检索结果-南通市图书馆

基于射线追踪法的矿井可见光通信信道特性分析

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

通信技术 2024年第8期57卷 769-774页

作者：马仲甜张隆康刘付刚路宁刘新宇周脉勇黑龙江科技大学黑龙江哈尔滨150001 双鸭山矿业集团有限公司黑龙江双鸭山155199

提出了一种新颖的基于射线追踪法的矿井可见光通信信道特性分析方法。首先,结合煤矿工作面可见光应用场景和煤矿工作面特点,基于射线追踪法建立可见光通信信道模型;其次,通过米尔散射理论对煤尘粒子对可见光的散射特征进行分析,计算得... 详细信息

提出了一种新颖的基于射线追踪法的矿井可见光通信信道特性分析方法。首先,结合煤矿工作面可见光应用场景和煤矿工作面特点,基于射线追踪法建立可见光通信信道模型;其次,通过米尔散射理论对煤尘粒子对可见光的散射特征进行分析,计算得出消光系数、散射系数和吸收系数与煤尘粒子大小的关系;最后,针对不同煤尘粒子浓度的吸光度和粒子半径之间的关系进行仿真,分析煤尘粒子浓度对吸光度的影响。实验结果表明,矿井可见光通信信道特性受煤尘粒子半径和浓度影响较大,当煤尘粒子半径小于1μm时,对光的散射和吸收极为敏感,随着煤尘粒子半径的增大,消光系数趋于稳定。此外,相同煤尘粒子半径下,煤尘粒子浓度越高,吸光度越大,散射越明显。

关键词：矿井可见光通信射线追踪法煤尘粒子浓度米尔散射

Constructing orthogonally structured graphene nanointerface on SiC nanowires reinforced carbon/carbon composites to boost mechanical strength and strength retention rate

在线全文

学校读者我要写书评

暂无评论

Journal of Materiomics 2024年第3期10卷 615-623页

作者： Yao Guo Shouyang zhang Qiang Song Fei Zhao longkang Cong Wei Li Ruimei Yuan State Key Laboratory of Solidification Processing Shaanxi Key Laboratory of Fiber Reinforced Light Composite MaterialsNorthwestern Polytechnical UniversityXi'an 710072China Advanced Interdisciplinary Research Center for Flexible Electronics Academy of Advanced Interdisciplinary ResearchXidian UniversityXi'an 710072China

Carbon/carbon composites with higher mechanical strength and better reliability at elevated tempera-tures are urgently needed to satisfy the practical applications *** nanowires(SiCNWs)modified C/C(SC-CC)composites have attracted an abundance of attention for their excellent mechanical *** further boost the mechanical strengths of composites and maximize the reinforcing efficiency of SiCNWs,we introduce orthogonally structured graphene nanosheets(OGNs)into SC-CC composites,in which OGNs are grafted on the SiCNWs via chemical vapor deposition(CVD)method,forming SC-G-CC *** from the nano-interface effects,uniform stress distribution,strong SiCNWs/PyC interfacial bonding and elevated stress propagation efficiency in the PyC matrix are achieved,thus SC-G-CC composites accomplish brilliant mechanical properties before and after 1,600℃ heat *** temperature rises to 2,100℃,SiCNWs lose efficacy,whereas OGNs with excellent thermal stability continue to play the nano-interface role in the PyC ***,SC-G-CC com-posites show better mechanical performance after 2,100℃ heat treatment,and the mechanical strength retention rate(MSR)of interlaminar shear strength,out-of-plane and in-plane compressive strength of SC-G-CC composites reach 61.0%,55.7%and 55.3%,*** work proposes an alternative thought for maximizing the potentiality of nanomaterials and edifies the mechanical modification of composites.

关键词： SiC nanowires Orthogonally structured graphene nanosheets Carbon/carbon composites Mechanical properties Heat treatment

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

广西农民运动讲习所的创办及农运干部培训

中共桂林市委党校学报 2017年第4期17卷 64-67页

作者：张隆康中共河池市委党校广西河池54700

广西农民运动讲习所,被誉为右江革命的摇篮,它是继广州农讲所之后开办时间较早、规模较大、影响颇为深远的农民运动讲习所。广西农讲所的举办,有力地推动了广西工农运动向前发展,为传播革命思想,推动右江农民运动、百色起义和红七军的创... 详细信息

广西农民运动讲习所,被誉为右江革命的摇篮,它是继广州农讲所之后开办时间较早、规模较大、影响颇为深远的农民运动讲习所。广西农讲所的举办,有力地推动了广西工农运动向前发展,为传播革命思想,推动右江农民运动、百色起义和红七军的创建,作出了重大的历史贡献。

