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钛/钢和钛/铜/钢复合板焊接接头组织和性能
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作者 褚巧玲 王君尧 +3 位作者 杨聃 王中莹 曹齐鲁 YAN Cheng 《焊接学报》 北大核心 2025年第2期25-35,共11页
采用电弧焊接方法(TIG/MIG)进行钛/钢(TA1/Q345)和钛/铜/钢(TA1/T2/Q345)复合板的对接焊接,借助SEM,EBSD,TEM,显微硬度、纳米压痕和拉伸试验系统研究了对接焊缝中的显微结构和力学性能.结果表明,钛/钢对接接头中,Cu-V焊缝主要以铜基固... 采用电弧焊接方法(TIG/MIG)进行钛/钢(TA1/Q345)和钛/铜/钢(TA1/T2/Q345)复合板的对接焊接,借助SEM,EBSD,TEM,显微硬度、纳米压痕和拉伸试验系统研究了对接焊缝中的显微结构和力学性能.结果表明,钛/钢对接接头中,Cu-V焊缝主要以铜基固溶体和铁基固溶体为主,局部生成的Fe_(2)Ti相被韧性较好的铜基固溶体包围;Cu-V/ERTi-1焊缝界面处存在多种Cu-Ti和Fe-Ti金属间化合物;Cu-V焊缝与TA1/Q345界面处,存在Fe-Ti,CuTi_(2)和β-Ti化合物.钛/铜/钢对接接头中,Cu/ERTi-1焊缝界面处分布着多种Cu-Ti金属间化合物,分布范围较广.钛/钢对接焊缝中Fe_(2)Ti脆性相的硬度较高,为20.7GPa,但由于其尺寸相对较小,因此接头的显微硬度分布与钛/铜/钢对接焊缝类似,高硬度区域均在铜基焊缝与ERTi-1焊缝界面处,达到400HV0.3,两种对接接头中大量分布的Cu-Ti化合物的硬度处于8~11GPa.钛/钢异质接头的抗拉强度为440MPa,钛/铜/钢异质接头的抗拉强度为225MPa,断裂位置均在焊缝区域,并且铜基焊缝与ERTi-1焊缝界面处均是脆性断裂特征.钛/钢对接焊缝中不可避免会存在Fe-Ti脆性相,虽然采用钛/铜/钢三层复合板的形式可以避免Fe-Ti脆性相的生成,但是接头中分布较广的Cu-Ti化合物仍旧是接头的一个薄弱区域. 展开更多
关键词 异质接头 钛/钢复合板 钛/铜/钢复合板 金属间化合物 力学性能
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A review of carbon-based hybrid materials for supercapacitors 被引量:2
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作者 Theodore Azemtsop Manfo Hannu Laaksonen 《新型炭材料(中英文)》 北大核心 2025年第1期81-110,共30页
Supercapacitors are gaining popularity due to their high cycling stability,power density,and fast charge and discharge rates.Researchers are ex-ploring electrode materials,electrolytes,and separat-ors for cost-effecti... Supercapacitors are gaining popularity due to their high cycling stability,power density,and fast charge and discharge rates.Researchers are ex-ploring electrode materials,electrolytes,and separat-ors for cost-effective energy storage systems.Ad-vances in materials science have led to the develop-ment of hybrid nanomaterials,such as combining fil-amentous carbon forms with inorganic nanoparticles,to create new charge and energy transfer processes.Notable materials for electrochemical energy-stor-age applications include MXenes,2D transition met-al carbides,and nitrides,carbon black,carbon aerogels,activated carbon,carbon nanotubes,conducting polymers,carbon fibers,and nanofibers,and graphene,because of their thermal,electrical,and mechanical properties.Carbon materials mixed with conducting polymers,ceramics,metal oxides,transition metal oxides,metal hydroxides,transition metal sulfides,trans-ition metal dichalcogenide,metal sulfides,carbides,nitrides,and biomass materials have received widespread attention due to their remarkable performance,eco-friendliness,cost-effectiveness,and renewability.This article explores the development of carbon-based hybrid materials for future supercapacitors,including electric double-layer capacitors,pseudocapacitors,and hy-brid supercapacitors.It investigates the difficulties that influence structural design,manufacturing(electrospinning,hydro-thermal/solvothermal,template-assisted synthesis,electrodeposition,electrospray,3D printing)techniques and the latest car-bon-based hybrid materials research offer practical solutions for producing high-performance,next-generation supercapacitors. 展开更多
关键词 Carbon-based hybrid material Structure design Electrode material Specific capacitance SUPERCAPACITORS
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Projectile impact and drop weight resistance of functionally graded fiber-reinforced magnetite aggregate concrete
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作者 Abbas Abbaspour Behnoud Ganjavi Mahdi Nematzadeh 《Defence Technology(防务技术)》 2025年第10期1-23,共23页
