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Shock-induced energy localization and reaction growth considering chemical-inclusions effects for crystalline explosives 被引量:1
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作者 Ruqin Liu Yanqing Wu +3 位作者 Xinjie Wang Fenglei Huang Xiaona Huang Yushi Wen 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期278-294,共17页
Chemical inclusions significantly alter shock responses of crystalline explosives in macroscale gap experiments but their microscale dynamics origin remains unclear.Herein shock-induced energy localization,overall phy... Chemical inclusions significantly alter shock responses of crystalline explosives in macroscale gap experiments but their microscale dynamics origin remains unclear.Herein shock-induced energy localization,overall physical responses,and reactions in a-1,3,5-trinitro-1,3,5-triazinane(a-RDX)crystal entrained various chemical inclusions were investigated by the multi-scale shock technique implemented in the reactive molecular dynamics method.Results indicated that energy localization and shock reaction were affected by the intrinsic factors within chemical inclusions,i.e.,phase states,chemical compositions,and concentrations.The atomic origin of chemical-inclusions effects on energy localization is dependent on the dynamics mechanism of interfacial molecules with free space volume,which includes homogeneous intermolecular compression,interfacial impact and shear,and void collapse and jet.As introducing various chemical inclusions,the initiation of those dynamics mechanisms triggers diverse decay rates of bulk RDX molecules and hereby impacts on growth speeds of final reactions.Adding chemical inclusions can reduce the effectiveness of the void during the shock impacting.Under the shockwave velocity of 9 km/s,the parent RDX decay rate in RDX entrained amorphous carbon decreases the most and is about one fourth of that in RDX with a vacuum void,and solid HMX and TATB inclusions are more reactive than amorphous carbon but less reactive than dry air or acetone inclusions.The lessdense shocking system denotes the greater increases in local temperature and stress,the faster energy liberation,and the earlier final reaction into equilibrium,revealing more pronounced responses to the present intense shockwave.The quantitative models associated with the relative system density(RD_(sys))were proposed for indicating energy-localization mechanisms and evaluating initiation safety in the shocked crystalline explosive.RD_(sys)is defined by the density ratio of defective RDX to perfect crystal after dynamics relaxation and reveals the global density characteristic in shocked systems filled with chemical inclusions.When RD_(sys)is below 0.9,local hydrodynamic jet initiated by void collapse dominates upon energy localization instead of interfacial impact.This study sheds light on novel insights for understanding the shock chemistry and physical-based atomic origin in crystalline explosives considering chemical-inclusions effects. 展开更多
关键词 Shock responses Energy localization crystalline explosives Chemical inclusions Reactive molecular dynamics
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融合卷积CR-FFD与偏置Transformer胶囊网络的单视图三维物体重建
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作者 连远锋 赵泽欣 《计算机辅助设计与图形学学报》 北大核心 2025年第4期623-634,共12页
针对复杂拓扑结构物体单视图三维重建过程中二维图像与三维形状之间难以准确映射的问题,提出一种融合卷积Catmull-Rom样条自由形变(CR-FFD)与偏置Transformer胶囊网络的单视图三维重建方法.首先通过Catmull-Rom样条基函数对点云模型控... 针对复杂拓扑结构物体单视图三维重建过程中二维图像与三维形状之间难以准确映射的问题,提出一种融合卷积Catmull-Rom样条自由形变(CR-FFD)与偏置Transformer胶囊网络的单视图三维重建方法.首先通过Catmull-Rom样条基函数对点云模型控制点进行插值,保持点云模型形变局部拓扑结构的一致性;然后提出卷积神经网络最小二乘求逆解法,通过非线性参数映射加速求解过程;最后设计偏置注意力Transformer胶囊网络增强局部特征表达能力,捕获点云形状的细粒度特征.实验结果表明,在ShapeNet数据集上,所提方法的EMD指标平均值为3.84, CD指标平均值为3.71;在Pix3D数据集上, EMD指标平均值为5.51, CD指标平均值为5.39;与已有的单视图点云三维重建方法相比,该方法有效地提升单视图的三维重建结果,能够从不同角度保持重建的一致性. 展开更多
