检索结果-南通市图书馆

Journal of Iron and Steel Research International 2016年第11期23卷 1160-1167页

作者： Feng PAN Qing-shan ZHU zhan DU Hao-yan SUN State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of Sciences(CAS)Beijing 100190China University of Chinese Academy of Sciences Beijing 100039China

The oxidation kinetics, structural changes, and elements migration during the oxidation process of the va- nadium-titanium magnetite （VTM） ore were analyzed. Kinetics analysis indicated that the oxidation process was con- trolled by diffusion control and could be divided into interface diffusion and lattice diffusion with apparent activation energy of 99.69 kJ/mol and 144.08 kJ/mol in the range of 800--1000℃, respectively. The surface structure changed with the oxidization temperature as follows： dense surface→nano sized sheets→submicron particles→molten particles. The compact structure changed into porous one because of the elements migration and enrichment. Both Fe and Ti elements migrated in the opposite direction during the oxidation process. The V etement in the raw ore stably existed in the form of V^5＋ state, some vanadium migrated and occupied the tetrahedral sites of the hematite during the oxidation process.

关键词： vanadium-titanium magnetite ore oxidation kinetics structural change element migration

Ternary superhydrides for high-temperature superconductivity at low pressures

在线全文

学校读者我要写书评

暂无评论

National Science Review 2024年第7期11卷 12-14页

作者： Pengfei shan Liang ma Jinguang Cheng Beijing National Laboratory for Condensed matter Physics and Institute of Physics Chinese Academy of Sciences School of Physical Sciences University of Chinese Academy of Sciences Key Laboratory of materials Physics Ministry of Education School of Physics and Microelectronics Zhengzhou University

The quest for room-temperature superconductivity(RTSC) has been a longstanding pursuit in physics since the discovery of superconductivity in *** to the conventional Bardeen-Cooper-Schrieffer theory, atomic metallic hydrogen holds great promise for achieving this goal due to its high Debye temperature and strong electron-phonon coupling.

关键词： temperature conductivity high perc pressures superhydrides ternary

REGIONAL CONTAINER PORT COMPETITION IN A DUAL GATEWAY-PORT SYSTEM

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Systems Science and Systems Engineering 2016年第4期25卷 491-514页

作者： Mingzhu Yu Jun shan Lijun ma Department of Transportation Engineering College of Civil Engineering Shenzhen University Shenzhen Guangdong 518060 China School of management Jinan University Guangzhou Guangdong 510632 China Department of management Science College of Management Shenzhen University Shenzhen Guangdong 518060 China

many ocean transportation hub systems consist of two container ports that share the container handling business in the area. The container flow passing through a port is the main measurement of the port＇s competitiveness. In this paper we adopt a Hotelling model to study the container port competition in a so-called ＂dual gateway-port system＂. The system contains two ports and two terminals, one belonging to each port. The two governments in which the two ports are located compete on cargo fees and the two terminals determine service price and service quality. We study two models with different levels of competition between the terminals. In the ftrst model, the two terminals are owned by two different operators and in the second model, the two terminals are centralized under one operator. The second model exists in practice but is not well studied in the literature. We derive the cargo fee, terminal service price, and service quality equilibria for these two models. We investigate the competition outcome sensitivity with a numerical study. The numerical results reveal that governments prefer terminals to compete with each other. If the terminals do not have competitive advantages in their service quality, then terminal centralization brings more profits to the terminal operator than the competition case.

关键词： Container port competition container terminal competition Hotelling model

Thermal Analysis and Identification of Potential Fire-proof Energy Building material Based on Artificial Leather

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

Journal of Thermal Science 2019年第1期28卷 88-96页

作者： ma Yujie DANG Xugang shan Zhihua The Key Laboratory of Leather Chemistry and Engineering (Sichuan University) Ministry of Education School of Chemistry and materials Science Sichuan Normal University