Many researchers have focused on the behavior of fiber-reinforced concrete(FRC)in the construction of various defensive structures to resist against impact forces resulting from explosions and projectiles.However,the ... Many researchers have focused on the behavior of fiber-reinforced concrete(FRC)in the construction of various defensive structures to resist against impact forces resulting from explosions and projectiles.However,the lack of sufficient research regarding the resistance of functionally graded fiber-reinforced concrete against projectile impacts has resulted in a limited understanding of the performance of this concrete type,which is necessary for the design and construction of structures requiring great resistance against external threats.Here,the performance of functionally graded fiber-reinforced concrete against projectile impacts was investigated experimentally using a(two-stage light)gas gun and a drop weight testing machine.For this objective,12 mix designs,with which 35 cylindrical specimens and 30 slab specimens were made,were prepared,and the main variables were the magnetite aggregate vol%(55%)replacing natural coarse aggregate,steel fiber vol%,and steel fiber type(3D and 5D).The fibers were added at six vol%of 0%,0.5%,0.75%,1%,1.25%,and 1.5%in 10 specimen series(three identical specimens per each series)with dimensions of 40×40×7.5 cm and functional grading(three layers),and the manufactured specimens were subjected to the drop weight impact and projectile penetration tests by the drop weight testing machine and gas gun,respectively,to assess their performance.Parameters under study included the compressive strength,destruction level,and penetration depth.The experimental results demonstrate that using the magnetite aggregate instead of the natural coarse aggregate elevated the compressive strength of the concrete by 61%.In the tests by the drop weight machine,it was observed that by increasing the total vol%of the fibers,especially by increasing the fiber content in the outer layers(impact surface),the cracking resistance and energy absorption increased by around 100%.Note that the fiber geometry had little effect on the energy absorption in the drop weight test.Investigating the optimum specimens showed that using 3D steel fibers at a total fiber content of 1 vol%,consisting of a layered grading of 1.5 vol%,0 vol%,and 1.5 vol%,improved the penetration depth by 76%and lowered the destruction level by 85%.In addition,incorporating the 5D steel fibers at a total fiber content of 1 vol%,consisting of the layered fiber contents of 1.5%,0%,and 1.5%,improved the projectile penetration depth by 50%and lowered the damage level by 61%compared with the case of using the 3D fibers. 展开更多
关键词 Steel fiber Projectile impact Gas gun Drop weight MAGNETITE Fiber-reinforced concrete(FRC)
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Growth kinetics of borided 316 L stainless steel obtained by selective laser melting
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作者 DEMIRCI Selim TÜNÇAY Mehmet Masum 《Journal of Central South University》 2025年第2期332-349,共18页
