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981.
磁化作用对汽油动态挥发性影响的研究   总被引:1,自引:0,他引:1  
用热重(TG)分析和自行设计的原位动态挥发实验,研究了在不同条件下汽油的挥发性,结果表明,磁化空气或磁化汽油都可提高汽油的挥发性,而汽油和空气共同磁化,可更大幅度地提高汽油的挥发性。  相似文献   
982.
The structure of hexadeca‐μ‐acetato‐tetra­aqua­dodeca‐μ3‐oxo‐dodecamanganese bis(acetic acid) tetrahydrate, [Mn12O12(CH3COO)16(H2O)4]·2CH3COOH·4H2O, known as Mn12–acetate, has been determined at 83 (2) K by X‐ray diffraction methods. The fourfold (S4) molecular symmetry is disrupted by a strong hydrogen‐bonding interaction with the disordered acetic acid mol­ecule of solvation, which displaces one of the acetate ligands in the cluster. Up to six Mn12 isomers are potentially present in the crystal lattice, which differ in the number and arrangement of hydrogen‐bonded acetic acid mol­ecules. These results considerably improve the structural information available on this molecular nanomagnet, which was first synthesized and characterized by Lis [Acta Cryst. (1980), B 36 , 2042–2046].  相似文献   
983.
In the title compound, poly[μ5‐pyrazine‐2,3‐dicarboxyl­ato‐cadmium(II)], [Cd(C6H2N2O4)]n or [Cd(pdc)]n, where pdc is the pyrazine‐2,3‐dicarboxyl­ate anion, the CdII atom is six‐coordinated by five carboxyl­ate O atoms and one N atom from five different pdc ligands in a distorted octa­hedral CdO5N coordination geometry. Two CdII atoms are bridged by carboxyl­ate groups of the pdc ligands to create a dimeric unit. The dimeric units are further connected by the pdc ligands to generate an inter­esting two‐dimensional structure.  相似文献   
984.
N,N′‐Bis(4‐pyridylmethyl)oxalamide, C14H14N4O2, exists as a dimer which is extended into a two‐dimensional network with other dimers through pyridine–amide hydrogen bonds. The crystal structure of the title coordination polymer, {[CoCl2(C14H14N4O2)]·0.5H2O}n, features a one‐dimensional zigzag chain, in which the cobalt ion sits at a twofold symmetry position and adopts a tetrahedral geometry, and the bridging ligand lies on an inversion center and connects to CoII ions in a bis‐monodentate mode. Furthermore, two interwoven chains create a cavity of ca 8.6 × 8.6 Å, which produces a three‐dimensional channel. Water molecules are held in the channel by hydrogen bonds.  相似文献   
985.
In the title compound, [Nd2(C4H4O4)2(C2O4)(H2O)2]n, the flexible succinate anion assumes the gauche conformation and bridges the nine‐coordinate Nd atoms to generate two‐dimensional layers parallel to (010). The coordination polymer layers are linked into a three‐dimensional framework by the rigid oxalate ligands. The oxalate ions are located on a center of inversion.  相似文献   
986.
A new norsesquiterpene named eupatorone (= (4S,4aR,6R)‐1‐acetyl‐6‐(acetyloxy)‐4,4a,5,6‐tetrahydro‐4,7‐dimethylnaphthalen‐2(3H)‐one; 1 ) and a new sesquiterpene derivative named 2‐deoxo‐2‐(acetyloxy)‐9‐oxoageraphorone (= (1R,4S,4aR,6R,8aS)‐6‐(acetyloxy)‐3,4,4a,5,6,8a‐hexahydro‐4,7‐dimethyl‐1‐(1‐methylethyl)naphthalen‐2(1H)‐one; 2 ), together with the five known cadinene derivatives 3 – 7 were isolated from the flower of Eupatorium adenophorum (Spreng. ). Their structures were established by extensive NMR experiments, including 1D and 2D NMR.  相似文献   
987.
In the title compound, [Zn(C17H10N5O)2(H2O)2]·4H2O, cyclic water hexa­mers forming one‐dimensional metal–water chains are observed. The water clusters are trapped by the co‐operative association of coordination inter­actions and hydrogen bonds. The ZnII ion resides on a centre of symmetry and is in an octa­hedral coordination environment comprising two O atoms and two N atoms from two 2′‐(4,5‐diaza­fluoren‐9‐yl­idene)picolinohydrazidate ligands and two water mol­ecules.  相似文献   
988.
Layer-by-layer fluorescent conjugated polyelectrolyte films have been studied. The photoluminescence of conjugate polyelectrolytes was observed to be highly tunable during this film assembly process. Efficient photoinduced electron transfer from thus prepared highly luminescent film to a natural electron-transfer protein cytochrome c has also been observed.  相似文献   
989.
Three new alkaloids, longistylumphyllines A–C (1–3), together with the six known alkaloids deoxycalyciphylline B, deoxyisocalyciphylline B, methyl homosecodaphniphyllate, daphnicyclidin A, daphnicyclidin B, and daphnicyclidin F, were isolated from the stems and leaves of Daphniphyllum longistylum. Their structures and relative configuration were elucidated on the basis of spectroscopic data, especially 1D and 2D NMR techniques.  相似文献   
990.
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