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回交后代纯合体频率递增量的分布规律 被引量:1
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作者 王汉宁 《草业科学》 CAS CSCD 2001年第2期46-49,56,共5页
回交后代纯合率是一单调递增函数 ,对每一个确定的杂合基因对数 n,都存在一个最大的纯合体频率递增量△ fmax及其对应的世代 r,导数法和统计法都可确定△fmax所在的 r,但用统计法推出的预测公式显得更便利且可靠 ,△ fmax所在的 r可用... 回交后代纯合率是一单调递增函数 ,对每一个确定的杂合基因对数 n,都存在一个最大的纯合体频率递增量△ fmax及其对应的世代 r,导数法和统计法都可确定△fmax所在的 r,但用统计法推出的预测公式显得更便利且可靠 ,△ fmax所在的 r可用于确定停止回交的适宜世代 ,且在左侧前推 2代 ,在右侧后延 4代 ,一共 7个世代 ,积累了 95%以上的纯合体 ,这一现象在n≥ 5时 ,不因 n的大小而异 ,表现出一致的规则性。 展开更多
关键词 回交后代 纯合体频率 递增量 分布规律 导数法 统计法 回交 自交
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ATP递增量治疗阵发性室上速的体会
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作者 靳文莲 孙素贞 《中华全科医学》 2003年第4期321-322,共2页
关键词 室上速 阵发性 递增量 房室结折返 PSVT 刺激迷走神经 先心病 药物评价 颈动脉窦按摩 甲亢性心脏病
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ATP递增量治疗阵发性室上速的体会
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作者 高位年 毕贞水 《中国社区医师(医学专业)》 2004年第11期14-15,共2页
我院于1999年8月-2003年2月共收住院阵发性室上速(PSVT)30例病人。经用ATP(三磷酸腺昔)静脉注射的方法,临床收到满意效果,现报告如下。
关键词 ATP递增量 阵发性室上速 心电图 心电监护 PSVT
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直缝焊管机组定径平辊底径递增量的探讨
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作者 曹国富 《钢管》 CAS 2000年第2期15-18,共4页
根据定径原理 ,提出直缝焊管机组定径平辊底径递增量Δd是焊管外径Dn 、管壁厚度S、定径余量ΔD、管材弹性ε的函数 ;并且从定径余量转换成焊管纵向增长量以及定径过程需要焊管保持一定张力的角度对定径平辊底径递增量进行推导 ,得到定... 根据定径原理 ,提出直缝焊管机组定径平辊底径递增量Δd是焊管外径Dn 、管壁厚度S、定径余量ΔD、管材弹性ε的函数 ;并且从定径余量转换成焊管纵向增长量以及定径过程需要焊管保持一定张力的角度对定径平辊底径递增量进行推导 ,得到定径平辊底径递增量的计算式 ,为科学合理设计定径平辊底径递增量提供了理论依据 ,对延长轧辊使用寿命、提高焊管表面质量。 展开更多
关键词 直缝焊管机组 定径平辊 底径递增量
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快速递增氨基酸量在极低出生体重儿静脉营养中的临床研究 被引量:2
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作者 杨寒微 冯静 +2 位作者 黄佳 覃广萍 陈秋萍 《江西医药》 CAS 2019年第8期949-950,966,共3页
目的对比分析早期快速递增氨基酸量在极低出生体重儿静脉营养中的应用效果。方法2016年6月—2019年5月,将48例极低出生体重儿作为研究对象,按照随机法分为对照组和观察组各24例,分别采用常规递增氨基酸量组与快速递增氨基酸量组,对比2... 目的对比分析早期快速递增氨基酸量在极低出生体重儿静脉营养中的应用效果。方法2016年6月—2019年5月,将48例极低出生体重儿作为研究对象,按照随机法分为对照组和观察组各24例,分别采用常规递增氨基酸量组与快速递增氨基酸量组,对比2组患儿出生体重恢复时间、住院时间。结果观察组患儿出生体重恢复时间、住院时间改善情况明显优于对照组(P<0.05)。观察组患儿的并发症及血气pH、碳酸氢盐、BE值、血尿素、血肌酐、甘油三酯、谷丙转氨酶、胆汁酸水平与对照组相比(P>0.05)差异均为统计学意义。结论早期快速递增氨基酸量在极低出生体重儿静脉营养中的应用效果突出,不会导致并发症和代谢异常的增加。 展开更多
关键词 早期快速递增氨基酸 极低出生体重儿 静脉营养
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输油管道输油量平均递增(减)率的计算
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作者 孙福林 关进波 《管道技术与设备》 CAS 2003年第1期9-11,共3页
通过求方程xn +xn- 1+ΛΛ+x +1=a(n=1,2 ,Λ ,a为一常数 )正实根给出了计算输油管道输油量的平均递增 (减 )率的一种方法 ,这种方法计算格式简单 ,操作方便。
关键词 石油管道 输油递增 迭代过程 牛顿迭代
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基于DeForm的密封条钢带滚压成形过程有限元分析 被引量:1
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作者 魏敏 《模具工业》 2021年第2期17-21,共5页
以某汽车密封条钢带骨架为研究对象,利用DeForm有限元分析技术对密封条钢带骨架滚压成形过程建立有限元仿真模型,根据模型分析滚轮基本直径递增量和摩擦系数变化对成形过程中带料等效应力和应变的影响规律。结果表明适当增大滚轮基本直... 以某汽车密封条钢带骨架为研究对象,利用DeForm有限元分析技术对密封条钢带骨架滚压成形过程建立有限元仿真模型,根据模型分析滚轮基本直径递增量和摩擦系数变化对成形过程中带料等效应力和应变的影响规律。结果表明适当增大滚轮基本直径的递增量和减小滚轮与带料之间的摩擦系数,可降低带料成形过程中的等效应力和应变,有利于保证密封条钢带骨架成形过程稳定并防止产生边缘波浪、褶皱等缺陷。 展开更多
