排序方式: 共有7条查询结果,搜索用时 140 毫秒
1
1.
2.
克拉霉素的电化学反应机理研究与应用 总被引:1,自引:0,他引:1
应用线性扫描伏安法、循环伏安法、常规脉冲伏安法等电化学手段并结合紫外吸收光谱研究了药物克拉霉素(clarithromycin, CAM)在pH 1.8~9.2 Britton-Robinson缓冲溶液和0.05 mol•L-1 NaOH溶液中的电化学行为. 在所研究的pH范围, CAM分别产生P1, P2, P3, P4四个还原波, 其中P1, P2, P4三个波均为其药效活性基团C-9位羰基的还原所产生. 实验结果表明: 在pH 1.8~5.7的B-R缓冲溶液条件下所获得的P1波为两电子不可逆弱吸附还原波; 在6.0<pH<9.2的B-R缓冲溶液中, CAM产生P2和P3两个波, 其中P2为两电子不可逆还原波, P3为催化氢波. 在0.05 mol• L-1 NaOH溶液中, CAM产生的P4波是一个单电子的不可逆吸附还原波. 根据P4波的峰电流iP与CAM浓度的线性关系, 建立了CAM含量测定的新方法. 相似文献
3.
Photo-acoustic spectrum and detection of nitrogen dioxide 总被引:1,自引:0,他引:1
The photo-acoustic (PA) spectrum of nitrogen dioxide (NO2) in the range of 420 - 520 nm with a Nd:YAG pumped optical parametric generator and amplifier as radiation source is presented. The spectrum has a characteristic of banded structure superimposed on continuum. The banded structure of the spectrum can be assigned to NO2 B2B1 ←X2A1 transition. While the continual one comes from the chaos states of the first excited state A2B2 and the high vibration levels of the ground state X2A1. The relationship of PA signal with buffer gas pressure and NO2 concentration is measured. The PA signal intensity increases with buffer gas pressure and almost is invariable when the buffer gas pressure is more than 3.00×104 Pa. The PA signal intensity has linearity with NO2 concentration. The detection limit is about 2×10-5 on the basis of SNR = 1, however lower value of the detection limit can be expected by improving the apparatus properties. 相似文献
4.
5.
The binding model of 3-(2-chloropyrid-5-ylmethylamino)-2-cyanoacrylate photosystem Ⅱ (PSⅡ) electron transport inhibitors with the D 1 protein of PSII was built. The high herbicidal activity of this kind of inhibitors was explained by docking studies: in addition to usual factors, the N atom on the pyridine ring could form an H-bond with the backbone amide of Phe265 on the D1 protein. 3D-QSAR analysis on sixteen 3-(2-chloropyrid-5-yl- methylamino)-2-cyanoacrylate compounds was performed using CoMFA method to explain the nature of interactions between the compounds and D1 protein. These studies may provide useful insights for designing new PSII electron transport inhibitors. 相似文献
6.
非肽类凝血酶抑制剂的比较分子力场分析 总被引:6,自引:0,他引:6
在血栓症和止血疗法中凝血酶起重要的生物调节作用,凝血酶抑制剂由于基溶 血栓作用成为药物设计的热点,对非肽类芳基磺酸酯系列凝血酶抑制剂进行了三维 定量构效关系研究。用Autodock方法和比较分子力场分析相结合构建了该类分子的 定量构效关系模型,得到三维等值线图。模型的传统相关系数r~2=0.956,交叉验 证系数q~2=0.681, F_(4,16) = 85.985,标准偏差S = 0.158。该模型为凝血酶抑 制剂的进一步结构改造提供了有益的启示。 相似文献
7.
NO2分子在440~495 nm范围内的激光诱导荧光激发谱 总被引:3,自引:3,他引:0
以 NdYAG脉冲激光器泵浦的光学参量发生器/放大器作激发光源, 获得了室温、低气压条件下, NO2分子在440~495 nm波长范围内的激光诱导荧光激发谱, 将所得谱线峰归属为NO2由基电子态X2A1态向第二电子激发态B2B1态的跃迁, 利用实验所得峰值波长计算了NO2分子B2B1态的角振动频率ωe. 通过对NO2分子B2B1→X2A1跃迁的荧光时间分辨光谱进行实验研究, 得到15 Pa气压下B2B1(0, 9, 0)振动态的能级寿命τ=49 μs. 测量了荧光寿命随气压的变化关系, 利用曲线拟合得到NO2 B2B1(0, 9, 0)振动态的自发辐射寿命τ0≈55 μs和无辐射跃迁弛豫速率常数. kq=1.2×10-9 cm3 molecule-1s-1. 相似文献
1