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Energy Conditions in Palatini Approach to Modified <i>f(R)</i>Gravity
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作者 Hamidreza Saiedi 《Journal of High Energy Physics, Gravitation and Cosmology》 2020年第4期671-679,共9页
In this paper, we review modified <i>f(R)</i> theories of gravity in Palatini formalism. In this framework, we use the Raychaudhuri’s equation along with the requirement that the gravity is attractive, wh... In this paper, we review modified <i>f(R)</i> theories of gravity in Palatini formalism. In this framework, we use the Raychaudhuri’s equation along with the requirement that the gravity is attractive, which holds for any geometrical theory of gravity to discuss the energy conditions. Then, to derive these conditions, we obtain an expression for effective pressure and energy density by considering FLRW metric. To simply express the energy conditions, we write the Ricci scalar and its derivatives in terms of the deceleration (<i>q</i>), jerk (<i>j</i>) and snap (<i>s</i>) parameters. Energy conditions derived in Palatini version of <i>f(R)</i> Gravity differ from those derived in GR. We will see that the WEC (weak energy condition) derived in Palatini formalism has exactly the same expression in its metric approach. 展开更多
关键词 modified Gravity Palatini Formalism Energy conditions
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Service Life Design for Concrete Engineering in Marine Environments of Northern China Based on a Modified Theoretical Model of Chloride Diffusion and Large Datasets of Ocean Parameters 被引量:4
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作者 Taotao Feng Hongfa Yu +3 位作者 Yongshan Tan Haiyan Ma Mei Xu Chengjun Yue 《Engineering》 SCIE EI CAS 2022年第10期123-139,共17页
In this study,through experimental research and an investigation on large datasets of the durability parameters in ocean engineering,the values,ranges,and types of distribution of the durability parameters employed fo... In this study,through experimental research and an investigation on large datasets of the durability parameters in ocean engineering,the values,ranges,and types of distribution of the durability parameters employed for the durability design in ocean engineering in northern China were confirmed.Based on a modified theoretical model of chloride diffusion and the reliability theory,the service lives of concrete structures exposed to the splash,tidal,and underwater zones were calculated.Mixed concrete proportions meeting the requirement of a service life of 100 or 120 years were designed,and a cover thickness requirement was proposed.In addition,the effects of the different time-varying relationships of the boundary condition(Cs)and diffusion coefficient(Df)on the service life were compared;the results showed that the time-varying relationships used in this study(i.e.,Cscontinuously increased and then remained stable,and Dfcontinuously decreased and then remained stable)were beneficial for the durability design of concrete structures in marine environment. 展开更多
关键词 Large datasets modified theoretical model Reliability theory Service life Boundary condition Diffusion coefficient
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New Exact Solutions and Evolution of Solitons in Background Waves for(2+1)-Dimensional Modified Dispersive Water-Wave System
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作者 MA Song-Hua JIANG Yong-Qing FANG Jian-Ping 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第10期938-942,共5页
With the help of the conditional similarity reduction method, some new exact solutions of the (2+1)- dimensional modified dispersive water-wave system (MDWW) are obtained. Based on the derived solution, we invest... With the help of the conditional similarity reduction method, some new exact solutions of the (2+1)- dimensional modified dispersive water-wave system (MDWW) are obtained. Based on the derived solution, we investigate the evolution of solitons in the background waves. 展开更多
关键词 conditional similarity reduction method modified dispersive water-wave system exact solutions EVOLUTION background waves
