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Research progress of traditional Chinese medicine nursing techniques for the management of postoperative complications in mixed hemorrhoids 被引量:2
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作者 Yu Leng Wei Xie Zhi Li 《TMR Integrative Nursing》 2018年第4期148-152,共5页
Mixed hemorrhoids,especially ring-shaped mixed hemorrhoid,is still a headache for anorectal surgeons due to its post-operative complications.In recent years,clinicians have been studying and exploring to avoid and all... Mixed hemorrhoids,especially ring-shaped mixed hemorrhoid,is still a headache for anorectal surgeons due to its post-operative complications.In recent years,clinicians have been studying and exploring to avoid and alleviate these complications.In the Chinese medicine industry,the application of traditional Chinese medicine nursing technology has good and unique effect in prevent local pain,perianal edema,promote wound healing,relieve urinary retention,improve constipation,relieve anxiety,and so on.This article summarized the evidences of investigated the role of traditional Chinese medicine nursing technique in preventing and treating mixed hemorrhoid so that practitioners can make decision based on the best available evidences. 展开更多
关键词 Traditional Chinese medicine nursing technique mixed hemorrhoid Postoperative complications Clinicalapplication
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Nonlinear mixed-effects height to crown base and crown length dynamic models using the branch mortality technique for a Korean larch( Larix olgensis ) plantations in northeast China 被引量:8
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作者 Weiwei Jia Dongsheng Chen 《Journal of Forestry Research》 SCIE CAS CSCD 2019年第6期2095-2109,共15页
Korean larch(Larix olgensis)is one of the main tree species for aff orestation and timber production in northeast China.However,its timber quality and growth ability are largely infl uenced by crown size,structure and... Korean larch(Larix olgensis)is one of the main tree species for aff orestation and timber production in northeast China.However,its timber quality and growth ability are largely infl uenced by crown size,structure and shape.The majority of crown models are static models based on tree size and stand characteristics from temporary sample plots,but crown dynamic models has seldom been constructed.Therefore,this study aimed to develop height to crown base(HCB)and crown length(CL)dynamic models using the branch mortality technique for a Korean larch plantation.The nonlinear mixed-eff ects model with random eff ects,variance functions and correlation structures,was used to build HCB and CL dynamic models.The data were obtained from 95 sample trees of 19 plots in Meng JiaGang forest farm in Northeast China.The results showed that HCB progressively increases as tree age,tree height growth(HT growth)and diameter at breast height growth(DBH growth).The CL was increased with tree age in 20 years ago,and subsequently stabilized.HT growth,DBH growth stand basal area(BAS)and crown competition factor(CCF)signifi cantly infl uenced HCB and CL.The HCB was positively correlated with BAS,HT growth and DBH growth,but negatively correlated with CCF.The CL was positively correlated with BAS and CCF,but negatively correlated with DBH growth.Model fi tting and validation confi rmed that the mixed-eff ects model considering the stand and tree level random eff ects was accurate and reliable for predicting the HCB and CL dynamics.However,the models involving adding variance functions and time series correlation structure could not completely remove heterogeneity and autocorrelation,and the fi tting precision of the models was reduced.Therefore,from the point of view of application,we should take care to avoid setting up over-complex models.The HCB and CL dynamic models in our study may also be incorporated into stand growth and yield model systems in China. 展开更多
关键词 Larix olgensis plantation Height to CROWN BASE CROWN LENGTH Branch MORTALITY technique NONLINEAR mixed-eff ects models
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Mixed Monotone Iterative Technique and Boundary Value Problem for a Class of Impulsive Integro-Differential Equations
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作者 支妍妍 陈海波 吕晨辉 《Journal of Donghua University(English Edition)》 EI CAS 2016年第1期46-53,共8页
In this paper,the existence and uniqueness of iterative solutions to the boundary value problems for a class of first order impulsive integro-differential equations were studied. Under a new concept of upper and lower... In this paper,the existence and uniqueness of iterative solutions to the boundary value problems for a class of first order impulsive integro-differential equations were studied. Under a new concept of upper and lower solutions, a new monotone iterative technique on the boundary value problem of integro-differential equations was proposed. The existence and uniqueness of iterative solutions and the error estimation in certain interval were obtained.An example was also given to illustrate the results. 展开更多
