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1.
ZHANG JiaChi WANG YuHua ZHANG ZhiYa WANG DeYin CI ZhiPeng SUN YunKui 《科学通报(英文版)》2007,52(16):2297-2300
The photoluminescence quenching behaviors of ^5D3-^7Fj and ^5D4-^7Fj (J = 0—6) transitions of Tb^3+ in YBO3:Tb under 130—290 nm excitation were systematically investigated. The results revealed that the quenching concentrations of both ^5D3-^7Fj and ^5D4-^7Fj transitions of Tb^3+ in YBO3:Tb were mainly dependent on excitation wavelength. Particularly, the quenching concentrations of ^5D4-^7Fj transitions of Tb^3+ under 130—290 nm excitation were correlated with excitation bands of YBO3:Tb. The quenching concentrations of ^5D3-^7Fj transitions remained at low concentration (2%) under 186—290 nm excitation and then increased gradually with energy of incoming excitation photon when excited at 130—186 nm. This dependence should be involved in their excitation mechanisms and quenching pathway in particular excitation region.[第一段] 相似文献
2.
红米因其独特的营养价值日益受到人们关注.红米由两对非同源染色体上的Rc、Rd显性基因控制,且Rc、Rd基因同时存在时,水稻才表现为红米表型.本研究分别在Rc和rc等位基因以及Rd和rd等位基因影响性状的关键性位点上建立了分子标记:Rc(+5150)和Rd(+276).检测结果显示:这2个分子标记可以分别用来区别控制红米性状的Rc/rc和Rd/rd基因型.开展本研究,为今后利用分子标记辅助快速有效地选育各类红米水稻新品种研究提供了重要的帮助. 相似文献
3.
21世纪初,动物育种已迈入分子水平,朝着快速改变动物基因型的方向发展.本文在总结作者近年来对牦牛各种分子遗传标记研究成果的基础上,分析了RFLP、RAPD、AFLP、微卫星DNA、m tDNA等分子遗传标记在牦牛遗传育种研究中的应用以及牦牛功能基因的研究现状,进而探讨了牦牛分子育种的理论和实践,以便为今后在牦牛生产中进一步地开展分子育种提供理论依据. 相似文献
4.
为了明确已克隆的部分稻瘟病抗性基因在上海市主栽水稻品种以及新培育的水稻品系中的分布,选取22份水稻为材料,利用分子标记检测技术,对10个已被克隆的抗稻瘟病基因进行基因型鉴定及分析.结果表明,22种水稻均含Pi36、Pi37、Pi-d2、Pib抗性基因,而Pi-kh、Pi9、Pi2、Pi-ta、Pikm抗性基因在22种水稻中分布各有不同,所有被测水稻中均不携带Pi25抗性基因. 相似文献
5.
Qinian Zhou 《科学通报(英文版)》2002,47(14):1170-1171
On the basis of our previous work, a configuration of H 5 + has been presented that is a square center structure, and the energy for the structure of H 5 + has been obtained by IACQM. The result showed that there is an extreme energy Ee: −2.45981 [2 Ry] atR = 2.50a 0. It indicates that the square center structure of H 5 + system has the certain stability, which is a possible configuration of H 5 + . 相似文献
6.
稻种亲缘关系分析是生产优质杂交水稻的必要条件。本研究选取均匀分布于水稻基因组12条染色体的SSR分子标记,对8份水稻样品进行SSR分子标记分析,通过聚类分析法将其归类并计算得出遗传相似系数后,对8份水稻样品的亲缘关系进行了鉴定。结果表明:所选取的8份水稻样品中,其相似系数为0.65~1.00,在遗传相似系数0.65处,8份水稻样品聚为两大类群,其中5号‘赣迟A04’单独为一类,其他水稻样品聚为一类。在遗传相似系数0.80处,可划分为三大类群:第一类囊括了6种样品,表明这6个品种亲缘关系较近,其中6号‘赣早A02’与7号‘吉安早A07’疑似同一样品,3号‘井冈山迟A03’与4号‘井冈山早A05’的亲缘关系最近,而6号、7号同时与8号‘吉安迟A09’保持有最近的亲缘关系;第二类只含有2号‘迟-2’样品株;第三类则仅有5号稻株‘赣迟A04’,说明其与其他7份水稻样品的亲缘关系最远。本研究结果为杂交水稻的应用提供重要信息。 相似文献
7.
