当前位置:文档之家› 毕业设计(论文)外文资料翻译〔含原文〕

毕业设计(论文)外文资料翻译〔含原文〕

毕业设计(论文)外文资料翻译〔含原文〕
毕业设计(论文)外文资料翻译〔含原文〕

南京理工大学

毕业设计(论文)外文资料翻译

教学点:南京信息职业技术学院

专业:电子信息工程

姓名:陈洁

学号: 014910253034

外文出处:《 Pci System Architecture 》

(用外文写)

附件: 1.外文资料翻译译文;2.外文原文。

指导教师评语:

该生外文翻译没有基本的语法错误,用词准确,没

有重要误译,忠实原文;译文通顺,条理清楚,数量与

质量上达到了本科水平。

签名:

年月日

注:请将该封面与附件装订成册。

附件1:外文资料翻译译文

64位PCI扩展

1.64位数据传送和64位寻址:独立的能力

PCI规范给出了允许64位总线主设备与64位目标实现64位数据传送的机理。在传送的开始,如果回应目标是一个64位或32位设备,64位总线设备会自动识别。如果它是64位设备,达到8个字节(一个4字)可以在每个数据段中传送。假定是一串0等待状态数据段。在33MHz总线速率上可以每秒264兆字节获取(8字节/传送*33百万传送字/秒),在66MHz总线上可以528M字节/秒获取。如果回应目标是32位设备,总线主设备会自动识别并且在下部4位数据通道上(AD[31::00])引导,所以数据指向或来自目标。

规范也定义了64位存储器寻址功能。此功能只用于寻址驻留在4GB地址边界以上的存储器目标。32位和64位总线主设备都可以实现64位寻址。此外,对64位寻址反映的存储器目标(驻留在4GB地址边界上)可以看作32位或64位目标来实现。

注意64位寻址和64位数据传送功能是两种特性,各自独立并且严格区分开来是非常重要的。一个设备可以支持一种、另一种、都支持或都不支持。

2.64位扩展信号

为了支持64位数据传送功能,PCI总线另有39个引脚。

●REQ64#被64位总线主设备有效表明它想执行64位数据传送操作。REQ64#与FRAME#信号具有相同的时序和间隔。REQ64#信号必须由系统主板上的上拉电阻来支持。当32位总线主设备进行传送时,REQ64#不能又漂移。

●ACK64#被目标有效以回应被主设备有效的REQ64#(如果目标支持64位数据传送),ACK64#与DEVSEL#具有相同的时序和间隔(但是直到REQ64#被主设备有效,ACK64#才可被有效)。像REQ64#一样,ACK64#信号线也必须由系统主板上的上拉电阻来支持。当32位设备是传送目标时,ACK64#不能漂移。

●AD[64::32]包含上部4位地址/数据通道。

●C/BE#[7::4]包含高4位命令/字节使能信号。

●PAR64是为上部4个AD通道和上部4位C/BE信号线提供偶校验的奇偶校验位。

以下是几小结详细讨论64位数据传送和寻址功能。

3.在32位插入式连接器上的64位卡

安装在32位扩展槽上的64位卡只能自动地使用总线的下半部来执行传送,这是事实,因为系统主板的设计者将连接器上的REQ64#输出引脚和ACK64#输入引脚与系统主板上的上拉电阻分别连接而没有其它连接。

当64位总线主设备安装在32位插槽并开始交易时,对于任何目标REQ64#的有效是不可见的。此外,ACK64#输出总被采样无效(因为它在系统主板上被上拉),这就迫使总线主设备在传送时只能使能总线下部分。而且,如果交易中被寻址的目标是64位的,它会采样无效的REQ64#(因为它在系统主板上被上拉),这就迫使目标在传送时只能利用总线下部分,并且使ACK64#输出为不可用。

在自身卡上的64位扩展信号线在它们使用时不能有漂移。如果插卡上的COMS输入接收器出现振动和泄露过量的电流,这就违反了规范的“绿色”原则。当插卡安装在32位槽时,它不能使用总线的上半部。插卡检测插槽的类型的方法(在启动开始时采样REQ64#无效)下一节将描述。

4.当未使用时,上拉可防止64位扩展的漂移

在未使用时如果允许64位扩展信号(AD[63::32]、C/BE[7::4]和PAR64)漂移,那么插卡上的CMOS输入缓存器将振动并且泄漏过量电流。当不再使用时,为了防止扩展的漂移,要求系统主板设计者在扩展信号上加上拉电阻来防止漂移,因为这些上拉电阻可保证扩展位不漂移,嵌入在系统板上的64位设备和安装在64位PCI插入式连接器上的64位卡,当它们不使用扩展位位时,不需要采取任何特殊措施防止扩展槽漂移。

64位扩展在以下环境中不使用:

1.PCI总线空闲。

2.32位总线组设备正与一个32为目标进行交易。

3.32位总线主设备与一个64位目标进行交易,当在交易的起始检测到REQ64#无效时,目标不用总线的上半部。

4.64位总线主设备寻址一个目标已进行32位数据传送(REQ64#无效),并且目标驻留在低于4GB地址边界以下(在地址段和数据段不使用总线上半部)。不管目标是32位还是64位,在数据中不使用总线的上半部(因为REQ64#无效)。

5.一个64位总线主设备试图与驻留在4GB边界以下的32位存储器目标进行传送时(REQ64#无效)。在此情况下,主设备在地址段中只能使用总线的下半部分(因为它仅生成32位地址)。当它发现当前寻址的目标是32位目标时(当DEVSEL#无效时ACK64#不能有效),主设备在数据段中停止使用总线的下半部。

4.1 32位PCI 连接器上的64位插卡

64位卡允许安装在32位卡插卡连接器上。连接器的主要部分(32位)包括所有32位PCI信号,同时连接器的扩展包含64位信号(除了放置在连接器32位部分的REQ64#和ACK64#).

