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不同改底剂与改性麦饭石协同作用下对苦草生长的影响研究
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作者 栾知明 盛又聪 +2 位作者 李世汨 徐扬帆 陈文峰 《环境科学与技术》 CAS CSCD 北大核心 2024年第8期26-34,共9页
该文从调节富营养化水体底质环境和沉水植物生态恢复的角度出发,系统研究并探索针对城市浅水湖泊沉水植物恢复的高效复合底泥改良剂。实验选取水环境治理常用的4种改底剂:氧化钙、过氧化钙、硝酸钙、过硫酸氢钾,联合镁元素负载改性麦饭... 该文从调节富营养化水体底质环境和沉水植物生态恢复的角度出发,系统研究并探索针对城市浅水湖泊沉水植物恢复的高效复合底泥改良剂。实验选取水环境治理常用的4种改底剂:氧化钙、过氧化钙、硝酸钙、过硫酸氢钾,联合镁元素负载改性麦饭石对污染底泥进行复合改良处理,同时结合沉水植物苦草种植生长效果综合评价不同改底剂与镁改性麦饭石组合对于苦草的生长效果的影响。结果表明,在与镁改性麦饭石复合处理过程中,氧化钙对于上覆水体中总磷及底泥氨氮的固定作用最好,但处理后水体环境对于苦草的生长具有一定抑制效果;硝酸钙处理后的水体富营养化风险较高,处理后苦草生长效果较差;过氧化钙和过硫酸氢钾进行底泥复合改良后植物生长状态较好,其中过氧化钙实验组沉水植物净重增长倍数最大,同时过氧化钙对于将富营养状态下的显著影响环境因子(底泥中氨氮、总磷、总有机碳)含量控制在适宜沉水植物苦草生长的范围内的效果优于过硫酸氢钾。过氧化钙+镁改性麦饭石复合改良底泥的措施较其他改底剂组合更适合水环境治理过程中沉水植物生态修复的底泥改良。 展开更多
关键词 苦草 改底 性麦饭石 原位修复 湖泊
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污水厂氧化沟表曝改底曝运行效果对比与分析
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作者 徐晶晶 谷二伟 黄金龙 《环境科技》 2024年第5期46-49,56,共5页
漯河市松江工业集聚区污水处理厂于2013年建成,处理能力为3×10^(4) m^(3)/d,生化工艺采用水解酸化池+改良型氧化沟,氧化沟原采用倒伞型表曝机进行曝气,2022年实施提标改造工程时将表曝机改为可提升式底部曝气系统。通过分析污水厂... 漯河市松江工业集聚区污水处理厂于2013年建成,处理能力为3×10^(4) m^(3)/d,生化工艺采用水解酸化池+改良型氧化沟,氧化沟原采用倒伞型表曝机进行曝气,2022年实施提标改造工程时将表曝机改为可提升式底部曝气系统。通过分析污水厂运行情况,发现工艺改造后在保证出水达标的基础上,底部曝气系统充氧效率高,受季节影响小,碳源投加量减少,耗电量减少且维修方便。提标改造为污水厂的长期稳定运行提供了有力的保障。 展开更多
关键词 氧化沟 表曝改底 降低能耗 稳定达标
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基于菌藻协同原理的充气刮泥改底肥水技术
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作者 陈畅 杨冬莉 +2 位作者 卢生华 高雅英 刘晓莉 《南方农业》 2023年第21期7-11,共5页
养殖池塘淤泥过厚危害养殖生产,而生物改底和化学改底都只是作用于池水和淤泥表面,没有深入到淤泥内部,难以“刮骨疗毒”。为解决现有改底措施面临的难题,重庆市水产技术推广总站联合重庆鑫乡科技有限公司,试制出移动充气刮泥链,研发出... 养殖池塘淤泥过厚危害养殖生产,而生物改底和化学改底都只是作用于池水和淤泥表面,没有深入到淤泥内部,难以“刮骨疗毒”。为解决现有改底措施面临的难题,重庆市水产技术推广总站联合重庆鑫乡科技有限公司,试制出移动充气刮泥链,研发出基于菌藻协同原理的充气刮泥改底肥水技术。该充气刮泥技术能够形成池塘内部生态循环系统,减少养殖生产有毒有害物质,改善水生动植物生长环境,减少养殖成本,增加经济效益,为养殖池塘淤泥原位治理提供了新的思路和技术措施。 展开更多
关键词 池塘淤泥 菌藻协同 充气刮泥 改底 重庆
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砖混改底框中墙体的托换设计与施工
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作者 曲楠 《中国新技术新产品》 2019年第6期108-109,共2页
随着城市化进程的加快,建筑物的结构设计越来越复杂。传统砖混结构建筑物的后期改造工作涉及的影响因素较多。为了有效地保证建筑物的整体结构安全性和使用寿命,设计改造和施工方案时要以原本工程为依托。将砖混结构建筑改造为底层大空... 随着城市化进程的加快,建筑物的结构设计越来越复杂。传统砖混结构建筑物的后期改造工作涉及的影响因素较多。为了有效地保证建筑物的整体结构安全性和使用寿命,设计改造和施工方案时要以原本工程为依托。将砖混结构建筑改造为底层大空间的底框结构建筑时,需要对托换梁和基础进行充分加固。该文针对这一改造方式涉及的墙体托换设计与施工方案展开分析和研究,对于改造过程中的注意事项进行了明确和阐述。希望为后续的相关研究和工程施工方案提供参考依据。 展开更多
关键词 砖混改底 墙体施工 托换梁 托换设计
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砖混改底框中墙体的托换设计与施工 被引量:1
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作者 王艳武 张志勇 《工程建设与设计》 2018年第19期218-220,共3页
介绍了砖混结构改为底层大空间底框结构的适用条件和设计原则,以实际工程为依托,对托换梁及基础的加固设计方法进行了分析讨论,并对其中需注意的事项进行了详细的阐述,顺利完成了双梁托换工程。