关键词 impulsive integro-differential equations L-quasi-upper and lower solutions mixed monotone iterative technique boundary value problem
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Traffic Conflict Technique Development for Traffic Safety Evaluation under Mixed Traffic Conditions of Developing Countries
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作者 Tran Quang Vuong 《Journal of Traffic and Transportation Engineering》 2017年第4期228-235,共8页
In developing countries, the numbers of traffic accidents, injuries and fatalities are very high and tend to increase atsignalized intersections. For example, in Ho Chi Minh City (HCMC) of Vietnam, the number of acc... In developing countries, the numbers of traffic accidents, injuries and fatalities are very high and tend to increase atsignalized intersections. For example, in Ho Chi Minh City (HCMC) of Vietnam, the number of accidents at signalized intersectionsaccounted for 45% of the total accidents at all the intersections. This fact leads to strong necessity for analyzing traffic safety atsignalized intersections. Nevertheless, the historical accident data in HCMC is not available for deep analysis, this study uses videocameras to capture and analyze conflicts that potentially lead to accidents using TCT (traffic conflict technique). Conflict severityidentification is one of the most significant steps to evaluate traffic safety at signalized intersections using TCT. Six zones (seriousconflict, common conflict, non-conflict, highest potential serious conflict, potential serious conflict, and potential common conflict) areexplored in this study to clarify conflict severity. This result is based on being the cut off value between serious conflicts and commonconflicts, according to 85% cumulative frequency of TTC (time to collision) and CS (conflict speed) under 3,050 samples size whichwere observed at 10 signalized intersections during August-November, 2014. Such a deep understanding is a scientific basis to studyhow to apply TCT to evaluate traffic safety at signalized intersections under mixed traffic conditions. 展开更多
关键词 TRAFFIC CONFLICT technique TRAFFIC safety signalized intersections TRAFFIC CONFLICT severity mixed TRAFFIC condition.
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A Posteriori Error Estimate of Two Grid Mixed Finite Element Methods for Semilinear Elliptic Equations
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作者 Yiming Wen Luoping Chen Jiajia Dai 《Journal of Applied Mathematics and Physics》 2023年第2期361-376,共16页
In this paper, we present the a posteriori error estimate of two-grid mixed finite element methods by averaging techniques for semilinear elliptic equations. We first propose the two-grid algorithms to linearize the m... In this paper, we present the a posteriori error estimate of two-grid mixed finite element methods by averaging techniques for semilinear elliptic equations. We first propose the two-grid algorithms to linearize the mixed method equations. Then, the averaging technique is used to construct the a posteriori error estimates of the two-grid mixed finite element method and theoretical analysis are given for the error estimators. Finally, we give some numerical examples to verify the reliability and efficiency of the a posteriori error estimator. 展开更多
关键词 Two-Grid mixed Finite Element Methods Posteriori Error Estimates Semilinear Elliptic Equations Averaging technique
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Green coal mining technique integrating mining-dressing-gas draining-backfilling-mining 被引量:16
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作者 Zhang Jixiong Zhang Qiang +3 位作者 Spearing A.J.S.(Sam) Miao Xiexing Guo Shuai Sun Qiang 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2017年第1期17-27,共11页
