A technology of mechanochemical treatment (MCT) is introduced to modify nanodiamond (ND) surface aiming to obtaining a stable suspension with well-dispersed ND particles in aqueous medium. ND investigated in this pape...A technology of mechanochemical treatment (MCT) is introduced to modify nanodiamond (ND) surface aiming to obtaining a stable suspension with well-dispersed ND particles in aqueous medium. ND investigated in this paper is a purified product of nanometer-sized diamond synthesized by explosive detonation. As obvious aggregation and sediment were observed when the sample was added into deionized water, it is crucial to conduct deaggregation and dispersion investigations. Amid a series of mechanical treatments, i.e. grinding, stirring, ultrasonic and classification, some reagents are introduced to modify the newly created surface during aggregates comminution. For the co-effects of mechanical forces and surfactants, the mean size of particles was reduced and a stable system containing ND with narrow size distribution was prepared. Mechanism of surface reaction and modification are discussed, while AFM, Zetasizer3000HS, XRD, XPS and FTIR are utilized for the analysis. The functional chemical structure of ND particle surface and surface electrical property changed during the modification processes, and the dispersion character and stability of suspension can consequently be improved.展开更多
Due to the high affinity between dithiocarbamate （DTC） and Hg2＋, a fluorescent probe based on squaraine chromophore with DTC side arm for Hg2＋ via coordination induced deaggregation signaling has been designed and...Due to the high affinity between dithiocarbamate （DTC） and Hg2＋, a fluorescent probe based on squaraine chromophore with DTC side arm for Hg2＋ via coordination induced deaggregation signaling has been designed and synthesized. Squaraine has a high tendency to aggregate in aqueous solution, and such self-aggregation usually results in a dramatic absorption spectral broadening with fluorescence emission quenching. The combination of the DTC side arm of the probe with Hg2＋ induces steric hindrance, leading to the deaggregation of the dye complex, companying with a fluorescence emission restoration. In EtOH-H2O （20：80, v/v） solution, this ＂turn on＂ fluorescent probe has high selectivity and sensitivity toward Hg2＋ over other metal ions, and the limit of detection for Hg2＋ was estimated as 2.19 × 10^-8 mol/L by 3σ/k.展开更多
Phosphatidylcholines and their analogs, the functional building block of the membrane, are recently found to mediate multiple physiological processes and exhibit a broad range of desirable pharmacological effects, whi...Phosphatidylcholines and their analogs, the functional building block of the membrane, are recently found to mediate multiple physiological processes and exhibit a broad range of desirable pharmacological effects, which involve hydrophobic lipophilic interactions (HLI) between the phospholipid and the cell membrane. The HLI behavior of phosphatidylcholines (Ln) and their analogues 1, 2-diacyI-sn-glycerol-3-phosphoric add bro-moethyl ester (Pn), have been investigated in MeOH-H2O binary systems of different volume fractions (designated as Φ) of the organic component, by employing a-nephthylethyl lauryl ether (Np-12) as fluorescent probe. A very interesting observation is that the Ln possesses double character, i.e., it behaves both as an aggregator and as a deaggregator. The effects of the structure and the environment on the coaggregation and deag-gregation are also discussed.展开更多
Many destructive earthquakes happened in Tehran, Iran in the last centuries. The existence of active faults like the North Tehran is the main cause of seismicity in this city. According to past investigations, it is e...Many destructive earthquakes happened in Tehran, Iran in the last centuries. The existence of active faults like the North Tehran is the main cause of seismicity in this city. According to past investigations, it is estimated that in the scenario of activation of the North Tehran fault, many structures in Tehran will collapse. Therefore, it is necessary to incorporate the near field rupture directivity effects of this fault into the seismic hazard assessment of important sites in Tehran. In this study, using calculations coded in MATLAB, Probabilistic Seismic Hazard Analysis （PSHA） is conducted for an important site in Tehran. Following that, deaggregation technique is performed on PSHA and the contribution of seis- mic scenarios to hazard is obtained in the range of distance and magnitude. After identifying the North Tehran fault as the most hazardous source affecting the site in 10000-year return period, rupture directivity effects of this fault is incorporated into the seismic hazard assessment using Somerville et al. （1997） model with broadband approach and Shahi and Baker （2011） model with narrowband approach. The results show that the narrowband approach caused a 27% increase in the peak of response spectrum in 10000-year return period compared with the conventional PSHA. Therefore, it is necessary to incorporate the near fault rupture directivity effects into the higher levels of seismic hazard assessment attributed to important sites.展开更多
