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1.
科幻作家韩松说,"某种程度上,世界按科幻的构造在发展,由于科幻的存在,我们已经事实上活在了未来世界里." 在科幻电影 《火星救援》中,当男主角被困在昼夜温差约100℃的火星瑟瑟发抖时,想出的自救办法是从沙尘中挖出埋藏已久的核电池取暖.  相似文献   

2.
模拟煤环境中几种无机硫的热分解行为   总被引:2,自引:0,他引:2  
徐龙  倪晋仁 《环境科学》2005,26(2):69-73
采用活性焦作为构造煤大分子网络的基质,将无机硫(黄铁矿、硫酸亚铁)混合于其上,形成模拟煤的环境.利用程序升温热解-火焰光度检测器或质谱联用(TPD-FPD/MS)技术和X-射线吸收精细结构(EXAFS)光谱对比研究了FeS2、FeSO4在活性焦上及纯态下热分解过程中硫逸出的动态特征及结构变化.结果表明:担载于活性焦上FeSO4的分解主要发生在200℃~500℃,而纯态FeSO4的分解温度范围为450℃~600℃,说明活性焦的存在使其分解温度显著降低,且硫的逸出情况更为复杂.黄铁矿与活性焦的物理混合并没有使FeS2的分解温度降低,但对其分解程度有一定的影响,并与热解气氛密切相关;温度高于400℃后FeS2分解的硫开始大量逸出,在550℃左右基本失去结构中与铁配位的第2层硫原子而形成FeS.  相似文献   

3.
福建东山苏峰山地区亲营山岩组含石榴石、黑云母和白云母。亲营山岩组原岩为泥质岩,经历了岩片俯冲、深埋挤压和逆冲3个构造-变质作用阶段,分别形成俯冲岩片(Ⅰ)、深埋挤压岩片(Ⅱ)和逆冲岩片(Ⅲ)。俯冲阶段为中温低压变质作用,深埋挤压阶段为高温中压进变质作用,逆冲阶段为高温低压退变质作用。石榴石、黑云母和白云母为主要变质矿物,均为无环带的均一矿物。选取相邻石榴石和黑云母矿物对作为地质温度计,结合白云母地质压力计,估算俯冲阶段温度为594~622℃,压力为0. 28~0. 52 GPa;深埋挤压阶段温度为629~655℃,压力为0. 6~0. 7 GPa;逆冲阶段温度为476~495℃,压力为0. 09~0. 1 GPa。  相似文献   

4.
北碚地区位于川东平行岭谷西缘,华蓥山构造带向西南帚状分支的温塘峡背斜、北碚向斜和观音峡背斜的偏北段。气候具有亚热带湿润季风气候特征,年平均气温18.2℃,最冷的一月平均气温7.5℃,最热七月平均气温28.6℃,年平均降水量1143mm。本文  相似文献   

5.
本文根据浑河断裂带及其邻近地区的水系格局、构造节理和地震震源机制解等资料研究该区新构造时期以来的构造应力场。本区在同一地质构造作用下,构造应力场相同,为NEE向。浑河断裂以抚顺市石门岭煤矿区为界,断裂的东南段最新活动时期为261.95±26.05ka.B.P,为中更新世活动断裂,而东北段断裂的最新活动时期为44.7±3.6ka.B.P,表明晚更新世以来仍有活动。在NEE向构造应力场的作用下,北东向的浑河断裂反映为右旋逆冲的运动性质。  相似文献   

6.
大别山东南麓有两套薄皮构造,以韧性剪切带为代表的韧性-半韧性薄皮构造和以逆冲推覆为特征的半脆性-脆性薄皮构造.后者可划分出六个一级薄皮层片体,总体上呈倒序迭瓦状结构.地球物理资料等证实大别地体仰冲于扬子地体之上.两者是以缓倾角断裂为边界的斜接碰撞,其南界为郯庐断裂南端、襄广断裂南东段及其间的隐伏拆离断层,主拼贴断裂在地表分枝为数条层滑-逆冲断裂.主体碰撞时代为225-75Ma,最终拼贴时代可延续到33~23Ma.韧性-半韧性薄皮构造形成于碰撞中、晚期,而半脆性-脆性薄皮构造则形成于碰撞末期及后造山期.在扬子地体俯冲过程中,俯冲于大别地体之下的盖层层片体被逐片“铲出”,呈上老下新的迭瓦状结构.广泛发育的薄皮构造调节了地体碰撞拼贴造成的强烈压缩变形.  相似文献   

