期刊文献+
共找到575篇文章
< 1 2 29 >
每页显示 20 50 100
Deep Consensus Network for Recycling Waste Detection in Smart Cities
1
作者 Manar Ahmed Hamza Hanan Abdullah Mengash +3 位作者 Noha Negm Radwa Marzouk Abdelwahed Motwakel Abu Sarwar Zamani 《Computers, Materials & Continua》 SCIE EI 2023年第5期4191-4205,共15页
Recently,urbanization becomes a major concern for developing as well as developed countries.Owing to the increased urbanization,one of the important challenging issues in smart cities is waste management.So,automated ... Recently,urbanization becomes a major concern for developing as well as developed countries.Owing to the increased urbanization,one of the important challenging issues in smart cities is waste management.So,automated waste detection and classification model becomes necessary for the smart city and to accomplish better recyclable waste management.Effective recycling of waste offers the chance of reducing the quantity of waste disposed to the land fill by minimizing the requirement of collecting raw materials.This study develops a novel Deep Consensus Network with Whale Optimization Algorithm for Recycling Waste Object Detection(DCNWORWOD)in Smart Cities.The goal of the DCNWO-RWOD technique intends to properly identify and classify the objects into recyclable and non-recyclable ones.The proposed DCNWO-RWOD technique involves the design of deep consensus network(DCN)to detect waste objects in the input image.For improving the overall object detection performance of the DCN model,the whale optimization algorithm(WOA)is exploited.Finally,Na飗e Bayes(NB)classifier is used for the classification of detected waste objects into recyclable and non-recyclable ones.The performance validation of theDCNWO-RWOD technique takes place using the open access dataset.The extensive comparative study reported the enhanced performance of the DCNWO-RWOD technique interms of several measures. 展开更多
关键词 Smart city waste management object detection recycling deep consensus network
下载PDF
Closed-loop cobalt recycling from spent lithium-ion batteries based on a deep eutectic solvent (DES) with easy solvent recovery 被引量:3
2
作者 Taibai Li Yige Xiong +4 位作者 Xiaohui Yan Tao Hu Siqi Jing Zhongjie Wang Xiang Ge 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第9期532-538,I0015,共8页
Efficient recycling technology for the rapid growth of spent lithium-ion batteries(LIBs)is essential to tackle the resources and environmental crisis.Hydrometallurgical approach has attracted extensive research due to... Efficient recycling technology for the rapid growth of spent lithium-ion batteries(LIBs)is essential to tackle the resources and environmental crisis.Hydrometallurgical approach has attracted extensive research due to its potential to reduce the consumption of energy and threat to the environment.However,the simultaneous realization of green,efficient and closed-loop recycling is still challenging.Herein,we report a closed-loop and highly efficient approach to recycle lithium cobalt oxide from spent LIBs based on a choline chloride:oxalic acid(ChCl:OA)type deep eutectic solvent(DES).An ultrafast leaching process is observed at 180°C for 10 s with no observable residues.The energy barrier during leaching is calculated to be 113.9 kJ/mol.Noteworthy,the solubility of cobalt ions can be reversibly tuned by simply adding/evaporating deionized water,thus avoiding the addition of precipitant and enabling the easy recovery of the leaching solvent for realizing a closed-loop recycling process.The simultaneous realization of high efficiency,green and closed-loop process is expected to push the DES into practical application for recycling the electrodes of LIBs. 展开更多
