AIE材料合成、表征及其在防伪印刷中的应用

荧光防伪印刷技术即是将特殊的荧光印刷油墨融合到标识上,并借助额外的激发光才能找到加密信息,从而起到防伪作用。荧光防伪多在膜或固态下使用,因此需要荧光油墨在这些状态下具有强的发光性质。聚集诱导发光(Aggregation-Induced Emission,AIE)分子是一类在单分子状态下发光较弱甚至不发光而在聚集状态下表现出强烈发光的分子。而水杨醛席夫碱分子作为一类合成简单、荧光强度高的典型AIE分子,具备刺激响应荧光机制,其在酸碱环境下表现出不同的荧光特性使得这一类分子在防伪印刷领域有突出的表现。本论文通过水杨醛与胺的亲核加成反应一步制备水杨醛席夫碱AIE分子,并进一步展示其在防伪印刷中的应用;通过对该分子在不同环境下的表征,阐明其AIE特性和刺激响应荧光机制在防伪印刷应用中的作用。本实验原料易得、安全、成本低廉,所需仪器常规,符合实验教学要求,通过本实验训练,学生不仅掌握了席夫碱类化合物的制备方法,同时也学习了水杨醛席夫碱分子的刺激响应荧光在防伪印刷中的应用。结合课堂教学和拓展阅读,使学生进一步了解防伪印刷产品的特性以及设计思路。

Optimization of Preparation of Fe_(3)O_(4)-L by Chemical Co-Precipitation and Its Adsorption of Heavy Metal Ions

To address the serious pollution of heavy metals in AMD,the difficulty and the high cost of treatment,Fe_(3)O_(4)-L was prepared by the chemical co-precipitation method.Based on the single-factor and RSM,the effects of particle size,total Fe concentration,the molar ratio of Fe^(2+)to Fe^(3+)and water bath temperature on the removal of AMD by Fe_(3)O_(4)-L prepared by chemical co-precipitation method were analyzed.Static adsorption experiments were conducted on Cu^(2+),Zn^(2+)and Pb^(2+)using Fe_(3)O_(4)-L prepared under optimal conditions as adsorbents.The adsorption properties and mechanisms were analyzed by combining SEM-EDS,XRD and FTIR for characterization.The study showed that the effects of particle size,total Fe concentration and the molar ratio of Fe^(2+)to Fe^(3+)are larger.Obtained by response surface optimization analysis,the optimum conditions for the preparation of Fe_(3)O_(4)-L were a particle size of 250 mesh,a total Fe concentration of 0.5 mol/L,and a molar ratio of Fe^(2+)to Fe^(3+)of 1:2.Under these conditions,the removal rates of Cu^(2+),Zn^(2+),and Pb^(2+)were 94.52%,88.49%,and 96.69%respectively.The adsorption of Cu^(2+),Zn^(2+)and Pb^(2+)by Fe_(3)O_(4)-L prepared under optimal conditions reached equilibrium at 180 min,with removal rates of 99.99%,85.27%,and 97.48%,respectively.The adsorption reaction of Fe_(3)O_(4)-L for Cu^(2+)and Zn^(2+)is endothermic,while that for Pb^(2+)is exothermic.Fe_(3)O_(4)-L can still maintain a high adsorption capacity after five cycles of adsorption-desorption experiments.Cu^(2+),Zn^(2+)and Pb^(2+)mainly exist as CuFe_(2)O_(4),Zn(OH)2,ZnFe_(2)O_(4)and PbS after being adsorbed by Fe_(3)O_(4)-L,which is the result of the combination of physical diffusion,ion exchange and surface complexation reaction.

Combustion mechanism of fluorinated organic compound-modified nano-aluminum composite particles:Towards experimental and theoretical investigations

Fluorinated Organic Compounds(FOCs)are commonly used as modifiers for Aluminum(Al)powder to improve its ignition,combustion,and agglomeration characteristics.However,the effects of FOCs on combustion and inhibition mechanisms of agglomeration of Al powder are not well understood.In this paper,based on the experimental study of Fluorinated Graphite(FG)-modified Al matrix composite particles,the combustion and aggregation inhibition mechanisms of FOCs on Al particles were studied by the quantum chemical calculation at B3LYP/6-311+G(d,P)and G3//B3LYP/6-311+G(d,p)levels.The flame behavior and single particle burning behavior of FG-modified samples were compared through ignition experiments,and the characteristic spectra of Al related oxides of different samples in the initial ignition stage were captured.It is found that FG increases the burning intensity of Al composite samples significantly,while it decreases the emission intensity of Al secondary oxides.Quantum chemical calculation results show that the thermal decomposition intermediates of FOCs,namely C_(2)F_(4),can react with AlO and Al_(2)O,which weakens the characteristic emission intensity of AlO and Al_(2)O in the sample,and thus inhibits the formation of Al_(2)O_(3)in the combustion process.These results contribute to enriching the combustion dynamics model of Al-FOCs reaction system.

Analysis of multi-center topological domain states in BiFeO_(3)nanodot arrays

High-density ferroelectric BiFeO_(3)(BFO)nanodot arrays were developed through template-assisted tailoring of epitaxial thin films.By combining piezoresponse force microscopy(PFM)and Kelvin probe force microscopy(KPFM)imaging techniques,we found that oxygen vacancies in nanodot arrays can be transported in the presence of an electric field.Besides triple-center domains,quadruple-center domains with different vertical polarizations were also identified.This was confirmed by combining the measurements of the domain switching and polarization vector distribution.The competition between the accumulation of mobile charges,such as oxygen vacancies,on the interface and the geometric constraints of nanodots led to the formation of these topological domain states.These abnormal multi-center topological defect states pave the way for improving the storage density of ferroelectric memory devices.

