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161.
针对洛阳分公司炼油碱渣处理装置存在的问题,从实验室和生产实践中总结找出一套合理的工艺参数,运行后,操作平稳,解决了炼油碱渣的出路问题。  相似文献   
162.
采用强碱性离子交换纤维对含氰废水中主要离子铜氰络合物、锌氰络合物的吸附性能进行了研究.实验结果表明:含氰废水的pH在8~11范围内,纤维材料对金属氰络合物具有良好的吸附性能;纤维对铜氰络合物、锌氰络合物的吸附速率很快,4 min左右就可达吸附平衡;温度对铜氰络合物、锌氰络合物吸附影响不大,纤维的这些吸附特点对工业应用非常有利.  相似文献   
163.
陕西黄河湿地自然保护区是以保护河流湿地生态系统与珍稀水禽为主的省级自然保护区,渭河入黄流路调整工程位于自然保护区的缓冲区和核心区,工程建设将对该自然保护区的生态系统产生一定的环境影响。在调查该自然保护区生态环境质量现状的基础上,客观分析了渭河入黄流路调整工程建设对该自然保护区保护区结构与功能、区域生态系统完整性和生物多样性等方面产生的环境影响,并提出了相应的环境保护措施。  相似文献   
164.
Time-dependent Zn and Cd accumulation and metallothionein like protein (MTLP) induction in the digestive glands of mussels, Perna virdis, were measured under different exposure conditions. The initial uptake rate at start of chase (ρ0) and mean residence time (τ) were calculated to determine the physiological response of organisms and their potential detoxification mechanisms. It was found that in digestive glands, Zn had obviously higher ρ0 and shorter mean residence time than Cd, indicating that these two metals had different accumulation dynamics even though they were very close in the periodic element table. MTLP levels in digestive glands varied from 0.51 to 1.05 μg/g ww (wet weight). The MTLP level increased continuously when mussels were exposed to low and middle levels of Zn and Cd media, and reached maximal levels at day 4, then decreased when they were exposed to high level Zn and Cd solutions. With regard to the fraction of Zn and Cd accumulated in the digestive glands, the ratios of soluble metal to total metal decreased continuously after exposure in low and middle levels of Zn and Cd media, and decreased continuously in the first 4 days and then to level off when mussels were exposed to media with high concentration of Zn and Cd. Results suggested that both MTLP induction and metal insolubilization were detoxification processes in digestive glands of mussels.  相似文献   
165.
利用1961~2006年陇东黄土高原气象观测站的雷暴资料,运用数理统计、函数分解、图表分析方法,分析了雷暴的时空分布特征.(结果表明:陇东雷暴次数的年际变化总体上呈波动状态,60年代为雷暴多发期,70年代波动明显,大致存在4.5年的振荡周期,80年代为增长期,以5年为周期振荡,90年代开始至今以4年为周期振荡并呈现减少趋势.根据41年NCEP/NCAR再分析格点资料,并考虑下垫面热力作用,用统计分析方法得到判别陇东黄土高原雷暴有无的预报函数,建立了雷暴短期短时预报的判别模型.检验表明:雷暴短期短时预报模型是可行的,2005~2006年试报,雷暴预报出现宰可达61.7%,在同一时效下模型的预报水平要高于预报员的主观预报.  相似文献   
166.
为了研究低剂量的全氟辛烷磺酸(perfluorooctane sulfonate,PFOS)对水生生物的内分泌干扰效应和作用机制,考察了PFOS对斑马鱼(Brachydanio rerio)血浆和组织匀浆中卵黄蛋白原(vitellogenin,VTG)含量的影响。将雄性和雌性斑马鱼分别暴露于0.1、1、10和100μg·L-1的PFOS中进行21d毒性实验,染毒结束后分别检测雄鱼和雌鱼的血浆、头尾组织匀浆液和全鱼匀浆液中的VTG含量。结果显示:(1)PFOS暴露可引起斑马鱼血浆、全鱼和头尾匀浆液中VTG含量的升高,VTG含量的排序为雌鱼(血浆>>全鱼匀浆>头尾匀浆)>>雄鱼(血浆>全鱼匀浆>>头尾匀浆);(2)PFOS暴露所引起的雄鱼血浆和头尾匀浆中VTG含量的升高与剂量呈负相关关系,暴露浓度为0.1μg·L-1时与对照组相比有显著性差异(p<0.05);(3)雌鱼血浆和头尾匀浆中VTG含量的升高与剂量呈倒U型曲线关系,暴露浓度为10μg·L-1时与对照组相比有显著性差异(p<0.05);(4)雄鱼和雌鱼的全鱼匀浆液中的VTG含量与对照组相比均无显著性差异。研究结果表明,PFOS暴露对斑马鱼的内分泌干扰作用明显,其毒性作用机制可能是类雌激素效应,血液和头尾匀浆液中VTG含量能够作为PFOS内分泌干扰效应评价的敏感生物标志物,但响应曲线可能因性别和组织部位的不同有所差异。  相似文献   
167.
