吡啶—2,6—二羧酸体系导数荧光法同时测定铀,钐,铕,铽,镝

本研究了吡啶－２，６－二羧酸（ＤＰＡ）体系导数荧光法同时测定铀，钐，铕，铽，镝的最佳条件。在ｐＨ５．５，４．８×１０＾－＾５ｍｏｌ／ＬＤＰＡ，激发波长２７２ｎｍ的条件下，可分别在５１８，６３９，６２１，５３９和６６ｎｍ处测定铀，钐，铕，铽和镝，检测限分别达到７，０．４，０．００４，０．０２６和０．２５ｎｇ／ｍＬ。应用本法测定了混合成试液中上术五种离子含量，回收率为９２．３－１０８．１％。     

Case for projectile kinetic energy gain in stopping power studies

Under certain collision conditions, a swift ion projectile colliding with a target will gain rather than lose kinetic energy, contrary to the standard conception of stopping power. In this work, we consider the conditions for such a collision such that the energy loss is negative, that is, that there will be projectile kinetic energy gain. In particular, for a target initially in the ground state we find that the projectile gains kinetic energy only when charge exchange and de‐excitation processes are involved. This occurs when the electron affinity of the projectile is larger than the ionization potential of the target. Consequences of this effect are analyzed. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem 94: 215–221, 2003     

14C-寡糖在西瓜幼苗植株体内吸收传导和分布

应用同位素示踪技术研究了14C-寡糖在西瓜幼苗植株体内的吸收、传导和分布行为.自显影结果显示,寡糖通过处理叶部或根部后能够被西瓜幼苗植株快速吸收,在叶片中的传导表现为从叶缘向叶片中心分布的趋势.将叶部处理8h和根部处理24h后,14C-寡糖即可以传导和分布到西瓜幼苗的整个植株体内,证明14C-寡糖在西瓜幼苗植株体内具有较强的扩散和向基或向顶传导特征.结果表明,处理叶部4～120h时,根系、茎与未被直接处理的叶片等其它部位的放射性比活度分别由0.18×105和23.08×105Bq/kg变化为0.32×105和3.02×105Bq/kg,总体上表现出向基传导和分布的态势.处理根部4～120h时,西瓜幼苗植株根系、茎部、子叶和真叶中放射性比活度分别由22.23×105,2.23×105,8.33×105和12.78×105Bq/kg变化为431.11×105,42.23×105,65.57×105和78.89×105Bq/kg,表现出14C-寡糖在西瓜幼苗植株体内向顶传导作用和在地上部的积累态势很强.     

磁共振方法研究12-钨磷酸水合物中水分子的运动状态

本文使用以Cu(Ⅱ)为顺磁探针的ESR以及宽谱线~1H-NMR等磁共振方法,研究了12-钨磷酸水合物中水分子的运动状态,结果表明水合水的活动性不仅取决于温度,而且还与12-钨磷酸水合物中的含水量有关。     

呋喃甲醛缩二乙撑三胺希夫碱铜配合物的合成及结构(英)

A novel copper(Ⅱ) complex CuL(NO₃)₂(where L=N,N′-bis(furaldehyde)-diethylenetriamine) was synthesized and characterized by X-ray crystallography analysis. The crystal belongs to monoclinic, space group C2/c with cell parameters a=1.924 0(6) nm, b=0.792 8(3) nm, c=2.504 1(8) nm, β=111.163(5)°, and Z=8. The coordination geometry around Cu(Ⅱ) is a distorted trigonal-bipyramid，and one-dimensional chain is formed through intermolecular hydrogen bonds. CCDC: 255629.     

冬凌草中的新对映-贝壳杉烷二萜化合物

对河南省济源地区产冬凌草[Isodon rubescens(Hemsl.)Hara]再次进行了深入 的研究，从其叶的乙酸乙酯提取物中分离得到了16个化合物，其中1和2为两个新的 7，20-环氧-对映-贝壳杉烷类二萜化合物，其结构通过波谱分析确定为16（S）-羟 甲基-1α，6β，7β，11β-甲羟基-7α，20-环氧-对映-贝壳杉烷-15-酮（1）和 16（R）-羟甲基-1α，6β，7β，14β-四羟基-7α，20-环氧-对映-贝壳杉烷-15- 酮（2），分别命名为冬凌草已素（1）和庚素（2）；其余的已知化合物分别鉴定 为lasiodonin（3），冬凌草甲素（oridonin，4），乙素（ponicidin），丙素（ rubescensin C），丁素（rubescensin D），牛尾草丙素（rabdoternin C），荛 花香茶菜乙素（wikstroemioidin B），enmenol-1α-O-β-D-glucoside， enmenol，胡麻素（pedalitin），水杨酸，乌索酸，β-谷甾醇和胡萝卜甙。     

SA耐火材料多晶结构与性能的研究

本实验采用磨具废砂和炉皮SiC废砂生产SA耐火材料，通过XRD分析和计算机处理确定各试样中的晶相（4H－SiC，33R－SiC，3C－SiC，α－Al2O3，β-石英和Al6Si2O13）及其各相的含量。通过材料性能与结构综合分析，确定较好的配方，其含量：磨具废砂50％，炉皮砂45％，结合剂5％，外加矿化剂2％。     

酰基吡唑啉酮双席夫碱配合物的电子结构、成键性与生物活性

The electronic structures of N,N′-bis[(1-phenyl-3-methyl-5-oxo-4-pyrazolinyl) α-furylmethylidyne]ethylendii- mine (and -o-phenylendiimine), and their complexes of transition metals M (M=Ni, Cu, Co, Pd, Pt) have been calculated by B3LYP method of DFT. Their geometries and bonding characters are discussed, and the relationship between their bioactivities and electronic structures are also discussed from the calculated results of electronic populations and frontier orbital energies.     

Synthesis and Crystal Structure of N-（1-Phenyl-3-methyl-4-benzal-pyrazolone-5）-furoic Hydrazide

1 INTRODUCTION In recent years, investigations on the com- pounds containing hydrazide or hydrazone moieties have been increased considerably because of their potentially biological activities, especially as poten- tial inhibitors for many enzymes[1～5]. The presence of weak molecular interactions such as hydrogen- bonding controls the conformational and structural features which are important to the drug action[6, 7]. We have synthesized the photochromic compounds of pyrazolone thiosemi…     

轻稀土B-15-C-5联吡啶三元配合物

合成了稀土(Ln=La—Eu)硝酸盐与苯并-15-冠-5和2,2’-联吡啶的三元配合物,并培养出La-配合物的单晶,测定了的分子结构和晶体结构。经元素分析确定其化学组成为Ln(NO_3)_3·bipy·2H_2O·B-15-C-5。晶体属单斜晶系,空间群为P2_1/n。晶胞参数:a=11.951(6),b=18.181(7),c=14.754(5);β=96.19(3)°;V=3187.0,Z=4,D_c=1.637g/cm~3。最后偏离因子R=0.035。