增强吸收型光双稳临界现象的平均场理论

阐明临界现象（包括两类临界点）与相变的平均场（Ｌａｎｄａｕ）理论同样可以适用于增强吸收型光学双稳性（ＩＡＯＢ）．分析了近期提出的ＩＡＯＢ模型^[９］的动力学特征，在此基础上引入了一种准热力学势。在临界点（第二类）附近，该种势不仅体现出双稳系统中相变的共性，而且也反映了ＩＡＯＢ的特殊性。 关键词：     

RCM-based synthesis of a variety of beta-C-glycosides and their in vitro anti-solid tumor activity

The synthesis of a number of biologically relevant C-glycosides has been carried out through the use of an esterification-ring-closing metathesis (RCM) strategy. The required acid precursors were readily prepared via a number of standard chemical transformations followed by dehydrative coupling of these acids with several olefin alcohols 1 to yield the precursor esters 3 in excellent yield. Methylenation of the esters 3 was followed by RCM and in situ hydroboration-oxidation of the formed glycals to furnish the protected beta-C-glycosides 6 in good overall yield. Several examples were converted to the corresponding C-glycoglycerolipids 17 and subsequently screened against solid-tumor cell lines for in vitro differential cytotoxicity.     

Fabrication of Co/CoO Exchange Bias System by Ion Implantation and Its Magnetic Properties

We use ion implantation as a new approach to build an anti-ferromagnetic （AFM） cluster embedded exchange bias （EB） system. Co film with thickness of 130nm is deposited on the Si （111） substrate using magnetron sputtering, 60keV O＋ is chosen to implanted into the Co film to form CoO AFM clusters coupling with Co matrix at the interface. By measuring the hysteresis loop after field-cooling, significant shifts of loop along the applied field are confirmed. When increasing the implantation dose to 2×1017/cm2 and annealed samples in N2 atmosphere, we obtain the highest HEB to 458Oe.     

Colorimetric Artificial Nose for Identification of Breath Volatile Organic Compounds of Patients with Lung Cancer

A novel and highly sensitive colorimetric sensor array was developed for the detection and identification of breath volatile organic compounds（VOCs） of patients with lung cancer.Employing dimeric metalloporphyrins,metallosalphen complexes,and chemically responsive dyes as the sensing elements,the developed sensor array of artificial nose shows a unique pattern of colorific changes upon its exposure to eight less-reactive VOCs and their mixture gas at a concentration of 735 nmol/L within 3 min.Potential of quantitative analysis of VOCs samples was proved.A good linear relationship of 490-3675 nmol/L was obtained for benzene vapor with a detection limit of 49 nmol/L（S/N=3）.Data analysis was carried out by Hierarchical cluster analysis（HCA） and principal component analysis（PCA）.Each category of breath VOCs clusters together in the PCA score plot.No errors in classification by HCA were observed in 45 trials.Additionaly,the colorimetric sensor array showed good reproducibility under the cyclic sensing experiments.These results demonstrate that the developed colorimetric artificial nose system is an excellent sensing platform for the identification and quantitative analysis of breath VOCs of patients with lung cancer.     

纳米碳酸钙基浅色导电粉的制备及性能研究

以纳米碳酸钙为核体,用聚电解质对其表面改性后,采用均相共沉淀法制备了锡掺杂氧化铟(ITO)包覆的碳酸钙基浅色导电粉.通过改变聚电解质层数、ITO的包覆量及煅烧时间等实验条件,探究了制备纳米碳酸钙基浅色导电粉的最佳条件.用X-射线粉末衍射仪、扫描电子显微镜、X-射线电子能谱以及粉末电阻率测试仪等对样品的结构、形貌、化学组成及电阻率等进行分析.结果表明:聚电解质层数为5层,CaCO3与ITO的质量比为6∶1,500℃煅烧4.5h制备的粉末具有最佳的导电性能,其电阻率为3.8×103 Ω·cm.     

pH值对水热合成磷酸铋的光催化性能的影响

利用水热法通过调节溶液的pH值合成了不同物相和形貌的磷酸铋.用X射线衍射仪(XRD)和扫描电子显微镜(SEM)对样品进行了物相和形貌表征,并以10 mg·L-1的亚甲基蓝溶液为目标降解物,对材料的光催化降解性能进行了评价.结果表明:前驱物溶液的pH值对磷酸铋的形貌、物相和光催化性能都有较大影响.前驱物溶液pH值为1.3时制得的磷酸铋的光催化性能最高,室温汞灯照射20 min,亚甲基蓝的降解率可达到99.61;.     

一种新型可光降解的PVC-OA-TiO_2纳米复合膜

采用包埋技术制备了一种新型可光降解的聚氯乙烯-草酸-TiO_2(PVC-OA-TiO_2)纳米复合膜,并研究了紫外光照射条件下该复合膜的光催化降解情况.结果表明,该纳米复合膜的光催化降解是一个氧化断链过程,经紫外光照射310 h后失重率达到55%,是PVC-TiO_2复合膜的2倍,是纯PVC膜的3.5倍,说明草酸的掺杂可以促进PVC-OA-TiO_2复合膜更快地被光降解.草酸作为一个良好的电子给体,能不可逆地与TiO_2表面产生的空穴或表面羟基反应,抑制电子和空穴的复合,从而显著提高PVC-OA-TiO_2的光催化降解速率.     

利用卟啉中位羧基基团直接缩合卟啉二聚体

卟啉单体的直接偶合法. 这种方法包括有β-β, meso-β直接连接的二聚体[8,9]和直接连接的N混杂的卟啉二聚体[10]. 我们利用二环己烷基羰化二亚胺(DCC)作催化剂, 在冰盐浴条件下, 通过两个5-(p-羧基苯基)-10,15,20-三苯基卟啉(H2CPTPP)周边上的羧酸基团一步直接缩合获得以羧酸酐连接的新型卟啉二聚体. 利用多种光谱手段证实所合成的物质为目标产物. 该方法具有反应物单一、 反应步骤简单、 副反应少、 产物纯化方便、 时间短和产率高等优点.