当64位设备安装在32位扩展槽上时,在AD[63::32]、C/BE[7::4]和PAR64上的系统主板上拉对插入式卡是不可用的。这就意味着连接到扩展信号号上的插入式输入缓存器将会漂移,震动和泄漏电流。

规范中强调插入卡设计者不能通过在插入卡的扩展线上提供上拉电阻来解决这个问题,当卡安装在64位扩展槽中用此方法会引起一些问题,在这些信号线上会需要2套上拉电阻(一套在插卡上,另一套在系统主板上)。如果所有设计者都用此方法,若共有多个64位插卡的设备装入连接器上时,将会由多个上拉电阻在扩展信号线上,这就会造成上拉电阻过载。

规范中对一个64位插卡给出了如何在起始时间确定是安装在了32位连接器上还是64位连接器上的方法。如果插卡检测出被插入了64位连接器上时,系统主板上的上拉电阻可在扩展信号不使用时防止卡上的输入接受不漂移;另一方面,如果64位插卡检测出被插入32位卡连接器上时,卡上的逻辑可防止输入接收器的漂移,规范中列举了近似于以下几种方法:

●将输入缓存器关闭。

●不断的驱动输出(因为它们没有连接任何器件)。

4.2 64位插卡如何确定所安装插槽的类型

当系统被加电时,复位信号会自动被有效。在此期间,系统主板上的逻辑必须有效REQ64#、还有RST#。REQ64#上面有一个上拉电阻与集成在系统主板上的所有64位设备和所有64位PCI扩展槽上的REQ64#引脚相连。规范指出了每个32位PCI扩展槽上的REQ64#信号线(REQ64#和ACK64#放置在连接器的32位部分),每一个都有自己独立的上拉电阻。

在复位期间,系统主板复位逻辑最初有效PCI RST#信号同时供电电源的POWERGOOD 信号被无效。在RST#有效过程中,系统主板逻辑有效REQ64#并保持有效直至它消除了RST#信号。在POWERGOOD被电源逻辑有效时,系统主板复位逻辑会无效PCI RST#信号。在RST#有效的尾部边沿,要求所有64位设备采样REQ64#信号的状态。

嵌入在系统主板或安装在64位扩展槽上的所有64位设备在RST#的尾沿采样REQ#

有效,这就要求它们镰刀系统主板上的扩展上拉电阻上并且当不使用它们时不需要采取特殊措施防止扩展信号漂移。

安装在32位插卡槽上的所有64位设备,在RST#的尾部边沿都可检测到无效的REQ64#,这就告知它们需要连接扩展信号上的系统主板的上拉电阻,插卡逻辑必须对本身的64位卡上的扩展信号线的状态负责。所以插卡必须使用前一节提过的方法之一,防止卡的输入接受器泄漏过量电流。

附件2:外文原文

The 64-bit PCI Extension

The 64-bit PCI Extension

This chapter describes the 64-bit extension that permits masters and targets to perform eight byte transfers during each data phase. It also describes 64-bit addressing used to address memory targets that reside above the 4GB boundary.

1.64-bit Ata Transfers and 64-bit Addressing: Seperate Capabilities

The PCI specification provides a mechanism that permits a 64-bit bus master to perform 64-bit data transfers with a 64-bit target. At the beginning of a transaction, the 64-bit bus maser automatically senses if the responding target is a 64-bit or a 32-bit device. If it’s a 64-bit device, up to eight bytes(a quadword) may be transferred during each data phase. Assuming a series of 0-wait state data phases, throughput of 264Mbytes/second can be achieved at a bus speed of 33MHz(8 bytes/transfer x 33 million transfers/second) and 528Mbytes/second at66MHz.If the responding target is a 32-bit device, the bus master automatically senses this and steers all data to or from the target over the lower four data paths(AD[31:0]).

The specification also defines 64-bit memory addressing capability. This capability is only used to address memory targets that reside above the 4GB address boundary. Both 32-and 64[bit bus masters can perform 64-bit addressing. In addition, memory target(that reside over the 4GB address boundary) that respond to 64-bit addressing can be implemented as either 32-or 64-bit targets.

2.64-Bit Extension Signals

In order to support the 64-bit data transfer capability, the PCI bus implements an additional thirty-nine pins:

●REQ64# is asserted by a 64-bit bus master to indicate that is would like to perform

64-bit data transfers.REQ64# has the same timing and duration a s the FRAME# signal.

The REQ64# signal line must be supplied with a pull up resistor on the system board.REQ64# cannot be permitted to float when a 32-bit bus master is performing a transaction.

●ACK64# is asserted by a target in response to REQ64# assertion by the master (if the

target supports 64-bit data transfers).ACK64# has the same timing and duration as DEVSEL#(but ACK64# must not be asserted unless REQ64# is asserted by the initiator).Like REQ64#,the AcK64# signal line must also be supplied with a pullup resistor on the system board.ACK64# cannot be permitted to float when a 32-bit device si the target of transaction.

●AD [63::32] comprise the upper four address/data paths.

●C/BE# [7::4] comprise the upper four command/byte enable signals.

●PAR64 is the parity bit that provides even parity for the upper four AD paths and the

upper four C/BE signal lines.

The following sections provide a detailed discussion of 64-bit data master and addressing capability.

3.64-bit Cards in 32-bit Add-in Connectors

A 64-bit card installed in a 32-bit expansion slot automatically only uses the lower half of the bus to perform transfers. This is true because the system board designer connects the

REQ64# output pin and the ACK64# input pin on the connector to individual pull-ups on the system board and to nothing else.

When a 64-bit bus master is installed in a 32-bit card slot and it initiates a transaction, its assertion of REQ64# is not visible to any of the target. In addition, its ACK64# input is always sampled deasserted (because it’s pulled up on the system board).This forces the bus master to use only the lower part of the bus during the transfer. Furthermore, if the target addressed in the transaction is a 64-bit target, it samples REQ74# deasserted (because it’s pulled up on the system board),forcing it to only utilize the lower half of the bus during the transaction and to disable its ACK64# output.

The 64-bit extension signal lines on the card itself cannot be permitted to float when they are not in use. The CMOS input receives on the card would oscillate and draw excessive current, thus violating the “green” aspect of the specification. hen the card is installed in a 32- bit slot, it cannot use the upper half of the bus. The manner in which the card detects the type of slot (REQ64# sampled deasserted at startup time) is described in the next section.