关键词 砖混改底 托换梁 钢筋混凝土
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浮船式改底机对池塘养殖环境的影响研究
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作者 凌空 牛江波 +2 位作者 李骏程 苏艳秋 罗国强 《水产养殖》 CAS 2016年第4期6-11,共6页
为探索改底机在养殖过程中对养殖环境的影响。通过一个月的连续跟踪,定时监测试验塘与对照塘中无机氮、无机磷、藻类生物量及初级生产力来评估其对养殖环境的影响。结果表明,改底机能够使试验塘底泥氨氮含量下降27.5%,水体氨氮浓度下降2... 为探索改底机在养殖过程中对养殖环境的影响。通过一个月的连续跟踪,定时监测试验塘与对照塘中无机氮、无机磷、藻类生物量及初级生产力来评估其对养殖环境的影响。结果表明,改底机能够使试验塘底泥氨氮含量下降27.5%,水体氨氮浓度下降28.6%,亚硝酸盐浓度下降45%,同时使水体无机磷浓度增加57.4%,藻类生物量增加50%。综合分析认为,改底机不仅能够降低池塘氨氮、亚硝酸盐,还能促进底泥释放氮、磷等营养物质,达到增加池塘藻类生物量与提高池塘初级生产力的目的。 展开更多
关键词 改底 水质 藻类生物量 初级生产力
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臭氧底改康对养殖水环境的修复改良作用研究
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作者 罗毅志 周冬仁 +1 位作者 叶雪平 施伟达 《现代农业科技》 2015年第6期266-267,共2页
研究臭氧底改康对养殖水环境的修复改良作用,结果表明:浙江省淡水水产研究所鱼药厂生产的臭氧底改康可有效降低养殖池水体氨氮含量,实验室条件下降解率可达12.0%,外塘试验条件下试验组较对照组氨氮含量降低20%;臭氧底改康在实验室条件... 研究臭氧底改康对养殖水环境的修复改良作用,结果表明:浙江省淡水水产研究所鱼药厂生产的臭氧底改康可有效降低养殖池水体氨氮含量,实验室条件下降解率可达12.0%,外塘试验条件下试验组较对照组氨氮含量降低20%;臭氧底改康在实验室条件下对亚硝酸盐的降解率可达26.52%,外塘试验条件下试验组较对照组亚硝酸盐含量降低23.53%。 展开更多
关键词 臭氧 养殖水环境 修复 氨氮 亚硝酸盐
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氧化底改联合有益活菌对池塘底泥总氮及总磷的降解 被引量:5
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作者 黎建斌 杨皓予 +4 位作者 李大列 陈福艳 杨琼 杨学明 农林生 《河北渔业》 2019年第4期35-36,62,共3页
在罗非鱼养殖中后期,研究了过硫酸氢钾复合盐类底改+有益活菌(光合细菌、芽孢杆菌和乳酸菌)对池塘底泥总氮及总磷的降解。结果表明,对照组养殖池底泥中总氮、总磷含量显著高于试验组(P<0.05),对照组底泥的总氮、总磷含量沉积浓度随... 在罗非鱼养殖中后期,研究了过硫酸氢钾复合盐类底改+有益活菌(光合细菌、芽孢杆菌和乳酸菌)对池塘底泥总氮及总磷的降解。结果表明,对照组养殖池底泥中总氮、总磷含量显著高于试验组(P<0.05),对照组底泥的总氮、总磷含量沉积浓度随着饲养周期的延长而不断增加,但使用复合过硫酸氢钾颗粒解毒底安+有益活菌进行综合调控后减缓了它们增加的幅度,使更多的营养物质释放到水体中,供给浮游植物利用和提高同化作用。从改良的效果来比对和分析,以复合过硫酸氢钾颗粒解毒底安+乳酸菌的协同作用对氮磷的改良效果更显著,总氮和总磷比试验前平均消减了30.75%和15.69%,可在水产养殖中全面推广应用。 展开更多
关键词 +有益活菌 池塘 降解
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Ecological risk assessment of heavy metals in sediments of Xiawan Port based on modified potential ecological risk index 被引量:40
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作者 祝慧娜 袁兴中 +7 位作者 曾光明 蒋敏 梁婕 张长 尹娟 黄华军 刘智峰 江洪炜 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第6期1470-1477,共8页
Modified potential ecological risk index (MRI) was proposed based on the potential ecological risk index (RI) and risk assessment code (RAC) by modifying an index. The modified index was relevant to the chemical... Modified potential ecological risk index (MRI) was proposed based on the potential ecological risk index (RI) and risk assessment code (RAC) by modifying an index. The modified index was relevant to the chemical speciation of heavy metals. Xiawan Port, a typical region contaminated by industrial production, was selected as a