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1.
在溴化十六烷基三甲胺(CTMAB)存在下,PH6,0的HAc-NaAc缓冲介质中,铝与新试剂3,5-二溴-4-偶氮8-羟基喹啉苯基荧光酮形成红色三元胶束配合物,最大吸收波长位于564nm,表观摩尔吸光系数ε为1.35×10^5.mol^-1.cm^-1,铝浓度在0~5μg/25mL范围内符合比耳定律,拟定的方法用于铝铁黄铜中微量铝的测定,结果满意。  相似文献   
2.
通过ESR光谱测定表明TiO2悬浮液在紫外光照射下产生羟基自由基氧化物种.羟基自由基氧化酸性桃红(sulforhodamine B,SRB)使其褪色,在565 nm处用分光光度法测定其吸光度值的变化,可间接测定羟基自由基的生成量.确定了体系的最佳实验条件pH为2.5;SRB浓度为2.0×10-5mol/L;TiO2浓度为0.1 g/L;光照时间为12 min.采用抗坏血酸为羟基自由基清除剂,测定了其自由基清除率,表明拟定该体系可作为筛选抗氧化剂的方法之一.  相似文献   
3.
Supported iron tetrasulfophthalocyanine can efficiently catalyze the degradation of organic pollutants by H2O2 under visible light irradiation in an aqueous solution, and the catalyst can be easily recycled without apparent loss of activity.  相似文献   
4.
新试剂3,5-二溴-4-偶氮对二甲苯胺苯基荧光酮与钨配合物的分光光度法研究*颜克美黄应平(湖北三峡学院化学系宜昌443000)关键词3,5-二溴-4-偶氮对二甲苯胺苯基荧光酮钨分光光度法中图分类号O657.32在表面活性剂存在下,苯基荧光酮类试剂测定...  相似文献   
5.
Russian Journal of Physical Chemistry A - g-C3N4/BiOBr composites were obtained via solvothermal method. XRD, SEM, FTIR, UV–Vis DRS, BET, and BJH methods were used to characterize the...  相似文献   
6.
A high yield method to extract alkaloids from Aconitum coreanum using pulsed electric field (PEF) was developed, and the optimized extraction method compared to the other four extraction methods, consisting of cold maceration extraction, percolation extraction, heat reflux extraction (HRE), and ultrasonic-assisted extraction (UE). The experimental factors of the extraction methods such as electric field intensity, pulse frequency and solid-to-solvent ratio were evaluated. The content of Guanfu base A (GFA) was quantified by liquid chromatography coupled with electrospray ionization tandem mass spectrometry. The results indicated that the highest yield of GFA was 3.94 mg g?1 by PEF with conditions of 20 kV cm?1 electric field intensity, 8 pulse, 1:12 solid-to-solvent ratio, and 90 % ethanol–water solution. Meanwhile, the extraction time of PEF was <1 min, which is much less than the HRE of 10 h and even the newly used technique UE of 40 min. Moreover, the results of PEF extraction method showed obvious advantages, with the highest efficiency (120 L h?1), the shortest extraction time (0.5–1 min), and the lowest energy costs, which could be applied in the industrial production of alkaloids from A. coreanum. Therefore, the application of the PEF extraction method is a promising and constructive method for extraction of GFA.  相似文献   
7.
Nasopharyngeal carcinoma (NPC) is a common malignant head and neck tumor. Drug resistance and distant metastasis are the predominant cause of treatment failure in NPC patients. Hispidulin is a flavonoid extracted from the bioassay-guided separation of the EtOH extract of Salvia plebeia with strong anti-proliferative activity in nasopharyngeal carcinoma cells (CNE-2Z). In this study, the effects of hispidulin on proliferation, invasion, migration, and apoptosis were investigated in CNE-2Z cells. The [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assay and the colony formation assay revealed that hispidulin could inhibit CNE-2Z cell proliferation. Hispidulin (25, 50, 100 μM) also induced apoptosis in a dose-dependent manner in CNE-2Z cells. The expression of Akt was reduced, and the expression of the ratio of Bax/Bcl-2 was increased. In addition, scratch wound and transwell assays proved that hispidulin (6.25, 12.5, 25 μM) could inhibited the migration and invasion in CNE-2Z cells. The expressions of HIF-1α, MMP-9, and MMP-2 were decreased, while the MMPs inhibitor TIMP1 was enhanced by hispidulin. Moreover, hispidulin exhibited potent suppression tumor growth and low toxicity in CNE-2Z cancer-bearing mice at a dosage of 20 mg/kg/day. Thus, hispidulin appears to be a potentially effective agent for NPC treatment.  相似文献   
8.
Yuan  Jun  Zhang  Chujun  Chen  Honggang  Zhu  Can  Cheung  Sin Hang  Qiu  Beibei  Cai  Fangfang  Wei  Qingya  Liu  Wei  Yin  Hang  Zhang  Rui  Zhang  Jidong  Liu  Ye  Zhang  Huotian  Liu  Weifang  Peng  Hongjian  Yang  Junliang  Meng  Lei  Gao  Feng  So  Shukong  Li  Yongfang  Zou  Yingping 《中国科学:化学(英文版)》2020,63(8):1159-1168
Recent advances in material design for organic solar cells(OSCs) are primarily focused on developing near-infrared nonfullerene acceptors, typically A-DA′D-A type acceptors(where A abbreviates an electron-withdrawing moiety and D, an electron-donor moiety), to achieve high external quantum efficiency while maintaining low voltage loss. However, the charge transport is still constrained by unfavorable molecular conformations, resulting in high energetic disorder and limiting the device performance. Here, a facile design strategy is reported by introducing the "wing"(alkyl chains) at the terminal of the DA′D central core of the A-DA′D-A type acceptor to achieve a favorable and ordered molecular orientation and therefore facilitate charge carrier transport. Benefitting from the reduced disorder, the electron mobilities could be significantly enhanced for the"wing"-containing molecules. By carefully changing the length of alkyl chains, the mobility of acceptor has been tuned to match with that of donor, leading to a minimized charge imbalance factor and a high fill factor(FF). We further provide useful design strategies for highly efficient OSCs with high FF.  相似文献   
9.
通过在N2气氛围下热裂解富集Mn的鸢尾可得到Mn/生物炭(BC)材料, 并按植物叶(Leaf)和根部(Root)分别将其分别命名为BC-L0, BC-L1, BC-L2, BC-R0, BC-R1和BC-R2. 采用扫描电子显微镜(SEM)、 能谱分析(EDS)仪、 X射线衍射(XRD)仪、 X射线光电子能谱(XPS)、 傅里叶变换红外光谱(FTIR)、 原子吸收光谱(AAS)和比表面积分析(BET)仪等对Mn/生物炭材料的Mn含量、 化学组成与形貌进行了表征, 发现鸢尾叶部为Mn主要富集部位, 最大富集量为13.0 mg/g, 且Mn以Mn2O3薄片存在于生物炭表面. 利用Mn/生物炭与H2O2构建了类Fenton体系, 在中性条件下BC-L2-H2O2体系对有机污染物罗丹明B(RhB, 3×10 -5 mol/L)的降解率达到50%(180 min), 表明该体系具备氧化去除RhB的能力, 并推测了该体系对RhB的催化氧化机理. 结果表明, 先将Mn超富集植物转化为Mn/生物炭材料, 再通过添加H2O2能构建具有氧化能力的类Fenton体系, 可用于对有机污染物的降解, 实现“以废治废”的绿色循环思路, 为Mn富集的植物后续处理提供一种新的转化及应用方式.  相似文献   
10.
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