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k-对等图与Ore-范条件
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作者 高敬振 《山东科学》 CAS 1999年第3期11-16,共6页
本文证明了:若 k≥3, G 为 n 阶 2边连通图且 n≥4k+ 1,kn 为偶数,δ( G)≥k+ 1,uv E( G)时 m ax(d(u),d(v))≥n/2,则 G 是 k对等图,除非 G 为一类例外图。
关键词 k-对等图 K-因子 Ore-范条件
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范条件图的上可嵌入性 被引量:2
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作者 吴向群 任韩 《泉州师范学院学报》 2004年第2期44-46,共3页
关于图的上可嵌入性,刘彦佩和Nebseky分别给出不同形式的充要条件,黄元秋从另一相反角度出发,提供了一个关于不是上可嵌入图的充要条件.文章利用关于不是上可嵌入图的充要条件,证明了范条件图是上可嵌入的.
关键词 范条件 上可嵌入性 最大亏格 BETTI亏数
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范-条件与具有给定端点的最长路
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作者 张运清 《南京大学学报(数学半年刊)》 CAS 2004年第1期77-85,共9页
令G是n阶2-连通图且d(u,v)=2→max{d(u),d(v)}≥n/2.设{x,y}不是G的2-割集,记最长的(x,y)-路的长度为p(x,y).本文证明了如下结论:(1)p(x,y)≥n-2;(2)若p(x,y)=n-2且P是最长的(x,y)-路中使得d(xp)最小的一条,那么d(xp)=2,... 令G是n阶2-连通图且d(u,v)=2→max{d(u),d(v)}≥n/2.设{x,y}不是G的2-割集,记最长的(x,y)-路的长度为p(x,y).本文证明了如下结论:(1)p(x,y)≥n-2;(2)若p(x,y)=n-2且P是最长的(x,y)-路中使得d(xp)最小的一条,那么d(xp)=2,3或者n/2,其中xp表示唯一一个不属于P的点.本文还刻画了3-连通且使得d(xp)=3的图. 展开更多
关键词 -条件 最长路 图论 连通图
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关于Q过程的逼近理论 被引量:1
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作者 陈作忠 《广西师范大学学报(自然科学版)》 CAS 1998年第3期14-22,共9页
在假定状态稳定的条件下提出了用一列(不必是Q过程的)ψn(λ)去逼近Q过程的转移概率的拉氏变换ψ(λ)的理论.
关键词 Q过程 范条件 预解条件 逼近 转移 概率
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[a,b]-因子存在性的范-型条件 被引量:1
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作者 周思中 《数学学报(中文版)》 SCIE CSCD 北大核心 2011年第5期803-810,共8页
设G是一个图,a,b是整数且满足0≤a≤b.如果存在G的一个支撑子图F,使对任意的x∈V(G)有a≤d_F(x)≤b,则称F是G的一个[a,b]-因子.本文给出图中具有特定性质的[a,b]-因子的范-型条件.进一步指出这个结果是最好的.
