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Selective separation of silica from a siliceous-calcareous phosphate rock

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Mining Science and Technology 2011年第1期21卷 135-139页

作者： guo Fang li jun College of Chemical Engineering Sichuan University Chengdu 610065. China

Selective separation of silica from a siliceous-calcareous phosphate ore that had been sieved into different size fractions is investigated by a combination of chemical analysis,zeta potential measurement and FTIR and XPS *** is a better choice than flotation for removing silica from the coarse *** P_2O_5 grade of the coarse fractions is increased to about 30%by scrubbing and the product yields are higher than those obtained by *** silica in the fine fraction is separated by reverse *** alkyl amine salt(DAH)is an effective collector and the P_2O_5 grade of the fine fraction can be increased by 7%to beyond 30%under acidic *** higher zeta potential obtained using DAH suggests that it is more strongly absorbed onto the ore particles than the other cationic collectors. FTIR and XPS results confirm physical absorption of the cationic collector onto the ore *** also indicate that calcite is dissolved at low pH values,which increases the Si concentration on the ore surface.

关键词： Siliceous-calcareous phosphate rock Silica separation Reverse flotation Calcite gangue

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基于大数据驱动的高职专业认证研究

职业教育研究 2024年第5期 38-44页

作者：石汉卿郭丽君湖南农业大学湖南长沙410128

高职专业认证事关高职教育的高质量发展全局,是助推职业教育内涵式发展的重要抓手。大数据技术中的多源数据融合技术、智能推荐算法技术、数据计算技术与高职专业认证的数据获取、体系完善、结果反馈及应用具有极大的联系性,满足高职专... 详细信息

高职专业认证事关高职教育的高质量发展全局,是助推职业教育内涵式发展的重要抓手。大数据技术中的多源数据融合技术、智能推荐算法技术、数据计算技术与高职专业认证的数据获取、体系完善、结果反馈及应用具有极大的联系性,满足高职专业认证客观化、精准化和科学化发展的现实需要。但大数据技术驱动高职专业认证可能引发伦理性问题、主体性困境和失真性风险三大问题。为此,应建立智能认证规章制度,规范认证行为;多元创新专业认证观念,校正认证方向;增强技术赋能的适切性,提升认证效能。

关键词：高职专业认证大数据技术认证效度技术限度伦理性风险

A Vertex Cover with Chorded 4-cycles

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Acta Mathematica Sinica,English Series 2011年第12期27卷 2351-2360页

作者： Yun Shu GAO guo jun li Jin YAN School of Mathematics and Computer Science Ningxia University Yinchuan 750021 P. R. China Department of Biochemistry and Molecular Biology University of Georgia GA 30602 U.S.A. School of Mathematics Shandong University Ji＇nan 250100 P. R. China

Let k be an integer with k ≥ 2 and G a graph with order n 〉 4k. We prove that if the minimum degree sum of any two nonadjacent vertices is at least n ＋ k, then G contains a vertex cover with exactly k components su... 详细信息

关键词： Degree condition vertex-disjoint chorded quadrilateral

Properties of ten-year-aged argon oxygen decarburization stainless steel slag

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Journal of Iron and Steel Research International 2021年第10期28卷 1233-1242页

作者： Ya-jun Wang Ya-nan Zeng jun-guo li Yu-zhu Zhang Wei Wang College of Metallurgy and Energy North China University of Science and TechnologyTangshan063210HebeiChina School of Metallurgy Northeastern UniversityShenyang110819LiaoningChina

The characteristics of argon oxygen decarburization slag(AODS)for smelting stainless steel that has been aged for 10 years were *** types of AODSs distributed at three positions in a slag heap were sampled for comparison *** analysis,mineral phase identification,thermogravimetric analysis,and micromorphology analysis were used to study the element migration trends and carbonation behavior of AODS after long-term *** leaching tests were performed to study the chromium leachability of the aged *** results show that during the long-term aging process,the AODS heap had undergone oxidation and carbonation,accompanied by element migration and mineralogical *** surface slag had the highest degree of carbonation but the weakest chromium *** chemical composition of the middle slag was the closest to that of the original *** the bottom steel slag,in addition to magnesium,certain depositions of other elements were *** matrix phases in the aged slag were dicalcium silicate and merwinite,and the chromium was mainly wrapped in these matrix phases in the form of oxides,spinels,or *** the combined effects of carbonation and oxidation,the leaching characteristics of the chromium in the aged slag varied greatly depending on the *** bottom slag had the strongest chromium leachability,and the hexavalent chromium had long-term continuous leachability.

