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Application and mechanism of calcium hypochlorite in replacing sodium sulfide for the clean separation of low-grade molybdenum-bismuth ore
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作者 CHAI Xu-jian ZHANG Hong-liang +2 位作者 LIU Wei-ping ZHOU Shuang LIN Shang-yong 《Journal of Central South University》 2025年第5期1775-1790,共16页
Stemming from the high costs and environmental pollution associated with the use of sodium sulfide in the separation and extraction processes of molybdenum bismuth ore,calcium hypochlorite was introduced as a substitu... Stemming from the high costs and environmental pollution associated with the use of sodium sulfide in the separation and extraction processes of molybdenum bismuth ore,calcium hypochlorite was introduced as a substitute to facilitate the cleaner production of low-grade molybdenum bismuth ore in this study.The effects of calcium hypochlorite on molybdenite,bismuthinite,and pyrite were investigated through micro-flotation,flotation kinetics,batch flotation,Fourier transform infrared(FTIR)spectra,scanning electron microscopy energy dispersion spectra(SEM-EDS),and inductively coupled plasma-optical emission spectra(ICP-OES).The flotation tests results showed that calcium hypochlorite could selectively depress bismuthinite and pyrite.In comparison to sodium sulfide,calcium hypochlorite not only improved the flotation indicators for molybdenum and bismuth concentrates but also reduced the dosage of flotation reagents.Moreover,the chemical oxygen demand(COD)of tailings wastewater significantly decreased when using calcium hypochlorite as a depressant.Mechanism research revealed that the use of calcium hypochlorite as a depressant led to BiOCl precipitation on bismuthinite,which hindered the attachment of the collector.In summary,calcium hypochlorite serves as a more efficient and environmentally friendly depressant compared to sodium sulfide in the industrial production processes of low-grade molybdenum bismuth ore. 展开更多
关键词 bismuthinite MOLYBDENITE selective separation calcium hypochlorite
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Commercial polydimethylsiloxane modified melamine sponge for highly efficient oil-water separation
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作者 BAI Gen QIAN Liang +5 位作者 MA De-peng HE Ying-xin ZHOU Xin LU Cui-hong ZHANG Yue-fei TAN Jing-lin 《Journal of Central South University》 2025年第4期1384-1399,共16页
Polydimethylsiloxane(PDMS)is considered a low surface energy material widely used in(super)hydrophobic modification.In this paper,the high hydrophobic melamine sponges(MS)were modified with commercial aminopropyl func... Polydimethylsiloxane(PDMS)is considered a low surface energy material widely used in(super)hydrophobic modification.In this paper,the high hydrophobic melamine sponges(MS)were modified with commercial aminopropyl functionalized polydimethylsiloxane(NH_(2)-PDMS)with different molecular mass.The chemical composition,surface morphology,and wettability of the NH_(2)-PDMS-modified MS were investigated by X-ray photoelectron spectroscopy(XPS),attenuated total reflection Fourier transform infrared spectroscopy(ATR-FTIR)and contact angle test.Owing to the porous structure and high hydrophobicity,NH_(2)-PDMS-modified MS possesses remarkable absorption capacity(ranging from 46 to 155 times their own mass).Simultaneously,it can effectively separate oil-water mixtures with high separation efficiencies exceeding 98.2%.NH_(2)-PDMS-modified MS has no obvious change after 10 cycles of oil-water separation.The results demonstrate PDMS molecular mass on surface can revise material properties and achieve high separation efficiencies in oil-water separation. 展开更多
