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Pollen limitation and variation in floral longevity in gynodioecious Potentilla tanacetifolia

Journal of Systematics and Evolution 2011年第6期49卷 539-545页

作者： 1,2Hong YAO 1Yi-Bo LUO 1(State Key Laboratory of Systematic and Evolutionary Botany,Institute of Botany,chinese academy of sciences,beijing 100093,china) 2(graduate university of the chinese academy of sciences,beijing 100049,china) (State Key Laboratory of Systematic and Evolutionary Botany Institute of Botany Chinese Academy of Sciences Beijing 100093 China) (graduate university of the chinese academy of sciences Beijing 100049 China) *Correspondence: Yi-Bo LUO *Correspondence: E-mail: luoyb@*** Tel.: 86-10-62836514 Fax: 86-10-62590843.

Pollination limitation is common in flowering plants and is thought to be a factor driving the evolution of floral *** plasticity of floral longevity to pollination may be an adaptation of plants to pollen ***,this adaptation is less critical in short-lived *** evaluate pollen limitation and the plasticity of floral longevity to pollination in Potentilla tanacetifolia,a gynodioecious herb with short-lived flowers,we analyzed its breeding system,tested sex-differential pollen limitation,and compared variations in floral display size in natural populations in Duolun County,Inner Mongolia,*** pollination experiments and pollinator exclusion treatments revealed that *** is self-compatible and non-autonomously apomictic and shows sex-differential pollen *** plasticity of floral longevity to pollination was observed;the floral duration of female plants was prolonged by approximately 3-4 hours with pollination exclusion ***,the percentage of flowers displayed on female plants during pollination exclusion treatment was significantly higher than that during natural *** natural pollination conditions,the percentage of flowers displayed on female plants was significantly higher than on hermaphrodite ***,approximately 50%of the pollen grains spread out of the anthers of hermaphrodite flowers within 2 h of anthesis;the number of pollen grains adhering to the stigmas of hermaphrodite flowers was significantly higher than that adhering to female flowers when flowers shed their *** results indicate that variation in floral longevity may be an adaptive strategy to pollination conditions for gynodioecious ***.

关键词： floral longevity gynodioecy plasticity pollen limitation Potentilla tanacetifolia.

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Effects of the grain size distribution on the temperature-dependent magnetic susceptibility of magnetite nanoparticles

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Science china Earth sciences 2010年第7期53卷 1071-1078页

作者： ZHAO XiangYu1,2 & LIU QingSong1 1 Paleomagnetism and Geochronology Laboratory (SKL-LE), Institute of Geology and Geophysics, chinese academy of sciences, beijing 100029, china 2 graduate university of chinese academy of sciences, beijing 100049, china 1. Paleomagnetism and Geochronology Laboratory (SKL-LE) Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China

Magnetite is an important magnetic remanence carrier in natural samples and therefore is of great interest in paleo-, rock-, and environmental magnetism. The magnetic properties of magnetite depend on many factors, e.g., concentration and grain size distribution (GSD). In this study, we theoretically investigated the temperature-dependent susceptibility (TDS) of magnetite nanoparticles with a lognormal GSD. Results show that the TDS is affected highly by the GSD mainly in three aspects. Firstly, the unblocking process becomes smoother with the increase of distribution width, characterizing as a wider Hopkinson peak on the TDS curve. Secondly, the blocking temperature increases with the increase of the median diameter or/and the distribution width. Thirdly, the maximum susceptibility decreases with the increase of distribution width, and has a logarithmic function relation with the standard deviation of the distribution. As a case study, this model was further applied to the thermal products of the chinese loess/paleosol samples to determine the granulometry of newly-formed magnetite upon heating based on TDS curves. The results demonstrate the fidelity and feasibility of this method to determine the GSD of nano-sized magnetic particles.

