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Modelling and development of recycled water conditioning of copper-molybdenum ores processing 预览
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作者 Irina Pestriak Valery Morozov Erdenetuya Otchir 《矿业科学技术学报:英文版》 CSCD 2019年第2期313-317,共5页
Current use of enrichment and processing technologies of ores requires the introduction of closed circuits of water treatment.A decrease in technological properties is caused by accumulations of ion-molecular componen... Current use of enrichment and processing technologies of ores requires the introduction of closed circuits of water treatment.A decrease in technological properties is caused by accumulations of ion-molecular components in the circulating water.The objective of the simulation is to determine the maximum allowable concentrations of ions and molecules as well as the choice of conditions for deposition or adsorption.First of all,our examinations decrease the concentration of copper ions and fatty acids in the circulating water.By pre-mixing water with the highest concentration of these ions,a reduction of copper ion and fatty acid concentrations in the recycled water occurs.The results do not only ensure the achievement of the maximum permitted concentration(MPC)of copper and iron,significantly reducing the amount of oxidized copper,they also make it possible to use the united sewage as current water for the flotation process.Mixing and adding filtrate of tailings,discharges of urban wastewater treatment and effluent of ash pit of thermal power stations(TPS)to recycled water causes an increase in the capacity of the enrichment plant by 15-17%. 展开更多
关键词 TAILINGS RECYCLING WATER Closed cycle Urban waste WATER CONDITIONING FLOTATION of ORE Natural WATER
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Impact of environmental variables on spatial and seasonal internal phosphorus loading in a mesoeutrophic lake 预览
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作者 Katarzyna Kowalczewska-Madura Ryszard Goldyn +1 位作者 Julia Bogucka Katarzyna Strzelczyk 《国际泥沙研究:英文版》 SCIE 2019年第1期14-26,共13页
Strzeszynskie Lake was formerly a slightly eutrophic(meso-eutrophic)water body.The aim of the current research was to define variables on both spatial and seasonal internal phosphorus loading from bottom sediments at ... Strzeszynskie Lake was formerly a slightly eutrophic(meso-eutrophic)water body.The aim of the current research was to define variables on both spatial and seasonal internal phosphorus loading from bottom sediments at five stations located in zones varying in depth,oxygenation,macrophyte presence,and uses of the neighboring catchment area.Ex situ experiments done with the use of intact bottom sediment cores have shown that the highest phosphorus release occurred in the deepest part of the lake and reached 3.6 mg P/m2d under anoxic conditions during summer thermal stratification.In turn,the internal loading from littoral sediments,which were well aerated all year round,was clearly lower.Furthermore,phosphorus accumulation in the bottom sediment was observed to reach a maximum of 1.45 mg P/m2 d in autumn.A comparison of the internal loading intensity in lake zones with different land uses of the neighboring catchment area has shown slightly higher values at stations adjacent to the forest catchment area than those used for recreation.Changes in the land use of the catchment area of Strzeszynskie Lake,especially the increase in impermeable surfaces,have led to an increased inflow of external loads after heavy rains,resulting in deterioration in water quality and a delayed increase in internal loading. 展开更多
关键词 BOTTOM sediments INTERSTITIAL WATER BOTTOM WATER Internal LOADING Sediment-water interface
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Impact of polymer mixtures on the stabilization and erosion control of silty sand slope
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作者 YANG Qing-wen PEI Xiang-jun HUANG Run-qiu 《山地科学学报:英文版》 SCIE CSCD 2019年第2期470-485,共16页
