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安陆方言的特殊正反问格式“有不有” 被引量:2
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作者 盛银花 《孝感学院学报》 2007年第1期69-72,共4页
安陆方言的特殊正反问“有不有”有五种变化格式,即“有不有N+语气词”,“有有N+语气词”,“有啊N+语气词”,“是不是有N+语气词”,“是是有N+语气词”。它与安陆方言一般单音节动词构成的正反问比较有联系,也有区别。“有不有”格式的... 安陆方言的特殊正反问“有不有”有五种变化格式,即“有不有N+语气词”,“有有N+语气词”,“有啊N+语气词”,“是不是有N+语气词”,“是是有N+语气词”。它与安陆方言一般单音节动词构成的正反问比较有联系,也有区别。“有不有”格式的形成有两方面的条件:一是跟安陆方言的否定词有关,二是跟疑问语气有关。 展开更多
关键词 安陆方言 正反问 “有不有
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类推而来的“有不有”——地方普通话特征性构式的个案研究
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作者 储泽祥 刘琪 《语言研究》 CSSCI 北大核心 2014年第3期13-19,共7页
地方普通话里存在"有不有"正反问句,它不同于基础方言的说法,也不同于标准普通话的说法,体现了地方普通话的句法特征,可以说是一种特征性构式。它的形成,不是历史传承的结果,也不是方言说法的迁移,也不是"不"与&qu... 地方普通话里存在"有不有"正反问句,它不同于基础方言的说法,也不同于标准普通话的说法,体现了地方普通话的句法特征,可以说是一种特征性构式。它的形成,不是历史传承的结果,也不是方言说法的迁移,也不是"不"与"没"的混用,而是参照"V不V"的整体架构而类推出来的结果。 展开更多
关键词 地方普通话 特征性构式 不有 类推
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异极式永磁偏置径向磁轴承的建模与实验 被引量:6
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作者 吴磊涛 王东 +2 位作者 苏振中 张贤彪 薛滟膑 《电工技术学报》 EI CSCD 北大核心 2018年第5期1051-1057,共7页
为了满足储能飞轮系统、卫星动量轮等对高空间利用率的需求,提出了一种异极式永磁偏置径向磁轴承的拓扑结构。通过在槽口放置平行充磁的永磁体获得紧凑的结构,同时永磁磁路和电励磁磁路耦合距离较短,有利于获取高解耦特性。该文首先采... 为了满足储能飞轮系统、卫星动量轮等对高空间利用率的需求,提出了一种异极式永磁偏置径向磁轴承的拓扑结构。通过在槽口放置平行充磁的永磁体获得紧凑的结构,同时永磁磁路和电励磁磁路耦合距离较短,有利于获取高解耦特性。该文首先采用磁力线法,分别获取考虑齿槽效应、转子偏心的永磁磁场、电励磁磁场的气隙磁通密度分布,建立了磁路模型;然后根据磁路模型求解位移刚度和电流刚度,建立磁轴承的数学模型;与有限元仿真进行对比,证明所建立的磁场模型能够准确计算气隙磁通密度分布。设计、制造一台实验样机并进行相关实验,实验结果验证了磁路模型及有限元仿真的可靠性。 展开更多
关键词 结构 磁路模型 有限元仿真 静态性能
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Approach to obtaining weights of uncertain ordered weighted geometric averaging operator 被引量:1
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作者 许叶军 达庆利 《Journal of Southeast University(English Edition)》 EI CAS 2008年第1期110-113,共4页
The ordered weighted geometric averaging(OWGA) operator is extended to accommodate uncertain conditions where all input arguments take the forms of interval numbers. First, a possibility degree formula for the compa... The ordered weighted geometric averaging(OWGA) operator is extended to accommodate uncertain conditions where all input arguments take the forms of interval numbers. First, a possibility degree formula for the comparison between interval numbers is introduced. It is proved that the introduced formula is equivalent to the existing formulae, and also some desired properties of the possibility degree is presented. Secondly, the uncertain OWGA operator is investigated in which the associated weighting parameters cannot be specified, but value ranges can be obtained and the associated aggregated values of an uncertain OWGA operator are known. A linear objective-programming model is established; by solving this model, the associated weights vector of an uncertain OWGA operator can be determined, and also the estimated aggregated values of the alternatives can be obtained. Then the alternatives can be ranked by the comparison of the estimated aggregated values using the possibility degree formula. Finally, a numerical example is given to show the feasibility and effectiveness of the developed method. 展开更多
关键词 interval numbers uncertain ordered weighted geometric averaging operator possibility degree
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“X不是/没有”的假设表义功能 被引量:1
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作者 张雪平 《汉语学习》 CSSCI 北大核心 2021年第5期24-32,共9页
"X不是/没有"是"如果、要"等假设连词与"不是/没有"连用而形成的连词化词语或词连。由在不同语义假设句中的语用分布得知,"X不是/没有"主要表反事实假设,较少表可能假设,其表义功能与假设连词... "X不是/没有"是"如果、要"等假设连词与"不是/没有"连用而形成的连词化词语或词连。由在不同语义假设句中的语用分布得知,"X不是/没有"主要表反事实假设,较少表可能假设,其表义功能与假设连词大致互补。本文通过语料分析与统计证明:"要不是"是典型反事实假设标记;"假如不是、若不是"是比较典型的反事实假设标记,"若非"、其他"X不是"和"X没有"也倾向表反事实假设。它们标记反事实假设的功能强弱为:要不是>假如不是>若不是>若非>其他"X不是">X没有。否定式假设成分"X不是/没有"的反事实假设表义倾向与反事实假设句的语义内涵、说话人的认知心理等都密切相关。 展开更多
关键词 “X不是/没有” 假设句 表义功能 反事实假设
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Characteristics of Soil Organic Carbon and Total Nitrogen in Rubber Plantations Soil at Different Age Stages in the Western Region of Hainan Island 被引量:17
