对称向量拟均衡问题有效解的存在性

利用标量化方法建立对称向量拟均衡问题有效解的存在性定理。作为标量化方法的应用，利用这一方法得到向量变分不等式和拟向量变分不等式有效解的存在性定理。     

Carboxylate anions binding and sensing by a novel tetraazamacrocycle containing ferrocene as receptor

A tetraazamacrocycle containing ferrocene moieties has been synthesized and characterized. The tetraprotonated form of this compound was evaluated as a receptor (R) for anion recognition of several substrates (S), Cl(-), PF(6)(-), HSO(4)(-), H(2)PO(4)(-) and carboxylates, such as p-nitrobenzoate (p-nbz(-)), phthalate (ph(2-)), isophthalate (iph(2-)) and dipicolinate (dipic(2-)). (1)H NMR titrations in CD(3)OD indicated that this receptor is not suitable for recognizing HSO(4)(-) and H(2)PO(4)(-), but weakly binds p-nbz(-), and strongly interacts with ph(2-), dipic(2-), and iph(2-) anions forming 1 : 2 assembled species. The largest beta(2) binding constant was determined for ph(2-), followed by dipic(2-) and finally iph(2-). The effect of the anionic substrates on the electron-transfer process of the ferrocene units of R was evaluated using cyclic voltammetry (CV) and square wave voltammetry (SWV) in methanol solution and 0.1 mol dm(-3)(CH(3))(4)NCl as the supporting electrolyte. Titrations of the receptor were undertaken by addition of anion solutions in their tetrabutylammonium or tetramethylammonium forms. The protonated ligand exhibits a reversible voltammogram, which shifts cathodically in the presence of the substrates. The data revealed kinetic constraints in the formation of the receptor/substrate entity for dipic(2-), ph(2-) and iph(2-) anions, but not for p-nbz(-). In spite of the slow kinetics of assembled species formation with the ph(2-) substrate, this anion provides the largest redox-response when the supramolecular entity is formed, followed by dipic(2-), iph(2-) and finally p-nbz(-) anions. This trend is in agreement with the (1)H NMR results and the values of the binding constants. Single crystal X-ray structures of the receptor with PF(6)(-), ph(2-), iph(2-) and p-nbz(-) were carried out and showed that supermolecules with a RS(2) stoichiometry are formed with the first three anions, but RS(4) with p-nbz(-). In all cases the binding occurs outside the macrocyclic cavity via N-H...O=C hydrogen bonds for carboxylate anions and N-H...F hydrogen bonds for the PF(6)(-) anion, which is in agreement with the solution results. The macrocyclic framework adopts different conformations in order to interact with each substrate having Fe...Fe intramolecular distances ranging from 10.125(14) to 12.783(15)A.     

锡—邻菲咯啉络合物吸附极谱波的研究及应用

研究了锡－邻菲咯啉体系的极谱行为，在ｐＨ＝２．５０的０．１０ｍｏｌ／Ｌ氯乙酸－氯乙酸钠介质中，在单扫描极谱上，Ｓｎ－邻菲咯啉络合物于－０．４１Ｖ电位处产生一良好的吸附还原波。波高与Ｓｎ的浓度在２．０×１０＾－８－４．０×１０＾－６ｍｏｌ／Ｌ范围内呈线性关系；检出限为１．０×１０＾－８ｍｏｌ／Ｌ Ｓｎ，对合金标样中的锡进行测定，取得了满意的结果。     

一类新型杂环聚芳酰胺的合成与性能研究

采用二氮杂萘类双酚 4 (4 羟基苯基 ) 2 ,3 二氮杂萘 1 酮 (DHPZ)与对氯苯腈反应制得二腈化合物 ,进一步水解为二酸 .以此新型二酸与不同二胺聚合制得的聚芳酰胺均具有较高的耐热性能 ,其Tg 在 2 91～318℃ ,且易溶于极性非质子溶剂中 .聚合物的特性粘数为 1 17～ 1 5 0dL g(2 5℃ ,0 5 %inNMP) ,对所得聚酰胺进行性能研究 ,其拉伸强度为 71～ 86MPa ,断裂伸长率为 8%～ 13% ,拉伸模量为 0 86～ 1 0 2GPa ,电阻系数数量级为 10 1 4～ 10     

Synthesis and electrochemical properties of nanostructured LiCoO2 fibers as cathode materials for lithium-ion batteries

Nanostructured LiCoO2 fibers were prepared by the sol-gel related electrospinning technique using metal acetate and citric acid as starting materials. The transformation from the xerogel fibers to the LiCoO2 fibers and the nanostructure of LiCoO2 fibers have been investigated in detail. The LiCoO2 fibers with 500 nm to 2 mum in diameter were composed of polycrystalline nanoparticles in sizes of 20-35 nm. Cyclic voltammetry and charge-discharge experiments were applied to characterize the electrochemical properties of the fibers as cathode materials for lithium-ion batteries. The cyclic voltammogram curves indicated faster diffusion and migration of Li+ cations in the nanostructured LiCoO2 fiber electrode. In the first charge-discharge process, the LiCoO2 fibers showed the initial charge and discharge capacities of 216 and 182 (mA.h)/g, respectively. After the 20th cycle, the discharge capacity decreased to 123 (mA.h)/g. The X-ray diffraction and high-resolution transmission electron microscopy analyses indicated that the large loss of capacity of fiber electrode during the charge-discharge process might mainly result from the dissolution of cobalt and lithium cations escaping from LiCoO2 to form the crystalline Li2CO3 and CoF2 impurities.     

