检索结果-南通市图书馆

Tracing suspended and bed sediments during high and low water periods using geochemical characteristics-Case study:Vazrood watershed,northern Iran

引用

Journal of Mountain Science 2024年第2期21卷 470-483页

作者： KARIMI Nabiyeh GHOLAMI Leila KAVIAN Ataollah KHALEDI DARVISHAN Abdulvahed Department of Watershed Management Faculty of Natural ResourcesSari Agricultural Sciences and Natural Resources UniversitySari ***Iran Department of Watershed Management engineering Faculty of Natural ResourcesTarbiat Modares UniversityNoor ***Iran

Complete and comprehensive information about sediment dynamic and identification of hotspots of sediment production and transport are necessary for understanding the erosion processes and increasing the efficiency of soil and water conservation *** studies used the sediment fingerprint techniques to investigate the contribution of different sources in suspended and bed sediment yield of the ***,the contribution of various land use/land covers in suspended and bed sediment yield for the great Caspian Sea basin is in an aura of ambiguity and the present study was conducted to gather information about an important part of this area in northern Iran,where rangelands are located upstream of Hyrcanian forests and dense agricultural lands are located *** surface soil of different land use/land covers including forest,rangeland,agriculture and streambank lands were sampled in 30 *** and bed sediments were sampled in the watershed outlet in two high and low water *** characteristics of soil and sediment samples containing 59 elements were measured using ICP-OES GBC *** reliable and suitable tracers from 59 elements were then selected using Range test,Kruskal-Wallis and Discriminant Function Analysis,respectively,in FingerPro package of R *** results showed that for suspended sediment,streambank and rangeland had the highest contributions of 86.2%and 47.5%,respectively,in two high and low water *** bed sediment,in two high and low water periods,rangeland and streambank had the highest contributions of 73.8%and 84.4%,*** use change and especially human activities such as agriculture,road construction and development of residential areas along the main river riparian zone has led to a significant increase in suspended and bed sediments.

关键词： Caspian Sea basin FingerPro Geochemistry Sediment transport Tracer combination

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Annual growth of Fagus orientalis is limited by spring drought conditions in Iran’s Golestan Province

引用

Journal of Forestry Research 2024年第1期35卷 128-142页

作者： Khalil Ghorbani Jahangir Mohammadi Laleh Rezaei Ghaleh Department of Water engineering Faculty of Water and Soil EngineeringGorgan University of Agricultural Sciences and Natural ResourcesGorganIran Department of Forestry Gorgan University of Agricultural Sciences and Natural ResourcesGorganIran Department of Water engineering Faculty of AgricultureUrmia UniversityUrmiaIran

Due to the lack of a uniform and accurate defi-nition of‘drought’,several indicators have been introduced based on different variables and methods,and the efficiency of each of these is determined according to their relationship with *** relationship between two drought indices,SPI(standardized precipitation index)and SPEI(standard-ized precipitation-evapotranspiration index)in different sea-sons was investigated using annual rings of 15 tree samples to determine the effect of drought on the growth of oriental beech(Fagus orientalis Lipsky)in the Hyrcanian forests of northern *** different evapotranspiration calcula-tion methods were evaluated on SPEI efficiency based on Hargreaves-Samani,Thornthwaite,and Penman-Monteith methods using the step-by-step M5 decision tree regression *** results show that SPEI based on the Penman-Monteith in a three-month time scale(spring)had similar temporal changes and a better relationship with annual tree rings(R^(2)=0.81)at a 0.05 significant *** change and a decreasing trend in the time series of annual tree rings are similar to the variation in the SPEI based on the Penman-Monteith *** affecting evapotranspiration,temperature,wind speed,and sunshine hours(used in the Penman-Monteith method),increased but precipitation *** non-linear modeling methods,SPEI based on Penman-Monteith best illustrated climate changes affecting tree growth.

