Synthesis,Crystal Structure and Magnetism Characterization of Two Coordination Polymers based on Ni(2‐mpac)2(H2O)2 as Molecular Building Block

Taking Ni(2‐mpac)₂(H₂O)₂ as molecular building block, two novel coordination polymers with the formula of [Ni(2‐mpac)₂(4,4′‐bpy)·(4,4′‐bpy)]_n ( 1 ) and [Ni(2‐mpac)₂(py)·4H₂O]_n ( 2 ) (2‐mpac = 5‐methyl‐2‐pyrazinecarboxylic acid; 4,4′‐bpy = 4,4′‐bipyridine; py = pyrazine) have been synthesized and structurally characterized by X‐ray single crystal diffraction method. In addition, elemental analysis, IR and magnetism characterization are presented.     

β-烷氧乙烯基三氟甲基酮类化合物在有机合成中的应用

β-烷氧乙烯基三氟甲基酮类化合物作为一类典型的含氟砌块, 被广泛地应用于含氟有机化合物的合成中. 综述了近年来此类含氟砌块的研究进展, 特别是在合成各种含氟杂环化合物中的应用.     

Microwave-assisted synthesis of fused heterocycles incorporating trifluoromethyl moiety

4,4,4-Trifluoro-1-(thien-2-yl)butane-1,3-dione (1) reacts with 5-aminopyrazole, 1,2,4-aminotriazole and 2-aminobenzimidazole derivatives, in the presence of triethylorthoformate under pressurized microwave irradiation to afford the corresponding trifluoromethyl derivatives of pyrazolo[1,5-a]pyrimidine, 1,2,4-triazolo[1,5-a]pyrimidine, and pyrimido[1,2-a]benzimidazoles. Also, compound 1 couples readily with azole diazonium salts to give pyrazolo[5,1-c]triazine, benzimidazo[5,1-c]1,2,4-triazine, and triazolo[3,4-c]1,2,4-triazine derivatives incorporating trifluoromethyl group.     

3-Fluoroalkyl (CF3, CHF2, CH2F) Cyclobutane-Derived Building Blocks for Medicinal Chemistry: Synthesis and Physicochemical Properties

Synthesis and physicochemical characterization of all possible cis- and trans-1,3-disubstituted cyclobutane-derived amines and carboxylic acids bearing mono-, di- and trifluoromethyl groups at the C-3 position is disclosed. Tetramethylammonium fluoride (TMAF)- or morpholinosulfur trifluoride (Morph-DAST)-mediated nucleophilic fluorination of appropriate cis- and trans-diastereomeric substrates was used as the key step for the preparation of CH₂F- and CHF₂-substituted derivatives. To obtain the corresponding cis- and trans-isomeric CF₃-substituted derivatives, resolution of known 3-(trifluoromethyl)cyclobutanecarboxylic acid (obtained as a mixture of diastereomers) was applied. The proposed procedures were suitable for the preparation of corresponding fluoroalkyl-substituted cyclobutane-derived amines and carboxylic acids on up to 50 g scale. All 12 building blocks obtained were characterized by measuring dissociation constants (pK_a) and lipophilicities (LogP, for model derivatives) to evaluate the effect of the fluoroalkyl substituents on their physicochemical properties relevant to further drug discovery applications.     

Multigram Synthesis of α- and γ-((Hetera)cyclo)alkylpyridines through α-Arylation of (Hetero)aliphatic Nitriles

A systematic study on the S_nAr reaction of halogenated fluoropyridines and (hetero)aliphatic nitrile anions as an approach to the synthesis of functionalized pyridines bearing a (cyclo)alkyl or saturated heterocyclic substituent by is described. The scope of the method was demonstrated on a wide range of (hetero)aliphatic nitriles (including three- to six-membered cycloalkane derivatives and N-, O-, S-containing saturated heterocycles) and all isomeric halogenated 2-and 4-fluoropyridines. High chemo- and regioselectivity (i. e., exclusive substitution of the fluorine atom), as well as excellent scalability of the proposed reaction sequence were demonstrated (up to 450 g for the arylation step or up to 77 g of cycloalkylpyridine over two steps in a single run). The utility of the synthesized products was illustrated in the additional functional group transformations resulting in synthetically valuable pyridine-containing building blocks.     