Aggregation and deaggregation behaviors of the phenol derivatives with a branched hydrocarbon chain have been studied in the CH3OH and buffer solution. Combination with the aggregation number measurement and the cell ...Aggregation and deaggregation behaviors of the phenol derivatives with a branched hydrocarbon chain have been studied in the CH3OH and buffer solution. Combination with the aggregation number measurement and the cell adhesion experiment, the structure effect on the deaggregating abilities of the target molecules are discussed. The results indicate that 2-phytyl-4-methoxylphenol （11） is the most effective deaggregator in the system studied.展开更多
A simple and effective polymer fluorescent thermosensitive system was successfully developed based on the synergistic effect of excimer/monomer interconversion of pyrene derivatives and electrostatic interaction betwe...A simple and effective polymer fluorescent thermosensitive system was successfully developed based on the synergistic effect of excimer/monomer interconversion of pyrene derivatives and electrostatic interaction between polyelectrolyte and charged fluorophore. As for the system, the excimer-monomer conversion, thermosensitive behavior and thermo-responsive reversibility were investigated experimentally. Temperature variation and temperature-distribution induced fluorescence changes can be observed directly by naked eyes. Thus, this polymer system holds promise for serving as a fluorescent thermometer.展开更多
Asphaltenes generally exist in the form of molecular aggregates in crude oil or in petroleum residues,and asphaltene aggregates can usually cause serious problems to oil exploitation,transportation,and processing.Achi...Asphaltenes generally exist in the form of molecular aggregates in crude oil or in petroleum residues,and asphaltene aggregates can usually cause serious problems to oil exploitation,transportation,and processing.Achieving deaggregation and separation of asphaltene aggregates is a premise and basis for molecular characterization and processing of heavy oils.Aiming at the intermolecular interactions in asphaltene molecular aggregates,it has proposed and summarized that aspahltene aggregates can be subject to deaggregation by means of five approaches,including solvent diluting,removing active sites,moderate heating,ultrasonication and on-line molecular collision.Moreover,asphaltenes can be further separated to narrow fractions for molecular-level research based on polarity difference,molecular size difference,acid-base properties,and reactivity difference.展开更多
Four new amphiphilic molecules, i.e., the bolaamphiphiles n-trimethylamino n-hexadecanoate (deAgr 16), n-dodecanoate (deAgr 12), n-undecanoate (deAgr 11), and n-octanoate (deAgr 8) were synthesized. Their ability as d...Four new amphiphilic molecules, i.e., the bolaamphiphiles n-trimethylamino n-hexadecanoate (deAgr 16), n-dodecanoate (deAgr 12), n-undecanoate (deAgr 11), and n-octanoate (deAgr 8) were synthesized. Their ability as deaggregators to break up the aggregating systems of hexadecyl β-naphthoate (A16) and dodecyl β-naphthoate (A12) in dioxanewater binary solvent systems was investigated in a number of solvent systems and at different A16 and A12 concentrations. The results reveal that this new type of bolaamphiphilic molecules appears to be one of the most efficient deaggregators reported, which, at very low concentrations, can effectively break up the aggregating systems of highly concentrated A16 and A12. It is also found that bolaamphiphfles with longer aliphatic chains possess greater deaggregating ability. However, when the overall concentrations of A16 and A12 are very low but still above their critical aggregating concentration, these bolaamphiphilic molecules lose their deaggregating power and tend to coaggregate with the aggregated A16 or A12 molecules. The quite efficient deaggregating ability of the long-chain bolaamphiphfles (deAgr 16 and deAgr 12), as compared to the short-chain deAgr 8, has been ascribed to their dynamic switch-on/switch-off behavior involving coiled-up and uncoiled conformations of their long aliphatic chains.展开更多
The deaggregating ability of β-CD and α-CD against the aggregated n-hexadecyl β-naphthoate （A16） and n-dodecyl β-naphthoate （A12） depended not only on the aggregating tendency of A16 and A12 but also on the in...The deaggregating ability of β-CD and α-CD against the aggregated n-hexadecyl β-naphthoate （A16） and n-dodecyl β-naphthoate （A12） depended not only on the aggregating tendency of A16 and A12 but also on the initial concentration of the aggregated A16 or A12. The inclusive ability of β-CD with the substrates is greater than that of α-CD under hydrophobiclipophilic interaction.展开更多