关键词 POLYDIMETHYLSILOXANE melamine sponges HYDROPHOBICITY oil-water separation
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Surface pretreatment effect on the separation and purification of magnesite and dolomite
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作者 GONG Xiu-feng YAO Jin +4 位作者 JIA Yu-kun YIN Chao YIN Wan-zhong WANG Yu-lian FU Ya-feng 《Journal of Central South University》 2025年第3期977-990,共14页
Surface pretreatment can change the surface properties of minerals,placing them in either a favorable or an unfavorable state for flotation.To solve the separation problem associated with magnesite and dolomite,surfac... Surface pretreatment can change the surface properties of minerals,placing them in either a favorable or an unfavorable state for flotation.To solve the separation problem associated with magnesite and dolomite,surface pretreatment experiments with citric acid,tartaric acid,and tannic acid(TA)on magnesite and dolomite as well as flotation experiments on pretreated samples were performed in this study.Experimental results demonstrated that when citric acid and tartaric acid are used for surface pretreatment,the separation effect of magnesite and dolomite is poor.However,when TA is used,the separation effect of magnesite and dolomite improves.SEM and BET analysis indicated that surface pretreatment with TA changes the surface morphology of the two minerals,resulting in additional concave pores on the dolomite surface,and a significant increase in pore size and specific surface area.The adsorption quantity test and contact angle measurement demonstrated that after surface pretreatment with TA,the magnesite adsorption capacity on sodium oleate(NaOL)slightly decreases and the dolomite adsorption capacity on NaOL considerably decreases.XPS detection concluded that the surface pretreatment of TA on the magnesite surface mainly relies on physical adsorption with weak adsorption ability and poor ability to act on Mg sites.The TA surface pretreatment action on the dolomite surface is mainly through chemical adsorption,and it is strongly and selectively adsorbed on the Ca site of dolomite through O.Actual ore rough selection experiments reveal that TA pretreatment successfully removes dolomite from magnesite,resulting in a high-quality magnesite concentrate characterized by a MgO grade of 45.49%and a CaO grade of 0.75%. 展开更多
关键词 surface pretreatment tannic acid MAGNESITE DOLOMITE separation PURIFICATION
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The application of multi-scale magnetic matrix materials in high-gradient magnetic separation:From micro-and nano-to millimeter-scale
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作者 WANG Dong KU Jian-gang +3 位作者 LEI Zhong-yun LI Xin YAN Ju-jian WANG Qian 《Journal of Central South University》 2025年第4期1299-1326,共28页
