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Mechanism and Improvement of Straight Edge Seam Defect on Hot-rolled Plate Surfaces through Use of Chamfered Slabs

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Journal of Iron and Steel Research International 2016年第6期23卷 539-546页

作者： hui ZHANG Peng hu Ming-lin WANG National Engineering and Research Center for Continuous Casting Technology Central Iron and Steel Research Institute School of Metallurgy Northeastern University

To improve the straight edge seam defect on hot-rolled steel plates,the deformation and temperature distribution of rectangular slabs and chamfered slabs during rolling in a pilot rolling experiment were analyzed in detail using the finite element *** results showed that the crease formed on the lateral side near the edge of the plate as a result of uneven stress during broadside *** creases rose to the surface with unrestricted spread and evolved into a straight edge seam during the subsequent straight *** eliminate the straight edge seam defect,chamfered slabs were developed and investigated for *** use of the chamfered slabs provided two advantages for rolling：the distribution of the temperature near the edge was ameliorated,and the deformation shape was improved by the chamfered *** a result,the risk of forming a straight edge seam defect was reduced by the use of a chamfered slab.

关键词： straight rolled rolling eliminate subsequent corner rectangular defects crease tensile

A面和C面AlGaN/GaN异质结的比较研究

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微电子学 2017年第4期47卷 562-565,571页

作者：胡仕刚吴青杨李劲湖南科技大学信息与电气工程学院湖南湘潭411201

采用MOCVD技术在R面和C面蓝宝石上生长非极性A面和极性C面Al Ga N/Ga N异质结。分别用X射线衍射仪和原子力显微镜比较了两种材料的结构特性及表面形貌,通过电容-电压测试比较了两种材料的电学特性。研究结果表明,较高浓度的二维电子气... 详细信息

采用MOCVD技术在R面和C面蓝宝石上生长非极性A面和极性C面Al Ga N/Ga N异质结。分别用X射线衍射仪和原子力显微镜比较了两种材料的结构特性及表面形貌,通过电容-电压测试比较了两种材料的电学特性。研究结果表明,较高浓度的二维电子气的存在使得极性材料在微波功率器件方面更有优势,而非极性材料可以消除与极化相关的电场,更适合应用于光电器件领域。

关键词：氮化镓原子力显微镜异质结非极性

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泡沫碳化硅陶瓷表面原位生长碳化硅晶须

材料研究学报 2006年第3期20卷 291-294页

作者：曹小明张劲松胡宛平杜庆洋中国科学院金属研究所沈阳市110016

采用固相和液相反应法在泡沫碳化硅陶瓷骨架表面原位生长碳化硅晶须,研究了催化剂和反应温度的影响．结果表明,催化剂氯化镍的作用使硅与碳直接反应生长出细长的碳化硅晶须．在适当的反应温度下生长的碳化硅晶须的表面光滑,线径比较大,... 详细信息

采用固相和液相反应法在泡沫碳化硅陶瓷骨架表面原位生长碳化硅晶须,研究了催化剂和反应温度的影响．结果表明,催化剂氯化镍的作用使硅与碳直接反应生长出细长的碳化硅晶须．在适当的反应温度下生长的碳化硅晶须的表面光滑,线径比较大, 有少量的呈弯曲状或竹节状;反应温度过高使得硅晶须的缺陷较多．在泡沫碳化硅陶瓷骨架的表面原位生长出碳化硅晶须属于LS 生长机理．具有表面晶须的碳化硅陶瓷以深床体积过滤的方式用于过滤柴油机汽车尾气中的碳颗粒,表面晶须既能提高泡沫陶瓷过滤器的过滤能力,又有利于过滤器的再生．

关键词：泡沫碳化硅陶瓷,碳化硅晶须,原位生长

基于红外热成像技术的着装热阻计算与热舒适:夏季室内不同活动水平下的人员研究

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建筑科学 2024年第8期40卷 139-149页

作者：刘国丹张瑶胡鹏城钟会阳姜姗青岛理工大学环境与市政工程学院山东青岛266033

针对如何实现非接触式采集数据并估计室内热舒适度,设置了代谢率为1 met、1.8 met和2.6 met共3种活动水平和常见的2种服装搭配组合,研究夏季不同工况下室内人员着装热阻值的计算算法,并由热阻值计算预计平均热感觉指数(PMV值),将PMV计... 详细信息

