共查询到20条相似文献,搜索用时 78 毫秒
1.
2.
本文使用文献中的N2H+(1-0)、H13CO+(1-0)、HCN(1-0)和HN13C(1-0)谱线数据研究大质量恒星形成团块的化学性质和演化,发现H13CO+和HN13C的丰度受H2柱密度的影响. 由于从A阶段到B阶段这两个丰度的中值增加了近10倍,H13CO+和HN13C适合追踪大质量恒星形成团块的演化. 从A到B阶段四种分子丰度增长速度从高到低依次为H13CO+、HCN、HN13C、N2H+. 结果表明进行光学薄分子谱线的高分辨率观测对于研究大质量恒星形成团块的化学演化是必要的. 相似文献
3.
宋立涛 周小红 张玉虎 郭应祥 雷相国 郑勇 柳敏良 G.de Angelis N.Marginean A.Gadea D.R.Napoli M.Axiotis C.Rusu T.Martinez 《中国物理 C》2005,29(8):736-740
通过重离子熔合蒸发反应和在束核谱学实验方法研究了奇A 核183Au的高自旋态能级结构. 扩展并更新了183Au的能级纲图. 首次建立了183Au的πi13/2转动带的能量非优先带. 分析并讨论了183Au中πh9/2转动带的能量非优先带和πf7/2转动带间的相互作用. 相似文献
4.
5.
对近几年来清华大学物理系核物理研究组原子核高自旋态实验研究的一些新进展进行了介绍.内容包括两个部分:第一部分介绍通过国际合作,利用测量裂变瞬发γ谱方法对A=140丰中子核区的奇A核143,145Ba,145,147La等的极形变研究的进展.第二部分简述对A=130缺中子核区的134,137,138Ce及122Ba等核高自旋态研究,包括形状驱动、八极关联、集体回弯等效应. 相似文献
6.
通过碳酸钙、γ-三氧化二铝、氯化钙在氯气/氩气混合气气氛下的固态反应制备了一种氯负离子存储-发射功能材料[Ca24Al28O64]4+·(Cl-)3.80(O2-)0.10(C12A7-Cl-).通过离子色谱、电子顺磁共振、拉曼光谱验证,C12A7-Cl-材料中存储的负离子主要是氯负离子,浓度为(2.21±0.24)×1021 cm-3,此外还有小部分的氧二价负离子、氧负离子、氧分子负离子.这与通过飞行时间质谱得到的结果一致:从C12A7-Cl-材料表面发射出的负离子主要是氯负离子(大约90%),还有小部分的氧负离子和电子.材料结构和表观变化分别由X射线衍射和场发射扫描电子显微镜表征 相似文献
7.
8.
近年原子核反应能量(包括核衰变能)的精密测定的累积,使我们有可能单独从核反应能的测量来确定轻原子核的质量。本文用近似的最小二乘统计平差,由原子核实验数据得出从中子到Ca41各同位素的原子量。主要结果如下:(1)由核反应能导出的、质量差2D2-He4的数值和质谱测定的比较,给质量和能量联系公式,E=mc2,提供了最精确的实验证明。准确度为1/6000。(2)从A=1到41一共79个同位素的原子量(表8),和统计平差后的Q值(表1)。这是现在由原子核转变的数据所能得到的,一组最可几的质量值。主要的质量是:n=1.008 9842(±17),H1=1.008 1440(±17),D2=2.014 7381(±29),He4=4.003 8732(±21),C12=12.003 807(±5),S32=31.982 188(±26),Ca40=39.975 204(±39)。(3)本文所得的结果显示作者所用的方法,在现阶段原子核实验知识的限度下,和全盘的最小二乘平差方法具有同样意义,达到同等的精密度,而手续较为简单有利,且便于发现实验结果中的系统偏差。(4)核反应能测定和最近质谱测定的比较表明,对于H1,D2,He4的质量,这两种方法已经符合。至于C12的质量,则仍有确定的差异;S32和Ca40则两种测定差异较大,尚未一致。 相似文献
9.
10.
11.
讨论了银道面内的引力场强分布和太阳在银河系中所受引力与到银心距离r的关系,指出引力场强g并不是与r的平方成反比,这是由于银河系的大小和形状不能忽略造成的.强调了万有引力定律的适用条件. 相似文献
12.
The investigation was made of the dependence of the intensity of Tl, Ga, Mo, Mg, Mn, Sn, Bi, Ni, Zn, Pt and Au spectral lines and the plasma parameters (temperature T, electron concentration ne, degree of 6 ionnization α) from concentration of lithium additive. 相似文献
13.
SJ Rose 《Contemporary Physics》2013,54(2):109-121
In this paper we describe experiments conducted with high-power lasers that are attempting to replicate, for a very short time and in miniature, conditions found in the Sun. Experiments to date have reached conditions in the outer part of the Sun. To reach the Sun's centre requires compression of material to very much greater than solid density and heating to over ten million degrees. To achieve this, a new class of experiments and a new generation of high-power lasers are required. 相似文献
14.
15.
We study the Cauchy problem for the Whitham modulation equations for increasing smooth initial data. The Whitham equations are a collection of one-dimensional quasi-linear hyperbolic systems. This collection of systems is enumerated by the genus g=0,1,2, ... of the corresponding hyperelliptic Riemann surface. Each of these systems can be integrated by the so-called hodograph transformation introduced by Tsarev. A key step in the integration process is the solution of the Tsarev linear overdetermined system. For each g>0, we construct the unique solution of the Tsarev system, which matches the genus g+1 and g–1 solutions on the transition boundaries. 相似文献
16.
17.
Let G be one of the local gauge groups C(X, U(n)),C
(X, U(n)), C(X, SU(n)) or C
(X, SU(n)) where X is a compact Riemannian manifold. We observe that G has a nontrivial group topology, coarser than its natural topology, w.r.t. which it is amenable, viz. the relative weak topology of C(X, M(n)). This topology seems more useful than other known amenable topologies for G. We construct a simple fermionic model containing an action of G, continuous w.r.t. this amenable topology. 相似文献
18.
Denis de Carvalho Braga 《Physics letters. A》2010,374(42):4316-4320
In this note we present an analytical study of the stability of the equilibria of the Rikitake system. We prove that the two non-hyperbolic equilibria of the Rikitake system are unstable for all positive values of the parameters. 相似文献
19.
The lightest supersymmetric particle (LSP) is a natural candidate for the cold dark matter of the universe. In this Letter we discuss how to test the mechanism responsible for the LSP stability at the LHC. We note that if R-parity is conserved dynamically one should expect a Higgs boson which decays mainly into two right-handed neutrinos (a “leptonic” Higgs) or into two sfermions. The first case could exhibit spectacular lepton number violating signals with four secondary vertices due to the long-lived nature of right-handed neutrinos. These signals, together with the standard channels for the discovery of SUSY, could help to establish the underlying theory at the TeV scale. 相似文献
20.