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1.
The stratospheric dust cloud from the 4 April 1982 eruption of El Chichón volcano in southern Mexico was observed to travel completely around the world in a 3-week period. Images from satellites operated by the National Oceanic and Atmospheric Administration were used to prepare daily maps of the location of the volcanic dust cloud, which is the largest and longest-lasting one so far observed with satellite imagery.  相似文献   

2.
Hoffer JM  P FG  Muela P 《Science (New York, N.Y.)》1982,218(4579):1307-1308
El Chichón volcano erupted at 2322 hours on 28 March 1982 after being dormant during historic times. Three major eruptions of tephra occurred between that date and 7 April, discharging approximately 0.3 cubic kilometer of andesitic pyroclastic material. The initial eruption produced crystal-rich tephra of higher silica and alkali content than the lithic pyroclastic materials of the second and third eruptions. The initial tephra consists of primarily juvenile materials, whereas the later eruptions produced both lithic and juvenile fractions.  相似文献   

3.
The eruption of El Chichón Volcano in March and April 1982 resulted in the nucleation of large numbers of new sulfuric acid droplets and an increase by nearly an order of magnitude in the size of the preexisting particles in the stratosphere. Nearly 10(7) metric tons of sulfuric acid remained in the stratosphere by the end of 1982, about 40 times as much as was deposited by Mount St. Helens in 1980.  相似文献   

4.
西藏土壤全硫测定的初探   总被引:1,自引:0,他引:1  
土壤全硫的测定方法多种多样,经典土壤全硫测定方法是在铂坩埚中用Na2C03和Na202熔融土壤,此方法对所有土壤全硫测定都适用,但手续比较繁琐,制约了土壤全硫的测定.目前根据实验室的条件以及西藏土壤含硫情况,用硝酸镁氧化-硫酸钡比浊法进行西藏土壤全硫含量的测定,西藏土壤全硫含量大部分在0.1-0.3g/kg之间,所测的土壤全硫的绝对相差都小于0.05g/kg,相对标准偏差RSD都小于1%,所以硝酸镁氧化-硫酸钡比浊法适合西藏耕作土壤全硫的测定.  相似文献   

5.
A brown polymeric material, produced under simulated Jovian conditions, is composed primarily of cyclic octatomic sulfur, although a range of complex organic compounds is also present. The polymeric sulfur, produced from the ultraviolet photolysis of hydrogen sulfide, exhibits its strongest band at 465 reciprocal centimeters, in fair agreement with the frequency of the unidentified Jovian absorber recently announced by Houck et al. Polymeric octatomic sulfur may be an important constituent of the Jovian clouds.  相似文献   

6.
Laboratory experiments show that solid carbon dioxide is an effective trap for ozone at temperatures as high as 156 degrees K. Ultraviolet reflection-absorption spectra of ozone in solid carbon dioxide at 127 degrees K indicate that the ozone observed over the polar cap of Mars may be trapped in solid carbon dioxide.  相似文献   

7.
[目的]探明不同园林草本花卉(草花)对二氧化硫(SO2)的抗性,为其在SO2污染地区的应用提供依据。[方法]在自行设计的密闭静态熏气箱中,采用急性静态熏气法,研究了SO2胁迫下13种常见园林草花植物被伤害症状、显症时间和阈值浓度,从而对其进行抗性分级。[结果]SO2处理浓度高于0.3g·m-3时,大部分材料均出现明显症状,主要表现为叶尖焦枯,叶片卷曲,出现黄褐色或者黑色斑点及萎蔫等。13种草花中,对SO2高度敏感型植物有飞燕草和孔雀草;中度敏感型有一串红和蜀葵,敏感型的有万寿菊,高抗型的有薰衣草、金光菊,中抗型的有石竹、串白和羽扇豆,微抗型的有毛地黄和鼠尾草。[结论]薰衣草等高抗和中抗的植物可以在SO2严重污染地区使用,孔雀草、一串红等可以作为污染指示植物。  相似文献   