针对如何实现非接触式采集数据并估计室内热舒适度,设置了代谢率为1 met、1.8 met和2.6 met共3种活动水平和常见的2种服装搭配组合,研究夏季不同工况下室内人员着装热阻值的计算算法,并由热阻值计算预计平均热感觉指数(PMV值),将PMV计算值与受试者问卷调查的实际热感觉投票(TSV)进行比较,分析每种算法的可行性和准确性。研究结果表明,非接触法在实现数据采集非接触测试的基础上,预测不同活动水平下室内人员的热舒适性与问卷调查最为接近,热感觉偏差均值为0.46个单位,但随着活动水平的增加,由于出汗对皮肤温度的影响,热感觉预测的准确性降低。本文还考虑了面颈部温度和皮肤湿润度对平均皮温的修正。并由非接触法得到的PMV值与ASV之间偏差均值降为0.42个单位,标准误差降低8.5%,相关性更强,可较精准地非接触实时预测冬季不同活动水平下室内人员的着装热阻值及热舒适性,对室内人员热舒适的获取和环境参数的智能化调节有一定意义。

关键词：服装热阻实际着装 PMV

Theoretical and Experimental Studies for the Transient Response of Cavity

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Journal of Thermal Science 2020年第1期29卷 232-240页

作者： hu Jianping LIU Zhenxia Zhu Pengfei LYU Yaguo School of Power and Energy Northwestern Polytechnical UniversityXi’an 710129China Shaanxi Key Laboratory of Internal Aerodynamics in Aero-Engine Xi’an 710129China

During the transient state of aero-engine,cavity has evidently transient characteristics in the secondary air *** investigate transient characteristics,theoretical and experimental studies were implemented for both static and rotating *** of all,the typical transient response phenomena in secondary air system were investigated based on the basic concepts of the dynamic *** to the basic theory of gas dynamics,the causes of transient phenomena were analyzed in two aspects,external disturbance,and system physical *** dimensionless parameters were introduced to analyze the transient response characteristics of air ***,the experimental results of the static cavity indicated that the actual response time increased with the increase of the inlet *** experimental results of the rotor-stator cavity showed that the low rotational speed on the response process had little effect,and the response time gradually increased when the speed continued to ***,the test results of multiple components suggested that when the valve was opening the inlet pressure of the static cavity increased quickly and then reached a stable value,but the pressure of the static cavity,stable pressure cavity and rotor-stator chamber rose *** was also obtained the actual response time of them was *** closer the measuring points were to the disturbance source,the shorter the delay time was.

关键词： secondary air system static cavity rotating cavity transient response experiment

Metabolism of adrenal androgen and its impacts on prostate cancer after castration

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Chinese Medical Journal 2008年第4期121卷 369-374页

作者： hu Ming-qiu NA Yan-qun Department of Urology Peking University First Hospital Beijing 100034 China

With the extensive utilization of PSA, digital rectum examination and transrectal ultrasound for screening in the aging population, the diagnosis of prostate cancer in China has markedly increased during the past years, particularly in developed regions. It was reported that the prevalence of prostate cancer in Shanghai city from 1973 to 1975 was 1.6/100 000 persons and rose to 7.7/100 000 persons by 2000.

关键词： adrenal androgen prostate cancer

噻吩基二维共价有机框架中的拓扑结构诱导局部电荷极化促进光催化制氢

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Chinese Journal of Catalysis 2024年第4期59卷 225-236页

作者：白浚贤沈荣晨梁桂杰秦朝朝许第发胡浩斌李鑫华南农业大学生物质工程研究院农业部能源植物资源与利用重点实验室广东广州510642 湖北文理学院低维光电材料与器件重点实验室湖北襄阳441053 河南师范大学物理学院红外材料与光谱测量及应用重点实验室河南新乡453007 长沙大学应用环境光催化重点实验室湖南长沙410022 陇东学院石油化工学院陇东油气资源高效利用重点实验室甘肃庆阳745000

