毕业设计英文
毕业设计 英文资料
Compensation of Control System1．Multiple Constrains in DesignThe performance of a feedback control system is of primary importance.We have found that a suitable control system should have some of the following properties.1)It should be stable and present acceptable response to inputcommand,i.e,the controlled variable should follow the changes in the input at a suitable speed without unduly large oscillations or overshoots.2)It should operate with as little error as possible.3)It should be able to mitigate the effect of undesirabledisturbances.A feedback control system that provided an optimum perfprmance without any necessary adjustments is rare ually it is necessary to compromise among the many conflicting and demanding specifications and to adjust the system parameters to provide a suitable and acceptable performance when it is not possible to obtain all the desired optimum specifications.The preceding chapters have showen that it is often possible to adjust the system parameters in order to provide the desired system response.When the achievement of a simple performance requirement may be met by selecting a particular value of K, the process is called gain compensation.However,we often find that it is not sufficient to adjust a system parameter and thus obtain the desired performance.Rather we are required to reconsider the structure of the system and redesign the system in order to obtain a suitable one.That is ,we must examine scheme of the system and obtain a new design that results in a suitable system.Thus the design of a control system is concerned with the arrangement of the systemstructure and the selection of suitable components and parameters.When we are not able to relax several perfprmance requirements,we must alter the system in some way.The alteration or adjustment of a control system in oreder to provider a suitable performance is called compensation.In redesigning a control system to alter the system response,an additional component or device is inserted within the structure of the feedback system to compensate for the performance deficiency.The compensating device may be electric,mechanical,hydraulic,pneumatic,or some other type of devices or networks and is often called a monly an electric network serves as a compensator in many control systems.Quite often,in practice,the best and simplest way to improve the performance of a control system is to alter,if possible,the plant itself.That is,if the system designer is able to specify and alter the design of the plant,then the performance of the system may be readily improved.For example,to improve the transient behavior of a servomechanism position controller,we often can choose a better motor for the system.Thus a control system designer should recognize that an alteration of the plant maybe result in an improved system.However,often the plant is unalterable or has been altered as much as possible and still result in unsatisfactory performance.Then the addition of compensator becomes useful for improving the performance of the system.2．Types of CompensationThe compensator is placed in a suitable location within the system,and can be done in several ways .An additional component may be interested in the forward path.This is called the cascade or serial compensation.The transfer function of the compensator is designated as Gc(s),whereas that of the original plant(or process)is denoted by Gp(s).Alternatively,the compensator may be placed in the feedbackpath .This is called the feedback compensation. A combination of these two schemes.The selection of the compensation scheme depends upon a consideration of the specifications, the power levels at various signal nodes in the system,and the compensators available for us.3.Cascade CompensationAlthough many different types of compensators can be used,the simplest among them are cascade phase-lead,phase-lag,and phase-lag-lead networks.Each of these can be realized by using an operational amplifier network.The Bode diagram is used to determine a suitable cascade compensator in preference to other frequence plots.The frequence response of the cascade compensator is added to the frequency response of the uncompensated system.It is assumed, in below discussion, that the compensator Gc(s),is used with an uncompensated system so that the overall open-loop gain can be set to satisfy the steady-state error requirement,then Gc(s) is used to adjust the system dynamics favorably without affecting the steady-stste error.For convenience,the open-loop transfer function of the uncompensated system,Gp(s)H(s),is denoted by Go(s).At first,consider a system described by the open-loop transfer functionGo(s)=k/s(0.2s+1)Suppose we wish the closed-loop system to meet the following performance requirements:a)The steady-state error for a unit ramp is to be no more than 0.00316.b)The phase margin is to be no less than 45.For the first requirement,the static velocity error constant can be cocalculated from equationεss=1/Kv=1/K≦0.00316and thus the required open-loop gain is K=Kv=3.16It may also be seen that the phase margin will be about 45.at w=5 rad/s;therefore,to meet the second requirement,the magnitude must be zero at this frequency.Obviously,it is not possible to satisfy both system performance requirements with a singular value of gain.The system needs to be modified in some way,i.e,the shape of the Bode diagram has to be altered in some way to allow it to achieve both perfprmance requirements. The system perfprmance requirements stated in the example are typical of those found in many design cases;a steady-state error determines one value of gain while a desired transient response determines anthor.Note how each requirement relates to a different region of frequency acxis in the Bode diagram.(1)The steady-state error relates to the slope and magnitude at lowfrequency.(2)The phase margin relates to the gain crossover frequency,which usuallyoccurs at higher frequency.4．Approaches to System DesignThe performance of a control system can be specified by requirement of certain maximum overshoot and setting time for a step input. Furthermore it is usually necessary to specify the maximum allowable steady-state error for several test signal inputs and disturbances .These performance specifications are related to the location of the poles and zeros of the closed-loop transfer function.Thus the location of the closed-loop poles and zeros can be specified.As we found in chapter4,the locus of the roots of the closed-loop system can be readily obtained for the variation of one system parameter.However,when the locus of roots does not result in a suitable root configuration,we must add a compensator to alter the locus of the roots as parameter is varied.Therefore we can use the root locus method and determine a suitsble compensator transfer function so that the resultant root ;ocus yields the desired closed-looproot configuration.Alternatively,the performance of a control system can be specified in terms of the relative resonant peak,resonant frequency,and bandwidth of the closed-loop frequency response,or in terms of the phase margin, gain margin and gain crossover frequency of the open-loop frequency response.We can add a suitable compensator,if necessary,in order to satisfy the system perfprmancr.The design of the compensator is developed in terms of the frequency response as portrayed on the polar plot,the Bode diagram,or the Nichols chart.Because a cascade transfer function is readily accounted for on a Bode diagram by adding the frequency response of the compensator,we usually prefer to approach the frequency response method by utilizing the Bode diagram.5．Phase-Lead Compensation1. Phase-Lead CompensationThe phase-lead compensator is a form of high-pass filter,through which the signals at high frequencies are amplified relatively than that at low frequencies.It introduces a gain at high frequencies,which in general is destabilizing.However,its positive phase angle is stablilzing .Hence,we must carefully choose two break frequencies so that the stabilizing effect of the positive phase angle is dominant.ments on the Applicability and ResultsPhase-lead compensation has some distinct advantages over other forms of compensation,wherease it may also be difficult to use .Some observations from the example just analyzed allow a few generalizations to be made regarding phase lead compensation.1)The phase-lead compensation method provides an additional phaselead to limit the system’s overshoot to a required value.2)The open-loop(and usually the closed-loop)bandwidths isincreased.This is usually beneficial since the inclusion ofhigher frequencies in the response results in a faster response.Itmay cause problem,however,if noise exists at the higherfrequencies.3)Problem may occur when the uncompensated phase plot has a steeoslope in the vicinity of φm.This occurs because,as the new gaincrossover point moves to the right ,larger and larger phase leadis required from the compensator,demanding very large value ofα.This is difficult to achieve when the compensator is realizedwith physical components.For this reason ,value of α>15 shouldbe avoided,and methods to compensate the system using othertechniques,such as phaselag,should be investigated.6．Phase-Lag Compensation1.Phase-Lag Compensation ProcessIn phase-lag compensation,the magnitude part of the uncompensated Bode diagram is attenuated in order to reduce the gain crossover frequency,thereby allowing the uncompensated phase plot to produce the necessary phase margin.The phase-lag compensator is used to provide an attenuation and therefore to lower the crossover frequency of the system.Furthermore,at lower crossover frequency,we usually find that the phase margin of the system is increased,and the specifications can be satisfied.Of cause,the influence of the phase lag caused by the compensator should be taken into ually,the lag phase is about 5~12 if the break frequency corresponding to the zero of the compensator is wz=(0.1~0.2)wc.ments on the Applicability and Results1)The phase-lag method provides the necessary damping ratio in orderto limit the overshoot to the required value.2)The compensation process is somewhat simpler than the phase-leadcompensation in that the selection of the break frequencies is not too critical.3)As can be seen from the compensated system,the phase-lag techniquereduces the open and hence the closed-loop bandwith,which results ina slower response.4)Unlike phase-lead compensation,theoretically,phase lag compensationmay change the phase margin by more than 90.7．Phase Lag-Lead CompensationIn the compensator design it is usual to assume that the two break frequencies of the lag portion are lower than the two break frequencies of the lead portion.Further features of the Bode diagram include the following.1)The magnitude at lower frequencies is 0 db while the magnitude athigher frequencies is 20lg(αβ)ually,the compensator provides attenuation only and no gain.2)The phase angle first lags and then leads ,but the high-andlow-frequency phases are both zeros.3)The maximum phase-lag and the maximum phase-lead occur between theirrespective break frequencies.The phase lag-lead compensator utilizes the best feature of the individual lag and lead portions,usually without their disadvantages.For example,the lag-lead compensation allows the introduction of phase lead to stabilize a system,while providing attenuation at higher frequencies to filter out noise.8．Feedback CompensationIn order to improve the system performances,besides the cascade compensation,the feedback compensation is often used as another scheme.By using local feedback compensation,almost same effect,as that of cascade compensation,can be obtained.Morever ,additional specific functions forimproving system perfprmance are obtained.。
毕业设计中英文翻译【范本模板】
英文The road (highway)The road is one kind of linear construction used for travel。
It is made of the roadbed，the road surface, the bridge, the culvert and the tunnel. In addition, it also has the crossing of lines, the protective project and the traffic engineering and the route facility。
The roadbed is the base of road surface, road shoulder，side slope, side ditch foundations. It is stone material structure, which is designed according to route's plane position .The roadbed, as the base of travel, must guarantee that it has the enough intensity and the stability that can prevent the water and other natural disaster from corroding.The road surface is the surface of road. It is single or complex structure built with mixture。
The road surface require being smooth，having enough intensity，good stability and anti—slippery function. The quality of road surface directly affects the safe, comfort and the traffic。
本科毕业设计英文翻译