4.Pullups Prevent 64-bit Extension from Floating When Not in Use

If the 64-bit extension signals (AD[63::32],C/BE[7::4]# and PAR64 are permitted to float when not in use, the CMOS input buffers on the card will oscillate and draw excessive current. In order to prevent the extension signals to keep them from floating. Because these pull-ups are guaranteed to keep the extension from floating when not in use, 64-bit devices that are embedded on the system board and 64-bit cards installed in 64-bit PCI add-in connectors don’t need to take any special action to keep the extension from floating when they are not using it.

The 64-bit extension is not in use under the following circumstance:

1.The PCI bus is idle.

2. A 32-bit bus master is performing a transaction with a 32-bit target.

3. A 32-bit bus master is performing a transaction with a 64-bit target. Upon

detecting REQ64# deasserted at the start of the transaction, the target will not

use the upper half of the bus.

4. A 64-bit bus master addresses a target to perform 32-bit data transfers (REQ64#

deasserted) and the target resides below the 4GB boundary. In this case, the

initiator only uses the lower half of the bus during the address phase(because it’

s only generating a 32-bit address).When it discovers the currently-addressed

target is a 32-bit target(ACK64# not asserted when DEVSEL# asserted),the

initiator ceases to use the upper half at the bus during the data phases.

4.1. a 64-bit Card in a 32-bit PCI Connector

Installation of a 64-bit card in a 32-bit card connector is permitted. The main(32-bit) portion of the connector contains all of the 32-bit PCI signals, which an extension to the connector contains the 64-bit extension signal(with the exception of REQ64# and ACK64# which are located on the 32-bit portion of the connector).

When a 64-bit device is installed in a 32-bit PCI expansion slot, the system board pull-ups on AD[63::32],C/BE#[7::4] and PAR64 are not available to the add-in card. This means that the add-in card’s input buffers that are connected to the extension signal pins will float, oscillate, and draw excessive current.

The specification states that the add-in card designer must not solve the problem by supplying pullup resistors on the extension lines on the add-in card. Using this approach would cause problems when the card is installed in a 64-bit expansion slot. There would then be tow

sets of pullup resistor on these signal line (the ones on the card plus the ones on the system board).If all designer solved the problem in this manner, a machine with multiple 64-bit cards inserted in 64-bit card connectors would have multiple pull-ups on the extension signal, resulting in pullup current overload.

The specification provides a method for a 64-b9it card to determine at startup time whether it’s installed in a 32-bit or a 64-bit connector. If the card detects that it is plugged into a 64-bit connector, the pull-ups on the system board will keep the input receives on the card from floating when the extension is not in use. On the other hand, if a y64-bit card detects that it is a 32-bit card connector, the logic on the card must keep the input receives from switching. The specification states that an approach similar to one of the following should be use:

●Biasing the input buffer to turning it off.

●Actively driving the outputs continually (since they aren’t connected to anything).

4.2.How 64-bit Card Determines Type of Slot installed In

When the system is powered up, the reset signal is automatically asserted. During this period of time, the logic on the system board must assert the REQ64# signal as well as RST#.REQ64# has a single pullup resistor on it and is connected to the REQ64# pin on all 64-bit devices integrated onto the system board and on all 64-bit PCI expansion slot. The specification states that the REQ64# signal line on each 32-bit PCI expansion slot (REQ64# and ACK64# are located on the 32-bit portion of the connector), however, each has its own independent pullup resistor. During reset time, the system board reset logic initially asserts the PCI RST# signal while the POWERGOOD signal from the power supply is deasserted .During the assertion of RST# signal. When POWERGOOD is asserted by the power supply logic, the system board reset logic deasserts the PCI RST# signal. On the trailing-edge of RST# assertion, all 64-bit devices are required to sample the stated of the REQ64# signal.

All 64-bit devices that are embedded on the system board or that they are installed in 64-bit expansion slots sample REQ64# asserted on the trailing-edge of RST#. This informs them that they are connected to the extension pull-ups on the system board and need take no special action to keep the extension from floating when not using it.

All 64-bit devices that are installed in 32-bit card slot, however detect REQ64# desserted on the trailing-edge of RST#. This informs them that they are not connected to the system board resident pull-ups on the extension signal. The card logic must therefore take responsibility for the state of its own on-card 64-bit extension signal lines. The card must therefore use one of the methods cited in the previous section to prevent excessive current draw by the card’s input receivers.

本科毕业设计文献综述范例(1)

###大学 本科毕业设计(论文)文献综述 课题名称: 学院(系): 年级专业: 学生姓名: 指导教师: 完成日期:

燕山大学本科生毕业设计(论文) 一、课题国内外现状 中厚板轧机是用于轧制中厚度钢板的轧钢设备。在国民经济的各个部门中广泛的采用中板。它主要用于制造交通运输工具(如汽车、拖拉机、传播、铁路车辆及航空机械等)、钢机构件(如各种贮存容器、锅炉、桥梁及其他工业结构件)、焊管及一般机械制品等[1~3]。 1 世界中厚板轧机的发展概况 19世纪五十年代,美国用采用二辊可逆式轧机生产中板。轧机前后设置传动滚道,用机械化操作实现来回轧制,而且辊身长度已增加到2m以上,轧机是靠蒸汽机传动的。1864年美国创建了世界上第一套三辊劳特式中板轧机,当时盛行一时,推广于世界。1918年卢肯斯钢铁公司科茨维尔厂为了满足军舰用板的需求,建成了一套5230mm四辊式轧机,这是世界上第一套5m以上的轧机。1907年美国钢铁公司南厂为了轧边,首次创建了万能式厚板轧机,于1931年又建成了世界上第一套连续式中厚板轧机。欧洲国家中厚板生产也是较早的。1910年,捷克斯洛伐克投产了一套4500mm二辊式厚板轧机。1940年,德国建成了一套5000mm四辊式厚板轧机。1937年,英国投产了一套3810mm中厚板轧机。1939年,法国建成了一套4700mm 四辊式厚板轧机。这些轧机都是用于生产机器和兵器用的钢板,多数是为了二次世界大战备战的需要。1941年日本投产了一套5280mm四辊式厚板轧机,主要用于满足海军用板的需要。20世纪50年代,掌握了中厚板生产的计算机控制。20世纪80年代,由于中厚板的使用部门萧条,许多主要产钢国家的中厚板产量都有所下降,西欧国家、日本和美国关闭了一批中厚板轧机(宽度一般在3、4米以下)。国外除了大的厚板轧机以外,其他大型的轧机已很少再建。1984年底,法国东北方钢铁联营敦刻尔克厂在4300mm轧机后面增加一架5000mm宽厚板轧机,增加了产量,且扩大了品种。1984年底,苏联伊尔诺斯克厂新建了一套5000mm宽厚板轧机,年产量达100万t。1985年初,德国迪林冶金公司迪林根厂将4320mm轧机换成4800mm 轧机,并在前面增加一架特宽得5500mm轧机。1985年12月日本钢管公司福山厂新型制造了一套4700mmHCW型轧机,替换下原有得轧机,更有效地控制板形,以提高钢板的质量。 - 2 -