关键词： Néel theory temperature dependence of susceptibility grain size distribution

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Modeling diameter distribution of the broadleaved-Korean pine mixed forest on Changbai Mountains of china

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Science china(Technological sciences) 2006年第z1期49卷 177-188页

作者： WANG Shunzhong, DAI Limin, LIU Guohua, YUAN Jianqiong, ZHANG Hengmin & WANG Qingli Institute of Applied Ecology, chinese academy of sciences, Shenyang 110016, china graduate university of chinese academy of sciences, beijing 100039, china State Key Lab of Systems Ecology, Research Center for Eco-Environmental sciences, chinese academy of sciences, beijing 100085, china Institute of Applied Ecology Chinese Academy of Sciences Shenyang 110016 China graduate university of chinese academy of sciences Beijing 100039 China State Key Lab of Systems Ecology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences Beijing 100085 China

The broadleaved-Korean pine mixed forest is a native vegetation in the Changbai Mountains, northeast china. The probability density functions including the normal, negative exponential, Weibull and finite mixture distribution, were used to describe the diameter distributions of the species groups and entire forest stand. There is a strong correlation between parameters and mean DBH except the shape parameters in the mixture distribution. The diameter classes of species and entire forest stand showed not negative exponential but normal and "S" distribution. The mixture function was better than normal and Weibull to describe the model distribution. The location parameter had an effect on the estimated frequency in the first diameter class, when the estimated location parameter was bigger than the lower limit of the first diameter class.

关键词： broadleaved-Korean pine mixed forest, diameter distribution, finite mixture distribution.

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Application of three-dimensional discrete element face-to-face contact model with fissure water pressure to stability analysis of landslide in Panluo iron mine

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Science china(Technological sciences) 2005年第z1期48卷 146-156页

作者： ZHANG Lei1,2, WEI Zuoan1, LIU Xiaoyu1 & LI Shihai1 1.Institute of Mechanics, chinese academy of sciences, beijing 100080, china 2.graduate School, chinese academy of sciences, beijing 100060, china chinese Acad Sci Inst Mech Beijing 100080 Peoples R China chinese Acad Sci Grad Sch Beijing 100060 Peoples R China

Three-dimensional discrete element face-to-face contact model with fissure water pressure is established in this paper and the model is used to simulate three-stage process of landslide under fissure water pressure in the opencast mine, according to the actual state of landslide in Panluo iron mine where landslide happened in 1990 and was fathered in 1999. The calculation results show that fissure water pressure on the sliding surface is the main reason causing landslide and the local soft interlayer weakens the stability of slope. If the discrete element method adopts the same assumption as the limit equilibrium method, the results of two methods are in good agreement; while if the assumption is not adopted in the discrete element method, the critical φ numerically calculated is less than the one calculated by use of the limit equilibrium method for the sameC. Thus, from an engineering point of view, the result from the discrete element model simulation is safer and has more widely application since the discrete element model takes into account the effect of rock mass structures.

关键词： face-to-facecontactmodel, fissure water pressure, three-dimensional discrete element method,landslide.

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Variation properties of ionospheric eclipse factor and ionospheric influence factor

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Progress in Natural Science:Materials International 2005年第6期15卷 573-576页

作者： ZHAO Chunmei 1,2 *, YUAN Yunbin1, OU Jikun1 and CHEN Jinping3(1. Institute of Geodesy and Geophysics, chinese academy of sciences, Wuhan 430077, china 2. graduate School of chinese academy of sciences, beijing 100039, china 3. Department of Precision Instrument and Mechanology, Tsinghua university, beijing 100084, china) Institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan 430077 China graduate School of chinese academy of sciences Beijing 100039 China Department of Precision Instrument and Mechanology Tsinghua University Beijing 100084 China

The concepts and calculation methods of ionospheric eclipse factor (IEF) and ionospheric influence factor (IFF) are further illustrated. The temporal and spacial variation properties of IEF and IFF are studied, which shows that the properties are influenced by the geographic position and season. The possibility of improving the precision of using GPS data to determine ionospheric delay based on the above variation properties is also analysed.