关键词 CATMULL-ROM样条 自由形变 三维重建 胶囊网络 偏置注意力
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Strength criterion for crystalline rocks considering grain size effect and tensile-compressive strength ratio
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作者 ZHANG Cheng-han JI Hong-guang +3 位作者 JIANG Peng YOU Shuang GENG Qian-cheng JIAO Chen-jiang 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第7期2365-2378,共14页
The macroscopic mechanical properties of rocks are significantly influenced by their microstructure.As a material bonded by mineral grains,the grain morphology of crystalline rock is the primary factor influencing the... The macroscopic mechanical properties of rocks are significantly influenced by their microstructure.As a material bonded by mineral grains,the grain morphology of crystalline rock is the primary factor influencing the strength.However,most strength criteria neglect the strength variations caused by different grain characteristics in rocks.Furthermore,the traditional linear criteria tend to overestimate tensile strength and exhibit apex singularity.To address these shortcomings,a piecewise strength criterion that considers the grain size effect has been proposed.A part of an ellipse was employed to construct the envelope of the tensive-shear region on the meridian plane,to accurately reproduce the low tensile-compressive strength ratio.Based on the analysis of experimental data,both linear and exponential modification functions that account for grain size effects were integrated into the proposed criterion.The corresponding finite element algorithm has been implemented.The accuracy and applicability of the proposed criterion were validated by comparing with the experimental data. 展开更多
关键词 crystalline rock grain size effect strength criterion tensile-compressive strength ratio finite element algorithm
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Annealing temperature influence on forming limit curve and fracture toughness of aluminium/silver bilayer sheets 被引量:1
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作者 Mohammad Delshad GHOLAMI Mojtaba KHODAKARAMI +1 位作者 Mohammad ABADIAN Ramin HASHEMI 《Journal of Central South University》 2025年第1期34-48,共15页
This article examines the influence of annealing temperature on fracture toughness and forming limit curves of dissimilar aluminum/silver sheets.In the cold roll bonding process,after brushing and acid washing,the pre... This article examines the influence of annealing temperature on fracture toughness and forming limit curves of dissimilar aluminum/silver sheets.In the cold roll bonding process,after brushing and acid washing,the prepared surfaces are placed on top of each other and by rolling with reduction more than 50%,the bonding between layers is established.In this research,the roll bonding process was done at room temperature,without the use of lubricants and with a 70%thickness reduction.Then,the final thickness of the Ag/Al bilayer sheet reached 350μm by several stages of cold rolling.Before cold rolling,it should be noted that to decrease the hardness created due to plastic deformation,the roll-bonded samples were subjected to annealing heat treatment at 400℃for 90 min.Thus,the final samples were annealed at 200,300 and 400℃for 90 min and cooled in a furnace to examine the annealing temperature effects.The uniaxial tensile and microhardness tests measured mechanical properties.Also,to investigate the fracture mechanism,the fractography of the cross-section was examined by scanning electron microscope(SEM).To evaluate the formability of Ag/Al bilayer