翻译部分英文原文SELF-ADVANCING HYDRAULIC POWERED SUPPORTSModern longwall mining employs hydraulic powered supports at the face area . The support not only holds up the roof , pushes the face chain conveyor , and advances itself , but also provides a safe environment for all associated mining activities . Therefore its successful selection and application are the prerequisite for successful longwall mining . Furthermore , due to the large number of units required , the capital invested for the powered support usually accounts for more than half of the initial capital for a longwall face . Therefore both from technical and economic points of view , the powered support is a very important piece of equipment in a longwall face .The application of modern powered supports can be traced back to the early 1950’s . Since then , following its adoption in every part of the world , there have been countless models designed and manufactured in various countries . But unfortunately , there still is no uniform system of classification .A simplified classification is used in this section . since a powered support consists of four major components(i. e. , canopy , caving shield , hydraulic legs or props , and base plate ) , the ways by which they are interrelated are used for classification . In this respect , two factors are most important : (1) presence or absence of a caving shield - if a caving shield is included , the support is a “ shield ”type , otherwise , a frame or a chock ; (2) number and type of arranging the hydraulic legs - since support capacity is generally proportional to the number of hydraulic legs , it is important to specify the number of hydraulic legs that a support has . Furthermore , the way the hydraulic legs are installed is important ; for example , a vertical installation between the base and the canopy has the highest efficiency of application whereas an inclined installation between the base and the caving shield has the least efficiency in supporting the roof .Based on this concept , there are four types of powered support , that is , the frame , chock , shield , and chock shield , in order of evolution of their development . However , it must be noted that the trend of development in each type is such that it becomes less distinguishable in terms of application .The four types of roof supports can be obtained for either longwall retreating or advancing systems , and they are available in standard , one-web-back , and immediate forward support ( IFS ) versions .With the standard system , the winning machine takes a cut or a slice , and the armored face conveyor is pushed over by the hydraulic rams that are fixed to the support units . The support units then are advanced sequentially to the conveyor . With the one-web-back system , a support is set back from the conveyor by a device that automatically keeps the leading edge of the support at a fixed distance from the conveyor .This allows easy access through the face and employs the standard method of advancing ; i. e. , pushing the conveyor first , and then advancing the support .With the IFS system , the support unit is advanced to the conveyor immediately after the cutting machine has passed , and the forward canopy of the support unit is long enough to support both the recently and newly exposed roof sections . After the supports have been advanced , the conveyor is pushed over .FRAMEThe frame support is an extension of the single hydraulic props conventionally used underground . Thus it is the first type developed in modern self-advancing hydraulic powered supports .It involves setting up two hydraulic props or legs vertically in tandem that are connected at the top by a single or two segmented canopies .The two segmented canopies can be hinge-jointed at any point between the legs or in front of the front leg .The base of the two hydraulic legs may be a circular steel shoe welded at bottom of each leg or a solid base connecting both legs (Fig .8.8) .Generally , a frame support consists of two or three sets of hydraulic legs . The set moving first is the secondary set , the set moving later is the primary set .There is a double-acting ram installed between each set . The piston of the ram is connected to the secondary set and the cylinder to the primary set . During support advance ( Fig. 8.9) , the primary set is set against the roof while the secondary set is lowered and pushed forward by the piston . Having reached the new position , the secondary set is set against the roof while the primary set is lowered and pulled forward by the cylinder . The distance of each advance ranges from 20 to 36 in. (0.50~0.91m) .Fig . 8.8 Frame supporta-primary set b-secondary setA B CFig . 8.9 Method of advancing the frame supportThe frame support is very simple , but more flexible or less stable structurally . There are considerable uncovered spaces between the two pieces of canopy which allows broken roof rock to fall through . Consequently , the frame support is not suitable for a weak roof . Frames have become seldom used because they are less stable and require frequent maintenance .CHOCKIn a chock support , the canopy is a solid piece and the base may be either a solid piece or two separate parts connected by steel bars at the rear and / or the front ends . In both cases a large open space is left at the center for locating the double-acting hydraulic ram which is used to push and pull the chain conveyor and the chock in a whole unit ,respectively , a distinctive difference from the frame support . This setupdesigned for thin seams with two legs in the front and four legs in the rear , separated by awalkwa is also used in the shields and chock shields .Again , all hydraulic legs are installed vertically between the base and the canopy (Fig. 8. 10) . The number of legs ranges from three to six , but the four-leg chocks are by far the most popular ones . The six-leg chocks are y (Fig. 8.10c) . For the six-leg chocks , the canopy is generally hinge-jointed above the walkway . Most chock are also equipped with a gob window hanging at the rear end of the canopy . The gob window consists of several rectangular steel plates connected horizontally at both ends.A B CFig . 8.10 Schematics of various chock supportIn most chock supports , there are hinge joint connections between the legs and the canopy and between the legs and the base . But in order to increase the longitudinal stability , it is reinforced mostly with a box-shaped steel frame between the base and each leg . A leg restoring device is installed around each leg at the top of the box-shaped steel frame .The chocks are suitable for medium to hard roof . When the roof overhangs well into the gob and requires induced caving , the chocks can provide access to the gob .SHIELDShields , a new entry in the early seventies , are characterized by the addition of a caving shield at the rear end between the base and the canopy . The caving shields , which in general are inclined , are hinge-jointed to the canopy and the base making the shield a kinematically stable support , a major advantage over the frames and the chocks . It also completely seals off the gob and prevents rock debris from getting into the face side of the support . Thus the shield-supported face is generally clean .The hydraulic legs in the shields are generally inclined to provide more open space for traffic . Because the canopy , caving shield , and base are interconnected , it can well resist the horizontal force without bending the legs . Thus , unlike the solid constraint in the frame/ chock supports , the pin connections between the legs and the canopy ,and between the legs and the base in a shield support make it possible that the angle of inclination of the hydraulic legs varies with the mining heights . Since only the vertical component of hydraulic leg pressure is available for supporting theroof ,the actual loading capacity of the shield also varies with the mining heights .There are many variations of the shield supports . In the following ,six items areused to classify the shields , which enables a unified terminology to be developed for all kinds of shields . The types of motional traces of the canopy tip , leg positions and orientation , number of legs , canopy geometry , and other optional designs and devices can be clearly specified by the terminology .TYPES OF MOTIONAL TRACES FOR THE LEADING EDGE OF THE CANOPY.This is the most commonly recognized way of classifying the shield . Based on this criterion , there are three types , lemniscate , caliper , and ellipse (Fig. 8. 11) .A . Lemniscate.LB . Caliper.C C . Ellipse.EFig . 8.11 Three types of motional traces for leading edge of the shield canopyA . Lemniscate . This is the most popular type . The caving shield and the base are jointed by two lemniscate bars which have a total of four hinges . As the hydraulic legs are raised and lowered , the dimentions of the lemniscate bars are selected such that the leading edge of the canopy moves up and down nearly vertically , thus maintaining a nearly constant unsupported distance between the face-line and the leading edge of the canopy .This is a feature that is widely considered most desirable for good roof control . There are clear limits of mining height within which the leading edge of the canopy moves nearly vertically . These limits are strictly controlled by the dimentional and positional arrangements of the canopy , caving shield , lemniscate bars , and the base . Beyond these limits , the edges will move rapidly away from the face-line creating a large unsupported area .B . Caliper . In a caliper shield , the caving shield and the base are connected by a single hinge .When the hydraulic legs are raised , the leading edge of the canopy moves in an arc away from the face , thus increasing the unsupported area This is considered by most users the least desirable feature of the caliper shield But in practice if the seam thickness varies little , the dimentional and positional arrangement of canopy , caving shield , and the base can be so designed that the distance change of unsupported area will not be significant . On the other hand , when the legs are lowered , it reduces the unsupported area .C . Ellipse . In this type the caving shield and the base are so connected that when the hydraulic legs are moved up and down , the leading edge of the canopy follows an elliptical trace . This type is seldom used .CHOCK SHIELDThe chock shield combines the features of the chocks and the shields . As such it possesses the advantages of both .If all of the four or six legs are installed between the canopy and the base , it is called a chock shield . There are regular four or six-leg chock shields in which all legs are vertical and parallel . Others form V or X shapes . Some canopies are a single piece and some are two pieces with a hydraulic ram at the hinge joint . The chock shield has the highest supporting efficiency . They are suitable for hard roof .中文译文自移式液压支架液压支架广泛应用于现代长臂采煤工作面上。
毕业设计开题报告--英文
Understood on the international present mainstream the technology, the application system as well as our country transform the technological strength and the hardware facility as well as the expenditure which needs.
Construct Enviroment & Equioment
一．The background of research:
Our country heating area are general, the heating time is long, is day by day intense to the energy demand and is urgent, but by the tradition fossil energy primarily our country, the resources dries up day by day, the consumption is big, the pollution serious also cannot regenerate, the energy tense situation aggravating, this requests us to have to improve the heating way unceasingly, the technical method, uses the least energy to produce the greatest quantity of heat in order to.But concentrates heats is not high in our country's popular degree, the centralism heats the production technology is not extremely advanced, this requests us studies the use to this kind of technology and the form, our country's centralism heats only distributes in the city and developed cities, also only is uses the winter various each household bunker coal regarding not the developed area and the general countrysides to warm up, this is to the energy huge waste and the environmental pollution, is the transformation key point.Even if already uses the area which the centralism heated, also was the level is uneven, does things their own way, could not form the unified system, did the heat energy assignment to be uneven, the hot heat, cold cold, affected the efficiency seriously, thus it can be seen, carried on the transformation to the obsolete pipe network, carried on the promotion to the existing equipment, established widespread also the unified big centralism heating pipe network system imperative.