关键词： GPS ionospheric eclipse factor ionospheric influence factor

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CH_4 uptake flux of Leymus chinensis steppe during rapid growth season in Inner Mongolia,china

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Science china Earth sciences 2010年第7期53卷 977-983页

作者： GENG YuanBo1, LUO GuangQiang1,2 & YUAN GuoFu1 1 Institute of Geographic sciences and Natural Resources Research, chinese academy of sciences, beijing 100101, china 2 graduate university of chinese academy of sciences, beijing 100049, china 1. Institute of Geographic sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China

The influence of near ground atmosphere CH4 concentration, soil water content, soil Eh, plants, soil temperature, and pH on CH4 uptake flux of Leymus chinensis steppe during rapid growth season was studied using field in-situ measurement in Xilin River basin of Inner Mongolia, china. The results showed that CH4 uptake flux was positively correlated with near ground atmosphere CH4 concentration and soil Eh but negatively correlated with soil water content. Precipitation may decrease the CH4 flux by increasing the soil water content. The average fluxes of three treatments during the observation period were 1.52 (natural conditions, 1.51 (aboveground plants were excluded), and 2.00 mg m?2 d?1 (all plants were removed), respectively. The difference between the CH4 flux of natural condition treatment and that of removing aboveground plants treatment is small, whereas the flux of removing all plants treatment is larger than the other two treatments. This means that the contribution of aboveground plants to CH4 uptake flux is smaller than that of roots or roots-removing process. CH4 uptake flux is not sensitive to soil temperature and the narrow-ranged soil pH (6.36–7.86). The Leymus chinensis steppe acts as a sink for CH4, and thus more studies should be focused on its affecting factors and related mechanisms.

关键词： CH4 uptake flux Leymus chinensis steppe affecting factors static opaque chamber/gas chromatography method

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Conceptual design and simulation analysis of thermal behaviors of TGR blast furnace and oxygen blast furnace

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Science china(Technological sciences) 2010年第1期53卷 85-92页

作者： ZHANG Hui1,2,LI HuiQuan1,TANG Qing1 & BAO WeiJun1 1 National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology,Institute of Process Engineering,chinese academy of sciences,beijing 100190,china 2 graduate university of chinese academy of sciences,beijing 100049,china 1. National Engineering Laboratory for Hydrometallurgical Cleaner Production Technology Institute of Process Engineering Chinese Academy of Sciences Beijing 100190 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China

Extensive use of carbon based fuel is the main inducement for global warming and more extreme *** carbon dioxide emission and enhancing energy use is a common subject in steel *** the integrated steel plant,decreasing carbon dioxide emission must consider energy balance in the whole iron and steel works,and secondary energy must be actively *** promising blast-furnaces,top gas recovery blast furnace(TGR-BF) and oxygen blast furnace have been *** this paper,conceptual TGR blast furnace and oxygen blast furnace are *** on the idea of blast furnace gas de-CO2 circulating as reducing agent and the idea of pure oxygen blast decreasing the thermal reserve zone temperature,process modeling is conducted with ASPEN *** is shown that the developed model reasonably describes the energy balance and mass balance feature of the furnace,and provides basic thermodynamic condition for *** effects of changes in different operation conditions are studied by sensitivity analysis and reference data from simulation.

关键词： TGR blast-furnace thermal behavior simulation analysis CO2 emission decreasing

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2023 Guideline for the management of hypertension in the elderly population in china

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Journal of Geriatric Cardiology 2024年第6期21卷 589-630页

作者： Hypertension Branch of chinese Geriatrics Society,beijing Hypertension Association,National Clinical Research Center of the Geriatric Diseases Qi HUA Li FAN Zeng-Wu WANG Jing LI 不详 Xuanwu Hospital Capital Medical UniversityBeijingChina chinese PLA General Hospital BeijingChina Fuwai Hospital Chinese Academy of Medical Sciences and Peking Union Medical CollegeBeijingChina

Preamble Hypertension is one of the most common chronic diseases and the primary risk factor for stroke,myocardial infarction and even cardiovascular *** than half of the elderly population has high blood *** people are a unique group,and strategies for the prevention,diagnosis,evaluation,and treatment of hypertension in elderly individuals differ significantly from those in the general population.