关键词 Lithium-ion batteries recycle deep eutectic solvent CLOSED-LOOP High efficiency Solvent recovery
下载PDF
The Damaging Effects of Abstracting the Deep Aquifers’Groundwater in Jordan-Quality Constraints
3
作者 Elias Salameh Ghaida Abdallat Taleb Odeh 《Journal of Geoscience and Environment Protection》 2024年第3期250-278,共29页
The deep aquifers in Jordan contain non-renewable and fossil groundwater and their extraction is quasi a mining process, which ends in the depletion of these resources. Although aquifers in the majority of groundwater... The deep aquifers in Jordan contain non-renewable and fossil groundwater and their extraction is quasi a mining process, which ends in the depletion of these resources. Although aquifers in the majority of groundwater basins in Jordan are vertically and horizontally interconnected stratification in different water quality horizons with generally increasing water salinity with the depth is observed. Many officials and planners advocate the extraction of deep salty and brackish water to be desalinated and used in household, industrial, and agricultural uses. In this article, the quality of the groundwater in the different deep aquifers and areas in Jordan is discussed. The results of this study show that the consequences of the deep groundwater exploitation are not restricted to depletion of the deep aquifers but also that the overlying fresh groundwater will, due to vertical and horizontal interconnectedness of the different aquifers, percolate down to replace the extracted deep groundwater. This will cause the down-percolating fresh groundwater to become salinized in the deep saline aquifers, which means that extracting the deep brackish and saline groundwater is not only an emptying process of the deep groundwater but also it is an emptying process of the fresh groundwater overlying them. The results allow to conclude that any extraction of the deep groundwater in areas lying to the north of Ras en Naqab Escarpment will have damaging impacts on the fresh groundwater in the overlying fresh groundwater aquifers. This article strongly advises not to extract the deep brackish and saline groundwater, but to conserve that groundwater as a base supporting the overlying fresh groundwater resources, and that will help in protecting the thermal mineralized water springs used in spas originating from these deep aquifers. The increasing water needs of the country can be covered by the desalination of seawater at Aqaba, which is the only viable option for Jordan at present and in the coming decades. 展开更多
关键词 groundwater Salinity Sources of Salinity Interconnectedness of Aquifers Absurdity of deep groundwater Exploitation
下载PDF
Colloid-facilitated release of polybrominated diphenyl ethers at an e-waste recycling site: evidence from undisturbed soil core leaching experiments 被引量:1
4
作者 Zebin Huo Mengjun Xi +2 位作者 Lianrui Xu Chuanjia Jiang Wei Chen 《Frontiers of Environmental Science & Engineering》 SCIE EI CSCD 2024年第2期91-101,共11页