Artificial leather fire-proof materials have obtained a good market due to stable production quality and low production price. Three kinds of artificial leather materials(polyvinyl chloride artificial leather(PVC), polyurethane artificial leather(PU) and polyurethane/polyvinyl chloride artificial leather(PU/PVC)) have been investigated, and then seven analysis methods were introduced to identify the materials. Thermo-gravimetric analysis indicated the materials had fine thermal stability. Fire-proof testing revealed the artificial leather materials had good flame retardancy, which could improve the applicability of fire-proof building materials. Tearing examination results indicated that there was a clear distinction between PVC and PU. The PU displayed significant differences compared with PVC or PVC/PU through pH indicator to observe the color of the pyrolysis gas aqueous solution. The dissolution tests results showed that cyclohexanone, dichloromethane and dimethylformamide(DMF) were efficient solvents that could be used for identifying PVC, PU and PU/PVC. The ATR-FTIR, a way to provide the high discriminating ability for identifying artificial leathers, indicated that the artificial leathers had different infrared characteristic peaks. In addition, the main compositive materials of the artificial leathers could be inferred by the relative contents analysis of N and Cl in artificial leathers.

关键词： polyvinyl chloride polyurethane artificial leather identification ATR-FTIR

Formation of a new intermediate phase and its evolution toward θ’ during aging of pre-deformed Al-Cu alloys

在线全文

学校读者我要写书评

暂无评论

Journal of materials Science & Technology 2019年第5期35卷 885-890页

作者： Peipei ma Chunhui Liu Ziyao ma Lihua zhan Minghui Huang Light Alloy Research Institute of Central South University State Key Laboratory of High-Performance Complex Manufacturing Central South University Changsha 410083 China School of Mechanical and Electrical Engineering Central South University Changsha 410083 China

The frequent occurrence of hitherto unknown phase Pre-θ′-2 and unusual 1.5 cθ′thick θ′precipitate was observed by atomic-resolution scanning transmission electron microscopy in the well-studied Al-Cu alloys. This phenomenon is associated with heterogeneous precipitate nucleation and growth on preexisting dislocations introduced by slight deformation prior to aging. In this study, the precise structure details of Pre-θ′-2 was determined by atomic scale imaging, image simulation based on image forming theories and first principle calculations. Pre-θ′-2 has a well-defined ordered structure sandwiched between two 2 aAl(~1.5 cθ′) spaced Cu layers on {200}Alplanes. The strong structural similarities between Pre-θ′-2 and 1.5 cθ′ thick θ′ in terms of interfacial structure and thickness, coupled with energetic calculations and preliminary in-situ observations, lead us to propose a new precipitation path toward key strengthening phase θ′

关键词： Aluminum alloys Precipitation Deformation Age-harde ning

双参通脉颗粒抑制ERK1/2-NF-κB信号通路改善急性心肌梗死模型大鼠心肌损伤作用机制研究

在线全文

学校读者我要写书评

暂无评论

中国药业 2025年第3期34卷 57-62页

作者：吴杨王秀詹三华高杉安徽省铜陵市人民医院安徽铜陵244000 安徽医科大学药学院安徽合肥230032

目的探讨双参通脉颗粒(GSG)是否通过抑制细胞外活化蛋白激酶1/2-核因子-κB(ERK1/2-NF-κB)信号通路改善急性心肌梗死(AMI)模型大鼠的心肌损伤。方法将60只SD大鼠分为假手术组(A组,等量生理盐水),模型组(B组,等量生理盐水),阿托伐他汀... 详细信息

目的探讨双参通脉颗粒(GSG)是否通过抑制细胞外活化蛋白激酶1/2-核因子-κB(ERK1/2-NF-κB)信号通路改善急性心肌梗死(AMI)模型大鼠的心肌损伤。方法将60只SD大鼠分为假手术组(A组,等量生理盐水),模型组(B组,等量生理盐水),阿托伐他汀组(C组,8 mg/kg),GSG低、中、高剂量组(D1组、D2组、D3组,5,10,15 g/kg),各10只。除A组外,其余各组大鼠通过左冠状动脉前降支结扎建造AMI模型,造模成功后24 h灌胃相应药物。检测各组大鼠的心功能;采用酶联免疫吸附试验(ELISA)法检测血清炎性因子,按试剂盒操作检测生化指标;分别采用2,3,5-氯化三苯基四氮唑(TTC)染色法、苏木精-伊红(HE)染色法、原位末端标记(TUNEL)法检测心肌梗死、病理损伤及细胞凋亡情况;采用免疫印迹(Western blot)法检测细胞凋亡与通路相关蛋白表达情况。结果与B组比较,D1组、D2组、D3组大鼠左心室收缩压(LVSP)、平均动脉压(maP)、左心室内压上升最大速率(+dp/dt_(max))、B细胞淋巴瘤-2(Bcl-2)表达水平均显著升高(Pmax))、左心室舒张末压(LVEDP)、肿瘤坏死因子-α(TNF-α)、单核细胞趋化蛋白1(MCP-1)、白细胞介素(IL)-6、IL-1β、肌钙蛋白I(cTnI)、肌酸激酶同工酶(CK-MB)、心肌梗死程度、心肌细胞凋亡率、胱天蛋白酶-3(caspase-3)、B淋巴细胞瘤2相关X蛋白(Bax)、p-ERK1、p-ERK2、NF-κB p65表达水平均显著降低(P<0.05)。结论GSG可能通过抑制ERK1/2-NF-κB信号通路改善AMI模型大鼠的心肌损伤。