Selective laser melting(SLM)is a cost-effective 3 D metal additive manufacturing(AM)process.However,AM 316 L stainless steel(SS)has different surface and microstructure properties as compared to conventional ones.Bori... Selective laser melting(SLM)is a cost-effective 3 D metal additive manufacturing(AM)process.However,AM 316 L stainless steel(SS)has different surface and microstructure properties as compared to conventional ones.Boriding process is one of the ways to modify and increase the surface properties.The aim of this study is to predict and understand the growth kinetic of iron boride layers on AM 316 L SS.In this study,the growth kinetic mechanism was evaluated for AM 316 L SS.Pack boriding was applied at 850,900 and 950℃,each for 2,4 and 6 h.The thickness of the boride layers ranged from(1.8±0.3)μm to(27.7±2.2)μm.A diffusion model based on error function solutions in Fick’s second law was proposed to quantitatively predict and elucidate the growth rate of FeB and Fe_(2)B phase layers.The activation energy(Q)values for boron diffusion in FeB layer,Fe_(2)B layer,and dual FeB+Fe_(2)B layer were found to be 256.56,161.61 and 209.014 kJ/mol,respectively,which were higher than the conventional 316 L SS.The findings might provide and open new directions and approaches for applications of additively manufactured steels. 展开更多
关键词 316L stainless steel BORIDING KINETICS additive manufacturing selective laser melting
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Performance of multi-layer steel fiber-reinforced mortar panels with air gaps against high-velocity bullets and successive firing
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作者 Apisit Techaphatthanakon Buchit Maho +5 位作者 Sittisak Jamnam Pochara Kruavit Manote Sappakittipakorn Phattharachai Pongsopha Gritsada Sua-iam Piti Sukontasukkul 《Defence Technology(防务技术)》 2025年第7期290-306,共17页
This research addresses the growing demand for high-performance protective materials against high-velocity projectile impacts.The performance of multi-layered steel fiber-reinforced mortar(SFRM)panels with varying thi... This research addresses the growing demand for high-performance protective materials against high-velocity projectile impacts.The performance of multi-layered steel fiber-reinforced mortar(SFRM)panels with varying thicknesses and air gaps,was experimentally investigated under single and repeated impacts of 7.62×51 mm bullets fired from a distance of 50 m.The impact events were recorded using a high-speed camera at 40000 fps.Panel performance was assessed in terms of failure modes,kinetic energy absorption,spalling diameter,and percentage of back-face damage area,and weight loss.Results showed that panel configuration significantly influenced performance.Panel P10,with 70 mm SFRM thickness and 20 mm air gaps,provided the highest resistance,dissipating 5223 J of kinetic energy and preventing back-face damage.In contrast,P7,which absorbed 4476 J,presented a back damage area percentage of 8.93%after three impacts.Weight loss analysis further confirmed durability improvements,with P10 showing only 1.53%cumulative loss compared to 3.26%in P7.The inclusion of wider air gaps enhanced energy dissipation and reduced damage.Comparison between single and repeated impacts demonstrated the sustained resistance of high-performance panels,with P10 maintaining minimal degradation across three consecutive impacts.These findings highlight the potential of multi-layer SFRM panels to enhance ballistic resistance,making them suitable for military,security,and civilian protective applications requiring long-term durability. 展开更多
关键词 Bullet resistance Steel fiber reinforced mortar Multilayer Impact behavior Failure mode
