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Critical behavior and magnetocaloric effect in magnetic Weyl semimetal candidate Co2-xZrSn

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Chinese Physics B 2019年第6期28卷 408-413页

作者： Tianlin Yu Xiaoyun Yu En Yang Chang sun.Xiao Zhang ming Lei State key Laboratory of Information Photonics and Optical Communications&School of Science Beijing University of Posts and Telecommunications

We investigate the critical exponents and magnetocaloric effect of Co2-xZrSn polycrystal. The Co2-xZrSn undergoes a second-order ferromagnetism phase transition around the Curie temperature of Tc ~280 k. The critical behavior in the vicinity of the magnetic phase transition has been investigated by using modified Arrott plot and kouvel–Fisher *** obtained critical exponents, β, γ, and δ can be well described by the scaling theory. The determined exponents of Co2-xZrSn obey the mean-field model with a long-range magnetic interaction. In addition, the maximum magnetic entropy change-?Sm ax m of Co2-xZrSn is about 0.57 J·kg-1·k-1 and the relative cooling power(RCP) is 14.68 J·kg-1 at 50 kOe(1 Oe = 79.5775 A·m-1).

关键词： critical phenomena magnetocaloric effect Heusler compound

Superior adsorption performance of graphitic carbon nitride nanosheets for both cationic and anionic heavy metals from wastewater

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Chinese Journal of Chemical Engineering 2019年第2期27卷 305-313页

作者： Gang Xiao Yaoqiang Wang Shengnan Xu Peifeng Li Chen Yang Yu Jin Qiufeng sun.Haijia Su State key Laboratory of Chemical Resource Engineering Beijing Advanced Innovation Center for Soft Matter Science and Engineering (BAIC-SM) Beijing University of Chemical Technology

Water pollution caused by highly toxic Cd(II), Pb(II), and Cr(VI) is a serious problem. In the present work,a green and low-cost adsorbent of g-C_3N_4 nanosheets was developed with superior capacity for both cationic and anionic heavy metals. The adsorbent was easily fabricated through one-step calcination of guanidine hydrochloride with thickness less than 1.6 nm and specific surface area of 111.2 m^2·g^(-1). kinetic and isotherm studies suggest that the adsorption is an endothermic chemisorption process, occurring on the energetically heterogeneous surface based on a hybrid mechanism of multilayer and monolayer adsorption. The tri-s-triazine units and surface N-containing groups of g-C_3N_4 nanosheets are proposed to be responsible for the adsorption *** study on pH demonstrates that electrostatic interaction plays an important role. The maximum adsorption capacity of Cd(II), Pb(II), and Cr(VI) on g-C_3N_4 nanosheets is 123.205 mg·g^(-1), 136.571 mg·g^(-1),and 684.451 mg·g^(-1), respectively. The better adsorption performance of the adsorbent than that of the recently reported nanomaterials and low-cost adsorbents proves its great application potential in the removal of heavy metal contaminants from wastewater. The present paper developed a promising adsorbent which will certainly find applications in wastewater treatment and also provides guiding significance in designing adsorption processes.

关键词： g-C3N4 nanosheets Nanomaterials Adsorption Heavy metals Wastewater

Cold stratification,temperature,light,GA3,and kNO3 effects on seed germination of Primula beesiana from Yunnan,China

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Plant Diversity 2020年第3期42卷 168-173页

作者： Li-E Yang De-Li Peng Zhi-min Li Li Huang Juan Yang Hang sun School of Tourism and Geography Yunnan Normal UniversityKunming650500YunnanChina School of Life Science Yunnan Normal UniversityKunming650500YunnanChina key Laboratory for Plant Diversity and Biogeography of East Asia Kunming Institute of BotanyChinese Academy of SciencesKunming650201YunnanChina National Germplasm Bank of Wild Species Kunming Institute of BotanyChinese Academy of SciencesKunming650201YunnanChina

Primula beesiana *** an attractive wildflower endemically distributed in the wet habitats of subalpine/alpine regions of southwestern *** study is an attempt to understand how this plant adapts to wet habitats and high ***,we examined the effects of cold stratification,light,GA3,kNO3,and temperature on *** seed ***3 and GA3 increased germination percentage and germination rate compared to control treatments at 15/5 and 25/15℃.Untreated seeds germinated well(>80%)at higher temperatures(20,25 and 28℃),whereas at lower(5,10 and15℃)and extremely high temperatures(30 and 32℃)germination decreased ***,after cold stratification(4-16 weeks),the germination percentage of *** seeds at low temperatures(5-15℃)and the germination rate at high temperatures(30℃)increased significantly,suggesting that *** has type 3 non-deep physiological *** base temperature and thermal time for germination decreased in seeds that were cold stratified for 16 ***-stratified seeds incubated at fluctuating temperatures(especially at 15/5℃)had significantly high germination percentages and germination rates in light,but not in dark,compared to the corresponding constant temperature(10℃).Seeds had a strict light requirement at all temperatures,even after experiencing cold stratification;however,the combinations of cold stratification and fluctuating temperature increased germination when seeds were transferred from dark to *** dormancy/germination responses to light and temperature are likely mechanisms that ensure germination occurs only in spring and at/near the soil surface,thus avoiding seedling death by freezing,inundation and/or germination deep in the soil.

