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Explosion resistance performance of reinforced concrete box girder coated with polyurea:Model test and numerical simulation

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Defence Technology（防务技术） 2024年第3期33卷 1-18页

作者： Guangpan zhou Rong Wang Mingyang Wang Jianguo ding Yuye Zhang School of Science Nanjing University of Science and TechnologyNanjing 210094JiangsuChina School of Mechanical Engineering Nanjing University of Science and TechnologyNanjing 210094JiangsuChina State Key Laboratory of Explosion and Impact and Disaster Prevention and Mitigation Army Engineering University of PLANanjing 210007JiangsuChina

To study the anti-explosion protection effect of polyurea coating on reinforced concrete box girder,two segmental girder specimens were made at a scale of 1:3,numbered as G(without polyurea coating)and PCG(with polyurea coating).The failure characteristics and dynamic responses of the specimens were compared through conducting explosion *** reliability of the numerical simulation using LS-DYNA software was verified by the test *** effects of different scaled distances,reinforcement ratios,concrete strengths,coating thicknesses and ranges of polyurea were *** results show that the polyurea coating can effectively enhance the anti-explosion performance of the *** top plate of middle chamber in specimen G forms an elliptical penetrating hole,while that in specimen PCG only shows a very slight local *** peak vertical displacement and residual displacement of PCG decrease by 74.8% and 73.7%,respectively,compared with those of specimen *** the TNT explosion with small equivalent,the polyurea coating has a more significant protective effect on reducing the size of *** the increase of TNT equivalent,the protective effect of polyurea on reducing girder displacement becomes more *** optimal reinforcement ratio,concrete strength,thickness and range of polyurea coating were also drawn.

关键词： Explosive load Explosion resistance performance Model test Polyurea Concrete box girder Numerical simulation

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Properties and Characteristics of Regolith-Based Materials for Extraterrestrial Construction

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Engineering 2024年第6期37卷 159-181页

作者： Cheng zhou Yuyue Gao Yan zhou Wei She Yusheng Shi Lieyun ding Changwen Miao National Center of Technology Innovation for Digital Construction Huazhong University of Science and TechnologyWuhan 430074China School of Civil and Hydraulic Engineering Huazhong University of Science and TechnologyWuhan 430074China School of Materials Science and Engineering Southeast UniversityNanjing 214135China State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and TechnologyWuhan 430074China

The construction of extraterrestrial bases has become a new goal in the active exploration of deep *** the construction techniques,in situ resource-based construction is one of the most promising because of its good sustainability and acceptable economic cost,triggering the development of various types of extraterrestrial construction materials.A comprehensive survey and comparison of materials from the perspective of performance was conducted to provide suggestions for material selection and *** types of typical construction materials are discussed in terms of their reliability and applicability in extreme extraterrestrial ***,thermal and optical,and radiation-shielding properties are *** influencing factors and optimization methods for these properties are *** the perspective of material properties,the existing challenges lie in the comprehensive,long-term,and real characterization of regolith-based construction ***,the suggested future directions include the application of high-throughput characterization methods,accelerated durability tests,and conducting extraterrestrial experiments.

关键词： Extraterrestrial construction Characterization Mechanical property Thermal property Optical property Radiation-shielding

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Migration Behavior of Impurity Iron in Silicon Melt Under Pulsed Electric Current

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Acta Metallurgica Sinica(English Letters) 2024年第5期37卷 889-903页

作者： Mengcheng zhou Yaxiong Dai Changhao Liu Shengli ding Xinfang Zhang School of Metallurgical and Ecological Engineering University of Science and Technology BeijingBeijing 100083China Guangdong Zhongnan Iron&Steel Co. Ltd.Guangdong 512123China

