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121.
122.
lmTR0DUCTI0NTrivanadium(III)ox0-carb0xylat0complexeshaveattractedmuchinterestre-cently"~".Manyc0mp0unds0fthiskindhavebeensynthesizedandtheirstructural,physicalandspectr0sc0picpr0pertieshavebeenstudied.Butnone0fthiskindofcom-plexeswithmixedmeta1shavebeensynthesized.Hereinwereportthecrystalstruc-tureofthefirstmixedmeta1carboxylatocomp0undofvanadium.2EXPERIMENTAL2.1Synthesis0.l6g(lmmol)VCl3,0.32g(2mmol)FeCl3and0.48g(6mm0l)NaCO,CH,wasdisso1vedinaso1uti0n0ft0luerie(20ml),THF(lOml),ac… 相似文献
123.
Study on the extraction and separation of rare earth with new extractants is important in the rare earth chemistry and nuclear reprocessing. In this work, the extraction of Ce(Ⅲ) with N,N,N′,N′-tetrabutylmalonamide (TBMA) in toluene from nitrate media has been investigated. The effect of the concentration of nitric acid, TBMA and salt-ing-out agent (LiNO3) and also the temperature on the distribution ratios was examined. The stoichiometries of the extracted complexes were determined to be Ce(NO3)3·3TBMA and Ce(NO3)3·4TBMA, respectively. The ap-parent extraction constants and the enthalpy of the extraction were calculated based on the extraction data, which are logKex1=3.97, logKex2=4.75 and ΔrHm?=-31.25kJ·mol-1, respectively. The IR spectra of the loaded organic phase supported the suggested extraction mechanism. 相似文献
124.
Li Qiu WANG Xiao Jun PENG* Rong ZHANG Guo Quan XU Jing Nan CUI State Key Laboratory of Fine Chemicals Dalian University of Technology Dalian 《中国化学快报》2003,(1)
Indocyanine dyes as fluorescent labeling reagents have been used in bioanalysis1,2. Arylsulfonate indocyanine dyes 1d and 1e developed by Waggoner A. S. et al.3,4 have excellent fluorescent properties combined with good aqueous solubility, are a new generation of fluorescent label compounds for proteins, oligonucleotides and other compounds containing hydroxyl, mercaptol or primary amine groups5. However, photostability of these dyes has been a problem. Z. G. YAO et al.6 reported that p… 相似文献
125.
常温直接沉淀法制备ZnO纳米棒 总被引:11,自引:1,他引:11
在常温下, 以PEG-400(聚乙二醇400)为表面活性剂, 采用直接沉淀法合成了ZnO纳米棒. 产物用XRD, TEM, SAED和 HRTEM等进行了表征. 结果表明, 所得ZnO为一维的纳米棒, 属于六方纤维矿的单晶结构. ZnO纳米棒的直径在20~40 nm之间, 长度在300~800 nm范围. (0001)面为ZnO纳米棒的生长方向. 讨论了ZnO相的生成和ZnO纳米棒的形成机理以及PEG-400在其形成过程中的作用. 相似文献
126.
不同波长紫外光照下纳米TiO2薄膜的光致亲水性与循环伏安行为 总被引:6,自引:1,他引:6
通过溶胶-凝胶方法分别在ITO和玻璃表面制备了纳米TiO_2薄膜,研究了纳米 TiO_2薄膜在254及365nm的紫外光照射下的循环伏安行为和光致超亲水性。在紫外 光的照射下,TiO_2薄膜电极可表现出两个光电化学过程,纳米TiO_2薄膜的光致超 亲水性转变及两个光电化学过程的速率均取决于紫外光的波长,原因在于纳米 TiO_2薄膜对两种波长的光的吸收率和光子的能量不同。提出了光电化学过程的机 理,认为紫外光照射下纳米TiO_2薄膜的超亲水性变化与产生Ti~(3+)的过程引起的 表面微观结构变化存在的一定的内在联系。 相似文献
127.
128.
The effect of active control imposed at the wall on optimal structures in wall turbulence is studied by using a linear transient growth model.When the detection plane of the control is located in the buffer layer,the influence of the control on the transient growth of large scale motion becomes negligible as Reynolds number increases.However,if the control signal is detected at the plane located in the logarithm region,the transient growth at large scale can be greatly suppressed.New peak values of transient growth resulting from the strong blowing and suction on the wall exist.The study indicates that a proper selection of control imposed on the wall can suppress the large scale motion in the logarithmic region. 相似文献
129.
Many dark energy models fail to pass the cosmic age test because of the old quasar APM 08279+5255 at redshift z=3.91,the ΛCDMmodel and holographic dark energy models being no exception.Inthis paper,we focus onthe topic of the age problem inthe new agegraphic dark energy(NADE)model.We determine the age of the universe in the NADE model by fitting the observational data,including type Ia supernovae(SNIa),baryon acoustic oscillations(BAO)and the cosmic microwave background(CMB).We find that the NADE model also... 相似文献
130.
In this paper, for a kind of risk models with heavy-tailed and delayed claims, we derive the asymptotics of the infinite-time ruin probability and the uniform asymptotics of the finite-time ruin probability. The numerical simulation results are also presented. The results of theoretical analysis and numerical simulation
show that the influence of the delay for the claim payment is nearly negligible to the ruin probability when the initial capital and running-time are all large. 相似文献