The controllable key factors in magnetorheological finishing device were studied to determine their influence on efficiency of magnetorheological finishing(MRF)and surface of MRF,as well as interaction between efficie...The controllable key factors in magnetorheological finishing device were studied to determine their influence on efficiency of magnetorheological finishing(MRF)and surface of MRF,as well as interaction between efficiency and surface.Based on theoretical and experimental research,the law of material removal was explored and a new process variable based material removal model(PVMR)was proposed.The experimental findings demonstrate that PVMR reveals the law of the material removal with introduction of three concepts and makes a material removal function z(y i)where the magnetorheological finishing process parameters are considered since they are easy to control and adjust.So the material function of this model is quadratic curve function which is readily suitable for stability and online control magnetorheological finishing.展开更多
Air pollution in modern city and industrial zones has become a serious public concern in recent years in China. Significance of air quality assessment and emission control strategy design is increasing. Most studies i...Air pollution in modern city and industrial zones has become a serious public concern in recent years in China. Significance of air quality assessment and emission control strategy design is increasing. Most studies in China focus on particulate matter(PM), especially PM2.5, while few account for photochemical secondary air pollutions represented by ozone(O3). In this paper, a procedure for air quality simulation with comprehensive air quality model with extensions(CAMx) is demonstrated for studying the photochemical process and ozone generation in the troposphere. As a case study, the CAMx photochemical grid model is used to model ozone over southern part of Beijing city in winter, 2011. The input parameters to CAMx include emission sources, meteorology field data, terrain definition, photolysis status, initial and boundary conditions. The simulation results are verified by theoretical analysis of the ozone generation tendency. The simulated variation tendency of domain-wide average value of hourly ozone concentration coincides reasonably well with the theoretical analysis on the atmospheric photochemical process, demonstrating the effectiveness of the procedure. An integrated model system that cooperates with CAMx will be established in our future work.展开更多
The removal of lead from ginseng ethanol extracts by a fixed-bed column filled with an adsorbent bearing amine and carboxyl groups was investigated. The Pb2+ content was determined by inductively coupled plasma mass s...The removal of lead from ginseng ethanol extracts by a fixed-bed column filled with an adsorbent bearing amine and carboxyl groups was investigated. The Pb2+ content was determined by inductively coupled plasma mass spectrometry. When the flowrate increased from 0.12 to 0.34 ml·min-1 , the column exhibited a marked increase in percentage of lead removal from 54.9% to 92.3%. Further increase in the flowrate did not bring evident changes to the lead removal, whereas an increase in the temperature could reinforce adsorption further, suggesting that the adsorption process was controlled by external film diffusion below the flowrate of 0.34 ml·min-1 , and by the intraparticle pore diffusion of lead ions when the flowrate exceeded it. A low remaining lead amount in extracts such as 0.11 mg·kg-1 (extracts powder) was achieved. The adsorbents also adsorbed effective constituents to some extent. But 88% of constituents adsorbed were taken off using a 70% ethanol aqueous solution.展开更多
Biosensor is an instrument which is sensitive to biological material and converts its concentration into electrical signals.Organisms such as enzymes, antibodies, tissues, cells and so on can selectively identify spec...Biosensor is an instrument which is sensitive to biological material and converts its concentration into electrical signals.Organisms such as enzymes, antibodies, tissues, cells and so on can selectively identify specific substances. Thesemolecular recognition functions can be combined with the target, such as the binding of antibodies and antigens, and thebinding of enzymes to the substrate through the recognition process. Biosensor has the advantages of high specificity,high sensitivity, fast reaction speed, low cost and easy operation. It has wide application prospect in food, pharmacy,chemical industry, clinical examination, biomedicine, environmental monitoring and so on, especially as a newtechnology means, in the field of modern herbal medicine research influence. Studies have demonstrated that thebiosensing technology has been applied to, traditional Chinese medicine （TCM） targets, isolation and purification ofTCM, the mechanism of TCM, quality control of TCM, the active ingredients detection of TCM and other basicresearches. Biosensor technology has made an important contribution to the research of modern herbal medicine, and hasbecome a Hot-spot in future research.展开更多
