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Enhancing the stability of Ni Fe-layered double hydroxide nanosheet array for alkaline seawater oxidation by Ce doping 被引量:1
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作者 Yongchao Yao Shengjun Sun +14 位作者 Hui Zhang Zixiao Li Chaoxin Yang Zhengwei Cai Xun He Kai Dong Yonglan Luo Yan Wang Yuchun Ren Qian Liu Dongdong Zheng Weihua Zhuang Bo Tang Xuping Sun Wenchuang(Walter)Hu 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第4期306-312,共7页
Electrocatalytic hydrogen production from seawater holds enormous promise for clean energy generation.Nevertheless,the direct electrolysis of seawater encounters significant challenges due to poor anodic stability cau... Electrocatalytic hydrogen production from seawater holds enormous promise for clean energy generation.Nevertheless,the direct electrolysis of seawater encounters significant challenges due to poor anodic stability caused by detrimental chlorine chemistry.Herein,we present our recent discovery that the incorporation of Ce into Ni Fe layered double hydroxide nanosheet array on Ni foam(Ce-Ni Fe LDH/NF)emerges as a robust electrocatalyst for seawater oxidation.During the seawater oxidation process,CeO_(2)is generated,effectively repelling Cl^(-)and inhibiting the formation of Cl O-,resulting in a notable enhancement in the oxidation activity and stability of alkaline seawater.The prepared Ce-Ni Fe LDH/NF requires only overpotential of 390 m V to achieve the current density of 1 A cm^(-2),while maintaining long-term stability for 500 h,outperforming the performance of Ni Fe LDH/NF(430 m V,150 h)by a significant margin.This study highlights the effectiveness of a Ce-doping strategy in augmenting the activity and stability of materials based on Ni Fe LDH in seawater electrolysis for oxygen evolution. 展开更多
关键词 Ce doping NiFe layered double hydroxide Seawater oxidation Electrocatalysis Cl^(-) repulsion
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Using a Modified Soil-Plant-Atmosphere Scheme(MSPAS)to Simulate the Interaction between Land Surface Processes and Atmospheric Boundary Layer in Semi-Arid Regions 被引量:20
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作者 树华 乐旭 +1 位作者 胡非 刘辉志 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2004年第2期245-259,共15页
This paper uses a Modified Soil-Plant-Atmosphere Scheme (MSPAS) to study the interaction between land surface and atmospheric boundary layer processes. The scheme is composed of two main parts: atmospheric boundary la... This paper uses a Modified Soil-Plant-Atmosphere Scheme (MSPAS) to study the interaction between land surface and atmospheric boundary layer processes. The scheme is composed of two main parts: atmospheric boundary layer processes and land surface processes. Compared with SiB and BATS, which are famous for their detailed parameterizations of physical variables, this simplified model is more convenient and saves much more computation time. Though simple, the feasibility of the model is well proved in this paper. The numerical simulation results from MSPAS show good agreement with reality. The scheme is used to obtain reasonable simulations for diurnal variations of heat balance, potential temperature of boundary layer, and wind field, and spatial distributions of temperature, specific humidity, vertical velocity, turbulence kinetic energy, and turbulence exchange coefficient over desert and oasis. In addition, MSPAS is used to simulate the interaction between desert and oasis at night, and again it obtains reasonable results. This indicates that MSPAS can be used to study the interaction between land surface processes and the atmospheric boundary layer over various underlying surfaces and can be extended for regional climate and numerical weather prediction study. 展开更多
关键词 modified soil-plant-atmosphere scheme (MSPAS) land surface processes (LSP) atmospheric boundary layer
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On the Kinematic Characteristics and Dynamic Process of Boundary faults of the Nansha Ultra-crust Layer-Block 被引量:10
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作者 LIU Hailing SUN Yan +4 位作者 GUO Lingzhi SHU Liangshu YANG Shukang ZHOU Di ZHANG Yixiang 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 1999年第4期452-463,共12页