sheets,forming limit curves were obtained experimentally through the Nakazima test.The resistance of composites to failure due to cracking was also investigated by fracture toughness.The results showed that annealing increases the elongation and formability of the Ag/Al bilayer sheet while reduces the ultimate tensile strength and fracture toughness.However,the changing trend is not the same at different temperatures,and according to the results,the most significant effect is obtained at 300℃and aluminum layers.It was also determined that by increasing annealing temperature,the fracture mechanism from shear ductile with small and shallow dimples becomes ductile with deep cavities. 展开更多
关键词 cold roll bonding Ag/Al bilayer sheet mechanical properties forming limit curve fracture toughness
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基于Deform的弯链板U弯成形分析及模具参数优化
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作者 汪永明 孙永文 连润柱 《塑性工程学报》 北大核心 2025年第6期79-86,共8页
针对弯链板在U弯成形过程中产生的向外弯曲现象,基于Deform软件在其U弯凹模上分别建立了无预弯块和有预弯块的2组U弯成形有限元仿真模型,仿真结果表明:有预弯块的U弯凹模对工件的向外弯曲变形有着很大的改善作用。建立了5组不同预弯块... 针对弯链板在U弯成形过程中产生的向外弯曲现象,基于Deform软件在其U弯凹模上分别建立了无预弯块和有预弯块的2组U弯成形有限元仿真模型,仿真结果表明:有预弯块的U弯凹模对工件的向外弯曲变形有着很大的改善作用。建立了5组不同预弯块间距的U弯成形有限元仿真模型,分析不同预弯块间距对工件的台阶面间距和平行度的影响,根据仿真结果对比:当预弯块间距为75 mm时,U弯成形件的成形效果最佳,此时其台阶面间距为38.36 mm,台阶面向内弯曲夹角为0.1°。取预弯块间距为最佳值75 mm时,分别研究了不同的U弯间隙与凹模圆角半径对工件U弯成形效果的影响,得出其最佳U弯间隙为5.15 mm,最佳凹模圆角半径为10 mm。基于优化后的模具参数进行了U弯成形实验,依据实验结果,U弯成形件的窄端面间距为27.41~27.47 mm,台阶面间距为38.45~38.61 mm,台阶面夹角为-0.14°~0.27°,实验结果满足U弯成形的工艺要求,有效解决了弯链板在U弯成形过程中的向外弯曲现象。 展开更多
关键词 弯链板 U弯成形 Deform仿真 模具改进 参数优化
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基于AK-FORM方法和降维方法的高效时变可靠度分析方法
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作者 张亮 唐亚可 +2 位作者 牛凯 李昊宇 余书君 《土木与环境工程学报(中英文)》 北大核心 2025年第3期162-170,共9页
PHI2方法是进行结构时变可靠度分析的常用方法,而跨越率的求解是该方法的关键,为达到足够精度往往需要计算大量时刻处的跨越率,然而,对于具有复杂极限状态面的实际问题,计算每个时刻的跨越率可能非常耗时。为进一步提高PHI2方法的效率,... PHI2方法是进行结构时变可靠度分析的常用方法,而跨越率的求解是该方法的关键,为达到足够精度往往需要计算大量时刻处的跨越率,然而,对于具有复杂极限状态面的实际问题,计算每个时刻的跨越率可能非常耗时。为进一步提高PHI2方法的效率,引入3种策略改进跨越率的计算效率:首先,采用无Cholesky分解策略以减少随机变量数目,并给出与之对应的相关系数计算方法;其次,引入基于主动学习Kriging模型的改进一次可靠度(AK-FORM)方法,以高效计算各时刻的可靠指标;最后,利用降维方法将二维积分转化为一维积分,以改善计算性能。将上述3种改进策略与PHI2方法相结合,形成基于AK-FORM方法和降维方法的高效时变可靠度分析方法,即KPHI2方法。与此同时,仅将无Cholesky分解策略与PHI2方法结合,形成PHI2-方法。数值算例和工程算例计算结果表明:提出的PHI2-、K-PHI2方法与PHI2方法一样具有高准确性,在精度上均优于PHI2+方法(一种基于PHI2的改进方法);相较于PHI2、PHI2+方法,PHI2-方法在效率上有一定提升,而K-PHI2方法在此基础上进一步提高了时变可靠度分析效率。 展开更多
关键词 时变可靠度 PHI2方法 一次可靠度方法 KRIGING模型 跨越率 降维方法
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PETROLOGY AND AGE OF THE KINNAR KAILAS GRANITE:EVIDENCES FOR AN ORDOVICIAN POST-OROGENIC EXTENSION IN THE HIGHER HIMALAYAN CRYSTALLINE, SUTLEJ, INDIA 被引量:3
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作者 H. S. Chawla\+1, D. Marquer\+1, J. D. Kramers\+2, I. M. Villa\+2, F. Bussy\+3(1 Geological Institute, Emile Argand, 11, 2007, Neuchatel, Switzerland 2 Isotopengeologie, Erlachstrasse 9a, 3012 Bern, Switzerland 3 Institute of Mineralogy and Geochemi 《地学前缘》 EI CAS CSCD 2000年第S1期50-51,共2页
Higher Himalayan Crystalline (HHC) rocks often show metamorphic zonations from lower greenschist facies to migmatites associated with leucogranite intrusions that are classically described as examples of Tertiary inve... Higher Himalayan Crystalline (HHC) rocks often show metamorphic zonations from lower greenschist facies to migmatites associated with leucogranite intrusions that are classically described as examples of Tertiary inverted metamorphism. The present study, based on structural, petrological and geochronological investigations in the Kinnar Kailas Granite (KKG) and surrounding HHC sequence, evidences a discordant intrusive contact of the Ordovician KKG with respect to Pre\|Alpine high grade deformed HHC sequence in the Sutlej