LA-D-B1,a novel Abemaciclib derivative,exerts anti-breast cancer effects through CDK4/6

Background:Regulatory proteins involved in human cellular division and proliferation,cyclin-dependent kinases 4 and 6(CDK4/6)are overexpressed in numerous cancers,including triple-negative breast cancer(TNBC).TNBC is a common pathological subtype of breast cancer that is prone to recurrence and metastasis,and has a single treatment method.As one of the CDK4/6 inhibitors,abemaciclib can effectively inhibit the growth of breast tumors.In this study,we synthesized LA-D-B1,a derivative of Abemaciclib,and investigated its anti-tumor effects in breast cancer.Methods:Cellular viability was assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide(MTT)assay.Cell cloning and migration abilities were determined by colony formation assay and wound healing assay.Cell invasion abilities and adhesion were determined by cell invasion assay and cell adhesion assay.The impact of compound LA-D-B1 on cell proliferation and the cell cycle was analyzed through Western blotting,which quantified the levels of proteins associated with the cyclin-dependent kinase(CDK)4/6-cyclin D-Rb-E2F pathway.The in vivo anti-tumor activity of compound LA-D-B1 was investigated using a chick chorioallantoic membrane(CAM)model.Results:The study demonstrated that LA-D-B1 effectively suppressed breast cancer cell proliferation,induced apoptosis,and caused cell cycle arrest.Furthermore,LA-D-B1 reduced the expression of key proteins in the CDK4/6-cyclin D-Rb-E2F pathway,including CDK4,CDK6 and E2F1.The results also indicated significant antitumor activity of LA-D-B1 in a transplanted tumor model.Conclusion:In this study,LA-D-B1 demonstrated a potent anti-tumor effect by effectively suppressing cell proliferation and inhibiting cell cycle progression in breast cancer.These findings highlight the potential of LA-D-B1 as a valuable compound for enhancing therapeutic outcomes and controlling the progression of breast cancer.

阿米巴-细菌互作:进化、生态与环境效应

阿米巴是原生动物的主要类群,是陆地和水生生态系统的关键组成部分。阿米巴与细菌之间有着密切而复杂的相互作用。一方面,阿米巴通过捕食直接影响细菌群落与多样性,增强细菌活性。另一方面,细菌也进化出抵抗捕食的机制来抵抗甚至感染阿米巴,反向影响阿米巴的生长和多样性。近年来,阿米巴-细菌互作的研究开始受到了广泛关注。本文总结了阿米巴-细菌互作的进化历史、生态关系(捕食、偏利共生、寄生和互利共生)以及其对环境的潜在影响,旨在更好地理解阿米巴-细菌互作这一研究领域,为其他原生动物-微生物之间的研究提供新的思路,也为探究宿主-微生物互作的机制提供参考。

铝–油酸/正庚烷基纳米浆体燃料液滴着火燃烧特性

采用液滴悬挂法研究了正庚烷液滴、油酸/正庚烷混合燃料液滴、含20wt%纳米铝粉的铝–油酸/正庚烷基纳米浆体燃料液滴在不同温度下(600~800℃)的着火燃烧特性。用高速摄像机观测液滴进入管式电阻炉后的着火燃烧过程,使用热电偶记录液滴周围的气相温度变化,同时通过对应的温度曲线计算液滴的着火延迟时间。结果表明,纳米铝粉和油酸的添加均能降低正庚烷液滴的着火延迟时间。随温度升高,正庚烷、油酸/正庚烷混合燃料、铝–油酸/正庚烷基纳米浆体燃料液滴的着火延迟时间显著降低,但变化趋势逐渐趋于平缓。铝–油酸/正庚烷基纳米浆体燃料液滴的着火延迟时间与环境温度满足阿累尼乌斯方程。与纯正庚烷、油酸/正庚烷混合液滴的燃烧过程相比,铝–油酸/正庚烷基浆体燃料液滴的燃烧过程有显著差异,其燃烧经历3个阶段:正庚烷稳定燃烧阶段、正庚烷微爆炸阶段和表面活性剂微爆炸阶段。铝–油酸/正庚烷基浆体燃料液滴燃烧时间延长,火焰熄灭后又复燃,且燃烧过程中发生剧烈的火焰形变和铝颗粒溅射现象,大部分铝以团聚体形式在第三阶段完成氧化还原反应。

Effects of reproductive experience on paternal behavior,levels of testosterone,prolactin in serum and dendritic spines in medial prefrontal cortex of mandarin voles

Maternal behaviors and brains change dramatically with pregnancy,parturition and other mothering experiences.However,whether paternal behavior,brain plasticity and levels of relevant hormones also change along with fathering experience and pups’age remains unclear.Using socially monogamous mandarin voles(Micro-tus mandarinus),we found that experienced fathers exhibited more active paternal behaviors,such as licking,retrievals and nest building,but less paternal care,such as huddling,than new fathers.The high levels of licking and nest building appeared in the earlier days of their mate’s lactation.Experienced fathers retrieved 9–13-day-old pups more frequently.However,these paternal behaviors did not show significant changes with age of pups in new fathers.In addition,experienced fathers had dramatically higher prolactin levels than new fathers but had similar concentrations of testosterone to new fathers.New fathers had lower levels of testosterone but higher levels of prolactin than new paired males.The fathers had higher prolactin levels in the earlier days of their mate’s lactation.The new and experienced fathers had similar dendritic length and spine density on pyramidal neurons in the medial prefrontal cortex but displayed higher levels than new paired males.Taken together,these results indicate that reduction of testosterone levels and increase of prolactin levels may be associated with initiation of paternal care.Fathering experience significantly affects levels of parental care and paternal behaviors toward different aged pups,and brain plasticity can also be enhanced by transition to fatherhood.