Micro-and nano-to millimeter-scale magnetic matrix materials have gained widespread application due to their exceptional magnetic properties and favorable cost-effectiveness.With the rapid progress in condensed matter... Micro-and nano-to millimeter-scale magnetic matrix materials have gained widespread application due to their exceptional magnetic properties and favorable cost-effectiveness.With the rapid progress in condensed matter physics,materials science,and mineral separation technologies,these materials are now poised for new opportunities in theoretical research and development.This review provides a comprehensive analysis of these matrices,encompassing their structure,size,shape,composition,properties,and multifaceted applications.These materials,primarily composed of alloys of transition state metasl such as iron(Fe),cobalt(Co),titanium(Ti),and nickel(Ni),exhibit unique attributes like high magnetization rates,low eleastic modulus,and high saturation magnetic field strengths.Furthermore,the studies also delve into the complex mechanical interactions involved in the separation of magnetic particles using magnetic separator matrices,including magnetic,gravitational,centrifugal,and van der Waals forces.The review outlines how size and shape effects influence the magnetic behavior of matrices,offering new perspectives for innovative applications of magnetic matrices in various domains of materials science and magnetic separation. 展开更多
关键词 magnetic matrix materials magnetic separation micro-and nano-magnetic matrix millimeter magnetic matrix
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Flotation separation performance and mechanism of sphalerite from pyrite by Fe^(3+)-Cu^(2+)-BX process
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作者 LIU Jun ZHANG Zhi-yong +3 位作者 SHI Jun-yang LIU Sheng HU Fang LIU Guang-yi 《Journal of Central South University》 2025年第6期2183-2194,共12页
The lime-Cu^(2+)-xanthate process is commonly used for the flotation separation of sphalerite from pyrite.In this process,lime is added to the pulp to inhibit the floatability of pyrite.However,the excessive use of li... The lime-Cu^(2+)-xanthate process is commonly used for the flotation separation of sphalerite from pyrite.In this process,lime is added to the pulp to inhibit the floatability of pyrite.However,the excessive use of lime can result in pipeline blockage and inadequate recovery of associated precious metals.Therefore,it is necessary to develop new flotation process that minimizes or eliminates the use of lime.In this paper,a novel Fe^(3+)-Cu^(2+)-butyl xanthate process was developed as an alternative to lime for separating of sphalerite from pyrite.The flotation results indicated that with the artificially-mixed minerals,the flotation recovery of pyrite was lower than 16%and that of sphalerite was higher than 47%at pH 5.0−10.0.The zeta potential measurements revealed that ferric ion preferred to adsorb on pyrite,and copper ion displaced with zinc ion from the lattice at the interface of sphalerite.The wettability analyses indicated that the hydrophobicity of sphalerite surface increased apparently after being treated with Fe^(3+)-Cu^(2+)-BX,while the hydrophobicity of pyrite surface remained nearly unchanged.With XPS analysis,Cu-S bond and hydrophilic ferric hydroxide were detected separately on the surface of sphalerite and pyrite after conditioning with Fe^(3+)-Cu^(2+)-BX,which facilitated the flotation separation of sphalerite from pyrite with butyl xanthate collector. 展开更多
