检索结果-南通市图书馆

Impact of fluorine on crystal-melt separation in high-silica magma: Insights from muscovite in the Ramba leucogranite of Tethyan Himalaya

引用

Journal of Earth Science 2024年

作者： li-ran chen Wang-Chun Xu lian-Xun Wang Hong-Fei Zhang Wuhan State Key Laboratory of Geological Processes and Mineral Resources and School of Earth Sciences China University of Geosciences

The process of crystal-melt separation in the high-silica magmatic mush is still a subject of debate. To explore the process， we conducted a detailed study of Late Miocene leucogranites (SiO2＞70 wt.%) in the Ramba Dome of the Tethyan Himalaya， focusing on the genesis and fluorine content of muscovite. The Ramba leucogranites consist of two-mica granite with minor garnet-bearing granite. Large and euhedral muscovites are found in both types of granite exhibiting different geochemical features. The muscovites from the two-mica granites exhibit lower F (mean value: ～0.41–0.43 wt.%)， FeO (mean value: ～1.75–1.81 wt.%)， but higher TiO2(mean value: ～0.61–0.73 wt.%) contents compared to those from the garnet-bearing granites (mean F value: ～0.72%; mean FeO value: 2.48 wt.%; mean TiO2value: ～0.23 wt.%). According to geochemical criteria， we categorized the muscovites from the two-mica granite as two groups: (1) crystallized from the early magma， and (2) formed from interstitial residual melt. In comparison， the muscovite from the garnet-bearing granite was likely crystallized from residual melt extracted from the same magmatic reservoir which underwent a higher degree of evolution. Accordingly， the two-mica granite represents the residual crystal mush consisting of early crystals crystallized from magma and trapped interstitial residual melt， while the garnet-bearing granite represents the aggregation of extracted residual melt. We examined the possibility of crystal-melt separation by estimating the variation of fluorine content and viscosity between the early magma and residual melt. Our results indicate a notable disparity in fluorine content between the residual melt (mean value: ～4364 ppm) and the early magma (mean value: ～2033 ppm). As a result， the estimated viscosity experiences a reduction from 106.52Pa s for the early magma to 105.87Pa s for the residual melt. The fluorine enrichment could have played a critical role in decreasing melt viscosity and initiating crys

关键词：

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

Neighboring optimal guidance using higher-order dynamics approximation with application to orbital injection problem

引用

Chinese Journal of Aeronautics 2024年第5期37卷 426-440页

作者： Xinglun chen ran ZHANG Huifeng li School of Astronautics Beihang UniversityBeijing 100191China

Neighboring optimal guidance,a method to obtain a suboptimal guidance law by approximately solving the first-order necessary conditions based on a nominal trajectory,is widely used in the aerospace field due to its high computational efficiency and low resource *** more advanced scenarios,the existing methods still have a problem that the guidance accuracy and optimality will seriously degrade when the actual state largely deviates from the nominal *** is mainly caused by the approximate description of the first-order conditions in terms of total flight time and nonlinear *** address this problem,a higher-order neighboring optimal guidance method is ***,a novel total flight time updating strategy,together with a normalized time scale,is presented that transforms the optimal problem with free total flight time into a more tractable optimal problem with fixed total flight ***,using the vector partial derivative method,a higher-order approximation is adopted,instead of the first-order approximation,to accurately describe the nonlinear dynamical and terminal constraints,thus obtaining a polynomially constrained quadratic optimal ***,to numerically solve the polynomially constrained quadratic optimal problem,a Newton-type iterative algorithm based on the orthogonal decomposition is *** the iterative solution within each guidance period,the corrections to control quantities and total flight time are *** proposed method is applied to a launch vehicle orbital injection problem,and simulation results show that it achieves high accuracy of orbital injection and optimality of performance index.