关键词：双参通脉颗粒细胞外活化蛋白激酶1/2 核因子-κB 急性心肌梗死心肌损伤

在线全文

学校读者我要写书评

暂无评论

粗粒土力学特性大型平面应变试验研究

长江科学院院报 2025年第1期42卷 129-135,143页

作者：姜景山左永振程展林黄鑫张超王志华南京工程学院建筑工程学院南京211167 长江科学院水利部岩土力学与工程重点实验室武汉430010 河海大学岩土工程科学研究所南京210098 南京吉欧地下空间科技有限公司南京211816

土石坝填料一般处于平面应变状态,目前填料力学特性研究基本采用大型三轴试验。由于三轴应力状态下中主应力等于小主应力,平面应变状态下大坝填料的力学性能会被低估。为充分认识填料潜能,科学设计和合理评估土石坝,有必要对填料开展平... 详细信息

土石坝填料一般处于平面应变状态,目前填料力学特性研究基本采用大型三轴试验。由于三轴应力状态下中主应力等于小主应力,平面应变状态下大坝填料的力学性能会被低估。为充分认识填料潜能,科学设计和合理评估土石坝,有必要对填料开展平面应变试验研究。应用大型真三轴仪对填料进行了大型平面应变试验,共开展了4种不同初始干密度的粗粒土平面应变各向等压固结排水剪切试验。结果表明:应力-应变关系主要为应变硬化型,应力曲线呈爬升型,体变表现为剪缩。某一小主应力下,大小主应力之差的最大值随初始干密度的增大呈线性增大;初始干密度一定时,大小主应力之差的最大值与小主应力呈线性关系增大。初始剪切阶段,小主应力一定时,偏应力与球应力之比曲线斜率随初始干密度的增大而增大,随剪切变形的发展,不同初始干密度的应力比曲线逐渐趋于接近。偏应力随球应力的增大单调增加则对应应变硬化型,若偏应力随球应力的增大先增加后减小则对应应变软化型。相同小主应力时,初始弹性模量随初始干密度的增大而增大,近似呈线性关系;某一初始干密度下,初始弹性模量随小主应力的增大基本呈线性关系增大。中主应力系数随大主应力方向应变的增大而增大,曲线形态呈三折线形,初始剪切阶段增长较为缓慢,随剪切变形的增大增长相对加快并呈线性关系增大,如曲线末端下弯为应变硬化型,曲线末端上翘为应变软化型。

关键词：粗粒土大型平面应变试验力学特性主应力偏应力球应力大型真三轴仪

在线全文

学校读者我要写书评

暂无评论

乡村振兴战略下培育乡村文化自信路径探析

邵阳学院学报(社会科学版) 2025年第01期24卷 70-75页

作者：山蕊蕊马婷婷西北大学马克思主义学院山东农业大学马克思主义学院

乡村文化自信是增强乡村凝聚力、促进乡村文化创造性转化和创新性发展的关键举措，为推动乡村振兴提供强大的精神动力和智力支持，也为凝聚乡村人才力量、创新乡村治理方式、营造文明乡风、建设宜居宜业和美乡村奠定了基础。当前，由于... 详细信息