关键词 -型条件 -[a b]-因子
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Optimization of the Conditions for Using Sewage to Cultivate Navicula tenera 被引量:14
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作者 吴夏芫 李环 韦萍 《Agricultural Science & Technology》 CAS 2009年第1期68-73,共6页
[ Objective] This study was to improve the biomass of Navicula tenera, and thus to provide reference for achieving the industrial production of Navicula tenera. [Method] The feasibility of using sewage to cultivate Na... [ Objective] This study was to improve the biomass of Navicula tenera, and thus to provide reference for achieving the industrial production of Navicula tenera. [Method] The feasibility of using sewage to cultivate Navicula tenera was preliminarily investigated based on the consideration of regional characteristics; and a series of culture conditions including the nutrient source of nitrogen(N), phosphorus(P), iron(Fe), silicon( Si ) and the salinity in medium for culturing Navicula tenera, were optimized by single factor test and orthogonal design.[Result] The optimized conditions for cultivating Navicula tenera using sewage are as follows: the water from Xiaoerlou Artificial Lake of Nanjing University of Technology as basic solvent; 360 mg/L urea; 150 mg/L N2HPO4 · 12H2O; 50 mg/L ferric citrate; 2 000 mg/L Na2SiO3 · 9H2O; 2.0 mol/L salinity. Navicula tenera was strongly adaptive to sewage and could well uptake the nutrient sources in the sewage. Under the optimized conditions, the culture cost decreased, and meanwhile the biomass of Navicula tenera reached 4. 766 g/L which is 3.57 multiples over original medium and 1.9 multiples over optimized medium No. 1.[ Conclusion] This study laid a foundation for the combination of culturing Navicula tenera in large scale and sewage treatment. 展开更多
关键词 Navicula tenera SEWAGE Culture condition Nutrient source Orthogonal design
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Analysis of Leakage in Bolted-Flanged Joints Using Contact Finite Element Analvsis 被引量:1
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作者 Hector Estrada 《Journal of Mechanics Engineering and Automation》 2015年第3期135-142,共8页
The evolution of leakage is studied using detailed contact finite element analysis. The distribution of stress at the gasket is analyzed using a contact condition based on slide-line elements using ABAQUS, a commercia... The evolution of leakage is studied using detailed contact finite element analysis. The distribution of stress at the gasket is analyzed using a contact condition based on slide-line elements using ABAQUS, a commercial finite element code, Slide-line elements also take into account pressure penetration as contact that is lost between flange and gasket. Results are presented for a particular flange, a raised face flange sealed by a mild steel gasket. A comparison of the results from the gasket contact analysis and the contact conditions specified by the ASME Boiler and Pressure Vessel Code, Sections VIII, Division 1 shows that the conditions specified in the ASME Code predict leakage relatively accurately. 展开更多
关键词 Flanged joints contact finite element analysis design codes.
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Inner Product and Norm
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作者 赵舜仁 《Chinese Quarterly Journal of Mathematics》 CSCD 2000年第3期39-43,共5页
In this paper,we give some new equivalent forms of the norm in inner produt space.
关键词 normed linear space immerproduct space NOR
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Some Equivalent Conditions for the Differentiability of Continuous Gauge Functions on Banach Space
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作者 南朝勋 《Chinese Quarterly Journal of Mathematics》 CSCD 1992年第4期84-88,共5页
In this paper,some equivalent conditions for differentiability of condtinuous gauge function are given.
关键词 gauge function SUBGRADIENT Gauteaux differentiability Frechet differentiability
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Alteration of Crime Risk Levels and Formal Aspect of Typical LowCost Housing Design Due to Site Conditions and Building Codes
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《Journal of Civil Engineering and Architecture》 2011年第11期967-978,共12页
As a component of the process of rationalization, lowcost housing Institution, as well as major investiment companies, commonly reuse a typical design as a standard. The goal of this procedure is to obtain cheaper cos... As a component of the process of rationalization, lowcost housing Institution, as well as major investiment companies, commonly reuse a typical design as a standard. The goal of this procedure is to obtain cheaper costs both in the construction and in the maintenance of an homogeneous lot of buildings. The paper shows that, nevertheless an identical design being proposed in different towns, the final results are buildings with a different aspect. This is mainly due to the influence of building codes of the urban plan of the specific town, and to the site conditions, such as street orientation, ground inclination and so on. As a result the paper offers the ability to evaluate the role of the external factors on a standard design (with the afore said scale vantages) under the criminological point of view as well. This may be considered a further vantage that aims to obtain a lower crime risk level in town design. 展开更多
关键词 Standardized housing design alterations crime risk levels.
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Ohmefentanyl stereoisomers induce changes of CREB phosphorylation in hippocampus of mice in conditioned place preference paradigm 被引量:6
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作者 CANGAO LIWEICHEN 《Cell Research》 SCIE CAS CSCD 2003年第1期29-34,共6页
The present study was designed to determine the changes of phosphorylation of cAMP- response ele-ment binding protein (CREB) in hippocampus induced by ohmefentanyl stereoisomers (F9202 and F9204)in conditioned place p... The present study was designed to determine the changes of phosphorylation of cAMP- response ele-ment binding protein (CREB) in hippocampus induced by ohmefentanyl stereoisomers (F9202 and F9204)in conditioned place preference (CPP) paradigm. The results showed that mice receiving F9202 and F9204displayed obvious CPP. They could all significantly stimulate CREB phosphorylation and maintained for along time without affecting total CREB protein levels. The effect of F9204 was similar to morphine whicheffect was more potent and longer than F9202. We also examined the effects of ketamine, a noncompetitiveN-mthyl-D-aspartate receptor (NR) antagonist, on morphine-, F9202- and F9204- induced CPP and phos-phorylation of CREB in hippocampus. Ketamine could suppress not only the place preference but also thephosphorylation of CREB produced by morphine, F9202 and F9204. These findings suggest that alterationsin the phosphorylation of CREB be relevant to opiates signaling and the development of opiates dependence.NR antagonists may interfere with opiates dependence and may have potential therapeutic implications. 展开更多
关键词 cAMP-response element binding protein (CREB) ohmefentanyl stereo isomers OPIATES HIPPOCAMPUS conditioned place preference (CPP).
