Some Alternating Double Binomial Sums

We consider some new alternating double binomial sums. By using the Lagrange inversion formula, we obtain explicit expressions of the desired results which are related to a third-order linear recursive sequence. Furthermore, their recursive relation and generating functions are obtained.     

大黄素联合5AzA-cdR对胰腺癌抑癌基因p16、RASSF1A去甲基化作用研究

目的研究大黄素是否可增强5AzA-cdR对胰腺癌Panc1细胞抑癌基因p16、RASSF1A的去甲基化作用。方法采用细胞增殖实验检测不同浓度大黄素对Panc1细胞的生长抑制情况,焦磷酸盐测序PCR（BSP）分别检测大黄素、5AzA-cdR及大黄素联合5AzA-cdR对Panc1细胞抑癌基因p16、RASSF1A甲基化状态的影响,并用荧光定量PCR（FQ-PCR）和Westernblot分别检测p16、RASSF1A及甲基转移酶DNMT1、DNMT3a在mRNA和蛋白水平的表达情况。结果大黄素以时间和浓度梯度依赖性抑制Panc1细胞生长。BSP结果显示大黄素具有微弱的去甲基化作用,5AzA-cdR具有一定程度的去甲基化作用,当两者联用时,去甲基化作用更加显著;FQ-PCR和Westernblot结果显示大黄素与5AzA-cdR联用时,p16、RASSF1A的表达水平均较空白对照明显增高（均P＜0.05）,DNMT1、DNMT3a的表达水平均较空白对照明显降低（均P＜0.05）。结论大黄素与5AzA-cdR联用可通过降低DNMT1和DNMT3a的表达水平来增强5AzA-cdR对胰腺癌抑癌基因p16、RASSF1A的去甲基化作用。     

具有5个不同素因子的Nicol数数数

通过计算机辅助,利用元素的阶、欧拉函数、因子和函数等数论函数的性质,继续研究了具有5个不同素因子的Nicol数,证明了具有5个不同素因子的Nicol数只能是3-Nicol数和4-Nicol数.     

关于罗尔定理的进一步讨论

对罗尔定理进行深入系统的探讨和研究.给出在更弱条件下的各种区间类型(包括有限区间和无限区间)的罗尔定理的推广形式.     

On surfaces immersed in Euclidean space R~4 Dedicated to Professor Yang Lo on the Occasion of his 70th Birthday

Let M be a closed oriented surface immersed in R4 . Associated it one has the generalized Gauss map from M into the Grassmann manifold G 4,2 . This note will be concerned with the geometry of the generalized Gauss map by using the moving frame theory and the quaternion interpretation of Plcker coordinates. As one of consequences,we get the celebrated theorem of Chern and Spanier,Hoffman and Osserman,who proved it by quite different methods. At last,we give an explicit construction of a series of immersions of S2 in R4 with any given normal Euler number.     

The Generalization on Inequalities of Hermite-Hadamard's Integration

Some new inequalities of Hermite-Hadamard's integration are established.As for as inequalities about the righthand side of the classical Hermite-Hadamard's integral inequality refined by S Qaisar in [3],a new upper bound is given.Under special conditions,the bound is smaller than that in [3].     

基于次梯度选取的非光滑优化强次可行方向法

本文结合次梯度选取技术及割平面法和强次可行方向法的思想,提出了一个求解目标函数非光滑约束优化问题的强次可行方向算法.通过设计一个新的寻找搜索方向子问题和构造新型线搜索,算法不仅能接受不可行的初始点,而且能保持迭代点的强次可行性,同时避免在可行域外目标函数值的不适度增加.算法具备全局收敛性,且初步的数值试验表明算法是稳定有效的.     

双诱导映射(L)集合范畴的幂对象及子对象分类子探讨

引入双诱导映射(L)集合范畴的幂对象及子对象分类子的概念,并分别讨论它们的判别定理,同时给出它们的具体结构.     

蔬果皮的续集——花青素衍生植物颜料的探究

秉持变废为宝的理念,对富含花青素的蔬果皮进行简单处理,获得花青素提取液,再添加白醋或苏打使其变成多彩的植物颜料并作画。在研究过程中发现,紫薯的新鲜度是影响颜料色彩的关键因素之一,新鲜紫薯的颜料色彩偏褐色,而久置紫薯的更鲜艳、明亮。此外,鉴于花青素对酸碱敏感,液体颜料在使用时需先判断纸张的酸碱性。本科普实验生动直观地展示了化学变化,材料简单易得、绿色安全、操作简便,且居家即可实践,有利于激发大众对化学的兴趣与爱好,进而培养学生的动手动脑能力。     

脱氢枞酸酯键合硅胶色谱固定相的制备及应用

A dehydroabietic acid glycidyl methacrylate ester (DAGME)-bonded silica stationary phase (Sil-DAGME) was fabricated in this paper. The DAGME was firstly prepared using dehydroabietic acid and glycidyl methacrylate via a ring-opening addition reaction, and then grafted onto the surface of a thiol-functionalized spherical silica by click reaction to obtain the Sil-DAGME. The successful immobilization of DAGME on the silica was confirmed through series of characterizations including Fourier-transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA)and elemental analysis (EA). The chromatographic performance and retention mechanisms of Sil-DAGME were validated using a variety of compounds including alkylbenzenes, Tanaka standard test mixtures, polycyclic aromatic hydrocarbons, phenols and flavonoids. Meanwhile, the Sil-DAG⁃ME exhibits multiple interactions, including hydrophobic, π-π and hydrogen bonding interaction between the stationary phase and the analytes during the separation process due to the co-existing of benzene ring, carbonyl group, hydroxyl group and hydrophobic rigid tricyclic hydrophenanthrene skeleton in the DAGME on the silica surface. Based on synergistic action of multiple retention mechanisms, the probe molecules metioned above achieved ideal resolution and flexible selectivity in separation. In addition, the Sil-DAGME not only exhibited good stability, repeatability and reproducibility with the run-to-run relative standard deviations (RSDs) of 0. 050%-0. 19% (n = 10), the daytoday RSDs of 0. 25%-1. 0% (n = 7), and the column-to-column RSDs of 0. 78%-2. 1% (n = 3) for the retention time, but also showed an excellent separation ability for Yew tree bark extract. In short, the application of dehydroabietic acid in chromatographic separation materials not only provided a new approach for the separation and detection of paclitaxel, but also presented a reference for the design stationary phase using natural product rosin as functional ligand. © 2023, China Association for Instrumental Analysis. All rights reserved.