Theoretical Studies on S-Phenyl-thiabenzene,S-Phenyl-thianaphthalene,and S-Phenyl-thiaanthracene

The molecular structures of S-phenyl-thiabenzene 1, S-phenyl-1-thianaphthalene 2, S-phenyl-2-thianaphthalene 3, and S-phenyl-9-thiaanthracene 4 are studied by ab initio calculations using HF as well as DFT methods at the 6–311+G? level of theory. The non-planar boat conformers of 1–4 with 6π electrons in the heterocyclic ring appear to be more stable than the corresponding planar conformers with 8π electrons in the ring. The activation energy for the inversion at the sulfur atom is compared for 1–4. Conformational flexibility of 1–4 is studied.     

挖掘机器人视觉目标定位

为实现挖掘机器人的自动挖掘,在挖掘机实验模型基础上进行了电路改造,构建了以单片机为核心的控制电路,通过无线蓝牙与上位机进行通讯,实现对挖掘机操作装置的控制。通过视觉传感器采集挖掘机铲斗、目标物的实时图像,经图像处理后,对目标物中心及铲斗标记中心进行提取、定位,计算出二者之间的实时距离,进而控制挖掘机铲斗对目标物进行挖掘。     

山区智能视觉火情高空图像搜集系统的设计与实现

介绍了一种针对山区多样性突发火情事件中基于智能视觉的高空图像搜集系统,采用以ST意法半导体公司的STM32F107VCT6为处理核心的开发平台,地面控制平台通过高空无人机的高速照相机对目标区域火情图像数据进行搜集,并将图像数据带回到地面控制平台的PC处理器上进行综合分析。地面控制平台根据智能视觉信息采集模块采集的山区遥感图像的均值作为初始背景,并对背景图像进行实时更新,利用光谱特征与距离算法获取差分图像,并进行图像处理,从而获取山区发生火情区域的图像分析数据,以实现对山区森林突发火情事件的及时监测,在火情发生初始阶段就能扑灭。本文对山区智能视觉火情高空搜集系统的实现原理、核心硬件设计、系统软件设计等分别进行了研究,并通过系统实验进行了验证,测试结果表明,该系统在对山区的高空图像搜集实验中,对不同颜色物体的分别识别率为100%,对火灾与地形地貌的识别率为95.55%和81.12%,非常适用于各种山区环境下的智能视觉监控系统。     

A characterization of almost simple K 3-groups

It is a well-known fact that characters of a finite group can give important information about the group's structure. Also it was proved by the third author of this article that a finite simple group can be uniquely determined by its character table. Here the authors attempt to investigate how to characterize a finite almost simple group by using less information of its character table, and successfully characterize the almost simple K₃-groups by their orders and at most three irreducible character degrees of their character tables.     

Two Aromatic Ester Organoimido Derivatives of Hexa­molybdate: Syntheses,Crystal Structures,and Spectroscopic Studies

Two alkylimido derivatives of hexamolybdate, (Bu₄N)₂[Mo₆O₁₈(≡N‐o‐COOCH₃C₆H₄)] ( 1 ) and (Bu₄N)₂[Mo₆O₁₈(≡N‐o‐COOCH₂CH₃C₆H₄)] ( 2 ), were synthesized in high purity and good yields by the reaction of [(C₄H₉)₄N]₄[α‐Mo₈O₂₆] and methyl anthranilate or ethyl‐o‐aminobenzoate hydrochloride with N,N′‐dicyclohexylcarbodiimide (DCC) as a dehydrating agent in dry acetonitrile solution, which were characterized by elemental analyses, IR, UV/Vis, and ¹H NMR spectroscopy as well as ESI‐MS, and single‐crystal X‐ray diffraction study. Compound 1 crystallizes in the monoclinic space group P2₁/n with one‐dimensional chain structure via intramolecular hydrogen bond. Compound 2 also crystallizes in the monoclinic space group P2₁/n with dimer structure by intramolecular hydrogen bonds and π–π interactions between the pairs of cluster anions.     

CM newforms with rational coefficients

We classify newforms with rational Fourier coefficients and complex multiplication for fixed weight up to twisting. Under the extended Riemann hypothesis for odd real Dirichlet characters, these newforms are finite in number. We produce tables for weights 3 and 4, where finiteness holds unconditionally. I am indepted to K. Hulek for his continuous interest and encouragement. Partial support by the DFG Schwerpunkt 1094 “Globale Methoden in der komplexen Geometrie” is gratefully acknowledged. My thanks go also to the referee for helpful comments. Part of the revising took place while I enjoyed the hospitality of the Dipartimento di Matematica “Frederico Enriques” of Milano University. Funding from the network Arithmetic Algebraic Geometry, a Marie Curie Research Training Network, is gratefully acknowledged. I particularly thank M. Bertolini and B. van Geemen. The final version was prepared while I was funded by DFG under grant Schu 2266/2-2.