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排序方式: 共有69条查询结果,搜索用时 31 毫秒
1.
Jianyi Shi Xia Chen Jingyun Huang Yantong Lu Zhendong Yang Mingli Zhong Dr. Zhongzhi Zhu Dr. Xiuwen Chen 《European journal of organic chemistry》2023,26(3):e202201231
The efficient three-component cascade coupling reaction of 3-haloisoquinolines, haloalkanes, and sp3-carbon nucleophiles (acetophenone or nitromethane) led to a series of structurally novel 1,2-disubstituted-3-isoquinolinones through the formation of C(sp3)−C(sp2), C−N, and C=O bonds. The NaOAc-promoted reaction described in this work is simple to operate, environment friendly, and highly selective. 相似文献
2.
Chiral Ammonium Betaine‐Catalyzed Highly Stereoselective Aza‐Henry Reaction of α‐Aryl Nitromethanes with Aromatic N‐Boc Imines 下载免费PDF全文
Dr. Daisuke Uraguchi Keigo Oyaizu Haruhiro Noguchi Prof. Dr. Takashi Ooi 《化学:亚洲杂志》2015,10(2):334-337
A highly stereoselective aza‐Henry reaction of α‐aryl nitromethanes with aromatic N‐Boc imines was established by using C1‐symmetric chiral ammonium betaine as a bifunctional organic base catalyst. Various substituted aryl groups for both imines and nitromethanes were tolerated in the reaction, and a series of precursors for the synthesis of unsymmetrical anti‐1,2‐diaryl ethylenediamines was provided. 相似文献
3.
Jinwei Sun Xinrui Yang Yun Liu Yi Wang Yi Pan 《Journal of heterocyclic chemistry》2020,57(3):1449-1455
An efficient synthesis of 3-nitroimidazo[1,2-a]pyridines has been developed via N-iodosuccinimide (NIS)-mediated multicomponents reaction of 2-aminopyridines, aldehydes, and nitromethane under metal-free conditions. This protocol has many advantages such as broad substituent scope, mild and eco-friendly conditions, high step economy, and good yields. 相似文献
4.
Peter Politzer Jane S. Murray Pat Lane 《International journal of quantum chemistry》2009,109(3):534-539
For five prototypical energetic molecules (nitrobenzene, methyl azide, methyl nitrate, nitromethane, and dimethylnitramine), we examine computationally the effects of external electric fields upon their “trigger linkage” bonds, the breaking of which is believed to play a key role in detonation initiation. The bonds are, respectively, C? NO2, N? N2, O? NO2, C? NO2, and N? NO2. The calculations are at the B3PW91/6–31G** level. We find that fields along these bonds that reinforce the molecules' intrinsic polarities also lower their energies and increase the bonds' stretching vibration frequencies. This suggests a strengthening of the bonds. Fields in the opposite direction do the reverse. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009 相似文献
5.
Barahman Movassagh 《Phosphorus, sulfur, and silicon and the related elements》2016,191(8):1114-1117
A task-specific ionic liquid, [bmim]OH, has been found to be a highly efficient catalyst for one-pot, three-component coupling of aryl aldehydes, nitromethane, and thiols for the synthesis of β-nitro sulfides in water. The main advantages of the present protocol include the use of inexpensive simple substrates and an ionic liquid as a basic catalyst. 相似文献
6.
Entropy of transfer of nitromethane, nitroethane, 1-nitrobutane, 1-nitropentane, and 1-nitrohexane from n-octane to water at 25°C is calculated using an electrostatic model. The calculations indicate that the electrostatic transfer entropy depends primarily on the dipole moment and the size of the-C–NO2 group, showing a trend which is similar to that previously found for the transfer free energy of the same process. 相似文献
7.
Two experimental values (?19.3 ± 0.3 and ?17.8 ± 0.1 kcal/mol) for the gas phase heat of formation (δfH) (298k) of nitromethane have been reported. Although these values differ by only 1.5 kcal/mol, substantially greater differences in theoretical and experimental results occur when these differing values are used to calculate thermodynamic properties. This is especially evident when these two values for the δfH of nitromethane are used to calculate thermodynamic properties of polynitro compounds. For example, when density functional theory (DFT) is coupled with the use of isodesmic reactions, the ΔfH of octanitrocubane is calculated to be 160.6 or 172.6 kcal/mol, depending on which value is used. It should also be appreciated that several computational theories depend upon having access to reliable experimental data for testing and development. We have examined this discrepancy using several computational models and several levels of theory. Our results coupled with a comprehensive review of the literature support the lower (?19.3 ± 0.3 kcal/mol) experimental value. This is problematic because the higher value (?17.8 ± 0.1 kcal/mol) has been used in the development and/or testing of several semiempirical quantum mechanical models as well as ab initio Gaussian theory (G2 and G3). Copyright © 2008 John Wiley & Sons, Ltd. 相似文献
8.
采用基于密度泛函理论的第一性原理分子动力学方法对液态硝基甲烷的热分解行为进行了模拟,结合各产物布居数随时间的演化,讨论了热分解初期可能发生的3种反应,即分子内/分子间的质子迁移反应和C—N键的断裂.在长时间(30 ps)的模拟过程中,H2O是主要产物.研究了液态硝基甲烷在不同密度(压力)条件下热分解的动力学行为.发现不同密度(压力)条件下液态硝基甲烷热分解呈现明显不同的变化趋势,并给出了解释.
关键词:
硝基甲烷
分子动力学
热分解
压力效应 相似文献
9.
Dip Singh Gill 《Journal of solution chemistry》1979,8(10):691-699
Precise conductances for tetrabutylammonium tetrabutylboride (Bu4NBBu4) at 25°C have been measured in a number of nonaqueous solvents, and the data have been analyzed by the 1957 Fuoss-Onsager conductance equation. Limiting ion conductances for the Bu4N+ ion at infinite dilution 0(Bu
4
N
+) in various solvents have been evaluated by dividing 0 values of the salt into two equal parts. The 0(Bu
4
N
+) values so obtained are in fairly good agreement (within±0.1–3.5%) with the corresponding values determined from direct transference number measurements in these solvents. 相似文献
10.
利用硝基甲烷还原法在室温条件下得到了纳米Pt粒径可控的担载Pt/γ-Al2O3催化剂, 并利用甲醇重整反应为反应探针考察了Pt粒径与催化反应性能之间的关系, 发现催化反应的性能与担载贵金属颗粒粒径之间存在明显的相关性. 通过透射电镜(TEM)、X射线衍射(XRD)、程序升温还原(TPR)等测试手段对催化剂进行表征, 发现钠米Pt的粒径大小不但影响甲醇重整反应的活性, 同时也影响反应的选择性, 即催化剂的催化性能与担载贵金属粒径之间存在明显的尺度效应. 相似文献