乡村文化自信是增强乡村凝聚力、促进乡村文化创造性转化和创新性发展的关键举措，为推动乡村振兴提供强大的精神动力和智力支持，也为凝聚乡村人才力量、创新乡村治理方式、营造文明乡风、建设宜居宜业和美乡村奠定了基础。当前，由于城市文化、外来文化的冲击，乡村文化面临着主体性缺失、认同感缺乏、凝聚力消解等多重危机，培育乡村文化自信遭到制约。在此情况下，应大力发展乡村文化事业和文化产业，传承创新乡村优秀文化并借助数字技术发扬乡村文化，激发农民文化主体意识，激活乡村文化建设内生动力，推动实现乡村文化自信。

关键词：乡村振兴乡村文化文化自信乡村文化振兴

强化固溶对Al-Mg-Si-Sn合金时效行为的影响

在线全文

学校读者我要写书评

暂无评论

中南大学学报(自然科学版) 2025年第1期56卷 55-67页

作者：柳旭刘春辉马培培湛利华尹焯炀中南大学轻合金研究院湖南长沙410083 中南大学极端服役性能精准制造全国重点实验室湖南长沙410083 中南大学高等研究中心湖南长沙410083

使用维氏显微硬度计、透射电子显微镜(TEM)研究固溶温度对Al-Mg-Si-Sn合金的时效硬化行为和微观结构的影响。研究结果表明:将固溶处理(ST)温度从560℃提高到590℃(强化固溶温度)显著延缓了Al-Mg-Si-Sn合金的自然时效(NA),合金固溶淬火后... 详细信息

使用维氏显微硬度计、透射电子显微镜(TEM)研究固溶温度对Al-Mg-Si-Sn合金的时效硬化行为和微观结构的影响。研究结果表明:将固溶处理(ST)温度从560℃提高到590℃(强化固溶温度)显著延缓了Al-Mg-Si-Sn合金的自然时效(NA),合金固溶淬火后,自然时效硬度峰值时间从3 d延缓到13 d,然而,强化固溶没有明显改变人工时效(AA)样品的峰时效态析出相的尺寸和峰值硬度;空位占比大于1的Sn-空位复合体更加稳定,说明强化固溶通过同时提高空位浓度和Sn的溶解度,增强Sn元素对空位的束缚,从而延缓自然时效团簇的形成;人工时效强化相主要为在含Sn团簇上异质形核形成的β"/β'复合相;由于强化固溶只能略微增加Sn的溶解度,因此,对峰值时效析出的影响很小;Sn元素的不同作用机制导致强化固溶对自然时效和人工时效产生不同影响。

关键词： Al-Mg-Si合金固溶处理 Sn元素自然时效时效析出

维普期刊数据库博看期刊

Comprehensive urbanization level and its dynamic factors for five Central Asian countries

在线全文

学校读者我要写书评

暂无评论

Journal of Geographical Sciences 2020年第11期30卷 1761-1780页

作者： ma Haitao SUN zhan Key Laboratory of Regional Sustainable Development Modeling Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China

In the context of accelerated development of the Silk Road Economic Belt,it is necessary to conduct in-depth research on urbanization of Central Asian *** paper analyzes the spatial and temporal patterns and evolution dynamics of urbanization during the period 1991-2017 from the perspective of internal-external *** results are as follows.(1)The urbanization process of the five Central Asian countries studied is significantly influenced by their political and economic situations and displays periodic *** five countries experienced a stagnation development stage at the beginning of independence,and then a rapid growth stage since the year *** average annual growth rates of the two stages were 0.19% and 1.45%,respectively.(2)Differences in the urbanization of the studied countries are obvious,and the evolutionary characteristics of each subsystem of urbanization are *** is therefore necessary to distinguish and clearly understand the urbanization process of each country.(3)Internal and external factors play a role in the urbanization processes of Central Asian *** railway transportation facilities are particularly important for the development of urbanization in these *** regression coefficients of railway construction length,total merchandise trade and actually utilized foreign capital are 0.5665,0.0937 and 0.0806,respectively.(4)Countries with smaller populations and economic scales need to engage in international cooperation to promote healthy development of *** results of the study indicate that internal and external factors work together in the urbanization process of Central Asian countries,and external forces are particularly important for the development of such urbanization.

关键词： Central Asia national scale comprehensive urbanization dynamic factors external dynamics Silk Road Economic Belt