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Fatigue behavior of press hardened Al-Si coated high strength steel
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作者 Wang Zijian Gui Zhongxiang Zhang Yisheng 《Engineering Sciences》 EI 2014年第5期28-32,共5页
The fatigue behavior of press hardened Al-Si coated high strength steel has been investigated,and the fatigue strength turns out to be about 1 000 MPa.Surface morphology of fractured and non-fractured specimen has bee... The fatigue behavior of press hardened Al-Si coated high strength steel has been investigated,and the fatigue strength turns out to be about 1 000 MPa.Surface morphology of fractured and non-fractured specimen has been observed,and the coating shows significant influence on the fatigue behavior.The difference of elastic modulus between coating and substrate led to the main cracks perpendicular to the loading direction.The coating close to fracture exfoliated thinly,while the coating far away from the fracture kept integrated.Though the specimen was polished to obtain high surface quality,3 types of cracks occurred during the fatigue test.What’s more,inclusion particles were proved to play a crucial role in causing these cracks. 展开更多
关键词 fatigue behavior high strength steel al-si coating CRACK
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Fabrication and characterization of multi-scale coated boron powders with improved combustion performance:A brief review 被引量:1
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作者 Rui Liu Danfeng Yang +2 位作者 Kunyu Xiong Ying-Lei Wang Qi-Long Yan 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第1期27-40,共14页
Boron has high mass and volume calorific values,but it is difficult to ignite and has low combustion efficiency.This literature review summarizes the strategies that are used to solve the above-mentioned problems,whic... Boron has high mass and volume calorific values,but it is difficult to ignite and has low combustion efficiency.This literature review summarizes the strategies that are used to solve the above-mentioned problems,which include coatings of boron by using fluoride compounds,energetic composites,metal fuels,and metal oxides.Coating techniques include recrystallization,dual-solvent,phase transfer,electrospinning,etc.As one of the effective coating agents,the fluorine compounds can react with the oxide shell of boron powder.In comparison,the energetic composites can effectively improve the flame temperature of boron powder and enhance the evaporation efficiency of oxide film as a condensed product.Metals and metal oxides would react with boron powder to form metal borides with a lower ignition point,which could reduce its ignition temperature. 展开更多
关键词 Boron powder coating Structure and morphology Condensed phase thermal reaction Ignition and combustion
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Coated sodium butyrate ameliorates high‑energy and low‑protein diet induced hepatic dysfunction via modulating mitochondrial dynamics, autophagy and apoptosis in laying hens
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作者 Sasa Miao Tianming Mu +5 位作者 Ru Li Yan Li Wenyan Zhao Jiankui Li Xinyang Dong Xiaoting Zou 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2024年第3期1190-1206,共17页
Background Fatty liver hemorrhagic syndrome(FLHS),a fatty liver disease in laying hens,poses a grave threat to the layer industry,stemming from its ability to trigger an alarming plummet in egg production and usher in... Background Fatty liver hemorrhagic syndrome(FLHS),a fatty liver disease in laying hens,poses a grave threat to the layer industry,stemming from its ability to trigger an alarming plummet in egg production and usher in acute mortality among laying hens.Increasing evidence suggests that the onset and progression of fatty liver was closely related to mitochondria dysfunction.Sodium butyrate was demonstrated to modulate hepatic lipid metabolism,alle-viate oxidative stress and improve mitochondrial dysfunction in vitro and mice models.Nevertheless,there is limited existing research on coated sodium butyrate(CSB)to prevent FLHS in laying hens,and whether and how CSB exerts the anti-FLHS effect still needs to be explored.In this experiment,the FLHS model was induced by administering a high-energy low-protein(HELP)diet in laying hens.The objective was to investigate the effects of CSB on