关键词： Climate change Drought index Hyrcanian forests SPEI'Annual growth rings Fagus orientalis

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Structural properties of residual carbon in coal gasification fine slag and their influence on flotation separation and resource utilization:A review

引用

International Journal of Minerals,Metallurgy and Materials 2024年第2期31卷 217-230页

作者： Rui Han Anning Zhou Ningning Zhang Kaiqiang Guo Mengyan Cheng Heng Chen Cuicui Li College of Chemistry and chemical engineering Xi’an University of Science and TechnologyXi’an 710054China Key Laboratory of Coal resources Exploration and Comprehensive Utilization Ministry of Natural Resources of ChinaXi’an 710021China

Coal gasification fine slag(FS)is a typical solid waste generated in coal *** current disposal methods of stockpil-ing and landfilling have caused serious soil and ecological *** recovery and the high-value utilization of residual carbon(RC)in FS are the keys to realizing the win-win situation of the coal chemical industry in terms of economic and environmental *** structural properties,such as pore,surface functional group,and microcrystalline structures,of RC in FS(FS-RC)not only affect the flotation recovery efficiency of FS-RC but also form the basis for the high-value utilization of *** this paper,the characteristics of FS-RC in terms of pore structure,surface functional groups,and microcrystalline structure are sorted out in accordance with gasification type and FS particle *** reasons for the formation of the special structural properties of FS-RC are analyzed,and their influence on the flotation separation and high-value utilization of FS-RC is *** methods based on the pore structural characterist-ics of FS-RC,such as ultrasonic pretreatment-pore-blocking flotation and pore breaking-flocculation flotation,are proposed to be the key development technologies for improving FS-RC recovery in the *** design of low-cost,low-dose collectors containing polar bonds based on the surface and microcrystalline structures of FS-RC is proposed to be an important breakthrough point for strengthening the flotation efficiency of FS-RC in the *** high-value utilization of FS should be based on the physicochemical structural proper-ties of FS-RC and should focus on the environmental impact of hazardous elements and the recyclability of chemical waste liquid to es-tablish an environmentally friendly utilization *** review is of great theoretical importance for the comprehensive understand-ing of the unique structural properties of FS-RC,the breakthrough of the technological bottleneck in the e

关键词： coal gasification fine slag residual carbon pore structure surface functional groups microcrystalline structure flotation sep-aration resource utilization

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Effective separation of coal gasification fine slag: Role of classification and ultrasonication in enhancing flotation

引用

International Journal of Mining Science and Technology 2024年第6期34卷 867-880页

作者： Rui Han Anning Zhou Ningning Zhang Zhen Li Mengyan Cheng Xiaoyi Chen Tianhao Nan College of Chemistry and chemical engineering Xi’an University of Science and TechnologyXi’an 710054China Key Laboratory of Coal resources Exploration and Comprehensive Utilization Ministry of Natural Resources of ChinaXi’an 710021China

Effective separation of residual carbon and ash is the basis for the resource utilization of coal gasification fine slag(CGFS).The conventional flotation process of CGFS has the bottlenecks of low carbon recovery and high collector *** order to address these issues,CGFS sample taken from Shaanxi,China was used as the study object in this paper.A new process of size classification-fine grain ultrasonic pretreatment flotation(SC-FGUF)was proposed and its separation effect was compared with that of wholegrain flotation(WGF)as well as size classification-fine grain flotation(SC-FGF).The mechanism of its enhanced separation effect was revealed through flotation kinetic fitting,flotation flow foam layer stability,particle size composition,surface morphology,pore structure,and surface chemical property *** results showed that compared with WGF,pre-classification could reduce the collector dosage by 84.09%and the combination of pre-classification and ultrasonic pretreatment could increase the combustible recovery by 17.29%and up to 93.46%.The SC-FGUF process allows the ineffective adsorption of coarse residual carbon to collector during flotation stage to be reduced by pre-classification,and the tightly embedded state of fine CGFS particles is disrupted and surface oxidizing functional group occupancy was reduced by ultrasonic pretreatment,thus carbon and ash is easier to be separated in the flotation *** addition,some of the residual carbon particles were broken down to smaller sizes in the ultrasonic pretreatment,which led to an increase in the stability of flotation flow foam layer and a decrease in the probability of detachment of residual carbon particles from the ***,SCFGUF could increase the residual carbon recovery and reduce the flotation collector dosage,which is an innovative method for carbon-ash separation of CGFS with good application prospect.

