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Synthesis of Citrinin Artificial Antigen and Its Coupling Ratio Determination 被引量:3
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作者 李娇 钟理 +5 位作者 田世民 金涌 崔艳芬 任香夫 祁淑红 刘畅 《Agricultural Science & Technology》 CAS 2010年第8期169-172,共4页
[Objective] This study was to establish a method for the rapid and accurate detection of the coupling ratio of artificial antigen. [Method] Artificial synthetic antigen of citrinin (CIT) was first conjugated with ve... [Objective] This study was to establish a method for the rapid and accurate detection of the coupling ratio of artificial antigen. [Method] Artificial synthetic antigen of citrinin (CIT) was first conjugated with vector protein bovine serum albumin (BSA) and then identified by SDS-PAGE electrophoresis,and its coupling ratio was measured by UV absorption and mass spectrometry. [Result] The identification result showed that artificial antigen of CIT was successfully coupled,and the coupling ratio was 8.4 by UV absorption while 6.0 by mass spectrometry. [Conclusion] The comparison experiment showed that mass spectrometry could rapidly identify the artificial antigen and accurately detect its coupling ratio. This study provided basis for the preparation of CIT antigen as well as the establishment of an for enzyme-linked immunosorbent assay (ELISA) for citrinin determination. 展开更多
关键词 CITRININ Artificial antigen coupling ratio Mass spectrometry
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Efficient Method to Extract Coupling Ratio and Round-trip Loss Parameters of Optical Waveguide Ring Resonator
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作者 HAN Xiu-you PANG Fu-fei +1 位作者 FANG Zu-jie ZHAO Ming-shan 《Semiconductor Photonics and Technology》 CAS 2008年第3期158-161,173,共5页
Based on the measurement of the contrast ratios of the transmission spectra from the throughput and drop ports of ring resonator, an efficient method is proposed to extract the coupling ratio and round-trip loss of th... Based on the measurement of the contrast ratios of the transmission spectra from the throughput and drop ports of ring resonator, an efficient method is proposed to extract the coupling ratio and round-trip loss of the integrated optical waveguide ring resonator. The parameters of a racetrack resonator prepared by ion-exchange technique in K9 optical glass substrate are examined, which demonstrates the validity of this method. The accuracy and applicable range of this method are also discussed. 展开更多
关键词 integrated optics waveguide ring resonator coupling ratio round-trip loss
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Coupling Effects of Depletion Interactions in Three-Sphere Systems with Different Size Ratio of Large- to Small-Sphere
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作者 Zhouan Zhou Dai Gang Changming Xiao 《Journal of Modern Physics》 2013年第6期761-765,共5页
The coupling effects of depletion interactions in three-sphere systems with different size ratio of large- to small-sphere are studied by Monte Carlosimulations in this paper. The numerical results show that this coup... The coupling effects of depletion interactions in three-sphere systems with different size ratio of large- to small-sphere are studied by Monte Carlosimulations in this paper. The numerical results show that this coupling effect is affected by the size ratio of large- to small-sphere: the larger the size ratio is, the larger the coupling effect will be. 展开更多
