空关系

环境影响评价的种类可依据工程的时、空关系分为两大类。

According to the temporal and spatial dimensions the environmental impact assessment can be classified into two categories .

这一理论利用信号的时&空关系通过对被测时间信号与其在长度空间上传输延迟的重合检测来测量短时间间隔，依此为基础可完成各种时间间隔与频率测量仪器。

It is an new approach of time interval and frequency measurement , which can be used to measurement short time interval by detecting the phase coincidence point between the signal and its transfer delay with related length .

含空值关系数据库中的多值逻辑的研究

On Null Values and Multi Logicals in the Relation Database

基于关系模型的含空值关系数据库的数据更新

Updating the Data in Relational Databases Containing Null Value Under Relational Model

含空值关系数据库泛关系及其实例的研究

Research and instance study of universal relations in relational database with null values

空值关系模型用来对关系数据库中暂时未知的、不确定的或模糊的信息进行表示和处理。

Null-Value relational model was used to deal with missing or uncertain information in relational database .

应用本文的设计计算方法研制了导管导向机器人样机，并对导管导向机器人进行转向性能实验和弯曲角度与PWM占空比的关系实验。

By the design calculation method , a prototype of catheter steering robot was developed . A series of test change direction capability and the relationship between bending angle and PWM duty cycle were carried out .

对该电路进行理论分析和PSPICE仿真后，得出输出电压同驱动占空比的关系近似为线性，同串联电感的平方根成反比，并通过实验对仿真结果进行了验证。

The circuit is theoretically analyzed and verified by simulation through PSPICE software and experiments . The output voltage is almost linear proportional to the driving duty ratio and inversely proportional to the square root of the series inductance .

通过试验得出，直流电机转速和PWM波占空比的关系，旋翼拉力满足系统要求，执行机构反应迅速、连续，辨识的直流电机数学模型为惯性环节。

It concludes that the relationship between the DC motor speed and the PWM duty cycle is confirmed , the requirement of the rotor pull is satisfied , the reaction of actuator is fast and continuous , and the model of DC motor is equaled to an inertial loop .

财富权力转眼成空，家庭关系淡薄如纸，名望地位飘忽不定。

Wealth and power can be fleeting , family bonds tenuous , status mercurial .

对提取的蚀变信息与控矿构造、已知矿点的空问相关关系进行分析，结果表明大部分的蚀变信息均与蚀变有关。

Analyzing the alteration information , structure and the relationship of known ore spots , the result showed that a large part of mineralization information involving alteration .

详细讨论了高度为1/4波长～1/2波长的鞭状天线的性能与对空通信的关系；

Detailed discussed the performance of whip antenna when its height is 1 / 4 wavelength ~ 1 / 2 wavelength and its relation to the ground-to-air communication ;

详细分析了该变换器的运行原理及工作状态，并通过计算推导出输入、输出以及占空比的关系式。

Analysis of the operating principle of the converter and working conditions in detail , and is derived by calculating the input and output and duty cycle of the relationship .

本文研究关系数据库理论中空值在函数依赖中的语义问题，提出了带标志空值的关系中函数依赖的三种定义。

This paper deals with the semantics of null values in functional dependencies in database theory , and presents three different definitions of FDs in a single relation with marked nulls .

本文讨论了地震波速变比异常在地震预报应用中的一些问题。如多台求波速比值方法的误差因子、是否存在正异常的问题、关于异常时间的判别指标以及异常与空区的关系等。

Some problems have been discussed , such as the error factors , the positive anomaly of velocity ratio , the anomalous time indices and the relation between anomaly and seismic gap .

推导得出了瞬时转矩改变量与合成电压矢量的关系，合成电压矢量与所选电压矢量及其占空比的关系。

The relation between the synthesized voltage vector and instantaneous torque increment is derived . At the same time , the synthesized voltage vector can be expressed as selected voltage vector and its duty ratio .

通过对开关损耗数学模型的建立，探讨了开关过程损耗与开关频率和开关传导损耗与占空比的关系，仿真结果验证了数学模型的正确性。

The relationship of switching transition losses and switching frequency , and switching conduction losses and duty cycle are discussed by modeling the mathematical model of the switching losses . The simulation results verify the legitimacy of the mathematical model .

空值和N关系代数

Nulls and N-Relational Algebra

空值环境下关系模式到（N）BCNF无损连接分解

Decompositions for Relational Schema Under Null Value Circumstances Into BCNF With Lossless Joins

空值环境下关系数据库查询处理方法

A query processing method under null values environment in relational databases

模糊空值环境下关系数据库的范式理论

Normal Form Theory of Relational Database under Fuzzy Null Value Circumstances

钢锭氧化烧损与空燃比的关系研究

A Study of Relationship Between Steel Ingot Oxidation and Air-Fuel Ratio

模糊空值环境下关系模型的冗余处理

Disposal of Redundancy in the Relational Model Under the Fuzzy Null Value Environment

深部开采岩爆及采空区与地应力关系的研究

Study on relations between rock burst , goaf area and ground stress in deep mining

空值环境下关系数据库的更新Ⅱ：更新处理的插入、删除和修改操作算法

Updating relational databases under null value circumstances ⅱ: the algorithms for insertion , deletion and modification operations

推导了其电压传输比与占空比之间函数关系的解析表达式，阐述了所采用的离散滑模控制策略的设计方法，并通过仿真对其有效性和可行性进行了验证。

In order to obtain excellent sinusoidal output voltage and optimize dynamic performance of inverters , discrete sliding mode control strategy based on buck-boost inverter is adopted in this paper .

研究了层面滑移量、滑移范围与采厚、弹性模量、主要影响半径及采空区位置的关系。

The relations are studied between amount and extent of gliding and mining height , elastic modulus , major influencing radius as well as location of the mined out area .

对电流内环进行变反馈系数调试，进行理论分析推导，绘制出反馈电流转换电压值与系统占空比及转速变化关系曲线；

Experiment current internal loop via change the feedback channel coefficient , through the theory construe , protract the feedback current changed voltage with system duty-cycle and rotate speed change curve ;

对强震破裂区闭锁段、背景空区、孕震空区的关系用实测震例进行了解释。

The relations among locked segment of great earthquake rupture areas , background gap and preparatory gap are explained with earthquake examples .