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21.
Jun Han Xiaokai Song Li Liu Chaoguo Yan 《Journal of inclusion phenomena and macrocyclic chemistry》2007,59(3-4):257-263
A series of aryl and ferrocenyl pyrogallol[4]arenes have been synthesized by the HCl-catalyzed condensation reactions of pyrogallol
with aromatic aldehydes and ferrocenecarbaldehyde. The fully acetyl and ethoxycarbonylmethoxy derivatives were also prepared
and fully characterized. The crystal structures show that acylated phenyl pyrogallol[4]arene exists in rctt (cis-trans-trans) configuration, while the corresponding ferrocenyl pyrogallol[4]arene in rccc (all cis) configuration. 相似文献
22.
23.
J. Adam K. Katovsky A. Balabekyan V. G. Kalinnikov M. I. Krivopustov H. Kumawat A. A. Solnyshkin V. I. Stegailov S. G. Stetsenko V. M. Tsoupko-Sitnikov W. Westmeier 《Pramana》2007,68(2):201-212
Target-blanket facility ‘Energy + Transmutation’ was irradiated by proton beam extracted from the Nuclotron Accelerator in
Laboratory of High Energies of Joint Institute for Nuclear Research in Dubna, Russia. Neutrons generated by the spallation
reactions of 0.7, 1.0, 1.5 and 2 GeV protons and lead target interact with subcritical uranium blanket. In the neutron field
outside the blanket, radioactive iodine, neptunium, plutonium and americium samples were irradiated and transmutation reaction
yields (residual nuclei production yields) have been determined using γ-spectroscopy. Neutron field's energy distribution
has also been studied using a set of threshold detectors. Results of transmutation studies of 129I, 237Np, 238Pu, 239Pu and 241Am are presented.
相似文献
24.
V. Wagner A. Krása M. Majerle F. Křížek O. Svoboda A. Kugler J. Adam V. M. Tsoupko-Sitnikov M. I. Krivopustov I. V. Zhuk W. Westmeier 《Pramana》2007,68(2):297-306
The set-up ‘energy plus transmutation’, consisting of a thick lead target and a natural uranium blanket, was irradiated by
relativistic proton beams with the energy from 0.7 GeV up to 2 GeV. Neutron field was measured in different places of this
set-up using different activation detectors. The possibilities of using the obtained data for benchmark studies are analyzed
in this paper. Uncertainties of experimental data are shown and discussed. The experimental data are compared with results
of simulation with MCNPX code.
相似文献
25.
J. Blomgren 《Pramana》2007,68(2):269-278
One of the outstanding new developments in the field of partitioning and transmutation (P&T) concerns accelerator-driven systems
(ADS) which consist of a combination of a high-power, high-energy accelerator, a spallation target for neutron production
and a sub-critical reactor core. The development of the commercial critical reactors of today motivated a large effort on
nuclear data up to about 20 MeV, and presently several million data points can be found in various data libraries. At higher
energies, data are scarce or even non-existent. With the development of nuclear techniques based on neutrons at higher energies,
nowadays there is a need also for higher-energy nuclear data. To provide alternative to this lack of data, a wide program
on neutron-induced data related to ADS for P&T is running at the 20–180 MeV neutron beam facility at ‘The Svedberg Laboratory’
(TSL), Uppsala. The programme encompasses studies of elastic scattering, inelastic neutron production, i.e., (n, xn′) reactions, light-ion production, fission and production of heavy residues. Recent results are presented and future program
of development is outlined.
相似文献
26.
27.
Bernard Riss Marion Garreau Prisca Fricero Patricia Podsiadly Nicolas Berton Sophie Buchter 《Tetrahedron》2017,73(23):3202-3212
The absolute configuration of bisabolangelone has been established by an eleven step total synthesis of the corresponding TMS protected antipode starting from (R)-(+)-pulegone. Comparison of the TMS-derivatives by GC on a chiral column, allowed us to assign the absolute configuration of the synthetic compound and thus of the corresponding natural product. The latter has been confirmed by the Mosher's ester analysis of the known secondary carbinol derivative. 相似文献
28.
在超声辐射和哌啶催化反应条件下,1,3-二氢吲哚-2-酮(1)与芳香醛2a~2m发生Knoevenagel缩合反应,合成了一系列3-芳亚甲基吲哚-2-酮衍生物3a~3m。该方法具有产率高、反应时间短、后处理简单和环境友好等优点,产物通过~1H NMR、~(13)C NMR和HRMS手段进行结构表征,并通过核磁2D NOESY确定了所有化合物几何构型。初步抑菌活性测试结果表明,化合物3d对革兰氏阳性菌具有较好的抑制作用,最小抑菌浓度(MIC)为15.6μg/m L,化合物3f、3g、3h和3k对油菜菌核病菌表现出良好的抑制活性,MIC为62.5μg/m L,与阳性对照多菌灵相当。此外,对此类化合物的构效关系进行了讨论。 相似文献
29.
A new method for constructing a Hamiltonian for configuration interaction calculations with constraints to energies of spherical configurations obtained with energy-density-functional (EDF) methods is presented. This results in a unified model that reproduced the EDF binding-energy in the limit of single-Slater determinants, but can also be used for obtaining energy spectra and correlation energies with renormalized nucleon–nucleon interactions. The three-body and/or density-dependent terms that are necessary for good nuclear saturation properties are contained in the EDF. Applications to binding-energies and spectra of nuclei in the region above 208Pb are given. 相似文献
30.
1前言压缩因子是比较实际气体与理想气体之差异的重要物理量,从某状态的压缩因子Z可求出该状态下实际气体的P或V来。现在高压气体的Z大多是在高压PVT实验台上用定容测试方法(绝对法)测试出来。但测试过程耗时费资,在新型气态工质不断涌现的今天,一些特殊高压高温条件很难在实验中满足;而工程上则多从对比态原理出发,从两参量或三参量的普遍化压缩因子图中近似求出,显然,其系统误差一般较大,一般说来,高压气体的Z是系统温度T,压力P和偏心因子。的函数Z=Z(T,P),其解析形式一直是热物性工作者努力探求的目标,… 相似文献