Polybrominated diphenyl ethers (PBDEs), a class of persistent organic pollutants, have been frequently detected in soil at e-waste recycling sites. However, the key factors controlling the transport of PBDEs from surf... Polybrominated diphenyl ethers (PBDEs), a class of persistent organic pollutants, have been frequently detected in soil at e-waste recycling sites. However, the key factors controlling the transport of PBDEs from surface soil to the vadose zone and groundwater are unclear. Here, colloid-enhanced leaching of PBDEs from undisturbed soil cores collected at an e-waste recycling site in Tianjin, China, is reported. Spatially heterogeneous release of colloids and PBDEs was observed in all the tested soil cores under chemical and hydrodynamic perturbations, indicating the presence of preferential flow paths. Colloid concentration in the effluent significantly increased as ionic strength decreased (from 10 to 0.01 mmol/L), probably due to the stronger electrostatic repulsion between colloidal particles and the soil matrix at lower ionic strength. In contrast, colloid mobilization was not significantly affected by the changes in pH of the influent (from 4.0 to 10.0) and flow rate (from a Darcy velocity of 1.5 to 6.0 cm/h). The concentrations of 2,2′,3,3′,4,4′,5,5′,6,6′-decabromodiphenyl ether (BDE-209), the predominant PBDE congener at the site, detected in the leachate (ranging from 1.09 to 3.43 ng/L) were much lower than previously reported results from packed column leaching tests, and were positively correlated with colloid concentrations. This indicates that remobilization of colloids at e-waste recycling sites can promote the leaching and downward migration of PBDEs from surface soil. The findings highlight the potential risk of surface soil PBDE contamination to groundwater quality and call for further understanding of colloid-facilitated transport for predicting the fate of PBDEs at e-waste recycling sites. 展开更多
关键词 Polybrominated diphenyl ether Colloid-facilitated transport E-waste recycling site Undisturbed soil core groundwater quality
原文传递
Deep structure of the Southeast Asian curved subduction system and its dynamic process
5
作者 Weiwei DING 《Journal of Oceanology and Limnology》 SCIE CAS CSCD 2024年第3期701-704,共4页
The deep structure,material circulation,and dynamic processes in the Southeast Asia have long been an elusive scientific puzzle due to the lack of systematic scientific observations and recognized theoretical models.B... The deep structure,material circulation,and dynamic processes in the Southeast Asia have long been an elusive scientific puzzle due to the lack of systematic scientific observations and recognized theoretical models.Based on the deep seismic tomography using long-period natural earthquake data,in this study,the deep structure and material circulation of the curved subduction system in Southeast Asia was studied,and the dynamic processes since 100 million years ago was reconstructed.It is pointed out that challenges still exist in the precise reconstruction of deep mantle structures of the study area,the influence of multi-stage subduction on deep material exchange and shallow magma activity,as well as the spatiotemporal evolution and coupling mechanism of multi-plate convergence.Future work should focus on high-resolution land-sea joint 3-D seismic tomography imaging of the curved subduction system in the Southeast Asia,combined with geochemical analysis and geodynamic modelling works. 展开更多
关键词 curved subduction system deep structure material recycling dynamic process Southeast Asia
下载PDF
Deep carbon recycling and isotope tracing:Review and prospect 被引量:6
6
作者 ZHANG HongMing LI ShuGuang 《Science China Earth Sciences》 SCIE EI CAS 2012年第12期1929-1941,共13页
