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1.
Dy3+在Ba3La(BO3)3 中的光致发光   总被引:1,自引:1,他引:1  
研究了Ba3La(BO3)3 基质中Dy3 的光致发光特性; 探讨了RE3 的电荷半径比(z/r)和Ce3 , Dy3 含量对Dy3 发光强度及发光颜色的影响; 分析了Ba3La(BO3)3 中Ce3 对Dy3 发光的敏化作用; 确定了Dy3 的 4F9/2→6H15/2及4F9/2→6H13/2跃迁发射的浓度猝灭机制均为电偶极-电四极相互作用.  相似文献   

2.
电化学方波伏安及循环伏安测量表明,钙钛矿CH3NH3PbI3晶体在有机电解质中的氧化还原过程伴随着化学降解。该化学降解源于CH3NH3PbI3晶体中铅离子的还原以及碘离子的氧化。通过电化学伏安法可以测定晶体的能带。  相似文献   

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4.
The interaction of [(η5-C5Me4R)Ru(CO)2]2 (1a: R = Me, 1b: R = Et) with yellor arsenic, As4, affords besides the pentaarsaruthenocenes [(η5-As5)Ru(η5-C5Me4R)] (2a, 2b) the tetranuclear clusters [{(η5-C5Me4R)Ru}3Ru(η3-As3)(μ33-As3)(μ3-As)3] (3a, 3b). The structure of 2b and 3b has been elucidated by X-ray analysis.  相似文献   

5.
The thermal behaviors of clusters [Ag3WS3Br](PPh3)3 and [Cu3WS3Br](PPh3)3 (PPh3=triphenyl phosphine) in a nitrogen atmosphere were studied under the non-isothermal conditions by simultaneous TG-DTG-DSC and EDS techniques. The results showed that the evolution of PPh3 generally proceeded before the release of the other moiety in one or two step-mode. The mechanisms, the kinetic and the thermodynamic parameters for decomposition of PPh3 of both clusters were determined and calculated by jointly using several methods, which showed that its evolution was controlled by Avrami-Erofeev equation. The results also showed that there was no new stable phase composed of W-Ag(Cu)-S-Br after release of organic moiety PPh3 and that CVD method was not applicable to their further processing.  相似文献   

6.
有关NdCl_3·3ROH-AlEt_3催化体系的活性   总被引:1,自引:0,他引:1  
<正> 我们曾指出,在NdCl_3·3ROH-AlEt_3体系中,醇的作用在于它的给电子性将会降低稀土离子的正电性,从而减弱Nd-Cl键的离子性,同时引起晶格的变化,使之有利于烷基化作用的发生,导致活性提高。本实验采用一种简便的方法证实了这种作用的发生。 这个方法所根据的原理是一般Ziegler-Natta型催化组分的熟知反应形式:  相似文献   

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8.
利用微乳液方法,合成了铈、铽共掺杂的氟镁钾纳米粒子,研究了体系中Ce3+→Tb3+的发光特性以及它们之间的相互作用,结果表明KMgF3:Ce3+Tb3+纳米粒子中存在Ce3+→Tb3+的能量传递过程,即Ce3+可以将吸收的能量直接传递给Tb3+离子,使得Tb3+的绿色发光强度大为增加.  相似文献   

9.
LaVO3和NdVO3的合成   总被引:1,自引:0,他引:1  
杨健美  苏锵 《应用化学》1994,11(1):116-117
以V2O3为起始原料,在氩气中合成了ABO3型稀土钒化合物,对加热前通氩气的时间,V2O3∶La2O3的配比等进行了探讨,得到了适宜的制备条件。首次报道了LnVO3(Ln=La,Nd)的热学性质,发现LaVO3具有吸附二氧化碳的特性。  相似文献   