Silty sand can be prone to erosion because it is short of stability cementation materials. In recent years, various emerging soil stabilizers, especially natural organic substance and polymer, have been used to improv... Silty sand can be prone to erosion because it is short of stability cementation materials. In recent years, various emerging soil stabilizers, especially natural organic substance and polymer, have been used to improve soil strength, water stability and ability of erosion resistance. In this study, a new type of soil stabilization additive modified carboxymethyl cellulose(M-CMC), consisting of carboxymethyl cellulose(CMC) and polyacrylamide(PAM), was developed for stabilization treatment of silty sand. A series of laboratory tests were conducted to evaluate the performance of M-CMC application on shear strength, permeability, water susceptibility and microstructure of the silty sand soil treated with additive concentration range of 0%-1.3%. Moreover, rainfall simulation experiments were conducted to evaluate the effect of M-CMC on the erosion control of silty sand which compacted soil in a large-sized runoff(1 m~2) plots. Test plot which treated with 1.1% concentration of soil stabilizer and control plot which treated with same amount of water were cured outdoor for 50 days before rainfall simulation test. Rainfall intensity was applied at 120 mm·h-1 for 60 min. Finally, a field test is performed in order to assess the practical application effect of silty sand with 1.1% M-CMC. In general, the results showed that an increase of the concentration of M-CMC resulted in an improvement in water susceptibility and shear strength but a decrease in the infiltration rate. Internal friction angle of the treated soil remarkably increased under a low M-CMC concentration(less than 0.7%), while cohesion of them sharply increased under a relatively high M-CMC concentration(larger than 0.7%). Water susceptibility of the treated samples was improved remarkably under a relatively high M-CMC concentration(larger than 0.7%). Permeability coefficient of them decreased significantly when the M-CMC concentration was increased from 0 to 0.5% and, then, from 0.9% to 1.3%. Based on the images obtained from a scanning electron microscopy( 展开更多
关键词 Soil STABILIZATION WATER SUSCEPTIBILITY permeability EROSION WATER RETENTION CEMENTATION
Influence of reclaimed water discharge on the dissemination and relationships of sulfonamide, sulfonamide resistance genes along the Chaobai River, Beijing
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作者 Ning Zhang Xiang Liu +6 位作者 Rui Liu Tao Zhang Miao Li Zhuoran Zhang Zitao Qu Ziting Yuan Hechun Yu 《中国环境科学与工程前沿:英文版》 SCIE EI CAS CSCD 2019年第1期87-98,共12页
Reclaimed water represents an important source of antibiotics and antibiotic resistance genes, threatening the ecological safety of receiving environments, while alleviating water resource shortages. This study invest... Reclaimed water represents an important source of antibiotics and antibiotic resistance genes, threatening the ecological safety of receiving environments, while alleviating water resource shortages. This study investigated the dissemination of sulfonamide (SAs), sulfonamide resistance genes (SRGs), and class one integrons (intl1) in the surface water of the recharging area of the Chaobai River. The three antibiotics sulfamethoxazole, trimethoprim, and sulfadiazine had the highest abundance. The highest absolute abundances were 2.91×10^6, 6.94×10^6, and 2.18×10^4 copies/mL for sul1, sul2, and intl 1 at the recharge point, respectively. SRGs and intl1 were widespread and had high abundance not only at the recharging point, but also in remote areas up to 8 km away. Seasonal variations of SRGs abundance followed the order of summer>autumn>spring>winter. Significant correlations were found between SRGs and intl1 (a = 0.887 and 0.786, p<0.01), indicating the potential risk of SRGs dissemination. Strong correlations between the abundance of SRGs and environmental factors were also found, suggesting that appropriate environmental conditions favor the spread of SRGs. The obtained results indicate that recharging with reclaimed water causes dissemination and enrichment of SAs and SRGs in the receiving river. Further research is required for the risk assessment and scientific management of reclaimed water. 展开更多
关键词 SULFONAMIDE RESIDUES SULFONAMIDE resistance genes Reclaimed WATER RECHARGE Surface WATER Class one INTEGRONS
干法氟化铝能源利用分析 预览
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作者 裴耀祖 李彩妍 唐惕 《云南化工》 CAS 2019年第1期96-97,99共3页
干法氟化铝生产工艺以流程短、工艺紧凑、原料利用率高、能耗低、环境污染少、产品质量好、市场竞争力强等特点而被广泛推广。然而,干法氟化铝在生产过程中,每天需要大量的新鲜水来提供系统的正常运行。但水资源为不可再生资源,全世界... 干法氟化铝生产工艺以流程短、工艺紧凑、原料利用率高、能耗低、环境污染少、产品质量好、市场竞争力强等特点而被广泛推广。然而,干法氟化铝在生产过程中,每天需要大量的新鲜水来提供系统的正常运行。但水资源为不可再生资源,全世界能被人类利用的淡水资源只占0.00768%。因此,做好水平衡工作,合理利用水资源迫在眉睫。 展开更多
关键词 干法氟化铝 水平衡
