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The role of aerial algae in the formation of the landscape of the Yunnan Stone Forest,Yunnan Province, china

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Science china Earth Sciences 2004年第9期47卷 846-864页

作者： TIAN Youping1,3. ZHANG Jie2, SONG Linhua1 & BAO Haosheng2 1. Institute of Geographic Sciences and Natural Resources research, Chinese Academy of Sciences, Beijing 100101, china 2. Department of Geography, Nanjing university, Nanjing 210093. china 3. School of Earth Sciences and Resources, china university of Geosciences, Beijing 100083. china Institute of Geographic Sciences and Natural Resources research Chinese Academy of Sciences Beijing 100101 China Department of Geography Nanjing University Nanjing 210093 China School of Earth Sciences and Resources China University of Geosciences Beijing 100083 China

Aerial algae on the surface of carbonate rocks at the Stone Forest, Shilin County, Yunnan Province, china, and their bioerosion were investigated in the field and studied in the laboratory in detail. Through the observation, identification and statistics of more than one hun- dred algal samples and rock samples with the optical microscopes (stereomicroscope, biological microscope) and the scanning electronic microscope (SEM), the relationships between erosional forms on the surface of the Stone Forest and algae and/or algal communities and the genetic mechanism for the formation of erosional forms were analyzed. It is suggested that aerial algae play an active role in bioerosive processes that may affect the formation of karst erosional forms. These effects include both direct and indirect ones. The direct effect is the initiative control (algal shape-controlling role) of algae on the formation of karst forms of various scales, mostly mi- cro-scale (3.) and minor-scale (10-3.10-1m) erosional forms. The algal shape-controlling roles can be divided into the algal individual shape-controlling role and the algal community shape-controlling role. The former mostly controls the formation of micro-scale erosional forms, while the latter mostly controls the formation of micro-scale and smaller minor-scale erosional forms. The indirect effect refers to the promoting role of algae in the formation of karst forms, which may affect the formation of karst forms of all types and scales. The bioerosion of algae accelerates the weathering process of the whole Stone Forest karst landforms.

关键词： aerial algae, bioerosion, the Stone Forest, Yunnan Province, china.

A new orthogonality relationship for orthotropic thin plate theory and its variational principle

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Science china(Physics,Mechanics & Astronomy) 2005年第3期48卷 371-380页

作者： LUO Jianhui 1 , LONG Yuqiu 2 & LIU Guangdong 1 1. College of Civil Engineering, Hunan university, Changsha 410082, china 2. Department of Civil Engineering, tsinghua university, Beijing {3., china 1. College of Civil Engineering Hunan University 410082 Changsha China 2. Department of Civil Engineering Tsinghua University 100084 Beijing China

The thought how dual vectors are constructed in a new orthogonality relationship for theory of elasticity is generalized into orthotropic thin plate bending problems by using the analogy theory between plane elasticity problems and plate bending problems. Dual differential equations are directly obtained by using a mixed variables method. A dual differential matrix to be derived possesses a peculiarity of which principal diagonal sub-matrixes are zero matrixes. Two independently and symmetrically orthogonality sub-relationships are discovered. By using the integral form for elastic bending theory of orthotropic thin plate the orthogonality relationship is demonstrated. By selecting felicitous dual vectors a new orthogonality relationship for theory of elasticity can be generalized into elastic bending theory of orthotropic thin plate. By using the integral form a variational principle which is relative to differential form and a whole function expression are proposed.

关键词： theory of elasticity, thin plate theory, dual vectors, orthogonality relationship, orthotropic, variational principle.

The first-principles study on the doping effect of Re in Ni3.l

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Progress in Natural Science:Materials International 2008年第7期18卷 861-866页

作者： Song Yu a,*, Chongyu Wanga,b, Tao Yua aCentral Iron and Steel research Institute, Beijing 100081, china bDepartment of Physics, tsinghua university, Beijing {3., china Central Iron and Steel research Institute Beijing 100081 China Department of Physics Tsinghua University Beijing 100084 China

Using first-principles density function for molecules method (DMol) and discrete variational method (DVM) based on the density functional theory, we studied the doping effect of Re in Ni3.l. The structure relaxation and the alloying energy show that Re has a strong Al site preference and leads to the local deformation, which is in agreement with the experimental results and other theoretical results. In addition, the charge density diffierence and the bond order show that Re can strongly enhance the interatomic interaction between the nearest neighbor atoms. From the density of states and the Pauli spectrum, we find that resonance states and localized states are induced by doping Re, and the doped Re atom forms the hybridized bond with the nearest neighbor atoms.