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Solving Different Types of Differential Equations Using Modified and New Modified Adomian Decomposition Methods
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作者 Justina Mulenga Patrick Azere Phiri 《Journal of Applied Mathematics and Physics》 2023年第6期1656-1676,共21页
The Modified Adomian Decomposition Method (MADM) is presented. A number of problems are solved to show the efficiency of the method. Further, a new solution scheme for solving boundary value problems with Neumann cond... The Modified Adomian Decomposition Method (MADM) is presented. A number of problems are solved to show the efficiency of the method. Further, a new solution scheme for solving boundary value problems with Neumann conditions is proposed. The scheme is based on the modified Adomian decomposition method and the inverse linear operator theorem. Several differential equations with Neumann boundary conditions are solved to demonstrate the high accuracy and efficiency of the proposed scheme. 展开更多
关键词 Neumann conditions modified Adomian Decomposition Method Solution Scheme New modified Adomian Decomposition Method Differential Equations
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A Modified Lagrange Method for Solving Convex Quadratic Optimization Problems
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作者 Twum B. Stephen Avoka John Christian J. Etwire 《Open Journal of Optimization》 2024年第1期1-20,共20页
In this paper, a modified version of the Classical Lagrange Multiplier method is developed for convex quadratic optimization problems. The method, which is evolved from the first order derivative test for optimality o... In this paper, a modified version of the Classical Lagrange Multiplier method is developed for convex quadratic optimization problems. The method, which is evolved from the first order derivative test for optimality of the Lagrangian function with respect to the primary variables of the problem, decomposes the solution process into two independent ones, in which the primary variables are solved for independently, and then the secondary variables, which are the Lagrange multipliers, are solved for, afterward. This is an innovation that leads to solving independently two simpler systems of equations involving the primary variables only, on one hand, and the secondary ones on the other. Solutions obtained for small sized problems (as preliminary test of the method) demonstrate that the new method is generally effective in producing the required solutions. 展开更多
关键词 Quadratic Programming Lagrangian Function Lagrange Multipliers Optimality conditions Subsidiary Equations modified Lagrange Method
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Mechanical properties and failure mechanisms of coarse carbonaceous mudstone particles as highway embankment filler under coupled temperature-moisture conditions
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作者 ZENG Ling LUO Jintao +7 位作者 ZHANG Hongri GAO Qianfeng BIAN Hanbing LI Junyan ZHANG Guangming YU Huicong SONG Jianping LI Youjun 《Journal of Mountain Science》 2025年第10期3818-3834,共17页
Carbonaceous mudstone is a potential embankment filler in mountainous regions with limited high-quality materials;however,its engineering performance in highway embankments under complex environmental conditions remai... Carbonaceous mudstone is a potential embankment filler in mountainous regions with limited high-quality materials;however,its engineering performance in highway embankments under complex environmental conditions remains poorly understood.This study aimed to investigate the mechanical properties and failure mechanisms of carbonaceous mudstone filler under different temperature-moisture coupled conditions.Triaxial shear tests were conducted under four temperaturemoisture coupled conditions:dry-heat to dry-cold(DHDC),wet-cold to wet-heat(WCWH),dry-cold to wet-heat(DCWH),and dry-heat to wet-cold(DHWC).The effects of these conditions on the strength characteristics,relative breakage ratio,failure mode,and microscopic morphology were examined.A segmented prediction model based on the DuncanChang model was applied to validate the experimental results under the DHWC condition.The failure mechanisms