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381.
目的:应用响应面法优化丹参毛状根诱导条件,提高其诱导率。方法:采用发根农杆菌ATCC15834侵染丹参无菌苗获得毛状根,在单因素实验的基础上,利用Box-Benhnkcn设计和响应面分析方法对丹参毛状根诱导过程的培养条件(叶片大小、农杆菌活力、侵染时间、共培养时间、抗生素浓度)进行分析,优选最佳培养条件。结果:丹参毛状根在无外源激素的MS培养基上自主生长,表现出典型的发根特征。毛状根的最优培养条件为:叶片大小0.8cm,农杆菌OD600为1.0,共培养时间2d,农杆菌侵染时间5min,头孢噻吩浓度400ng/L。在此条件下,丹参毛状根的诱导率为69.8%。结论:该研究优化了丹参毛状根的培养条件,为丹参的进一步开发利用提供了依据。 相似文献
382.
周灿 《云南地理环境研究》2008,20(1):102-106
通过问卷调查和访谈法,从旅游发展、旅游培训教育、旅游参与、环境影响等方面分析大等喊傣寨社区居民的旅游发展意识状况。结果表明,大等喊傣寨的社区居民的旅游发展意识水平整体上不高,受教育程度普遍偏低,乡村旅游专业技术人才匮乏,因此,农村劳动者素质的提高,就成为乡村旅游发展成败的关键。 相似文献
383.
Nitrous oxide (N2O) is a potent greenhouse gas. Mitigating N2O emission is critical for combating global climate change and improving the ecological environment. Many studies have focused on factors affecting N2O emission from agricultural soils, but rarely on the relationship among these factors. In the present study, continuous measurement on N2O emission was conducted in a maize system in Griffith, Australia and the relationships between N2O emission, soil properties and weather conditions were examined. Principal component analysis and path analysis were used to analyze these data in correlation coefficient and the direct and indirect effects to N2O emission. Results indicated that (1) the major factors affecting N2O emission were WFPS, mineralized nitrogen (Mineral N), daily mean temperature (T mean) and CO2 concentration. The factors of direct influence N2O emission were following Mineral N, CO2, WFPS, and T mean. The indirect influence N2O emission was following T mean, WFPS, Mineral N, and CO2 concentration. (2) The standard multiple regression describing the relationship between N2O emission and its major factors were Y = ?37.162 + 0.5267 X 1 + 0.4331 X 2 + 0.3014 X 3 + 0.2392 X 4 (r = 0.924, p < 0.01, n = 151), where Y is N2O emission, X 1 is Mineral N, X 2 is CO2, X 3 is WFPS and X 4 is T mean. (3) N2O emission from agricultural soils can be monitored and mitigated through improved management practices such as irrigation, straw retention and fertilizer application. 相似文献
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<正>1 Introduction Shallow water delta in the middle-newborn Stratum Widely developed with huge oil and gas in China(Hu Shengwu et al.,2013).The control factors on the deltadevelopment like Climate,sea level,tectonic subsidence,sediment supply(flow,type),the geometric characteristics of the upstream river,the energy(wave, 相似文献
387.
球粒状(綠)帘石产出于四川雷波基性火山碎屑岩的晶洞或层间裂隙中,与其共生的有石英、赤铁矿等矿物.镜下研究表明,绿帘石至少有2个世代,第一世代(綠)帘石呈浅(綠)色的针状体,集合体为菊花状;第二世代(綠)帘石呈暗(綠)色的柱状或楔形,集合体为球粒状或椭球状.它们都由球核与球枝两部分组成,两者间有明显的接触界线,表明球核与球枝不是同时结晶的产物,而是有先后形成关系.EPMA分析表明绿帘石成分中普遍含有较高的SrO(0.51%~1.13%),与其共生的水晶晶体的流体包裹体测温及拉曼光谱分析表明,气液包裹体主要由H2O及微量CH4组成,,(綠)帘石属低温(164~177℃)与低盐度(7.31%~7.73%)的热液产物.(綠)帘石的球粒是在低温、过饱和度大、环境条件转变时快速结晶形成的. 相似文献
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Joseph Canérot 《Comptes Rendus Geoscience》2006,338(9):658-665
This work disproves the magmatic (ophitic rises) and sedimentological (submarine trans-Pyrenean trough filled with breccias and hemipelagites) arguments presented in favour of a Danian distension step following a major Upper to Late Cretaceous Pyrenean compression phase. In the western Pyrenees (Bearn area) the tholeiitic magmatism is really Triassic or Lowermost Liassic in age. The ophites cross mechanically the Jurassic and Cretaceous enclosing sedimentary beds without any contact metamorphism, which could give proof of a Palaeocene age for the magmatic emplacement. As for the supposed submarine breccias rich in planktonic foraminifera, they really correspond to diapiric Early Cretaceous breccias, to Cretaceous or Tertiary tectono-karstic breccias or to Quaternary colluvial deposits. The Danian/Selandian trough does not exist. The proposed interpretation assigns that the Palaeocene interval must be included within the long compression (transpression) period, which begins in the Upper Cretaceous times and increases during the Early Cenozoic, leading to the main structural step of the Pyrenean cycle, towards the Middle–Upper Eocene. To cite this article: J. Canérot, C. R. Geoscience 338 (2006). 相似文献