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 ;…     

应变速率和电位对应力腐蚀裂纹扩展的影响

以滑移-溶解-再钝化模型为基础,推导出应力腐蚀裂纹扩展速率与裂尖应变速率和电位之间的理论公式.计算表明,在裂纹扩展速率与裂尖应变速率的关系曲线中有两个特征区域.裂纹扩展速率在区域I随裂尖应变速率增加而增大,而在区域II不随裂尖应变速率的改变而变化.用慢应变速率拉伸技术（SSRT）测量了304L不锈钢的裂纹增长速率.当电位控制在区域II的阳极区时,理论计算的裂纹扩展速率与实验得到的结果比较吻合.     

Remarkable nanosize effect of zirconia in Au/ZrO2 catalyst for CO oxidation

Nanosize effect of ZrO2 in Au/ZrO2 catalyst was studied by deposition-precipitation of Au nanoparticles in similar sizes (4-5 nm) on ZrO2 nanoparticles of varying sizes. The catalysts were characterized with XRD, TEM, XPS, and nitrogen adsorption to understand the effect of ZrO2 particle size on the catalytic nanostructures. Nanocomposite Au/ZrO2 catalysts consisting of comparably sized Au-metal (4-5 nm) and ZrO2 (5-15 nm) nanoparticles are found advantageous over those containing similarly sized Au-metal but larger ZrO2 (40-200 nm) particles for CO oxidation. This finding may have important implications on the designed preparation of advanced nanostructured catalysts and other chemical materials.     

The Intelligent Properties of Micro－reactors for Preparating Nanoparticles

TiO2 nanoparticles were synthesized by using micro-reactors. The shape and size of the nanoparticles produced from the original micro-reactors and the five times recycled micro-reactorsmother liquor were investigated on transmission electron microscopy (TEM) by using the original sample, freeze prepared sample, and dyeing treated sample, respectively. UV-VIS spectrometry was used to study the growth process of TiO2 nanoparticles in main reactors. The results showed that micro-reactors with nanometer magnitude had spherical or oval structures, and could restore to their original structure after they were destroyed. The products prepared in the original micro-reactors were similar to that in the micro-reactors recycled for many times, suggesting that the micro-reactors had memory function.     

Two New Steroidal Saponins from Tacca plantaginea

Two new C27 steroidal glycosides, named taccaoside A(1) and B(2), were isolated from the traditional Chinese herb Tacca plantaginea. The spectroscopic and chemical evidences revealed their structures to be 26-O-β-D-glucopyranosyl-(25R)-3β,26-dihydroxy furost-5,20-diene-3-O-[α-L-rhamnopyranosyl(1→2)]-[α-L-rhamnopyranosyl(1→3)]-β-D-glucopyranoside(1) and 26-O-β-D-glucopyranosyl-(25R)-3β,26-dihydroxy furost-5,20-diene-3-O-[α-L-rhamnopyranosyl-(1→2)]-[β-D-glucopyranosyl(1→3)-α-L-rhamnopyranosyl(1→3)]-β-D-glucopyranoside(2),respectively.     

Coaxial electrospinning core-shell fibers for self-healing scratch on coatings

Polystyrene (PS) fibers with core-shell structure were prepared by coaxial electrostatic spinning using liquid epoxy or curing agent as the core and PS solution as the shell. Scratch self-healing coatings were realized by using the healant-loaded core-shell fibers in the matrix.     

南药巴戟天中十二种无机元素与药效关系的进一步研究

在初步研究的基础上，进一步研究了不同产地巴戟天的无机元素含量差异，通过对比各元素含量、相关系数及TE图谱，说明地道药材与非地道药材的巴戟天，其特征元素的含量存在非常明显的差异，要使大面积扩种的药材提高药效，建议根据当地土壤含Mn、Fe、Cr、Co、Ni的含量，以旋微量元素肥料的方法来补充这些元素在土壤中的不足。但在微量元素肥料配方中，应注意巴戟天吸收土壤中的元素时的协同作用和拮抗作用。     

超声辐射下某些含官能团化合物与二氯卡宾的反应

超声辐射在有机反应中的应用日趋广泛。我们曾报道了超声辐射与相转移催化相结合产生二氯卡宾和二溴卡宾的方法及其与烯烃加成反应的结果。该法比单纯使用相转移催化剂或超声辐射更为可取。本文进一步将它用于二氯卡宾与某些含官能团化合物的反应,考察超声辐射的影响。反应是在固-液两相条件下进行的,即以粉末状氢氧化钠为碱,氯仿过量兼作溶剂。结果表明,超声辐射对各类化合物反应的影响有相当明显的差异。     

氟烷基化C_(60)与四（N，N-二甲基）氨基乙烯电荷转移复合物磁性的EPR研究

变温ERP研究揭示氟烷基化富勒烯C_(60)(R_f)_n与四(N,N-二甲基)氨基乙烯 (TDAE)间稳定的电荷转移络合物TDAE-C_(60)(R_f)_n的居里温度高达190K[R_f = C_3F_7，H（CF_2）_4]。而非氟烷基化络合物TDAE-C_(60)的相应值仅为16.1K。 这种铁磁性可能是络合物分子中氟烷基化富勒烯多价阴离子基在相应居里温度下具 有某种有序排列的缘故。     

Order from Chaos: Self‐Assembly of Nanoprism from a Mixture of Tetratopic Terpyridine‐Porphyrin Conformers

Porphyrins have been widely used in the self‐assembly of metallo‐supramolecules. In this study, we introduced 2,2':6,2"‐terpyridine (tpy) into a porphyrin core to synthesize a tetratopic building block with multiple conformers. During the self‐assembly with Zn(II), such a mixture of conformers was able to form a discrete nanoprism with all building blocks in one conformation. Detailed characterizations, including NMR, ESI‐MS and traveling‐wave ion mobility‐mass spectrometry (TWIM‐MS), all supported the formation of the desired assemblies. AFM and TEM further confirmed the dimensions of assembled nanoprisms. Moreover, the photophysical properties of the ligands and complexes were noticeably different depending upon size and metal ion center.