两性离子流动相测定杂多酸中的磷酸根、氯离子和硫酸根

采用离子色谱法测定杂多酸中痕量阴离子。由于常规的淋洗液(如Na2CO3,NaOH)呈碱性,使杂多酸迅速分解生成磷酸根,致使测定结果偏高。实验通过在常规淋洗液中加入适量两性离子后,调节淋洗液的pH为中性,从而能准确测定杂多酸中磷酸根氯离子和硫酸根的含量值。经过比较分别用去离子水和流动相稀释的样品中磷酸根的测定结果,确定淋洗液的最佳条件为2.5mmol/LNa2CO3-9.0mmol/LCHES,在该条件下测定,快速、准确、灵敏,且有较好的灵敏度和重现性。     

铟(Ⅲ)-向红菲啰啉络合物极谱吸附波的研究

在pH=3.8的磷酸柠檬酸盐缓冲体系中,铟(Ⅲ)-向红菲(口罗)啉络合物在单扫描示波极谱仪上于-0.67 V(vs.SCE)处产生一灵敏的吸附还原波,其二阶导数波灵敏度高,波形好.峰电位Ⅰ~O_P与钢(Ⅲ)浓度在 2.0X10~(-8)~2.0X10~(-6)mol/L范围内呈良好的线性关系,其检测限为8X10~(-9)mol/L铟(Ⅲ).该法用于试剂氧化锌和镀膜玻璃中铟(Ⅲ)的恻定,结果较好.     

磁性壳聚糖-聚丙烯酸微球的制备及表征

壳聚糖通过与丙烯酸接枝共聚制得壳聚糖聚丙烯酸悬浮液,在铁磁流体(Fe3O4)与聚乙二醇(分散剂)存在下通过与戊二醛交联,制备了磁性壳聚糖聚丙烯酸微球。用扫描电镜、红外光谱对合成的高分子微球进行形貌观察和结构表征,并进行了元素分析和磁性能测试,研究了磁性微球对牛血清白蛋白(BSA)的吸附效果。结果表明,合成的磁性微球外表呈球形,粒径为100～400nm;当Fe含量为2.47%时,磁性微球的饱和磁化强度约为1.30emug,磁矫顽力为280Oe,磁化率为2.16×10-4(常温下),属于顺磁性材料;其对BSA有较好的吸附效果,饱和吸附量约为400mgg。     

Engineering Multifunctional Gold Decorated Dendritic Mesoporous Silica/Tantalum Oxide Nanoparticles for Intraperitoneal Tumor‐Specific Delivery

Nonspecific high‐energy radiation for treatment of metastatic ovarian cancer is limited by damage to healthy organs, which can be mitigated by the use of radiosensitizers and image‐guided radiotherapy. Gold (Au) and tantalum oxide (TaO_x) nanoparticles (NPs), by virtue of their high atomic numbers, find utility in the design of bimetallic NP systems capable of high‐contrast computed tomography (CT) imaging as well as a potential radiosensitizing effect. These two radio‐dense metals are integrated into dendritic mesoporous silica NPs (dMSNs) with radial porous channels for high surface‐area loading of therapeutic agents. This approach results in stable, monodispersed dMSNs with a uniform distribution of Au on the surface and TaO_x in the core that exhibits CT attenuation up to seven times greater than iodine or monometallic dMSNs without either TaO_x or Au. Tumor targeting is assessed in a metastatic ovarian cancer mouse model. Ex vivo micro‐CT imaging of collected tumors shows that these NPs not only accumulate at tumor sites but also penetrate inside tumor tissues. This study demonstrates that after intraperitoneal administration, rationally designed bimetallic NPs can simultaneously serve as targeted contrast agents for imaging tumors and to enhance radiation therapy in metastatic ovarian cancer.     

Palladium(II)-catalyzed tandem annulation reaction of o-alkynylbenzoates with methyl vinyl ketone for the synthesis of isocoumarins

A palladium(II)-catalyzed highly regioselective tandem reactions of o-alkynylbenzoates with methyl vinyl ketone for the synthesis of isocoumarins was developed. It is a convenient, mild and environmentally benign reaction with moderate to high yield. The reaction is initiated by the Pd(II) species and regenerate the Pd(II) species to complete the catalytic cycle without the necessity of a redox system.