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381.
11个猕猴桃品种间的遗传多样性分析   总被引:6,自引:0,他引:6  
利用随机扩增多态性DNA标记(RAPD)技术对采自四川省猕猴桃科研基地的11个猕猴桃品种进行了遗传多样性分析.通过引物筛选,从15个RAPD引物中扩增出135条带,其中100条为多态带,占74.07%.UPGMA聚类分析结果揭示了各品种间的亲缘关系.RAPD标记说明猕猴桃品种间遗传距离与地理分布有一定关系,地理位置较近的材料能聚在一起.分子标记可用于猕猴桃种质资源的分类、鉴定及良种选育.图2表2参15  相似文献   
382.
中国东部季风区末次冰期以来古气候模拟   总被引:5,自引:0,他引:5  
通过对我国东部季风区现代青土样品孢粉组合与气候因子间的回归分析,分别建立了孢粉组合与一月,七月气温和年降水量的转换函数,进而建立了本区末次冰期以来的孢粉-气候数据库,模拟末次冰期盛冰期,消冰期,全新世前北方期-北方期,大西洋期,亚北方期等五个古气候期的冬季和夏季温度场,降水场。  相似文献   
383.
程新  张建强 《重庆环境科学》2003,25(11):28-29,31
ABR反应器的处理效率受多方面的因素影响,本文通过BP人工神经网络,利用ABR反应器进水CODcr浓度、容积负荷、温度、稳定运行时间四个参数对其反应器处理效率进行预测。结果表明,BP人工神经网络可较好的用于ABR反应器处理效率的预测,具有较高的精度,在实际生产中,可以运用人工神经网络,对ABR反应器的运行参数进行调整,使之达到最优化的运行状态。  相似文献   
384.
本文首次详细论述了赛都糜棱岩型金矿的矿石类型、矿石组构和金属矿物的特征,对金矿物特征和金的赋存状态作了详细描述,并在矿石矿物学分析基础上提出了该金矿的矿化阶段。  相似文献   
385.
本文校系统地研究了成矿元素及微星元素.稀土元素和铅、硫、氢、氧同位素等成矿地球化学特征.研究结果表明,研究区内成矿物质来源是多方面的;成矿过程中的介质水在成矿主要阶段是大气降水与再平衡岩浆水的混会,在成矿晚期则主要来自大气降水;成矿是多阶段的,可依据各阶段的矿化程度来确定今后应侧重的矿种.  相似文献   
386.
The real-time detection of the mixing states of polycyclic aromatic hydrocarbons (PAHs) and nitro-PAHs in ambient particles is of great significance for analyzing the source, aging process, and health effects of PAHs and nitro-PAHs; yet there is still few effective technology to achieve this type of detection. In this study, 11 types of PAH and nitro-PAH standard samples were analyzed using a high performance-single particle aerosol mass spectrometer (HP-SPAMS) in lab studies. The identification principles ‘parent ions’ and ‘mass-to-charge (m/z) = 77’ of each compound were obtained in this study. It was found that different laser energies did not affect the identification of the parent ions. The comparative experiments of ambient atmospheric particles, cooking and biomass burning emitted particles with and without the addition of PAHs were conducted and ruled out the interferences from primary and secondary organics on the identification of PAHs. Besides, the reliability of the characteristic ions extraction method was evaluated through the comparative study of similarity algorithm and deep learning algorithm. In addition, the real PAH-containing particles from vehicle exhaust emissions and ambient particles were also analyzed. This study improves the ability of single particle mass spectrometry technology to detect PAHs and nitro-PAHs, and HP-SPAMS was superior to SPAMS for detecting single particles containing PAHs and nitro-PAHs. This study provides support for subsequent ambient observations to identify the characteristic spectrum of single particles containing PAHs and nitro-PAHs.  相似文献   
387.
