.03%, 10.26% and 18.47%.

Analysis of rainfall runoff characteristics from a subtropical urban lawn catchment in South-east China

Characteristics of rainfall runoff from a 3.26 hm^2 urban catchment with predominant land-use as lawn in Xiamen City, South-east China were investigated and analyzed. Water quality and quantity measurements of rainfall runoff were conducted for ten rainfall events over the period March, 2008 to April, 2009. The results indicated that chemical oxygen demand （COD） and total phosphorus （TP） were the major pollutants with event mean concentrations of 56.09 and 0.44mg.L^-1. From hydrograph and pollutograph analysis of two typical rainfall events, it was clear that the peak rainfall preceded the peak flowrate by about 15-20 min. Meanwhile, concentrations of major pollutants showed multiple peaks and these peaks usually preceded peak flowrate. There were no distinctive first-flush effects except for the rainfall events with the longest rainfall duration and largest runoff volume, which was verified by the fact that the first 30% runoff volume （FF30） carried 39.36% of the total suspended solids （TSS） load, 35.17% of the COD load, 28.13% of the TP load and 39.03% of the nitrate nitrogen load. Multivariate regression analysis further demonstrated that the total runoffvolume had a positive correlation with the FF30 of TSS and COD.