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国家创新发展绩效格局分析方法与实证研究 认领
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作者 穆荣平 张婧婧 陈凯华 《科研管理》 CSSCI CSCD 北大核心 2020年第1期12-21,共10页
创新发展已经成为世界潮流,全球创新发展绩效格局正在经历深刻变革,科学监测创新发展绩效格局演进方向是政府和学术界共同关注的问题。本文界定了"国家格局"、"格局分析方法"、"国家格局分析方法"等基本... 创新发展已经成为世界潮流,全球创新发展绩效格局正在经历深刻变革,科学监测创新发展绩效格局演进方向是政府和学术界共同关注的问题。本文界定了"国家格局"、"格局分析方法"、"国家格局分析方法"等基本概念,研究提出了国家创新发展绩效格局二维分析方法,并选择40个国家创新发展指数和创新能力指数及其子指数排名进行了实证研究。本文主要得出三个结论:(1)基于国家创新能力和国家创新发展水平指数排名,采用K-均值聚类法将40个国家分为四类,即创新引领型国家、创新先进型国家、创新追赶型国家和非常规创新追赶型国家;(2)增加辅助特征量"人均GDP"以气泡图形式分析国家创新发展绩效格局的研究发现,经济发展水平(以人均GDP衡量)较高的国家,其创新发展指数与创新能力指数通常排名也较高,说明经济发展水平与国家创新发展绩效高度正相关;(3)分别增加辅助特征量"GDP"和"人均GDP"以气泡图形式分析国家创新能力格局的研究发现,经济规模(以GDP衡量)较大的国家,其创新实力指数排名通常较高,经济发展水平(以人均GDP衡量)较高的国家,其创新效力指数排名通常较高。 展开更多
关键词 格局 格局分析方法 国家创新发展绩效格局 国家创新能力格局
Neutron diffraction studies of permanent magnetic materials 认领
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作者 Wen-Yun Yang Dong Liang +1 位作者 Xiang-Dong Kong Jin-Bo Yang 《稀有金属:英文版》 SCIE EI CAS CSCD 2020年第1期13-21,共9页
Neutron diffraction technology as an advanced material research technique has special advantages in studying magnetic materials compared to the conventional techniques such as X-ray diffraction(XRD),scanning electron ... Neutron diffraction technology as an advanced material research technique has special advantages in studying magnetic materials compared to the conventional techniques such as X-ray diffraction(XRD),scanning electron microscopy(SEM),transmission electron microscopy(TEM),and X-ray photoelectron spectroscopy(XPS).In this review,the applications of neutron diffraction technology on permanent magnetic materials were briefly reviewed:(1)the determination of the crystal structure and magnetic structure of the typical permanent magnet material,(2)in situ neutron diffraction study of the crystal structure evolution of the permanent magnets,and(3)phase transition in permanent magnetic materials. 展开更多
关键词 NEUTRON DIFFRACTION PERMANENT MAGNETIC materials Crystal STRUCTURE MAGNETIC STRUCTURE STRUCTURE evolution Phase TRANSITION
Prospect and Reality of Concentration Gradient Cathode of Lithium-ion Batteries 认领
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作者 LIU Tong-Chao PAN Feng AMINE Khalil 《结构化学》 SCIE CAS CSCD 2020年第1期11-15,1共6页
Li[NixMnyCoz]O2 cathodes are currently the most practicable materials in the timing of developing high-performance rechargeable batteries for next-generation technologies.With the ever-growing demand for energy densit... Li[NixMnyCoz]O2 cathodes are currently the most practicable materials in the timing of developing high-performance rechargeable batteries for next-generation technologies.With the ever-growing demand for energy density,a significant breakthrough has been achieved by the controllable concentration design forming core-shell and concentration gradient structures to push Li[NixCoyMnz]O2 toward higher energy density,longer lifetime and safety.Herein,we review the recent progress on advanced concentration gradient cathode materials.Furthermore,we prospect that this novel approach will continuously extend its advantages in developing extremely fast charging and Co-free cathode materials in the near future. 展开更多
关键词 LITHIUM-ION batteries Li[NixMnyCoz]O2 CORE-SHELL STRUCTURE concentration gradient STRUCTURE
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Sedimentology, Structure and Depositional Environments of the Subsurface Cretaceous, North Sinai, Egypt Using Well Logs 认领
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作者 Fouad Shaaban Amani Bourselli +1 位作者 Adam El-Shahat Mostafa El-Belqasi 《地球科学国际期刊(英文)》 2020年第3期37-57,共21页
