盐卤硼酸盐化学(非汉字字符)——MgO·nB_2O_3-18%MgCl_2-H_2O过饱和溶液20℃结晶动力学

用结晶动力学方法对不同摩尔比的 Mg O/B2 O3在摩尔分数为 1 8% Mg Cl2 -H2 O中的过饱和溶液在2 0℃的结晶动力学过程进行了研究 .n(Mg O) /n(B2 O3) =1 /1和 1 /1 .5时分别结晶析出 2 Mg O· 2 B2 O3·Mg Cl2 · 1 4H2 O和 2 Mg O· 3 B2 O3· 1 5 H2 O(多水硼镁石 ) .n(Mg O) /n(B2 O3) =1 /2时依次结晶析出 Mg O·3 B2 O3· 7.5 H2 O,Mg O· 2 B2 O3· 9H2 O和 2 Mg O· 3 B2 O3· 1 5 H2 O(多水硼镁石 ) 3种固相 .n(Mg O) /n(B2 O3)=1 /3时结晶析出不同结晶水的六硼酸镁 Mg O· 3 B2 O3· 7H2 O和 Mg O· 3 B2 O3· 7.5 H2 O.析出固相采用X射线粉末衍射、红外光谱和热分析进行物相鉴定 .拟合并给出结晶动力学方程 ,同时对水合镁硼酸盐的结晶反应机理进行了探讨     

化学发光磁酶免疫法检测O157∶H7大肠埃希菌

O157∶H7大肠埃希菌是一种致病力非常强的微生物.近年来,陆续有其引起食物中毒事件的报道.1996年日本发生O157∶H7大肠埃希菌食物中毒的爆发流行,感染病例逾万人,死亡9例.2001年我国江苏及安徽等地也发生了肠出血性O157∶H7大肠埃希菌所引发的感染性腹泻事件.目前O157∶H7大肠埃希菌实验室常规检测方法为分离培养计数法,此法费时费力,需要几天的时间才能得到检测结果[1,2],缺乏应对突发事件的能力,因此亟需开发快速检测技术.近年来,多种微生物快速检测技术如ELISA法[3]、热解质谱测定法[4]、多聚酶链反应[5]、荧光成像技术[6]、生物发…     

CuZnAl水滑石衍生催化剂上甲醇水蒸气重整制氢Ⅲ.合成水滑石用金属盐的影响

采用共沉淀法,用不同金属盐为Cu源和Zn源合成了一系列CuZnAl水滑石,以此为前体经600℃焙烧后制得相应催化剂.用硝酸盐和醋酸盐合成的水滑石结晶度高,其衍生催化剂比表面积大、Cu的分散性好且易于还原;而用硫酸盐和盐酸盐合成的水滑石结晶度差,其衍生催化剂比表面积小、Cu的分散性差且不易还原.反应评价结果显示,用硝酸盐和醋酸盐制得的催化剂活性高、反应稳定性好;而用硫酸盐和盐酸盐制得的催化剂由于低的Cu表面积以及S和Cl的毒化作用而几乎无催化活性.在醋酸盐制备的催化剂上,产物干气中CO的浓度明显较低,在250℃和WHSV=3.28 h-1的条件下约为0.03%~0.04%,仅为硝酸盐所制催化剂上CO浓度的1/5;在210℃和WHSV=0.5 h-1的条件下,该催化剂上甲醇几乎完全转化,同时CO浓度降至约0.005%.N2O滴定、CO2程序升温脱附和程序升温还原结果显示,用醋酸盐和硝酸盐制备的催化剂具有极相近的Cu表面积和表面碱性,但前者CuO的还原峰温较后者低近70℃,归因于ZnO与CuO间的强相互作用,这是催化剂具有良好选择性的可能原因.     