关键词： Optimal control Neighboring optimal guidance Launch vehicles Orbital injection Higher-order approximation

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

Recent advancements in hydrometallurgical recycling technologies of spent lithium-ion battery cathode materials

引用

Rare Metals 2024年第3期43卷 879-899页

作者： Juan Wu li Xiao li Shen Jian-Jun ran Hui Zhong Yi-Rong Zhu Han chen College of Materials and Advanced Manufacturing Hunan University of TechnologyZhuzhou412007China School of Resources Processing and Bioengineering Central South UniversityChangsha410083China Guangdong JiaNa Energy Technology Company Qingyuan513000China

The rapidly increasing production of lithium-ion batteries(liBs)and their limited service time increases the number of spent liBs,eventually causing serious environmental issues and resource *** the perspectives of clean production and the development of the liB industry,the effective recovery and recycling of spent liBs require urgent *** study provides an overview of the current hydrometallurgical processes employed in the recycling of spent cathode materials,focusing on the leaching of valuable metals and their *** particular,this research reviews the various leaching systems(inorganic acid,organic acid,and ammonia)and the separation of valuable metals,and then,recommendations for subsequent study are offered in an attempt to contribute to the development of highly efficient methods for recycling spent cathode *** addition,a range of existing technologies,such as solvent extraction,chemical precipitation,electrochemical deposition,and regeneration,for the postprocessing of leaching solutions are ***,the promising technologies,existing challenges and suggestions with respect to the development of effective and environmentally friendly recycling methods for handling spent cathode materials are identified.

关键词： Spent lithium-ion batteries(liBs) Cathode material Hydrometallurgy Leaching Recycling

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

Prediction for permeability index of blast furnace based on VMD-PSO-BP model

引用

Journal of Iron and Steel Research(International) 2024年第3期31卷 573-583页

作者： Xiao-jie liu Yu-jie Zhang Xin li Zhi-feng Zhang Hong-yang li ran liu Shu-jun chen School of Metallurgy and Energy North China University of Science and TechnologyTangshan 063210HebeiChina chengde Branch HBIS Group Co.Ltd.Chengde 067000HebeiChina

The permeability index is one of the important production indicators to monitor the operation of blast *** is crucial to grasp the trends of changes in the new permeability index in *** the complex vibration spectrum of the permeability index,a prediction model of the permeability index based on the VMD-PSO-BP(variational mode decomposition-particle swarm optimization-back propagation)method was ***,the key factors that affect the permeability index of blast furnace were studied from multiple ***,the permeability index was divided into multiple sub-modes based on the difference of frequency bands by the VMD algorithm,and a PSO-BP prediction model was established for each ***,the prediction results of each sub-mode were summed to obtain the final *** results show that the composite prediction accuracy by using the VMD algorithm is 3%higher than that of the traditional prediction method,which has better applicability.

关键词： Big data-Blast furnace Air permeability Variational mode decomposition Particle swarm optimization Back propagation Model prediction

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

Structure and Representations for Electrical lie Algebra of Type D_(5)

引用

Algebra Colloquium 2024年第2期31卷 271-284页

作者： Yulu chen ran Shen Yucai Su College of Science Donghua UniversityShanghai 201620China 不详

In this paper,we prove that the electrical lie algebra e D_(5)is isomorphic to the semidirect product of sp_(4)and a 2-step nilpotent lie ***,we classify the irreducible highest weight modules for e D_(5).

关键词： electrical lie algebra 2-step nilpotent lie algebra highest weight module

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

Effects of in-situZrB_2 nanoparticles and scandium on microstructure and mechanical property of 7N01 aluminum alloy

引用

Journal of Rare Earths 2024年第3期42卷 612-620,I0007页

作者： Xizhou Kai Yuhui Wang Ruikun chen Yanjie Peng Anjun Shi ran Tao Xiangfeng liang Guirong li Gang chen Xiaojing Xu Yutao Zhao School of Material Science and Engineering Jiangsu UniversityZhenjiang212013China Institute for Advanced Manufacturing and Modern Equipment Technology Jiangsu UniversityZhenjiang212013China