Abstract The Nansha ultra-crust layer-block is confined by ultra-crustal boundary faults of distinctive features, bordering the Kangtai-Shuangzi-Xiongnan extensional faulted zone on the north, the Baxian-Baram-Yoca-Cu... Abstract The Nansha ultra-crust layer-block is confined by ultra-crustal boundary faults of distinctive features, bordering the Kangtai-Shuangzi-Xiongnan extensional faulted zone on the north, the Baxian-Baram-Yoca-Cuyo nappe faulted zone on the south, the Wan'an-Natuna strike-slip tensional faulted zone on the west and the Mondoro-Panay strike-slip compressive faulted zone on the east. These faults take the top of the Nansha asthenosphere as their common detachmental surface. The Cenozoic dynamic process of the ultra-crust layer-block can be divided into four stages: K2-E21, during which the northern boundary faults extended, this ultra-crust layer-block was separated from the South China-Indosinian continental margin, the Palaeo-South China Sea subducted southwards and the Sibu accretion wedge was formed; E22-E31, during which the Southwest sub-sea basin extended and orogeny was active due to the collision of the Sibu accretion wedge; E32-N11, during which the central sub-sea basin extended, the Miri accretion wedge was formed and “A-type” subduction of the southern margin of the north Balawan occurred; N12-the present, during which large-scale thrusting and napping of the boundary faults in the south and mountain-building have taken place and the South China Sea stopped its extension. 展开更多
关键词 Nansha ultra-crust layer-block boundary fault layer slip glide dip slip strike slip fault system dynamic process
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Preparation of layered oxide Li(Co_(1/3)Ni_(1/3)Mn_(1/3))O_2 via the sol-gel process 被引量:4
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作者 ZHANG Wen LIU Hanxing HU Chen ZHU Xianjun LI Yanxi 《Rare Metals》 SCIE EI CAS CSCD 2008年第2期158-164,共7页
To obtain homogenous layered oxide Li(Co1/3Ni1/3Mn1/3)O2 as a lithium insertion positive electrode material, the sol-gel process using citric acid as a chelating agent was applied. The material Li(Co1/3Ni1/3Mn1/3)... To obtain homogenous layered oxide Li(Co1/3Ni1/3Mn1/3)O2 as a lithium insertion positive electrode material, the sol-gel process using citric acid as a chelating agent was applied. The material Li(Co1/3Ni1/3Mn1/3)O2 was synthesized at different calcination temperatures. XRD experiment indicated that the layered Li(Co1/3Ni1/3Mn1/3)O2 material could be synthesized at a lower temperature of 800℃, and the oxidation state of Co, Ni, and Mn in the cathode confirmed by XPS were +3, +2, and +4, respectively. SEM observations showed that the synthesized material could form homogenous particle morphology with the particle size of about 200 nm. In spite of different calcination temperatures, the charge-discharge curves of all the samples for the initial cycle were similar, and the cathode synthesized at 900℃ showed a small irreversible capacity loss of 11.24% and a high discharge capacity of 212.2 mAh·g^-1 in the voltage range of 2.9-4.6 V. 展开更多
关键词 lithium-ion battery layered transition metal oxide sol-gel process high capacity
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Fabrication of ceramic layer on an Al-Si alloy by MAO process 被引量:2
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作者 SONG Xigui, BIAN Xiufang, QI Xiaogang, and ZHANG JunyanKey Laboratory of Liquid Structure and Heredity of Materials, Ministry of Education, Shandong University (Southern Campus), Jinan 250061, China (Received 2002-04-11) 《Rare Metals》 SCIE EI CAS CSCD 2003年第2期103-106,共4页
The MAO (Micro-Arc Oxidation) process is applied to a eutectic Al-Si alloy(Al-12.0 percent Si-l.0 percent Cu-0.9 percent Mg (mass fraction)). The oxide ceramic layer wasfabricated with about 220 mum thickness and 3000... The MAO (Micro-Arc Oxidation) process is applied to a eutectic Al-Si alloy(Al-12.0 percent Si-l.0 percent Cu-0.9 percent Mg (mass fraction)). The oxide ceramic layer wasfabricated with about 220 mum thickness and 3000 Hv micro-hardness. By XRD (X-ray diffractometry)and DSC (differential scanning calorimetry) analyses, the oxide layer consists of amorphous Al_2O_3,which is distinct from the results reported by the other researchers. The SEM photographs of suchlayer show that the layer is fixed tightly on the substrate alloy. So this alloy can he used in thehigh temperature and friction environment alter it is treated with such process. 展开更多
关键词 metal material ceramic layer MAO process Al-Si alloy
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Freeze-thaw processes of active-layer soils in the Nanweng'he River National Natural Reserve in the Da Xing'anling Mountains,northern Northeast China 被引量:2
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作者 RuiXia He HuiJun Jin +2 位作者 XiaoLi Chang YongPing Wang LiZhong Wang 《Research in Cold and Arid Regions》 CSCD 2018年第2期104-113,共10页
