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1.
单双介质阻挡放电降解苯的对比研究   总被引:1,自引:0,他引:1  
在相同实验条件下,研究了单、双介质阻挡放电反应器的等离子体发射光谱,对苯的降解效率,以及CO和CO2的生成,检测了NO和NO2的浓度.结果表明,与单介质阻挡放电反应器相比,双介质阻挡放电反应器的发射光谱具有红移现象;单、双介质阻挡放电反应器对苯的降解效率、CO2的生成浓度及选择性几乎一致;采用双介质阻挡放电明显降低了CO的生成浓度,CO的生成选择性也有所下降.更为重要的是,双介质阻挡放电反应器极大地降低了NO2的生成,在本文的实验条件下,没有检测到NO.  相似文献   

2.
邻苯二甲酸二(2-乙基己基)酯酶促降解研究   总被引:2,自引:1,他引:2  
研究了本室从污水处理厂的活性污泥和塑料厂排污口土壤中分离到的两株邻苯二甲酸二(2-乙基己基)酯(DEHP)降解菌CQ0110Y和CQ0110G粗酶液的相关性状及其对DEHP的酶促降解,结果表明,菌株CQ0110Y和XQ0110G降解酶都属于胞内酶.CQ0110Y粗酶液在pH6.0~8.0之间较为稳定,CQ0110G粗酶液在pH6.0~7.5之间较为稳定,CQ0110Y和CQ0110G粗酶液在10℃较为稳定.DEHP的降解产物中含有邻苯二甲酸单(2-基己基)酯、邻苯二甲酸、苯甲酸、对羟基苯甲酸、苯酚以及一些小分子酸类和醇类物质.图4表1参9  相似文献   

3.
钼和硼污染对大豆品质的影响   总被引:1,自引:0,他引:1  
以3个大豆(Glycine max)品种(浙春3号、浙春2号和3811)为材料,设置了4个钼、硼处理(适量钼和硼、高钼、高硼及高钼高硼同施),研究了钼污染和硼污染对大豆品质的影响.结果表明:高钼或高硼促使大豆种子蛋白质、维生素C、氮、磷、钾的含量显著减少,氨基酸的总量和必需氨基酸的总量大大降低,氨基酸各组分(除脯氨酸外)的含量都明显下降,脂肪的组分也发生变化,对种子中钙镁含量的影响不大,且高硼对大豆品质的毒害作用明显大于高钼.在过量条件下,钼和硼在大豆体内呈现相互抑制作用.3个大豆品种的品质问存在一定的基因型差异,3个品种对高钼和高硼的反应也存在差异.图2表3参18  相似文献   

4.
人体摄入的硝酸盐主要来自蔬菜,因而蔬菜硝酸盐的积累间接地影响人体健康.据调查,广州市主要食用蔬菜特别是叶菜硝酸盐超标已十分严重.钼的生理功能主要是参与固氮作用和硝态氮的还原.缺钼会使植物体内硝酸还原酶活性降低,造成过量的硝酸盐积累.本试验通过对广州菜区土壤钼含量进行调查研究,并分析低钼土壤增施钼肥与叶菜硝酸盐含量的关系,为减少广州市蔬菜硝酸盐污染提供理论依据.1材料与方法1.1广州主要莱区土壤有效钼含量测定根据广州市主要菜区(石井、江高、新市、沙河、新窖、大沙地、东圃等地区)不同的成土条件,分别采…  相似文献   

5.
中国癌症与土壤中钼元素的关系   总被引:7,自引:0,他引:7  
利用土壤中钼元素资料110 376个数据,癌死亡调查资料787080例,研究了胃 癌、食管癌、肝癌、宫颈癌、肺癌、大肠癌、白血病、鼻咽癌、乳腺癌死亡率与人群生存区土壤环境中钼元素的关系。结果表明,胃癌、食管癌、宫劲癌死亡率与钼元素有相关性,等级相关系数分别为-0.4246(P〈0.025),-0.5453(P〈0.0025),-0.3369(P〈0.05)。  相似文献   

6.
张大仁 《环境化学》1996,15(6):536-540
本文对30种单取代苯衍生物的结构和毒性关系进行了研究,由于取代基的多样性和性质的各不相同,用量子化学计算所得电子性质参数,拓扑指数和某些经验参数作描述参数,均不能得到好的与毒性的相关性,为此,引入了与取代基相关的取代基活性基团表面积,再加上反映分子总体性质和形状分子表面积及三阶形状指数,所得回归方程较好反映了结构和毒性关系,这也说明了对于单取代苯衍生物,取代基在致毒作用中可能起重要作用。  相似文献   

7.
采用氟、磷、钾化肥三因素通用旋转组合设计,通过计算机模拟寻优,建立了湘南砂岩红壤玉米-大豆立体栽培模式中玉米施肥量-产量、玉米施肥量-利润数学模型;优选出玉米产量和利润最高的各10套施肥方案;计算出玉米最高产量的施肥量为:尿素750kg/hm2,过磷酸钙1125kg/hm2,氯化钾332kg/hm2,N∶P2O5∶K2O=1∶0.39∶0.58;计算出玉米最佳经济效益施肥量为:尿素712.8kg/hm2,过磷酸钙1125kg/hm2,氯化钾285.2kg/hm2,N∶P2O5∶K2O=1∶0.41∶0.52.玉米与大豆的产量间以及两者的利润间均呈极显著正相关.  相似文献   

