新型胺羧单酯-酰胺钆配合物的合成及其对大鼠肝区T1弛豫增强作用

通过DTPA、EDTA单活化酯与双乳酸酰乙二胺二醇、双乳酸酰己二胺二醇反应，合成了四种新型胺羧单酯-酰胺配体及其钆配合物。表征了配体和配合物的结构，测定了钆配合物水溶液水质子的弛豫效能。选取其中一个配合物进行了动物急性毒性测试和活体T₁加权成像实验。结果表明：该配合物无明显急性毒性，且对大鼠肝区质子有明显的增强。     

Synthesis and in vitro studies of Gd-DTPA derivatives as new potential MRI contrast agents

A new type of dendritic molecules, Gd-DTPA derivatives, which work as a functionalized ligand coordinating gadolinium(III) ion at the center of their frameworks with different terminal moieties on the molecular surfaces, was readily synthesized with high yield. The structures were established by ¹H, ¹³C NMR, and mass spectral studies. In vitro studies showed them to have enhanced r₁ value in albumin medium and good potentiality as MRI contrast agent.     

Impact of Different [Tc(N)PNP]-Scaffolds on the Biological Properties of the Small cRGDfK Peptide: Synthesis,In Vitro and In Vivo Evaluations

Background: The [^99mTc][Tc(N)(PNP)] system, where PNP is a bisphosphinoamine, is an interesting platform for the development of tumor ‘receptor-specific’ agents. Here, we compared the reactivity and impact of three [Tc(N)(PNP)] frameworks on the stability, receptor targeting properties, biodistribution, and metabolism of the corresponding [^99mTc][Tc(N)(PNP)]-tagged cRGDfK peptide to determine the best performing agent and to select the framework useful for the preparation of [^99mTc][Tc(N)(PNP)]-housing molecular targeting agents. Methods: cRGDfK pentapeptide was conjugated to Cys and labeled with each [Tc(N)(PNP)] framework. Radioconjugates were assessed for their lipophilicity, stability, in vitro and in vivo targeting properties, and performance. Results: All compounds were equally synthetically accessible and easy to purify (RCY ≥ 95%). The main influences of the synthon on the targeting peptide were observed in in vitro cell binding and in vivo. Conclusions: The variation in the substituents on the phosphorus atoms of the PNP enables a fine tuning of the biological features of the radioconjugates. ws[^99mTc][Tc(N)(PNP3OH)]– and [^99mTc][Tc(N)(PNP3)]– are better performing synthons in terms of labeling efficiency and in vivo performance than the [^99mTc][Tc(N)(PNP43)] framework and are therefore more suitable for further radiopharmaceutical purposes. Furthermore, the good labeling properties of the ws[^99mTc][Tc(N)(PNP3OH)]– framework can be exploited to extend this technology to the labeling of temperature-sensitive biomolecules suitable for SPECT imaging.     

脉冲激光沉积NiCo2S4薄膜及其电化学特征

采用脉冲激光沉积法制备了NiCo₂S₄薄膜,利用恒流充放电和循环伏安测试研究了NiCo₂S₄薄膜作为锂离子电池负极材料的电化学性能和充放电机理。采用高分辨电子显微镜和选区电子衍射(TEM&SAED)表征了NiCo₂S₄薄膜首次循环过程中的组成与结构变化。恒流充放电测试结果显示NiCo₂S₄薄膜在3 μA·cm^-2的放电电流下,0~3 V(vs Li⁺/Li)范围内,薄膜的首次放电容量为698 mAh·g^-1,经过200次循环之后的放电容量为365 mAh·g^-1;在循环伏安测试中得到了分步反应的可逆氧化还原峰。TEM和SAED分析结果揭示了NiCo₂S₄薄膜与Li的电化学反应机理：首次放电过程中NiCo₂S₄与Li发生转化反应生成了Li₂S、Ni和Co,充电后生成了CoS和NiS复合薄膜。后续循环为CoS和NiS复合薄膜的可逆分解与形成。研究表明NiCo₂S₄是一种有潜在应用价值的锂离子电池负极材料。     

