西兰花种子提取萝卜硫素的酶解体系

以提取萝卜硫素主要酶解因素:pH、催化缓冲液类型、Zn2+浓度、Vc的浓度为4个考察因素,分别设立3个水平,采用L9(34)正交试验设计,优化提取酶解体系.结果表明,各因素的重要性顺序为:pH＞催化缓冲液类型＞Vc的浓度＞Zn2+浓度.西兰花种子生产萝卜硫素的最佳条件为:pH 5.0、Zn2+浓度为0.1mol/L、Vc的浓度为0.5mg/mL、以0.1mol/L醋酸-醋酸钠萝卜汁缓冲液为酶解缓冲体系.验证结果显示优选的缓冲液体系高效、稳定,可以作为西兰花种子提取萝卜硫素的酶解体系.     

Using permutations to detect dependence between time series

In this paper, we propose an independence test between two time series which is based on permutations. The proposed test can be carried out by means of different common statistics such as Pearson’s chi-square or the likelihood ratio. We also point out why an exact test is necessary. Simulated and real data (return exchange rates between several currencies) reveal the capacity of this test to detect linear and nonlinear dependences.     

Development of aryl-containing dipyrrolyldiketone difluoroboron complexes(BONEPYs):Tune the hydrogen bond o-C—H…F for fluoride recognition

Dipyrrolyldiketone difluoroboron complexes(BONEPYs)were synthesized by condensation of the corresponding pyrroles and malonyl chloride followed by treatment with BF3·OEt2.The aryl-substituted pyrrole is introduced to form a cyclic system in order to investigate anion binding studies.In BONEPYs 1-3 the o-H of the aryl group forms hydrogen bonding with F to give a more table complex.In contrast,the intramolecular hydrogen-bonded BONEPY endo-4 is more stable than its exo isomer.While adding F,the hydrogen bonds must be broken first to give 4·(3)F.Owing to the electron-rich group(-OMe),the o-H of the phenyl group can hardly interact with F via hydrogen bonding to give the less stable complex4-(5)F.The energy diffe rences between the different conformations were calculated using DFT methods,which is consistent to the experimental observations.     

花菁-脱氧核糖核酸的共振光散射光谱及其分析应用

研究了一种苯并噻唑阳离子花菁与脱氧核糖核酸(DNA)作用的共振光散射光谱,在pH 6.0的六次甲基四胺-HCl缓冲介质中,痕量DNA的加入使花菁在590nm的共振光散射强度显著增强.在最佳实验条件下,增强的共振光散射强度与DNA浓度具有良好的线性关系,据此建立了一种测定DNA的共振光散射光谱法.方法的线性范围为:小牛胸腺DNA(CT DNA),0～20μg/mL,鱼精子DNA(FS DNA),0～ 15μg/mL;检出限分别为0.005 μg/mL和0.008μg/mL.该方法已用于合成样品中DNA的测定.     

焙烧温度对Fe/γ-Al2O3催化剂去除苯酚模拟废水COD的影响

利用浸渍法制备了Fe/γ-Al2O3催化剂。考察了催化剂中Fe含量,催化剂焙烧温度对苯酚废水COD去除率的影响。发现300℃焙烧的Fe0.01/γ-Al2O3催化剂对苯酚废水的COD去除率最高,在反应温度为30℃,pH为3,加入100μL H2O2时,反应1 h后COD去除率约为65%。同时,采用N2物理吸附,XRD以及SEM等技术手段考察了催化剂的性质及其表面形貌。结果表明:300℃焙烧的催化剂中含有AlO(OH)。对于活性组分含量相同的催化剂而言,AlO(OH)的存在有助于苯酚废水COD去除率的提高。同时,焙烧温度的增加,催化剂表面会发生烧结,比表面积下降,催化剂活性降低。     

一类催化抑制系统反应扩散方程的奇摄动(英文)

研究了一类奇摄动非线性催化抑制系统反应扩散方程.在适当的条件下,首先求出了原问题的外部解,然后利用伸长变量、多重尺度和幂级数展开理论构造出解的形式渐近展开式最后利用微分不等式理论讨论了问题解的一致有效性和渐近性态.     

An Extra-Large-Pore Pure Silica Zeolite with 16×8×8-Membered Ring Pore Channels Synthesized using an Aromatic Organic Directing Agent

Extra-large-pore zeolites for processing large molecules have long been sought after by both the academia and industry. However, the synthesis of these materials, particularly extra-large-pore pure silica zeolites, remains a big challenge. Herein we report the synthesis of a new extra-large-pore silica zeolite, designated NUD-6, by using an easily synthesized aromatic organic cation as structure-directing agent. NUD-6 possesses an intersecting 16×8×8-membered ring pore channel system constructed by four-connected (Q⁴) and unusual three-connected (Q³) silicon species. The organic cations in NUD-6 can be removed in nitric acid to yield a porous material with high surface area and pore volume. The synthesis of NUD-6 presents a feasible means to prepare extra-large pore silica zeolites by using assembled aromatic organic cations as structure-directing agents.