The active-layer soils overlying the permafrost are the most thermodynamically active zone of rock or soil and play important roles in the earth-atmosphere energy system. The processes of thawing and freezing and thei... The active-layer soils overlying the permafrost are the most thermodynamically active zone of rock or soil and play important roles in the earth-atmosphere energy system. The processes of thawing and freezing and their associated complex hydrothermal coupling can significantly affect variation in mean annual temperatures and the formation of ground ice in permafrost regions. Using soil-temperature and-moisture data obtained from the active layer between September 2011 and October 2014 in the permafrost region of the Nanweng'he River in the Da Xing'anling Mountains, the freeze-thaw characteristics of the permafrost were studied. Based on analysis of ground-temperature variation and hydrothermal transport characteristics, the thawing and freezing processes of the active layer were divided into three stages:(1) autumn-winter freezing,(2) winter freeze-up, and(3) spring-summer thawing. Variations in the soil temperature and moisture were analyzed during each stage of the freeze-thaw process, and the effects of the soil moisture and ground vegetation on the freeze-thaw are discussed in this paper. The study's results show that thawing in the active layer was unidirectional, while the ground freezing was bidirectional(upward from the bottom of the active layer and downward from the ground surface).During the annual freeze-thaw cycle, the migration of soil moisture had different characteristics at different stages. In general, during a freezing-thawing cycle, the soil-water molecules migrate downward, i.e., soil moisture transports from the entire active layer to the upper limit of the permafrost. In the meantime, freeze-thaw in the active layer can be significantly affected by the soil-moisture content and vegetation. 展开更多
关键词 Nanweng'he RIVER NATIONAL NATURAL RESERVE ACTIVE layer freeze-thawing processes moisture content vegetation effect
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Solidification process and microstructure of transition layer of Cu-Al composite cast prepared by method of pouring molten aluminum 被引量:4
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作者 Shu-ying CHEN Guo-wei CHANG +1 位作者 Xu-dong YUE Qing-chun LI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2016年第8期2247-2256,共10页
The Cu?Al composite casts were prepared by the method of pouring molten aluminum. The solidification process and themicrostructure of the transition layer were investigated during the recombination process of the liqu... The Cu?Al composite casts were prepared by the method of pouring molten aluminum. The solidification process and themicrostructure of the transition layer were investigated during the recombination process of the liquid Al and the solid Cu. The results reveal that the microstructure of the transition layer in the Cu?Al composite cast consists of α(Al)+α(Al)?CuAl2 eutectic,α(Al)?CuAl2 eutectic, CuAl2+α(Al)?CuAl2 eutectic and Cu9Al4. Additionally, the pouring temperature, cooling mode of the Cu platesurface and start time of the forced cooling after pouring have no effect on the microstructure species. But the proportion of thevarious microstructures in the transition layer changes with the process parameters. The pure Al at the top of the transition layer startsto solidify first and then the α(Al) phase grows in a dendritic way, while the CuAl2 phase exhibits plane or cellular crystal growth from the two sides of the transition layer towards its interior. The stronger the cooling intensity of the Cu plate outer surface, the more developed the dendrite, and the easier it is for the CuAl2 phase to grow into a plane crystal. 展开更多
关键词 copper cladding aluminum pouring aluminum method transition layer solidification process solidification microstructure
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Boosting Peroxymonosulfate Activation via Co-Based LDH-Derived Magnetic Catalysts:A Dynamic and Static State Assessment of Efficient Radical-Assisted Electron Transfer Processes
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作者 Wenhan Yang Junming Xia +8 位作者 Fanfan Shang Ge Ge Yang Bin Wang Hairui Cai Lingyun Jing Hao Zhu Shengchun Yang Chao Liang Guosheng Shao 《Energy & Environmental Materials》 SCIE EI CAS CSCD 2024年第5期301-312,共12页
