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Three-Dimensional Simulations of RESET Operation in Phase-Change Random Access Memory with Blade-Type Like Phase Change Layer by Finite Element Modeling 被引量:2
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作者 金秋雪 刘波 +8 位作者 刘燕 王维维 汪恒 许震 高丹 王青 夏洋洋 宋志棠 封松林 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第9期128-131,共4页
An optimized device structure for reducing the RESET current of phase-change random access memory (PCRAM) with blade-type like (BTL) phase change layer is proposed. The electrical thermal analysis of the BTL cell ... An optimized device structure for reducing the RESET current of phase-change random access memory (PCRAM) with blade-type like (BTL) phase change layer is proposed. The electrical thermal analysis of the BTL cell and the blade heater contactor structure by three-dimensional finite element modeling are compared with each other during RESET operation. The simulation results show that the programming region of the phase change layer in the BTL cell is much smaller, and thermal electrical distributions of the BTL cell are more concentrated on the TiN/GST interface. The results indicate that the BTL cell has the superiorities of increasing the heating efficiency, decreasing the power consumption and reducing the RESET current from 0.67mA to 0.32mA. Therefore, the BTL cell will be appropriate for high performance PCRAM device with lower power consumption and lower RESET current. 展开更多
关键词 PCRAM cell RESET Three-Dimensional Simulations of RESET Operation in phase-Change Random Access Memory with Blade-Type Like phase Change layer by Finite Element Modeling of by in with
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The Effect of Varied Dietary Crude Protein Levels with Balanced Amino Acids on Performance and Egg Quality Characteristics of Layers at First Laying Phase 被引量:3
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作者 Gbemiga Oladimeji Adeyemo Sulaiman Adewole Abioye Foluke A. Aderemi 《Food and Nutrition Sciences》 2012年第4期526-529,共4页
Four diets were formulated to study the influence of varying crude protein levels on the performance, egg quality, serum and haematological characteristics at the first phase of laying cycle of sixty Bovan Nera laying... Four diets were formulated to study the influence of varying crude protein levels on the performance, egg quality, serum and haematological characteristics at the first phase of laying cycle of sixty Bovan Nera laying birds that were randomly allotted to dietary treatments. The four experimental diets had five replicates each and three birds per repli-cate. Diet 1 contained 14% crude protein (CP), while diet 2 contained 15% CP, diets 3 and 4 contained 16% and 17% CP respectively. The experimental birds were fed for 10 weeks and the data collected were statistically analysed. Apparent variations recorded for all the performance characteristics such as Egg number, Hen-day production, Feed Conversion Ratio (FCR) and weight gain were significantly different (p < 0.05). The best FCR value were recorded by birds fed 17% CP (3.45), while the highest weight gain mean value were also recorded by birds fed 17% CP value. Findings indicated a direct relationship between dietary crude protein values and performance. 展开更多
关键词 EGG Quality FIRST LAYING phase layerS PERFORMANCE and Varied Crude Protein Levels
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Comparison of liquid-liquid extraction-thin layer chromatography with solid-phase extraction-high-performance thin layer chromatography in detection of urinary morphine 被引量:1
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作者 Ali Ahadi Alireza Partoazar +1 位作者 Mohammad Hassan Abedi Khorasgani Seyed Vahid Shetab Boushehri 《The Journal of Biomedical Research》 CAS 2011年第5期362-367,共6页
Liquid-liquid extraction-thin layer chromatography (LLE-TLC) has been a common and routine combined method for detection of drugs in biological materials. Solid-phase extraction (SPE) is gradually replacing the tr... Liquid-liquid extraction-thin layer chromatography (LLE-TLC) has been a common and routine combined method for detection of drugs in biological materials. Solid-phase extraction (SPE) is gradually replacing the tra- ditional LLE method. High performance thin layer chromatography (HPTLC) has several advantages over TLC. The present work studied the higher efficiency of a new SPE-HPTLC method over that of a routine LLE-TLC method, in extraction and detection of urinary morphine. Fifty-eight urine samples, primarily identified as mor- phine-positive samples by a strip test, 'were re-screened by LLE-TLC and SPE-HPTLC. The results of LLE-TLC and SPE-HPTLC were then compared with each other. The results showed that the SPE-HPTLC detected 74% of total samples as morphine-positive samples whereas the LLE-TLC detected 48% of the same samples. We further discussed the effect of codeine abuse on TLC analysis of urinary morphine. Regarding the importance of morphine detection in urine, the present combined SPE-HPTLC method is suggested as a replacement method for detection of urinary morphine by many reference laboratories. 展开更多
