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Tuning support morphology to control alloy over PtCo/γ-Al_(2)O_(3) for the preferential oxidation of CO
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作者 SONG Lichuan ZHONG Liding +3 位作者 SHEN Jia LOU Yake GUO Yun WANG Li 《燃料化学学报(中英文)》 北大核心 2025年第1期96-105,共10页
The preferential oxidation of CO(CO-PROX)reaction is a cost-effective method for eliminating trace amounts of CO from the fuel H2.Pt-based catalysts have been extensively studied for COPROX,with their activity influen... The preferential oxidation of CO(CO-PROX)reaction is a cost-effective method for eliminating trace amounts of CO from the fuel H2.Pt-based catalysts have been extensively studied for COPROX,with their activity influenced by the morphology of the support.Hydrothermal synthesis was employed to produce different morphologies ofγ-Al_(2)O_(3):flower-likeγ-Al_(2)O_(3)(f)exposing(110)crystal faces,sheet-likeγ-Al_(2)O_(3)(s)revealing(100)crystal faces,and rod-likeγ-Al_(2)O_(3)(r)displaying(111)crystal faces,followed by loading PtCo nanoparticles.The exposed crystal faces of the support impact the alloying degree of the PtCo nanoparticles,and an increase in the alloying degree correlates with enhanced catalyst reactivity.Pt_(3)Co intermetallic compounds were identified onγ-Al_(2)O_(3)(f)exposing(110)crystal faces,and PtCo/γ-Al_(2)O_(3)(f)showed high catalytic activity in the CO-PROX reaction,achieving 100%CO conversion across a broad temperature range of 50−225°C.In contrast,only partial alloying of PtCo was observed onγ-Al_(2)O_(3)(s).Furthermore,no alloying between Pt and Co occurred in PtCo/γ-Al_(2)O_(3)(r),resulting in a reaction rate at 50°C that was merely 11%of that of PtCo/γ-Al_(2)O_(3)(f).The formation of Pt3Co intermetallic compounds led to a more oxidized state of Pt,which significantly diminished the adsorption of CO on Pt and augmented the active oxygen species,thereby facilitating the selective oxidation of CO. 展开更多
关键词 PtCo catalysts γ-Al_(2)O_(3) support morphology CO-PROX
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Research progress on metal-support interactions over Ni-based catalysts for CH_(4)-CO_(2)reforming reaction
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作者 SUN Kai JIANG Jianfei +4 位作者 LIU Zixuan GENG Shiqi LIU Zhenmin YANG Jiaqian LI Shasha 《燃料化学学报(中英文)》 北大核心 2025年第4期434-451,共18页
With ongoing global warming and increasing energy demands,the CH_(4)-CO_(2)reforming reaction(dry reforming of methane,DRM)has garnered significant attention as a promising carbon capture and utilization technology.Ni... With ongoing global warming and increasing energy demands,the CH_(4)-CO_(2)reforming reaction(dry reforming of methane,DRM)has garnered significant attention as a promising carbon capture and utilization technology.Nickel-based catalysts are renowned for their outstanding activity and selectivity in this process.The impact of metal-support interaction(MSI),on Ni-based catalyst performance has been extensively researched and debated recently.This paper reviews the recent research progress of MSI on Ni-based catalysts and their characterization and modulation strategies in catalytic reactions.From the perspective of MSI,the effects of different carriers(metal oxides,carbon materials and molecular sieves,etc.)are introduced on the dispersion and surface structure of Ni active metal particles,and the effect of MSI on the activity and stability of DRM reactions on Ni-based catalysts is discussed in detail.Future research should focus on better understanding and controlling MSI to improve the performance and durability of nickel-based catalysts in CH_(4)-CO_(2)reforming,advancing cleaner energy technologies. 展开更多
关键词 CO_(2)utilization CH_(4)-CO_(2)reforming Ni-based catalysts metal-support interactions supports
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Stress gradient analytic solution and reasonable support prestress of roadway surrounding rock based on unified strength criterion:A case study