Heterogeneous catalysts promoting efficient production of reactive species and dynamically stabilized electron transfer mechanisms for peroxomonosulfates(PMS)still lack systematic investigation.Herein,a more stable ma... Heterogeneous catalysts promoting efficient production of reactive species and dynamically stabilized electron transfer mechanisms for peroxomonosulfates(PMS)still lack systematic investigation.Herein,a more stable magnetic layered double oxides(CFLDO/N-C),was designed using self-polymerization and high temperature carbonization of dopamine.The CFLDO/N-C/PMS system effectively activated PMS to remove 99%(k=0.737 min^(-1))of tetracycline(TC)within 10 min.The CFLDO/N-C/PMS system exhibited favorable resistance to inorganic anions and natural organics,as well as satisfactory suitability for multiple pollutants.The magnetic properties of the catalyst facilitated the separation of catalysts from the liquid phase,resulting in excellent reproducibility and effectively reducing the leaching of metal ions.An electronic bridge was constructed between cobalt(the active platform of the catalyst)and PMS,inducing PMS to break the O-O bond to generate the active species.The combination of static analysis and dynamic evolution confirmed the effective adsorption of PMS on the catalyst surface as well as the strong radical-assisted electron transfer process.Eventually,we further identified the sites where the reactive species attacked the TC and evaluated the toxicity of the intermediates.These findings offer innovative insights into the rapid degradation of pollutants achieved by transition metals in SR-AOPs and its mechanistic elaboration. 展开更多
关键词 advanced oxidation process degradation mechanisms electron transport layered double hydroxide reactive species
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Values of macular ganglion cell-inner plexiform layer and 10-2 visual field measurements in detecting and evaluating glaucoma
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作者 Hai-Jian Hu Ping Li +7 位作者 Bin Tong Yu-Lian Pang Hong-Dou Luo Fei-Fei Wang Chan Xiong Yu-Lin Yu Hai He Xu Zhang 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2024年第5期852-860,共9页
AIM:To assess the performance of macular ganglion cell-inner plexiform layer thickness(mGCIPLT)and 10-2 visual field(VF)parameters in detecting early glaucoma and evaluating the severity of advanced glaucoma.METHODS:T... AIM:To assess the performance of macular ganglion cell-inner plexiform layer thickness(mGCIPLT)and 10-2 visual field(VF)parameters in detecting early glaucoma and evaluating the severity of advanced glaucoma.METHODS:Totally 127 eyes from 89 participants(36 eyes of 19 healthy participants,45 eyes of 31 early glaucoma patients and 46 eyes of 39 advanced glaucoma patients)were included.The relationships between the optical coherence tomography(OCT)-derived parameters and VF sensitivity were determined.Patients with early glaucoma were divided into eyes with or without central 10°of the VF damages(CVFDs),and the diagnostic performances of OCT-derived parameters were assessed.RESULTS:In early glaucoma,the mGCIPLT was significantly correlated with 10-2 VF pattern standard deviation(PSD;with average mGCIPLT:β=-0.046,95%CI,-0.067 to-0.024,P<0.001).In advanced glaucoma,the mGCIPLT was related to the 24-2 VF mean deviation(MD;with average mGCIPLT:β=0.397,95%CI,0.199 to 0.595,P<0.001),10-2 VF MD(with average mGCIPLT:β=0.762,95%CI,0.485 to 1.038,P<0.001)and 24-2 VF PSD(with average mGCIPLT:β=0.244,95%CI,0.124 to 0.364,P<0.001).Except for the minimum and superotemporal mGCIPLT,the decrease of mGCIPLT in early glaucomatous eyes with CVFDs was more severe than that of early glaucomatous eyes without CVFDs.The area under the curve(AUC)of the average mGCIPLT(AUC=0.949,95%CI,0.868 to 0.982)was greater than that of the average circumpapillary retinal nerve fiber layer thickness(cpRNFLT;AUC=0.827,95%CI,0.674 to 0.918)and rim area(AUC=0.799,95%CI,0.610 to 0.907)in early glaucomatous eyes with CVFDs versus normal eyes.CONCLUSION:The 10-2 VF and mGCIPLT parameters are complementary to 24-2 VF,cpRNFLT and ONH parameters,especially in detecting early glaucoma with CVFDs and evaluating the severity of advanced glaucoma in group level. 展开更多
关键词 10-2 visual field ganglion cell-inner plexiform layer retinal nerve fiber layer thickness GLAUCOMA
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Influences of burial process on diagenesis and high-quality reservoir development of deep-ultra-deep clastic rocks:A case study of Lower Cretaceous Qingshuihe Formation in southern margin of Junggar Basin,NW China
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作者 CHEN Sirui XIAN Benzhong +4 位作者 JI Youliang LI Jiaqi TIAN Rongheng WANG Pengyu TANG Heyuan 《Petroleum Exploration and Development》 SCIE 2024年第2期364-379,共16页
