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本科毕业设计外文翻译(原文)

本科毕业设计外文翻译(原文)
本科毕业设计外文翻译(原文)

Real-time interactive optical micromanipulation of a mixture of high- and low-index particles

Peter John Rodrigo, Vincent Ricardo Daria and Jesper Glückstad Optics and Plasma Research Department, Ris? National Laboratory, DK-4000 Roskilde, Denmark

jesper.gluckstad@risoe.dk

http://www.risoe.dk/ofd/competence/ppo.htm

Abstract: We demonstrate real-time interactive optical micromanipulation

of a colloidal mixture consisting of particles with both lower (n L < n0) and

higher (n H > n0) refractive indices than that of the suspending medium (n0).

Spherical high- and low-index particles are trapped in the transverse plane

by an array of confining optical potentials created by trapping beams with

top-hat and annular cross-sectional intensity profiles, respectively. The

applied method offers extensive reconfigurability in the spatial distribution

and individual geometry of the optical traps. We experimentally

demonstrate this unique feature by simultaneously trapping and

independently manipulating various sizes of spherical soda lime micro-

shells (n L≈ 1.2) and polystyrene micro-beads (n H = 1.57) suspended in

water (n0 = 1.33).

?2004 Optical Society of America

OCIS codes: (140.7010) Trapping, (170.4520) Optical confinement and manipulation and

(230.6120) Spatial Light Modulators.

References and links

1. A. Ashkin, “Optical trapping and manipulation of neutral particles using lasers,” Proc. Natl. Acad. Sci. USA

94, 4853-4860 (1997).

2. K. Svoboda and S. M. Block, “Biological applications of optical forces,” Annu. Rev. Biophys. Biomol. Struct.

23, 247-285 (1994).

3. D. G. Grier, “A revolution in optical manipulation,” Nature 424, 810-816 (2003).

4. M. P. MacDonald, G. C. Spalding and K. Dholakia, “Microfluidic sorting in an optical lattice,” Nature 426,

421-424 (2003).

5. J. Glückstad, “Microfluidics: Sorting particles with light,” Nature Materials 3, 9-10 (2004).

6. A. Ashkin, “Acceleration and trapping of particles by radiation-pressure,”Phys. Rev. Lett. 24, 156-159 (1970).

7. A. Ashkin, J. M. Dziedzic, J. E. Bjorkholm and S. Chu, “Observation of a single-beam gradient force optical

trap for dielectric particles,” Opt. Lett. 11, 288-290 (1986).

8. K. Sasaki, M. Koshioka, H. Misawa, N. Kitamura, and H. Masuhara, “Optical trapping of a metal particle and a

water droplet by a scanning laser beam,” Appl. Phys. Lett. 60, 807-809 (1992).

9. K. T. Gahagan and G. A. Swartzlander, “Trapping of low-index microparticles in an optical vortex,” J. Opt.

Soc. Am. B 15, 524-533 (1998).

10. K. T. Gahagan and G. A. Swartzlander, “Simultaneous trapping of low-index and high-index microparticles

observed with an optical-vortex trap,” J. Opt. Soc. Am. B 16, 533 (1999).

11. M. P. MacDonald, L. Paterson, W. Sibbett, K. Dholakia, P. Bryant, “Trapping and manipulation of low-index

particles in a two-dimensional interferometric optical trap,” Opt. Lett. 26, 863-865 (2001).

12. R. L. Eriksen, V. R. Daria and J. Glückstad, “Fully dynamic multiple-beam optical tweezers,” Opt. Express 10,

597-602 (2002), https://www.sodocs.net/doc/522493730.html,/abstract.cfm?URI=OPEX-10-14-597.

13. P. J. Rodrigo, R. L. Eriksen, V. R. Daria and J. Glückstad, “Interactive light-driven and parallel manipulation

of inhomogeneous particles,” Opt. Express 10, 1550-1556 (2002),

https://www.sodocs.net/doc/522493730.html,/abstract.cfm?URI=OPEX-10-26-1550.

14. V. Daria, P. J. Rodrigo and J. Glückstad, “Dynamic array of dark optical traps,” Appl. Phys. Lett. 84, 323-325

(2004).

15. J. Glückstad and P. C. Mogensen, “Optimal phase contrast in common-path interferometry,” Appl. Opt. 40,

268-282 (2001).

