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quantitative relationship between flagellate abundance and suspended particle density in Huanghai Sea and East China Sea in summer

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Acta Oceanologica Sinica 2006年第2期25卷 109-118页

作者： HUANG Lingfeng PAN Ke GUO Feng Department of Oceanography ＆ Institute of Subtropical Oceanography Xiamen University Xiamen 361005 China State Key Laboratory of Marine Environmental Science Xiamen University Xiamen 361005 China

An investigation was carried out in the Huanghai Sea and the East China Sea to study the quantitative relationship between the abundance of flagellates and the density of suspended particles in the summer of 2001. The results show that the abundance of flagellates varies from 44-12 600 cell/cm^3, and flagellates sometimes constitutes a significant part of suspended particles. The size-spectra of suspended particles can be divided into four categories： flat spectrum, humped spectrum, plankton spectrum and mixed spectrum. In general, the abundance of flagellates varies in proportion to the density of suspended particles. However, their quantitative relations reveal different characteristics in the seawater samples of different types of particle-size spectrum. This is only a preliminary study of the quantitative relationship between flagellates and suspended particles, which might lead to a potential convenient approach to the estimation of flagellate abundance in the sea.

关键词： marine flagellates suspended particles particle-size spectra quantitative relationship

Deformation mechanism of fine structure and its quantitative relationship with quasi-static mechanical properties in near β-type Ti-4.5Mo-5.1Al-1.8Zr-1.1Sn-2.5Cr-2.9Zn alloy

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Progress in Natural Science:Materials International 2021年第5期31卷 742-748页

作者： Xinjie Zhu Qunbo Fan Duoduo Wang Haichao Gong Yu Gao Hong Yu Xingwang Cheng Zhiming Zhou Liu Yang National Key Laboratory of Science and Technology on Materials Under Shock and Impact School of Materials Science and Engineering Beijing Institute of Technology Beijing Institute of Technology Chongqing Innovation Center School of Materials Science and Engineering Chongqing University of Technology Chengdu Advanced Metal Materials Industrial Technology Research Institute Co.Ltd.

The deformation mechanism of the fine structure composed of primary α phase(αp) and acicular secondary αphase(αs) on quasi-static mechanical properties is still not very clear. The main controversy is focused on the role of αpin the mechanical behavior. In this paper, the microstructure of the heat-treated near β-type Ti-4.5 Mo-5.1 Al-1.8 Zr-1.1 Sn-2.5 Cr-2.9 Zn alloy after tensile tests was observed by transmission electron microscopy(TEM). And the results showed that in the slight deformation region the dislocations were accumulated at the intersection ofαpand β matrix separated by αs, while only a few dislocations nucleated in β matrix. In the severe deformation region, a large quantity of dislocations in both αpand β matrix were observed. It can be inferred that αpdeformed firstly and then activated the deformation of β matrix, that is, the thickness of αpand the inter-particle spacing ofαsplayed a dominant role in the deformation process. The quantitative relationship between the yield strength and the microstructure parameters is consistent with this inference. By adjusting the solution treatment parameters and the subsequent aging treatment, three fine structures were obtained, and the corresponding mechanical properties were determined. Furthermore, the yield strength can be described by the mathematical model σy= 756.4 + 135.6/hp1/2+32.2/ds1/2, where hpand dsare the thickness of αpand the inter-particle spacing of αs,respectively.

关键词： Deformation mechanism Fine structure quantitative relationship Titanium alloy

长江下游潮汐河段航道与边心滩演变的定量关系——对河流治理的启示

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Journal of Geographical Sciences 2021年第12期31卷 1837-1851页

作者：杨云平郑金海张蔚朱玉德柴元方王建军闻云呈 State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai UniversityNanjing 210098China Tianjin Research Institute for Water Transport Engineering Ministry of TransportTianjin 300456China Vrije Universiteit Amsterdam Department of Earth SciencesBoelelaan 10851081 HV Amsterdamthe Netherlands Nanjing Hydraulic Research Institute Nanjing 210029China

Deep-water navigation channels in the tidal reaches of the lower Yangtze River are affected by water and sediment fluxes that produce complex shoals and unstable channel *** Fujiangsha reach is particularly difficult to manage,as it has many braided channels within the tidal fluctuation *** this study,hydrologic and topographic data from the Fujiangsha reach from 2012 to 2017 were used to examine the variations in deposition and erosion,flow diversion,shoals,and channel *** the Three Gorges Dam became operational and water storage was initiated,the Fujiangsha reach has shown an overall tendency toward *** deeper than 10 m accounted for 83.7% of the total erosion of the Fujiangsha reach during ***,the dominant channel-forming sediments have gradually changed from suspended sediments to a mixed load of suspended and bed-load *** volumes of these sediments has varied significantly among different channels,but has mainly occurred in the Fubei ***,periodic variations in the Jingjiang point bar have followed a deposition-erosion-deposition pattern,and the downstream Shuangjian shoal mid-channel bar has been scoured and *** 44.0% of the bed load from the upstream Fujiangsha reach is deposited within the 12.5-m deep Fubei *** increased erosion and river flow from the Jingjiang point bar and the Shuangjian shoal during the flood season constituted 59.3% and 40.7%,respectively,of the total amount of siltation in the Fubei channel.

