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1The characteristics of CO_2 assimilation of photosynthesis and chlorophyll fluorescence in transgenic PEPC rice显示文摘With PEPC, PPDK, NADP-ME and PEPC+ PPDK transgenic and untransformed rice (Orysa sativa L.), the activities of related C4 photosynthesis enzymes, the chlorophyll fluorescence parameters, CO2 exchange and other physiological indexes were compared, in which the physiological characteristics of PEPC transgenic rice were mainly studied. The results were as follows: (i) The activities of PEPC in PEPC transgenic rice were 20-fold higher than those in untransformed rice; the light-saturation photosynthetic rates and the carboxylation efficiency of PEPC transgenic rice were increased by 55% and 50% more than those of untransformed rice, respectively, while the CO2 compensation point decreased by 27%. (ii) The PS II photochemical efficiency (Fv/Fm) and photochemical quenching (qp) of transgenic PEPC rice decreased less in comparison with those of untransformed rice after the treatment with high light intensity (3 h) or methyl viologen (MV), a photooxidative reagent, which demonstrated that the tolerance of PEPCJIAO Demao, LI Xia, HUANG Xueqing, CHI Wei, KUANG Tingyun & Ku SB Maurice1. Institute of Agrobiological Genetics and Physiology, Jiangsu Academy of Agricultural Sciences, Nangjing 210014, China 2. Institute of Botany, the Chinese Academy of Sciences, Beijing 100093, China 3. Botany Department, Washington State University, Pullman, WA 99164-4236, USA 2001Chinese Science Bulletin2001,46,13:29
2Damage and progressive failure of concrete structures using non-local peridynamic modeling显示文摘Peridynamics (PD), a recently developed theory of solid mechanics, which employs a non-local model of force interaction and makes use of integral formulation rather than the spatial partial differential equations used in the classical continuum mechanics theory, has shown effectiveness and promise in solving discontinuous problems at both macro and micro scales. In this paper, the peridynamics theory is used to analyze damage and progressive failure of concrete structures. A non-local peridynamic model for a rectangular concrete plate is developed, and a central pairwise force function is introduced to describe the interior interactions between particles within some definite distance. Damage initiation, evolution and crack propagation in the concrete model subject to in-plane uni-axial tension, in-plane uni-axial compression and out-of-plane impact load are investigated respectively. The numerical results show that discontinuities appear and grow spontaneously as part of the solution to the peridynamic equations of motion, and no special failure criteria or re-meshing techniques are required, which proves the potential of peridynamic modeling as a promising technique for analyzing the progressive failure of concrete materials and structures.HUANG Dan1,2, ZHANG Qing1,2 & QIAO PiZhong1,3 1 State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, China 2 Department of Engineering Mechanics, Hohai University, Nanjing 210098, China 3 Department of Civil and Environmental Engineering, Washington State University, Pullman, WA 99164-2910, USA 2011Science China(Technological Sciences)2011,54,3:24
3A 60-year journey of mycorrhizal research in China:Past,present and future directions显示文摘The significance of mycorrhizas(fungal roots in 90% of land plants) in plant nutrient acquisition and growth,element biogeo-chemical cycling and maintaining of terrestrial ecosystem structures has been globally established for more than 120 years.Great progress in mycorrhizal research in the past 60 years(1950-2009,1981-2009 in particular) has also been made across China,particularly in the mainland,Hong Kong and Taiwan.For instance,a total of 20 new and ~120 records of arbuscular mycorrhizal(AM) fungal species,30 new and ~800 records of ectomycorrhizal(EM) fungal species,a dozen of new and ~100 records of orchid mycorrhizal(OM) fungal species have been isolated by morphological observation and/or molecular identification in China since the 1950s.Great accomplishment has also been made in the following area,including fungal species richness and genetic structure,relationships between species composition and plant taxa,effects of mycorrhizal fungi on plant nutrient uptake and growth,resistances to pathogens and interactions with other soil microorganisms,potential of mycorrhizal fungi in phytoremediation and/or land reclamation,alterations of enzymatic activities in mycorrhizal plants,and elevated CO2 and O3 on root colonization and species diversity.Unfortunately,the international community cannot easily appreciate almost all Chinese mycorrhizal studies since the vast majority of them have been published in Chinese and/or in China-based journals.The aim of this review is to make a comprehensive exposure of the past and present China's major mycorrhizal research to the whole world,and then to