The new method for determining ground-motion parameters in the Indonesian Earthquake Resistant Building Code SNI （Indonesia National Standard） 03-1726-2012 has significant changes than the previous code. The maps of...The new method for determining ground-motion parameters in the Indonesian Earthquake Resistant Building Code SNI （Indonesia National Standard） 03-1726-2012 has significant changes than the previous code. The maps of mean and modal of magnitude and distance presented here are intended to convey information about the distribution ofprobabilistic seismic sources and to provide prescriptions or suggestions for seismic sources to use in developing artificial ground motion in building design or retrofit projects. This paper presents deaggregation of Indonesia Seismic Hazard Map 2010 for Sumatra. Deaggregation for 0.2-s and 1.0-s pseudo SA （spectral acceleration） is performed for 10% PE （probability of exceedance） in 50 years （475-year mean return period） and 2% PE in 50 years （2,475-year mean return period）. The information of deaggregation analysis can and perhaps should be considered in a complex seismic-resistant design decision-making environment.展开更多
In the field of earthquake engineering,the advent of the performance-based design philosophy,together with the highly uncertain nature of earthquake ground excitations to structures,has brought probabilistic performan...In the field of earthquake engineering,the advent of the performance-based design philosophy,together with the highly uncertain nature of earthquake ground excitations to structures,has brought probabilistic performance-based design to the forefront of seismic design.In order to design structures that explicitly satisfy probabilistic performance criteria,a probabilistic performance-based optimum seismic design(PPBOSD)framework is proposed in this paper by extending the state-of-the-art performance-based earthquake engineering(PBEE)methodology.PBEE is traditionally used for risk evaluation of existing or newly designed structural systems,thus referred to herein as forward PBEE analysis.In contrast,its use for design purposes is limited because design is essentially a more challenging inverse problem.To address this challenge,a decision-making layer is wrapped around the forward PBEE analysis procedure for computer-aided optimum structural design/retrofit accounting for various sources of uncertainty.In this paper,the framework is illustrated and validated using a proof-of-concept problem,namely tuning a simplified nonlinear inelastic single-degreeof-freedom(SDOF)model of a bridge to achieve a target probabilistic loss hazard curve.For this purpose,first the forward PBEE analysis is presented in conjunction with the multilayer Monte Carlo simulation method to estimate the total loss hazard curve efficiently,followed by a sensitivity study to investigate the effects of system(design)parameters on the probabilistic seismic performance of the bridge.The proposed PPBOSD framework is validated by successfully tuning the system parameters of the structure rated for a target probabilistic seismic loss hazard curve.The PPBOSD framework provides a tool that is essential to develop,calibrate and validate simplified probabilistic performance-based design procedures.展开更多
文摘A technology of mechanochemical treatment (MCT) is introduced to modify nanodiamond (ND) surface aiming to obtaining a stable suspension with well-dispersed ND particles in aqueous medium. ND investigated in this paper is a purified product of nanometer-sized diamond synthesized by explosive detonation. As obvious aggregation and sediment were observed when the sample was added into deionized water, it is crucial to conduct deaggregation and dispersion investigations. Amid a series of mechanical treatments, i.e. grinding, stirring, ultrasonic and classification, some reagents are introduced to modify the newly created surface during aggregates comminution. For the co-effects of mechanical forces and surfactants, the mean size of particles was reduced and a stable system containing ND with narrow size distribution was prepared. Mechanism of surface reaction and modification are discussed, while AFM, Zetasizer3000HS, XRD, XPS and FTIR are utilized for the analysis. The functional chemical structure of ND particle surface and surface electrical property changed during the modification processes, and the dispersion character and stability of suspension can consequently be improved.
基金financially supported by the National Science Foundation for Fostering Talents in Basic Research of the National Natural Science Foundation of China (No.J1103303)the National Natural Science Foundation of China (No.20702005)+2 种基金the Fujian Provincial Department of Science and Technology,China (No.2013Y0062)Funding (Type A) from Fujian Education Department,PR China (Nos.JA12038 and JA13043)the Science and Technology Development Fund of Fuzhou University,China (No.600902)
文摘Due to the high affinity between dithiocarbamate （DTC） and Hg2＋, a fluorescent probe based on squaraine chromophore with DTC side arm for Hg2＋ via coordination induced deaggregation signaling has been designed and synthesized. Squaraine has a high tendency to aggregate in aqueous solution, and such self-aggregation usually results in a dramatic absorption spectral broadening with fluorescence emission quenching. The combination of the DTC side arm of the probe with Hg2＋ induces steric hindrance, leading to the deaggregation of the dye complex, companying with a fluorescence emission restoration. In EtOH-H2O （20：80, v/v） solution, this ＂turn on＂ fluorescent probe has high selectivity and sensitivity toward Hg2＋ over other metal ions, and the limit of detection for Hg2＋ was estimated as 2.19 × 10^-8 mol/L by 3σ/k.