关键词 flotation separation SPHALERITE PYRITE Fe^(3+)-Cu^(2+)-butyl xanthate
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Fluorinated semi-interpenetrating polymer networks for enhancing the mechanical performance and storage stability of polymer-bonded explosives by controlling curing and phase separation rates
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作者 Chao Deng Huihui Liu +1 位作者 Yongping Bai Zhen Hu 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第8期58-66,共9页
Herein, the effect of fluoropolymer binders on the properties of polymer-bonded explosives(PBXs) was comprehensively investigated. To this end, fluorinated semi-interpenetrating polymer networks(semiIPNs) were prepare... Herein, the effect of fluoropolymer binders on the properties of polymer-bonded explosives(PBXs) was comprehensively investigated. To this end, fluorinated semi-interpenetrating polymer networks(semiIPNs) were prepared using different catalyst amounts(denoted as F23-CLF-30-D). The involved curing and phase separation processes were monitored using Fourier-transform infrared spectroscopy, differential scanning calorimetry, a haze meter and a rheometer. Curing rate constant and activation energy were calculated using a theoretical model and numerical method, respectively. Results revealed that owing to its co-continuous micro-phase separation structure, the F23-CLF-30-D3 semi-IPN exhibited considerably higher tensile strength and elongation at break than pure fluororubber F2314 and the F23-CLF-30-D0 semi-IPN because the phase separation and curing rates matched in the initial stage of curing.An arc Brazilian test revealed that F23-CLF-30-D-based composites used as mock materials for PBXs exhibited excellent mechanical performance and storage stability. Thus, the matched curing and phase separation rates play a crucial role during the fabrication of high-performance semi-IPNs;these factors can be feasibly controlled using an appropriate catalyst amount. 展开更多
关键词 Semi-interpenetrating polymer networks FLUOROPOLYMER Curing rate Phase separation rate Polymer-bonded explosives
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Blind radar signal separation algorithm based on third-order degree of cyclostationarity criteria
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作者 FAN Xiangyu LIU Bin +2 位作者 DONG Danna CHEN You WANG Yuancheng 《Journal of Systems Engineering and Electronics》 CSCD 2024年第6期1441-1453,共13页
Separation and recognition of radar signals is the key function of modern radar reconnaissance,which is of great sig-nificance for electronic countermeasures and anti-countermea-sures.In order to improve the ability o... Separation and recognition of radar signals is the key function of modern radar reconnaissance,which is of great sig-nificance for electronic countermeasures and anti-countermea-sures.In order to improve the ability of separating mixed signals in complex electromagnetic environment,a blind source separa-tion algorithm based on degree of cyclostationarity(DCS)crite-rion is constructed in this paper.Firstly,the DCS criterion is con-structed by using the cyclic spectrum theory.Then the algo-rithm flow of blind source separation is designed based on DCS criterion.At the same time,Givens matrix is constructed to make the blind source separation algorithm suitable for multiple sig-nals with different cyclostationary frequencies.The feasibility of this method is further proved.The theoretical and simulation results show that the algorithm can effectively separate and re-cognize common multi-radar signals. 展开更多