valley.Four main phases of deformation are recorded in this HHC sequence and pre\|Ordovician sediments. The first three phases of deformation occurred under high\|grade metamorphic conditions, before the intrusion of the KKG. The geometry of the main progressive ductile deformation (D2—D3) results from SW vergent doming and migmatisation. The latest deformation is expressed by local shearing under greenschist facies conditions. This late D4 deformation corresponds to N—S oriented ductile normal faults lowering the eastern blocks. The KKG is a shallow depth intrusion, showing discordant contacts with the surrounding basement rocks and large scale magmatic stoping. The KKG crosscuts the high\|grade deformation structures (D2—D3) but is locally affected by the local late D4 extensional deformation. The granite textures reflect only slight orientation related to magmatic deformation and even at few centimetres from the intrusion contact, the granite appears undeformed in contrast to the surrounding highly foliated rocks. Furthermore, xenoliths of Kyanite\|Sillimanite bearing basement rocks are present within the KKG. 展开更多
关键词 HIGHER Himalaya crystalline GRANITE ORDOVICIAN post\|orogenic EXTENSION
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Schur Forms and Normal-Nilpotent Decompositions 被引量:1
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作者 LI Zhen 《应用数学和力学》 CSCD 北大核心 2024年第9期1200-1211,共12页
Real and complex Schur forms have been receiving increasing attention from the fluid mechanics community recently,especially related to vortices and turbulence.Several decompositions of the velocity gradient tensor,su... Real and complex Schur forms have been receiving increasing attention from the fluid mechanics community recently,especially related to vortices and turbulence.Several decompositions of the velocity gradient tensor,such as the triple decomposition of motion(TDM)and normal-nilpotent decomposition(NND),have been proposed to analyze the local motions of fluid elements.However,due to the existence of different types and non-uniqueness of Schur forms,as well as various possible definitions of NNDs,confusion has spread widely and is harming the research.This work aims to clean up this confusion.To this end,the complex and real Schur forms are derived constructively from the very basics,with special consideration for their non-uniqueness.Conditions of uniqueness are proposed.After a general discussion of normality and nilpotency,a complex NND and several real NNDs as well as normal-nonnormal decompositions are constructed,with a brief comparison of complex and real decompositions.Based on that,several confusing points are clarified,such as the distinction between NND and TDM,and the intrinsic gap between complex and real NNDs.Besides,the author proposes to extend the real block Schur form and its corresponding NNDs for the complex eigenvalue case to the real eigenvalue case.But their justification is left to further investigations. 展开更多
关键词 Schur form normal matrix nilpotent matrix tensor decomposition vortex identification
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STUDY ON INCLUSION COMPLEXATION: 2.THE MOLECULAR AND CRYSTALLINE STRUCTURE OF INCLUSION COMPLEX OF CHIRAL 2,5-PIPERAZINEDIONE DERIVEDFROM (S)-PROLINE WITH 1,1'-BI-NAPHTHOL
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《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 1999年第S1期191-191,共1页
关键词 BI-NAPHTHOL THE MOLECULAR AND crystalline STRUCTURE OF INCLUSION COMPLEX OF CHIRAL 2 5-PIPERAZINEDIONE DERIVEDFROM STUDY ON INCLUSION COMPLEXATION PROLINE WITH 1 1
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Bioaccumulation,subcellular distribution and chemical forms of cadmium in Aster subulatus Michx.