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Advanced composite wing design for next-generation military UAVs:A progressive numerical optimization framework
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作者 M.Atif Yilmaz Kemal Hasirci +1 位作者 Berk Gündüz Alaeddin Burak Irez 《Defence Technology(防务技术)》 2025年第6期141-155,共15页
The design of unmanned aerial vehicles(UAVs)revolves around the careful selection of materials that are both lightweight and robust.Carbon fiber-reinforced polymer(CFRP)emerged as an ideal option for wing construction... The design of unmanned aerial vehicles(UAVs)revolves around the careful selection of materials that are both lightweight and robust.Carbon fiber-reinforced polymer(CFRP)emerged as an ideal option for wing construction,with its mechanical qualities thoroughly investigated.In this study,we developed and optimized a conceptual UAV wing to withstand structural loads by establishing progressive composite stacking sequences,and we conducted a series of experimental characterizations on the resulting material.In the optimization phase,the objective was defined as weight reduction,while the Hashin damage criterion was established as the constraint for the optimization process.The optimization algorithm adaptively monitors regional damage criterion values,implementing necessary adjustments to facilitate the mitigation process in a cost-effective manner.Optimization of the analytical model using Simulia Abaqus~(TM)and a Python-based user-defined sub-routine resulted in a 34.7%reduction in the wing's structural weight after 45 iterative rounds.Then,the custom-developed optimization algorithm was compared with a genetic algorithm optimization.This comparison has demonstrated that,although the genetic algorithm explores numerous possibilities through hybridization,the custom-developed algorithm is more result-oriented and achieves optimization in a reduced number of steps.To validate the structural analysis,test specimens were fabricated from the wing's most critically loaded segment,utilizing the identical stacking sequence employed in the optimization studies.Rigorous mechanical testing revealed unexpectedly high compressive strength,while tensile and bending strengths fell within expected ranges.All observed failure loads remained within the established safety margins,thereby confirming the reliability of the analytical predictions. 展开更多
关键词 Aircraft wing Carbon fiber Composite Optimization UAV
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Damage analysis caused by ^(60)Co ions in functionally graded materials
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作者 Zübeyde Özkan Ugur Gökmen Sema Bilge Ocak 《Defence Technology(防务技术)》 2025年第2期248-256,共9页
Functionally graded composite/hybrid materials(FGCM/FGHCM)were produced by adding B_(4)C,TiO_(2),and B_(4)C+TiO_(2)ceramic materials at various ratios(0-50%)into the AA6082 matrix.The analysis of the damage caused by^... Functionally graded composite/hybrid materials(FGCM/FGHCM)were produced by adding B_(4)C,TiO_(2),and B_(4)C+TiO_(2)ceramic materials at various ratios(0-50%)into the AA6082 matrix.The analysis of the damage caused by^(60) ions'(1.173-1.1332 MeV)on the material was examined using the SRIM/TRIM Monte Carlo simulation software.In the simulation,the following data regarding the atoms of the target materials were obtained:ion distribution,target ionization,total displacements,surface binding energy,lattice binding energy,and displacement energy.Among the studied four materials,the one with the highest ion range value was found to be AA6082 with 8550A.TiO_(2)was found to be the reinforcement material that reduced the ion range the most in the material.Due to its high binding energy,B_(4)C reinforced AA6082+(0-50%)B_(4)C FGCM was found to have the least vacancy with 4782/ion. 展开更多
