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Synthesis of(HfZrTiNbTa)N powders via nitride thermal reduction with soft mechano-chemical assistance

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Journal of Advanced Ceramics 2023年第3期12卷 565-577页

作者： Xiang Liu Youjun lu Qian Xu lutong Yang hongfang Shen Wenzhou Sun Xiao Zhang Yanmin Wang School of Materials Science&Engineering North Minzu UniversityYinchuan 750021China College of Materials Science&Engineering South China University of TechnologyGuangzhou 510641China

High-entropy nitride powders are one of prerequisite materials for the preparation of high-performance high-entropy nitride ceramics.In this paper,high-entropy(HfZrTiNbTa)N powders were synthesized via nitride(i.e.,silicon nitride(Si_(3)N_(4)))thermal reduction with soft mechanochemical assistance.The results show that metal oxides like hafnium dioxide(HfO_(2)),zirconium dioxide(ZrO_(2)),titanium dioxide(TiO_(2)),niobium pentoxide(Nb_(2)O_(5)),and tantalum pentoxide(Ta_(2)O_(5))can all be transformed into the corresponding metal nitrides in the presence of Si_(3)N_(4)at 1700℃,and solid solution of the metal nitrides can be formed as the temperature increases to 2100℃.The high-entropy(HfZrTiNbTa)N powders with submicron-sized particles,a narrower size distribution,and a single face-centered cubic(fcc)structure are obtained from raw material mixtures ground for 10 h and subsequently sintered at 1800℃.In addition,the high-entropy bulk nitride ceramics with relative density(Rw)of 94.31%±0.76%,Vickers hardness of 21.00±0.94 GPa,and fracture toughness(KIC)of 3.18±0.16 MPa·m1/2 are obtained with submicron-sized powders,which are superior to those obtained with micron-sized powders.

关键词： soft mechanochemistry thermal reduction high-entropy nitride powders high-entropy nitrideceramics

Physiological mechanisms underlying reduced photosynthesis in wheat leaves grown in the field under conditions of nitrogen and water deficiency

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The Crop Journal 2023年第2期11卷 638-650页

作者： Juan Kang Yingying Chu Geng Ma Yanfei Zhang Xiaoyan Zhang Mao Wang Hongfang LU Lifang Wang Guozhang Kang Dongyun Ma Yingxin Xie Chenyang Wang College of Agronomy&State Key Laboratory of Wheat and Maize Crop Science Henan Agricultural UniversityZhengzhou 450046HenanChina National Engineering Research Center for Wheat Henan Agricultural UniversityZhengzhou 450046HenanChina

Reduced photosynthesis results directly from nitrogen or water deficiency in wheat plants,and leads to a decrease in grain yield.In this study,by measuring the effects of water and N deficiencies,both individually and combined,we characterized the responses of wheat(Triticum aestivum L.Yumai 49-198)plants to these two deficiencies using physiological measurements and comparative proteomics.Significant decreases in grain yield and leaf photosynthetic performance were observed in all deficiency conditions,and 106 photosynthetic proteins that showed responses were identified.Nitrogen deficiency induced the least change in photosynthetic proteins,and similar changes in most of these proteins were also observed for the combined nitrogen and water deficiencies.Water deficiency induced the largest change in photosynthetic proteins and resulted in the lowest 1000-kernel weight.Severe decreases in photosynthesis in both the water-deficiency and combined N and water deficiency groups were reflected mainly in an imbalanced ATP/NADPH ratio associated with the light reaction,which influences carbon metabolism in the Calvin cycle.Photorespiration was respectively stimulated or inhibited by N or water deficiency,while suppression of photorespiratory flux and activation of nitrogen recycling were observed in the combined N and water deficiency treatments.Comparison of photosynthetic proteins between experimental sites suggested that precipitation affected linear electron flow in the photoreaction,and thus photosynthetic efficiency.Our results provide a baseline for future studies of the roles of these photosynthetic proteins in the response to N or water deficiency and their effect on 1000-kernel weight.

关键词： Wheat Photosynthesis Nitrogen Water Proteomics

High-temperature phase relations of ZrN–ZrO_2–Y_2O_3 ternary system

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Journal of Advanced Ceramics 2018年第4期7卷 388-391页

作者： Youjun lu Zhenxia YUAN hongfang SHEN Xiaochen HUAI Zhenkun HUANG School of Materials Science and Engineering North Minzu University School of Materials Science and Engineering Tsinghua University

Zirconium nitride(ZrN) ceramics were prepared via hot pressed sintering(HP) at 1750 ℃ in N_2 atmosphere with ZrO_2–Y_2O_3 as sintering additive. X-ray diffraction was applied to analyze the phase composition of the as-prepared ceramics to study the high temperature phase relation in ZrN –ZrO_2–Y_2O_3 ternary system and establish ZrN –ZrO_2–Y_2O_3 ternary phase diagrams. The results show that ZrN and tetragonal ZrO_2(t-ZrO_2) solid solution, face-centered cubic ZrO_2(c-ZrO_2) solid solution, body-centered cubic Y_2O_3(c-Y_2O_3) solid solution coexist in the system of ZrN –ZrO_2–Y_2O_3.