Deep carbon recycling is an essential part of the global carbon cycle.The carbonates at the bottom of the ocean are brought to the mantle by subduction.Subsequently, deep carbon is released to the atmosphere in the fo... Deep carbon recycling is an essential part of the global carbon cycle.The carbonates at the bottom of the ocean are brought to the mantle by subduction.Subsequently, deep carbon is released to the atmosphere in the form of CO2 through volcanism.At present, research on deep carbon recycling is still at its early stage.The proportion of subduction-related carbon and primary mantle-derived carbon in CO2 released by volcano is an important issue.Carbon isotopes can easily distinguish organic carbon from inorganic carbon.However, ~95% of subduction-related and primary mantle-derived carbon released by volcano is inorganic, which carbon isotopes find difficult to distinguish.Recently, Ca and Mg isotope geochemistry has provided important tools for tracing crust-derived material recycling.Here we focus on this topic by introducing the principles of C, Ca, and Mg isotopes in tracing deep carbon recycling and previous research results.We also summarize the research progress on the total storage and phases of deep carbon, CO2 fluxes which depend on the release via volcanism, the partial melting of the carbon-bearing mantle, and carbon behaviour during oceanic subduction. 展开更多
关键词 deep carbon carbon recycling Ca isotope Mg isotope
原文传递
Assessment of deep groundwater over-exploitation in the North China Plain 被引量:7
7
作者 Jiansheng Shi Zhao Wang Zhaoji Zhang Yuhong Fei Yasong Li Feng'e Zhang Jingsheng Chen Yong Qian 《Geoscience Frontiers》 SCIE CAS 2011年第4期593-598,共6页
A series of environmental—geological problems have been caused by over-exploitation of deep groundwater(i.e.,confined aquifer water) in the North China Plain.In order to better understand the status of deep groundw... A series of environmental—geological problems have been caused by over-exploitation of deep groundwater(i.e.,confined aquifer water) in the North China Plain.In order to better understand the status of deep groundwater over-exploitation and the resultant environmental—geological problems on a regional scale,the over-exploitation of groundwater has been assessed by way of the groundwater exploitation potential coefficient(i.e.,the ratio of exploitable amount of deep groundwater to current exploitation), cumulative land subsidence,and long-term average lowering rate of the groundwater table.There is a good correlation among the results calculated by the different methods.On a regional scale,deep groundwater has been over-exploited and there is no further exploitation potential under the current conditions.The groundwater exploitation degree index takes the exploitation in 2003 as the reference for the calculations, so the results mainly reflect the degree of current groundwater exploitation.The results of over-exploitation of deep groundwater obtained by land subsidence data and long-term average rate of depression of the water table mainly reflect environmental—geological problems caused by exploitation of deep groundwater. 展开更多
关键词 North China Plain deep groundwater Assessment of over-exploitation Land subsidence Water table depression
下载PDF
The Hydrogeological Consequences of the Proposed Extraction of the Deep Groundwater in Jordan 被引量:2
8
作者 Elias Salameh 《Journal of Geoscience and Environment Protection》 2021年第8期111-128,共18页