suggest potential directions for the enhancement of future mycorrhizal research within and/or between the Chinese and international mycorrhizal community.HE XinHua1,2,3*,DUAN YingHua2,CHEN YingLong4 & XU MingGang2 1School of Life Sciences,Yunnan Normal University,Kunming 650092,China 2Key Laboratory of Crop Nutrition and Fertilization,Ministry of Agriculture of China,Institute of Agricultural Resources and Regional Planning,Chinese Academy of Agricultural Sciences,Beijing 100081,China 3Centre for Ecosystem Management,School of Natural Resources,Edith Cowan University,Joondalup,WA 6027 State Centre of Excellence for Ecohydrology,School of Plant Biology,University of Western Australia,Crawley,WA 6009,Australia 4School of Earth and Environment,University of Western Australia,Crawley,WA 6009,Australia 2010Science China(Life Sciences)2010,53,12:23
4Experimental studies on perturbed acoustic resonant spectroscopy by a small rock sample in a cylindrical cavity显示文摘A measurement system for acoustic resonant spectroscopy (ARS) is estab-lished,and the effects of resonant cavity geometry,inner perturbation samples and envi-ronmental temperature on the ARS are investigated. The ARSs of the small samples with various sizes and acoustic properties are measured. The results show that at the normal pressure,the resonant frequency decreases gradually with the increase of liquid tem-perature in the cylindrical cavity,while the resonant amplitude increases. At certain pres-sure and temperature,both the resonant frequency and the amplitude decrease greatly when there exist air bubbles inside the cavity fluid. The ARS is apparently affected by the sample porosity and the sample location in the resonant cavity. At the middle of the cavity,the resonant frequencies reach their maximum values for all of the measurement samples. The resonant frequencies of the porous rock samples are smaller than those of the com-pacted samples if other acoustic parameters are the same. As the sample is moved from the top to the middle of the cavity along its axis,the resonant amplitude increases gradu-ally for the compacted rocks while decreases for the unconsolidated rocks. Furthermore,the resonant amplitude increases firstly and then decreases if the porosity of the rock sample is relatively small. In addition,through the comparisons between the experimental and theoretical results,it is found that the effects of the acoustic parameters and sizes of the samples and the size of the cylindrical cavity on the laboratory results agree well with the theoretical ones qualitatively. These results may provide basic reference for the ex-periment study of rock acoustic properties in a low frequency using ARS.CHEN Dehua1,2,WANG Xiuming2,3,CONG Jiansheng1,XU Delong1,SONG Yanjie1 & MA Shuilong4 1. Department of Geophysics,Daqing Petroleum Institute,Daqing 163318,China 2. Institute of Acoustics,Chinese Academy of Sciences,Beijing 100080,China 3. Division of Petroleum,Australian Commonwealth Scientific and Industrial Research Organization,Bent-ley WA 6102,Australia 4. Daqing Testing and Technology Services Corporation,Daqing 163153,China 2006Science China(Physics,Mechanics & Astronomy)2006,49,6:8
5An extended displacement discontinuity method for analysis of stress wave propagation in viscoelastic rock mass显示文摘An extended displacement discontinuity method (EDDM) is proposed to analyze the stress wave propagation in jointed viscoelastic rock mass (VRM).The discontinuities in a rock mass are divided into two groups.The primary group with an average geometrical size larger than or in the same order of magnitude of wavelength of a concerned stress wave is defined as 'macro-joints',while the secondary group with a high density and relatively small geometrical size compared to the wavelength is known as 'micro-defects'.The rock mass with micro-defects is modeled as an equivalent viscoelastic medium while the macro-joints in the rock mass are modeled explicitly as physical discontinuities.Viscoelastic properties of a micro-defected sedimentary rock are obtained by longitudinally impacting a cored long sedimentary rod with a pendulum.Wave propagation coefficient and dynamic viscoelastic modulus are measured.The EDDM is then successfully employed to analyze the wave propagation across macro-joint in VRM.The effect of the rock viscosity on the stress wave propagation is evaluated by comparing the results of VRM from the presented EDDM with those of an elastic rock mass (ERM) from the conventional displacement discontinuity method (CDDM).The CDDM is a special case of the EDDM under the condition that the rock viscosity is ignored.Comparison of the reflected and transmitted waves shows that the essential rock viscosity has a significant effect on stress wave attenuation.When a short propagation distance of a stress wave is considered,the results obtained from the CDDM approximate to the EDDM solutions,however,when the propagation distance is sufficiently long relative to the wavelength,the effect of rock viscosity on the stress wave propagation cannot be ignored.L.F.Fan1,F.Ren1,G.W.Ma2 1 School of Civil and Environmental Engineering,Nanyang Technological University,Singapore,639798,Singapore 2 School of Civil and Resource Engineering,The University of Western Australia,Crawley,WA 6009,Australia 2011Journal of Rock Mechanics and Geotechnical Engineering2011,3,1:8