8.
一株能分解纤维素的高温耐碱放线菌   总被引:22,自引:0,他引:22  
对一株分离于堆肥的分解纤维素的放线菌的形态学和生理生化特征进行了研究.结果表明:基丝由分枝发达的不断裂的菌丝组成,气丝发达;孢子单个长在气丝上,孢子表面光滑,细胞壁含meso-DAP;该菌能分解纤维素,液化明胶、水解酪素和淀粉,在35-60℃生长,pH范围为6.0—12.0.按《伯杰氏系统细菌学鉴定手册》进行了鉴定,初步将此菌归为高温单孢菌属(Thermomonospora sp.)的一个新种.研究了产羧甲基纤维素酶(CMCase)和滤纸酶(FPA)的条件.CMCase最适产酶时间为5d,FPA为8d,最适产酶温度为50℃,产酶最适起始pH为9.5—10.5.最适氮源为黄豆粉,最佳碳源为棉花纤维.图6表2参10  相似文献   

9.
张治宏  薛峰 《环境化学》2012,31(5):677-681
采用水溶液合成法制备了具有Keggin型结构的十一镍锆钼杂多酸盐Na6[Ni(Mo11ZrO39)].20H2O(NiZrMo),并对其进行表征及分析.元素分析表明,镍锆钼之间的物质的量之比满足1∶1∶11的关系;热重/差热分析说明合成的杂多酸盐具有比较好的热稳定性并带有20个结晶水;红外光谱、X射线衍射及紫外光谱表征充分表明合成的杂多酸盐其阴离子仍保持Keggin型结构;扫描电镜分析表明,具有比较好的大分子化合物的基本特征和比较规则的晶体结构.以NiZrMo杂多酸盐为催化剂降解酸性绿B(AGB)染料废水,降解率最高可达95.72%.  相似文献   

10.
本文提出用平头粉末发射光谱法测定水系沉积物和煤飞灰中的Cu、Pb、Ni、Be、Mn、Fe、Co、Ba八个元素,选择SiO_2∶Li_2CO_3=1∶1为缓冲剂,试样与缓冲剂的混合比例是1∶1,1%甲基纤维素水溶液平头电极粉末装样,交流电弧激发。本法消耗样品少,具有快速、简便、准确、干扰少等优点。  相似文献   

11.
The Ankang black shales in P. R. of China provides an important example of natural geological materials containing toxic elements. This paper presents the results of environmental geochemical research on black shales, soils, waters and edible plants in the Ankang area, Shaanxi Province, P. R. of China. The study area lies in the northern margin of the Yangtze Platform; there are black shales which contains black shale, carbonaceous rocks and coal in the Cambrian Donghe Formation throughout the area. Mean trace element concentrations of the coal were high. Soils derived from these rocks tend to reflect their extreme geochemical composition. Chemical analysis of common plant species in the Ankang area showed a heterogeneous distribution of Se, Mo, and V within a single and among plant species. Selenium was more concentrated in radish than in legumes, and in potato more than in green vegetable. High V concentrations were found in two kinds of Chinese tea. Legume had more Mo in the seed than potato, although Mo concentrations in radish vary. Higher concentrations of Se and Mo are present in the leaf of radish.  相似文献   

12.
硼配施多种微量元素对桉树生长的效应   总被引:2,自引:0,他引:2  
针对广东省雷州半岛桉树人工林出现缺素生理病的现象,进行了桉树施硼及配施其它微量元素的田间试验,旨为桉树人工林持续发展提供依据。试验结果表明:(1)单施硼对刚果12号桉W5(Eucalyptus ABL12W5)和尾叶桉U6(Eucalyptus urophyllas U6)均有明显效果,但前者施硼的效果好于后者;(2)硼与铜、锌、铁、锰、钼等配施效果明显好于单施硼,但桉树不同树种对微量元素营养有一定的选择性;硼与铜、锌、铁、锰等配施可使刚果12W5大幅增产,而硼与钼配施对尾叶桉U6生长效应显著;(3)缺硼是诱发雷州半岛桉树缺素生理病的重要原因,施用硼可有效消除雷州半岛桉树垂稍病。  相似文献   

13.
Heavy metal contamination of soils is widespread and induces a long-term risk to ecosystem health. This research focuses on the heavy metal contamination, transfer values and risk assessment in the Ko?ani Field plant system (Republic of Macedonia). To identify the heavy metal concentrations in Ko?ani crops (rice and maize), the geochemical analysis was performed by inductive coupled plasma mass spectrometer and thereupon the transfer factor (TF) and estimated daily intake amount values were calculated. The highest As, Cd, Mo, Pb and Zn values were determined in the rice samples grown in the paddy fields near the Zletovska River. The highest Pb and Mo concentrations measured in the maize samples were from the maize fields near the Zletovska River and Ciflik city. High TF values for Mo, Zn, Cd and Cu revealed a strong accumulation of Mo, Zn and Cd by rice and Mo and Zn by maize crops. The results of the estimated daily intake showed that the regular consumption of rice and maize crops containing the highest Cd, Mo, Pb and Zn concentrations could pose a serious threat to human health, because the daily intake of Cd, Mo, Pb and Zn for crops grown in the fields around the Zletovska River exceeded the recommended provisional tolerable daily intake values. Taking into account the results, the area around Zletovska River is considered as the most anthropogenically impacted part of Ko?ani Field.  相似文献   

