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Fuzzy logic for large mining bucket wheel reclaimer motion control—from an engineer's perspective 被引量:4
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作者 LU Tienfu 《智能系统学报》 2011年第1期85-94,共10页
The bucket wheel reclaimer(BWR) is a key piece of equipment which has been widely used for stacking and reclaiming bulk materials(i.e.iron ore and coal) in places such as ports,iron-steel plants,coal storage areas,and... The bucket wheel reclaimer(BWR) is a key piece of equipment which has been widely used for stacking and reclaiming bulk materials(i.e.iron ore and coal) in places such as ports,iron-steel plants,coal storage areas,and power stations from stockpiles.BWRs are very large in size,heavy in weight,expensive in price,and slow in motion.There are many challenges in attempting to automatically control their motion to accurately follow the required trajectories involving uncertain parameters from factors such as friction,turbulent wind,its own dynamics,and encoder limitations.As BWRs are always heavily engaged in production and cannot be spared very long for motion control studies and associated developments,a BWR model and simulation environment closely resembling real life conditions would be beneficial.The following research focused mainly on the implementation of fuzzy logic to a BWR motion control from an engineer's perspective.First,the modeling of a BWR including partially known parameters such as friction force and turbulence to the system was presented.This was then followed by the design of a fuzzy logic-based control built on a model-based control loop.The investigation provides engineers with an example of applying fuzzy logic in a model based approach to properly control the motion of a large BWR following defined trajectories,as well as to show possible ways of further improving the controller performance.The result indicates that fuzzy logic can be applied easily by engineers to overcome most motion control issues involving a large BWR. 展开更多
关键词 bucket wheel reclaimer modeling simulation motion control fuzzy logic
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Developing Communal Recycling Programs to Empower Reclaimers in Developing Cities Such as Tshwane
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作者 Jacques Snyman 《Journal of Civil Engineering and Architecture》 2015年第8期951-960,共10页
Excessive MSW (municipal solid waste) production is a growing management problem for cities in developing countries, such as South Africa. A major problem in the city of Tshwane is that all the MSW generated in the ... Excessive MSW (municipal solid waste) production is a growing management problem for cities in developing countries, such as South Africa. A major problem in the city of Tshwane is that all the MSW generated in the city is currently being landfilled with very little recycling initiatives. Selective waste collection and sorting waste fractions out of the waste stream have become a popular survival strategy for the economically excluded population in Tshwane. Reclaimers (waste pickers) work under severe and chronic occupational health and injury risk on landfill sites. The middlemen who purchase their recovered materials exploit and marginalize them. Environmental and social awareness is however a growing issue in South Africa. The study was conducted with the aim of investigating and proposing community recycling programs and technologies to be sustainably implemented in the city of Tshwane. Successful established community recycling programs in Brazil was investigated to verify its socioeconomic and environmental impacts in a sustainable waste management perspective. Community recycling initiatives have been increasingly used as a strategy to address both the MSW problem and urban poverty in Brazil. The study focused on the city of Tshwane, but it can be argued that the findings can be implemented in any other South African municipality and in other emerging countries in Africa. 展开更多
关键词 RECYCLING MSW community recycling LANDFILLS waste collection reclaimers.