关键词 coupling Effects of Depletion INTERACTIONS Three-Sphere SYSTEMS SIZE ratio
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Coupling dehydrogenation of isobutane in the presence of carbon dioxide over chromium oxide supported on active carbon 被引量:4
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作者 Jian Fei Ding Zhang Feng Qin +2 位作者 Xue Kuan Li Guo Fu Wang Jian Guo Wang 《Chinese Chemical Letters》 SCIE CAS CSCD 2008年第9期1059-1062,共4页
The dehydrogenation of isobutane (IB) to produce isobutene coupled with reverse water gas shift in the presence of carbon dioxide was investigated over the catalyst Cr2O3 supported on active carbon (Cr2O3/AC). The... The dehydrogenation of isobutane (IB) to produce isobutene coupled with reverse water gas shift in the presence of carbon dioxide was investigated over the catalyst Cr2O3 supported on active carbon (Cr2O3/AC). The results illustrated that isobutane conversion and isobutene yield can be enhanced through the reaction coupling in the presence of carbon dioxide. Moreover, carbon dioxide can partially eliminate carbonaceous deposition on the catalyst and keep the active phase (Cr2O3), which are then helpful to alleviate the catalyst deactivation. 展开更多
关键词 DEHYDROGENATION ISOBUTANE Carbon dioxide ISOBUTENE Reaction coupling cr2O3/AC
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Optimization of Cr/Mo molar ratio in FeCoCrMoCBY alloys for high corrosion resistance 被引量:3
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作者 Cheng-jie WANG Qing-jun CHEN Huai-xiao XIA 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2017年第12期2663-2672,共10页
The corrosion behavior of bulk metallic glasses(BMGs)(Fe41Co7Cr15Mo14C15B6Y2)100-xCrx(x=0,4,8,12,molar fraction,%)was investigated in1mol/L HCl aqueous solution with electrochemical tests.The electrochemical measureme... The corrosion behavior of bulk metallic glasses(BMGs)(Fe41Co7Cr15Mo14C15B6Y2)100-xCrx(x=0,4,8,12,molar fraction,%)was investigated in1mol/L HCl aqueous solution with electrochemical tests.The electrochemical measurements demonstrate that the passive current density of Fe-based amorphous alloy is reduced by about one order of magnitude,and meanwhile,the stability of passive film can be guaranteed by the Cr/Mo molar ratio.The Mott–Schottky(M–S)curves show that the passive film is the densest when the molar ratio of Cr/Mo is between1.37and1.69.X-ray photoelectron spectroscopy(XPS)analysis was performed to clarify chemical states of elements in the passive films.The results show that the corrosion resistance of the alloy is related to the molar ratio of Cr/Mo.The stability of passive film is determined by the synergistic action of Cr and Mo elements.The main component of the passive film is Cr3+oxide.When the potential is greater than0.5V(vs SCE),Mo6+ions play an important role in keeping the stability of the passive film.The appropriate molar ratio of Cr/Mo can reduce the dissolution rate of the passive film. 展开更多
关键词 bulk metallic glasses corrosion resistance passive film electrochemical measurement cr/Mo molar ratio
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Upper Bound Solution of Soil Slope Stability under Coupling Effect of Rainfall and Earthquake 被引量:1
