Side reactions in controlling the quality, yield, and stability of high quality colloidal nanocrystals

Effects of side reactions during the formation of high quality colloidal nanocrystals were studied using ZnO as a model system. In this case, an irreversible side reaction, formation of esters, was identified to accompany formation of ZnO nanocrystals through the chemical reaction between zinc stearate and an excess amount of alcohols in hydrocarbon solvents at elevated temperatures. This irreversible side reaction made the resulting nanocrystals stable and with nearly unity yield regardless of their size, shape, and size/shape distribution. Ostwald ripening and intraparticle ripening were stopped due to the extremely low solubility/stability of the possible monomers because all free ligands in the solution were consumed by the side reaction. However, focusing on size distribution and 1D growth that are needed for the growth of high quality nanocrystals could still occur for high yield reactions. Upon the addition of a small amount of stearic acid or phosphonic acid, immediate partial dissolution of ZnO nanocrystals took place. Although the excess alcohol could not react with the resulting zinc phosphonic acid salt, it could force the newly formed zinc stearate gradually but completely back onto the existing nanocrystals. The results in this report indicate that side reactions are extremely important for the formation of high quality nanocrystals by affecting their quality, yield, and stability under growth conditions. Due to their lack of information in the literature and obvious practical advantages, studies of side reactions accompanying formation of nanocrystals are important for both fundamental science related to crystallization and industrial production of high quality nanocrystals.     

Assessment of ultrasound pulsation loops for measurement of local pulse wave velocity of carotid artery

Flow-area (QA) method and ln(diameter)-velocity (ln(D)U) methods based on si-multaneous measurements of velocity (U) and arterial diameter (D) using ultrasound ...     

低温翅片管换热器的传热试验研究

为了研究翅片管换热器在低温工况下的传热性能,进行了翅片管汽化器的气化试验。采用低温热电偶连续测量翅片管汽化器8个不同位置的温度,得到8条温度曲线。分析曲线表明气化过程可归结为非稳态与稳态两个阶段,并经历液相、汽液两相及气相三个传热区。试验结果为同类换热器的分段设计提供了依据。     

卷烟内在质量的气相色谱－数学聚类法研究

采用吸附丝色谱方法采集和分析了红塔山牌卷烟的挥发性成分,对 10个真品进行 R型聚类分析和 R型因子分析,从 26个组分提取出对卷烟质量起主导作用的 7个特征变量（组分）,并对其丰度进行了讨论,进而建立了红塔山卷烟的质量数学模型,用 2个真品和 2 个假冒品对模型进行了检验,结果令人满意。     

Synthesis of Isoquinoline-1, 3-Dicarboxylic Acid

Chiropticalluminescencemeasurementslhavebeenusedforstudyingchiralitydependentmolecularexcited-statedynamic,forstlldyingexcited-stateracemizationkineticsassociatedwithintermolecularchiralrecognitionprocessesinsolution2.Intheseprocesses,therearetwomolecularspecies,lanthanidecomplexes(luminophore)andresolvedtransitioncomplexes(AorA,quencher).Manykindsoftransitionmetalcomplexeshavebeenusedasquencherstoinvestigateinfluenceoftheintermolecularchiralrecognition.However,theluminophoreswereonlyconfined…     

含砂水对离心泵叶轮磨损的实验研究

黄河、长江流域的河水中泥砂含量较高,严重影响了这些地区输水水泵的使用寿命．本文利用固液两相流水泵实验台和一般的清水离心泵,在不同流量、不同砂粒粒径、不同含砂浓度条件下进行了磨损实验,弄清了上述参数对水泵叶轮磨损部位和程度的影响,为今后进一步探讨叶轮磨损机理和叶型改进提供了有益的实验资料。     

反箭形耦合腔微波电子枪腔结构

 研究了反箭形耦合腔微波电子枪腔体结构。它具有减少电子对阴极反轰、径向电场对称性好 、横向尺寸小、易制造、公差较低等优点。     

Fully synthetic Mincle-dependent self-adjuvanting cancer vaccines elicit robust humoral and T cell-dependent immune responses and protect mice from tumor development

A new strategy based on a macrophage-inducible C-type lectin (Mincle) agonist was established to construct synthetic cancer vaccines. Using sialyl-Tn (STn) as a model antigen, four conjugates with the Mincle agonist as a built-in adjuvant were designed and synthesized through a facile and efficient method. All conjugates could induce BMDMs to produce inflammatory cytokines in a Mincle-dependent manner and were found to elicit robust humoral and T cell-dependent immune responses alone in mice. The corresponding antibodies could recognize, bind and exhibit complement-dependent cytotoxicity to STn-positive cancer cells, leading to tumor cell lysis. Moreover, all conjugates could effectively inhibit tumor growth and prolong the mice survival time in vivo, with therapeutic effects better than STn-CRM197/Al. Notably, compared to conventional glycoprotein conjugate vaccines, these fully synthetic conjugate vaccines do not cause “epitope suppression.” Mincle ligands thus hold great potential as a platform for the development of new vaccine carriers with self-adjuvanting properties for cancer treatment. Preliminary structure–activity relationship analysis shows that a vaccine containing one STn antigen carried by vizantin exhibits the best efficacy, providing support for further optimization and additional investigation into Mincle agonists as the carrier of self-adjuvanting cancer vaccines.

A new strategy based on a Macrophage-inducible C-type lectin (Mincle) agonist was established to construct synthetic cancer vaccines.     

Photo-fabrication of surface relief gratings on polymer films

Surface relief gratings were optically produced on a number of azobenzene-based polymer films. The surface grating formation was investigated by monitoring the diffraction efficiency and using atomic force microscopy. The effect of the structure of the chromophores on surface modulation was investigated. The surface deformation process depended on the polarization state of the writing beams. The localized variations of the light intensity and alteration of the resulting electric field polarization were essential writing conditions to the formation of the surface relief gratings. The surface pattern from straight edge diffraction established that the surface profile of the recorded gratings is proportional to negative gradient of the intensity pattern incident on the polymer film.