期刊文献+
共找到27篇文章
< 1 2 >
每页显示 20 50 100
冬小麦子粒增重过程的模拟模型研究 被引量:6
1
作者 刘章勇 梅楠 郁明谏 《湖北农业科学》 1997年第3期14-18,共5页
利用1989~1991年2年度田间试验资料及北京市多年大量田间观测资料在IBMXT机上建立了子粒增重过程的模拟模型。子粒干物质的累积过程符合Logistic曲线。在前人研究的基础上进一步明确了模型参数的生物学意义,... 利用1989~1991年2年度田间试验资料及北京市多年大量田间观测资料在IBMXT机上建立了子粒增重过程的模拟模型。子粒干物质的累积过程符合Logistic曲线。在前人研究的基础上进一步明确了模型参数的生物学意义,离析出了品种、栽培技术措施和气象因素分别对子粒增重过程的影响,并进行了初步的定量描述。模型除了考虑灌浆期间气象因素对粒重的影响之外,将品种和栽培措施因素对粒重的影响也给予了明确的表达,因而不仅具有解释和预测功能,同时也可以用来进行初步的决策和调控。 展开更多
关键词 冬小麦 子粒 模拟模型 预测 调控
下载PDF
Opaque-2基因导入各类隐性纯合体玉米早代子粒粒重和含油率的效应研究 被引量:2
2
作者 昂沃 郝小琴 吴子恺 《玉米科学》 CAS CSCD 北大核心 2012年第1期24-29,34,共7页
选用微胚乳等各类隐性纯合体玉米为试验材料,利用杂交法把opaque-2基因导入各类隐性纯合体玉米,并以被导原隐性纯合体为对照,分析各类玉米杂交导入o2后的早代o2隐性纯合体子粒粒重和含油率的变化。结果表明,在导入opaque-2后的微胚乳等... 选用微胚乳等各类隐性纯合体玉米为试验材料,利用杂交法把opaque-2基因导入各类隐性纯合体玉米,并以被导原隐性纯合体为对照,分析各类玉米杂交导入o2后的早代o2隐性纯合体子粒粒重和含油率的变化。结果表明,在导入opaque-2后的微胚乳等各类隐性纯合体玉米杂交早代中,整粒重、胚和非胚部重、整粒含油率、胚和非胚部含油率都发生了增减两个方向的变异,效应随不同类玉米及子粒不同部位而异。导入o2后的o2微胚乳玉米(o2we)的粒重和含油率都极显著降低,表明o2基因对所选用的微胚乳玉米早代的粒重和含油率都具极显著的减少效应。o2bw(39)、o2w(45)、o2w(49)、o2w(51)和o2w(53)等玉米整粒重极显著增加;o2hw(27)、o2w(45)、o2w(49)、o2w(51)和o2w(53)等玉米胚重极显著增加;o2hw(27)、o2bw(39)、o2w(49)和o2w(53)等玉米整粒含油率显著或极显著增加;o2w(49)和o2w(53)玉米胚含油率显著或极显著增加;o2hw(27)、o2bw(39)和o2w(53)等玉米非胚部含油率显著或极显著增加。表明导入o2后对这几类玉米部分材料的粒重和含油率具有显著的改良效应,通过选择有望获得相应的优良品系。 展开更多
关键词 玉米 o2基因 子粒含油量 子粒重 SSR标记
原文传递
Face tracking algorithm based on particle filter with mean shift importance sampling 被引量:2
3
作者 高建坡 杨浩 +1 位作者 安国成 吴镇扬 《Journal of Southeast University(English Edition)》 EI CAS 2007年第2期196-201,共6页
The condensation tracking algorithm uses a prior transition probability as the proposal distribution, which does not make full use of the current observation. In order to overcome this shortcoming, a new face tracking... The condensation tracking algorithm uses a prior transition probability as the proposal distribution, which does not make full use of the current observation. In order to overcome this shortcoming, a new face tracking algorithm based on particle filter with mean shift importance sampling is proposed. First, the coarse location of the face target is attained by the efficient mean shift tracker, and then the result is used to construct the proposal distribution for particle propagation. Because the particles obtained with this method can cluster around the true state region, particle efficiency is improved greatly. The experimental results show that the performance of the proposed algorithm is better than that of the standard condensation tracking algorithm. 展开更多
关键词 face tracking particle filter importance sampling CONDENSATION mean shift
下载PDF
Facile Preparation of Danazol Nanoparticles by High-Gravity Anti-solvent Precipitation (HGAP) Method 被引量:8
4
作者 赵宏 王洁欣 +3 位作者 张海霞 沈志刚 甄崇礼 陈建峰 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2009年第2期318-323,共6页