关键词： high temperature phase relations zirconium nitride (ZrN) ternary system X-ray diffraction

Low temperature hydrothermal synthesis of SrTiO3 nanoparticles without alkali and their effective photocatalytic activity

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Journal of Advanced Ceramics 2016年第4期5卷 298-307页

作者： hongfang SHEN Youjun lu Yanmin WANG Zhidong PAN Guozhong CAO Xianghui YAN Guoli FANG School of Materials Science and Engineering South China University of Technology Guangzhou 510640 ChinaSchool of Materials Science and Engineering Beifang University of Nationalities Yinchuan 750021 China School of Materials Science and Engineering Beifang University of Nationalities Yinchuan 750021 China School of Materials Science and Engineering South China University of Technology Guangzhou 510640 China Department of Materials Science and Engineering University of Washington Seattle WA 98195 USA

SrTiO3 nanoparticle (NP) photocatalyst was synthesized with a facile and environmentalfriendly hydrothermal method using tetrabutyltitanate, strontium oxide, and ethanolamine as precursors at low temperature without alkali as mineralizer for the first time. The SrTiO3 nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), and N2 Brunauer–Emmett–Teller (BET) method. The SrTiO3 catalyst synthesized at 120 °C (STO-120) exhibited the highest photocurrent intensity among the samples synthesized at different hydrothermal temperatures. The high photocatalytic performance of STO-120 was mainly attributed to the more homogeneous and minimum nanoparticle size, the highest surface area, and the maximum light absorption property among the four different samples. This work presented an applicable and facile method to fabricate a highly active and stable SrTiO3 photocatalyst for organic pollutant degradation.

关键词： polyhedral SrTiO 3 hydrothermal synthesis low temperature photocurrent property photocatalytic activity stability

Mining Representative Subset Based on Fuzzy Clustering

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Wuhan University Journal of Natural Sciences 2007年第5期12卷 799-803页

作者： ZHOU hongfang FENG Boqin lu Lintao School of Computer Science and Engineering Xi＇an University of Technology Xi＇an 710048 Shaanxi China School of Electronics and Information Engineering Xi＇an Jiaotong University Xi＇an 710049 Shaanxi China

Two new concepts-fuzzy mutuality and average fuzzy entropy are presented. Then based on these concepts, a new algorithm-RSMA （representative subset mining algorithm） is proposed, which can abstract representative subset from massive data. To accelerate the speed of producing representative subset, an improved algorithm-ARSMA（accelerated representative subset mining algorithm） is advanced, which adopt combining putting forward with backward strategies. In this way, the performance of the algorithm is improved. Finally we make experiments on real datasets and evaluate the representative subset. The experiment shows that ARSMA algorithm is more excellent than RandomPick algorithm either on effectiveness or efficiency.

关键词： representative subset fuzzy mutuality fuzzy entropy coverage redundancy

The Influence of Urbanization on Cooling Energy Consumption in Xi＇an

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Meteorological and Environmental Research 2018年第1期9卷 25-29页

作者： Shen Jiaojiao Hao Yu lu Shan Zhang hongfang Shaanxi Meteorological Service Center Xi'an 710014 China

Based on data of daily air temperature during 1951-2013,long-term variation characteristics of cooling degree days（ CDD） in Xi＇an and Chang＇an in summer were analyzed by using CDD to evaluate cooling energy consumption and 26 ℃ as the basic temperature of CDD. The results indicated that the changing trends of CDD in Xi＇an and Chang＇an were basically identical within a year,and the demand for cooling refrigeration was large mainly from June to August,especially in July. The maximum of urban-rural difference of CDD between Xi＇an and Chang＇an appeared in June.In order to achieve the same temperature,energy needed by the urban area was 5-7 ℃·d more than the suburb from June to August. Temperature and the cooling energy consumption were closely related,and the correlation degree increased with the rise of temperature. The effects of temperature increase of 1 ℃ on cooling energy consumption rate in Xi＇an were more obvious than that in Chang＇an. In both Xi＇an and Chang＇an,the effects of temperature increase of 1 ℃ on cooling energy consumption rate in July and August were greater than that in May,June and September.Evaluation models of cooling energy consumption in summer in Xi＇an and Chang＇an were built using temperature anomaly and CDD variability and can be applied to business systems.