8.
BP神经网络模型在香菇中SO2含量分析中的应用   总被引:1,自引:0,他引:1  
以‘庆元9015’香菇作为研究对象,以香菇样品的生长天数(d)和样品中总SO2-3含量、鲜香菇样品的SO2含量和采摘期的出菇时间(d)为输入层参数,以干香菇中SO2含量为输出层参数,建立三层BP神经网络模型,经过356次训练后模型收敛,模型具有满意的预测能力。  相似文献   

9.
10.
SO_2胁迫对紫丁香和连翘叶片生理生化指标的影响   总被引:1,自引:0,他引:1  
采用两种SO2浓度对紫丁香(Syringa oblata)和连翘(Forsythia suspensa)截枝进行熏气处理,分析了叶片中叶绿素a、叶绿素b和叶绿素(a+b)含量的动态变化以及叶绿素(a+b)与细胞汁液pH值、细胞质膜相对透性(PMP)、脯氨酸(Pro)、丙二醛(MDA)和可溶性糖(SS)含量的相关性.结果表明,在10 mg/m3和30 mg/m3SO2浓度胁迫下,随着胁迫时间的延长和浓度的增加,叶绿素总量有所上升,膜脂过氧化产物丙二醛含量明显增加,细胞质膜相对透性明显增大,脯氨酸含量先降低而后升大,可溶性糖含量有所增大,细胞汁液pH值变小.经相关分析表明,叶绿素含量与可溶性糖、丙二醛含量和细胞汁液pH值呈显著正相关,而与脯氨酸含量呈显著负相关.  相似文献   

11.
为确定SO24-与Ba2 比浊反应的最佳条件,找出影响比浊的关键因子。应用正交试验设计,探讨了酸度、缓冲液用量、BaCl2用量、搅拌时间、静置时间对比浊结果的影响,通过方差分析选择最佳比浊条件。该比浊条件应用于植株样品中全硫含量的测定,结果可靠,回收率为96.8%~104.5%。利用最佳比浊条件测定了茶树叶标样(GBW08315)中全硫含量,与证书推荐值一致。  相似文献   

12.
为了研究SO2对昆虫天敌的影响,本试验采用单体和群体饲养的方法研究了0(ck) 、855、1995、3990和5700 mg/m3 5个SO2浓度处理对异色瓢虫[Harmonia axyridis(Pallas)]的生长发育和体内保护酶的影响.结果表明:各个不同浓度的SO2都能促进异色瓢虫幼虫的发育进度,提高幼虫的体重...  相似文献   

13.
Barr S 《Science (New York, N.Y.)》1982,216(4550):1111-1112
A fortuitous and dramatic photograph of the Soufriere eruption column of 17 April 1979 displays a series of highly structured skirt clouds. The gentle distortion of thin, quasi-horizontal layers of moist air has been documented in meteorological situations. It is proposed that at St. Vincent subhorizontal layers of moist air were intensely deformed by the rapidly rising eruption column and were carried to higher altitudes, where they condensed to form the skirt clouds.  相似文献   

14.
The distribution of radioactive polonium-210, a decay product of radon-222, shows enhanced concentrations at the edges of lunar maria. Enhancements are seen at the edges of Mare Fecunditatis, Mare Crisium, Mare Smythii. Mare Tranquillitatis, Mare Nubium, Mare Cognitum, and Oceanus Procellarum. The observation is indicative of the transient emission of radon gas from the perimeters of lunar maria.  相似文献   

15.
Chain decomposition of ozone by hydroxyl and hydroperoxyl radicals has been observed. The rate constant at 3000 degrees K for OH + O(3)-->HO(2) + O(2) is 8 x 10(-14) cubic centimeters per second. The rate constant for HO(2) + O(3)--> OH + 2O(2), is 3 x 10(-15) cubic centimeters per second. These results have implications concerning stratospheric ozone.  相似文献   