关键词： Coal gasification fine slag Size classification Ultrasonic pretreatment Flotation Carbon recovery

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Recovery of scandium from silicate minerals by high-pressure leaching in sulfuric acid

引用

Journal of Rare Earths 2024年第7期42卷 1375-1384,I0007页

作者： Peng Yan Xiaoming Chen Likun Gao Bo Yang faculty of Metallurgical and Energy engineering Kunming University of Science and TechnologyKunming650093China faculty of Land resources engineering Kunming University of Science and TechnologyKunming650093China School of Chemistry and chemical engineering Kunming UniversityKunming650214China

This study investigated the leaching of scandium from a Sc-bearing silicate *** Sc concentrate obtained by beneficiation pre-enrichment has 1.03×10^(−4) wt%Sc and 14.66 wt%*** main Sc-bearing minerals are limonite,chlorite,sericite,and hornblende,in the form of ***-pressure leaching(HPL)with sulfuric acid(98 wt%)and NaF was used to dispose this *** Sc leaching efficiency of 91.82%was obtained under the optimum conditions,which are pressure of 5.0×10^(5) Pa,A/O value of 1.1,L/S value of 1.8,NaF dosage of 2 wt%,at 130℃ for 6 *** X-ray diffraction(XRD)and scanning electron microscopy(SEM)results show that the residue is mainly quartz phase in the multihole *** with ordinary leaching for silicate,high-pressure leaching has significant advantages in saving acid and energy consumption.

关键词： Silicate minerals Scandium High-pressure Leaching Concentrated sulfuric acid Rare earths

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Extract lithium from clay-type lithium ore by mixed acid and its mechanism Author links open overlay panel

引用

Particuology 2024年第8期91卷 323-332页

作者： Wuchang Zhou Ruiqi Xie Xiong Tong Xian Xie Yang Liu Zhihui Zhao faculty of Land Resource engineering Kunming University of Science and TechnologyKunming650093China Technology Innovation Center for Comprehensive Utilization of Strategic Mineral resources Ministry of Natural ResourcesChengdu610041China National&Regional engineering Research Center for Green comprehensive Utilization of Tailing resources from Metal Minerals Kunming650093China

A roasting-leaching test was carried out for the efficient utilization of clay-type lithium ore in the central region of Yunnan *** test used the mixed acid of sulfuric acid and phosphoric acid as the leaching *** the conditions of roasting temperature of 600℃,roasting time of 1 h,liquid-solid ratio of 5:1,volume ratio of H_(2)SO_(4)solution to H_(3)PO_(4)solution of 45:5,leaching time of 2 h and leaching temperature of 80℃,the leaching rate of lithium was as high as 97.83%.The leaching mechanism was studied by SEM,pore property analysis,XRD and *** was found that the morphology of the ore changed obviously after roasting and leaching,and a certain degree of collapse and fragmentation occurred,which provided favorable spatial conditions for the leaching of *** porosity,total intrusion volume and total pore area also increased after roasting and leaching,thus promoting the leaching of Li^(+).The results showed that chemical reaction taken placed during the roasting and *** phase of the sample changed from chlorite,kaolinite and diaspore(boehmite)mainly to corundum,hematite,periclase and quartz after ***,after leaching,no new phase was produced in the ore sample,and no S and P elements were found on the surface of the ore sample,indicating that the leaching mechanism of lithium might be the ion exchange between H^(+)and Li^(+).