3000英文翻译 毕业设计
Chip STC12C5204AD I/O port configuration STC12C5204AD series microcontroller its all I/O ports are controlled by the software configuration into 4 kinds of work type 4 types are respectively: quasi two-way mouth (standard the 8051 output mode), push-pull output, only for input (high resistance) or open-drain output functions. Every mouth consists of two control register the relevant position control each pin type of work. STC12C5204AD series microcontroller to electricity reattachment shall prevail two-way mouth (standard the 8051 output mode) mode: 2V above high level, 0.8 V for low level below.1. Quasi two-way mouth output configurationQuasi two-way mouth output type can be used as output and input function but don't need to reconfigure mouth lines output state. This is because juncture lines output is 1 drive ability is very weak, allowing external devices will its down. When pins for low, it output driving ability, can absorb the considerable current. Quasi two-way mouth have 3 pull_up transistor adapted to different needs.In the three and one transistor, pull up transistor called weak on pull ", for 1 and paternal line registers itself pins for 1 open. This pull_up provides basic drive current make prospective two-way mouth for 1 output. If a pin for 1 and output by external devices to drop down to low, pull up close and weak "very weak pull_up" maintain open position, in order to put this pin for low, strong to pull the external devices must have enough power to make pin infused current threshold voltage of a voltage to the following.Article 2 pull_up transistors, called "extremely weak on pull", 1 latch paternal line when open. When pin, the very weak suspended the pull_up source generates very weak and current will pin and high level.Article 3 pull_up transistor called "powerful pull". Juncture line latches from 0 to 1, the jumping to accelerate must pull up by logic 0 to two-way mouth logic 1 conversion. When this happened, powerful pull open about 2 machine cycle to make pins can quickly pull to the earth high level.Quasi two-way mouth output shown below.STC12C520 series microcontroller 3V device, if the user is in pins plus 5V voltage, there will be a current flow from pins, this has caused additional VDD power consumption. Accordingly, the proposal is not in quasi two-way mouth mode 3V microcontroller pins to exert 5V voltage, such as the use of words, will add current limiting resistor, or using diode do input isolation, or use triode do output segregation.Quasi two-way mouth with a schmidt trigger input and a interference suppression circuit.2. The push-pull output configurationThe drop-down push-pull output configuration open-drain output and the structure and the prospective two-way mouth down same structure, but when latches is 1 provides continuous strong pull up. The push-pull model need more commonly used for driving current situation.The push-pull pins configuration are shown below.3. Only for input (high resistance) configurationInput port configuration are shown below.Input port with a schmidt trigger input and a interference suppression circuit.4. Open-drain output configurationJuncture line latches is 0, the open-drain output close all pull_up transistors. When, as a logical output, this configuration mode must have externally pull, usually by resistance receiving V D D outside. This style of drop-down and quasi two-way mouth the same. The jammer line configuration are shown below.Open-drain port with a schmidt trigger input and a interference suppression circuit.A typical transistor control circuitIf use weak pull_up control, suggestion plus pull-up resistors R1 (3.3 K ~ 10K), if not add pull-up resistors R 1 (3.3 K ~ 10K), suggest R2 value in the 15K above, or use a strong push-pull output.STC12C5204AD series microcontroller programmable counter array(PCA)PCA contains a special 16 timer, has four 16 bits of capture/comparison of module and connected. Each module programmable workIn four mode: increase/decrease along the capture, software timer, high-speed output or could be modulated pulse output. Modules connected to P3.7 (0 CEX0 / PCA0 / PWM0), module 1 connected to P3.5 (CEX1 / PCA1 / PWM1), modules connected to P2.0 (2 CEX2 / PCA2 / PWM2), modules connected to P2.4 (3 CEX3 / PCA3 / PWM3). Register the content of CH and CL is free of 16 PCA increasing count the value of the timer. PCA timer is four modules, the public time benchmark by programming work .Programmable Counter ArrayPCA Timer/CounterCMOD SFR there are 2 bytes and PCA related. They were: CIDL, idle mode allows stop PCA; ECF, buy a, enabling PCA interrupt, when PCA timer spillover will PCA counting overflow marks CCON SFR (CF) buy bits.CCON SFR contains PCA operating control bits (CR) and PCA timer mark (CF) and symbol of each module CCF3 / CCF2 (CCF0). CCF1 / / Through the software for a CR bits (CCON. 6) to run PCA. CR bit is reset when PCA closed. When PCA counteroverflow, CF patients (CCON. 7) buy a, if CMOD register, it produces ECF position a disruption. CF bits can only through software cleared. CCON register a 0 ~ 3 is PCA modules logo (a 0 0, a corresponding module 1 corresponding module 1, bits 2 corresponding module 2, a 3 corresponding module 3), when there is a match or by hardware buy a comparisons. These signals are the only through software cleared.PCA capture of patterningIf CCON SFR bits of the throne of CCFn and CCAPMn SFR ECCFn bit is set position, will produce the interruption.A software timer modeThrough the CCAPMn registers for a ECOM and MA T bits, can make the PCA module used for software timer (below). PCA timer values and module of the register compared to capture, when both values equal, if a CCON SFR in CCFn (in) and a ECCFn CCAPMn SFR) in all buy bits, will produce the interruption.PCA Software Timer Mode/Software Timer model/PCA comparative ModePCA Software Timer Mode/Software Timer model/PCA comparative ModeHigh-speed output modelThis model (below), when PCA counter plan of the numerical and module capture registers matching, PCA value CEXn output will happen module of the flip. To activate the high-speed output modes of CCAPMn TOG SFR, modules, MAT and ECOM bit must buy bits.PCA High - Speed, Output Mode/PCA high-speed Output ModeIn use PCA high-speed output mode special application note:If a certain PCA module working in high speed pulse output mode, want to use software output change the same group of other common I/O port state, need to do first, whether CCAPnH judge CH is equal to abide, can freely modify, if equal, and determineCCAPnL circumstances > CL is allowed to change the same group of other common I/O port state. If use P3.7 / PCA0 / PWM0 do PCA high-speed pulse output, and the program inside and with software output change when the state P3.4 mouth, you need to do judgment.When one has the PCA high-speed pulse output function of I/O mouth working in high speed pulse output mode, if the software for the same group of other I/O port operation, if meet PCA comparator matching, this operation can change the pulse output function with PCA high-speed mouth of the I/O.PCA PWM mode/modulation pulse width output modeSince all share only PCA timer modules, all their output frequency is same. The output of each module 390v is independent of the changes, and using EPCnL, captured CCAPnL}} {of registers concerned. When CL SFR value is less than CCAPnL}} {EPCnL, when output is low, and the value of SFR when PCA CL is equal to or greater than EPCnL, CCAPnL}} {, the output as high. When the value of the CL by FF into EPCnH, 00 overflow, CCAPnH}} {the contents of EPCnL, loaded into the CCAPnL}} {. In this way, can realize update PWM without interference. To make CCAPMn PWM mode, module can PWMn and ECOMn bits of the register to buy bits.译文芯片STC12C5204AD的I/O口配置STC12C5204AD系列单片机其所有I/O口均可由软件配置成4 种工作类型4 种类型分别为：准双向口（标准8051输出模式）、推挽输出、仅为输入（高阻）或开漏输出功能。
毕业设计英文作文范文
毕业设计英文作文范文Title: The Importance of the Graduation Project in Academic Development。
The graduation project holds a pivotal role in the academic journey of students. It serves as a culmination of years of learning, a platform to showcase acquired skills, and an opportunity to delve deep into a specific subject matter. In this essay, I will elaborate on the significance of the graduation project and its impact on academic development.Firstly, the graduation project fosters independent learning and critical thinking skills. Unlike regular coursework where the parameters are often well-defined, the graduation project requires students to identify a research question or a problem statement independently. This process necessitates thorough literature review, data collection, and analysis, thereby honing research and analytical abilities. Moreover, formulating hypotheses, designingexperiments, or proposing solutions demand creativethinking and problem-solving skills, which are essentialfor academic and professional success.Secondly, the graduation project encourages interdisciplinary learning and collaboration. Many projects involve aspects from various fields, prompting students to integrate knowledge acquired from different courses. This interdisciplinary approach not only enriches the project but also broadens students' perspectives, enabling them to appreciate the interconnectedness of different subjects. Furthermore, collaboration with peers, mentors, or industry professionals enhances teamwork, communication, and project management skills, which are indispensable in any academic or professional setting.Additionally, the graduation project cultivates resilience and perseverance. Research, by its nature, is fraught with challenges, setbacks, and uncertainties. Students encounter obstacles ranging from experimental failures to data inconsistencies, requiring them to adapt, troubleshoot, and persist in the face of adversity.Overcoming these hurdles instills resilience and fortitude, attributes that are invaluable not only in academia but also in life.Moreover, the graduation project offers a platform for personal and intellectual growth. It provides students with the autonomy to explore topics of their interest, delveinto uncharted territories, and push the boundaries of knowledge. This journey of self-discovery not only enhances academic curiosity but also fosters a sense of ownership and accomplishment. Furthermore, presenting findings, defending arguments, and receiving feedback during project evaluations contribute to the development of presentation, communication, and critical evaluation skills, which are essential for academic and professional success.In conclusion, the graduation project is a cornerstone of academic development, offering students a unique opportunity to apply theoretical knowledge to real-world problems, fostering independent learning, interdisciplinary collaboration, resilience, and personal growth. By engaging in this endeavor, students not only demonstrate theiracademic prowess but also equip themselves with essential skills and attributes for future endeavors. Therefore, the graduation project stands as a testament to the culmination of academic journey and the beginning of a new chapter in students' intellectual and professional pursuits.。
毕业设计作品英文