Zikun Wang 《科学通报(英文版)》1999,44(5):418-418
The definition of n-parameter infinite-dimensional (r,δ) -Ornstein-Uhlenbeck process {xt (·) } ((r, δ)-OUPn∞ for short) is given. The absolute continuity of distribution μt of Xt(·) and the limit of Xt(·) when |t| →∞ is discussed. 相似文献
8.
稻米食味品质改良是目前水稻育种的重要研究方向之一.明确不同水稻食味品质基因型,可为优质水稻育种研究的亲本选择提供依据.本研究利用分子标记检测技术,对22个目前上海市种植的重要常规水稻和杂交稻亲本食味品质基因的基因型进行检测.结果发现,\"紫香糯861\"水稻含有相对较多不良食味品质基因型.3种杂交稻父本,\"湘晴\"、\"R44\"和\"繁14\"的食味品质基因型比这3种杂交稻母本,\"寒风A\"、\"秋风A\"和\"申9A\"以及其他常规稻有欠缺.从蜡质基因多态性分析显示,在本研究选用的22种水稻中,2个为糯稻、20个为粳稻,但其中有4个为软米型粳稻;在16个非软米型粳稻中,\"宝农34\"、\"金丰\"和\"银香18\"是具有相对最好食味品质基因型的水稻品种. 相似文献
9.
LI PanLai YANG ZhiPing WANG ZhiJun GUO QingLin LI Xu 《科学通报(英文版)》2008,53(7):974-977
The Sr3SiO5:Eu^2+ phosphor was synthesized by high temperature solid-state reaction. The emission spectrum of Sr3SiO5:Eu^2+ shows two bands centered at 487 and 575 nm, which well agree with the theoretic values of emission spectrum. The excitation spectrum for 575 nm emission center has several excitation bands at 365, 418, 458 and 473 nm. And the results show that the emission spectrum of Sr3SiO5:Eu^2+ is influenced by the Eu^2+ concentration. The relative emission spectra of the white-emitting InGaN-based YAG:Ce^3+ LED and Sr3SiO5:Eu^2+ LED were investigated. The results show that the color development of InGaN-based Sr3SiO5:Eu^2+ is better than that of InGaN-based YAG:Ce^3+, and the CIE chromaticity of InGaN-based Sr3SiO5:Eu^2+ is (x=0.348, y=0.326). 相似文献
10.
为开发新型储氢材料提供更为丰富的理论基础,采用B3LYP泛函在6-311++G(d,p)基组水平上对BLi6+超碱团簇和BLi72+超碱土团簇的稳定性结构、电荷分布等方面进行理论研究,进而研究团簇的储氢性能。结果表明:两个离子团簇均比它们所对应的中性团簇均具有较高的动力学稳定性。两个离子团簇中的每个Li原子同时有效吸附2个氢分子,BLi6+团簇中氢分子在团簇表面平均吸附能为0.969~2.162kCal/mol,储氢质量分数达31.56wt%。而BLi7+团簇中氢分子在团簇表面平均吸附能为1.764~3.714kCal/mol,储氢质量分数达32.21wt%。它们的储氢性能表明BLi6+团簇和BLi72+团簇均有望成为良好的储氢媒介。 相似文献
11.
氢是一种理想的二次能源,它将成为化石燃料最有希望的替代能源之一,也是亟待开发的重要能源。而氢能的储存成本高,危险性大是急需解决的问题。理论上预测CNa_4~(2+)的储氢性能,通过理论分析,发现了每个CNa_4~(2+)团簇最多可与16个H2分子有效结合,获得23.5%的质量储氢密度。在B3LYP理论水平上,H2分子与CNa_4~(2+)团簇的平均相互作用能在2.107~4.948Kcal/mol之间。由于CNa_4~(2+)的质量储氢密度在7.1~23.7wt%之间,符合美国能源部的要求目标(5.5 wt%)。研究结果表明,CNa_4~(2+)在一定环境条件下可逆吸放氢性能良好,可作为潜在的理想高容量储氢材料。 相似文献
12.