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作者 吴志祥 谢贵水 +2 位作者 陶忠良 周兆德 王旭 《Agricultural Science & Technology》 CAS 2010年第1期147-153,共7页
[Objective]The aim was to study on the characteristics of soil organic carbon and nitrogen in rubber (Hevea brasiliensis Muell-Arg) plantations at different age stages in the western region of Hainan Island,so as to... [Objective]The aim was to study on the characteristics of soil organic carbon and nitrogen in rubber (Hevea brasiliensis Muell-Arg) plantations at different age stages in the western region of Hainan Island,so as to evaluate the ecological benefits of rubber plantations and provide basic data for studying the effect of tropical land utilization/cover change on the global carbon and nitrogen cycle. [Method]The situs was in Danzhou city,western region of Hainan Island,and the samples were four kinds of rubber plantations soil at different ages and one kind of control check (pepper,Piper nigrum L.) soil. In this research,four quadrats were set up in each sample,and the size of each was 20 cm×20 cm. Four specimens were gathered from four layers of 0-15,15-30,30-45,45-60,and the average of them was the last analysis result of each sample. Soil density was measured by cutting ring method,soil containing and hygroscopic water was detected by oven drying method,soil organic carbon (SOC) was measured by low temperature heated outside potassium dichromate oxidation-colorimetry method,and soil total nitrogen (STN) was detected by semimicro Kjeldahl method. [Result]SOC contents of different layers in rubber plantations soil at different age stages (including the CK pepper soil,the same as below) varied little,and the content of SOC in surface layer (0-15 cm) was higher,while the underlayer (45-60 cm) was lower than the average value; there was significant difference in SOC content among different kinds of soil,and the content was of 6.03-7.78 g/kg,tapping young trees (7 years) CK pepper mature age trees (30 years) prophase of young trees (2 years) tapping trees (16 years); there was no significant difference in SOC storage among different kinds of soil,and the storage was of 61.33-74.29 t/hm2,mature age trees (30 years) tapping young trees (7 years) prophase of young trees (2 years) CK pepper tapping trees (16 years); there was significant difference in STN content among rubber plantations soil at different age stages,the content was of 410.86-664.14 mg/kg2,CK pepper tapping young trees (7 years) prophase of young trees (2 years) mature age trees (30 years) tapping trees (16 years),and STN content of tapping trees (16 years) soil was extremely lowest; there was significant difference in C/N ratio among different kinds of soil,the ratio was of 10.94-14.47,and the ratio of tapping trees (16 years) mature age trees (30 years) tapping young trees (7 years) CK pepper prophase of young trees (2 years). [Conclusion]There wasn't unhealthy effect of rubber trees planted in tropical area on the content and storage of SOC,the content of STN and the ratio of C/N. there was no significant difference between rubber plantations and CK pepper soil,and the effects of rubber plantation on soil carbon-nitrogen was similar to that of other tropical crops (such as pepper). 展开更多
关键词 Different age stages of trees Rubber (Hevea brasiliensis) plantations Soil organic carbon (SOC) Soil total nitrogen (STN) Hainan Island
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Transformations and Tautomeric Equilibrium among Different Intermediates in Proline-Catalyzed Reactions of Aldehydes or Ketones
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作者 甘利华 苌青 周瑾 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2013年第1期54-60,I0003,共8页