The nanoparticles of the hydrophobic drug of danazol with narrow size distribution are facilely prepared by controlled high-gravity anti-solvent precipitation (HGAP) process. Intensified micromixing and uniform nucl... The nanoparticles of the hydrophobic drug of danazol with narrow size distribution are facilely prepared by controlled high-gravity anti-solvent precipitation (HGAP) process. Intensified micromixing and uniform nucleation environment are created by the high-gravity equipment (rotating packed bed) in carrying out the anti-solvent precipitation process to produce nanoparticles. The average particle size decreases from 55 μm of the raw danazol to 190 nm of the nanoparticles. The Brunauer-Emmett-Teller (BET) surface area sharply increases from 0.66 m^2·g^-1 to 15.08 m^2·g^-l. Accordingly, the dissolution rate is greatly improved. The molecular state, chemical composition, and crystal form of the danazol nanoparticles remains unchanged after processing according to Fourier transform infrared (FTIR) and X-ray diffraction (XRD), The high recovery ratio and continuous production capacity are highly appreciated in industry. Therefore, the HGAP method might offer a general and facile platform for mass production of hydrophobic pharmaceutical danazol particles in nanometer range. 展开更多
关键词 high-gravity antisolvent precipitation rotating packed bed danazol nanoparticles dissolution rate
下载PDF
Extra-Large Seed Germplasms of Brassica Napus Created through Microspore Culture 被引量:1
5
作者 Chen Wei Zhao Kaiqin +8 位作者 Zhang Guojian Zhou Picai Zhao Desheng Qu Guan Luo Yangqing Zu Feng Li Jingfeng Dong Yunsong Wang Jingqiao 《Journal of Environmental Science and Engineering(A)》 2016年第2期90-96,共7页
Thousand Seed Weight (TSW) is one of the major yield components of rapeseed (Brassica napus L.). Here reports an extra-large seed germplasm GM01 which was obtained through isolated microspore culture. Three-way cr... Thousand Seed Weight (TSW) is one of the major yield components of rapeseed (Brassica napus L.). Here reports an extra-large seed germplasm GM01 which was obtained through isolated microspore culture. Three-way cross was made: H8--a Yunnan spring early-maturing rapeseed variety, "Legeney"--a Canadian canola variety and "020010"--a semi-winter late-maturing rapeseed variety. One hundred and forty eight doubled hyploid lines were obtained from the F~ plants of three-way cross through isolated mierospore culture. Among them, the TSW of GM01 amounted to 8.68 g and the TSW of 53 lines were above 5.0 g. The TSWs of GM01 were relatively stable among the multi-location field trials from 2007 to 2014 with variation being only 10%-15% among the locations and years. Compared with H8, GM01 had larger flowers, stigmas, siliques and seed diameters, but less branches, siliques per plant and seeds per silique. 展开更多
关键词 Brassica napus GERMPLASM seed weight morphological trait microspore culture.
