高富勒烯的提取,分离和分析

采用二硫化碳重结晶富勒烯混合物或二硫化碳二次抽提烟灰以提取高富勒烯（ｈｉｇｈｅｒｆｕｌｅｒｅｎｅｓ，Ｃｎ，ｎ＞７０）。产物经高效液相色谱分析，高富勒烯的含量从１％分别提高到４％和６％；经激光飞行时间质谱证明，产物中除含主要成分Ｃ６０和Ｃ７０以外，还含有Ｃ７６、Ｃ７８、Ｃ８２、Ｃ８４以及更高碳原子的富勒烯。     

Two New ent-Kaurane Diterpenoids from Isodon xerophilus

In continuation of our research on diterpenoids in the Isodon species, several newcompounds"' were obtained from the leaves oflsodon xerophilus (C. Y. Wu et H. W. Li)H. Hara (Labiatae), a perennial shrub native to Yunnan province. Further fractionation ofthe EtOAc extract led to the isolation of tWo new enl-kauranoids, xerophilusin E (l) andxerophilusin F (2). This paper deals with the structUral elucidation of the newcompounds.Xerophilusin E (l), a minor constitUent, was obtained as p…     

新型含氟聚芳醚酮的合成与表征

聚芳醚酮具有很高的热稳定性和优良的电性能及机械性能 ,已经被广泛应用于宇航、电子及核能等高技术领域 [1] .氟元素的引入可以降低材料介电常数、折光指数和吸水率 ,提高热稳定性、溶解性和阻燃性 ,增加材料透明度 ,使这类聚合物在光电子、光学和微电子等应用领域的研究倍受关注 [2～ 4 ] .本文在合成含三氟甲基苯侧基的聚芳醚酮 [5] 的基础上 ,设计并合成了新型的含氟量更高的单体和聚合物 ,并对其性能进行了初步研究 .1　实验部分1 .1　试剂与仪器　 [3,5 -二 (三氟甲基 ) ]苯代对苯醌 (自制 ) ;锌粉 ,A.R.级 ,天津化学试剂一厂产品 ;…     

PABA疏水缔合水溶性共聚物溶液的合成与性能研究

本文根据高分子的分子设计原理，合成了带苯基的疏水单体N－苯基对正丁基丙烯酰胺（BBAM）。采用自由基胶束共聚的方法制备了水溶性丙烯胺／N－苯基对正丁基丙烯酰胺（BBAM）疏水缔合型共聚物（PABA）。研究了共聚物溶液的性能及影响因素。结果表明，随共聚物溶液浓度的增加，在临界缔合浓度以上，分子间缔合大量形成，水溶液表现粘度迅速增加，表现出明显的疏水缔合行为，与HPAM相比有优异的抗盐性。     

Supramolecular assemblies of a naturally derived sophorolipid

Acidic sophorolipid (SL) molecules derived from yeasts represent a novel type of asymmetrical bolaamphiphiles due to their unique structural features that include an asymmetrical polar head size (disaccharide vs COOH), a kinked hydrophobic core (cis-9-octadecenoic chain), and a non-amide polar-nonpolar linkage. Light microscopy, small- and wide-angle X-ray scattering, FT-IR spectroscopy, and dynamic laser light scattering were used to investigate the supramolecular structures of the self-assembled aggregates of SL molecules at different pH values. In acidic conditions (pH < 5.5), giant twisted and helical ribbons of 5-11 microm width and several hundreds of micrometers length were observed for the first time. Increase in solution pH values slowed ribbon formation, decreased ribbon yield, and increased the helicity and entanglements of the giant ribbons. An interdigitated lamellar packing model of acidic SL-COOH molecules with a long period of 2.78 nm, stabilized by both the strong hydrophobic association between the cis-9-octadecenoic chains and strong disaccharide-disaccharide hydrogen bonding, is proposed. The neutralization of SL-COOH in water to SL-COONa produced clear solutions with the formation of short-range ordered aggregates. At concentrations below 1.0 mg/mL, the size of self-assembled aggregates increased as the concentration increased. At concentrations above 1.0 mg/mL, narrowly distributed micellar aggregates with a constant hydrodynamic radius (R(h)) of about 100 nm are formed. The large micelles show strong angular dependence with the fast mode appearing at scattering angle theta >/= 60 degrees.     

