查询词典 parameter variable

Density Functional Theory method was used to optimize the geometries of 209 PCDE molecules, 209 PBDE molecules and 75 PCDD molecules at the B3LYP/6-31G* level. Using computed structural parameters as theoretical descriptors, the forward stepwise multiple regression technique was adopted to obtain QSPR models of environmental partition properties for these POPs by using GQSARF 2.0 and SPSS12.0 for windows programs. The obtained QSPR models are as follows:(1) QSPR models for predicting subcooled liquid vapor pressure, n-octanol/water partition coefficients lgK_(ow and subcooled liquid water solubilities -lgS_(w,l of PCDEs, of which correlative coefficients (R~2) are 0.988, 0.958 and 0.959 and the root-mean-square-error of estimation are 0.134, 0.116 and 0.327 respectively.(2) QSPR models of lgPL and n-octanol/air partition coefficients lgK_(oa for PBDEs, which both contain three structural parameters. The values of R2 for the two models are both 0.997 while the values of RMSEE are 0.073 and 0.062 respectively.(3) QSPR models of lgKow and–lgS_ for PCDEs, which both have one variable (mean molecular polarizability,α). The values of R~2 for the two models are 0.978 and 0.866 and the values of RMSEE are 0.300 and 0.270 respectively.(4) The molecular structures of 24 substituted naphthaline compounds were optimized using Hartree-Fock and DFT methods at four different levels and the same means was used to obtain four three-parameter (EHOMO, q~+ andα) QSPR models of lgK_. The model at the HF/6-311G** level is the best one of which R2 is 0.9662 and RMSEE is 0.380.(5) QSPR study for environmental partition properties of PCDEs was also performed using position of Cl substitution method in which simple parameters of substitution position were taken as descriptors. The multiple linear regression was performed with GQSARF 2.0 and SSPS 12.0 for windows programs to obtain QSPR models of lgP_L, lgK_ and–lgS_ for PCDEs of which R~2 are 0.991, 0.983 and 0.965 and RMSEE are 0.311, 0.100 and 0.300 respectively.

采用密度泛函理论方法在B3LYP/6-31G*水平上对PCDEs、PBDEs和PCDDs的分子结构进行了全优化计算，以计算得到的量子化学参数作为理论描述符，采用GQSARF 2.0和SPSS 12.0 for windows统计程序进行正向逐步回归分析，建立了这些POPs的环境分配性质的QSPR模型：(1) PCDEs的过冷液体蒸汽压、正辛醇/水分配系数lgK_(ow和水溶解度-lgS_(w，l的QSPR模型，这3个QSPR模型的相关系数(R2)分别为0.988、0.958和0.959，估计的均方根误差分别为0.134、0.116和0.327；(2) PBDEs的lgPL和正辛醇/空气分配系数lgK_(oa的QSPR模型，这两个模型都包含三个分子结构参数，其R~2都为0.997，RSMEE分别为0.073和0.062；(3) PCDDs类化合物的lgK_和-lgS_w的QSPR模型，两个模型都只含一个变量，其R~2分别为0.978和0.866，RSMEE分别为0.300和0.270；(4)采用Hartree-Fock和DFT方法，在4种不同水平上优化计算了24个取代萘系列化合物的分子结构，采用上述同样的方法分别建立了四种水平上的三变量lgK_模型，通过比较得到，在HF/6-311G**水平计算得到的模型最好，R为0.966，RSMEE为0.380；(5)同时，采用氯原子取代位置方法对PCDEs的环境分配性质进行QSPR研究，建立了PCDEs的lgPL、lgK_和-lgS_的QSPR模型，其R~2分别为0.991、0.983和0.965，RSMEE分别为0.110、0.100和0.300。

In this paper,a new variable structure robust model reference adaptive control scheme is proposed,which deals with a class of SISO plants under parameter and unmodelled dynamical uncertainties.It is shown that even with the existence of unmodelled dynamics,the output tracking error will converge to zero in finite time, and the SPRcondition for reference model is not required.

摘 要 讨论了含结构不确定SISO系统的变结构模型参考鲁棒自适应控制问题，提出了一种新的变结构控制方法，使得：1系统在同时含参数及结构不确定性时，跟踪误差仍能在有限时间内收敛到零；2无须假设参考模型为SPR函数。

During the tele-rehabilitation traing, the rehabilitant's muscle spasm may result in the bilateral telerobot system instability and cause its slave's speed unsmoothness, which make the rehabilitation training inefficient. In order to guarantee the stability and reduce the fluctuation of the speed, a new method based on the variable parameter with BP neural network was brought forward.

为使患者的远程康复训练达到更为理想的效果，针对患者在训练时肌肉痉挛对双向遥操作系统的稳定性以及对从机械手的速度平滑性的影响，提出了一种新的基于BP神经网络变参数控制方法。

Bone metabolism was the most intense and variable parameter with the growing of age.

骨代谢变化是随年龄增长最剧烈、变化量最大的一个参数。

We will generally use parameter for a variable named in the parenthesized list in a function. The terms formal argument and actual argument are sometimes used for the same distinction.

我们通常把函数定义中圆括号内列表中出现的变量称为形式参数，而把函数调用中与形式参数对应的值称为实际参数。

A control parameter is a variable that regulates change in the behavior of the entire system.

控制参数是一个管理整个系统行为变化的变量。

Where a and b are major and minor semi-axis, respectively, and t is a variable parameter.

这里的a和b是大型和小型半轴，分别吨，是一个可变参数。

Stability analysis of nonlinear magnetic suspension, the magnetic suspension system model was found based on electromagnet dynamics and voltage balance of the electromagnet coil; The feedback of position and velocity and current are used as the control variable; After the control rule was applied to the electromagnetic system, the louts criterion was used to get the range of the control parameter in which the system was steady-going.

非线性磁悬浮系统的稳定性分析，通过电磁铁动力学和电磁线圈的电压平衡方程，建立磁悬浮系统基本模型。求出系统奇点后，通过系统线性展开求出系统矩阵。用PD控制外加电流反馈量，将控制规律带入系统模型方程组求出矩阵的特征方程，由劳斯判据得知非线性系统稳定的位置反馈系数及取值范围。

In accordance with the characteristics of shoe press and the design of sleeve,the paper discusses the factors to be considered in felt design,in particular,the variable parameter of system void volume and puts forward the cleaning and adjusting measures for shoe press felt.

根据高速纸机上靴型压榨的特点和靴套的设计，论述了靴压毛布设计时要考虑的因素，尤其是系统空隙率这一变量参数；提出了靴压毛布使用时清洗和调整的措施。

The dissertation is concentrating on the topic of a high power, tunable, millimeter wave free electron laser. The tunable ability of the mm wave FEL is studied. FEL powers are improved by novel variable parameter wigglers. A high brightness electron beam is achieved for FEL. These technologies are very important for realization of high power compact free electron lasers.

本博士论文围绕高功率可调谐毫米波自由电子激光器的研究主题，研究毫米波自由电子激光的调谐特性，用新型磁场逐渐增强的摇摆器等手段提高自由电子激光的效率，研究体积小的高亮度电子束源用于自由电子激光，为研制新一代小型化高功率自由电子激光器提供关键技术。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。