Many officials and planners in Jordan have advocated in the last decade extracting the deep brackish, thermal, and salty groundwater resources, desalinate them, and use them for household water supplies. Generally, su... Many officials and planners in Jordan have advocated in the last decade extracting the deep brackish, thermal, and salty groundwater resources, desalinate them, and use them for household water supplies. Generally, such groundwater is non-renewable and is found in aquifers underlying fresh renewable groundwater bodies building the base support for them. The deep groundwater feeds the thermal mineralized springs issuing along the eastern escarpment of the Dead Sea-Jordan Rift Valley used for therapeutic purposes. In this article, the geologic set-up of the aquifer series underlying the different parts of the country is outlined to illustrate that all such aquifers extending from ground surface to the impermeable granitic Basement Complex are, in the majority of areas, directly or indirectly interconnected and that extractions from any aquifer, shallow or deep, are effectively taken from the same stock of the groundwater body. Hence, it is concluded that advocating the extraction of the deep salty or brackish groundwater is quasi extracting the same amount of groundwater from the overlying, shallower fresh water aquifers. The deep groundwater issues along the eastern escarpment of the Jordan Rift Valley and is used in household supplies, in irrigation and in spas as curative agent. In addition, the intended use of the deep groundwater to be extracted according to the suggested policy in household supplies requiring desalination, which is a costly unnecessary process accompanied with rigorous environmental ramifications of disposing off the desalination brines. 展开更多
关键词 Exploitation Implications deep groundwater Shallow groundwater Interconnectedness DESALINATION JORDAN
下载PDF
Design of an Index System for Deep Groundwater Management Efficiency Evaluation: A Case Study in Tianjin City, China 被引量:1
9
作者 NAN Tian SHAO Jingli +2 位作者 CAO Xiaoyuan ZHANG Qiulan CUI Yali 《Chinese Geographical Science》 SCIE CSCD 2016年第3期325-338,共14页
An effective evaluation system can provide specific and practical suggestions to the deep groundwater management. But such kind of evaluation system has not been proposed in China. In this study, an evaluation index s... An effective evaluation system can provide specific and practical suggestions to the deep groundwater management. But such kind of evaluation system has not been proposed in China. In this study, an evaluation index system is specifically developed to evaluate deep groundwater management efficiency. It is composed of three first-level indicators(law enforcement capability, management ability, and management effectiveness) and eleven second-level indicators. The second-level indicators include seven mandatory indicators and four optional indicators. Piecewise linear function is used to normalize the quantitative indicators, and expert scoring method and questionnaire survey method are used to normalize the qualitative indicators. Then a comprehensive indicator weighting evaluation method is used to evaluate the first-level indicators and the target topic. A case study is carried out to evaluate deep groundwater management efficiency in Tianjin City. According to the evaluation score in each period, the management efficiency of every district in Tianjin City gradually improved. The overall evaluation score in the early deep groundwater extraction period is 0.12. After a series of deep groundwater protection efforts, this score reached to 0.61 in 2007, and met the regulation criteria. The evaluation results also showed that the further groundwater management efforts in Tianjin City should be focused on building a dynamic database to collect comprehensive deep well-log data; and on a reasonable design and distribution of the groundwater monitoring network. It demonstrated that the index system is suitable to locate the deficiencies of current groundwater management systems and to guide further improvements. It can then be used to protect deep groundwater. 展开更多