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作者 JING Suo-lin WEN Zhi-jie +2 位作者 ZUO Yu-jun LI Qiu-ju HAO Peng 《Journal of Central South University》 2025年第2期449-468,共20页
The stress gradient of surrounding rock and reasonable prestress of support are the keys to ensuring the stability of roadways.The elastic-plastic analytical solution for surrounding rock was derived based on unified ... The stress gradient of surrounding rock and reasonable prestress of support are the keys to ensuring the stability of roadways.The elastic-plastic analytical solution for surrounding rock was derived based on unified strength theory.A model for solving the stress gradient of the surrounding rock with the intermediate principal stress parameter b was established.The correctness and applicability of the solution for the stress gradient in the roadway surrounding rock was verified via multiple methods.Furthermore,the laws of stress,displacement,and the plastic zone of the surrounding rock with different b values and prestresses were revealed.As b increases,the stress gradient in the plastic zone increases,and the displacement and plastic zone radius decrease.As the prestress increases,the peak stress shifts toward the sidewalls,and the stress and stress gradient increments decrease.In addition,the displacement increment and plastic zone increment were proposed to characterize the support effect.The balance point of the plastic zone area appears before that of the displacement zone.The relationship between the stress gradient compensation coefficient and the prestress is obtained.This study provides a research method and idea for determining the reasonable prestress of support in roadways. 展开更多
关键词 PRESTRESS support compensation surrounding rock damage stress gradient analytic solution unified strength theory
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Bearing characteristics of anchor box beam support system in deep thick roof coal roadway and its application
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作者 WANG Qi WANG Ming-zi +1 位作者 JIANG Bei XU Chuan-jie 《Journal of Central South University》 2025年第5期1887-1902,共16页
Considering the characteristics of deep thick top coal roadway,in which the high ground stress,coal seam with low strength,and a large range of surrounding rock fragmentation,the pressure relief anchor box beam suppor... Considering the characteristics of deep thick top coal roadway,in which the high ground stress,coal seam with low strength,and a large range of surrounding rock fragmentation,the pressure relief anchor box beam support system with high strength is developed.The high-strength bearing characteristics and coupling yielding support mechanism of this support system are studied by the mechanical tests of composite members and the combined support system.The test results show that under the coupling effect of support members,the peak stress of the box-shaped support beam in the anchor box beam is reduced by 21.9%,and the average deformation is increased by 135.0%.The ultimate bending bearing capacity of the box-shaped support beam is 3.5 times that of traditional channel beam.The effective compressive stress zone applied by the high prestressed cable is expanded by 26.4%.On this basis,the field support comparison test by the anchor channel beam,the anchor I-shaped beam and the anchor box beam are carried out.Compared with those of the previous two,the surrounding rock convergence of the latter is decreased by 41.2%and 22.2%,respectively.The field test verifies the effectiveness of the anchor box beam support system. 展开更多
关键词 thick roof coal roadway anchor box beam bearing characteristics combined support field application
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Design method of high prestressed support for shallow-buried large-span caverns
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作者 JIANG Bei WEI Hua-yong +3 位作者 WANG Qi WANG Ming-zi YIN Chen ZHANG Yan-bo 《Journal of Central South University》 2025年第3期1099-1116,共18页
