Ceric-ion-initiated grafting of methyl methacrylate onto (1 → 5)-α-D-ribofuranan and (1 → 5)-α-D-xylofuranan

We report herein studies of grafting of MMA onto (1 → 5)-α-D -ribofuranan and (1 → 5)-α-D -xylofuranan by ceric ion initiation both in water and in dimethyl sulfoxide (DMSO). In aqueous medium, the graft polymer having high grafting (%) can be obtained easily without adding any nitric acid. The degradation of polysaccharide by the acidic ceric ion solution is not serious; 73–82% of its original molecular weight remained after the polymerization. In DMSO, graft polymers having lower grafting (%) and lower molecular weight of grafts were obtained.     

金属－助剂相互作用对SiO_2载铑催化剂化学吸附的影响──Ⅱ．Rh－V／SiO_2催化剂

由ＲｈＣｌ_３·ｘＨ_２Ｏ制备了不同Ｒｈ含量的Ｒｈ／ＳｉＯ_２和Ｒｈ－Ｖ／ＳｉＯ_２催化剂，采用化学吸附和原位ＴＰＤ－ＩＲ方法考察钒助剂对Ｒｈ／ＳｉＯ_２催化剂在常温和高温的Ｈ_２和ＣＯ化学吸附的影响。结果再次表明：１）不同Ｒｈ中心对Ｈ_２和ＣＯ的化学吸附性能不同，钒助剂对不同Ｒｈ中心的Ｈ_２和ＣＯ吸附的影响也不同。Ｈ_２主要吸附在Ｒｈ~Ⅱ和Ｒｈ~Ⅲ中心上，而在Ｒｈ~Ⅰ中心上的吸附弱。２）Ｒｈ－钒助剂的强相互作用主要是Ｒｈ~Ⅱ和Ｒｈ~Ⅲ与钒助剂之间的相互作用，Ｈ_２吸附受到比ＣＯ吸附更强烈的抑制。钒助剂对Ｒｈ／ＳｉＯ_２的Ｈ_２和ＣＯ吸附性能的影响可用覆盖模型解释。     

Separation and determination of podophyllum lignans by micellar electrokinetic chromatography

A micellar electrokinetic chromatography method was established for the quantitative analysis of seven podophyllum lignans in Podophyllum emodi Wall. var. chinesis sprague. The optimum buffer system was 10 mM NaH2PO4-5 mM borate-100 mM sodium dodecylsulfate-30% isopropanol (pH 7.20). Voltage was 18 kV and detection at 214 nm. The second derivative chromatogram was used to determine a low-content component and those not fully separated from adjacent ones. The RSD values of migration times and peak areas were <2.2 and <5.5%, respectively. The effects of several CE parameters on the resolutions were studied systematically.     

二茂铁及其胺甲基类取代衍生物的紫外光解自由基的研究

本文用自旋捕捉-ESR技术研究了二茂戊铁、环二烯和胺甲基类取代二茂铁的紫外光解过程中的活泼自由基。结果表明,二茂铁光解初级过程中生成的自由基为(C_5H_5Fe)·和C_5H_5·,其衍生物光解则生成(C_5H_5Fe)·和RC_5H_4·,而(C_5H_5Fe)·还可以进一步分解给出C_5H_5和Fe。     

镉化合物的~(113)Cd屏蔽张量2-氨基二甲基吡啶镉单晶的研究

2-氨基二甲基吡啶镉的单晶已被单晶定向的~(113)Cd核磁共振进行了研究。在CdCl_2+2-氨基二甲基吡啶中对于两个氯-四个氮的~(113)Cd的屏蔽张量元素分别是σ_(33)=368,σ_(22)=266,和σ_(11)=236×10~(-6)。     

旋转填充床的流体力学特性与传递过程的理论研究进展

旋转填充床(RPB)是一种高效的强化传递过程设备，亦是一种高效的混合与多相反应设备，在化工、材料、冶金、能源、环保等领域有着广泛的应用前景。本文概要地介绍了近年来对该类装置的流体力学特性和传递过程的理论研究进展。     

固体Hp[EuA_4]配合物异构体的研究

合成了化学式为Hp[EuA_4]的配合物(A=对甲氧基苯甲酰苯甲酰甲烷;Hp=六氢吡啶),用X-射线粉末衍射法,荧光光谱及热谱等方法研究了它们的性质,并发现由于合成条件(反应物的摩尔投量比,反应温度,所用溶剂)不同,在固体Hp[EuA_4]配合物中配体空间的排布不同,而有不同的异构体存在。     

混合型杂多化合物Mx[GaW9M3O40]·nH2O的合成和性质

本文报道了M_x[GaW₉M₃^′O₄₀]nH₂O(M′=Mo,V,Ti,Fe(Ⅲ),Co(Ⅱ),Ni(Ⅱ),Mn(Ⅱ);M=k,Na,Gua,Me₄N,Et₄N,Bu₄N)的合成。通过元素分析,阴离子电荷的确定,极谱、IR及UV光谱、可见光谱、ESR、磁化率测定对其进行了表征。并研究了它们在水溶液中对酸碱的稳定性     

Localized molecular orbitals and the problem of quasi-aromaticity in trinuclear molybdenum cluster compounds with cores of the type [MO3(μ3-X)(μ-Y)3] (X, Y = O, S, n = 4; X = O, Y = Cl, n = 5)

Calculations of localized molecular orbitals (LMO) and their energy levels for the cluster cores [MO₃O₄]⁴⁺, [MO₃SO₃]⁴⁺, [MO₃OS₃]⁴⁺, [Mo₃S₄]⁴⁺ and [MO₃OCl₃]⁵⁺ have been made by the use of energy-localized CNDO/2-LMO. The results of these LMO calculations show that the six-membered closed and continuous π-conjugated systems around the [MO₃Y₃] rings, each of which is formed from three synergically connected three-centered two-electron π bonds, is the most significant feature of the electronic structure for the quasi-aromatic clusters [Mo₃(μ₃-Y)(μ-X)₃]⁴⁺ (X, Y = O, S), and the size and electronegativity of the bridging Y atoms exhibit significant effects on the degree of quasi-aromaticity of these cluster compounds. For the non-aromatic reference cluster [Mo₃OCl₃]⁵⁺, the results of our calculations also show a bonding scheme with only one isolated π bond, thus leading to the loss of quasi-aromaticity; and meanwhile, there is a pair of extra electrons localized on the apical molybdenum atom of the Mo₃ triangle, thus with three Mo---Mo single bonds.     

A novel small-molecule near-infrared II fluorescence probe for orthotopic osteosarcoma imaging

Osteosarcoma is the most common primary malignant tumor of bone, particularly among children and adolescents. Advances in imaging, surgical techniques, and implants have dramatically reduced the need for amputation in the past three decades.Recently, in vivo fluorescence imaging in the second near-infrared window(NIR-II, 1,000–1,700 nm) shows impressive advantages of deeper tissue penetration and higher spatial resolution, which makes it a promising tool for the early diagnosis and post-operative observation of Osteosarcoma. To the best of our knowledge, this paper is the first time to develop a novel NIR-II fluorescence probe conjugated with an osteosarcoma targeted oligopeptide for molecular tumor imaging in a xenograft orthotopic osteosarcoma mouse model.