可靠数字

Air-Pressure indirect testing method was brought into effect successfully. While implementing this new testing method, digital filter was used for the first time and good results were obtained.

在实施该测试方法过程中，首次引入可靠的数字滤波环节，取得了良好的测试效果，使该方法提高到了实用化水平。

Less lose medium, strong in transmiting signal, and the weak signal of analogue and digital can be transmited reliably.

抗干扰性能好，介质损耗小，传输型号能力强，可靠的传送微弱的模拟信号和数字信号。

It is capable of reliable transmission of feeble analogue and digital signal in harsh working environment and has excellent interference immunity to magnetic field and static and stable electric properties, barely affected by either high or low temperature , chemical solvents or corrosive gases , thereby providing accurate transmission of signal data and guarantee of safe operation of the control system .

工作环境比较恶劣的情况下，不但能可靠的传送微弱的模拟信号和数字信号，而且抗干扰性能高，电气性能稳定，不受高低温及各种化学溶剂和腐蚀性气体影响，可确保传输信号参数的准确性和控制系统的安全运行。

Firstly, oscilloscope control system based on GPIB technique is presented with friendly operation environment to the HIFU system, and it uses multithreading technique in programming to realize real-time recording and display of the signal; Secondly, temperature collection and data recording system is designed, which also could get real-time recording and display of the 16 channel temperature signal, and it's believed to be of great use for further experiments of the HIFU system; Thirdly, multiple ultrasonic phased array's phase shifter is designed,which could provide 8-bit phase control in a range of frequency where the centrical frequency is 1MHZ. Fourthly, the module of serial communication is realized to insure the communication between devices and computer, including both synchronous and asynchronous communication, which enables the system to transfer data reliably and stably; Finally, the module of digital quantity control is accomplished, which provide for upper application the consistent solution to the control of exterior devices via digital interface. It can get or set the devices state using interrupt mode to receive input signal or send output signal.

主要有以下几个方面：设计了基于GPIB的示波器控制系统，给课题的研究工作提供了一个良好的环境，它采用了多线程编程的方法，能够较好的实时显示当前波形并记录数据；设计了温度采集和数据记录系统，能够对16路温度信号进行并行同步的实时采集，用于HIFU剂量学研究中温度场检测和医疗评价；设计了相控阵相位延时电路并且通过调试，满足了课题的相位控制的要求，在中心频率为1MHZ左右的频率范围内都能够达到8-bit相位控制；实现了串口通讯模块，为各项设备与计算机之间的通讯提供保证，它提供同步和异步的通讯能力，使系统能够可靠稳定的传输数据；建立了数字量控制模块，为上层应用程序提供一致的方法使用数字接口控制外部仪器，它使用中断的方式来接收输入或输出设定的开关量信号，从而得到或设定各种仪器的状态。

The matching device automatic test-board is the checking tool checked the matching device capability, precision and reliability are the technique of the the matching device, the precision is the precondition of checking the matching device, the reliability is credibility degree of the decision checking consequent.the topic in view of the existing technique level, the main factors, which influence the measurement precision of the large scale test system, are analyzed in this paper, and the solutions improving the precision are put forward.1 using the multi-channel independent ac to transfer dc module, the power supply of the digit part and the simulation part is discerption, reducing the crosstalk between the digital signal and the simulated signal;2the feedback self-checking module is constructed by singlechip compositive 16 high accuracy a/d , established a closed-loop control system through this module and improved system's overall precision effectively.

匹配装置自动测试台是检测匹配装置性能的检测工具，其重要的技术指标是精度与可靠性，其高精度是作为检测匹配装置的前提，可靠性是决定了检测结果的可靠度。本课题针对现有的技术水平，分析了影响大型检测系统测量精度的主要因素，提出了提高精度的具体方案和办法：1采用了多路独立交流转直流模块，数字部分与模拟部分分开供电，减小了数字信号与模拟信号之间的串扰。2利用单片机集成的16位高精度a/d构建了反馈自检模块，通过该模块建立了一个闭环控制系统，有效地改善了系统的整体精度。

Considering the randomness of the structural physical parameters and utilizing the random variable's functional moment method and the algebra synthesis method, the mean value and the variance of the mean square value of the structural displacement response under stationary random excitation are computed firstly from the expressions of structural stationary response in frequency domain. And then the expressions of the mean value and the variance of stochastic rigid frames dynamic reliability are educed from the Poisson formula of calculating dynamic reliability.