16. S. Maruo, K. Ikuta and H. Korogi, “Submicron manipulation tools driven by light in a liquid,” Appl. Phys.

Lett. 82, 133-135 (2003).

#3781 - $15.00 US Received 4 February 2004; revised 29 March 2004; accepted 29 March 2004 (C) 2004 OSA 5 April 2004 / Vol. 12, No. 7 / OPTICS EXPRESS 1417

1. Introduction

Light carries both linear and angular momenta. Momentum transfer that accompanies light-matter interaction has provided us means to trap and manipulate particles in the mesoscopic scale. Significant developments in the past decades have resulted in a variety of applications of conventional optical trapping in the biological and the physical fields and the emergence of a ‘next-generation’ of optical micromanipulation schemes [1-5].

In 1970, Ashkin demonstrated that a transparent dielectric micro-sphere suspended in water is radially drawn towards the optical axis of a Gaussian laser beam where the intensity is strongest [6]. He observed this behavior with latex spheres having relative refractive index m greater than unity (m = n/n0 where n and n0 are the refractive indices of the particle and the suspending medium, respectively). Upon radial attraction towards the region of stronger intensity, the high-index particle accelerates in the direction of the Poynting vector due to an axial scattering force. On the other hand, Ashkin noted that for an air bubble (m < 1) in water the sign of the radial force due to the intensity gradient is reversed; hence, the low-index particle is repelled away from the beam axis. Ashkin and co-workers later showed that by tightly focusing a Gaussian beam to a high-index particle an axial force due to an intensity gradient is also produced, strong enough to counteract the scattering force, resulting in a stable 3D confinement of the particle [7]. However, a stationary tightly focused Gaussian beam does not provide a confining potential for low-index particles.

Optical trapping of a low-index microscopic particle requires a beam with an annular intensity profile. A straightforward approach is to apply high-speed deflectable mirrors that enable time multiplexing of a desired beam pattern at the trapping plane. Scanning the beam in a circular locus creates a ring of light that confines a low-index particle in its dark central spot [8]. A low-index particle can also be trapped in an optical vortex produced from a focused TEM01* beam [9]. An optical vortex has been used to trap a low-index sphere and a high-index sphere, at the same time, in two neighboring positions along the beam axis [10]. Low-index particles were also trapped between bright interference fringes produced at the focal plane of an objective lens where two coherent plane waves converge [11]. However, dynamic and parallel manipulation of a larger array of high- and low-index partic les has not been achieved with the above techniques.

Here, we demonstrate real-time user-interactive manipulation of a mixture of high- and low-index particles by reading out 2D phase patterns encoded onto an input beam by a programmable spatial light mo dulator (SLM) using the generalized phase contrast (GPC) approach to produce tailored light distributions that result in optical confinement of the mixed particles in the transverse plane. For spherical particles, trapping beams with radial symmetry are utilized. High-index micro-spheres were efficiently trapped and manipulated using trapping beams with top-hat transverse profiles at the trapping plane [12, 13]. On the other hand, low-index particles are trapped using beams with annular transverse profiles [14]. We demonstrate that, unlike other methods, the GPC approach readily provides both the ability to create independently controllable optical traps for high- and low-index particles, and the flexibility to render, in real time, arbitrary dynamics for these two types of particles simultaneously. This exceptional functionality may facilitate particle encapsulation in air-bubbles or in water-in-oil emulsions applied in petroleum, food, and drug processing.

2. Experiment

Trapping and manipulation of colloidal particles is achieved using the experimental setup shown in Fig. 1. The system makes use of a continuous wave (CW) Titanium:Sapphire (Ti:S) laser (wavelength-tunable, Spectra Physics, 3900s) pumped with a CW frequency-doubled Neodymium:Yttrium Vanadate (Nd:YVO4) laser (532 nm, Spectra Physics, Millenia V). The Ti:S laser utilizes built-in birefringent quartz filter plates to select the operating wavelength within the near infrared (NIR) spectrum from 700 to 850 nm. In our experiments, the operation wavelength is set to λ= 830 nm. With a maximum pump power of 5.0 W from the Nd:YVO4, the Ti:S laser provides a maximum power of 1.5 W. The laser is expanded and #3781 - $15.00 US Received 4 February 2004; revised 29 March 2004; accepted 29 March 2004 (C) 2004 OSA 5 April 2004 / Vol. 12, No. 7 / OPTICS EXPRESS 1418

collimated before incidence on a reflection-type phase-only SLM. The SLM, employing parallel-aligned nematic liquid crystals (Hamamatsu Photonics), is optically addressed by a VGA-resolution (480x480 pixels) liquid crystal projector element that is controlled from the video output of a computer.