alleviating FLHS with a focus on the role of CSB in modulating mitochondrial function.Methods A total of 288 healthy 28-week-old Huafeng laying hens were arbitrarily allocated into 4 groups with 6 replicates each,namely,the CON group(normal diet),HELP group(HELP diet),CH500 group(500 mg/kg CSB added to HELP diet)and CH750 group(750 mg/kg CSB added to HELP diet).The duration of the trial encompassed a period of 10 weeks.Results The result revealed that CSB ameliorated the HELP-induced FLHS by improving hepatic steatosis and patho-logical damage,reducing the gene levels of fatty acid synthesis,and promoting the mRNA levels of key enzymes of fatty acid catabolism.CSB reduced oxidative stress induced by the HELP diet,upregulated the activity of GSH-Px and SOD,and decreased the content of MDA and ROS.CSB also mitigated the HELP diet-induced inflammatory response by blocking TNF-α,IL-1β,and F4/80.In addition,dietary CSB supplementation attenuated HELP-induced activation of the mitochondrial unfolded protein response(UPRmt),mitochondrial damage,and decline of ATPase activity.HELP diet decreased the autophagosome formation,and downregulated LC3B but upregulated p62 protein expression,which CSB administration reversed.CSB reduced HELP-induced apoptosis,as indicated by decreases in the Bax/Bcl-2,Caspase-9,Caspase-3,and Cyt C expression levels.Conclusions Dietary CSB could ameliorate HELP diet-induced hepatic dysfunction via modulating mitochondrial dynamics,autophagy,and apoptosis in laying hens.Consequently,CSB,as a feed additive,exhibited the capacity to prevent FLHS by modulating autophagy and lipid metabolism. 展开更多
关键词 AUTOPHAGY coated sodium butyrate Laying hens Lipid metabolism MITOCHONDRIA
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Tailoring Iron-Ion Release of Cellulose-Based Aerogel-Coated Iron Foam for Long-Term High-Power Microbial Fuel Cells
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作者 Zhengyang Ni Huitao Yu +6 位作者 Haoran Wang Mengmeng Qin Feng Li Hao Song Xiangyu Chen Yiyu Feng Wei Feng 《Transactions of Tianjin University》 EI CAS 2024年第5期436-447,共12页
The presence of iron(Fe) has been found to favor power generation in microbial fuel cells(MFCs). To achieve long-term power production in MFCs, it is crucial to effectively tailor the release of Fe ions over extended ... The presence of iron(Fe) has been found to favor power generation in microbial fuel cells(MFCs). To achieve long-term power production in MFCs, it is crucial to effectively tailor the release of Fe ions over extended operating periods. In this study, we developed a composite anode(A/IF) by coating iron foam with cellulose-based aerogel. The concentration of Fe ions in the anode solution of A/IF anode reaches 0.280 μg/mL(Fe^(2+) vs. Fe^(3+) = 61%:39%) after 720 h of aseptic primary cell operation. This value was significantly higher than that(0.198 μg/mL, Fe^(2+) vs. Fe^(3+) = 92%:8%) on uncoated iron foam(IF), indicating a continuous release of Fe ions over long-term operation. Notably, the resulting MFCs hybrid cell exhibited a 23% reduction in Fe ion concentration(compared to a 47% reduction for the IF anode) during the sixth testing cycle(600-720 h). It achieved a high-power density of 301 ± 55 mW/m^(2) at 720 h, which was 2.62 times higher than that of the IF anode during the same period. Furthermore, a sedimentary microbial fuel cell(SMFCs) was constructed in a marine environment, and the A/IF anode demonstrated a power density of 103 ± 3 mW/m^(2) at 3240 h, representing a 75% improvement over the IF anode. These findings elucidate the significant enhancement in long-term power production performance of MFCs achieved through effective tailoring of Fe ions release during operation. 展开更多
关键词 Microbial fuel cells coating Fe ions Tailor release LONG-TERM
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Study on the application of optical interferometry in the measurement of the coating thickness of color-coated plates
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作者 ZHANG Xiaota FAN Chun REN Yuling 《Baosteel Technical Research》 CAS 2024年第3期39-47,共9页
