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941.
添加剂对垃圾焚烧飞灰熔融特性的影响   总被引:4,自引:2,他引:2  
研究制备了1种具有多重作用效果的飞灰熔融复合型添加剂,并选用上海和福州2种典型飞灰,利用荧光光谱仪和电感耦合等离子体质谱仪等仪器,分析了添加剂对飞灰熔融过程中的挥发率,流动温度,重金属固定率以及熔融渣的重金属浸出特性的影响.结果表明,添加10%添加剂可以将飞灰的流动温度降低150℃左右,挥发率降低10%~20%,重金属Cu和Pb的固定率提高了10%~20%,对重金属Zn的固定率可提高近40%;同时,采用我国毒性浸出方法和美国EPA的TCLP方法,分析测试熔融渣中重金属浸出量,结果证实几种重金属的浸出浓度均低于相应的标准限值.  相似文献   
942.
Lignite fly ash (LFA), being alkaline and endowed with excellent pozzolanic properties, a silt loam texture, and plant nutrients, has the potential to improve soil quality and productivity. Long-term field trials with groundnut, maize, and sun hemp were carried out to study the effect of LFA on growth and yield. Before crop I was sown, LFA was applied at various doses with and without press mud (an organic waste from the sugar industry, used as an amendment and source of nutrients). LFA with and without press mud was also applied before crops III and V were cultivated. Chemical fertilizer, along with gypsum, humic acid, and biofertilizer, was applied in all treatments, including the control. With one-time and repeat applications of LFA (with and without press mud), yield increased significantly (7.0–89.0%) in relation to the control crop. The press mud enhanced the yield (3.0–15.0%) with different LFA applications. The highest yield LFA dose was 200 t/ha for one-time and repeat applications, the maximum yield being with crop III (combination treatment). One-time and repeat application of LFA (alone and in combination with press mud) improved soil quality and the nutrient content of the produce. The highest dose of LFA (200 t/ha) with and without press mud showed the best residual effects (eco-friendly increases in the yield of succeeding crops). Some increase in trace- and heavy-metal contents and in the level of γ-emitters in soil and crop produce, but well within permissible limits, was observed. Thus, LFA can be used on a large scale to boost soil fertility and productivity with no adverse effects on the soil or crops, which may solve the problem of bulk disposal of fly ash in an eco-friendly manner.  相似文献   
943.
Abstract: New species conservation strategies, including the EDGE of Existence (EDGE) program, have expanded threatened species assessments by integrating information about species' phylogenetic distinctiveness. Distinctiveness has been measured through simple scores that assign shared credit among species for evolutionary heritage represented by the deeper phylogenetic branches. A species with a high score combined with a high extinction probability receives high priority for conservation efforts. Simple hypothetical scenarios for phylogenetic trees and extinction probabilities demonstrate how such scoring approaches can provide inefficient priorities for conservation. An existing probabilistic framework derived from the phylogenetic diversity measure (PD) properly captures the idea of shared responsibility for the persistence of evolutionary history. It avoids static scores, takes into account the status of close relatives through their extinction probabilities, and allows for the necessary updating of priorities in light of changes in species threat status. A hypothetical phylogenetic tree illustrates how changes in extinction probabilities of one or more species translate into changes in expected PD. The probabilistic PD framework provided a range of strategies that moved beyond expected PD to better consider worst‐case PD losses. In another example, risk aversion gave higher priority to a conservation program that provided a smaller, but less risky, gain in expected PD. The EDGE program could continue to promote a list of top species conservation priorities through application of probabilistic PD and simple estimates of current extinction probability. The list might be a dynamic one, with all the priority scores updated as extinction probabilities change. Results of recent studies suggest that estimation of extinction probabilities derived from the red list criteria linked to changes in species range sizes may provide estimated probabilities for many different species. Probabilistic PD provides a framework for single‐species assessment that is well‐integrated with a broader measurement of impacts on PD owing to climate change and other factors.  相似文献   
944.
Arsenic removal from aqueous solutions by adsorption on red mud   总被引:3,自引:0,他引:3  
Use of red mud, which is a waste product from bauxite processing, has been explored as an alternate adsorbent for arsenic in this study. The tests showed that the alkaline aqueous medium (pH 9.5) favored the removal of As(III), whereas the pH range from 1.1 to 3.2 was effective for As(V) removal. The process of arsenic adsorption follows a first-order rate expression and obeys the Langmuir's model. It was found that the adsorption of As(III) was exothermic, whereas As(V) adsorption was endothermic. It would be advantageous to use this residue as an adsorbent replacing polyvalent metal salts.  相似文献   
945.
研究以苏州沙家浜红色旅游风景区为案例地,以数字田野调查为基础,剖析了红色旅游地资源的网络空间生产中“人—地”关系转变为“人—网—地”关系的过程,探索了红色旅游地资源的网络空间的多维生产模式特征。结论指出:(1)红色旅游资源网络空间打破了传统时空界限,单向的红色价值观传递转变为主客价值共创,体现了红色精神民主化生产过程;(2)红色网络流动性空间需面对红色教育、娱乐和审美等价值的多元性,空间多维主体以“遥在场”的方式产生了新的主客网络地缘争夺,即网络话语权的争夺;(3)传统游客转变为红色资源网络空间的消费者、参与者与生产者,去中心化特征明显,红色网络空间通过超文本表征和非计划互动得以建构,要求红色目的地官方在网络供给侧掌握更高水平的治理能力;(4)红色旅游官方主体尝试使用流行元素融入网络实践,但也展示出泛娱乐化的趋向,需在红色网络空间的多维精神建构中合理整合多元价值,促进集体情感的深度内化。  相似文献   
946.