Simple high-performance liquid chromatography-ultraviolet method for simultaneous separation and detection of 14 bisphenol pollutants in building materials

A high-performance liquid chromatography-ultraviolet method was developed for rapidly and simultaneously analyzing novel and typical bisphenols in building materials, including bisphenol S, diphenolic acid, bisphenol F, bisphenol E, bisphenol A, bisphenol B, bisphenol AF, bisphenol AP, bisphenol C, bisphenol FL, bisphenol Z, bisphenol BP, bisphenol M, and bisphenol P. By using a Kromasil 100–5 C18 column, these bisphenols were completely separated in 40 min via gradually increasing the concentration of methanol in the mobile phase from 45 to 80% during the elution process. In particular, this method achieved the synchronous analysis of bisphenol S, diphenolic acid, bisphenol FL, bisphenol BP, and bisphenol M through HPLC, which were difficult to separate and had to be identified and detected through mass spectrometry. The limits of detection of the method ranged from 0.002 to 0.040 mg/L for these 14 bisphenols, with a precision of less than 4.9% (n = 7, c = 0.05 mg/L). The analytical results for five types of building materials (phenolic, epoxy, polycarbonate, polyester, and polysulfone resins) indicated that the proposed method is appropriated for the rapid measurement of bisphenols in real samples.     

The arithmetic and combinatorics of buildings for

In this paper, we investigate both arithmetic and combinatorial aspects of buildings and associated Hecke operators for with a local field. We characterize the action of the affine Weyl group in terms of a symplectic basis for an apartment, characterize the special vertices as those which are self-dual with respect to the induced inner product, and establish a one-to-one correspondence between the special vertices in an apartment and the elements of the quotient .

We then give a natural representation of the local Hecke algebra over acting on the special vertices of the Bruhat-Tits building for . Finally, we give an application of the Hecke operators defined on the building by characterizing minimal walks on the building for .

     

地震激励下参数不确定结构重叠分散保性能控制

对参数不确定结构振动控制方法进行了研究。基于包含原理,采用重叠分散控制策略与保性能控制算法相结合的方法,将高层建筑结构划分成一组子结构,对每一个子结构采用保性能控制方法设计控制器,提出了参数不确定结构重叠分散保性能控制方法,较好地解决了地震激励下参数不确定建筑结构的振动控制问题。以20层Benchmark结构模型为研究对象,采用重叠分散保性能控制策略和集中保性能控制策略进行数值模拟。结果表明,对于结构系统建模存在误差或系统本身存在不确定性的情况,本文提出的重叠分散保性能控制方法均能有效降低结构的地震响应,且能够保证控制系统的可靠性和稳定性。     

甘肃马家塬战国墓地M4出土硅酸盐珠饰的科学分析研究

结合X射线荧光光谱、拉曼光谱和X射线衍射分析,对甘肃马家塬战国墓地M4出土的11件装饰性硅酸盐珠饰进行了无损分析研究。依据分析结果将这些样品划分为钠钙硅酸盐玻璃、铅钡硅酸盐玻璃和釉砂三种类型。化学成分分析结果表明：钠钙硅酸盐蜻蜓眼玻璃珠的蓝色眼珠部分采用Co2+着色。拉曼光谱分析在铅钡体系硅酸盐样品中检测到了人工合成的硅酸钡铜系中国蓝和中国紫颜料,在钠钙蜻蜓眼玻璃的白色区域检测到了锑酸钙(CaSb₂O₆)乳浊剂/着色剂。结合已有的研究结果,探讨了所分析样品的可能来源及其反映的早期文化和技术交流状况。含有中国蓝、中国紫的装饰性珠子的制作材料和工艺应当是受到当时秦人的影响。而钠钙蜻蜓眼珠的成分特点,又与新疆等西北地区出土的同类珠子有相似之处。可见西戎人在玻璃制作技术方面同时受到北方草原民族文化和秦文化的共同影响。这批样品中以泥芯和玻璃化材料共同组成的装饰珠子,可能是从釉砂珠向玻璃珠的过渡类型,这对于研究我国玻璃的起源问题提供了新的参考资料。     

地下爆炸冲击波引起的基底滑移隔震建筑的动力响应

对埋置在土体中的圆形衬砌内发生意外爆炸引起的附近地表的滑移隔震建筑 (考虑了土 结构相互作用 )的动力响应进行了研究。在土 结构相互作用分析中 ,分别采用有限元、无穷元和集中质点体系建立了衬砌周围的有限土区、四周的无限土区以及基底滑移隔震建筑的计算模型 ;在基底滑移隔震分析中 ,提出了用连续摩擦力模型取代传统的库仑摩擦力模型 ,避免跟踪啮合滑移的过渡边界并可减小计算误差。通过数值模拟 6层基底滑移隔震建筑在遭受地下爆炸冲击波作用且考虑土 结构相互作用所产生的动力响应 ,分析了基底滑移隔震效果以及不同隔震参数对隔震效果的影响 ,为相关的理论研究和工程实践提供了依据。