under different conditions were also analyzed.The results indicate that the degradation of carbonaceous mudstone increases in the following order:DHDC,WCWH,DCWH,and DHWC.Under the DHDC condition,the stress-strain curves exhibit strain-softening behavior,while other conditions show strain-hardening behavior,with peak deviatoric stress occurring at 2%and 4%axial strains,respectively.The shear strength decreases by up to 40%under the DHWC condition but remains nearly unchanged under the DHDC condition,showing a positive correlation with particle breakage.As the number of cycles increases,the failure surfaces gradually move downward.Higher confining pressure shifts failure mode from shear failure to shear slip or localized compression,and eventually to overall compression or expansion failure.The modified Duncan-Chang model accurately predicts the experimental results.These findings provide important guidance for the application of carbonaceous mudstone filler in highway embankment construction in humid mountainous regions. 展开更多
关键词 Carbonaceous mudstone Temperature-moisture coupled conditions Mechanical properties Particle breakage modified Duncan-Chang model
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Compressive mechanical behavior and microstructure evolution of Ti−5.7Al−2.9Nb−1.8Fe−1.6Mo−1.5V−1Zr alloy under extreme conditions
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作者 Wen-fei PENG Chao-qi DONG +2 位作者 Qiao-dong HUANG Xiao-feng WANG Oleksandr MOLIAR 《Transactions of Nonferrous Metals Society of China》 2025年第10期3323-3341,共19页
Compressive mechanical behavior and microstructure evolution of Ti−5.7Al−2.9Nb−1.8Fe−1.6Mo−1.5V−1Zr alloy under extreme conditions were systematically investigated.The results show that strain rate and temperature hav... Compressive mechanical behavior and microstructure evolution of Ti−5.7Al−2.9Nb−1.8Fe−1.6Mo−1.5V−1Zr alloy under extreme conditions were systematically investigated.The results show that strain rate and temperature have a significant influence on the mechanical behavior and microstructure.The alloy exhibits a positive strain rate sensitivity and negative temperature sensitivity under all temperature and strain rate conditions.The hot-rolled alloy is composed of a bimodal structure including an equiaxed primary α_(p) phase and a transformedβphase.After compression deformation,the bimodal deformed structural features highly rely on the temperature and strain rate.At low temperature and room temperature,the volume fraction and size of α_(p) phase decrease with increasing temperature and strain rate.At high temperature,the volume fraction of the α_(p)hase is inversely correlated with temperature.A modified Johnson−Cook constitutive model is established,and the predicted results coincide well with the experimental results. 展开更多
关键词 titanium alloy extreme condition mechanical behavior microstructure modified Johnson−Cook constitutive model
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Two-stage optimization of route,speed,and energy management for hybrid energy ship under sea conditions
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作者 Xiaoyuan Luo Jiaxuan Wang +1 位作者 Xinyu Wang Xinping Guan 《iEnergy》 2025年第3期174-192,共19页
As future ship system,hybrid energy ship system has a wide range of application prospects for solving the serious energy crisis.However,current optimization scheduling works lack the consideration of sea conditions an... As future ship system,hybrid energy ship system has a wide range of application prospects for solving the serious energy crisis.However,current optimization scheduling works lack the consideration of sea conditions and navigational circumstances.There-fore,this paper aims at establishing a two-stage optimization framework for hybrid energy ship power system.The proposed framework considers multiple optimizations of route,speed planning,and energy management under the constraints of sea conditions during navigation.First,a complex hybrid ship power model consisting of diesel generation system,propulsion system,energy storage system,photovoltaic power generation system,and electric boiler system is established,where sea state information and