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Prediction of Skewed Bridge Behaviors with Arbitrary Boundary Conditions—— Theoretical Approach and Its Design Application
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作者 Pang-jo Chun Gongkang Fu 《Journal of Civil Engineering and Architecture》 2012年第6期639-650,共12页
In this paper, we report on an analytical solution for beam-type skewed highway bridges subjected to truck loading. To confirm the analysis derivation and the solution obtained, the moment and shear responses to the d... In this paper, we report on an analytical solution for beam-type skewed highway bridges subjected to truck loading. To confirm the analysis derivation and the solution obtained, the moment and shear responses to the design truck load are acquired using the analytical method for a number of typical US highway bridges and compared with those from numerical finite element method (FEM) analysis. In addition, the lateral distribution factors for moment and shear used in routine design are investigated based on comparison of the analytical approach and FEM. The analytical solution is shown in good agreement with the FEM result. Furthermore, the relevant provisions in the American Association of State Highway Transportation Officials' (AASHTO's) LRFD Bridge Design Specifications are also discussed here for comparison, particularly with respect to design application. It is observed that the design code specified load distribution factor may not predict well, especially for shear and/or severe skew. 展开更多
关键词 Skewed plates thick plates skewed bridges truck loading analytical solution.
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Electrodeposition of aluminum and aluminum-magnesium alloys at room temperature 被引量:6
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作者 阚洪敏 祝跚珊 +1 位作者 张宁 王晓阳 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第10期3689-3697,共9页
Electrodeposition of aluminum from benzene-tetrahydrofuran-Al Cl3-Li Al H4 was studied at room temperature. Galvanostatic electrolysis was used to investigate the effect of various parameters on deposit morphology and... Electrodeposition of aluminum from benzene-tetrahydrofuran-Al Cl3-Li Al H4 was studied at room temperature. Galvanostatic electrolysis was used to investigate the effect of various parameters on deposit morphology and crystal size, including current density, temperature, molar ratio of benzene/tetrahydrofuran and stirring speed. The deposit microstructure was adjusted by changing the parameters, and the optimum operating conditions were determined. Dense, bright and adherent aluminum coatings were obtained over a wide range of current densities(10-25 m A/cm2), molar ratio of benzene and tetrahydrofuran(4:1 to 7:8) and stirring speeds(200-500 r/min). Smaller grain sizes and well-adhered deposits were obtained at lower temperatures. Aluminum-magnesium alloys could potentially be used as hydrogen storage materials. A novel method for Al-Mg deposition was proposed by using pure Mg anodes in the organic solvents system benzene-tetrahydrofuran-Al Cl3-Li Al H4. XRD shows that the aluminum-magnesium alloys are mainly Al3Mg2 and Al12Mg17. 展开更多
关键词 ELECTRODEPOSITION aluminum coating aluminum-magnesium(Al-Mg) coating organic solvent system
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Analysis on Path and Countermeasures of Modem Agricultural Development in Beijiang District of Xinjiang
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作者 Jiang Xiuying Jin Cailiang 《International Journal of Technology Management》 2013年第12期140-142,共3页
To realize the fusion development of modem agricultural demonstration zone in Beijiang District, on one hand, it should fully depend on its own resource conditions; on the other hand, it should positively promote the ... To realize the fusion development of modem agricultural demonstration zone in Beijiang District, on one hand, it should fully depend on its own resource conditions; on the other hand, it should positively promote the policy innovation and system mechanism innovation. The author thinks that promoting the fusion development of modern agriculture in Beijiang District should first recognize the importance and necessity of fusion development strategy, and then promote this fusion engineering from system and mechanism. Finally, it should make innovations in policy, in order to provide overall protection of modern agricultural fusion development in Beijiang District. 展开更多
关键词 Beijiang modern agricultural development path and countermeasures ANALYSIS
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Nonconforming Finite Element Method for Gradient flow Equations in Robin Conditions
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作者 Changhui Yao Shaorong Li 《Journal of Mathematics and System Science》 2014年第5期315-326,共12页
In this paper, Crouzeix-Raveart type nonconforming rectangular element is applied to the Mumford-Shah functional for image segmentation subjected to Robin boundary conditions. Meanwhile, by using the special orthogona... In this paper, Crouzeix-Raveart type nonconforming rectangular element is applied to the Mumford-Shah functional for image segmentation subjected to Robin boundary conditions. Meanwhile, by using the special orthogonality of this element's basic functions, the convergence analysis for L2-norm and broken H1-norm with semi-implicit scheme is presented. And the error order is improved to the optimal, too. 展开更多
关键词 Image segmentation nonconforming finite element Robbin boundary conditions error estimate.
