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Floral display and breeding system of Jatropha curcas L.

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Forestry Studies in China 2007年第2期9卷 114-119页

作者： luo Chang-wei Li kun Chen You Sun Yong-yu Research Institute of Insect Resources Chinese Academy of Forestry Kunming 650224 P. R. China yunnan Provincial Forestry Vocational College Kunming 650224 P. R. China

Plant flowering and breeding characteristics are important for us to understand the reproduction of plant populations. In this paper, we studied the reproduction characteristics of Jatropha curcas in yuanjiang County （23°36＇1＇4, 101°00＇E）, yunnan Province. The plant produces flowers in dichasial inflorescences. Normally, the flowers are unisexual, and male and female flowers are produced in the same inflorescence. Only a few male flowers are produced in an inflorescence, and fruits are produced only through pollination between different flowers from the same or different plants. By the treatments of emasculation, bagging and artificial pollination in this experiment, there were few but same fruit set ratios when the inflorescences were emasculated, bagged, or bagged with net, except artificial pollination treatments, which showed that Jatropha curcas could produce fruit through apomixis but not wind pollination. When the inflorescences were unbagged, unemasculated and with free pollination treatments, or bagged, emasculated and with artificial cross-pollination treatments, or unbagged, emasculated and with free pollination treatments, there were many fruits produced. It showed that Jatropha curcas shows outcrossing, is self-compatible, and demanding for pollinators. Normally, the male flowers open first and a few flowers bloom in one day in a raceme. These flowers last a long time in bloom. However, a large number of female flowers open from the third to the fifth day, with some female flowers opening first in a few raceme. This shows a tendency to promote xenogamy and minimize geitonogamy.

关键词： Jatropha curcas floral display breeding system outcrossing index pollen-ovule ratio

Towards precise synthesis of functional polymers by iterative electropolymerization

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Science China Chemistry 2020年第9期63卷 1175-1176页

作者： kun Tang yu-Wu Zhong Beijing National Laboratory for Molecular Sciences CAS Key Laboratory of PhotochemistryCAS Research/Education Center for Excellence in Molecular SciencesInstitute of ChemistryChinese Academy of SciencesBeijing 100190China School of Chemical Sciences University of Chinese Academy of SciencesBeijing 100049China

The controllable synthesis of polymers and macromolecules with precise structures is one of the biggest challenges in polymer chemistry[1].Although polymers with welldefined architectures and compositions could now be prepared by various living polymerization techniques[1],it remains elusive to produce macromolecular materials with precise controls of monomer sequences and easy purification procedures.

关键词： precise polymerization synthesis

Finite particle method for kinematically indeterminate bar assemblies

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第5期10卷 669-676页

作者： Ying yu Yao-zhi luo Space Structures Research Center Zhejiang University Hangzhou 310058 China

This study presents a structural analysis algorithm called the finite particle method （FPM） for kinematically indeterminate bar assemblies. Different from the traditional analysis method, FPM is based on the combination of the vector mechanics and numerical calculations. It models the analyzed domain composed of finite particles. Newton＇s second law is adopted to describe the motions of all particles. A convected material flame and explicit time integration for the solution procedure is also adopted in this method. By using the FPM, there is no need to solve any nonlinear equations, to calculate the stiffness matrix or equilibrium matrix, which is very helpful in the analysis of kinematically indeterminate structures. The basic formulations for the space bar are derived, following its solution procedures for bar assemblies. Three numerical examples are analyzed using the FPM. Results obtained from both the straight pretension cable and the suspension cable assembly show that the FPM can produce a more accurate analysis result. The motion simulation of the four-bar space assembly demonstrates the capability of this method in the analysis ofkinematically indeterminate structures.

关键词： Finite particle method (FPM) Vector mechanics Convected material frame Explicit time integrations Kinematicallyindeterminate bar assemblies

Assessment of Heavy Metal Pollution in Estuarine Surface Sediments of Tangxi River in Chaohu Lake Basin

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Chinese Geographical Science 2010年第1期20卷 9-17页

作者： LI Ruzhong SHU kun luo yueying SHI Yong School of Resources and Environmental Engineering Hefei University ofTechnology Hefei 230009 China School of Chemistry and Materials Science University of Science and Technology of China Hefei 230026 China

A total of 30 surface sediments samples from the estuary wetland of the Tangxi River, Chaohu Lake Basin were obtained and tested. Enrichment factor （EF） and geoaccumulation index （Igeo） as well as multivariate statistical analysis methods including Factor Analysis （FA） and Hierarchical Cluster Analysis （HCA） were applied for the assessment of heavy metal pollution in surface sediments. The results of EF values show that the pollution of copper （Cu） and cadmium （Cd） occurs in the estuarine sediments, and that zinc （Zn）, lead （Pb） and chrome （Cr） may originate from crustal materials or natural weathering process. The mean EF values of the five heavy metals are in the decreasing order： Cu〉Cd）Zn〉Pb〉Cr. Based on the lgeo of target heavy metals, the surface sediments collected from the study area can be approximately categorized as unpolluted with Zn, Pb and Cr, and moderately polluted with Cu and Cd. The degree of heavy metal pollution decreases in the order of Cu〉Cd〉Zn〉Pb〉Cr. Three groups of pollution factors are presented from FA： Zn-TOC, Cu-Cd and Cr-Pb, which respectively accounte for 27.22%, 25.20% and 21.05% of variance. By means of HCA, a total number of seven groups are distinguished from 30 sampling sites. Results indicate that Cu and Cd are the prior controlled pollutants in the estuarine sediments of the Tangxi River.