A complete set of well logs was used to study the sedimentology, structural and depositional environments of the subsurface Cretaceous rocks of northern Sinai, as a promising hydrocarbon province in Egypt. The sedimen... A complete set of well logs was used to study the sedimentology, structural and depositional environments of the subsurface Cretaceous rocks of northern Sinai, as a promising hydrocarbon province in Egypt. The sedimentological interpretations of well logs show sedimentary sequence of the Early Cretaceous, represented by the Neocomian, Aptian and Albian, which is composed mainly of shales and marls with minor carbonate and sandstone intercalations. Based on the Th/K ratios, the argillaceous sediments are composed of illite, montmorillonite and micas with little amounts of glauconite and chlorite. The environmental interpretations revealed sedimentological environments vary from estuarine to lagoonal and backreef of the Barremian-Aptian rocks, and from continental to estuarine in the Aptian-Albian. By contrast, the Late Cretaceous rocks, represented by the Cenomanian, Turonian, Santonian and Maastrichtian, are mainly composed of carbonates with few shale and marl intercalations. This sequence was accumulated under lagoonal to neritic and bathyal environments. The structural interpretations of well logs show that the Cretaceous section attains a wide range of dip magnitudes and dispersed azimuths all over the study area, which is probably attributed to tectonic and sedimentological processes. The inherited structural complexities indicate possible rejuvenations along old fault planes and rotation of the faulted blocks. 展开更多
关键词 NORTH SINAI CRETACEOUS SEDIMENTOLOGY STRUCTURE Environment Well LOGS
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An Analysis of the Characters of Chinese Calligraphy Art Based on Mathematical Elements 认领
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作者 Yuexi Wu 《应用科学(英文)》 2020年第2期25-40,共16页
Mathematics is an effective way to measure or describe things objectively and accurately. It is of great significance to accurately master stroke trend, font structure and component position to improve the level of ca... Mathematics is an effective way to measure or describe things objectively and accurately. It is of great significance to accurately master stroke trend, font structure and component position to improve the level of calligraphy art. This paper tries to use mathematical elements to analyze the art of calligraphy. It is concluded that through the knowledge of angle, golden section, structure and curve in mathematics, the rule of stroke trend, font structure, component position, and work shape as well as the overall layout of characters can be identified. 展开更多
关键词 CALLIGRAPHY MATHEMATICS ANGLE Structure CURVE
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Anisotropic phononic crystal structure with low-frequency bandgap and heat flux manipulation 认领
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作者 Ting Guo XiongWei Yang +4 位作者 Qian Geng Zhen Li YueMing Li Xian Wang Hu Zhang 《中国科学:物理学、力学、天文学英文版》 SCIE EI CAS CSCD 2020年第2期93-103,共11页
This study presents a two-dimensional phononic crystal with heat flux manipulation and wide bandgaps of out-of-plane modes within the low-frequency range. The anisotropic matrix made of spiral-multilayered materials w... This study presents a two-dimensional phononic crystal with heat flux manipulation and wide bandgaps of out-of-plane modes within the low-frequency range. The anisotropic matrix made of spiral-multilayered materials with different thermal conductivities, and the coating layer inserted with metal are designed for heat flux manipulation. Rubber-coated metal cylinders are periodically embedded in the anisotropic matrix to obtain the low-frequency bandgaps of out-of-plane modes. Numerical simulation is carried out to validate the heat and elastic characteristics of the spiral-multilayered anisotropic structure and reveal the effects of the laying angle and temperature on the bandgaps. Subsequently, a spiral-multilayered plate with periodic structures is studied, which shows an obvious vibration attenuation in the frequency ranges of the bandgaps and a deflected heat flux from the initial propagation direction. In the experimental investigation, the multi-phase spiral-multilayered anisotropic plate is simplified to a single-phase anisotropic plate made of aluminum. The characteristics of this type of anisotropic phononic crystal structure may pave the way for the design of a new kind of thermo-acoustic metamaterial serving in combined thermal and acoustic environments. 展开更多