考虑结构的物理参数具有随机性，从结构随机响应的频域表达式出发，利用求解随机变量数字特征的代数综合法和矩法，导出随机参数刚架结构在平稳随机激励下的位移及速度响应均方值的数字特征，再由动力可靠性的Poisson公式导出结构动力可靠度的计算公式。

One of the ways to solve the problem above is actualizing the digital corresponding, transforming the image to the digital signals, wiping off the redundancy outlying of the image quality. Furthermore, on the precondition of ensuring the quality, storaging, recording and transmitting the digital signals is oecumenical, credible and all wool and a yard wide using least bits or bits ratio.

解决这个问题的途径之一，是实现图像通信的数字化，把图像信息转换成数字信号，去除与图像质量无关的冗余信息，并且在保证质量的前提下，用最少量的数码或数码率，实现各类图像的数字存储、数字记录或数字传输，达到优质、可靠、经济的要求。

The step motor can receive digital signal directly and has the ability to response outer environment immediately and has no accumulation error, which often is used in driving system. In this driving system, open-loop control system is composed of stepping motor, which can satisfy the demand not only for control precision but also for the target of economic and practicality. On this basis , the analysis of stepping motor in power calculating and style selecting is also given.

由于步进电机能够直接接收数字量，响应速度快而且工作可靠并无累积误差，常用作数字控制系统驱动机构的动力元件，因此，在驱动装置中采用由步进电机构成的开环控制方式，这种方式既能满足控制精度的要求，又能达到经济性、实用化目的，在此基础上，对步进电机的功率计一算及选型问题经行了分析。

The requirements for this are as follows: no need to analyze the primitive data;the information net system and subsidiary facilities for analyzing must be safe and reliable;signature needed after the data before analyzing;the concrete and detailed account of obtaining process should not only be given,but be classified and stored.

电子取证的要求是：不要对原始数据进行直接分析；分析数据的信息网络系统及其辅助的设备必须安全、可靠；分析前对数据进行数字签名；对数据获取过程进行详细、具体的描述，并归档、保存。电子取证的方法包括：数字鉴定法；数据检查法；数据对比法；数据保护法；数据分析法；证据抽取法。

As communicating madia is power line ,which needn't the extra line , and not take in the existing frepuncy resource.In the power system ,the power line is using steadily and reliable high press power line as the signal's trans madia,which may save a great deal of the building investment,in additional to the route is suitble ,scurity and may reuse the far away mobile signal ,of which makes this power system develop a particular communicating way ,while in number micro-wave,one point more address,optical fiber,super-high frequency repeatly renew today ,which also last developing.

由于电力线载波在电力系统中使用坚固可靠的高压电力线作为信号的传输媒介，可节省大量的通道建设投资，再加上电力线载波信息传输稳定可靠，路由合理，安全保密以及能够同时复用远动信号等特点，使得这种电力系统独有的通信方式在数字微波，一点多址，光纤，特高频等通信方式相继出现的今天仍得到持续的发展。

Fancy gold-plated dangling earrings with facetted White Opal crystals.

花式镀金悬垂耳环与facetted白欧泊水晶。

This essay chooses the study aim from biology teachers in middle school in Shi Jiazhuang which tells us that most of the middle school biology teachers in Shi Jiazhuang have the"burnout", lower successfulness, individualize.

本文选取石家庄市初中生物教师作为研究对象，运用问卷调查的方法对石家庄市初中生物教师职业倦怠的现状进行调查，调查结果发现，石家庄市初中生物教师这一群体普遍存在职业倦怠，情感枯竭程度偏高，成就感偏低，去个性化程度最为严重。