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A selective optical chemical sensor for the determination of iodine based on fluorescence quenching of LiTOE
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作者 LONG Li-ping ZHONG Tong-sheng WANG Jiao-liang YIN Zhi-fang LI Wang-ying LEI Cun-xi 《Journal of Environmental Science and Engineering》 2008年第1期72-77,共6页
An optical chemical sensor has been developed for the determination of iodine based on the reversible fluorescence quenching of 2, 2, 7, 7, 12, 12, 17, 17-octamethyl-21, 22, 23, 24-tetraoxaquaterene-Li (LiTOE) imm... An optical chemical sensor has been developed for the determination of iodine based on the reversible fluorescence quenching of 2, 2, 7, 7, 12, 12, 17, 17-octamethyl-21, 22, 23, 24-tetraoxaquaterene-Li (LiTOE) immobilized in a plasticized poly(vinyl chloride) (PVC) membrane. The optimum membrane of the sensor consists of 100 mg of PVC, 200 mg of bis (2-ethytbexyl) sebacate (BOS) and 3.0 mg of LiTOE. The maximum response of the optode membrane for iodine is obtained in Tris-HCl buffer solutlon (pH 8.0). With the optimum conditions described, the proposed sensor responds linearly in the measuring range of 3.90×10^-2 to 3.90×10^-4 mol/L, and has a detection limit of 6.0×10^-8 mol/L. The response time of the sensor is less than I rain. In addition to high reproducibility and reversibility of the fluorescence signal, the sensor also exhibits good selectivity. It is not interfered by some common anions and cations. It is applied for the determination of iodine in table salt samples. The results agree with those obtained by another method. 展开更多
关键词 a selective optical chemical sensor IODINE fluorescence quenching 2 2 7 7 12 12 17 17-Octamethyl-21 22 23 24-tetraoxaquaterene-Li (LiTOE) optode membrane
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Enhancement of Critical Heat Flux in Tight Rod Bundle with Wire Spacer
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作者 Dan Tri Le Minoru Takahashi 《Journal of Energy and Power Engineering》 2016年第2期109-115,共7页
The experiment of CHF (critical heat flux) was conducted for water boiling two-phase flow in three-pin tight rod bundle. The effects of with and without wire spacers and the pitch to diameter ratio p/d on CHF were i... The experiment of CHF (critical heat flux) was conducted for water boiling two-phase flow in three-pin tight rod bundle. The effects of with and without wire spacers and the pitch to diameter ratio p/d on CHF were investigated under the conditions of mass flux range 250-430 kg/(m2·s), inlet temperature from 70 ℃ to 92 ℃ and the pressure of 0.1 MPa. The CHF was enhanced by wire spacers in comparison with the results of CHF without wire spacers. The CHF was enhanced by reducing thep/dfrom 1.18 to 1.10 under the same flow rate condition, although it did not change appreciably with the change ofp/d under the same mass flux condition. 展开更多
关键词 Critical heat flux tight lattice core boiling two-phase flow wire spacer.