关键词 heat flux MANIPULATION bandgap ANISOTROPIC STRUCTURE thermal stress spiral-multilayered STRUCTURE
Interactive association between processing induced molecular structure changes and nutrient delivery on a molecular basis,revealed by cutting-edge vibrational biomolecular spectroscopy 认领
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作者 Aya Ismael Victor Hugo Guevara-Oquendo +1 位作者 Basim Refat Peiqiang Yu 《畜牧与生物技术杂志:英文版》 SCIE CAS CSCD 2020年第1期211-226,共16页
Background:This study was conducted to determine protein molecular structure profiles and quantify the relationship between protein structural features and protein metabolism and bioavailability of blend pel eted prod... Background:This study was conducted to determine protein molecular structure profiles and quantify the relationship between protein structural features and protein metabolism and bioavailability of blend pel eted products(BPP)based on co-products(canola or carinata)from processing with different proportions of pulse pea screenings and lignosulfonate chemical compound.Method:The protein molecular structures were determined using the non-invasive advanced vibrational molecular spectroscopy(ATR-FT/IR)in terms of chemical structure and biofunctional groups of amides(ⅠandⅡ),α-helix andβ-sheet.Results:The results showed that increasing the level of the co-products in BPP significantly increased the spectral intensity of the amide area and amide height.The products exhibited similar protein secondaryα-helix toβ-sheet ratio.The protein molecular structure profiles(amidesⅠandⅡ,α-helix toβ-sheet)were highly associated with protein degradation kinetics and intestinal digestion.In conclusion,the non-invasive vibrational molecular spectroscopy(ATR-FT/IR)could be used to detect inherent structural make-up characteristics in BPP.Conclusion:The molecular structural features related to protein biopolymer were highly associated with protein utilization and metabolism. 展开更多
关键词 ALPHA-HELIX and BETA-SHEET Amides(ⅠandⅡ) Biofunctional groups Chemical STRUCTURE PROTEIN metabolism and bioavailability PROTEIN molecular STRUCTURE
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The flexural property and its synergistic mechanism of multibody molded beetle elytron plates 认领
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作者 YU XinDi ZHANG XiaoMing +3 位作者 CHEN JinXiang ZHAO CaiQi ZHAO TiDong FU YaQin 《中国科学:技术科学英文版》 SCIE EI CAS CSCD 2020年第5期768-776,共9页
To improve the applications of beetle elytron plates(BEPs,which are biomimetic sandwich plates inspired by beetle elytra),the flexural performance and its synergistic mechanism of multibody molded BEPs were investigat... To improve the applications of beetle elytron plates(BEPs,which are biomimetic sandwich plates inspired by beetle elytra),the flexural performance and its synergistic mechanism of multibody molded BEPs were investigated via cantilever testing and finite element method(FEM).The results are summarized as follows.(1)Although debonding damage causes failure of the multibody molded BEPs and honeycomb plate and the reasonable range of trabecular size for BEPs is narrow,both the optimal loading capacity per mass and failure deformation of the BEPs are over two times those of the honeycomb plate.(2)A flexural synergistic mechanism is revealed in the trabecular-honeycomb core structure of BEPs;this mechanism causes the maximum deformation of core structure to gradually transfer from the honeycomb wall to the trabeculae with the increase inη(the ratio of the trabecular radius to the distance between the center points of two trabeculae),which means the different stretching behaviors in these core structures.