The sterility of Pingxiang male-sterile rice (Pms), possibly derided from a spontaneous mutation in Pingxiang fertile rice (Pmf), was previously reported to be controlled by a single dominant nuclear gene. It can be restored to fertility either by a dominant epistatic gene or by higher temperature treatment at the early stage of inflorescence development. In order to tag the genic male-sterile gene, Pms, Pmf and Ce 64, a cytoplasmic male-sterile restoring line without the epistatic gene for Pms, were used to construct mapping populations. Two segregation populations, “(Pms/Ce 64) F1s (sterile plant)//Pmf ” F1 and “Pms//(Pmf/Ce 64) F1” F1, were simultaneously developed. Subsequently, the genic male- sterile gene was mapped between a simple sequence length polymorphism marker, RM228, and a restriction fragment length polymorphism marker, G2155, with distances of 14.9 and 2.6 cM, respectively. The tagged dominant genic male-sterile gene is temporarily designated Ms-p. 相似文献
13.
用TPSSTPSS密度泛函方法, Pu离子和H2O分子分别采用相对论有效原子实势(RECP)和6-31g基组, 研究了Pu(H2O)53+和Pu(H2O)54+ 团簇溶剂化和非溶剂化效应中的几何结构及紫外可见吸收光谱. 计算结果表明: 水溶剂环境对Pu(H2O)53+及Pu(H2O)54+ 团簇的几何结构影响都比较明显. NBO电荷分析表明水分子与钚离子之间没有直接的电荷转移. 所研究团簇的未配对电子都占据5f轨道. 在气相及水溶剂环境下, 所研究团簇的紫外可见吸收光谱存在较大差距. 主要的吸收峰大都源于f电子之间的跃迁. 相似文献
14.
Sub 16 is a substitution line with G. hirsutum cv. TM-1 genetic background except that the 16th chromosome (Chr. 16) is replaced by the corresponding homozygous chromosome of G. barbadense cv. 3-79, and T586 is a G. hirsutum multiple gene marker line with 8 dominant mutation genes. The R 1 gene for anthocyanin pigmentation was tagged in Chr. 16 in T586. The objective of this research was to screen SSR markers tightly linked with R 1 by using the F2 segregating population containing 1259 plants derived from the cross of Sub 16 and T586 and the backbone genetic linkage map from G. hirsutum×G. barbadense BC1 newly updated by our laboratory. Genetic analysis suggested that the segregation ratio of red plants in the F2 population fit Mendelian 1:2:1 inheritance, confirming that the red plant trait was controlled by an incomplete dominance gene. Preliminary mapping of R 1 was conducted using 237 randomLy selected F2 individuals and JoinMap v3.0 software. Then, a fine map of R1 was constructed using the F2 segregating population containing 1259 plants, and R 1 was located between NAU4956 and NAU6752, with only 0.49 cM to the nearest maker loci (NAU6752). These results provided a foundation for map-based cloning of R 1 and further development of cotton cultivars with red fibers by transgenic technology. Supported by National Natural Science Foundation of China (Grant No. 30730067) and Programme of Introducing Talents of Discipline to Universities (Grant No. B08025) 相似文献
15.
为提升非饱和煤矸石室内淋滤试验的可靠性与准确性,对传统非饱和煤矸石淋滤仪的降雨模拟系统进行改良,实现了随机降雨路径的模拟,并增大了煤矸石有效淋滤体积。同时,以韩城桑树坪煤矿煤矸石为研究对象,揭示了不同降雨强度和风化程度组合条件下煤矸石淋滤特征,试验结果是:(1)淋滤液电导率(EC)及SO42-浓度(c)均随淋滤时间呈整体下降趋势,且可划分为快速下降和缓降趋稳两个阶段;(2)采用指数型函数、傅里叶函数及幂函数对不同试验条件下EC-t和c-t关系曲线进行拟合,拟合函数R2介于0.87~1.00;(3)167mm/h降雨强度下,淋滤液电导率及SO42-浓度对风化程度的敏感性指数最大,分别为3.14和7.64;(4)相较其它条件下淋滤液电导率及SO42-浓度,83mm/h降雨强度和风化3a矸石条件下淋滤液EC值和c值更高。分析得到三点结论:(1)煤矸石可溶元素释放量主要呈指数型函数衰减,并在试验进行3~5h后趋于稳定;(2)风化程度为影响煤矸石可溶元素释放能力的主控因素;(3)较小的降雨强度和较高的风化程度有利于煤矸石元素持续淋滤释放。 相似文献
16.