共价有机框架(COFs)是近年来新兴的一类多孔聚合物,在气体吸附、传感器、能源转换和光/电催化等领域表现出较大的应用潜力.然而,欲实现多样化的应用需求常需要对其结构进行合成后改性,这在单一步骤中难以实现.二维亚化学计量共价有机框... 详细信息

共价有机框架(COFs)是近年来新兴的一类多孔聚合物,在气体吸附、传感器、能源转换和光/电催化等领域表现出较大的应用潜力.然而,欲实现多样化的应用需求常需要对其结构进行合成后改性,这在单一步骤中难以实现.二维亚化学计量共价有机框架(2D-SSCOFs)因其独特的周期性官能团和保持结晶性及孔隙率的能力,成为COFs功能化的新途径.然而,已报道的2D-SSCOFs多具有相同的拓扑结构以及弱电荷极化等问题,限制了其应用潜力.因此,开发具有新颖拓扑结构的2D-SSCOFs对于实现更前沿的功能至关重要.窄带隙噻吩是有机半导体材料的常见单元,它们可以显著地调控共价聚合物骨架的电子和化学环境.本文通过5,5',5''-(苯-1,3,5-三基)三(噻吩-2-甲醛)(TT-3CHO)与4,4',4'',4''-(芘-1,3,6,8-四基)四苯胺(PY-4HN2)的席夫碱缩合反应合成具有大表面积和高结晶度的亚胺连接的新型2D-SSCOF(PTT-COF).噻吩环中2,5位之间的键的弯曲角度使得PTT-COF具有新型的2D亚化学计量拓扑结构,并呈现出非中心对称的优势极化结构.在使用有机空穴传输配体(二茂铁甲醛,FC)精确修饰和Pt作为助催化剂时,PTT-COF-FC体系在可见光照明下表现出较高的析氢产率(79.610 mmol g^(-1) h^(-1)).同时,在420 nm波长的光照下,2 mg的光催化剂表观量子效率达到1.72%.此外,经过24 h循环稳定性测试,PTT-COF-FC体系的活性没有明显下降.为了深入研究PTT-COF-FC体系的高效的产氢机制,通过X射线衍射、红外和固体碳谱等对PTT-COF-FC体系的组成和结构进行分析,确定了PTT-COF-FC的成功合成.通过瞬态吸收、变温荧光和理论计算等研究了材料的激子解离和载流子转移行为.结果表明,得益于独特的富含噻吩的结构设计以及有机空穴传输配体的修饰作用,PTT-COF-FC展现出高效的激子解离和丰富的自由电荷载流子特性.综上所述,本文设计和合成了一种新型PTT-COF光催化材料,其独特的二维亚化学计量拓扑结构和显著的局部电荷极化特性赋予了材料良好的光催化性能.实验和理论研究表明,PTT-COF中的非中心对称拓扑结构和噻吩单元的引入,有效扩展了π离域,进而诱导了局部极化并抑制了激子效应,从而大幅提高了光催化效率.此外,通过二茂铁甲醛的后修饰,结合这些独特的结构特性,PTT-COF在光催化析氢反应中表现出高活性和出色的长期耐久性.本文的研究不仅为设计和构建具有独特结构的新型2D-SSCOF提供新思路,也为构建具有丰富光催化功能的材料开辟了新途径.

关键词：光催化产氢电荷分离亚化学计量共价有机框架拓扑结构激子效应

Comparative Study on Optical Properties and Scratch Resistance of Nanocomposite Coatings Incorporated with Flame Spray Pyrolyzed Silica Modified via in-situ Route and ex-situ Route

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Journal of Materials Science & Technology 2016年第3期32卷 251-258页

作者： Yun Wang Ling Zhang Yanjie hu Chunzhong Li Key Laboratory for Ultrafine Materials of Ministry of Education School of Materials Science and Engineering East China University of Science and Technology