14.
磷钼杂多化合物脱除H2S回收硫磺反应机理研究   总被引:1,自引:0,他引:1  
王睿 《环境化学》2001,20(1):76-80
综合运用离子选择电极分析、微分量热分析与能谱分析等手段对磷钼杂多酸钠盐与硫化氢的反应机理进行了研究。发现:1)磷钼酸钠体系在脱硫过程中具有稳定的化学性能,硫产物中基本不含Mo,V的物相;2)脱硫过程中,复配体系磷钼酸钠与偏钒酸钠独立作用,两者之间不存在协同效应;3)磷钼酸钠吸收H2S过程的化学反应式为:H2S Na3PMo( Ⅵ)12O40→S↓+Na3H2PMo(Ⅵ)10Mo(Ⅴ)2O40。即在磷钼酸钠分子中有2个Mo(Ⅵ)被还原成Mo(Ⅴ),因此,相同摩尔浓度下,磷钼酸钠的饱和硫容量是螯合铁的两倍。  相似文献   

15.
In this study, we prepared a new adsorbent and evaluated its ability to adsorb Mo(VI). Gibbsite was granulated with colloidal alumina or colloidal silica. The amount of Mo(VI) adsorbed onto granular gibbsite with a binder, effect of contact time and pH on the adsorption of Mo(VI), and column experiments were investigated. The amount of Mo(VI) adsorbed was greater in the order of ST12 (colloidal silica, 12%)?相似文献   

16.
玉米自交系吸收利用磷素的差异及其相关性   总被引:11,自引:0,他引:11  
大田选取11份玉米自交系,在两个供磷水平下研究了玉米自交系籽粒产量基因型差异及吸收效率、利用效率与磷效率的相关关系。试验结果表明:在磷胁迫的条件下,不同玉米自交系不仅产量存在较大的差异,而且对磷的响应度也不相同,产量最高的基因型中宗2号为最低的忻9005的5.15倍,将这些品种在二磷水平下以产量进行磷效率双向划分可以分为4种类型:双高效型(太411、KH12、58、中宗2号);高磷高效型(187);低磷高效型(冀257);双低效型(478、冀35、XL12、忻9005、H21),成熟期吸收、利用效率与磷效率的关系表明,在同一供磷条件下,11份自交系吸收、利用效率均有显著的差异,在两个供磷水平下,吸收效率与磷效率存在显著的正相关关系,而利用效率仅在高磷条件下与磷效率存在正相关性,表明在低磷水平下,成熟期磷效率主要由吸收效率决定,在高磷水平下,磷效率是吸收效率和利用效率共同作用的结果。图2表1参7。  相似文献   

17.
取广东省几个花生主产区土壤作盆栽试验,探讨硼、钼施用对花生朋、钼的吸收、运转和积累分配的影响。结果表明,花生施用B、Mo后,各生育期和各部作的B、Mo含量和吸收量均极显著地增加:B、Mo配合施用抑制植株对B的吸收而促进其对Mo的吸收;在高P下配合施用B、Mo对植株B、Mo吸收均有一定的促进作用:植林吸收B、Mo后.B主要向叶转移.Mo主要积累花籽粒中。  相似文献   

18.
In their natural environment, plants are often attacked simultaneously by many insect species. The specificity of induced plant responses that is reported after single herbivore attacks may be compromised under double herbivory and this may influence later arriving herbivores. The present study focuses on the dynamics of induced plant responses induced by single and double herbivory, and their effects on successive herbivores. Morphological (leaf length, area and trichome density) and chemical changes (leaf alkenyl and indole glucosinolates) in Brassica juncea were evaluated 4, 10, 14 and 20 days after damage by the specialist Plutella xylostella alone, or together with the generalist Spodoptera litura. To assess the biological effect of the plant’s responses, the preference and performance of both herbivores on previously induced plants were measured. We found that alkenyl glucosinolates were induced 20 days after damage by P. xylostella alone, whereas their levels were elevated as early as 4 days after double herbivory. Trichome density was increased in both treatments, but was higher after double herbivory. Interestingly, there was an overall decrease in indole glucosinolates and an increase in leaf size due to damage by P. xylostella, which was not observed during double damage. S. litura preferred and performed better on undamaged plants, whereas P. xylostella preferred damaged plants and performed better on plants damaged 14 and 10 days after single and double herbivory, respectively. Our results suggest that temporal studies involving single versus multiple attacker situations are necessary to comprehend the role of induced plant responses in plant–herbivore interactions.  相似文献   

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