In this study, the in-situ synthesized ZrB_(2) nanoparticles and rare earth Sc were introduced to enhance the strength and ductility of 7N01 aluminum alloy, via the generation of high-melting and uniform nanodispersoids. The microstructure and mechanical property evolution of the prepared composites and the interaction between ZrB_(2) and Sc were studied in detail. The microstructure investigation shows that the introduction of rare earth scandium(Sc) can promote the distribution of ZrB_(2) nanoparticles, by improving their wettability to the Al melt. Meanwhile, the addition of rare earth Sc also modifies the coarse Al Zn Mg Mn Fe precipitated phases, refines the matrix grains and generates high-melting Al_3(Sc,Zr)/Al_3Sc nanodispersoids. Tensile tests of the composites show that with the combinatorial introduction of ZrB_(2) and Sc, the strength and ductility of the composites are improved simultaneously compared with the corresponding 7N01 alloy, ZrB_(2) /7N01 composite and Sc/7N01 alloy. And the optimum contents of ZrB_(2) and Sc are 3 wt% and 0.2 wt% in this study. The yield strength, ultimate strength and elongation of(3 wt% ZrB_(2) +0.2 wt% Sc)/7N01 composite are 477 MPa, 506 MPa and 9.8%, increased about 18.1%, 12.2%and 38% compared to 7N01 alloy. Furthermore, the cooperation strengthening mechanisms of ZrB_(2) and Sc are also discussed.

关键词： 7N01 aluminum alloy In-situ ZrB_(2)nanoparticles Rare earth Sc Microstructure Mechanical property Mechanism

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

Effect of micro-Al_(2)O_(3) powders on oxidation and corrosion behaviors of low-carbon MgO-C refractories

引用

Journal of Iron and Steel Research(International) 2024年第6期31卷 1522-1534页

作者： Yang chen Zeng-yi li Hao-bo Tan Yu-ran Fu Jun Ding cheng-ji Deng Chao Yu School of Materials Science and Engineering Hunan Institute of TechnologyHengyang 421002HunanChina The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina

To solve the problem of poor high-temperature service performance caused by low carbonization of MgO-C refractories,low-carbon MgO–C refractories with excellent thermal shock,oxidation and corrosion resistances were successfully designed by using SiC whiskers as reinforcing phases and introducing micro-Al_(2)O_(3) powders as *** results indicated that the addition of micro-Al_(2)O_(3) powders optimized the internal structure of the material,like the columnar β-Si_(3)N_(4) with a stepped distribution and the mosaic structure formed between granular and flaky Mg_(2)SiO_(4),which synergistically strengthened and toughened the material and gave the material excellent mechanical properties and thermal shock ***,the cold modulus of rupture and cold crushing strength after thermal shock were increased by 4.1 and 20.3 MPa,***,the addition of micro-Al_(2)O_(3) powders promoted the formation of fine particles of Mg_(2)SiO_(4),MgAl_(2)O_(4) and MgO,as well as a dense protective layer of Mg_(2)SiO_(4) in the material under high-temperature ***,spinel and high-temperature solid solution were formed in the corrosion *** oxidation and corrosion resistances were greatly improved by 41%and 15%,respectively.

关键词： Low-carbon MgO-C refractory Oxidation resistance Corrosion resistance Thermal shock resistance Micro-Al_(2)O_(3)powder

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

Biochar alleviates apple replant disease by reducing the growth of Fusarium oxysporum and regulating microbial communities

引用

Horticultural Plant Journal 2024年第3期10卷 657-671页

作者： Yinghao liu Can Wang ran chen Weitao Jiang Yun li chengmiao Yin Yanfang Wang Zhiquan Mao College of Chemistry and Material Science Shandong Agricultural UniversityTaianShandong 271018China State Key Laboratory of Crop Biology/College of Horticultural Science and Engineering Shandong Agricultural UniversityTaianShandong 271018China

Apple replant disease(ARD)negatively affects plant growth and reduces yields in replanted *** this study,biochar was applied to apple replant soil with Fusarium *** aim was to investigate whether biochar could promote plant growth and alleviate apple replant disease by reducing the growth of harmful soil microorganisms,changing soil microbial community structure and improving the soil *** experiment included five treatments:apple replant soil(CK),methyl bromide fumigation apple replant soil(FM),replant soil with biochar addition(2%),replant soil with *** spore solution(8×10^(7)spores·mL^(-1)),and replant soil with biochar and *** spore solution *** biomass,the activity of antioxidant enzymes in the leaves and roots,and soil environmental variables were *** community composition and community structure were analyzed using 16SrDNA and ITS2 gene *** significantly reduced the abundance of *** and increased soil microbial diversity and *** also increased the soil enzyme activities(urease,invertase,neutral phosphatase,and catalase),the biomass(plant height,fresh weight,dry weight)and the activity of antioxidant enzymes(superoxide dismutase,peroxidase,and catalase).The root indexes of apple seedlings was also increased in replant soil by *** sum,biochar promoted the growth of plants,improved the replant soil environment,and alleviated apple replant disease.

