A Dual‐Phase Ceramic Membrane with Extremely High H2 Permeation Flux Prepared by Autoseparation of a Ceramic Precursor

A novel concept for the preparation of multiphase composite ceramics based on demixing of a single ceramic precursor has been developed and used for the synthesis of a dual‐phase H₂‐permeable ceramic membrane. The precursor BaCe_0.5Fe_0.5O_3?δ decomposes on calcination at 1370 °C for 10 h into two thermodynamically stable oxides with perovskite structures: the cerium‐rich oxide BaCe_0.85Fe_0.15O_3?δ (BCF8515) and the iron‐rich oxide BaCe_0.15Fe_0.85O_3?δ (BCF1585), 50 mol % each. In the resulting dual‐phase material, the orthorhombic perovskite BCF8515 acts as the main proton conductor and the cubic perovskite BCF1585 as the main electron conductor. The dual‐phase membrane shows an extremely high H₂ permeation flux of 0.76 mL min^?1 cm^?2 at 950 °C with 1.0 mm thickness. This auto‐demixing concept should be applicable to the synthesis of other ionic‐electronic conducting ceramics.     

谈基础化学实验教学改革观念

教育改革成功的关键是改革者教育观念的改革,基础化学实验教学的改革应首先从教师的教育观念和教学方式的改变人手。明确基础化学实验教育的目的是为创新打好坚实的实验素质基础,在实验过程中于细节处渗透知识点、培养问题意识,同时应提高教师自身的科研素质。     

Cocaine reward and locomotion stimulation in mice with reduced dopamine transporter expression

Background  

The dopamine transporter (DAT) plays a critical role in regulating dopamine neurotransmission. Variations in DAT or changes in basal dopaminergic tone have been shown to alter behavior and drug responses. DAT is one of the three known high affinity targets for cocaine, a powerful psychostimulant that produces reward and stimulates locomotor activity in humans and animals. We have shown that cocaine no longer produces reward in knock-in mice with a cocaine insensitive mutant DAT (DAT-CI), suggesting that cocaine inhibition of DAT is critical for its rewarding effect. However, in DAT-CI mice, the mutant DAT has significantly reduced uptake activity resulting in elevated basal dopaminergic tone, which might cause adaptive changes that alter responses to cocaine. Therefore, the objective of this study is to determine how elevated dopaminergic tone affects how mice respond to cocaine.     

Synthesis and photoluminescence stability of non-conjugated polymers based on fluorene and benzoxazole

A kind of non-conjugated blue luminescent polymer based on fluorene and benzoxazole was synthesized via solution condensation polymerization from 2,2-bis(3-amino-4-hydroxyphenyl)-propane and 2,7-dicarboxyl-9,9-dioctyl-fluorene and was characterized with H NMR, FT-IR, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), UV-vis absorption and photoluminescence (PL) spectroscopy. The polymer displayed the maximum photoluminescence emission peak at 415 nm and showed high PL spectroscopic stability. The green-to-blue emission intensity ratio I_Green/I_Blue is only 0.073 even after thermal annealing at 150 °C for 30 h. After being exposed to UV light for 30 min, no bathochromic emission or obvious crosslink is observed. The common phenomenon of greenish blue emission of fluorene-based polymer around 525 nm has been effectively restrained in this polymer by introducing the isopropylidene group into the backbone of polymer.     

四臂聚乙二醇-聚丙交酯立体复合胶束及其药物传输性能

以异辛酸亚锡为催化剂,通过四臂聚乙二醇(4-armed PEG)引发右旋丙交酯(DLA)或左旋丙交酯(LLA)开环聚合合成四臂PEG-PLA对映体共聚物.通过纳米沉淀的方法制备了四臂PEG-b-PDLA胶束(PDM)、四臂PEG-b-PLLA胶束(PLM)和四臂PEG-b-PDLA/四臂PEG-b-PLLA立体复合胶束(SCM),并对其形貌、粒径、稳定性和立体复合机理等进行系统表征.以阿霉素(DOX)为模型抗肿瘤药物载入胶束中,与PDM和PLM相比,SCM具有更优异的药物负载能力.与DOX相比,载药四臂PEG-PLA胶束,尤其是负载DOX的SCM,表现出更优异的肿瘤细胞增殖抑制效果,作用更持久,并且对正常细胞的毒性较小,从而揭示了其作为潜在抗肿瘤药物载体的良好前景.     