The enamines, iminium ions, and oxazolidinones are thought to be the key intermediates in the proline-catalyzed reactions of aldehydes or ketones, but there is an extensive contro- versy about their roles. Here, the c... The enamines, iminium ions, and oxazolidinones are thought to be the key intermediates in the proline-catalyzed reactions of aldehydes or ketones, but there is an extensive contro- versy about their roles. Here, the corresponding transition states connecting any two of the three kinds of species are located at the wB97XD/6-311++G** level of theory. The calcula- tions demonstrate that the oxazolidinones are the predominant species in both the gas phase and solvents; there exists tautomeric equilibrium among these species and the equilibriums are controlled by the employed solvents and temperature in the reaction. These results demonstrate that the concentration and role of the mentioned species are controlled by the employed solvent and temperature. A new reaction pathway is presented herein for the trans- formation between iminium ions and oxazolidinones through iminium ion-water complex and oxazolidinone-water complex. The calculations demonstrate that the rate-limiting step in proline-catalyzed Mannich reaction between acetaldehyde/keteones and N-Boc imines is the formation of the C-C bond rather than the intermediates tautomerization. These calculations rationalize the available experimental observations and can be valuable in optimizing the experimental conditions of asymmetric organic-catalyzed reactions of aldehydes or ketones. 展开更多
关键词 Asymmetric organocatalysis TAUTOMERISM Transition state Intermediate Density functional theory
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语法化札记三则 被引量:1
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作者 徐时仪 《南阳师范学院学报》 CAS 2004年第4期46-51,共6页
进一步探讨疑问副词和语气助词“不成”的虚化年代、“没”和“没有”与语气词“么”的关系、近指指代词“这”的来源。
关键词 语法 疑问副词 语气助词 近指指代词 词源学
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Boundary Value Problems of p-Laplace Equations with Finite Time Delay
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作者 王宏洲 邓立虎 葛渭高 《Journal of Beijing Institute of Technology》 EI CAS 2001年第1期1-6,共6页
By establishing equivalent fixed point theorem, the boundary value problems of p Laplace equations with finite time delay are studied. It’s the first time that the functional differential equation is discussed w... By establishing equivalent fixed point theorem, the boundary value problems of p Laplace equations with finite time delay are studied. It’s the first time that the functional differential equation is discussed with p Laplacian. The topological degree and fixed point theorem on cone are used to prove the existence of solution and positive solution. The conditions are all easy to check. 展开更多
关键词 boundary value problem n Laplacian finite time delay fixed point
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“不瑕有害”之“瑕”义辨正
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作者 王进安 林惠玲 《宜春学院学报》 2022年第4期77-81,共5页
《邶风》是《诗经》中的经典篇章之一。学者对《邶风》中“不瑕有害”之“瑕”的解释莫衷一是。前贤对“瑕”的阐释有四种,一即郑玄的“瑕犹过也”;二即毛亨的“以瑕为远”;三即周悦让的“以瑕为暇”;四即朱熹《诗集传》的“瑕,何,古音... 《邶风》是《诗经》中的经典篇章之一。学者对《邶风》中“不瑕有害”之“瑕”的解释莫衷一是。前贤对“瑕”的阐释有四种,一即郑玄的“瑕犹过也”;二即毛亨的“以瑕为远”;三即周悦让的“以瑕为暇”;四即朱熹《诗集传》的“瑕,何,古音相近,通用”。文章收集各家对“不瑕有害”的注释,并类比与其高度一致的“不遐有佐”“不遐有愆”句型,结合具体的语境,得出“瑕”当作“何”解更为合适的结论。 展开更多
关键词 《邶风》 不瑕有害 “瑕”义辨正
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DELAY-TIME MODEL BASED ON IMPERFECT INSPECTION OF AIRCRAFT STRUCTURE WITHIN FINITE TIME SPAN 被引量:2
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作者 蔡景 左洪福 朱磊 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2012年第2期159-163,共5页