关键词： hypertension prevention diagnosis

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Effect of concentration on surfactant micelle shapes——A molecular dynamics study

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Science china Chemistry 2005年第5期48卷 470-475页

作者： GAO Jian1,2, GE Wei1 & LI Jinghai1 1. Multiphase Reaction Laboratory, Institute of Process Engineering, chinese academy of sciences, beijing 100080, china 2. graduate School of The chinese academy of sciences, beijing 100085, china 1. Multiphase Reaction Laboratory Institute of Process Engineering Chinese Academy of Sciences 100080 Beijing China 2. graduate School of The chinese academy of sciences 100085 Beijing China

Many aspects of the behavior of surfactants have not been well understood due to the coupling of many different mechanisms. Computer simulation is, therefore, attractive in the sense that it can explore the effect of different mechanisms separately. In this paper, the shapes, structures and sizes of sodium dodecylbenzenesulfonate (SDBS) micelles under different con-centrations in an oil/water mixture were studied via molecular dynamics (MD) simulations using a simplified atomistic model which basically maintains the hydrophile and lipophile properties of the surfactant molecules. Above the critical micellar concentration (cmc), surfactant molecules ag-gregate spontaneously to form a wide variety of assemblies, from spherical to rodlike, wormlike and bilayer micelles. Changes in their ratios of the principle moments of inertia (g1/g3, g2/g3) in-dicated the transition of micelle shapes at different concentrations. The aggregation number of micelle is found to have a power-law dependence on surfactant concentration.

关键词： surfactant, MD simulation, sodium dodecylbenzenesulfonate, micelle shape.

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Trend of urban system structure under the restriction of water and land resources in Xinjiang

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chinese Science Bulletin 2006年第A01期51卷 179-188页

作者： ZHANG Xiaolei & LEIJun Xinjiang Institute of Ecology and Geography, chinese academy of sciences, Urumqi 830011, china Institute of Geographical Science and Natural Resources Research, chinese academy of sciences, beijing 100101, china graduate School, chinese academy of sciences, beijing 100039, china chinese Acad Sci Xinjiang Inst Ecol & Geog Urumqi 830011 Peoples R China chinese Acad Sci Inst Geog Sci & Nat Resources Res Beijing 100101 Peoples R China chinese Acad Sci Grad Sch Beijing 100039 Peoples R China

根据在 Xinjiang 影响城市的开发和城市的系统结构的水和陆地资源上的研究，这篇论文分析利用地位和城市的水资源的缺乏。城市的水资源的消费和浪费在一个增加趋势，这被考虑。然而，在 Xinjiang 的大多数城市和镇在水资源的缺乏水资源... 详细信息

根据在 Xinjiang 影响城市的开发和城市的系统结构的水和陆地资源上的研究，这篇论文分析利用地位和城市的水资源的缺乏。城市的水资源的消费和浪费在一个增加趋势，这被考虑。然而，在 Xinjiang 的大多数城市和镇在水资源的缺乏水资源的废物是严肃的，特别在小镇上。megapolis 和中等城市的发展被有限陆地资源显然限制。尽管有扩展小城市和镇的相对大的空格，水和陆地资源的输出好处是低的。为了完成城市的系统的顺序的扩大，在 Xinjiang 组织，在都市化的快速的发展拿一个圆和三条带和节俭资源的策略的城市的空间发展模式被建议。

关键词：城镇体系结构水资源土地资源供水能力新疆

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