关键词 blind signal separation cyclostationary frequency Givens matrix degree of cyclostationarity(DCS)blind source separation algorithm
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Dephosphorization of high-phosphorus iron ore by direct reduction of hydrogen-rich gases and melting separation
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作者 ZHAO Lian-da WU De-yin +6 位作者 YOU Xiao-min DENG Xing-jian ZUO Hai-bin SHE Xue-feng XUE Qing-guo WANG Guang WANG Jing-song 《Journal of Central South University》 CSCD 2024年第11期4120-4136,共17页
This study developed a direct reduction route to smelt refractory high-phosphorus iron ores by using hydrogen rich gas.The effects of temperature,gas composition,and gangue on the reduction behavior of iron ore pellet... This study developed a direct reduction route to smelt refractory high-phosphorus iron ores by using hydrogen rich gas.The effects of temperature,gas composition,and gangue on the reduction behavior of iron ore pellets were investigated.Additionally,the migration behavior of phosphorus throughout the reduction-smelting process was examined.The apparent activation energy of the reduction process increased from 64.2 to 194.2 kJ/mol.Increasing the basicity from 0.5 to 0.9 increased the metallization rate from 85.9%to 89.2%.During the reduction process,phosphorus remained in the gangue phase.Carbon deposition and phosphorus removal behaviors of the pellets were investigated and correlated with the gas composition,temperature,pressure,metallization rate,and basicity.Increasing the FeO and CaO contents led to an increase in the liquidus temperature.A high metallization rate of the pellets reduced the phosphorus removal rate but increased the carbon content of the final iron product.Increasing basicity restricted the migration of phosphorus and improved the rate of phosphorus removal.The optimum dephosphorization parameters were separation temperature of 1823 K,basicity of 2.0,and metallization rate of 82.3%.This study presents a high-efficiency and low carbon method for smelting high-phosphorus iron ores. 展开更多
关键词 high-phosphorus iron ore hydrogen-rich gas reduction phosphorus transport mineral evolution melting separation
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气体分离膜材料从空气中分离氙气性能研究 被引量:1
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作者 陈占营 刘蜀疆 +3 位作者 常印忠 盛毓强 王建龙 黑东炜 《膜科学与技术》 北大核心 2025年第1期137-145,共9页
大气放射性氙监测对于核试验检测具有重要意义.以从空气中分离浓缩氙为应用背景,实验测试了N_(2)、O_(2)、CO_(2)和Xe 4种气体在不同类别膜材料中的渗透性,评价了不同膜材料对4种气体之间的分离性能;考察了温度、压力等操作条件变化对... 大气放射性氙监测对于核试验检测具有重要意义.以从空气中分离浓缩氙为应用背景,实验测试了N_(2)、O_(2)、CO_(2)和Xe 4种气体在不同类别膜材料中的渗透性,评价了不同膜材料对4种气体之间的分离性能;考察了温度、压力等操作条件变化对氙气分离性能的影响.结果表明,在聚酰亚胺(PI)、聚苯醚(PPO)和聚砜(PSf)3类材料中,PI具有明显优于其他两类材料的氙气分离性能;温度和压力变化对氙气分离性能的影响均不明显.上述研究工作对于气体分离膜从空气中分离氙气的实际应用具有重要意义. 展开更多
关键词 气体分离膜 放射性氙 渗透性能 分离性能
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Development of Ni_(x)/Mg_(1-x)-MOF-74 for highly efficient CO_(2)/N_(2) separation
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作者 ZHANG Xin LI Guoqiang +7 位作者 HONG Mei BAN Hongyan YANG Lixia LIU Xingchen LI Feng Ekaterina Vladimirovna Matus LI Congming LI Lei 《燃料化学学报(中英文)》 EI CAS CSCD 北大核心 2024年第11期1745-1758,共14页