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作者 YIN Xiaojun WANG Lanmin 《Journal of Donghua University(English Edition)》 EI CAS 2019年第4期357-363,共7页
Based on the limit analysis upper bound method,a new model of soil slope collapse has been proposed which consists of two rigid block zones and a plastic shear zone.Soil slope was induced failure by coupling effect of... Based on the limit analysis upper bound method,a new model of soil slope collapse has been proposed which consists of two rigid block zones and a plastic shear zone.Soil slope was induced failure by coupling effect of rainfall and earthquake,and these blocks were also incorporated horizontal earthquake force and vertical gravitate.The velocities and forces were analyzed in three blocks,and the expression of velocity discontinuities was obtained by the principle of incompressibility.The external force work for the blocks,the internal energy of the plastic shear zone and the velocity discontinuous were solved.The present stability ratios are compared to the prevenient research,which shows the superiority of the mechanism and rationality of the analysis.The critical height of the soil slope can provide theoretical basis for slope support and design. 展开更多
关键词 soil slope coupling effect upper BOUND SOLUTION STABILITY ratio EARTHQUAKE RAINFALL
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Investigation of block foundations resting on soil-rock and rock-rock media under coupled vibrations 被引量:1
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作者 Renuka Darshyamkar Ankesh Kumar Bappaditya Manna 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2017年第2期305-317,共13页
In the present study,the dynamic response of block foundations of different equivalent radius to mass(R;/m) ratios under coupled vibrations is investigated for various homogeneous and layered systems.The frequency-d... In the present study,the dynamic response of block foundations of different equivalent radius to mass(R;/m) ratios under coupled vibrations is investigated for various homogeneous and layered systems.The frequency-dependent stiffness and damping of foundation resting on homogeneous soils and rocks are determined using the half-space theory.The dynamic response characteristics of foundation resting on the layered system considering rock-rock combination are evaluated using finite element program with transmitting boundaries.Frequencies versus amplitude responses of block foundation are obtained for both translational and rotational motion.A new methodology is proposed for determination of dynamic response of block foundations resting on soil-rock and weathered rock-rock system in the form of equations and graphs.The variations of dimensionless natural frequency and dimensionless resonant amplitude with shear wave velocity ratio are investigated for different thicknesses of top soil/weathered rock layer.The dynamic behaviors of block foundations are also analyzed for different rock-rock systems by considering sandstone,shale and limestone underlain by basalt.The variations of stiffness,damping and amplitudes of block foundations with frequency are shown in this study for various rock—rock combinations.In the analysis,two resonant peaks are observed at two different frequencies for both translational and rotational motion.It is observed that the dimensionless resonant amplitudes decrease and natural frequencies increase with increase in shear wave velocity ratio.Finally,the parametric study is performed for block foundations with dimensions of 4 m × 3 m × 2 m and 8m×5m×2m by using generalized graphs.The variations of natural frequency and peak displacement amplitude are also studied for different top layer thicknesses and eccentric moments. 展开更多