Tailoring 3,3′‐Dihydroxyisorenieratene to Hydroxystilbene: Finding a Resveratrol Analogue with Increased Antiproliferation Activity and Cell Selectivity

Four novel compounds were designed by “tailoring” 3,3′‐dihydroxyisorenieratene (a natural carotenoid) based on an isoprene unit retention truncation strategy. Among them, the smallest molecule 1 (2,3,6,2′,3′,6′‐hexamethyl‐4,4′‐dihydroxy‐trans‐stilbene) was concisely synthesized in a one‐pot Stille–Heck tandem sequence, and surfaced as a promising lead molecule in terms of its selective antiproliferative activity mediated by blocking the NCI‐H460 cell cycle in G1 phase. Additionally, theoretical calculations and cell uptake experiments indicate that the unique polymethylation pattern of compound 1 significantly induces a conformational change shift out of planarity and increases its cell uptake and metabolic stability. The observation should be helpful to rationally design resveratrol‐inspired antiproliferative agents.     

离子色谱法测定水果及其树叶的含氯量

本文提出用离子色谱法测定水果及其树叶中氯含量的方法,在IC-PAK阴离子柱上,用4 mmol/L邻苯二甲酸(pH4.5)作流动相进行洗脱,电导检测器检测。方法简便、快速,灵敏、准确。氯的最小检出量为0.14μg,相对标准偏差为2.4%,回收率为99.4%。     

Salting-in/Salting-out Mechanism of Carbon Dioxide in Aqueous Electrolyte Solutions

The solvation of carbon dioxide in sea water plays an important role in the carbon circle and the world climate. The salting-out/salting-in mechanism of CO₂ in electrolyte solutions still remains elusive at molecule level. The ability of ion salting-out/salting-in CO₂ in electrolyte solution follows Hofmeister Series and the change of water mobility induced by salts can be predicted by the viscosity B-coefficients. In this work, the chemical potential of carbon dioxide and the dynamic properties of water in aqueous NaCl, KF and NaClO₄ solutions are calculated and analyzed. According to the viscosity B-coefficients, NaClO₄ (0.012) should salt out the carbon dioxide relative to in pure water, but the opposite effect is observed for it. Our simulation results suggest that the salting-in effect of NaClO₄ is due to the strongly direct anion-CO₂ interaction. The inconsistency between Hofmeister Series and the viscosity B-coefficient suggests that it is not always right to indicate whether a salt belongs to salting-in or salting-out just from these properties of the salt solution in the absence of solute.     

超级电容器用细菌纤维素基电极材料

超级电容器由于能提供比电池更高的功率密度,比传统电容器更高的能量密度而备受关注。但目前其应用仍存在能量密度低的问题。碳材料、金属氧化物和导电聚合物是常见的三种超级电容器电极材料,而其中不同形式碳材料是电容器中研究和应用最广泛的电极材料。细菌纤维素是由细菌分泌产生的具有一定纳米级孔径分布的多孔生物材料,具有高强度和模量、高孔隙率、极好的尺寸和热稳定性的特性。以细菌纤维素为原料制备电极材料是近年来超级电容器领域的热点研究方向之一。本文以细菌纤维素基电极材料的种类、制备方法和性能为线索,综述了国内外细菌纤维素基超级电容器电极材料的研究进展,并归纳总结了电极材料最优的形态和制备方法,进一步对该类电极材料的发展趋势进行了展望。