A new type of transparent scratch resistant coatings including in-situ modified SiO2 （g-SiO2） in flame spray pyrolysis （FSP） process was prepared. The maximum content of g-SiO2 in the coating was 15 wt%, which is higher than that of SiO2 modified by traditional wet chemical route （I-SiO2, only 10 wt%）. The results of transmission electron microscopy have demonstrated that in-situ surface modified g-SiO2 particles dispersed well with smaller agglomerates in the final coating, which was much better than the particles modified via wet chemical route. Visible light transmittance and haze tests were introduced to characterize the optical quality of the films. All coatings were highly transparent with the visible light transmittance of above 80%, especially for coatings containing g-SiO2, which exhibited slightly higher visible light transmittance than l-SiO2 embedded one. The haze value of coatings incorporated with 15 wt% g-SiO2 was 1.85%, even lower than the coating with 5 wt% I-SiO2 （haze value of 2.09%）, indicating much better clarity of g-SiO2. The excellent optical property of g-SiO2 filled coatings was attributed to the good dispersion and distribution of particles. Nano-indention and nano-scratch tests were con- ducted to investigate the scratch resistance of coatings on nano-scale. The surface hardness of the coatings rose by 18% and 14%, and the average friction coefficient decreased by 15% and 11%, respectively, compared to the neat coat due to the addition of 10 wt% g-SiO2 and I-SiO2. The pencil hardness of the coating with 15 wt% g-SiO2 increased from 2B for the neat coating to 2H. However, the pencil hardness of coating with 10 wt% I-SiO2 was only H. The results showed that the g-SiO2 embedded coatings exhibited higher scratch resistance and better optical properties.

关键词： ln-situ modification Silica Coating Scratch resistance Optical property

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北黄海东部次盆地构造热机制与成烃效应

地学前缘 2024年第4期31卷 206-218页

作者：刘金萍王改云简晓玲朱传庆胡小强袁晓蔷王超自然资源部海底矿产资源重点实验室广东广州511458 广州海洋地质调查局广东广州511458 中国石油大学(北京)油气资源与探测国家重点实验室北京102249

北黄海东部次盆地属于中新生代小型叠合断陷盆地,是我国海域勘探程度较低的一个盆地,对其经历的复杂构造-热演化史尚未有相关研究。本文利用镜质体反射率(R_o)和磷灰石裂变径迹(AFT)两种古温标进行多方法的热史模拟,获得了盆地中新生界... 详细信息

北黄海东部次盆地属于中新生代小型叠合断陷盆地,是我国海域勘探程度较低的一个盆地,对其经历的复杂构造-热演化史尚未有相关研究。本文利用镜质体反射率(R_o)和磷灰石裂变径迹(AFT)两种古温标进行多方法的热史模拟,获得了盆地中新生界的热流史及地温梯度的变化,并恢复了盆地的剥蚀量及抬升剥蚀过程,在此基础上研究了盆地内烃源岩的热演化历史。结果表明,东部次盆地从中侏罗世至今,经历了古热流由高(75~90 mW/m^(2),120~100 Ma)到低(60 mW/m^(2),40 Ma),然后再升高至现今(70 mW/m^(2))的过程,且早期(100~70 Ma)降温缓慢,后期(70~40 Ma)降温快速。古地温梯度相应地呈现由高(34~36℃/km)到低(23℃/km),再升高(28℃/km)的变化趋势。东部次盆地晚白垩世之前的古地温梯度和古热流高于现今的地温梯度和热流,这与盆地由断陷阶段-坳陷阶段的演化过程一致。东部次盆地晚白垩世—始新世经历了较强的抬升剥蚀,地层的剥蚀厚度为1.0~1.5 km,在100~90 Ma地层沉积开始缓慢或停止,明显的剥蚀过程发生在85~40 Ma,其中70~40 Ma为快速剥蚀阶段。东部次盆地的构造热演化史影响了盆地内烃源岩的生烃过程。中上侏罗统两套烃源岩都存在早期(晚侏罗世—早白垩世)生烃过程,在中部坳陷内的主体生烃坳陷,晚白垩世—始新世地层剥蚀厚度较小,且渐新世之后地层沉积厚度较大,现今能够达到的地温也越高,有利于烃源岩晚期生烃,证实了该盆地具有一定的勘探潜力,应围绕主体生烃坳陷寻找有利成藏区。

关键词：东部次盆地磷灰石裂变径迹镜质体反射率构造热演化史成烃效应