1000 resultados para K-regelverk


Relevância:

20.00% 20.00%

Publicador:

Resumo:

本文给出了原子和离子能量表达式中的库仑积分与交换积分系数f~k与g~k的计算方法,同时给出了计算中所涉及的Racah系数、U~(k)、V~(lk)和C~(k)矩阵等光谱参量的计算方法,我们用FORTRAN语言编写了关于f~k与g~k的计算机程序,只要输入与光谱项有关的量子数,即可迅速得到相应的f~k与g~k值,避免了烦琐的人工推算。

Relevância:

20.00% 20.00%

Publicador:

Resumo:

利用1083K 时的 X-射线衍射数据,导出了 LaF_3-4LiF 和 LaF_3-4KF 系熔盐溶液的径向分布函数;获得了熔盐的离子间距数据,其中 LaF_3-4LiF 熔盐系中 La~(3+)-F~-的相互作用距离为0.238nm,LaF_3-4KF 系中的为0.233nm。还就熔盐离子间距结果讨论了温度与 La~(3+)的库伦力的问题。

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The tetranuclear nearly-linear complex (eta-8-C8H8)Er(mu-eta-8-C8H8)K(mu-eta-8-C8H8)Er(mu-eta-8-C8H8)K(THF)4 (THF = tetrahydrofuran) is first synthesised by the reaction of benzylcyclopentadienyl erbium dichloride (PhCH2C5H4)ErCl2.3THF with cyclooctatetraenyl potassium K2C8H8 in 1:1 molar ratio in THF; a single crystal X-ray study has shown that the complex has the tetralayer-sandwich structure and that the adjacent Er3+ and K+ ions are bridged by eta-8-cyclooctatetraenyl group.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

本文系统地研究了化合物ASm_2I_5(A=K,Rb,Cs,T1)固体粉末的荧光光谱和反射光谱.讨论了Sm~(2+)在立方晶体场中的分裂能随着碱金属离子半径的增大而减小和f-d激发能随着A-I(A=Rb,T1)键的共价性增加而明显降低的现象.并从晶场效应和化学键性质两个方面解释了ASm_2I_5(A=K,Rb,Cs)和ASm_2I_5(A=Rb,T1)中的Sm~(2+)荧光光谱分别发生蓝移和红移的现象.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

用吡啶吸附法研究了Co-Mo-K/Al_2O_3催化剂的酸性,K的加入,由于改变了催化剂的酸性,使其活性得以提高,硫的丢失也可改变酸性,但使催化剂的活性降低。初步探讨了催化剂酸性对活性影响的实质,提出了新的反应机理。

Relevância:

20.00% 20.00%

Publicador:

Resumo:

以XRD,XPS和TPR研究了一系列K助化的Co-Mo/Al_2O_3催化剂,考察了K对Co和Mo在载体上分散的影响。实验表明,K的加入分解了原来存在於催化剂中的CoMoO_4,促进了Mo的硫化还原,是提高水煤气变换反应的一个因素。

Relevância:

20.00% 20.00%

Publicador:

Resumo:

钴离子在γ-Al_2O_3上的吸附速度比钼酸根离子的慢,但钴离子的视扩散系数比钼酸根的大(25℃下D_(Co)=1.2×10~(-5)cm~2/s,D_(Mo)=4.4×10~(-6)cm~2/s)。钴的吸附等温线符合Langmuir等温式,而钼的符合Freundlich等温式。在等孔容积共浸法制备催化剂时,低pH值下由于Al_2O_3吸附Mo较多而导致Co、Mo在颗粒中分布不均;在高pH值下由于Mo的吸附量锐减,可用共浸法得到分布均匀的催化剂。K_2CO_3在均匀型Co-Mo/Al_2O_3催化剂上的吸附等温线符合Langmuir等温式,虽然吸附量较大,但在浸渍液中含量足够时也可得到均匀分布的结果。

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Co-Mo 系催化剂由于其优越的耐硫性能和对水煤气变换反应的高活性,因此在制氢工业中日益得到重视。已知 Co-Mo-K/Al_2O_3催化剂是一种优良的水煤气变换催化剂,该催化剂在使用前须经硫化。实际上催化剂在反应时