The surrounding rock is prone to large-scale loosening and failure after the excavation of shallow large-span caverns because of the thin overlying strata and large cross-section span.The rational design of bolt suppo... The surrounding rock is prone to large-scale loosening and failure after the excavation of shallow large-span caverns because of the thin overlying strata and large cross-section span.The rational design of bolt support is very important to the safety control of surrounding rock as a common support means.The control mechanism and design method of bolt support for shallow-buried large-span caverns is carried out.The calculation method of bolt prestress and length based on arched failure and collapsed failure mode is established.The influence mechanism of different influencing factors on the bolt prestress and length is clarified.At the same time,the constant resistance energy-absorbing bolt with high strength and high toughness is developed,and the comparative test of mechanical properties is carried out.On this basis,the design method of high prestressed bolt support for shallow-buried large-span caverns is put forward,and the field test is carried out in Qingdao metro station in China.The monitoring results show that the maximum roof settlement is 6.8 mm after the new design method is adopted,and the effective control of the shallow-buried large-span caverns is realized.The research results can provide theoretical and technical support for the safety control of shallow-buried large-span caverns. 展开更多
关键词 Hoek-Brown strength criterion shallow-buried large-span caverns limit analysis upper bound method high prestress bolt support design method
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基于Supporting-Ellipsoid方法的自由曲面构造 被引量:3
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作者 顾国超 刘洪波 +1 位作者 陈家奇 高雁 《中国光学》 EI CAS 2014年第5期823-829,共7页
为了在特定平面上获得任意形式的辐照分布,采用了Supporting-Ellipsoid设计方法来构造自由曲面反射镜。介绍了其设计思想和设计过程,并以具体的设计实例为例构建了自由曲面光学系统。仿真结果表明,在不计反射损失的情况下,系统效率达到... 为了在特定平面上获得任意形式的辐照分布,采用了Supporting-Ellipsoid设计方法来构造自由曲面反射镜。介绍了其设计思想和设计过程,并以具体的设计实例为例构建了自由曲面光学系统。仿真结果表明,在不计反射损失的情况下,系统效率达到了97%,较传统太阳模拟器光学系统提升了3倍以上,不均匀度达到5.26%,与理想状态有一定差距,这是因为设计中兼顾了计算时间和自由曲面光滑性所造成的。 展开更多
关键词 supporting-Ellipsoid方法 自由曲面 均匀照明
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Application of a combined supporting technology with U-shaped steel support and anchor-grouting to surrounding soft rock reinforcement in roadway 被引量:19
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作者 王辉 郑朋强 +1 位作者 赵文娟 田洪铭 《Journal of Central South University》 SCIE EI CAS CSCD 2018年第5期1240-1250,共11页
Soft rock surrounding deep roadway has poor stability and long-term rheological effect. More and larger deformation problems of surrounding rock occur due to adverse supporting measures for such roadways, which not on... Soft rock surrounding deep roadway has poor stability and long-term rheological effect. More and larger deformation problems of surrounding rock occur due to adverse supporting measures for such roadways, which not only affects the engineering safety critically but also improves the maintenance costs. This paper takes the main rail roadway with severely deformation in China's Zaoquan coal mine as an example to study the long-term deformation tendency and damage zone by means of in-situ deformation monitoring and acoustic wave testing technique. A three-dimensional finite element model reflecting the engineering geological condition and initial design scheme is established by ABAQUS. Then, on the basis of field monitoring deformation data, the surrounding rock geotechnical and theological parameters of the roadway are obtained by back analysis. A combined supporting technology with U-shaped steel support and anchor-grouting is proposed for the surrounding soft rock. The numerical simulation of the combined supporting technology and in-situ deformation monitoring results show that the soft rock surrounding the roadway has been held effectively. 展开更多
关键词 soft rock roadway rheological effect supporting technology numerical simulation REINFORCEMENT
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Upper bound solutions for supporting pressures of shallow tunnels with nonlinear failure criterion 被引量:20
