期刊文献+
共找到161篇文章
< 1 2 9 >
每页显示 20 50 100
Concurrence of Quantum States: Algebraic Dynamical Method Study XXX Models in a Time-Depending Random External Field 被引量:2
1
作者 付传技 朱钦圣 邬劭轶 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第6期1072-1076,共5页
Based on algebraic dynamics and the concept of the concurrence of the entanglement, we investigate the evolutive properties of the two-qubit entanglement that formed by Heisenberg XXX models under a time-depending ext... Based on algebraic dynamics and the concept of the concurrence of the entanglement, we investigate the evolutive properties of the two-qubit entanglement that formed by Heisenberg XXX models under a time-depending external field. For this system, the property of the concurrence that is only dependent on the coupling constant J and total values of the external field is proved. Furthermore, we found that the thermal concurrence of the system under a static random external field is a function of the coupling constant J, temperature T, and the magnitude of external field. 展开更多
关键词 CONCURRENCE algebraic dynamical method ENTANGLEMENT
下载PDF
Dynamic Location Method for Shallow Ocean Bottom Nodes Using the Levenberg-Marquart Algorithm
2
作者 TONG Siyou LI Junjie +2 位作者 XU Xiugang FANG Yunfen WANG Zhongcheng 《Journal of Ocean University of China》 SCIE CAS CSCD 2024年第4期953-960,共8页
Ocean bottom node(OBN)data acquisition is the main development direction of marine seismic exploration;it is widely promoted,especially in shallow sea environments.However,the OBN receivers may move several times beca... Ocean bottom node(OBN)data acquisition is the main development direction of marine seismic exploration;it is widely promoted,especially in shallow sea environments.However,the OBN receivers may move several times because they are easily affected by tides,currents,and other factors in the shallow sea environment during long-term acquisition.If uncorrected,then the imaging quality of subsequent processing will be affected.The conventional secondary positioning does not consider the case of multiple movements of the receivers,and the accuracy of secondary positioning is insufficient.The first arrival wave of OBN seismic data in shallow ocean mainly comprises refracted waves.In this study,a nonlinear model is established in accordance with the propagation mechanism of a refracted wave and its relationship with the time interval curve to realize the accurate location of multiple receiver movements.In addition,the Levenberg-Marquart algorithm is used to reduce the influence of the first arrival pickup error and to automatically detect the receiver movements,identifying the accurate dynamic relocation of the receivers.The simulation and field data show that the proposed method can realize the dynamic location of multiple receiver movements,thereby improving the accuracy of seismic imaging and achieving high practical value. 展开更多
关键词 OBN dynamic location method Levenberg-Marquart algorithm seismic exploration of shallow sea
下载PDF
Analogue Correction Method of Errors by Combining Statistical and Dynamical Methods 被引量:7
3
作者 任宏利 丑纪范 《Acta meteorologica Sinica》 SCIE 2006年第3期367-373,共7页
Based on the atmospheric analogy principle, the inverse problem that the information of historical analogue data is utilized to estimate model errors is put forward and a method of analogue correction of errors (ACE... Based on the atmospheric analogy principle, the inverse problem that the information of historical analogue data is utilized to estimate model errors is put forward and a method of analogue correction of errors (ACE) of model is developed in this paper. The ACE can combine effectively statistical and dynamical methods, and need not change the current numerical prediction models. The new method not only adequately utilizes dynamical achievements but also can reasonably absorb the information of a great many analogues in historical data in order to reduce model errors and improve forecast skill. Purthermore, the ACE may identify specific historical data for the solution of the inverse problem in terms of the particularity of current forecast. The qualitative analyses show that the ACE is theoretically equivalent to the principle of the previous analogue-dynamical model, but need not rebuild the complicated analogue-deviation model, so has better feasibility and operational foreground. Moreover, under the ideal situations, when numerical models or historical analogues are perfect, the forecast of the ACE would transform into the forecast of dynamical or statistical method, respectively. 展开更多
