A Paclitaxel Prodrug Activatable by Irradiation in a Hypoxic Microenvironment

The innate hypoxic microenvironment of most solid tumors has a major influence on tumor growth, invasiveness, and distant metastasis. Here, a hypoxia-activated self-immolative prodrug of paclitaxel (PTX₂-Azo) was synthesized and encapsulated by a peptide copolymer decorated with the photosensitizer chlorin e6 (Ce6) to prepare light-boosted PTX nanoparticle (Ce6/PTX₂-Azo NP). In this nanoparticle, PTX₂-Azo prevents premature drug leakage and realizes specific release in hypoxic tumor microenvironment and the photosensitizer Ce6 not only efficiently generates singlet oxygen under light irradiation but also acts as a positive amplifier to promote the release of PTX. The combination of photodynamic therapy (PDT) and chemotherapy results in excellent antitumor efficacy, demonstrating the great potential for synergistic cancer therapy.     

Effect of mesh phase on wave vibration of spur planetary ring gear

The distinctive wave vibration of a ring gear affected by mesh effect is investigated based on the inherent symmetry of spur planetary gears. Compared to prior analysis, this work mainly examines the forced flexural and extensional vibrations. The superposition principle and the Fourier series are introduced to jointly deal with the wave vibrations. The dynamics of the ring gear shows that the effect of the mesh phase on the wave vibration is mainly embodied by the specific relationships between the tooth number, the planet number, the largest common factor of them, the planets’ circumferential position, and the excited wave numbers in the typical rotational, translational and planet modes. For the equal systems, the three modes can be possibly excited depending on the specific mesh phase. And the dominant vibration orders of them are 0, 1 and 2, respectively. The non-zero lowest order is equal to the largest common factor of the two numbers. But for the diametrical ones, only the first two modes can be excited, and the dominant orders of them are 0 and 1, respectively. And the lowest non-zero wave number is 2 for even tooth number and 1 for odd tooth number. As a typical application, these relationships can be used to predict and suppress some potential wave resonances of the ring gear by optimizing the ring-planet mesh phase. The main results are demonstrated with finite element examples and comparisons with the existing literature.     

退火对Hf_(1-x)Y_(x)O_(2 )体系的结构与磁性的影响

利用溶胶凝胶法制备不同掺杂浓度的Hf_(1-x)Y_(x)O_(2 )(α=0,0.07,0.3,0.5)系列样品,探究了不同退火时间对样品的结构、形貌、磁学性质的影响.X射线衍射分析表明,随着掺杂浓度的提高,样品从单斜相逐渐转变为立方相.掺杂浓度为=0.07的样品为单斜和立方的混合相,且随着退火时间的延长,单斜相的比例逐渐增加.扫描电子显微镜结果表明,样品为几十微米大小的不规则颗粒,不同退火时间对样品形貌无显著影响.磁性测量结果表明,掺杂样品在室温下具有铁磁特性,而且可以利用掺杂浓度和退火时长进行调控.我们认为Hf_(1-x)Y_(x)O_(2 )体系的室温铁磁性可能与Y掺杂导致的样品内氧空位及缺陷有关.     

Electrochemical biosensor for amplified detection of Pb2+ based on perfect match of reduced graphene oxide–gold nanoparticles and single-stranded DNAzyme

Analytical and Bioanalytical Chemistry - In this study, a sensitive amplification strategy for Pb2+ detection using reduced graphene oxide (RGO) and gold nanoparticles (AuNPs) was proposed....     

叉型试管的妙用——日本中学化学实验选译

一、卤族元素实验实验目的:研究氯、溴、碘的化学性质和相互之间的关系实验用品:试管叉型试管带橡皮塞的导气管吸管软木塞漂白粉稀盐酸溴化钾碘化钾淀粉溶液苯实验方法:操作1在叉型试管中放入漂白粉和少量稀     

Regulating the nucleation of Li2CO3 and C by anchoring Li-containing carbonaceous species towards high performance Li-CO2 batteries

Li-CO₂ batteries provide an attractive and potential strategy for CO₂ utilization as well as energy conversion and storage with high specific energy densities.However,the poor reversibility caused by the decomposition obstacles of Li₂CO₃ and C products is still a challenge for Li-CO₂ batteries,which seriously influences its electrochemical performances.Herein,a free-standing MnOOH arrays cathode has been prepared and employed in Li-CO₂ battery,which realizes a great improvement of electrochemical performances by adjusting the discharge products distribution.Experiments coupled with theoretical calculations verifies that the formation of Li-containing carbonaceous species(LiCO₂,LiCO and Li₂ CO₃)bonded with MnOOH through Li ion regulates the nucleation behavior of Li₂CO₃ and C,making them grown on MnOOH uniformly.The fine Li₂ CO₃ grains(with a size about 5 nm)embedded into carbon matrix greatly enlarges the contact interface between them,facilitating the transmission of electrons through the discharge products and finally improves CO₂ evolution activity.This ingenious design strategy of regulating discharge products distribution to improve electrochemical performances provides a promising way to develop advanced Li-CO₂ batteries.     

圆锯片辊压适张后应力分布的有限元分析

分析了圆锯片辊压适张后的应力分布,并与国产圆锯片辊压适张后X射线衍射法的实验结果进行了对比,考虑到特定辊压工艺和不同锯片材质对适张效果的影响,以弹性力学中接触理论为基础,应用ANSYS软件的塑性分析法,建立了适张后应力状态的弹塑性分析模型。该模型引入影响辊压适张度的主要因素：锯片基材塑性应力应变关系,辊轮结构、转速,以及辊压载荷、位置和次数,结果表明应力分布的有限元计算结果与实验结果比较一致。     

在化学实验教学中培养学生的创造动机

教育的长效性使它成为一项未来事业,有位未来科学家预言:“从某种意义上可以说,历史留给人类的唯一任务就是要求每个人都必须从事不同程度的创造工作,而这一任务的完成,只有创造性的发掘和培养每一个受教育者的创造精神,才有可能。”因此,我们每个教育工作者,在教与学的双边活动中,注意保护和培养受教育者的创造动机,就成为一项着眼于未来的系统工程。     

LF拓扑线性空间上Fuzzy线性泛函的连续性

文（４）中给出了Ｘ（Ｌ）上的模糊线性算子的定义。作为其特例，本文证明了ＬＦ拓扑线性空间上模糊线性泛函连续性的几个等价命题和模糊线性泛函的Ｈａｈｎ－Ｂａｎａｃｈ延拓定理，进而给出了ＬＦ拓扑线性空间上存在非零连续模糊线性泛函的一个充要条件。     

过渡金属硫化物改性锂硫电池正极材料

锂硫电池(LSBs)由于单质硫正极具有超高能量密度(2600 Wh/kg)和超高理论比容量(1675 mAh/g),且环境友好、成本低廉,被认为是最有前景的储能体系之一。然而,硫正极的绝缘性和严重体积膨胀以及多硫化物(LiPSs)的“穿梭效应”等问题导致活性物质利用率低、循环稳定性差及电化学反应动力不足,严重阻碍了LSBs的商业化发展。最新研究表明,过渡金属硫化物作为载体或添加剂能够显著改善LSBs正极材料的电化学性能。本文从等效/共正极作用、导电性增强作用、LiPSs吸附作用和电化学反应催化作用四个方面梳理了过渡金属硫化物在LSBs正极材料中的改性机理,并指出多元过渡金属硫化物复合﹑纳米结晶和量子化作为增加比表面积和活性位点的方法是过渡金属硫化物用于锂硫电池正极材料的重要发展方向,可大幅提升LSBs的电化学性能。