毕业设计作品英文Graduation ProjectThe completion of a graduation project is a significant milestone in the academic journey of a student. It represents the culmination of years of hard work, dedication, and the acquisition of knowledge and skills. The graduation project serves as a platform for students to demonstrate their mastery of a particular subject or field, and to showcase their ability to conduct independent research, analyze data, and present their findings in a coherent and compelling manner.The process of undertaking a graduation project is often a challenging and rewarding experience. It requires students to delve deeply into a topic of their choice, to critically analyze existing research and theories, and to develop their own unique perspectives and solutions. Throughout this process, students are expected to work closely with faculty advisors, who provide guidance, support, and feedback to ensure the success of the project.One of the key aspects of a graduation project is the ability toconduct thorough and rigorous research. This involves reviewing relevant literature, identifying gaps in existing knowledge, and formulating a research question or hypothesis that can be explored through empirical investigation. Students must then design and implement a research methodology that is appropriate for their topic, and collect and analyze data using a variety of qualitative and quantitative techniques.In addition to research skills, the graduation project also requires strong writing and communication abilities. Students must be able to articulate their ideas clearly and concisely, and to present their findings in a well-organized and coherent manner. This often involves the creation of a written thesis or dissertation, as well as the development of visual aids and presentations that can be used to effectively communicate their work to a wider audience.Throughout the graduation project process, students are also expected to demonstrate their ability to think critically and to solve complex problems. This may involve the development of innovative solutions to real-world challenges, or the application of theoretical concepts to practical scenarios. By engaging in this process, students gain valuable experience in problem-solving, decision-making, and critical thinking, all of which are essential skills for success in their future careers.One of the most rewarding aspects of the graduation project is the opportunity for students to make a meaningful contribution to their field of study. Through their research and analysis, students may uncover new insights or develop novel approaches that can be applied to address pressing social, economic, or environmental issues. This sense of making a difference can be a powerful motivator for students, and can inspire them to continue pursuing their passions and interests long after the completion of their graduation project.Despite the challenges and demands of the graduation project, many students find the experience to be deeply fulfilling and transformative. The process of conducting independent research, developing new skills, and presenting their work to a wider audience can be a source of immense pride and accomplishment. Moreover, the skills and knowledge gained through the graduation project can serve as a foundation for future academic and professional pursuits, and can open up a world of new opportunities for students as they embark on the next chapter of their lives.In conclusion, the graduation project is a crucial component of the academic experience, one that challenges students to push the boundaries of their knowledge and capabilities. Through this process, students develop a deeper understanding of their chosen field, hone their critical thinking and problem-solving skills, and make ameaningful contribution to the broader academic and professional community. For those who embrace the challenges and opportunities of the graduation project, the rewards can be truly transformative, shaping their future trajectories and opening up new avenues for personal and professional growth.。
毕业设计 英文
毕业设计英文Graduation ProjectIntroduction:The graduation project is an essential part of completing our education. It is a significant milestone in our academic journey and an opportunity to showcase our skills and knowledge in a particular field. In this project, I will outline the details of my chosen graduation project.Objective:The main objective of my graduation project is to design and develop a mobile application that will assist users in managing their personal finance effectively. This application will provide a range of features and tools that will enable users to track their expenses, create budgets, and set savings goals.Project Description:The mobile application will be developed for both iOS and Android platforms, ensuring compatibility with a wide range of devices. The user interface will be intuitive and user-friendly, allowing users to easily navigate through the app's features. The application will require users to create an account to access its functionalities securely.Features:1. Expense Tracking: Users will be able to add their daily expenses and categorize them based on different predefined categories, such as food, transportation, entertainment, etc. The app will display the total expenses, along with a breakdown of expenses by category,enabling users to identify areas for potential cost-cutting.2. Budget Creation: The application will allow users to set monthly budgets for different expense categories. Users will receive notifications when they exceed their budget limits, reminding them to manage their spending efficiently.3. Savings Goals: Users can set savings goals based on their financial targets. The app will track their progress towards achieving these goals, providing visual representations of their savings growth and estimating the time required to reach their objectives.4. Transaction History: Users will have access to a transaction history that will allow them to review their past expenses and monitor their financial activities over time. This feature will provide users with a comprehensive overview of their spending habits.Conclusion:The development of this mobile application will provide users with a useful tool for managing their personal finance. In an increasingly digital world, it is crucial to leverage technology to streamline and optimize our financial management processes. This graduation project will not only enhance my technical skills but also contribute to society by providing a practical solution for individuals to improve their financial well-being.。
毕业设计的英文
毕业设计的英文毕业设计的英文是"Graduation Project"，它是大学生在毕业前完成的一个重要学术项目。
毕业设计是对所学专业知识的综合应用和实践，旨在培养学生的独立思考、创新能力和解决问题的能力。
本文将从毕业设计的重要性、选择合适的毕业设计题目、开展毕业设计的步骤以及毕业设计的意义等方面进行论述。
首先，毕业设计在学生的大学生涯中具有重要的意义。
它是学生在校期间所学知识的综合运用，对学生的专业素养和实践能力有很大的考验。
通过毕业设计，学生可以更好地理解和掌握所学专业知识，并将其应用于实际问题的解决中。
同时，毕业设计也是学生展示自己学术能力和研究成果的机会，对于进一步深造或就业都具有积极的影响。
其次，选择一个合适的毕业设计题目至关重要。
一个好的毕业设计题目应该具备以下几个特点：首先，题目应该与学生所学专业相关，能够充分发挥学生专业知识的应用和创新能力。
其次，题目应该具备一定的研究性和创新性，能够对现有问题进行深入的探索和解决方案的提出。
最后，题目应该具备可行性，学生在规定的时间内能够完成，并且有足够的资源和数据支持。
开展毕业设计需要经过一系列的步骤。
首先，学生需要明确自己的研究目标和研究方法，制定详细的研究计划。
其次，学生需要进行相关文献的查阅和资料的收集，了解已有的研究成果和理论基础。
接下来，学生需要进行实验设计和数据采集，并进行数据分析和结果展示。
最后，学生需要撰写毕业设计论文，并进行答辩和评审。
整个过程需要学生具备良好的时间管理和组织能力，以及扎实的研究和写作能力。
毕业设计的意义不仅在于学生个人的成长和发展，也对学校和社会具有重要的价值。
对于学校而言，毕业设计是对教学质量和培养目标的一种检验和评估，学校可以通过毕业设计的质量和成果来评估自身的教学效果和培养质量。
对于社会而言，毕业设计是对学生实际能力和解决问题能力的一种考核，也是对学生未来就业的重要参考。
优秀的毕业设计成果可以为学生争取更好的就业机会和职业发展空间。
毕业设计英文怎么说
毕业设计英文怎么说毕业设计英文怎么说？在大学生活中，毕业设计是一个重要的环节，它是学生通过独立研究和实践，展示自己所学知识和技能的机会。
但是，对于一些同学来说，他们可能会遇到一个问题：毕业设计英文怎么说呢？首先，我们可以从整体上来看待这个问题。
毕业设计在英文中可以被称为"graduation project"或者"final year project"。
这两个短语都可以用来表达毕业设计的含义。
"Graduation project"更加强调这是一个与毕业相关的项目，而"final year project"则更加突出了它是在大学最后一年完成的。
接下来，我们可以进一步探讨毕业设计的具体内容。
毕业设计的内容通常是根据学生所学专业的要求来确定的。
例如，对于计算机科学专业的学生来说，他们的毕业设计可能涉及软件开发、数据分析或者人工智能等方面。
而对于艺术设计专业的学生来说，他们的毕业设计可能会涉及绘画、雕塑或者摄影等方面。
因此，在选择毕业设计的英文表达时，我们可以根据具体的专业内容来进行描述。
除了上述的短语之外，我们还可以使用一些动词来描述毕业设计。
例如，我们可以使用"conduct"来表示进行毕业设计的过程，使用"complete"来表示完成毕业设计的过程，使用"present"来表示展示毕业设计的过程。
这些动词可以帮助我们更加准确地描述毕业设计的各个阶段。
此外，我们还可以通过描述毕业设计的目的和意义来进一步丰富我们的英文表达。
毕业设计不仅仅是一个学术项目，它也是一个展示学生能力和才华的机会。
通过毕业设计，学生可以将所学的理论知识应用到实际项目中，提升自己的实践能力和解决问题的能力。
因此，我们可以使用一些形容词来描述毕业设计的目的和意义，例如"meaningful"、"challenging"、"rewarding"等。
毕业设计(论文)英文扉页参考模板
Southwest Petroleum UniversityGraduation ThesisSynthesis and Evaluation of a Highly Absorbent CompositeGrade: 2008Name:Speciality: Petroleum EngineeringInstructor:School of Petroleum Engineering2007-6附：我校设置的专业中英文对照（摘自《普通高等学校本科专业目录和专业介绍》）1、石油工程学院080102石油工程Petroleum Engineering081203油气储运工程Oil/ Gas Storage and Transportation Engineering2、资源与环境学院080105资源勘查工程Natural Resources Prospecting Engineering080104勘查技术与工程Prospecting Techniques and Engineering070702资源环境与城乡规划管理Urban and Rural Planning & Resource Management070703地理信息系统Geographical Information System3、机电工程学院080305Y机械工程及自动化Mechanical Engineering and Automation080304过程装备与控制工程Process Equipment and Control080303工业设计Industrial Design4、化学化工学院081101化学工程与工艺Chemical Engineering and Technology070302应用化学Applied Chemistry081001环境工程Environmental Engineering081801生物工程Bioengineering070301化学Chemistry5、材料科学与工程学院080204高分子材料与工程Macromolecular Materials and Engineering080205Y材料科学与工程Material Science and Engineering6、计算机科学学院080605计算机科学与技术Computer science and Technology080611W软件工程Software Engineering080613W网络工程Network Engineering7、电信工程学院080401测控技术与仪器Measuring & Control Technology and Instrumentations 080602自动化Automation080603电子信息工程Electronic and Information Engineering080601电气工程及其自动化Electrical Engineering and Automation080604通信工程Telecommunications Engineering8、建筑工程学院080703土木工程Civil Engineering080704建筑环境与设备工程Building Environment and Equipment Engineering 080901测绘工程Surveying & Mapping Engineering110104工程管理Project Management9、理学院070102信息与计算科学Information and Computing Science070101数学与应用数学Mathematics and Applied Mathematics071201电子信息科学与技术Electronic and Information Science and Technology 070202应用物理学Applied Physics10、经济管理学院110201工商管理Business Administration110202市场营销Marketing110102信息管理与信息系统Information Management & Information System 020101经济学Economics110209W电子商务Electronic Business020102国际经济与贸易International Economics & Trade11、人文社会科学学院030302社会工作Social Work110309W公共管理Public Administration12、法学院030101法学Law13、外语系050201英语English14、体育系。
毕业设计_英文翻译
9 Continuous-Time DynamicNeural Networks9 连续时间动态神经网络9.1 Dynamic Neural Network Structures: An Introduction9.2 Hopfield Dynamic Neural Network (DNN) and Its Implementation 9.3 Hopfield Dynamic Neural Networks (DNNs) as Gradient-like Systems9.4 Modifications of Hopfield Dynamic Neural Networks9.5 Other DNN Models9.6 Conditions for Equilibrium Points in DNN9.7 Concluding RemarksProblems9.1动态神经网络结构导论9.2动态的Hopfield神经网络（DNN）及其实现9.3动态的Hopfield神经网络（DNNS）为梯度样系统9.4修改动态的Hopfield神经网络9.5其他DNN模型9.6条件平衡点在DNN9.7结语问题As seen in the previous chapters, a neural network consists of many interconnected simple processing units, called neurons, which form the layered configurations. An individual neuron aggregates its weighed inputs and yields an output through a nonlinear activation function with a threshold. In artificial neural networks there are three types of connections: intralayer, interlayer, and recurrent connections. The intralayer connections, which are also called lateral connections or cross-layer connections, are links between neurons in the same layer of the network. The interlayer connections are links between neurons in different layers. The recurrent connections provide self-feedback links to the neurons. In interlayer connections, the signals are transformed in one of the two ways: either feedforward or feedback.就像在前面的章节中，神经网络由许多互连简单处理单元，称为神经元，形成层状结构。
英文毕业设计教案模板范文
