小功率空气-氩气混合气冷却ICP中电子密度的测定

在与小功率全Ａｒ－ＩＣＰ类似的条件下,使用顺序扫描等离子体光谱,用Ｓｔａｒｋ加宽法,选择Ｈβ（４８６．１ｎｍ）谱线,测定了空气－氩气混合气冷却ＩＣＰ中在感应线圈上０、２、５、１０ｍｍ处电子密度的侧向分布并将其中部分侧向分布经Ａｂｅｌ变换为径向分布。     

激光差拍波等离子体加速装置中约束磁场的计算研究

通过对等离子体发生器建立三维模型,计算得到磁场在该装置中的分布情况。所得结果与实际测量基本一致,从而说明所建模型的合理性。通过调节一些参数,对该模型进一步搞清了导致等离子体发生器中真实磁场较实验设计要求偏低的主要原因,并提出了相应的改进方案。     

新型可溶固定相分离法研究—光度法测定水中痕量铁(Ⅱ)

以硝酸纤维素粉末为固定相,以乙二醇独甲醚为溶剂,处理Ｆｅ（Ⅱ）－ｐｈｅｎ－ＤＳ三元离子缔合型络合物体系,提出了一种新型可溶固定相分离方法。该法简便,快速,富集倍数高达１００。本文探讨了固定相的分离条件－固定相粉末用量,颗粒度,柱径等对富集的影响,并对反应的酸度,试剂用量,方法的灵敏度,选择性等作了讨论。     

丁基罗丹明B-高碘酸盐动力学催化光度法测定纳克量钌

提出了在弱酸介质中钌催化高碘酸盐氧化丁基罗丹明Ｂ（ＢＲＢ）,以光度法测定钌。催化反应速率与催化剂浓度呈线性关系的范围为０．２～１８ｎｇ／２５ｍ Ｌ,检出限为２．８×１０－ １２ ｇ／ｍ Ｌ。相对标准偏差小于１４％ 。催化反应对Ｒｕ（Ⅲ）、ＢＲＢ、ＫＩＯ４ 和Ｈ３ＰＯ４ 均为一级反应,表观活性能为４２．１２ ｋＪｍ ｏｌ－ １。探讨了反应机理。本法已用于某些岩矿和冶金产品中钌的测定。ＲＳＤ为１．０２％ ～２．２９％ ,回收率为９８．７％ ～１０２．０％     

CPHPUN 的合成及其在分析化学中的应用

阐述了Ｎ－１－（３－３－二羧基－４,４’－联苯撑）－（３－Ｎ－苯基三氮）,（Ｎ－１,１‘－３（３,３’－ｄｉｃａｒｂｏｘｙ１－４,４－ｄｉｐｈｅｎｙｌ）－ｈｉｓ－（３－Ｎ－ｈｙｄｒｏｘｙ－３－Ｎ－ｐｈｅｎｙｌ－ａｚｉｄｅ的合成方法。结构论证、分析性能及在光度分析中的。ＣＰＨＰＵＮ对外一有很高的显色灵敏度和很好的识别能力。在光度分析中,ε４６７．５达２．３５×１０＾６Ｌ·ｍｏｌ＾－１·ｃｍ＾－１。用     

CH3COSbCl6催化四氢呋喃聚合的研究

ＣＨ_３ＣＯＳｂＣｌ_６催化四氢呋喃聚合的研究栗方星，王红军，马克勤（南开大学化学系，天津，３０００７１）关键词聚四氢呋喃，乙酰基六氯锑酸盐，表观聚合反应速率常数，五氯化锑ＴＨＦ聚合为平衡聚合反应应［１，２］，文献报道［３，４］Ｅｔ３ＯＢＦ４、Ｅｔ３Ｏ...     

Theoretical studies on the band structures of superconducting solid compounds: Nb3X (X=Si, Ge, Sn, Pb)

The band structures of several analogous superconducting A-15 type solid compounds, Nb3X (X=Si, Ge, Sn, Pb), have been calculated by use of the tight-binding method within the Extended Huckel approximation (EHT). By analysis of their energy bands, densities of states and crystal orbital overlap populations, the dependence of the superconducting transition temperatures (Tc) on the electronic structures and bondings is qualitatively elucidated.     

Synthesis，X－ray Structure and Spectral Propertiesofa Tetra－component Heteropoly Compound

Ｓｙｎｔｈｅｓｉｓ，Ｘ－ｒａｙＳｔｒｕｃｔｕｒｅａｎｄＳｐｅｃｔｒａｌＰｒｏｐｅｒｔｉｅｓｏｆａＴｅｔｒａ－ｃｏｍｐｏｎｅｎｔＨｅｔｅｒｏｐｏｌｙＣｏｍｐｏｕｎｄＺＨＡＮＧＨｅｎｇ－ｂｉｎ，ＹＡＮＧＧｕａｎｇ－ｄｉ，ＱＩＸｉｎｇ－ｙｉａｎｄＬＩＳｈｕ...     

The Synthesis, Identification, and Kinetic Characterization of the Photoaffinity Label: 3-Azidopyridine Adenosine Dinucleotide: An Advanced Undergraduate Laboratory Experiment Appropriate for Organic, Biochemistry, or Bio-organic Chemistry

We present here a complete photochemical experiment suitable for biochemistry, bioorganic, and organic chemistry laboratories. It provides experiences in chemical and enzymatic syntheses, spectroscopy (IR, NMR, UV), chromatography (TLC, GC-MS), and a simple enzyme kinetic study utilizing UV spectroscopy. The application of light energy to produce chemical changes has recently expanded beyond photography, lithography, and organic synthesis to include use in tumor phototherapy [1] and as antiviral agents [2]. Dyes and a variety of photoactive chemicals have demonstrated potential use as environmentally benign insecticides, herbicides, and fungicides [3, 4]. Nevertheless, the traditional undergraduate chemical laboratory curriculum provides little exposure to photochemistry.     

Effect of substituent distribution on water solubility of O-methylcellulose

The effect of substituent distribution on the water solubility of O-methylcellulose (MC) was re-examined to elucidate the lower limit of the degree of substitution (DS) in water-soluble MC. To this end, a series of 2,3-MCs which are regioselectively substituted at the C-2 and C-3 hydroxyl groups were prepared by homogeneous methylation. It was found that the lower limit for the DS value of water-soluble 2,3-MC was almost the same as that for MCs having even distributions of substituents along the cellulose chain as well as in the anhydroglucose units. This revised version was published online in August 2006 with corrections to the Cover Date.