关键词 密封条钢带 滚压成形 等效应力 直径递增量
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电力变压器铁心柱公差带的设计
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作者 郑斌 《城市建设(下旬)》 2010年第3期129-129,共1页
电力变压器的设计中很重要的一个环节就是铁心柱的截面如何设计。我国变压器制造业通常采用全国统一的标准铁心设计图纸。根据多年的生产经验,各生产厂存在着对已有设计方案的疑问:能否改进及如何改进这些设计,才能在提高使用效果的... 电力变压器的设计中很重要的一个环节就是铁心柱的截面如何设计。我国变压器制造业通常采用全国统一的标准铁心设计图纸。根据多年的生产经验,各生产厂存在着对已有设计方案的疑问:能否改进及如何改进这些设计,才能在提高使用效果的同时降低变压器的成本。本文主要研究的是电力变压器铁心柱线圈的内筒直径和铁心柱的外接圆直径配合公差带设计,在实际生产中线圈的内筒直径和铁心柱的外接圆直径不是精确地相等,而留有一定的间隙以便于安装和维修,设计的两个直径的取值范围称为各自的公差带。因此可以在设计铁心截面时稍微增加铁心柱的外接圆的直径以使得铁心柱有更好的截面形状,所以在模型中加入尺寸具有公差带这一因素,考虑公差带对截面优化的影响。 展开更多
关键词 非线性整数规划 铁心利用率 递增量 公差带
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CFD simulation with enhancement factor of sulfur dioxide absorption in the spray scrubber 被引量:6
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作者 Xiang GAO Wang HUO +1 位作者 Zhong-yang LUO Ke-fa CEN 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2008年第11期1601-1613,共13页
A model describing the absorption process of SO2 into limestone slurry with a spray scrubber is presented. Both the physical performance of the spray liquid in the scrubber and the involved chemical reactions are anal... A model describing the absorption process of SO2 into limestone slurry with a spray scrubber is presented. Both the physical performance of the spray liquid in the scrubber and the involved chemical reactions are analyzed in the model. A con- tinuous concentration change of H+ was solved by iterative coupling using Matlab, and it was found that there was a remarkable influence on the concentration of the other elements in the process of SO2 absorption. The calculations show that the enhancement factor exponentially grows with an increasing value of pH and logarithmically decays with an increasing value of the driving force. To verify the accuracy of the model, experiments were also carried out, and the results suggest that the model, after combining the physical performance of the spray and the enhancement factor, can more precisely describe SO2 absorption in a spray scrubber. Furthermore, a commercial computational fluid dynamics (CFD) tool is used to perform several simulations which describe and clarify the effects of variables on SO2 absorption. The results of numerical simulation can provide a basis for further design and optimization of the scrubber. 展开更多
关键词 SO2 absorption Limestone dissolution Enhancement factor Mass transfer Concentration profile
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宇宙并非在膨胀的验证
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作者 周吉善 《济源职业技术学院学报》 2003年第4期26-27,共2页
持膨胀宇宙论的人们认为引力红移可以忽略不计,依据60年代精密实验的数据计算的结果,引力效应却是哈勃效应的10^(10)倍。建议重做一次精密实验,即可以对“宇宙在膨胀”予以证否。
关键词 宇宙在膨胀 红移 多普勒效应 引力红移 红移逐年递增
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Effect of MgO and SiO_2 on surface tension of fluoride containing slag 被引量:2