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Hot compression deformation characteristics of Mg-Mn alloys
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作者 方超 张静 +3 位作者 廖爱林 薛绍展 袁付庆 潘复生 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2010年第10期1841-1845,共5页
The hot deformation behaviors of solution treated Mg-1.8Mn-0.4Er-0.2Al alloys were investigated by means of compression tests on Gleeble-1500 in strain rate range of 0.01-10s-1,deformation temperature range of 250-450... The hot deformation behaviors of solution treated Mg-1.8Mn-0.4Er-0.2Al alloys were investigated by means of compression tests on Gleeble-1500 in strain rate range of 0.01-10s-1,deformation temperature range of 250-450℃ and a true strain of 0.6.The constitutive relationships among flow stress,strain rate and deformation temperature were described by Arrhenius-type equations,based on the fact that the material constants could be calculated under a wide range of strains.The results show that the flow stress of the experimental alloy decreases with temperature increasing and strain rate decreasing.Under the experimental conditions,the products of constant α and n in the constitutive equation are stable within certain strains,and the deformation activation energy ranges from 160 to 220 kJ/mol.It is proved that the values of calculated flow stress are close to the experimental results with average error of 2.01%. 展开更多
关键词 magnesium alloy thermal deformation flow stress constitutive equation
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On Zero One Symmetric and Normal Matrices
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作者 王伯英 张福振 《Journal of Mathematical Research and Exposition》 CSCD 1998年第2期159-164,共6页
We present additional equivalent conditions on the existence of a 0 1 symmetric matrix with given row sum vector. The case of a 0 1 normal matrix is also considered.
关键词 incidence matrix majorization normal matrix row sum vector.
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Auto-ignition of biomass synthesis gas in shock tube at elevated temperature and pressure 被引量:2
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作者 Linqi Ouyang Hua Li +2 位作者 Shuzhou Sun Xiaole Wang Xingcai Lu 《Science Bulletin》 SCIE EI CAS CSCD 2015年第22期1935-1946,共12页
Ignition delay times of multi-component biomass synthesis gas (bio-syngas) diluted in argon were measured in a shock tube at elevated pressure (5, 10and 15 bar, 1 bar = 105 Pa), wide temperature ranges (1,100-1,7... Ignition delay times of multi-component biomass synthesis gas (bio-syngas) diluted in argon were measured in a shock tube at elevated pressure (5, 10and 15 bar, 1 bar = 105 Pa), wide temperature ranges (1,100-1,700 K) and various equivalence ratios (0.5, 1.0, 2.0). Additionally, the effects of the variations of main constituents (H2:CO = 0.125-8) on ignition delays were investigated. The experimental results indicated that the ignition delay decreases as the pressure increases above certain temperature (around 1,200 K) and vice versa. The ignition delays were also found to rise as CO concentration increases, which is in good agreement with the literature. In addition, the ignition delays of bio-syngas were found increasing as the equivalence ratio rises. This behavior was primarily discussed in present work. Experimental results were also compared with numerical predictions of multiple chemical kinetic mechanisms and Li's mechanism was found having the best accuracy. The logarithmic ignition delays were found nonlinearly decrease with the H2 concentration under various conditions, and the effects of temperature, equivalence ratio and H2 concentration on the ignition delays are all remarkable. However, the effect of pressure is rela- tively smaller under current conditions. Sensitivity analysis and reaction pathway analysis of methane showed that R1 (H +O2= O -9 OH) is the most sensitive reaction promot- ing ignition and R13 (H +O2 (+M) = HO2 (+M)), R53(CH3+H (+M)= CH4 (+M)), R54 (CH4+H= CH3 + H2) as well as R56 (CH4 + OH = CH3 + H2O) are key reactions prohibiting ignition under current experimental conditions. Among them, R53 (CH3 + H (+M) = CH4 (+M)), R54 (CH4 + H = CH3 + H2) have the largest posi- tive sensitivities and the high contribution rate in rich mixture. The rate of production (ROP) of OH of R1 showed that OH ROP of R1 decreases sharply as the mixture turns rich. Therefore, the ignition delays become longer as the equiva- lence ratio increases. 展开更多
关键词 Shock tube Biomass synthesis gas Ignition delay time Sensitivity analysis Reactionpathway analysis
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