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991.
湿式除尘脱硫装置的循环喷淋洗涤液PH值的控制 总被引:1,自引:0,他引:1
孙申 《城市环境与城市生态》2000,13(1):55-57
介绍湿工脱硫使用的几种硫剂的净化原理及脱硫剂制备和吸收液的PH值控制值,采用NaOH-Ca(OH)2作为脱硫吸收液在研制高效导旋除尘脱硫净化的实际运行情况,对湿式脱硫吸收液PH值控制具有借鉴作用。 相似文献
992.
苯并(a)芘对大弹涂鱼(Boleophthalmus pectinirostris)卵巢还原型谷胱甘肽含量的影响 总被引:1,自引:1,他引:0
分析了大弹涂鱼肌肉、鳃、肝脏、内脏 (不含肝脏 )以及卵巢等的GSH含量 ;并以GSH含量最高的卵巢为研究对象 ,在实验条件下 ,经 0 (CK) ,0 .0 5 ,0 .2和 0 .5mg/L等不同浓度的BaP暴露 7d ,分析其卵巢GSH含量变化的时间 -效应和剂量 -效应特征 ,结果显示 :0 .5mg/L浓度组的大弹涂鱼卵巢GSH含量迅速升高 ,暴露 12h即显著高于CK(P≤ 0 .0 5 ) ,但随暴露时间的延长 ,其GSH含量显著降低 ,7d的样品显著低于CK(P≤ 0 .0 5 ) ;在暴露 3d ,GSH水平与BaP浓度的剂量 -效应关系表现为正相关 ,而在 7d ,则呈负相关 ,这可能表明大弹涂鱼卵巢对BaP暴露由适应性反应到产生毒性效应的过程 .以上研究结果表明 ,卵巢GSH可对BaP暴露作出快速灵敏的反应 ,GSH水平有可能作为具氧化 -还原循环活性的污染物暴露的一种敏感的生物标记 .图 2表 2参 9 相似文献
993.
用氯化铈 (CeCl3 )沉淀的电镜细胞化学方法 ,对常温下及 2℃低温处理后的冬小麦 (TriticumaestiviumL .)幼苗质膜Ca2 ATPase活性进行定位 .结果显示 :(1)常温下生长的冬小麦幼苗 ,质膜上有部分Ca2 ATPase活性反应 .(2 )冬小麦幼苗经 2℃低温处理 1h ,质膜上Ca2 ATPase活性增加 .处理 3h ,活性进一步加强 .2℃下处理 12h ,有强的酶活性反应 .处理 2 4h后 ,活性反应达到最强 .2℃处理 3d ,Ca2 ATPase活性有所下降 ,但仍高于CK .细胞结构完整 .据结果推测 ,质膜Ca2 ATPase活性受细胞内Ca2 浓度反馈调节 .图 1参 10 相似文献
994.
针对S.xinjiangensis分类地位的争议,从新疆再次分离获得34株快生大豆根瘤菌,在16SrDNAPCR-RFLP分析和SDS全细胞蛋白电泳分群的基础上,进行了16SrDNA全序列相似性和DNA同源性分析.所测4个菌株和S.fredii模式菌株USDA205的16SrDNA全序列有很高的相似性.而DNA同源性分析说明新分离的菌株代表与原定的S.xinjiangensis为一个DNA同源群.其模式菌株CCBAU110与S.fredii的2株参比菌株USDA194、2048之间的DNA同源性分别为31.5%和28.7%.S.fredii的模式菌株USDA205与新分离的菌株代表及原定的S.xinjiangensis的模式菌株和2个参比菌株之间的DNA同源性为20.8%~39%,远低于70%.属于种水平上的差异.按照国际细菌分类委员会以DNA同源性≥70%且△Tm≤5℃作为定种的标准,S.xinjiangensis是Sinorhizobium属中不同于S.fredii的一个独立的种.表3参20 相似文献
995.