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Multidisciplinary co-design optimization of structural and control parameters for bucket wheel reclaimer 被引量:4
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作者 Yongliang YUAN Liye LV +1 位作者 Shuo WANG Xueguan SONG 《Frontiers of Mechanical Engineering》 SCIE CSCD 2020年第3期406-416,共11页
Bucket wheel reclaimer(BWR)is an extremely complex engineering machine that involves multiple disciplines,such as structure,dynamics,and electromechanics.The conventional design strategy,namely,sequential strategy,is ... Bucket wheel reclaimer(BWR)is an extremely complex engineering machine that involves multiple disciplines,such as structure,dynamics,and electromechanics.The conventional design strategy,namely,sequential strategy,is structural design followed by control optimization.However,the global optimal solution is difficult to achieve because of the discoordination of structural and control parameters.The co-design strategy is explored to address the aforementioned problem by combining the structural and control system design based on simultaneous dynamic optimization approach.The radial basis function model is applied for the planning of the rotation speed considering the relationships of subsystems to minimize the energy consumption per volume.Co-design strategy is implemented to resolve the optimization problem,and numerical results are compared with those of sequential strategy.The dynamic response of the BWR is also analyzed with different optimization strategies to evaluate the advantages of the strategies.Results indicate that co-design strategy not only can reduce the energy consumption of the BWR but also can achieve a smaller vibration amplitude than the sequential strategy. 展开更多
关键词 bucket wheel reclaimer CO-DESIGN energy-minimum optimization sequential strategy
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Selective adsorption of tetracycline by β-CD-immobilized sodium alginate aerogel coupled with ultrafiltration for reclaimed water
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作者 Xi Quan Jun Zhang +2 位作者 Linlin Yin Wei Zuo Yu Tian 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第4期27-34,共8页
In this work,a novel composite material based on β-cyclodextrin-immobilized sodium alginate aerogel(β-CD/NaAlg) was developed utilizing cross-linker of epichlorohydrin and applied as an adsorbent to remove tetracycl... In this work,a novel composite material based on β-cyclodextrin-immobilized sodium alginate aerogel(β-CD/NaAlg) was developed utilizing cross-linker of epichlorohydrin and applied as an adsorbent to remove tetracycline antibiotics from reclaimed wastewater.A series of characterizations were utilized to confirm the successful synthesis of the adsorbent and this β-CD/NaAlg presented a three-dimensional network at the nanoscale or microscale.Under optimal conditions(pH=4,t=8 h,β-CD:NaAlg=9,adsorbent dosage = 1.5 g·L-1),the maximum removal rate of β-CD/NaAlg to tetracycline was 70%.The adsorption behavior of tetracycline on β-CD/NaAlg conformed to the Freundlich isotherm model(R2=0.9977) and the pseudo-second-order kinetic model(R^(2)=0.9993).Moreover,the adsorbent still removed 55.3% of tetracycline after five cycles.Specially,the adsorbent was integrated with ultrafiltration to adsorb tetracycline antibiotics from simulated reclaimed wastewater,and the removal rate of tetracycline reached 78.9% within 2 h.The existence of Cr(Ⅵ) had a negligible impact on tetracycline removal,while the presence of humic acid exhibited a promoting effect.The possible adsorption mechanisms were also elucidated through X-ray photoelectron spectroscopy and density functional theory analysis.In summary,β-CD/NaAlg represents an environmentally friendly,efficient,and sustainable adsorbent for removing tetracycline antibiotics from reclaimed water. 展开更多
关键词 b-CD/NaAlg aerogel Covalent grafting Tetracycline antibiotics ULTRAFILTRATION Selective adsorption Reclaimed water
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Dynamic Analysis and Dimensional Synthesis of Easy-to-Protect Large-Load Robot for Extracting Fermented Grains
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作者 Yubin Zhang Jinzhu Zhang +2 位作者 Congming Li Xiaoyan Xiong Hongjie Du 《Journal of Beijing Institute of Technology》 EI CAS 2023年第4期529-550,共22页