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作者 LIANG Xue-lian CHEN Wei +7 位作者 JIANG Wen-yan LIAO Jie YANG Yu-xia WANG Hai-jun LI Hui-ling LU Wei-fan WANG Tian-shun XIE Hong-zhao 《南方农业学报》 CAS CSCD 北大核心 2024年第8期2386-2395,共10页
【Objective】Through analyzing the bioaccumulation capacity,subcellular distribution and chemical forms of cadmium(Cd)in Aster subulatus Michx.,this study was to provide reference for revealing the Cd tolerance mechan... 【Objective】Through analyzing the bioaccumulation capacity,subcellular distribution and chemical forms of cadmium(Cd)in Aster subulatus Michx.,this study was to provide reference for revealing the Cd tolerance mechanism of A.subulatus Michx.【Method】After cultured for 24 d under the action of Hoagland nutrient solution and gradient Cd concentrations(0,30,60 and 90 mg/L),A.subulatus Michx.were harvested,and its leaf,stem and root were treated by differential centrifugation,chemical reagent extraction,and digested with graphite digester,respectively,then the Cd content in the root,stem and leaf were determined by atomic absorption spectroscopy.【Result】The experimental results indicated that the bioaccumulation capacity of Cd in A.subulatus Michx.was root>stem>leaf,and the maximum Cd concentration in the root,stem and leaf of A.subulatus Michx.were 130.74,78.69 and 56.62 mg/kg(fresh matter),respectively.Most of Cd stored in the cell wall and the soluble fractions of the root and leaf of A.subulatus Michx.,with only a smaller portion Cd in organelle fraction.Analysis result of subcellular Cd content showed that 52.27%-58.61%of Cd for root was mainly stored in the soluble fraction,but 42.10%-63.28%of Cd for leaf was mainly stored in the cell wall fraction.The concentration of pectates and protein integrated-Cd was higher in the root and leaf compared to other chemical forms Cd.Pectates and protein integrated-Cd was the main chemical forms Cd in the root and leaf of A.subulatus Michx.,and their percentages were 68.91%-74.80%and 57.38%-83.80%,respectively.Cd treatment could significantly increase the proportion of water-soluble organic acid Cd from 13.64%to 22.72%in root and undissolved phosphate Cd from 10.02%to 32.78%in leaf with increasing Cd concentration in the culture medium.【Conclusion】The root,stem and leaf of A.subulatus Michx.has strong bioaccumulation capacity to Cd,Cd is primarily stored in the soluble fractions of the root and cell wall fractions of the leaf,and less toxic pectates and protein integrated-Cd is the main chemical forms Cd in the root and leaf of A.subulatus Michx.,this might be the main mechanism of Cd tolerance in A.subulatus Michx. 展开更多