软件开发概念和设计方法大学毕业论文外文文献翻译及原文

毕业设计(论文)外文文献翻译 文献、资料中文题目:软件开发概念和设计方法文献、资料英文题目: 文献、资料来源: 文献、资料发表(出版)日期: 院(部): 专业: 班级: 姓名: 学号: 指导教师: 翻译日期: 2017.02.14

外文资料原文 Software Development Concepts and Design Methodologies During the 1960s, ma inframes and higher level programming languages were applied to man y problems including human resource s yste ms,reservation s yste ms, and manufacturing s yste ms. Computers and software were seen as the cure all for man y bu siness issues were some times applied blindly. S yste ms sometimes failed to solve the problem for which the y were designed for man y reasons including: ?Inability to sufficiently understand complex problems ?Not sufficiently taking into account end-u ser needs, the organizational environ ment, and performance tradeoffs ?Inability to accurately estimate development time and operational costs ?Lack of framework for consistent and regular customer communications At this time, the concept of structured programming, top-down design, stepwise refinement,and modularity e merged. Structured programming is still the most dominant approach to software engineering and is still evo lving. These failures led to the concept of "software engineering" based upon the idea that an engineering-like discipl ine could be applied to software design and develop ment. Software design is a process where the software designer applies techniques and principles to produce a conceptual model that de scribes and defines a solution to a problem. In the beginning, this des ign process has not been well structured and the model does not alwa ys accurately represent the problem of software development. However,design methodologies have been evolving to accommo date changes in technolog y coupled with our increased understanding of development processes. Whereas early desig n methods addressed specific aspects of the

毕业论文英文参考文献与译文

Inventory management Inventory Control On the so-called "inventory control", many people will interpret it as a "storage management", which is actually a big distortion. The traditional narrow view, mainly for warehouse inventory control of materials for inventory, data processing, storage, distribution, etc., through the implementation of anti-corrosion, temperature and humidity control means, to make the custody of the physical inventory to maintain optimum purposes. This is just a form of inventory control, or can be defined as the physical inventory control. How, then, from a broad perspective to understand inventory control? Inventory control should be related to the company's financial and operational objectives, in particular operating cash flow by optimizing the entire demand and supply chain management processes (DSCM), a reasonable set of ERP control strategy, and supported by appropriate information processing tools, tools to achieved in ensuring the timely delivery of the premise, as far as possible to reduce inventory levels, reducing inventory and obsolescence, the risk of devaluation. In this sense, the physical inventory control to achieve financial goals is just a means to control the entire inventory or just a necessary part; from the perspective of organizational functions, physical inventory control, warehouse management is mainly the responsibility of The broad inventory control is the demand and supply chain management, and the whole company's responsibility. Why until now many people's understanding of inventory control, limited physical inventory control? The following two reasons can not be ignored: First, our enterprises do not attach importance to inventory control. Especially those who benefit relatively good business, as long as there is money on the few people to consider the problem of inventory turnover. Inventory control is simply interpreted as warehouse management, unless the time to spend money, it may have been to see the inventory problem, and see the results are often very simple procurement to buy more, or did not do warehouse departments . Second, ERP misleading. Invoicing software is simple audacity to call it ERP, companies on their so-called ERP can reduce the number of inventory, inventory control, seems to rely on their small software can get. Even as SAP, BAAN ERP world, the field of

概率论毕业论文外文翻译

Statistical hypothesis testing Adriana Albu,Loredana Ungureanu Politehnica University Timisoara,adrianaa@aut.utt.ro Politehnica University Timisoara,loredanau@aut.utt.ro Abstract In this article,we present a Bayesian statistical hypothesis testing inspection, testing theory and the process Mentioned hypothesis testing in the real world and the importance of, and successful test of the Notes. Key words Bayesian hypothesis testing; Bayesian inference;Test of significance Introduction A statistical hypothesis test is a method of making decisions using data, whether from a controlled experiment or an observational study (not controlled). In statistics, a result is called statistically significant if it is unlikely to have occurred by chance alone, according to a pre-determined threshold probability, the significance level. The phrase "test of significance" was coined by Ronald Fisher: "Critical tests of this kind may be called tests of significance, and when such tests are available we may discover whether a second sample is or is not significantly different from the first."[1] Hypothesis testing is sometimes called confirmatory data analysis, in contrast to exploratory data analysis. In frequency probability,these decisions are almost always made using null-hypothesis tests. These are tests that answer the question Assuming that the null hypothesis is true, what is the probability of observing a value for the test statistic that is at [] least as extreme as the value that was actually observed?) 2 More formally, they represent answers to the question, posed before undertaking an experiment,of what outcomes of the experiment would lead to rejection of the null hypothesis for a pre-specified probability of an incorrect rejection. One use of hypothesis testing is deciding whether experimental results contain enough information to cast doubt on conventional wisdom. Statistical hypothesis testing is a key technique of frequentist statistical inference. The Bayesian approach to hypothesis testing is to base rejection of the hypothesis on the posterior probability.[3][4]Other approaches to reaching a decision based on data are available via decision theory and optimal decisions. The critical region of a hypothesis test is the set of all outcomes which cause the null hypothesis to be rejected in favor of the alternative hypothesis. The critical region is usually denoted by the letter C. One-sample tests are appropriate when a sample is being compared to the population from a hypothesis. The population characteristics are known from theory or are calculated from the population.