To improve the operation situation of difficulty and low efficiency in the extraction of fermented grains(FG),a high-load and large-workspace reclaiming robot for ceramic cylinder fermentation is designed,and a reclai... To improve the operation situation of difficulty and low efficiency in the extraction of fermented grains(FG),a high-load and large-workspace reclaiming robot for ceramic cylinder fermentation is designed,and a reclaiming effector is designed according to the operating characteristics.Firstly,the kinematics and singularity of the mechanism are analyzed.A multi-domain polar coordinate search method is proposed to obtain the workspace and the volume of the mechanism.Secondly,the dynamic modeling is completed and the example simulation is carried out.Thirdly,the motion-force transmission index of the mechanism is established.And based on the global transmissibility and the good-transmission workspace,the dimensional synthesis of the driving mechanism is completed by using the performance atlas-based method.Finally,aiming at the regular workspace size,stiffness and loading capacity,the Pareto optimal solution set of the executive mechanism dimension is obtained by using the multi-objective particle swarm optimization(MOPSO)algorithm.This paper can provide a theoretical basis for the optimal design and control of FG reclaiming robot. 展开更多
关键词 reclaiming robot configuration design performance index dynamic modeling multi-objective optimization
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Effect of Rural Sewage Irrigation Regime on Water-Nitrogen Utilization and Crop Growth of Paddy Rice in Southern China
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作者 Menghua Xiao Yuanyuan Li Shizong Zheng 《Phyton-International Journal of Experimental Botany》 SCIE 2023年第4期1215-1233,共19页
Reclaimed water irrigation has become an effective mean to alleviate the contradiction between water availability and its consumption worldwide.In this study,three types of irrigation water sources(rural sewage’s pri... Reclaimed water irrigation has become an effective mean to alleviate the contradiction between water availability and its consumption worldwide.In this study,three types of irrigation water sources(rural sewage’s primary treated water R1 and secondary treated water R2,and river water R3)meeting the requirements of water quality for farmland irrigation were selected,and three types of irrigation water levels(low water levelW1 of 0–80 mm,medium water level W2 of 0–100 mm,and high water level W3 of 0–150 mm)were adopted to carry out research on the influence mechanismS of different irrigation water sources and water levels on water and nitrogen use and crop growth in paddy field.The water quantity indicators(irrigation times and irrigation volume),soil ammonium nitrogen(NH4+-N)and nitrate nitrogen(NO3−-N),rice yield indicators(thousand-grain weight,the number of grains per spike,and the number of effective spikes),and quality indicators(the amount of protein,amylose,vitamin C,nitrate and nitrite content)of rice were measured.The results showed that,the average irrigation volume under W3 was 2.4 and 1.9 times of that under W1 and W2,respectively.Compared with R3,the peak consumption of rice was lagged behind under R1 and R2,and the nitrogen form in 0–40 cm soil layers under rural sewage irrigation was mainly NH4+-N.The changes of NO3−-N and NH4+-N in the 0–40 cm soil layer showed the trend of declining and then increasing.The water level control only had a significant effect on the change of NO3−-N in the 60–80 cm soil layer.Both irrigation water use efficiency and crop water use efficiency were gradually reduced with the increase of field water level control.The nitrogen utilization efficiency under rural sewage irrigation was significantly higher than that under R3.Compared with the R3,rural sewage irrigation could significantly increase the yield of rice,and as the field water level rose,the effect of yield promotion was more obvious.It was noteworthy that the grain of rice under R1 monitored the low nitrate and nitrite content,but no nitrate and nitrite was discovered under R2 and R3.Therefore,reasonable rural sewage irrigation(R2)and medium water level(W2)were beneficial to improve nitrogen utilization efficiency,crop yield and crop quality promotion. 展开更多
关键词 Reclaimed water irrigation water level control water use efficiency nitrogen utilization crop quality
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Performance evaluation and chemical property analysis of RWMA binders with 100% artificial reclaimed asphalt 被引量:2