脉冲激光沉积NiCo2S4薄膜及其电化学特征研究

采用脉冲激光沉积法制备了NiCo₂S₄薄膜,利用恒流充放电和循环伏安测试研究了NiCo₂S₄薄膜作为锂离子电池负极材料的电化学性能和充放电机理。采用高分辨电子显微镜和选区电子衍射(TEM&SAED)表征了NiCo₂S₄薄膜首次循环过程中的组成与结构变化。恒流充放电测试结果显示NiCo₂S₄薄膜在3 μA·cm^-2的放电电流下,0~3 V(vs Li⁺/Li)范围内,薄膜的首次放电容量为698 mAh·g^-1,经过200次循环之后的放电容量为365 mAh·g^-1;在循环伏安测试中得到了分步反应的可逆氧化还原峰。TEM和SAED分析结果揭示了NiCo₂S₄薄膜与Li的电化学反应机理：首次放电过程中NiCo₂S₄与Li发生转化反应生成了Li₂S、Ni和Co,充电后生成了CoS和NiS复合薄膜。后续循环为CoS和NiS复合薄膜的可逆分解与形成。研究表明NiCo₂S₄是一种有潜在应用价值的锂离子电池负极材料。     

次甲基硅SiH与H2X(X=O,S)反应的热力学及动力学性质研究

在量子化学对SiH与H₂O和H₂S反应计算的基础上,运用统计热力学和Wigner校正的Eyring过渡态理论,计算了上述两反应在200～2000 K温度范围内的热力学函数、平衡常数、频率因子A和速率常数随温度的变化。计算结果表明,两反应在低温下具有热力学优势,而在高温下具有动力学优势。比较两反应的计算结果发现,在相同的温度下,SiH与H₂O反应比SiH与H₂S反应放热较多,但速率常数却较小。SiH与H₂O反应和前文报道的SiH与HF反应的比较表明,SiH与H₂O反应放热较少,而且在相同温度下,速率常数也较小。     

沉积Pt对Ag2CO3纳米晶的物理化学性质和光催化性能影响

采用NaBH_4还原法合成了系列Pt沉积的Ag_2CO_3复合光催化剂。通过在可见光照射下降解甲基橙研究沉积不同含量的Pt对Ag_2CO_3光催化性能的影响。应用X射线粉末衍射(XRD)、扫描电子显微镜(SEM)、透射电镜(TEM)、光电子能谱(XPS)、傅立叶变换红外光谱(FT-IR)、光致发光光谱(PL)、紫外可见漫反射吸收光谱(DRS)、光电流(PC)和N_2物理吸附等研究了沉积Pt纳米颗粒对Ag_2CO_3纳米晶的物理化学性质的影响。结果表明,沉积质量分数为0.1%～0.5%的Pt,可使Ag_2CO_3的活性提升3倍以上,同时光催化剂的稳定性得到极大改善。Pt/Ag_2CO_3光催化性能大幅提升的主要原因是,沉积少量的Pt可以增强Ag_2CO_3对可见光的吸收,同时增大Ag_2CO_3的比表面积和表面羟基的数量;另外,沉积在Ag_2CO_3表面的Pt粒子可以承担电子俘获中心的作用,使Ag_2CO_3中光激发产生的电子(e~-)有效地转移到Pt上,加速光生电子-空穴对的分离速率,产生更多的光催化活性自由基,在提升光催化活性的同时,减少Ag_2CO_3中的Ag~+被光生电子(e~-)还原的几率,增强Ag_2CO_3的抗光腐蚀能力。     

ST-2191, an Anellated Bismorpholino Derivative of Oxy-Fingolimod,Shows Selective S1P1 Agonist and Functional Antagonist Potency In Vitro and In Vivo

