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111.
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By incorporating the solvent effect into the Born effective radius, we have proposed an electronegativity scale of metal ions in aqueous solution with the most common oxidation states and hydration coordination numbers in terms of the effective ionic electrostatic potential. It is found that the metal ions in aqueous solution are poorer electron acceptors compared to those in the gas phase. This solution-phase electronegativity scale shows its efficiency in predicting some important properties of metal ions in aqueous solution such as the aqueous acidities of the metal ions, the stability constants of metal complexes, and the solubility product constants of the metal hydroxides. We have elaborated that the standard reduction potential and the solution-phase electronegativity are two different quantities for describing the processes of metal ions in aqueous solution to soak up electrons with different final states. This work provides a new insight into the chemical behaviors of the metal ions in aqueous solution, indicating a potential application of this electronegativity scale to the design of solution reactions. 相似文献
113.
为进行快点火实验,需对高能拍瓦激光聚焦系统中的核心元件即大口径离轴抛物面,进行深入量化研究,以便对其结构选型和精密调整提供准确的理论依据。利用基于严格的矢量衍射理论的数值计算方法,并结合像差分析得到了大孔径、大离轴量的抛物面镜(OAP)的物理光学成像特性。首先用理想平行光入射,得出OAP的三维平动公差与其焦深密切相关,OAP绕旋转对称轴的转动可归结为平动问题,其公差与焦深也有简单关系;入射光轴失准时,像散占主导作用,并可由一结构因子来定性描述其对像斑的影响。其次当入射光有一定的发散角时,除引起最佳像面位置变化外,还会由于OAP不对称性而引起的彗差使得像斑的峰值光强大大降低,并论述了OAP的结构参数对此的影响。 相似文献
114.
Copper hydroxyphosphate [Cu(2)(OH)PO(4)] with complex architectures has been synthesized through a simple and mild hydrothermal route in the absence of any external inorganic additives or organic structure-directing templates. Powder X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectrometry are used to characterize various properties of the obtained samples. Single-crystals, twinned-crystals, and various novel architectures of copper hydroxyphosphate can be constructed through a careful control of synthetic parameters, such as the molar ratio of initial reagents, reagent concentration, reaction time, and temperature. On the basis of structure and chemical bond analysis, copper hydroxyphosphate crystals tend to grow along the c-axis and have a rotation twinned-crystal growth habit, which is essential for the formation of various complex architectures. The current approach provides a facile strategy to synthesize copper hydroxyphosphate crystals with unique morphologies and complex architectures, which may be applicable to the synthesis of other inorganic materials. 相似文献
115.
Two novel homochiral lanthanide-silver heterometallic coordination polymers LnAg(OAc)(IN)3 [Ln = Nd (1), Eu (2), HIN = isonicotinic acid, HOAc = acetic acid] have been prepared under hydrothermal conditions, which were characterized by elemental analysis, infrared, thermogravimetric analysis, and single-crystal X-ray diffraction. Both complexes are isostructural and crystallize in a hexagonal system, chiral space group P6(1)22. Both polymers are constructed from infinite right-handed homochiral helical chains with Ln-O-Ag connectivity, representing the first examples of homochiral lanthanide-transition metal heterometallic coordination polymers with a 3D coordination framework based on spontaneous resolution. Furthermore, the luminescent properties of 2 were studied. 相似文献
116.
Treatment of mer-VCl3(THF)3 with KTp [Tp = hydridotris(3,5-dimethylpyrazol-1-yl)borate], followed by [NEt4]CN in acetonitrile, affords [NEt4][(Tp)V(III)(CN)3].H2O (1.H2O); aerobic oxidation affords [NEt4][(Tp)V(IV)(O)(CN)2] (2). Subsequent treatment of 2 with Mn(II)(OTf)2 (OTf = trifluoromethanesulfonate) and 2,2'-bipyridine affords {[(Tp)V(O)(CN)2]2[Mn(II)(bipy)2]2[OTf]2}.2MeCN (3). Magnetic measurements indicate that 1-3 exhibit S = 1, (1/2), and 4 spin ground states, respectively. 相似文献
117.
Treatment of 1-chloro-6-iodohexane or 1-chloro-10-iododecane with lithium tris(pyrazolyl)methanide, followed by potassium thioacetate, affords bifunctional 1-S(acetyl)-tris(pyrazolyl)alkanes (L) (pz)3C(CH2)nSAc (n = 6, 1; 10, 2). Magnetic studies of {[(pzTp)Fe(III)(CN)3]4[Ni(II)L]4[OTf]4}.solvent (4, L = 1; 5, L = 2) boxes suggest that -(CH2)6 chains (4) limit intermolecular interactions while -(CH2)10 chains in 5 introduce crystallographic disorder and a distribution of relaxation times; 4 and 5 exhibit slow relaxation of the magnetization. 相似文献
118.
Liu H Wang EQ Chen Z Liu P Larson CR Huang D 《The Journal of the Acoustical Society of America》2010,128(6):3739-3746
The purpose of this cross-language study was to examine whether the online control of voice fundamental frequency (F(0)) during vowel phonation is influenced by language experience. Native speakers of Cantonese and Mandarin, both tonal languages spoken in China, participated in the experiments. Subjects were asked to vocalize a vowel sound /u/at their comfortable habitual F(0), during which their voice pitch was unexpectedly shifted (± 50, ± 100, ± 200, or ± 500 cents, 200 ms duration) and fed back instantaneously to them over headphones. The results showed that Cantonese speakers produced significantly smaller responses than Mandarin speakers when the stimulus magnitude varied from 200 to 500 cents. Further, response magnitudes decreased along with the increase in stimulus magnitude in Cantonese speakers, which was not observed in Mandarin speakers. These findings suggest that online control of voice F(0) during vocalization is sensitive to language experience. Further, systematic modulations of vocal responses across stimulus magnitude were observed in Cantonese speakers but not in Mandarin speakers, which indicates that this highly automatic feedback mechanism is sensitive to the specific tonal system of each language. 相似文献
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