According to the failure characteristics of aircraft structure, a delay-time model is an effective method to optimize maintenance for aircraft structure. To imitate the practical situation as much as possible, imperfe... According to the failure characteristics of aircraft structure, a delay-time model is an effective method to optimize maintenance for aircraft structure. To imitate the practical situation as much as possible, imperfect inspections, thresholds and repeated intervals are concerned in delay-time models. Since the suggestion by the existing delay-time models that the inspections are implemented in an infinite time span lacks practical value, a de- lay-time model with imperfect inspection within a finite time span is proposed. In the model, the nonhomogenous Poisson process is adopted to obtain the renewal probabilities between two different successive inspections on de- fects or failures. An algorithm is applied based on the Nelder-Mead downhill simplex method to solve the model. Finally, a numerical example proves the validity and effectiveness of the model. 展开更多
关键词 aircraft structure delay-time model imperfect inspection optimal maintenance finite time
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Solving Navier-Stokes equation by mixed interpolation method 被引量:1
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作者 万水 Mogens Peter Nielsen 《Journal of Southeast University(English Edition)》 EI CAS 2006年第1期93-95,共3页
The operator splitting method is used to deal with the Navier-Stokes equation, in which the physical process described by the equation is decomposed into two processes: a diffusion process and a convection process; a... The operator splitting method is used to deal with the Navier-Stokes equation, in which the physical process described by the equation is decomposed into two processes: a diffusion process and a convection process; and the finite element equation is established. The velocity field in the element is described by the shape function of the isoparametric element with nine nodes and the pressure field is described by the interpolation function of the four nodes at the vertex of the isoparametric element with nine nodes. The subroutine of the element and the integrated finite element code are generated by the Finite Element Program Generator (FEPG) successfully. The numerical simulation about the incompressible viscous liquid flowing over a cylinder is carded out. The solution agrees with the experimental results very well. 展开更多
关键词 Navier-Stokes equation finite element method incompressible viscous flow mixed interpolation method
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Wavefield simulation in porous media saturated with two immiscible fluids 被引量:2
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作者 田迎春 马坚伟 杨慧珠 《Applied Geophysics》 SCIE CSCD 2010年第1期57-65,99,100,共11页
Wavefields in porous media saturated by two immiscible fluids are simulated in this paper.Based on the sealed system theory,the medium model considers both the relative motion between the fluids and the solid skeleton... Wavefields in porous media saturated by two immiscible fluids are simulated in this paper.Based on the sealed system theory,the medium model considers both the relative motion between the fluids and the solid skeleton and the relaxation mechanisms of porosity and saturation(capillary pressure).So it accurately simulates the numerical attenuation property of the wavefields and is much closer to actual earth media in exploration than the equivalent liquid model and the unsaturated porous medium model on the basis of open system theory.The velocity and attenuation for different wave modes in this medium have been discussed in previous literature but studies of the complete wave-field have not been reported.In our work,wave equations with the relaxation mechanisms of capillary pressure and the porosity are derived.Furthermore,the wavefield and its characteristics are studied using the numerical finite element method.The results show that the slow P3-wave in the non-wetting phase can be observed clearly in the seismic band.The relaxation of capillary pressure and the porosity greatly affect the displacement of the non-wetting phase.More specifically,the displacement decreases with increasing relaxation coefficient. 展开更多
关键词 porous medium immiscible fluids capillary pressure finite element method wavefield simulation