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作者 YANG Xiao-li ZHANG Dao-bing WANG Zuo-wei 《Journal of Central South University》 SCIE EI CAS 2013年第7期2034-2040,共7页
Linear failure criterion is widely used in calculation of earth pressure acting on shallow tunnels. However, experimental evidence shows that nonlinear failure criterion is able to represent fairly well the failure of... Linear failure criterion is widely used in calculation of earth pressure acting on shallow tunnels. However, experimental evidence shows that nonlinear failure criterion is able to represent fairly well the failure of almost all types of rocks, A nonlinear Hock-Brown failure criterion is employed to estimate the supporting pressures of shallow tunnels in limit analysis framework. Two failure mechanisms are proposed for calculating the work rate of extemal force and the internal energy dissipation. A tangential line to the nonlinear failure criterion is used to formulate the supporting pressure problem as a nonlinear programming problem. The objective function formulated in this way is minimized with respect to the failure mechanism and the location of tangency point. In order to assess the validity, the supporting pressures for the proposed failure mechanisms are calculated and compared with each other, and the present results are compared with previously published solutions when the nonlinear criterion is reduced to linear criterion. The agreement supports the validity of the proposed failure mechanisms. An experiment is conducted to investigate the influences of the nonlinear criterion on collapse shape and supporting pressures of shallow tunnels. 展开更多
关键词 shallow tunnel nonlinear criterion limit analysis supporting pressure failure mechanism
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Influences of anisotropy and inhomogeneity on supporting pressure of tunnel face with kinematical approach 被引量:3
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作者 杨小礼 李闻韬 潘秋景 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第9期3536-3543,共8页
Based on the active failure mechanism generated by a spatial discretization technique, the stability of tunnel face was studied. With the help of the spatial discretization technique, not only the anisotropy and inhom... Based on the active failure mechanism generated by a spatial discretization technique, the stability of tunnel face was studied. With the help of the spatial discretization technique, not only the anisotropy and inhomogeneity of the cohesion but also the inhomogeneity of the internal friction angle was taken into account in the analysis of the supporting forces. From the perspective of upper bound theorem, the upper bound solutions of supporting pressure were derived. The influence of the anisotropy and heterogeneity on the supporting forces as well as the failure mechanisms was discussed. The results show that the spatial discretization characteristics of cohesion and internal frictional angle impose a significant effect on the supporting pressure, which indicates that above factors should be considered in the actual engineering. 展开更多
关键词 tunnel face supporting forces ANISOTROPY INHOMOGENEITY upper bound theorem
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Sensor monitoring of a newly designed foundation pit supporting structure 被引量:3
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作者 杨宇友 吕建国 +1 位作者 黄学刚 涂晓明 《Journal of Central South University》 SCIE EI CAS 2013年第4期1064-1070,共7页
A new type of pit supporting structure, which was tested and verified using the sensor monitoring technology, was presented. The new supporting structure is assembled by prefabricated steel structural units. The adjac... A new type of pit supporting structure, which was tested and verified using the sensor monitoring technology, was presented. The new supporting structure is assembled by prefabricated steel structural units. The adjacent steel structural units are jointed with fasteners, and each steel structural unit has a certain radian and is welded by two steel tubes and one piece of steel disc. In order to test and verify the reliability of the new supporting structure, the field tests are designed. The main monitoring programs include the hoop stress of supporting structure, lateral earth pressure, and soil deformation. The monitoring data of the field tests show that the new supporting structure is convenient, reliable and safe. 展开更多