基金National Natural Science Foundation of China(No.29392201).
文摘Phosphatidylcholines and their analogs, the functional building block of the membrane, are recently found to mediate multiple physiological processes and exhibit a broad range of desirable pharmacological effects, which involve hydrophobic lipophilic interactions (HLI) between the phospholipid and the cell membrane. The HLI behavior of phosphatidylcholines (Ln) and their analogues 1, 2-diacyI-sn-glycerol-3-phosphoric add bro-moethyl ester (Pn), have been investigated in MeOH-H2O binary systems of different volume fractions (designated as Φ) of the organic component, by employing a-nephthylethyl lauryl ether (Np-12) as fluorescent probe. A very interesting observation is that the Ln possesses double character, i.e., it behaves both as an aggregator and as a deaggregator. The effects of the structure and the environment on the coaggregation and deag-gregation are also discussed.
文摘Many destructive earthquakes happened in Tehran, Iran in the last centuries. The existence of active faults like the North Tehran is the main cause of seismicity in this city. According to past investigations, it is estimated that in the scenario of activation of the North Tehran fault, many structures in Tehran will collapse. Therefore, it is necessary to incorporate the near field rupture directivity effects of this fault into the seismic hazard assessment of important sites in Tehran. In this study, using calculations coded in MATLAB, Probabilistic Seismic Hazard Analysis （PSHA） is conducted for an important site in Tehran. Following that, deaggregation technique is performed on PSHA and the contribution of seis- mic scenarios to hazard is obtained in the range of distance and magnitude. After identifying the North Tehran fault as the most hazardous source affecting the site in 10000-year return period, rupture directivity effects of this fault is incorporated into the seismic hazard assessment using Somerville et al. （1997） model with broadband approach and Shahi and Baker （2011） model with narrowband approach. The results show that the narrowband approach caused a 27% increase in the peak of response spectrum in 10000-year return period compared with the conventional PSHA. Therefore, it is necessary to incorporate the near fault rupture directivity effects into the higher levels of seismic hazard assessment attributed to important sites.
基金Project supported by the National Natural Science Foundation of China （No. 20272078） and the Shanghai Municipal Science and Technology Commission （No. 03JC14083）.
文摘Aggregation and deaggregation behaviors of the phenol derivatives with a branched hydrocarbon chain have been studied in the CH3OH and buffer solution. Combination with the aggregation number measurement and the cell adhesion experiment, the structure effect on the deaggregating abilities of the target molecules are discussed. The results indicate that 2-phytyl-4-methoxylphenol （11） is the most effective deaggregator in the system studied.
基金financially supported by the Science and Technology Planning Project of Guangdong Province(No.2014A010105009)the National Key Basic Research Program of China(No.2013CB834702)+1 种基金the National Natural Science Foundation of China(Nos.21574044 and 21474031)the Fundamental Research Funds for the Central Universities(No.2015ZY013)
文摘A simple and effective polymer fluorescent thermosensitive system was successfully developed based on the synergistic effect of excimer/monomer interconversion of pyrene derivatives and electrostatic interaction between polyelectrolyte and charged fluorophore. As for the system, the excimer-monomer conversion, thermosensitive behavior and thermo-responsive reversibility were investigated experimentally. Temperature variation and temperature-distribution induced fluorescence changes can be observed directly by naked eyes. Thus, this polymer system holds promise for serving as a fluorescent thermometer.
文摘Asphaltenes generally exist in the form of molecular aggregates in crude oil or in petroleum residues,and asphaltene aggregates can usually cause serious problems to oil exploitation,transportation,and processing.Achieving deaggregation and separation of asphaltene aggregates is a premise and basis for molecular characterization and processing of heavy oils.Aiming at the intermolecular interactions in asphaltene molecular aggregates,it has proposed and summarized that aspahltene aggregates can be subject to deaggregation by means of five approaches,including solvent diluting,removing active sites,moderate heating,ultrasonication and on-line molecular collision.Moreover,asphaltenes can be further separated to narrow fractions for molecular-level research based on polarity difference,molecular size difference,acid-base properties,and reactivity difference.