下载PDF
Remote Preparation of a Two-Particle Entangled State by a Bipartite Entangled State and a Tripartite Entangled W State 被引量:4
6
作者 XIAO Xiao-Qi LIU Jin-Ming 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第2期247-252,共6页
We propose a scheme to remotely prepare a general two-particle entangled state by using a bipartite entangled state and a tripartite entangled W state as the quantum channel. Our scheme consists of one sender and two ... We propose a scheme to remotely prepare a general two-particle entangled state by using a bipartite entangled state and a tripartite entangled W state as the quantum channel. Our scheme consists of one sender and two remote receivers. The sender can help either one of the receivers to remotely reconstruct the original state with the assistance of the other receiver's single-partlcle orthogona/measurement. We obtain the total success probability and discuss the classical communication cost in our remote state preparation scheme. 展开更多
关键词 remote state preparation W state projective measurement unitary transformation
下载PDF
Fabrication of Poly(y-glutamic acid)-coated Fe3O4 Magnetic Nanoparticles and Their Application in Heavy Metal Removal 被引量:6
7
作者 常菁 仲兆祥 +2 位作者 徐虹 姚忠 陈日志 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2013年第11期1244-1250,共7页
In this study, poly(y-glutamic acid)-coated Fe3O4 magnetic nanoparticles (y-PGA/Fe304 MNPs) were successfully fabricated using the co-precipitation method. Fe3O4 MNPs were also prepared for comparison. The av erag... In this study, poly(y-glutamic acid)-coated Fe3O4 magnetic nanoparticles (y-PGA/Fe304 MNPs) were successfully fabricated using the co-precipitation method. Fe3O4 MNPs were also prepared for comparison. The av erage size and specific surface area results reveal that 7-PGA/Fe304 MNPs (52.4 nm, 88.41 m2.g-1) have smaller particle size and larger specific surface area_ than Fe3O4 MNPs (62.0 nm, 76.83 mLg-1). The y-PGA/Fe3O4 MNPs 展开更多
关键词 y-PGA magnetic nanoparticles Fe3fO4 heavy metal removal
下载PDF
Pipe Shape Solution of Faddeev Model 被引量:1
8
作者 SHI Chang-Guang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第2期428-430,共3页
Utilizing the results that the Faddeev model is equivalent to the mesonic sector of the SU(2) Skyrme model, where the baryon number current vanishes everywhere, some exact solutions including the vortex solutions of... Utilizing the results that the Faddeev model is equivalent to the mesonic sector of the SU(2) Skyrme model, where the baryon number current vanishes everywhere, some exact solutions including the vortex solutions of the Faddeev model axe discussed. The solutions are classified by the 2, the new multisoliton solutions are obtained and the pipe shape found. first Chern number. When the Chern number equals distribution of the energy density of the solutions are 展开更多
关键词 pipe shape vortex solution Faddeev model
下载PDF
Quark-Quark Scattering
9
作者 Zaheer Uddin Khursheed Ather Siddiqui 《Journal of Physical Science and Application》 2012年第4期139-142,共4页
Scattering process always reveal valuable information. For example scattering of alpha particle in Rutherford's well known experiment revealed the existence of nucleus. Physicists have been studying collision process... Scattering process always reveal valuable information. For example scattering of alpha particle in Rutherford's well known experiment revealed the existence of nucleus. Physicists have been studying collision process both experimentally as well as theoretically to know much about particle Physics. It is believed that the quark-quark scattering results are same as those of lepton-lepton systems and they are mass independent. The aim of this work was to calculate amplitude cross section for heavy quarks. Our results reveal a mass dependence of these results for heavy quarks. 展开更多
关键词 Particles scattering scattering amplitude QUARKS quarks scattering.
下载PDF
In vitro reassembly of nuclear envelopes and organelles in Xenopus egg extracts
10
作者 Ping Lu Hui Zheng Zhonghe Zhai 《Cell Research》 SCIE CAS CSCD 2006年第7期632-640,共9页
We reconstituted bilayer nuclear membranes, multilayer membranes, and organelles from mixtures ofXenopus laevis egg extracts and demembranatedXenopus sperm nuclei. Varying proportions of the cytosolic and vesicular fr... We reconstituted bilayer nuclear membranes, multilayer membranes, and organelles from mixtures ofXenopus laevis egg extracts and demembranatedXenopus sperm nuclei. Varying proportions of the cytosolic and vesicular fractions from the eggs were used in the reconstitution mixtures. A cytosol:vesicle ratio of 10:1 promoted reassembly of the normal bilayer nuclear membrane with inserted nuclear pore complexes around the decondensed Xenopus sperm chromatin. A cytosol: vesicle ratio of 5:1 caused decondensed and dispersed sperm chromatin to be either surrounded by or divided by unusual multilayer membrane structures with inlaid pore complexes. A cytosol:vesicle ratio of 2.5:1 promoted reconstitution of mitochondria, endoplasmic reticulum networks, and Golgi apparatus. During reassembly of the endoplasmic reticulum and Golgi apparatus, vesicular fragments of the corresponding organelles fused together and changed their shape to form flattened cistemae, which were then stacked one on top of another. 展开更多
关键词 cell-free system endoplasmic reticulum Golgi apparatus MITOCHONDRIA nuclear reconstitution Xenopus egg extracts
下载PDF
Interaction between Fermions via Mass less Bosons and Massive Particles
11
作者 Voicu Dolocan Voicu Octavian Dolocan Andrei Dolocan 《Journal of Physical Science and Application》 2013年第5期332-340,共9页
By using a Hamiltonian based on the coupling through flux lines, we have calculated the interaction energy between two fermions via mass less bosons as well as via massive particles. In the case of interaction via mas... By using a Hamiltonian based on the coupling through flux lines, we have calculated the interaction energy between two fermions via mass less bosons as well as via massive particles. In the case of interaction via mass less bosons we obtain an equivalent expression for the Coulomb's energy on the form cthc/r, where a is the fine structure constant. In the case of the interaction via massive particles we obtain that the interaction energy contains a term building the potential well. Also, we take into account the spin-spin interaction of the nucleons and we show that this interaction modulates the interaction potential through a cosine factor. The obtained results are in a good agreement with experimental data, for example, of deuteron. We have determined the radial functions for the deuteron. 展开更多
关键词 Particle interactions one pion exchange deuteron.