关键词 foundation pit supporting structure sensor monitoring earth pressure horizontal displacement
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Supporting Processes of Syndiospecific Metallocene Catalyst for Polymerization of Propylene
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作者 Cui Chunming, Chen Wei, Sun Chunyan, Jing Zhenhua, Hong Xiaoyu (Research Institute of Petroleum Processing, Beijing 100083) 《石油学报(石油加工)》 EI CAS CSCD 北大核心 1997年第S1期58-63,共6页
SupportingProcesesofSyndiospecificMetaloceneCatalystforPolymerizationofPropyleneCuiChunming,ChenWei,SunChuny... SupportingProcesesofSyndiospecificMetaloceneCatalystforPolymerizationofPropyleneCuiChunming,ChenWei,SunChunyan,JingZhenhua,Ho... 展开更多
关键词 SYNDIOSPECIFIC METALLOCENE supporting process POLYMERIZATION supportED METALLOCENE triisobutylaluminium
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Bearing mechanism of roof and rib support structure in automatically formed roadway and its support design method 被引量:2
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作者 JIANG Bei WANG Ming-zi +4 位作者 WANG Qi XIN Zhong-xin XING Xue-yang DENG Yu-song YAO Liang-di 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第7期2467-2487,共21页
Non-pillar mining technology with automatically formed roadway is a new mining method without coal pillar reservation and roadway excavation.The stability control of automatically formed roadway is the key to the succ... Non-pillar mining technology with automatically formed roadway is a new mining method without coal pillar reservation and roadway excavation.The stability control of automatically formed roadway is the key to the successful application of the new method.In order to realize the stability control of the roadway surrounding rock,the mechanical model of the roof and rib support structure is established,and the influence mechanism of the automatically formed roadway parameters on the compound force is revealed.On this basis,the roof and rib support structure technology of confined lightweight concrete is proposed,and its mechanical tests under different eccentricity are carried out.The results show that the bearing capacity of confined lightweight concrete specimens is basically the same as that of ordinary confined concrete specimens.The bearing capacity of confined lightweight concrete specimens under different eccentricities is 1.95 times higher than those of U-shaped steel specimens.By comparing the test results with the theoretical calculated results of the confined concrete,the calculation method of the bearing capacity for the confined lightweight concrete structure is selected.The design method of confined lightweight concrete support structure is established,and is successfully applied in the extra-large mine,Ningtiaota Coal Mine,China. 展开更多
关键词 automatically roadway with non-pillar confined lightweight concrete roof and rib support mechanical model bearing behaviour
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Research on the flow stability and noise reduction characteristics of quasi-periodic elastic support skin
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作者 Lu Chen Shao-gang Liu +5 位作者 Dan Zhao Li-qiang Dong Kai Li Shuai Tang Jin Cui Hong Guo 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第3期222-236,共15页