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11.
以4-羟基苯甲酸乙酯为原料,经烃化、水解、缩合、脱保护、磺酰化反应,合成了6个含有磺酰基取代的4-苯氧基-N-(4-哌啶基)苯甲酰胺衍生物。 其结构经1H NMR、13C NMR和MS谱等技术手段进行了表征,并以索拉非尼为阳性对照药对HepG2细胞株进行了初步体外抗肝癌细胞增殖活性的评价。 实验发现,4-苯氧基-N-(1-甲磺酰基哌啶-4-基)苯甲酰胺的体外抗肝癌生物活性优于索拉非尼,IC50值为8.42 μmol/L。 研究结果表明,新结构4-苯氧基-N-(4-哌啶基)苯甲酰胺类化合物具有良好的抗肝癌活性。  相似文献   

12.
A series of novel indolin-2-one derivatives containing 4-thiazolidinone moiety(7a―7r) were synthesized and evaluated for their in vitro antitumour activities against MDA-MB-231(human breast cancer), H460(human lung cancer) and HT-29(human colon cancer) cell lines by standard 3-(4,5-dimethylthiazae-2-yl)-2,5-diphenyltetrazo- lium bromide(MTT) assay. Representative compounds(7d, 7k, 7m, 7p) with higher cytotoxicity were further examined against one normal cell line(WI-38, human fetal lung fibroblasts). The preliminary investigation shows that most of the compounds display moderate to excellent potency and high selectivity against different human cancer cell lines. In particular, the most potent compound 7m shows promising cytotoxicity against MDA-MB-231, H460 and HT-29 cell lines with IC50 values of 0.78, 0.056 and 0.018 μmol/L, respectively. The potency is much higher than that of Sunitinib(IC50=3.46 μmol/L against MDA-MB-231, IC50=2.59 μmol/L against H460, IC50=1.50 μmol/L against HT-29) by 4.4, 46.3 and 83.3 fold.  相似文献   

13.
A series of novel sorafenib derivatives have been designed and synthesized.The cytotoxic activities of these compounds were tested in three tumor cell lines.Most of the compounds showed potent antiproliferative activity against the tested cell lines with IC50= 0–20 mmol/L.Some compounds demonstrated competitive antiproliferative activities to sorafenib against all three cancer cell lines.Among them,compound 5g demonstrated significant inhibitory activity against A549,ACHN and MDAMB-231 cell lines with IC50values of 1.29,1.99,3.11 mmol/L,respectively.  相似文献   

14.
A series of novel 3-substituted-4-hydroxycoumarin derivatives 6(a–1) were synthesized in high yield using one-pot three component coupling reaction catalyzed by ceric ammonium nitrate. These compounds were evaluated for antileishmanial activity against Leishmania donovani promastigotes and antioxidant activity(DPPH-radical scavenging activity). Two compounds, 6h(IC_(50)= 9.90 μmol/L) and 6i(IC_(50)= 6.90 μmol/L) displayed potent antileishmanial activity when compared with standard antileishmanial agents pentamidine(IC_(50)= 16.15 μmol/L) and miltefosine(IC_(50)= 12.50 μmol/L). Three compounds, 6c(IC_(50)= 10.79 μmol/L), 6h(IC50= 10.60 μmol/L), and 6i(IC_(50)= 10.73 μmol/L) showed significant antioxidant activity favorably with the antioxidant standards butylated hydroxy toluene(IC_(50)= 16.47 μmol/L) and ascorbic acid(IC_(50)= 12.69 μmol/L). A molecular docking study of compounds 6(a–1) suggested a possible mode of binding with the Adenine phosphoribosyltransferase enzyme of L.donovani. ADME properties were predicted in silico and support the potential of 6(a–1) to show favorable drug-like properties.  相似文献   

15.
A series of derivatives of tetrandrine and fangchinoline was designed and synthesized to find more active anti-cancer compounds. Their anti-cancer activities were tested against human hcpatocellular carcinoma BEL-7402 and PLC/PRF/5 cells, human lung adenocarcinoma A549 cells as well as human leukaemia K562 cells, and the structure-activity relationship(SAR) was also studied. All the compounds except BI exhibited superior inhibitory ac- tivities against PLC/PRF/5 cells with half maximal inhibitory conccntration(ICs0) values of less than 15 μmol/L, and compounds A2, A4, B2 and B4 showed IC50 values of less than 9 pmol/L. Compounds A2, A6, B2 and B4 showed potent anti-cancer activities against all the tested cells with 1C5o values of less than 10 pmol/L. The results show that terandrine and fangchinoline derivatives are potential suppressors to human cancer.  相似文献   