关键词 morphine detection liquid-liquid extraction thin-layer chromatography solid-phase extraction highperformance thin layer chromatography
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Properties of Phase Transformation of Ferroelectric Thin Films with Surface Layers
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作者 Lian Cui Xu Xu +3 位作者 JiXin Che Zelong He Huijie Xue Tianquan Lv 《Journal of Modern Physics》 2011年第9期1037-1040,共4页
Using the generalized Ginzburg-Landau-Devonshire theory, the characteristics of phase transformation of a ferroelectric thin film with surface layers are investigated. We study the effect of the surface layer on the p... Using the generalized Ginzburg-Landau-Devonshire theory, the characteristics of phase transformation of a ferroelectric thin film with surface layers are investigated. We study the effect of the surface layer on the properties (coercive field, critical thickness) of a ferroelectric thin film. Our theoretical results show that the surface layer is likely to answer for the emergence of phase transformation. 展开更多
关键词 FERROELECTRIC THIN FILM Surface layer phase TRANSFORMATION
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STUDY ON DETERMINATION OF TRACE Cu(Ⅱ) BY DDCT CHELATING RESIN PRECONCENTRATION AND THIN LAYER RESIN PHASE SPECTROPHOTOMETRY
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作者 LI Chunxiang YAN Yongsheng +1 位作者 SONG Huanyu WANG Yun 《Chinese Journal of Reactive Polymers》 2006年第2期161-166,共6页
A new method for determination of Cu(Ⅱ) by DDCT chelating resin preconcentration and thin layer resin phase spectrophotometry was developed. The method has a high sensitivity (ε455= 3.6×10^5L/mol·cm), ... A new method for determination of Cu(Ⅱ) by DDCT chelating resin preconcentration and thin layer resin phase spectrophotometry was developed. The method has a high sensitivity (ε455= 3.6×10^5L/mol·cm), which is 33 times higher than that of liquid phase spectrophotometry. It has a good selectivity (most coexisting ions could not influence determination) and an ideal precision [30μg Cu(Ⅱ), n=6, RSD= l.67%]. The content of Cu(Ⅱ) in water, high purity rare earth and its oxide was determined. The detection limit of Cu(Ⅱ) is 5.3μg/L , and the linear range is 0-7.2μg/ml. The result is satisfactory. 展开更多
关键词 Chelating resin PRECONCENTRATION Thin layer resin phase spectrophotometry TRACE Cu(Ⅱ)
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STUDY ON DETERMINATION OF TRACE Fe BY Fe(Ⅱ)-VA THIN LAYER RESIN PHASE SPECTROPHOTOMETRY
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作者 SONG Huanyu YAN Yongsheng WANG Yun 《Chinese Journal of Reactive Polymers》 2006年第2期155-160,共6页
A new method for the determination of Fe by thin layer resin phase spectrophotometry in alkali condition was reported. The complex anion formed by Fe(Ⅱ) and VA was absorbed on the 717w resin and Fe was determined b... A new method for the determination of Fe by thin layer resin phase spectrophotometry in alkali condition was reported. The complex anion formed by Fe(Ⅱ) and VA was absorbed on the 717w resin and Fe was determined by making thin layer. This method had a high sensitivity (ε620= 3.0×10^5L/mol.cm), which was 15 times higher than that of liquid phase spectrophotometry. It had been proved a satisfactory precision (5.01μg Fe, n=6, RSD=1.8%). The trace Fe in natural water was determined and the recovery was 97%. 展开更多
关键词 Thin layer resin phase spectrophotometry TRACE FE
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STUDY ON THE DETERMINATION OF TRACE Fe(Ⅲ) BY THIN LAYER RESIN PHASE SPECTROPHOTOMETRY
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作者 HOU Yanmin YANG Yongsheng +1 位作者 XIE Jimin HUANG Weihong 《Chinese Journal of Reactive Polymers》 2007年第1期80-84,共5页
A method to determine Fe(Ⅲ) by thin layer resin phase spectrophotometry has been developed in this paper. The colored complex formed by Fe(Ⅲ) and 1,2-benzendiol is concentrated on the 717^# resin, then Fe(Ⅲ) ... A method to determine Fe(Ⅲ) by thin layer resin phase spectrophotometry has been developed in this paper. The colored complex formed by Fe(Ⅲ) and 1,2-benzendiol is concentrated on the 717^# resin, then Fe(Ⅲ) can be determined directly by making thin layer. The method is sensitive with a apparent molar absorption of 4.8×10^4L/mol.cm, which is 16 times higher than that of liquid phase spectrophotornetry, most coexisting ions do not influence the determination. The detection limit for Fe(Ⅲ) is 1.47μg/L with the precision of 3.3% [n=6, 7μg/50mL Fe(Ⅲ)]. The calibration curve is linear in the range of 0-25μg/50mL. The preposed method was applied to the determination of Fe(Ⅲ) in water sample with satisfactory results. 展开更多
关键词 1 2-benzendiol Thin layer resin phase spectrophotometry Fe(Ⅲ).
