废水中Cr(Ⅲ)的吸附热力学和动力学研究进展

含铬废液中三价铬含量控制是含铬废液处理的重要组成部分。作为微量元素,体内含铬量不能超标吸收或体内缺失。铬在不同情形下显示不同形态化学变化。三价铬吸附热力学与动力学为从宏观和微观角度理解三价铬在吸附剂上的吸附行为提供理论基础。本文介绍铬价态变化、三价铬含量的传统与最新测试方式,分析近期三价铬吸附相关文献的吸附热力学与动力学成果,为进一步准确分析三价铬的吸附热力学函数和吸附参数随时间的变化提供理论依据,并指出目前的废水Cr(Ⅲ)吸附热力学与动力学中的研究空白。     

Real‐Time and High‐Resolution Bioimaging with Bright Aggregation‐Induced Emission Dots in Short‐Wave Infrared Region

Fluorescence imaging in the spectral region beyond the conventional near‐infrared biological window (700–900 nm) can theoretically afford high resolution and deep tissue penetration. Although some efforts have been devoted to developing a short‐wave infrared (SWIR; 900–1700 nm) imaging modality in the past decade, long‐wavelength biomedical imaging is still suboptimal owing to the unsatisfactory materials properties of SWIR fluorophores. Taking advantage of organic dots based on an aggregation‐induced emission luminogen (AIEgen), herein microscopic vasculature imaging of brain and tumor is reported in living mice in the SWIR spectral region. The long‐wavelength emission of AIE dots with certain brightness facilitates resolving brain capillaries with high spatial resolution (≈3 µm) and deep penetration (800 µm). Owning to the deep penetration depth and real‐time imaging capability, in vivo SWIR microscopic angiography exhibits superior resolution in monitoring blood–brain barrier damage in mouse brain, and visualizing enhanced permeability and retention effect in tumor sites. Furthermore, the AIE dots show good biocompatibility, and no noticeable abnormalities, inflammations or lesions are observed in the main organs of the mice. This work will inspire new insights on development of advanced SWIR techniques for biomedical imaging.     

NIR-IIb excitable bright polymer dots with deep-red emission for in vivo through-skull three-photon fluorescence bioimaging

Nano Research - It is of great significance to study the brain structure and function in deep-tissue for neuroscience research and bio-medical applications because of the urgent demand for precise...     

双(3-烷氧基-2-羟基)丙基双季铵盐阳离子表面活性剂的合成与表征

以长链烷基醇、四甲基乙二胺和环氧氯丙烷为原料,经一步反应合成了双季铵盐阳离子表面活性剂(BQAS)。研究了反应时间、反应温度对BQAS产率的影响,确定了合成目标产物的最佳反应时间为24～32h、反应温度为70～80℃,其产率达70.2%～83.3%。目标产物结构通过IR和1HNMR确证。利用吊环法测定目标产物的水溶液在20℃的表面活性,临界胶束浓度(CMC)为7.6×10-6～9.5×10-4mol.L-1,表面张力(γCMC)为34.2～40.6mN.m-1。     

漏极散射机制对弹道和非弹道沟道应变硅二极管中电子输运特性的影响

在漏极区域，多重散射对于沟道区域有无散射的应变硅二极管中电子传输性能的影响进行了数值研究。使用应变和散射模型，对于非弹道（有散射）沟道硅二极管的性能与弹道（无散射）沟道的硅二极管的性能进行了比较研究。研究结果表明应变模型中的电子速度和电流的值比无应变模型的相应值更高，弹道沟道模型中的电子速度和电流的值比非弹道沟道模型中的相应值更高。使用应变和散射模型，漏极区域中的每个散射机制对于硅二极管性能的影响进行了分析。对于弹道沟道模型，结果表明谷间光学声子散射会提高器件的性能，而谷内声学声子散射会降低器件的性能。对于应变模型，结果表明较大应变硅能带分裂可以抑制谷间声子散射率。总而言之，为了提高纳米级弹道器件性能，对于漏极区域应变和散射机制模型的研究是很有必要的。     

离子型糖基表面活性剂的合成研究进展

详细综述了近年来国内外对离子型糖基表面活性剂的合成研究成果,按照其结构特点对其进行归纳和总结,主要介绍了阴离子型、阳离子型、两性离子型和阴阳离子型糖基表面活性剂的合成方法和制备过程,并展望了其合成研究发展方向.     