6Simulations of explosion-induced damage to underground rock chambers显示文摘A numerical approach is presented to study the explosion-induced pressure load on an underground rock chamber wall and its resultant damage to the rock chamber.Numerical simulations are carried out by using a modified version of the commercial software AUTODYN.Three different criteria,i.e.a peak particle velocity (PPV) criterion,an effective strain (ES) criterion,and a damage criterion,are employed to examine the explosion-induced damaged zones of the underground rock chamber.The results show that the charge chamber geometry,coupling condition and charge configuration affect significantly the dynamic pressure exerted on the rock chamber wall.Thus the chamber is damaged.An inaccurate approximation of pressure boundary ignoring the influences of these factors would result in an erroneous prediction of damaged area and damage intensity of the charge chamber.The PPV criterion yields the largest damaged zone while the ES criterion gives the smallest one.The presented numerical simulation method is superior in consideration of the chamber geometry,loading density,coupling condition and rock quality.The predicted damage intensity of rock mass can be categorized quantitatively by an isotropic damage scalar.Safe separation distance of adjacent chambers for a specific charge weight is also estimated.G.W.Ma1,H.Hao1,F.Wang2 1 School of Civil and Resource Engineering,The University of Western Australia,Crawley,WA 6009,Australia 2 Defense Science and Technology Agency,Singapore,109679,Singapore 2011Journal of Rock Mechanics and Geotechnical Engineering2011,3,1:7
7Oroclinal bending and block rotations in South China since the Mesozoic——Geological and paleomagnetic evidence显示文摘THE South China Block exhibits a complex structural pattern in its Neoproterozoic-Mesozoic sedimentary cover. The lack of knowledge about the formation of this pattern hinders our understanding of the regional tectonic evolution and paleogeography, and the reconstruction of Phanerozoic apparent polar wander path(s). In this note we present a synthesis based on a paleomagnetic and tectonic analysis, which suggests that (i) the structural pattern overLI Zhengxiang, FANG Dajun, Christopher McA. Powell and LOU Gang1. Department of Geology and Geophysics, The University of Western Australia, Nedlands WA 6907, Australia 2. Department of Earth Sciences, Zhejiang University, Hangzhou 310027, China 1997Chinese Science Bulletin1997,42,2:7
8STEP-POOL MORPHOLOGY IN HIGH-GRADIENT STREAMS显示文摘The focus of this study is to examine bed stability and morphology in high-gradient gravel-bed streams, and thus to improve understanding of the various parameters governing the sediment flow characteristics in mountain streams. Ultimately, this knowledge can be used to design pseudo-natural channels, as in the stream simulation method of culvert design; with this in mind, prototype conditions are evaluated in a flume with slopes ranging from 3% to 7%, and particle relative submergence varying from 0.5 to 2.5 for three bed size distributions. These experiments are designed to satisfy the conditions of dynamic similarity for flow and sediment, and they are preferred over field measurements since they allow a high degree of control over testing conditions. It is found that step-pool bedforms are the most ubiquitous features along the gravel bed. A new formula is developed that correlates step height with the gravel-bed size distribution, relative submergence of the particles, and the Froude number. The step spacing is found to be related to step height and streambed longitudinal slope. Flow resistance is also examined, and a formula is developed which accounts for the resistance due to the bedforms (form resistance), as well as the individual sediment particles (grain resistance).A.R. MAXWELL and A.N. PAPANICOLAOU Research Assistant, Dept. of Civil and Envir. Engrg., Washington State University, Pullman, WA 99164-2910, Professor, Dept. of Civil and Envir. Engrg., Washington State University, Pullman, WA 99164-2910, 2001International Journal of Sediment Research2001,16,3:5