关键词 combination of statistical and dynamical methods inverse problem numerical prediction analogue correction of errors (ACE)
原文传递
Dynamical Properties of Two Coupled Dissipative QED Cavities Driven by Coherent Fields 被引量:2
4
作者 HOU Bang-Pin WANG Shun-Jin +1 位作者 WANG Gang SUN Wei-Li 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第2X期232-242,共11页
When two identical QED cavities driven by the coherent fields are located in a uniform environment, in addition to dissipation, there appears an indirect coupling between the two cavities induced by the background fie... When two identical QED cavities driven by the coherent fields are located in a uniform environment, in addition to dissipation, there appears an indirect coupling between the two cavities induced by the background fields. We investigate the effects of the coherent fields, the dissipation as well as the incoherent coupling on the following dynamical properties of the system: photon transfer, reversible decoherence, and quantum state transfer, etc. We find that the photons in the cavities do not leak completely into the environment due to the collective coupling between the cavities and the enviroment, and the photons are transferred irreversibly from the cavity with more photons to the cavity with less ones due to the incoherent coupling so that they are equally distributed among the two cavities. The coherent field pumping on the two cavities increases the mean photons, complements the revived magnitude of the reversible decoherence, but hinders the quantum state transfer between the two cavities. The above phenomena may find applications in quantum communication and other basic fields. 展开更多
关键词 photon transfer reversible decoherence quantum state transfer algebraic dynamical method two coupled dissipative QED cavities driven by coherent fields
下载PDF
Numerical Study on the Aerodynamic and Fluid−Structure Interaction of An NREL-5MW Wind Turbine
5
作者 ZHAO Mi YU Wan-li +2 位作者 WANG Pi-guang QU Yang DU Xiu-li 《China Ocean Engineering》 SCIE EI CSCD 2024年第3期363-378,共16页
A 5-MW wind turbine has been modeled and analyzed for fluid-structure interaction and aerodynamic performance.In this study, a full-scale model of a 5-MW wind turbine is first developed based on a computational fluid ... A 5-MW wind turbine has been modeled and analyzed for fluid-structure interaction and aerodynamic performance.In this study, a full-scale model of a 5-MW wind turbine is first developed based on a computational fluid dynamics(CFD) approach, in which the unsteady, noncompressible Reynolds Averaged Navier-Stokes(RANS) method is used. The main focus of the study is to analyze the tower shadow effect on the aerodynamic performance of the wind turbine under different inlet flow conditions. Subsequently, the finite element model is established by considering fluid/structure interactions to study the structural stress, displacement, strain distributions and flow field information of the structure under the uniform wind speed. Finally, the fluid-structure interaction model is established by considering turbulent wind and the tower shadow effect. The variation rules of the dynamic response of the one-way and two-way fluid-structure interaction(FSI) models under different wind speeds are analyzed, and the numerical calculation results are compared with those of the centralized mass model. The results show that the tower shadow effect and structural deformation are the main factors affecting the aerodynamic load fluctuation of the wind turbine, which in turn affects the aerodynamic performance and structural stability of the blades. The structural dynamic response of the coupled model shows significant similarity, while the structural displacement response of the former exhibits less fluctuation compared with the conventional centralized mass model. The one-way fluid-structure interaction(FSI)model shows a higher frequency of stress-strain and displacement oscillations on the blade compared with the two-way FSI model. 展开更多
关键词 computational fluid dynamics methods(CFD) tower shadow effect aerodynamic performance fluidstructure interaction space flow field
下载PDF
规范场论中自对偶磁单极子解的存在唯一性
6
作者 陈筱 《Chinese Quarterly Journal of Mathematics》 2024年第1期86-96,共11页
Magnetic monopoles stand for the static solution arising from a(1 + 3)–dimensional theory describing the interaction between a real scalar triplet and non–Abelian gauge field. In this paper, we obtain a two–point b... Magnetic monopoles stand for the static solution arising from a(1 + 3)–dimensional theory describing the interaction between a real scalar triplet and non–Abelian gauge field. In this paper, we obtain a two–point boundary value problem of a first–order ordinary differential equations from the self–dual monopole model. Then we establish the existence and uniqueness theorem for the problem by using a dynamical shooting method, we also obtain sharp asymptotic estimates for the solutions at infinity. 展开更多