下载PDF
Continuous Quantum Nondemolition Measurements of a Particle in Electromagnetic and Gravitational Fields
12
作者 ZHU Chun-Hua ZHA Chao-Zheng 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第3X期455-458,共4页
The detection of a particle in electromagnetic plus gravitational fields is investigated. We obtain a set of quantum nondemolition variables. The continuous measurements of these nondemolition parameters are analyzed ... The detection of a particle in electromagnetic plus gravitational fields is investigated. We obtain a set of quantum nondemolition variables. The continuous measurements of these nondemolition parameters are analyzed in the framework of restricted path integral formalism. We manipulate the corresponding propagators, and deduce the probabilities associated with the possible measurement outputs. 展开更多
关键词 continuous quantum nondemolition measurements restricted path integral
下载PDF
Selective removal of heavy metal ions from aqueous solutions with surface functionalized silica nanoparticles by different functional groups 被引量:3
13
作者 孔祥峰 杨斌 +4 位作者 熊恒 周阳 薛生国 徐宝强 王世兴 《Journal of Central South University》 SCIE EI CAS 2014年第9期3575-3579,共5页
The industrial silica fume pretreated by nitric acid at 80 °C was re-used in this work. Then, the obtained silica nanoparticles were surface functionalized by silane coupling agents, such as(3-Mercaptopropyl) tri... The industrial silica fume pretreated by nitric acid at 80 °C was re-used in this work. Then, the obtained silica nanoparticles were surface functionalized by silane coupling agents, such as(3-Mercaptopropyl) triethoxysilane(MPTES) and(3-Amincpropyl) trithoxysilane(APTES). Some further modifications were studied by chloroaceetyl choride and 1,8-Diaminoaphalene for amino modified silica. The surface functionalized silica nanoparticles were characterized by Fourier transform infrared(FI-IR) and X-ray photoelectron spectroscopy(XPS). The prepared adsorbent of surface functionalized silica nanoparticles with differential function groups were investigated in the selective adsorption about Pb2+, Cu2+, Hg2+, Cd2+ and Zn2+ions in aqueous solutions. The results show that the(3-Mercaptopropyl) triethoxysilane functionalized silica nanoparticles(SiO2-MPTES) play an important role in the selective adsorption of Cu2+ and Hg2+, the(3-Amincpropyl) trithoxysilane(APTES) functionalized silica nanoparticles(SiO2-APTES) exhibited maximum removal efficiency towards Pb2+ and Hg2+, the 1,8-Diaminoaphalene functionalized silica nanoparticles was excellent for removal of Hg2+ at room temperature, respectively. 展开更多
关键词 industrial silica fume surface functionalization heavy metal ions selective removal
下载PDF
Single-particle 3D reconstruction on specialized stream architecture and comparison with GPGPUs
14
作者 段勃 Wang Wendi +1 位作者 Tan Guangming Meng Dan 《High Technology Letters》 EI CAS 2014年第4期333-345,共13页
The wide acceptance and data deluge in medical imaging processing require faster and more efficient systems to be built.Due to the advances in heterogeneous architectures recently,there has been a resurgence in the fi... The wide acceptance and data deluge in medical imaging processing require faster and more efficient systems to be built.Due to the advances in heterogeneous architectures recently,there has been a resurgence in the first research aimed at FPGA-based as well as GPGPU-based accelerator design.This paper quantitatively analyzes the workload,computational intensity and memory performance of a single-particle 3D reconstruction application,called EMAN,and parallelizes it on CUDA GPGPU architectures and decouples the memory operations from the computing flow and orchestrates the thread-data mapping to reduce the overhead of off-chip memory operations.Then it exploits the trend towards FPGA-based accelerator design,which is achieved by offloading computingintensive kernels to dedicated hardware modules.Furthermore,a customized memory subsystem is also designed to facilitate the decoupling and optimization of computing dominated data access patterns.This paper evaluates the proposed accelerator design strategies by comparing it with a parallelized program on a 4-cores CPU.The CUDA version on a GTX480 shows a speedup of about 6 times.The performance of the stream architecture implemented on a Xilinx Virtex LX330 FPGA is justified by the reported speedup of 2.54 times.Meanwhile,measured in terms of power efficiency,the FPGA-based accelerator outperforms a 4-cores CPU and a GTX480 by 7.3 times and 3.4 times,respectively. 展开更多