This investigation reports on the effects of soil organic matter (SOM) during the oxidation of chlorophenols with Fe2+-catalyzed H2O2 (Fenton oxidation) system. The soil pH was 7.1 and was not altered. Sorption experiments of soil pre-treated under various oxidation conditions were performed. Concentrations of organic matter in the liquid phase and soil before and after oxidation were analyzed. The results were correlated to the observation in batch Fenton oxidation tests. They showed that the oxidation of chlorophenols at natural soil pH depended on the dose of H2O2 and Fe2+. The soil organic content did not vary significantly after various Fenton treatments, while the sorption of chlorophenols was 10-25% less by the oxidation. The concentration of chlorophenols in the liquid phase exhibited a "decrease and rebound" phenomenon in the batch Fenton oxidation tests. It appeared that the oxidation of SOM resulted in the release of sorbed chlorophenols which were then oxidized by the excess H2O2. An "oxidation-desorption-oxidation" scheme was proposed to describe one of the interaction mechanisms among the oxidant, SOM, and chlorophenols during oxidation.  相似文献   
388.
Combined glassification of EAF dust and incinerator fly ash   总被引:7,自引:0,他引:7  
Cheng TW 《Chemosphere》2003,50(1):47-51
Stainless steelmaking dust contains large amount of heavy metals, such as Cr and Ni. If these hazardous materials are not treated properly, they will cause detrimental secondary contamination. Preliminary study on recycling stainless steelmaking dust employed the thermal molten technology. Glass-ceramics were formed by combination stainless steel dust and incinerator fly ash with the ratio of 1:9. The major phases were Augite, Akermanite, and Donathite. It was found that the glass-ceramics shows the best characteristic at 900 degrees C after 5 h of heat treatment. This product can be used as building materials or refractory materials.  相似文献   
389.
Cheng MT  Lin YC  Chio CP  Wang CF  Kuo CY 《Chemosphere》2005,61(10):1439-1450
Aerosol samples for PM(2.5) and PM(2.5-10) were collected at four locations in central Taiwan from 26 to 31 March 2000, a period that experienced exceedingly high PM levels from 29 to 30 March due to the passage of an Asian dust storm. The samples were analyzed for mass, metallic elements, ions, and carbon. The purpose of this paper is to investigate the influence of the dust storm on the characteristics of local ambient particulate matter. The results indicate that the concentrations of the crustal elements Ca, Mg, Al, Fe and the sea salt species Na+ and Cl- in PM(2.5-10) during the dust episode exceed the mean concentrations in the non-dust period by factors of 3.1, 2.9, 2.6, 2.2, 2.3 and 2.1 respectively. Enrichment factors of Ca, Fe, and Mg in PM(2.5-10) during the dust event are close to unity, indicating that these elements are from soil. Reconstruction of aerosol compositions revealed that soil of coarse particulates elevated approximately 50% in the dust event. It is noted that during the dust event, the ratio of Mg/Al in PM(2.5-10) ranged from 0.21 to 0.25 while that of Ca/Al ranged from 0.6 to 0.9, levels more constant than those obtained in non-dust period.  相似文献   
390.
Yang HH  Hsieh LT  Cheng SK 《Chemosphere》2005,60(10):1447-1453
In this study, both atmospheric particulates and dry deposited particulates were collected at a highway intersection, coastal location and suburban area in Taichung, Taiwan for the characterization of nitrate containing particulates (NCPs) in size distribution and dynamic properties. Collected particulates were placed in contact with nitron (C20H16N4) to form distinctive products of NCPs, which were examined by a SEM. For total atmospheric particulates, the sum of NCP and non-nitrate containing particulate (NNCP), the average shape factor values are 1.69, 1.49, and 1.36 for the highway intersection, coastal area and suburban area, respectively. The calculated shape factors show no significant differences with sizes. Dry deposition fluxes and atmospheric concentrations at various size ranges were estimated. The mass distributed in fine particle range (相似文献   
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