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New algorithm for solving 3D incompressible viscous equations based on projection method
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作者 牛晓峰 梁伟 +4 位作者 赵宇宏 侯华 穆彦青 黄志伟 杨伟明 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第8期1826-1832,共7页
A new algorithm based on the projection method with the implicit finite difference technique was established to calculate the velocity fields and pressure.The calculation region can be divided into different regions a... A new algorithm based on the projection method with the implicit finite difference technique was established to calculate the velocity fields and pressure.The calculation region can be divided into different regions according to Reynolds number.In the far-wall region,the thermal melt flow was calculated as Newtonian flow.In the near-wall region,the thermal melt flow was calculated as non-Newtonian flow.It was proved that the new algorithm based on the projection method with the implicit technique was correct through nonparametric statistics method and experiment.The simulation results show that the new algorithm based on the projection method with the implicit technique calculates more quickly than the solution algorithm-volume of fluid method using the explicit difference method. 展开更多
关键词 implicit finite difference method 3D incompressible viscous equations projection method nonparametric statistics
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Soil Aggregates, Organic Matter, and Labile C and N Fractions after 37 Years of N, P and K Applications to an Irrigated Subtropical Soil under Maize-Wheat Rotation 被引量:3
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作者 S. Kumar M. S. Aulakh A. K. Garg 《Journal of Agricultural Science and Technology(A)》 2011年第2X期170-181,共12页
Abstract: Physical, chemical and biological soil properties in surface (0-5 cm) and subsurface soil (5-15 cm) were determined in a field experiment conducted with seven treatments consisted of different combinati... Abstract: Physical, chemical and biological soil properties in surface (0-5 cm) and subsurface soil (5-15 cm) were determined in a field experiment conducted with seven treatments consisted of different combinations of fertilizer N (0, 100 and 200 kg N ha^-1), P (0, 22 and 44 kg P2O5 ha^-1) and K (0, 41 and 82 kg K2O ha^-1) applied both to summer-grown maize (Zea mays L.) and winter-grown wheat (Triticum aestivum L.) crops continuously for 37 years under irrigated subtropical conditions. Application of N, P and K significantly increased water stable aggregates and had profound effects in increasing the mean weight diameter as well as the formation of macro-aggregates, which were highest in both surface (81%) and subsurface (74%) soil layers with application of 100 kg N + 22 kg P2O5 + 41 kg K2O ha^-1 (N100P22K41). The N100P22K41 treatment also enhanced total organic C (TOC) from 4.4 g kg^-1 in no-NPK control to 4.8 g kg^-1in surface layer and from 3.3 to 4.1 g kg1 in subsurface layer leading to the 20% higher TOC stocks in 0-15 cm soil. The labile C and N fractions such as water soluble C, particulate and light fraction organic matter, potentially mineralizable N and microbial biomass were also highest under the optimized balanced application of N100P22K41. Relatively higher increase in all labile fractions of C and N as proportion of TOC and total N, respectively suggested that these are potential indicators to reflect changes in management practices long before changes in TOC and TN are detectable. These results demonstrated that optimized balanced application of N, P and K is crucial for improving soil health ensuring long-term sustainability of farming systems in semiarid subtropical soils. 展开更多
关键词 Total organic C water stable aggregate water soluble C particulate and light fraction organic matter potentiallymineralizable N microbial biomass C and N soil health.