The principle and application of optical interferometry to measure the coating thickness of color-coated plates were introduced in this paper.Additionally,several factors affecting the test results,including coating r... The principle and application of optical interferometry to measure the coating thickness of color-coated plates were introduced in this paper.Additionally,several factors affecting the test results,including coating refractive index,wavelength range,and film thickness range setting,were analyzed.Among these,the refractive index of the color coating,which cannot be measured directly,was identified as the key factor.A solution to this problem was proposed.Finally,the optical interference method and the current detection methods,including the micrometer method and the magnetic eddy current method,were analyzed and compared.The results show that optical interferometry has better repeatability and reproducibility than the current methods and show no significant difference from the current methods through statistical tests.Therefore,the method can be applied to the detection of the coating thickness of color-coated plates. 展开更多
关键词 optical interferometry color-coated plates coating thickness
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Mitigating the negative catalytic effect of CuO by FAS-17 coated Al nanopowder:Isothermal ageing of Al/CuO nanothermite at 71°C and 60%relative humidity
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作者 Fuwei Li Qian Wang +6 位作者 Jian Cheng Zehua Zhang Yuxuan Zhou Keer Ouyang Jianbing Xu Yinghua Ye Ruiqi Shen 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第4期156-167,共12页
The safety and reliability of weapon systems would be significantly affected by changes in the performance of energetic materials due to ambient temperature and humidity.Nanothermites have promising applications due t... The safety and reliability of weapon systems would be significantly affected by changes in the performance of energetic materials due to ambient temperature and humidity.Nanothermites have promising applications due to their excellent reactivity.Therefore it becomes extremely important to understand their aging and failure process in the environment before using them.Here,the aging and failure process of Al/CuO in 71°C/60%RH were investigated,and showed that CuO nanoparticles negatively catalyze Al nanopowders,resulting in rapid hydration.The anti-aging effect of FAS-17-coated Al nanopowder was also examined.The aging process of Al,Al/CuO,and Al@FAS-17/CuO in high humidity and heat environment were revealed by quasi-in situ SEM and TEM methods.Compared with the aging of pure Al,the Al nanopowder in the nanothermites strongly agglomerated with the CuO nanopowder and hydrated earlier.This may be caused by CuO catalyzed hydration of Al nanopowder.The energy release experiments showed that the performance of Al/CuO decreased rapidly and failed to ignite after 4 h of aging.In contrast,the Al@FAS-17/CuO thermite can achieve long-term stability of up to 60 h in the same environment by simple cladding of FAS-17.It is found that FAS-17 coated Al nanopowder can prevent both particle agglomeration and water erosion,which is an effective means to make nanothermites application in high humidity and heat environment. 展开更多
关键词 Al/CuO nanothermite FAS-17 coating Aging and failure process
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CoS Nanosheets Coated with Dopamine-Derived Carbon Standing on Carbon Fiber Cloth as Binder-Free Anode for Li-ion Batteries
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作者 Lianyuan Ji Mingchen Shi +1 位作者 Zengkai Feng Hui Yang 《Journal of Renewable Materials》 EI CAS 2024年第2期259-274,共16页
Cobalt sulphides attract much attention as anode materials for Li-ion batteries(LIBs).However,its poor conductivity,low initial column efficiency and large volume changes during cycling have hindered its further devel... Cobalt sulphides attract much attention as anode materials for Li-ion batteries(LIBs).However,its poor conductivity,low initial column efficiency and large volume changes during cycling have hindered its further development.Herein,novel interlaced CoS nanosheets were firstly prepared on Carbon Fiber Cloth(CFC)by two hydrothermal reactions followed with carbon coating via carbonizing dopamine(CoS NS@C/CFC).As a freestanding anode,the nanosheet structure of CoS not only accommodates the volume variation,but also provides a large interface area to proceed the charge transfer reaction.In addition,CFC works as both a three-dimensional skeleton and an active substance which can further improve the areal capacity of the resulting