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作者 陈静云 王维营 +2 位作者 孙依人 刘佳音 许斌 《Journal of Southeast University(English Edition)》 EI CAS 2017年第1期91-95,共5页
The performance evaluation and chemical property analysis of the recycled warm mix asphalt (RWMA) binders containing 100% artificial reclaimed asphalt ( RA) are presented, and the combined effects of different p... The performance evaluation and chemical property analysis of the recycled warm mix asphalt (RWMA) binders containing 100% artificial reclaimed asphalt ( RA) are presented, and the combined effects of different percentages of the rejuvenator and warm mix additive (WMA) additives on RWMA binders are analyzed through laboratory tests. Three types of WMA additives ad one commercial rejuvenator named GST were selected to restore the artificial RA. The laboratory performace tests including the penetration test, softening test ad rotary, viscosity (RV) test were carried out. In addition, the Fourier transform infrared spectroscopy (FTIR) test was performed to explore the chemical property of RWMA binders. The results of the performance tests indicate that the rejuvenator GST has the ability to restore the artificial RA; choosing the optimum content of WMA additives and rejuvenator is the key to restoring 100% artificial RA, since the combined effects of them play an important role in determining the basic laboratory performance of RWMA binders. The FTIR tests show that the process of recycling mainly adjusts the chemical component of aged asphalt and no remarkable change is observed in the FTI1R spectra of RWMA binders in terms of chemical functional groups with the introduction of WMA additives. 展开更多
关键词 artificial reclaimed asphalt recycled warm mix asphalt WMA aditives rejuvenator performance test Fourier transform infrared spectroscopy
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美国区域排污权交易市场“RECLAIM计划”的经验及启示 被引量:4
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作者 赵文娟 宋国君 《环境保护》 CSSCI 2018年第5期75-77,共3页
美国是最早实践排污权交易政策的国家,在南加州地区实施的区域排污权交易市场"RECLAIM计划",通过激励固定源NO_x和SO_x持续减排,最终实现空气质量改善,形成了完善的交易机制和政策体系。RECLAIM计划在政策目标设定、管理对象... 美国是最早实践排污权交易政策的国家,在南加州地区实施的区域排污权交易市场"RECLAIM计划",通过激励固定源NO_x和SO_x持续减排,最终实现空气质量改善,形成了完善的交易机制和政策体系。RECLAIM计划在政策目标设定、管理对象纳入标准、削减目标制定、初始配额分配、交易市场运行机制、监测数据核查以及排污许可证制度保障等方面进行详细规定和论证,对我国排污权交易市场的优化具有重要借鉴意义。基于此,提出建立区域排污权交易市场、制定科学的排污权交易政策内容、颁发区域固定源排污许可证等对策建议。 展开更多
关键词 排污权交易 区域排污权交易市场 RECLAIM计划 固定源排污许可证 大气污染 空气质量 美国
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Impacts of Irrigation with Reclaimed Water on Endophytic Bacteria in Chinese Cabbage in Urumqi City 被引量:1
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作者 陈治江 师秋菊 陈晓 《Agricultural Science & Technology》 CAS 2012年第11期2355-2357,共3页
[Objective] This study aimed to investigate the feasibility of agricultural irri- gation with reclaimed water in Urumqi City. [Method] Chinese cabbages were used as experimental materials and irrigated with control wa... [Objective] This study aimed to investigate the feasibility of agricultural irri- gation with reclaimed water in Urumqi City. [Method] Chinese cabbages were used as experimental materials and irrigated with control water, 50% reclaimed water and 100% reclaimed water, and then the number of endophytic bacteria in Chinese cab- bages was measured. [Result] Using 50% reclaimed water, the fresh weight of Chi- nese cabbage was improved by 68.94%; however, with the deepening internalization of exogenous microorganism internalization, the total number of endophytic bacteria and coliform flock in Chinese cabbages treated with 50% reclaimed water was sig- nificantly higher than the other two treatment groups (P〈0.05). [Conclusion] Re- claimed water enhances both the weight of Chinese cabbage and the number of endophytic bacteria, which is unsuitable for irrigation of edible crops such as Chi- nese cabbage. Strengthening disinfection during the process of sewerage treatment could solve this problem. 展开更多
关键词 URUMQI Reclaimed water Chinese cabbage Endophytic bacteria
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一种排污权初始分配结构设计框架 被引量:7
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作者 吴征帆 向晓东 《环境科学与技术》 CAS CSCD 北大核心 2012年第1期201-205,共5页
作为一种新型环境政策,排污权交易在美国已经成功地演进为总量控制型排污权交易,这被认为是最接近市场经济的环境管理手段。在国内,排污权交易也日益受到政府的重视。自1988年以来,中国的许多地方都先后试点了排污权交易,但多停留在补... 作为一种新型环境政策,排污权交易在美国已经成功地演进为总量控制型排污权交易,这被认为是最接近市场经济的环境管理手段。在国内,排污权交易也日益受到政府的重视。自1988年以来,中国的许多地方都先后试点了排污权交易,但多停留在补偿政策,很少有关于总量控制型排污权交易的尝试。在政策设计的技术层面,造成这种状况的一个主要原因是缺乏有效的排污权初始分配结构设计框架。为此,在区域清洁激励市场计划排污权初始分配结构的基础上,针对渐进式减排战略指导下的总量控制型排污权交易计划,分纵向结构设计和横向结构设计两部分,提出了一种具有通用性的排污权初始分配结构设计框架。这有助于合理进行排污权初始分配。 展开更多