Trees in the subalpine environment, a particularly vulnerable area being the first to reflect climate changes, are most likely to show strong effects of climate variability. The aim of this study was to identify growth responses of subalpine fir (Abies fargesii) to climate variability, and investigate range shifts along an altitudinal gradient in the subalpine region of the Qinling Mountains, China. Standard correlation functional analysis showed different growth responses of fir trees to climatic variables between north and south aspects. In the north aspect, radial growth was significantly positively correlated with temperatures in early spring (February–April) and summer (July) of the current year, while radial growth was significantly positively correlated with temperatures in November and December of the previous year and early spring (February–April) of the current year in the south aspect. Analysis of age structure distribution displayed a decrease in number of mature fir trees and an increase in number of saplings along the altitudinal gradient on both aspects. Fir saplings/seedlings only occur in the treeline environment, and this fir population was significantly younger than that at lower elevations. Thus, fir trees show different radial growth patterns in response to climatic variability between north and south aspects, and age-class distributions along the altitudinal gradient imply an upward shift in range in the subalpine region during the past century in the Qinling Mountains of China.  相似文献   
168.
为解决粉煤灰提取有价成分后固体残渣中由于含氟硅酸盐而难以利用的问题,利用氟硅酸盐在微晶玻璃制备中可作成核剂的特性,提出了将两条工艺路线相结合的新方法,即以该类固体残渣为原料制备微晶玻璃,实现此类固体废物的资源化利用。通过等温晶化制度对产品进行晶化处理。研究表明,晶化产物中生成了大量以镁橄榄石为主晶相的微晶体,该方法是可行的。  相似文献   
169.
In this article, we show how a disease could bias stable isotope analyzes of trophic networks and propose a strategy in the choice of tissues to be analyzed. In the past few years, a new pathology (brown muscle disease or BMD) affecting the posterior adductor muscle of Ruditapes philippinarum has emerged in Arcachon Bay. BMD induces a necrosis of muscle tissues which become infused by conchiolin and hence calcified. As muscle of mollusks are often used for trophic food webs studies through stable isotopic analyzes, this work investigated the effect of BMD on carbon and nitrogen isotopic ratios of anterior and posterior adductor muscles of clams collected in February and August 2007. Infected clams displayed a lower condition index and a posterior adductor muscle δ13C enrichment of 1.2‰ in February and 0.7‰ in August. δ15N of posterior muscles was however not affected by the disease. Anterior muscle of diseased clams remained healthy and displayed the same isotopic signature as both posterior and anterior muscular tissues of healthy clam. Acidification significantly depleted δ13C in posterior muscles of infected clams, suggesting calcification, contrary to anterior muscles of infected clam and to both muscles of healthy clams, where no effect was observed. An X-ray diffractometry analysis confirmed the presence of CaCO3 (aragonite). Trophic food web studies relying on stable isotope ratios should utilize only healthy animals or anterior adductor muscles when expertise in mollusk pathology is lacking.  相似文献   
170.
土壤镉、锌污染对蚯蚓纤维素酶活性的影响   总被引:2,自引:0,他引:2  
为了探究土壤镉、锌污染对土壤动物蚯蚓的生理毒害情况,为土壤生态环境质量评价提供数据支持,以赤子爱胜蚓(Eisennia foetida)为研究对象,采用自然土壤法进行急性毒性试验,研究了土壤外源添加镉(Cd)和锌(Zn)单一污染与复合污染对蚯蚓纤维素酶活性的毒性效应.试验结果表明,蚯蚓体内纤维素酶活性在培养过程中呈先增大后减小的变化趋势.单一污染试验,酶活性的最大值出现在第7至第9天,最小值出现在第14天;复合污染试验,同一处理不同培养时间的酶活性最小值也大多出现在第14天.土壤Cd和Zn单一及复合污染都会对蚯蚓体内纤维素酶活性产生抑制作用.单一污染在培养的前5天抑制效果明显,且随着污染物添加剂量的增加抑制效果增强.复合污染,镉和锌在土壤中的联合效应除个别测定结果表现为加和作用或协同作用外,多数处理都表现为拮抗作用,且主要是受体拮抗.相比较而言,镉对蚯蚓体内纤维素酶活性的抑制作用强于锌.  相似文献   
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