I. IntroductionThe graduation design is an essential part of the undergraduate education process, providing students with an opportunity to apply the knowledge and skills acquired during their studies to real-world problems. This teaching plan outlines the structure, objectives, and methodology for conducting a successful graduation design project.II. Course OverviewCourse Title: Graduation Design (Undergraduate)Course Code: [Insert Course Code]Credit Hours: [Insert Credit Hours]Course Duration: [Insert Duration, e.g., 16 weeks]III. Course ObjectivesUpon completion of this course, students will be able to:1. Identify and define a specific research problem or design challenge.2. Conduct comprehensive literature reviews and analyze existing research or solutions.3. Develop a research plan or design proposal, including methodology, data collection, and analysis techniques.4. Implement the research plan or design project, adhering to ethical guidelines and professional standards.5. Present and defend their research findings or design solutions in a professional manner.6. Reflect on the project experience and articulate the learned lessons and personal growth.IV. Course Content1. Introduction to Graduation Design- Importance of graduation design in undergraduate education- Overview of the graduation design process- Role of the supervisor in the graduation design project2. Problem Identification and Definition- Techniques for identifying and defining research problems- Importance of clear and concise problem statements3. Literature Review- Conducting a comprehensive literature review- Analyzing and synthesizing existing research- Identifying gaps in the current literature4. Research Plan and Design Proposal- Developing a research plan or design proposal- Methodology, including data collection and analysis techniques - Ethical considerations and professional standards5. Implementation of the Project- Time management and project planning- Implementation of research methods or design solutions- Documentation and progress reporting6. Presentation and Defense- Preparing for the final presentation- Guidelines for effective presentations- Preparing for the defense of the project7. Reflection and Conclusion- Reflecting on the project experience- Articulating learned lessons and personal growth- Final project submission and evaluationV. Teaching MethodologyThe course will employ a combination of lectures, seminars, individual work, and group discussions to facilitate learning. The following methods will be used:1. Lectures: To provide an overview of the concepts, methodologies, and ethical considerations involved in graduation design.2. Seminars: To facilitate in-depth discussions on specific topics, allowing students to share their progress and receive feedback frompeers and instructors.3. Individual Work: To enable students to develop their research plansor design proposals independently.4. Group Discussions: To encourage collaborative learning and the exchange of ideas among students.5. Supervision: Regular meetings with the supervisor to provide guidance, feedback, and support throughout the project.VI. AssessmentThe assessment of the graduation design project will be based on the following criteria:1. Problem Identification and Definition (10%): Clarity and relevance of the research problem or design challenge.2. Literature Review (20%): Depth and breadth of the literature review, identification of research gaps.3. Research Plan and Design Proposal (30%): Soundness of the research plan or design proposal, adherence to ethical guidelines.4. Implementation of the Project (20%): Quality of the research or design implementation, adherence to the project plan.5. Presentation and Defense (10%): Clarity, coherence, and persuasiveness of the presentation, defense of the project.VII. ConclusionThis teaching plan aims to provide a comprehensive。
毕业设计展 英文
毕业设计展英文Graduation Design ExhibitionThe graduation design exhibition is an important event that showcases the culmination of years of hard work and creativity by graduating students. It provides a platform for students to present their innovative ideas and projects to the public, industry professionals, and potential employers. In this article, we will explore the significance of the graduation design exhibition and its impact on the future careers of these talented individuals.The graduation design exhibition serves as a bridge between academia and the professional world. It allows students to demonstrate their ability to apply theoretical knowledge to real-world problems. Through their projects, students showcase their problem-solving skills, creativity, and technical expertise. This exhibition not only provides an opportunity for students to gain recognition for their work but also enables them to receive valuable feedback and suggestions from industry experts.One of the key benefits of the graduation design exhibition is the exposure it provides to students. It allows them to network with professionals from various industries who attend the event. This networking opportunity can open doors to internships, job offers, and collaborations. The exhibition also serves as a platform for students to build their professional portfolios, which are essential for securing employment after graduation. The recognition received at the exhibition can significantly enhance their chances of finding a job in their desiredfield.Furthermore, the graduation design exhibition fosters a sense of pride and accomplishment among the graduating students. It is a moment of celebration and validation for their hard work and dedication throughout their academic journey. The exhibition not only showcases their individual projects but also highlights their growth and development as designers. It serves as a reminder of their achievements and acts as a motivation for future endeavors.The impact of the graduation design exhibition extends beyond the individual students. It also benefits the educational institutions hosting the event. The exhibition serves as a testament to the quality of education and training provided by the institution. It showcases the institution's ability to nurture and produce talented individuals who are ready to make a significant contribution to their respective industries. The success of the exhibition reflects positively on the reputation of the institution and attracts potential students and sponsors.In conclusion, the graduation design exhibition is a significant event that plays a crucial role in the professional development of graduating students. It provides them with a platform to showcase their skills, gain exposure, and network with industry professionals. The exhibition also instills a sense of pride and accomplishment among the students and acts as a validation of their hard work. Moreover, it benefits the educational institutions by enhancing their reputation and attracting potential students and sponsors. Overall, the graduation design exhibition is a valuable opportunity for students to kickstart their careers andmake a mark in the professional world.。
毕业设计英文翻译中英文对照版
Feasibility assessment of a leading-edge-flutter wind power generator前缘颤振风力发电机的可行性评估Luca Caracoglia卢卡卡拉克格里亚Department of Civil and Environmental Engineering, Northeastern University, 400 Snell Engineering Center, 360 Huntington A venue, Boston, MA 02115, USA美国东北大学土木与环境工程斯内尔工程中心400，亨廷顿大道360，波士顿02115This study addresses the preliminary technical feasibility assessment of a mechanical apparatus for conversion of wind energy. 这项研究涉及的是风能转换的机械设备的初步技术可行性评估。
The proposed device, designated as ‘‘leading-edge-fl utter wind power generator’’, employs aeroelastic dynamic instability of a blade airfoil, torsionally rotating about its leading edge. 这种被推荐的定义为“前缘颤振风力发电机”的设备，采用的气动弹性动态不稳定叶片翼型，通过尖端旋转产生扭矩。
Although the exploitation of aeroelastic phenomena has been proposed by the research community for energy harvesting, this apparatus is compact, simple and marginally susceptible to turbulence and wake effects.虽然气动弹性现象的开发已经有研究界提出可以通过能量采集。
旅游线路毕业设计(英文)
Three-Day Quality Tour From Zhengzhou To Luoyang Slogans: Visiting mountain，Playing water，Appreciating flowers，Feeling culture，Let’s go！I.ItineraryDay OneGathering time: the traveling day at seven in the morningAssembly point：Zhengzhou two seven square (Note: remember the information about the meeting place and gathering time and the bus license which the guide told you a day before your travel day between18 and 20. Please keep the guests in touch. Please choose riding according to their own short distance, and arrive on time. )Morning: Longmen Grottoes. We will arrive in Longmen by G2007 at about eight forty .Then we will get all things ready and have a three-hour travel.. Longmen Grottoes is one of three big stone art treasures in china. after .It has been excavated for more than 400 years from the Northern Wei to the Northern Song Dynasty. Nowdays there are more than 2300 caves and niches , and also 100000 statues, more than 3600 pieces of inscriptions, most of which locate in the West Bank. The number of Chinese stone cave located in the first. Afternoon: Luoyang Peony Garden. We will stay here for about 150 mimutes.Let’s go to experience the meaning of” Peony Flower in Luoyang, Finest under heaven”Night:we will have dinner in the four star hotel and stay there for one night. Day TowMorning: We will meet at 6:30after breakfast.When everything is ok.We will have a tour of the famous landscape—chongdugou.We plan to view the Millennium banyan tree, rainbow falls, Golden Valley, bamboo sea，falls, Suojiao cliff and so on.Noon: Lunch at scenic spotsAfternoon: We will travel green river scenic area, and have a view of water curtain falls, and have free farming activities.Night: Dinner and rest in the Peasant at night.Day ThreeMorning: We will meet at 6:30 after breakfast and set to the culture of Taoism sacred Laojun Mountain. Then get to Zhongtian gate by the high-speed cablecar and have a view of the Funiu Jinding, the Millennium Temple -- Laojunmiao, Liang Po, Yuhuangding, South Gate, the world 's largest granite Fenglin attractions.Noon: having dining within scenic spots.Afternoon: We visit the Laozi Cultural Park, where we will see the 59 meters high bronze statue of Laozi . We can feel Laozi’s opinions about morality and civilization.Next,we should visit the Pingyang Plaza, Laojun Mountain Screen Wall, Bell Tower and Drum Tower,Laozi Relief Wall and so on.Evening: We will return to Zhengzhou by the traveling bus. Lodging: Your warm home.II.Characteristics Of The Tour" If you want to know the prosperity in the ancient and modern time, just look at Luoyang city ". Luoyang, the Millennium Royal Park, the ancient cultural city , which is full of solemn atmosphere Longmen Grottoes, the rich handsome of Luoyang Peony,three characteristics of Chongdugou,the special and beauty of Laojun Mountain.III.AvailabilityFor every April or May to tour.IV.Each Scenic Spot Typical Featuresi.Longmen Grottoes:The Longmen Grottoes are located in the south of Luoyang City. They are between Mount Xiang and Mount Longmen and face Yi River. Longmen Grottoes, Y ungang Caves and Mogao Caves are regarded as the three most famous treasure houses of stone inscriptions in China.The grottoes were started around the year 493 when Emperor Xiaowen of the Northern Wei Dynasty (386-534) moved the capital to Luoyang and were continuously built during the 400 years until the Northern Song Dynasty (960-1127). The scenery measures 1,000 meters from north to south where there are over 2,300 holes and niches, 2,800 steles, 40 dagobas, 1,300 caves and 100,000 statues. Most of them are the works of the Northern Wei Dynasty and the flourishing age of the Tang Dynasty (618-907). Lots of historical materials concerning art, music, religion, calligraphy, medicine, costume and architecture are kept in Longmen Grottoes.ii. Luoyang peony：peony is a kind of deciduous sub-shrub of common peony genes, buttercup family. Since it looked similar to “shaoyao”, a kind ofherbaceous plant of peony genus, it started to be called “shrubby shaoyao”. According to historical records, in Luoyang, peonies were beginning to be grown in the Sui, and became popular in the Tang and their flowers were known as “the finest of their kind on earth” in the Song Dynasty. Since 1983, Luoyang has held the Peony-fair-festival in April, every year. During decades, the varieties of peony have grown from 30 in the 1950’s to more than 700 now. Commonly, we can see peony of 9 colors: red, white, yellow, pink, purple, green, lilac, black-purple and so on. After a while when we get to the greenhouse, we can see white Bai xueta, yellow Y aohuang, blackish-purpleY an rongzi and the 2 rare varieties green Doulv and Er-qiao with 2 colors in one petal. I’m sure you will get your eyes feasted in the garden but do not enter in the flowering shrubs in case of hurting the branches.iii.Chongdugou:Chongdugou is located in Luoyang City, it is named to the Eastern Han Dynasty emperor Liu Xiu . The mystery of the historical legends and the three characteristics of Chongdugou make it from fresh is well-known not authoritative in one fell swoop to famous landscape, become the most vigorous ten hot spots . The authority person—— Mr. Wei Xiaoan praised Chongfugou as "China's first village farmhouse hotel ".iv.Mount Laojunshan: Henan Mount Laojunshan ecological tourist area is located in Luoyang city Luanchuan county .It is the World Geological Park Central Park, the national 4A grade scenic spot, the national level nature protection area, the provincial scenic area, a provincial heritage conservation units.Mount Laojunshan is named for LIEr whom live here.Mount Laojunshan is 2217 meters above sea level,It is the main peak of the eight hundred kilometer Funiu The temple has a long history on the summit. Taoism culture has a long history.V. Offers:i. Price·768 yuan per personii. Inclouding:·Tickets: Longmen Grottoes, Luoyang peony garden, re-channel ferry, first big ticket to Laojun Mountain..