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991.
Frank Wolter 《Mathematical Logic Quarterly》1996,42(1):481-500
Based on the results of [11] this paper delivers uniform algorithms for deciding whether a finitely axiomatizable tense logic
- has the finite model property,
- is complete with respect to Kripke semantics,
- is strongly complete with respect to Kripke semantics,
- is d-persistent,
- is r-persistent.
992.
J. Spiliotis 《Applied Mathematics and Optimization》1997,35(3):265-282
The complex parabolic type Monge-Ampère equation we are dealing with is of the form
inB × (0,T),u=ϕ on Γ, whereB is the unit ball in ℂ
d
,d>1, and Γ is the parabolic boundary ofB × (0,T). Solutionu is proved unique in the class
. 相似文献
993.
Costa Metallinos Deanna Tremblay Nicholas J. Taylor 《Journal of organometallic chemistry》2006,691(9):2044-2047
Subtle differences in the electron-richness of nitrogen atoms in 1,1′-bis(phosphoranylidenamino)ferrocenes can change the coordination geometry of their palladium(II) complexes from cis to trans. Trans complexation results in concomitant formation of a relatively short dative Fe-Pd bond of 2.67 Å. 相似文献
994.
长期以来,人们对Co(I)与SChiff诚配合物的研究范围限于同种配体的多,对复合配体络合物的研究较少·我们曾合成了过渡金属与N一本基水杨醛亚胺及其衍生物(以L表示)的络合物Mll)L。,并研究了它们的晶体结构[‘一句.结构表明,Mll)L。的中心离子与配位原子形成四面体构型·为了研究复合配体对低价CO(11)离子络合配位构型的影响,探索复合配体络合物的结构与性能的关系,我们选用易与低价金属形成稳定络合物的双齿配体二氯杂菲和配合物CO(11)L。为反应物,合成了d’组态高自旅Co11)离子的复合配体络合物·本文将报道该络… 相似文献
995.
Hydrous manganese oxide/carbon nanotube composite electrodes for electrochemical capacitors 总被引:2,自引:0,他引:2
Y.?K.?Zhou B.?L.?He F.?B.?Zhang H.?L.?LiEmail author 《Journal of Solid State Electrochemistry》2004,8(7):482-487
A novel type of composite electrode based on hydrous manganese oxide and a single-walled carbon nanotube has been prepared and used in electrochemical capacitors. Cyclic voltammetry, galvanostatic charging/discharging tests and electrochemical impedance measurements were applied to investigate the performance of the composite electrodes with different ratios of hydrous manganese oxide and single-walled carbon nanotube. For comparison, the performance of pure hydrous manganese oxide and pure carbon nanotubes was also studied. In this way, the composite electrode with a 6:4 ratio of hydrous manganese oxide to carbon nanotube was found to be the most promising active material for an electrochemical capacitor, which shows both good capacitance and power characteristics. 相似文献
996.
Ca3Co4O9/Ag composites incorporating different amounts of Ag were synthesized by solid-state reaction. Scanning electron microscopy revealed Ag particles dispersed among and combined with Ca3Co4O9 grains several times larger in size. The electrical resistivity (ρ) of the composites is favorably lower than that of Ca3Co4O9 alone and decreases with increasing Ag content. It can thus be inferred that the highly conductive Ag particles between the oxide grains contribute to the reduction of ρ. Although minimal in smaller amounts, the addition of Ag also seems to have a negative impact on the Seebeck coefficient (S) of the composites due to its poor S. Since the reduction of ρ is more significant than the degradation of S, the power factor is found to be improved by the addition of 10 wt% Ag. 相似文献
997.
998.
《European Polymer Journal》2002,38(6):1245-1254
The results of radical terpolymerization of maleic anhydride (MA), trans-stilbene (Stb) and acrylic monomers (n-butyl methacrylate (BMA) and acrylonitrile (AN)) as acceptor-donor-acceptor monomer systems are discussed. The structure and composition of terpolymers are determined by chemical (acid number for MA units) and elemental (content of N for AN units and O for BMA units) analyses, as well as by FTIR spectroscopy through recorded analytical absorption bands for MA (1770 and 1845 cm−1), Stb (864 cm−1) and BMA (1730 cm−1) units, respectively. The considerable change in the terpolymer compositions is observed when a strong acceptor MA is substituted with BMA (or AN), having comparatively low acceptor character in the system studied. Copolymerization constants for the MA ? Stb complex and acrylic comonomers pairs are determined according to the modified Kelen-Tüdös equation. Obtained results show that at the chosen ratios of comonomers, radical terpolymerization proceeded mainly by a true “complex” mechanism in the stage of near binary copolymerization of MA ? Stb complexed monomers with free BMA (or AN). The kinetics of terpolymerization and terpolymer compositions are studied in the low and high conversion stages. It is shown that for the MA-Stb-BMA system the dependence of Rp on the concentration of individual comonomers has extreme character, while for BMA-Stb-AN this dependence does not have similar character. This fact indicated that terpolymerization in the BMA-Stb-AN system proceeds according to a classical statistical copolymerization mechanism. The terpolymer composition-thermal behaviour relationships are also studied by differential scanning calorimetry and thermogravimetric analysis methods. 相似文献
999.
高聚物固体电解质聚氧化乙烯-溴化铜复阻抗谱及介电常数的静水压效应 总被引:1,自引:0,他引:1
采用分子量500万的聚氧化乙烯和无水溴化铜,通过混溶蒸发法制备成高聚物固体电解质P(EO)n-CuBr2薄膜,并在0.1~300MPa范围不同的流体静水压下详细测量其复平面阻抗谱,分别得到在不同压力下离子电导率和介电常数与测量频率的关系.进一步解谱准确地求出P(EO)n-CuBr2(n=12、16)薄膜离子电导率和介电常数的静水压效应,并结合X-光物相分析,根据离子迁移通道的物理图象和高聚物的极化机构进行了初步的讨论.添加20%的增塑剂碳酸丙烯酯,较大改进了压力下的导电性.120~300MPa的离子电导率提高一个数量级 相似文献
1000.
CSTR中H2O2-KSCN-CuSO4非线性反应体系的研究 总被引:2,自引:1,他引:2
非统性化学反应现象(包括化学振荡、化学波和化学混饨等)的研究近二十年来进展较快,BZ反应*、NADH氧化的生化反应*及卤类化合物主导的其它反应体系[’-’]的混饨、双节律等复杂非线性现象不断被发现并得到不同程度的确证.无卤无机反应体系的复杂非线性现象未见报导,我们选择H202-KSCN-CllS04-N。OH无卤体系K7]进行探索,此反应在连续搅拌反应器(CSTR)和封闭反应器(batch)皆有振荡现象,在体系中加入鲁米诺(11J.----n由产生发光振荡现象问,我们对这个反应体系的进一步研究发现复杂振荡(包括非周期过程)… 相似文献