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Tuning the phase separation in La_(0.325)Pr_(0.3)Ca_(0.375)MnO_3 using the electric double-layer field effect
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作者 崔丽敏 李洁 +5 位作者 张玉 赵璐 邓辉 黄克强 李贺康 郑东宁 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第9期528-534,共7页
Electric double-layer field effect experiments were performed on ultrathin films of La0.325Pr0.3Ca0.375MnO3, which is noted for its micrometer-scale phase separation. A clear change of resistance up to 220% was observ... Electric double-layer field effect experiments were performed on ultrathin films of La0.325Pr0.3Ca0.375MnO3, which is noted for its micrometer-scale phase separation. A clear change of resistance up to 220% was observed and the characteristic metal-insulator transition temperature Tp was also shifted. The changes of both the resistance and Tp, suggest that the electric field induced not only tuning of the carrier density but also rebalancing of the phase separation states. The change of the charge-ordered insulating phase fraction was estimated to be temperature dependent, and a maximum of 16% was achieved in the phase separation regime. This tuning effect was partially irreversible, which might be due to an oxygen vacancy migration that is driven by the huge applied electric field. 展开更多
关键词 electric double-layer field effect MANGANITES phase separation
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AN IMPLICIT ALGORITHM OF THIN LAYER EQUATIONS IN VISCOUS,TRANSONIC,TWO-PHASE NOZZLE FLOW
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作者 何洪庆 侯晓 +1 位作者 蔡体敏 吴心平 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 1994年第4期323-334,共12页
Omitting viscosity along flow direction, we have simplified the dimensionless N-Sequations in arbitrary curved coordinate system as the thin layer equations. Using theimplicit approximate-factorization algorithm to so... Omitting viscosity along flow direction, we have simplified the dimensionless N-Sequations in arbitrary curved coordinate system as the thin layer equations. Using theimplicit approximate-factorization algorithm to solve the gas-phase governing equ-ations and the characteristic method to follow the tracks of particles, we then obtainedthe full coupled numerical method of two-phase.transonic, turbulent flow. Here, par- ticle size may be grouped, the subsonic boundary condition at entry of nozzle is ireatedby quasi-characteristic method in reference plane and the algebraic model is used forturbulent flow. These methods are applied in viscous two-phase flow. calculation