毕业设计外文翻译资料

外文出处: 《Exploiting Software How to Break Code》By Greg Hoglund, Gary McGraw Publisher : Addison Wesley Pub Date : February 17, 2004 ISBN : 0-201-78695-8 译文标题: JDBC接口技术 译文: JDBC是一种可用于执行SQL语句的JavaAPI(ApplicationProgrammingInterface应用程序设计接口)。它由一些Java语言编写的类和界面组成。JDBC为数据库应用开发人员、数据库前台工具开发人员提供了一种标准的应用程序设计接口,使开发人员可以用纯Java语言编写完整的数据库应用程序。 一、ODBC到JDBC的发展历程 说到JDBC,很容易让人联想到另一个十分熟悉的字眼“ODBC”。它们之间有没有联系呢?如果有,那么它们之间又是怎样的关系呢? ODBC是OpenDatabaseConnectivity的英文简写。它是一种用来在相关或不相关的数据库管理系统(DBMS)中存取数据的,用C语言实现的,标准应用程序数据接口。通过ODBCAPI,应用程序可以存取保存在多种不同数据库管理系统(DBMS)中的数据,而不论每个DBMS使用了何种数据存储格式和编程接口。 1.ODBC的结构模型 ODBC的结构包括四个主要部分:应用程序接口、驱动器管理器、数据库驱动器和数据源。应用程序接口:屏蔽不同的ODBC数据库驱动器之间函数调用的差别,为用户提供统一的SQL编程接口。 驱动器管理器:为应用程序装载数据库驱动器。 数据库驱动器:实现ODBC的函数调用,提供对特定数据源的SQL请求。如果需要,数据库驱动器将修改应用程序的请求,使得请求符合相关的DBMS所支持的文法。 数据源:由用户想要存取的数据以及与它相关的操作系统、DBMS和用于访问DBMS的网络平台组成。 虽然ODBC驱动器管理器的主要目的是加载数据库驱动器,以便ODBC函数调用,但是数据库驱动器本身也执行ODBC函数调用,并与数据库相互配合。因此当应用系统发出调用与数据源进行连接时,数据库驱动器能管理通信协议。当建立起与数据源的连接时,数据库驱动器便能处理应用系统向DBMS发出的请求,对分析或发自数据源的设计进行必要的翻译,并将结果返回给应用系统。 2.JDBC的诞生 自从Java语言于1995年5月正式公布以来,Java风靡全球。出现大量的用java语言编写的程序,其中也包括数据库应用程序。由于没有一个Java语言的API,编程人员不得不在Java程序中加入C语言的ODBC函数调用。这就使很多Java的优秀特性无法充分发挥,比如平台无关性、面向对象特性等。随着越来越多的编程人员对Java语言的日益喜爱,越来越多的公司在Java程序开发上投入的精力日益增加,对java语言接口的访问数据库的API 的要求越来越强烈。也由于ODBC的有其不足之处,比如它并不容易使用,没有面向对象的特性等等,SUN公司决定开发一Java语言为接口的数据库应用程序开发接口。在JDK1.x 版本中,JDBC只是一个可选部件,到了JDK1.1公布时,SQL类包(也就是JDBCAPI)

毕业设计文献综述范文

四川理工学院毕业设计(文献综述)红外遥控电动玩具车的设计 学生:程非 学号:10021020402 专业:电子信息工程 班级:2010.4 指导教师:王秀碧 四川理工学院自动化与电子信息学院 二○一四年三月

1前言 1.1 研究方向 随着科技的发展,越来越多的现代化电器走进了普通老百姓的家庭,而这些家用电器大都由红外遥控器操控,过多不同遥控器的混合使用带来了诸多不便。因此,设计一种智能化的学习型遥控器,学习各种家用电器的遥控编码,实现用一个遥控器控制所有家电,已成为迫切需求。首先对红外遥控接收及发射原理进行分析,通过对红外编码理论的学习,设计以MSP430单片机为核心的智能遥控器。其各个模块设计如下:红外遥控信号接收,红外接收器把接收到的红外信号经光电二极管转化成电信号,再对电信号进行解调,恢复为带有一定功能指令码的脉冲编码;接着是红外编码学习,利用单片机的输入捕捉功能捕捉载波的跳变沿,并通过定时器计时记下载波的周期和红外信号的波形特征,进行实时编码;存储电路设计,采用I2C总线的串行E2PROM(24C256)作为片外存储器,其存储容量为8192个字节,能够满足所需要的存取需求;最后是红外发射电路的设计,当从存储模块中获取某红外编码指令后,提取红外信号的波形特征信息并进行波形还原;将其调制到38KHZ的载波信号上,通过三极管放大电路驱动红外发光二极管发射红外信号,达到红外控制的目的。目前,国外进口的万能遥控器价格比较昂贵,还不能真正走进普通老百姓的家中。本文在总结和分析国外设计的基础上,设计一款以MSP430单片机为核心的智能型遥控器,通过对电视机和空调的遥控编码进行学习,能够达到预期的目的,具有一定的现实意义。 1.2 发展历史 红外遥控由来已久,但是进入90年代,这一技术又有新的发张,应用范围更加广泛。红外遥控是一种无线、非接触控制技术,具有抗干扰能力强,信息传输可靠,功耗低,成本低,易实现等显著优点,被诸多电子设备特别是家用电器广泛采用,并越来越多的应用到计算机系统中。 60年代初,一些发达国家开始研究民用产品的遥控技术,单由于受当时技术条件限制,遥控技术发展很缓慢,70年代末,随着大规模集成电路和计算机技术的发展,遥控技术得到快速发展。在遥控方式上大体经理了从有线到无限的超声波,从振动子到红外线,再到使用总线的微机红外遥控这样几个阶段。无论采用何种方式,准确无误传输新信号,最终达到满意的控制效果是非常重要的。最初的无线遥控装置采用的是电磁波传输信号,由于电磁波容易产生干扰,也易受干扰,因此逐渐采用超声波和红外线媒介来传输信号。与红外线相比,超声传感器频带窄,所能携带的信息量少扰而引起误动作。较为理想的是光控方式,逐渐采用红外线的遥控方式取代了超声波遥控方式,出现了红外线多功能遥控器,成为当今时代的主流。 1.3 当前现状 红外线在频谱上居于可见光之外,所以抗干扰性强,具有光波的直线传播特性,不易产生相互间的干扰,是很好的信息传输媒体。信息可以直接对红外光进行调制传输,例如,信息直接调制红外光的强弱进行传输,也可以用红外线产生一定频率的载波,再用信息对载波进调制,接收端再去掉载波,取到信息。从信