Sphingosine 1-phosphate (S1P) is an extensively studied signaling molecule that contributes to cell proliferation, survival, migration and other functions through binding to specific S1P receptors. The cycle of S1P₁ internalization upon S1P binding and recycling to the cell surface when local S1P concentrations are low drives T cell trafficking. S1P₁ modulators, such as fingolimod, disrupt this recycling by inducing persistent S1P₁ internalization and receptor degradation, which results in blocked egress of T cells from the secondary lymphoid tissues. The approval of these compounds for the treatment of multiple sclerosis has placed the development of S1PR modulators in the focus of pharmacological research, mostly for autoimmune indications. Here, we report on a novel anellated bismorpholino derivative of oxy-fingolimod, named ST-2191, which exerts selective S1P₁ agonist and functional antagonist potency. ST-2191 is also effective in reducing the lymphocyte number in mice, and this effect is not dependent on phosphorylation by sphingosine kinase 2 for activity. These data show that ST-2191 is a novel S1P₁ modulator, but further experiments are needed to analyze the therapeutic impact of ST-2191 in animal models of autoimmune diseases.     

The Influence of Porosity on the Electromechanical and Pyroelectric Properties of Ca-Modified PbTiO3 Thin Films

The properties of Pb_1-xCa_xTiO₃ (x = 0–30) thin films for electromechanical and pyroelectric applications can be further improved if porous, low-dielectric constant layers are being used. The electric field dependent strain, piezoelectric coefficient, pyroelectric coefficient and the pyroelectric figure of merit were evaluated as a function of the Ca-content and relative density of the thin films. The heating-rate during the final anneal was observed to be the controlling parameter for the evolution of either dense or porous microstructures. Both 2-methoxyethanol and 1,3-propanediol based solution precursors were used for spin-coating platinized Si₃N₄/SiO₂/Si wafers. Microstructure-property relationships and electrical properties concerning the domain mobility were examined.     

不同结构颗粒对PMMA基复合材料性能影响

采用原位本体聚合法制备PMMA/MCM-41(with template),PMMA/SBA-15(with template),PMMA/SiO2三种复合材料.研究了介孔分子筛MCM-41,SBA-15和SiO2对PMMA复合材料拉伸强度,冲击强度,热稳定性的影响.由于合成介孔分子筛MCM-41,SBA-15时所用的模板剂CTAB和P123分布于孔口处和颗粒表面上,分别与PMMA基体产生物理缠结作用,增加了两者的相容性;且P123(EO20PO70EO20)表面有较大的PO/EO比率,与小分子量的CTAB相比有较强的疏水性,使得PMMA/SBA-15(with template)复合材料的性能要优于PMMA/MCM-41(with template).     

(ZrO2)1-x(Yb2O3)x纳米晶的水热法合成及其烧结体的电性能

(ZrO₂)_1-x(Yb₂O₃)_x (x=0.07, 0.09, 0.11) nanocrystallites were hydrothermally prepared in basic media by using co-precipitated Zr(OH)₄ and Yb(OH)₃ as precursor. The nanocrystallites have small particle sizes of 5.8~7.5 nm, narrow size distribution, less agglomeration and high sinterability. The oxide-ionic conduction properties of the prepared ceramics were investigated by means of AC impedance spectroscope, oxygen concentration cell at 600~1 000 ℃. The results show that the ceramic with x=0.09 is superior to the ceramics with x=0.07 and 0.11 in oxide-ionic conduction.     

基质环境对氨基苯甲酸/硅凝胶复合材料荧光特性的影响

近年来，溶胶－凝胶技术在制备无机－有机复合材料中的应用越来越广泛犤１～６犦。该方法既可以制得具有很好机械性能和光学均匀性的块体材料，也可以制得薄膜和粉体材料。有机光学活性物质在无机基质中的存在状态及其化学环境，有机分子之间及有机分子与无机基质之间的相互作用对材料的热稳定性、光学特性以及实际应用影响极大犤７～１０犦。研究无机基质的微环境与有机光学活性分子之间的相互作用，对于复合材料的组成、性能、制备工艺的优化设计和实际应用至关重要。但是，目前有关这方面的系统研究报道很少。本文在硅溶胶中分别掺入了一…     