关键词： The first-principles Re Ni3.l

Study on an intelligent fault-tolerant technique for multiple satellite configured navigation under highly dynamic conditions

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Science china(Information Sciences) 2011年第3期54卷 529-541页

作者： WANG ShiCheng 1 , ZHAO Xin 1 , MIN HaiBo 1 , LIU ZhiGuo 1 & SI XiaoSheng 2 1 High-Tech Institute of Xi’an, Xi’an 710025, china 2 Department of Automation, tsinghua university, Beijing 100084, china 1. High-Tech Institute of Xi’an Xi’an 710025 China2. Department of Automation Tsinghua University Beijing 100084 China

The probability of pseudo-range information being faulty will increase when there is increased noise in the receiver due to highly dynamic conditions. In this paper, an intelligent fault-tolerant federated Kalman filter (IFFKF) is presented to solve the problem of invalid position information as a result of the uncertainty in the category and quantity of failed satellites in a multiple configured satellite system. At the same time, a corresponding intelligent fault-tolerant system structure based on a cell-level fusion mode of operation was designed. Furthermore, a fault diagnosis strategy is proposed to deal with gradually or suddenly changing faults. By monitoring the residual and the residual rate, an observation quality gene is obtained using a fuzzy logic control system, and the local filter is adaptively adjusted on-line. Consequently, any filtering divergence arising from a gradually changing fault can, to a large extent, be prevented. The results show that the proposed algorithm and structure can achieve reliable positioning by fully utilizing new multiple satellites, monitoring and managing the gradual fault, as well as detecting and isolating any sudden fault in a synchronous manner. As such, the proposed algorithm has the potential to improve the reliability of a multiple satellite configured navigation system.

关键词： multiple satellite configured systems fuzzy logic control intelligent fault-tolerant filtering federated filtering fault detection and isolation

Cilia and ciliopathies:From Chlamydomonas and beyond

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Science china(Life Sciences) 2008年第6期51卷 479-486页

作者： PAN JunMin Department of Biological Sciences and Biotechnology, tsinghua university, Beijing 100084, china 1. Department of Biological Sciences and Biotechnology Tsinghua University Beijing 100084 China

The biological function of motile cilia/flagella has long been recognized. The non-motile primary cilium, once regarded as a vestigial organelle, however, has been found recently to play unexpected roles in mammalian physiology and development. Defects in cilia have profound impact on human health. Diseases related to cilia, collectively called ciliopathies include male infertility, primary cilia dyskinesia, renal cyst formation, blindness, polydactyly, obesity, hypertension, and even mental retardation. Our current understanding of cilia and ciliopathies has been fueled by basic research employing various model organisms including Chlamydomonas, a unicellular green alga. This review article provides a general introduction to the cell biology of cilia and an overview of various cilia-related diseases.

关键词： Chlamydomonas cilia flagellla human disease ciliopathy

Adsorption of surfactants onto acrylic ester resins with different pore size distribution

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Science china Chemistry 2006年第5期49卷 445-453页

作者： YANG Weiben1,2,3.LI Aimin1,3.CAI Jianguo1,3.MENG Guanhua1,3.& ZHANG Quanxing1,3.1. State Key Laboratory of Pollution Control and Resource Reuse,School of the Environment,Nanjing university,Nanjing 210093.china 2. Nanjing College of Chemical Technology,Nanjing 210048,china 3. Jiangsu Engineering & Technology {3. center for Organic Toxicant Control and Resource Reuse,Nanjing 21003.,china 1. State Key Laboratory of Pollution Control and Resource Reuse School of the Environment Nanjing University Nanjing 210093 China 2. Nanjing College of Chemical Technology Nanjing 210048 China 3. Jiangsu Engineering & Technology research center for Organic Toxicant Control and Resource Reuse Nanjing 210038 China