3D Supramolecular Network Based on Hydrogen Bonds Between 1D [ Ni（μ2-C2O4） （ Him）2] Zigzag Chains

Introduction In recent years,considerable attention has been paid to supramolecular networks based on metal organic building blocks because of their potential applications in diverse fields,such as,catalysis,optics,sensors, magnetism,and molecular recognition[1-3].On the ba-     

表面膨胀粘度的测定研究

用不同浓度的NaCl和表面活性剂直链的十二烷基苯磺酸钠(LAS)、稳定剂聚丙烯酰胺和水所组成的泡沫体系为研究对象,通过表面压松弛的方法,利用计算机数据拟合,得到了计算表面膨胀粘度的方法。     

[Co(amp)2Cl2]2[ZnCl4]体系中两对称异构体的2D NMR研究

The two symmetrical isomers in [Co(amp)₂Cl₂]₂[ZnCl₄](amp=2-(Aminomethyl)pyridine) system were syn-thesized by general oxidation method and were separated by chromatography and recrystallization method. Their configurations were assigned by using 2D NMR techniques, particularly the NOESY NMR spectra. Solvent used was Me₂SO-d₆ with the central peak of the CD₃ septet as the reference ( ₁₃C,δ 39.37; ₁H,δ 2.49 relative to SiMe₄). Cation exchange media used was Dowex 50Wx 2(H⁺ form, 200～400mesh; Biorad).     

三维聚合物双(三丁基锡)戊二酸酯的合成及晶体结构研究

用三丁基氯化锡与戊二羧酸二钠以2:1摩尔比反应,合成了双（三丁基锡）戊二羧酸酯,并用元素分析、红外光谱、核磁共振氢谱及X-射线单晶衍射进行了表征和结构测定。X-射线单晶衍射法测定表明,化合物属单斜晶系,空间群为Cc,晶胞参数:a=13.984（3）,b=16.164（3）,c=16.894（3）A,β=107.457（3）°,V=3642.9（11）A3,Z=4,C29H60O4Sn2,Dc=1.251g/cm3,μ=1.394 mm-1,R=0.0500,wR=0.0874,F（000）=1416。晶体结构中存在2种化学环境不同的三角双锥构型的锡原子,由于配体中2个羧基在不同方向的交联作用,使化合物呈现三维立体骨架结构,并且在骨架结构中存在沿a、b、c轴3个方向伸展的规则的大环直孔道。     

球形钴酸锂的乳液法合成及其结构、性能研究

采用一种特殊乳液法, 制备了锂离子电池正极材料球形LiCoO₂. 分别研究了一次颗粒尺寸、烧结时间对于二次造粒的影响. 还对LiCoO₂球体内部的结构进行了SEM和HRTEM研究, 发现一次颗粒非常紧密地融合在一起, 晶体边界区域没有明显的非晶相区, 也没有纳米级别的孔洞、裂缝. 电化学性能研究表明, 在900 ℃烧结4 h的材料具有较高的首次放电容量(143 mAh•g^－1)和良好的循环性能     

INTERNALIZATION OF GAP JUNCTIONS BETWEEN NEURON AND GLIAL CELL AND FORMATION OF ANNULAR LAMELLAR BODIES IN CHINESE LEECH Whitmania pigra

This paper reveals the formation of annular lamellar body (ALB) in the ganglion of leech by means of in situ fixation and the lanthanum nitrate tracer technique. This formation involves both wrapping and internalization of the gap junctions between glial processes themselves, as well as between neuron and glial process. The results indicate that there is probably an active process of internalization of membrane structures involving gap junctions between neuron and glial cell in the central nervous system in leech. The functions of ALB are discussed.     

A Dynamic Analysis and Numerical Simulation of Explosive Development of an Extratropical Cyclone Over Land

The present paper has made a dynamic and diagnostic study of the process of explosive deepening of an extratropical cyclone over North China on April 25-26, 1983, in order to gain an insight into the physical mechanism of explosive development of cyclone over land. It turns out that this cyclone occurred in the strong baroclinic zone, and the vorticity and thermal advection triggered the initial development of the cyclone. Subsequently, as the rainfall increased, the effect of condensational heating became more and more important. During the time period of rapid intensification (from 1200GMT 25 to 0000GMT 26 April, 1983, the central surface pressure fell down from 998. 2 to 988. 3 hPa), the peak of diabatic heating profile continuously descended, leading to a rapid increase in heating amount in the lower troposphere. This condition is favorable to the explosive development of rotational circulation or vortex. The numerical simulations have further demonstrated the importance of the lowering of heating p