electrode.Furthermore,the coated carbon combined with the CFC work as a 3D conductive network to facilitate the electron conduction.The obtained CoS NS@C/CFC,and the contrast sample prepared with the same procedure but without carbon coating(CoS NS/CFC),are characterized with XRD,SEM,TEM,XPS and electrochemical measurements.The results show that the CoS NS@C/CFC possesses much improved electrochemical performance due to the synergistic effect of nanosheet CoS,the coated carbon and the CFC substrate,exhibiting high initial columbic efficiency(~87%),high areal capacity(2.5 at 0.15 mA cm−2),excellent rate performance(1.6 at 2.73 mA cm−2)and improved cycle stability(87.5%capacity retention after 300 cycles).This work may provide a new route to explore freestanding anodes with high areal specific capacity for LIBs. 展开更多
关键词 Lithium-ion battery cobalt sulfide carbon coating carbon fiber cloth freestanding anode
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THE INTERIOR TRANSMISSION EIGENVALUE PROBLEM FOR AN ANISOTROPIC MEDIUM BY A PARTIALLY COATED BOUNDARY
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作者 向建立 严国政 《Acta Mathematica Scientia》 SCIE CSCD 2024年第1期339-354,共16页
We consider the interior transmission eigenvalue problem corresponding to the scattering for an anisotropic medium of the scalar Helmholtz equation in the case where the boundary?Ωis split into two disjoint parts and... We consider the interior transmission eigenvalue problem corresponding to the scattering for an anisotropic medium of the scalar Helmholtz equation in the case where the boundary?Ωis split into two disjoint parts and possesses different transmission conditions.Using the variational method,we obtain the well posedness of the interior transmission problem,which plays an important role in the proof of the discreteness of eigenvalues.Then we achieve the existence of an infinite discrete set of transmission eigenvalues provided that n≡1,where a fourth order differential operator is applied.In the case of n■1,we show the discreteness of the transmission eigenvalues under restrictive assumptions by the analytic Fredholm theory and the T-coercive method. 展开更多
关键词 interior transmission eigenvalue anisotropic medium partially coated boundary the analytic Fredholm theory T-coercive method
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Critical current degradation in an epoxy-impregnated rare-earth Ba_(2)Cu_(3)O_(7-x)coated conductor caused by damage during a quench
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作者 Donghui LIU Huadong YONG Youhe ZHOU 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2024年第9期1557-1572,共16页
High-temperature superconducting(HTS)rare-earth Ba_(2)Cu_(3)O_(7-x)(REBCO)coated conductors(CCs)have significant potential in high-current and high-field applications.However,owing to the weak interface strength of th... High-temperature superconducting(HTS)rare-earth Ba_(2)Cu_(3)O_(7-x)(REBCO)coated conductors(CCs)have significant potential in high-current and high-field applications.However,owing to the weak interface strength of the laminated composite REBCO CCs,the damage induced by the thermal mismatch stress under a combination of epoxy impregnation,cooling,and quenching can cause premature degradation of the critical current.In this study,a three-dimensional(3D)electromagnetic-thermal-mechanical model based on the H-formulation and cohesive zone model(CZM)is developed to study the critical current degradation characteristics in an epoxy-impregnated REBCO CC caused by the damage during a quench.The temperature variation,critical current degradation of the REBCO CC,and its degradation onset temperature calculated by the numerical model are in agreement with the experimental data taken from the literature.The delamination of the REBCO CC predicted by the numerical model is consistent with the experimental result.The numerical results also indicate that the shear stress is the main contributor to the damage propagation inside the REBCO CC.The premature degradation of the critical current during a quench is closely related to the interface shear strength inside the REBCO CC.Finally,the effects of the coefficient of thermal expansion(CTE)of the epoxy resin,thickness of the substrate,and substrate material on the critical current degradation characteristics of the epoxy-impregnated REBCO CC during a quench are also discussed.These results help us understand the relationship between the current-carrying degradation and damage in the HTS applications. 展开更多