关键词： Alpine plant Fluctuating temperature Germination ecology Light requirement Seed dormancy

焊接热循环峰值温度对1000 mPa级超高强钢热影响区组织性能的影响

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热力发电 2024年第4期53卷 165-173页

作者：孙琦李太江李巍李生文余阳李聚涛娄正计许博炜程晔锋西安热工研究院有限公司陕西西安710054

为研究1 000 mPa级超高强钢焊接热影响区(HAZ)不同区域的组织性能,采用焊接热模拟技术制备了试验钢在不同热循环峰值温度下的试样,通过夏比冲击试验研究了HAZ不同区域的冲击韧性。结果表明:在亚临界区(SCHAZ)、临界区(ICHAZ)和细晶区(FG... 详细信息

为研究1 000 mPa级超高强钢焊接热影响区(HAZ)不同区域的组织性能,采用焊接热模拟技术制备了试验钢在不同热循环峰值温度下的试样,通过夏比冲击试验研究了HAZ不同区域的冲击韧性。结果表明:在亚临界区(SCHAZ)、临界区(ICHAZ)和细晶区(FGHAZ),样品冲击吸收能量、裂纹扩展能量和动态冲击韧度较大,断口上形成较大面积的脚跟形纤维区和剪切唇,微观可看到大小不一的韧窝,样品冲击韧性较好;在粗晶区(CGHAZ),样品各项冲击数据均急剧下降,断口呈宏观脆性断裂,几乎全为放射区,微观下显示准解理断裂特征,表明裂纹扩展时受到的阻力减小,裂纹萌生后稳定扩展的时间减少,失稳扩展较快,样品的冲击韧性恶化,CGHAZ为HAZ中的韧性谷区;组织分析表明,粗大的晶粒和粗大的马氏体板条是导致CGHAZ脆化的主要原因。该结论为探究1 000 mPa级超高强钢在水电工程中的优选研制及工程应用奠定了理论基础。

关键词：超高强钢焊接热模拟焊接热影响区冲击吸收能量断裂韧度

mn含量对铸态Cu-Ni-Cr合金组织和性能的影响

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材料热处理学报 2024年第1期45卷 103-112页

作者：朱莹莹国秀花李韶林宋克兴王强松孙文明河南科技大学材料科学与工程学院河南洛阳471023 河南省有色金属材料科学与加工技术重点试验室河南洛阳471023 河南省科学院河南郑州450052 有研科技集团有限公司有色金属材料制备加工国家重点试验室北京100088 有研工程技术研究院有限公司北京101407

采用大气熔炼制备了Cu-Ni-Cr-xmn(x=0、1、3、5、7和9 mass%)合金,采用光学显微镜、扫描电镜、X射线衍射仪和电子万能试验机等研究了mn含量对铸态Cu-Ni-Cr-xmn合金显微组织和性能的影响。结果表明:铸态Cu-Ni-Cr-xmn合金的组织由富Cu相(... 详细信息

采用大气熔炼制备了Cu-Ni-Cr-xmn(x=0、1、3、5、7和9 mass%)合金,采用光学显微镜、扫描电镜、X射线衍射仪和电子万能试验机等研究了mn含量对铸态Cu-Ni-Cr-xmn合金显微组织和性能的影响。结果表明:铸态Cu-Ni-Cr-xmn合金的组织由富Cu相(γ1)、富Ni相(γ2)和富Cr相组成,mn的添加显著改变了Cu-Ni-Cr-xmn合金组织中第二相的偏聚形式。mn的加入使Cu-Ni-Cr-xmn合金组织中的Cr元素在富Ni区显著聚集,富Ni区的Cr含量显著增高。随着mn含量的增加,基体上结节状富Ni相(γ2)和富Cr相尺寸减小,分布更加均匀,大量细小富Cr第二相的存在显著提升了合金的力学性能。当mn含量为3%时,小尺寸富Cr第二相开始在晶界处偏聚形成链状结构,对合金的力学性能产生了不利影响。当mn含量为7%时,mn原子固溶强化及第二相细化效果显著,合金的力学性能最佳,其硬度和抗拉强度分别为195.06 HB和401 mPa。