关键词 Aster subulatus Michx. CADMIUM BIOACCUMULATION chemical form subcellular distribution
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Forming and Springback Prediction of Strips Under Multi-square Punch Concave Forming Process Considering Partial-unloading Effects
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作者 LIANG Qi-yu ZHANG Long ZHU Ling 《船舶力学》 EI CSCD 北大核心 2024年第12期1953-1969,共17页
To further investigate the forming mechanism and springback characteristics of strips under multi-square punch forming (MSPF) considering partial-unloading effects, a series of concave form ing tests of strips are con... To further investigate the forming mechanism and springback characteristics of strips under multi-square punch forming (MSPF) considering partial-unloading effects, a series of concave form ing tests of strips are conducted on the MSPF machine. This paper aims to reveal the physical mecha nism of the elastic-plastic deformation in the MSPF process considering the effect of the forming ap proaches, and derive appropriate mathematical interpretations. The theoretical model is firstly estab lished to analyse the concave forming mechanism and springback characteristics of the strip, and its accuracy is then validated by experimental data. The forming history and load evolutions are depicted to explore the required forming capacity through the proposed analytical method. Besides, the paramet ric studies are carried out to discuss their effects on the springback of the strip. The results suggest that the deformation paths of the strip are influenced by the forming approach, and the springback of the strip in convex forming is larger than that in concave forming. 展开更多
关键词 multi-square punch forming(MSPF) follower load elastic-plastic deformation partial unloading springback prediction
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Xenia Materials将在FORMNEXT EXPO 2023上推出新型树脂材料
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《塑料工业》 CAS CSCD 北大核心 2024年第1期160-160,共1页
特种热塑性化合物领域的全球领先企业Xenia^(■)Materials宣布,在FORMNEXT EXPO 2023上推出其全新系列的3D打印材料。该系列包括与纤维和添加剂相结合的独特树脂,可用于任何基于颗粒的FDM打印机,既可用于LSAM生产也可用于高精度生产。... 特种热塑性化合物领域的全球领先企业Xenia^(■)Materials宣布,在FORMNEXT EXPO 2023上推出其全新系列的3D打印材料。该系列包括与纤维和添加剂相结合的独特树脂,可用于任何基于颗粒的FDM打印机,既可用于LSAM生产也可用于高精度生产。这些高性能复合材料3DP MATERIALS在高温和低温条件下都能表现出令人印象深刻的刚度、尺寸稳定性、低密度、低热膨胀性和高耐用性。 展开更多
关键词 高性能复合材料 热膨胀性 新型树脂 NEXT 尺寸稳定性 EXPO LSAM form
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构网型技术:演进历程、功能定位与应用展望 被引量:6