毕业设计外文翻译附原文

外文翻译 专业机械设计制造及其自动化学生姓名刘链柱 班级机制111 学号1110101102 指导教师葛友华

外文资料名称: Design and performance evaluation of vacuum cleaners using cyclone technology 外文资料出处:Korean J. Chem. Eng., 23(6), (用外文写) 925-930 (2006) 附件: 1.外文资料翻译译文 2.外文原文

应用旋风技术真空吸尘器的设计和性能介绍 吉尔泰金,洪城铱昌,宰瑾李, 刘链柱译 摘要:旋风型分离器技术用于真空吸尘器 - 轴向进流旋风和切向进气道流旋风有效地收集粉尘和降低压力降已被实验研究。优化设计等因素作为集尘效率,压降,并切成尺寸被粒度对应于分级收集的50%的效率进行了研究。颗粒切成大小降低入口面积,体直径,减小涡取景器直径的旋风。切向入口的双流量气旋具有良好的性能考虑的350毫米汞柱的低压降和为1.5μm的质量中位直径在1米3的流量的截止尺寸。一使用切向入口的双流量旋风吸尘器示出了势是一种有效的方法,用于收集在家庭中产生的粉尘。 摘要及关键词:吸尘器; 粉尘; 旋风分离器 引言 我们这个时代的很大一部分都花在了房子,工作场所,或其他建筑,因此,室内空间应该是既舒适情绪和卫生。但室内空气中含有超过室外空气因气密性的二次污染物,毒物,食品气味。这是通过使用产生在建筑中的新材料和设备。真空吸尘器为代表的家电去除有害物质从地板到地毯所用的商用真空吸尘器房子由纸过滤,预过滤器和排气过滤器通过洁净的空气排放到大气中。虽然真空吸尘器是方便在使用中,吸入压力下降说唱空转成比例地清洗的时间,以及纸过滤器也应定期更换,由于压力下降,气味和细菌通过纸过滤器内的残留粉尘。 图1示出了大气气溶胶的粒度分布通常是双峰形,在粗颗粒(>2.0微米)模式为主要的外部来源,如风吹尘,海盐喷雾,火山,从工厂直接排放和车辆废气排放,以及那些在细颗粒模式包括燃烧或光化学反应。表1显示模式,典型的大气航空的直径和质量浓度溶胶被许多研究者测量。精细模式在0.18?0.36 在5.7到25微米尺寸范围微米尺寸范围。质量浓度为2?205微克,可直接在大气气溶胶和 3.85至36.3μg/m3柴油气溶胶。

毕业设计外文资料翻译译文

附件1:外文资料翻译译文 包装对食品发展的影响 一个消费者对某个产品的第一印象来说包装是至关重要的,包括沟通的可取性,可接受性,健康饮食形象等。食品能够提供广泛的产品和包装组合,传达自己加工的形象感知给消费者,例如新鲜包装/准备,冷藏,冷冻,超高温无菌,消毒(灭菌),烘干产品。 食物的最重要的质量属性之一,是它的味道,其影响人类的感官知觉,即味觉和嗅觉。味道可以很大程度作退化的处理和/或扩展存储。其他质量属性,也可能受到影响,包括颜色,质地和营养成分。食品质量不仅取决于原材料,添加剂,加工和包装的方法,而且其预期的货架寿命(保质期)过程中遇到的分布和储存条件的质量。越来越多的竞争当中,食品生产商,零售商和供应商;和质量审核供应商有显着提高食品质量以及急剧增加包装食品的选择。这些改进也得益于严格的冷藏链中的温度控制和越来越挑剔的消费者。 保质期的一个定义是:在食品加工和包装组合下,在食品的容器和条件,在销售点分布在特定系统的时间能保持令人满意的食味品质。保质期,可以用来作为一个新鲜的概念,促进营销的工具。延期或保质期长的产品,还提供产品的使用时间,方便以及减少浪费食物的风险,消费者和/或零售商。包装产品的质量和保质期的主题是在第3章中详细讨论。 包装为消费者提供有关产品的重要信息,在许多情况下,使用的包装和/或产品,包括事实信息如重量,体积,配料,制造商的细节,营养价值,烹饪和开放的指示,除了法律准则的最小尺寸的文字和数字,有定义的各类产品。消费者寻求更详细的产品信息,同时,许多标签已经成为多语种。标签的可读性是为视障人士的问题,这很可能成为一个对越来越多的老年人口越来越重要的问题。 食物的选择和包装创新的一个主要驱动力是为了方便消费者的需求。这里有许多方便的现代包装所提供的属性,这些措施包括易于接入和开放,处置和处理,产品的知名度,再密封性能,微波加热性,延长保质期等。在英国和其他发达经济体显示出生率下降和快速增长的一个相对富裕的老人人口趋势,伴随着更加苛

毕业论文外文翻译模版

吉林化工学院理学院 毕业论文外文翻译English Title(Times New Roman ,三号) 学生学号:08810219 学生姓名:袁庚文 专业班级:信息与计算科学0802 指导教师:赵瑛 职称副教授 起止日期:2012.2.27~2012.3.14 吉林化工学院 Jilin Institute of Chemical Technology