关键词 SRIM/TRIM Damage analysis AA6082 ^(60)Co ion
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Erratum to:Evolution of microstructure and mechanical properties in multi-layer 316 L-TiC composite fabricated by selective laser melting additive manufacturing
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作者 Sasan YAZDANI Suleyman TEKELI +2 位作者 Hossein RABIEIFAR Ufuk TAŞCI Elina AKBARZADEH 《Journal of Central South University》 2025年第2期691-691,共1页
Because of an unfortunate mistake during the production of this article,the Acknowledgements have been omitted.The Acknowledgements are added as follows:Sasan YAZDANI would like to thank the Scientific and Technologic... Because of an unfortunate mistake during the production of this article,the Acknowledgements have been omitted.The Acknowledgements are added as follows:Sasan YAZDANI would like to thank the Scientific and Technological Research Council of Turkey(TÜB˙ITAK)for receiving financial support for this work through the 2221 Fellowship Program for Visiting Scientists and Scientists on Sabbatical Leave(Grant ID:E 21514107-115.02-228864).Sasan YAZDANI also expresses his gratitude to Sahand University of Technology for granting him sabbatical leave to facilitate the completion of this research. 展开更多
关键词 additive manufacturing microstructure mechanical properties fellowship program multi layer L TIC composite selective laser melting
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Recent Advances in Non-Enzymatic Electrochemical Sensors for Theophylline Detection
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作者 Ernis Gustria Putri Yulia M T A +5 位作者 Syauqi Muhammad Iqbal Jiwanti Prastika Krisma Hartati Yeni Wahyuni Kondo Takeshi Anjani Qonita Kurnia Gunlazuardi Jarnuzi 《电化学(中英文)》 北大核心 2025年第3期1-24,共24页
Detection of target analytes at low concentrations is significant in various fields,including pharmaceuticals,healthcare,and environmental protection.Theophylline(TP),a natural alkaloid used as a bronchodilator to tre... Detection of target analytes at low concentrations is significant in various fields,including pharmaceuticals,healthcare,and environmental protection.Theophylline(TP),a natural alkaloid used as a bronchodilator to treat respiratory disorders such as asthma,bronchitis,and emphysema,has a narrow therapeutic window with a safe plasma concentration ranging from 55.5-111.0μmol·L^(-1)in adults.Accurate monitoring of TP levels is essential because too low or too high can cause se-rious side effects.In this regard,non-enzymatic electrochemical sensors offer a practical solution with rapidity,portability,and high sensitivity.This article aims to provide a comprehensive review of the recent developments of non-enzymatic electrochemical sensors for TP detection,highlighting the basic principles,electro-oxidation mechanisms,catalytic effects,and the role of modifying materials on electrode performance.Carbon-based electrodes such as glassy carbon electrodes(GCEs),carbon paste electrodes(CPEs),and carbon screen-printed electrodes(SPCEs)have become the primary choices for non-enzymatic sensors due to