Taking the Lower Cretaceous Qingshuihe Formation in the southern margin of Junggar Basin as an example,the influences of the burial process in a foreland basin on the diagenesis and the development of high-quality res... Taking the Lower Cretaceous Qingshuihe Formation in the southern margin of Junggar Basin as an example,the influences of the burial process in a foreland basin on the diagenesis and the development of high-quality reservoirs of deep and ultra-deep clastic rocks were investigated using thin section,scanning electron microscope,electron probe,stable isotopic composition and fluid inclusion data.The Qingshuihe Formation went through four burial stages of slow shallow burial,tectonic uplift,progressive deep burial and rapid deep burial successively.The stages of slow shallow burial and tectonic uplift not only can alleviate the mechanical compaction of grains,but also can maintain an open diagenetic system in the reservoirs for a long time,which promotes the dissolution of soluble components by meteoric freshwater and inhibits the precipitation of dissolution products in the reservoirs.The late rapid deep burial process contributed to the development of fluid overpressure,which effectively inhibits the destruction of primary pores by compaction and cementation.The fluid overpressure promotes the development of microfractures in the reservoir,which enhances the dissolution effect of organic acids.Based on the quantitative reconstruction of porosity evolution history,it is found that the long-term slow shallow burial and tectonic uplift processes make the greatest contribution to the development of deep-ultra-deep high-quality clastic rock reservoirs,followed by the late rapid deep burial process,and the progressive deep burial process has little contribution. 展开更多
关键词 deep-ultra-deep layer clastic rock reservoir DIAGENESIS burial process Lower Cretaceous Qingshuihe Formation southern margin of Junggar Basin
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Dual-function protective layer for highly reversible Zn anode
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作者 Jiaming Li Hanhao Liang +6 位作者 Yini Long Xiao Yu Jiaqi Li Nan Li Junyi Han Jianglin Wang Zhanhong Yang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2024年第11期12-23,共12页
The thermodynamic instability of zinc anodes in aqueous electrolytes leads to issues such as corrosion,hydrogen evolution reactions(HER), and dendrite growth, severely hindering the practical application of zinc-based... The thermodynamic instability of zinc anodes in aqueous electrolytes leads to issues such as corrosion,hydrogen evolution reactions(HER), and dendrite growth, severely hindering the practical application of zinc-based aqueous energy storage devices. To address these challenges, this work proposes a dualfunction zinc anode protective layer, composed of Zn-Al-In layered double oxides(ILDO) by rationally designing Zn-Al layered double hydroxides(Zn-Al LDHs) for the first time. Differing from previous works on the LDHs coatings, firstly, the ILDO layer accelerates zinc-ion desolvation and also captures and anchors SO_(4)^(2-). Secondly, the in-situ formation of the Zn-In alloy phase effectively lowers the nucleation energy barrier, thereby regulating zinc nucleation. Consequently, the zinc anode with the ILDO protective layer demonstrates long-term stability exceeding 1900 h and low voltage hysteresis of 7.5 m V at 0.5 m A cm^(-2) and 0.5 m A h cm^(-2). Additionally, it significantly enhances the rate capability and cycling performance of Zn@ILDO//MnO_(2) full batteries and Zn@ILDO//activated carbon zinc-ion hybrid capacitors.This simple and effective dual-function protective layer strategy offers a promising approach for achieving high-performance zinc-ion batteries. 展开更多
关键词 Protection layer Zn-Al-In layered double oxide Captures and anchors SO_(4)^(2-) Zn-In alloy phase Zn metal anode
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A New Self-assembly Metal CMG Discriminator by Multi-exposure LiGA Like Process and Sacrificial Layer Process 被引量:1
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作者 张卫平 陈文元 +2 位作者 赵小林 丁桂甫 李胜勇 《Journal of Donghua University(English Edition)》 EI CAS 2005年第4期91-93,共3页
The counter-meshing gears (CMG) discriminator is a mechanically coded lock, which is used to prevent the occurrence of High Consequence Events. This paper advanced a new kind of self-assembly metal CMG discriminator... The counter-meshing gears (CMG) discriminator is a mechanically coded lock, which is used to prevent the occurrence of High Consequence Events. This paper advanced a new kind of self-assembly metal CMG discriminator based on multi-exposure LiGA like process and sacrificial layer process. The new CMG discriminator has the following characters except low cost: 1) it has only discrimination teeth sections; 2) the thickness of each gear layer exceeds one hundred micrometers; 3) it is axially driven by a separate dectronic magnetic micromotor directly; 4) its CMG is made of metal and is batch fabricated in the assembled state; 5) it is prevented from rotating in the opposite direction by pawl/ratchet wheel mechanism; 6) it has simpler structure. This device has better strength and reliability in abnormal environment compared to the existing surface micro machining (SMM) discriminator. 展开更多
关键词 Counter-meshing gears (CMG) discriminator multi-exposure LiGA like process sacrificial layer process.