Fig. 1. Experimental setup for simultaneous optical manipulation of high- and low-index

particles at the trapping plane. The expanded beam (λ = 830 nm) incident at the spatial light

modulator (SLM) comes from a CW Ti:Sapphire (Ti:S) laser pumped by a visible CW

Nd:YVO4 laser. Under computer control, arbitrary 2D phase patterns are encoded onto the

reflective SLM. A high-contrast intensity mapping of the phase pattern is formed at the image

plane (IP) and is captured by a CCD camera via partial reflection from a pellicle. The intensity

distribution is optically relayed to the trapping plane. Standard brightfield detection is used to

observe the trapped particles. PCF: phase contrast filter, Ir: iris diaphragm, L1, L2 and L3:

lenses, MO: microscope objective, DM: dichroic mirror, TL: tube lens.

We use the SLM to imprint a programmable 2D binary phase pattern (0 or π phase delays) to the wavefront of the 830 nm laser beam. The phase-modulated wavefront is directed into a 4-f filtering system composed of lenses L1 and L2, and a phase contrast filter (PCF) located at the Fourier plane. The PCF is constructed by deposi ting a 30-μm-diameter circular transparent photoresist (Shipley, Microposit S1818) structure on an optical flat. Centered at the Fourier plane, the PCF introduces a π-phase shift between low and high spatial frequency components of the phase-encoded beam. The diameters of the SLM iris (Ir) and the on-axis PCF are adjusted to optimize the throughput and contrast of the output intensity distribution [15]. A high-contrast intensity distribution, which is geometrically identical to the phase-pattern at the SLM, is generated at the image plane (IP). To monitor the output intensity distribution, a pellicle is inserted in the path and directs a small fraction (~3%) of the light towards a CCD camera. The intensity pattern at the IP is scaled and relayed by lens L3 and the microscope objective (MO) to a conjugate plane (trapping plane). The fluorescence port of the inverted microscope (Leica, DM-IRB) is used to direct the near-infrared laser light to the back-focal plane of the MO via a dichroic mirror. The same MO and a built-in microscope tube lens allow brightfield images to be captured by a second CCD camera.

The quality of the intensity patterns synthesized at the image plane via the GPC approach is depicted in Fig. 2 where variably sized beams with top-hat and annular transverse profiles are generated at different positions at the transverse x-y plane. The condition for achieving

#3781 - $15.00 US Received 4 February 2004; revised 29 March 2004; accepted 29 March 2004 (C) 2004 OSA 5 April 2004 / Vol. 12, No. 7 / OPTICS EXPRESS 1419

optimal intensity contrast is described in the previous analysis of the GPC method [15]. Optimum phase-to-intensity conversion requires that the ratio of the SLM area encoded with πphase shift to that with 0 phase remains less than or equal to 0.25 for the operating diameters of the SLM iris and the PCF. When the condition is satisfied, the maximum intensity of the trapping pattern is approximately four times the average intensity of the SLM input beam.

Fig. 2. (a) Measured high-contrast intensity pattern at the output plane IP. Corresponding

surface intensity plots for the representative (b) top-hat (in yellow square) and (c) annular or

doughnut (in green square) trapping beams.

A trapping beam with a top-hat transverse intensity profile provides a radially symmetric potential well for a high-index particle as shown in Fig. 3(a). When a top-hat beam is positioned in the vicinity of a high-index particle, the particle gets attracted to the beam axis. We have observed previously that a beam with diameter slightly larger than that of the particle provides better transverse confinement especially when the trapped particle is moved along the horizontal plane [12].

In contrast, a top-hat beam acts as a potential barrier for a low-index particle. Unstable at the beam center, the low-index particle gets repelled to either side of the optical potential as shown in Fig. 3(a). This is evident in the experiment we performed with spherical shells made of soda lime glass material (Polysciences) with de-ionized water as host medium. These air-filled hollow glass spheres have shell thickness of ~1 μm and outer diameters in the range of 2-20 μm. The hollow glass spheres with outer diameters greater than 5 μm effectively behave as low-index particles in water (n0 = 1.33). Similar hollow glass spheres where found to have average density of ~0.2 g/mL and effective refractive index n L = 1.2 [9]. A 6 μm hollow sphere in the presence of a top-hat beam is shown in Fig. 4. The sequence of images shows the displacement of the low-index particle as a result of its repulsion from the region of stronger light intensity.