关键词 Self-dual monopole dynamical shooting method Existence and uniqueness
下载PDF
DETERMINING CRITICAL TIME OF ROCK DYNAMIC FRACTURE BY DYNAMIC MOIRE METHOD
7
作者 喻勇 张宗贤 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 1995年第2期113+109-113,共6页
An effective Dynamic Moire method was presented to determine the critical time of crack instable propagation in rock dynamic fracture. Two pieces of grating were installed near the notch of Short Rod specimen to form ... An effective Dynamic Moire method was presented to determine the critical time of crack instable propagation in rock dynamic fracture. Two pieces of grating were installed near the notch of Short Rod specimen to form the Moire fringes, then the COD versus time could be monitored from the movement of the Moire fringes, and finally the critical time could be determined from the velocity of COD. This method was also compared with another one.It could be concluded that the critical time determined by Dynamic Moire method corresponds with that of the Transmitted Wave method at the loading rates from 103 to 104 MPa·m(1/2)·S(-1). 展开更多
关键词 ROCK Moire method/dynamic fracture critical time
下载PDF
Dynamic Analysis of Customer Demand Based on Intuitionistic Fuzzy Number in Product Planning
8
作者 Yongguang Yi Zengqiang Wang 《Proceedings of Business and Economic Studies》 2024年第5期127-131,共5页
To address the fuzziness and variability in determining customer demand importance,a dynamic analysis method based on intuitionistic fuzzy numbers is proposed.First,selected customers use intuitionistic fuzzy numbers ... To address the fuzziness and variability in determining customer demand importance,a dynamic analysis method based on intuitionistic fuzzy numbers is proposed.First,selected customers use intuitionistic fuzzy numbers to represent the importance of each demand.Then,the preference information is aggregated using customer weights and time period weights through the intuitionistic fuzzy ordered weighted average operator,yielding a dynamic vector of the subjective importance of the demand index.Finally,the feasibility of the proposed method is demonstrated through an application example of a vibrating sorting screen. 展开更多
关键词 Quality function deployment Customer demand Intuitionistic fuzzy number Dynamic analysis method
下载PDF
Analysis for the Deployment of Single-Point Mooring Buoy System Based on Multi-Body Dynamics Method 被引量:5
9
作者 常宗瑜 唐原广 +2 位作者 李华军 杨建明 王磊 《China Ocean Engineering》 SCIE EI 2012年第3期495-506,共12页
Deployment of buoy systems is one of the most important procedures for the operation of buoy system. In the present study, a single-point mooring buoy system which contains surface buoy, cable segments with components... Deployment of buoy systems is one of the most important procedures for the operation of buoy system. In the present study, a single-point mooring buoy system which contains surface buoy, cable segments with components, anchor and so on is modeled by applying multi-body dynamics method. The motion equations are developed in discrete node description and fully Cartesian coordinates. Then numerical method is used to solve the ordinary differential equations and dynamics simulations are achieved while anchor is casting from board. The trajectories and velocities of different nodes without current and with current in buoy system are obtained. The transient tension force of each part of the cable is analyzed in the process of deployment. Numerical results indicate that the transient payload increases to a peak value when the anchor is touching the seabed and the maximum tension force will vary with different floating configuration. This work is helpful for design and deployment planning of buoy system. 展开更多
关键词 multi-body dynamics method DEPLOYMENT single-point mooring buoy system fully Cartesian coordinates
下载PDF
Slope stability analysis under seismic load by vector sum analysis method 被引量:15
10
作者 Mingwei Guo Xiurun Ge Shuilin Wang 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE 2011年第3期282-288,共7页
