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球墨铸铁轨道垫板在垂直生产线上的工艺改进

现代铸铁 2024年第2期44卷 35-37,42页

作者：王文青梁瑞学刘瑞海赵胜波方喜邯郸市宝特铸造有限公司河北邯郸057350

介绍了采用垂直分型线生产的球墨铸铁轨道垫板的原生产工艺及存在密集的砂眼、渣眼缺陷,通过对浇注系统和冒口进行改进,有效解决了大平面存在的砂眼、渣眼问题,最后指出:(1)在垂直线上生产板类铸件,可以实现液面的快速上升,避免高温铁... 详细信息

介绍了采用垂直分型线生产的球墨铸铁轨道垫板的原生产工艺及存在密集的砂眼、渣眼缺陷,通过对浇注系统和冒口进行改进,有效解决了大平面存在的砂眼、渣眼问题,最后指出:(1)在垂直线上生产板类铸件,可以实现液面的快速上升,避免高温铁液对砂型平面的烘烤变形,但上下部同时引入铁液且上部流量大于下部流量的浇注系统不可取,会导致型腔内铁液的严重紊流,不利于夹渣、砂粒的稳定上浮;(2)内浇道充型铁液的速度较高,不应正对砂芯或砂胎,会导致冲砂风险;(3)对于板类铸件,采用半开放式阶梯浇注系统很好地解决了原工艺存在的密集型砂眼、渣眼问题。

关键词：球墨铸铁轨道垫板垂直生产线

Large-scale characteristics of thermokarst lakes across the source area of the Yellow River on the Qinghai-Tibetan Plateau

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Journal of Mountain Science 2023年第6期20卷 1589-1604页

作者： liu Wen-hui ZHOU Guang-hao liu hai-rui LI Qing-peng XIE Chang-wei LI Qing ZHAO Jian-yun ZHANG Qi State Key Laboratory of Plateau Ecology and Agriculture Qinghai UniversityXining 810016China Department of Geological Engineering Qinghai UniversityXining 810016China College of Eco-Environmental Engineering Qinghai UniversityXining 810016China Cryosphere Research Station on the Qinghai-Tibet Plateau State Key Laboratory of Cryosphere SciencesNorthwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 73ooooChina

As significant evidence of permafrost degradation,thermokarst lakes play an important role in the permafrost regions by regulating hydrology,ecology,and *** the Sources Area of the Yellow River(SAYR),permafrost degradation has accelerated since the 1980s,and numerous thermokarst lakes have been *** this paper,we use Sentinel-2 images to extract thermokarst lake boundaries and perform a regional-scale study on their geometry across the permafrost region in the *** also explored the spatiotemporal variations and potential drivers from the perspectives of the permafrost,climate,terrain and vegetation *** results showed that there were 47,518 thermokarst lakes in 2021 with a total area of 190.22×106 m^(2),with an average size of 4,003.3 m^(2).The 44,928 ponds(≤10,000 m^(2))predominated the whole lake number(94.1%)but contributed to a small portion of the total lake area(28.8%).With 2,590 features(5.9%),small-sized(10,000 to 100,000 m^(2))and large-sized lakes(>100,000 m^(2))constituted up to 71.2%of the total lake *** lakes developed more significantly in warm permafrost regions than in cold permafrost areas;74.1%of lakes with a total area of 119.6×106 m^(2)(62.9%),were distributed in warm permafrost *** thermokarst lakes were likely to develop within the elevation range of 4,500~4,800 m,on flat terrain(slope<10°),on SE and S aspects and in alpine meadow *** thermokarst lakes in the study region experienced significant shrinkage between 1990 and 2021,characterized by obvious lake drainage;the lake numbers decreased by 5418(56.1%),with a decreasing area of 58.63×106 m^(2)(49.0%).This shrinkage of the thermokarst lake area was attributable mainly to the intensified degradation of rich-ice permafrost thawing arising from continued climate warming,despite the wetting climatic trend.

