Synthesis and Crystal Structure of N,N′-4-aminomethyl-pyromellitic diimide

1 INTRODUCTION N,N?-4-aminomethyl-pyromellitic diimide (4-pmpmdwas firstly obtained[1] in 1989 as one of the bypro-ducts by refluxing equimolar quantities of pyrome-llitic anhydride, n-hexylamine and 4-aminomethyl py-ridine in dry DMF to assemble electronic donor-spa-cer-acceptor systems, but its structure and coordina-tion chemistry did not receive attention at that time.For 4-pmpmd, the entity of two methylene groups(-CH2-) between the rigid pyromellitic diimide (PMDcore and two fre…     

富氧燃烧条件下煤焦的燃尽特性

本文利用平面火焰携带流反应器研究了DT烟煤在富氧燃烧条件下的燃烧实验。采用灰示踪法分析煤焦的燃尽和元素释放特性,并采用等密度模型计算了基于氧化反应C+0.5O_2→CO的表观反应动力学参数。研究结果表明;煤粉在富氧燃烧条件下的燃尽慢于空气燃烧;富氧燃烧条件下,煤焦与CO_2的气化反应会导致煤焦表面对O的化学吸附,进而导致氧元素释放速率减慢;高氧浓度条件下,高浓度CO_2对煤焦燃尽的抑制作用大于CO_2气化反应对煤焦燃尽的促进作用,降低环境氧浓度可以逐步提高CO_2气化反应对煤焦燃尽的贡献。     

LPL3层膜的结构、磁性和磁电阻效应的研究

采用直流溅射法在 ( 1 0 0 )LaAlO3 单晶基片上制备了La_0.67Sr_0.33MnO_3+δ/Pr_0.7Ca_0.3MnO_3+δ/La_0.67Sr_0.33MnO_3+δ(简称为LPL) 3层膜 .用X射线粉末衍射法(XRD)研究了系列样品的摇摆曲线和衍射全图 ,结果表明所有的样品均为高度取向的外延膜 .SQUID磁强计的测量结果证实了 3层膜中磁耦合的存在 .用常规的四端引线法测量了LSMO、PCMO和LPL 3层膜的电阻 ,分析了logρ 1 /T曲线 .由此可以得出如下结论 :具有铁磁性的PCMO中间层在 3层膜中可能起到了内磁场的作用 ,使得LSMO膜的顺磁性被削弱 ,这个作用与外加磁场的作用一样 ,降低了 ρ_max,增大了由金属到半导体的转变温度T_p;PCMO中间层还诱发了LSMO的能隙中的态密度的变化 .以上两个原因使得在零场中样品的电阻率和T_p 随着中间层PCMO的厚度变化而明显变化 .     

多态性及基因测序分析方法研究苯丙酮尿症患者的基因突变

应用聚合酶链反应-单链构象多态性分析及基因测序的方法,分析35例苯丙酮尿症患者PAH基因第6和7外显子以及其两侧部分内含子序列,进行了突变的筛查和确定.研究吉林地区苯丙酮尿症人群中苯丙氨酸羟化酶(Phenylalanine hydroxylase,PAH)基因突变特征.结果显示:(1)在70个PAH等位基因中共检测出9...     

InxGa1-xAs/GaAs量子阱应变量对变温光致发光谱的影响

利用变温光致发光(PL)研究了In0.182Ga0.818As/GaAs应变及应变补偿量子阱在77～300 K温度范围内的发光特性.随着温度T的升高,PL峰位向低能方向移动.在应力作用下In0.182Ga0.818As/GaAs量子阱的价带顶轻空穴带和重空穴带发生了劈裂.通过理论计算推导应变随温度变化对InxGa1-x...     

含氟丙烯酸酯共聚物结晶性与涂膜表面润湿性能研究

以甲基丙烯酸2-全氟辛基乙酯( FOEMA)分别和不同烷烃链长丙烯酸酯(RA,CH2=CHCOOCnH2n+1,n=4,8,12,16,18)为单体,用自由基聚合法合成了一系列的含氟丙烯酸酯共聚物,通过X射线衍射(XRD)和示差扫描量热法(DSC)对共聚物进行了表征,发现结晶性与丙烯酸酯的烷烃链长度密切相关,当n=4,...     

响应曲面法优化大粒车前子苯乙醇苷乙醇回流提取工艺

在单因素试验的基础上,研究提取温度（℃）、乙醇体积分数(v·v^-1)及液料比(mL·g^-1)等因素对苯乙醇苷类提取得率的影响,优化车前子苯乙醇苷的乙醇回流提取工艺。应用Design-Expert.8.0.6软件进行响应曲面分析,模拟得到二次多项式回归方程的预测模型。苯乙醇苷的最佳提取工艺条件为温度90℃、乙醇体积分数71%、液料比47mL·g-1,在此条件下苯乙醇苷的提取得率为0.99%,与模型预测值1.02%吻合良好。优化后的工艺参数可为乙醇回流提取大粒车前子中苯乙醇苷的产业化提供指导。 更多还原     

Studies on Intestinal Transport of Ginsenoside Compatibility with Veratrum nigrum via Caco-2 Cell Monolayer Model Coupled with UPLC-ESI-MS Method

The Caco-2 cells have been recognized as effective tools to be applied to imitating the drug absorption in human intestine for the transport of drug. Herein, Caco-2 cell monolayer model was used to study the transport of the ginsenoside compatibility with Veratrum nigrum in different proportions. A specific high performance liquid chromatography-electrospray ionization-mass spectrometry(HPLC-ESI-MS) method was developed for the semiquantitative determination of ginsenoside in intestinal transport with Dioscin as an internal standard. For the Caco-2 model constructed, two influencing factors were investigated, including time and concentration. The results suggest that the absorption of ginsenoside Re, Rg1, Rb1, Rc, Rb2 and Rd are time- and concentration-dependent and the excretions of Rb1, Rc, Rb2 and Rd have a relatronship with some transport proteins. The bioavailability of the ginsenosides has reduced compared to the single Panax ginseng extract when compatibility with a certain amount of Veratrum nigrum.