关键词 Rock-rock system Block foundation coupled vibration Homogeneous medium Equivalent radius to mass ratio Half-space theory
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Interfacial coupling effects in g-C_(3)N_(4)/In_(x)Sb_(2-x)S_(3) heterojunction for enhanced photocatalytic activity under visible light 被引量:3
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作者 YANG Ting HU Xin-yu +2 位作者 WANG Jun-tao YANG Tian-li WANG Wen-lei 《Journal of Central South University》 SCIE EI CAS CSCD 2022年第5期1447-1462,共16页
A series of In_(x)Sb_(2-x)S_(3) nanosheets modified g-C_(3)N_(4)(In_(x)Sb_(2-x)S_(3)-TCN)heterojunctions with different g-C_(3)N_(4) contents were fabricated by an in situ deposition method.All the In_(x)Sb_(2-x)S_(3)... A series of In_(x)Sb_(2-x)S_(3) nanosheets modified g-C_(3)N_(4)(In_(x)Sb_(2-x)S_(3)-TCN)heterojunctions with different g-C_(3)N_(4) contents were fabricated by an in situ deposition method.All the In_(x)Sb_(2-x)S_(3)-TCN composites were applied as photocatalysts in Cr(Ⅵ)polluted water treatment and the results displayed that In_(x)Sb_(2-x)S_(3)-TCN could effectively remove Cr(Ⅵ)under visible light through synergistic effects of adsorption and photocatalytic reduction.Especially,In_(x)Sb_(2-x)S_(3)-TCN-70(70 mg g-C_(3)N_(4)) exhibited the most excellent adsorption and photocatalytic reduction performance among all composites,which possessed a high equilibrium adsorption capacity of 12.45 mg/g in a 30.0 mg/L Cr(Ⅵ)aqueous solution,and reduced Cr(Ⅵ)to Cr(Ⅲ)within 10 min under visible light irradiation.DRS and PL results indicated that the interfacial coupling effect between g-C_(3)N_(4)and In_(x)Sb_(2-x)S_(3) enhanced the utilization efficiency of visible light and suppressed photoinduced carrier recombination,which improved the photocatalytic activity of composites.Moreover,the photocatalyst exhibited satisfactory reduction activity and good stability after 5 cycles of Cr(Ⅵ)adsorptionphotoreduction. 展开更多
关键词 In_(x)Sb_(2-x)S_(3)-TCN PHOTOCATALYST interfacial coupling effects cr(Ⅵ)-contained wastewater adsorption photocatalytic reduction
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导流管参数对真空紧耦合气雾化法制备Fe-Cr合金粉末的影响 被引量:1
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作者 苏才津 孙耀宁 +3 位作者 董开基 尹燕 张瑞华 姜立恒 《粉末冶金技术》 CAS CSCD 北大核心 2024年第1期68-74,共7页
采用真空紧耦合气雾化法制备Fe–Cr合金粉末,研究了导流管直径与导流管伸出长度对Fe–Cr合金粉末粒度分布、收得率、中位粒径(D_(50))的影响。结果表明,在其他工艺参数不变的情况下,当导流管直径从4.5 mm增大到6.0 mm时,Fe–Cr合金粉末... 采用真空紧耦合气雾化法制备Fe–Cr合金粉末,研究了导流管直径与导流管伸出长度对Fe–Cr合金粉末粒度分布、收得率、中位粒径(D_(50))的影响。结果表明,在其他工艺参数不变的情况下,当导流管直径从4.5 mm增大到6.0 mm时,Fe–Cr合金粉末累积粒度分布曲线右移,中位粒径增大,细粉收得率减小,粉末流动性减小,松装密度减小;当导流管伸出长度由2.0 mm增加到2.5 mm时,Fe–Cr合金粉末累积粒度分布曲线左移,中位粒径减小,细粉收得率增加,粉末流动性增加,松装密度升高。综上所述,雾化压力3.8 MPa,过热度250℃,导流管直径4.5 mm,导流管伸出长度2.5 mm,制备得到的Fe–Cr合金粉末综合性能最优。 展开更多
关键词 真空紧耦合气雾化法 Fe–cr金属粉末 导流管 粉末性能
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Critical Cyclic Stress Ratio of Undisturbed Saturated Soft Clay in the Yangtze Estuary under Complex Stress Conditions
