系数问题
- 与 系数问题 相关的网络例句 [注:此内容来源于网络,仅供参考]
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It possesses properties of low theremal conductivity, excellent in heat resistant, low density and IPO, saving energy, environment friendly and non-toxicity, no peeling, sanitary.
该材料导热系数更低,隔热性能更优,质量极轻,节能高效,低能耗,无毒环保,无粉尘问题,安全卫生。
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Radon and thoron calibration factors are 1.78 and7.63 respectively , the relative error of radon concentration ERS-2 measured is 3.0%compared to the standard radon concentration and thoron is 3.2%. We deduced theequations which can eliminate the mutual interference between radon and thoronmeasurement .
通过 ERS—2 氡析出率仪器的研究,对 ERS—2 测量析出率中道址的选择以及扣除氡钍干扰问题进行了讨论,氡道道址设置为 60—115,钍道道址设置为 119—128,氡钍的刻度系数分别选为 1.78 和 7.63,测得的氡浓度与标准氡浓度的相对误差为 3.0%,测得的钍射气浓度与标准钍射气浓度的相对误差为 3.2%。
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objective to study the correlation among psychosomatic health factors,depression,anxiety and sleep status in college students,to analyze influence factors in sleep status.methods with questionnaire opened in-vestigation,200college students were evaluated using cornell medical index,self-rating depression,self-rating anxiety scaleand pittsburgh sleep quality index.stepwise regression analysis was used.re-sults total score of sds was35.55±7.8,and sas was0.48±0.9.each score of cmi was higher than normal range,the highest was digestion system,next was respiration system,then,fatigue,eyes and ears,anxiety,sensitivity,tension,maladjustment in turn.total average score of psqi was6.32±3.6,ordinary sleep were115cases(57.5%),good and bad sleep were42(21%)and43(21.5%)cases respectively.influence factors in total score of psqi were sas,cmi,respiration system,anxiety,past healthy,digestion system,fatigue,sensitivity,sds and malad-justment in turn,using stepwise regression analysis,total score of psqi as dependent variable,each factor score of cmi,total score of sds and sas as independent variables.conclusion problems of psychosomatic health,anxiety and depression could both lead to sleep disorder.
目的 研究在校大学生心身健康因素及抑郁焦虑等与睡眠状况的相关性,并对影响睡眠状况的有关因素进行分析。方法采用问卷式的开放性研究,对在校的200名大学生进行康奈尔心身健康问卷、自评抑郁量表、焦虑自评量表和匹兹堡睡眠质量量表的测定,采用逐步回归分析方法。结果 sds总分为35.55±7.8、sas总分为0.48±0.9,cmi评分:消化系统最为严重评分为2.52,其次为呼吸系统、疲劳感、眼和耳、焦虑、敏感、紧张、不适应等,评分均高于正常常模。psqi总均分为6.32±3.6,一般睡眠有115例占57.5%,睡眠质量较好42例占21.0%,睡眠质量较差43例占21.5%。评估对睡眠状况的影响程度,以psqi总分为因变量,选择cmi各因子分和sds、sas总分作为自变量,进行多因素逐步回归分析,进入方程的因素依据标准化偏回归系数,影响psqi总分的因素依次为sas总分、cmi总分、呼吸系统、焦虑、既往健康、消化系统、疲劳感、敏感、sds总分、不适应(f=226.8;p.01;r=0.73)。结论心身健康问题和焦虑抑郁可导致睡眠障碍。
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Finally, the boundary feedback control of the undamped Euler-Bernoulli beamwith both ends free is concerned.
最后,对两端自由的变系数无阻尼Euler-Bernoulli梁采用旋转角、角速度和位移、速度的线性边界反馈指数稳定化问题进行了讨论。
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The "divide and conquer" strategy is used to improve the key steps of the undetermined coefficient algorithm for constructing polynomial conservation laws of nonlinear DDEs, so the calculation complexity problem caused by the dramatic increase of redundancy is solved. Furthermore, Wu\'s elimination method is applied to solve the obtained nonlinear algebraic equations thus to get a more efficient algebraic algorithm.
本文从微分方程的标度变换出发,利用"分治"策略改进了构造非线性DDE守恒律待定系数算法中的关键步骤,有效解决了因冗余项急剧增加引起的中间计算过程膨胀问题,并将吴消元法应用到非线性代数方程组的求解上,从而给出了一个更高效的代数算法。
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The polynomial function bases are used to form the approximately matching function. Moreover, the discrete values of grey image is transformed to polinomial function that are exact fit at the considered pixel locations. As a result, The mathematical operations performed such as derivation, integration, and gradient evaluation also give out the polynomial functions, therefore, the system of undetermined coefficient equations is derived to be a system of linear algebraic equations.