In this paper,an HPLC-DAD-ELSD method was developed to determine main 20 components of Ginkgo biloba L.leaves from different ages and sources,including six flavonol glycosides,five terpene lactones and nine organic ac...In this paper,an HPLC-DAD-ELSD method was developed to determine main 20 components of Ginkgo biloba L.leaves from different ages and sources,including six flavonol glycosides,five terpene lactones and nine organic acids.Using statistics method and establishing relevant mathematics models,the measured data has proceeded correlation analysis,principal component analysis,and regression statistics and the results showed generality and specific characteristics.We defined p-hydroxybenzoic acid,catechinic,KRcG and ginkgolide A as characteristic indexes representing commonness and speciality of Ginkgo biloba L.leaf.The four characteristic indexes can reflect the quality of Ginkgo biloba L.leaf,and the intermal relations between them are significant.The contents of other compounds could define the quantity relation with characteristic markers.It simplified the approach of quality control,and provided a basis for quality control of Ginkgo biloba L.展开更多
In this article, we present a facile, direct, synthetic approach of preparing monodisperse [Au2s（SePh）ls]- nanoclusters in high yield. In this synthetic approach, two-phase Brust-Schiffrin method is used. Both PhSeH...In this article, we present a facile, direct, synthetic approach of preparing monodisperse [Au2s（SePh）ls]- nanoclusters in high yield. In this synthetic approach, two-phase Brust-Schiffrin method is used. Both PhSeH and NaBH4 should be added drop-wise to the solution of Au （III） at the same time. The formula and molecular purity of [Au25（SePh）ls] TOA＋ clusters are characterized by MALDI-TOF mass spectrometry, NMR and TGA analysis. Furthermore, some critical parameters to obtain pure [Au25（SePh）18]-TOA＋ are identified, including the NaBH4-to-Au ratio, the selenolate-to-Au ratio and the temperature. The facile, direct, high yield synthetic method can be widely applied in the theoretical research of Au clusters protected by selenol.展开更多
基金National Science and Technology Major Project,China(No.2009ZX04001-101)National Program on Key Basic Research Project(973Program)(No.2009CB724400)Shanghai Leading Academic Discipline Project,China(No.B602)
文摘The controllable key factors in magnetorheological finishing device were studied to determine their influence on efficiency of magnetorheological finishing(MRF)and surface of MRF,as well as interaction between efficiency and surface.Based on theoretical and experimental research,the law of material removal was explored and a new process variable based material removal model(PVMR)was proposed.The experimental findings demonstrate that PVMR reveals the law of the material removal with introduction of three concepts and makes a material removal function z(y i)where the magnetorheological finishing process parameters are considered since they are easy to control and adjust.So the material function of this model is quadratic curve function which is readily suitable for stability and online control magnetorheological finishing.
文摘Air pollution in modern city and industrial zones has become a serious public concern in recent years in China. Significance of air quality assessment and emission control strategy design is increasing. Most studies in China focus on particulate matter(PM), especially PM2.5, while few account for photochemical secondary air pollutions represented by ozone(O3). In this paper, a procedure for air quality simulation with comprehensive air quality model with extensions(CAMx) is demonstrated for studying the photochemical process and ozone generation in the troposphere. As a case study, the CAMx photochemical grid model is used to model ozone over southern part of Beijing city in winter, 2011. The input parameters to CAMx include emission sources, meteorology field data, terrain definition, photolysis status, initial and boundary conditions. The simulation results are verified by theoretical analysis of the ozone generation tendency. The simulated variation tendency of domain-wide average value of hourly ozone concentration coincides reasonably well with the theoretical analysis on the atmospheric photochemical process, demonstrating the effectiveness of the procedure. An integrated model system that cooperates with CAMx will be established in our future work.