关键词： Clay-type lithium ore Lithium extraction Roasting Leaching

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Recovery of rare earth elements from rare earth molten salt electrolytic slag via fluorine fixation by MgCl2 roasting

引用

Journal of Rare Earths 2024年第10期42卷 1979-1987页

作者： Minghui Zhang Bingxuan He Yinliang Liu Luewei Xu Yong Liang faculty of Metallurgical engineering Jiangxi University of Science and Technology Key Laboratory of Ionic Rare Earth resources and Environment Ministry of Natural Resources Jiangxi Provincial Key Laboratory of Green and Low Carbon Metallurgy for Strategic Nonferrous Metals

Rare earth fluoride molten-salt electrolytic slag（REFES） is a precious rare earth element（REE） secondary resource,and conside rable amounts of REEs exist in REFES as REF3;they are difficult to dissolve in acid or water and impede efficient REE *** REFES recovery,the REF3species in REFES are usually transformed into acid-soluble rare earth compounds by NaOH roasting or sulfating roasting and then extracted by acid leaching,Moreover,the fluorides in REFES are released as HF gas in the roasting process or enter the liquid phase during the water washing process;both of these processes cause fluorine *** the fluorine into the solid slag provides a way to avoid fluorine *** this study,a novel method was proposed to extract REEs from REFES via MgCl2roasting followed by HCl *** calculations and the rmogravimetry-differential thermal analyses（TG-DTA） were conducted to investigate the reactions occurring in the roasting process,First,MgCl2reacts with the REF3and RE2O3to form RECl3and REOCl,***,the RECI3absorbs water and forms RE（OH）***,MgCl2·6H2O is gradually dehydrated to MgCl2·2H2O and reacts with REF3and RE（OH）3,and REOCl,MgF2and MgO are *** HCl leaching,the REOCl in the roasting products is leached by HCl acid,while fluoride re mains in the solid slag as *** optimum experimental conditions are as follows:mass ratio of MgCl2to REFES of 30%,roasting temperature of 700℃,roasting time of 2 h,hydrochloride acid concentration of 4 mol/L,leaching time of 2 h,leaching temperature of 90 ℃ and leaching L/S ratio of 20:*** efficiencies for total leaching of the REEs,La,Ce,Pr,and Nd are 99.13%,99.20%,98.42%,99.38%,and 99.08%,***,the concentration of fluoride in the leaching solution is 2.191×10-6mol/*** method has a short process flow with low reagent costs,and the problem of fluoride pollution from REFES recovery is solved;thus,our study has great industrial application pot

关键词： Fluorine Leaching Molten-salt electrolytic slag Rare earths Recovery

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Unveiling the protective role of biofilm formation on the photoaging of microplastics

引用

Science China Technological Sciences 2024年第10期67卷 3067-3078页

作者： ZHANG HaiYu LIU Peng ZHANG JiaYu DAI JiaMin ZHANG XinRui ZHANG ZiXuan JIA HanZhong Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China Ministry of AgricultureCollege of Natural Resources and EnvironmentNorthwest A&F University Key Laboratory of Organic Compound Pollution Control engineering School of Environmental and Chemical EngineeringShanghai University

In natural water, microplastics（MPs） inevitably undergo microbial colonization to form biofilm, while the effect of biofilm formation on the photoaging of MPs remains unknown. This study systematically investigated the photoaging behavior of disposable box-derived polypropylene（PPMPs） and polystyrene（PSMPs） mediated by formed biofilm in water. After incubating in Weihe water samples for 105 d, the biofilm was validated to form in PPMPs and PSMPs, with higher formation in PSMPs. In particular, biofilm formation inhibited the photoaging of PPMPs and PSMPs, with an 11.1% and 50.6% decrease in photooxidation compared to their virgin counterparts after 20 d of ultraviolet（UV） irradiation. Moreover, the photoaging route of MPs such as the reaction priority of functional groups（e.g., C–H, C=O, and benzene ring） was altered, indicating the important role of biofilm formation in the photoaging process of MPs. The protective effect of the biofilm was mainly caused by the role of optical light filters that absorbed UV energy by sacrificing themselves. Also, as the main attacker on MPs, the production of reactive oxygen species（ROS, mainly1O2and ·OH） was inhibited by biofilm, which was mainly responsible for the decreased photoaging of MPs. This study revealed the important role of biofilm in the photoaging process of MPs and suggested a higher resistance of（micro）plastics in natural water than that in the laboratory using pure MPs, which contributed to a deeper understanding of the environmental fate and pollution of MPs.