The impurity iron in silicon material will seriously affect the photoelectric conversion efficiency of silicon solar ***,the traditional silicon purification method has the disadvantages of long cycle,high energy consumption and serious *** this study,an efficient and green pulsed electric current purification technology is *** electromigration effect of iron elements,the current density gradient driving of iron phase,and the gravity of iron phase all affect the migration behavior of iron phase in silicon melt under pulsed electric *** of the depth of electrode insertion into the silicon melt,the solubility of iron in silicon decreases under the pulsed electric current,which helps to form the iron *** the same time,the iron phase tends to sink toward the bottom under the influence of *** the electrode is shallowly inserted,a non-uniform electric field is formed in the silicon melt,and the iron phase is mainly driven by the current density gradient to accelerate sink toward the *** the electrode is fully inserted,an approximately uniform electric field is formed in the silicon melt,and iron elements are preferentially migrated to the cathode by electromigration,forming iron phase sinking at the *** study of impurity iron migration behavior in silicon melt under pulsed electric current provides a new approach for the purification of polycrystalline silicon.

关键词： Metallurgical silicon Pulsed electric current Iron-rich phase Current density gradient Electromigration

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Influence of rare earth promoters on the performance of Ni/Mg(Al)O catalysts for hydrogenation and steam reforming of toluene

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Rare Metals 2009年第6期28卷 582-589页

作者： ZHANG Yuwen CHENG Hongwei LU Xionggang ding Weizhong zhou Guozhi Shanghai Key Laboratory of Modem Metallurgy and Materials Processing School of Materials Science and Engineering Shanghai University Shanghai 200072 China School of Metallurgical and Ecological Engineering University of Science and Technology Beijing Beijing 100083 China

CeO2-, La2O3-, and ZrO2-promoted Ni/Mg（Al）O catalysts synthesized by hydrotalcite-type precursors have been investigated with respect to catalytic activity and carbon formation in the hydrogenation and steam reforming of toluene as a model tar compound. X-ray diffraction （XRD）, Brunauer-Emmett-Teller （BET） specific surface area and Hz-temperature programmed reduction （TPR） were used to observe the characteristics of the prepared catalysts. The carbon formation and its amount on the used catalysts were examined by transmission electron microscope （TEM）, scanning electron microscope （SEM） and thermogravimetric （TG）. The trend of catalytic activity as derived from the experimental results followed the order： Ni-Ce〉Ni-La〉Ni-Zr〉Ni. The catalyst modified with CeO2 exhibited the highest catalytic performance and had good carbon resistance in the hydrogenation and steam reforming of toluene. A toluene conversion of 96.8%, a CH4 yield of 45.2% and a CO yield of 50.4% have been achieved. The addition of promoters led to better dispersion of nickel species and higher interaction nickel-support, which were favorable for increasing the catalytic activity and effectively preventing carbon formation.

关键词： hydrogen production hydrogenation rare earth hydrotalcite

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Preliminary Studies on Thickness of Nondestructive Rice (Oryza sativa L.) Leaf Blade

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Agricultural Sciences in China 2007年第7期6卷 802-807页

作者： CHEN You-ding ZHANG Xu zhou Xin-qiao CHEN Guan-hua Rice Research Institute Guangdong Academy of Agricultural Sciences Guangzhou 510640 P.R. China

Two varieties, Yuexinzhan and Guangchao 3, were used to study leaf thickness in rice in this experiment. The thickness of the leaf blade was measured by the nondestructive leaf thickness instrument, which was modified from the thickness instrument for steel objects （John Bull, England）. The contacting area between the leaf and the probe of the instrument was 0.5 cm^2. There was no significant difference between the thickness of steel materials measured by the nondestructive rice leaf thickness instrument and the micrometer. The correlation between the thickness of the rice leaf blade measured by the nondestructive rice leaf thickness instrument and the specific leaf weight （SLW） was significant （P 〈 0.05 or P〈 0.01）. The results also showed that the rice leaf thickness was uneven and asymmetric. The thickness and SLW of flag leaf tended to increase from the base to the tip of the leaf blade. The middle part of the second and third top leaf was the thickest, but no significant difference in thickness between the basal part and the fore part was found. Drawing a line on the main vein in the top three leaves, the left part was thinner than the right part. The thickness of the lower leaves （6/0-9/0） on the main culm tended to increase with increasing positions of the leaves in the early and middle stages, but the tendency was not the same for the higher leaves （10/0 upwards）, although the higher leaves （10/0 upward） were thicker than the lower leaves （9/0 or downward）. Furthermore, different CO2 concentrations （550±30, 460 ± 30 μmol mol^-1） in the growth boxes had no effect on the thickness of rice leaf blades. It can be concluded that the measurement of rice leaf thickness using the nondestructive rice leaf thickness instrument is simple, precise, and nondestructive.