16.
硫肥对大豆蛋白亚基含量的影响   总被引:1,自引:0,他引:1  
试验利用SDS-PAGE方法分析了硫肥水平对3个大豆品种东农46、黑农35和北9395的7S和11S球蛋白亚基含量的影响。小区试验结果表明,施硫增加北9395 7S和11S球蛋白亚基含量,11S/7S降低。东农467S球蛋白亚基含量增加,11S球蛋白亚基含量降低,11S/7S降低。黑农35 7S和11S球蛋白亚基含量降低,11S/7S增加。盆栽试验结果表明,施硫增加北9395 7S球蛋白亚基含量,11S球蛋白亚基含量降低,11S/7S降低。东农46 7S和11S球蛋白亚基含量降低,11S/7S增加。黑农35 7S和11S亚基含量降低,11S/7S增加。  相似文献   

17.
We have developed a chemical ionization mass spectrometry technique for precise in situ measurements of hydrochloric acid (HCl) from a high-altitude aircraft. In measurements at subtropical latitudes, minimum HCl values found in the upper troposphere (UT) were often near or below the detection limit of the measurements (0.005 parts per billion by volume), indicating that background HCl values are much lower than a global mean estimate. However, significant abundances of HCl were observed in many UT air parcels, as a result of stratosphere-to-troposphere transport events. We developed a method for diagnosing the amount of stratospheric ozone in these UT parcels using the compact linear correlation of HCl with ozone found throughout the lower stratosphere (LS). Expanded use of this method will lead to improved quantification of cross-tropopause transport events and validation of global chemical transport models.  相似文献   

18.
为满足野外勘测土壤重金属含量的快速性,X射线荧光光谱仪(XRF)得到了广泛使用。本文采用XRF对昌宁县松山村茶园土壤pH、土壤质量、总砷含量进行测定,结合实验室原子荧光光谱法测定结果,比较XRF快递测定土壤重金属的准确性和可靠性,对野外勘测中使用XRF快速检测土壤重金属提供理论参考依据。结果表明:在pH>5.0时,XRF现场检测数据与实验室检测数据相关系数最高;在砂质土的土壤质地下,XRF现场检测数据与实验室检测数据相关系数最高;在茶园土壤中总砷含量10-40mg/kg的影响下,XRF现场检测数据与实验室检测数据相关系数最高。此外,XRF现场检测数据的平均值与标准偏差均比实验室检测数据高,其最低值和最高值也比实验室检测数据高,测定结果具有可比性。XRF法测定土壤比实验室原子荧光光谱法方便、快捷、操作简单,可以同时测定多种性质,可以在野外勘测中进行使用。  相似文献   

19.
目的 观察臭氧加玻璃酸钠治疗创伤性踝关节炎的应用效果.方法 采用随机对照实验设计,将76例创伤性踝关节炎患者分为实验组和对照组两组,每组38例.实验组采用关节腔注射臭氧加玻璃酸钠治疗,并配合系统干预措施;对照组口服非甾体消炎止痛药.用长海痛尺评分和踝关节Kofoed评分评价两组的治疗效果.结果 治疗7d、5周、6个月,实验组的长海痛尺评分均低于对照组[(3.38±0.84) vs (5.53±o.35)、(0.68±0.74) vs (3.83±0.86)、(0.85±0.33)vs(6.75±0.74),均P<0.01],踝关节Kofoed评分均高于对照组[(75.58±0.17) vs (68.88±0.08)、(86.55±0.14) vs(75.45±0.13)、(85.65±0.15) vs (65.55±0.15),均P<0.01].结论 臭氧加玻璃酸钠治疗创伤性踝关节炎,能有效缓解创伤性关节炎的疼痛症状,改善踝关节的活动度,系统护理干预是疗效的保障.  相似文献   

20.
The polonium-210 activity of the lunar surface is significantly larger than the activity of its progenitor radon-222. This result establishes unequivocally that radon emanation from the present-day moon varies considerably within the 21-year half-life of lead-210, the parent nuclide of polonium-210. There are large variations and well-localized enhancements in polonium-210 activity over much of the moon's surface.  相似文献   

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