To enhance flow stability and reduce hydrodynamic noise caused by fluctuating pressure,a quasiperiodic elastic support skin composed of flexible walls and elastic support elements is proposed for fluid noise reduction... To enhance flow stability and reduce hydrodynamic noise caused by fluctuating pressure,a quasiperiodic elastic support skin composed of flexible walls and elastic support elements is proposed for fluid noise reduction.The arrangement of the elastic support element is determined by the equivalent periodic distance and quasi-periodic coefficient.In this paper,a dynamic model of skin in a fluid environment is established.The influence of equivalent periodic distance and quasi-periodic coefficient on flow stability is investigated.The results suggest that arranging the elastic support elements in accordance with the quasi-periodic law can effectively enhance flow stability.Meanwhile,the hydrodynamic noise calculation results demonstrate that the skin exhibits excellent noise reduction performance,with reductions of 10 dB in the streamwise direction,11 dB in the spanwise direction,and 10 dB in the normal direction.The results also demonstrate that the stability analysis method can serve as a diagnostic tool for flow fields and guide the design of noise reduction structures. 展开更多
关键词 Flow stability Quasi-period Flexible wall Elastic support element Hydrodynamic noise
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Influence of confined water on the limit support pressure of tunnel face in weakly water-rich strata
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作者 LI Yun-fa WU Guo-jun +2 位作者 CHEN Wei-zhong YUAN Jing-qiang HUO Meng-zhe 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第8期2844-2859,共16页
In the process of shield tunneling through soft soil layers,the presence of confined water ahead poses a significant threat to the stability of the tunnel face.Therefore,it is crucial to consider the impact of confine... In the process of shield tunneling through soft soil layers,the presence of confined water ahead poses a significant threat to the stability of the tunnel face.Therefore,it is crucial to consider the impact of confined water on the limit support pressure of the tunnel face.This study employed the finite element method(FEM)to analyze the limit support pressure of shield tunnel face instability within a pressurized water-containing layer.Subsequently,a multiple linear regression approach was applied to derive a concise solution formula for the limit support pressure,incorporating various influencing factors.The analysis yields the following conclusions:1)The influence of confined water on the instability mode of the tunnel face in soft soil layers makes the displacement response of the strata not significant when the face is unstable;2)The limit support pressure increases approximately linearly with the pressure head,shield tunnel diameter,and tunnel burial depth.And inversely proportional to the thickness of the impermeable layer,soil cohesion and internal friction angle;3)Through an engineering case study analysis,the results align well with those obtained from traditional theoretical methods,thereby validating the rationality of the equations proposed in this paper.Furthermore,the proposed equations overcome the limitation of traditional theoretical approaches considering the influence of changes in impermeable layer thickness.It can accurately depict the dynamic variation in the required limit support pressure to maintain the stability of the tunnel face during shield tunneling,thus better reflecting engineering reality. 展开更多
关键词 weakly water-rich strata confined aquifer limit support pressure finite element method multiple linear regression
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Support design method for deep soft-rock tunnels in non-hydrostatic high in-situ stress field
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作者 ZHENG Ke-yue SHI Cheng-hua +3 位作者 ZHAO Qian-jin LEI Ming-feng JIA Chao-jun PENG Zhu 《Journal of Central South University》 SCIE EI CAS CSCD 2024年第7期2431-2445,共15页