关键词： Temperature change Cooling degree days （CDD） Cooling energy consumption Evaluation model Urbanization

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城市街道空间微商业设施布局探讨

规划师 2019年第17期35卷 57-62页

作者：吕小勇李红芳北京建筑大学建筑与城规学院

文章以城市中微商业设施的空间布局合理性为目标,基于环境行为学、环境心理学和空间规划学原理,解析影响微商业设施布局的 7 个主要指标,通过不同的数据处理方式对指标进行量化,并采用适宜性评价的方法对街道空间进行适宜性空间划分,据... 详细信息

文章以城市中微商业设施的空间布局合理性为目标,基于环境行为学、环境心理学和空间规划学原理,解析影响微商业设施布局的 7 个主要指标,通过不同的数据处理方式对指标进行量化,并采用适宜性评价的方法对街道空间进行适宜性空间划分,据此指导微商业设施的布局。同时,文章以哈尔滨市中山花园街区为例进行实证研究,分析得出了研究区内合理的微商业设施空间布局结构,并针对现状问题提出微商业设施的空间布局建议,以实现空间结构的合理优化。

关键词：街道空间适宜性评价微商业设施空间布局

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丹霞山世界自然遗产地旅游生态系统能值分析

生态环境学报 2019年第7期28卷 1297-1306页

作者：隋春花陆宏芳韶关学院旅游与地理学院广东韶关512005 中国科学院华南植物园广东广州510650

基于能值理论与方法,通过实地调研、访谈咨询和查阅文献,搜集研究所需的相关数据,构建丹霞山旅游生态系统能量分析结构图和能值指标体系。从遗产地母系统和景区、乡村旅游亚系统两个层面,从生态、社会和经济3个角度,对丹霞山旅游生态系... 详细信息

基于能值理论与方法,通过实地调研、访谈咨询和查阅文献,搜集研究所需的相关数据,构建丹霞山旅游生态系统能量分析结构图和能值指标体系。从遗产地母系统和景区、乡村旅游亚系统两个层面,从生态、社会和经济3个角度,对丹霞山旅游生态系统的自然资产、生态服务、经济功能和社会效益等主要能值指标进行分析,并将丹霞山的能值研究结果,与其他方法研究丹霞山的研究结果、与其他地区的能值研究结果进行比较。结果表明,丹霞山世界自然遗产地拥有的砂砾岩自然资产总能值为1.94×10^43 sej,生物多样性总能值为6.09×10^27 sej,二者合计的总能值--货币价值为4.25×10^31 yuan(￥)。同时,2016年丹霞山世界自然遗产地的生态服务总能值为2.61×10^20 sej·a^-1,社会教育总能值为4.27×10^21 sej·a^-1。得益于得天独厚的自然资源优势,丹霞山景区旅游亚系统社会经济投入强度较低,其能值自给率和能值经济效益分别是乡村旅游亚系统的45倍和4倍。以餐饮和民宿为主的乡村旅游亚系统的人力投入是景区旅游的3倍多的同时,污染物排放环境压力是景区的81倍。丹霞山旅游生态系统、景区旅游亚系统和乡村旅游亚系统的能值可持续ESI指数分别为10.83、4.05和0.02,3个系统分属不同旅游经济发展状态。最后从遗产地、景区、乡村和政府4个方面提出丹霞山旅游生态系统的优化建议,如遗产地方面,扩大遗产地接待游客的面积;景区旅游方面,重点打造科普旅游品牌;乡村旅游方面,规范管理引领美丽乡村建设;地方政府方面,加强环境整治和开发引导。

关键词：丹霞山世界自然遗产地景区旅游乡村旅游能值评价

民族旅游小镇地方性生产的阶段性“蝶变”及特征研究--以云南省大理市双廊镇为例

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地域研究与开发 2022年第5期41卷 105-111页

作者：刘宏芳明庆忠韩璐云南财经大学旅游文化产业研究院昆明650221

以地方性生产为主线、以大理市双廊镇为研究对象,采用历时性研究法,以标志性事件为断裂点将其发展分为初始期、探索期、剧烈变化期及整改提升期4个阶段,解析不同阶段地方性生产特征、效应及其发生机理。结果表明:民族旅游小镇地方性生... 详细信息

以地方性生产为主线、以大理市双廊镇为研究对象,采用历时性研究法,以标志性事件为断裂点将其发展分为初始期、探索期、剧烈变化期及整改提升期4个阶段,解析不同阶段地方性生产特征、效应及其发生机理。结果表明:民族旅游小镇地方性生产的主要力量是地方政府引导及新移民地方实践。初始期是政府主导下的官方塑造与自在呈现;发展期政府对地方景观建设有所引导,市场化、资本化力量逐渐介入;剧烈变化期在资本掌控下旅游情境中的地方性生产出现无序状态,政府规制效力甚微;整改提升期多重政策叠加优势显著,政府逐步建立起有力的话语体系、规制框架与行动方案,地方性彰显与生态保护、艺术气息注入、旅游服务设施建设、传统文化复振一道共轭,呈现出良性“蝶变”态势。在经济欠发达的民族旅游小镇,民族文化与时尚文化的创造性转化以及政府对旅游开发的理性管控起重要作用。

关键词：旅游小镇民族旅游地方性生产与建构大理市双廊镇