·Transportation fee: go to Luoyang high-speed rail travel and tour bus on the way back.·Meals: two breakfast and five dinner·Accommodation: four star hotels and farmhouse·Guide service: excellent tour guide service·Insurance: travel agency liability insurance, life accident insurance travel ·Souvenir: quality tourism capiii. Exclouding·Small car traffic, cable and guests own expense tickets in the scenic spots.·Due to force majeure causing additional expensesVI. Reminders·Please take good care of your valuables during the outside travel,.be sure to pay attention to personal safety.·Please " viewing don't walk, walk not viewing " during your tour.·We recommend wearing a light sports shoes, a little casual clothes. You’d better not wear high-heeled shoes and remember to bring sunscreen cream ·If you have motion sickness history, you should not eat too full before traveling, and you should take and carry carsick medicine in advance . If you have gastric disease, hypertension disease, please bring daily drug.·Due to objective reasons in some areas, if the food or defects in travelling is not very perfect to you, also please forgive me. Don't eat fruit and fungi, to prevent food poisoning.The Longmen GrottoesThe longmen grottoes Around 13 km south of Luoyang, there are two picturesque hills confronting each other with the Yi River flowing northward between them, connected by an arched stone bridge resembling a natural gate tower. This is the right place named Longmen, where the well-known Longmen Grottoes is located. The grottoes, which earns the fame of one of the Three Treasure Houses of Stone Sculpture in China, was created over 1500 years age. It was first known in the year 493 AD, when Emperor Xiaowen moved his capital to Luoyang from Datong, Shannxi Province, which marked the initiation of development and expanse of Buddhism in Central China. It prolongs for 1000 meters from north to south. According to the statistics conducted in recent years, there are 2300 caves and niches with over 100000 Buddhist figures. In addition, more than 2800 tablet inscriptions and some 40 Buddhist pagodas were preserved in or out of the caves.Now, we’ve got to the grottoes. In front of you, here is the Qianxi Temple. It was built in the early Tang Dynasty around 640 AD. It has altogether 7 Buddhist statues inside, of which, AmitabhaBuddha is sitting in the central part with 2 of his favorite disciples, 2 Bodhisattvas, and 2 Heavenly Kings. Please come with me.Now we are in front of the Bin yang Caves. The Bin yang Caves consist of 3 large caves, the North, the Middle and the South caves. The Mid and the South caves were built under Emperor Xuanwu for practicing the merits and virtues for his diseased parents, late Emperor Xiaowen and late Empress DowagerWenzhao. While the North Bin yang cave was added for the late Emperor Xuanwu by a eunuch in the palace. In the Western Hill of Longmen, there are several “the most” caves to feast your eyes. Just now, we visited the Ten-thousand Buddha Cave with 15000 Buddhist images, which has the most Buddha images, and the Lotus Cave with 2cm-high Buddha images, which are the tiniest Buddha images.N ow, we’ve come to another “most”, the Fengxian Temple. Fengxian Temple was built in the Tang Dynasty and it is the largest grotto in Longmen Temple with a width of 36 meters and a length of 41 meters. The most impressive figure is the statue of Vairocana Buddha sitting cross-legged on the eight-square lotus throne. It is 17.14 meters in total height with the head4meters in height and the ears 1.9 meters in length. At the sides of Vairocana there are two statues of Vairocana Buddha's disciples, Kasyapa and Ananda, wearing prudent and devout expressions,next are 2 Bodhisattvas, Heavenly Kings, and Great Men of Strength. Vairocana means illuminating all things in the sutra. The Buddha has a well-filled figure, a sacred and kindly expression and an elegant smile. The chief Buddha gives you an impression of dignified manner, magnificent looking, wise, farsighted and kind nature. The various appearances and delicate designs are the representations of Empire Tang's powerful material and spiritual strength as well as the high crystallization of people's wisdoms. Looking around the overall arrangement, we would rather say that the Fengxian Temple is a scene of a grand imperial court than a spot of Buddhism. Generally speaking, the Fengxian Temple is the most magnificent and artistic among all the shrines of the Tang Dynasty as well as an example of success in integrating politics with Buddhism in ancient China. Ok everyone, now you can take photos here. Or you can ask questions that you don’t understand. After 15 minutes we will gather right here. See you then.。
毕业设计英文版
Graduation ProjectCourse Code： 82157600Couse Title： Graduation ProjectCredits：6 Semester Classes：The 11’s SemesterTeaching People：All undergraduate students of the School of Mathematical and StatisticsPre-Course：Mathematical ModelThe Charger of the Course：Qi Haitao，DoctorCourse Description：《 Graduation Project》 will play a significant role in assisting students to demonstrate their learned knowledge and skills through a 21st Century performance-based process. This process will involve students, schools, parents and communities. It is an opportunity for students to spend extended time delving into a topic for which they have a particular interest and passion, and serves as a summary and reflect ion of the student’s experience. Prior to graduation, students are given the opportunity to present what they have accomplished and learned to their project partners, school family, and members of the community. This culminating demonstration is a personal affirmation of a student’s individual achievement and a memorable experience to mark the conclusion of four years of undergraduate education.Practice Teaching：We will study some applications of Mathematical and Statistics.Course Assesement：The examination results will be decided by the papers that students finished.。
毕业设计英文 翻译(原文)
编号：毕业设计(论文)外文翻译（原文）院（系）：桂林电子科技大学专业：电子信息工程学生姓名： xx学号： xxxxxxxxxxxxx 指导教师单位：桂林电子科技大学姓名： xxxx职称： xx2014年x月xx日Timing on and off power supplyusesThe switching power supply products are widely used in industrial automation and control, military equipment, scientific equipment, LED lighting, industrial equipment,communications equipment,electrical equipment,instrumentation, medical equipment, semiconductor cooling and heating, air purifiers, electronic refrigerator, LCD monitor, LED lighting, communications equipment, audio-visual products, security, computer chassis, digital products and equipment and other fields.IntroductionWith the rapid development of power electronics technology, power electronics equipment and people's work, the relationship of life become increasingly close, and electronic equipment without reliable power, into the 1980s, computer power and the full realization of the switching power supply, the first to complete the computer Power new generation to enter the switching power supply in the 1990s have entered into a variety of electronic, electrical devices, program-controlled switchboards, communications, electronic testing equipment power control equipment, power supply, etc. have been widely used in switching power supply, but also to promote the rapid development of the switching power supply technology .Switching power supply is the use of modern power electronics technology to control the ratio of the switching transistor to turn on and off to maintain a stable output voltage power supply, switching power supply is generally controlled by pulse width modulation (PWM) ICs and switching devices (MOSFET, BJT) composition. Switching power supply and linear power compared to both the cost and growth with the increase of output power, but the two different growth rates. A power point, linear power supply costs, but higher than the switching power supply. With the development of power electronics technology and innovation, making the switching power supply technology to continue to innovate, the turning points of this cost is increasingly move to the low output power side, the switching power supply provides a broad space for development.The direction of its development is the high-frequency switching power supply, high frequency switching power supply miniaturization, and switching power supply into a wider range of application areas, especially in high-tech fields, and promote the miniaturization of high-tech products, light of. In addition, the development and application of the switching power supply in terms of energy conservation, resource conservation and environmental protection are of great significance.classificationModern switching power supply, there are two: one is the DC switching power supply; the other is the AC switching power supply. Introduces only DC switching power supply and its function is poor power quality of the original eco-power (coarse) - such as mains power or battery power, converted to meet the equipment requirements of high-quality DC voltage (Varitronix) . The core of the DC switching power supply DC / DC converter. DC switching power supply classification is dependent on the classification of DC / DC converter. In other words, the classification of the classification of the DC switching power supply and DC/DC converter is the classification of essentially the same, the DC / DC converter is basically a classification of the DC switching power supply.DC /DC converter between the input and output electrical isolation can be divided into two categories: one is isolated called isolated DC/DC converter; the other is not isolated as non-isolated DC / DC converter.Isolated DC / DC converter can also be classified by the number of active power devices. The single tube of DC / DC converter Forward (Forward), Feedback (Feedback) two. The double-barreled double-barreled DC/ DC converter Forward (Double Transistor Forward Converter), twin-tube feedback (Double Transistor Feedback Converter), Push-Pull (Push the Pull Converter) and half-bridge (Half-Bridge Converter) four. Four DC / DC converter is the full-bridge DC / DC converter (Full-Bridge Converter).Non-isolated DC / DC converter, according to the number of active power devices can be divided into single-tube, double pipe, and four three categories. Single tube to a total of six of the DC / DC converter, step-down (Buck) DC / DC converter, step-up (Boost) DC / DC converters, DC / DC converter, boost buck (Buck Boost) device of Cuk the DC / DC converter, the Zeta DC / DC converter and SEPIC, the DC / DC converter. DC / DC converters, the Buck and Boost type DC / DC converter is the basic buck-boost of Cuk, Zeta, SEPIC, type DC / DC converter is