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作者 刘功勋 栾茂田 +2 位作者 唐小微 王忠涛 郭莹 《Transactions of Tianjin University》 EI CAS 2010年第4期295-303,共9页
There exists a critical cyclic stress ratio when sand or clay is subjected to cyclic loading. It is an index dis-tinguishing stable state or failure state. The soil static and dynamic universal triaxial and torsional ... There exists a critical cyclic stress ratio when sand or clay is subjected to cyclic loading. It is an index dis-tinguishing stable state or failure state. The soil static and dynamic universal triaxial and torsional shear apparatus de-veloped by Dalian University of Technology in China was employed to perform different types of tests on saturated soft marine clay in the Yangtze estuary. Undisturbed samples were subjected to undrained cyclic vertical and torsional coupling shear and cyclic torsional shear after three-directional anisotropic consolidation with different initial consoli-dation parameters. The effects of initial orientation angle of major principal stress, initial ratio of deviatoric stress,initial coefficient of intermediate principal stress and stress mode of cyclic shear on the critical cyclic stress ratio wereinvestigated. It is found that the critical cyclic stress ratio decreases significantly with increasing initial orientation angle of major principal stress and initial ratio of deviatoric stress. Compared with the effects of the initial orientationangle of major principal stress and initial ratio of deviatoric stress, the effect of initial coefficient of intermediate prin-cipal stress is less evident. Under the same consolidation condition, the critical cyclic stress ratio from the cyclic cou-pling shear test is lower than that from the cyclic torsional shear test, indicating that the stress mode of cyclic shear has an obvious effect on the critical cyclic stress ratio. The main reason is that the continuous rotation in principal stressdirections during cyclic coupling shear damages the original structure of soil more than the cyclic torsional shear does. 展开更多
关键词 complex stress condition undisturbed saturated soft clay critical cyclic stress ratio three-directional anisotropic consolidation cyclic coupling shear cyclic torsional shear
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Unity Formulas for the Coupling Constants and the Dimensionless Physical Constants
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作者 Stergios Pellis 《Journal of High Energy Physics, Gravitation and Cosmology》 CAS 2023年第1期245-294,共50页
In this paper in an elegant way will be presented the unity formulas for the coupling constants and the dimensionless physical constants. We reached the conclusion of the simple unification of the fundamental interact... In this paper in an elegant way will be presented the unity formulas for the coupling constants and the dimensionless physical constants. We reached the conclusion of the simple unification of the fundamental interactions. We will find the formulas for the Gravitational constant. It will be presented that the gravitational fine-structure constant is a simple analogy between atomic physics and cosmology. We will find the expression that connects the gravitational fine-structure constant with the four coupling constants. Perhaps the gravitational fine-structure constant is the coupling constant for the fifth force. Also will be presented the simple unification of atomic physics and cosmology. We will find the formulas for the cosmological constant and we will propose a possible solution for the cosmological parameters. Perhaps the shape of the universe is Poincare dodecahedral space. This article will be followed by the energy wave theory and the fractal space-time theory. 展开更多