16.
正A series of 2,6-disubstituted-4-morpholinothieno[3,2-d]pyrimidine derivatives were synthesized and their cytotoxic activity against H460,HT-29,MDA-MB-231,U87MG and H1975 cancer cell lines were evaluated in vitro.Most of the target compounds exhibited moderate to excellent activity to the tested cell lines.The most promising compound 23(0.84μmol/L,0.23μmol/L, 2.52μmol/L,1.80μmol/L) was 1.0,2.9,29.3 and 4.3 times more active than GDC-0941(0.87μmol/L,0.66μmol/L,73.8μmol/L, 7.77μmol/L) against H460,HT-29,MDA-MB-231 and U87MG cell lines,respectively.  相似文献   

17.
Aziridine derivatives of N5-methyltetrahydrofolate were designed and synthesized based on the mechanism of methionine synthase, and their biological activities were investigated as well. The aziridine derivatives 1 and 6 exhibited superior inhibitory activities(IC50: 5.05 and 4.15 μmol/L, respectively) compared to the corresponding chain analogue 4(IC50=24.42 μmol/L). The results suggest that the aziridine derivatives can get potential activities against nucleophilic methionine synthase.  相似文献   

18.
A series of novel 2-hydrazinyl-4-morpholinothieno[3,2-d]pyrimidine derivatives was designed and synthesized.All of them were screened for their cytotoxic activities against large cell lung cancer(H460),colon cancer (HT-29) and adenocarcinomic lung cancer(A549) cell lines in vitro.The pharmacological results indicate that most of the target compounds show moderate to significant activities.Especially compound 17 exhibits the most potent antitumor activities against H460,HT-29 and A549 cell lines with IC50 values of 0.57,0.45 and 1.45 μmol/L,respectively.  相似文献   

19.
以非经典叶酸拮抗剂2,4-二氨基-6-(4-甲基苯基)乙基吡啶并[3,2-d]嘧啶(wm-5b)及其侧链简化产物2,4-二氨基吡啶并[3,2-d]嘧啶为先导化合物, 选取具有抗肿瘤活性的基团, 通过微波法高效合成了2-位或4-位取代吡啶并嘧啶类非经典叶酸拮抗剂, 研究了2-位及4-位取代基对抗肿瘤活性的影响, 为非经典叶酸拮抗剂的设计合成提供了更多的理论依据. 目标化合物的结构均经核磁共振波谱(NMR)和质谱(MS)确证. 生物活性测定结果表明, 所有目标化合物均具有抗肿瘤活性, 其中, 6-(4-甲基苯基)乙基-4-氨基-2-(3-氯-4-氟苯基)氨基吡啶并[3,2-d]嘧啶(6b)对HL-60细胞的IC50=(4.09±0.48) μmol/L, 对A549细胞的IC50=(17.99±7.20) μmol/L, 而对HCT116细胞的IC50=(14.52±4.74) μmol/L; 部分目标化合物具有二氢叶酸还原酶抑制活性. 此外, 对部分目标化合物和先导物进行了二氢叶酸还原酶晶体结构的分子对接, 对活性结果和构效关系从分子水平上进行解释.  相似文献   

20.
A series of novel 1,2,3-benzotriazin-4-one derivatives were designed,synthesized and their inhibitory activities against leulcotriene A_4 hydrolase aminopeptidase in vitro were evaluated.Many compounds showed moderate to good activities at the concentration of 10 μmol/L.Among them,compound Ⅳ-16 exhibited the highest inhibitory activity up to 80.6% with an IC_(50) of 1.30 ± 0.20 μmol/L The compound Ⅳ-16 was also tested the proliferation inhibitory activities in THP1 human AML cell line and its binding model with LTA_4H enzyme by molecular docking was studied.It indicated that 1,2,3-benzotriazin-4-one was a promising scaffold for further study.The relationship between structure and inhibitory activity was also preliminarily discussed.  相似文献   

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