离子交换法制备层状LixNi0.3Mn0.7O2正极材料及其离子交换规律的研究

通过共沉淀法高温固相反应在空气气氛中合成出具有P2型结构特征的碱青铜前驱体Na_0.66Ni_0.3Mn_0.7O₂，研究了在4种不同离子交换条件下进行离子交换反应得到目标正极材料Li_xNi_0.3Mn_0.7O₂的离子交换规律，并用XRD、SEM、粒度分析和电性能测试考察了目标正极材料及其前驱体的结构、形貌和电化学性能。结果表明，以熔融LiNO₃为介质于300 ℃离子交换4h反应进行得最为完全，离子交换率达98 %，且目标正极材料具有较完善的O2型层状结构，在2.6～2.9 V存在唯一的充放电平台，循环过程中未发现向尖晶石相转变；而离子交换时间过长，目标正极材料将出现尖晶石相而影响其放电容量和循环稳定性。     

高密度非球形和球形LiNi1/3Mn1/3Co1/3O2的合成和性能比较

利用二次干燥法和共沉淀法分别制备出了非球形的Ni_1/3Co_1/3Mn_1/3OOH前驱体和球形Ni_1/3Co_1/3Mn_1/3(OH)₂前驱体, 并分别和LiNO₃混合烧结合成高密度非球形和球形的锂离子正极材料Li(Ni_1/3Co_1/3Mn_1/3)O₂. XPS分析表明, 二次干燥法制备的非球形Ni_1/3Co_1/3Mn_1/3OOH前驱体其过渡金属Ni, Co和Mn的价态分别是＋2, ＋3和＋4, 而共沉淀法制备的球形Ni_1/3Co_1/3Mn_1/3(OH)₂前驱体其各金属价态为＋2; X射线衍射分析表明, 非球形的Ni_1/3Co_1/3Mn_1/3OOH前驱体比球形的前驱体具有较高的活性, 能够在低温下合成出Li(Ni_1/3Co_1/3Mn_1/3)O₂, 而且制备的产物结晶度高, 具有规整的层状α-NaFeO₂结构, 扫描电镜显示制备的非球形产物颗粒均匀, 颗粒间隙小, 振实密度高达2.95 g•cm^－3, 远高于球形的振实密度2.35 g•cm^－3; 充放电实验表明, 由非球形前驱体制备的Li(Ni_1/3Co_1/3Mn_1/3)O₂其充放电性能和循环性能以及体积比容量均高于球形正极材料.     

Cs取代对Ni-H3PW12O40/SiO2催化剂结构性质和催化性能的影响

采用两步浸渍法和载体上的原位反应制备了一系列Cs部分取代的Ni-Cs_xH_3-xPW₁₂O₄₀/SiO₂催化剂,并用N₂吸附比表面积测定(BET)、电感耦合等离子体发射光谱(ICP)、X射线衍射(XRD)、拉曼光谱(Raman)、原位X射线衍射(in situ XRD)、NH₃程序升温脱附(NH₃-TPD)、H₂程序升温还原(H₂-TPR)、H₂程序升温脱附(H₂-TPD)、吡啶吸附傅里叶变换红外(FTIR)光谱等分析测试技术对催化剂进行了表征. 以正癸烷为模型化合物,对催化剂的加氢裂化性能进行了评价. 结果表明,8%Ni-50%Cs_1.5H_1.5PW/SiO₂催化剂具有最高的C₅₊收率,明显优于8%Ni-50%H₃PW/SiO₂催化剂和工业催化剂. 随着Cs 在Cs_xH_3-xPW中比例的增加,正癸烷的转化率逐渐降低,而C₅₊选择性则逐渐提高. 当催化剂具有合适的孔径时,选择性的提高是由于催化剂酸性的减弱,而转化率的降低则是由于催化剂加氢能力的减弱.     

