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1.
J. Gr?ter P.A. Amaudruz R. Bilger P. Camerini J. Clark H. Clement E. Friedman L. Felawka S.N. Filippov E. Friagiacomo Y.K. Gavrilov E. Gibson N. Grion G.J. Hofman B. Jamieson T.L. Karavicheva M. KermaniPresent address: Sonigistix Corporation Richmond B.C. Canada VA-E--> E.L. Mathie R. Meier G. Moloney D. Ottewell J. P?tzold O. Patarakin K. Raywood R. Rui M. Schepkin M.E. Sevior G.R. Smith H. Staudenmaier R. Tacik G. Tagliente G.J. Wagner M. Yeomans 《The European Physical Journal A - Hadrons and Nuclei》1999,4(1):5-7
A search for the production of a bound trineutron state has been performed using the reaction 3He(π−,π+)nnn at incident pion energies of 65, 75, and 120 MeV. No evidence for the existence of the 3n was found, and an upper limit for the production cross section of approximately 30 nb/sr (2σ confidence level) was obtained.
Received: 22 October 1998 相似文献
2.
离子型共聚单体参与下的全氟丙烯酸酯无皂乳液共聚 总被引:4,自引:0,他引:4
离子型共聚单体参与下的全氟丙烯酸酯无皂乳液共聚;全氟烷基丙烯酸酯;无皂乳液;离子型共聚单体 相似文献
3.
Lasers and amplifiers in a single fiber have been developed rapidly, especially for optical fiber communication and various sensors, in the recent years. However, remarkable progress and achievement have been made mainly in silica fiber doped with rare earth elements. In this paper, we report the progress on the development of the Yb3+-doped phosphate fiber laser. 相似文献
4.
MATTHEW T. STONE PIETER J. IN 'T VELD YING LU ISAAC C. SANCHEZ 《Molecular physics》2013,111(17):2773-2792
In this study Monte Carlo simulations are used to determine the solvation properties of model hydrophobic (xenon and hard sphere) and hydrophilic (dimethyl ether) solutes in SPC/E water. Various contributions to the experimental solvation entropy, including the solvent reorganization entropy, have been determined. The main conclusion drawn, which is in accord with solubility data, is that poor solubility correlates with poor solute-water interaction. At room temperature, energy dominates the aqueous solubility of both hydrophobic and hydrophilic solutes, rather than entropy. However, at higher temperatures the solubility can pass through a minimum, and then entropy becomes dominant. Another interesting finding is the presence of larger than expected cavities in water. Two different simulation results support this finding. This unexpected hollow structure in water explains why a hard sphere solute is more soluble in water than in a comparable hard sphere or Lennard-Jones solvent. Hydrogen bonding causes water to aggregate into clusters that produce a few large cavities rather than many smaller cavities. The propensity for clustering also explains why water gives the illusion of being a low density liquid. Sufficient theoretical apparatus is developed to connect theoretical solvation properties to those measured by simulation and experiment. Finally, based on gas solubility, an intuitive hydrophobic/hydrophilic scale is developed. 相似文献
5.
T.R. Canada R.A. Eisenstein C. Ellegaard P.D. Barnes J. Miller 《Nuclear Physics A》1973,205(1):145-167
The γ-decay of excited states in 210Bi up to 3330 keV excitation energy has been studied using the 209Bi(d, pγ)210Bi reaction. From the observed decay scheme, tentative Jπ values are made for 25 states. The excitation energies, (d, p) strengths and decay branching ratios of these states are compared with those calculated using the two-particle shell-model wave functions of Kim and Rasmussen and Kuo and Herling. 相似文献
6.
M. IN HET PANHUIS C. H. PATTERSON R. M. LYNDEN-BELL 《Molecular physics》2013,111(6):963-972
Atomistic simulations are reported of a model of CO2 in water. CO2 is modelled by partial charges and Lennard-Jones interaction sites on each atom; the SPC/E model for water is used. Good agreement with experiment is found for the translational diffusion constants. The variation of the dynamics with the potential parameter was investigated. As expected, the orientational correlation times increase as the magnitude of the quadrupole moment is increased, but the translational diffusion constants are found to be surprisingly insensitive to the magnitude of the CO2 quadrupole moment. The translational friction coefficient was resolved into electrostatic, Lennard-Jones and cross-terms; the Lennard-Jones contribution is found to be the largest. Varying the Lennard-Jones size parameter affects both translational and reorientational motion. In order to try to understand these results further, the variation of solvation free energy was investigated and the solvent structure around carbon dioxide was examined as the electrostatic and Lennard-Jones parameters were changed. The temperature dependence of the self-diffusion constant of pure SPC/E water was determined. 相似文献
7.