关键词 deep groundwater management evaluation index system law enforcement capability management ability management effectiveness
下载PDF
Study on the residence time of deep groundwater for high-level radioactive waste geological disposal
10
作者 ZHOU Zhi-chao WANG Ju +5 位作者 SU Rui GUO Yong-hai LI Jie-biao JI Rui-li ZHANG Ming DONG Jian-nan 《Journal of Groundwater Science and Engineering》 2016年第1期52-59,共8页
Residence time of deep groundwater is one of the most important parameters in safety and performance assessment for high-level radioactive waste geological disposal. In this study, we collected the deep groundwater sa... Residence time of deep groundwater is one of the most important parameters in safety and performance assessment for high-level radioactive waste geological disposal. In this study, we collected the deep groundwater samples of Jijicao in Gansu Beishan pre-selected region. The deep groundwater residence time at two depths estimated by Helium-4 accumulation method were 3.8 ka and 5.0 ka respectively upon measurement and calculation, which indicates that the deep groundwater is not derived from the deep crust circulation process. Hence, deep groundwater is featured with long residence time as well as slow circulation and update rate, and such features are conductive to the safe disposal of high-level radioactive waste. 展开更多
关键词 deep groundwater HIGH-LEVEL RADIOACTIVE WASTE 4He GEOLOGICAL DISPOSAL
下载PDF
Assessment of Arsenic Contamination in Deep Groundwater Resources of the Kathmandu Valley, Nepal
11
作者 Suman Man Shrestha Kedar Rijal Megh Raj Pokhrel 《Journal of Geoscience and Environment Protection》 2015年第10期79-89,共11页
This study was carried out to assess arsenic in deep groundwater resources in the Kathmandu Valley, Nepal and to predict arsenic mobilization process in relation to iron, manganese, pH and ORP. Forty-one deep groundwa... This study was carried out to assess arsenic in deep groundwater resources in the Kathmandu Valley, Nepal and to predict arsenic mobilization process in relation to iron, manganese, pH and ORP. Forty-one deep groundwater samples were collected during pre monsoon and post monsoon in 2013. The depths of the wells were ranged from 84 to 304 m. In pre monsoon and post monsoon, arsenic concentration in 17% and 26% of examined groundwater wells, respectively exceeded permissible World Health Organization (WHO) guideline value of 0.010 mg/L for drinking water. The concentrations of arsenic were in the range between < 0.003 to 0.137 mg/L. The study demonstrated elevated concentrations of iron and manganese in the groundwater. Arsenic is highly correlated with iron and manganese. The strong negative correlation between arsenic and ORP indicates that arsenic mobilization occurs under reducing condition. These distinct relationships indicate that arsenic release is considered to be affected by the reductive dissolution of Fe/Mn oxides in the groundwater. Arsenic has very weak negative correlation with pH suggesting less effect of pH on arsenic mobilization. Arsenic is not significantly correlated with the season which infers similar distribution of arsenic in both seasons. Arsenic varies spatially in groundwater of the valley showing high concentrations in central groundwater district. 展开更多
关键词 ARSENIC deep groundwater REDUCTIVE DISSOLUTION Kathmandu VALLEY