关键词 epoxy-impregnated rare-earth Ba_(2)Cu_(3)O_(7-x)(REBCO)coated conductor(CC) QUENCH DAMAGE critical current degradation shear stress
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Two-Dimensional Graphitic Carbon-Nitride(g-C_(3)N_(4))-Coated LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)Cathodes for High-Energy-Density and Long-Life Lithium Batteries
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作者 Zhenliang Duan Pengbo Zhai +1 位作者 Ning Zhao Xiangxin Guo 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第6期140-149,共10页
High-capacity nickel-rich layered oxides are promising cathode materials for high-energy-density lithium batteries.However,the poor structural stability and severe side reactions at the electrode/electrolyte interface... High-capacity nickel-rich layered oxides are promising cathode materials for high-energy-density lithium batteries.However,the poor structural stability and severe side reactions at the electrode/electrolyte interface result in unsatisfactory cycle performance.Herein,the thin layer of two-dimensional(2D)graphitic carbon-nitride(g-C_(3)N_(4))is uniformly coated on the LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(denoted as NCM811@CN)using a facile chemical vaporization-assisted synthesis method.As an ideal protective layer,the g-C_(3)N_(4)layer effectively avoids direct contact between the NCM811 cathode and the electrolyte,preventing harmful side reactions and inhibiting secondary crystal cracking.Moreover,the unique nanopore structure and abundant nitrogen vacancy edges in g-C_(3)N_(4)facilitate the adsorption and diffusion of lithium ions,which enhances the lithium deintercalation/intercalation kinetics of the NCM811 cathode.As a result,the NCM811@CN-3wt%cathode exhibits 161.3 mAh g^(−1)and capacity retention of 84.6%at 0.5 C and 55°C after 400 cycles and 95.7 mAh g^(−1)at 10 C,which is greatly superior to the uncoated NCM811(i.e.129.3 mAh g^(−1)and capacity retention of 67.4%at 0.5 C and 55°C after 220 cycles and 28.8 mAh g^(−1)at 10 C).The improved cycle performance of the NCM811@CN-3wt%cathode is also applicable to solid–liquid-hybrid cells composed of PVDF:LLZTO electrolyte membranes,which show 163.8 mAh g^(−1)and the capacity retention of 88.1%at 0.1 C and 30°C after 200 cycles and 95.3 mAh g^(−1)at 1 C. 展开更多
关键词 cathode materials g-C_(3)N_(4)coating LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) lithium batteries PVDF:LLZTO electrolyte membranes
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The Efficacy and Safety of Drug-Coated Balloons in the Treatment of Acute Myocardial Infarction
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作者 Mingliang Du Hui Hui 《World Journal of Cardiovascular Diseases》 CAS 2024年第1期1-9,共9页
The incidence of acute myocardial infarction (AMI) is increasing year by year, which seriously endangers human health around the world. The preferred treatment strategy for AMI patients is the use of drug-eluting sten... The incidence of acute myocardial infarction (AMI) is increasing year by year, which seriously endangers human health around the world. The preferred treatment strategy for AMI patients is the use of drug-eluting stents (DES), as there is ample evidence to suggest that stent implantation can reduce major adverse cardiovascular events (MACEs). With the application of drug-coated balloons (DCBs) and the enhancement of the concept of interventional without implantation, the question is whether DCBs can be safely and effectively used in patients with AMI? The purpose of this study was to investigate the safety and effectiveness of DCBs in the treatment of AMI. A retrospective review of clinical data was conducted on 55 AMI patients who underwent primary percutaneous coronary intervention (PCI) from January 2020 to December 2021. Of these patients, 25 were treated with DCBs and 30 were treated with DESs. Optical coherence tomography (OCT) was used to measure the minimum lumen diameter, lumen stenosis, and coronary artery dissection before and after surgery, and angina pectoris attacks and various MACEs were recorded at 1, 6, and 12 months after surgery. The results showed that there were no significant differences in clinical baseline data between the two groups. However, the