9Hydrocarbon accumulation in network and its application in the continental rift basin显示文摘The concept of hydrocarbon accumulation in network was presented on basis of the overall analysis of the formation and evolution characteristics of the continental faulted basin and of the systemic re-search on the major controlling factors on the hydrocarbon accumulation. The hydrocarbon accumu-lation in network can be defined as hydrocarbon accumulation in a three-dimensional network system which is constituted by the hydrocarbon migration passages under multiple dynamics,following the hydrocarbon generation from source rocks. The research shows that the hydrocarbon accumulation in network is composed of four elements,i.e.,hydrocarbon source (source rock kitchen),hydrocarbon accumulation terminal (trap),network pathway connecting source and terminal (transporting system),and network potential driving hydrocarbon migration in the network pathway (migration dynamics). Compared with other networks,hydrocarbon accumulation in network has three basic characteristics: the irreversible geological process of material and information flow in the network; the loss of material and information in the flow process in the network; the multiple dynamics in the flow process. Interac-tion of all the elements in the geological process can be called hydrocarbon accumulation in network. There are three basic models for hydrocarbon accumulation in network,that is,hydrocarbon accumu-lation in the network source area,hydrocarbon accumulation in the network pathway,and hydrocarbon accumulation in the network terminal. The key in the application of the hydrocarbon accumulation models in network in practice is to confirm the major accumulation stage and the function range of the four elements controlling the hydrocarbon firstly,to predict the profitable accumulation region by su-perposition of the favorable areas confirmed by four elements consequently,and to evaluate the oil-bearing property of the trap as well as confirm drilling targets. This paper takes the Dongying De-pression in the Bohai Bay Basin as an application example.PANG XiongQi1,2,CHEN DongXia1,ZHANG ShanWen3,HAO Fang1,LIU Zheng1,LIU KeYu3,SONG GuoQi4,WANG YongShi4,LUO XiaoRong5 & WU XiaoChun61 State Key Laboratory of Petroleum Resource and Prospecting,Chinese University of Petroleum,Beijing 102249,China 2 Basin and Reservoir Center,Chinese University of Petroleum,Beijing 102249,China 3 SINOPEC Shengli Oilfield,Dongying 257051,China 4 CSIRO Petroleum,P. O. Box 1130,Bentley,WA 6102,Australia 5 Institute of Geology and Geophysics,Chinese Academy of Science,Beijing 100029,China 6 China National Petroleum Corporation,Beijing 100724,China 2008Science China Earth Sciences2008,51,S2:3
10BATE curve in assessment of clinical utility of predictive biomarkers显示文摘In this paper,for time-to-event data,we propose a new statistical framework for casual inference in evaluating clinical utility of predictive biomarkers and in selecting an optimal treatment for a particular patient.This new casual framework is based on a new concept,called Biomarker Adjusted Treatment Effect (BATE) curve.The BATE curve can be used for assessing clinical utility of a predictive biomarker,for designing a subsequent confirmation trial,and for guiding clinical practice.We then propose semi-parametric methods for estimating the BATE curves of biomarkers and establish asymptotic results of the proposed estimators for the BATE curves.We also conduct extensive simulation studies to evaluate finite-sample properties of the proposed estimation methods.Finally,we illustrate the application of the proposed method in a real-world data set.ZHOU XiaoHua 1,2,3,& MA YunBei 4,5 1 Northwest HSR&D Center of Excellence,VA Puget Sound Health Care System,Seattle,WA 98198,USA 2 Department of Biostatistics,University of Washington,Seattle,WA 98198,USA 3 Beijing International Center for Mathematical Research,Peking University,Beijing 100871,China 4 Department of Operations Research and Financial Engineering,Princeton University,Princeton,NJ 08540,USA 5 School of Statisitcs,Southwest University of Finance and Economics,Chengdu 611130,China 2012Science China Mathematics2012,55,8:2
11Formation mechanisms of heavy oils in the Liaohe Western Depression,Bohai Gulf Basin显示文摘The Liaohe Oilfield in the Liaohe Western Depression of the Bohai Gulf Basin is the third-largest oil producing province and the largest heavy oil producing oilfield in China. A total of 65 oil samples,35 rock samples and 36 reservoir sandstone samples were collected and analyzed utilizing conventional geochemical and biogeochemical approaches to unravel the mechanisms of the formation of the heavy oils. Investigation of the oils with the lowest maturity compared with the oils in the Gaosheng and Niuxintuo oilfields indicates no apparent relation between the maturity and physical properties of the heavy oils. It is suggested that the heavy oil with primary origin is not likely the main mechanism re-sponsible for the majority of the heavy oils in the Liaohe Western Slope. The absence and/or depletion of n-alkanes etc.,with relatively low molecular weight and the occurrence of 25-norhopane series in the heavy oils as well as the relatively high acidity of the oils all suggest that the majority of the heavy oils once experienced secondary alteration. The fingerprints of the total scanning fluorescence (TSF) of the inner adsorbed