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Stability of finite difference numerical simulations of acoustic logging-while-drilling with different perfectly matched layer schemes 被引量:3
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作者 王华 陶果 +2 位作者 尚学峰 方鑫定 Daniel R Burns 《Applied Geophysics》 SCIE CSCD 2013年第4期384-396,510,511,共15页
In acoustic logging-while-drilling (ALWD) finite difference in time domain (FDTD) simulations, large drill collar occupies, most of the fluid-filled borehole and divides the borehole fluid into two thin fluid colu... In acoustic logging-while-drilling (ALWD) finite difference in time domain (FDTD) simulations, large drill collar occupies, most of the fluid-filled borehole and divides the borehole fluid into two thin fluid columns (radius -27 mm). Fine grids and large computational models are required to model the thin fluid region between the tool and the formation. As a result, small time step and more iterations are needed, which increases the cumulative numerical error. Furthermore, due to high impedance contrast between the drill collar and fluid in the borehole (the difference is 〉30 times), the stability and efficiency of the perfectly matched layer (PML) scheme is critical to simulate complicated wave modes accurately. In this paper, we compared four different PML implementations in a staggered grid finite difference in time domain (FDTD) in the ALWD simulation, including field-splitting PML (SPML), multiaxial PML(M- PML), non-splitting PML (NPML), and complex frequency-shifted PML (CFS-PML). The comparison indicated that NPML and CFS-PML can absorb the guided wave reflection from the computational boundaries more efficiently than SPML and M-PML. For large simulation time, SPML, M-PML, and NPML are numerically unstable. However, the stability of M-PML can be improved further to some extent. Based on the analysis, we proposed that the CFS-PML method is used in FDTD to eliminate the numerical instability and to improve the efficiency of absorption in the PML layers for LWD modeling. The optimal values of CFS-PML parameters in the LWD simulation were investigated based on thousands of 3D simulations. For typical LWD cases, the best maximum value of the quadratic damping profile was obtained using one do. The optimal parameter space for the maximum value of the linear frequency-shifted factor (a0) and the scaling factor (β0) depended on the thickness of the PML layer. For typical formations, if the PML thickness is 10 grid points, the global error can be reduced to 〈1% using the optimal PML parameters, and the error will decrease as the PML thickness increases. 展开更多
关键词 PML schemes FD simulation LWD acoustic
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Estimation of surface tension of organic compounds using quantitative structure-property relationship 被引量:2
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作者 戴益民 刘又年 +3 位作者 李浔 曹忠 朱志平 杨道武 《Journal of Central South University》 SCIE EI CAS 2012年第1期93-100,共8页
A novel quantitative structure-property relationship (QSPR) model for estimating the solution surface tension of 92 organic compounds at 20℃ was developed based on newly introduced atom-type topological indices. Th... A novel quantitative structure-property relationship (QSPR) model for estimating the solution surface tension of 92 organic compounds at 20℃ was developed based on newly introduced atom-type topological indices. The data set contained non-polar and polar liquids, and saturated and unsaturated compounds. The regression analysis shows that excellent result is obtained with multiple linear regression. The predictive power of the proposed model was discussed using the leave-one-out (LOO) cross-validated (CV) method. The correlation coefficient (R) and the leave-one-out cross-validation correlation coefficient (Rcv) of multiple linear regression model are 0.991 4 and 0.991 3, respectively. The new model gives the average absolute relative deviation of 1.81% for 92 substances. The result demonstrates that novel topological indices based on the equilibrium electro-negativity of atom and the relative bond length are useful model parameters for QSPR analysis of compounds. 展开更多
关键词 surface tension quantitative structure-property relationship (QSPR) topological indice organic compound
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Emission characteristics and combustion instabilities in an oxy-fuel swirl-stabilized combustor 被引量:9
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作者 Guo-neng LI Hao ZHOU Ke-fa CEN 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第11期1582-1589,共8页