关键词： heavy metal pollution sediment estuary multivariate analysis Chaohu Lake Basin

Trend of mass change in the Antarctic ice sheet recovered from the GRACE temporal gravity field

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Science China Earth Sciences 2012年第1期55卷 76-82页

作者： luo ZhiCai LI Qiong ZHANG kun WANG HaiHong School of Geodesy and Geomatics Wuhan UniversityWuhan 430079China Key Laboratory of Geospace Environment and Geodesy Ministry of EducationWuhan 430079China State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan 430079China

It is important to quantify mass variations in the Antarctic ice sheet hybrid filtering scheme employing a combination of the decorrelated to study the global sea-level rise and climate change. A filter P3M6 and 300 km Fan filter was used, and the sur- face mass variations over the Antarctic are recovered from GRACE CSR RL04 monthly gravity field models from August 2002 to June 2010. After deduction of leakage errors using the GLDAS hydrological model and postglacial rebound effects using the glacial isostatic adjustment model IJ05, the variations in the ice sheet mass are obtained. The results reveal that the rate of melting of the Antarctic ice sheet is 80.0 Gt/a and increasing and contributes 0.22 mm/a to the global sea-level rise; the mass loss rate is 78.3 Gt/a in the West Antarctic and 1.6 Gt/a in the East Antarctic. The average mass loss rate increases from 39.3 Gt/a for the period 2002-2005 to 104.2 Gt/a for the period 2006-2010, and its corresponding contribution to the global sea-level rise increases from 0.11 to 0.29 mm/a, which indicates accelerated ice mass loss over the Antarctic since 2006. Moreover, the mass accumulation rates for Enderby Land and Wilkes Land along the coast of East Antarctica decrease for the period 2006-2008 but increase evidently after 2009.

关键词： GRACE temporal gravity field Antarctic ice sheet mass variation

Recent progress in synthesis of composite powders and their applications in low-carbon refractories

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Journal of Iron and Steel Research International 2022年第7期29卷 1041-1051页

作者： Ji-yuan luo Xin-ming Ren Xiao-chuan Chong Dong-hai Ding Bei-yue Ma Guo-qing Xiao Jing-kun yu College of Materials Science and Engineering Xi’an University of Architecture and TechnologyXi’an 710055ShaanxiChina School of Metallurgy Northeastern UniversityShenyang 110819LiaoningChina

The development of low-carbon refractories is of great significance,but it is limited by the deteriorated properties that resulted from the decreased graphite *** composite powders has proved to be effective in improving the properties of low-carbon *** recent progress in the synthesis of composite powders including modified graphite,nanocarbon-containing composite powders,oxide/non-oxide and non-oxide composite powders and their applications in low-carbon refractories were reviewed,and the future development of composite powder technology was prospected.

关键词： Composite powder Modified graphite Nanocarbon-containing composite powder Oxide/non-oxide Non-oxide Low-carbon refractory

On the complexity of sequentially lifting cover inequalities for the knapsack polytope

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Science China Mathematics 2021年第1期64卷 211-220页

作者： Wei-kun Chen yu-Hong Dai School of Mathematics and Statistics Beijing Institute of TechnologyBeijing100081China LSEC ICMSECAcademy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing100049China

The well-known sequentially lifted cover inequality is widely employed in solving mixed integer ***,it is still an open question whether a sequentially lifted cover inequality can be computed in polynomial time for a given minimal cover(Gu et al.(1999)).We show that this problem is N P-hard,thus giving a negative answer to the question.

关键词： integer programming sequentially lifted cover inequality complexity lifting problem

Generalized Inverses and Units in a Unitary Ring

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Acta Mathematica Sinica,English Series 2024年第4期40卷 1000-1014页

作者： yu kun ZHOU Jian Long CHEN School of Mathematics Southeast UniversityNanjing 210096P.R.China

Let R be a unitary ring and a,b∈R with ab=*** find the 2/3 property of Drazin invertibility:if any two of a,b and a+b are Drazin invertible,then so is the third ***,we combine the 2/3 property of Drazin invertibility to characterize the existence of generalized inverses by means of *** applications,the need for two invertible morphisms used by You and Chen to characterize the group invertibility of a sum of morphisms is reduced to that for one invertible morphism,and the existence and expression of the inverse along a product of two regular elements are obtained,which generalizes the main result of Mary and Patricio(2016)about the group inverse of a product.

关键词： Leftπ-regular element stronglyπ-regular element group inverse Drazin inverse inverse along an element

OSCILLATORY SHEAR-ACCELERATED EXFOLIATION OF GRAPHITE IN POLYPROPYLENE MELT DURING INJECTION MOLDING

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Chinese Journal of Polymer Science 2013年第1期31卷 98-109页

作者： Nan Li Wei Cheng kun Ren Feng luo 王柯傅强 College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan University

In this study, good dispersion status of graphite in a nonpolar, intractable polymer, i.e. polypropylene （PP）, was realized in melt processing by using a specific dynamic packing injection molding （DPIM） technique. The exfoliation extent of graphite increased remarkably from the skin zone to the core zone of the molded part, as confirmed by combination of WAXD, SEM and TEM analyses, indicating an accelerated exfoliation occurred during the DPIM processing. This phenomenon is due to decreased melt flow channel and increased melt viscosity as the solidification takes place from the wall into the center, which leads to greatly increased shear force. The good dispersion of graphite results in obvious reinforcements of both tensile strength and impact strength by adding moderate amount of graphite. The present study proposes a promising route for realizing the large-scale fabrication of structural parts of polymer/exfoliated-graphite nanocomposites with excellent mechanical properties.

关键词： Polymer-matrix composites Mechanical properties Injection moulding.