minimum lumen diameter of the DCB group immediately after the operation was smaller than that of the DES group, and the stenosis degree of the lumen in the DCB group was higher than that in the DES group. The incidence of coronary artery dissection in the DCB group was significantly higher than that in the DES group, but the majority of them were type B. At 1, 6, and 12 months after treatment, there was no significant difference in the occurrence of MACEs between the two groups. In conclusion, DCBs is a safe and effective treatment for AMI. However, the incidence of coronary artery dissection in DCB patients is higher than that in DES patients, but the majority of them are type B. . 展开更多
关键词 Myocardial Infarction Drug-coated Balloon Drug-Eluting Stents
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Clinical Effect of Ilaprazole Enteric-Coated Tablets in Patients with Peptic Ulcer
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作者 Fanghui Chen 《Journal of Biosciences and Medicines》 2024年第9期155-160,共6页
Objective: To discuss the actual effect of ilaprazole enteric-coated tablets in the treatment of peptic ulcer patients. Methods: 200 peptic ulcer patients who received treatment from January to December 2023 were sele... Objective: To discuss the actual effect of ilaprazole enteric-coated tablets in the treatment of peptic ulcer patients. Methods: 200 peptic ulcer patients who received treatment from January to December 2023 were selected as the study sample, and all patients were randomly and evenly divided into the study group (n = 100) and the control group (n = 100), and the serum inflammatory factors and the disappearance time of symptoms were compared. Results: After treatment, the serum inflammatory factors in the observation group were better than those in the control group, and the time of belching and burning sensation in the observation group was shorter than that in the control group, all of which were statistically significant (P Conclusion: Ilaprazole enteric-coated tablets in the treatment of peptic ulcer have a good effect and can effectively improve the symptoms of patients with clinical signs, with reference significance. 展开更多
关键词 Ilaprazole Enteric-coated Tablets Peptic Ulcer SYMPTOMS
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Sr含量对Al-Si合金显微组织和热导率的影响 被引量:2
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作者 张瑞英 李继承 +1 位作者 沙君浩 李家康 《材料热处理学报》 CAS CSCD 北大核心 2024年第1期53-61,共9页
以纯铝、Al-20Si和Al-10Sr中间合金为原料,Sr为变质剂(含量为0.01%、0.02%、0.04%和0.06%,质量分数),制备了Al-7Si-xSr、Al-12Si-xSr和Al-20Si-xSr合金,研究了Sr含量对Al-Si合金相变储热材料显微组织及热导率的影响。利用Hot Disk热常... 以纯铝、Al-20Si和Al-10Sr中间合金为原料,Sr为变质剂(含量为0.01%、0.02%、0.04%和0.06%,质量分数),制备了Al-7Si-xSr、Al-12Si-xSr和Al-20Si-xSr合金,研究了Sr含量对Al-Si合金相变储热材料显微组织及热导率的影响。利用Hot Disk热常数分析仪测量合金的热导率,通过扫描电镜观察及分析合金的显微组织。结果表明:在Al-Si合金中添加变质元素Sr会影响合金的热导率,Al-7Si-0.04Sr合金热导率较Al-7Si合金增加了73.47 W·m^(-1)·K^(-1),Al-20Si-0.04Sr合金的热导率较Al-20Si合金增加了24.09 W·m^(-1)·K^(-1),Al-12Si-0.04Sr合金的热导率较Al-12Si合金增加了17.79 W·m^(-1)·K^(-1)。铝硅合金热导率的增长主要与α(Al)、共晶硅和初晶硅的形貌有关。经过Sr变质之后,Al-7Si合金中共晶Si立体形貌均由片层状转变为珊瑚状,Al-12Si和Al-20Si合金中共晶Si立体形貌由片层状转变为枝条状;其中,Al-7Si合金中α(Al)尺寸明显减少、排列紧密,二次枝晶臂间距逐渐减小;Al-20Si合金中的初晶Si尺寸明显减小,其形貌由多角的大块状变为小块状;α(Al)形态的转变不仅能够为自由电子的传输提供快速通道,而且还会使得共晶Si的排列更加规则,减少自由电子发生散射的几率,对合金的热导率影响较大。共晶Si由片层状转变为珊瑚状或枝条状,增加电子的平均自由程,有利于电子的传输。Al-20Si合金的热导率与初晶Si的形态有着重要联系,大尺寸且形状完整的初晶Si会发生晶格振动,会提高合金的热导率。 展开更多
关键词 al-si合金 变质剂Sr 相变储热材料 热导率
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Al-Si镀层22MnB5激光焊的熔池流动特性及元素分布 被引量:1
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作者 朱李斌 汪乾 +4 位作者 潘宣军 李思良 葛星 张衡 刘海江 《焊接学报》 EI CAS CSCD 北大核心 2024年第6期1-11,共11页
熔池流动行为对镀层元素在焊缝中的分布起决定性作用.采用建立激光焊熔池三维瞬态数值模型的方法,分析AlSi镀层22MnB5高强度钢激光焊的熔池流动行为及其对焊缝中Al元素分布的影响规律.在焊接试验中,根据能谱仪对焊接接头的扫描数据验证... 熔池流动行为对镀层元素在焊缝中的分布起决定性作用.采用建立激光焊熔池三维瞬态数值模型的方法,分析AlSi镀层22MnB5高强度钢激光焊的熔池流动行为及其对焊缝中Al元素分布的影响规律.在焊接试验中,根据能谱仪对焊接接头的扫描数据验证数值模型的可靠性.结合模拟结果与试验结果对激光焊熔池流动行为及焊缝Al元素分布规律进行研究.结果表明,根据激光焊热输入与功率密度阈值的不同,熔池形貌呈现无匙孔、未完全贯穿匙孔和完全贯穿匙孔3种特征,并存有不同的温度场、流场、流速和稳定性.无匙孔熔池由于流速分布均匀,涡流产生较少,稳定性最好.镀层Al元素在焊接接头上下焊趾区域易产生偏聚,较之上表面镀层,下表面镀层进入熔池后Al元素偏聚现象更明显.因此,上部Al元素均质化分布显著优于下部. 展开更多
关键词 al-si镀层22MnB5高强度钢 数值模拟 熔池流动 Al元素均质化
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Enhanced Microwave Absorption for High Filler Content Composite Molded from Polymer Coated Flaky Carbonyl Irons Modified by Silane Coupling Agents 被引量:2