ship resistance model are considered.With objective optimization functions of cost and greenhouse gas(GHG)emissions,a two-stage optimization framework consisting of route planning,speed scheduling,and energy management is constructed.Wherein the improved A-star algorithm and grey wolf optimization algorithm are introduced to obtain the optimal solutions for route,speed,and energy optimization scheduling.Finally,simulation cases are employed to verify that the proposed two-stage optimization scheduling model can reduce load energy consumption,operating costs,and carbon emissions by 17.8%,17.39%,and 13.04%,respectively,compared with the non-optimal control group. 展开更多
关键词 Hybrid ship power system two-stage optimization dispatch speed scheduling sea conditions modified A-star algorithm improved grey wolf optimization algorithm
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热-光-水耦合条件下SBS改性沥青老化性能与机理研究
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作者 康迪 杨春烨 +2 位作者 王志清 任皎龙 李颖 《山东理工大学学报(自然科学版)》 2026年第1期52-57,共6页
SBS改性沥青在使用过程中会受到热氧、紫外线、湿度的作用而发生老化。本文以广州、西安、拉萨3个城市近年气候特征为依据,建立热氧-紫外线-湿度耦合老化条件,分析不同条件下SBS改性沥青老化性能,进而利用红外光谱试验和荧光显微镜试验... SBS改性沥青在使用过程中会受到热氧、紫外线、湿度的作用而发生老化。本文以广州、西安、拉萨3个城市近年气候特征为依据,建立热氧-紫外线-湿度耦合老化条件,分析不同条件下SBS改性沥青老化性能,进而利用红外光谱试验和荧光显微镜试验揭示耦合老化条件下SBS改性沥青老化机制。研究结果表明:沥青老化后延度下降约25%~77%,软化点下降约15%~24%;经关联分析发现,紫外线关联度最高,但当中等湿度条件时,湿度关联度最高,主要体现为对紫外线老化的削减;老化后红外光谱羰基指数最高增长率为433.9%,亚砜基指数最高增长率为1220%,验证了关联分析的结果,而荧光微观形貌分析也证实了这个结果。 展开更多
关键词 SBS改性沥青 老化 热-光-水耦合条件 机理 相关性
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Modified conditioning regimen busulfan-cyclophosphamide followed by allogeneic stem cell transplantation in patients with multiple myeloma 被引量:7
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作者 ZHANG Xiao-hui HUANG Xiao-jun LIU Kai-yan XU Lan-ping LIU Dai-hong CHEN Huan CHEN Yu-hong WANG Jing-zhi HAN Wei LU Dao-pei 《Chinese Medical Journal》 SCIE CAS CSCD 2007年第6期463-468,共6页
Background Allogeneic stem cell transplantation is a potential curative approach in patients with multiple myeloma. The very high transplant related mortality associated with standard allogeneic stem cell transplantat... Background Allogeneic stem cell transplantation is a potential curative approach in patients with multiple myeloma. The very high transplant related mortality associated with standard allogeneic stem cell transplantation is currently the major limitation to wider use of this potentially curative treatment modality. The challenge for clinical investigators is to reduce the incidence of post-transplant complications for patients receiving autologous hematopoietic stem cell transplantion for multiple myeloma. In this study the toxicity and efficacy of modified myeloablative conditioning regimen followed by allogeneic stem cell transplantation was investigated in patients with multiple myeloma. Methods The conditioning regimen consisted of hydroxyurea, cytarabine, busulfan, cyclophosphamide, and semustine. Ten patients underwent allogeneic transplantation among them hydroxyurea (40 mg/kg) was administered twice on day -10 and cytarabine (2 g/ms) was given on day -9, busulfan was administered orally in four divided doses daily for 3 days (days -8 to -6). The dose of busulfan was 12 mg/kg in the protocol followed by cyclophosphamide intravenously over 1 hour on days -5 and -4 (1.8 g/m^2), and with semustine (Me-CCNU) 250 mg/m^2 on day -3. Results Chimerism data were available on all patients and all patients achieved full donor chimerism without graft failure. Six patients had not acute graft-versus-host disease (GVHD, 36.4%; 95% CI: 13.9%-38.6%). Two patients (18.2%) developed grade Ⅰ acute GVHD (95% CI: 10.9%-35.9%) and grade Ⅱ acute GVHD occurred in one patient (9.1%; 95% Cl. 8.4%-32.3%). Severe grade IVa GVHD was seen in one patient, who died from acute GVHD. The incidence of chronic GVHD was 22.2% (95% Cl: 11.7%-36.7%), among them one died of severe grade IV GVHD and one developed multiorgan failure on day +170; the treatment-related mortality was 22.0% (95% Cl: 10.3%-34.1%). The overall 4-year survival rate was 67.8% (95% Cl: 16.3%-46.7%). The estimated 4-year progression-free survival rate was 58.5% (95% CI: 13.7%-41.8%). The 4-year complete remission was 72.7% (95% CI: 27.8%-49.6%). One patient relapsed after 4 months and achived the complete remission after receiving the donor lymphocyte infusion. Conclusions Modified conditioning regimen busulfan-cyclophosphamide with peripheral blood stem cells+bone marrow cells transplantation result in a low incidence of severe GVHD with a relatively low treatment-related mortality, high complete remission rates and a long-term survival. 展开更多