Aiming to address the following major engineering issues faced by the Pingdingshan No. 12 mine:(1) difficulty in implementing auxiliary lifting because of its depth(i.e., beyond 1000 m);(2) highly gassy main coal seam... Aiming to address the following major engineering issues faced by the Pingdingshan No. 12 mine:(1) difficulty in implementing auxiliary lifting because of its depth(i.e., beyond 1000 m);(2) highly gassy main coal seam with low permeability;(3) unstable overlying coal seam without suitable conditions for implementing conventional mining techniques for protective coal seam; and(4) predominant reliance on ‘‘under three" coal resources to ensure production output. This study proposes an integrated, closed-cycle mining-dressing-gas draining-backfilling-mining(MDGBM) technique. The proposed approach involves the mining of protective coal seam, underground dressing of coal and gangue(UDCG), pressure relief and gas drainage before extraction, and backfilling and mining of the protected coal seam. A system for draining gas and mining the protective seam in the rock stratum is designed and implemented based on the geological conditions. This system helps in realizing pressure relief and gas drainage from the protective seam before extraction. Accordingly, another system, which is connected to the existing production system, is established for the UDCG based on the dense medium-shallow trough process. The mixed mining workface is designed to accommodate both solid backfill and conventional fully mechanized coal mining, thereby facilitating coal mining, USCG, and backfilling. The results show that: The mixed mining workface length for the Ji15-31010 protected seam was 220 m with coal production capacity 1.2 million tons per year, while the backfill capacity of gangue was 0.5 million tons per year. The gas pressure decreased from 1.78 to 0.35 MPa, and the total amount of safely mined coal was 1.34 million tons. The process of simultaneously exploiting coal and draining gas was found to be safe, efficient, and green.This process also yielded significant economic benefits. 展开更多
关键词 Integrated green mining technique Protective and protected coal seams mixed workface Solid backfill with gangueGas drainage
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A reduced-order extrapolation algorithm based on CNLSMFE formulation and POD technique for two-dimensional Sobolev equations 被引量:2
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作者 LIU Qun TENG Fei LUO Zhen-dong 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2014年第2期171-182,共12页
A reduced-order extrapolation algorithm based on Crank-Nicolson least-squares mixed finite element (CNLSMFE) formulation and proper orthogonal decomposition (POD) technique for two-dimensional (2D) Sobolev equat... A reduced-order extrapolation algorithm based on Crank-Nicolson least-squares mixed finite element (CNLSMFE) formulation and proper orthogonal decomposition (POD) technique for two-dimensional (2D) Sobolev equations is established. The error estimates of the reduced-order CNLSMFE solutions and the implementation for the reduced-order extrapolation algorithm are provided. A numerical example is used to show that the results of numerical computations are consistent with theoretical conclusions. Moreover, it is shown that the reduced-order extrapolation algorithm is feasible and efficient for seeking numerical solutions to 2D Sobolev equations. 展开更多
关键词 Reduced-order extrapolation aigorithm Crank-Nicolson least*squares mixed finite element for-mulation proper orthogonal decomposition technique Sobolev equations.
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Auxiliary principle and three-step iterative algorithms for generalized set-valued strongly nonlinear mixed variational-like inequalities 被引量:1
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作者 徐海丽 郭兴明 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2007年第6期721-729,共9页
An auxiliary principle technique to study a class of generalized set-valued strongly nonlinear mixed variational-like inequalities is extended. The existence and uniqueness of the solution of the auxiliary problem for... An auxiliary principle technique to study a class of generalized set-valued strongly nonlinear mixed variational-like inequalities is extended. The existence and uniqueness of the solution of the auxiliary problem for the generalized set-valued strongly nonlinear mixed variational-like inequalities are proved, a novel and innovative three-step iterative algorithm to compute approximate solution is constructed, and the existence of the solution of the generalized set-valued strongly nonlinear mixed variational-like inequality is shown using the auxiliary principle iterative sequences generated by the algorithm technique. The convergence of three-step is also proved. 展开更多
关键词 mixed variational-like inequality three-step iterative algorithm set-valued mapping auxiliary principle technique
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Combined heat and mass transfer by mixed convection MHD flow along a porous plate with chemical reaction in presence of heat source 被引量:1
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作者 J.ZUECO S.AHMED 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2010年第10期1217-1230,共14页