关键词： Cu-Ni-Cr-xmn合金显微组织性能

山东省植被NPP时空变化特征及气候影响分析

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山东科学 2024年第5期37卷 103-110页

作者：刘建军孙开争公华林朱玉玲山东省济南生态环境监测中心山东济南250101 济南市食品药品检验检测中心山东济南250014

基于山东省2010—2022年mOD17A3产品数据,采用一元回归趋势分析、变异系数法、偏相关分析、Hurst指数法探讨山东省生态系统植被净初级生产力(NPP)时空分布特征及气候因子的影响。结果显示:2010—2022年山东省植被NPP呈波动上升的趋势,... 详细信息

基于山东省2010—2022年mOD17A3产品数据,采用一元回归趋势分析、变异系数法、偏相关分析、Hurst指数法探讨山东省生态系统植被净初级生产力(NPP)时空分布特征及气候因子的影响。结果显示:2010—2022年山东省植被NPP呈波动上升的趋势,多年均值为(398.03±150.20)g/(m^(2)·a),高于全国均值,与京津冀地区相近。NPP空间分布差异明显,东部沿海丘陵区高于内陆平原区域。年际变化上,山东省植被NPP整体较为稳定(C_(V)值为0.09)。未来植被NPP变化趋势上,正向趋势与负向趋势的面积接近,结合趋势分析,27.86%的区域呈增长趋势,33.49%的区域呈降低趋势,但由增转降的区域多集中于植被NPP较高的林地区域,需进一步研究。山东省植被NPP与气候因素有正相关关系,气温升高和降水增加有利于植被NPP的增长,但气温较降水对植被NPP有更广的显著性影响区域,且平原农作区植被NPP与气候因子相关性较差。

关键词：植被NPP 时空变化气候因子山东省

滕州市木石镇秋季大气VOCs污染特征及来源解析

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四川环境 2024年第1期43卷 16-23页

作者：纪尚平王彦张栩崔朋孙家洋中节能数字科技有限公司北京100096

使用大气挥发性有机物(VOCs)在线连续自动监测系统,对滕州市木石镇2019年11月环境空气中VOCs进行观测,并分析了VOCs的浓度状况、组成特征、光化学影响和来源。结果表明:观测期间,木石镇大气中TVOC平均体积分数为(32.75±28.96)×10^(-9)... 详细信息

使用大气挥发性有机物(VOCs)在线连续自动监测系统,对滕州市木石镇2019年11月环境空气中VOCs进行观测,并分析了VOCs的浓度状况、组成特征、光化学影响和来源。结果表明:观测期间,木石镇大气中TVOC平均体积分数为(32.75±28.96)×10^(-9),各物种体积分数从大到小顺序依次为烷烃>烯烃>OVOC>芳香烃>卤代烃>乙炔>含硫化合物;日变化规律呈双峰型,峰值在6:00~7:00时与0:00~1:00时出现。大气VOCs的平均臭氧生成潜势(OFP)为102.02×10^(-9),烯烃对臭氧生成潜势贡献率最大,为69.5%;乙烯、丙烯、正丁烯、萘和1,3-丁二烯等是臭氧生成潜势较高的物种。对OH自由基消耗速率(L OH)贡献最大的为烯烃,其次为芳香烃,两者贡献率占到76.8%。VOCs对二次气溶胶(SOA)浓度的贡献值为0.85μg/m^(3),其中芳香烃对SOA生成贡献占比为92.8%,对SOA生成贡献最大的前5个物种为萘、甲苯、苯、乙苯、间/对二甲苯。利用PmF模型对VOCs进行来源解析,结果表明:机动车排放和油气挥发源对VOCs的贡献(32.5%)最高,其次为溶剂使用及挥发源(30.9%)、工业源(25.1%)和燃煤源(11.5%)。

关键词：挥发性有机物污染特征臭氧生成潜势二次气溶胶来源解析正交矩阵因子分析法

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抽吸减容术治疗乳腺癌术后上肢淋巴水肿

组织工程与重建外科 2024年第1期20卷 69-74,82页

作者：郝昆孙宇光王仁贵沈文彬首都医科大学附属北京世纪坛医院淋巴外科北京市100038 首都医科大学附属北京世纪坛医院放射科北京市100038

目的探索抽吸减容术治疗不同程度乳腺癌术后上肢淋巴水肿的效果。方法回顾性分析2020年1月至2022年12月就诊的42例乳腺癌术后上肢淋巴水肿患者的临床资料。患者均为女性,年龄(57.19±8.79)岁;根据严重程度分为非重度组(25例)和重度组(17... 详细信息