关键词：广西农讲所韦拔群农运干部

脱金属-还原策略诱导创制高分散PtZn合金催化剂用于丙烷脱氢反应

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Catalysis 2023年第12期55卷 241-252页

作者：张龙康马跃刘昌呈万志鹏翟承伟王新徐浩关业军吴鹏华东师范大学化学与分子工程学院上海市绿色化学与化工过程重点实验室上海200062 中石化石油化工科学研究院有限公司石油化工分子转化与反应工程全国重点实验室北京100083 中石化石油化工科学研究院有限公司北京100083

丙烷脱氢(PDH)是一种高效的丙烯生产工艺.近年来随着页岩气产量的增加,PDH逐渐成为替代石油催化裂化增产丙烯的重要方法之一.Pt基双金属催化剂在催化PDH领域被广泛研究.其中,PtZn合金双金属催化剂因较好的催化活性和较强的经济可行性,... 详细信息

丙烷脱氢(PDH)是一种高效的丙烯生产工艺.近年来随着页岩气产量的增加,PDH逐渐成为替代石油催化裂化增产丙烯的重要方法之一.Pt基双金属催化剂在催化PDH领域被广泛研究.其中,PtZn合金双金属催化剂因较好的催化活性和较强的经济可行性,被认为是PDH反应的理想催化剂之一.PtZn合金主要有Pt_(1)Zn_(1),PtZn1.7和Pt3Zn等,其中Pt_(1)Zn_(1)催化PDH反应的活性最好.采用传统共浸渍法制备的PtZn双金属催化剂的金属物种容易分布不均匀,并且成分组成复杂,可能会有多种PtZn合金以及金属单质生成,因此催化活性不理想.如何制备高分散的Pt_(1)Zn_(1)合金催化剂对于PDH工艺的发展有着重要的意义.本文报道了一种分子筛脱金属-还原诱导的策略,将高分散的PtZn合金纳米颗粒负载到Beta沸石上用于PDH反应.首先,在乙二胺的辅助下通过一步水热法合成了杂原子分子筛Zn@Beta.X射线衍射、高分辨透射电镜和紫外-可见光(UV-vis)光谱等结果证明Zn@Beta被成功合成,并且Zn主要以单分散的骨架Zn物种存在.随后,通过简单的浸渍法负载金属***-vis光谱、X射线光电子能谱(XPS)、傅里叶变换红外光谱和氢气程序升温还原等结果表明,在浸渍的过程中骨架Zn物种从分子筛骨架移出,并与游离的Pt物种产生了强相互作用.再经H2还原最终得到催化剂0.3Pt1Zn@Beta (Pt和Zn的负载量分别为0.3 wt%和1 wt%).XPS、同步辐射吸收谱和球差矫正电镜结果表明,0.3Pt1Zn@Beta形成了以Pt_(1)Zn_(1)合金物种为主的金属纳米颗粒,而通过共浸渍法制备的PtZn双金属催化剂0.3Pt1Zn/Beta中除了Pt_(1)Zn_(1)合金以外,还有大量的金属Pt单质生成.PDH催化性能评价结果表明,与0.3Pt1Zn/Beta和单金属催化剂0.3Pt/Beta相比,0.3Pt1Zn@Beta表现出更好的PDH催化活性和稳定性.550°C反应时,0.3Pt1Zn@Beta催化生成丙烯的速率为128 mmol/gcat./h,而0.3Pt1Zn/Beta和0.3Pt/Beta催化生成丙烯的仅为75和21 mmol/gcat./h.在550°C,1 bar,C3H8:N2 (V:V)=1:4,丙烷空速4.7 h^(-1)的反应条件下,丙烷初始转化率和丙烯初始选择性分别为36.8%和99.3%,24 h连续反应失活率低至0.004 h^(-1).并且在共氢气条件下实现了180 h的平稳运行.0.3Pt1Zn@Beta也表现出了良好的再生性能,经7次循环后仍能保持较好的催化活性,并且再生过程仅需简单的氢气吹扫,避免了空气焙烧导致的金属颗粒的团聚和温室气体的排放.综上所述,本文发展了一种分子筛脱金属-还原诱导策略,可合成高分散的Pt_(1)Zn_(1)合金催化剂并高效催化PDH反应.该方法的关键是Pt浸渍过程中骨架Zn物种迁移出分子筛骨架并与Pt产生强相互作用,有效克服了共浸渍法制备的双金属催化剂分布不均匀、成分不单一的缺点,为沸石负载双金属催化剂的合成提供新思路.