7.
下扬子区中上元古界,可以分为四个构造层次.中元古界早期构造层,为一套巨厚的地槽型火山碎屑岩及砂泥质复理石建造,形成于1900-1400Ma;中元古界晚期构造层,为滨海——浅海——半深海砂泥质复理石建造.形成于1400-1000Ma;晚元古界早期构造层,为山前凹地或山间盆地磨拉石堆积,形成于1000-800Ma;晚元古界晚期(震旦系)构造层,则为砂泥质、硅质、碳酸盐岩夹冰碛砾岩建造,形成于800-600Ma.这些构造层之间不同形式的接触关系都代表着不同性质的构造运动,九岭群和修水间的修水运动,形成扬子准地台的雏型;上溪群和历口群邓家组间的祁门运动是形成扬子准地台的主褶皱幕;历口群铺岭组和震且系间的休宁运动,只使地壳抬升.这些不同性质的构造运动,也是推动地质历史演化的主要动力.  相似文献   

8.
齐求Ⅰ号金矿产于中晚石炭统海相基性火山喷发沉积岩中,为典型的中温热液矿床,以石英脉型金矿为主,蚀变岩型金矿为辅.矿化受断裂控制,系火山机构与断裂构造复合控矿,环状构造内北西向断裂矿化较好,矿脉向西南深部有归并趋势.  相似文献   

9.
江南古陆中元古代地层的划分与对比   总被引:6,自引:0,他引:6  
江南古陆是扬子板块与华夏板块长期活动拼贴而成,构造极为复杂,地层的划分与对比也是众说纷纭.通过对江南古陆的变质岩的研究,认为江南古陆大地构造可划分三个Ⅰ级构造地层区:扬子地层区、江南古陆地层区及华夏地层区.江南古陆地层区又可进一步划分Ⅱ级构造地层区5个(宜丰-景德镇-歙县构造地层分区、万年构造地层分区、赣东北构造地层分区、怀玉构造地层分区及丰城-鹰潭-龙游构造地层分区);各构造地层分区之间以构造(蛇绿)混杂岩亚带或韧性剪切带相拼接.双桥山群及周潭岩群仅分别分布在扬子地层区修水-祁门分区及华夏地层区北武夷地层分区内,而且是一套史密斯地层.而江南古陆内则发育非史密斯地层.  相似文献   

10.
高温ASBR处理热水解污泥的梯度升温法启动试验研究   总被引:2,自引:0,他引:2  
欧阳二明  王伟  龙能  李怀 《环境科学》2009,30(4):1105-1109
采用序批式运行方式、梯度升温方法进行了高温ASBR处理热水解污泥的启动实验.结果表明,梯度升温法能在131 d内较快地启动高温ASBR反应器.在3个梯度升温阶段中(35℃→40℃→47℃→53℃),反应器的性能都出现了一定的波动,其中在中温→中温(35℃→40℃)、高温→高温(47℃→53℃)阶段出现的波动比较小,而在中温→高温(40℃→47℃)阶段反应器的产气量、甲烷含量、出水COD和反应器内微生物量都出现了较大的变化,反应器的性能波动较大,40℃和47℃分别为中温和高温的上限和下限.在反应器启动过程的稳态期,反应器的平均产气量为2.038 L/d,甲烷含量为72.0%,COD产气率(CH4/COD投入)为188.8 mL/g,TCOD和SCOD平均去除率分别为63.8%和83.3%.扫描电镜和DGGE分析结果表明,启动过程中反应器中的微生物形态和种类都发生了变化,启动初期(35℃)和稳定期(53℃)的优势菌种明显不同.  相似文献   

11.
The potential harm of heavy metals is a primary concern in application of sludge to the agricultural land. A pot experiment was conducted to evaluate the effect of two sludges on fractionation of Zn and Cu in soil and their phytotoxicity to pakchoi. The loamy soil was mixed with 0%, 20%, 40%, 60% and 80% (by weight) of digested sewage sludge (SS) and composted sludge (SC). The additions of both sludges caused a significant raise in all fractions, resulting in that exchangeable (EXCH) and organic bound (OM) became predominance of Zn and organic bound Cu occupied the largest portion. There was more available amount of Zn and Cu in SS treatments than SC treatments. During the pot experiment, the concentration of Zn in EXCH, carbonate (CAR) and OM and Cu in EXCH and OM fractions decreased in all treatments, so their bioavailability reduced. Germination rate and plant biomass decreased when the addition rate was high and the best yield appeared in 20% mixtures at the harvest of pakchoi. The two sludges increased tissue contents of Zn and Cu especially in the SS treatments. Zn in pakchoi was not only in relationship to ΔEXCH and ΔCAR forms but also in ΔOM forms in the sludge-soil mixtures. Tissue content of Cu in pakchoi grown on SC-soils could not be predicted by ΔEXCH. These correlation rates between Zn and Cu accumulation in pakchoi and variation of different fractions increased with time, which might indicate that sludges represented stronger impacts on the plant in long-term land application.  相似文献   