利用光与物质相互作用的密度矩阵方程及其数值解研究Λ型Pr3+∶Y2SiO5晶体的电磁感应光透明(EIT)和光群速度减慢(SGV), 分析非均匀加宽及相干驱动场强度对EIT和SGV的影响, 理论与实验结果相符. 相似文献
17.
葡萄糖-BrO3--Mn2+-H2SO4-丙酮体系的振荡反应 总被引:1,自引:0,他引:1
以葡萄糖为有机底物,与-BrO3--Mn2+-H2SO4-丙酮组成振荡反应体系,在恒温条件下进行振荡反应。结果表明:反应有诱导期,体系电导(L)不随时间(t)变化;振荡周期,L随t发生周期变化,溶液颜色在粉红色与无色之间交替变化,有典型的振荡波型。诱导期及振荡周期反应的表观活化能分别为84.275kJ/mol和98.153kJ/mol。体系振荡反应物浓度范围[葡萄糖]0.01~0.02mol/L,[BrO3-]0.03~0.045mol/L,[Mn2+]0.06~0.08mol/L,[丙酮]0.27~0.30mol/L,[H2SO4]0.8~1.2mol/L。振荡反应有Br2产生,Br2准一级消耗速率常数kBr2=1.6×10-5S-。对温度、反应物浓度、丙酮、Mn2+、Cl-、底物对振荡反应的影响作了探讨。 相似文献
18.
Qixiang Yang 《科学通报(英文版)》1999,44(24):2221-2225
An atomic decomposition in Lp ( 1 <p < 2) with tent space is given. 相似文献
19.
分子标记辅助选育香型软米水稻“上师大18号” 总被引:1,自引:0,他引:1
以香型软米水稻\"青香软粳\"作为软米基因供体亲本,以香型非软米水稻\"光明粳2号\"作为转育亲本,结合软米基因分子标记辅助筛选,成功培育出香型软米水稻\"上师大18号\".\"上师大18号\"水稻全生育期约148 d,早于\"青香软粳\"水稻约5 d.\"上师大18号\"水稻主要农艺性状和产量性状都与\"光明粳2号\"接近.\"上师大18号\"稻米直链淀粉质量分数为8. 2%,符合软米特征.\"上师大18号\"水稻的成功选育有助于上海地区推广生育期相对较短的香型软米水稻. 相似文献
20.
Ping Ding ChengDe Shen Ning Wang WeiXi Yi XingFang Ding DongPo Fu KeXin Liu Ping Zhao 《科学通报(英文版)》2010,55(23):2548-2556
Carbon isotopic compositions of soil CO2 in rainy season (July) from two natural soil profiles (DHLS & DHS) in the monsoon evergreen broadleaf forest in the Dinghushan Biosphere Reservoir (DBR), South China, are presented. Turnover and origins of soil CO2 are preliminarily discussed in this paper. Results show that the content of soil CO2 varies between 6120 and 18718 ppmv, and increases with increasing depth until 75 cm, and then it declines. In DHLS, soil CO2 δ13C ranges from −24.71‰ to −24.03‰, showing a significant inverse correlation (R2=0.91) with the soil CO2 content in the same layer. According to a model related to soil CO2 δ13C, the soil CO2 is mainly derived from the root respiration (>80%) in DHLS. While in DHS, where soil CO2 ? 13C ranges from −25.19‰ to −22.82‰, soil CO2 is primarily originated from the decomposition of organic matter (51%–94%), excluding the surface layer (20 cm, 90%). Radiocarbon data suggest that the carbon in soil CO2 is modern carbon in both DHLS and DHS. Differences in 14C ages between the “oldest” and “youngest” soil CO2 in DHLS and DHS are 8 months and 14 months, respectively, indicating that soil CO2 in DHLS has a faster turnover rate than that in DHS. The 14C values of soil CO2, which range between 100.0‰ and 107.2‰ and between 102.5‰ and 112.1‰ in DHLS and DHS, respectively, are obviously higher than those of current atmospheric CO2 and SOC in the same layer, suggesting that soil CO2 is likely an important reservoir for Bomb-14C in the atmosphere. 相似文献