Fetal nucleated red blood cells (n-rbc) occur in the maternal circulation from 7 weeks of pregnancy. The enrichment of these cells from maternal blood will depend upon their stage of differentiation, which changes during development. We characterised the fetal n-rbc from chorionic villus sample (CVS) washings and used them to model first trimester non-invasive prenatal diagnosis. The ratio of ε- to γ-globin-producing cells declined rapidly from 10 to 13 weeks, as did the ratio of nucleated to non-nucleated rbc. By 13 weeks the great majority of cells containing γ- or ε-globin are anucleate. The fetal n-rbc were highly variable in size and density and sedimented over a wide density range with a high proportion (>80%) at a density overlapping with that of maternal rbc. We have devised an enrichment procedure using Orskoff lysis to differentially lyse the maternal cells followed by density centrifugation and separation using magnetic beads. This simple protocol allowed recovery of 70% (69±22%) of fetal cells when added at approximately 10 fetal cells/ml maternal blood. When 1 fetal cell/ml millilitre maternal blood was added (total volume 10 ml) the recovery was more variable but remained at approximately 70% (72±47%), with at least one fetal cell recovered in all cases. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   
947.
David Sztybel has argued that defenders of the moralsignificance of animals have not made an effective case against theirenemy: anthropocentrism. He maintains that they have refuted only``straw' versions of that view. Sztybel opposes anthropocentrism, butis convinced that it is a much more difficult view to defeat than hasbeen thought. He develops the strongest argument possible for``Obligatory Anthropocentrism' (OA), defending it against manyobjections. He also holds that OA does not have unpalatable implicationsfor the treatment of average, below average, and mentally challengedhumans. While I agree that Sztybel has done an admirable job ofdefending anthropocentrism, indeed a better job than theanthropocentrists themselves, I argue that his case for OA is subtly butfatally flawed. I also argue that OA does not dodge two very seriouscriticisms concerning its implications for the treatment of certainhuman beings: the charge of invidious perfectionism and the argumentfrom marginal cases. I conclude that the strongest version ofanthropocentrism is, in fact, not strong enough.  相似文献   
948.
唐青青  方治国  嵇雯雯  夏会龙 《环境科学》2014,35(11):4212-4217
采用发光二极管(light emitting diode,LED)调制光谱,研究了不同光质(红光、蓝光、白光、红蓝混光8∶1,红蓝混光8∶2,红蓝混光8∶3)对蛋白核小球藻(Chlorella pyrenoidosa)生长特性及生化组成的影响.结果表明,蓝光下蛋白核小球藻生长效果最佳,其接种后培养30 d,光密度为2.4,比生长速率为0.10 d-1,生物量为0.64 g·L-1,而其它光质下光密度、比生长速率和生物量分别在1.0~1.7、0.07~0.10 d-1和0.27~0.38 g·L-1之间,蓝光条件下其光密度、比生长速率和生物量分别约为红光下的2.05倍、1.33倍和2.06倍;红蓝混光有利于蛋白核小球藻叶绿素a和β-胡萝卜素的合成,蓝光可促进叶绿素b的合成,红蓝混光8∶1其叶绿素a和β-胡萝卜素的含量分别为13.5 mg·g-1和5.8 mg·g-1,而蓝光下分别为8.4 mg·g-1和3.6mg·g-1;红蓝混光更有利于蛋白核小球藻单位细胞干重蛋白质和总脂的积累,红蓝8∶3蛋白质含量为489.3 mg·g-1,红蓝8∶1总脂含量为311.2 mg·g-1,而蓝光下蛋白质和总脂含量均较低,分别为400.9 mg·g-1和231.9 mg·g-1.  相似文献   
949.
水泥工业大气污染物排放控制水平确立研究   总被引:3,自引:2,他引:1  
国家修订发布了GB 4915-2013《水泥工业大气污染物排放标准》,新建企业自2014年3月1日起实施,现有企业自2015年7月1日起实施.在修订过程中,如何确定可行的大气污染物排放控制水平,成为标准限值确定的关键.标准编制组系统调查分析了我国水泥工业污染排放现状、污染控制技术应用情况、环境管理需求、国外标准控制水平等,提出了可行的排放控制要求.新标准扩大了标准适用范围,增加了污染物控制项目,提高了颗粒物、NOx等指标的排放控制要求,同时增加了适用于重点地区的大气污染物特别排放限值.新标准的实施将成为水泥工业污染防治、总量减排、调整产业结构、优化布局的重要抓手,新标准将促进水泥工业生产工艺和污染治理技术的进步.  相似文献   
950.
分别以印染废水污泥和生活污水污泥接种微生物燃料电池(MFC-I和MFC-M),以刚果红为模型染料,研究了接种源对MFC同步脱色偶氮染料和产电性能的影响.结果表明,接种源对MFC同步降解刚果红与产电性能影响显著.产电方面,MFC-I的启动电压高于MFC-M,但稳定运行后二者最大输出电压差别不大.稳定运行阶段,MFC-M最大功率密度达到29.09 mW·m-2,比MFC-I高2.11倍;阳极极化阻抗(R ct)为748.9Ω,比MFC-I低38.0%.脱色方面,MFC-I对刚果红的脱色速率比MFC-M高14.4%~20.3%;但脱色产物一样,均为2-氨基—1,4-萘醌、2,2'-二氨基联苯、4,4'-二氨基联苯.经分离、纯化和鉴定,二者阳极均存在优势菌Pseudomonas sp.,但MFC-M阳极还存在优势菌Bacillus sp.,而MFC-I的阳极还存在优势菌Aquamicrobium sp..  相似文献   
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