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作者 王伟 周少泽 +4 位作者 黄萌 艾诚 李奕曈 韦徵 郑玉平 《电力系统自动化》 北大核心 2025年第1期1-13,共13页
为支撑新能源高效利用和电力保供,构网型技术在电力系统不同应用场景中已获得初步探索实践。为促进构网型技术的规模化应用,文中探讨了构网型技术在新型电力系统中的功能定位和应用发展方向。通过梳理构网型技术的演进历程,以及国内外... 为支撑新能源高效利用和电力保供,构网型技术在电力系统不同应用场景中已获得初步探索实践。为促进构网型技术的规模化应用,文中探讨了构网型技术在新型电力系统中的功能定位和应用发展方向。通过梳理构网型技术的演进历程,以及国内外现有的标准和规范,分析了构网型技术发展的内在驱动需求,明晰了不同形态电网场景下构网型技术的功能定位;最后,从静、动、暂态的稳定性分析等维度,剖析了构网型技术当前面临的挑战,并对其大规模应用所需解决的问题进行了展望。 展开更多
关键词 构网型控制 构网型装备 新型电力系统 新能源 功能定位
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鸡蛋壳/三聚氰胺复合材料的制备及其对结晶紫的吸附研究
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作者 玉澜 蒙艳娜 +3 位作者 文胜 陈燕萌 谢馨怡 兰兴先 《化学研究与应用》 北大核心 2025年第5期1093-1100,共8页
以鸡蛋壳和三聚氰胺为原料,通过热聚合法制备鸡蛋壳/三聚氰胺复合材料。以复合材料对结晶紫的吸附效果为评价指标,探究复合材料最佳合成工艺条件及复合材料对结晶紫的最佳吸附条件。结果表明,复合材料最佳合成条件是:鸡蛋壳与三聚氰胺... 以鸡蛋壳和三聚氰胺为原料,通过热聚合法制备鸡蛋壳/三聚氰胺复合材料。以复合材料对结晶紫的吸附效果为评价指标,探究复合材料最佳合成工艺条件及复合材料对结晶紫的最佳吸附条件。结果表明,复合材料最佳合成条件是:鸡蛋壳与三聚氰胺质量比为1:1、焙烧温度为600℃、焙烧时间为180 min;复合材料对结晶紫的最佳吸附条件是:结晶紫初始浓度为600 mg/L、复合材料投加量为0.04 g、吸附时间为40 min,复合材料对结晶紫的吸附率可达到95%。通过FT-IR、XRD、SEM、TG表征结果表明,鸡蛋壳与三聚氰胺成功进行了复合。复合材料对结晶紫的吸附过程,其等温线服从Langmuir模型,并遵循准二阶动力学,说明复合材料对结晶紫的吸附以单分子层为主的化学吸附行为。 展开更多
关键词 鸡蛋壳 结晶紫 吸附 复合材料
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园林垃圾对市政污泥热解过程减量及含碳物质变化的影响 被引量:1
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作者 于涛 俞存天 +6 位作者 张婷 肖懿 李东阳 杨天学 黄启飞 席北斗 卢欢亮 《环境工程技术学报》 北大核心 2025年第1期289-296,共8页
市政污泥(SS)的高含水率、高灰分、高热解耗能、低产物品质等特点,制约其热解资源化技术的应用。向SS中添加比自身热值和有机物含量更高的园林垃圾(GW)进行共热解,通过热重分析仪、气相色谱质谱仪等测定其减量效果与物质组成,并采用Coat... 市政污泥(SS)的高含水率、高灰分、高热解耗能、低产物品质等特点,制约其热解资源化技术的应用。向SS中添加比自身热值和有机物含量更高的园林垃圾(GW)进行共热解,通过热重分析仪、气相色谱质谱仪等测定其减量效果与物质组成,并采用Coats-Redfern法分析了热解动力学。结果表明,SS与GW共热解过程中主要分为失水、挥发分分解、难降解有机物分解3个阶段;GW和SS共热解后可以降低活化能,热解反应向低温段偏移,当GW掺入量为50%时,挥发分分解阶段(155~380℃)活化能为4.64 kJ/mol,比SS单独热解减少10.25%;此外,共热解还可减少二次污染物的产生,在GW掺入量为50%时,热解后热解油中的有机碳氧化合物、脂烃类质量分别由单独热解的376和94 mg/g降为252和30 mg/g。基于以上研究结果,GW可以减少SS热解的能源投入,降低污染物的产生,为SS与GW减量化及资源化实际工程提供理论支撑。 展开更多
关键词 市政污泥 园林垃圾 共热解 动力学 碳素形态
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内置CFRP圆管的方钢管再生混凝土偏压短柱力学性能研究 被引量:1
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作者 许伟 程嘉宝 +1 位作者 佟舟 张海霞 《沈阳建筑大学学报(自然科学版)》 北大核心 2025年第1期39-46,共8页
研究外截面形式、受压类型和偏心率等变化参数对内置CFRP圆管的方钢管再生混凝土短柱力学性能的影响。利用ABAQUS有限元分析软件建立组合柱力学模型,在有限元模拟和轴压试验结果吻合的基础上,进一步研究试件的偏压力学性能。增加CFRP层... 研究外截面形式、受压类型和偏心率等变化参数对内置CFRP圆管的方钢管再生混凝土短柱力学性能的影响。利用ABAQUS有限元分析软件建立组合柱力学模型,在有限元模拟和轴压试验结果吻合的基础上,进一步研究试件的偏压力学性能。增加CFRP层数,对轴压试件的极限承载力和位移延性系数提高幅度可分别达到30.44%、41.11%,对偏压试件的极限承载力和位移延性系数提高幅度分别为5.97%、37.49%;增加偏心率,对方截面试件的极限承载力和位移延性系数降低幅度分别达到41.22%、20.16%,对圆截面试件的极限承载力和位移延性系数降低幅度分别为45.79%、33.02%。内置CFRP圆管能够改善方钢管再生混凝土短柱的力学性能,但对偏压柱的影响小于轴压柱;在模拟参数范围内,随着偏心率的增加,试件力学性能降低;但同等截面面积下,方截面试件的偏压力学性能比圆截面试件的偏压力学性能更稳定。 展开更多