下载PDF
Ground Subsidence Following Groundwater Drawdown by Excavating of 500 m Deep Investigation Shafts in Granite Body in Mizunami, Central Japan in 2004-2012
12
作者 Fumiaki Kimata Yasuhiro Asai +3 位作者 Ryo Honda Toshiyuki Tanaka Hiroshi Ishii Rikio Miyajima 《Engineering(科研)》 2015年第7期424-433,共10页
Two 500 m deep investigation shafts were excavating in the granite body in Mizunami, central Japan by JAEA (Japan Nuclear Cycle Development Institute) in 2004-2012. Groundwater with volume of 700 m3 was generally pump... Two 500 m deep investigation shafts were excavating in the granite body in Mizunami, central Japan by JAEA (Japan Nuclear Cycle Development Institute) in 2004-2012. Groundwater with volume of 700 m3 was generally pumping a day to prevent the shafts from submerging in 2012 following the excavating. As a result of pumping the groundwater, the ground water level lowered to 60 m in the borehole with the distance of 200 m from the excavating shafts in 2012. Leveling network extending 2 km × 2 km around the shafts was established to detect the vertical deformation around the shafts in 2004, and precise leveling was done every year. An 18 mm ground subsidence was detected in the benchmark close to the shafts for 8 years in 2004-2012, and time series of subsidence at benchmark was consistent with the groundwater drawdown. The groundwater drawdown and ground subsidence were caused by the pumping ground water in excavating shafts. 展开更多
关键词 Ground Subsidences groundwater DRAWDOWN 500 M deep EXCAVATION Shaft Precise LEVELING groundwater Drainage
下载PDF
Assessment of Heavy Metals in Deep Groundwater Resources of the Kathmandu Valley, Nepal
13
作者 Suman Man Shrestha Kedar Rijal Megh Raj Pokhrel 《Journal of Environmental Protection》 2016年第4期516-531,共16页
A study was carried out to address distribution of some heavy metals in deep groundwater resources of the Kathmandu Valley. Groundwater samples were analyzed for pH, ORP, EC, iron, manganese, zinc, and arsenic in 41 d... A study was carried out to address distribution of some heavy metals in deep groundwater resources of the Kathmandu Valley. Groundwater samples were analyzed for pH, ORP, EC, iron, manganese, zinc, and arsenic in 41 deep groundwater wells during pre monsoon and post monsoon seasons for two consecutive years. The study showed elevated concentrations of iron and manganese in the groundwater of the valley. The occurrence of elevated concentrations of arsenic was also exhibited and observed up to 0.160 mg/L. The spatial distribution patterns demonstrated elevated levels of EC, iron, manganese, zinc, and arsenic in central groundwater district (CGWD) of the valley. The monitored parameters except ORP are not significantly correlated with studied time series, inferring similar distribution of the metals. Correlation analysis and principal component analysis (PCA) were performed to find out relationships among examined parameters and metals. The ORP has strong negative correlations with iron, manganese, and arsenic, suggesting reductive mobilization mechanism of the metals in the groundwater. PCA results showed that iron and manganese with high positive loading factors were due to common natural source of origin of these metals in the groundwater, while negative loading factors of pH and ORP indicated that iron and manganese mobilization was favorable in low pH and reducing environment. Cluster analysis (CA) evidenced high mineralization in most of the wells in the CGWD. 展开更多
关键词 Heavy Metals deep groundwater Principal Component Analysis Cluster Analysis MINERALIZATION