A low-index particle finds a minimum potential at the center of the beam with an annular transverse intensity profile as shown in Fig. 3(b). However, unlike the spontaneous attraction of a high-index particle towards the center of a top-hat beam, a low-index particle is not readily drawn to the dark central spot of the annular beam. From the outer region to the dark center of the annular beam, the low-index particle needs to overcome the potential barrier associated with the bright ring of light.

#3781 - $15.00 US Received 4 February 2004; revised 29 March 2004; accepted 29 March 2004 (C) 2004 OSA 5 April 2004 / Vol. 12, No. 7 / OPTICS EXPRESS 1420

Fig. 3. Diagram of the optical potential (a) for a high-index (solid curve) and a low-index

(dashed curve) particle due to a beam with top-hat transverse intensity profile, and (b) for a

low-index particle due to a beam with annular transverse intensity profile.

Fig. 4. (AVI, 1.656 MB) Deflection of a soda lime hollow glass sphere from a computer-mouse

controlled trapping beam with top-hat intensity profile.An arrow in each frame indicates the

location of the beam at that instant. Scale bar, 10 μm.

Next, we demonstrate a scheme where we take advantage of the repulsive forces induced by intensity gradients to low-index particles. The sample we prepared contained a mixture of polystyrene micro-spheres (index n H = 1.57, Bangs Laboratories) and the low-index hollow spheres in de-ionized water in ~30 μm-thick glass cell. The sample is mounted on the microscope stage. Due to density mismatch, the polystyrene spheres (1.05 g/mL) settle to the bottom surface of glass cell while the air-filled hollow glass spheres (0.2 g/mL) float to the top portion. Axial adjustment of the MO allows us to view the two types of particles. To bring more particles into a particular region, we generate and scan a vertical line beam pattern resulting in the simultaneous deflection of low-index particles in the scan direction as shown in Fig. 5. Raking of the low-index particles is made either by non-mechanical scanning of the linear beam pattern using the graphical user-interface or by horizontal displacement of the microscope stage. This simple procedure allows us to drag a number of low-index particles into the operating region where polystyrene spheres are found directly below.

#3781 - $15.00 US Received 4 February 2004; revised 29 March 2004; accepted 29 March 2004 (C) 2004 OSA 5 April 2004 / Vol. 12, No. 7 / OPTICS EXPRESS 1421

Fig. 5. (AVI, 1.126 MB) Raking of low-index particles to a region of interest achieved by

scanning a bright linear intensity pattern in the x-y plane.The arrow (frame 1) indicates the

scanning direction. Scale bar, 10 μm.

The ability to interactively generate and change phase patterns at the SLM in real-time allows each doughnut trap to be independently switched on and off, and be transversely displaced such that it correctly coincides with the position of the corresponding particle. In Fig. 6, we demonstrate the steps for trapping low-index particles with doughnut optical traps. In the first frame, a doughnut trap is positioned next to a particle which is located almost outside the field of view. From its initial position, the trap is then positioned directly in the location of the particle and moved slightly to the center of the observation region. In the third frame, a new trap is added by the click of the computer mouse and brought to one of the untrapped particles. The same procedure is done in the succeeding frames until all four particles are trapped as shown in the 15th frame. Once all particles are trapped, they are brought into a diamond formation (20th frame) and then into a linear arrangement (25th frame). The sizes of the particles vary within 6 – 10 μm and the corresponding doughnut traps are configured with appropriate diameters and thickness by a “click and draw” computer mouse sequence.

The high-index polystyrene spheres are lifted off the bottom surface of the sample cell by corresponding optical traps with top-hat profiles. As the high-index particles accelerate upward, they appear in-focus with the low-index particles pre-positioned at the upper surface of the sample cell. As high-index particles are brought to the upper glass surface by top-hat beams, doughnut optical traps are also created for low-index particles. Figure 7 shows a mixture of high- and low-index particles simultaneously trapped by top-hat and annular trapping beams, respectively. From an irregular spatial distribution, the particles are individually displaced and sorted according to their index contrast with the suspending medium. This process illustrates the versatility of the GPC method in generating trapping patterns with arbitrary (symmetric or asymmetric) spatial configurations in real-time.