基金NSFC (No .2 9832 0 40 )andStateKeyProjectofFundamentalResearch (No .G2 0 0 0 0 7810 1)
文摘Four new amphiphilic molecules, i.e., the bolaamphiphiles n-trimethylamino n-hexadecanoate (deAgr 16), n-dodecanoate (deAgr 12), n-undecanoate (deAgr 11), and n-octanoate (deAgr 8) were synthesized. Their ability as deaggregators to break up the aggregating systems of hexadecyl β-naphthoate (A16) and dodecyl β-naphthoate (A12) in dioxanewater binary solvent systems was investigated in a number of solvent systems and at different A16 and A12 concentrations. The results reveal that this new type of bolaamphiphilic molecules appears to be one of the most efficient deaggregators reported, which, at very low concentrations, can effectively break up the aggregating systems of highly concentrated A16 and A12. It is also found that bolaamphiphfles with longer aliphatic chains possess greater deaggregating ability. However, when the overall concentrations of A16 and A12 are very low but still above their critical aggregating concentration, these bolaamphiphilic molecules lose their deaggregating power and tend to coaggregate with the aggregated A16 or A12 molecules. The quite efficient deaggregating ability of the long-chain bolaamphiphfles (deAgr 16 and deAgr 12), as compared to the short-chain deAgr 8, has been ascribed to their dynamic switch-on/switch-off behavior involving coiled-up and uncoiled conformations of their long aliphatic chains.
基金We thank the Natural Science Foundation of China（No.20172069）for financial support.
文摘The deaggregating ability of β-CD and α-CD against the aggregated n-hexadecyl β-naphthoate （A16） and n-dodecyl β-naphthoate （A12） depended not only on the aggregating tendency of A16 and A12 but also on the initial concentration of the aggregated A16 or A12. The inclusive ability of β-CD with the substrates is greater than that of α-CD under hydrophobiclipophilic interaction.
文摘The new method for determining ground-motion parameters in the Indonesian Earthquake Resistant Building Code SNI （Indonesia National Standard） 03-1726-2012 has significant changes than the previous code. The maps of mean and modal of magnitude and distance presented here are intended to convey information about the distribution ofprobabilistic seismic sources and to provide prescriptions or suggestions for seismic sources to use in developing artificial ground motion in building design or retrofit projects. This paper presents deaggregation of Indonesia Seismic Hazard Map 2010 for Sumatra. Deaggregation for 0.2-s and 1.0-s pseudo SA （spectral acceleration） is performed for 10% PE （probability of exceedance） in 50 years （475-year mean return period） and 2% PE in 50 years （2,475-year mean return period）. The information of deaggregation analysis can and perhaps should be considered in a complex seismic-resistant design decision-making environment.
文摘In the field of earthquake engineering,the advent of the performance-based design philosophy,together with the highly uncertain nature of earthquake ground excitations to structures,has brought probabilistic performance-based design to the forefront of seismic design.In order to design structures that explicitly satisfy probabilistic performance criteria,a probabilistic performance-based optimum seismic design(PPBOSD)framework is proposed in this paper by extending the state-of-the-art performance-based earthquake engineering(PBEE)methodology.PBEE is traditionally used for risk evaluation of existing or newly designed structural systems,thus referred to herein as forward PBEE analysis.In contrast,its use for design purposes is limited because design is essentially a more challenging inverse problem.To address this challenge,a decision-making layer is wrapped around the forward PBEE analysis procedure for computer-aided optimum structural design/retrofit accounting for various sources of uncertainty.In this paper,the framework is illustrated and validated using a proof-of-concept problem,namely tuning a simplified nonlinear inelastic single-degreeof-freedom(SDOF)model of a bridge to achieve a target probabilistic loss hazard curve.For this purpose,first the forward PBEE analysis is presented in conjunction with the multilayer Monte Carlo simulation method to estimate the total loss hazard curve efficiently,followed by a sensitivity study to investigate the effects of system(design)parameters on the probabilistic seismic performance of the bridge.The proposed PPBOSD framework is validated by successfully tuning the system parameters of the structure rated for a target probabilistic seismic loss hazard curve.The PPBOSD framework provides a tool that is essential to develop,calibrate and validate simplified probabilistic performance-based design procedures.