case study area. The total concentrations and chemical speciation of heavy metals in sediments of Xiawan Port were analyzed. The experimental data indicate that Xiawan Port is seriously polluted by heavy metals, especially by Cd. The risks of heavy metals are evaluated by RI, RAC and MRI, respectively. The resluts of MRI show that the risks of heavy metals are in the decreasing order of Cd〉Pb〉Cu〉Zn. Comparison of results by different methods reveals that MRI integrates the characters of RI and RAC. MRI is recognized to be useful for risk managemnt of heavy metals in sediments. 展开更多
关键词 heavy metals chemical speciation modified potential ecological risk index SEDIMENTS Xiawan Port
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Recycling of Spent Mushroom Substrate (SMS) in Avocado Orchards
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作者 Ofer Danai Hadar Cohen +2 位作者 Nirit Ezov Noam Yehieli Dan Levanon 《Journal of Agricultural Science and Technology(B)》 2012年第11期1165-1170,共6页
Spent mushroom substrates (SMS) are usually treated as wastes. One of the main beneficial uses of SMS is as soil amendment, after further composting, for horticulture. Avocado orchards in Northern Israel, are grown ... Spent mushroom substrates (SMS) are usually treated as wastes. One of the main beneficial uses of SMS is as soil amendment, after further composting, for horticulture. Avocado orchards in Northern Israel, are grown mainly on heavy clay soils, suffering from poor drainage and limited aeration. This situation can cause yield decrease and lead to tree's degeneration. In the present study, two soil cover (mulch) treatments were compared, in an avocado orchard, as means to solve this problem: SMS and cattle manure compost (CMC). The yields of two avocado varieties were higher on SMS than CMC mulch. Thick growth of avocado roots was found in and under both mulch types. Soil's electrical conductivity (EC) values were high under both mulch types, although they later decreased, due to annual rainfall. There are treatments (leaching etc.) that can be used, for minimizing the increase of soil's salinity after SMS application. Enhancement of avocado root growth into and under the mulch can lead to improvement of avocado trees growth, especially on heavy un-drained soils. Therefore, SMS recycling is advantageous for both avocado and mushroom growers. The commercial utilization of SMS in avocado orchards should be done carefully, with monitoring its impact on soil's EC (salinity) and taking the needed measures to avoid unnecessary damages. 展开更多
关键词 SMS CMC AVOCADO heavy clay soils.