The vibration characteristics and dynamic responses of rock and soil under seismic load can be estimated with dynamic finite element method (DFEM). Combining with the DFEM, the vector sum analysis method (VSAM) is... The vibration characteristics and dynamic responses of rock and soil under seismic load can be estimated with dynamic finite element method (DFEM). Combining with the DFEM, the vector sum analysis method (VSAM) is employed in seismic stability analysis of a slope in this paper. Different from other conventional methods, the VSAM is proposed based on the vector characteristic of force and current stress state of the slope. The dynamic stress state of the slope at any moment under seismic load can he obtained by the DFEM, thus the factor of safety of the slope at any moment during earthquake can be easily obtained with the VSAM in consideration of the DFEM. Then, the global stability of the slope can be estimated on the basis of time-history curve of factor of safety and reliability theory. The VSAM is applied to a homogeneous slope under seismic load. The factor of safety of the slope is 1.30 under gravity only and the dynamic factor of safety under seismic load is 1.21. The calculating results show that the dynamic characteristics and stability state of the slope with input ground motion can be actually analyzed. It is believed that the VSAM is a feasible and practical approach to estimate the dynamic stability of slopes under seismic load. 展开更多
关键词 slope stability vector sum analysis method (VSAM) seismic load dynamic finite element method (DFEM)
下载PDF
Improvements to the fuzzy mathematics comprehensive quantitative method for evaluating fault sealing 被引量:4
11
作者 Da-Wei Dong Ji-Yan Li +2 位作者 Yong-Hong Yang Xiao-Lei Wang Jian Liu 《Petroleum Science》 SCIE CAS CSCD 2017年第2期276-285,共10页
Fuzzy mathematics is an important means to quantitatively evaluate the properties of fault sealing in petroleum reservoirs.To accurately study fault sealing,the comprehensive quantitative evaluation method of fuzzy ma... Fuzzy mathematics is an important means to quantitatively evaluate the properties of fault sealing in petroleum reservoirs.To accurately study fault sealing,the comprehensive quantitative evaluation method of fuzzy mathematics is improved based on a previous study.First,the single-factor membership degree is determined using the dynamic clustering method,then a single-factor evaluation matrix is constructed using a continuous grading function,and finally,the probability distribution of the evaluation grade in a fuzzy evaluation matrix is analyzed.In this study,taking the F1 fault located in the northeastern Chepaizi Bulge as an example,the sealing properties of faults in different strata are quantitatively evaluated using both an improved and an un-improved comprehensive fuzzy mathematics quantitative evaluation method.Based on current oil and gas distribution,it is found that our evaluation results before and after improvement are significantly different.For faults in"best"and"poorest"intervals,our evaluation results are consistent with oil and gas distribution.However,for the faults in"good"or"poor"intervals,our evaluation is not completelyconsistent with oil and gas distribution.The improved evaluation results reflect the overall and local sealing properties of target zones and embody the nonuniformity of fault sealing,indicating the improved method is more suitable for evaluating fault sealing under complicated conditions. 展开更多
关键词 Fault sealing property Fuzzy mathematics Dynamic clustering method Quantitative study
下载PDF
An improved pseudo-static method for seismic resistant design of underground structures 被引量:4
12
作者 刘如山 石宏彬 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2006年第2期189-193,共5页
This paper describes a commonly used pseudo-static method in seismic resistant design of the cross section of underground structures. Based on dynamic theory and the vibration characteristics of underground structures... This paper describes a commonly used pseudo-static method in seismic resistant design of the cross section of underground structures. Based on dynamic theory and the vibration characteristics of underground structures, the sources of errors when using this method are analyzed. The traditional seismic motion loading approach is replaced by a method in which a one-dimensional soil layer response stress is differentiated and then converted into seismic live loads. To validate the improved method, a comparison of analytical results is conducted for internal forces under earthquake shaking of a typical shallow embedded box-shaped subway station structure using four methods: the response displacement method, finite element response acceleration method, the finite element dynamic analysis method and the improved pseudo-static calculation method. It is shown that the improved finite element pseudo-static method proposed in this paper provides an effective tool for the seismic design of underground structures. The evaluation yields results close to those obtained by the finite element dynamic analysis method, and shows that the improved finite element pseudo-static method provides a higher degree of precision. 展开更多