In this study, a series of acrylic ester resins with different pore size distribution were prepared successfully by varying the type and the amount of pore-forming agents. In order to inves-tigate the adsorption behavior and mechanism of surfactants on acrylic ester resins, three kinds of surfactants were utilized as adsorbates that were sodium 6-dodecyl benzenesulfonate (6-NaDBS), sodium 1-dodecyl benzene sulfonate (1-NaDBS) and sodium 1-dodecyl sulfonate, respectively. It was observed that the surface area was available in a particular pore size and an appropriate pore size of resins appeared to be more important for the adsorption of surfactants. As compared to commercial acrylic ester resins XAD-7 and HP2MG, 50# and 3.# resins exhibited more excellent adsorption properties toward 1-NaDBS and 6-NaDBS. The experimental equilibrium data were fitted to the Langmuir, and double-Langmuir models. Two models provided very good fittings for all resins over the temperature range studied. The investigation indicated that electrostatic attraction and hydrogen bond between resins and surfactants were the main forces and had an obvious effect on adsorption proc-ess.

关键词： acrylic ester resin, surfactant, adsorption, pore size distribution, isotherm.

Sediment pollution and its effect on fish through food chain in the Yangtze River

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International Journal of Sediment research 2008年第4期23卷 338-347页

Suspended sediment adsorbs pollutants from flowing water in rivers and deposits onto the bed. However, the pollutants accumulated in the river bed sediment may affect the bio-community through food chain for a long period of time. To study the problem the concentration of heavy metals (Cr, Cd, Hg, Cu, Fe, Zn, Pb and As) in water, sediment, and fish/invertebrate were investigated in the middle and lower reaches of the Yangtze River during 2006-2007. The concentrations of heavy metals were 100-10,000 times higher in the sediment than in the water. Benthic invertebrates had relatively high concentrations of heavy metals in their tissues due to their proximity to contaminated sediments. Benthic invertivore fish had moderately high concentrations of heavy metals whereas phytoplanktivore fish, such as the silver carp, accumulated the lowest concentration of heavy metals. The concentrations of Cu, Zn, and Fe were higher than Hg, Pb, Cd, Cr, and As in the tissue samples. The concentration of heavy metals was lower in the river sediments than in the lake sediments. Conversely, the concentration of heavy metals was higher in river water than in lake water. While a pollution event into a water body is often transitory, the effects of the pollutants may be long-lived due to their tendency to be absorbed in the sediments and then released into the food chain. The heavy metals were concentrated in the following order: bottom material > demersal fish and benthic fauna > middle-lower layer fish > upper-middle layer fish > water.

关键词： Sediment pollution Heavy metal Fish Invertebrate Yangtze River

The coupling instability of Rossby and topographic Rossby waves in the equatorial area

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Science china Earth Sciences 2005年第10期48卷 1792-1801页

作者： CHAO Jiping1,2, LIU Lin1,3.& YU Weidong1 1. Laboratory of Marine Science and Numerical Modeling, State Oceanic Administration, Qingdao 266061, china 2. National research center for Marine Environmental Forecasts, State Oceanic Administration, Beijing 100081, china 3. Ocean university of china, Qingdao 266003. china Laboratory of Marine Science and Numerical Modeling State Oceanic Administration Qingdao china National research center for Marine Environmental Forecasts State Oceanic Administration Beijing china Ocean university of china Qingdao china

In case of considering the fact that the tropical ocean thermocline or the lower at-mosphere height field has the meridional variation, the topographic Rossby wave will be excited. Also the background geostrophic current emerges. Under such conditions, the topographic Rossby wave can interact with the classical Rossby wave at some parameter band and thus brings a new kind of instability, which may be of potential application in understanding some phenomena of the ENSO cycle.

关键词： thermocline variation, equatorial jet, Rossby wave, topographic Rossby wave, coupling instability

LARGE DEFLECTION THEORY OF NANOBEAMS

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Acta Mechanica Solida Sinica 2010年第5期23卷 394-399页

作者： Dujuan Zeng Quanshui Zheng 1(Department of Engineering Mechanics,tsinghua university,Beijing 100084,china) [a] Department of Engineering Mechanics Tsinghua University Beijing 100084 China

One-dimensional nanostructured materials are often used as beams in many applications such as ultrahigh-frequency resonators and ultrasensitive sensors. Compared with usual macroscopic beams, nanobeams have much higher surface/volume ratios so that their surface energies may play a significant role. Besides, they often bear large deflections due to their typically large slenderness ratios and larger elastic ranges. There is, however, lack of a theory that takes into account of both the above two features owned by nanobeams. In this paper, we present such a theory and give applied examples to show that surface energy and large deflection may individually or jointly have notable effects.

关键词： nanobeam surface energy large deflection