关键词： paddy rice leaf thickness nondestructive rice leaf thickness instrument

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Treatment and Prevention of 100 Cases with Allergic Rhinitis by Acupoint Sticking Therapy

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Journal of Acupuncture and Tuina Science 2013年第3期11卷 169-172页

作者： Wen Mu-sheng Liu Li zhou ding-wei Chinese Medicine Hospital of Ba'nan District Chongqing City

Objective: To observe the clinical effects of acupoint sticking therapy in the three ten-day periods in summer and three nine-day periods in winter. Methods: Herbal medicines were prepared into crude herbal powder and made into paste with ginger juice, and were respectively applied to the corresponding acupoints in the three ten-day periods in summer and three nine-day periods in winter. Results: The results showed 45 cases were cured, 50 cases were improved, and 5 cases failed out of 100 cases, with the total effective rate of 95%. Conclusion: The acupoint sticking therapy for the treatment and prevention of allergic rhinitis is simple in method, remarkable in effects, acceptable to the patients, and is worthy of clinical popularization.

关键词： Acupoint Sticking Therapy Allergic Rhinitis Point, Dazhui (GV 14) Point, Feishu (BL 13) Point, Gaohuang (BL 43)

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A design and application of compound multi-functional sensor in wood-based panel processing

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Journal of Forestry Research 2006年第4期17卷 319-322页

作者： XU Kai-hong zhou ding-guo Nanjing Forestry University Nanjing 210037 P. R. China Northeast Forestry University Harbin 150040 P. R.. China

A compound multi-functional sensor was designed by the study on the on-line testing technology of wood-based panels, and its properties of shape, functions, size, resistance to special environment were studied in details. The operational principles of different sensors, technical flow of manufacturing, development of software systems of special functions, and the assessments of technical specification were also be introduced. This sensor adopted many new technologies, such as the applications of piezoresistant effect and heat sensitive effect can effectively measure the pressure and temperature, digital signal processing technology was used to extract and treat signals, and resist interference, encapsulation technology was used to keep the normal run of sensor under a harsh environment. Thus, the on-line compound multi-functional temperature/pressure sensor can be applied better to supervise the production of wood-based panels. All technical specifications of the compound multi-functional sensor were tested and the results met the requirements of the equipments.

关键词： Wood-based panel processing Multi-functional sensor Piezoresistant effect Heat sensitive effect

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Paleogene integrative stratigraphy,biotas,and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

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Science China Earth Sciences 2024年第4期67卷 1290-1325页

作者： Jia LIU Ai SONG Lin ding Tao SU Zhekun zhou CAS Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMengla 666303China State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and PalaeontologyChinese Academy of SciencesNanjing 210008China Institute of Paleontology Yunnan UniversityKunming 650500China State Key Laboratory of Tibetan Plateau Earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China