CHEN RuiLin ZENG QingYuan HUANG YunQing XIANG Jun WEN Ying GUO XiaoGang YIN ChangJun DONG Hui & ZHAO Gang Hunan Key Laboratory for Computation Simulation in Science Engineering Xiangtan University Xiangtan China School of Civil Engineering & Mechanics School of Civil Architecture Central South University Changsha AMEC Toronto MAG Canada 《中国科学:物理学 力学 天文学(英文版)》2010,(4)
Based on the analysis theory of random energy of train derailment, an analysis theory of random energy of train derailment in wind is suggested. Two methods are proposed -the time domain method and the frequency domain method of analysis theory of random energy of train derailment in wind. The curves of σ pw -v under various wind speeds are obtained through the computation. The original curve of σ p -v is expanded, which turns the analysis theory of random energy of train derailment into the all-weather theory. Train derailment condition has been established under wind action. The first and second criterions of train derailment have been proposed in light of wind action. The analysis of train derailment cases at home or abroad is made, in- cluding the first analysis of Xinjiang train derailment case encountered 13-level of gale, which explained the inevitability of train derailment. The analysis theory of random energy of train derailment in wind shows its validity and accuracy. The input energy σ pw of the transverse vibration of train-track(bridge)-wind system is linked to train speed. With the establishment of the analysis theory of random energy of train derailment in wind, It is likely to initiate an all-weather speed limit map for a train or any high-speed train. 相似文献
8.
The luminescent properties of terbium ions are used to investigate the interaction of adriamycin and cisplatin with GH3/B6 pituitary tumor cells. Clinically relevant concentrations of adriamycin were found to quench the intensity (IC50 = 0.6 μM) and excited-state lifetime (τ/τ0 = 0.73) of the Tb3+—GH3/B6 complex. Inspection of the Tb3+—GH3/B6 emission spectrum and the visible absorption spectrum of adriamycin strongly strongly suggests that the quenching of Tb3+ luminescence by adriamycin is due to dipole-dipole resonant energy transfer; and, according to Forster's theory (R0 = 33.6 Å), the adriamycin receptor site is located ca. 40 Å away from the bound probe, at the lipid/protein interface. The quenching of Tb3+ luminescence by cisplatin is best explained by a static energy-exchange mechanism; in that the cisplatin receptor site is contiguous with the Tb3+ binding site at the outer surface of the membrane. The data suggest that, in the plasma membrane of tumorigenic cells, the adriamycin and ciplatin receptor sites are intimately associated with the same calcium-binding protein. 相似文献
9.
Groves P Offermann S Rasmussen MO Canada FJ Bono JJ Driguez H Imberty A Jimenez-Barbero J 《Organic & biomolecular chemistry》2005,3(8):1381-1386
Lipochitooligosaccharides (LCOs) signal the symbiosis of rhizobia with legumes and the formation of nitrogen-fixing root nodules. LCOs 1 and 2 share identical tetrasaccharide scaffolds but different lipid moieties (1, LCO-IV(C16:1[9Z], SNa) and , LCO-IV(C16:2[2E,9Z], SNa)). The conformational behaviors of both LCOs were studied by molecular modeling and NMR. Modeling predicts that a small lipid modification would result in a different relative orientation of the lipid and tetrasaccharide moieties. Diffusion ordered spectroscopy reports that both LCOs form small aggregates above 1 mM. Nuclear Overhauser spectroscopy (NOESY) data, collected under monomeric conditions, reveals lipid-carbohydrate contacts only for 1, in agreement with the modeling data. The distinct molecular structures of 1 and 2 have the potential to contribute to their selective binding by legume proteins. 相似文献
10.
Bestenur YALIN Doan AKCAN brahim Erturul YALIN Mehmet Can ALPHAN Kenan ENTÜRK brahim lker
ZYT Lütfi ARDA 《Turkish Journal of Chemistry》2020,44(4):1177
The objective of this study is to synthesize ZnO and Mg doped ZnO (Zn1−xMgxO) nanoparticles via the sol-gel method, and characterize their structures and to investigate their biological properties such as antibacterial activity and hemolytic potential.Nanoparticles (NPs) were synthesized by the sol-gel method using zinc acetate dihydrate (Zn(CH3COO)2.2H2O) and magnesium acetate tetrahydrate (Mg(CH3COO)2.4H2O) as precursors. Methanol and monoethanolamine were used as solvent and sol stabilizer, respectively. Structural and morphological characterizations of Zn1−xMgxO nanoparticles were studied by using XRD and SEM-EDX, respectively. Photocatalytic activities of ZnO and selected Mg-doped ZnO (Zn1−xMgxO) nanoparticles were investigated by degradation of methylene blue (MeB). Results indicated that Mg doping (both 10% and 30%) to the ZnO nanoparticles enhanced the photocatalytic activity and a little amount of Zn0.90 Mg0.10 O photocatalyst (1.0 mg/mL) degraded MeB with 99% efficiency after 24 h of irradiation under ambient visible light. Antibacterial activity of nanoparticles versus Escherichia coli ( E. coli ) was determined by the standard plate count method. Hemolytic activities of the NPs were studied by hemolysis tests using human erythrocytes. XRD data proved that the average particle size of nanoparticles was around 30 nm. Moreover, the XRD results indicatedthat the patterns of Mg doped ZnO nanoparticles related to ZnO hexagonal wurtzite structure had no secondary phase for x ≤ 0.2 concentration. For 0 ≤ x ≤ 0.02, NPs showed a concentration dependent antibacterial activity against E. coli . While Zn0.90Mg0.10 O totally inhibited the growth of E. coli , upper and lower dopant concentrations did not show antibacterial activity. 相似文献