库仑滴定法测定有机硅样品中的氮含量

本文利用库仑滴定法研究了高分子和低分子硅氮化合物及含氮有机硅样品中氮含量的测定,并研究和讨论了影响测定结果准确性的因素。     

免疫亲和柱净化/柱前衍生化-高效液相色谱荧光检测法测定粮谷中的T-2毒素

建立了免疫亲和柱净化/柱前衍生化-高效液相色谱荧光检测器测定粮谷中T-2毒素含量的方法。样品经甲醇-水(体积比为80∶20)混合溶剂提取,通过免疫亲和柱(IAC)净化,以氰酸蒽(1-AN)为衍生化试剂、4-二甲基氨基吡啶(DMAP)为催化剂进行衍生,以ZORBAX Eclipse XDB-C18 柱为分离柱,乙腈-水(体积比为80∶20)为流动相进行高效液相色谱分离及荧光检测，荧光检测的激发波长为381 nm，发射波长为470 nm。T-2毒素的质量浓度为0.01~1.5 mg/L时与峰高呈良好的线性,相关系数为0.9985。在0.01~1.5 μg/g添加水平下，回收率为79.7%~94.5%,相对标准偏差小于7%；检出限（S/N＝3）为0.01 μg/g。该方法净化效果好,灵敏度高,操作简便快速。     

Reduction of Secondary Carboxamides to Imines

This article reports in detail on the discovery that zirconium(IV) salts of secondary amides and lactams are transformed by Cp(2)ZrHCl to N-substituted imines in one step. The method represents the first controlled reduction of amides and lactams to the corresponding imines, a transformation that is otherwise very difficult to achieve because imines are reduced more rapidly than carboxamides by most metal hydride reagents. No products of reductive cleavage of the carboxamides are observed. Efforts to replace 2 mol equiv of Cp(2)ZrHCl with simpler, less costly alternatives led to the finding that a diisobutylaluminum enolate can be substituted for the initial zirconium enolate. Such aluminum amides are smoothly reduced to the corresponding imine using Cp(2)ZrHCl in good yield. Moreover, aluminum amides are also reduced to imines using either low-valent titanium species or triethylsilane. In these alternative procedures, use of Cp(2)ZrHCl is eliminated altogether in the title transformation.     

Self-assembled hybrid nanofibers confer a magnetorheological supramolecular hydrogel

Most magnetorheological materials, composed of magnetic microparticles in a liquid, require significant amounts of magnetic particles and a large magnetic field to achieve the desired effects. Here, we report on a new type of magnetorheological materials consisting of small amounts of magnetic nanoparticles (0.8 wt %) but exhibiting large rheological change (i.e., a gel-sol transition) upon the application of a small magnetic field. We use self-assembly to create hybrid nanofibers, which consist of supramolecular hydrogelators and magnetic nanoparticles, as the matrices of the hydrogel. Localized in the nanofibers at a distance of 1-2 nm, the magnetic nanoparticles occupy a small volume fraction of the hydrogel, significantly enhancing the magnetic dipole interactions between them, which results in the large magnetoresponse. This strategy generates a hierarchical nanostructure and eliminates several drawbacks of the simple mixture of polymers with nanoparticles, and thus provides a new methodology that uses magnetic force to control the nanostructures and properties of soft materials.     

新型6-氟-4(3H)-喹唑啉酮类Schiff碱的合成及其抑菌活性

以2-氨基-5-氟苯甲酸为起始原料，与醋酐酰化关环制得6-氟-2-甲基噁嗪-4-酮(1)； 1在80%水合肼中回流反应制得6-氟-2-甲基-3-氨基-4(3H)-喹唑啉酮(2)； 2分别与羟基芳醛和杂环芳醛反应合成了6个6-氟-4(3H)-喹唑啉酮类Schiff碱（3a~3f），其中3b~3f为新化合物，其结构经¹H NMR， ¹³C NMR， IR和元素分析表征。采用琼脂扩散法研究了3a~3f对大肠杆菌、金黄色葡萄球菌和枯草杆菌的抑制活性。结果表明：用药浓度为400 μg·mL^-1时，3a~3f对受试菌种均有一定的抑制活性，其中6-氟-2-甲基-3-(4-吡咯苯亚甲氨基)-4(3H)-喹唑啉酮(3c)抑菌活性最强，对大肠杆菌和枯草杆菌的抑菌圈直径分别为9.38 mm和9.00 mm。