关键词 underground structures seismic design finite element method pseudo-static method dynamic analysis method
下载PDF
OPTIMIZATION OF AUTOBODY PANEL STAMPING PROCESS BASED ON DYNAMIC EXPLICIT FINITE ELEMENT METHOD 被引量:6
13
作者 X. G. Bao D. N. He +2 位作者 D. Lu C. X. Li J. L. Cheng and J. Y. Jiang( 1) National Mold and Dies CAD Engineering Research Center, Shanghai 200030, China 2) Shanghai Volkswagen Automotive Company Ltd.(SVW), Shanghai 201805, China) 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2000年第1期387-393,共7页
Taking CPU time cost and analysis accuracy into account, dynamic explicit finite ele- ment method is adopted to optimize the forming process of autobody panels that often have large sizes and complex geometry. In this... Taking CPU time cost and analysis accuracy into account, dynamic explicit finite ele- ment method is adopted to optimize the forming process of autobody panels that often have large sizes and complex geometry. In this paper, for the sake of illustrating in detail how dynamic explicit finite element method is applied to the numerical simulation of the autobody panel forming process,an example of optimization of stamping process pain meters of an inner door panel is presented. Using dynamic explicit finite element code Ls-DYNA3D, the inner door panel has been optimized by adapting pa- rameters such as the initial blank geometry and position, blank-holder forces and the location of drawbeads, and satisfied results are obtained. 展开更多
关键词 dynamic explicit finite element method autobody panel OPTIMIZATION stamping process
下载PDF
COMPUTERIZED SIMULATION OF MOLTEN SALT SOLUTION OF Li,KF,Cl SYSTEM BY MOLECULAR DYNAMIC METHOD 被引量:2
14
作者 SHAO Jun Shanghai University of Science and Technology,Shanghai,ChinaXU Hua CHEN Nianyi Shanghai Institute of Metallurgy,Academia Sinica,Shanghai,China SHAO Jun Associate Professor,Dept.of Chemistry,Shanghai University of Science and Technology,Shanghai 201800,China 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 1990年第10期221-225,共5页
The structure and properties of molten salt solution o J Li,K|F,Cl system have been investiged by computerized simulation of molecular dynamic method.The partial RDF,the partial molar energy of mixing and the diffusio... The structure and properties of molten salt solution o J Li,K|F,Cl system have been investiged by computerized simulation of molecular dynamic method.The partial RDF,the partial molar energy of mixing and the diffusion coeffients of Li^+,K^+,F^- and Cl^- have been calculated. The results are in agreement with the experimental values.The regularities of the distribution of ions and mieroscopic holes are discussed based on the results of computerized simulation. 展开更多
关键词 alkali halide molten salt molecular dynamic method computerized simulation
下载PDF
Transient analysis of 1D inhomogeneous media by dynamic inhomogeneous finite element method 被引量:4
15
作者 Yang Zailin Wang Yao Hei Baoping 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2013年第4期569-576,共8页
The dynamic inhomogeneous finite element method is studied for use in the transient analysis of one dimensional inhomogeneous media. The general formula of the inhomogeneous consistent mass matrix is established based... The dynamic inhomogeneous finite element method is studied for use in the transient analysis of one dimensional inhomogeneous media. The general formula of the inhomogeneous consistent mass matrix is established based on the shape function. In order to research the advantages of this method, it is compared with the general finite element method. A linear bar element is chosen for the discretization tests of material parameters with two fictitious distributions. And, a numerical example is solved to observe the differences in the results between these two methods. Some characteristics of the dynamic inhomogeneous finite element method that demonstrate its advantages are obtained through comparison with the general finite element method. It is found that the method can be used to solve elastic wave motion problems with a large element scale and a large number of iteration steps. 展开更多
关键词 inhomogeneous media elastic wave transient analysis dynamic inhomogeneous finite element method DISCRETIZATION
下载PDF