An exact and a numerical solutions to the problem of a steady mixed convective MHD flow of an incompressible viscous electrically conducting fluid past an infinite vertical porous plate with combined heat and mass tra... An exact and a numerical solutions to the problem of a steady mixed convective MHD flow of an incompressible viscous electrically conducting fluid past an infinite vertical porous plate with combined heat and mass transfer are presented.A uniform magnetic field is assumed to be applied transversely to the direction of the flow with the consideration of the induced magnetic field with viscous and magnetic dissipations of energy.The porous plate is subjected to a constant suction velocity as well as a uniform mixed stream velocity.The governing equations are solved by the perturbation technique and a numerical method.The analytical expressions for the velocity field,the temperature field,the induced magnetic field,the skin-friction,and the rate of heat transfer at the plate are obtained.The numerical results are demonstrated graphically for various values of the parameters involved in the problem.The effects of the Hartmann number,the chemical reaction parameter,the magnetic Prandtl number,and the other parameters involved in the velocity field,the temperature field,the concentration field,and the induced magnetic field from the plate to the fluid are discussed.An increase in the heat source/sink or the Eckert number is found to strongly enhance the fluid velocity values.The induced magnetic field along the x-direction increases with the increase in the Hartmann number,the magnetic Prandtl number,the heat source/sink,and the viscous dissipation.It is found that the flow velocity,the fluid temperature,and the induced magnetic field decrease with the increase in the destructive chemical reaction.Applications of the study arise in the thermal plasma reactor modelling,the electromagnetic induction,the magnetohydrodynamic transport phenomena in chromatographic systems,and the magnetic field control of materials processing. 展开更多
关键词 MHD perturbation technique network simulation method Eckert number mixed convection induced magnetic field viscous dissipation heat source/sink
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Use of Agroecological Techniques by Smallholder Farmers to Improve Sorghum Productivity in Burkina Faso 被引量:1
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作者 Zomboudré Georges Youma Issaka Abdoulaye +3 位作者 Batta Fatou Kaboré Roger Bourgou Tsuamba Gubbels Peter 《Journal of Agricultural Science and Technology(B)》 2018年第8期499-506,共8页
The prevailing farming system in Burkina Faso is smallholder agriculture based on cereal production, especially sorghum (Sorghum bicolor (L.) Moench) which form the staple diet for the population. Production is consta... The prevailing farming system in Burkina Faso is smallholder agriculture based on cereal production, especially sorghum (Sorghum bicolor (L.) Moench) which form the staple diet for the population. Production is constantly challenged by climate hazards, striga (Striga hermonthica (Del.) Benth.) infestation, inefficient farming practices and declining soil fertility. To address these concerns, one study on several agroecological techniques was conducted from 2013 to 2015 in a participative manner with more than 150 male and female farmers from four communities. Each farmer was asked to test out two or three agroecological techniques of his choice and to measure these new techniques against their usual farming practices. These techniques combined the use of organic fertilizer (5 t/ha) and/or mineral fertilizer (2 g/seed hole) with the systems of crop rotation and mixed cropping, in addition to the improved za? technique and the half-moon method. Plant material was composed of local landraces and improved varieties of sorghum, sesame and cowpea. On-farm application of agroecological techniques resulted in significantly increased sorghum production in all four communities. The rates of increase for grain yield were 8% for the half-moon fields and more than 130% for the rotation systems when compared to the farmers’ usual practices. More limited results were achieved with the chemical components of the soil after two years of experimentation. Only the soil’s organic matter showed improvement over the first year. This study shows that crop rotation, mixed cropping and the improved za? technique in combination with compost and improved drought-resistant varieties constitute agroecological strategies favorable to the intensification and diversification of farming systems in the studied locations. The farmers were above all impressed by the on-site management of compost by means of the za? technique which enabled large-scale fertilization of fields. 展开更多
关键词 Agroecological techniqueS SORGHUM yield COMPOST mineral FERTILIZER CROP rotation mixed CROPPING zai.