12.
A hydroponic experiment was carried out to study intraspecific differences in the effects of different concentrations of cadmium (Cd)(0-10 mg/L) and arsenate (As(V)) (0-8 mg/L) on the growth parameters and accumulation of Cd and As in six wheat varieties Jing-9428, Duokang-1, Jingdong-11, Jing-411, Jingdong-8 and Zhongmai-8. The endpoints of wheat seedlings, including seed germination,biomass, root length and shoot height, decreased with increasing the Cd and As concentrations. Significant differences in seed germination, biomass, root length, shoot height and the accumulation of Cd and As were observed between the treatments and among the varieties (p < 0.05). The lethal dosage 50% were about 20, 80, 60, 60, 80 and 20 mg As/L for Jing-9428, Duokang-1, Jingdong-11,Jing-411, Jingdong-8 and Zhongmai-8, respectively, and the corresponding values for Cd were about 30, 80, 20, 40, 60 and 10 mg Cd/L, respectively. Among the six varieties, Duokang-1 was found to be the most resistant to Cd and As toxicity, and Zhongmai-8 was the most sensitive to Cd and As co-contamination. The resistance of the six varieties was found dependant on the seedling uptake of Cd and As. Duokang-1 was the most suitable for cultivation in Cd and As co-contaminated soils.  相似文献   

13.
Toxic effects of two agrochemicals on nifH gene in agricultural black soil were investigated using denaturing gradient gel electrophoresis (DGGE) and sequencing approaches in a microcosm experiment. Changes of soil nifH gene diversity and composition were examined following the application of acetochlor, methamidophos and their combination. Acetochlor reduced the nifH gene diversity (both in gene richness and diversity index values) and caused changes in the nifH gene composition. The effects of acetochlor on nifH gene were strengthened as the concentration of acetochlor increased. Cluster analysis of DGGE banding patterns showed that nifH gene composition which had been affected by low concentration of acetochlor (50 mg/kg) recovered firstly. Methamidophos reduced nifH gene richness that except at 4 weeks. The medium concentration of methamidophos (150 mg/kg) caused the most apparent changes in nifH gene diversity at the first week while the high concentration of methamidophos (250 mg/kg) produced prominent effects on nifH gene diversity in the following weeks. Cluster analysis showed that minimal changes of nifH gene composition were found at 1 week and maximal changes at 4 weeks. Toxic effects of acetochlor and methamidophos combination on nifH gene were also apparent. Different nifH genes (bands) responded differently to the impact of agrochemicals: four individual bands were eliminated by the application of the agrochemicals, five bands became predominant by the stimulation of the agrochemicals, and four bands showed strong resistance to the influence of the agrochemicals. Fifteen prominent bands were partially sequenced, yielding 15 different nifH sequences, which were used for phylogenetic reconstructions. All sequences were affiliated with the alpha- and beta-proteobacteria, showing higher similarity to eight different diazotrophic genera.  相似文献   

14.
The effects of arbuscular mycorrhizal (AM) fungus (Glomus mosseae) and phosphorus (P) addition (100 mg/kg soil) on arsenic (As) uptake by maize plants (Zea mays L.) from an As-contaminated soil were examined in a glasshouse experiment.Non-mycorrhizal and zero-P addition controls were included.Plant biomass and concentrations and uptake of As,P,and other nutrients,AM colonization,root lengths,and hyphal length densities were determined.The results indicated that addition of P significantly inhibited root colonization and development of extraradical mycelium.Root length and dry weight both increased markedly with mycorrhizal colonization under the zero-P treatments,but shoot and root biomass of AM plants was depressed by P application.AM fungal inoculation decreased shoot As concentrations when no P was added,and shoot and root As concentrations of AM plants increased 2.6 and 1.4 times with P addition,respectively.Shoot and root uptake of P,Mn,Cu,and Zn increased,but shoot Fe uptake decreased by 44.6%,with inoculation, when P was added.P addition reduced shoot P,Fe,Mn,Cu,and Zn uptake of AM plants,but increased root Fe and Mn uptake of the nonmycorrhizal ones.AM colonization therefore appeared to enhance plant tolerance to As in low P soil,and have some potential for the phytostabilization of As-contaminated soil,however,P application may introduce additional environmental risk by increasing soil As mobility.  相似文献   

15.
Phytoremediation is a potential cleanup technology for the removal of heavy metals from contaminated soils.Bidens maximowicziana is a new Pb hyperaccumulator,which not only has remarkable tolerance to Pb but also extraordinary accumulation capacity for Pb.The maximum Pb concentration was 1509.3 mg/kg in roots and 2164.7 mg/kg in overground tissues.The Pb distribution order in the B. maximowicziana was:leaf>stem>root.The effect of amendments on phytoremediation was also studied.The mobility of soil Pb and the Pb concentrations in plants were both increased by EDTA application.Compared with CK(control check),EDTA application promoted translocation of Pb to overground parts of the plant.The Pb concentrations in overground parts of plants was increased from 24.23-680.56 mg/kg to 29.07-1905.57 mg/kg.This research demonstrated that B.maximowicziana appeared to be suitable for phytoremediation of Pb contaminated soil,especially,combination with EDTA.  相似文献   