关键词 multiple myeloma stem cell transplantation modified conditioning regimen
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Numerical Treatment of Initial-Boundary Value Problems with Mixed Boundary Conditions 被引量:2
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作者 Nawal Abdullah Alzaid Huda Omar Bakodah 《American Journal of Computational Mathematics》 2018年第2期153-174,共22页
In this paper, we extend the reliable modification of the Adomian Decom-position Method coupled to the Lesnic’s approach to solve boundary value problems and initial boundary value problems with mixed boundary condit... In this paper, we extend the reliable modification of the Adomian Decom-position Method coupled to the Lesnic’s approach to solve boundary value problems and initial boundary value problems with mixed boundary conditions for linear and nonlinear partial differential equations. The method is applied to different forms of heat and wave equations as illustrative examples to exhibit the effectiveness of the method. The method provides the solution in a rapidly convergent series with components that can be computed iteratively. The numerical results for the illustrative examples obtained show remarkable agreement with the exact solutions. We also provide some graphical representations for clear-cut comparisons between the solutions using Maple software. 展开更多
关键词 DECOMPOSITION METHOD modified Adomian DECOMPOSITION METHOD Linear and Nonlinear Partial Differential EQUATIONS Mixed BOUNDARY conditions Initial-Boundary Value Problem
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Testing Some f(R,T) Gravity Models from Energy Conditions 被引量:1
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作者 Flavio Gimenes Alvarenga Mahouton Jonas Stephane Houndjo +1 位作者 Adjimon Vincent Monwanou Jean Bio Chabi Orou 《Journal of Modern Physics》 2013年第1期130-139,共10页
We consider f(R,T) theory of gravity, where R is the curvature scalar and T is the trace of the energy momentum tensor. Attention is attached to the special case, f(R,T)=R+2f(T) and two expressions are assumed for the... We consider f(R,T) theory of gravity, where R is the curvature scalar and T is the trace of the energy momentum tensor. Attention is attached to the special case, f(R,T)=R+2f(T) and two expressions are assumed for the function f(T),(a1Tn+b1)/(a2Tn+b2) and a3Inq(b3Tm), where a1,a2 ,b1,b2,n,a3 ,b3,q and m are input parameters. We observe that by adjusting suitably these input parameters, energy conditions can be satisfied. Moreover, an analysis of the perturbations and stabilities of de Sitter solutions and power-law solutions is performed with the use of the two models. The results show that for some values of the input parameters, for which energy conditions are satisfied, de Sitter solutions and power-law solutions may be stables. 展开更多
关键词 modified GRAVITY Energy conditIONS COSMOLOGICAL STABILITY
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Construction of Wave-free Potentials and Multipoles in a Two-layer Fluid Having Free-surface Boundary Condition with Higher-order Derivatives 被引量:2
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作者 Dilip Das 《Journal of Marine Science and Application》 CSCD 2015年第3期270-282,共13页