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超声波流量计在企业水平衡测试中的应用与分析 预览
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作者 王征 《科技风》 2019年第7期244-245,共2页
企业水平衡测试是实行工业节水的一项行之有效的基本方法。以一个化工企业为例,通过企业水平衡测试掌握企业厂区内各个单元具体用水情况。在水平衡测试工作中选用超声波流量计来协助测试工作,提升测试工作的效率与准确度,并同时优化了... 企业水平衡测试是实行工业节水的一项行之有效的基本方法。以一个化工企业为例,通过企业水平衡测试掌握企业厂区内各个单元具体用水情况。在水平衡测试工作中选用超声波流量计来协助测试工作,提升测试工作的效率与准确度,并同时优化了企业的节水长效管理。 展开更多
关键词 超声波 流量计 水平衡测试 工业节水
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Comparative evaluation for catalytic gasification of petroleum coke and asphaltene in subcritical and supercritical water 预览
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作者 Rachita Rana Sonil Nanda +3 位作者 Aimee Maclennan Yongfeng Hu Janusz A. Kozinski Ajay K. Dalai 《能源化学:英文版》 SCIE EI CAS CSCD 2019年第4期107-118,共12页
Subcritical and supercritical water gasification of petroleum coke and asphaltene was performed at variable temperatures (350-650℃),feed concentrations (15-30 wt%) and reaction times (15-60 min).Nickel-impregnated ac... Subcritical and supercritical water gasification of petroleum coke and asphaltene was performed at variable temperatures (350-650℃),feed concentrations (15-30 wt%) and reaction times (15-60 min).Nickel-impregnated activated carb on (Ni/AC) was synr hesized as a catalyst for en hancing syngas yields at optimal gasification conditions (650℃,15 wt% and 60 min).Structural chemistry of precursors and chars developed at different gasification temperatures was studied using physicochemical and synchrotronbased approaches such as carbon-hydrogen-nitrogen-sulfur (CHNS) analysis,thermogravimetric and differential thermogravimetric analysis (TGA/DTA),scanning electron microscopy (SEM),Fourier-Transform Infrared spectroscopy (FTIR),Raman spectroscopy,X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS).Asphaltene testified to be a better precursor for catalytic hydrothermal gasification leading to 11.97 mmol/g of total gas yield compared to petroleum coke (8.04 mmol/g).In particular,supercritical water gasification using 5 wt% Ni/AC at 650℃ with 15 wt% feed concentration for 60 min resulted in 4.17 and 2.98 mmol/g of H2 from asphaltene and petroleum coke,respectively.Under the same conditions,the respective CH4 yields from catalytic gasification of asphaltene and petroleum coke were 2.54 and 1.07 mmol/g.Nonetheless,asphaltene also seemed to an attractive feedstock for the production of highly aromatic chars through hydrothermal gasification. 展开更多
关键词 ASPHALTENE Petroleum coke SUBCRITICAL WATER SUPERCRITICAL WATER GASIFICATION CHAR
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Temperature and silicate are significant driving factors for the seasonal shift of dominant diatoms in a drinking water reservoir 预览
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作者 ZHANG Yun PENG Chengrong +4 位作者 WANG Jun HUANG Shun HU Yao ZHANG Jinli LI Dunhai 《海洋湖沼学报(英文)》 SCIE CAS CSCD 2019年第2期568-579,共12页
The individual or combined eff ect of water temperature and silicate on seasonal shift of dominant diatom species in a drinking water reservoir in China was studied in this paper. These eff ects were analyzed based on... The individual or combined eff ect of water temperature and silicate on seasonal shift of dominant diatom species in a drinking water reservoir in China was studied in this paper. These eff ects were analyzed based on the field investigation of temporal dynamics in species composition and abundance of phytoplankton and environmental factors from September 2015 to August 2016. We firstly found that six dominant diatom species ( Fragilaria nanana , Achnanthidium catenatum , Aulacoseira ambigua , Ulnaria ulna , Cyclotella meneghiniana and Asterionella formosa (Class Bacillariophyceae)), which accounted for 98.7% of the total abundance of diatoms and 46.8% of the total abundance of phytoplankton, showed an obvious seasonal succession. Then significant driving factors for seasonal shift of the dominant diatom species were selected by Redundancy Analysis. The result showed that water temperature and silicate were the main environmental factors aff ecting the growth of diatoms on temporal scales. Next, the regressions of water temperature and silicate and dominant diatom abundance were fitted in Generalized Additive Model separately, and the smoothers of water temperature and diatom species suggested that the dominant diatom species adapted to diff erent optimum temperature ranges, which corresponded with the growth of seasonal changes. A positive linear correlation between silicate and diatom abundance was generated by Generalized Additive Model. Finally, the ordinal controls of water temperature and silicate on the growth of diatoms were analyzed on temporal scales specifically. We suggested that water temperature and silicate controlling the growth of diatoms in order. Diatoms grow well only when the two controlling factors simultaneously satisfy the growth conditions;as limiting factors, the two factors played their respective limiting roles in turn on temporal scales. 展开更多
