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81.
采用飞秒频率上转换技术测量了两种可溶聚乙炔衍射生物poly(phenylacetylene(PPA)和poly(1-phenyl-1-buty1)PPB)的发光动力学过程。采用非均匀展宽态密我规行走理论对上述结果进行了分析。 相似文献
82.
83.
M.W Wong 《Journal of Functional Analysis》1981,44(2):163-173
The spectrum and essential spectrum in Lp(n) of a strongly Carleman pseudo-differential operator with symbol of class S?,0m, 0 ? p ? 1, are shown to coincide with the range of the symbol for some (but need not be all) p different from 2. The absolutely continuous spectra of perturbations of operators with strongly Carleman symbols (but without the assumption of being in S?,0m) are also investigated. 相似文献
84.
黄钾铁矾的生物合成与鉴定 总被引:23,自引:1,他引:23
利用氧化亚铁硫杆菌的生物催化氧化作用,在FeSO4—K2SO4—H2O体系中和常温常压条件下合成赭黄色的黄钾铁矾。借助SEM,XRD,FTIR,ICP—AES等方法对它的化学组成和结构进行了分析与表征。结果表明,Thiobacillus ferrooxidans休止细胞可在2天内将FeSO4-K2SO4-H2O体系中的Fe^2 全部氧化为Fe^3 ,Fe^3 在高浓度硫酸根、K^ 存在和酸性条件下水解生成赭黄色高铁沉淀,经鉴定为黄钾铁矾,其晶体粒径均匀,分散性好,且没有无定形的羟基硫酸高铁副产物。 相似文献
85.
Extensive experimental results are presented to reveal the relaxations of polystyrene surface deformed by rubbing with a velvet
cloth. We found that surface topographic features, such as ditches and ridges created by rubbing, relax at temperatures at
about 20°
C below the bulk glass transition temperature of the polystyrene for a molecular weight of 442 kg/mol, even though we estimate
the Laplace Pressure driving the relaxation to be 1/500 of the yield limit. The relaxation is independent of the thermal history
before the rubbing process, and post rubbing thermal history below 55°
C . In other words, physical-aging processes at 23°
C for up to 7 days and at 50°
C for 2 days, which would have drastic effects on the relaxations of bulk polymers, have little effects on the relaxations
of rubbed surfaces. This is consistent with the mobility enhancement in the surface layer previously reported in the literature. 相似文献
86.
Y. T. Angel Wong Vinicius Martins Dr. Bryan E. G. Lucier Prof. Dr. Yining Huang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(8):1848-1853
Metal–organic frameworks (MOFs) have shown great potential in gas separation and storage, and the design of MOFs for these purposes is an on-going field of research. Solid-state nuclear magnetic resonance (SSNMR) spectroscopy is a valuable technique for characterizing these functional materials. It can provide a wide range of structural and motional insights that are complementary to and/or difficult to access with alternative methods. In this Concept article, the recent advances made in SSNMR investigations of small gas molecules (i.e., carbon dioxide, carbon monoxide, hydrogen gas and light hydrocarbons) adsorbed in MOFs are discussed. These studies demonstrate the breadth of information that can be obtained by SSNMR spectroscopy, such as the number and location of guest adsorption sites, host–guest binding strengths and guest mobility. The knowledge acquired from these experiments yields a powerful tool for progress in MOF development. 相似文献
87.
A Model for Evaluation of Transport Policies in Multimodal Networks with Road and Parking Capacity Constraints 总被引:1,自引:0,他引:1
Zhi-Chun Li Hai-Jun Huang William H. K. Lam S. C. Wong 《Journal of Mathematical Modelling and Algorithms》2007,6(2):239-257
This paper presents a model for evaluation of transport policies in multimodal networks with road and parking capacity constraints.
The proposed model simultaneously considers choices of travelers on route, parking location and mode between auto and transit.
In the proposed model, it is assumed that auto drivers make a simultaneous route and parking location choice in a user equilibrium
manner, and the modal split between auto and transit follows a multinomial logit formulation. A mathematical programming model
with capacity constraints on road link and parking facilities is proposed that generates optimality conditions equivalent
to the requirements for multimodal network equilibrium. An augmented Lagrangian dual algorithm embedded by partial linearization
approach is developed to solve the proposed model. Numerical results on two example networks are presented to illustrate the
proposed methodology. The results show that the service level of transit, parking charges, road link and parking capacities,
and addition of a new parking location may bring significant impacts on travelers’ behavior and network performance. In addition,
transport policies may result in paradoxical phenomenon. 相似文献
88.
In this paper, we present a new car-following model by taking into
account the effects of the traffic interruption probability on the
car-following behaviour of the following vehicle. The stability
condition of the model is obtained by using the linear stability
theory. The modified Korteweg--de Vries (KdV) equation is constructed
and solved, and three types of traffic flows in the
headway sensitivity space---stable, metastable, and unstable---are
classified. Both the analytical and simulation results show that the
traffic interruption probability indeed has an influence on driving
behaviour, and the consideration of traffic interruption probability
in the car-following model could stabilize traffic flow. 相似文献
89.
Let X be a locally compact Hausdorff space and C
0(X) the Banach space of continuous functions on X vanishing at infinity. In this paper, we shall study unbounded disjointness preserving linear functionals on C
0(X). They arise from prime ideals of C
0(X), and we translate it into the cozero set ideal setting. In particular, every unbounded disjointness preserving linear functional of c
0 can be constructed explicitly through an ultrafilter on complementary to a cozero set ideal. This ultrafilter method can be extended to produce many, but in general not all, such functionals on C
0(X) for arbitrary X. We also make some remarks where C
0(X) is replaced by a non-commutative C*-algebra. 相似文献
90.