Postharvest Control of Green Mold Decay of Citrus Fruit Using Combined Treatment with Sodium Bicarbonate and Rhodosporidium paludigenum

The objective of this study was to analyze the impact of the marine yeast Rhodosporidium paludigenum and sodium bicarbonate (SBC) treatments applied separately or in combination to control green mold of two cultivars of citrus fruit (Citrus reticulata Blanco cv. Subcompressa and C. reticulata Blanco cv. Ponkan) caused by Penicillium digitatum. In the assay of C. reticulata Blanco cv. Subcompressa, R. paludigenum at 10⁷ cells/mL significantly (P?<?0.05) reduced green mold incidence compared to the control, and the combination of 10⁷ cells/mL R. paludigenum and 5 % SBC was as effective as fungicide (500 ppm Fungaflor). In the assay of C. reticulata Blanco cv. Ponkan, the treatment with R. paludigenum at 10⁸ cells/mL and 2 % SBC were equally effective and significantly (P?<?0.05) reduced the decay incidence. Moreover, the combination of the two treatments completely eliminated the decay incidence, matching the effectiveness of fungicide. This work demonstrated that proper combination of R. paludigenum and SBC can be an alternative to synthetic fungicides for the control of postharvest green mold decay of citrus.     

Ultrastable and Biocompatible NIR‐II Quantum Dots for Functional Bioimaging

Fluorescence bioimaging in the second near‐infrared spectral region (NIR‐II, 1000–1700 nm) can provide advantages of high spatial resolution and large penetration depth, due to low light scattering. However, NIR‐II fluorophores simultaneously possessing high brightness, good stability, and biocompatibility are very rare. Hydrophobic NIR‐II emissive PbS@CdS quantum dots (QDs) are surface‐functionalized, via a silica and amphiphilic polymer (Pluronic F‐127) dual‐layer coating method. The as‐synthesized PbS@CdS@SiO₂@F‐127 nanoparticles (NPs) are aqueously dispersible and possess a quantum yield of ≈5.79%, which is much larger than those of most existing NIR‐II fluorophores. Thanks to the dual‐layer protection, PbS@CdS@SiO₂@F‐127 NPs show excellent chemical stability in a wide range of pH values. The biocompatibility of PbS@CdS@SiO₂@F‐127 NPs is studied, and the results show that the toxicity of the NPs in vivo could be minimal. PbS@CdS@SiO₂@F‐127 NPs are then utilized for in vivo and real‐time NIR‐II fluorescence microscopic imaging of mouse brain. The architecture of blood vessels is visualized and the imaging depth reaches 950 µm. Furthermore, in vivo NIR‐II fluorescence imaging of gastrointestinal tract is achieved, by perfusing PbS@CdS@SiO₂@F‐127 NPs into mice at a rather low dosage. This work illustrates the potential of ultrastable, biocompatible, and bright NIR‐II QDs in biomedical and clinical applications, which require deep tissue imaging.     

N-氨基酰基甲脒类化合物的合成研究

以N-取代脲和甲酰胺为原料,合成了一系列N-氨基酰基甲脒类化合物,讨论了活化剂、溶剂、反应温度及底物投料比对反应的影响。结果表明,以草酰氯为活化剂、二氯甲烷为溶剂,在n(N-取代脲)∶n(甲酰胺)∶n(草酰氯)为1.0∶1.5∶1.2时,室温反应1～4 h可得到产率高达98%的目标化合物。该方法具有底物范围广、操作简便、反应条件温和、反应时间短、产率高等优点。