关键词 DIATOM drinking WATER RESERVOIR seasonal succession SILICATE WATER TEMPERATURE
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河流静水滩区潜流带水交换空间分布模式研究(英文)
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作者 宋进喜 程丹东 +4 位作者 张军龙 张永强 龙永清 张妍 申卫博 《地理学报:英文版》 SCIE CSCD 2019年第3期377-388,共12页
Hyporheic zone(HZ) influences hydraulic and biogeochemical processes in and alongside streams, therefore, investigating the controlling geographic factors is beneficial for understanding the hydrological processes in ... Hyporheic zone(HZ) influences hydraulic and biogeochemical processes in and alongside streams, therefore, investigating the controlling geographic factors is beneficial for understanding the hydrological processes in HZ. Slack water pool (SWP) is an essential micro-topographic structure that has an impact on surface water and groundwater interactions in the HZ during and after high flows. However, only a few studies investigate HZ surface water and groundwater exchange in the SWP. This study used the thermal method to estimate the HZ water exchange in the SWP in a segment of the Weihe River in China during the winter season. The findings show that on the flow-direction parallel to the stream, river recharge dominates the HZ water exchange, while on the opposing flow-direction bank groundwater discharge dominates the water exchange. The water exchange in the opposing flow-direction bank is about 1.6 times of that in the flow-direction bank. The HZ water exchange is not only controlled by flow velocity but also the location and shape of the SWP. Great water exchange amount corresponds to the shape with more deformation. The maximum water exchange within the SWP is close to the river bank where the edge is relatively high. This study provides some guidelines for water resources management during flooding events. 展开更多
关键词 HYPORHEIC WATER exchange thermal method discharge RECHARGE surface water-groundwater interactions
One-year survey of opportunistic premise plumbing pathogens and free-living amoebae in the tap-water of one northern city of China
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作者 Lizhong Liu Xueci Xing +1 位作者 Chun Hu Haibo Wang 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第3期20-31,共12页
In this study, qPCR was used to quantify opportunistic premise plumbing pathogens(OPPPs) and free-living amoebae in 11 tap water samples collected over four seasons from a city in northern China. Results demonstrated ... In this study, qPCR was used to quantify opportunistic premise plumbing pathogens(OPPPs) and free-living amoebae in 11 tap water samples collected over four seasons from a city in northern China. Results demonstrated that the average numbers of gene copies of Legionella spp. and Mycobacterium spp. were significantly higher than those of Aeromonas spp.(p < 0.05). Legionella spp. and Mycobacterium spp. were 100%(44/44) positively detected while P. aeruginosa and Aeromonas spp. were 79.54%(35/44) and 77.27%(34/44) positively detected. Legionella pneumophila was only detected in 4 samples(4/44), demonstrating its occasional occurrence. No Mycobacterium avium or Naegleria fowleri was detected in any of the samples. The average gene copy numbers of target OPPPs were the highest in summer,suggesting seasonal prevalence of OPPPs. Average gene copy numbers of OPPPs in the taps of low-use-frequency were higher than in taps of high-use-frequency, but the difference was not significant for some OPPPs(p > 0.05). Moderate negative correlations between the chlorine concentration and the gene copy numbers of OPPPs were observed by Spearman analysis(rsranged from -0.311 to -0.710, p < 0.05). However, no significant correlations existed between OPPPs and AOC, BDOC, or turbidity. Moderate positive correlations were observed between the target microorganisms, especially for Acanthamoeba spp., through Spearman analysis(p < 0.05). Based on our studies, it is proposed that disinfectant concentration, season, taps with different-use frequency, OPPP species, and potential microbial correlations should be considered for control of OPPPs in tap water. 展开更多