基金Supported by the National＇Natural Science Foundation of China （20976012, 20806009）, and the Specialized Research Fund for the Doctoral Program of Higher Education （20070007055, 20091101110035）.
文摘The removal of lead from ginseng ethanol extracts by a fixed-bed column filled with an adsorbent bearing amine and carboxyl groups was investigated. The Pb2+ content was determined by inductively coupled plasma mass spectrometry. When the flowrate increased from 0.12 to 0.34 ml·min-1 , the column exhibited a marked increase in percentage of lead removal from 54.9% to 92.3%. Further increase in the flowrate did not bring evident changes to the lead removal, whereas an increase in the temperature could reinforce adsorption further, suggesting that the adsorption process was controlled by external film diffusion below the flowrate of 0.34 ml·min-1 , and by the intraparticle pore diffusion of lead ions when the flowrate exceeded it. A low remaining lead amount in extracts such as 0.11 mg·kg-1 (extracts powder) was achieved. The adsorbents also adsorbed effective constituents to some extent. But 88% of constituents adsorbed were taken off using a 70% ethanol aqueous solution.
文摘Biosensor is an instrument which is sensitive to biological material and converts its concentration into electrical signals.Organisms such as enzymes, antibodies, tissues, cells and so on can selectively identify specific substances. Thesemolecular recognition functions can be combined with the target, such as the binding of antibodies and antigens, and thebinding of enzymes to the substrate through the recognition process. Biosensor has the advantages of high specificity,high sensitivity, fast reaction speed, low cost and easy operation. It has wide application prospect in food, pharmacy,chemical industry, clinical examination, biomedicine, environmental monitoring and so on, especially as a newtechnology means, in the field of modern herbal medicine research influence. Studies have demonstrated that thebiosensing technology has been applied to, traditional Chinese medicine （TCM） targets, isolation and purification ofTCM, the mechanism of TCM, quality control of TCM, the active ingredients detection of TCM and other basicresearches. Biosensor technology has made an important contribution to the research of modern herbal medicine, and hasbecome a Hot-spot in future research.
基金National Administration of Traditional Chinese Medicine Standardization Project(Grant No.ZYBZH-C-HEB-16)
文摘In this paper,an HPLC-DAD-ELSD method was developed to determine main 20 components of Ginkgo biloba L.leaves from different ages and sources,including six flavonol glycosides,five terpene lactones and nine organic acids.Using statistics method and establishing relevant mathematics models,the measured data has proceeded correlation analysis,principal component analysis,and regression statistics and the results showed generality and specific characteristics.We defined p-hydroxybenzoic acid,catechinic,KRcG and ginkgolide A as characteristic indexes representing commonness and speciality of Ginkgo biloba L.leaf.The four characteristic indexes can reflect the quality of Ginkgo biloba L.leaf,and the intermal relations between them are significant.The contents of other compounds could define the quantity relation with characteristic markers.It simplified the approach of quality control,and provided a basis for quality control of Ginkgo biloba L.
基金the financial support by the National Natural Science Foundation of China (20871112, 21072001, 21372006)Changjiang Scholars Program+1 种基金the Scientific Research Foundation for Returning Overseas Chinese Scholars, State Education Ministry, Ministry of Human Resources and Social Security, Anhui Province International Scientific and Technological Cooperation Project211 Project of Anhui University
文摘In this article, we present a facile, direct, synthetic approach of preparing monodisperse [Au2s（SePh）ls]- nanoclusters in high yield. In this synthetic approach, two-phase Brust-Schiffrin method is used. Both PhSeH and NaBH4 should be added drop-wise to the solution of Au （III） at the same time. The formula and molecular purity of [Au25（SePh）ls] TOA＋ clusters are characterized by MALDI-TOF mass spectrometry, NMR and TGA analysis. Furthermore, some critical parameters to obtain pure [Au25（SePh）18]-TOA＋ are identified, including the NaBH4-to-Au ratio, the selenolate-to-Au ratio and the temperature. The facile, direct, high yield synthetic method can be widely applied in the theoretical research of Au clusters protected by selenol.
