硼酸三甲酯为探针红外光谱定量研究氧化镁的路易斯碱性

采用硼酸三甲酯(BATE)作为探针分子对MgO的路易斯碱性进行了红外光谱定量研究。MgO对硼酸三甲酯的吸附使硼酸三甲酯在1360cm-1的谱峰分裂成1410cm-1和1300cm-1两个峰,1036cm-1的谱峰紫移到1060cm-1。低压下吸收峰高与硼酸三甲酯压力成正比,与MgO含量成正比。结果表明MgO有一定的路易斯碱强度,与硼酸三甲酯之间的吸附是单分子层化学吸附。     

新的Schiff碱-双(2,3-二甲氧基苯甲醛)缩联苯胺的合成与光谱研究

以2,3-二甲氧基苯甲醛和联苯胺为原料,在无水甲醇溶剂中合成了一种新的Schiff碱,收率为86.0%.反应的最佳条件是2,3-二甲氧基苯甲醛与联苯胺的比例为3:1,反应时间为1h,反应温度为30℃.这种新的Schiff碱结构利用IR和UV光谱表征.     

牛磺酸2吡-啶甲醛Schiff碱镧配合物的合成及表征

采用直接合成法用牛磺酸和2-吡啶甲醛合成牛磺酸Schiff碱,并以此为配体合成La（Ⅲ）的配合物,同时对Schiff碱及金属配合物进行元素分析,红外光谱,紫外光谱,差热-热重分析及摩尔电导的测定等表征,从而推测配合物的组成为[L aL2（H2O）2]NO3.H2O,HL=C8H10N2O3S。     

水杨醛缩二乙基三胺铜配合物的合成与结构分析

合成了水杨醛缩二乙基三胺 (配体 L,2 - [(N- Salicylideneamino) ethyl]amine)与 Cu( )形成的配合物[Cu L(H2 O) ]Cl,通过元素分析、红外光谱、X射线单晶衍射进行了结构分析。配合物为单斜晶系 ,空间群P2 (1) / c,晶体学结构数据 ,a=0 .912 3(5 ) nm,b=1.382 1(7) nm,c=1.0 82 9(5 ) nm,β=10 1.712 (7)°,V=1.336 9(11) nm3 ,Z=4 ,Dcalcd=1.6 0 6 mg/ m3 ,F(0 0 0 ) =6 6 8,R1=0 .0 377,w R2 =0 .10 18。结构分析表明 ,配合物通过氢键形成二聚结构     

Nd-四甘醇醛缩苯丙氨酸Schiff碱配合物与DNA相互作用的光谱研究

研究了Nd-四甘醇醛缩苯丙氨酸Schiff碱配合物(NdL)与天然和变性DNA的相互作用.在DNA存在下,测定了NdL的紫外吸收光谱(UV)和荧光激发光谱(FL).利用紫外滴定法,测定了NdL与DNA的结合常数.在20mmol/L Tris-HCl缓冲溶液(pH=7.0),Nd-四甘醇醛缩苯丙氨酸Schiff碱配合物与小牛胸腺DNA的结合常数为4.11×103L/mol,化合物本身的UV和FL峰强度减小.NdL与DNA的作用模式为"静电引力".     

RS和GIS技术在新疆地质和矿产资源评价中的应用

发展宏观、快速、高效地资源管理及评价方法是开展现代地质找矿工作的需要，“3S”技术由于具有上述特点而在地质找矿领域得到越来越广泛的应用。本文针对新疆地质找矿现状，通过对“3S”技术特点的介绍，在以往新疆地质找矿工作的基础之上，系统的提出了在新疆运用RS和GIS技术建立遥感本底数据库及进行矿产资源评价、地质灾害预测的主要内容、方法，同时指出了存在的问题和发展前景。     

牛磺酸Schiff碱及其Cu（Ⅱ）配合物的合成与表征

用牛磺酸与2-吡啶甲醛反应合成了一种牛磺酸Schiff碱,并制备了它与Cu（Ⅱ）的配合物[CuL（H2O）].NO3,其中HL=C8H10N2O3S,利用元素分析,红外光谱,紫外光谱,差热-热重分析及摩尔电导的测定等方法对Schiff碱及金属配合物进行了表征。     

On the complexity of enumerating pseudo-intents

We investigate whether the pseudo-intents of a given formal context can efficiently be enumerated. We show that they cannot be enumerated in a specified lexicographic order with polynomial delay unless P=NP. Furthermore we show that if the restriction on the order of enumeration is removed, then the problem becomes at least as hard as enumerating minimal transversals of a given hypergraph. We introduce the notion of minimal pseudo-intents and show that recognizing minimal pseudo-intents is polynomial. Despite their less complicated nature, surprisingly it turns out that minimal pseudo-intents cannot be enumerated in output-polynomial time unless P=NP.     

Sequentially Cohen-Macaulay Modules Under Base Change

ABSTRACT

Assume that ?:(R, ± 𝔪) → (S, ± 𝔫) is a local flat homomorphism between commutative Noetherian local rings R and S. Let M be a finitely generated R-module. We investigate the ascent and descent of sequentially Cohen-Macaulay properties between the R-module M and the S-module M ? _R  S.     

Metal‐Ion‐Binding Analogs of Ribonucleosides: Preparation and Formation of Ternary Pd2+ and Hg2+ Complexes with Natural Pyrimidine Nucleosides

Four metal‐ion‐binding nucleosides, viz. 2,6‐bis(1‐methylhydrazinyl)‐9‐(β‐D ‐ribofuranosyl)‐9H‐purine ( 2a ) and its N‐acetylated derivative, 2b , 2,4‐bis(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)‐5‐(β‐D ‐ribofuranosyl)pyrimidine ( 3 ), and 2,4‐bis(1‐methylhydrazinyl)‐5‐(β‐D ‐ribofuranosyl)pyrimidine ( 4 ) have been synthesized. The ability of these nucleosides and the previously prepared 2,6‐bis(3,5‐dimethyl‐1H‐pyrazol‐1‐yl)‐9‐(β‐D ‐ribofuranosyl)‐9H‐purine to form Pd²⁺‐ and Hg²⁺‐mediated complexes with uridine has been studied by ¹H‐NMR spectroscopy. To obtain additional support for the interpretation of the NMR data, comparative measurements on the ternary‐complex formation between pyridine‐2,6‐dicarboxamide ( 5 ), pyrimidine nucleosides, and K₂PdCl₄ were carried out.