关键词 OPPORTUNISTIC premise PLUMBING pathogens(OPPPs) Free-living amoebae(FLA) Drinking WATER distribution systems(DWDS) Tap-water Quantitative PCR(qPCR)
An experimental study on the influences of water erosion on wind erosion in arid and semi-arid regions
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作者 YANG Huimin ZOU Xueyong +1 位作者 WANG Jing’ai SHI Peijun 《干旱区科学:英文版》 SCIE CSCD 2019年第2期208-216,共9页
Complex erosion by wind and water causes serious harm in arid and semi-arid regions. The interaction mechanisms between water erosion and wind erosion is the key to further our understanding of the complex erosion. Th... Complex erosion by wind and water causes serious harm in arid and semi-arid regions. The interaction mechanisms between water erosion and wind erosion is the key to further our understanding of the complex erosion. Therefore, in-depth understandings of the influences of water erosion on wind erosion is needed. This research used a wind tunnel and two rainfall simulators to investigate the influences of water erosion on succeeding wind erosion. The wind erosion measurements before and after water erosion were run on semi-fixed aeolian sandy soil configured with three slopes(5°, 10° and 15°), six wind speeds(0, 9, 11, 13, 15 and 20 m/s), and five rainfall intensities(0, 30, 45, 60 and 75 mm/h). Results showed that water erosion generally restrained the succeeding wind erosion. At a same slope, the restraining effects decreased as rainfall intensity increased, which decreased from 70.63% to 50.20% with rainfall intensity increased from 30 to 75 mm/h. Rills shaped by water erosion could weaken the restraining effects at wind speed exceeding 15 m/s mainly by cutting through the fine grain layer, exposing the sand layer prone to wind erosion to airflow. In addition, the restraining effects varied greatly among different soil types. The restraining effects of rainfall on the succeeding wind erosion depend on the formation of a coarsening layer with a crust and a compact fine grain layer after rainfall. The findings can deepen the understanding of the complex erosion and provide scientific basis for regional soil and water conservation in arid and semi-arid regions. 展开更多
关键词 WIND EROSION WATER EROSION SANDY soil particle size surface ROUGHNESS wind-water EROSION agriculturalpastoral ECOTONE
Spatial distribution of water-active soil layer along the south-north transect in the Loess Plateau of China
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作者 ZHAO Chunlei SHAO Ming’an +2 位作者 JIA Xiaoxu HUANG Laiming ZHU Yuanjun 《干旱区科学:英文版》 SCIE CSCD 2019年第2期228-240,共13页
Soil water is an important composition of water recycle in the soil-plant-atmosphere continuum.However, intense water exchange between soil-plant and soil-atmosphere interfaces only occurs in a certain layer of the so... Soil water is an important composition of water recycle in the soil-plant-atmosphere continuum.However, intense water exchange between soil-plant and soil-atmosphere interfaces only occurs in a certain layer of the soil profile. For deep insight into water active layer(WAL, defined as the soil layer with a coefficient of variation in soil water content >10% in a given time domain) in the Loess Plateau of China,we measured soil water content(SWC) in the 0.0–5.0 m soil profile from 86 sampling sites along an approximately 860-km long south-north transect during the period 2013–2016. Moreover, a dataset contained four climatic factors(mean annual precipitation, mean annual evaporation, annual mean temperature and mean annual dryness index) and five local factors(altitude, slope gradient, land use, clay content and soil organic carbon) of each sampling site was obtained. In this study, three WAL indices(WALT(the thickness of WAL), WAL-CV(the mean coefficient of variation in SWC within WAL) and WALSWC(the mean SWC within WAL)) were used to evaluate the characteristics of WAL. The results showed that with increasing latitude, WAL-T and WAL-CV increased firstly and then decreased. WAL-SWC showed an opposite distribution pattern along the south-north transect compared with WAL-T and WAL-CV.Average WAL-T of the transect was 2.0 m, suggesting intense soil water exchange in the 0.0–2.0 m soil layer in the study area. Soil water exchange was deeper and more intense in the middle region than in the southern and northern regions, with the values of WAL-CV and WAL-T being 27.3% and 4.3 m in the middle region,respectively. Both climatic(10.1%) and local(4.9%) factors influenced the indices of WAL, with climatic factors having a more dominant effect. Compared with multiple linear regressions, pedotransfer functions(PTFs) from arti?cial neural network can better estimate the WAL indices. PTFs developed by artificial neural network respectively explained 86%, 81% and 64% of the total variations in WAL-T, WAL-SWC and WAL-CV. K 展开更多