of ro-cket nozzle and in the prediciton of thrust and specific impulse for solid propellant ro-cket motor. The calculation results are in good agreement with the measurerment va-lues. Moreover, the influences of different particle radius, different particle mass frac-tion and particle size grouped on flow field have been discussed, and the influences of particle two-dimensional radial velosity component and viscosity on specific impulse ofrocket motor have been analysed.The method of this paper possesses the advantage of saving computer time. More important, the effect is more obvious for the calculation of particle size being grouped. 展开更多
关键词 thin layer equations two-phase viscous transonic nozzle flow implicit algorithm
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Effect of Phase Change Materials on the Thermal Protective Performance of the Multi-layered Fabrics Examined by TPP Tester under Flash Fire 被引量:1
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作者 赵蒙蒙 李俊 《Journal of Donghua University(English Edition)》 EI CAS 2016年第1期150-154,共5页
Cotton fabrics treated with phase change materials( PCMs)were used in multi-layered fabrics of the fire fighter protective clothing to study its effect on thermal protection. The thermal protective performance( TPP) o... Cotton fabrics treated with phase change materials( PCMs)were used in multi-layered fabrics of the fire fighter protective clothing to study its effect on thermal protection. The thermal protective performance( TPP) of the multi-layered fabrics was measured by a TPP tester under flash fire. Results showed that the utilization of the PCM fabrics improved the thermal protective performance of the multi-layered fabrics. The fabric with a PCM add on of 41. 9% increased the thermal protection by 50. 6% and reduced the time to reach a second degree burn by 8. 4 s compared with the reference fabrics( without PCMs). The employment of the PCM fabrics also reduced the blackened areas on the inner layers. The PCM fabrics with higher PCM melting temperature could bring higher thermal protective performance. 展开更多
关键词 phase change material(PCM) multi-layered fabrics thermal protection performance(TPP) fire fighter protective clothing
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Comparison of Isobaric and Non-isobaric Operations on a Two-Phase Dynamic Model for PEFC Cathode Gas Diffusion Layer
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作者 纪光霁 陈翌 +1 位作者 周苏 陈凤祥 《Journal of Donghua University(English Edition)》 EI CAS 2011年第6期539-546,共8页