#3781 - $15.00 US Received 4 February 2004; revised 29 March 2004; accepted 29 March 2004 (C) 2004 OSA 5 April 2004 / Vol. 12, No. 7 / OPTICS EXPRESS 1422

Fig. 6. (AVI, 2.512 MB) User-interactive procedure for trapping different sizes of hollow glass

spheres using doughnut optical traps.

Fig. 7. (AVI, 1.113 MB) Image sequences of trapping and user-interactive sorting of an

inhomogeneous mixture of soda lime hollow glass spheres and polystyrene beads in water

solution. (a) The particles are first captured by appropriate trapping beams and then (b-c)

displaced one by one. The size of the beam used at each trapping site is proportional to the size

of the corresponding particle. Arrows indicate the directions at which particles are transported.

(d) Two separate rows of optically trapped high-index (lower row) and low-index particles

(upper row). Scale bar, 10 μm.

#3781 - $15.00 US Received 4 February 2004; revised 29 March 2004; accepted 29 March 2004 (C) 2004 OSA 5 April 2004 / Vol. 12, No. 7 / OPTICS EXPRESS 1423

Aside from the ability to individually manipulate high- and low-index particles, the system also allows one to pre-define the path and the speed of m otion of each trapping beam. Such an experiment is illustrated in Fig. 8 where a row of high-index polystyrene sphere and a row of low-index particles are simultaneously set into oscillatory motion by corresponding trapping beams. The limiting factor for the dynamics of the trapping beams (but not necessarily the particle manipulation speed) is the response time of the liquid crystals in the SLM. For our nematic liquid crystal-based SLM, the response time (time needed for one SLM pixel to change between two extreme states associated with phase delays 0 and π) is in the order of ~100 ms. On the trapping plane, this corresponds to a maximum average speed of ~2.5 μm·s-1 at which a trapping beam can be moved with quantization in displacement at the single pixel-image level. Faster average speeds of moving traps can be achieved by using displacement quantization of more than one pixel. However, this results in a coarser or more discrete motion of the traps. We note at this point that, contrary to other alternatives, the GPC method requires only (but not limited to) binary phase objects to generate 2D intensity patterns with arbitrary symmetry. This robustness permits us to take advantage of the faster response time characteristic to binary SLMs based on other technologies (e.g., ferroelectric liquid crystals, multiple quantum well devices and microelectromechanical system (MEMS) -based devices), and hence to achieve faster, yet smooth, trap displacements. On the other hand, the speed at which a particle can be displaced while maintaining its confinement in the trap depends on the stiffness of the optical trap and the hydrodynamic drag force induced to the moving particle by the viscous medium. The trap stiffness for both the top-hat and annular beams may be improved by increasing the power of the input beam to the SLM.

Fig. 8. (AVI, 1.518 MB) Simultaneously transported high- and low-index particles confined in

respective optical traps with pre-programmed dynamics. The time interval between adjacent

frames is ~15 s. Scale bar, 10 μm.

3. Conclusion

We have demonstrated the use of a real-time user-interactive array of trapping beams with tailored intensity profiles for the interactive manipulation of microscopic particles with opposite index contrast with respect to the suspending liquid medium. High- and low-index particles suspended in water find confining optical potentials in trapping beams with top-hat and annular transverse profiles, respectively. To our knowledge, this is the first demonstration of simultaneous trapping and user-controlled manipulation of multiple high- and low-index particles using optical traps. Arbitrarily shaped trapping beam configurations are obtained from the light-efficient conversion of SLM-encoded phase patterns into corresponding intensity distributions by the generalized phase contrast method. Although in principle the GPC approach is applicable at other operating wavelengths, the use of biologically non-invasive NIR laser source (e.g. 830 nm) makes the current system highly attractive for optical manipulation of colonies of cells in aqueous solutions. Finally, we envision that the technique offers a versatile tool for studying particle dynamics in a variety of aqueous systems #3781 - $15.00 US Received 4 February 2004; revised 29 March 2004; accepted 29 March 2004 (C) 2004 OSA 5 April 2004 / Vol. 12, No. 7 / OPTICS EXPRESS 1424

containing both high- and low-index microscopic objects and has the potential for optically powering specially fabricated microstructures with irregular geometries or inhomogeneous optical properties [16].

Acknowledgments

We thank the European Science Foundation and the Danish Natural Scientific Research Council (SNF) for supporting this research through the Eurocores-SONS programme. We acknowledge T. Hara and Y. Kobayashi of Hamamatsu Photonics and J. Stubager for fabricating the phase contrast filters.