To enhance the separation selectivity of Mg-MOF-74 towards CO_(2) in a CO_(2)/N_(2) mixture,a series of Mg-MOF-74 and Ni_(x)/Mg_(1-x)-MOF-74 adsorbents were prepared by solvothermal synthesis in this paper.It was foun... To enhance the separation selectivity of Mg-MOF-74 towards CO_(2) in a CO_(2)/N_(2) mixture,a series of Mg-MOF-74 and Ni_(x)/Mg_(1-x)-MOF-74 adsorbents were prepared by solvothermal synthesis in this paper.It was found that the adsorption capacity of Mg-MOF-74 for CO_(2) could be effectively increased by optimizing the amount of acetic acid.On this basis,the bimetal MOF-74 adsorbent was prepared by metal modification.The multi-component dynamic adsorption penetration analysis was utilized to examine the CO_(2) adsorption capacity and CO_(2)/N_(2) selectivity of the diverse adsorbent materials.The results showed that Ni0.11/Mg0.89-MOF-74 showed a CO_(2) adsorption capacity of 7.02 mmol/g under pure CO_(2) atmosphere and had a selectivity of 20.50 for CO_(2)/N_(2) under 15% CO_(2)/85%N_(2) conditions,which was 10.2% and 18.02% higher than that of Mg-MOF-74 respectively.Combining XPS,SEM and N_(2) adsorption-desorption characterization analysis,it was attributed to the effect of the more stable unsaturated metal sites Ni into the Mg-MOF-74 on the pore structure and the synergistic interaction between the two metals.Density Functional Theory(DFT)simulations revealed that the synergistic interaction between modulated the electrostatic potential strength and gradient of the material,which was more favorable for the adsorption of CO_(2) molecules with small diameters and large quadrupole moment.In addition,the Ni0.11/Mg0.89-MOF-74 showed commendable cyclic stability,underscoring its promising potential for practical applications. 展开更多
关键词 CO_(2)capture Mg-MOF-74 CO_(2)/N_(2)separation adsorption breakthrough curve density functional theory
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萤石与方解石浮选分离药剂研究进展 被引量:7
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作者 李宏静 刘春光 +1 位作者 刘剑飞 王丽明 《中国矿业》 北大核心 2025年第1期226-232,共7页
萤石是一种不可再生的战略性矿产资源,其用途非常广泛。我国萤石矿储量丰富,但富矿少,贫矿、伴生矿及难选矿多,且萤石矿物嵌布粒度细,与脉石矿物共生状态复杂,致使常规物理选矿方法无法高效回收该部分萤石资源,造成巨大资源浪费。浮选... 萤石是一种不可再生的战略性矿产资源,其用途非常广泛。我国萤石矿储量丰富,但富矿少,贫矿、伴生矿及难选矿多,且萤石矿物嵌布粒度细,与脉石矿物共生状态复杂,致使常规物理选矿方法无法高效回收该部分萤石资源,造成巨大资源浪费。浮选作为细粒矿物的有效分选方法,目前也被广泛应用于萤石矿选矿。由于萤石与方解石两种矿物表面活性位点相似且具有同质化效应,导致浮选分离困难,故这两种矿物的高效浮选药剂开发是萤石浮选药剂研究领域的难点。本文立足于萤石与方解石两种矿物浮选分离药剂研究现状,着重进行正浮选常用捕收剂、抑制剂种类及效果、金属离子对药剂作用效果概述,并分析未来药剂研究方向,得出改性捕收剂与组合捕收剂、组合抑制剂及新型抑制剂的研发,金属离子的正向助抑制作用探索,是萤石与同类型碳酸盐含钙矿物浮选分离药剂的主要研究趋势。 展开更多
关键词 方解石 萤石 浮选分离 捕收剂 抑制剂
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Vertical phase separation and morphology optimization of layer-by-layer non-fullerene organic solar cells
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作者 NING Bo-cheng MA Yu-meng +4 位作者 ZHANG Jun ZOU Ying-ping YANG Jun-liang YUAN Yong-bo ZHANG Lin 《Journal of Central South University》 CSCD 2024年第12期4338-4365,共28页