(3)Unlike the compressive mechanism of BEPs,by controlling and balancing the deformation degrees of the trabeculae and honeycomb walls,the flexural mechanism achieves a minimum core deformation and an optimal flexural performance.These results suggest a qualitative relationship between the deformation behavior of trabecular-honeycomb core structure and bending performance of the whole BEP,and provide a solid foundation for subsequent research and the considerable application potential of this biomimetic sandwich structure in many fields. 展开更多
关键词 beetle elytra BEP biomimetic structure sandwich structure honeycomb plate flexural property
Taking into Account the Complex Nature and the Intrinsic Parameters of Agro-Food 认领
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作者 Ganame Abdou-Salam Ouoba Kondia Honore Zougmore Fran?ois 《生物物理化学(英文)》 2020年第1期1-13,共13页
In this paper, we perform experiments on the drying of widely consumed food products in Africa. Tomatoes and peppers are considered as products with a complex structure. Zucchini, cucumber, eggplant and cabbages are t... In this paper, we perform experiments on the drying of widely consumed food products in Africa. Tomatoes and peppers are considered as products with a complex structure. Zucchini, cucumber, eggplant and cabbages are the other products used in these drying experiments, having different intrinsic parameters. Most food products have three components, namely skin, flesh containing seeds and the central spongy structure, that do not have the same behavior during their convective drying. Skin is the component that significantly reduces drying while the flesh is easy to dry. By drying the samples considering their intrinsic parameters, one quickly realizes the complex nature of mass and heat transfers during the drying of biological products. 展开更多
关键词 Skin FLESH Structure CONVECTIVE DRYING Agri-Food Products
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The Analysis of"of"Structure in English and"de"in Chinese—Based on The Sad Young Men and its Translation 认领
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作者 郑丽妍 《海外英语》 2020年第1期248-249,共2页
Translations between the English"of"structure and Chinese"de"structure are not completely equivalence,which needs careful consideration.In the present study,an explanatory writing The Sad Young Man... Translations between the English"of"structure and Chinese"de"structure are not completely equivalence,which needs careful consideration.In the present study,an explanatory writing The Sad Young Man and its translation were selected to explore the structure"of"in English based on functional syntax and the structure"de"in Chinese.Inequivalent translations of"of"struc-ture were shown to help second language learners better understand the appropriate translation of"of"structure in English. 展开更多
关键词 "of"structure "de"structure TRANSLATION
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A Study on the Rhetorical Structure of Xi Jinping's Important Speeches for the New Era 认领
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作者 周桐宇 《海外英语》 2020年第5期275-276,共2页
Based on the Rhetorical Structure Theory (hereinafter referred to as RST), the study selected and analyzed the English versions of ten important speeches made by President Xi for the new era and drew up rhetorical tre... Based on the Rhetorical Structure Theory (hereinafter referred to as RST), the study selected and analyzed the English versions of ten important speeches made by President Xi for the new era and drew up rhetorical trees.Through a thorough investiga-tion of rhetorical structures of Xi's speeches on the basis of RST, the study found that:1) Elaboration, Background and Evidence re-lations are the dominant relations in President Xi's speeches;2) The preference of forward arrow direction is an unexpected find-ing;3) There are two patterns of macrostructure of rhetorical relations in Xi's speeches. 展开更多