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FE simulation and process analysis on forming of aluminum alloy multi-layer cylinder parts with flow control forming 被引量:5
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作者 王新云 吴有生 +1 位作者 夏巨谌 胡国安 《中国有色金属学会会刊:英文版》 CSCD 2005年第2期452-456,共5页
The aluminum alloy parts used in airbag of car were studied with flow control forming(FCF) method, which was a good way to low forming force and better mechanical properties. The key technology of FCF was the design o... The aluminum alloy parts used in airbag of car were studied with flow control forming(FCF) method, which was a good way to low forming force and better mechanical properties. The key technology of FCF was the design of control chamber to divide metal flow. So, the design method of FCF was analyzed and two type of control chamber were put forward. According to divisional principle, calculation model of forming force and approximate formula were given. Then forming process of aluminum alloy multi-layer cylinder parts was simulated. The effect of friction factor, die radius and punch velocity on metal flow and forming force was obtained. Finally, the experiment was preformed under the direction of theory and finite element(FE) simulation results. And the qualified parts were manufactured. The simulation data and experimental results show that the forming sequence of inner wall and outer wall, and then the force step, can be controlled by adjusting the process parameters. And the FCF technology proposed has very important application value in precision forging. 展开更多
关键词 流动控制成型 多层圆筒 力学计算 铝合金 有限元
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The hydrothermal changes of permafrost active layer and their impact on summer rainfall-runoff processes in an alpine meadow watershed,northwest China
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作者 Jia Qin YongJian Ding +3 位作者 TianDing Han YaPing Chang FaXiang Shi YanHui You 《Research in Cold and Arid Regions》 CSCD 2022年第6期361-369,共9页
The freezing-thawing variation of permafrost active layer increases the complexity of rainfall-runoff processes in alpine river basins,Northwest China.And alpine meadow is the prominent ecosystem in these basins.This ... The freezing-thawing variation of permafrost active layer increases the complexity of rainfall-runoff processes in alpine river basins,Northwest China.And alpine meadow is the prominent ecosystem in these basins.This study selected a small alpine meadow watershed in the upper reaches of the Shule River Basin,China.We investigated alpine rainfall-runoff processes,as well as impacts of summer thaw depth of active layer,soil temperature and moisture variation on streamflow based on in-situ observations from July 2015 to December 2020.Some hydrologic parameters or indices were calculated using statistical methods,and impacts of permafrost change on river runoff were assessed using the variable infiltration capacity model(VIC).In the alpine meadow,surface soil(0–10 cm depth)of the active layer starts to freeze in mid-October each year,and begins to thaw in early April.Also,the deeper soil(70–80 cm depth)of the active layer starts to freeze in late October,and begins to thaw in late June.Moisture content in shallow soils fluctuates regularly,whereas deeper soils are more stable,and their response to rainstorms is negligible.During active layer thawing,the moisture content increases with soil depth.In the alpine meadow,vertical infiltration only occurred in soils up to 40 cm deep,and lateral flow occurred in0–20 and 60–80 cm deep soils at current rainfall intensity.Summer runoff ratios were 0.06–0.31,and runoff floods show lags of 9.5–23.0 h following the rainfall event in the study area.The freeze–thaw process also significantly impacts runoff regression coefficients,which were 0.0088–0.0654 per hour.Recession coefficient decrease negatively correlates with active layer thawing depth in summer and autumn.Alpine river basin permafrost can effectively increase peak discharge and reduce low flow.These findings are highly significant for rainfall–runoff conversion research in alpine areas of inland rivers. 展开更多
关键词 Rainfall-runoff process Alpine meadow Permafrost active layer Northwest China
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Structures and Properties of Iron Matrix Composites with Tungsten Carbide Particle by EPC-V Process 被引量:5
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作者 Xu Daqing Luo Jirong Huang Naiyu 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 1999年第2期29-32,共4页