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作者 崔正明 MA Guoqing +5 位作者 WANG Mengqi LUO Chuangyu CHEN Zhihong MA Huiru LI Qifan 李维 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2023年第1期42-51,共10页
A microwave absorbing sheet with a high complex permeability and a relatively low complex permittivity is obtained by molding of the densely coated flaky carbonyl iron particles(FCIPs)by styrenebutadiene-styrene block... A microwave absorbing sheet with a high complex permeability and a relatively low complex permittivity is obtained by molding of the densely coated flaky carbonyl iron particles(FCIPs)by styrenebutadiene-styrene block copolymer(SBS)in the assistance of coupling agent modification.Direct molding of the core-shell FCIPs without adding extra binder results in a large permeability due to the high filling ratio(55vol%)of absorbents.Importantly,the permittivity is well suppressed by the dense insulate polymer shell on the FCIPs,avoiding the severe impedance mismatch problem of the high filler content microwave absorbing materials.Investigations show that modifying the surface of FCIPs by proper amount of silane coupling agent is critical for the coating quality of the SBS shell,which is verified by resistivity and corrosion current density measurements,and can be interpreted by improved interfacial compatibility between the modified FCIPs and SBS.The obtained microwave absorbing sheet shows a minimum reflection loss of-38.74 dB at 1.57 GHz and has an effective absorption bandwidth from 1.1 to 2.3 GHz at a relatively small thickness of 2 mm. 展开更多
关键词 microwave absorber coating quality magnetic permeability PERMITTIVITY low frequency
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3D Raman mapping as an analytical tool for investigating the coatings of coated drug particles 被引量:1
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作者 Georgia Koutentaki Pavel Krýsa +3 位作者 Dan Trunov Tomás Pekarek Marketa Pislova Miroslav Soos 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2023年第3期276-286,共11页
The properties of dry-coated paracetamol particles(fast-dissolving model drug)with carnauba wax particles as the coating agent(dissolution retardant)were investigated.Raman mapping technique was used to non-destructiv... The properties of dry-coated paracetamol particles(fast-dissolving model drug)with carnauba wax particles as the coating agent(dissolution retardant)were investigated.Raman mapping technique was used to non-destructively examine the thickness and homogeneity of coated particles.The results showed that the wax existed in two forms on the surface of the paracetamol particles,forming a porous coating layer:i)whole wax particles on the surface of paracetamol and glued together with other wax surface particles,and ii)deformed wax particles spread on the surface.Regardless of the final particle size fraction(between 100 and 800 mm),the coating thickness had high variability,with average thickness of 5.9±4.2 mm.The ability of carnauba wax to decrease the dissolution rate of paracetamol was confirmed by dissolution of powder and tablet formulations.The dissolution was slower for larger coated particles.Tableting further reduced the dissolution rate,clearly indicating the impact of subsequent formulation processes on the final quality of the product. 展开更多
关键词 Raman mapping Dry-coating DISSOLUTION Particle coating thickness POLYMERS
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Effect of NiO-NiCr2O4 nano-oxides on the microstructural,mechanical and corrosion properties of Ni-coated carbon steel 被引量:1
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作者 Saeed Mojallal Hurieh Mohammadzadeh +1 位作者 Abbas Aghaeinejad-Meybodi Robabeh Jafari 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2023年第6期1078-1092,共15页
Pure Ni and its composites with different percentages of Ni-Cr nano-oxides were coated over carbon steel to assess the coating features and mechanical and corrosion behavior.A nano-oxide composite of Ni-Cr was first s... Pure Ni and its composites with different percentages of Ni-Cr nano-oxides were coated over carbon steel to assess the coating features and mechanical and corrosion behavior.A nano-oxide composite of Ni-Cr was first synthesized through chemical coprecipitation with uniform distribution constituents.Electrodeposition was employed to coat pure Ni and Ni-(Ni-Cr)oxides(10,20,30,40,and 50 g/L)on the steel sheets.Transmission electron microscope and field emission scanning electron