双波长分光光度法同时测定灌木饲料中的铁和铝

利用铁、铝与邻苯二酚紫（PCV）形成的络合物的最大吸收波长相差30nm的光谱性质，建立了同时测定铁和铝的双波长分光光度法，并对络合物的形成条件及相互干扰情况进行研究，方法用于灌木饲料样品中铁和铝测定。     

用热重法研究我国四种煤显微组分的燃烧特性

本文用热天平考察了平朔煤，红阳煤，大同煤和东胜煤显微组分的燃烧特性，以及原生矿物质对显微组分燃烧的影响。研究表明，各显微组分的燃烧特征温度，镜质组低于惰质组，壳质组在燃烧的有，中期，特征温度较低，在燃烧后期，与其它两个显微组分的特征温度差值变小。     

Highly enantioselective Michael addition of <Emphasis Type="Italic">α,α</Emphasis>-disubstituted aldehydes to nitroolefins

A highly enantioselective Michael addition reaction of α,α-disubstituted aldehydes to β-nitrostyrenes has been developed. In the presence of rosin-based chiral primary amine-thiourea, γ-nitroaldehydes were afforded in excellent enantioselectivities (up to 99 % ee) with up to 99 % yield.     

Tetravalent Vertex-Transitive Graphs of Order Twice A Prime Square

A graph is vertex-transitive if its automorphism group acts transitively on vertices of the graph. A vertex-transitive graph is a Cayley graph if its automorphism group contains a subgroup acting regularly on its vertices. In this paper, a complete classification is given of tetravalent vertex-transitive non-Cayley graphs of order \(2p^2\) for any prime p.     

Stereodivergent Synthesis of Functionalized Tetrahydropyrans Accelerated by Mechanism‐Based Allylboration and Bioinspired Oxa‐Michael Cyclization

A stereodivergent strategy enabled by bioinspired oxa‐Michael cyclization was developed for the synthesis of functionalized tetrahydropyrans on the basis of the inherent symmetry in 1,3‐diols, the symmetries of which were tunable by stereoselective hydroboration of an allene with a variety of alkylborane reagents and subsequent allylation of an aldehyde. The mechanism‐based utilization of monoalkyl borane in the hydroboration and allylation cascade is unprecedented.     

Higher-Order Logic Formalization of Conformal Geometric Algebra and its Application in Verifying a Robotic Manipulation Algorithm

Conformal geometric algebra (CGA) is an advanced geometric language used in solving three-dimensional Euclidean geometric problems due to its simple, compact and coordinate-free formulations. It promises to stimulate new methods and algorithms in all areas of science dealing with geometric properties, especially for engineering applications. This paper presents a higher-order logic formalization of CGA theories in the HOL-Light theorem prover. First, we formally define the classical algebraic operations and representations of geometric entities in the new framework. Second, we use these results to reason about the correctness of operation properties and geometric features such as the distance between the geometric entities and their rigid transformations in higher-order logic. Finally, in order to demonstrate the practical effectiveness and utilization of this formalization, we use it to formally model the grasping algorithm of a robot based on the conformal geometric control technique and verify the property that whether the robot can grasp firmly or not.     

An easily Prepared Fluorescent pH Probe Based on Dansyl

A novel fluorescent pH probe from dansyl chloride and thiosemicarbazide was easily prepared and fully characterized by ¹H NMR, ¹³C NMR, LC-MS, Infrared spectra and elemental analysis. The probe exhibited high selectivity and sensitivity to H⁺ with a pK _a value of 4.98. The fluorescence intensity at 510 nm quenched 99.5 % when the pH dropped from 10.88 to 1.98. In addition, the dansyl-based probe could respond quickly and reversibly to the pH variation and various common metal ions showed negligible interference. The recognition could be ascribed to the intramolecular charge transfer caused by the protonation of the nitrogen in the dimethylamino group.     

低价钛盐还原反应的研究——Ⅱ.低价钛盐与芳基三卤甲烷的反应

用LiAlH_4或Zn、Mg等与四氯化钛作用得到的低价钛盐能使芳基三卤甲烷还原偶联为1,1,2,2-四卤-1,2-二芳基乙烷、1,2-—二卤-1,2-二芳基乙烯或二芳基乙炔,反应可能生成ArCX_2·自由基,然后偶联为二芳基四卤代乙烷,后者能脱去卤素生成二芳基二卤代乙烯。TiCl_3和Ti°与三氯甲苯作用能得到相似的后果。     

Two new lactones and one new aryl-8-oxa-bicyclo[3,2,1]oct-3-en-2-one from Descurainia sophia

Two new lactones (1, 2), descurainolide A and B, and one new aryl-8-oxa-bicyclo[3,2,1]-oct-3-en-2-one (3), descurainin, together with five known compounds (4-8), were isolated from the seeds of Descurainia sophia (L.) WEBB ex PRANTL. The structures of the new compounds were elucidated by extensive studies of their 1D, 2D NMR and HR-MS. Compounds 4 and 5 showed cytotoxicity.