关键词 Stream architecture general purpose graphic processing unit GPGPU) field programmable gate array (FPGA) CRYO-EM
下载PDF
An Introduction to AdS/CFT Correspondence for Phenomenologists
15
作者 陈斌 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第11期895-904,共10页
We give a brief introduction to the AdS/CFT correspondence and its application to QCD physics,especiallyits application in the study of quark-gluon-plasma (QGP)formed in the relativistic heavy ion collision (RHIC).Thi... We give a brief introduction to the AdS/CFT correspondence and its application to QCD physics,especiallyits application in the study of quark-gluon-plasma (QGP)formed in the relativistic heavy ion collision (RHIC).Thisreview is based on the talks given in several schools and programs for the phenomenologists working on nuclear physicsand particle physics. 展开更多
关键词 AdS/CFT correspondence QUARK-GLUON-PLASMA QCD
下载PDF
Pyrolysis and combustion kinetics of lycopodium particles in thermogravimetric analysis 被引量:1
16
作者 Seyed Alireza Mostafavi Sadjad Salavati +1 位作者 Hossein Beidaghy Dizaji Mehdi Bidabadi 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第9期3409-3417,共9页
Biomass is a kind of renewable energy which is used increasingly in different types of combustion systems or in the production of fuels like bio-oil. Lycopodium is a cellulosic particle, with good combustion propertie... Biomass is a kind of renewable energy which is used increasingly in different types of combustion systems or in the production of fuels like bio-oil. Lycopodium is a cellulosic particle, with good combustion properties, of which microscopic images show that these particles have spherical shapes with identical diameters of 31 μm. The measured density of these particles is 1.0779 g/cm2. Lycopodium particles contain 64.06% carbon, 25.56% oxygen, 8.55% hydrogen and 1.83% nitrogen, and no sulfur. Thermogravimetric analysis in the nitrogen environment indicates that the maximum of particle mass reduction occurs in the temperature range of 250-550 ℃ where the maximum mass reduction in the DTG diagrams also occurs in. In the oxygen environment, an additional peak can also be observed in the temperature range of 500-600 ℃, which points to solid phase combustion and ignition temperature of lycopodium particles. The kinetics of reactions is determined by curve fitting and minimization of error. 展开更多
关键词 lycopodium dust particles thermogravimetric analysis PYROLYSIS COMBUSTION ignition temperature chemical kinetics
下载PDF
How the Orbital System of Particles Consolidates Gravity and Electromagnetism
17
作者 William Day 《Journal of Philosophy Study》 2012年第9期619-630,共12页
There is an actual reality that underlies the relative reality of physics. The orbital system is shown to be the principle by which motion transforms space into matter. The support of the universe is the absolute thre... There is an actual reality that underlies the relative reality of physics. The orbital system is shown to be the principle by which motion transforms space into matter. The support of the universe is the absolute three-stage hierarchy of particles, atoms, and gravitational systems. Below 1/c waves are dissociated into strands and neutrinos are separated as points of charge. The electron and positron are single strands with opposed helical turns. Protons and neutrons have a nucleus of positrinos and negatrinos surrounded by concentric shells of strands in 2"~ resonance. The orbital strands reverberate into space creating a field with gravitational and electromagnetic aspects. The orbital system defines matter, energy, motion, and time based on composition. The three stages have a constant field content but differ by field density and components. 展开更多
关键词 orbital systems GRAVITY electromagnetism STRANDS NEUTRINOS positrino negatrino proton compositionspace matrix
下载PDF
夏玉米果穗不同部位小穗轴维管束显微结构特点及其对子粒发育的影响 被引量:2
18
作者 张善平 冯海娟 +2 位作者 刘鹏 陈海宁 胡兆平 《玉米科学》 CAS CSCD 北大核心 2017年第6期58-62,72,共6页