关键词 排污权初始分配 总量控制型排污权交易(CAT) 区域清洁激励市场计划(RECLAIM)
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Effect of heavy metals on soil microbial activity and diversity in a reclaimed mining wasteland of red soil area 被引量:23
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作者 LIAO Min CHEN Cheng-li HUANG Chang-yong 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2005年第5期832-837,共6页
The microbial biomass, basal respiration and substrate utilization pattern in copper mining wasteland of red soil area, southern China, were investigated. The results indicated that soil microflora were obviously diff... The microbial biomass, basal respiration and substrate utilization pattern in copper mining wasteland of red soil area, southern China, were investigated. The results indicated that soil microflora were obviously different compared with that of the non-mine soil. Microbial biomass and basal respiration were negatively affected by the elevated heavy metal levels. Two important microbial ecophysiological parameters, namely, the ratio of microbial biomass C( Cmic )/organic C( Corg ) and metabolic quotient(qCO2 ) were closely correlated to heavy metal stress. There was a significant decrease in the Cmic/Corg ratio and an increase in the metabolic quotient with increasing metal concentration. Multivariate analysis of Biolog data for sole carbon source utilization pattern demonstrated that heavy metal pollution had a significant impact on microbial community structure and functional diversity. All the results showed that soil microbiological parameters had great potential to become the early sensitive, effective and liable indicators of the stresses or perturbations in soils of mining ecosystems. 展开更多
关键词 reclaimed mining wasteland soil microorganism soil microbial diversity
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Plant Diversity Performance After Natural Restoration in Reclaimed Deyeuxia angustifolia Wetland 被引量:8
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作者 WANG Xuehong TONG Shouzheng +5 位作者 LI Yunzhao Qi Qing ZHANG Dongjie LYU Xianguo GUO Yue LIU Yan 《Chinese Geographical Science》 SCIE CSCD 2019年第3期437-445,共9页
Deyeuxia angustifolia wetlands were widely distributed in the Sanjiang Plain in Northeast China. Due to strong demand for food production, large-area wetlands were reclaimed to farmlands, which threatened regional eco... Deyeuxia angustifolia wetlands were widely distributed in the Sanjiang Plain in Northeast China. Due to strong demand for food production, large-area wetlands were reclaimed to farmlands, which threatened regional ecological security greatly. Since the 21 th century, returning farmlands to wetlands was widely adopted for natural restoration in the Sangjiang Plain. As the first reflection of wetland restoration, vegetation succession of restored D. angustifolia wetlands should be fully assessed. In this study, vegetation investigation was carried out in three restored D. angustifolia wetlands with 5, 8 and 12 yr restoration, respectively. Meanwhile, a natural D. angustifolia wetland was selected as reference wetland. Results showed that community composition changed greatly and there was visible community succession. Community dominant species changed from composite to gramineae as restoration time increasing.At first, weeds community appeared in the restored wetlands, especially the xerophytes developed to the pioneer species rapidly. And then, mesophytes and wetland species became the dominant species in the restored wetlands. Finally, wetland species, especially D. angustifolia, occupied the dominant position of restored community. Shannon-wiener index(H) and Simpson index(D) both decreased to close to natural D. angustifolia wetlands. Compared with natural D. angustifolia wetland, species composition and diversity in restored wetlands were more complex and higher. As restoration time increasing, there were not significant differences between community characteristics of restored wetlands and natural wetland. All these suggested that vegetation in reclaimed D. angustifolia wetland could be restored naturally, but its restored period is 10 yr at least. From another angle, it is important to protect current natural wetlands. 展开更多
关键词 reclaimed Deyeuxia angustifolia WETLAND COMMUNITY COMPOSITION plant DIVERSITY NATURAL RESTORATION
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水泥稳定全深式沥青路面回收料配合比试验研究 被引量:2