Due to the long-term plate tectonic movements in southwestern China,the in-situ stress field in deep formations is complex.When passing through deep soft-rock mass under non-hydrostatic high in-situ stress field,tunne... Due to the long-term plate tectonic movements in southwestern China,the in-situ stress field in deep formations is complex.When passing through deep soft-rock mass under non-hydrostatic high in-situ stress field,tunnels will suffer serious asymmetric deformation.There is no available support design method for tunnels under such a situation in existing studies to clarify the support time and support stiffness.This study first analyzed the mechanical behavior of tunnels in non-hydrostatic in-situ stress field and derived the theoretical equations of the ground squeezing curve(GSC)and ground loosening curve(GLC).Then,based on the convergence confinement theory,the support design method of deep soft-rock tunnels under non-hydrostatic high in-situ stress field was established considering both squeezing and loosening pressures.In addition,this method can provide the clear support time and support stiffness of the second layer of initial support.The proposed design method was applied to the Wanhe tunnel of the China-Laos railway in China.Monitoring data indicated that the optimal support scheme had a good effect on controlling the tunnel deformation in non-hydrostatic high in-situ stress field.Field applications showed that the secondary lining could be constructed properly. 展开更多
关键词 non-hydrostatic stress field high in-situ stress deep soft-rock tunnel squeezing pressure loosening pressure support design method
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Artificial Intelligence Based Meteorological Parameter Forecasting for Optimizing Response of Nuclear Emergency Decision Support System
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作者 BILAL Ahmed Khan HASEEB ur Rehman +5 位作者 QAISAR Nadeem MUHAMMAD Ahmad Naveed Qureshi JAWARIA Ahad MUHAMMAD Naveed Akhtar AMJAD Farooq MASROOR Ahmad 《原子能科学技术》 EI CAS CSCD 北大核心 2024年第10期2068-2076,共9页
This paper presents a novel artificial intelligence (AI) based approach to predict crucial meteorological parameters such as temperature,pressure,and wind speed,typically calculated from computationally intensive weat... This paper presents a novel artificial intelligence (AI) based approach to predict crucial meteorological parameters such as temperature,pressure,and wind speed,typically calculated from computationally intensive weather research and forecasting (WRF) model.Accurate meteorological data is indispensable for simulating the release of radioactive effluents,especially in dispersion modeling for nuclear emergency decision support systems.Simulation of meteorological conditions during nuclear emergencies using the conventional WRF model is very complex and time-consuming.Therefore,a new artificial neural network (ANN) based technique was proposed as a viable alternative for meteorological prediction.A multi-input multi-output neural network was trained using historical site-specific meteorological data to forecast the meteorological parameters.Comprehensive evaluation of this technique was conducted to test its performance in forecasting various parameters including atmospheric pressure,temperature,and wind speed components in both East-West and North-South directions.The performance of developed network was evaluated on an unknown dataset,and acquired results are within the acceptable range for all meteorological parameters.Results show that ANNs possess the capability to forecast meteorological parameters,such as temperature and pressure,at multiple spatial locations within a grid with high accuracy,utilizing input data from a single station.However,accuracy is slightly compromised when predicting wind speed components.Root mean square error (RMSE) was utilized to report the accuracy of predicted results,with values of 1.453℃for temperature,77 Pa for predicted pressure,1.058 m/s for the wind speed of U-component and 0.959 m/s for the wind speed of V-component.In conclusion,this approach offers a precise,efficient,and wellinformed method for administrative decision-making during nuclear emergencies. 展开更多
关键词 prediction of meteorological parameters weather research and forecasting model artificial neural networks nuclear emergency support system