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作者 董艳伍 姜周华 +2 位作者 曹玉龙 张洪奎 沈海军 《Journal of Central South University》 SCIE EI CAS 2014年第11期4104-4108,共5页
Surface tensions of slag addition Mg O and Si O2 based on conventional 70%CaF 2-30%Al2O3 and 60%Ca F2-20%Ca O-20%Al2O3(mass fraction) at 1300 °C, 1400 °C and 1500 °C were investigated. Influence mechani... Surface tensions of slag addition Mg O and Si O2 based on conventional 70%CaF 2-30%Al2O3 and 60%Ca F2-20%Ca O-20%Al2O3(mass fraction) at 1300 °C, 1400 °C and 1500 °C were investigated. Influence mechanism of Mg O and Si O2 on slag surface tension was also analyzed. Results indicate that surface tension decreases with the increase of Mg O content in the case of the Mg O content(mass fraction) less than 8%, however, when Mg O content(mass fraction) is from 8% to 30%, surface tension increases with the increase of Mg O content. When Si O2 content(mass fraction) is from 2% to 8%, surface tension decreases with the increase of Si O2 content. Additionally, the relationship between surface tension and optical basicity is a monotonically increasing linear function. Research findings can provide important reference for slag design and the study of slag-metal interfacial tension. 展开更多
关键词 electroslag metallurgy fluoride containing slag surface tension influence mechanism
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Numerical Simulation of Hot Spot Growth in Detonation with Regard to the Turbulent Mechanism of Energy Transfer
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作者 Yury Vasilyevich Yanilkin Vitaly Grigoryevich Morozov Irina Isorevna Karpenko Olga Nikolaevna Chernyshova 《Journal of Physical Science and Application》 2015年第3期226-237,共12页
The paper presents the results of numerical modeling of hot spot growth process in detonation with account for turbulent mixing. The performed investigation has shown that large-scale HE (High explosives) particles ... The paper presents the results of numerical modeling of hot spot growth process in detonation with account for turbulent mixing. The performed investigation has shown that large-scale HE (High explosives) particles mix up and split down to smaller sizes in the result of shock wave impact, instability development on the HE-EP (Explosion product) interface and vortex flow; at these sizes, due to the developed surface of the HE-EP contact, HE has enough time to get heated (energy transfer from EP), and the decomposition reaction effectively continues. Numerical modeling make the calculation of the hot spot growth rate (about 100-200 m/s) possible. This has proved the hypothesis saying that at mechanical material transport the turbulence in the reaction zone plays an important role and it must be taken into account in the detonation theory. 展开更多
关键词 Hot spot DETONATION turbulent mixing numerical simulation.