关键词 Fine-Structure Constant Proton To Electron Mass ratio Dimensionless Physical Constants coupling Constant Gravitational Constant Avogadro’s Number Fundamental Interactions Gravitational Fine-Structure Constant Cosmological Constant
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Effect of coil and chamber structure on plasma radial uniformity in radio frequency inductively coupled plasma
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作者 赵洋 周晓华 +2 位作者 高升荣 宋莎莎 赵玉真 《Plasma Science and Technology》 SCIE EI CAS CSCD 2024年第7期58-66,共9页
Enhancing plasma uniformity can be achieved by modifying coil and chamber structures in radio frequency inductively coupled plasma(ICP)to meet the demand for large-area and uniformly distributed plasma in industrial m... Enhancing plasma uniformity can be achieved by modifying coil and chamber structures in radio frequency inductively coupled plasma(ICP)to meet the demand for large-area and uniformly distributed plasma in industrial manufacturing.This study utilized a two-dimensional self-consistent fluid model to investigate how different coil configurations and chamber aspect ratios affect the radial uniformity of plasma in radio frequency ICP.The findings indicate that optimizing the radial spacing of the coil enhances plasma uniformity but with a reduction in electron density.Furthermore,optimizing the coil within the ICP reactor,using the interior point method in the Interior Point Optimizer significantly enhances plasma uniformity,elevating it from 56%to 96%within the range of the model sizes.Additionally,when the chamber aspect ratio k changes from 2.8 to 4.7,the plasma distribution changes from a center-high to a saddleshaped distribution.Moreover,the plasma uniformity becomes worse.Finally,adjusting process parameters,such as increasing source power and gas pressure,can enhance plasma uniformity.These findings contribute to optimizing the etching process by improving plasma radial uniformity. 展开更多
关键词 inductively coupled plasma fluid simulation optimized coil chamber aspect ratio plasma uniformity
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Cr^(3+)掺杂对Mn_(3)O_(4)结构、形貌以及磁电性能的影响
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作者 崔梦范 王松伟 +4 位作者 张鑫 杨瑞鑫 张亚乐 邓胜龙 周欣 《桂林电子科技大学学报》 2024年第3期292-298,共7页
为了探究Cr^(3+)掺杂对Mn_(3)O_(4)体系磁电效应的影响,采用传统固相法成功制备了Mn_(3)O_(4)及Mn_(1.8)Cr_(1.2)O_(4)的单相多晶样品。X射线衍射及精修结果表明,掺杂前后存在晶体结构的改变,由四方晶系转变为立方晶系,其空间群由I41/am... 为了探究Cr^(3+)掺杂对Mn_(3)O_(4)体系磁电效应的影响,采用传统固相法成功制备了Mn_(3)O_(4)及Mn_(1.8)Cr_(1.2)O_(4)的单相多晶样品。X射线衍射及精修结果表明,掺杂前后存在晶体结构的改变,由四方晶系转变为立方晶系,其空间群由I41/amd变为Fd3m。场发射扫描电镜结果显示,掺杂前样品的晶粒呈紧密的镶嵌结构,掺杂后样品呈离散的五面体及八面体形貌,且尺寸约是掺杂前的1/8。磁性研究结果表明,掺杂前、后样品Yafet-Kittel型亚铁磁相变温度由43 K提高到60 K,这源自Cr^(3+)掺杂使Mn^(3+)(Cr^(3+))/Mn^(2+)—O键长缩短,Mn^(3+)(Cr^(3+))—O—Mn^(3+)(Cr^(3+))键角增大,磁相互作用增强。此外,掺杂后矫顽力显著降低,这可根据离散的晶粒间作用力减小来理解。介电效应研究发现,掺杂前、后样品在磁相变点附近存在不随频率移动的介电异常峰,表明该体系存在与磁序相关的铁电极化,这源自体系的非线性磁结构。 展开更多
关键词 固相法 cr^(3+)掺杂 磁性测量 介电测量 磁电耦合
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Applications of Compliance to Cost Ratio (C-CR) Analysis in the Determination of Optimum Mix of Insulating Bricks in Masonry