their chemical stability,low cost,and flexibility in modification.This article identifies the sig-nificant contribution of various modifying materials,including nanomaterials such as carbon nanotubes(CNTs),graphene,metal oxides,and multi-element nanocomposites.These modifications enhance sensors’electron transfer,sensitivity,and selectivity in detecting TP at low concentrations in complex media such as blood plasma and pharmaceutical samples.The electro-oxidation mechanism of TP is also discussed in depth,emphasizing the hydroxyl and carbonyl reaction pathways strongly influenced by pH and electrode materials.These mechanisms guide the selection of the appropriate electrode ma-terial for a particular application.The main contribution of this article is to identify superior modifying materials that can improve the performance of non-enzymatic electrochemical sensors.In a recent study,the combination of multi-element nanocomposites based on titanium dioxide(TiO_(2)),CNTs,and gold nanoparticles(AuNPs)resulted in the lowest detection limit of 3×10^(-5)μmol·L^(-1),reflecting the great potential of these materials for developing high-performance electrochemical sensors.The main conclusion of this article is the importance of a multidisciplinary approach in electrode material design to support the sensitivity and selectivity of TP detection.In addition,there is still a research gap in understanding TP’s more detailed oxidation mechanism,especially under pH variations and complex environments.Therefore,further research on electrode modification and analysis of the TP oxidation mechanism are urgently needed to improve the accuracy and sta-bility of the sensor while expanding its applications in pharmaceutical monitoring and medical diagnostics.By integrating various innovative materials and technical approaches,this review is expected to be an essential reference for developing efficient and affordable non-enzymatic electrochemical sensors. 展开更多
关键词 Theophylline detection Non-enzymatic sensors Electrochemical sensors Modifier electrode Reaction mechanism
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现代黄河三角洲潮滩原状沉积物冲刷试验 被引量:17
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作者 时连强 李九发 +3 位作者 应铭 李为华 陈沈良 董平 《海洋工程》 CSCD 北大核心 2006年第1期46-54,共9页
在海岸防护工程决策中,沉积物的抗冲能力成为需要考虑的重要因素之一。以2004年4月在黄河三角洲北部海岸高潮滩取得的一个30m沉积物柱状样为例,在测定沉积物的结构、颗粒组成、密度、含水率等基础上,进行了分层沉积物的冲刷试验。结... 在海岸防护工程决策中,沉积物的抗冲能力成为需要考虑的重要因素之一。以2004年4月在黄河三角洲北部海岸高潮滩取得的一个30m沉积物柱状样为例,在测定沉积物的结构、颗粒组成、密度、含水率等基础上,进行了分层沉积物的冲刷试验。结果表明,沉积物临界起动切应力与含水率、中值粒径成一定的负相关关系,与粘士含量呈显著正相关关系,同一类型沉积物的临界起动切应力与密度成一定的正相关关系。同时,近表层沉积物抗冲性最差,9.1~13.5m深度存在抗冲性较强的沉积层。沉积物的颗粒组成、结构、密度、含水率等决定了冲刷率与剪应力的变化关系。 展开更多
关键词 现代黄河三角洲 沉积物特性 冲刷试验 临界冲刷切应力 冲刷率
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基于不同三组分模型解析生物质热解过程 被引量:18
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作者 胡松 Andreas Jess +3 位作者 向军 孙路石 邱建荣 徐明厚 《化工学报》 EI CAS CSCD 北大核心 2007年第10期2580-2586,共7页
三组分模型(three-pseudocomponent model)通常被用来表征生物质热解过程。传统三组分模型中单个模型的反应级数被限定为1或3。在本研究过程中,利用非线性最小二乘法,在不限定反应级数的前提下回归三组分模型动力学参数(活化能、指前因... 三组分模型(three-pseudocomponent model)通常被用来表征生物质热解过程。传统三组分模型中单个模型的反应级数被限定为1或3。在本研究过程中,利用非线性最小二乘法,在不限定反应级数的前提下回归三组分模型动力学参数(活化能、指前因子、反应级数)。通过研究发现,纤维素(cellulose)分解反应级数接近1,与前人结果相一致。木质素(lignin)分解级数与生物质种类有关,接近于1或3。半纤维素(hemicellulose)的分解过程最复杂,其反应级数在1.5~4之间变化。以Ozawa方法计算得到的活化能作为相对标准,对3种三组分模型进行比较,发现反应级数未确定时的模型比其他两种模型更精确地表征生物质热解过程。 展开更多
关键词 生物质 热解 Ozawa方法 三组分模型
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能源光电转换与大规模储能二次电池关键材料的研究进展 被引量:26