关键词 Rhetorical Structure Theory Rhetorical Structure Xi Jinping's Important Speeches New Era
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Synthesis and Crystal Structure of a New Noble Metalcontaining Supramolecular Self-assembly with Decamethylcucurbit[5]uril 认领
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作者 陈茹茹 杨炜光 +1 位作者 曹敏纳 李红芳 《结构化学》 SCIE CAS CSCD 2020年第3期535-542,379共9页
A new supramolecular self-assembly [Li(H2 O)2]2[(H2 O@Me10 CB[5])][PtC l6]·7 H2 O(1, Me10 CB[5] = decamethylcucurbit[5]uril), has been successfully constructed with Me10 CB[5] and [PtCl6]~(2-) anion in the presen... A new supramolecular self-assembly [Li(H2 O)2]2[(H2 O@Me10 CB[5])][PtC l6]·7 H2 O(1, Me10 CB[5] = decamethylcucurbit[5]uril), has been successfully constructed with Me10 CB[5] and [PtCl6]~(2-) anion in the presence of lithium cation(Li+). Single-crystal X-ray diffraction study reveals that compound 1 crystallizes in monoclinic space group P21/n with a = 11.1681(18), b = 28.5425(4), c = 18.9342(3) ?, β = 99.0143(15)°, V = 5961.02(16) ?~3, Z = 4, F(000) = 3224, μ = 2.714 mm~(-1), R = 0.0470 and wR = 0.1076(I > 2σ(I)). In the supramolecular self-assembly, two of the portal carbonyl oxygen atoms of Me10 CB[5] are coordinated to Li+ cation, yielding a "half-open" molecular capsule. Then adjacent molecular capsules are connected with each other through hydrogen-bonding to form a one-dimensional(1 D) supramolecular chain structure. The [PtCl6]~(2-) anions are fixed on one side of the 1 D supramolecular chain through supramolecular interactions. The thermal stability, electronic valence and morphology of compound 1 are also investigated. 展开更多
关键词 uril NOBLE metal SUPRAMOLECULAR SELF-ASSEMBLY crystal structure
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Toward accurate measurement of property-dependent galaxy clustering I.Comparison of the Vmax method and the“shuffled”method 认领
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作者 Lei Yang Yi-Peng Jing +1 位作者 Zhi-Gang Li Xiao-Hu Yang 《天文和天体物理学研究:英文版》 SCIE CAS CSCD 2020年第4期87-98,共12页
Galaxy clustering provides insightful clues to our understanding of galaxy formation and evolution,as well as the universe.The redshift assignment for the random sample is one of the key steps to accurately measure ga... Galaxy clustering provides insightful clues to our understanding of galaxy formation and evolution,as well as the universe.The redshift assignment for the random sample is one of the key steps to accurately measure galaxy clustering.In this paper,by virtue of the mock galaxy catalogs,we investigate the effect of two redshift assignment methods on the measurement of galaxy two-point correlation functions(hereafter 2 PCFs),the Vmax method and the"shuffled"method.We have found that the shuffled method significantly underestimates both of the projected 2 PCFs and the two-dimensional 2 PCFs in redshift space,while the Vmax method does not show any notable bias on the 2 PCFs for volume-limited samples.For fluxlimited samples,the bias produced by the Vmax method is less than half of the shuffled method on large scales.Therefore,we strongly recommend the Vmax method to assign redshifts to random samples in the future galaxy clustering analysis. 展开更多
关键词 galaxies:statistics galaxies:galaxy formation and evolution large-scale structure of universe
Performance Analysis of Cushioned Sport Soles with Plantar Pressure Test 认领
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作者 李静 于海滨 +2 位作者 崔丽娜 张锐 邱夷平 《东华大学学报:英文版》 EI CAS 2020年第2期108-115,共8页