关键词： microplastics biofilm photoaging physical shielding reactive oxygen species

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Microwave irradiation-induced alterations in physicochemical properties and methane adsorption capability of coals:An experimental study using carbon molecular sieve

引用

Chinese Journal of chemical engineering 2024年第4期68卷 165-180页

作者： Xuexiang Fu Xing Tang Yi Xu Xintao Zhou Dengfeng Zhang faculty of chemical engineering Kunming University of Science and TechnologyKunming 650500China

In order to comprehend the applicability of microwave irradiation for recovering coalbed methane,it is necessary to evaluate the microwave irradiation-induced alterations in coals with varying levels of *** this work,the carbon molecular sieve combined with KMnO_(4)oxidation was selected to fabricate carbon molecular sieve with diverse oxidation degrees,which can serve as model substances toward ***,the microwave irradiation dependences of pores,functional groups,and highpressure methane adsorption characteristics of model substances were *** results indicated that microwave irradiation causes rearrangement of oxygen-containing functional groups,which could block the micropores with a size of 0.40-0.60 nm in carbon molecular sieve;meanwhile,naphthalene and phenanthrene generated by macro-molecular structure pyrolysis due to microwave irradiation could block the micropores with a size of 0.70-0.90 *** alterations in micropore structure weaken the saturated methane adsorption capacity of oxidized carbon molecular sieve by 2.91%-23.28%,suggesting that microwave irradiation could promote methane ***,the increased mesopores found for oxidized carbon molecular sieve after microwave irradiation could benefit CH4 *** summary,the oxidized carbon molecular sieve can act as model substances toward coals with different ***,microwave irradiation is a promising technology to enhance coalbed methane recovery.

关键词： Microwave irradiation Physicochemical property Coal matrix Adsorption Carbon molecular sieve

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Synergistic precipitant powered self-assembly of papain for cross-linked enzyme crystals preparation

引用

Particuology 2024年第2期85卷 102-112页

作者： Qi Hao Pan Guo Honghai Wang Min Su Chunli Li Yuqi Hu Weiyi Su School of chemical engineering and Technology Hebei University of TechnologyTianjin300130China National-Local Joint engineering Laboratory for Energy Conservation of chemical Process Integration and resources Utilization Tianjin300130China

In this study,we prepared cross-linked enzyme crystals(CLECs)of papain to further broaden the application of the enzyme with high activity in extreme ***,papain crystals were successfully obtained based on the micro-batch,batch,and expanded batch crystallization ***,ammonium sulfate and polyethylene glycol 6000(PEG6000)were synergistically used as the precipitants,while L-cysteine was applied to enhance the activity of ***,the interaction between L-cysteine and papain was modeled by molecular docking *** was found that L-cysteine could form a hydrogen bond with aspartic acid residue(Asp)at site 158,and the electrostatic attraction with lysine residue(Lys)at site 156 was also quite *** the enzyme crystals were cross-linked by glutaraldehyde at optimized *** papain CLECs were identified by various methods,and it was found that the thermal stability and enzymatic activity both increased compared to the raw *** importantly,it could be applied at more rigorous conditions,for example,pH of 4.

关键词： Papain Cross-linked enzyme crystals L-cysteine Molecular docking Crystallization

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：