关键词： Argon oxygen decarburization slag Aging Chromium Leaching Mineral phase

Kinetic model of chromium release from argon oxygen decarburisation(AOD)slag in a neutral leachate

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Journal of Iron and Steel Research International 2020年第11期27卷 1303-1310页

作者： Ya-nan Zeng Qian-qian Ren Bao liu jun-guo li School of Metallurgy and Energy North China University of Science and TechnologyTangshan 063200HebeiChina

Valorisation of argon oxygen decarburisation(AOD)slag,a suitable recycling resource,is limited by the release of a notable amount of heavy metals,such as *** mineralogical component of AOD slag was characterised by X-ray diffraction and scanning electron microscopy-energy-dispersive X-ray *** explore the release kinetics of chromium from AOD slag,neutral leaching tests were performed at various *** results indicated the existence of two leaching stages:quick and slow leaching *** 2 h,the chromium release fraction increased sharply as the leaching time *** the leaching time in creased,the chromium release rate gradually *** on the shrinking core model,chromium release kinetic models for the quick and slow leaching stages from the AOD slag were independently *** chromium release was controlled by solid product diffusion during the quick leaching stage and a complicated process in the slow leaching *** activation energy of chromium leaching was calculated based on the Arrhenius *** product diffusion was the velocity-determining step during the 2 h leaching *** the slow leaching stage,chromium release was controlled by complicated hybrid control dominated by solid product diffusion.

关键词： Kinetic model Chromium release Shrinking core model-AOD slag

Componentwise Complementary Cycles in Multipartite Tournaments

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Acta Mathematicae Applicatae Sinica 2012年第1期28卷 201-208页

作者： Zhi-hong HE guo-jun li Xue-qin ZHOU School of Mathematics and Information Science Yantai UniversityYantai 264005China School of Mathematics and System Sciences Shandong UniversityJinan 250100China

The problem of complementary cycles in tournaments and bipartite tournaments was completely solved. However, the problem of complementary cycles in semicomplete n-partite digraphs with n 〉 3 is still open. Based on the definition of componentwise complementary cycles, we get the following result. Let D be a 2-strong n-partite （n 〉 6） tournament that is not a tournament. Let C be a 3-cycle of D and D ／ V（C） be nonstrong. For the unique acyclic sequence D1, D2,..., Da of D ／ V（C）, where a 〉 2, let Dc = {Di｜Di contains cycles, i = 1,2,...,a}, Dc = {D1,D2,...,Da} ／ De. If Dc≠ 0, then D contains a pair of componentwise complementary cycles.

关键词： complementary cycles componentwise complementary cycles multipartite tournaments

用于催化裂化装置强制循环泵的三元导叶设计方法及性能分析研究

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风机技术 2024年第2期66卷 31-37页

作者：裴林李国君张建茹西安交通大学热流科学与工程教育部重点实验室沈鼓集团股份有限公司

强制循环泵是催化裂化装置烟气热量回收系统中重要的水循环动力设备,蜗壳为半球形结构带导叶的LUV型泵是一种广泛应用的强制循环泵,其导叶结构对泵的性能有着至关重要的影响。本文针对强制循环泵二元导叶在不同叶高处的进口叶片安装角... 详细信息