我们把立体匹配过程看作泛函的极小化过程,因此选用变分问题近似解法的Ritz法构造数值算法,以多项式函数为基构作匹配函数的近似解,进而又利用多项式过样值点的拟合将离散的灰度图象变换为多项式函数,因此计算中所需的求导,积分,及梯度运算的结果仍然是多项式函数,最终将待定系数方程组化为线性代数方程组。
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For convection-dominated diffusion problems, because the diffusive coefficient is very small, it is expected that the new upwind schemes in this section can get very high computational accuracy.
对于对流占优扩散问题,由于扩散系数比较小,可以期望,本节所给的新型迎风格式能够达到比较高的计算精度。
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Through grey relation estimation matrix, the threat sequencing is transformed into a MADM problem. The algorithm for the weight of each threat criteria is proposed by information entropy to reduce the effect of the extreme numerical value. Applied the grey related projection value, the treat sequencing is carried out from the aspect of vector projection. In addition, the effects of the identification coefficient and the criteria weights on threat sequencing are investigated respectively.
首先通过建立灰色关联判断矩阵将威胁排序转化为多指标决策问题;其次为缩小极端值的影响提出了基于信息熵的威胁指标权重算法;最后从矢量投影角度应用灰色关联投影值进行威胁排序;并分别研究了分辨系数和指标权重对威胁排序的影响。
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In this dissertation, InGaAs/InGaAsP/InP MQW microdisk laser and its characterization were presented. Some conclusions are as following: the characteristics of lasing threshold was discussed by using rate equation. The dependent relations between threshold and cavity volume, spontaneous emission coupling efficiency β were investigated. The whispering gallery mode and spontaneous emission in a microdisk geometry were then studied. Almost all spontaneous emission was coupled into the lowest order TE mode when the normalized thickness of photonics well was between 0.15 and 0.5. The design principle and device process of InGaAs/InGaAsP/InP MQW microdisk laser were presented. The microdisk lasers with the diameter of 8μm, 4. 5μm and 2μm were succesfully fabricated by using etching techniques. The pulse lasing thresholds for the microdisk with the diameter of 8μm and 4. 5μm were 170μW and 15μW, a record results compared with the published in the literature. The cw lasing threshold for a 2-μm-diameter microdisk was only a few μW. We haven't found similar report up to now. To solve the problem of directional output in a microdisk laser, the power coupling efficiency in a double disk geometry was investigated with the theory of waveguide mode couple. A new structure of electrically pumped microdisk laser with output waveguide was designed, making a foundation for the practical use of microdisk laser.
本文主要研究InGaAs/InGaAsP/InP多量子阱半导体碟型激光器的研制和特性表征,并取得如下结果:利用速率方程理论讨论了激光器激射阈值的特性,分析了阈值与腔体积和自发发射耦合系数β之间的关系;讨论了微碟光子阱结构中的自发发射特性和微碟中WGM模式特性;光子阱结构在其归一化厚度在0.15-0.5之间时,几乎全部自发发射进入到最低阶TE模式中;研究了InGaAs/InGaAsP/InP多量子阱微碟激光器的结构设计原理和器件的制备工艺;利用刻蚀方法成功制备出直径分别为8μm、4.5μm、2μm的碟型微腔激光器;直径8μm和4.5μm的微碟脉冲光泵浦激射阈值分别为170μW、15μW,是目前所见文献报导中比较低的;直径2μm的微碟连续光泵浦激射阈值仅几μW,目前尚未见到达到类似结果的研究报导;为解决微碟激光器激射光定向引出的问题,通过波导耦合模理论分析了双层碟之间功率耦合效率;据此设计了新型带耦合输出波导的电泵浦微腔激光器,为进一步研制可实用的电泵浦微腔激光器打下基础。
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The aseismic control for pile-foundation bridges considering soil-structure-interaction was studied. There are two problems were solved:(1) The coefficient matrix is singularity because the elements of rotational degree in mass matrix equal to zero due to the flexiblity of the pier.(2) The iteration of control gain was not convergent because the dumped mass of the beam is very large comparing with that of the pier.
为将Smith[162]方法用于桥梁结构,本文解决了如下两个问题:(1)以弯曲变形为主的桥梁结构,其质量矩阵中相应于转动自由度的元素数值为零,由此导致等效固基模型中的系数矩阵奇异;(2)桥梁结构堆聚到顶部节点的梁体质量很大,由于质量分布不均匀导致控制增益的迭代计算不收敛。
- 推荐网络例句
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The split between the two groups can hardly be papered over.
这两个团体间的分歧难以掩饰。
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This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.
这种做法不仅鼓励了更多的反应,而且减少跟风的可能性。
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The new PS20 solar power tower collected sunlight through mirrors known as "heliostats" to produce steam that is converted into electricity by a turbine in Sanlucar la Mayor, Spain, Wednesday.
聚光:照片上是建在西班牙桑路卡拉马尤城的一座新型PS20塔式太阳能电站。被称为&日光反射装置&的镜子将太阳光反射到主塔,然后用聚集的热量产生蒸汽进而通过涡轮机转化为电力