414 research outputs found
N′-Diphenylmethylene-2-hydroxybenzohydrazide
The title compound, C20H16N2O2, was synthesized by the reaction of 2-hydroxybenzohydrazide with diphenylmethanone. The dihedral angle between the phenyl rings is 76.28 (11)°. The amino H atom is involved in an intramolecular N—H⋯O hydrogen bond. In the crystal structure, the hydroxy groups and carbonyl O atoms form intermolecular O—H⋯O hydrogen bonds, which link the molecules into chains running along the b axis
1-(2-Chlorobenzylidene)-2-(2,4-dinitrophenyl)hydrazine
In the title compound, C13H9ClN4O4, there are two crystallographically independent molecules in the asymmetric unit, which have very similar conformations. The C=N—N angles in each independent molecule are 115.0 (2) and 116.6 (2)°, which are significantly smaller than the ideal value of 120° expected for sp
2-hybridized N atoms. This is probably a consequence of repulsion between the nitrogen lone pairs and the adjacent N—N bonds. Two bifurcated intramolecular N—H⋯O hydrogen bonds help to establish the molecular conformation and consolidate the crystal packing
罕见混合型完全性肺静脉异位连接1例
Cases of mixed total anomalous pulmonary venous connection were rare, while cases of the vertical vein drained to jugular vein were even rarer. Pay attention to the size of pulmonary vein and left atrial anastomosis, increase the left atrium volume with pericardial patch, which play an important role to prevent postoperative pulmonary edema caused by anastomosis stenosis, poor back flow of coronary sinus and smaller left atrial volume.混合型完全性肺静脉异位连接(total anomalous pulmonary venous connection,TAPVC)罕见,而垂直静脉异位引流至颈静脉者更为罕见。术中应注意肺静脉与左房吻合口应足够大,心包补片应扩大左心房容积,防治术后吻合口狭窄、冠状静脉窦回流不畅、以及左房容积过小引起的肺水肿等并发症
2-Hydroxy-N′-[(1E,2E)-3-phenylprop-2-enylidene]benzohydrazide
In molecule of the title compound, C16H14N2O2, the two aromatic rings form a dihedral angle of 6.93 (3)° and an intramolecular N—H⋯O hydrogen bond occurs. In the crystal structure, intermolecular O—H⋯O hydrogen bonds link the molecules into zigzag chains running in the [10] direction
1-Cyclopentylidene-2-(2,4-dinitrophenyl)hydrazine
The title compound, C11H12N4O4, was synthesized by the reaction of (2,4-dinitrophenyl)hydrazine with cyclopentanone. The cyclopentyl fragment is disordered over two sites with occupancies of 0.63 (1) and 0.37 (1). An intramolecular N—H⋯O hydrogen bond helps to establish the conformation. Pairs of molecules are held together by π–π interactions between adjacent benzene rings [centroid-to-centroid distance 3.589 (2) Å]
Investigation on Microstructure and Optical Property of Nanocrystalline Silicon Thin Film
Nanocrystalline silicon (nc-Si:H) thin films were deposited by capacitive coupled radio-frequency plasma enhanced chemical vapor deposition (RF-PECVD) system with direct current (DC) bias applied. Raman, XRD and ultraviolet-visible transmission spectra were employed to investigate their microstructure and optical properties, respectively. Both the crystalline volume fraction and the average crystalline size increase with the substrate temperature. With the increase of silane concentration, the crystalline volume fraction increases, while the average crystalline size decreases. With the increase of the radio frequency (RF) power or the DC negative bias voltage, the crystalline volume fraction and the average crystalline size increase firstly, then decreases. Finally, the optical band gaps were discussed in detail
2-(1H-1,2,3-Benzotriazol-1-yl)-N′-cyclopentylideneacetohydrazide
The title compound, C13H15N5O, was synthesized by the reaction of 2-(1H-1,2,3-benzotriazol-1-yl)acetohydrazide with cyclopentanone. In the cyclopentane ring, two C atoms and their attached H atoms are disordered over two positions; the site occupancy factors are ca 0.63 and 0.37. In the crystal structure, molecules are linked into infinite chains directed along the b axis by N—H⋯O hydrogen bonds. In addition, there are weak C—H⋯O and C—H⋯N hydrogen bonds, as well as C—H⋯π-ring interactions in the structure
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