1 外文翻译的基本内容 应选择与本课题密切相关的外文文献(学术期刊网上的),译成中文,与原文装订在一起并独立成册。在毕业答辩前,同论文一起上交。译文字数不应少于3000个汉字。 2 书写规范 2.1 外文翻译的正文格式 正文版心设置为:上边距:3.5厘米,下边距:2.5厘米,左边距:3.5厘米,右边距:2厘米,页眉:2.5厘米,页脚:2厘米。 中文部分正文选用模板中的样式所定义的“正文”,每段落首行缩进2字;或者手动设置成每段落首行缩进2字,字体:宋体,字号:小四,行距:多倍行距1.3,间距:前段、后段均为0行。 这部分工作模板中已经自动设置为缺省值。 2.2标题格式 特别注意:各级标题的具体形式可参照外文原文确定。 1.第一级标题(如:第1章绪论)选用模板中的样式所定义的“标题1”,居左;或者手动设置成字体:黑体,居左,字号:三号,1.5倍行距,段后11磅,段前为11磅。 2.第二级标题(如:1.2 摘要与关键词)选用模板中的样式所定义的“标题2”,居左;或者手动设置成字体:黑体,居左,字号:四号,1.5倍行距,段后为0,段前0.5行。 3.第三级标题(如:1.2.1 摘要)选用模板中的样式所定义的“标题3”,居左;或者手动设置成字体:黑体,居左,字号:小四,1.5倍行距,段后为0,段前0.5行。 标题和后面文字之间空一格(半角)。 3 图表及公式等的格式说明 图表、公式、参考文献等的格式详见《吉林化工学院本科学生毕业设计说明书(论文)撰写规范及标准模版》中相关的说明。

毕业设计外文翻译原文.

Optimum blank design of an automobile sub-frame Jong-Yop Kim a ,Naksoo Kim a,*,Man-Sung Huh b a Department of Mechanical Engineering,Sogang University,Shinsu-dong 1,Mapo-ku,Seoul 121-742,South Korea b Hwa-shin Corporation,Young-chun,Kyung-buk,770-140,South Korea Received 17July 1998 Abstract A roll-back method is proposed to predict the optimum initial blank shape in the sheet metal forming process.The method takes the difference between the ?nal deformed shape and the target contour shape into account.Based on the method,a computer program composed of a blank design module,an FE-analysis program and a mesh generation module is developed.The roll-back method is applied to the drawing of a square cup with the ˉange of uniform size around its periphery,to con?rm its validity.Good agreement is recognized between the numerical results and the published results for initial blank shape and thickness strain distribution.The optimum blank shapes for two parts of an automobile sub-frame are designed.Both the thickness distribution and the level of punch load are improved with the designed blank.Also,the method is applied to design the weld line in a tailor-welded blank.It is concluded that the roll-back method is an effective and convenient method for an optimum blank shape design.#2000Elsevier Science S.A.All rights reserved. Keywords:Blank design;Sheet metal forming;Finite element method;Roll-back method

毕业设计(论文)外文资料翻译〔含原文〕

南京理工大学 毕业设计(论文)外文资料翻译 教学点:南京信息职业技术学院 专业:电子信息工程 姓名:陈洁 学号: 014910253034 外文出处:《 Pci System Architecture 》 (用外文写) 附件: 1.外文资料翻译译文;2.外文原文。 指导教师评语: 该生外文翻译没有基本的语法错误,用词准确,没 有重要误译,忠实原文;译文通顺,条理清楚,数量与 质量上达到了本科水平。 签名: 年月日 注:请将该封面与附件装订成册。

附件1:外文资料翻译译文 64位PCI扩展 1.64位数据传送和64位寻址:独立的能力 PCI规范给出了允许64位总线主设备与64位目标实现64位数据传送的机理。在传送的开始,如果回应目标是一个64位或32位设备,64位总线设备会自动识别。如果它是64位设备,达到8个字节(一个4字)可以在每个数据段中传送。假定是一串0等待状态数据段。在33MHz总线速率上可以每秒264兆字节获取(8字节/传送*33百万传送字/秒),在66MHz总线上可以528M字节/秒获取。如果回应目标是32位设备,总线主设备会自动识别并且在下部4位数据通道上(AD[31::00])引导,所以数据指向或来自目标。 规范也定义了64位存储器寻址功能。此功能只用于寻址驻留在4GB地址边界以上的存储器目标。32位和64位总线主设备都可以实现64位寻址。此外,对64位寻址反映的存储器目标(驻留在4GB地址边界上)可以看作32位或64位目标来实现。 注意64位寻址和64位数据传送功能是两种特性,各自独立并且严格区分开来是非常重要的。一个设备可以支持一种、另一种、都支持或都不支持。 2.64位扩展信号 为了支持64位数据传送功能,PCI总线另有39个引脚。 ●REQ64#被64位总线主设备有效表明它想执行64位数据传送操作。REQ64#与FRAME#信号具有相同的时序和间隔。REQ64#信号必须由系统主板上的上拉电阻来支持。当32位总线主设备进行传送时,REQ64#不能又漂移。 ●ACK64#被目标有效以回应被主设备有效的REQ64#(如果目标支持64位数据传送),ACK64#与DEVSEL#具有相同的时序和间隔(但是直到REQ64#被主设备有效,ACK64#才可被有效)。像REQ64#一样,ACK64#信号线也必须由系统主板上的上拉电阻来支持。当32位设备是传送目标时,ACK64#不能漂移。 ●AD[64::32]包含上部4位地址/数据通道。 ●C/BE#[7::4]包含高4位命令/字节使能信号。 ●PAR64是为上部4个AD通道和上部4位C/BE信号线提供偶校验的奇偶校验位。 以下是几小结详细讨论64位数据传送和寻址功能。 3.在32位插入式连接器上的64位卡

毕业论文 外文翻译#(精选.)