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作者 杨跃焕 吴英彪 《路基工程》 2014年第4期102-107,共6页
在沥青路面病害详细调查的基础上,确定沥青路面再生的施工方式。将水泥稳定全深式沥青路面回收料用于道路基层配合比,并设计水泥稳定再生混合料基层;通过调节水泥掺配剂量和回收沥青路面材料掺配比例,进行配合比设计试验。对试验结果进... 在沥青路面病害详细调查的基础上,确定沥青路面再生的施工方式。将水泥稳定全深式沥青路面回收料用于道路基层配合比,并设计水泥稳定再生混合料基层;通过调节水泥掺配剂量和回收沥青路面材料掺配比例,进行配合比设计试验。对试验结果进行统计分析,最终确定适宜于道路基层的最优配合比为:回收料掺配比例50%,水泥剂量2%。 展开更多
关键词 水泥稳定 全深式再生 沥青路面回收料 无侧限抗压强度 析因分析 reclaimed ASPHALT PAVEMENT (RAP)
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Effects of reclaimed water irrigation and nitrogen fertilization on the chemical properties and microbial community of soil 被引量:11
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作者 GUO Wei Mathias N Andersen +4 位作者 QI Xue-bin LI Ping LI Zhong-yang FAN Xiang-yang ZHOU Yuan 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2017年第3期679-690,共12页
The ecological effect of reclaimed water irrigation and fertilizer application on the soil environment is receiving more attention.Soil microbial activity and nitrogen(N)levels are important indicators of the effect... The ecological effect of reclaimed water irrigation and fertilizer application on the soil environment is receiving more attention.Soil microbial activity and nitrogen(N)levels are important indicators of the effect of reclaimed water irrigation on environment.This study evaluated soil physicochemical properties and microbial community structure in soils irrigated with reclaimed water and receiving varied amounts of N fertilizer.The results indicated that the reclaimed water irrigation increased soil electrical conductivity(EC)and soil water content(SWC).The N treatment has highly significant effect on the ACE,Chao,Shannon(H)and Coverage indices.Based on a 16S ribosomal RNA(16S rRNA)sequence analysis,the Proteobacteria,Gemmatimonadetes and Bacteroidetes were more abundant in soil irrigated with reclaimed water than in soil irrigated with clean water.Stronger clustering of microbial communities using either clean or reclaimed water for irrigation indicated that the type of irrigation water may have a greater influence on the structure of soil microbial community than N fertilizer treatment.Based on a canonical correspondence analysis(CCA)between the species of soil microbes and the chemical properties of the soil,which indicated that nitrate N(NO3-–-N)and total phosphorus(TP)had significant impact on abundance of Verrucomicrobia and Gemmatimonadetes,meanwhile the p H and organic matter(OM)had impact on abundance of Firmicutes and Actinobacteria significantly.It was beneficial to the improvement of soil bacterial activity and fertility under 120 mg kg^-1 N with reclaimed water irrigation. 展开更多
关键词 reclaimed water NITROGEN soil chemical properties 16S rRNA sequence soil microbe community
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Heavy metal pollution and potential ecological risk in reclaimed soils in Huainan mining area 被引量:27
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作者 YAO Duo-xi MENG Jun ZHANG Zhi-guo 《Journal of Coal Science & Engineering(China)》 2010年第3期316-319,共4页
In order to determine the environmental quality condition of reclaimed soils inHuainan mining area, soil samples were collected from three representative mines, suchas Panyi Mine, Xinzhuangzi Mine and Datong Mine.The ... In order to determine the environmental quality condition of reclaimed soils inHuainan mining area, soil samples were collected from three representative mines, suchas Panyi Mine, Xinzhuangzi Mine and Datong Mine.The total concentration of Cd, Hg, Cu,Pb and As in the samples were analyzed.The potential ecological risk was used to evaluatethe heavy metals pollution.The investigation reveals that the reclaimed soils are contaminatedto a certain degree and the trace elements in coal gangue transferred to thesurface soil.The order of potential ecological risk is Cd>Hg>Cu>Pb>As; the pollution degreeof each sampling site is arranged in the following order: Xinzhuangzi Mine>DatongMine>Panyi Mine, and the multiform of heavy metals of potential ecological risk index is at357.35~484.62. 展开更多
关键词 heavy metal pollution potential ecological risk reclaimed soils
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Influence of Reclamation Works on the Marine Environment in a Semi-Enclosed Bay 被引量:5
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作者 Lee M. Ock Park S. Jin Kang T. Soon 《Journal of Ocean University of China》 SCIE CAS 2006年第3期219-227,共9页