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Novel wavelet-homotopy Galerkin technique for analysis of lid-driven cavity flow and heat transfer with non-uniform boundary conditions
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作者 Qiang YU Hang XU 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2018年第12期1691-1718,共28页
In this paper, a brand-new wavelet-homotopy Galerkin technique is developed to solve nonlinear ordinary or partial differential equations. Before this investigation,few studies have been done for handling nonlinear pr... In this paper, a brand-new wavelet-homotopy Galerkin technique is developed to solve nonlinear ordinary or partial differential equations. Before this investigation,few studies have been done for handling nonlinear problems with non-uniform boundary conditions by means of the wavelet Galerkin technique, especially in the field of fluid mechanics and heat transfer. The lid-driven cavity flow and heat transfer are illustrated as a typical example to verify the validity and correctness of this proposed technique. The cavity is subject to the upper and lower walls’ motions in the same or opposite directions.The inclined angle of the square cavity is from 0 to π/2. Four different modes including uniform, linear, exponential, and sinusoidal heating are considered on the top and bottom walls, respectively, while the left and right walls are thermally isolated and stationary.A parametric analysis of heating distribution between upper and lower walls including the amplitude ratio from 0 to 1 and the phase deviation from 0 to 2π is conducted. The governing equations are non-dimensionalized in terms of the stream function-vorticity formulation and the temperature distribution function and then solved analytically subject to various boundary conditions. Comparisons with previous publications are given,showing high efficiency and great feasibility of the proposed technique. 展开更多
关键词 wavelet-homotopy Galerkin technique mixed boundary condition liddriven inclined cavity non-uniform heat transfer
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EXISTENCE AND ALGORITHM OF SOLUTIONS FOR GENERAL MULTIVALUED MIXED IMPLICIT QUASI-VARIATIONAL INEQUALITIES
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作者 曾六川 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2003年第11期1324-1333,共10页
A new class of general multivalued mixed implicit quasi-variational inequalities in a real Hilbert space was introduced, which includes the known class of generalized mixed implicit quasi-variational inequalities as a... A new class of general multivalued mixed implicit quasi-variational inequalities in a real Hilbert space was introduced, which includes the known class of generalized mixed implicit quasi-variational inequalities as a special case , introduced and studied by Ding Xie-ping . The auxiliary variational principle technique was applied to solve this class of general multivalued mixed implicit quasi-variational inequalities. Firstly, a new auxiliary variational inequality with a proper convex , lower semicontinuous , binary functional was defined and a suitable functional was chosen so that its unique minimum point is equivalent to the solution of such an auxiliary variational inequality . Secondly , this auxiliary variational inequality was utilized to construct a new iterative algorithm for computing approximate solutions to general multivalued mixed implicit quasi-variational