关键词： Thermokarst lake Spatial characteristic Influencing factor Source area of the Yellow River

Layer Hall effect induced by hidden Berry curvature in antiferromagnetic insulators

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National Science Review 2024年第2期11卷 15-23页

作者： rui Chen hai-Peng Sun Mingqiang Gu Chun-Bo Hua Qihang liu hai-Zhou Lu X.C.Xie Shenzhen Institute for Quantum Science and Engineering and Department of Physics Southern University of Science and Technology(SUSTech) International Quantum Academy Institute for Theoretical Physics and Astrophysics University of Würzburg School of Electronic and Information Engineering Hubei University of Science and Technology Guangdong Provincial Key Laboratory of Computational Science and Material Design Southern University of Science and Technology Shenzhen Key Laboratory of Quantum Science and Engineering International Center for Quantum Materials School of PhysicsPeking University Collaborative Innovation Center of Quantum Matter CAS Center for Excellence in Topological Quantum Computation University of Chinese Academy of Sciences

The layer Hall effect describes electrons spontaneously deflected to opposite sides at different layers, which has been experimentally reported in the MnBi2Te4thin films under perpendicular electric fields. Here, we reveal a universal origin of the layer Hall effect in terms of the so-called hidden Berry curvature, as well as material design principles. Hence, it gives rise to zero Berry curvature in momentum space but non-zero layer-locked hidden Berry curvature in real space. We show that, compared to that of a trivial insulator, the layer Hall effect is significantly enhanced in antiferromagnetic topological insulators. Our universal picture provides a paradigm for revealing the hidden physics as a result of the interplay between the global and local symmetries, and can be generalized in various scenarios.

关键词： layerHall effect hidden Berry curvature antiferromagnetic insulator axion insulator, quantum transport

Development of a high-repetition-rate lumped-inductance kicker magnet prototype for the beam switchyard of SHINE

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Nuclear Science and Techniques 2024年第2期35卷 20-31页

作者： Yong-Fang liu rui-Ping Wang Jin Tong Bo Zhang Si Chen Qi-Bing Yuan hai-Xiao Deng Ming Gu Bo liu Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201412People’s Republic of China

The Shanghai high-repetition-rate X-ray free-electron laser and extreme light facility(SHINE)operates at a maximum repetition rate of 1 *** magnets are key components that distribute electron bunches into three different undulator lines in a bunch-by-bunch *** kicker field width must be less than the time interval between bunches.A lumpedinductance kicker prototype was developed using a vacuum chamber with a single-turn *** full magnetic field strength was 0.005 *** paper presents the requirements,design considerations,design parameters,magnetic field calculations,and measurements of the kicker *** relevant experimental results are also *** pulse width of the magnetic field was approximately 600 ns,and the maximum operation repetition rate was 1 *** developed kicker satisfies the requirements for the SHINE ***,numerous recommendations for the future optimization of kicker magnets are provided.

关键词： X-ray free-electron laser Kicker magnet Beam switchyard High repetition rate Ni-Zn ferrites

Protein succinylation,hepatic metabolism,and liver diseases

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World Journal of Hepatology 2024年第3期16卷 344-352页

作者： Shuang liu rui Li Ya-Wen Sun hai Lin hai-Fang Li College of Animal Science and Veterinary Medicine Shandong Agricultural UniversityTai’an 271018Shandong ProvinceChina College of Life Sciences Shandong Agricultural UniversityTai’an 271018Shandong ProvinceChina

Succinylation is a highly conserved post-translational modication that is processed via enzymatic and non-enzymatic *** exhibits strong effects on protein stability,enzyme activity,and transcriptional *** succinylation is extensively present in the liver,and increasing evidence has demonstrated that succinylation is closely related to hepatic *** instance,histone acetyltransferase 1 promotes liver glycolysis,and the sirtuin 5-induced desuccinylation is involved in the regulation of the hepatic urea cycle and lipid ***,the effects of succinylation on hepatic glucose,amino acid,and lipid metabolism under the action of various enzymes will be discussed in this *** addition,how succinylases regulate the progression of different liver diseases will be reviewed,including the desuccinylation activity of sirtuin 7,which is closely associated with fatty liver disease and hepatitis,and the actions of lysine acetyltransferase 2A and histone acetyltransferase 1 that act as succinyltransferases to regulate the succinylation of target genes that influence the development of hepatocellular *** view of the diversity and significance of protein succinylation,targeting the succinylation pathway may serve as an attractive direction for the treatment of liver diseases.

