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1.
利用南京大学太阳塔的CCD二维成像光谱观测系统,于1993年3月19日得到了一个SN级耀斑区域的Hα光谱资料.由线心强度分布显示,该耀斑带有三个明显发射区,它们的形态、结构、演化情况都不同;而线翼呈现明显的红不对称性.基于Hα谱线的红不对称性,我们导出了两维色球速度场,结果发现不同区域具有不同速度,有的区域向下最大速度可达30~40km/s,而有的区域只有10km/s左右;此外,色球物质向下运动的持续时间也不等,有的仅约1min,而有的长达6min之久.最后我们还证实了红不对称性仅发生在线翼,而线心几乎无位移.  相似文献   

2.
中国满洲里—绥芬河地学断面地震学研究   总被引:9,自引:0,他引:9  
满洲里-绥芬河地学断面域地震学研究表明:沿断面可划分额尔古纳-大兴安岭、松辽盆地-张广才岭和佳木斯-兴凯三个波速块体;纵向上地壳分为三层,地壳厚度29 ̄38km;P波平均速度6.25 ̄6.40km/s;松辽盆地沉积盖层较厚,基底面下方附近低角度断层发育;Moho面厚度1.5 ̄5.0km,内部结构复杂;上地幔低速层埋深差异较大,松嫩块体埋深最浅;深源地震频度高、强度大、震源深,浅源地震相对较少和较弱  相似文献   

3.
通过74个样方共55.17km2,分别对陕西分布的4种鹿类动物中的3种的种群数量进行了调查,借助数理统计学方法,对其资源贮存量进行了估计.结果表明,林麝(Muschusberezovski)1985年的密度是2.49±0.37只/km2,秦巴山区的资源估计贮存量为85200±10400只;1983~1984年黄麂(Muntiacusrevesi)的密度为9.80±0.75只/km2,安康地区10县黄麂资源存量为64700±4900只,年种群自然增长率为35%,适宜猎取量为13000~14000只;陕北黄土高原狍(Capreoluscapre-olus)1976年的密度为6.02±0.83只/km2,资源贮存量为81200±11200只.1981年狍的密度为5.09±0.61只/km2,资源存量为68700±8200只,狍的年种群自然增长率为38%,适宜猎取量为12000~15000只.文中对陕西省鹿类动物资源的保护、管理和利用进行了探讨.  相似文献   

4.
木聚糖降解菌的筛选和木聚糖酶性质的研究   总被引:15,自引:0,他引:15  
筛选两株生长快、产木聚糖酶活力高的菌种;黑曲霉(Aspergillusniger,AN01)、链霉菌(Streptomycessp.Str7B),酶活力分别达128mg/L·min和176mg/L·min;酶反应最适温度分别为60℃与50℃;最适pH值为5.0和6.0,并分别在pH2.2~5.0,5.8~6.4酶活性稳定;在60℃条件下保温1.5h,酶活力分别剩余20.5%,88.5%,其中AN01株原酶液在90℃保温10min,活力仍剩余14.5%.Cu2+对酶活表现出极强抑制,Fe2+,Mg2+,Ca2+等离子则有促进作用;用纸层析法探讨了不同培养时间各种产物产生的情况.  相似文献   

5.
从华荠(MoslachinensisMaxim)中分离鉴定了6种黄酮类化合物,经光谱分析及化学方法鉴定为:5-羟基-6,7-甲基黄酮;5,7-二羟基-4'-甲氧基黄酮;洋芹素;鼠李柠檬素;桑色素-7-O-β-D-葡萄糖甙;山奈素-3-O-β-D-葡萄糖甙.均为首次从该植物中分得.  相似文献   

6.
苏云金杆菌SD-5菌剂对豆天蛾的防治研究   总被引:3,自引:0,他引:3  
利用SD-5菌剂对豆天蛾系统地进行了室内毒力测定,不同龄期敏感性试验,对卵的毒力试验,田间药效试验,示范及推广。结果:孢晶混合物和纯化晶体感染3龄虫72hLC50分别为3.02×10 ̄6个孢晶/ml和1.86×10 ̄6个晶体/ml,且晶体致死速度较快;不同龄期的幼虫对SD-5菌剂敏感性有一定差异,小龄虫更为敏感。喷施SD-5菌剂对豆天蛾卵的孵化无明显影响,但孵出的幼虫48h内死亡率高达91.6%~100%;田间小区试验SD-50.5亿/ml防效为91.7%,优于7216;大田示范推广125.48hm ̄2.防效达92.35%~98.73%;SD-5防区内天敌种类和数量明显高于化防区。  相似文献   

7.
研究了一种快速凝固的熔融金属取样器;其冷却速度可达105K/s,凝固速度达67.6mm/s,传热系数达105(W·m-2·K-1).该装置能够实现在现场或实验室的熔融金属中不同部位抽取液淬.  相似文献   

8.
反相高效液相色谱法测定补肾益寿颗粒中淫羊藿甙的含量   总被引:1,自引:0,他引:1  
应用反相高效液相色谱法,建立了测定纯中药制剂补肾益寿颗粒中活性成分淫羊藿甙含量的方法.样品以70%乙醇超声波振荡提取,在下列色谱条件下测定:固定相shimpackCLC-ODS(150mm×6mm,5μm);流动相乙腈甲醇-0.1mol/L磷酸二氢钠(6∶46∶50,v/v);流速1.0ml/min;检测波长270nm;线性范围0.115~0.690μg(r=0.9999);加样回收率99.08±1.76%;日内精密度1.05%~1.19%.该法简便、快速、准确  相似文献   

9.
产于凹凸棒石粘土矿层中的硅岩具有特征的沉积构造,SiO2含量高(77.92~89.44%),U/Th>1、Zn、As、Sb等元素含量高,稀土总量低(4.5×10-6~16.55×10-6)。稀土配分型式及氧稳定同位素组成与热水沉积硅岩一致,推算形成温度为71℃~81℃。上述特征表明硅岩为热水沉积产物,亦说明在苏皖凹凸棒石粘土矿床形成过程中存在有热水事件。  相似文献   

10.
1,10-菲罗啉-5,6-二醌伏安行为研究   总被引:1,自引:0,他引:1  
在0.50mol·L~(-1)NH_3-NH_4Cl缓冲溶液中,1,10-菲罗啉-5,6-二醌有一还原伏安峰。当静止富集2min,v=100mV·s~(-1)时,其峰电位E_p=-1.31V(vs.Ag/AgCl)。用线性扫描和循环伏安法等手段研究体系的伏安行为,特别是吸附性。实验表明,该体系属具有吸附性的不可逆过程。用于单扫示波极谱法测定,线性范围为5.0×10~(-8)~5.0×10~(-6)mol·L~(-1),其相关系数为0.9995。  相似文献   

11.
Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.  相似文献   

12.
何延凌 《科技信息》2008,(4):258-258
Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women's language from these perspectives: pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women's language, more attention should be paid to language use in social context. What's more, the linguistic phenomena in a speaking community can be understood more thoroughly.  相似文献   

13.
理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。  相似文献   

14.
As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.  相似文献   

15.
正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-  相似文献   

16.
We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-  相似文献   

17.
正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that  相似文献   

18.
For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the  相似文献   

19.
Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of  相似文献   

20.
<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with  相似文献   

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