采用大田试验,设置不同种植密度,选用不同类型玉米品种,研究果穗小穗轴维管束的解剖结构变化及其与不同部位子粒干重的关系。结果表明,正常情况下,小穗轴维管束的韧皮部发达,且其"喇叭"结构十分有利于子粒灌浆,败育子粒的小... 采用大田试验,设置不同种植密度,选用不同类型玉米品种,研究果穗小穗轴维管束的解剖结构变化及其与不同部位子粒干重的关系。结果表明,正常情况下,小穗轴维管束的韧皮部发达,且其"喇叭"结构十分有利于子粒灌浆,败育子粒的小穗轴维管束则发育不良;相同粒位,ZD958的小穗轴维管束面积显著大于ND08的小穗轴维管束面积;两个品种的小穗轴维管束面积均随密度增加而降低;小穗轴维管束的面积受密度影响较大,但受基因(品种)影响更大。耐密性品种在较高密度下小穗轴维管束的结构仍然正常,其面积虽然也减少但不足以成为灌浆障碍,这也是其获得高产的原因之一。因此,在品种选育上,应优选小穗轴维管束面积较大的材料。 展开更多
关键词 夏玉米 小穗轴维管束 密度 子粒
原文传递
Resampling methods for particle filtering: identical distribution, a new method, and comparable study 被引量:7
19
作者 Tian-cheng LI Gabriel VILLARRUBIA +2 位作者 Shu-dong SUN Juan M.CORCHADO Javier BAJO 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2015年第11期969-984,共16页
Resampling is a critical procedure that is of both theoretical and practical significance for efficient implementation of the particle filter. To gain an insight of the resampling process and the filter, this paper co... Resampling is a critical procedure that is of both theoretical and practical significance for efficient implementation of the particle filter. To gain an insight of the resampling process and the filter, this paper contributes in three further respects as a sequel to the tutorial (Li et al., 2015). First, identical distribution (ID) is established as a general principle for the resampling design, which requires the distribution of particles before and after resampling to be statistically identical. Three consistent met- rics including the (symmetrical) Kullback-Leibler divergence, Kolmogorov-Smimov statistic, and the sampling variance are introduced for assessment of the ID attribute of resampling, and a corresponding, qualitative ID analysis of representative resampling methods is given. Second, a novel resampling scheme that obtains the optimal ID attribute in the sense of minimum sampling variance is proposed. Third, more than a dozen typical resampling methods are compared via simulations in terms of sample size variation, sampling variance, computing speed, and estimation accuracy. These form a more comprehensive under- standing of the algorithm, providing solid guidelines for either selection of existing resampling methods or new implementations 展开更多
关键词 Particle filter RESAMPLING Kullback-Leibler divergence Kolmogorov-Smimov statistic
原文传递
Simultaneous estimation of soil moisture and hydraulic parameters using residual resampling particle filter 被引量:3
20
作者 BI HaiYun MA JianWen +1 位作者 QIN SiXian ZHANG HongJuan 《Science China Earth Sciences》 SCIE EI CAS 2014年第4期824-838,共15页
Land data assimilation(DA) has gradually developed into an important earth science research method because of its ability to combine model simulations and observations.Integrating new observations into a land surface ... Land data assimilation(DA) has gradually developed into an important earth science research method because of its ability to combine model simulations and observations.Integrating new observations into a land surface model by the DA method can correct the predicted trajectory of the model and thus,improve the accuracy of state variables.It can also reduce uncertainties in the model by estimating some model parameters simultaneously.Among the various DA methods,the particle filter is free from the constraints of linear models and Gaussian error distributions,and can be applicable to any nonlinear and non-Gaussian state-space model;therefore,its importance in land data assimilation research has increased.In this study,a DA scheme was developed based on the residual resampling particle filter.Microwave brightness temperatures were assimilated into the macro-scale semi-distributed variance infiltration capacity model to estimate the surface soil moisture and three hydraulic parameters simultaneously.Finally,to verify the scheme,a series of comparative experiments was performed with experimental data obtained during the Soil Moisture Experiment of 2004 in Arizona.The results show that the scheme can improve the accuracy of soil moisture estimations significantly.In addition,the three hydraulic parameters were also well estimated,demonstrating the effectiveness of the DA scheme. 展开更多
关键词 data assimilation residual resampling particle filter microwave brightness temperature soil moisture hydraulic parameter
原文传递
上一页 1 2 下一页 到第
使用帮助 返回顶部