The flow and seawater exchange rates have been predicted using a two-dimensional numerical model and a Lagrangian method for a semi-enclosed shallow bay where reclaiming and dredging works are scheduled. The wind effe... The flow and seawater exchange rates have been predicted using a two-dimensional numerical model and a Lagrangian method for a semi-enclosed shallow bay where reclaiming and dredging works are scheduled. The wind effect on the flow and material transport has been emphasized, and a thirty-year mean value of wind has been considered in the numerical simulation. As a whole, even after the reclaiming and dredging are conducted, the flow pattern looks similar to the original state. However, velocity variations up to 20% to 100% appear in the vicinity of the construction area. In the case of summcr wind forcing, the seawater exchange rate increases from 71.6% to 82.9% after the reclaiming and dredging, as indicated by a particle-tracking method. On the contrary, in the case of winter wind forcing, thc seawater cxchange rate appears to be 97.2% under natural conditions but decrcases slightly to 93.2% aftcr the rcclaiming and dredging. Thus, the wind forcing plays an important role in controlling the seawater exchangc rates. The seawater cxchange rate is further improved by 15% if the dredging is simultaneously carried out with the reclaiming. This suggests that the dredging can be an effective means to mitigate the variation of flow. 展开更多
关键词 DREDGING random walk method reclaiming seawater exchange rate semi-enclosed bay wind forcing
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Dry reusing and wet reclaiming of used sodium silicate sand 被引量:4
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作者 Zitian FAN Naiyu HUANG +1 位作者 Huafang WANG Xuanpu DONG 《China Foundry》 SCIE CAS 2005年第1期38-43,共6页
Based on the characteristics of used sodium silicate sand and the different use requirements for recycled sand, "dry reusing and wet reclaiming of used sodium silicate sand" is considered as the most suitabl... Based on the characteristics of used sodium silicate sand and the different use requirements for recycled sand, "dry reusing and wet reclaiming of used sodium silicate sand" is considered as the most suitable technique for the used sand. When the recycled sand is used as support sand, the used sand is only reused by dry process including breaking, screening, dust-removal, etc., and it is not necessary that the used sand is reclaimed with strongly rubbing and scraping method, but when the recycled sand is used as facing sand (or single sand), the used sand must be reclaimed by wet method for higher removal rate of the residual binders. The characteristics and the properties of the dry reused sand are compared with the wet reclaimed sand after combining the different use requirements of support sand and facing sand (or single sand), and above the most adaptive scheme has also been validated. 展开更多
关键词 USED SODIUM SILICATE SAND DRY reusing WET reclaiming
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An investigation of oxygen pressure acid leaching of Gacun complex Cu-Pb bulk concentrate 被引量:6
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作者 Xu, Bin Zhong, Hong Jiang, Tao 《Rare Metals》 SCIE EI CAS CSCD 2012年第1期96-101,共6页
The treatment of the Gacun complex Cu-Pb bulk concentrate with high Zn,Ag,etc.,by oxygen pressure acid leaching was studied.The pri-mary copper and leadminerals in the concentrate are tetrahedrite and galena.The treat... The treatment of the Gacun complex Cu-Pb bulk concentrate with high Zn,Ag,etc.,by oxygen pressure acid leaching was studied.The pri-mary copper and leadminerals in the concentrate are tetrahedrite and galena.The treatment of tetrahedrite was rarely studied,and most of silver occurred in themineral too.The optimum operating parameters of oxygen pressure acid leaching were established by conditional tests.Under these parameters,the result of pilot scale test showed that the leaching percentages of copper and zinc were separately as high as 98.9 wt.% and 94.9 wt.%,while lead and silver were transformed into sulfate and sulfide precipitations,respectively.The copper and zinc in lixivium were reclaimed by extraction-electrowinning and purification-electrowinning,respectively,and the lead and silver in the residue were reclaimed separately by carbonate transformation-silicofluoric acid leaching and thiourea leaching. 展开更多
