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结合国内外水体富营养化的研究现状,分析了水生植物的重要生态功能和生态地位,归纳了浅水湖泊水生植物生态修复和水华水体水生植物生态治理相关技术,并展望了今后的治理思路. 相似文献
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用矿化垃圾作为水生植物床的基质代替基质中土壤的作用,分别选择水葫芦和空心莲子草作为水生植物床的植物,制成了人工水生植物床,来尝试处理染料水溶液制成的模拟印染废水,并对比了染料在自然条件下的降解。 相似文献
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用矿化垃圾作为水生植物床的基质代替基质中土壤的作用,分别选择水葫芦和空心莲子草作为水生植物床的植物,制成了人工水生植物床,来尝试处理染料水溶液制成的模拟印染废水,并对比了染料在自然条件下的降解. 相似文献
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用矿化垃圾作为水生植物床的基质代替基质中土壤的作用,分别选择水葫芦和空心莲子草作为水生植物床的植物,制成了人工水生植物床,来尝试处理染料水溶液制成的模拟印染废水,并对比了染料在自然条件下的降解。 相似文献
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严清湖 《金属材料与冶金工程》1980,(3)
含重金属废水的治理,除采用工程、物理、化学等方法外,生物防治已成为一条重要途径。水生植物如灯心草、芦苇、藻类等对有严重污染危害的废水进行天然解毒和净化,已有人作了研究。一般地说,用工程法、物理法、化学法净化废水往往要留下含水量很高的污泥,不利于实用;而水生植物通过附着在它们身上的 相似文献
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[目的]探讨入侵植物凤眼莲生长对滇池水生植物的影响.[方法]通过测定不同月份滇池浮游植物、沉水植物(篦齿眼子菜)的叶绿素含量,结合凤眼莲根培养液对铜绿微囊藻的化感作用,探讨凤眼莲生长对滇池水生植物的影响.[结果]滇池凤眼莲生长降低了浮游植物及沉水植物(篦齿眼子菜)的叶绿素含量,对二者的生长有一定的抑制作用;凤眼莲根培养液明显抑制了铜绿微囊藻的生长.[结论]该研究为滇池凤眼莲生态安全防控提供了科学依据. 相似文献
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笔者于2007~2009年在慈溪市龚家甲江开展了水生维管柬植物在生态景观方面的应用研究,结果显示:在该河道上组成了较为完整的水生维管束植物群落,并体现了种类的多样性、层次的丰富性、明显的季相景观、水生植物形态美与意境美.与试验前相比.该研究河道的污染因子减少,污染程度减轻,水体自净能力增加,水质改善.但各部门的配合、管理、人的保护与参与、污染负荷的控制会直接影响到水生维管束植物在河道生态景观方面的应用效果. 相似文献
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青海湖是我国最大的内陆咸水湖泊,对这种湖泊沉积物中正构烷烃及其氢同位素进行了分析,研究了沉积物中正构烷烃及其同位素组成,并且与青海湖水生植物及其周围陆生植物的研究结果进行了对比,研究了它们的成因.结果显示了青海湖表层和柱状沉积物中正构烷烃分布都是类似的,其特征反映了它们起源于湖泊周围陆生草本植物.青海湖表层沉积物中正构烷烃氢同位素组成特征也与柱状沉积物中的类似,沉积物样品中正构烷烃氧同位素的组成和分布特征反映了它们主要来自陆生草本植物.从而进一步证实了水体中沉积物的正构烷烃氢同位素组成,反映了生物源的氢同位素组成,后者与古气候相关,因此沉积物的正构烷烃氢同位素组成可以指示古气候. 相似文献
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为提高人工湿地系统全年对农村散户生活废水的处理效率、运行稳定性及经济价值,对四种基质进行了试验研究,并针对春夏秋和冬季分别构建了四种复合型水生植物人工湿地系统,结果表明:绿沸石和页岩陶粒对NH_3-N、TP分别表现出最好的吸附效果;旱伞草+空心菜/水芹菜复合湿地系统在秋季和冬季分别表现出较高的污染物整体去除率及较好的长期运行稳定性,旱伞草+空心菜对COD、NH_3-N和TP去除率分别为75%~80%、80%以上、59%~63%;旱伞草+水芹菜对COD、NH_3-N和TP去除率分别为68%~72%,74%~77%和53%~57%。复合型人工湿地全年污染物去除效率高,并可提供优质蔬菜、美化农村环境,具有较好的观赏和经济价值及应用前景。 相似文献
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通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。 相似文献
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K Ohta M Nishi M Ueda S Ohyama T Matsubara T Takahashi T Nakajima 《Canadian Metallurgical Quarterly》1998,99(9):589-594
Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients. 相似文献
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Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
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The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies. 相似文献
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鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美". 相似文献
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针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。 相似文献
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The effect of 20 different antibiotics on chemotaxis by human neutrophils was studied. Human leukocytes incubated with chloramphenicol, rifampin, sodium fusidate, and tetracyclines in vitro showed markedly depressed migration. The mechanisms by which these antibiotics affect leukotaxis are discussed. 相似文献