Key words,: Two 1-D dynamical and isothermal models of cathode gas diffusion layer(GDL) with isobaric and non-isobaric operations for polymer electrolyte fuel cells(PEFCs) were developed and implemented in COMSOL... Key words,: Two 1-D dynamical and isothermal models of cathode gas diffusion layer(GDL) with isobaric and non-isobaric operations for polymer electrolyte fuel cells(PEFCs) were developed and implemented in COMSOL Multiphysics v3.5.The artificial diffusion coefficient was introduced as well to make the numerical computation be stable.In the non-isobaric model,the pressure of gas mixture was obtained by summing up the governing equations of gaseous components,instead of Navier-Stoks equation.Comparison of the two models were carried out with the steady-states and dynamical simulations under given conditions.The corresponding analysis based on the simulated results was also given simultaneously.This paper is contributed to finding the differences between the isobaric and non-isobaric operation in the two-phase model of cathode GDL. 展开更多
关键词 TWO-phase model gas diffusion layer(GDL) ISOBARIC and non-isobaric operations polymer electrolyte fuel cell(PEFC)
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耐久型超薄铺装层的树脂沥青胶结料开发及其性能研究
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作者 刘攀 万佳鑫 +4 位作者 牛开民 王斌斌 方彪 龚娅 李媛媛 《应用化工》 北大核心 2026年第2期273-278,共6页
为提升超薄铺装层的耐久性及施工和易性,解决机场水泥道面和公路沥青道面因裂缝、沉降及抗滑性能退化引发的安全隐患问题,利用高温固化剂、预交联固化剂及复配增韧体系对沥青进行改性,制备了一种高性能低掺量树脂沥青胶结料。研究了树... 为提升超薄铺装层的耐久性及施工和易性,解决机场水泥道面和公路沥青道面因裂缝、沉降及抗滑性能退化引发的安全隐患问题,利用高温固化剂、预交联固化剂及复配增韧体系对沥青进行改性,制备了一种高性能低掺量树脂沥青胶结料。研究了树脂沥青胶结料的微观相态、动态热机械性能、时温特性及固化行为。试验结果表明,树脂沥青胶结料体系呈连续相态,环氧树脂与沥青在体系中相互穿插形成了均匀分散的两相结构,具有优异的相容性;其玻璃化转变温度为21.9℃,表现出宽温域适应性和良好的均相体系特征;170~180℃下该材料的旋转黏度低于700 mPa·s,施工容留时间超过180 min,完全满足工程需求,并通过建立固化动力学方程预测固化进程。该材料可有效延缓道面病害发展,延长使用寿命,为机场水泥道面和公路沥青道面功能与结构协同增强提供技术支撑。 展开更多
关键词 超薄铺装 树脂沥青胶结料 微观相态 动态热机械性能 时温特性 固化行为
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一种增强相控阵天线性能的介质层设计方法
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作者 张明月 许广钰 +2 位作者 刘志惠 刘兆松 高仁璟 《计算力学学报》 北大核心 2026年第1期33-39,共7页
堆叠介质层是实现相控阵天线宽带宽角扫描的常用方法,但传统PCB材料性质(介质特性和厚度等)常面临无法满足实现天线性能所需的材料特性的问题,进而限制了天线的性能提升空间。针对这一问题,本文提出一种考虑3D打印精度的介质层设计方法... 堆叠介质层是实现相控阵天线宽带宽角扫描的常用方法,但传统PCB材料性质(介质特性和厚度等)常面临无法满足实现天线性能所需的材料特性的问题,进而限制了天线的性能提升空间。针对这一问题,本文提出一种考虑3D打印精度的介质层设计方法,以改善相控阵天线的阻抗匹配特性。该方法首先通过优化算法确定最优的介质层尺寸和介电参数,然后基于散射参数反演法设计具有上述特征的材料单胞,用于构建所需的介质层。为保证设计的介质层的可制造性,将3D打印精度作为材料单胞的尺寸约束。基于该方法,设计了由馈电区、辐射区和匹配区组成的工作在X波段的相控阵天线单元,通过设计介质层微结构实现介质层减重47.89%;从仿真结果看,设计的天线可以在X波段实现法向驻波比小于2,在E平面和H平面实现±60°扫描时驻波比均小于2.5,并且具有良好的极化纯度。 展开更多
关键词 散射参数反演法 3D打印 堆叠介质层 相控阵天线 宽带宽角扫描
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耦合微通道与相变材料的太阳能光伏/热系统实验研究