Plantar pressure distribution of the designed cushioned soles was studied and compared with that of the commercially available sport shoes.A three-dimensional motion measurement system was used to obtain the peak plan... Plantar pressure distribution of the designed cushioned soles was studied and compared with that of the commercially available sport shoes.A three-dimensional motion measurement system was used to obtain the peak plantar force,the peak plantar pressure,force-time integrals and pressure-time integrals,and one-way analysis of variance was used to analyze the performance of the designed cushioned shoes.The results revealed that in normal walking and jogging states,compared with the commercially available sport shoes,the peak plantar pressure in the heel region decreased by 13.65%and 6.05%,respectively.The peak plantar force decreased by 15.98%and 15.32%,respectively.The force-time integral decreased by 4.36%and 6.83%,respectively,and the pressure-time integral decreased by 10.58%and 11.00%,respectively.In conclusion,the cushioning performance of shoes is related to the exercise mode.For normal walking,the designed cushioned soles absorbed greater impact in the heel region,which was effectively cushioned,whereas in the jogging state,the designed cushioned soles exhibited a favorable cushioning effect in the forefoot region.The designed cushioned soles exhibited cushioning performance through the coupling design of material and structure,which effectively reduced impact force when landing and could optimize plantar pressure distribution. 展开更多
关键词 BIONIC structure midsole PLANTAR PRESSURE distribution PEAK PLANTAR
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涂层和薄膜态准晶材料的研究现状及展望 认领
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作者 辛先峰 董闯 +1 位作者 庞厂 万鹏 《表面技术》 EI CAS CSCD 北大核心 2020年第5期19-25,共7页
准晶材料兼具硬度高、摩擦系数小、耐磨损、耐腐蚀、表面能低等特性,有着十分广阔的应用前景。但受限于本征脆性,准晶材料不能作为结构件单独使用,涂层和薄膜形态成为研究热点。综述了准晶涂层和薄膜的几种制备工艺,主要介绍了热喷涂技... 准晶材料兼具硬度高、摩擦系数小、耐磨损、耐腐蚀、表面能低等特性,有着十分广阔的应用前景。但受限于本征脆性,准晶材料不能作为结构件单独使用,涂层和薄膜形态成为研究热点。综述了准晶涂层和薄膜的几种制备工艺,主要介绍了热喷涂技术、激光熔覆技术、电子束沉积技术、真空蒸镀技术、磁控溅射技术,并对这几种镀膜技术的特点进行了归纳、对比、总结。详细概述了制备过程中涂层和薄膜的生长过程、生长机理,为之后相关研究工作奠定了良好的基础。对结构和性能的研究现状及在界面结合、组织转变、后续热处理工艺中面临的问题进行了讨论,性能方面主要包括准晶涂层和薄膜优良的抗氧化、耐腐蚀、耐磨损性能及其优异的不粘性,并对存在的相关问题提出了一些可能的解决方案。最后对准晶涂层和薄膜更先进的制备方法以及准晶材料在热障涂层、不粘涂层和固体润滑剂等方面的应用前景进行了展望。 展开更多
关键词 准晶薄膜 准晶涂层 制备工艺 结构 性能
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Chiral metal phosphonates: assembly, structures and functions 认领
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作者 Guo-Guo Weng Li-Min Zheng 《中国科学:化学英文版》 SCIE EI CAS CSCD 2020年第5期619-636,共18页
As an important class of inorganic-organic hybrid materials, metal phosphonates can exhibit versatile structures, interesting functions and high water and thermal stabilities. Despite a large number of metal phosphona... As an important class of inorganic-organic hybrid materials, metal phosphonates can exhibit versatile structures, interesting functions and high water and thermal stabilities. Despite a large number of metal phosphonates reported in the past two decades,the development of chiral metal phosphonates is still in its infancy. This review summarizes the current status in this topical field including the synthetic strategies, the crystal structures of chiral metal phosphonates reported thus far, and their physical and chemical properties. Future challenges in this promising field are also discussed. 展开更多
关键词 CHIRAL metal PHOSPHONATE structure PROPERTY
Enhanced removal of I^- on hierarchically structured layered double hydroxides by in suit growth of Cu/Cu2O 认领
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作者 Jiuyu Chen Junyi Wang +6 位作者 Qianhong Gao Xiaomei Zhang Ying Liu Peng Wang Yan Jiao Zongxiang Zhang Yi Yang 《环境科学学报:英文版》 SCIE EI CAS CSCD 2020年第2期338-348,共11页