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作者 Davies Oladayo Folorunso Abayomi Adewale Akinwande 《Journal of Minerals and Materials Characterization and Engineering》 2021年第2期134-147,共14页
The scarcity of housing increases as population continues to rise all over the world. Despite government efforts at providing houses, yearly demand keeps on exceeding available houses and hence the hike in rent, the c... The scarcity of housing increases as population continues to rise all over the world. Despite government efforts at providing houses, yearly demand keeps on exceeding available houses and hence the hike in rent, the cost of erecting houses and the cost of building materials. This ultimately calls for a decisive solution. This study therefore applied compliance to cost ratio (C-CR) analysis in evaluating the optimum properties of fired ceramic bricks. The optimum mix proportions of waste glass (WG) and wood saw dust (WSD) in fired bricks, that will be suitable for housing constructions were hence determined. Fired clay brick samples which contained varied proportions of WG and WSD were examined for physical, mechanical and thermal properties in line with standard procedures. The results were compared with existing standards and property evaluation index, compliance level and C-CR were applied in analyzing the results obtained. It was observed that with increasing WG content, compliance level increased. Also, cost ratio and experimental cost of each brick sample trended upward. Sample with mix proportion;20 wt% WG, 5 wt% WSD and 75 wt% clay had compliance level of 94% and C-CR index of 7.81, hence chosen as optimum mix proportion for masonry bricks. 展开更多
关键词 Properties Evaluation HOUSING Fired Clay Bricks Compliance to Cost ratio (C-cr) and Masonry
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Preliminary Study of CAS-LIBB Single-Particle MicrobeamⅡEndstation:Ⅱ.Considerations for Choosing the Right CCD Camera
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作者 胡智文 许永建 余增亮 《Plasma Science and Technology》 SCIE EI CAS CSCD 2006年第4期497-501,共5页
The proposed multi-dimensional quantitative fluorescence microscopy for the CASLIBB single-particle microbeam II endstation is a CCD-based imaging system. We systematically analyse the theoretical and the practical co... The proposed multi-dimensional quantitative fluorescence microscopy for the CASLIBB single-particle microbeam II endstation is a CCD-based imaging system. We systematically analyse the theoretical and the practical considerations pertinent to choosing the right CCD camera and unveiling the principles underlying multifarious parameters. Therefore, this analysis can be a valuable tool in scrutinizing each parameter and clarifying proper usage of a scientific CCD camera. 展开更多
关键词 single-particle microbeam quantitative fluorescence microscopy Charge-coupled Device (CCD) camera signal-to-noise ratio
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功能化石墨烯复合吸附剂对Cr(Ⅵ)的吸附性能
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作者 刘小静 李俊燕 +2 位作者 党泽静 祖丹怡 吴代文 《化工科技》 CAS 2024年第2期22-27,共6页