Evaluation of the possible slip surface of a highly heterogeneous rock slope using dynamic reduction method 被引量:2
16
作者 CHEN Guo-qing HUANG Run-qiu +3 位作者 ZHANG Feng-shou ZHU Zhen-fei SHI Yu-chuan WANG Jian-chao 《Journal of Mountain Science》 SCIE CSCD 2018年第3期672-684,共13页
A new method, the dynamic reduction method(DRM) combined with the strain-softening method, was applied to evaluate the possible slip surface of a highly heterogeneous rock slope of the Dagangshan hydropower station in... A new method, the dynamic reduction method(DRM) combined with the strain-softening method, was applied to evaluate the possible slip surface of a highly heterogeneous rock slope of the Dagangshan hydropower station in Southwest China.In DRM, only the strength of the failure elements is reduced and the softening reduction factor K is adopted to calculate the strength parameters. The simulation results calculated by DRM show that the further slip surface on the right slope of the Dagangshan hydropower station is limited in the middle part of the slope, while both SRM(strength reduction method) and LEM(limit equilibrium method) predict a failure surface which extends upper and longer. The observations and analysis from the three recorded sliding events indicate that the failure mode predicted by DRM is more likely the scenario.The results in this study illustrate that for highly heterogeneous slopes with geological discontinuities in different length scales, the proposed DRM can provide a reliable prediction of the location of the slip surface. 展开更多
关键词 Dynamic Reduction method Strainsoftening Highly heterogeneous rock slope Slip surface Geological discontinuity Hydropower station
下载PDF
Applying the Dynamic Two-Step Method to Forecast Remaining Oil Distribution of Lower Series ,Xiaermen Oilfield 被引量:2
17
作者 周红 汤传意 李增辉 《Journal of China University of Geosciences》 SCIE CSCD 2006年第1期65-70,共6页
The distribution of remaining oil is often described qualitatively. The remaining oil distributed in the whole reservoir is calculated according to the characteristics of the space distribution of the saturation of re... The distribution of remaining oil is often described qualitatively. The remaining oil distributed in the whole reservoir is calculated according to the characteristics of the space distribution of the saturation of remaining oil. Logging data are required to accomplish this. However, many such projects cannot be completed. Since the old study of remaining oil distribution could not be quantified efficiently, the "dynamic two-step method" is presented. Firstly, the water cut of every flow unit in one well at one time is calculated according to the comprehensive water cut of a single well at one time. Secondly, the remaining oil saturation of the flow unit of the well at one time is calculated based on the water cut of the flow unit at a given time. The results show that "dynamic two-step method" has characteristics of simplicity and convenience, and is especially suitable for the study of remaining oil distribution at high water-cut stage. The distribution of remaining oil presented banding and potato form, remaining oil was relatively concentrated in faultage neighborhood and imperfect well netting position, and the net thickness of the place was great. This proposal can provide an effective way to forecast remaining oil distribution and enhance oil recovery, especially applied at the high water-cut stage. 展开更多
关键词 dynamic two-step method flow unit quantitative forecast remaining oil
下载PDF
Application of strength reduction method to dynamic anti-sliding stability analysis of high gravity dam with complex dam foundation 被引量:3
18
作者 Deng-hong CHEN Cheng-bin DU 《Water Science and Engineering》 EI CAS 2011年第2期212-224,共13页
Considering that there are some limitations in analyzing the anti-sliding seismic stability of dam-foundation systems with the traditional pseudo-static method and response spectrum method, the dynamic strength reduct... Considering that there are some limitations in analyzing the anti-sliding seismic stability of dam-foundation systems with the traditional pseudo-static method and response spectrum method, the dynamic strength reduction method was used to study the deep anti-sliding stability of a high gravity dam with a complex dam foundation in response to strong earthquake-induced ground action. Based on static anti-sliding stability analysis of the dam foundation undertaken by decreasing the shear strength parameters of the rock mass in equal proportion, the seismic time history analysis was carried out. The proposed instability criterion for the