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841.
Masatoshi Takeda Manabu Terui Norihito Takahashi Noriyoshi Ueda 《Journal of solid state chemistry》2006,179(9):2823-2826
Thermoelectric (TE) and transport properties of alkaline-earth hexaborides were examined to investigate the possibility of improvement in their TE performance. As carrier concentration increased, electrical conductivity increased and the absolute value of the Seebeck coefficient decreased monotonically, while carrier mobility was almost unchanged. These results suggest that the electrical properties of the hexaboride depend largely on carrier concentration. Thermal conductivity of the hexaboride was higher than 10 W/m K even at 1073 K, which is relatively high among TE materials. Alloys of CaB6 and SrB6 were prepared in order to reduce lattice thermal conductivity. Whereas the Seebeck coefficient and electrical conductivity of the alloys were intermediate between those of CaB6 and SrB6 single phases, the thermal conductivities of the alloys were lower than those of both single phases. The highest TE performance was obtained in the vicinity of Ca0.5Sr0.5B6, indicating that alloying is effective in improving the performance. 相似文献
842.
843.
844.
We develop a new analytical model for the time-cost trade-off problem via optimal control theory in Markov PERT networks.
It is assumed that the activity durations are independent random variables with generalized Erlang distributions, in which
the mean duration of each activity is a non-increasing function of the amount of resource allocated to it. Then, we construct
a multi-objective optimal control problem, in which the first objective is the minimization of the total direct costs of the
project, in which the direct cost of each activity is a non-decreasing function of the resources allocated to it, the second
objective is the minimization of the mean of project completion time and the third objective is the minimization of the variance
of project completion time. Finally, two multi-objective decision techniques, viz, goal attainment and goal programming are
applied to solve this multi-objective optimal control problem and obtain the optimal resources allocated to the activities
or the control vector of the problem 相似文献
845.
Hideki Katagiri Masatoshi SakawaKosuke Kato Ichiro Nishizaki 《European Journal of Operational Research》2008
This paper considers multiobjective linear programming problems with fuzzy random variables coefficients. A new decision making model is proposed to maximize both possibility and probability, which is based on possibilistic programming and stochastic programming. An interactive algorithm is constructed to obtain a satisficing solution satisfying at least weak Pareto optimality. 相似文献
846.
We construct certain raising operators of row type for Macdonald's symmetric polynomials by an interpolation method. 相似文献
847.
Mechanochemical coupling was studied for myosin II and V consistently. The fluctuation in myosin V motility was determined by correlating the stochasticity of the ATPase reaction with regular displacements per one ATP, consistent with a tight mechanochemical coupling. In contrast, myosin II, working in an ensemble, was explained by a loose coupling, generating variable step sizes which depend on [ATP] and realizing a much larger step (200 nm) per one ATP than myosin V through its cooperativity at zero load. These different mechanics are ideal for their physiological functions. 相似文献
848.
This paper presents the theoretical basis for both static and dynamic numerical approaches to the elastic stability and elasto-plastic stability of a folding multi-layered truss. Both analyses are based on bifurcation theory and include geometrical non-linearity. The dynamic analysis includes an allowance for contact between nodes. Comparisons are made between elastic behaviour and elasto-plastic behaviour obtained from both numerical dynamic methods in which bifurcations are demonstrated as a theoretically elastic analysis. Our analysis reveals that several folding behaviours in the pantographic truss are identified during the elastic and elasto-plastic instabilities, where the folding behaviour of the truss is shown to be a function of the initial geometry and velocity of the dynamic loading. The authors suggest that understanding this behaviour will be very useful for developing light-weight structures subject to dynamic loading based on static bifurcation analysis and dynamic analysis. 相似文献
849.
Qizhao Li Masatoshi Ishida Hiroto Kai Tingting Gu Chengjie Li Xin Li Glib Baryshnikov Xu Liang Weihua Zhu Hans gren Hiroyuki Furuta Yongshu Xie 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(18):5986-5990
A hybrid thia‐norhexaphyrin comprising a directly linked N‐confused pyrrole and thiophene unit ( 1 ) revealed unique macrocycle transformations to afford multiply inner‐annulated aromatic macrocycles. Oxidation with 2,3‐dichloro‐5,6‐dicyano‐1,4‐benzoquinone triggered a cleavage of the C?S bond of the thiophene unit, accompanied with skeletal rearrangement to afford unique π‐conjugated products: a thiopyrrolo‐pentaphyrin embedded with a pyrrolo[1,2]isothiazole ( 2 ), a sulfur‐free pentaphyrin incorporating an indolizine moiety ( 3 ), and a thiopyranyltriphyrinoid containing a 2H‐thiopyran unit ( 4 ). Furthermore, 2 underwent desulfurization reactions to afford a fused pentaphyrin containing a pyrrolizine moiety ( 5 ) under mild conditions. Using expanded porphyrin scaffolds, oxidative thiophene cleavage and desulfurization of the hitherto unknown N‐confused core‐modified macrocycles would be a practical approach for developing unique polypyrrolic aromatic macrocycles. 相似文献
850.
Three water-soluble arsenic compounds were isolated from the green seaweed Codium fragile. These compounds were identified as 1-glycerophosphoryl-2-hydroxy-3-[5′-deoxy-5′-(dimethylarsinoyl)-β-ribofuranosyloxy]propane (1a), 1′ -(1,2-dihydroxypropyl)-5′ -deoxy-5′ -(dimethylarsinoyl)-β-ribofuranoside (1b), and dimethylarsinic acid ((CH3)2AsOOH). The structures of these compounds were ascertained by 1H NMR spectroscopy. Compounds 1a and 1b accounted for 60 % and dimethylarsinic acid for 5% of the water-soluble arsenic. 相似文献