关键词 CFRP层数 偏心率 受压类型 外截面形式
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钛合金精密铸造技术在航空航天领域的应用进展 被引量:3
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作者 张鹏飞 张林嘉 +3 位作者 周瑜 孙峰 王军 李金山 《航空制造技术》 北大核心 2025年第7期22-36,共15页
钛合金精密铸件具有高比强度、耐腐蚀和耐热等性能,同时兼具高尺寸精度、低生产成本的优势,已广泛应用于航空航天领域的关键结构件。为推动我国钛合金精密铸造技术的持续完善进步和钛合金精密铸件产品的进一步推广应用,本文综述了近年... 钛合金精密铸件具有高比强度、耐腐蚀和耐热等性能,同时兼具高尺寸精度、低生产成本的优势,已广泛应用于航空航天领域的关键结构件。为推动我国钛合金精密铸造技术的持续完善进步和钛合金精密铸件产品的进一步推广应用,本文综述了近年来钛合金精密铸造技术在航空航天领域的应用和发展,重点介绍了钛合金精密铸造工艺、耐高温铸造钛合金材料以及钛合金精密铸件产品研制进展。最后,总结了国内钛合金精密铸造技术,以及应用方面存在的重点问题,提出了建立材料数据库、降低生产成本和发展铸造模拟软件等未来发展方向。 展开更多
关键词 钛合金 TIAL合金 精密铸造 精确成形 Ti_(2)AlNb合金
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作为符号形式的神话思维——卡西尔文化哲学研究 被引量:1
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作者 王瑜 《求是学刊》 北大核心 2025年第2期10-19,共10页
符号形式是卡西尔哲学的核心概念,而他对神话问题的关注贯穿了他一生的学术写作。神话既作为一种封闭独立的符号体系,又是整个符号大厦得以不断建构的基石。人类文化生活的基本形式起源于神话意识。文章拟从三个方面解读卡西尔的“神话... 符号形式是卡西尔哲学的核心概念,而他对神话问题的关注贯穿了他一生的学术写作。神话既作为一种封闭独立的符号体系,又是整个符号大厦得以不断建构的基石。人类文化生活的基本形式起源于神话意识。文章拟从三个方面解读卡西尔的“神话思维”概念:一是神话思维作为符号形式的元形态即神话意识的原动力在人类精神的全部历程中一再地创造力量;二是符号形式与黑格尔“象征型艺术”的勾联即卡西尔文化现象学的维度;三是符号形式与康德“形式”概念的关系即揭示神话思维的先天性与普遍性。 展开更多
关键词 卡西尔 符号形式 神话思维
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水利工程白蚁防治药剂现状和发展方向 被引量:1
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作者 王伟 邓刚 +3 位作者 张茵琪 严俊 裴东东 李维朝 《中国水利水电科学研究院学报(中英文)》 北大核心 2025年第2期112-120,共9页
白蚁是主要的害堤动物之一,给堤坝工程的正常运行带来了巨大的安全隐患。本文介绍了水利工程白蚁预防和灭治措施对药物的需求,分析了各防治措施使用的化学药剂有效成分和剂型特点,总结了生物药剂研发现状和发展方向。施用白蚁防治药剂... 白蚁是主要的害堤动物之一,给堤坝工程的正常运行带来了巨大的安全隐患。本文介绍了水利工程白蚁预防和灭治措施对药物的需求,分析了各防治措施使用的化学药剂有效成分和剂型特点,总结了生物药剂研发现状和发展方向。施用白蚁防治药剂是开展水利工程白蚁预防和灭治的重要途径,亟需研发适用于监测-灭杀一体法的高耐久性饵剂和粉剂,并扩大生物药剂有效成分获取渠道。 展开更多
关键词 水利工程 白蚁防治 化学药剂 生物药剂 有效成分 剂型
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气井拟压力产能方程的推导、简化及应用 被引量:1
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作者 陈元千 《油气地质与采收率》 北大核心 2025年第1期147-151,共5页
对于新区发现天然气的探井或是老区新打的调整井,在完井试气并关井取得地层压力之后,都要进行气井的产能测试或成为供气能力测试,用于确定气井的绝对无阻流量和流入动态关系曲线,为气藏开发方案的编制提供可靠的技术基础。在国际上,评... 对于新区发现天然气的探井或是老区新打的调整井,在完井试气并关井取得地层压力之后,都要进行气井的产能测试或成为供气能力测试,用于确定气井的绝对无阻流量和流入动态关系曲线,为气藏开发方案的编制提供可靠的技术基础。在国际上,评价气井产能的方法主要是利用压力平方表示的二项式和指数式,并通过多点测试(一般为四点)气井产量和相应的井底流压求解。本文基于Forchheimer(1901)的压力梯度与流动速度的二次方程,利用Al-Hussainy(1966)的拟压力函数,推导得到了气井拟压力的产能方程。同时,利用Rawlines(1936)提出的修正方法,得到了拟压力的指数式产能方程。通过实例应用表明,利用拟压力表示的二项式和指数式产能方程,评价的绝对无阻流量结果基本一致。 展开更多
关键词 气井 拟压力 产能方程 二项式 指数式 绝对无阻流量 IPR曲线
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