含CexZr1-xO2三效催化剂设计的神经网络仿真与优化

提出一种含CexZr1-xO2的三效催化剂的设计方法,即利用人工神经网络来进行辅助设计.首先考察了影响三效催化剂性能的一些重要因素,确定了所研究的三效催化剂模型.然后采用共沉淀方法制备了一系列铈锆固溶体,并将它们作为三效催化剂的助催化剂.采用传统的催化剂制备方法制备了一系列负载贵金属的三效催化剂,所制备的催化剂在模拟尾气中进行评价,得到的数据作为神经网络的训练样本和测试样本,建立了神经网络模型,并初步进行了预测和优化.     

钴希夫碱配合物及其分子氧加合物的合成与表征

以β-萘酚醛与一系列二胺缩合为配体,合成了钴的配合物。通过测定配合物在各种溶剂中吸收的氧气,得到了配合物与分子氧的摩尔比。并从各种溶剂中分离出了一系列2:1和1:1(Co/O_2)的分子氧加合物。对这些配合物和分子氧加合物进行了元素分析,红外、紫外一可见光谱和磁化率的表征,并研究了性质与结构的关系。     

Rotational Hypersurfaces with Constant Gauss-Kronecker Curvature

The authors study rotational hypersurfaces with constant Gauss-Kronecker curvature in Rⁿ. They solve the ODE associated with the generating curve of such hypersurface using integral expressions and obtain several geometric properties of such hypersurfaces. In particular, they discover a class of non-compact rotational hypersurfaces with constant and negative Gauss-Kronecker curvature and finite volume, which can be seen as the higher-dimensional generalization of the pseudo-sphere.     

Cartan’s Second Main Theorem and Mason’s Theorem for Jackson Difference Operator

Let f : C → Pⁿ be a holomorphic curve of order zero. The authors establish a Jackson difference analogue of Cartan’s second main theorem for the Jackson q-Casorati determinant and introduce a truncated second main theorem of Jackson difference operator for holomorphic curves. In addition, a Jackson difference Mason’s theorem is proved by using a Jackson difference radical of a polynomial. Furthermore, they extend the Mason’s theorem for m + 1 polynomials. Some examples are constructed to show that their results are accurate.     

油菜花粉气味成分研究

为了提高气相色谱/质谱的检出灵敏度,采用进样新方法对油菜花粉气味组分进行分离测定,对下列11种成分作了鉴定:二甲二硫;正辛烷;1,3-二甲苯,异硫氰酸丙烯酯;1,4-二甲苯;1,2-二甲苯;3,4-二甲基庚烷;二甲三硫;2-甲基-5-已烯腈;萘;对-甲氧基苯丙烯。     

Versatile Hypoxic Extracellular Vesicles Laden in an Injectable and Bioactive Hydrogel for Accelerated Bone Regeneration

Extracellular vesicles (EVs) derived from mesenchymal stem cells (MSCs) have emerged as an appealing alternative to cell therapy in regenerative medicine. Unlike bone marrow MSCs (BMSCs) cultured in vitro with normoxia, bone marrow in vivo is exposed to a hypoxic environment. To date, it remains unclear whether hypoxia preconditioning can improve the function of BMSC-derived EVs and be more conducive to bone repair. Herein, it is found that hypoxia preconditioned BMSCs secrete more biglycan (Bgn)-rich EVs via proteomics analysis, and these hypoxic EVs (Hypo-EVs) significantly promote osteoblast proliferation, migration, differentiation, and mineralization by activating the phosphatidylinositide 3-kinase/protein kinase B pathway. Subsequently, an injectable bioactive hydrogel composed of poly(ethylene glycol)/polypeptide copolymers is developed to improve the stability and retention of Hypo-EVs in vivo. The Hypo-EVs-laden hydrogel shows continuous liberation of Hypo-EVs for 3 weeks and substantially accelerates bone regeneration in 5-mm rat cranial defects. Finally, it is confirmed that Bgn in EVs is a pivotal protein regulating osteoblast differentiation and mineralization and exerts its effects through paracrine mechanisms. Therefore, this study shows that hypoxia stimulation is an effective approach to optimize the therapeutic effects of BMSC-derived EVs and that injectable hydrogel-based EVs delivery is a promising strategy for tissue regeneration.