强制循环泵是催化裂化装置烟气热量回收系统中重要的水循环动力设备,蜗壳为半球形结构带导叶的LUV型泵是一种广泛应用的强制循环泵,其导叶结构对泵的性能有着至关重要的影响。本文针对强制循环泵二元导叶在不同叶高处的进口叶片安装角与水流角不匹配的问题,发展了采用后盖板和前盖板的叶片中弧线角度分布和叶片厚度分布来构建叶型的三元导叶叶片结构设计方法,并数值研究了导叶后盖板和前盖板处进出口叶片安装角对泵额定工况效率和内部流动特性的影响。结果表明:随着前后盖板叶片进出口安装角中一个变量的增大,额定流量点效率均先增大后减小;设计的三元导叶方案比二元导叶方案在额定工况下的效率提高了0.9%;后盖板附近的叶片安装角与水流角的匹配性对泵的效率起到了更加重要的作用;三元导叶方案在后盖板附近0.1叶高截面上进口水流角与叶片安装角的匹配关系得到改善,此截面上的旋涡区减少,导叶内的能量耗散减小。

关键词：强制循环泵离心泵数值模拟导叶设计导叶进出口角流动分析

Photoinduced Charge Transfer in MBB-PPV/C_(60) Composite Film

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Chinese Physics Letters 2000年第11期17卷 829-831页

作者： guo li-jun MA guo-Hong SHAN Fu-Kai MO Yu-jun QIAN Shi-Xiong Department of Physics Fudan UniversityShanghai 200433 Department of Physics Henan UniversityKaifeng 475001

The photoconductive properties of MBB-PPV/C_(60) composite films fabricated by the physical jet deposition(PJD)technique have been studied on the basis of the photoinduced charge transfer *** the photoex-citation,the transverse photoconductivity of the composite films is greatly enhanced by 4 orders of magnitude due to the efficient excitation transfer process from MBB-PPV(as donor)to C_(60)(as acceptor)occurring at the interface,the separation of charges and the existence of in-layer free *** results indicate that the conjugated polymer/fullerene composite films optimized by an appropriate configuration have potential applications in photoelectric devices and photonic fields.

关键词： composite V/C films

Leaching behavior and mineralogical evolution of vanadium released from sodium roasted-acid leaching tailing of vanadium slag

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Journal of Iron and Steel Research International 2022年第5期29卷 772-782页

作者： Bao liu Jin li Qian-qian Ren Shuang Cai Xue Yang Ya-nan Zeng jun-guo li College of Metallurgy and Energy North China University of Science and TechnologyTangshan063210HebeiChina

The sodium roasted-acid leaching tailing(SRALT)of vanadium slag with a certain amount of vanadium exhibits potential environmental *** investigate the leaching behavior of vanadium from the SRALT,neutral batch leaching tests were *** evolution of vanadium concentration,pH,redox potential(Eh),dissolved oxygen,and conductivity as a function of time was *** diagrams of V–H2O system with different vanadium concentrations were obtained to identify the ionic speciation of vanadium in leachate.X-ray diffraction,X-ray photoelectron spectroscopy,field emission-scanning electron microscopy,and thermogravimetry–differential scanning calorimetry analysis were conducted to investigate the mineralogical evolution of the SRALT during the leaching *** was found that the major minerals of the original SRALT are titanomagnetite,spinel,olivine,and *** valence states of V existing in the original SRALT are V^(3+)and V^(5+).The pH and Eh values of the obtained leachates are 10.00–10.58 and(−43)–(+67)mV,*** this pH and Eh region,the released vanadium is mainly present as HVO_(4)^(2−).The FeOOH and CaCO_(3)would form during the leaching *** HVO_(4)^(2−)would be mainly adsorbed by the FeOOH and slightly incorporated into the CaCO_(3),resulting in the decline in the vanadium *** vanadium concentration above 27 mg L^(−1)and the dissolved oxygen value below 5.0 mg L^(−1)can be obtained after a short leaching *** a V(V)-releasing and oxygen-depleting substance,the leaching toxicity of the SRALT should not be ignored.

关键词： Vanadium Vanadium slag Tailing Leaching toxicity Mineralogical analysis