关键词： Biochar Fusarium oxysporum Apple replant disease Soil environment

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

Relationship between the Stratospheric Arctic Vortex and Surface Air Temperature in the Midlatitudes of the Northern Hemisphere

引用

Journal of Meteorological Research 2024年第1期38卷 39-52页

作者： Xue ran Dingzhu HU Yang ZHANG Mei-chen liU Key Laboratory of Meteorological Disaster Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environmental Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)Nanjing University of Information Science&TechnologyNanjing 210044 School of Atmospheric Sciences Nanjing UniversityNanjing 210023

It is known that different relationships exist between the strength and displacement of the stratospheric polar vortex(SPV),and the surface air temperature(SAT)patterns in Eurasia and North America,but the mechanisms behind these relationships remain unclear,especially on an interannual *** on empirical orthogonal function(EOF)analysis using NCEP reanalysis data over 1958–2018,this study attempts to ascertain the relationship between the SPV intensity and displacement over the Arctic and the SATs in the midlatitudes of the Northern *** results indicate that a strengthened SPV corresponds to an SAT increase in Eurasia and a decrease in eastern North America and *** the SPV is shifted towards Eurasia,however,a corresponding SAT increase occurs in both North America and Eurasia,with a larger increase in North America than in ***,a strengthened SPV tends to correspond to a positive North Atlantic Oscillation-like circulation in the troposphere with negative geopotential height(GH)anomalies in Greenland and eastern North American continent and positive GH anomalies to the north of 45°N in Eurasia,which corresponds to lower SATs in North America than in ***,when the SPV shifted towards Eurasia,it was accompanied by a positive Pacific/North American-like pattern with a deepened Aleutian low,which corresponds to the increasing SATs in North *** tropospheric circulation changes are related to the response of tropospheric planetary wave activity to the SPV.A strengthened SPV corresponds to the weakening of tropospheric planetary wave-1 waves,which is accompanied by a negative GH in North America but a positive GH in *** the SPV shifted towards Eurasia,the tropospheric planetary wave-1(-2)waves strengthened(weakened),and the combined effects of the planetary wave-1 and wave-2 waves would cause positive GH anomalies in both Eurasia and North America.

关键词： stratospheric polar vortex surface air temperature teleconnection patterns planetary waves

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

Assessment of the three representative empirical models for zenith tropospheric delay(ZTD) using the CMONOC data

引用

Geodesy and Geodynamics 2024年第5期15卷 488-494页

作者： Debao Yuan Jian li Yifan Yao Fei Yang Yingying Wang ran chen Tairan Xu College of Geoscience and Surveying Engineering China University of Mining and Technology-Beijing Hubei Luojia Laboratory

The precise correction of atmospheric zenith tropospheric delay(ZTD) is significant for the Global Navigation Satellite System(GNSS) performance regarding positioning accuracy and convergence time. In the past decades, many empirical ZTD models based on whether the gridded or scattered ZTD products have been proposed and widely used in the GNSS positioning applications. But there is no comprehensive evaluation of these models for the whole China region, which features complicated topography and climate. In this study, we completely assess the typical empirical models, the IGGtropSH model(gridded, non-meteorology), the SHAtropE model(scattered, non-meteorology),and the GPT3 model(gridded, meteorology) using the Crustal Movement Observation Network of China(CMONOC) network. In general, the results show that the three models share consistent performance with RMSE/bias of 37.45/1.63, 37.13/2.20, and 38.27/1.34 mm for the GPT3, SHAtropE and IGGtropSH model, respectively. However, the models had a distinct performance regarding geographical distribution, elevation, seasonal variations, and daily variation. In the southeastern region of China, RMSE values are around 50 mm, which are much higher than that in the western region, approximately 20 mm. The SHAtropE model exhibits better performance for areas with large variations in elevation. The GPT3 model and the IGGtropSH model are more stable across different months, and the SHAtropE model based on the GNSS data exhibits superior performance across various UTC epochs.

关键词： GNSS Zenith tropospheric delay Empirical ZTD model CMONOC data

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

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：