以氧化石墨烯(GO)、聚乙烯醇(PVA)为原料,3-缩水甘油醚氧基丙基三甲氧基硅烷(GLYMO)为桥接剂,采用原位水热法制备氧化石墨烯/聚乙烯醇(GPGO)复合吸附剂。借助红外、扫描电镜等表征GPGO的结构,通过静态吸附实验探索m(GLYMO)、pH值、吸附... 以氧化石墨烯(GO)、聚乙烯醇(PVA)为原料,3-缩水甘油醚氧基丙基三甲氧基硅烷(GLYMO)为桥接剂,采用原位水热法制备氧化石墨烯/聚乙烯醇(GPGO)复合吸附剂。借助红外、扫描电镜等表征GPGO的结构,通过静态吸附实验探索m(GLYMO)、pH值、吸附时间、Cr(Ⅵ)初始质量浓度、共存阴离子对GPGO吸附Cr(Ⅵ)性能的影响。结果表明,GLYMO的桥接作用和强酸环境可极大地促进GPGO对Cr(Ⅵ)的吸附。二级动力学和Langmuir等温吸附模型能够很好地描述GPGO对Cr(Ⅵ)的吸附过程,由Langmuir模型计算出GPGO吸附剂对Cr(Ⅵ)的最大吸附量为384.6 mg/g。Cl^(-)和NO^(-)_(3)的存在对GPGO吸附Cr(Ⅵ)性能影响不大,但SO^(2-)_(4)对该吸附过程产生较强的抑制作用。 展开更多
关键词 石墨烯 聚乙烯醇 偶联 cr(Ⅵ) 吸附
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CHF患者CRP/Alb、PDGF、BUN/Cr水平变化及对预后的评估价值
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作者 宋鑫 先本婧 刘峥嵘 《河北医药》 CAS 2024年第1期34-38,共5页
目的 探讨慢性心力衰竭(CHF)患者C-反应蛋白与白蛋白比值(CRP/Alb)、血小板源性生长因子(PDGF)联合血尿素氮与肌酐比值(BUN/Cr)水平变化,并分析各指标预测心血管死亡和全因死亡的效能。方法 选取2020年1月至2022年3月收治的109例CHF患者... 目的 探讨慢性心力衰竭(CHF)患者C-反应蛋白与白蛋白比值(CRP/Alb)、血小板源性生长因子(PDGF)联合血尿素氮与肌酐比值(BUN/Cr)水平变化,并分析各指标预测心血管死亡和全因死亡的效能。方法 选取2020年1月至2022年3月收治的109例CHF患者,根据1年内心血管死亡和全因死亡情况分为死亡组(26例)和存活组(83例)。比较2组社会人口学资料和临床特征[美国纽约心脏病学会心功能分级(NYHA)、左心室射血分数、左心室舒张末期内径、左心室收缩末期内径、N-末端脑钠肽前体(NT-proBNP)、临床用药]、CRP/Alb、PDGF、BUN/Cr水平,分析CRP/Alb、PDGF、BUN/Cr水平的相关性,采用Cox回归分析CHF患者心血管死亡和全因死亡的相关影响因素,采用受试者工作特征曲线(ROC)分析预测价值,采用卡普兰-迈耶曲线(K-M)生存曲线分析不同CRP/Alb、PDGF、BUN/Cr水平患者的生存率。结果 死亡组NYHA心功能分级、左心室舒张末期内径、左心室收缩末期内径、NT-proBNP高于存活组,左心室射血分数低于存活组(P<0.05);死亡组CRP/Alb、PDGF、BUN/Cr高于存活组(P<0.05);CHF患者CRP/Alb与PDGF、BUN/Cr呈正相关,PDGF与BUN/Cr呈正相关(P<0.05);在校正了NYHA心功能分级等混杂因素后,CRP/Alb、PDGF、BUN/Cr仍是CHF患者心血管死亡和全因死亡的相关影响因素(P<0.05);CRP/Alb、PDGF、BUN/Cr预测心血管死亡和全因死亡的ROC下面积(AUC)分别为0.712、0.801、0.738,三者联合时的AUC为0.911(P<0.05);CRP/Alb、PDGF、BUN/Cr高水平患者生存率低于低水平患者(P<0.05)。结论 CRP/Alb、PDGF、BUN/Cr与CHF患者心血管死亡和全因死亡有关,联合检测可作为预测患者病情转归的一个方案,为临床评估预后、治疗等提供参考依据。 展开更多
关键词 crP/Alb PDGF BUN/cr 慢性心力衰竭 心血管死亡 全因死亡
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中坝遗址地层的Cr/Cu值对干湿环境的指示意义 被引量:10
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作者 李中轩 朱诚 +3 位作者 朱青 马春梅 张广胜 欧阳杰 《地理科学》 CSCD 北大核心 2008年第6期799-803,共5页
将中坝遗址5 ka以来连续沉积地层按文化序列分为12层,分别测量Rb、Sr和Cr、Cu含量,对比显示,Cr/Cu比值与Rb/Sr比值明显正相关。Cr与Rb的属性相似,Cr化学活性低,易于在粉砂质沉积物中富集;而Cu和Sr在成壤过程中容易迁移,在粘土质沉积层... 将中坝遗址5 ka以来连续沉积地层按文化序列分为12层,分别测量Rb、Sr和Cr、Cu含量,对比显示,Cr/Cu比值与Rb/Sr比值明显正相关。Cr与Rb的属性相似,Cr化学活性低,易于在粉砂质沉积物中富集;而Cu和Sr在成壤过程中容易迁移,在粘土质沉积层中含量较高。通过对Cr、Cu元素在表生环境下的化学性质、沉积地层的属性、微地貌特征、与泥炭腐殖化度古里雅冰芯氧同位素曲线等指标对比表明,Cr/Cu比值变化对环境干湿变化的指示具有普遍意义。 展开更多
关键词 中坝遗址 cr/Cu值 Rb/Sr值
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Cr-Cu/SiO_2 催化剂上顺酐和1,4-丁二醇的耦合反应 被引量:9
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作者 沈伟 潘超 +1 位作者 杨新艳 徐华龙 《化学学报》 SCIE CAS CSCD 北大核心 2008年第11期1287-1292,共6页
研究了Cr-Cu/SiO2催化剂上顺酐加氢反应和1,4-丁二醇脱氢反应耦合制备重要的精细化学品γ-丁内酯.耦合反应显著提高了顺酐转化率和γ-丁内酯选择性.Cr修饰提高了催化剂的脱氢活性,抑止了催化剂的过度加氢活性,使1,4-丁二醇的转化率和γ... 研究了Cr-Cu/SiO2催化剂上顺酐加氢反应和1,4-丁二醇脱氢反应耦合制备重要的精细化学品γ-丁内酯.耦合反应显著提高了顺酐转化率和γ-丁内酯选择性.Cr修饰提高了催化剂的脱氢活性,抑止了催化剂的过度加氢活性,使1,4-丁二醇的转化率和γ-丁内酯选择性显著提高.Cr修饰量为w=5%的Cr-Cu/SiO2催化剂上耦合反应的原料转化率为100%,γ-丁内酯选择性达98.8%.XRD,XPS等研究表明,Cr修饰促进了催化剂上铜元素的分散,氧化铬对氧化铜有给电子作用,Cr修饰的Cr-Cu/SiO2催化剂还原后比Cu/SiO2具有更多的Cu+,这有利于催化剂脱氢活性和γ-丁内酯选择性的提高. 展开更多
关键词 顺丁烯二酸酐 1 4-丁二醇 Γ-丁内酯 耦合反应 cr-Cu/SiO2
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高温均质化对高碳Cr合金钢锭组织和元素分布的影响 被引量:9
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作者 彭坤 金曼 +2 位作者 张洪奎 杨弋涛 邵光杰 《上海金属》 CAS 2010年第1期15-18,共4页
采用光学显微镜、扫描电镜及能谱仪分析了含铬合金钢锭铸态及均质化后的显微组织和元素偏析规律,旨在确定钢锭的高温均质化工艺。研究结果表明,经过1160℃、1210℃和1260℃分别进行6h和12h的均质化处理后,含铬合金钢锭的元素偏析得到不... 采用光学显微镜、扫描电镜及能谱仪分析了含铬合金钢锭铸态及均质化后的显微组织和元素偏析规律,旨在确定钢锭的高温均质化工艺。研究结果表明,经过1160℃、1210℃和1260℃分别进行6h和12h的均质化处理后,含铬合金钢锭的元素偏析得到不同程度的改善,1260℃保温12h的均质化处理效果最为理想,而1210℃保温6h的均质化最为经济实用。 展开更多
关键词 高碳cr合金钢 高温均质化 偏析比
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