关键词：脱金属-还原诱导策略 PtZn合金 Beta分子筛丙烷脱氢

在线全文

学校读者我要写书评

暂无评论

孔挤压工艺在钛合金回转梁上的应用工艺研究

制造技术与机床 2023年第10期 111-115页

作者：李成华吴明春张隆康曹焱唐和城冯健光成都飞机工业(集团)有限责任公司四川成都610092

开缝衬套冷挤压强化是抗疲劳增寿技术中行之有效的强化技术,广泛应用于飞机关键零件连接孔的强化中,实际工程应用场景下强化的孔端面多为非配合平面,对于强化后的孔出口端的材料凸起可通过修挫、铣削加工去除,无难度;但针对飞机全动小... 详细信息

开缝衬套冷挤压强化是抗疲劳增寿技术中行之有效的强化技术,广泛应用于飞机关键零件连接孔的强化中,实际工程应用场景下强化的孔端面多为非配合平面,对于强化后的孔出口端的材料凸起可通过修挫、铣削加工去除,无难度;但针对飞机全动小翼的核心零件回转梁圆柱轴线上的相贯孔的孔挤压强化实施难度大,主要是因为回转梁材料为钛合金、外圆尺寸精度高且有防腐蚀的喷涂层,强化后如何去除圆轴上孔口周围隆起的材料并保证高精度外圆尺寸,如何保证孔挤压强化不破坏喷涂层等都是施工中的工艺难点,这造成孔挤压工艺在这类场景下迟迟不能应用。文章针对此场景,从工程应用角度进行试验设计及验证,最终得出了可行的工艺方案,成功解决了孔挤压工艺在钛合金回转梁圆柱相贯孔上的应用难题。

关键词：孔挤压相贯孔钛合金回转梁

High-entropy(Y_(0.2)Gd_(0.2)Dy_(0.2)Er_(0.2)Yb_(0.2))2Hf_(2)O_(7) ceramic: A promising thermal barrier coating material

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2022年第6期101卷 199-204页

作者： longkang Cong Wei Li Jiancheng Wang Shengyue Gu Shouyang zhang State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China Department of Materials Physics School of ScienceXi’an University of Posts and TelecommunicationsXi’an 710121China

Thermal barrier coating(TBC)materials perform an increasingly important role in the thermal or chemical protection of hot components in a gas *** this study,a novel high entropy hafnate(Y_(0.2)Gd_(0.2)Dy_(0.2)Er_(0.2)Yb_(0.2))_(2)Hf_(2)O_(7) was synthesized by solution combustion method and investigated as a potential TBC *** as-synthesized(Y_(0.2)Gd_(0.2)Dy_(0.2)Er_(0.2)Yb_(0.2))_(2)Hf_(2)O_(7) possesses a pure single disordered fluorite phase with a highly homogeneous distribution of rare earth(RE)cations,exhibiting prominent phase stability and excellent chemical compatibility with Al_(2)O_(3) even at 1300°***,(Y_(0.2)Gd_(0.2)Dy_(0.2)Er_(0.2)Yb_(0.2))_(2)Hf_(2)O_(7) demonstrates a more sluggish grain growth rate than Y_(2)Hf_(2)O_(7).The thermal conductivity of(Y_(0.2)Gd_(0.2)Dy_(0.2)Er_(0.2)Yb_(0.2))_(2)Hf_(2)O_(7)(0.73-0.93 W m^(-1)K^(-1))is smaller than those of components RE_(2)Hf_(2)O_(7) and many high entropy TBC ***,the calculated thermal expansion coefficient(TEC)of(Y_(0.2)Gd_(0.2)Dy_(0.2)Er_(0.2)Yb_(0.2))_(2)Hf_(2)O_(7)(10.68×10^(-6)/K,1100°C)is smaller than that of yttriastabilized zirconia(YSZ).Based on the results of this work,(Y_(0.2)Gd_(0.2)Dy_(0.2)Er_(0.2)Yb_(0.2))_(2)Hf_(2)O_(7) is suitable for the next generation TBC materials with outstanding properties.

关键词： High entropy ceramic Thermal barrier coating material Disordered fluorite structure Thermophysical properties

Thermophysical properties of a novel high entropy hafnate ceramic

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2021年第26期85卷 152-157页

作者： longkang Cong Shouyang zhang Shengyue Gu Wei Li State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi'an710072China Author links open overlay panel Department of Materials Physics School of ScienceXi’an University of Posts and TelecommunicationsXi’an710121China State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi'an710072China