inequalities . Here , the equivalence guarantees that the algorithm can generate a sequence of approximate solutions. Finally, the existence of solutions and convergence of approximate solutions for general multivalued mixed implicit quasi-variational inequalities are proved. Moreover, the new convergerce criteria for the algorithm were provided. Therefore, the results give an affirmative answer to the open question raised by M. A . Noor, and extend and improve the earlier and recent results for various variational inequalities and complementarity problems including the corresponding results for mixed variational inequalities, mixed quasi-variational inequalities and quasi-complementarity problems involving the single-valued and set- valued mappings in the recent literature . 展开更多
关键词 general multivalued mixed implicit quasi-variational inequality auxiliary variational principle technique EXISTENCE algorithm
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System of set-valued mixed quasi-variational-like inclusions involving H-η-monotone operators in Banach spaces
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作者 丁协平 王中宝 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2009年第1期1-12,共12页
A new system of the set-valued mixed quasi-variational-like inclusions (SSMQVLI) involving H-η-monotone operators is studied in general Banach spaces without uniform smoothness. By using the resolvent operator tech... A new system of the set-valued mixed quasi-variational-like inclusions (SSMQVLI) involving H-η-monotone operators is studied in general Banach spaces without uniform smoothness. By using the resolvent operator technique of H-η-monotone operators, a new iterative algorithm for finding approximate solutions to SSMQVLI is proposed. It is shown that the iterative sequences generated by the algorithm converge strongly to the exact solution of SSMQVLI under appropriate assumptions. These obtained new results have extended and improved previous results. 展开更多
关键词 H-η-monotone operators resolvent operator technique system of set-valued mixed quasi-variational-like inclusions iterative algorithm Banach spaces
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Existence and Algorithm of Solutions for Generalized Mixed Implicit Quasi-Variational-Like Inequalities
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作者 胡润雪 张勇 张红龄 《Journal of Southwest Jiaotong University(English Edition)》 2005年第1期87-91,共5页
By applying the auxiliary variational principle technique, the existence of solutions for a new class of generalized mixed implicit quasi-variational-like inequalities and the convergence criteria of a new iterative a... By applying the auxiliary variational principle technique, the existence of solutions for a new class of generalized mixed implicit quasi-variational-like inequalities and the convergence criteria of a new iterative algorithm to compute approximate solutions are proved in Hilbert spaces. The obtained result is a improvement over and generalization of the main theorem proposed by Ding. 展开更多
关键词 Generalized mixed implicit quasi-variational-like inequality Auxiliary principle technique Gap function Iterative algorithm
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EXISTENCE OF SOLUTIONS FOR MIXED MONOTONE IMPULSIVE VOLTERRA INTEGRAL EQUATIONS IN BANACH SPACES 被引量:6
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作者 陈芳启 《Acta Mathematica Scientia》 SCIE CSCD 1998年第4期371-378,共8页