This paper presents an experimental study on the emission characteristics and combustion instabilities of oxy-fuel combustions in a swirl-stabilized combustor. Different oxygen concentrations (Xoxy=25%~45%, where Xox... This paper presents an experimental study on the emission characteristics and combustion instabilities of oxy-fuel combustions in a swirl-stabilized combustor. Different oxygen concentrations (Xoxy=25%~45%, where Xoxy is oxygen concentra- tion by volume), equivalence ratios (φ=0.75~1.15) and combustion powers (CP=1.08~2.02 kW) were investigated in the oxy-fuel (CH4/CO2/O2) combustions, and reference cases (Xoxy=25%~35%, CH4/N2/O2 flames) were covered. The results show that the oxygen concentration in the oxidant stream significantly affects the combustion delay in the oxy-fuel flames, and the equivalence ratio has a slight effect, whereas the combustion power shows no impact. The temperature levels of the oxy-fuel flames inside the combustion chamber are much higher (up to 38.7%) than those of the reference cases. Carbon monoxide was vastly produced when Xoxy>35% or φ>0.95 in the oxy-fuel flames, while no nitric oxide was found in the exhaust gases because no N2 participates in the combustion process. The combustion instability of the oxy-fuel combustion is very different from those of the reference cases with similar oxygen content. Oxy-fuel combustions excite strong oscillations in all cases studied Xoxy=25%~45%. However, no pressure fluctuations were detected in the reference cases when Xoxy>28.6% accomplished by heavily sooting flames which were not found in the oxy-fuel combustions. Spectrum analysis shows that the frequency of dynamic pressure oscillations exhibits randomness in the range of 50~250 Hz, therefore resulting in a very small resultant amplitude. Temporal oscillations are very strong with amplitudes larger than 200 Pa, even short time fast Fourier transform (FFT) analysis (0.08 s) shows that the pressure amplitude can be larger than 40 Pa. 展开更多
关键词 SWIRL OXY-FUEL Combustion instability Pollutant emissions
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Passive target tracking with intermittent measurement based on random finite set 被引量:4
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作者 罗小波 范红旗 +1 位作者 宋志勇 付强 《Journal of Central South University》 SCIE EI CAS 2014年第6期2282-2291,共10页
In the tracking problem for the maritime radiation source by a passive sensor,there are three main difficulties,i.e.,the poor observability of the radiation source,the detection uncertainty(false and missed detections... In the tracking problem for the maritime radiation source by a passive sensor,there are three main difficulties,i.e.,the poor observability of the radiation source,the detection uncertainty(false and missed detections)and the uncertainty of the target appearing/disappearing in the field of view.These difficulties can make the establishment or maintenance of the radiation source target track invalid.By incorporating the elevation information of the passive sensor into the automatic bearings-only tracking(BOT)and consolidating these uncertainties under the framework of random finite set(RFS),a novel approach for tracking maritime radiation source target with intermittent measurement was proposed.Under the RFS framework,the target state was represented as a set that can take on either an empty set or a singleton; meanwhile,the measurement uncertainty was modeled as a Bernoulli random finite set.Moreover,the elevation information of the sensor platform was introduced to ensure observability of passive measurements and obtain the unique target localization.Simulation experiments verify the validity of the proposed approach for tracking maritime radiation source and demonstrate the superiority of the proposed approach in comparison with the traditional integrated probabilistic data association(IPDA)method.The tracking performance under different conditions,particularly involving different existence probabilities and different appearance durations of the target,indicates that the method to solve our problem is robust and effective. 展开更多
关键词 passive target tracking maritime target joint detection and tracking intermittent measurement random finite set poor observability
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Boundedness of Solutions for Elliptic Variational Inequalities
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作者 Ye Ruifen(Department of Mathematics, Guangzhou Teachers’ College, 510400) 《Chinese Quarterly Journal of Mathematics》 CSCD 1996年第1期56-62,共7页
The boundedness is proved under more general structural conditions to solutions of elliptic variational inequalities and a priori estimates are obtained to maximum modulus of solutions for some special cases.
关键词 elliptic variational inequality generalized solution bounded solution:maximum modulus priori estimate
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