16.
Laogang landfill near Shanghai is the largest landfill in China, and receives about 10000 t of daily garbage per day, Samples of topsoil and plants were analyzed to evaluate mercury pollution from the landfill. For topsoil samples, there were significant correlations among total mercury (HgT), combinative mercury (Hgc) and gaseous mercury (HgG), and content of total organic carbon (TOC), but, no significantly relationship was found between Hg content and filling time. Hg content changes in vertical profiles with time showed that the average Hgv of profiles 1992, 1996, and 2000 was similar, but their average HgG was quite different. HgT was significantly correlated with Hgc in profile 1992 and 2000, and Hgv was significantly correlated with Hg6 in profile 1996. HgG/Hgv ratio in profile samples decreased in the order of (HgG,/HgT)1992〉(HgG/HgT)1996〉〉(HgG/HgT)2000. A simple outline of Hg release in landfill could be drawn: with increasing of filling time, degradation undergoes different biodegradation, accordingly, gaseous mercury goes through small, more, and small proportion to total mercury. Distribution of Hg in plants was inhomogeneous, following the order of leaf〉root〉stem. The highest value of leaf may be associated with higher atmospheric Hg from landfill. Ligneous plants (e.g. Phyllostachys glanca, Prunus salicina and Ligustrum lucidum) are capable of enriching more Hg than herbaceous plants.  相似文献   

17.
The influence of the nonionic surfactant Tween 80 on pentachlorophenol (PCP) oxidation catalyzed by horseradish peroxidase was studied. The surfactant was tested at concentrations below and above its critical micelle concentration (CMC). Enhancement of PCP removal was observed at sub-CMCs. The presence of Tween 80 in the reaction mixture reduced enzyme inactivation which occurred through a combination of free radical attack and sorption by precipitated products. A simple first-order model was able to simulate time profiles for enzyme inactivation in the presence or absence of Tween 80. At supra-CMCs, the surfactant caused noticeable reductions in PCP removal, presumably through micelle partitioning of PCP which precluded the hydrophobic PCP molecule from interacting with the enzyme.  相似文献   

18.
Decomposition of alachlor by ozonation and its mechanism   总被引:1,自引:0,他引:1  
Decomposition and corresponding mechanism of alachlor, an endocrine disruptor in water by ozonation were investigated. Results showed that alachlor could not be completely mineralized by ozone alone. Many intermediates and final products were formed during the process, including aromatic compounds, aliphatic carboxylic acids, and inorganic ions. In evoluting these products, some of them with weak polarity were qualitatively identified by GC-MS. The information of inorganic ions suggested that the dechlorination was the first and the fastest step in the ozonation of alachlor.  相似文献   

19.
以三峡大学的校园河道求索溪为研究对象,利用综合水质标识指数法确定求索溪水质类别,分析其水质时空变化规律,并利用对应分析法得出求索溪中不同监测点的主要污染因子.研究结果表明:求索溪整体的综合水质标识指数为7.423,整体水质为劣V类(地表水环境质量标准GB 3838-2002)且黑臭.从时间变化来看,求索溪4月份的水质最差,5月份次之,4、5月份所有监测点的水质都劣于V类且黑臭;8月份水质最好,水质为Ⅳ类;从空间分布来看,8个监测点综合水质标识指数均超过6.0,水质为劣V类,其中6号监测点的水质相对最好,监测点3号的水质相对最差;对应分析法得出求索溪的整体水体污染程度受总氮因子的影响最大,其次为总磷.该研究拟为求索溪及类似校园河道的水环境治理研究提供基础依据和参考.  相似文献   

20.
In this study an effort has been made to use plant polyphenol oxidases; potato (Solanum tuberosum) and brinjal (Solanum melongena), for the treatment of various important dyes used in textile and other industries. The ammonium sulphate fractionated enzyme preparations were used to treat a number of dyes under various experimental conditions. Majority of the treated dyes were maximally decolorized at pH 3.0. Some of the dyes were quickly decolorized whereas others were marginally decolorized. The initial first hour was sufficient for the maximum decolorization of dyes. The rate of decolorization was quite slow on long treatment of dyes. Enhancement in the dye decolorization was noticed on increasing the concentration of enzymes. The complex mixtures of dyes were treated with both preparations of polyphenol oxidases in the buffers of varying pH values. Potato polyphenol oxidase was significantly more effective in decolorizing the dyes to higher extent as compared to the enzyme obtained from brinjal polyphenol oxidase. Decolorization of dyes and their mixtures, followed by the formation of an insoluble precipitate, which could be easily removed simply by centrifugation.  相似文献   

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