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31.
Svatopluk Zeman Michal Roh
Zdenk Friedl Ale Ri
ka Antonín Ly
ka 《Propellants, Explosives, Pyrotechnics》2010,35(2):130-135
An X‐ray crystallographic study of 2,2″,4,4′,4″,6,6′,6″‐octanitro‐1,1′ : 3′,1″‐terphenyl (ONT) has been carried out. The dihedral angles between benzene rings vary from 84.9° to 89.4°. Nonbinding interatomic distances of oxygen atoms inside all the nitro groups are shorter than the intermolecular contact radii for oxygen. On the basis of the DFT B3LYP/6‐31(d, p) method it was found that the difference between the X‐ray structure in the solid phase and DFT result for the gas phase is 98 kJ mol−1, and the bearer of the highest initiation reactivity of the ONT molecule in the solid phase should be the nitro group at 4″‐position, in contrast to those at 4′‐ or 6′‐position that play this role in the isolated molecule. It has been stated that the nitro groups at the reaction centers of the ONT molecule are relatively well specified by their 15N NMR chemical shifts. 相似文献
32.
The paper is focused on 2,4,6,4′,6′,2″,4″,6″-octanitro[1,1′,3′,1″]-terphenyl (ONT), 2,2′,2″,4,4′,4″,6,6′,6″-nonanitro[1,1′,3′,1″]-terphenyl (NONA), 2,4,6-tris(2,4,6-trinitrophenyl)-1,3,5-triazine (TPT), N,N-bis(2,4-dinitrophenyl)-2,4,6-trinitroaniline (NTFA), 2,2′,4,4′,6,6′-hexanitrobiphenyl (HNB), 1,3-dinitrobenzene (1,3-DNB) and 1,3,5-trinitrobenzene (TNB). The initiation reactivity of these substances has been studied by means of the data obtained from non-isothermal differential thermal analysis (DTA), their ignition temperatures, impact sensitivity, the data obtained from the Russian manometric method and the detonation characteristics. For comparison, also the data published about 2,2′,2″,2″′,4,4′,4″,4″′,6,6′,6″,6″′-dodecanitro-[1,3′,1′,1″]quaterphenyl (DODECA) have been included. The paper specifies and discusses the relationships between the results of various methods used, inclusive of the forms of modified Evans-Polanyi-Semenov relationship. It has been stated that the technologically most attractive substances, out of those studied, can be ordered in the sequence ONT-TPT-NONA-NTFA according to their increasing thermal reactivity. 相似文献
33.
The values of bond dissociation energies, BDE, of the weakest N–N bonds and total energies, Etotal, of molecules have been calculated for 14 cyclic nitramines by means of the UB3LYP/6-31G? and UB3LYP/6-31+G? // PM3 methods. Ambiguous relationships were found between the logarithms of detonation velocities and BDE/Etotal ratios of these nitramines. The reason of this found ambiguity mainly lies in a real conformation of the respective molecules and intermolecular force effects in real molecular crystals, which are included in neither of the two calculation methods. However, partial relationships of this type can be used for evaluation of effectiveness of the method of designing molecular structures of energetic cyclic nitramines for obtaining products with the maximum possible performance. 相似文献
34.
Abstract Electronic charges, q, at nitrogen atoms of twelve m-dinitrobezopolyazaarenes were calculated by means of ab initio HF/6–31G?? and semi-empirical AM1 methods. The relationships have been confirmed between squares of the detonation velocities or, as the case may be, the detonation heats of the azaarenes and q-values for primarily split off nitro groups. These relationships were considered as an analogue of modified Evans-Polanyi-Semenov equation and so they directly specify the most reactive nitro groups of m-dinitrobenzopolyazaarene molecules in the detonation. 相似文献
35.
36.
用聚异丁烯(PIB),丙烯腈-聚丁橡胶(ABR),维通A黏结剂和RDX,HMX,BCHMX和ε-HNIW四种硝胺炸药制备了一系列塑性炸药.PETN和以PETN为基的三种塑性炸药用于比较.测试了这些炸药的爆速,撞击和摩擦感度.摩擦感度与撞击感度的关系以及两种感度与D<'2>的关系表明摩擦力向硝胺炸药分子反应中心的转移机理... 相似文献
37.
The friction sensitivity (FS) of five aliphatic linear and eight cyclic nitramines has been determined and correlated with DFT B3LYP/6-31-G(d,p) // 6-311 + G(d,p) positive ( VS,max ) and negative ( VS,... 相似文献
38.
Impact Sensitivity in Respect of the Crystal Lattice Free Volume and the Characteristics of Plasticity of Some Nitramine Explosives(英) 总被引:1,自引:1,他引:0
The relationship between the crystal lattice free volume,ΔV,and impact sensitivity,E_(dr),of ten nitramines has been analyzed. It was found that this relationship is not uniquely determined,i. e. it is not given only by their own ΔV values but fundamentally by the type and intensity of the intermolecular forces in the nitramine crystals. Also,relationships between the E_(dr)values,on the one hand,and bulk modulus,K,and shear modulus,G,on the other,have been the subject of discussion not only for pure cyclic nitramines but also for their PBXs,bonded by a poly-fluoro binder. The closest linear correlation exists between the E_(dr)values and dimensionless K·G~(-1) ratio which indicates the plasticity range. A similar relationship is valid also for the ΔV values. Relationships of the E_(dr) and / or ΔV values with the shear modulus or to the K·G~(-1) ratio reflect an unusual behavior of ε-HNIW to which the published morphological instability of this particular HNIW version might also be related. 相似文献
39.
Martin Kalbá? Ladislav Kavan Svatopluk Civiš Michal Bittner Vladimír Vorlí?ek 《Carbon》2005,43(8):1610-1616
Double-walled carbon nanotubes were prepared by XeCl-laser irradiation of fullerene (C60 or C70) peapods. Raman spectroscopy evidences less defect structure of outer tubes, as compared to those in double-walled carbon nanotubes grown by thermal treatment of peapods. The diameter distribution also differs from that of the thermally prepared nanotubes. At the given laser fluence, the conversion of C70@SWCNT into double-walled carbon nanotubes was more efficient than the corresponding conversion of C60@SWCNT. 相似文献
40.
Published data of impact sensitivity of 33 polynitro compounds detected by sound were expressed as the drop energy, Edr, required for 50 percent initiation probability. A logarithmic relationship has been found between the Edr values and heats of fusion of the said compounds. The relationship has been found to be in accordance with the idea concerning the role of plastic deformations of crystal played in the initiation of energetic materials by impact and shock. An analogous application of heats of sublimation has not given convincing results. 相似文献