derived from a single tube in this six. The twin-tube cascaded double-barreled boost (buck-boost) DC / DC converter DC / DC converter. Four DC / DC converter is used, the full-bridge DC / DC converter (Full-Bridge Converter).Isolated DC / DC converter input and output electrical isolation is usually transformer to achieve the function of the transformer has a transformer, so conducive to the expansion of the converter output range of applications, but also easy to achieve different voltage output , or a variety of the same voltage output.Power switch voltage and current rating, the converter's output power is usually proportional to the number of switch. The more the number of switch, the greater the output power of the DC / DC converter, four type than the two output power is twice as large,single-tube output power of only four 1/4.A combination of non-isolated converters and isolated converters can be a single converter does not have their own characteristics. Energy transmission points, one-way transmission and two-way transmission of two DC / DC converter. DC / DC converter with bi-directional transmission function, either side of the transmission power from the power of lateral load power from the load-lateral side of the transmission power.DC / DC converter can be divided into self-excited and separately controlled. With the positive feedback signal converter to switch to self-sustaining periodic switching converter, called self-excited converter, such as the the Luo Yeer (Royer,) converter is a typical push-pull self-oscillating converter. Controlled DC / DC converter switching device control signal is generated by specialized external control circuit.the switching power supply.People in the field of switching power supply technology side of the development of power electronic devices, while the development of the switching inverter technology, the two promote each other to promote the switching power supply annual growth rate of more than two digits toward the light, small, thin, low-noise, high reliability, the direction of development of anti-jamming. Switching power supply can be divided into AC / DC and DC / DC two categories, AC / AC DC / AC, such as inverters, DC / DC converter is now modular design technology and production processes at home and abroad have already matured and standardization, and has been recognized by the user, but AC / DC modular, its own characteristics make the modular process, encounter more complex technology and manufacturing process. Hereinafter to illustrate the structure and characteristics of the two types of switching power supply.Self-excited: no external signal source can be self-oscillation, completely self-excited to see it as feedback oscillation circuit of a transformer.Separate excitation: entirely dependent on external sustain oscillations, excited used widely in practical applications. According to the excitation signal structure classification; can be divided into pulse-width-modulated and pulse amplitude modulated two pulse width modulated control the width of the signal is frequency, pulse amplitude modulation control signal amplitude between the same effect are the oscillation frequency to maintain within a certain range to achieve the effect of voltage stability. The winding of the transformer can generally be divided into three types, one group is involved in the oscillation of the primary winding, a group of sustained oscillations in the feedback winding, there is a group of load winding. Such as Shanghai is used in household appliances art technological production of switching power supply, 220V AC bridge rectifier, changing to about 300V DC filter added tothe collector of the switch into the transformer for high frequency oscillation, the feedback winding feedback to the base to maintain the circuit oscillating load winding induction signal, the DC voltage by the rectifier, filter, regulator to provide power to the load. Load winding to provide power at the same time, take up the ability to voltage stability, the principle is the voltage output circuit connected to a voltage sampling device to monitor the output voltage changes, and timely feedback to the oscillator circuit to adjust the oscillation frequency, so as to achieve stable voltage purposes, in order to avoid the interference of the circuit, the feedback voltage back to the oscillator circuit with optocoupler isolation.technology developmentsThe high-frequency switching power supply is the direction of its development, high-frequency switching power supply miniaturization, and switching power supply into the broader field of application, especially in high-tech fields, and promote the development and advancement of the switching power supply, an annual more than two-digit growth rate toward the light, small, thin, low noise, high reliability, the direction of the anti-jamming. Switching power supply can be divided into AC / DC and DC / DC two categories, the DC / DC converter is now modular design technology and production processes at home and abroad have already matured and standardized, and has been recognized by the user, but modular AC / DC, because of its own characteristics makes the modular process, encounter more complex technology and manufacturing process. In addition, the development and application of the switching power supply in terms of energy conservation, resource conservation and environmental protection are of great significance.The switching power supply applications in power electronic devices as diodes, IGBT and MOSFET.SCR switching power supply input rectifier circuit and soft start circuit, a small amount of applications, the GTR drive difficult, low switching frequency, gradually replace the IGBT and MOSFET.Direction of development of the switching power supply is a high-frequency, high reliability, low power, low noise, jamming and modular. Small, thin, and the key technology is the high frequency switching power supply light, so foreign major switching power supply manufacturers have committed to synchronize the development of new intelligent components, in particular, is to improve the secondary rectifier loss, and the power of iron Oxygen materials to increase scientific and technological innovation in order to improve the magnetic properties of high frequency and large magnetic flux density (Bs), and capacitor miniaturization is a key technology. SMT technology allows the switching power supply has made considerable progress, the arrangement of the components in the circuit board on bothsides, to ensure that the light of the switching power supply, a small, thin. High-frequency switching power supply is bound to the traditional PWM switching technology innovation, realization of ZVS, ZCS soft-switching technology has become the mainstream technology of the switching power supply, and a substantial increase in the efficiency of the switching power supply. Indicators for high reliability, switching power supply manufacturers in the United States by reducing the operating current, reducing the junction temperature and other measures to reduce the stress of the device, greatly improve the reliability of products.Modularity is the overall trend of switching power supply, distributed power systems can be composed of modular power supply, can be designed to N +1 redundant power system, and the parallel capacity expansion. For this shortcoming of the switching power supply running noise, separate the pursuit of high frequency noise will also increase, while the use of part of the resonant converter circuit technology to achieve high frequency, in theory, but also reduce noise, but some The practical application of the resonant converter technology, there are still technical problems, it is still a lot of work in this field, so that the technology to be practical.Power electronics technology innovation, switching power supply industry has broad prospects for development. To accelerate the pace of development of the switching power supply industry in China, it must take the road of technological innovation, out of joint production and research development path with Chinese characteristics and contribute to the rapid development of China's national economy.Developments and trends of the switching power supply1955 U.S. Royer (Roger) invented the self-oscillating push-pull transistor single-transformer DC-DC converter is the beginning of the high-frequency conversion control circuit 1957 check race Jen, Sen, invented a self-oscillating push-pull dual transformers, 1964, U.S. scientists canceled frequency transformer in series the idea of switching power supply, the power supply to the size and weight of the decline in a fundamental way. 1969 increased due to the pressure of the high-power silicon transistor, diode reverse recovery time shortened and other components to improve, and finally made a 25-kHz switching power supply.At present, the switching power supply to the small, lightweight and high efficiency characteristics are widely used in a variety of computer-oriented terminal equipment, communications equipment, etc. Almost all electronic equipment is indispensable for a rapid development of today's electronic information industry power mode. Bipolar transistor made of 100kHz, 500kHz power MOS-FET made, though already the practical switching power supply is currently available on the market, but its frequency to be further improved. Toimprove the switching frequency, it is necessary to reduce the switching losses, and to reduce the switching losses, the need for high-speed switch components. However, the switching speed will be affected by the distribution of the charge stored in the inductance and capacitance, or diode circuit to produce a surge or noise. This will not only affect the surrounding electronic equipment, but also greatly reduce the reliability of the power supply itself. Which, in order to prevent the switching Kai - closed the voltage surge, RC or LC buffers can be used, and the current surge can be caused by the diode stored charge of amorphous and other core made of magnetic buffer . However, the high frequency more than 1MHz, the resonant circuit to make the switch on the voltage or current through the switch was a sine wave, which can reduce switching losses, but also to control the occurrence of surges. This switch is called the resonant switch. Of this switching power supply is active, you can, in theory, because in this way do not need to greatly improve the switching speed of the switching losses reduced to zero, and the noise is expected to become one of the high-frequency switching power supply The main ways. At present, many countries in the world are committed to several trillion Hz converter utility.the principle of IntroductionThe switching power supply of the process is quite easy to understand, linear power supplies, power transistors operating in the linear mode and linear power, the PWM switching power supply to the power transistor turns on and off state, in both states, on the power transistor V - security product is very small (conduction, low voltage, large current; shutdown, voltage, current) V oltammetric product / power device is power semiconductor devices on the loss.Compared with the linear power supply, the PWM switching power supply more efficient process is achieved by "chopping", that is cut into the amplitude of the input DC voltage equal to the input voltage amplitude of the pulse voltage. The pulse duty cycle is adjusted by the switching power supply controller. Once the input voltage is cut into the AC square wave, its amplitude through the transformer to raise or lower. Number of groups of output voltage can be increased by increasing the number of primary and secondary windings of the transformer. After the last AC waveform after the rectifier filter the DC output voltage.The main purpose of the controller is to maintain the stability