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Performance Improvement of Combined Cycle Power Plant Based on the Optimization of the Bottom Cycle and Heat Recuperation 被引量:3
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作者 Wenguo XIANG Yingying CHEN 《Journal of Thermal Science》 SCIE EI CAS CSCD 2007年第1期84-89,共6页
Many F class gas turbine combined cycle (GTCC) power plants are built in China at present because of less emission and high efficiency. It is of great interest to investigate the efficiency improvement of GTCC plant... Many F class gas turbine combined cycle (GTCC) power plants are built in China at present because of less emission and high efficiency. It is of great interest to investigate the efficiency improvement of GTCC plant. A combined cycle with three-pressure reheat heat recovery steam generator (HRSG) is selected for study in this paper. In order to maximize the GTCC efficiency, the optimization of the HRSG operating parameters is performed. The operating parameters are determined by means of a thermodynamic analysis, i.e. the minimization of exergy losses. The influence of HRSG inlet gas temperature on the steam bottoming cycle efficiency is discussed. The result shows that increasing the HRSG inlet temperature has less improvement to steam cycle efficiency when it is over 590℃. Partial gas to gas recuperation in the topping cycle is studied. Joining HRSG optimization with the use of gas to gas heat recuperation, the combined plant efficiency can rise up to 59.05% at base load. In addition, the part load performance of the GTCC power plant gets much better. The efficiency is increased by 2.11% at 75% load and by 4.17% at 50% load. 展开更多
关键词 Heat Recovery Steam Generators (HRSG) Thermodynamic optimization Exergy analysis Combined cycle power plant EFFICIENCY Heat rate
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Judicial Amendment and Lack of Thoroughness:Analysis of Provisions on Evidence in the Amendment to the Criminal Procedure Law
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作者 张建伟 《Social Sciences in China》 2012年第4期149-156,共8页
China's Amendment to the Criminal Procedure Law of 2012 revises the provisions on rules of evidence. There are a number of positive changes compared to the original text, but some shortcomings still exist. For instan... China's Amendment to the Criminal Procedure Law of 2012 revises the provisions on rules of evidence. There are a number of positive changes compared to the original text, but some shortcomings still exist. For instance, although the legislation recognizes the right against compulsory self-incrimination, it does not acknowledge the right to silence and retains the obligation of the accused to confess; the amended provisions are more tolerant of the use of illegal tactics like "threats," "enticement" and "deceit" to obtain confessions; the legislative approach does not resolutely deter unlawful search and seizure in the collection of evidence; and although there are provisions for protection of persona/safety, financial compensation and judicial sanctions to ensure that witnesses appear before court to testify, there are no provisions on the most important rule in the evidence system, the hearsay rule. 展开更多
关键词 criminal procedure judicial amendment rules of evidence lack of thoroughness
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