The development of high-performance non-fullerene acceptors with extended exciton diffusion lengths has positioned the sequential layer-by-layer(LBL)solution processing technique as a promising approach for fabricatin... The development of high-performance non-fullerene acceptors with extended exciton diffusion lengths has positioned the sequential layer-by-layer(LBL)solution processing technique as a promising approach for fabricating high-performance and large-area organic solar cells(OSCs).This method allows for the independent dissolution and deposition of donor and acceptor materials,enabling precise morphology control.In this review,we provide a comprehensive overview of the LBL processing technique,focusing on the morphology of the active layer.The swelling intercalation phase-separation(SIPS)model is introduced as the mainstream theory of morphology evolution,with a detailed discussion on vertical phase separation.We summarize recent strategies for morphology optimization.Additionally,we review the progress in LBL-based large-area device and module fabrication,as well as green processing approaches.Finally,we highlight current challenges and future prospects,paving the way for the commercialization of LBL-processed OSCs. 展开更多
关键词 organic solar cells layer-by-layer(LBL)solution processing technique vertical phase separation morphology optimization non-fullerene acceptors
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聚乙烯超细纤维非织造工艺研究进展 被引量:2
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作者 张莉彦 殷荣政 +5 位作者 谭晶 侯钦正 李长金 杨涛 杨卫民 李好义 《中国塑料》 北大核心 2025年第2期100-105,共6页
为深入了解化工产品聚乙烯超细纤维制备现状,从纤维细度出发,对国内外聚乙烯超细纤维非织造工艺进行综述分析。梳理了凝胶纺丝、闪蒸相分离、静电纺丝、熔喷4条路线的成丝机理、细化方法及目前存在的问题,剖析了凝胶纺丝中溶胀、溶解行... 为深入了解化工产品聚乙烯超细纤维制备现状,从纤维细度出发,对国内外聚乙烯超细纤维非织造工艺进行综述分析。梳理了凝胶纺丝、闪蒸相分离、静电纺丝、熔喷4条路线的成丝机理、细化方法及目前存在的问题,剖析了凝胶纺丝中溶胀、溶解行为及高品质凝胶液与超倍拉伸的关联;探讨了闪蒸相分离中的相态变化、超临界CO_(2)“绿色制造”方法;针对聚乙烯非极性、分子量大、黏度高的物性,归纳了使用溶剂、添加导电粒子的溶液电纺以及通过共混小分子极性物质、提高降解温度升温降黏、增设环境温度延长鞭动时间来细化纤维的熔体电纺;分析了工艺参数对共混熔喷后开纤剥离多组分纤维的影响。最后指出使用超临界绿色流体、无卤素环境友好型溶剂等绿色制备方式为未来热点研究方向。 展开更多
关键词 超细纤维 聚乙烯 相分离 熔喷 静电纺丝
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“三软”厚煤层开采覆岩多层位离层注浆减沉技术及应用 被引量:4
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作者 郭文兵 吴东涛 +3 位作者 郭明杰 胡玉杭 杨伟强 王比比 《煤炭科学技术》 北大核心 2025年第5期1-12,共12页
采动覆岩离层注浆中注浆层位精准识别及保护层厚度合理确定,对防治地表沉陷、保护地表建(构)筑物具有重要意义。为了实现覆岩多层位离层精准注浆减沉,基于组合梁理论改进了离层位置判别方法,确定了覆岩多层位离层注浆充填位置;通过弹性... 采动覆岩离层注浆中注浆层位精准识别及保护层厚度合理确定,对防治地表沉陷、保护地表建(构)筑物具有重要意义。为了实现覆岩多层位离层精准注浆减沉,基于组合梁理论改进了离层位置判别方法,确定了覆岩多层位离层注浆充填位置;通过弹性薄板理论,建立了覆岩离层注浆保护层采动岩体结构力学模型;构建了覆岩多层位离层注浆充填空间的等效模型,并根据注浆空间上位岩层和下位岩层破断规律,给出了充填空间的最小和最大总体积;采用概率积分法并结合地表实际监测结果,评价了“三软”厚煤层覆岩多层位离层注浆效果,并对郑州矿区裴沟煤矿22151工作面开展了实例分析。结果表明:钻孔窥视验证了多层位离层注浆位置的准确性,在距煤层152.6 m中粒砂岩底部和距煤层168.6 m处细粒砂岩下方之间成功实施覆岩多层位离层注浆;工作面在开采厚度为7.1 m时,保护层厚度为25.2 m能够实现覆岩离层注浆工作的安全实施;理论计算注浆量为9.5×10^(4)~14.7×10^(4)t,实际工程注浆量约为13.3×10^(4)t,注采比约为0.41;采用覆岩多层位离层注浆开采后,地表最大下沉量为649.8 mm,大部分民房处地表最大水平变形值处于Ⅰ级损害程度内;覆岩多层位离层注浆开采地表沉陷控制效果显著,减沉率约77.91%。 展开更多
关键词 “三软”厚煤层 软硬交互覆岩 覆岩离层 多层位注浆 保护层 沉陷控制
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催化裂化反应系统耦合强化装备技术的开发 被引量:1
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作者 卢春喜 范怡平 +3 位作者 王龙延 张振千 刘梦溪 许栋五 《石油炼制与化工》 北大核心 2025年第5期156-168,共13页
催化裂化反应系统相关装备的开发需要满足“高-快协同”,即应实现流动-传递环境的“三高”[油气-催化剂(简称油-剂)高效接触、油-剂高效分离、催化剂高效汽提]与反应动力学所要求的“快”的相互协同。基于将单一非均匀流化区域分解-重... 催化裂化反应系统相关装备的开发需要满足“高-快协同”,即应实现流动-传递环境的“三高”[油气-催化剂(简称油-剂)高效接触、油-剂高效分离、催化剂高效汽提]与反应动力学所要求的“快”的相互协同。基于将单一非均匀流化区域分解-重构的方法,开发了新型预提升装备和汽提装备;将空气动力学理论用于多相流分析,形成了可调控多股受限射流-多相流的进料装备技术;通过强化有效切向速度,开发了全新理念的提升管出口油-剂快速分离装备。这些装备不仅具备优良的性能,还可实现催化裂化反应系统内两相流型的快速转捩,获得了广泛的工业应用。 展开更多
关键词 耦合装备 预提升 进料 快速分离 汽提
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某含铬海滨砂矿选矿试验研究
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作者 廖乾 张胜广 +2 位作者 张建文 马崇振 梁汉 《矿冶工程》 北大核心 2025年第1期57-60,共4页