Relevância:

20.00% 20.00%

Publicador:

Resumo:

研究了激活离子Eu~(3+),Dy~(3+)和Bi~(3+)在具有相同结构的LaMSb_2O_7(M=Li,Na,K)中的发光特性,得到了发白光的磷光体LaNaSb_2O_7:Dy~(3+)。讨论了化学键的共价程度对Eu~(3+)和Dy~(3+)超灵敏跃迁强度比的影响。发现当用281nm激发试样时,Bi~(3+)对Eu~(3+)具有敏化作用并解释了其原因。

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Further chemical investigation of the stem bark of Aglaia cordata has led to the isolation and identification of three new lignans, namely, aglacins I-K (1-3), all of which contain two contiguous trimethoxylated phenyl systems. Among them, aglacins I and J (1 and 2) are new members of the aryltetralin cyclic lactol class, while aglacin K (3) is a new example of tetralrydrofuran lignan. The structures of these compounds were established on the basis of spectroscopic data interpretation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The structure of the title compound, [Zn(C8H4O4)(C12H8N2)-(H2O)(3)]center dot H2O, displays a distorted octahedral coordination geometry, with two N atoms from the bidentate phenanthroline ligand, three O atoms from three meridional H2O molecules and one O atom from the monodentate phthalate ion.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

In this paper, We analyzed the geological and geographical settings of dinosaurs extinction at the end of Cretaceous, especially the effect of the change of the elements contents on dinosaurs extinction. We studied basis on the two typical sections-Cretaceous-Paleocene boundary (Baishantou section (in Jiayin, Heilongjiang province of China) and Arkhara-Boguchan Coal Mine section (in Far East of Russian)) and Longgushan section (in Jiayin, Heilongjiang province of China) mainly. This work provided some evidences for forecasting the effects of global environmental change on bio-circle. The followings are the primary gains: According to the paleo-climate indexes (CaO/MgO,Sr/Ba) and the results of Factor Analysis, we found that there were similar climate in Baishantou section and Arkhara-Boguchan Coal Mine section near the K/E boundary, and both of them took on the trend of temperature declining and precipitation heightening after transitory high-temperature and drought. There are similar change and evlution rule of the elements contents near the boundary in the both sections (Baishantou section and Arkhara-Boguchan Coal Mine section). Both iron group elements and chalcophile elements appeared obvious abnormity. There are not visible correlation between the change of elements contents and climate indexes. This shows that the elements abnormity maybe came from the factors excluding climate or the factors were too many to conceal the influence of climate. --The result of cluster analysis showed that the boundary between BST3-8 and BST3-9 may be the K/E boundary of Baishantou section, and the top of twofold coal were the K/E boundary of Arkhara-Boguchan Coal Mine section which was consistent with accepted conclusion formerly. By contrast of elements contents in dinosaur bones and general organism, in surrounding rock and general sand stone, the regulation of the change of elements contents in dinosaur bones and surrounding rock, we confirmed that dinosaur extinction in Jiayin were relative with the high abnormities of Sr, Ba, Pb, Cr and the low abnormity of Zn, at least, it was them which speeded up dinosaurs extinction. After a series of analysis, we concluded that dinosaurs extinction of this areas tied up with the relative high background values of geo-chemical elements , paleo-climate and disaster incidents. First of all, high background values provided the necessary condition for the accumulation of the elements. Secondly, the drought climate adverse to the survival of dinosaurs, and led them to extinct gradually. finally, disaster incidents, the eruption of volcano or the collision of aerolites, made them exit this planet.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

利用紫外线和氯化锂对一株紫红曲Monascus purpureus 菌株进行复合诱变试验。在最佳紫外照射时间为45s 和最佳氯化锂浓度为1.0‰的情况下,获得了一株Monacolin K 高产突变菌Monascu purpureus ZT32 且连续传接5 代产量稳定,用紫外分光光度法检测其Monacolin K 含量为219.9μg/mL,较原始菌株高出2 倍多,然后将其用于固态发酵,结果表明:红曲米中的Monacolin K 的含量达到8.33mg/g,是原始菌株的3.3 倍。