This paper studies the existence of solutions for mixed monotone impulsive Volterra integral equations on the infinite interval R+ with an infinite number of moments of impulse effect in Banach spaces. By using the mi... This paper studies the existence of solutions for mixed monotone impulsive Volterra integral equations on the infinite interval R+ with an infinite number of moments of impulse effect in Banach spaces. By using the mixed monotone iterative technique and Monch fixed point theorem, Some existence theorems of solutions and coupled minimal and maximal quasisolutions are obtained. Finally, an example is worked out. 展开更多
关键词 impulsive Volterra integral equation mixed monotone iterative technique Monch fixed point theorem cone and partial ordering
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Static response of functionally graded multilayered two-dimensional quasicrystal plates with mixed boundary conditions
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作者 Xin FENG Liangliang ZHANG +3 位作者 Yuxuan WANG Jinming ZHANG Han ZHANG Yang GAO 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2021年第11期1599-1618,共20页
The unusual properties of quasicrystals(QCs)have attracted tremendous attention from researchers.In this paper,a semi-analytical solution is presented for the static response of a functionally graded(FG)multilayered t... The unusual properties of quasicrystals(QCs)have attracted tremendous attention from researchers.In this paper,a semi-analytical solution is presented for the static response of a functionally graded(FG)multilayered two-dimensional(2 D)decagonal QC rectangular plate with mixed boundary conditions.Based on the elastic theory of FG 2 D QCs,the state-space method is used to derive the state equations composed of partial differential along the thickness direction.Besides,the Fourier series expansion and the differential quadrature technique are utilized to simulate the simply supported boundary conditions and the mixed boundary conditions,respectively.Then,the propagator matrix which connects the field variables at the upper interface to those at the lower interface of any homogeneous layer can be derived based on the state equations.Combined with the interface continuity condition,the static response can be obtained by imposing the sinusoidal load on the top surfaces of laminates.Finally,the numerical examples are presented to verify the effectiveness of this method,and the results are very useful for the design and understanding of the characterization of FG QC materials in their applications to multilayered systems. 展开更多
关键词 two-dimensional(2D)quasicrystal(QC)laminate functionally graded material(FGM) mixed boundary condition static response differential quadrature technique
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Progress on the Use of Stable Isotope Techniques in Catchment Hydrograph Separation: A Review
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作者 Feng Fang Jin Shuang Zhang Tao 《Meteorological and Environmental Research》 CAS 2015年第2期1-5,共5页