Chemical stability of La1−xSrxCrO3 in oxidizing atmospheres

The single-phase region of La_1−xSr_xCrO₃ (x=0.1, 0.2, 0.3) was precisely determined as a function of temperature, P_O2 and Sr content. The powders with the nominal composition of La_1−xSr_xCrO₃ were equilibrated under various conditions, and then identified by XRD analyses. To confirm the equilibration, two independent experiments were performed for each composition observing (i) the precipitation of the second phase from a single-phase solid solution, and (ii) the formation of the single phase from the constituent oxides. Two kinds of second phases, SrCrO₄ and an unknown phase, were observed depending on the conditions. The second phases tended to appear at low temperature, in high P_O2 and with a large Sr content. The single-phase regions obtained via the two equilibration routes were in good agreement with each other. The thermodynamic calculations on the supposition of ideality of the solid solution essentially reproduced the experimental results. When this material is used as the interconnects of solid oxide fuel cells, much attention should be paid to its relatively narrow solubility range of Sr; for example, the solubility limit is approximately 0.1 under a typical cathode-side condition (1273 K, air).     

核壳结构PS/CeO2复合微球的制备及其在化学机械抛光中的应用

以原位化学沉淀的方法制备了不同粒径、包覆结构PS(核)/CeO2(壳)复合微球,利用X射线衍射仪、透射电子显微镜、选区电子衍射、场发射扫描电子显微镜、能谱分析仪、Fourier转换红外光谱仪、热失重分析仪和ζ电位测定仪等手段对所制备样品的微观结构进行了表征。将所制备的复合微球用做磨料,考察其对二氧化硅介质层的抛光性能,用原子力显微镜观察和测量抛光表面的微观形貌、轮廓曲线和粗糙度。结果表明,所制备的PS/CeO2复合微球具有核壳包覆结构,粒径分别约为140,180和220 nm,PS内核被粒径约为5 nm的CeO2颗粒均匀包覆。AFM结果显示,复合磨料的粒径越小,抛光后表面粗糙度越低;且酸性(pH=3)比碱性(pH=10)抛光浆料具有更好的抛光效果。     

Influence of Organic Additive on the Morphological, Electrical and Electrochromic Properties of Sol-Gel Derived WO3 Coatings

The WO₃ electrode is ubiquitous in an electrochromic device (ECD) and is a common choice as the electrochromic (EC) layer. EC films were deposited on different substrates by spin coating using peroxotungstic acid based precursor solutions followed by appropriate thermal treatment. Many properties of the films, including some of the EC properties dependant on microstructure of the films, were found to be modified by the addition of small amounts of organic acid to the precursor solution. A study of structural, electrical and electrochromic properties of films cast by using precursor solution comprising 0 to 10 wt% of oxalic acid dihydrate (OAD) was carried out in terms of surface morphology, electrical resistance, structure and EC response. The important findings are that the addition of oxalic acid to the precursor solution results in films with excellent EC properties, devoid of cracks and decreases their dc electrical resistance.     

Reactions of Cinnoline, Cinnoline N-Oxides, and Their Chloro Derivatives with Alkylamines: the First Case of Nucleophilic Substitution of Hydrogen in the Cinnoline Series

In contrast to cinnoline and cinnoline N₍₁₎-oxide, cinnoline N₍₂₎-oxide reacts with primary and secondary amines on prolonged heating or in the presence of oxidants to give 3-alkylaminocinnolines.     

Quantum Chemical Calculations on the Structure and Adsorption Properties of NO and N2O on Ag+ and Cu+ Ion-Exchanged Zeolites

Ab initio cluster quantum chemical calculations at the Hartree–Fock (HF/Lanl2dz) and correlated second-order Moller–Plesset perturbation theory (MP2/Lanl2dz) levels were performed for NO and N₂O interactions with Ag⁺ and Cu⁺ ion-exchanged zeolites. The interaction energies were estimated in a conventional way and also corrected for basis set superposition errors. It was shown that the highly dispersed Ag⁺ counterions establish twofold coordination to the lattice oxygens on the zeolite surface, similar to the case of Cu⁺ ions. However, both NO and N₂O bind relatively strongly to the Cu active sites of Cu⁺ ion-exchanged zeolites than those of the Ag⁺ site of the Ag⁺ ion-exchanged zeolites. Based on the results of these calculations, the two different forms of adsorption for these molecules on the catalyst surface, the nature of their binding and characteristics of the adsorption properties have been discussed. Finally, some comparisons with the results obtained by a variety of density functional theory calculations on target systems have been presented.