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作者 梁叔全 程一兵 +5 位作者 方国赵 曹鑫鑫 沈文剑 钟杰 潘安强 周江 《中国有色金属学报》 EI CAS CSCD 北大核心 2019年第9期2064-2114,共51页
化石能源的过度使用引发了一系列严峻的环境问题,有可能在化石能源枯竭前带来十分严重的环境伤害。发展清洁新能源和与之相匹配的高效储能新技术意义特别重大。太阳能绿色环保、取之不尽,"光伏+储能"将最有可能成为能源问题... 化石能源的过度使用引发了一系列严峻的环境问题,有可能在化石能源枯竭前带来十分严重的环境伤害。发展清洁新能源和与之相匹配的高效储能新技术意义特别重大。太阳能绿色环保、取之不尽,"光伏+储能"将最有可能成为能源问题的终极解决方案。经多年研究,钙钛矿太阳能电池已被公认为是最具潜力的系统,目前的主要挑战是器件的稳定性还需突破,对环境友好也还需改善。能量存储方面,将锂离子电池拓展到大规模储能领域,必须克服资源短缺及安全性因素的制约;钠离子电池和水系锌离子电池由于资源、成本、安全和环保等优势明显,在大规模储能领域有很大的发展空间。本文综述了相关关键材料的最新研究进展,主要包括钙钛矿材料、钠/锌离子电池的关键正负极材料。通过关键材料成分、结构和性能本征关系的解析,为高品质钙钛矿太阳能电池和低成本、高比能、长寿命的大规模储能二次电池新系统研发提供指导。 展开更多
关键词 光电转换 储能 太阳能电池 钠离子电池 水系锌离子电池 材料科学
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秸秆深埋还田开沟灭茬机设计与试验 被引量:30
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作者 王瑞丽 杨鹏 +1 位作者 Rabiu Falalu Jahun 窦森 《农业工程学报》 EI CAS CSCD 北大核心 2017年第5期40-47,共8页
秸秆还田是农作物秸秆综合利用最为直接的形式,深埋还田能打破犁底层、培肥地力,并提高土壤抗旱保墒能力。在秸秆深埋还田时,由于作物根茬未粉碎,深开沟的同时会出现大块土垡。秸秆深埋后还需对根茬和土垡进行二次粉碎,增加了作业成本... 秸秆还田是农作物秸秆综合利用最为直接的形式,深埋还田能打破犁底层、培肥地力,并提高土壤抗旱保墒能力。在秸秆深埋还田时,由于作物根茬未粉碎,深开沟的同时会出现大块土垡。秸秆深埋后还需对根茬和土垡进行二次粉碎,增加了作业成本。为满足秸秆深埋还田开沟灭茬碎土的需求,设计研制了一种集开深沟、碎土、灭茬等多道工序的用于秸秆深埋还田的开沟灭茬机。以导向铲入土深度、灭茬刀转速、灭茬深度为试验因素,机器的作业阻力和灭茬碎土率为试验指标,进行了三因素三水平正交试验。结果表明导向铲入土深度和灭茬深度对作业阻力有极显著影响,灭茬刀转速对灭茬碎土率有极显著影响。在开沟深度为35 cm时,导向铲入土深度、灭茬刀转速和灭茬深度分别为100 mm、340 r/min和60 mm时,开沟灭茬机的作业性能最好,作业阻力为21.6 k N、灭茬碎土率为96.3%、开沟深度稳定性为92.4%。试验表明该机具有很好的开沟、灭茬、碎土效果,该研究为秸秆深埋还田机具的研制和配备提供参考。 展开更多
关键词 机械化 农作物 设计 深埋还田 开沟 灭茬 碎土
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降低CO_(2)-原油最小混相压力的助混剂研究进展 被引量:17
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作者 郭平 张万博 +4 位作者 JIA Na 陈馥 刘煌 汪周华 葛性波 《油气藏评价与开发》 CSCD 2022年第5期726-733,共8页
CO_(2)驱最小混相压力(MMP)是衡量能否达到混相驱的重要参数,因此,为提高混相驱的应用率,迫切需要降低CO_(2)与原油间的最小混相压力,而油藏中加入助混剂是降低最小混相压力的有效手段。目前助混剂按照所含元素可分为碳氟、硅氧烷、碳氢... CO_(2)驱最小混相压力(MMP)是衡量能否达到混相驱的重要参数,因此,为提高混相驱的应用率,迫切需要降低CO_(2)与原油间的最小混相压力,而油藏中加入助混剂是降低最小混相压力的有效手段。目前助混剂按照所含元素可分为碳氟、硅氧烷、碳氢(含氧)三大类。为了降低成本,提高助混效果,应在碳氟类助混剂加入碳氢类结构,向混合型的方向发展,而碳氢类助混剂具有良好的助混效果,并且有提升的空间,关键是找到合适的亲CO_(2)结构,计算机模拟是研究微观机理,辅助结构设计的重要手段。相比于碳氟类和硅氧烷类,碳氢类助混剂的成本较低,从成本的角度看最有应用潜力。目前影响助混剂规模化应用的主要因素是成本上的限制,未来推广应用需要石油与化工从业者的密切配合,重点介绍助混剂降低MMP的机理,总结了目前已有助混剂的结构以及助混效果,分析了助混效果的影响因素,展望了助混剂设计的发展方向。 展开更多
关键词 CO_(2)混相驱 助混剂 降低MMP 表面活性剂 微观机理
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FTIR分析脉冲电场和热处理后的大豆分离蛋白结构变化 被引量:41
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作者 刘燕燕 曾新安 陈晓东 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2010年第9期2340-2344,共5页
采用自行研制的脉冲电场设备,利用傅里叶变换红外光谱(FTIR)比较研究了脉冲电场(PEF)和热处理对大豆分离蛋白(SPI)分子结构的影响。结果表明:50 kV.cm-1的脉冲场强处理引起SPI分子内和分子间氢键增强,分子中C—O—O糖苷键伸缩振动和P O,... 采用自行研制的脉冲电场设备,利用傅里叶变换红外光谱(FTIR)比较研究了脉冲电场(PEF)和热处理对大豆分离蛋白(SPI)分子结构的影响。结果表明:50 kV.cm-1的脉冲场强处理引起SPI分子内和分子间氢键增强,分子中C—O—O糖苷键伸缩振动和P O,P—O—C伸缩振动增强,且其增加值与PEF处理时间呈正相关。研究发现较短时间(1 600μs)PEF处理导致了SPI分子结构中α-螺旋和β-折叠分别减少了5.9%和0.7%,β-转角和侧链结构分别增加了7.5%和9.6%;处理时间延长至2 400μs,其α-螺旋和β-折叠减少量增至6.0%和5.6%。对比而言,热处理对SPI分子结构中C—O—O糖苷键伸缩振动和P O,P—O—C伸缩振动的影响程度较大,而对蛋白质二级结构影响程度较小:90℃热处理30 min,α-螺旋和β-折叠分别减小5.1%和6.6%,β-转角结构增加19.1%。由此可以认为PEF和热处理对SPI的影响机理是不一样的。 展开更多
关键词 高强脉冲电场 热处理 大豆分离蛋白 红外光谱 蛋白质二级结构
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Raman光谱分析脉冲电场对大豆分离蛋白的影响 被引量:7
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作者 刘燕燕 曾新安 韩忠 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2010年第12期3236-3239,共4页
采用自行研制的高强脉冲电场设备,利用拉曼光谱分析脉冲电场对大豆分离蛋白微观结构的影响。结果表明,在50 kV.cm-1的高强脉冲场强下,PEF诱导2 886 cm-1附近峰明显消失,脂肪族侧链C—H伸缩振动微环境极性和色氨酸残基微环境极性不断增强... 采用自行研制的高强脉冲电场设备,利用拉曼光谱分析脉冲电场对大豆分离蛋白微观结构的影响。结果表明,在50 kV.cm-1的高强脉冲场强下,PEF诱导2 886 cm-1附近峰明显消失,脂肪族侧链C—H伸缩振动微环境极性和色氨酸残基微环境极性不断增强;诱使C—H平面弯曲振动、C—N伸缩振动,以及天冬氨酸和谷氨酸中的C O伸缩振动减弱;诱导酰胺键C O伸缩振动和N—H摇摆振动增强。同时发现酪氨酸被包埋程度随着脉冲时间的延长而先增加后减小,在脉冲处理时间为1 600μs时,酪氨酸包埋程度最大。 展开更多