hydrocarbons on the reservoir grains and the included hydrocarbons in fluid inclusions are similar to that of the normal oils in the area but are different from the outer adsorbed and reser-voired free oils at present,further indicating that most of the heavy oils are secondary in origin. Analyses of bacteria (microbes) in 7 oil samples indicate that anaerobic and hyperthermophilic Ar-chaeoglobus sp. are the dominant microbes relevant to oil biodegradation,which coincides with the shallow commercial gas reservoirs containing anaerobic bacteria derived gas in the Gaosheng and Leijia teotonic belts. The biodegradation most likely occurs at the water/oil interface,where the forma-tion water is essential for microbe removal and nutrient transportation. We think that biodegradation,water washing and oxidization are interrelated and are the main mechanisms for the formation of the heavy oils. Biodegradation was the predominant process with water washing being a prerequisite,and oxidization acting as a metabolic manifestation. This study provides unique approaches for further investigation of the formation mechanisms of heavy oils in general,and may provide some important insight for the exploration of shallow biogas in the area.LI SuMei1,2,PANG XiongQi1,2,LIU KeYu3,GAO XianZhi1,2,LI XiaoGuang4,CHEN ZhenYan4 & LIU BaoHong41 State Key Laboratory of Petroleum Resource and Prospecting,China University of Petroleam,Beijing 102249,China 2 Basin and Reservoir Research Center,China University of Petroleum,Beijing 102249,China 3 CSIRO Petroleum,P.O. Box 1130,Bentley WA 6102,Australia 4 Liaohe Oilfield Co. Ltd,PetroChina,Panjin 124010,China 2008Science China Earth Sciences2008,51,S2:2
12Computational simulation of wave propagation problems in infinite domains显示文摘This paper deals with the computational simulation of both scalar wave and vector wave propagation problems in infinite domains. Due to its advantages in simulating complicated geometry and complex material properties, the finite element method is used to simulate the near field of a wave propagation problem involving an infinite domain. To avoid wave reflection and refraction at the common boundary between the near field and the far field of an infinite domain, we have to use some special treatments to this boundary. For a wave radiation problem, a wave absorbing boundary can be applied to the common boundary between the near field and the far field of an infinite domain, while for a wave scattering problem, the dynamic infinite element can be used to propagate the incident wave from the near field to the far field of the infinite domain. For the sake of illustrating how these two different approaches are used to simulate the effect of the far field, a mathematical expression for a wave absorbing boundary of high-order accuracy is derived from a two-dimensional scalar wave radiation problem in an infinite domain, while the detailed mathematical formulation of the dynamic infinite element is derived from a two-dimensional vector wave scattering problem in an infinite domain. Finally, the coupled method of finite elements and dynamic infinite elements is used to investigate the effects of topographical conditions on the free field motion along the surface of a canyon.ZHAO ChongBin1,2* 1 Computational Geosciences Research Centre, Central South University, Changsha 410083, China 2 CSIRO Division of Exploration and Mining, P. O. Box 1130, Bentley, WA 6102, Australia 2010Science China(Physics,Mechanics & Astronomy)2010,53,8:2
13Surfactant - replacement therapy for respiratory distress in the preterm and term neonate 显示文摘Engle WA American Academy of Pediatrics Committee on Fetus and Newborn 2008Pediatrics2008,121,2:1
14Short-term hydrothermal scheduling with reservoir volume constraints,Ⅰ,Simulated annealing approach显示文摘Kit Po Wong and Yin Wa Wong 1993Advances in Power System Control Operation and Management1993,,2:1
15Blood lipids, cardiovascular fitness, obesity, and blood pressure: The presence of potential coronary heart disease risk factors in adolescents 显示文摘Anding JD Kubena KS Mcintosh WA 1996J Am Diet Assoc1996,96,3:1
16Genetic regulation of embryo death and senescence显示文摘DH and King WA 2001Theriogenology2001,55,:1
17Adenosine receptors and the control of endothelial cell function in inflammatory disease显示文摘Sands WA and Palmer TM 2005Immunol Lett2005,101,1:1
18Surfactant-replacement therapy for respiratory distress in the preterm and term neonate 显示文摘Engle WA American Academy of Pediatrics Committee on Fetus and Newborn 2008Pediatrics2008,121,2:1
19Surfactant - replacement therapy for respiratory distress in the preterm and term neonate显示文摘Engle WA American Academy of Pediatrics Committee on Fetus and Newborn 2008Pediatrics2008,121,2:1
20Surfaetant-replaeement therapy for respiratory distress in preterm and term neonate 显示文摘ENGLE WA American Academy of Pediatrics Committee on Fetus and Newborn 2008Pediatrics2008,121,2:1
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