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Non-Nehari manifold method for asymptotically periodic Schrodinger equations 被引量:8
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作者 TANG XianHua 《Science China Mathematics》 SCIE CSCD 2015年第4期715-728,共14页
We consider the semilinear Schrdinger equation-△u + V(x)u = f(x, u), x ∈ RN,u ∈ H 1(RN),where f is a superlinear, subcritical nonlinearity. We mainly study the case where V(x) = V0(x) + V1(x),V0∈ C(RN), V0(x) is 1... We consider the semilinear Schrdinger equation-△u + V(x)u = f(x, u), x ∈ RN,u ∈ H 1(RN),where f is a superlinear, subcritical nonlinearity. We mainly study the case where V(x) = V0(x) + V1(x),V0∈ C(RN), V0(x) is 1-periodic in each of x1, x2,..., x N and sup[σ(-△ + V0) ∩(-∞, 0)] < 0 < inf[σ(-△ +V0)∩(0, ∞)], V1∈ C(RN) and lim|x|→∞V1(x) = 0. Inspired by previous work of Li et al.(2006), Pankov(2005)and Szulkin and Weth(2009), we develop a more direct approach to generalize the main result of Szulkin and Weth(2009) by removing the "strictly increasing" condition in the Nehari type assumption on f(x, t)/|t|. Unlike the Nahari manifold method, the main idea of our approach lies on finding a minimizing Cerami sequence for the energy functional outside the Nehari-Pankov manifold N0 by using the diagonal method. 展开更多
关键词 Schrodinger equation non-Nehari manifold method asymptotically periodic ground state solutions of Nehari-Pankov type
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TYPE X MONOTONE SYSTEMS WITH AN ORDER-INCREASING INVARIANT FUNCTION
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作者 JIANG JIFA(Department of Mathematics, The University of Science and Technology of China, Hefei 230036, China.) 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 1996年第3期335-342,共8页
The author considers the asymptotic behavior of solutions of a class of ordinary dmerentialequations x = F(x) in the nonnegative orthant R7. Suppose that F(o) = o, Fi(x1,..., xn) isnondecreasing in xk for all k≠ i an... The author considers the asymptotic behavior of solutions of a class of ordinary dmerentialequations x = F(x) in the nonnegative orthant R7. Suppose that F(o) = o, Fi(x1,..., xn) isnondecreasing in xk for all k≠ i and that F possesses an order-increasing invarian function.Then it is shown that every bounded solution to such a system converges to a single equilibrium. 展开更多
关键词 Type K monotone system Monotone flow Invariant function EQUILIBRIUM Convergence
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A three-process quantum engine cycle consisting of a two-level system 被引量:3
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作者 OU CongJie HUANG ZhiFu +1 位作者 LIN BiHong CHEN JinCan 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2014年第7期1266-1273,共8页
Based on the thermodynamic properties of isoenergetic,adiabatic and isothermal quantum processes,it is shown that it is possible to combine the three processes into a quantum engine cycle.The efficiency of the three-p... Based on the thermodynamic properties of isoenergetic,adiabatic and isothermal quantum processes,it is shown that it is possible to combine the three processes into a quantum engine cycle.The efficiency of the three-process cycle can be derived and is dependent on the highest and lowest temperatures.The efficiency in some operation regions does not demonstrate a monotonically increasing function of the temperature difference.When the highest temperature of the cycle is larger than the critical temperature,which can be determined by the characteristics of the three-process cycle,a unique region where the efficiency decreased with the increase of the temperature difference exists. 展开更多
关键词 quantum engine isoenergetic process critical temperature
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