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作者 陈梦汝 林文野 +5 位作者 黄超 宋文吉 郑瑞芸 顾晓滨 崔兴兰 年洪恩 《储能科学与技术》 北大核心 2026年第3期747-759,共13页
太阳能可再生能源的开发利用被认为是缓解全球能源危机与环境压力的重要途径。然而,传统太阳能利用系统仍面临多重技术瓶颈,如光伏光电转换效率受其温度影响、系统综合能效偏低、能量产需时空失配等。因此,本研究提出一种耦合多层微通... 太阳能可再生能源的开发利用被认为是缓解全球能源危机与环境压力的重要途径。然而,传统太阳能利用系统仍面临多重技术瓶颈,如光伏光电转换效率受其温度影响、系统综合能效偏低、能量产需时空失配等。因此,本研究提出一种耦合多层微通道与定形相变材料的温控-蓄热一体式光伏/热系统。通过搭建实验测试平台,对比分析了光伏系统、常规光伏-相变材料系统及新型耦合系统的热电性能,并重点探讨了太阳辐照度、工质流量、相变材料质量等关键参数对系统运行特性的影响规律。实验结果表明,该温控-蓄热一体式光伏/热系统展现出优异的综合性能。在1000 W/m^(2)太阳辐照度下,光伏电池最高工作温度可以控制在55.3℃以内,系统平均电效率和平均热效率分别达到12.8%和24.7%。通过实验对比可知,常规光伏系统和光伏-相变材料复合系统的整体效率分别为29.2%和46.2%,而本系统的最高整体效率可达58.3%。进一步分析发现,随着太阳辐照度的增加,系统电效率、热效率及整体效率呈下降趋势,但最大输出功率持续提升。此外,提高微通道内工质流量以及增加相变材料的装载质量,可显著降低光伏组件工作温度,并增强系统的电效率与热效率。另一方面,在无太阳辐照条件下,该系统能够有效延缓相变材料的冷却凝固过程。与常规光伏/热系统相比,储热单元保温时间从78 min可以延长至154 min。 展开更多
关键词 光伏/热系统 多层微通道 相变材料 热能存储 热管理
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马氏体耐热钢/镍基合金异种金属界面过渡层设计
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作者 高健飞 付佳 +4 位作者 夏美玲 穆浪 于云鹤 侯纪新 夏志新 《精密成形工程》 北大核心 2026年第2期60-72,共13页
目的 针对超超临界火电领域对马氏体耐热钢/镍基合金高质量结合的需求,设计过渡层成分,并探究合金体系及元素扩散对组织与性能的影响。方法 综合考虑耐高温与抗腐蚀性能,并结合熵焓比-原子半径差(Ω-δ)、混合焓(∆H_(mix))和电子浓度(VEC... 目的 针对超超临界火电领域对马氏体耐热钢/镍基合金高质量结合的需求,设计过渡层成分,并探究合金体系及元素扩散对组织与性能的影响。方法 综合考虑耐高温与抗腐蚀性能,并结合熵焓比-原子半径差(Ω-δ)、混合焓(∆H_(mix))和电子浓度(VEC)等固溶体判据,初步筛选出FeNiCr中熵合金过渡层体系。利用JMat Pro软件模拟Fe、Ni、Cr元素扩散对G115马氏体耐热钢与617B镍基合金相平衡、物理性能及力学性能的影响。结果 计算结果表明,FeNiCr合金易形成面心立方结构简单固溶体。Cr元素扩散使G115钢中M_(6)C相消失,当Cr的质量分数达到9%时,会诱发σ相;Fe元素扩散促使617B合金形成MC相,而Cr扩散使M_(6)C相消失并出现MC相。Ni元素扩散显著影响G115钢的线膨胀系数与力学性能,Fe元素扩散导致617B合金力学性能下降,而Cr元素扩散可提升617B合金的力学性能。结论 Fe NiCr合金过渡层可对Fe、Ni元素无限固溶,有助于实现界面成分梯度平缓过渡,通过控制元素扩散可形成物理性能梯度分布、提升力学性能,为马氏体耐热钢/镍基合金异种金属连接界面设计与性能优化提供了重要的理论参考。 展开更多
关键词 异种金属 过渡层 固溶体 相平衡 元素扩散
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消防机器人热防护材料与技术研究进展
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作者 李亚澍 祝薇 邓元 《材料工程》 北大核心 2026年第3期67-80,共14页
消防机器人作为一种可以替代消防员进入火场进行灭火施救的关键装备,逐渐受到广泛的关注,其智能化与自主化已成为主要发展趋势。然而,消防机器人在火场作业中将面临复杂的热环境挑战,其核心控制部件以及为实现智能化自主作业加装的传感... 消防机器人作为一种可以替代消防员进入火场进行灭火施救的关键装备,逐渐受到广泛的关注,其智能化与自主化已成为主要发展趋势。然而,消防机器人在火场作业中将面临复杂的热环境挑战,其核心控制部件以及为实现智能化自主作业加装的传感器也面临高温失效的风险。因此,高效可靠的热防护材料与技术对于保障消防机器人稳定运行至关重要。本文聚焦消防机器人热防护问题,重点综述了防热涂层、隔热材料、相变储能材料等关键热防护材料的应用现状,并系统梳理了整体热防护方案和核心部件防护设计等热防护技术的研究进展。同时,总结了现有技术的不足,主要包括材料耐高温极限与轻量化矛盾、长期稳定性与成本控制等方面仍尚需研究,并从智能化热防护系统、传感器集成与数据融合及动态热管理调控这几方面对未来研究方向进行展望,以期推动消防机器人的工程化应用。 展开更多
关键词 消防机器人 热防护 隔热材料 多层隔热结构 相变储热材料
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跨层特征交互和偏移相位校正的结直肠息肉分割
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作者 李自洁 吕晓琪 李菁 《计算机工程与应用》 北大核心 2026年第6期267-278,共12页