To further improve the removal ability of layered double hydroxide(LDH) for iodide(I^-) anions from wastewater, we prepared hierarchically porous Cu5Mg10Al5-LDH and used as a matrix for in suit growth of Cu/Cu2O on it... To further improve the removal ability of layered double hydroxide(LDH) for iodide(I^-) anions from wastewater, we prepared hierarchically porous Cu5Mg10Al5-LDH and used as a matrix for in suit growth of Cu/Cu2O on its surface, forming Cu/Cu2O-LDH, which was characterized and applied as an adsorbent.Results displayed high I^-saturation uptake capability(137.8 mg/g) of Cu/Cu2O-LDH compared with Cu5Mg10Al5-LDH(26.4 mg/g) even thermal activated LDH(76.1 mg/g).Thermodynamic analysis showed that the reaction between I^-anions and Cu/Cu2O-LDH is a spontaneous and exothermic.Uptake kinetics analysis exhibited that adsorption equilibrium can be reached after 265 min.Additionally, the adsorbent showed satisfactory selectivity in the presence of competitive anions(e.g., SO4^2-), and could achieve good adsorption performance in a wide pH range of 3–8.A cooperative adsorption mechanism was proposed on the basis of the following two aspects:(1) ion exchange between iodide and interlayer anions;(2) the adsorption performance of Cu, Cu(Ⅱ) and Cu2O for I^-.Meanwhile, the difference between the adsorption mechanism of Cu/Cu2O-LDH, Cu5Mg10Al5-LDH and Cu5Mg10Al5-CLDH adsorbents was also elaborated and verified. 展开更多
关键词 Layered double HYDROXIDE Cu/Cu2O IODIDE adsorption Hierarchical structure In SUIT GROWTH
灵芝多糖的结构及其表征方法研究进展 认领
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作者 张汇 聂少平 +3 位作者 艾连中 夏永军 熊智强 王光强 《中国食品学报》 EI CAS CSCD 北大核心 2020年第1期290-301,共12页
灵芝多糖结构复杂、种类繁多,由于具有良好的生物活性而受到广泛关注。结构是灵芝多糖发挥生物活性的基础,为探明灵芝多糖的构效关系。近年来,有大量关于灵芝多糖结构表征的研究。本文从灵芝多糖的组成、化学结构和溶液构象入手,对灵芝... 灵芝多糖结构复杂、种类繁多,由于具有良好的生物活性而受到广泛关注。结构是灵芝多糖发挥生物活性的基础,为探明灵芝多糖的构效关系。近年来,有大量关于灵芝多糖结构表征的研究。本文从灵芝多糖的组成、化学结构和溶液构象入手,对灵芝多糖的结构特征进行系统概述,结合现代仪器分析技术,总结多糖结构表征的方法学研究进展,以期为灵芝多糖一级结构和高级结构的深入研究提供参考,并为进一步探讨灵芝多糖的构效关系奠定基础。 展开更多
关键词 灵芝 多糖 结构 溶液构象 表征方法
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Modeling of deformation processes in rock massif in the vicinity of underground goafs considering the formation of discontinuity zones 认领
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作者 Michael Zhuravkov Shunying Ji Aleg Kanavalau 《力学快报:英文版》 CAS CSCD 2020年第2期92-97,共6页
The construction of mechanical-mathematical model and numerical method for the deformation processes of rock massifs with goafs and underground structures is very complex and also important task in modern rock mechani... The construction of mechanical-mathematical model and numerical method for the deformation processes of rock massifs with goafs and underground structures is very complex and also important task in modern rock mechanics.In this study,the mechanical-mathematical model is developed for rock massif in vicinity of underground goafs considering the internal block-layered structure of the rock massif.A new constitutive model is introduced in this study to describe the negative Poisson’s ratio for the lock-layered structure.Two types of defining equations systems for studying the state of a rock massif taking into account the block-layered structure are described.Finally,several examples are given using the present mechanical-mathematical model. 展开更多
关键词 Block-layered structure Rock massif Stress-strain state Destruction and limit criteria Negative Poisson's ratio
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DZ125镍基合金表面Al-Ce-Y渗层的组织及抗热腐蚀性能 认领
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作者 李涌泉 李吉林 +2 位作者 秦春 蒋亮 耿桂宏 《中南大学学报:英文版》 SCIE EI CAS CSCD 2020年第2期381-387,共7页
采用扩散渗方法在DZ125合金表面制备了Al-Ce-Y渗层。分析了渗层的组织结构和形成机制,对比研究了DZ125合金基体及渗层在900°C的25%K2SO4+75%Na2SO4熔盐(质量分数wt.%)中的热腐蚀行为,探讨了其腐蚀速率和腐蚀机理。结果表明:经950&#... 采用扩散渗方法在DZ125合金表面制备了Al-Ce-Y渗层。分析了渗层的组织结构和形成机制,对比研究了DZ125合金基体及渗层在900°C的25%K2SO4+75%Na2SO4熔盐(质量分数wt.%)中的热腐蚀行为,探讨了其腐蚀速率和腐蚀机理。结果表明:经950°C保温2 h所制备的Al-Ce-Y渗层厚约120μm,主要由Al3Ni2、Al3Ni和少量Cr7Ni3相组成。在K2SO4+Na2SO4熔盐中,DZ125合金腐蚀产物膜分为两层,外层主要为Cr2O3和NiCr2O4,内层主要为Al2O3、Ni3S2和镍基固溶体,内氧化和内硫化是其失效的主要原因;Al-Ce-Y渗层在热腐蚀的过程中,渗层表面形成了致密的富Al的Al2O3膜层,显著提高了DZ125合金的抗热腐蚀性能。 展开更多
关键词 DZ125合金 Ce-Y改性渗铝涂层 组织 热腐蚀
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