microscope were adopted to examine the microstructure of powders and coatings,and X-ray diffraction analysis was employed to study the chemical composition.The microhardness,thickness,and wear resistance of the coatings were assessed,polarization and electrochemical impedance spectroscopy(EIS)tests were conducted to analyze the corrosion behavior,and the corresponding equivalent circuit was developed.Results showed flawless and crack-free coatings for all samples and uniform distribution of nano-oxides in the Ni matrix for the samples of 10-30 g/L.Agglomerated oxides were detected at high concentrations.Maximum microhardness(HV 661),thickness(116μm),and wear resistance of coatings were found at 30 g/L.A three-loop equivalent circuit corresponded satisfactorily to all EIS data.The corrosion resistance increased with the nano-oxide concentration of up to 30 g/L but decreased at 40 g/L.The sample of 50 g/L showed the best corrosion resistance. 展开更多
关键词 nanocomposite powder electroplating coating corrosion resistance electrochemical impedance spectroscopy wear resistance
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SiCp/Al-Si基复合材料界面结构调控及强化机制的研究进展
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作者 苏嶓 王爱琴 +4 位作者 谢敬佩 刘瑛 张津浩 柳培 梁婷婷 《材料热处理学报》 CAS CSCD 北大核心 2024年第2期1-12,共12页
SiCp/Al-Si基复合材料具有高的比强度、比刚度、比模量,良好的导热、导电、耐磨性及尺寸稳定性等优点,作为结构功能性材料应用于空间工程、电子封装、交通运输和精密仪器等领域。其研究热点主要集中在界面结构调控、强化机制及性能调控... SiCp/Al-Si基复合材料具有高的比强度、比刚度、比模量,良好的导热、导电、耐磨性及尺寸稳定性等优点,作为结构功能性材料应用于空间工程、电子封装、交通运输和精密仪器等领域。其研究热点主要集中在界面结构调控、强化机制及性能调控等方面。在SiCp/Al-Si复合材料中存在着增强体与基体界面、析出相与基体界面、析出相与增强体界面,这些界面受各种因素影响,会出现多种界面反应和界面产物,界面结构和结合状态复杂而多样。基于此,本文综述了制备工艺、基体合金成分和SiCp表面改性等方面对SiCp/Al-Si基复合材料界面结构的影响及调控,并总结了影响其力学性能的因素及强化机制的研究现状,最后对复合材料未来的发展及研究方向进行了展望。 展开更多
关键词 SiCp/al-si复合材料 界面结构调控 力学性能 强化机制 多尺度研究
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Si含量对Al-Si-Cu-Ni-Mg合金组织和性能的影响
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作者 韩杨 相志磊 陈子勇 《铸造》 CAS 2024年第6期779-787,共9页
采用搅拌铸造工艺制备不同Si含量合金,旨在揭示Si含量对Al-Si-Cu-Ni-Mg合金微观组织、力学性能和耐磨性的影响。结果表明,随着Si含量升高,合金中共晶Si长径比和平均长度先升高后降低,Si含量为16wt.%合金的长径比和平均长度最大,分别为8.... 采用搅拌铸造工艺制备不同Si含量合金,旨在揭示Si含量对Al-Si-Cu-Ni-Mg合金微观组织、力学性能和耐磨性的影响。结果表明,随着Si含量升高,合金中共晶Si长径比和平均长度先升高后降低,Si含量为16wt.%合金的长径比和平均长度最大,分别为8.8μm、24.1μm。经过520℃/6 h固溶+180℃/5 h时效处理后,共晶Si形貌由纤维状变为球状,初晶Si棱角钝化。合金中共晶Si长径比和平均长度均有明显降低,保持与铸态合金相同的变化趋势;Si含量为16wt.%合金的长径比和平均长度分别为3.5μm、12.4μm,初晶Si尺寸没有明显变化。随着Si含量的升高,铸态合金拉伸性能逐渐降低,宏观硬度逐渐上升。经过T6热处理后,合金的拉伸性能和宏观硬度有了明显提升,保持与铸态合金相同的变化趋势,随着Si含量的升高,合金磨损失重减少,耐磨性得到改善。Si含量为16wt.%的合金磨损失重最少,耐磨性最好;继续增加Si含量时,合金耐磨性降低。 展开更多
关键词 al-si合金 SI含量 微观组织 耐磨性 力学性能
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High corrosion and wear resistant electroless Ni–P gradient coatings on aviation aluminum alloy parts 被引量:2
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作者 Bo Wang Jiawei Li +2 位作者 Zhihui Xie Gengjie Wang Gang Yu 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CSCD 2024年第1期155-164,共10页
A Ni–P alloy gradient coating consisting of multiple electroless Ni–P layers with various phosphorus contents was prepared on the aviation aluminum alloy. Several characterization and electrochemical techniques were... A Ni–P alloy gradient coating consisting of multiple electroless Ni–P layers with various phosphorus contents was prepared on the aviation aluminum alloy. Several characterization and electrochemical techniques were used to characterize the different Ni–P coatings’ morphologies, phase structures, elemental compositions, and corrosion protection. The gradient coating showed good adhesion and high corrosion and wear resistance, enabling the application of aluminum alloy in harsh environments. The results showed that the double zinc immersion was vital in obtaining excellent adhesion (81.2 N). The optimal coating was not peeled and shredded even after bending tests with angles higher than 90°and was not corroded visually after 500 h of neutral salt spray test at 35℃. The high corrosion resistance was attributed to the misaligning of these micro defects in the three different nickel alloy layers and the amorphous structure of the high P content in the outer layer. These findings guide the exploration of functional gradient coatings that meet the high application requirement of aluminum alloy parts in complicated and harsh aviation environments. 展开更多
关键词 aluminum alloy ELECTROLESS nickel coating CORROSION ADHESION
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