关键词 nonferrous metallurgy synthetic reclaiming oxygen pressure acid leaching complex Cu-Pb bulk concentrate TETRAHEDRITE
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Biofilm structure and its influence on clogging in drip irrigation emitters distributing reclaimed wastewater 被引量:4
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作者 YAN Dazhuang BAI Zhihui +3 位作者 Mike Rowan GU Likun Ren Shumei YANG Peiling 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2009年第6期834-841,共8页
Using reclaimed wastewater for crop irrigation is a practical alternative to discharge wastewater treatment plant effluents into surface waters.However,biofouling has been identified as a major contributor to emitter ... Using reclaimed wastewater for crop irrigation is a practical alternative to discharge wastewater treatment plant effluents into surface waters.However,biofouling has been identified as a major contributor to emitter clogging in drip irrigation systems distributing reclaimed wastewater.Little is known about the biofilm structure and its influence on clogging in the drip emitter flow path.This study was first to investigate the microbial characteristics of mature biofilms present in the emitters and the effect of flow path structures on the biofilm microbial communities.The analysis of biofilm matrix structure using a scanning electron microscopy(SEM) revealed that particles in the matrix of the biofilm coupled extracellular polysaccharides(EPS) and formed sediment in the emitter flow path.Analysis of biofilm mass including protein,polysaccharide,and phospholipid fatty acids(PLFAs) showed that emitter flow path style influenced biofilm community structure and diversity.The correlations of biofilm biomass and discharge reduction after 360 h irrigation were computed and suggest that PFLAs provide the best correlation coeffcient.Comparatively,the emitter with the unsymmetrical dentate structure and shorter flow path(Emitter C) had the best anti-clogging capability.By optimizing the dentate structure,the internal flow pattern within the flow path could be enhanced as an important method to control the biofilm within emitter flow path.This study established electron microscope techniques and biochemical microbial analysis methods that may provide a framework for future emitter biofilm studies. 展开更多
关键词 emitter clogging drip irrigation BIOFILM microbial community phospholipid fatty acid reclaimed wastewater scanningelectron microscopy
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Soil erosion and soil properties in reclaimed forestland of loess hilly region 被引量:3
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作者 ZHAXiaochun TANGKeli 《Journal of Geographical Sciences》 SCIE CSCD 2003年第3期373-378,共6页
Based on data observed from 1989 to 1998 in the Ziwuling survey station, changes of soil erosion and soil physico-mechanical properties were studied after forestland reclamation. When the man-induced fac... Based on data observed from 1989 to 1998 in the Ziwuling survey station, changes of soil erosion and soil physico-mechanical properties were studied after forestland reclamation. When the man-induced factors changed the eco-environment by reclaiming forestlands, the intensity of man-made soil erosion in reclaimed lands was 1,000 times more than that of natural erosion in forestlands. From the analysis of soil physical and mechanical properties, the clay content and physical clay content decreased 2.74% and 3.01% respectively, and the >0.25 mm water stable aggregate content decreased 58.7%, the soil unit weight increased and the soil shear strength decreased, all of which were easier to cause soil erosion. The results of the correlation analysis showed that the >0.25 mm water stable aggregate content was the greatest influencing factor on soil erosion, the partial correlated coefficient was 0.9728, and then were soil coarse grain and soil shear strength, the partial correlated coefficients being 0.8879 and 0.6020 respectively. The relationships between the >0.25 mm water stable aggregate content, the soil sheer strength and the soil erosion intensity were analyzed, which showed that the first and seventh years were the turning years of the soil erosion intensity after the forestland reclamation. The degenerative eroded soil and eco-environment formed the peculiar erosion environment, which aggravated the soil erosion rapidly. 展开更多
关键词 LOESS reclaimed forestland soil erosion soil properties SHAANXI
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