关键词 WATER ACTIVE layer soil WATER content REDUNDANCY analysis pedotransfer function artificial neural network LOESS Plateau
Fertirrigation with Low-Pressure Multi-Gate Irrigation Systems in Sugarcane Agroecosystems:A Review
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作者 Arturo GARC′IA-SALDA?NA Ces′areo LANDEROS-S′ANCHEZ +3 位作者 Mar′?a del Refugio CASTA?NEDA-CH′AVEZ Juan Pablo MART′INEZ-D′AVILA Arturo P′EREZ-V′AZQUEZ Eugenio CARRILLO-′AVILA 《土壤圈:英文版》 SCIE CAS CSCD 2019年第1期1-11,共11页
There are very few studies on the application of fertilizers through irrigation water(fertirrigation) using a multi-gate irrigation system in sugarcane AES. Through fertirrigation, the application of fertilizers can b... There are very few studies on the application of fertilizers through irrigation water(fertirrigation) using a multi-gate irrigation system in sugarcane AES. Through fertirrigation, the application of fertilizers can be simplified, and their distribution uniformity in sugarcane fields improved. This paper provides an overview of the state of the art regarding fertirrigation with multi-gate irrigation in sugarcane agroecosystems(AES). In order to systematize, organize, and discuss the scientific data on fertirrigation with low-pressure multi-gate irrigation systems in sugarcane AES, bibliographic material from the following full-text scientific journal databases was screened: the Elsevier Science Direct Freedom Collection, Springer Link, and the International Society for Horticultural Science. Next,a matrix of keywords was used to analyze the interrelationships among the available literature, current issues, and the recent findings.We conclude that development of fertirrigation technologies with low-pressure multi-gate irrigation is much needed. 展开更多
关键词 climate change crop WATER requirement FERTILIZER application FERTILIZER distribution UNIFORMITY SUGARCANE industry WATER use efficiency
2017年青海省互助县饮水型氟中毒防治状况调查
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作者 蒲光兰 孟献亚 +8 位作者 白生录 陈黎林 周昕 鲁青 沈洪婷 何多龙 马静 魏生英 张强 《中华地方病学杂志》 CAS CSCD 北大核心 2019年第1期50-53,共4页
目的 了解青海省互助县饮水型氟中毒病区改水工程运行情况及病情变化趋势,评价防控措施效果。 方法 2017年,选择互助县7个乡(镇)、60个饮水型氟中毒历史病区村作为调查点,调查病区村人口学资料。对已改水的病区村,调查改水工程运转情况... 目的 了解青海省互助县饮水型氟中毒病区改水工程运行情况及病情变化趋势,评价防控措施效果。 方法 2017年,选择互助县7个乡(镇)、60个饮水型氟中毒历史病区村作为调查点,调查病区村人口学资料。对已改水的病区村,调查改水工程运转情况,并采集1份末梢水水样测定水氟含量;对尚未改水的病区村,按照东、西、南、北、中5个方位在饮用水源各采集1份水样,测定水氟含量。对调查村90%以上的8-12岁儿童进行氟斑牙检查。根据历史资料,选出儿童病情较重的1个病区村,选择25岁及以上且在当地居住5年以上人群50人,进行氟骨症临床和X线检查,同时采集尿样,进行尿氟含量的检测。 结果 7个乡(镇)、60个病区村中6个村已搬迁,截止2017年历史饮水型氟中毒病区村为54个,54个病区村已全部改水。共调查改水工程16个,其中小型改水工程6个,占37.50%,大型改水工程10个,占62.50%;正常运转工程16个,占100.00%;水氟含量合格工程16个,合格率为100.00%,水氟含量范围为0.10-0.66 mg/L,覆盖人口16.084 6万人。共检查8-12岁儿童2 399人,检出氟斑牙患者117例,检出率为4.88%,氟斑牙指数为0.13。其中极轻度89例,占3.71%;轻度21例,占0.88%;中度7例,占0.29%;无重度病例。25岁及以上成人氟骨症临床检查68人,检出轻度氟骨症12人,检出率为17.65%;X线拍片检查46人,检出轻度1人,检出率为2.17%;临床和X线检查均未检出中度及以上氟骨症患者。检测成人尿样50份,尿氟几何均数为0.72 mg/L。 结论 互助县改水工程运行良好,无重度儿童氟斑牙和成人氟骨症患者,饮水型氟中毒防治工作成效显著,应继续加强改水工程与病情监测,彻底控制饮水型氟中毒流行。 展开更多
关键词 氟中毒 结果评价
Co9S8 nanowires@NiCo LDH nanosheets arrays on nickel foams towards efficient overall water splitting
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作者 Jingan Yan Ligang Chen Xin Liang 《科学通报:英文版》 SCIE EI CSCD 2019年第3期158-165,共8页
Water electrolysis is considered to be an effective way to fabricate hydrogen, and it is desirable to find the highly efficient, inexpensive and good durability bifunctional electrocatalysts for overall water splittin... Water electrolysis is considered to be an effective way to fabricate hydrogen, and it is desirable to find the highly efficient, inexpensive and good durability bifunctional electrocatalysts for overall water splitting.In this paper, we synthesis a unique structured catalyst that was composed by Co9S8 nanowires and nickel cobalt layered double hydroxide(NiCo-LDH) nanosheets. The ultrathin nanosheets decorated on the Co9S8 nanoarrays offer large specific surface area, numerous active edge sites and excellent electrical conductivity for fast electron transfer. Benefiting from this heterogeneous structure, the catalyst presents excellent catalytic performance in alkaline media. It requires 168 mV to reach current density of 10 mA/cm2 for HER and 278 m V to reach current density of 30 mA/cm2 for OER. When used as electrode in a homemade two-electrode system, it only needs t a voltage of 1.63 V to achieve current densities of 10 mA/cm2, which proves Co9S8@NiCo LDH/NF as a superior bifunctional catalyst for water splitting. 展开更多
