查询词典 essential parameter

In order to determine the technological parameter of essential oil extracted from bitter almond by wet distillation,factors influenced the oil yield,such as hydrolysis time and temperature、distilling time、water adding amount and hydrolysis pH,etc.

为确定水蒸气蒸馏提取杏仁精油的工艺参数，以正交试验和单因素试验相结合的方法对影响杏仁精油提取率的水解时间、水解温度、蒸馏时间、加水量以及水解pH等因素进行了研究。

Therefore, research about camera photosensitivity characteristic parameter testing system is particularly essential.

因此对于摄像机感光特性参数测试系统的研究是十分必要的。

Therefore, it is essential to analyze the dynamic characteristics and to optimize the parameter of DEH control system of reheat extraction steam turbine, which would do benefit to design the control system with excellent performance and to guarantee the safety of the turbines.

全面掌握中间再热抽汽式汽轮机控制系统的动态特性，优化控制器的参数，是设计性能优良的控制系统，保证机组安全运行的关键，具有重要的工程应用背景。

And it uses a penalty parameter technique to enforce the essential boundary condition. MLPG is developed to solve axisymmetric problems in this paper.

MLPG方法处在发展中，关于其求解效率、精度以及可应用的领域等方面的研究非常有限，有待大力改进和完善。

Through to digital simulation operation observation and design of course of model , get simulation output parameter and essential feature of system, so as to estimate and infer the true parameter of the real system and true performance.

通过对数字仿真模型的运行过程的观察和设计，得到被仿真系统的仿真输出参数和基本特征，以此来估计和推断实际系统的真实参数和真实性能。

The model and parameter accuracy are essential for excitation system modelling and parameter idenfication, and the criteria of testing the vadlity is given too.

模型和参数的精度是发电机励磁系统建模和参数辨识的关键，本文提出评判基于现场测试得出的数学模型和参数正确性的方法。

This article used basicity electrochemic synthesized the polymerization aluminum chloride solution through the active control electrolysis process essential parameter was allowed to prepare basicities differently the hydroxyl polymerization aluminum chloride solution .

本文采用电解法合成了聚合氯化铝溶液，通过有效控制电解过程的关键参数，可以制备出不同盐基度的羟基聚合氯化铝溶液。

A new technology, Supercritical Fluid CO_2 Extraction, was also supplied to study the plant. The technological parameter was optimal. Total extract of SFE-CO_2 were 4.86 times of the essential oil extracted by SDE, main active extracted constituents were 1.36% high than SDE. The chemical constituents of SFE-CO_2 were also analyzed by GC-MS. 57 constituents were identified, 29 constituents of them were first discovered. 24 constituents were discovered in two extract. Fingerprint is a good technology to elevate the quality of herb medicine. The main active fraction can be extracted by SDE and SFE, Fingerprint was studied respective, chromatographic parameter was acquired. 22 peaks were assigned common peaks in the spectrum of essential oil, 17 peaks were assigned to common peaks in the spectrum of SFE extract.

采用现代共性关键技术超临界CO_2萃取技术，通过正交试验，优选了超临界CO_2提取牛至挥发油的工艺，并与传统的水蒸气蒸馏法进行了比较研究，结果显示：前者提取有效部位的收率为后者的4.87倍，主要有效成分的转移率是后者的1.36倍；采用GC-MS分析方法和NIST质谱库检索，对SFE和SDE所提化学成分进行比较，SFE分离鉴定了57种化合物，占提取物总含量的86.96％，其中29种化合物为首次从该植物中鉴定；后者分离鉴定了69个化合物，占提取物总量的98.28％，其中27种化合物为首次从该植物中鉴定；两种方法的提取物中共有成分25种，包括主要有效成分麝香草酚、香荆芥酚、对聚伞花素等。

In order to improve the reliability of the nuclear Generating Sets and the stabilization of the power system, prevent the long time low frequency oscillation caused by the disturbed of the outside electrical net, assured improving the stabilization margin of the nuclear generating sets in the precondition of enough transient stability, validate the sensitivity of the parameter to the damping of Generating Sets of the MEC5220 digital excitation adjustor produce in Japan that used in the Second Project of Qinshan Nuclear Power Plant, confirm the parameter rationality of the digital excitation adjustor, optimize the parameter of PSS, in this paper, we put up a in-depth study to the principle of MEC5220 digital adjustor produce in Japan by the PSS/E software that develop by the PTI Company in the USA, completed the modeling of the excitation adjustor, PSS, generator, excitor, described the performance of this excitation adjustor, analyzed the essential reason that caused the low frequency oscillation, illuminated the factor that influence the damping characteristic of the MEC5220 digital excitation adjustor. Based on model and emulate, this paper optimized the primary parameter of the excitation adjustor, make a reasonable regulation to the PSS parameter.

为提高核电机组的运行可靠性和接入系统的安全稳定性，防止在外电网的干扰下核电机组发生长时间的低频振荡，保证机组在暂态稳定的前提下提高其稳定裕度，验证秦山核电二期核电机组所配日产MEC5220型数字式励磁调节器参数对机组阻尼的灵敏性，确定数字式励磁调节器的参数的合理性，优化PSS整定参数，本文利用美国PTI公司研发的PSS／E软件对日产MEC5220型数字调节器的原理进行进行了深入细化的研究，完成了励磁调节器、PSS、发电机、励磁机的建模，描述了该型励磁调节器的性能，分析了产生低频振荡的根本原因，阐明了影响阻尼特性的因素。

Chapter four studies the chaotic responses in a system consisting of simple pendulum and harmonic oscillator under bounded noise excitation. Firstly, the Melnikov function of the two-degree-of-freedom system under Hamiltonian perturbation is derived. The essential condition of the autonomous system for the probable onset of chaos is obtained, the Poincare maps of the system under small Hamiltonian perturbation and the effect of increasing perturbation on the Poincare maps are studies. Then for the non-autonomous system under damping and harmonic or bounded noise excitation, the largest Lyapunov exponent and Poincare maps are calculated. From the analysis of the largest Lyapunov exponent, the critical criterion for the onset of chaos, and the conclusion that the threshold of bounded noise amplitude for the onset of chaos in the system increases as the intensity parameter of Wiener process increases are obtained. The result from the analysis of Poincare maps is in agreement with that obtained from the Largest Lyapunov exponent. The effect of varying damping coefficient and intensity parameter of Wiener process is also analyzed.

第四章研究了有界噪声激励下的两自由度单摆—谐振子系统的混沌运动，首先推导了该两自由度系统仅在Hamilton扰动下的Melnikov函数，得到该自治系统可能产生混沌的必要条件；研究了该系统在小的Hamilton扰动和增大摄动情形下的Poincare截面；然后对有阻尼、谐和或有界噪声激励下的非自治系统数值计算了其最大Lyapunov指数和Poincare截面；从Lyapunov指数分析得到了这个两自由度系统产生混沌运动的临界条件及产生混沌的临界激励幅值随Wiener过程强度参数值的增大而增大的结论，Poincare截面分析的结果亦符合Lyapunov指数分析的结论；研究了Wiener过程强度参数、阻尼系数变化对Poincare截面的影响。

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。