Hydrograph separation is a fundamental catchment descriptor,revealing information about sources of water in runoff generation processes. The water isotopes are ideal tracers in studying hydrological processes since th... Hydrograph separation is a fundamental catchment descriptor,revealing information about sources of water in runoff generation processes. The water isotopes are ideal tracers in studying hydrological processes since the isotope fractionation produces a natural labeling effect within the hydrologic cycle. The water isotope technique has become one of effective means for investigating complex hydrologic system on a catchment scale. This paper reviews the progress on the use of stable water isotope techniques in catchment hydrograph separation in last decades. Also,the isotope mixing model for hydrograph separation and its uncertainties are explained in detail. In future research,there are three hot issues in the use of isotopic hydrograph separation( IHS) : integrating new approaches into IHS,calibration and verification of IHS model and IHS application in large river basins. 展开更多
关键词 Stable isotope techniques Hydrograph separation Catchment scale mixing model Uncertainty China
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沥青温拌技术分类及温拌效果的试验评价方法 被引量:1
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作者 延西利 郑涛 +1 位作者 蒋双全 李卫成 《材料导报》 EI CAS CSCD 北大核心 2024年第4期80-87,共8页
沥青温拌技术日益广泛应用于路面工程,为了定量评价温拌沥青混合料在拌和生产过程中的温拌效果,提供试验评价方法,本研究自主开发了一种沥青混合料变速拌和试验装置,采用70^(#)基质和SBS改性两种沥青、自主研发的一种表面活性剂型沥青... 沥青温拌技术日益广泛应用于路面工程,为了定量评价温拌沥青混合料在拌和生产过程中的温拌效果,提供试验评价方法,本研究自主开发了一种沥青混合料变速拌和试验装置,采用70^(#)基质和SBS改性两种沥青、自主研发的一种表面活性剂型沥青温拌剂(取名为Alube)和一种有机降黏型沥青温拌剂(取名为ACMP),以市场成熟产品Evotherm为参照,分别制备了温拌沥青及其AC-13C型混合料,测试了不同沥青和温拌沥青的三大指标、布氏黏度和动态剪切流变指标,分析了沥青的黏温曲线特性,通过混合料的变温击实试验和变速拌和试验,研究了沥青混合料的压实特性和拌和流动特性,提出了沥青混合料的拌和流动模型。研究结果表明,有机降黏型温拌剂减小了沥青的黏度,增大了沥青的流动性,改变了沥青的技术性能,如针入度、延度、相位角等增大,软化点、布氏黏度等减小,而表面活性剂型温拌剂不改变沥青的基本技术性能;黏温曲线法仅可表征有机降黏型温拌沥青的温度变化,等黏温度降低约9℃,变温击实法和变速拌和法则可以同时表征两大类温拌剂的温拌效果;沥青混合料的拌和流动性服从宾汉黏塑性模型,从流变理论上解答了混合料的拌和流动性及和易性,推荐采用变速拌和试验来评价温拌沥青混合料的温拌效果;综合考察现有沥青温拌技术可知,在常用温拌剂掺量下,温拌沥青的生产拌和温度可比热拌沥青混合料低20~30℃,符合常规认识。 展开更多
关键词 道路工程 沥青混合料 沥青温拌技术 试验评价 变速拌和试验 宾汉模型
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搅拌工艺对高掺量丁苯乳液改性硫铝酸盐水泥性能的影响
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作者 元强 钟福文 +3 位作者 姚灏 左胜浩 谢宗霖 姜孟杰 《材料导报》 EI CAS CSCD 北大核心 2024年第9期261-267,共7页
研究了搅拌速度与搅拌时间对高掺量丁苯乳液改性硫铝酸盐水泥砂浆的匀质性、含气量、流变性能、早期强度等宏观性能的影响,采用TGA、BET等微观手段研究了硬化砂浆的水化程度和孔隙特征。结果表明:延长搅拌时间、提高搅拌速率均可改善砂... 研究了搅拌速度与搅拌时间对高掺量丁苯乳液改性硫铝酸盐水泥砂浆的匀质性、含气量、流变性能、早期强度等宏观性能的影响,采用TGA、BET等微观手段研究了硬化砂浆的水化程度和孔隙特征。结果表明:延长搅拌时间、提高搅拌速率均可改善砂浆的匀质性和力学强度。但以176 r/min搅拌时,延长搅拌时间会提高新拌砂浆含气量,增大硬化砂浆“凝胶孔”含量,抑制水泥前1 h的水化。以108 r/min搅拌时,延长搅拌时间则促进水泥前1 h的水化。延长搅拌时间和提升搅拌速率阻碍砂浆絮凝,破坏水泥颗粒桥接,显著降低结构构筑速率。延长搅拌时间,砂浆屈服应力和塑性黏度降低。优化搅拌工艺,有助于为充填层修补砂浆的搅拌规范制定提供重要参数。 展开更多
关键词 硫铝酸盐水泥 搅拌工艺 丁苯乳液 流变性能 孔隙率
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缙云山针阔混交林水热通量特征及其影响因子 被引量:1
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作者 刘烜沃 白浪 +4 位作者 王云琦 冯印成 刘双楠 孟祥江 师贺雄 《中国水土保持科学》 CSCD 北大核心 2024年第1期77-85,共9页
基于涡度相关技术,对重庆市缙云山观测站内的针阔混交林生态系统的净辐射(Rn)、显热通量(H)、潜热通量(LE)、土壤热通量(G)等进行处理,分析研究区水热通量及各环境因子的变化过程,明确水热通量变化的外在驱动因子,为森林经营及林业可持... 基于涡度相关技术,对重庆市缙云山观测站内的针阔混交林生态系统的净辐射(Rn)、显热通量(H)、潜热通量(LE)、土壤热通量(G)等进行处理,分析研究区水热通量及各环境因子的变化过程,明确水热通量变化的外在驱动因子,为森林经营及林业可持续发展提供科学依据。结果表明:1)该生态系统能量闭合缺失为0.26。2)各水热通量在日变化上呈现单峰变化趋势,在季节变化上呈现出夏季最大(日均值124.66 W/m^(2)),冬季最小(日均值31.68 W/m^(2));空气温度(Ta)、饱和水气压差(VPD)呈现多峰变化趋势;降水集中于一年的4、7、8,9和10月;叶面积指数(LAI)在生长季(4—10月)呈现单峰变化。3)非雾天情况下显热通量(H)显著大于雾天情况,冠层导度(Gs)表现出多维度的复杂特征。缙云山针阔混交林能量循环损失较小,数据可靠;太阳高度角变化引起的净辐射变化是水热通量变化的主导因素;降水量(Pr)的不规则分布及LAI的变化导致Ta和VPD多峰变化;雾气对土壤热量的导向会造成显热通量下降;较高的空气温度导致了大气与下垫面之间湍流形式的热流显著增加而使显热通量上涨。一般情况下,H主要受到Rn的影响,且分别受到VPD和土壤温度(Tsoil)的次要影响(雾天环境)以及VPD和风速WS的次要影响(非雾天环境)。Rn、Gs、Ta、VPD均对LE产生显著影响,未发现研究区Pr和Tsoil与LE存在显著关系。Gs受多种因素(Rn、VPD、Ta、VWC、P等)综合影响。 展开更多
关键词 针阔混交林 水热通量 涡度相关技术 冠层导度
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