关键词： tidal current fluctuating reach point and central bar channel conditions quantitative relationship lower reaches of the Yangtze River Fujiangsha reach

Regulating off-centering distortion maximizes photoluminescence in halide perovskites

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National Science Review 2021年第9期8卷 60-67页

作者： Xujie Lu Constantinos Stoumpos Qingyang Hu Xuedan Ma Dongzhou Zhang Songhao Guo Justin Hoffman Kejun Bu Xiaofeng Guo Yingqi Wang Cheng Ji Haijie Chen Hongwu Xu Quanxi Jia Wenge Yang Mercouri G.Kanatzidis Ho-Kwang Mao Center for High Pressure Science and Technology Advanced Research Department of Chemistry Northwestern University Department of Materials Science and Technology Voutes Campus University of Crete Center for Nanoscale Materials Argonne National Laboratory Partnership for Extreme Crystallography University of Hawaii at Manoa Department of Chemistry and Alexandra Navrotsky Institute for Experimental Thermodynamics Washington State University Earth and Environmental Sciences Division Los Alamos National LaboratoryLos Alamos Department of Materials Design and Innovation University at Buffalo The State University of New York

Metal halide perovskites possess unique atomic and electronic configurations that endow them with high defect tolerance and enable high-performance photovoltaics and optoelectronics. Perovskite light-emitting diodes have achieved an external quantum efficiency of over 20%. Despite tremendous progress,fundamental questions remain, such as how structural distortion affects the optical properties. Addressing their relationships is considerably challenging due to the scarcity of effective diagnostic tools during structural and property tuning as well as the limited tunability achievable by conventional methods. Here,using pressure and chemical methods to regulate the metal off-centering distortion, we demonstrate the giant tunability of photoluminescence (PL) in both the intensity (>20 times) and wavelength(>180 nm/GPa) in the highly distorted halide perovskites [CH3NH3GeI3, HC(NH2)2GeI3, and Cs Ge I3].Using advanced in situ high-pressure probes and first-principles calculations, we quantitatively reveal a universal relationship whereby regulating the level of off-centering distortion towards 0.2 leads to the best PL performance in the halide perovskites. By applying this principle, intense PL can still be induced by substituting CH3NH~3+with Cs~+to control the distortion in (CH3NH3)1-xCsxGeI3, where the chemical substitution plays a similar role as external pressure. The compression of a fully substituted sample of CsGe I3further tunes the distortion to the optimal value at 0.7 GPa, which maximizes the emission with a10-fold enhancement. This work not only demonstrates a quantitative relationship between structural distortion and PL property of the halide perovskites but also illustrates the use of knowledge gained from high-pressure research to achieve the desired properties by ambient methods.

关键词： halide perovskites high pressure off-centering distortion optical properties lone-pair electrons quantitative relationship

Numerical Study of the Intensity Correlation between Secondary Flow and Heat Transfer of Circle Tube-Finned Heat Exchanger with Vortex Generators

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Computer Modeling in Engineering & Sciences 2020年第4期123卷 237-256页

作者： Yong Guan Wanling Hu Yun Zhang Kewei Song Liangbi Wang School of Environmental and Municipal Engineering Lanzhou Jiaotong UniversityLanzhouChina Key Laboratory of Railway Vehicle Thermal Engineering(Lanzhou Jiaotong University) Ministry of Education of ChinaLanzhouChina Department of Mechanical Engineering Lanzhou Jiaotong UniversityLanzhouChina

The application of vortex generators in tube-finned heat exchangers is very *** vortex generators can generate secondary flow,and as we all know secondary flow can obviously strengthen heat *** use vortex generators much more efficiently in the circle tube-finned heat exchangers,the intensity correlation study between secondary flow and heat transfer is needed.22 different structures of circle tube-finned heat exchangers were numerically studied,including the plain fin cases and the cases with vortex *** addition,the influence of fin spacing,transverse and longitudinal tube pitch,heights and attack angle of vortex generators,positions of vortex generators and shape of vortex generators on heat transfer and fluid flow are studied,*** non-dimensional parameter Se is applied to quantify the secondary flow *** results show that Se can describe the secondary flow intensity very *** is very close corresponding relationship between overall averaged Nu and volumetrically averaged Se for all the researched cases and the relational expression is ***,there is no one-to-one correlation not only between Re and f but also between volumetrically averaged Se and f for all the studied cases.

关键词： Enhanced heat transfer numerical analysis quantitative relationship secondary flow.

STUDY ON PCT CURVE FOR Zr-Ni HYDROGEN STORAGE AMORPHOUS ALLOY

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Journal of Wuhan University of Technology(Materials Science) 1999年第4期14卷 53-56页

作者： ZHANG Dongming FU Zhengyi Wuhan University of Technology Wuhan University of Technology China State Key Lab Adv. Technol. Mat. S. Wuhan University of Technology Wuhan 430070 China

Based on the comprehensive analysis of hydrogen storageexperimental results for Zr-Ni amor- phous alloy, the quantitativerelationship of PCT curve was established, the calculated results areconsistent with experimenta... 详细信息

关键词： quantitative relationship PCT curve amor phous alloy

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