There is a large class of problems in the field of fluid structure interaction where higher-order boundary conditions arise for a second-order partial differential equation. Various methods are being used to tackle th... There is a large class of problems in the field of fluid structure interaction where higher-order boundary conditions arise for a second-order partial differential equation. Various methods are being used to tackle these kind of mixed boundary-value problems associated with the Laplace’s equation (or Helmholtz equation) arising in the study of waves propagating through solids or fluids. One of the widely used methods in wave structure interaction is the multipole expansion method. This expansion involves a general combination of a regular wave, a wave source, a wave dipole and a regular wave-free part. The wave-free part can be further expanded in terms of wave-free multipoles which are termed as wave-free potentials. These are singular solutions of Laplace’s equation or two-dimensional Helmholz equation. Construction of these wave-free potentials and multipoles are presented here in a systematic manner for a number of situations such as two-dimensional non-oblique and oblique waves, three dimensional waves in two-layer fluid with free surface condition with higher order partial derivative are considered. In particular, these are obtained taking into account of the effect of the presence of surface tension at the free surface and also in the presence of an ice-cover modelled as a thin elastic plate. Also for limiting case, it can be shown that the multipoles and wave-free potential functions go over to the single layer multipoles and wave-free potential. 展开更多
关键词 two-layer fluid wave-free potentials Laplace’s equation modified Helmholtz equations higher order boundary conditions MULTIPOLES
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Special Conditional Similarity Reduction Solutions for Two Nonlinear Partial Differential Equations 被引量:1
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作者 MA Zheng-Yi 《Communications in Theoretical Physics》 SCIE CAS CSCD 2007年第2X期199-204,共6页
We present a method of special conditional similarity reduction solutions for nonlinear partial differential equations, As concrete examples of its application, we apply this method to the (2+1)-dimensional modifie... We present a method of special conditional similarity reduction solutions for nonlinear partial differential equations, As concrete examples of its application, we apply this method to the (2+1)-dimensional modified Broer- Kaup equations and the variable coefficient KdV-mKdV equation, which have extensive physics backgrounds, and obtain abundant exact solutions derived from some reduction equations. 展开更多
关键词 conditional similarity reduction (2+1)-dimensional modified Broer-Kaup equations
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Cocycle Hopf Algebra Structures on Free Modified Rota–Baxter Algebras by Vertex-decorated Rooted Trees
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作者 Shanghua Zheng Yukun Liu 《Acta Mathematica Sinica,English Series》 2026年第2期508-540,共33页
A modified Rota–Baxter operator originates from the convolution theorem for the Hilbert transformation by Tricomi.It also satisfies the modified classical Yang–Baxter equation discovered by Semenov-Tian-Shansky,and ... A modified Rota–Baxter operator originates from the convolution theorem for the Hilbert transformation by Tricomi.It also satisfies the modified classical Yang–Baxter equation discovered by Semenov-Tian-Shansky,and is applied to Lax equations and affine geometry of Lie groups later.In this paper,we provide an alternative explicit construction of free modified Rota–Baxter associative algebras from the perspective of combinatorial objects.First,we revisit a construction of free operated bialgebra structure on vertex-decorated rooted forests via a variant of the Hochschild 1-cocycle condition.Applying an isomorphism between two kinds of free operated algebras given by different carriers,we construct free modified Rota–Baxter algebras on vertex-decorated rooted forests.We then obtain a combinatorial coproduct on the free modified Rota–Baxter algebra by means of the universal property of free operated algebras,leading to a cocycle bialgebra structure and further a cocycle Hopf algebra structure on it. 展开更多
关键词 Rooted tree Hopf algebra modified Rota-Baxter algebra modified classical Yang-Baxter equation 1-cocycle condition
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波浪与船舶相互作用下主甲板海水飞沫分布数值模拟方法研究
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作者 白旭 武道磊 王爱民 《中国造船》 北大核心 2025年第5期29-40,共12页