大玉竹低聚糖硫酸酯抗HSV-2病毒活性的研究 总被引:8,自引:0,他引:8
从传统中药大玉竹中提取低聚糖Poos,用吡啶-氯磺酸法制备了它的硫酸酯衍生物S-Poos,产物经红外鉴定,证实Poos硫酸酯化后羟基连上硫酸基,硫含量为8.47%,取代度(Ds)为0.6体外实验研究了Poos、S-Poos对非洲绿猴肾细胞(Vero)的细胞毒怀和抗单纯疱疹病毒2型(HSV-2)活性。结果表明,Poos和S-Poos都无细胞毒性。Poos本身无抗病毒活性,对HSV-2引起的细胞病变和 相似文献
996.
G. S. Kalacheva E. S. Zadereev V. G. Gubanov I. V. Gribovskaya 《Russian Journal of Ecology》2000,31(2):113-117
The chemical composition of water conditioned by colonies ofMoina macrocopa and involved in the regulation of their life cycle was analyzed in comparison with water samples from natural water bodies.
Dechlorinated tap water was used as the control medium. The results showed that metabolism of crustaceans leads to an increase
in the concentrations of phosphorus and nitrogen in all forms, the appearance of protein and carbohydrate fractions, and changes
in the composition of lipid fractions in the water conditioned by their colonies. The contents of all organic components are
very low, which makes their identification difficult. Concentrations of substances identified in the conditioned water do
not exceed those occurring in nature. 相似文献
997.
Gradients of genetic distances (GGDs) between 26 adjacent cenopopulations of Scotch pine (Pinus sylvestris L.) along the transects through the distinct landscape-ecotopic isolation borders were analyzed graphically. The results
made it possible to reveal and quantitatively estimate gradients and borders of gene-pool structural patterns in populations
of this species in the central part of Northern Eurasia. In lowland areas, the most distinct borders were found between pine
populations growing on dry lands and bogs (Pineta sphagnosa) in the forest zone of the Transural region, as well as between the Arakaragaiskii and Amankaragaiskii island pine forests
in the steppe zone (Northern Turgai). In highland areas (the Urals and the Carpathians), the greatest GGDs were observed between
low-mountain (about 600 m above sea level) and middle-mountain (850–900 m) populations. Analysis of GGDs is a promising gene-geographic
method for determining population borders and studying the chorogenetic structure of species. 相似文献
998.
Based on the data of 30 Chinese provinces for the period from 2004 to 2015, this paper expounds the carbon emissions effect of two-way foreign direct investment (FDI) from the perspective of scale effect and factor market distortions. This study uses Kaya identity to decompose carbon emission and construct simultaneous equations model to empirically examine the factor market distortion and the carbon emission scale effect of two-way FDI. The results show that the inward foreign direct investment (IFDI) increase regional carbon emission through scale effect and also exacerbates factor market distortion in China, whereas the outward FDI trends reduce carbon emission and reduces factor market distortions in China. The study also shows that human capital, research and development (R&D), trade openness, and capital accumulation are important determinants of two-way FDI. Therefore, the study proposes that IFDI policies should focus on acquiring green technologies. In addition, the domestic enterprises should be encouraged to participate in global business. 相似文献
999.
This paper examines recent advertisements used by the World Wildlife Fund (WWF) to raise awareness about the predicament of endangered, vulnerable, and threatened species. By engaging in a critical discourse analysis of a selection of advertisements, this study demonstrates how the WWF uses intertextuality as a discourse strategy to articulate its message and objectives. In this paper, I argue that by engaging in the juxtaposition of various paratexts (“layers of meaning”), the WWF produces a narrative which reveals an anthropocentric lens through which we view the world. The advertisements are found to resort to paratexts of anthropomorphism with the intent of extending the bounds of personhood to non-human animal species. In closing, I maintain that intertextuality is employed not only to question the dominant human-centric paradigm, but serve the heuristic function of encouraging a more empathetic identification with the animals in question and the creation of a more holistic worldview. 相似文献
1000.
Lea Nicita Giovanni Signorello Maria De Salvo 《Journal of Environmental Planning and Management》2016,59(7):1225-1237
This paper applies the Kuhn–Tucker model to estimate recreation demand of parks in Sicily. We estimate a fixed coefficient specification and a random coefficient specification to take into account heterogeneity across visitors. Estimates suggest a diversity of preferences across the population and that parks with higher level of quality attributes are more likely to be visited. We also simulate two sets of hypothetical policy scenarios to evaluate and compare the recreational value of each park and the welfare impacts of changes in a quality attribute. 相似文献