均分散胶体的研究 V. 锆化合物均分散颗粒的制备

根据部分稳定氧化锆陶瓷(PSZ)的增韧机制,减小陶瓷粉料ZrO_2颗粒的尺寸是提高陶瓷韧性及其它机械性能的关键,因此合成细微ZrO_2粉料的研究开展得十分活跃.韩利成等用液相沉淀法制备尺寸在微米级以下的氢氧化锆颗粒.村濑嘉夫等在H_2O_2存在下升温水解ZrOCl_2溶液,制备ZrO_2超细颗粒.从所发表的透射电子显微镜(TEM)照片看,他们所制得的颗粒形状和尺寸都不均一,而且粘连,恐难以满足烧制高韧性PSZ     

The Generalization on Inequalities of Hermite-Hadamard's Integration

Some new inequalities of Hermite-Hadamard's integration are established.As for as inequalities about the righthand side of the classical Hermite-Hadamard's integral inequality refined by S Qaisar in [3],a new upper bound is given.Under special conditions,the bound is smaller than that in [3].     

离子液体电沉积CuInxGa1-xSe2薄膜

采用循环伏安法(CV)对离子液体Reline中三元CuCl₂+InCl₃+SeCl₄体系和四元CuCl₂+InCl₃+GaCl₃+SeCl₄体系的电化学行为进行了研究。研究表明,In³⁺并入三元CIS(Cu-In-Se)薄膜体系和Ga³⁺并入四元CIGS(Cu-In-Ga-Se)薄膜体系均有两种途径：一是发生共沉积,二是直接还原。利用电感耦合等离子体发射光谱(ICP)和扫描电镜(SEM)对沉积电势、镀液温度和主盐浓度对CIGS薄膜组成、镀层表面形貌的影响进行了测试,结果表明通过工艺参数的选择可以控制Ga/(Ga+In)和CIGS薄膜组成并得到化学计量比为Cu_1.00In_0.78Ga_0.27Se_2.13的薄膜。     

磁载光催化剂Fe3O4/C/TiO2的制备及对三氯苯酚的降解

以FeCl3为铁源,葡萄糖为碳源,钛酸四丁酯为钛源,采用水热法制备了磁载光催化剂Fe3O4/C/TiO2,用TEM、EDX、VSM、XRD和IR对Fe3O4/C/TiO2的粒径、形貌和物相等进行了表征。研究了该催化剂对三氯苯酚的降解性能,探讨了其重复使用的可能性,用荧光光谱法推测了可能的反应机理。结果表明该材料结合了光催化与可再生的优点,1 g·L-1 Fe3O4/C/TiO2在18 W紫外灯下,50 min内可将三氯苯酚降解97.9%以上,6次循环使用后降解率仍保持在95.1%,降解过程中有羟基自由基生成。     

Regulating the Oil-Water Interface to Construct Double Emulsions: Current Understanding and Their Biomedical Applications

Double emulsions have been extensively used in scientific researches and industrial applications due to their attractive unique feature of multiple phases. However, constructing droplets with such a complex structure is not a simple task for all time. The simultaneous existence of two contradictory interfaces makes it hard to prepare stable double emulsions in principle and in practice. Over the past century, tremendous efforts have been devoted by myriads of scientists to make progresses in both theory and preparation of double emulsions. In this review, the current understanding of double emulsions is systematically revealed. In addition to emphasizing the corresponding pioneer and landmark works as many as possible, the state-of-the-art achievements will also be discussed. By regulating the oil-water interface with smartly designed interface-active agents in combination with varying the phase volume fractions, the basic theory framework based on the phase inversion from simple emulsions to double emulsions is also summarized. Technical preparation strategies of emulsification are introduced to show the building process of the two contradictory interfaces in one system. Furthermore, some specific biomedical applications of double emulsions are also discussed, which is expected to stimulate further innovation and utilization of double emulsions.     