关键词： Protein succinylation Hepatic metabolism Fatty liver Hepatitis Hepatocellular carcinoma

Construction of multifunctional lanthanum manganese mixed nanoparticles mediated by ionic liquids for selective aerobic oxidation of cyclohexane

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Rare Metals 2024年第5期43卷 2205-2221页

作者： Hao Li rui-rui Zhang Ke-Xin Li Shuang Wei Yu-Mei liu rui-Xia liu Beijing Key Laboratory of Ionic Liquids Clean Process CAS Key Laboratory of Green Process and EngineeringState Key Laboratory of Multiphase Complex SystemsInstitute of Process EngineeringChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

Selective oxidation of alkanes to produce highvalue chemicals is an essential strategy and means to realize efficient utilization of *** this work,a strategy of lanthanum manganese mixed metal oxides(LMMO)regulated via a facile ionic liquid(IL)-assisted hydrothermal method was proposed to construct the multifunctional catalysts,which exhibited excellent catalytic performance in the selective aerobic oxidation of *** 8.9%cyclohexane conversion with 90%KA oi(cyclohexanol and cyclohexanone)selectivity was achieved over the optimal LMMO catalyst under mild *** effects of anion type,carbon chain length and concentration of ILs on the structure and properties of catalysts were investigated through various characterizations,indicating the structure-directing and template effect of ILs on the multifunctional *** formation of self-assembled spherical nanoparticles followed the"dissolution-nucleation-proliferation"mechanism with the introduction of 1-butyl-3-methylimidazolium hydrogen sulfate,ascribing the synergistic effect between the microenvironment of ILs and the hydrothermal ***,the high reactive oxygen concentration redox capacity,and suitable basic sites of LMMO catalysts mediated by ILs enhance the activation of C-H bonds and molecular oxygen,simultaneously influencing the adsorption and desorption of the substrate.A comprehensive understanding of the high KA oil selectivity and radical reaction mechanism was elucidated based on in situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS)and radical trapping *** recycling and regeneration experiments further illuminated that the removal of adsorbed cyclohexanone acting on the LMMO catalyst was the key to achieve high KA oil selectivity.

关键词： Ionic liquids Nanoparticle Multifunctional catalyst Cyclohexane oxidation

Strong and tough chitin hydrogel constructed by dehydration and rehydration strategy

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Nano Research 2024年第9期17卷 8192-8199页

作者： rui-rui liu Li-Bo Mao Shu-Hong Yu Division of Nanomaterials and Chemistry Hefei National Research Center for Physical Sciences at the MicroscaleDepartment of ChemistryInstitute of Biomimetic Materials and ChemistryAnhui Engineering Laboratory of Biomimetic MaterialsUniversity of Science and Technology of ChinaHefei 230026China Institute of Innovative Materials Department of Materials Science and EngineeringDepartment of ChemistrySouthern University of Science and TechnologyShenzhen 518055China

As a renewable,biocompatible,biodegradable soft material,chitin hydrogels have better advantages in stability,antibacterial activity,antifouling,cost,immunogenicity,and so on than most polymer ***,compared with other widely used polymer hydrogels with high strength and toughness,the practical applications of chitin-based hydrogels have been limited by their weak mechanical properties,such as cartilage repair and meniscus ***,we present the design and fabrication of chitin hydrogels with excellent mechanical strength and toughness by a dehydration and rehydration *** sequential dehydration and rehydration processes,the crystalline domains in the chitin hydrogels can be properly *** optimized crystallinity,the elastic modulus of the chitin hydrogels exceeds all previously reported values,and the fracture toughness is even comparable to some synthetic polymer hydrogels,while maintaining a high-water-content of about 80 wt.%.At the same water content,the mechanical properties of the chitin hydrogels are positively correlated with the hydrogel crystallinity,which proves that the change of mechanical properties of hydrogels is not simply dependent on weight *** hydrogels can be further strengthened by incorporating other biopolymers that are intrinsically weak,which makes the hydrogels promising for applications in fields such as cartilage repair and meniscus ***,the hydrogels enable loading and release of water-soluble and poorly water-soluble *** highly extendable strengthening and toughening strategy of chitin and chitin-based biopolymer hydrogels paves the way for their widely applications.