The Paleogene is a crucial period when terrestrial and marine ecosystems recovered from major disruptions and gradually approached their modern *** the Qinghai-Tibetan Plateau and its surrounding regions,the Paleogene also represents a significant phase of tectonic evolution in the Qinghai-Tibetan Plateau-Himalaya orogeny,reorganization of Asian climates,and evolution of *** to limitations in research conditions and understanding,there are still many controversies regarding stratigraphic divisions in the Qinghai-Tibetan Plateau and its surrounding *** recent years,extensive studies on sedimentary petrology,magnetostratigraphy,and isotope dating have been conducted in the *** fossils have been discovered and reported,contributing to a more systematic understanding of *** studies have laid a solid foundation for the comprehensive investigation of the stratigraphy,biotas and paleogeographic evolution of the Qinghai-Tibetan Plateau and its surrounding regions during the *** this paper,we integrate recent research on fossils,isotopic dating,magnetostratigraphy,and geochemistry to refine the stratigraphic divisions and correlation framework of different tectonic units in the region,building upon previous *** the Second Tibetan Plateau Scientific Expedition and Research,the knowledge of Paleogene floras has gradually *** paper discusses the biostratigraphic significance of extinct and newly appeared taxa based on the latest dating results of these plant *** new understanding of fossil species such as the“Eucalyptus”and Arecaceae establishes connections between the Paleogene flora of the Qinghai-Tibetan region and the biotas of Gondwana,specifically Oceania and South *** evolutionary history of key taxa near the Yarlung Zangbo suture zone indicates that the collision between the Indian and Eurasian plates occurred approximately 65-54 *** reconstructions,based o

关键词： Qinghai-Tibetan Plateau Fossils Biostratigraphy Paleoenvironment Paleogeography Paleogene

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Prescribed time control based on the periodic delayed sliding mode surface without singularities

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Science China(Information Sciences) 2024年第7期67卷 256-270页

作者： Bin zhou Yi ding Kang-Kang ZHANG Guang-Ren DUAN Center for Control Theory and Guidance Technology Harbin Institute of Technology

In this paper, nonsingular prescribed-time control is studied based on periodic delayed sliding mode surfaces. Different from the existing sliding mode control, where either singularity problems may appear or the convergence time depends on the initial state, the proposed sliding mode control approaches can achieve prescribed-time convergence without singularity. The proposed nonsingular sliding mode control approaches can be applied to both second-order and high-order nonlinear systems with prescribed-time convergence. As applications of the proposed sliding mode control approaches, the control of hypersonic vehicle systems is revisited. Numerical simulations on the nonlinear model of the hypersonic vehicle system show the effectiveness of the proposed methods.

关键词： prescribed-time control smooth periodic delayed feedback sliding mode control high-order nonlinear systems hypersonic vehicle systems

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Graphene-manganese oxide hybrid porous material and its application in carbon dioxide adsorption

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Chinese Science Bulletin 2012年第23期57卷 3059-3064页

作者： zhou ding LIU Qing CHENG QianYi ZHAO YanChao CUI Yi WANG Tao HAN BaoHang National Center for Nanoscience and Technology Beijing 100190 China State Key Laboratory of Transducer Technology Chinese Academy of Sciences Shanghai 200050 China)

Graphene-Mn3O4 (GMNO) hybrid porous material is prepared by a hydrothermal method and its performance in carbon dioxide adsorption is *** the synthesis of the GMNO materials,MnO(OH)2 colloid obtained by the hydrolysis of Mn 2+ in basic solution was using as the precursor of the *** a hydrothermal reaction of the mixture of graphene oxide (GO) and MnO(OH)2,GO was reduced into graphene and the MnO(OH)2 was transformed into Mn3O4 with enhanced crystallization.X-ray diffraction,thermal gravimetric analysis,transmission electron microscopy,infrared spectra and Raman spectroscopy were taken to characterize the hybrid *** porosity and the carbon dioxide adsorption ability are measured by gas sorption analysis,in which the as-prepared GMNO hybrid materials exhibit a specific surface area ranging from 140 to 680 m2g-1 and a maximum carbon dioxide capacity of about 11 wt%.

关键词： graphene manganese oxide porous material carbon dioxide adsorption

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