of the output voltage, the course of their work is very similar to the linear form of the controller. That is the function blocks of the controller, the voltage reference and error amplifier can be designed the same as the linear regulator. Their difference lies in the error amplifier output (error voltage) in the drive before the power tube to go through a voltage / pulse-width conversion unit.Switching power supply There are two main ways of working: Forward transformand boost transformation. Although they are all part of the layout difference is small, but the course of their work vary greatly, have advantages in specific applications.the circuit schematicThe so-called switching power supply, as the name implies, is a door, a door power through a closed power to stop by, then what is the door, the switching power supply using SCR, some switch, these two component performance is similar, are relying on the base switch control pole (SCR), coupled with the pulse signal to complete the on and off, the pulse signal is half attentive to control the pole voltage increases, the switch or transistor conduction, the filter output voltage of 300V, 220V rectifier conduction, transmitted through the switching transformer secondary through the transformer to the voltage increase or decrease for each circuit work. Oscillation pulse of negative semi-attentive to the power regulator, base, or SCR control voltage lower than the original set voltage power regulator cut-off, 300V power is off, switch the transformer secondary no voltage, then each circuit The required operating voltage, depends on this secondary road rectifier filter capacitor discharge to maintain. Repeat the process until the next pulse cycle is a half weeks when the signal arrival. This switch transformer is called the high-frequency transformer, because the operating frequency is higher than the 50HZ low frequency. Then promote the pulse of the switch or SCR, which requires the oscillator circuit, we know, the transistor has a characteristic, is the base-emitter voltage is 0.65-0.7V is the zoom state, 0.7V These are the saturated hydraulic conductivity state-0.1V-0.3V in the oscillatory state, then the operating point after a good tune, to rely on the deep negative feedback to generate a negative pressure, so that the oscillating tube onset, the frequency of the oscillating tube capacitor charging and discharging of the length of time from the base to determine the oscillation frequency of the output pulse amplitude, and vice versa on the small, which determines the size of the output voltage of the power regulator. Transformer secondary output voltage regulator, usually switching transformer, single around a set of coils, the voltage at its upper end, as the reference voltage after the rectifier filter, then through the optocoupler, this benchmark voltage return to the base of the oscillating tube pole to adjust the level of the oscillation frequency, if the transformer secondary voltage is increased, the sampling coil output voltage increases, the positive feedback voltage obtained through the optocoupler is also increased, this voltage is applied oscillating tube base, so that oscillation frequency is reduced, played a stable secondary output voltage stability, too small do not have to go into detail, nor it is necessary to understand the fine, such a high-power voltage transformer by switching transmission, separated and after the class returned by sampling the voltage from the opto-coupler pass separated after class, so before the mains voltage, and after the classseparation, which is called cold plate, it is safe, transformers before power is independent, which is called switching power supply.the DC / DC conversionDC / DC converter is a fixed DC voltage transformation into a variable DC voltage, also known as the DC chopper. There are two ways of working chopper, one Ts constant pulse width modulation mode, change the ton (General), the second is the frequency modulation, the same ton to change the Ts, (easy to produce interference). Circuit by the following categories:Buck circuit - the step-down chopper, the average output voltage U0 is less than the input voltage Ui, the same polarity.Boost Circuit - step-up chopper, the average output voltage switching power supply schematic U0 is greater than the input voltage Ui, the same polarity.Buck-Boost circuit - buck or boost chopper, the output average voltage U0 is greater than or less than the input voltage Ui, the opposite polarity, the inductance transmission.Cuk circuit - a buck or boost chopper, the output average voltage U0 is greater than or less than the input voltage Ui, the opposite polarity, capacitance transmission.The above-mentioned non-isolated circuit, the isolation circuit forward circuits, feedback circuit, the half-bridge circuit, the full bridge circuit, push-pull circuit. Today's soft-switching technology makes a qualitative leap in the DC / DC the U.S. VICOR company design and manufacture a variety of ECI soft-switching DC / DC converter, the maximum output power 300W, 600W, 800W, etc., the corresponding power density (6.2 , 10,17) W/cm3 efficiency (80-90)%. A the Japanese Nemic Lambda latest using soft-switching technology, high frequency switching power supply module RM Series, its switching frequency (200 to 300) kHz, power density has reached 27W/cm3 with synchronous rectifier (MOSFETs instead of Schottky diodes ), so that the whole circuit efficiency by up to 90%.AC / DC conversionAC / DC conversion will transform AC to DC, the power flow can be bi-directional power flow by the power flow to load known as the "rectification", referred to as "active inverter power flow returned by the load power. AC / DC converter input 50/60Hz AC due must be rectified, filtered, so the volume is relatively large filter capacitor is essential, while experiencing safety standards (such as UL, CCEE, etc.) and EMC Directive restrictions (such as IEC, FCC, CSA) in the AC input side must be added to the EMC filter and use meets the safety standards of the components, thus limiting the miniaturization of the volume of AC / DC power, In addition, due to internal frequency, high voltage, current switching, making the problem difficult to solve EMC also high demands on the internal high-density mountingcircuit design, for the same reason, the high voltage, high current switch makes power supply loss increases, limiting the AC / DC converter modular process, and therefore must be used to power system optimal design method to make it work efficiency to reach a certain level of satisfaction.AC / DC conversion circuit wiring can be divided into half-wave circuit, full-wave circuit. Press the power phase can be divided into single-phase three-phase, multiphase. Can be divided into a quadrant, two quadrant, three quadrants, four-quadrant circuit work quadrant.he selection of the switching power supplySwitching power supply input on the anti-jamming performance, compared to its circuit structure characteristics (multi-level series), the input disturbances, such as surge voltage is difficult to pass on the stability of the output voltage of the technical indicators and linear power have greater advantages, the output voltage stability up to (0.5)%. Switching power supply module as an integrated power electronic devices should be selected。
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毕业设计英文篇一：毕业设计英文翻译使用高级分析法的钢框架创新设计1．导言在美国，钢结构设计方法包括允许应力设计法(ASD)，塑性设计法(PD)和荷载阻力系数设计法(LRFD)。
在允许应力设计中，应力计算基于一阶弹性分析，而几何非线性影响则隐含在细部设计方程中。
在塑性设计中，结构分析中使用的是一阶塑性铰分析。
塑性设计使整个结构体系的弹性力重新分配。
尽管几何非线性和逐步高产效应并不在塑性设计之中，但它们近似细部设计方程。
在荷载和阻力系数设计中，含放大系数的一阶弹性分析或单纯的二阶弹性分析被用于几何非线性分析，而梁柱的极限强度隐藏在互动设计方程。
所有三个设计方法需要独立进行检查，包括系数K计算。
在下面，对荷载抗力系数设计法的特点进行了简要介绍。
结构系统内的内力及稳定性和它的构件是相关的，但目前美国钢结构协会（AISC）的荷载抗力系数规范把这种分开来处理的。
在目前的实际应用中，结构体系和它构件的相互影响反映在有效长度这一因素上。
这一点在社会科学研究技术备忘录第五录摘录中有描述。
尽管结构最大内力和构件最大内力是相互依存的（但不一定共存），应当承认，严格考虑这种相互依存关系，很多结构是不实际的。
与此同时，众所周知当遇到复杂框架设计中试图在柱设计时自动弥补整个结构的不稳定（例如通过调整柱的有效长度）是很困难的。
因此，社会科学研究委员会建议在实际设计中，这两方面应单独考虑单独构件的稳定性和结构的基础及结构整体稳定性。
图28.1就是这种方法的间接分析和设计方法。
在目前的美国钢结构协会荷载抗力系数规范中，分析结构体系的方法是一阶弹性分析或二阶弹性分析。
在使用一阶弹性分析时，考虑到二阶效果，一阶力矩都是由B1,B2系数放大。
在规范中，所有细部都是从结构体系中独立出来，他们通过细部内力曲线和规范给出的那些隐含二阶效应，非弹性，残余应力和挠度的相互作用设计的。
理论解答和实验性数据的拟合曲线得到了柱曲线和梁曲线，同时Kanchanalai 发现的所谓“精确”塑性区解决方案的拟合曲线确定了梁柱相互作用方程。
为了证明单个细部内力对整个结构体系的影响，使用了有效长度系数，如图28.2所示。
有效长度方法为框架结构提供了一个良好的设计。
然而，有效长度方法的使用存在着一些困难，如下所述：1、有效长度的方法不能准确核算的结构系统及其细部之间的互相影响。
这是因为在一个大的结构体系中的相互作用太复杂不能简单地用有效长度系数K代表。
因此，这种方法不能准确地测算框架单元实际需要的强度。
2、有效长度的方法无法获取结构体系中内力非弹性再分配，因为带有B1、B2系数的一阶弹性分析只证明二阶影响，但不是非弹性内力再分配。
有效长度的方法只是保守的估计了最终承载大型结构体系的能力。
3、有效长度方法无法测算的结构体系受负荷载下的失效模式。
这是因为荷载抗力系数相互作用方程不提供在任何负载下结构体系的失效模式的信息。
4、有效长度的方法与计算机程序不兼容。
5、有效长度的方法在涉及系数K的单独构件能力检测时需要耗费比较长的时间。
随着电脑技术的发展，细部结构的稳定性和整体结构的稳定性这两个方面，可以通过结构的最大强度测定来被严格对待。
图28.1就是这种方法的间接分析和设计方法。
直接设计方法的发展被称为高级分析，或者更具体地说，二阶弹性分析框架设计。
用这种直接的方式，无须计算有效长度系数，因为不需要规范方程包含的单独构件能力检测。
凭借目前现有的计算技术，直接使用高级分析法技术框架设计是可行的。
这种方法过去在办公室设计使用时一直被认为是不切实际的。
本章的目的是提出一个切实可行的，直接的钢框架设计方法，使用高级分析法产生跟荷载抗力系数法的相同的结果。
利用高级设计分析的优点概述如下：1、高级分析法是结构工程师进行钢结构设计的另一个工具，它的通过不是强制性的，而是为设计人员提供灵活的选择。
2、高级分析法直接获取了整个结构体系和细部结构极限状态的强度和稳定性，这样就不需要规范方程包含的单独构件能力检测。
3、相比荷载阻力系数设计法和允许应力设计法，高级分析法通过直接弹性二阶分析提供了更多结构性能的信息。
4、高级分析法解决了常规荷载阻力系数设计法中由于不兼容弹性全球分析和单元极限状态设计的困难。
5、高级分析法与计算机程序兼容性良好，但荷载阻力系数设计法和允许应力设计法则无法与计算机程序兼容，因为它们在过程中都需要有对系数K的单独构件能力检测的计算。
6、高级分析法可以得到整个结构体系弹性内力再分配的结果，并且节约高度不确定的钢框架的材料。
7、过去在设计室使用高级分析法被认为不切实际，而现在则是可行的，因为个人电脑和工程工作站的能力正在迅速提高。
8、通过高级分析法测定的各项数据都接近了荷载抗力系数法测定的那些数据，因为高级分析法对荷载抗力系数法的柱曲线和梁柱的相互作用方程进行了校准。
因此，高级分析法替代了荷载抗力系数法。
9、高级分析法比较高效，因为它完全消除了经常引起混淆的冗长的单独构件能力检测，包括荷载阻力系数设计法和允许应力设计法中的系数K的计算。
在各种高级分析法中，包括塑性区准塑性铰法，弹性区塑性铰法，名义负荷塑性铰法和改进塑性铰法，推荐使用改进塑性铰法，因为它保留了计算的效率和简便性及实际应用的准确度。
这个方法是对简单的传统的弹塑性铰法的改进。
其中包括一个简单的修改，证明在塑性铰位置截面刚度的逐步退化和包括细部两个塑性铰之间的逐步刚度退化。
表28.1中对常规荷载抗力系数法和高级实用性分析方法的关键因素做了比较。
荷载抗力系数方法用来证明主要影响隐含在其柱强度和梁柱相互作用方程之中，而高级分析法通过稳定性的功能，刚度退化的功能和几何缺陷方面来证明那些影响，在28.2中有详细讨论。
高级分析法持有许多钢结构实际问题的答案，同样地，我们推荐寻找有效地合理地完成框架设计方法提供给工程师，但这要符合荷载抗力系数规范。
在下面的章节里，我们将提出符合荷载抗力系数钢框架结构设计的高级先进实用分析方法。
该方法的有效性将通过比较基于精确塑性区解决方案和荷载抗力系数设计分析及设计结果的细部和框架的实际案例研究。
大范围的案例研究和比较可以这种高级方法的有效性。
2．高级实用性分析本节介绍了一种消除规范单独构件能力检测的直接设计钢框架的高级实用性分析方法。
改进后的塑性铰法是由简单的传统的弹塑性铰法发展调整而来，实现了简单和真实的反映了实际情况。
下一节将提供了最终确认该方法的有效性的核查方法。
高级分析能够验证连接的灵活性。
常规分析和钢结构的设计通常在假设梁柱连接不是完全刚性或理想的固定下进行。
然而，在大部分实际的连接是半刚性的并且它们的状态介于这两个极端的例子之间。
在允许应力设计-荷载抗力系数规范，有两类特定的建筑：FR（完全受限）结构和PR（部分受限）结构。
荷载抗力系数规范允许通过“合理途径”连接灵活性评估。
瞬间旋转的关系代表了连接的状态，已经完成多方面的试点连接工作和收集大批的瞬时旋转数据。
有了这个数据库，研究人员已经开发了数个连接模型，包括线性，多项式，B 曲线，动力和指数。
鉴于此，Kishi和Chen提出的三参数幂函数模型被采用了。
在使用高级分析时，几何缺陷必须由框架单元加以塑造。
几何缺陷在构造或架设过程中导致不可避免的错误。
对于建筑结构的结构构件，几何缺陷的种类属于非线性和非垂直的。
明确建模和等效名义载荷被研究人员用来证明几何缺陷。
在这一章节中，发展了基于进一步减小构件切线刚度的新方法。
这种方法提供了一种简易的途径用来证明没有输入名义载荷或明确几何缺陷的不完善的影响。
本节中描述的高级实用性分析方法仅限于受静载的两维支撑，无支撑，和半刚架。
不考虑结构的空间状态，并且假定有足够的侧向支撑防止侧扭屈曲。
假设W节就是这样的节可以在无局部屈曲情况下发挥全塑性时刻能力。
强轴和弱轴弯曲宽凸缘部分的研究都采用高级实用性分析方法。
该方法可被视为介于现在广泛使用的篇二：毕业设计英文翻译附录中南大学本科生毕业论文（设计）英文译文及原件题目Overlay Networks and the Future of theInternet 学生姓名迪丽努尔.阿不来提指导教师杨淑平学院数学科学与计算技术学院专业班级信息与计算科学0504班完成时间 XX年6月覆盖网和互联网的未来摘要近年来，我们在互联网上看到多种类型的所谓的“覆盖”网络的出现。
这样的覆盖网络有许多不同的例子，其中包括容量分发缓存网络，被公司生效像Akamai公司一样，点对点文件共享网络与应用软件，如BitTorrent公司，IP 语音服务通过Skype和各种试验网络，如PlanetLab 。
这种覆盖具有重要的技术和政策影响下一代互联网架构的发展。
本文提供如此的互联网架构重叠，工业结构和政策的第一次尝试理解的影响。
我们介绍了一种分类的思考这些规模和日益重要的互联网的一些覆盖例子，并提出一些工业结构和政策的覆盖当中所产生的初步的观点。
关键词：网络结构，覆盖网络，互联网服务供应商，互联网的政策。
互联网最早是以政府资助的研究网络上运行的顶部的公共交换电信网（ PSTN ）而出现的。
互联网是一个数据的应用，主要是不受管制，这是支持顶部的公共电话网络实用规范。
互联网是一个“覆盖网”，是基本基础设施的补充，是增加新功能的PSTN网（分组交换数据网）来支持研究团体的特殊需要（点对点计算机通信）。
大部分的增量投资，路由器，服务器和接入设备（电脑）进行了新类型的供应商（互联网服务供应商或互联网服务供应商）和最终用户（用户端设备或设备），来补充已在坐标上的PSTN基础设施。
在20世纪80年代，随着互联网的商业化以及90年代为宽带通信以大众市场平台的形式出现，互联网已经发展成为我们全球公共通信基础设施的主要平台。
逐渐地，IP数据包运输为电话和其它多媒体应用软件（语音，视频和数据）提供了基本的运输媒介，。
什么是“重叠网”应用已成为基本的基础设施。
随着时间，传统的PSTN供应商在管理基础设施和投资需要来支持互联网当中起着更大的作用。
反常，市场的扩大以及改革带来了更为复合和相互依存的互联网基础设施生态系统。
互联网的成功在很大程度上归功于互联网的互操作性和连接，这些由IP协议和坚持“端到端”（e2e）的设计原则的普遍存在的采取来支持的，那些设计原则支配互联网架构很长时间了。
然而，互联网的成功也引进了重大的问题。
发展带来了异构服务（不是每个人都需要或希望相同的功能） ;新的需要和要求（支持实时业务或增强的安全性） ;复杂性和规模问题（起因于今天的交通时期和连接的互联网衡量的巨大重要性）。
为了迎接这些挑战，互联网需要继续发展。
在这个过程中，有时看起来就像历史重演一样，目前互联网在大量生产自己的“重叠网”网络的收集。
这里有多种有关覆盖的类型和实例（见表1 ），以满足一系列的目的和需求（见下文的讨论）。