对TiO_(2)品位3.33%、Cr_(2)O_(3)品位0.36%的某海滨砂矿进行了选矿试验研究。采用重选-弱磁选-中强磁选预处理和焙烧-干式磁选再处理成套选矿技术,可获得TiO_(2)品位47.72%、Cr_(2)O_(3)品位0.071%、TiO_(2)回收率64.76%的钛精矿产品,... 对TiO_(2)品位3.33%、Cr_(2)O_(3)品位0.36%的某海滨砂矿进行了选矿试验研究。采用重选-弱磁选-中强磁选预处理和焙烧-干式磁选再处理成套选矿技术,可获得TiO_(2)品位47.72%、Cr_(2)O_(3)品位0.071%、TiO_(2)回收率64.76%的钛精矿产品,实现了提钛降铬、生产合格钛精矿的目标。 展开更多
关键词 海滨砂矿 钛铁矿 铬铁矿 选矿 重选 磁选 焙烧 钛精矿
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特朗普现象是美国总统制的危机吗? 被引量:1
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作者 李少文 《太平洋学报》 北大核心 2025年第2期15-25,共11页
特朗普两度出任美国总统,都引起了全世界对美国政治制度的关注。从政治学角度看,这背后隐藏着总统制可能导致政治衰败的问题。美国总统制是“孟德斯鸠—麦迪逊”分权理论的结果。分权体制设定了总统具有较高权威和较大权力,在防范总统... 特朗普两度出任美国总统,都引起了全世界对美国政治制度的关注。从政治学角度看,这背后隐藏着总统制可能导致政治衰败的问题。美国总统制是“孟德斯鸠—麦迪逊”分权理论的结果。分权体制设定了总统具有较高权威和较大权力,在防范总统滥用权力时,也要保障总统正当行使其职权。目前看来,美国总统制仍是稳固的,并未突破分权体制,但仍存在着巨大挑战。特朗普现象的出现,是因为美国近年来面对着一系列政治危机,包括政府虚弱、政治极化、党争加剧等。特朗普登上政治舞台是美国政治制度自我调适的一种反应。相较于议会制,总统制体现了一定的宽度、韧性和稳定性,借助于此的特朗普政府能够加强治理、削弱政党,以及实现与法院共治。然而,在美国政治经济社会文化皆存在巨大分歧的背景下,特朗普的强势主张与鲜明个性有可能造成激烈对抗,冲击美国总统制所贯彻的共和精神。在第二个任期中,特朗普政府面对着如何重塑和恢复共和精神的挑战。 展开更多
关键词 特朗普 总统制 分权 共和
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彭波半细毛羊冷冻保存睾丸组织支持细胞分离、纯化及鉴定 被引量:1
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作者 刘海霞 王健 +4 位作者 平措班旦 朱爱文 德庆卓嘎 王军 格桑加措 《中国畜牧兽医》 北大核心 2025年第1期249-257,共9页
[目的]睾丸支持细胞(Sertoli cells, SCs)位于生精小管内上皮,为不同分化阶段雄性生殖细胞发育提供物理构架和能量物质支持,对精子发生过程产生至关重要的作用。试验旨在研究新鲜绵羊睾丸组织样品获取不便的情况下,从冷冻保存的彭波半... [目的]睾丸支持细胞(Sertoli cells, SCs)位于生精小管内上皮,为不同分化阶段雄性生殖细胞发育提供物理构架和能量物质支持,对精子发生过程产生至关重要的作用。试验旨在研究新鲜绵羊睾丸组织样品获取不便的情况下,从冷冻保存的彭波半细毛羊睾丸组织分离支持细胞的技术方法。[方法]将冷冻保存液预处理后冻存的彭波半细毛羊睾丸组织进行复苏,采用苏木精-伊红(HE)染色检测复苏后睾丸组织形态,利用组合酶消化法、差速贴壁法进行睾丸组织支持细胞分离纯化培养,观察细胞生长规律,绘制生长曲线,采用RT-PCR和免疫荧光染色(IF)技术进行睾丸支持细胞特异性基因鉴定。[结果]冻存复苏睾丸组织曲细精索及睾丸间质保存完好。组合酶消化后能获得满足试验需要的生精上皮细胞混悬液,分离培养2~4 h后支持细胞贴壁,形态呈梭形或不规则多边形,培养3~4 d后汇合,其中培养1~2 d生长速度缓慢,培养3~6 d进入对数期,增殖速度加快,培养7~8 d后增殖速度下降。RT-PCR检测显示,GNDF、WT1、ABP、SOX9基因均在彭波半细毛羊睾丸支持细胞中特异性表达;免疫荧光染色显示,特异性抗体GATA4、Vimentin免疫阳性。[结论]经冻存液预处理的冷冻保存睾丸组织复苏后,可分离出满足试验条件的原代支持细胞,应用于科学试验研究。 展开更多
关键词 彭波半细毛羊 冷冻保存 睾丸支持细胞 分离鉴定 细胞培养
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螺旋分离器进液结构对油水两相螺旋流场的影响
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作者 徐保蕊 贾耀崇 +3 位作者 张晓光 赵立新 蒋明虎 赵珊珊 《化学工程》 北大核心 2025年第8期64-70,76,共8页
螺旋分离器进液结构具有减缓入口流体冲击流场和增强离散相聚结效果的双重作用。为研究不同进液结构对螺旋分离器的影响,采用数值模拟方法对比分析5种进液方式和8种稳流结构下螺旋分离器内的速度场、压降场以及相体积分数分布特点。结... 螺旋分离器进液结构具有减缓入口流体冲击流场和增强离散相聚结效果的双重作用。为研究不同进液结构对螺旋分离器的影响,采用数值模拟方法对比分析5种进液方式和8种稳流结构下螺旋分离器内的速度场、压降场以及相体积分数分布特点。结果表明:在入口管段各进液结构对其速度场影响明显,在螺旋管段之后速度场分布趋于相同,速度场变化规律基本一致;切向和侧向进液结构的压降相对较高,在螺旋管段之后压降趋于稳定;各进液方式分离器的分离效率稳定,变化率在2%之内;随着稳流结构高度的增加,分离器内压降有增大趋势;在稳流结构高度与主直径相等时,分离器的分离效果最好。通过对比分析,在长螺旋流道导流后,入口管段的结构形式对螺旋管段和出口管段的速度场分布、压降、分离效率影响较小,体现出入口结构形式多样化的特点,该特点对螺旋分离器未来实际应用中适应各种复杂工作环境和井下等特殊工作空间条件是非常有利的。 展开更多
关键词 螺旋分离器 进液结构 油水分离 螺旋流场 数值模拟
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基于YOLOv5s的轻量化森林火灾探测算法 被引量:2
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作者 刘惠临 方琼 +3 位作者 江宇 魏华章 王涛 张树川 《中国安全科学学报》 北大核心 2025年第1期75-83,共9页
为解决当前基于深度学习的森林火灾探测算法存在结构复杂、规模庞大,且难以兼顾检测精度和效率的问题,提出一种基于YOLOv5s的轻量化森林火灾探测算法。首先,采用优化的背景差分技术消除背景图像中类火物体的干扰,减少分析图像所需的时间... 为解决当前基于深度学习的森林火灾探测算法存在结构复杂、规模庞大,且难以兼顾检测精度和效率的问题,提出一种基于YOLOv5s的轻量化森林火灾探测算法。首先,采用优化的背景差分技术消除背景图像中类火物体的干扰,减少分析图像所需的时间;其次,设计分组混洗策略优化常规卷积,并在特征提取的C3模块中融入高效通道注意力(ECA)机制和深度可分离卷积,增强图像特征提取与融合能力的同时有效降低模型的参数量;然后,采用动态非单调聚焦机制优化Wise-交并比(WIOU)损失函数,减少低质量样本产生的有害梯度;最后,在构建的森林火灾数据集上将所提算法与其他算法做充分的试验对比。结果表明:所提算法在各类场景均展现出良好的泛化性,对火焰目标的检测精度达到86.1%,较标准YOLOv5s检测精度提升2.7%,检测速度提升11.4%,有效降低了火灾误报率,增强了模型的检测性能。 展开更多
关键词 YOLOv5s 轻量化 森林火灾探测 深度可分离卷积 注意力 Wise-交并比(WIOU)
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