In this paper the Expendable Pattern Casting with dry sand Vacuum(EPC-V) process is used to manufacture iron matrix composites with tungsten carbide particle.Microstructures of the composites layers were analyzed.The ... In this paper the Expendable Pattern Casting with dry sand Vacuum(EPC-V) process is used to manufacture iron matrix composites with tungsten carbide particle.Microstructures of the composites layers were analyzed.The abrasive wear resistance of the composites layers were tested and compared with that of high chromium cast iron.The results show that the iron matrix composites with tungsten carbide particle have high hardness.The abrasive wear resistance of composites with tungsten carbide particle is higher than that of high chromium cast iron.The properties of the matrix materials have been improved remarkably. 展开更多
关键词 ABSTRACT:In this paper the Expendable Pattern Casting with dry sand Vacuum (EPC V) process is used to manufacture iron matrix COMPOSITES with TUNGSTEN CARBIDE particle. Microstructures of the COMPOSITES layers were analyzed. The ABRASIVE wear
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In situ monitoring methods for selective laser melting additive manufacturing process based on images-A review 被引量:9
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作者 Bo Wu Xiao-yuan Ji +5 位作者 Jian-xin Zhou Huan-qing Yang Dong-jian Peng Ze-ming Wang Yuan-jie Wu Ya-jun Yin 《China Foundry》 SCIE CAS 2021年第4期265-285,共21页
Selective laser melting(SLM)has been widely used in the fields of aviation,aerospace and die manufacturing due to its ability to produce metal components with arbitrarily complex shapes.However,the instability of SLM ... Selective laser melting(SLM)has been widely used in the fields of aviation,aerospace and die manufacturing due to its ability to produce metal components with arbitrarily complex shapes.However,the instability of SLM process often leads to quality fluctuation of the formed component,which hinders the further development and application of SLM.In situ quality control during SLM process is an effective solution to the quality fluctuation of formed components.However,the basic premise of feedback control during SLM process is the rapid and accurate diagnosis of the quality.Therefore,an in situ monitoring method of SLM process,which provides quality diagnosis information for feedback control,became one of the research hotspots in this field in recent years.In this paper,the research progress of in situ monitoring during SLM process based on images is reviewed.Firstly,the significance of in situ monitoring during SLM process is analyzed.Then,the image information source of SLM process,the image acquisition systems for different detection objects(the molten pool region,the scanned layer and the powder spread layer)and the methods of the image information analysis,detection and recognition are reviewed and analyzed.Through review and analysis,it is found that the existing image analysis and detection methods during SLM process are mainly based on traditional image processing methods combined with traditional machine learning models.Finally,the main development direction of in situ monitoring during SLM process is proposed by combining with the frontier technology of image-based computer vision. 展开更多
关键词 selective laser melting(SLM) forming process IMAGES in situ monitoring molten pool region monitoring scanned layer and powder layer monitoring
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Intercalation Assembly Method and Intercalation Process Control of Layered Intercalated Functional Materials 被引量:5
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作者 李凯涛 王桂荣 +2 位作者 李殿卿 林彦军 段雪 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第4期453-462,共10页
Layered intercalated functional materials of layered double hydroxide type are an important class of functional materials developed in recent years. Based on long term studies on these materials in the State Key Labor... Layered intercalated functional materials of layered double hydroxide type are an important class of functional materials developed in recent years. Based on long term studies on these materials in the State Key Laboratory of Chemical Resource Engineering in Beiiing University of Chemical Technology, the orinciole for the design of controlled intercalation processes in the light of tuture production processing requirements has been developed. Intercalation assembly methods and technologies have been invented to control the intercalation process for preparing layered intercalated materials with various structures and functions. 展开更多
关键词 layered intercalated structure functional material intercalation assembly methods intercalation process
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一种交通场景下人车检测的VHA-CenterNet无锚方法研究
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作者 陈鑫影 吕娜 吕硕 《大连交通大学学报》 CAS 2024年第4期101-107,共7页