针对结直肠图像中息肉边界模糊、定位不准确以及尺度差异大等问题,提出了跨层特征交互和偏移相位矫正的结直肠息肉分割网络模型。以金字塔视觉Transformer作为编码器逐级提取息肉图像中多尺度的语义信息;提出跨层特征交互模块,提取空间... 针对结直肠图像中息肉边界模糊、定位不准确以及尺度差异大等问题,提出了跨层特征交互和偏移相位矫正的结直肠息肉分割网络模型。以金字塔视觉Transformer作为编码器逐级提取息肉图像中多尺度的语义信息;提出跨层特征交互模块,提取空间和通道信息,进行多层次的特征交互;构建偏移相位校正模块,通过局部相似度计算出偏移量进行重采样,减少边界或类别内不一致区域的模糊性;设计空间上下文感知模块,提取全局上下文信息来表示像素之间的跨空间关系,从而抑制背景噪声,增强目标和背景的区分度。实验结果显示,模型在CVC-ClinicDB、Kvasir、CVC-ColonDB和ETIS数据集上的平均Dice系数分别为0.941、0.932、0.817和0.804,平均交并比分别为0.896、0.885、0.738和0.723,与现有的主流模型相比,该模型能够在提升息肉分割性能的同时保证其泛化性。 展开更多
关键词 息肉分割 Transformer 跨层特征交互 相位校正 上下文感知
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U75VG钢轨钢相变白层在摩擦磨损过程中表面组织和性能的变化
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作者 吕兴达 刘佳朋 +2 位作者 刘鹏涛 任瑞铭 赵秀娟 《热加工工艺》 北大核心 2026年第5期221-225,231,共6页
对U75VG钢轨钢试样表面进行局部激光淬火,在试样表面获得具有条带状的马氏体相变白层,U75VG钢轨钢淬火前后两种试样与配试样车轮钢ER8C对磨,在GPM-40滚动接触摩擦疲劳实验机进行滚动磨损实验。采用硬度计、精密电子天平、扫描电镜等分... 对U75VG钢轨钢试样表面进行局部激光淬火,在试样表面获得具有条带状的马氏体相变白层,U75VG钢轨钢淬火前后两种试样与配试样车轮钢ER8C对磨,在GPM-40滚动接触摩擦疲劳实验机进行滚动磨损实验。采用硬度计、精密电子天平、扫描电镜等分析相变白层在摩擦磨损过程中表面的组织和性能。结果表明:U75VG钢轨钢激光淬火处理试样在磨损实验运行时,易在激光淬火相变白层条带的起始端、终止端和两侧表面萌生裂纹,裂纹易在相变白层边缘与基体交界面及白层内扩展。没有相变白层条带的部位和原始试样磨损形貌一样,损伤均匀。在磨损实验运行70万转时,根据失重,U75VG钢轨钢激光淬火处理试样相对于U75VG钢轨钢原始试样磨损性能好,但U75VG钢轨钢淬火试样存在相变白层边缘与基体交界面易萌生裂纹、裂纹扩展和剥落等缺陷。 展开更多
关键词 激光淬火 摩擦磨损 高速轮轨材料 相变白层 马氏体
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基于相位调制自发辐射光的微波光子隐蔽通信技术
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作者 刘占琪 朱华涛 +7 位作者 姜丰 刘一伯 张鑫 徐向明 杨晨昊 丁海洋 赵永利 张杰 《移动通信》 2026年第1期59-67,共9页
放大自发辐射(ASE)光是光隐蔽通信的理想光源,其具有与光噪声相同的信号特征,相位调制不会改变ASE光的时频域特性。然而,由于ASE光的相干长度仅为亚毫米级,基于延迟线干涉仪的解调器无法适用。基于此,提出了一种用于相位调制ASE光的新... 放大自发辐射(ASE)光是光隐蔽通信的理想光源,其具有与光噪声相同的信号特征,相位调制不会改变ASE光的时频域特性。然而,由于ASE光的相干长度仅为亚毫米级,基于延迟线干涉仪的解调器无法适用。基于此,提出了一种用于相位调制ASE光的新型微波光子滤波检测方法,相位调制后的ASE光在光域内通过25 km的公共光信道实现隐蔽传输。为验证电域微波光子隐蔽通信的可行性,加入了可重构智能表面用于反射光电探测器输出的电信号。通过阐述微波光子隐蔽通信原理,对原理验证实验装置进行介绍,给出了实验结果与讨论,并得出结论,该方案将拓展微波光子学在隐蔽通信及6G安全通信的应用。 展开更多
关键词 6G 隐蔽通信 物理层安全 光通信 相位调制
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Al-Co-Ni-Cr新型黏结相硬质合金的耐腐蚀性研究
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作者 包宇衡 龙坚战 +6 位作者 汤梅芳 罗娆 赵声志 曾瑞霖 崔焱茗 成祥 尹超 《硬质合金》 2026年第1期34-43,共10页
为了解决传统以Co为黏结相的硬质合金在复杂工况条件下易腐蚀失效的难题,本文通过添加Al、Ni、Cr等元素,构建Al-Co-Ni-Cr多元固溶体黏结相,以提升材料的耐腐蚀性能,并研究其在酸性与盐介质环境中的电化学稳定性。在低、高浓度盐溶液中,... 为了解决传统以Co为黏结相的硬质合金在复杂工况条件下易腐蚀失效的难题,本文通过添加Al、Ni、Cr等元素,构建Al-Co-Ni-Cr多元固溶体黏结相,以提升材料的耐腐蚀性能,并研究其在酸性与盐介质环境中的电化学稳定性。在低、高浓度盐溶液中,以Al-Co-Ni-Cr为黏结相的硬质合金展现出最佳的耐腐蚀性能,而在酸溶液中NiCr黏结相的耐腐蚀性最佳。同时揭示了酸、盐溶液中溶液离子吸附、氧化层腐蚀、黏结相腐蚀的三阶段腐蚀机制。通过腐蚀试验与性能表征,本文为开发高耐蚀、高韧性的硬质合金提供了理论支撑和技术路径,从而推动硬质合金向高端化、专业化方向发展。 展开更多
关键词 硬质合金 黏结相 耐腐蚀性能 氧化层
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