关键词 Co9S8 NANOWIRE NiCo LDH Hydrogen EVOLUTION REACTION Oxygen EVOLUTION REACTION Water splitting
Effect of an eco-friendly o/w emulsion stabilized with amphiphilic sodium alginate derivatives on lambda-cyhalothrin adsorption-desorption on natural soil minerals
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作者 Yang Peng Dunchao Xiao +6 位作者 Gaobo Yu Yuhong Feng Jiacheng Li Xinyu Zhao Yiyuan Tang Longzheng Wang Quan Zhang 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第4期230-238,共9页
The effects of amphiphilic O/W emulsions,stabilized by the alkyl polyglycoside(APG)or cholesterol-grafted sodium alginate(CSAD)/APG systems,on lambda-cyhalothrin adsorption/desorption mechanisms on natural soil minera... The effects of amphiphilic O/W emulsions,stabilized by the alkyl polyglycoside(APG)or cholesterol-grafted sodium alginate(CSAD)/APG systems,on lambda-cyhalothrin adsorption/desorption mechanisms on natural soil minerals(i.e.,illite and kaolinite)were investigated.Sorption and desorption of lambda-cyhalothrin onto soil minerals was studied via batch equilibration to give insight into the adsorption equilibrium,kinetics,and thermodynamics of lambda-cyhalothrin adsorption onto minerals.The results indicate the following:(i)The adsorption processes for the APG system and CSAD/APG system include:rapid adsorption,slow adsorption,and adsorption equilibrium.The adsorption kinetics of pesticide on illite and kaolinite are in accordance with the Ho and McKay model,and the adsorption isotherm conforms to the Freundlich model.In addition,the adsorption processes of pesticide for the two systems on minerals were spontaneous and feasible(ΔG0<0),endothermic(ΔH0>0),and mainly involved chemical bonding(ΔH0>60).(ii)The equilibrium adsorption percentages of the pesticide on illite for the APG system and CSAD/APG system were 42.4%and 64.8%,and the corresponding equilibrium adsorption percentages on kaolinite were 40.8%and 61.8%,respectively.Moreover,the pesticide adsorption rate K2-CSAD/APGwas faster than K2-APG,and its adsorption capacity Kf-CSAD/APG was greater than Kf-APG.Meanwhile,the pesticide desorption Kfdin the CSAD/APG system was smaller than that in the APG system.As a result,this eco-friendly O/W emulsion based on amphiphilic sodium alginate derivatives might provide a green pesticide formulation,since it could reduce the amount of lambda-cyhalothrin entering aquatic systems to threaten non-target fish and invertebrate species. 展开更多
关键词 Sodium ALGINATE DERIVATIVES Alkyl polyglycoside Synergetic EFFECT Green pesticide Water pollution remediation LAMBDA-CYHALOTHRIN
Effects of rough surface on sound propagation in shallow water
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作者 刘若芸 李整林 《中国物理B:英文版》 SCIE EI CAS CSCD 2019年第1期423-430,共8页
Underwater acoustic applications depend critically on the prediction of sound propagation, which can be significantly affected by a rough surface, especially in shallow water. This paper aims to investigate how random... Underwater acoustic applications depend critically on the prediction of sound propagation, which can be significantly affected by a rough surface, especially in shallow water. This paper aims to investigate how randomly fluctuating surface influences transmission loss(TL) in shallow water. The one-dimension wind-wave spectrum, Monterey–Miami parabolic equation(MMPE) model, Monte Carlo method, and parallel computing technology are combined to investigate the effects of different sea states on sound propagation. It is shown that TL distribution properties are related to the wind speed,frequency, range, and sound speed profile. In a homogenous waveguide, with wind speed increasing, the TLs are greater and more dispersive. For a negative thermocline waveguide, when the source is above the thermocline and the receiver is below that, the effects of the rough surface are the same and more significant. When the source and receiver are both below the thermocline, the TL distributions are nearly the same for different wind speeds. The mechanism of the different TL distribution properties in the thermocline environment is explained by using ray theory. In conclusion, the statistical characteristics of TL are affected by the relative roughness of the surface, the interaction strength of the sound field with the surface, and the changes of propagating angle due to refraction. 展开更多