在真实的交通场景中,车辆和行人检测器容易受到复杂背景的干扰,导致严重的误检和漏检。此外,由于交通场景图像中存在各种不同尺度的目标,大多数检测方法对小物体的检测性能较差,且难以适应交通物体的多样性。为了解决这些问题,提出了一... 在真实的交通场景中,车辆和行人检测器容易受到复杂背景的干扰,导致严重的误检和漏检。此外,由于交通场景图像中存在各种不同尺度的目标,大多数检测方法对小物体的检测性能较差,且难以适应交通物体的多样性。为了解决这些问题,提出了一种基于注意力和前景注意模块的无锚方法VHA-CenterNet。在主干网络中加入一个卷积块注意模块(CBAM),以提高对小目标的关注能力。在前景注意模块(FAM)中引入前景信息,以减少复杂背景的干扰。结果表明:在中等难度下,所提出的VHA⁃CenterNet方法在KITTI数据集上的mAP达71.92%,在RTX 2080 Ti上的推理速度为10.68 FPS,可以显著提高人车识别的准确率和速度。在所有情况下,交通场景的人车检测准确率都高于传统模型。 展开更多
关键词 图像处理 人车检测 深层聚合 深度学习 注意力
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Modeling Hydrothermal Transfer Processes in Permafrost Regions of Qinghai-Tibet Plateau in China 被引量:4
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作者 HU Guojie ZHAO Lin +6 位作者 LI Ren WU Tonghua WU Xiaodong PANG Qiangqiang XIAO Yao QIAO Yongping SHI Jianzong 《Chinese Geographical Science》 SCIE CSCD 2015年第6期713-727,共15页
Hydrothermal processes are key components in permafrost dynamics; these processes are integral to global wanning. In this study the coupled heat and mass transfer model for (CoupModel) the soil-plant-atmosphere-syst... Hydrothermal processes are key components in permafrost dynamics; these processes are integral to global wanning. In this study the coupled heat and mass transfer model for (CoupModel) the soil-plant-atmosphere-system is applied in high-altitude permafrost regions and to model hydrothermal transfer processes in freeze-thaw cycles. Measured meteorological forcing and soil and vegetation properties are used in the CoupModel for the period from January 1, 2009 to December 31, 2012 at the Tanggula observation site in the Qinghai-Tibet Plateau. A 24-h time step is used in the model simulation. The results show that the simulated soil temperature and water content, as well as the frozen depth compare well with the measured data. The coefficient of determination (R2) is 0.97 for the mean soil temperature and 0.73 for the mean soil water content, respectively. The simulated soil heat flux at a depth of 0-20 cm is also consistent with the monitored data. An analysis is performed on the simulated hydrothermal transfer processes from the deep soil layer to the upper one during the freezing and thawing period. At the beginning of the freezing period, the water in the deep soil layer moves upward to the freezing front and releases heat during the freezing process. When the soil layer is completely frozen, there are no vertical water ex- changes between the soil layers, and the heat exchange process is controlled by the vertical soil temperature gradient. During the thaw- ing period, the downward heat process becomes more active due to increased incoming shortwave radiation at the ground surface. The melt water is quickly dissolved in the soil, and the soil water movement only changes in the shallow soil layer. Subsequently, the model was used to provide an evaluation of the potential response of the active layer to different scenarios of initial water content and climate warming at the Tanggula site. The results reveal that the soil water content and the organic layer provide protection against active layer deepening in summer, so climate warming will cause the permafrost active layer to become deeoer and permafrost degradation. 展开更多
关键词 PERMAFROST coupled heat and mass transfer model (CoupModel) soil temperature soil moisture hydrothermal processes active layer
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Electron beam welding of Ti-15-3 titanium alloy to 304 stainless steel with copper interlayer sheet 被引量:9
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作者 王廷 张秉刚 +2 位作者 陈国庆 冯吉才 唐奇 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第10期1829-1834,共6页
Electron beam welding of Ti-15-3 titanium alloy to 304 stainless steel with a copper sheet as interlayer was carried out.Microstructures of the joint were studied by optical microscopy(OM),scanning electron microscopy... Electron beam welding of Ti-15-3 titanium alloy to 304 stainless steel with a copper sheet as interlayer was carried out.Microstructures of the joint were studied by optical microscopy(OM),scanning electron microscopy(SEM) and X-ray diffractometry(XRD).In addition,the mechanical properties of the joint were evaluated by tensile test and the microhardness was measured.These two alloys were successfully welded by adding copper transition layer into the weld.Solid solution with a certain thickness was located at the interfaces between weld and base metal in both sides.Regions inside the weld and near the stainless steel were characterized by solid solution of copper with TiFe2 intermetallics dispersedly distributed in it.While weld near titanium alloy contained Ti-Cu and Ti-Fe-Cu intermetallics layer,in which the hardness of weld came to the highest value.Brittle fracture occurred in the intermetallics layer when the joint was stretched. 展开更多
关键词 Ti-15-3 titanium alloy 304 stainless steel electron beam welding interrnetallics layer mechanical properties
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