关键词： chitin hydrogel crystallinity rehydration chemical transformation strong and tough

Combustion characteristics of millimeter-sized aluminum particles in fluidized bed under various O_(2)/CO_(2)/H_(2)O atmospheres Author links open overlay panel

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Particuology 2024年第8期91卷 315-322页

作者： Jialing Zhou rui Zhang Dong liu Key Laboratory of Thermal Control of Electronic Equipment Ministry of Industry and Information TechnologyNanjing210094China Advanced Combustion Laboratory School of Energy and Power EngineeringNanjing University of Science and TechnologyNanjing210094China

Aluminum is an attractive alternative fuel,but it burns very inefficiently due to the formation of a dense Al_(2)O_(3)layer which prevents O_(2)from diffusion to the surface of Al *** previous experiments,the combustion of millimeter-sized Al(mAl)particles in the fluidized bed has achieved a substantial increase in the combustion efficiency,but further improvements are still *** this study,the effects of reaction atmosphere on the fluidized combustion of mAl particles were *** experiments with different O_(2)/H_(2)O/CO_(2)concentrations were *** experimental results indicate that the combustion efficiency of mAl particles in fluidized bed increases as the mole fraction of O_(2),H_(2)O or CO_(2)increases,and the highest combustion efficiency can reach 38.7%.After the analysis of the oxide film on the surface of aluminum particles,it was found that it is easier to generate the unstableθ-Al_(2)O_(3)under CO_(2)atmosphere,and it is easier to generate the unstableγ-Al_(2)O_(3)andθ-Al_(2)O_(3)under H_(2)O *** unstable Al_(2)O_(3)film is more likely to be abraded in the fluidized bed,which leads to the effective improvement of the combustion efficiency.

关键词： Al combustion Fluidized bed Atmosphere Combustion efficiency

Large-aperture Telescope Tracking Control Based on Time-synchronization Strategy

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Research in Astronomy and Astrophysics 2024年第3期24卷 34-46页

作者： Yun Li Yu Ye Shi-hai Yang Ling-Zhe Xu Jin Xu hai Wang Zhuang-Zhuang Deng rui-Qiang liu Xiao-Jie Gu Bo-Zhong Gu Nanjing Institute of Astronomical Optics&Technology Chinese Academy of SciencesNanjing 210042China CAS Key Laboratory of Astronomical Optics&Technology Nanjing Institute of Astronomical Optics&TechnologyNanjing 210042China University of Chinese Academy of Sciences Beijing 100049China

A time-synchronization strategy for packetized transmission of target position about a large-aperture telescope observation control system has been proposed in this *** with the existing telescope tracking strategy,the target position packing and sending strategy based on the time synchronization method proposed in this paper has the advantages of high stability and ***,the telescope tracking observation control method was elaborated in this paper,including the motion pattern during telescope ***,the strategy for packetizes transmission of target positions based on time-synchronization is established and lists the detailed ***,the performance of the tracking strategy is verified using the 2.5 m telescope for the simulated uniform speed star and the blind-tracking fixed star HIP 31216,*** test results show that the accuracy root mean square of the tracking strategy proposed in this paper is less than 0".02 at 30 minutes,and the performance is much better than the design requirement of 0".*** most important advantage of this tracking strategy is that the telescope can guarantee normal tracking for a certain period of time even if the hardware or software of the host computer is abnormal.

关键词： miscellaneous-telescopes-methods observational-methods analytical