关键词 SURFACE FLUCTUATION SHALLOW water TRANSMISSION LOSS STATISTICAL characteristics
浅谈黄河主河槽水中桩基钢护筒施工 预览
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作者 时伟 《价值工程》 2019年第3期86-89,共4页
通过东明黄河大桥水中桩基钢护筒的施工,了解黄河主河槽段桩基钢护筒施工过程的控制,了解深水、流水中长桩的钢护筒施工工艺,了解施工中的质量要点及质量控制。
关键词 钢护筒 黄河主河槽 水中 施工工艺
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Determination of water equivalent ratio for some dosimetric materials in proton therapy using MNCPX simulation tool 预览
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作者 Reza Bagheri Alireza Khorrami Moghaddam +2 位作者 Bakhtiar Azadbakht Mahmoud Reza Akbari Seyed Pezhman Shirmardi 《核技术:英文版》 SCIE CAS CSCD 2019年第2期19-28,共10页
The water equivalent ratio(WER)was calculated for polypropylene(PP),paraffin,polyethylene(PE),polystyrene(PS),polymethyl methacrylate(PMMA),and polycarbonate materials with potential applications in dosimetry and medi... The water equivalent ratio(WER)was calculated for polypropylene(PP),paraffin,polyethylene(PE),polystyrene(PS),polymethyl methacrylate(PMMA),and polycarbonate materials with potential applications in dosimetry and medical physics.This was performed using the Monte Carlo simulation code,MCNPX,at different proton energies.The calculated WER values were compared with National Institute of Standards and Technology(NIST)data,available experimental and analytical results,as well as the FLUKA,SRIM,and SEICS codes.PP and PMMA were associated with the minimum and maximum WER values,respectively.Good agreement was observed between the MCNPX and NIST data.The biggest difference was 0.71%for PS at 150 MeV proton energy.In addition,a relatively large positive correlation between the WER values and the electron density of the dosimetric materials was observed.Finally,it was noted that PE presented the most analogous Depth Dose Characteristics to liquid water. 展开更多
关键词 WATER EQUIVALENT RATIO PROTON therapy Dosimetric MATERIALS MCNPX code
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The influence of the NCO/OH ratio and the 1,6-hexanediol/ dimethylol propionic acid molar ratio on the properties of waterborne polyurethane dispersions based on 1,5-pentamethylene diisocyanate
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作者 Jiao Feng Qiuhao Lu +2 位作者 Weimin Tan Kequan Chen Pingkai Ouyang 《化学科学与工程前沿:英文版》 EI CAS CSCD 2019年第1期80-89,共10页
1,5-Pentamethylene diisocyanate, a novel aliphatic diisocyanate formed from bio-based 1,5-pentamethylenediamine, has been used as a hard segmented material to synthesize polyurethane. In this study, several waterborne... 1,5-Pentamethylene diisocyanate, a novel aliphatic diisocyanate formed from bio-based 1,5-pentamethylenediamine, has been used as a hard segmented material to synthesize polyurethane. In this study, several waterborne polyurethane (WPU) dispersions have been successfully prepared by a prepolymer process from 1,5-pentamethylene diisocyanate poly(polyether) with different NCO/OH ratios and 1,6-hexanediol (HDO)/dimethylol propionic acid (DMPA) molar ratios. The Fourier transfonn infrared (FTIR) spectra, thermogravimetric analysis, differential scanning calorimetry, X-ray diffiraction, and a mechanical tensile test were used to investigate the structures, thermal stability, phase separation, crystallinity, mechanical properties, and adhesive performance of the WPU dispersions. The FTIR results indicate that the degree of hydrogen bonding and the numbers of urea groups increase as the NCO/OH ratio and HDO/DMPA molar ratio increase. Furthermore, the phase separation increases and the thermal stability decreases as the NCO/OH ratio increases or the HDO/DMPA molar ratio decreases. Finally, WPU3.0-2.4 (NCO/OH = 3, HDO/DMPA = 2.4) exhibits a maximum tensile strength and shear strength, pointing to its possible use as an adhesive. These results could provide a very valuable reference for industrial applications of WPU. 展开更多
关键词 1 5-pentamethylene DIISOCYANATE POLYURETHANE water BASED
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