极地航行船舶与波浪相互作用下生成的海水飞沫是主要的结冰水源。论文构建了波浪与中型渔船相互作用的SPH模型,并引入修正的动态边界条件,以消除界面间隙。数值计算不同波陡的波浪中渔船主甲板飞沫的分布,飞沫通量与实际观测结果的平均... 极地航行船舶与波浪相互作用下生成的海水飞沫是主要的结冰水源。论文构建了波浪与中型渔船相互作用的SPH模型,并引入修正的动态边界条件,以消除界面间隙。数值计算不同波陡的波浪中渔船主甲板飞沫的分布,飞沫通量与实际观测结果的平均误差为20.50%,较现有模型的平均误差降低17.46%。船体砰击载荷越大,飞沫通量越大。提出的方法在规则波适用范围内可准确预报海水飞沫分布。 展开更多
关键词 极地航行船舶 海水飞沫 光滑粒子流体动力学 修正的动态边界条件 分布特征
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面向航空软件需求模型的MC/DC测试用例生成方法 被引量:1
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作者 丁鼎 胡军 +2 位作者 王康星 董泽华 王立松 《小型微型计算机系统》 北大核心 2025年第7期1783-1792,共10页
充分的测试是确保现代航空软件正常运行的必要环节,而传统软件测试方法往往难以满足要求.为此,本文设计了一种面向航空软件领域的测试用例自动生成方法,为自然语言描述下的航空软件需求构建变量关系模型,解析其模型语义创建需求语义树,... 充分的测试是确保现代航空软件正常运行的必要环节,而传统软件测试方法往往难以满足要求.为此,本文设计了一种面向航空软件领域的测试用例自动生成方法,为自然语言描述下的航空软件需求构建变量关系模型,解析其模型语义创建需求语义树,根据安全关键等级选取测试路径、生成不同的覆盖集.为缓解条件互相关联而可能导致修改的条件/判定覆盖失效的问题,本文定义了适用于该需求模型的耦合条件判断及约束准则,提出3种修改的条件/判定覆盖形式并给出相应的覆盖集生成方法;基于覆盖集所确定的等价类和边界,设计了合理有效的测试用例选取策略,自动生成测试用例集.最后,对一个航空软件需求实例进行形式化建模和测试用例生成,证明了上述方法的可行性. 展开更多
关键词 测试用例生成 修改的条件/判定覆盖 基于需求的测试 形式化需求建模
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汽车座椅后倾乘员下潜与腰椎损伤研究
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作者 平梦浩 梁微微 +1 位作者 周青 唐亮 《浙江大学学报(工学版)》 北大核心 2025年第4期679-687,共9页
使用改进的Hybrid Ⅲ 5th假人对影响下潜的约束系统参数进行敏感性分析,提出6种防止智能驾驶汽车乘员在后倾座椅工况下发生下潜的保护方案.通过碰撞车速为48 km/h的正面碰撞有限元分析和台车碰撞试验验证所提方案的有效性.结果表明,后... 使用改进的Hybrid Ⅲ 5th假人对影响下潜的约束系统参数进行敏感性分析,提出6种防止智能驾驶汽车乘员在后倾座椅工况下发生下潜的保护方案.通过碰撞车速为48 km/h的正面碰撞有限元分析和台车碰撞试验验证所提方案的有效性.结果表明,后倾工况在增加乘员下潜风险的同时,增大了乘员头部、颈部和腰椎的伤害风险.所有防下潜方案均导致腰椎轴向力增加,提示防下潜措施会增加腰椎损伤风险,表明防下潜与腰椎损伤之间存在矛盾关系.肩带限力器与安全带单向锁止器的组合、髋部气囊、卷收器预紧器与锁扣预紧器的组合,可以消除乘员在后倾工况中的下潜现象,保护腰椎,乘员头部、颈部、胸部和腿部的伤害指标均符合FMVSS 208的限值要求. 展开更多
关键词 正面碰撞 后倾工况 防下潜 腰椎损伤 改进的假人模型
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改良塞替派预处理方案化疗联合自体造血干细胞移植治疗原发中枢神经系统淋巴瘤的疗效和安全性分析
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作者 李艳 杨萍 +5 位作者 包芳 李森 马兰 董菲 王继军 景红梅 《中国实验血液学杂志》 北大核心 2025年第5期1435-1442,共8页
目的:探索和评价改良塞替派预处理方案联合自体造血干细胞移植的疗效和安全性。方法:通过回顾性、单中心、单臂临床研究,收集2021年3月-2024年12月应用改良塞替派预处理方案化疗联合自体造血干细胞移植治疗原发中枢神经系统淋巴瘤的患... 目的:探索和评价改良塞替派预处理方案联合自体造血干细胞移植的疗效和安全性。方法:通过回顾性、单中心、单臂临床研究,收集2021年3月-2024年12月应用改良塞替派预处理方案化疗联合自体造血干细胞移植治疗原发中枢神经系统淋巴瘤的患者资料,分析患者的临床特征、移植预处理方案、预处理相关毒副反应、移植后疾病缓解状态及生存结局等。结果:共纳入28例患者,19例患者在疾病完全缓解/部分缓解状态接受了自体移植一线巩固治疗,9例复发/难治患者进行了挽救性移植治疗。所有患者粒细胞中位植入时间为9(5-11)d,血小板中位植入时间为10(6-13)d。所有患者自体移植后首次疗效评估均为完全缓解。移植期间主要并发症为粒细胞缺乏伴发热(26例)和3级腹泻(9例)。未发生移植相关死亡。移植后有19例患者接受了维持治疗,维持治疗安全有效。移植后3例复发、1例死亡。患者中位PFS和OS均未达到,1年和2年累积无进展生存率分别为88.4%和66.3%,总生存率均为94.1%。结论:改良塞替派预处理方案联合自体造血干细胞移植治疗原发中枢神经系统淋巴瘤安全有效。 展开更多
关键词 原发中枢神经系统淋巴瘤 改良塞替派预处理方案 大剂量化疗 自体造血干细胞移植 维持治疗
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An implicit algorithm based on iterative modified approximate factorization method coupling with characteristic boundary conditions for solving subsonic viscous flows 被引量:2
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作者 LEE XuZhi LEE ChunHian 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2013年第6期1187-1208,共22页
An algorithm composed of an iterative modified approximate factorization(MAF(k)) method with Navier-Stokes characteristic boundary conditions(NSCBC) is proposed for solving subsonic viscous flows.A transformation on t... An algorithm composed of an iterative modified approximate factorization(MAF(k)) method with Navier-Stokes characteristic boundary conditions(NSCBC) is proposed for solving subsonic viscous flows.A transformation on the matrix equation in MAF(k) is made in order to impose the implicit boundary conditions properly.To be in consistent with the implicit solver for the interior domain,an implicit scheme for NSCBC is formulated.The performance of the developed algorithm is investigated using spatially evolving zero pressure gradient boundary layer over a flat plate and a wall jet mixing with a cross flow over a flat plate with a square hole as the test cases.The numerical results are compared to the existing experimental datasets and a number of general correlations,together with other available numerical solutions,which demonstrate that the developed algorithm possesses promising capacity for simulating the subsonic viscous flows with large CFL number. 展开更多
关键词 iterative modified approximate factorization Navier-Stokes characteristic boundary conditions subsonic viscous flow
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