下载PDF
Analysis of the deep groundwater quality in Daqing district
14
《Global Geology》 1998年第1期33-33,共1页
关键词 deep Analysis of the deep groundwater quality in Daqing district
下载PDF
The environmental negative effect for exploitation of the deep groundwater in mining area
15
《Global Geology》 1998年第1期7-7,共1页
关键词 deep The environmental negative effect for exploitation of the deep groundwater in mining area
下载PDF
华北地区深井水位对飑线天气过程的水力响应
16
作者 杨小林 冯静 +1 位作者 苏利娜 杨锦玲 《地震学报》 CSCD 北大核心 2024年第4期663-676,共14页
为探讨华北地区飑线天气对深井水位干扰的特征和影响机制,以2017年9月21日发生在华北中部的一次飑线事件为例,使用时频分析和线性回归等方法系统地诊断了此次飑线对无极、辛集、永清和宁晋等四口千米级深井的水位扰动特征。结果表明:在... 为探讨华北地区飑线天气对深井水位干扰的特征和影响机制,以2017年9月21日发生在华北中部的一次飑线事件为例,使用时频分析和线性回归等方法系统地诊断了此次飑线对无极、辛集、永清和宁晋等四口千米级深井的水位扰动特征。结果表明:在宏观层面,飑线过境各深井时会引起气压快速涌升,在气压的激励下,深井水位出现了即时的脉冲状波动,该干扰的持续时间可长达127 min;此次飑线过程中周期性气压波动的主频段为15—25 cpd,在该频段内,各深井水位与气压扰动的形态高度负相关,相关系数均低于-0.95,气压系数主要集中在-4.9—-6.9 mm/hPa之间。 展开更多
关键词 华北地区 深井水位 水位波动 飑线 气压 气温
下载PDF
可调弯鞘在回收困难的伞形下腔静脉滤器取出术中的应用
17
作者 蒋盘强 顾叶秋 +1 位作者 高敏亚 王宏飞 《血管与腔内血管外科杂志》 2024年第7期797-800,821,共5页
目的探讨可调弯鞘在回收困难的伞形下腔静脉滤器取出术中的应用价值。方法收集2021年7月至2023年2月于南京中医药大学附属无锡医院就诊的24例滤器回收困难患者临床资料,均采用可调弯鞘进行滤器回收,分析所有患者的手术成功率,观察下腔... 目的探讨可调弯鞘在回收困难的伞形下腔静脉滤器取出术中的应用价值。方法收集2021年7月至2023年2月于南京中医药大学附属无锡医院就诊的24例滤器回收困难患者临床资料,均采用可调弯鞘进行滤器回收,分析所有患者的手术成功率,观察下腔静脉血流通畅情况、管壁情况、造影剂外溢或滞留情况、滤器情况、相关并发症发生情况。结果23例患者手术成功,1例因患有阿尔茨海默病,术中不能配合而放弃手术。回收滤器均结构完整、无折断,无变形,滤器取出后行下腔静脉造影均未发现造影剂滞留或外渗。手术时间25~120 min,平均58 min,未明显增加手术时间及费用,无相关并发症发生。结论应用可调弯鞘可以显著提高回收钩贴壁的下腔静脉滤器回收成功率,安全、有效,具有一定的临床应用价值。 展开更多
关键词 下肢深静脉血栓形成 下腔静脉滤器 可调弯鞘 伞形滤器 回收钩贴壁
下载PDF
酸/碱性低共熔溶剂预处理对轻木物化性质及酶水解影响 被引量:1
18
作者 唐义泉 芮安娜 +3 位作者 杨积有 商赛男 司传领 边静 《中国造纸》 CAS 北大核心 2024年第6期1-8,共8页
采用酸/碱性低共熔溶剂(DES)在110℃和5 h下预处理轻木原料,分析了预处理前后轻木的化学组成、表面形貌、结构变化和酶水解性能。结果表明,3种酸/碱性DES预处理均可有效解构轻木原料。酸性DES可去除几乎所有的半纤维素和部分木质素,且... 采用酸/碱性低共熔溶剂(DES)在110℃和5 h下预处理轻木原料,分析了预处理前后轻木的化学组成、表面形貌、结构变化和酶水解性能。结果表明,3种酸/碱性DES预处理均可有效解构轻木原料。酸性DES可去除几乎所有的半纤维素和部分木质素,且酸性较强的氯化铝六水合物/丙三醇体系处理导致部分纤维素降解。碱性氯化胆碱/乙醇胺体系预处理后木质素大量去除,残留物中保留大量碳水化合物。预处理可显著增效纤维素酶水解,葡萄糖得率由原料的16.5%提升至52.6%~60.7%。DES经循环使用3次后纤维素酶解效率仍可达原料的2.5倍以上。 展开更多
关键词 轻木 低共熔溶剂 预处理 酶解 循环使用
下载PDF
甘肃北山新场深部地下水中铀的赋存形态及其影响因素的地球化学模拟研究
19
作者 吴鹏 王驹 +4 位作者 凌辉 周志超 段佳欣 李南 段先哲 《原子能科学技术》 EI CAS CSCD 北大核心 2024年第5期1007-1016,共10页
核能的快速发展产生了大量的高水平放射性废物(简称高放废物),对生态环境和人类健康构成了巨大的威胁,其安全处置已成为国际放射性废物管理的重难点问题。深部地质处置被普遍认为是高放废物最安全可靠、技术上非常可行的处置方法。目前... 核能的快速发展产生了大量的高水平放射性废物(简称高放废物),对生态环境和人类健康构成了巨大的威胁,其安全处置已成为国际放射性废物管理的重难点问题。深部地质处置被普遍认为是高放废物最安全可靠、技术上非常可行的处置方法。目前,我国已启动了甘肃北山新场高放废物地质处置地下实验室的建设,放射性元素铀在深部地下水中的形态分布及其影响因素从微观层面能为北山深地质处置性能评价提供基础数据,但尚不明晰,亟需开展相关地球化学模拟研究。基于PHREEQC中的llnl.dat数据库,添加NEA-TDB和ThermoChimie数据库中U(Ⅵ)的热力学数据,使用地球化学模拟软件PHREEQC.v3和PhreePlot.v11对铀在我国甘肃北山新场高放废物地质处置地下实验室场址BS28孔深部地下水中的赋存形态及分布进行了模拟计算,旨在厘清铀在北山深部地下水中的赋存形态,探讨pH、pE以及Ca^(2+)与HCO_(3)^(-)浓度比对铀在北山深部地下水中形态分布的影响。模拟结果表明,在该深部地下水环境下,铀主要以六价的形式存在,Ca_(2)UO_(2)(CO_(3))_(3)(aq)和CaUO_(2)(CO_(3))_(3)^(2-)是主要的赋存形态,其占比分别为84.14%和15.16%。受氧化还原氛围的影响,铀的价态在pE<1时逐渐由U(Ⅵ)转变为U(Ⅳ),且在pE=-1~1时,UO_(2)(s)和可溶性碳酸铀酰络合物可同时存在。Ca^(2+)与HCO_(3)^(-)的浓度比低倾向于形成CaUO_(2)(CO_(3))_(3)^(2-),浓度比高易于形成Ca_(2)UO_(2)(CO_(3))_(3)(aq)。Ca^(2+)-UO_(2)^(2+)-CO_(3)^(2)三元体系很大程度上会影响铀在北山深部地下水的溶解度和迁移能力。本研究结果将有助于查明铀在北山花岗岩裂隙中的迁移和吸附机理。 展开更多
关键词 高放废物 铀赋存形态 深部地下水 地球化学模拟 甘肃北山新场
下载PDF
深层地下水人工回补的国际经验及对我国的启示
20
作者 马蒙 吴初 +3 位作者 曹文庚 赵勇 吴文勇 Yan Zheng 《中国水利》 2024年第7期34-39,共6页
地下水人工回补是一种主动向含水层进行补给,以便后续进行开采或获取环境效益的水处理综合方法。介绍了地下水人工回补的关键要素、主要回补方式,以及地下水人工回补可持续性评价体系。结合澳大利亚、英国、美国等发达国家深层地下水人... 地下水人工回补是一种主动向含水层进行补给,以便后续进行开采或获取环境效益的水处理综合方法。介绍了地下水人工回补的关键要素、主要回补方式,以及地下水人工回补可持续性评价体系。结合澳大利亚、英国、美国等发达国家深层地下水人工回补典型案例,介绍了国外地下水人工回补的先进经验和特色做法,从项目实施、科学研究、标准管理等方面为我国开展深层地下水人工回补提供建议。 展开更多
关键词 深层地下水 地下水人工回补 可持续性评价 国外实践经验
下载PDF
上一页 1 2 29 下一页 到第
使用帮助 返回顶部