毕业论文(设计)外文翻译 题目:中国上市公司偏好股权融资:非制度性因素 系部名称:经济管理系专业班级:会计082班 学生姓名:任民学号: 200880444228 指导教师:冯银波教师职称:讲师 年月日

译文: 中国上市公司偏好股权融资:非制度性因素 国际商业管理杂志 2009.10 摘要:本文把重点集中于中国上市公司的融资活动,运用西方融资理论,从非制度性因素方面,如融资成本、企业资产类型和质量、盈利能力、行业因素、股权结构因素、财务管理水平和社会文化,分析了中国上市公司倾向于股权融资的原因,并得出结论,股权融资偏好是上市公司根据中国融资环境的一种合理的选择。最后,针对公司的股权融资偏好提出了一些简明的建议。 关键词:股权融资,非制度性因素,融资成本 一、前言 中国上市公司偏好于股权融资,根据中国证券报的数据显示,1997年上市公司在资本市场的融资金额为95.87亿美元,其中股票融资的比例是72.5%,,在1998年和1999年比例分别为72.6%和72.3%,另一方面,债券融资的比例分别是17.8%,24.9%和25.1%。在这三年,股票融资的比例,在比中国发达的资本市场中却在下跌。以美国为例,当美国企业需要的资金在资本市场上,于股权融资相比他们宁愿选择债券融资。统计数据显示,从1970年到1985年,美日企业债券融资占了境外融资的91.7%,比股权融资高很多。阎达五等发现,大约中国3/4的上市公司偏好于股权融资。许多研究的学者认为,上市公司按以下顺序进行外部融资:第一个是股票基金,第二个是可转换债券,三是短期债务,最后一个是长期负债。许多研究人员通常分析我国上市公司偏好股权是由于我们国家的经济改革所带来的制度性因素。他们认为,上市公司的融资活动违背了西方古典融资理论只是因为那些制度性原因。例如,优序融资理论认为,当企业需要资金时,他们首先应该转向内部资金(折旧和留存收益),然后再进行债权融资,最后的选择是股票融资。在这篇文章中,笔者认为,这是因为具体的金融环境激活了企业的这种偏好,并结合了非制度性因素和西方金融理论,尝试解释股权融资偏好的原因。

毕业设计外文翻译

毕业设计(论文) 外文翻译 题目西安市水源工程中的 水电站设计 专业水利水电工程 班级 学生 指导教师 2016年

研究钢弧形闸门的动态稳定性 牛志国 河海大学水利水电工程学院,中国南京,邮编210098 nzg_197901@https://www.doczj.com/doc/1413801482.html,,niuzhiguo@https://www.doczj.com/doc/1413801482.html, 李同春 河海大学水利水电工程学院,中国南京,邮编210098 ltchhu@https://www.doczj.com/doc/1413801482.html, 摘要 由于钢弧形闸门的结构特征和弹力,调查对参数共振的弧形闸门的臂一直是研究领域的热点话题弧形弧形闸门的动力稳定性。在这个论文中,简化空间框架作为分析模型,根据弹性体薄壁结构的扰动方程和梁单元模型和薄壁结构的梁单元模型,动态不稳定区域的弧形闸门可以通过有限元的方法,应用有限元的方法计算动态不稳定性的主要区域的弧形弧形闸门工作。此外,结合物理和数值模型,对识别新方法的参数共振钢弧形闸门提出了调查,本文不仅是重要的改进弧形闸门的参数振动的计算方法,但也为进一步研究弧形弧形闸门结构的动态稳定性打下了坚实的基础。 简介 低举升力,没有门槽,好流型,和操作方便等优点,使钢弧形闸门已经广泛应用于水工建筑物。弧形闸门的结构特点是液压完全作用于弧形闸门,通过门叶和主大梁,所以弧形闸门臂是主要的组件确保弧形闸门安全操作。如果周期性轴向载荷作用于手臂,手臂的不稳定是在一定条件下可能发生。调查指出:在弧形闸门的20次事故中,除了极特殊的破坏情况下,弧形闸门的破坏的原因是弧形闸门臂的不稳定;此外,明显的动态作用下发生破坏。例如:张山闸,位于中国的江苏省,包括36个弧形闸门。当一个弧形闸门打开放水时,门被破坏了,而其他弧形闸门则关闭,受到静态静水压力仍然是一样的,很明显,一个动态的加载是造成的弧形闸门破坏一个主要因素。因此弧形闸门臂的动态不稳定是造成弧形闸门(特别是低水头的弧形闸门)破坏的主要原是毫无疑问。

毕业设计外文翻译原文

编号: 毕业设计(论文)外文翻译 (原文) 院(系):应用科技学院 专业:机械设计制造及其自动化 学生姓名:邓瑜 学号:0501120501 指导教师单位:应用科技学院 姓名:黄小能 职称: 2009年 5 月20 日

The Injection Molding The Introduction of Molds The mold is at the core of a plastic manufacturing process because its cavity gives a part its shape. This makes the mold at least as critical-and many cases more so-for the quality of the end product as, for example, the plasticiting unit or other components of the processing equipment. Mold Material Depending on the processing parameters for the various processing methods as well as the length of the production run, the number of finished products to be produced, molds for plastics processing must satisfy a great variety of requirements. It is therefore not surprising that molds can be made from a very broad spectrum of materials, including-from a technical standpoint-such exotic materials as paper matched and plaster. However, because most processes require high pressures, often combined with high temperatures, metals still represent by far the most important material group, with steel being the predominant metal. It is interesting in this regard that, in many cases, the selection of the mold material is not only a question of material properties and an optimum price-to-performance ratio but also that the methods used to produce the mold, and thus the entire design, can be influenced. A typical example can be seen in the choice between cast metal molds, with their very different cooling systems, compared to machined molds. In addition, the production technique can also have an effect; for instance, it is often reported that, for the sake of simplicity, a prototype mold is frequently machined from solid stock with the aid of the latest technology such as computer-aided (CAD) and computer-integrated manufacturing (CIM). In contrast to the previously used methods based on the use of patterns, the use of CAD and CAM often represents the more economical solution today, not only because this production capability is available pin-house but also because with any other technique an order would have to be placed with an outside supplier. Overall, although high-grade materials are often used, as a rule standard materials are used in mold making. New, state-of-the art (high-performance) materials, such as ceramics, for instance, are almost completely absent. This may be related to the fact that their desirable characteristics, such as constant properties up to very high temperatures, are not required on molds, whereas their negative characteristics, e. g. low tensile strength and poor thermal conductivity, have a clearly related to ceramics, such as sintered material, is found in mild making only to a limited degree. This refers less to the modern materials and components

相关主题
文本预览
相关文档 最新文档