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Electrochemical-Method-Induced Strong Metal-Support Interaction in Pt-CNT@SnO_(2) for CO-Tolerant Hydrogen Oxidation Reaction
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作者 Shen-Zhou Li Zi-Jie Lin +2 位作者 Qi-An Chen Zhao Cai Qing Li 《电化学(中英文)》 北大核心 2024年第12期28-38,共11页
Inducing the classic strong metal-support interaction(SMSI)is an effective approach to enhance the performance of supported metal catalysts by encapsulating the metal nanoparticles(NPs)with supports.Conventional therm... Inducing the classic strong metal-support interaction(SMSI)is an effective approach to enhance the performance of supported metal catalysts by encapsulating the metal nanoparticles(NPs)with supports.Conventional thermal reduction method for inducing SMSI processes is often accompanied by undesirable structural evolution of metal NPs.In this study,a mild electrochemical method has been developed as a new approach to induce SMSI,using the cable structured core@shell CNT@SnO_(2) loaded Pt NPs as a proof of concept.The induced SnO_(x) encapsulation layer on the surface of Pt NPs can protect Pt NPs from the poisoned of CO impurity in hydrogen oxidation reaction(HOR),and the HOR current density could still maintain 85% for 2000 s with 10,000 ppm CO in H_(2),while the commercial Pt/C is completely inactivated.In addition,the electrons transfer from SnO_(x) to Pt NPs improved the HOR activity of the E-Pt-CNT@SnO_(2),achieving the excellent exchange current density of 1.55 A·mgPt^(-1).In situ Raman spectra and theoretical calculations show that the key to the electrochemical-method-induced SMSI is the formation of defects and the migration of SnO_(x) caused by the electrochemical redox operation,and the weakening the SneO bond strength by Pt NPs. 展开更多
关键词 Strong metal-support interaction Pt supported metal catalyst Hydrogen oxidation reaction CO tolerance
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基于运动姿态感知的综放支架主动控顶空间研究 被引量:1
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作者 曾庆良 雷小万 +3 位作者 孟昭胜 万丽荣 班新亮 胡雨龙 《煤炭学报》 北大核心 2025年第1期645-660,共16页
综放支架是综放采场关键支护与主动放煤装置,其主动触支顶煤行为可有效引导顶煤智能有序破碎。为开展支架主动扰控顶煤理论及相关研究,明确综放支架对顶煤的主动触支工作空间,提出一种综放支架各部件相对空间姿态及绝对空间位姿动态感... 综放支架是综放采场关键支护与主动放煤装置,其主动触支顶煤行为可有效引导顶煤智能有序破碎。为开展支架主动扰控顶煤理论及相关研究,明确综放支架对顶煤的主动触支工作空间,提出一种综放支架各部件相对空间姿态及绝对空间位姿动态感知方法,以期提升综放支架对顶煤碎放过程可控性。首先,借助Denavit-Hartenberg(D-H)方法建立了综放支架空间姿态数学模型,分析得到支架顶梁和放煤机构在各关节节点坐标系与本体坐标系下坐标,明确了综放支架各关键部件之间的相对姿态及运动耦合关系;在此基础上建立了综放工作面全局感知模型并求解得到了支架的绝对空间位姿数据,获得了工作面顶板、底板倾角对综放支架空间支护姿态影响。其次,提出并计算了综放支架顶梁触支空间和放煤机构支护空间分布模型,获得了综放支架对顶煤的主动调控范围,同时使用初值优选的Levenberg-Marquardt(L-M)优化算法探究支架主动触顶姿态的调控方法与立柱的有效驱动行程。最后,搭建了支架姿态数据采集系统,依托山东省菏泽市赵楼煤矿7303综放工作面获取了支架运动过程中真实空间姿态参数数据,对比理论解算数据与传感器实测数据,验证了该空间位姿测量方法的可行性与准确性。结果表明,使用该方法解算的顶梁姿态与传感器测量结果重合率达98.26%,为进一步提高支架的空间位姿感知技术提供了研究思路。 展开更多
关键词 智能综放开采 综放支架 触支空间 顶煤调控 触顶姿态
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从理念到机制:关于建设生育友好型社会的理论思考 被引量:4
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作者 刘中一 《理论与改革》 北大核心 2025年第1期142-154,171,共14页
为了推动实现适度生育水平、促进人口高质量发展,党和政府提出了建设生育友好型社会的战略部署。马克思主义人口观和生育观、传统生育文化以及计划行为理论分别构成了生育友好型社会的思想基础、文化基础和理论基础。生育友好型社会是... 为了推动实现适度生育水平、促进人口高质量发展,党和政府提出了建设生育友好型社会的战略部署。马克思主义人口观和生育观、传统生育文化以及计划行为理论分别构成了生育友好型社会的思想基础、文化基础和理论基础。生育友好型社会是指一种理想型的社会状态,在此状态下,生育尊严得到普遍尊重,生育权利得到强力维护,生育潜力得到有效释放,育儿焦虑得到缓解,家庭福祉得到政府和社会的关切。进一步说,生育友好的内涵包括生育过程的安适性、生育政策的包容性、生育服务的公平性、生育价值的人文性以及生育权益维护的主动性等多个方面。制度友好、服务友好、空间友好和文化友好共同组成生育友好型社会的基本框架。目前,我国社会存在“想生不能生”和“愿生不敢生”等多种生育不友好现象,以及片面追求生育工具性和忽视生育人文性的价值取向与认知误区。另外,建设生育友好型社会是一项长期艰巨的任务,需要适时对其动力机制、激励机制、整合机制和保障机制做出调整和优化。 展开更多
关键词 人口问题 生育友好型社会 生育支持政策 生育服务支持 生育权益 生育文化
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职业教育现场工程师项目社会支持系统的建构思考 被引量:2
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作者 郭高萍 何景师 《成人教育》 北大核心 2025年第2期78-85,共8页
职业教育现场工程师项目是创新产教融合机制的新载体。从学徒制培养模式、职业能力标准研制、工程师身份认同等方面分析了现场工程师项目实施的困境,引入协同学理论建构职业教育现场工程师项目的“三环聚合、协同联动”社会支持系统模型... 职业教育现场工程师项目是创新产教融合机制的新载体。从学徒制培养模式、职业能力标准研制、工程师身份认同等方面分析了现场工程师项目实施的困境,引入协同学理论建构职业教育现场工程师项目的“三环聚合、协同联动”社会支持系统模型,并从建立目标协同机制、开放联动机制、利益协调机制等方面探索高质量实施项目的运行机制,通过整体性的制度设计促进政企校深度协同,推动教育链、人才链与产业链、创新链有机衔接。 展开更多
关键词 现场工程师 职业教育 协同 社会支持系统
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