马面鲀鱼皮复制及润湿性研究

以具有防污功能的马面鲀皮为生物复制模板,采用铸膜方法对其微观形貌进行了大面积复制,并对复制表面的润湿性进行了分析研究。研究结果表明,复制的PDMS样品表面产生了与生物样品一致性较好的绒毛结构。该结构大大增加了表面的疏水性,将使海洋生物附着的难度大幅度增大,从而改善表面的污损释放性能。     

保留时间两点校正反相高效液相色谱法测定持久性有机污染物的正辛醇-水分配系数

采用改进的反相高效液相色谱法(RP-HPLC)测定了持久性有机污染物(POPs)包括多环芳烃(PAHs)、多氯二苯并二恶英(PCDDs)、多氯二苯并呋喃(PCDFs)和十溴二苯乙烷(DBDPE)等的正辛醇-水分配系数(logKow)。采用保留时间双点校正法(DP-RTC)校正因色谱柱老化等引起的保留时间漂移。以37种有可靠logKow实验值的苯系物、PAHs、PCDD/Fs类似物为模型化合物,建立了logKow和外推至纯水相的保留因子logkw的定量结构-色谱保留关系(QSRR)模型,回归方程为logKow=(1.18±0.02)logkw+(0.36±0.11),其相关系数(R2)为0.985,交叉验证相关系数(R2cv)为0.983,标准偏差(SD)为0.16。进而,用4个已有可靠logKow实验值的验证化合物(联苯、芴、PCDD 1和PCDF 114)对模型进行了外部验证,表明RP-HPLC测得的logKow值与摇瓶法/慢搅法结果有很好的一致性,尤其是对疏水性强的化合物。采用该模型测定了29种特别受关注的POPs的logKow值,这些化合物的logKow实验值均未见报道。所建立的DP-RTC-HPLC是测定强疏水性POPs的logKow值的一种值得推荐的方法。     

生物基超韧聚乳酸复合材料的制备与性能

采用来源于可再生资源的聚醚酰胺弹性体（PEBA）增韧聚乳酸（PLA）制备超韧聚乳酸（PLA/PEBA-GMA）复合材料.为了提高PEBA与PLA之间的相容性,选择极性单体甲基丙烯酸缩水甘油酯（GMA）、共接枝单体乙烯基吡咯烷酮（NVP）及引发剂过氧化二异丙苯（DCP）对PEBA进行接枝改性制备PEBA-GMA.研究了接枝单体组分的用量（m/g）对PLA/PEBA-GMA复合材料性能的影响.研究发现,随着接枝单体组分用量的提高,复合材料的缺口冲击强度逐渐增大,当接枝单体组分GMA,NVP和DCP的用量分别为2.5,2.5和0.25 g时,复合材料的冲击强度高达88.6 kJ/m²,断裂伸长率为164.1%.研究表明,在熔融共混过程中,聚乳酸的端基（—OH和—COOH）与PEBA-GMA上环氧基团发生反应,有效改善两相间的界面相容性,随着接枝单体组分比例的提高,分散相PEBA-GMA的粒子尺寸逐渐减小且分布均匀.     

Fast and Selective Semihydrogenation of Alkynes by Palladium Nanoparticles Sandwiched in Metal–Organic Frameworks

The semihydrogenation of alkynes into alkenes rather than alkanes is of great importance in the chemical industry. Unfortunately, state-of-the-art heterogeneous catalysts hardly achieve high turnover frequencies (TOFs) simultaneously with almost full conversion, excellent selectivity, and good stability. Here, we used metal–organic frameworks (MOFs) containing Zr metal nodes (“UiO”) with tunable wettability and electron-withdrawing ability as activity accelerators for the semihydrogenation of alkynes catalyzed by sandwiched palladium nanoparticles (Pd NPs). Impressively, the porous hydrophobic UiO support not only leads to an enrichment of phenylacetylene around the Pd NPs but also renders the Pd surfaces more electron-deficient, which leads to a remarkable catalysis performance, including an exceptionally high TOF of 13835 h⁻¹, 100 % phenylacetylene conversion 93.1 % selectivity towards styrene, and no activity decay after successive catalytic cycles. The strategy of using molecularly tailored supports is universal for boosting the selective semihydrogenation of various terminal and internal alkynes.     

Total Syntheses of Norrisolide‐Type Spongian Diterpenes Cheloviolene C,Seconorrisolide B,and Seconorrisolide C

The first total syntheses of three unusual norrisolide‐type rearranged spongian diterpenes, cheloviolene C, seconorrisolide B, and seconorrisolide C, have been accomplished via a common intermediate through late‐stage ring‐scissoring. The synthesis features a Wolff ring contraction for the synthesis of the trans‐hydrindane system, and a crucial retro Diels–Alder reaction/intramolecular ene cyclization for the rapid stereoselective construction of the furo[2,3‐b]furan system, which is commonly seen in rearranged spongian diterpenes.