dynamic strength reduction method was that the peak values of dynamic displacements and plastic strain energy change suddenly with the increase of the strength reduction factor. The elasto-plastic behavior of the dam foundation was idealized using the Drucker-Prager yield criterion based on the associated flow rule assumption. The result of elasto-plastic time history analysis of an overflow dam monolith based on the dynamic strength reduction method was compared with that of the dynamic linear elastic analysis, and the reliability of elasto-plastic time history analysis was confirmed. The results also show that the safety factors of the dam-foundation system in the static and dynamic cases are 3.25 and 3.0, respectively, and that the F2 fault has a significant influence on the anti-sliding stability of the high gravity dam. It is also concluded that the proposed instability criterion for the dynamic strength reduction method is feasible. 展开更多
关键词 dynamic anti-sliding stability complex dam foundation dynamic strength reduction method instability criteria elasto-plastie model dynamic time history analysis gravity dam
下载PDF
A simplified dynamic method for field capacity estimation and its parameter analysis 被引量:1
19
作者 Zhen-tao CONG Hua-fang Lü Guang-heng NI 《Water Science and Engineering》 EI CAS CSCD 2014年第4期351-362,共12页
This paper presents a simplified dynamic method based on the definition of field capacity. Two soil hydraulic characteristics models, the Brooks-Corey (BC) model and the van Genuchten (vG) model, and four soil dat... This paper presents a simplified dynamic method based on the definition of field capacity. Two soil hydraulic characteristics models, the Brooks-Corey (BC) model and the van Genuchten (vG) model, and four soil data groups were used in this study. The relative drainage rate, which is a unique parameter and independent of the soil type in the simplified dynamic method, was analyzed using the pressure-based method with a matric potential of -1/3 bar and the flux-based method with a drainage flux of 0.005 cm/d. As a result, the relative drainage rate of the simplified dynamic method was determined to be 3% per day. This was verified by the similar field capacity results estimated with the three methods for most soils suitable for cultivating plants. In addition, the drainage time calculated with the simplified dynamic method was two to three days, which agrees with the classical definition of field capacity. We recommend the simplified dynamic method with a relative drainage rate of 3% per day due to its simple application and clearly physically-based concept. 展开更多
关键词 field capacity simplified dynamic method pressure-based method flux-basedmethod soil water HYDRUS
下载PDF
Ultravilolet-radiation-induced graft polymerization of acrylamide onto the melt-blown polypropylene filter element by dynamic method 被引量:1
20
作者 WU Lin-lin WU Guang-xia +10 位作者 XU Shu-guang ZHONG Hui SHEN Ying-jie LIU He-zhi HUANG Zheng-ming YANG Xin-bo YUAN Zong-huan TANG Lian-yi LIN Xiang-wei ZHANG Shao-lai ZHANG Wei-jun 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第11期1387-1392,共6页
By dynamic method under UV irradiation, commercial melt-blown polypropylene (PPMB) filter element was modified with acrylamide (AAm) using benzophenone (BP) as initiator. Attenuated total reflection-Fourier tran... By dynamic method under UV irradiation, commercial melt-blown polypropylene (PPMB) filter element was modified with acrylamide (AAm) using benzophenone (BP) as initiator. Attenuated total reflection-Fourier transform infrared spectroscopy and scanning electron microscope verified that polyacrylamide chain was grafted on the fiber surface of PPMB filter element. Elemental content analysis with energy dispersive X-ray of fibers revealed that the polymerization content in the inner part of filter element was relatively higher than that in the outer. Degree of grafting changed with initiator concentration, monomer concentration, reaction temperature and reached 2.6% at the reaction condition: CBp=0.06 mol/L, CAAm=2.0 mol/L, irradiation time: 80 min, temperature: 60℃. Relative water flux altered with the hydrophilicity and pore size of filter element. In the antifouling test, the modified filter gave greater flux recovery (approximately 70%) after filtration of the water extract of Liuweidihuang, suggesting that the fouling layer was more easily reversible due to the hydrophilic nature of the modified filter. 展开更多
关键词 melt-blown polypropylene filter element UV-induced graft polymerization surface modification dynamic method
下载PDF
上一页 1 2 9 下一页 到第
使用帮助 返回顶部