目的探索抽吸减容术治疗不同程度乳腺癌术后上肢淋巴水肿的效果。方法回顾性分析2020年1月至2022年12月就诊的42例乳腺癌术后上肢淋巴水肿患者的临床资料。患者均为女性,年龄(57.19±8.79)岁;根据严重程度分为非重度组(25例)和重度组(17例),分析不同程度患者的临床特征,以及抽吸减容术治疗的效果。结果非重度组平均年龄为(54.6±8.85)岁,重度组平均年龄为(61.0±7.39)岁,差异有统计学意义(P=0.019)。术前非重度组BmI为(26.58±3.64)kg/m^(2),重度组BmI为(29.11±5.83)kg/m^(2),两组差异无统计学意义(P=0.091)。手术方式上,非重度/重度乳腺癌术后上肢淋巴水肿患者行淋巴水肿抽吸术,而少数极重度乳腺癌术后上肢淋巴水肿行淋巴水肿抽吸术联合病变组织切除术。非重度组与重度组相比,手术时间、注入膨胀液量、吸出脂肪悬浊液量、吸脂量、术中出血量均有统计学差异(P<0.01)。两组术毕及术后3个月肿胀程度均有明显改善(P<0.01),非重度组术毕及术后3个月的肿胀改善程度明显优于重度组,差异具有统计学意义(P<0.01)。结论抽吸减容术可以明显改善不同严重程度的乳腺癌术后上肢淋巴水肿。

关键词：减容手术吸脂术乳腺癌术后上肢淋巴水肿

In situ atomic-scale observation of size-dependent (de) potassiation and reversible phase transformation in tetragonal FeSe anodes

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Infomat 2023年第1期5卷 161-171页

作者： Ran Cai Lixia Bao Wenqi Zhang Weiwei Xia Chunhao sun.Weikang Dong Xiaoxue Chang Ze Hua Ruiwen Shao Toshio Fukuda Zhefei sun.Haodong Liu Qiaobao Zhang Feng Xu Lixin Dong Beijing Advanced Innovation Center for Intelligent Robots and Systems School of Medical TechnologyBeijing Institute of TechnologyBeijingPeople's Republic of China Analysis&Testing Center Beijing Institute of TechnologyBeijingPeople's Republic of China Department of Biomedical Engineering City University of Hong KongHong KongPeople's Republic of China Shaanxi materials Analysis and Research Center School of Materials Science and EngineeringNorthwestern Polytechnical UniversityXi'anPeople's Republic of China School of Environmental and Safety Engineering North University of ChinaTaiyuanPeople's Republic of China Department of materials Science and Engineering College of MaterialsXiamen UniversityXiamenFujianPeople's Republic of China Department of Nanoengineering University of California San DiegoLa JollaCaliforniaUSA SEU-FEI Nano-Pico Center Key Laboratory of MEMS of Ministry of EducationSoutheast UniversityNanjingPeople's Republic of China

Potassium-ion batteries(PIBs)are considered promising alternatives to lithium-ion batteries owing to cost-effective potassium resources and a suitable redox potential of-2.93 V(vs.-3.04 V for Li+/Li).However,the exploration of appro-priate electrode materials with the correct size for reversibly accommodating large k+ions presents a significant *** addition,the reaction mecha-nisms and origins of enhanced performance remain ***,tetragonal FeSe nanoflakes of different sizes are designed to serve as an anode for PIBs,and their live and atomic-scale potassiation/depotassiation mechanisms are revealed for the first time through in situ high-resolution transmission electron *** found that FeSe undergoes two distinct structural evolutions,sequen-tially characterized by intercalation and conversion reactions,and the initial intercalation behavior is *** expansion induced by the intercalation of k+ions is observed in small-sized FeSe nanoflakes,whereas unexpected cracks are formed along the direction of ionic diffusion in large-sized *** significant stress generation and crack extension originating from the combined effect of mechanical and electrochemical interactions are elucidated by geometric phase analysis and finite-element *** the different intercalation behaviors,the formed products of Fe and k_(2)Se after full potassiation can be converted back into the original FeSe phase upon *** particular,small-sized nanoflakes exhibit better cycling perfor-mance with well-maintained structural *** article presents the first successful demonstration of atomic-scale visualization that can reveal size-dependent potassiation ***,it provides valuable guidelines for optimizing the dimensions of electrode materials for advanced PIBs.

关键词： elucidated by geometric phase analysis and finite-element analysis. Despite the different intercalation behaviors the formed products of Fe and k 2 Se after full potassiation can be converted back into the original FeSe phase upon depotassiation. In particular small-sized nanoflakes exhibit better cycling perfor- mance with well-maintained structural integrity. This article presents the first successful demonstration of atomic-scale visualization that can reveal size- dependent potassiation dynamics. moreover it provides valuable guidelines for optimizing the dimensions of electrode materials for advanced PIBs. kEYWOR DS in situ transmission electron microscopy potassium-ion batteries potassium-ion storage mechanism size-dependent effects tetragonal FeSe