关键词 高强脉冲电场 大豆分离蛋白 拉曼光谱
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塑料排水板结合真空预压法的径向固结解析解 被引量:9
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作者 高广运 聂春晓 +1 位作者 张海丘 雷丹 《同济大学学报(自然科学版)》 EI CAS CSCD 北大核心 2017年第9期1290-1297,共8页
塑料排水板结合真空预压的软土地基加固方法是一种经济高效并被逐渐广泛应用的地基加固方法,该方法不仅可以减少堆载预压坝体的高度,还能减少土体的侧向位移.推导的塑料排水板与真空预压结合的非线性径向固结解析解可以较好地用于该种... 塑料排水板结合真空预压的软土地基加固方法是一种经济高效并被逐渐广泛应用的地基加固方法,该方法不仅可以减少堆载预压坝体的高度,还能减少土体的侧向位移.推导的塑料排水板与真空预压结合的非线性径向固结解析解可以较好地用于该种地基加固的预测和分析.求解过程认为软土在一维固结条件下孔隙比与平均有效应力、水平渗透系数成对数线性关系,而非以前认为的一维线性关系,因排水板周围土体被扰动,所以涂抹区中水平渗透系数采用抛物线分布形式,同时还考虑真空预压对固结的作用.退化提出的解析解与前人解析解进行对比验证、完成解析解与试验结果验证,证明了该解析解的正确性.最后,分析了参数κ和C_k/C_c对固结的影响,结果表明C_k/C_c值越大,固结时间越短,κ值增大,固结时间增长. 展开更多
关键词 塑料排水板 非线性土体本构 非达西定律 真空预压 径向固结
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基于能值分析的蜜柚园生草模式生态经济效益评价 被引量:7
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作者 罗旭辉 卢新坤 +4 位作者 刘岑薇 张丽君 陈恩 Gordon WPrice 翁伯琦 《中国生态农业学报(中英文)》 CAS CSCD 北大核心 2019年第12期1916-1924,共9页
蜜柚是福建省平和县优势特色产业,目前面临发展困境。生草栽培是推动蜜柚绿色发展的重要途径,为科学评价蜜柚园生草模式的生态经济效益,本文应用能值分析法测评平和县五寨镇前岭村蜜柚园生草模式和蜜柚园清耕模式的能值自给率、能值投... 蜜柚是福建省平和县优势特色产业,目前面临发展困境。生草栽培是推动蜜柚绿色发展的重要途径,为科学评价蜜柚园生草模式的生态经济效益,本文应用能值分析法测评平和县五寨镇前岭村蜜柚园生草模式和蜜柚园清耕模式的能值自给率、能值投资率、净能值产出率、环境负载率、有效能产出率和能值反馈率。结果表明:2017-2018年蜜柚园生草模式、蜜柚园清耕模式的能值自给率均为0.003,能值投资率分别为339.291、295.763,净能值产出率均为1.003,环境负载率分别为0.348、0.321,有效能产出率为4.57E-7 J·sej^-1、2.90E-7J·sej^-1,能值反馈率为0.002、0.000。与清耕模式相比,生草模式能值总投入下降9.21%,不可更新环境资源下降76.71%,购买能值比重大,显示更高的能值投资率;同时商品果能值提高1.00E+17 sej·hm^-2,能量产出提高4.60E+10 J·hm^-2,表现出更强的经济活力。劳动力能值投入占能值总投入70.45%~72.90%,其中采摘、日常管理、水肥施用比重大。生草模式在除草环节增加劳动力投入1.31E+16 sej×hm-2,但通过减少农药施用、水肥施用和有机肥搬运节约劳动力,同时优化日常管理,生草模式总劳动力投入降低了3.30E+16sej×hm^-2,基于能值的劳动生产率提高17.50%。生草模式使有机肥、劳动力等可更新资源购买量减少,环境负载率增加0.027。蜜柚园生草模式实现了柚树增产、柚农增收、蜜柚园增绿,为蜜柚产业供给侧结构性改革提供赋能路径。 展开更多
关键词 农业生态系统 蜜柚 生草栽培 能值分析 生态经济效率
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黄河流域煤炭开发区地下水污染成因分析及防治建议 被引量:5
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作者 焦华喆 陈曦 +5 位作者 张铁岗 杨柳华 陈新明 HONAKER Rick 马俊伟 余洋 《中国地质》 CAS CSCD 北大核心 2024年第1期143-156,共14页
[研究目的]黄河流域内由于煤炭资源开发导致地下水污染严重,从整体角度对流域内重点煤炭开发区地下水进行归纳总结,为其可持续健康发展和地下水资源改善提供防治建议。[研究方法]从黄河流域战略地位出发,对地下水污染成因和污染模式进... [研究目的]黄河流域内由于煤炭资源开发导致地下水污染严重,从整体角度对流域内重点煤炭开发区地下水进行归纳总结,为其可持续健康发展和地下水资源改善提供防治建议。[研究方法]从黄河流域战略地位出发,对地下水污染成因和污染模式进行归纳总结。采用改进后的综合水质指数法对流域内九大煤炭基地的地下水进行水质评价。选用主成分分析法赋权指标,并引入改进的内梅罗污染指数法,按照WPI分级法进行评价。[研究结果]通过对黄河流域各重点断面水质评价,得到目前流域内煤炭基地水质结果中Ⅲ、Ⅳ类占比较多,水质较差。分析成因当前流域内存在高矿化度矿井水、酸性矿井水和含特殊组分矿井水污染,同时阐述污染地下水形成的浅层和深层两种污染模式。[结论]对3种矿井水采用相应防治方法,并提出膏体充填技术和微生物修复技术2种防治技术建议,通过应用实际矿山为例,印证污染防治技术能够改善由煤炭开采引发的流域内地下水污染严重的问题,以期研究结果能够对成功推动中国绿色矿山的快速发展具有参考意义。 展开更多
关键词 地下水 煤炭开采 水质评价 水文地质调查工程 矿产勘查工程 黄河流域
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钙华非经典沉积的纳米生长过程与调控机制初探——以九寨沟—黄龙钙华形成为例 被引量:5
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作者 董发勤 郑飞 +8 位作者 代群威 李琼芳 陈禹衡 刘明学 蒋忠诚 张强 李博文 Alper BaBa Andelka Plenkovic-Moraj 《中国岩溶》 CAS CSCD 北大核心 2021年第1期55-67,共13页
钙华是自然界重要的岩溶碳酸盐沉淀之一,其形成过程往往受到生命活动的影响,弄清钙华生物沉积作用有助于更好地理解钙华微岩相结构和地球化学特征的气候环境指示意义。本文以黄龙-九寨沟钙华形成为例,阐述黄龙-九寨沟现代钙华纳米结晶... 钙华是自然界重要的岩溶碳酸盐沉淀之一,其形成过程往往受到生命活动的影响,弄清钙华生物沉积作用有助于更好地理解钙华微岩相结构和地球化学特征的气候环境指示意义。本文以黄龙-九寨沟钙华形成为例,阐述黄龙-九寨沟现代钙华纳米结晶特征、纳米钙华的生长和集合体形态,分析模拟实验中生物有机质对钙华生长和形貌的调控原因,揭示了生物活动和代谢产物对纳米钙华成核、生长及钙华晶体形貌的调控两途径四阶段机制;为探究钙华成因、碳酸钙生长调控机制、钙华退化的因素及其保护和可持续利用钙华景观具有重要的科学价值。 展开更多
关键词 纳米钙华 非典型沉积 代谢活动 晶型和形貌 调控机制
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