High-entropy oxides(HEOs)are considered promising thermal barrier coating(TBC)materials due to their unique thermophysical performances induced by the entropy *** this work,(La_(0.2)Ce_(0.2)Pr_(0.2)Sm_(0.2)Eu_(0.2))_(2)Hf_(2)O_(7)high entropy hafnate,as a thermal barrier coating(TBC)material,was successfully synthesized by solution combustion method for the first *** the X-ray diffraction,scanning electron microscopy,and transmission electron microscopy results,it is confirmed that(La_(0.2)Ce_(0.2)Pr_(0.2)Sm_(0.2)Eu_(0.2))_(2)Hf_(2)O_(7)has pure single-phase ordered pyrochlore structure with highly homogeneous composition at both micrometer and nanometer *** synthesized(La_(0.2)Ce_(0.2)Pr_(0.2)Sm_(0.2)Eu_(0.2))2 Hf2O7 possesses excellent phase stability at 1600℃and demonstrates a low thermal conductivity(1.0-1.24 W·m^(-1)·K^(-1))which is lower than those of rare earth hafnates(RE2Hf2O7,RE=La,Ce,Pr,Sm,Eu).Therefore,it provides a new perspective and potential to prompt the next generation TBC materials with better performance.

关键词： High-entropy ceramic Rare-earth hafnate Thermal barrier coating Thermal conductivity

Geochemistry of Late Triassic pelitic rocks in the NE part of Songpan-Ganzi Basin,western China:Implications for source weathering,provenance and tectonic setting

在线全文

学校读者我要写书评

暂无评论

Geoscience Frontiers 2012年第5期3卷 647-660页

作者： Yah Tang longkang Sang Yanming Yuan Yunpeng zhang Yunlong Yang College of Earth Science and Resources Chang'an University Xi'an 710054 PR China Faculty of Earth Sciences China University of Geosciences Wuhan 430074 PR China Xi'an Center of Geological Survey China Geological Survey Xi'an 710054 PR China SINOPEC Exploration Southern Company Chengdu 610082 PR China

Major, trace and rare earth element （REE） concentrations of Late Triassic sediments （fine- grained sandstones and mudstones） from Hongcan Well 1 in the NE part of the Songpan-Ganzi Basin, western China, are used to reveal weathering, provenance and tectonic setting of inferred source areas. The Chemical Index of Alteration （CIA） reflects a low to moderate degree of chemical weathering in a cool and somewhat dry climate, and an A-CN-K plot suggests an older upper continental crust prove- nance dominated by felsic to intermediate igneous rocks of average tonalite composition. Based on the various geochemical tectonic setting discrimination diagrams, the Late Triassic sediments are inferred to have been deposited in a back-arc basin situated between an active continental margin （the Kunlun- Qinling Fold Belt） and a continental island arc （the Yidun Island Arc）. The Triassic sediments in the study area underwent a rapid erosion and burial in a proximal slope-basin environment by the petrographic data,while the published flow directions of Triassic turbidites in the Aba-Zoige region was not supported Yidun volcanic arc source. Therefore, we suggest that the Kunlun-Qinling terrane is most likely to have supplied source materials to the northeast part of the Songpan-Ganzi Basin during the Late Triassic.

关键词： Fine-grained sandstone-mudstone Geochemistry Source area weathering Provenance Tectonic setting Songpan-Ganzi Basin,China

Illite Crystallinity Mapping of Very Low Grade Metamorphism of Triassic Metapelites in the Zoigê Area,Western China

在线全文

学校读者我要写书评

暂无评论

Acta Geologica Sinica(English Edition) 2012年第1期86卷 96-105页

作者： TANG Yan SANG longkang YUAN Yanming YU Jishun zhang Yunpeng QI Xianmao YANG Yunlong Faculty of Earth Sciences China University of GeosciencesWuhan 430074China College of Earth Science and Resources Chang'an UniversityXi'an 710054China State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesWuhan 430074China Xi'an Center of Geological Survey China Geological SurveyXi'an 710054China Chengdu Institute of Geology and Mineral Resources Chengdu 610082China Sinopec Exploration Southern Company Chengdu 610082China

X-ray diffraction methods for estimating the metamorphic grade of diagenetic, anchizone and epizone in metapelites are reviewed and applied to samples from a 7000 m＋ borehole in western China and surface samples from the surrounding Zoige area. Kiibler＇s illite crystallinity （IC） measurements provide more consistent results than calculated values of percentage of illite in the I/S mixed layers and percentage of I/S mixed layers. Down-borehole IC values display a typical burial metamorphic relationship between stratigraphic level and IC. A method for preparing very low grade metamorphic maps is described, and isograds plotted on a regional geological map at selected values of IC, delineating a high temperature diagenetic zone, an anchizone, and an epizone. The map shows that IC values are controlled by stratigraphic level in the north of the study area （i.e. burial metamorphism）, and proximity to an igneous intrusive body in the south （i.e. contact metamorphism）.

关键词： X-ray diffraction metapelitic zone illite crystallinity percentage of illite in I/S mixed layers percentage of I/S mixed layers the metamorphic map