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11.
以三苯胺、咔唑、4,4′-二羧基联吡啶为原料,设计并合成了两个联吡啶铱(III)配合物Ir1和Ir2,其结构经1H NMR, 13C NMR和HR-MS(MALDI-TOF)表征。并利用紫外可见光谱(UV-Vis)、荧光发射光谱(Photoluminescence)和循环伏安法研究了化合物的光学和电学性质。结果表明:Ir1和Ir2的紫外可见光吸收波长分别位于456 nm 和448 nm,相应的发射波长分别为645 nm和678 nm,说明其均能利用可见光; Ir1和Ir2的HOMO电位为-5.125~-5.510 eV, LOMO电位为-2.880~-0.310 eV,满足作为光敏剂的基本条件。研究了化合物在可见光照射下光催化水分解产生氢气的效果。结果表明:Ir1和Ir2的氢气值TONs(turnover numbers)达到2 827和1 908。 相似文献
12.
In this paper, three hotly discussed problems, namely the neutrino bursts, the blue progenitor, and the mixing phenomenon, observed in SN1987A are summarized. But it is pointed that while all the observations on SN1987A do not favour a twice-banged scenario, we have found three historical cases from ancient Chinese documents that might be interpreted as twice- or even multi-explosions of a supernova. Finally in a one-dimensional simulation we demonstrate that an induced gravitational collapse b possible. 相似文献
13.
本文报道从变色马兜铃(Aristolochia versicolar)的块根中提取的一种新倍半萜内酯-银袋内酯乙的乙酰化物的晶体结构和分子结构.分子式为C~17H~22O~4,分子量290.4,晶体属单斜晶系,空间群为P2~1,a=0.9594(5),b=0.6626(6),c=1.2924(12)um,β=94.48(6)`,V=0.819(1)nm^3,Z=2,Dx=1,18g.cm^-^3,F(000)=266e,μ=0.77cm^-^1(MoKa).结构用直接法解出,经最小二乘法修正后1280个衍射点偏离因子为R=5.5%,Rw=5.2%.分子由椅型.椅型的1,5二烯十员环([2323]矩形)和共用两个相邻DunitzIII型碳C(4),C(5),一个Dunitz II型碳C(6)的五员内酯环组成.十员环与五员内酯环之间夹角为99.该分子骨架拓扑在迄今已知的倍半萜内酯中只与银袋内酯丙相似.所有非氢原子的键长和键角均在实验误差范围内接近理论值。 相似文献
14.
It is shown that in the pion induced double charge exchange reaction on Jp=O+→O+ nuclei,there exists a possible new reaction mechanism π+(Δ0,Δ++)π- or π+(Δ-,Δ+)π- in so-called single step process,while that old speculative mechanism π+(N,Δ)π- or π+(N,Δ)π- is firbidden by a well-known selection rule which has been indicated in the theory of the nuclear 2β-decay. 相似文献
15.
It is found that owing to the large energy difference in K-and L-shells of the daughter atom, 158Tb is not the best candidate for neutrino "balance". Instead, l57Tb can offer a better chance for. neutrino mass determination if the Q-value 55 far obtained is verified. If it is so,then the relevant atomic calculation with high precision is very necessary. It is shown that to include the radiative correction in the Hartree-Fock calculation is very important for such atoms as 157Gd and 157Tb. 相似文献
16.
APPROXIMATE B.S. WAVE FUNCTIONS FOR AN ELECTROMAGNETIC BOUND SYSTEM OF SPINS (1/2, 1/2) OR (1/2, 1/2) WITH UNEQUAL MASSES 下载免费PDF全文
The Bethe-Salpeter equation for an electromagnetic bound system of spins (1/2—1/2) or (1/2—1/2) with unequal masses are solved in this paper. The approximate B.S. wave functions for these systems are given. Utilising these wave functions, the decay rate and branching ratio for Ξ0→(Σ+μ-)+vμ are calculated with accuracy up to order O(α). The results are wΞ0→(Σ+μ-)+vμ1.12(1/sec) and R=[wΞ0→(Σ+μ-)+vμ]/[wΞ0→(Σ+μ-)+vμ]4.7×10-7. Similarly, the process Λ→(pμ-)+vμ is also discussed. 相似文献
17.
In this paper a kind of fireball model for subquark stratum is proposed, which can be used to explain the cosmic ray experiments for superhigh energy range, e. g., the mean multiplicity of secondary particles increases as S increases average transversal momentum ⊥> increases as S increases …etc. It can also give predictions which can be verified experimentally. This means that the information of the existence of subquark can be probed in the experiments on superhigh energy cosmic ray. Furthermore, this also means that some new phenomena observed in the experiments. on superhigh energy cosmiq ray provide. probably this kind of information. 相似文献
18.
The rapid increase of both and T> as S increases in superhigh energy cosmic ray experiments manifests some inconsistencies with the 1> ≤ π/4 S1/2 rule. It is shown that these inconsistencies can be weakened with the assumption that only the secondary particles of the small fireballs are measured in the Ashtonsr experiment [3], but still not removed. 相似文献
19.
We point out that although the neutrino mass is finite,the left-handed neutrino density still dominates over the righthanded one in the universe unless there exists one or more elementary fernions (quark or lepton) whose mass is larger than 106 GeV. or MWR/MWL≤102. (MWLand MWR are the left and right handed intermediate boson respectively.If there exists neutrino the mass of which is about 34 ev. as indicated in some experiments, then one can conclude that the total neutrino mass of the universe s,bvld contribute abput 99%. to the whole masses and lead to the closeness of the universe.This conclusion can be brought to the agreement of all observation datd which have been-obtained so far. A mass limit of all species of neutrinos obtained by reexamining all data is ≤ 200 eV. 相似文献
20.
By direct calculation of rotation matrices of SO(3), we show how certain specific sequence of eight consecutive rotations of digital angles can yield a tilting of a facet mirror. We also design a detailed program specifically to tilt an array of mirrors from planar orientation to the required focusing orientation. We describe how to use the 8-step to realize the focusing of the mirror array. We have found, in our designed program, an important feature of row-sharing during the rotations for the columns and similarly the column-sharing during the rotations for the row. This feature can save a lot of operating time during the actual realization of the mechanical movements. 相似文献