排序方式: 共有65条查询结果,搜索用时 15 毫秒
1.
采用水热法合成了2个化合物{[Cu2(Hpimdc)(4,4′-bpy)]·H2O}n(1)和[Mn3(pimdc)2·6H2O]n(2)(H3pimdc=2-丙基-4,5-咪唑二甲酸,4,4′-bpy=4,4′-联吡啶),并对2个化合物进行了红外、元素分析、晶体结构和热稳定性分析。晶体结构分析发现化合物1之中的H3pimdc和4,4′-bpy交替与铜(Ⅰ)配位形成一维链线性铜(Ⅰ)配合物。沿a轴和(100)面去观察,2个一维链分子通过游离水连接而形成1个"U"型拓扑结构。而化合物2通过2-丙基-4,5-咪唑二甲酸链与锰(Ⅱ)连接为三维的网状结构。沿b轴方向,三维结构中存在交替的左/右手螺旋状二维结构。 相似文献
2.
The present work is devoted to giving new insights into the Liu chaotic system. The local dynamical entities, such as the number of equilibria, the stability of hyperbolic equilibria, and the stability of the nonhyperbolic equilibrium obtained by using the center manifold theorem, the pitchfork bifurcation, the degenerate pitchfork bifurcation, and Hopf bifurcations, are all analyzed when the parameters are varied in the space of parameters. All the closed orbits of the system are also proven rigorously to be nonplanar but only to be curves in space. Moreover, the existence of singularly degenerate heteroclinic cycles for a suitable choice of the parameters is investigated. 相似文献
3.
4.
ZHANG Jin-lei TAN Xue-cai ZHAO Dan-dan TAN Sheng-wei HUANG Zeng-wei MI Yan HUANG Zai-yin 《高等学校化学研究》2010,(4):541-545
<正>A novel third-generation hydrogen peroxide(H_2O_2) biosensor(Hb/CdS/MWNTs/GCE) was fabricated through hemoglobin(Hb) adsorbed onto the mercaptoacetic acid modified CdS QDs/carboxyl multiwall carbon nanotubes'(MWNTs) films.Cyclic voltammogram of Hb/CdS/MWNTs/GCE showed a pair of well-defined and quasi-reversible redox peaks with a formal potential(E~0) of-0.230 V(vs.Ag/AgCl) in 0.1 mol/L pH=8.0 phosphate buffer solution(PBS),which was the characteristic of the Hb heme Fe(Ⅲ)/Fe(Ⅱ) redox couple.The biosensor shows an excellent electrocatalytic activity to the reduction of H_2O_2.The response time of the designed biosensor to H_2O_2 at a potential of -0.30 V was less than 2 s and linear relationships were obtained in the concentration ranges of 2.0×10~(-6)—2.7×10~(-3) mol/L and 2.7×10~(-3)—7.7×10~(-3) mol/L with a detection limit of 3.0×10~(-7)mol/L(S/N=3).The apparent Michaelis-Menten constant K_m was estimated to be 1.324 mmol/L that illustrated the excellent biological activity of the fixed Hb. 相似文献
5.
拥挤收费是改善城市交通的有效手段.对拥挤收费定价的研究方法之一,就是针对固定的出行量进行收费设计.由于出行量预测不确定的因素,应针对长期出行量预测不确定的情况,利用灵敏度分析的方法,对拥挤收费定价的问题进行研究.首先研究了出行者出行的广义费用,然后考虑出行者的出行决策及出行量预测不确定的因素,给出一个拥挤收费定价模型,为交通管理者提供理论依据. 相似文献
6.
《Tetrahedron letters》1988,29(45):5767-5768
Enantioselective total synthesis of (+)-monomorine I was achieved starting from diethyl L-tartrate via 1,2-asymmetric induction based on highly diastereoselective hydride addition to acyclic α,β-dialkoxy ketones. 相似文献
7.
为了解中药中微量元素的含量与其药物的作用机制关系,用原子吸收分光光度计测定了玄参、生地黄、紫草、水牛角、牡丹皮、赤芍中铁(Fe)、镁(Mg)、铜(Cu)、钙(Ca)、锌(Zn)、铬(Cr)、钼(Mo)等7种微量元素的含量.结果表明,Ca的含量最高,Cu的含量几乎最低.这6种中草药含有多种对人体有益的微量元素,与它们的药... 相似文献
8.
9.
10.
Polyalkynylene groups are known to function as excellent electronic conductors at the molecular level. Such moieties have now been used to interconnect redox and photoactive transition metal oligopyridine complexes so that the efficiency of light-induced energy or electron transfer along the molecular axis can be monitored. The important issues that control the effectiveness of electronic coupling through the alkyne are discussed. In particular, attention is given to separating the effects of electron delocalization within the triplet manifold from the more general decoupling of metal-centered and charge-transfer excited states that occurs upon lowering the triplet energy. The role of the auxiliary ligands is considered, as is the effect of nuclearity. Similarly, the size of the nuclear reorganization energy has to be taken into account in a proper discussion of the photophysical properties of such systems. A second issue of importance to the design of photoelectronic devices concerns the use of interspersed groups to modulate the electronic coupling properties of the alkyne spacer. Such electron relays may be aryl hydrocarbons or platinum bis-acetylides, both groups being able to curtail electron flow along the molecular axis. 相似文献