#3781 - $15.00 US Received 4 February 2004; revised 29 March 2004; accepted 29 March 2004 (C) 2004 OSA 5 April 2004 / Vol. 12, No. 7 / OPTICS EXPRESS 1425

毕业设计外文翻译资料

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基于WEB的J2EE的信息系统的方法研究 摘要:本文介绍基于工程的Java开发框架背后的概念,并介绍它如何用于IT 工程开发。因为有许多相同设计和开发工作在不同的方式下重复,而且并不总是符合最佳实践,所以许多开发框架建立了。我们已经定义了共同关注的问题和应用模式,代表有效解决办法的工具。开发框架提供:<1)从用户界面到数据集成的应用程序开发堆栈;<2)一个架构,基本环境及他们的相关技术,这些技术用来使用其他一些框架。架构定义了一个开发方法,其目的是协助客户开发工程。 关键词:J2EE 框架WEB开发 一、引言 软件工具包用来进行复杂的空间动态系统的非线性分析越来越多地使用基于Web的网络平台,以实现他们的用户界面,科学分析,分布仿真结果和科学家之间的信息交流。对于许多应用系统基于Web访问的非线性分析模拟软件成为一个重要组成部分。网络硬件和软件方面的密集技术变革[1]提供了比过去更多的自由选择机会[2]。因此,WEB平台的合理选择和发展对整个地区的非线性分析及其众多的应用程序具有越来越重要的意义。现阶段的WEB发展的特点是出现了大量的开源框架。框架将Web开发提到一个更高的水平,使基本功能的重复使用成为可能和从而提高了开发的生产力。 在某些情况下,开源框架没有提供常见问题的一个解决方案。出于这个原因,开发在开源框架的基础上建立自己的工程发展框架。本文旨在描述是一个基于Java的框架,该框架利用了开源框架并有助于开发基于Web的应用。通过分析现有的开源框架,本文提出了新的架构,基本环境及他们用来提高和利用其他一些框架的相关技术。架构定义了自己开发方法,其目的是协助客户开发和事例工程。 应用程序设计应该关注在工程中的重复利用。即使有独特的功能要求,也

(完整版)建筑外文翻译毕业设计论文

随着我国经济的发展,建筑行业已经朝着多元化方向发展,建筑行业在我国经济发展中起着非常重要的作用。而建筑工程管理工作直接关系到工程的质量、成本管理、人员的安全、企业的经营效益,甚至关系到企业的生死存亡,但是我国建筑工程管理在现阶段存在许多的不足:管理体制不健全。我国大部分的建筑工程为了节约人员开支,减少了建筑工程管理机构的人员数量和质量。管理制度深入性不足。建筑行业的相关管理制度都是由一些著名的建筑行业专家等共同研究制定的,但是在各建筑单位中就只是一张纸,他们也都只是为了应付上级的检查,并不能应用到建筑工程管理上。 在我国建筑工程管理工作中,难以全面确立我国建筑工程管理思路体系,主要是因为我国缺乏管理理论和经验。建立建筑工程管理思路体系是专业性较强的问题,其实施必须由资深的建筑学科专家和具有丰富工作经验的管理人员来组织,只有这样才能实现。国外建筑行业无论是技术还是理论都比较先进,因此我国在建筑工程管理思路体系的建立过程中,必须借鉴国外的先进理念,另外,还必须吸取先进的建筑工程管理方法,并对各方面的资料加以综合和整体。总之,要想确保我国建筑工程管理工作的有序进行,必须以健全的工程管理思路体系作为建筑工程总体管理水平提升的基本保障。加强施工质量管理,建立合理可行的质量保证体系,将工程的质量工作落到实处。工程施工企业要根据质量保证体系,形成行之有效的质量保证系统,树立质量方针,从而让其更加有指令性、系统性及可操作

性。要将人、材料和机械各个要素有效结合起来。 首先,人是质量控制的核心,要把人作为控制的推动力,充分调动人的积极性,树立工程质量第一的观念。其次,施工材料作为建筑产品的主体,对材料质量的控制是工程质量控制的关键。最后,工程施工的机械是进行施工机械化的主要标志,对现代化项目施工起到不可缺少的作用,它直接影响了施工项目的进度和质量,所以,选好用好工程机械设备非常重要。所以,应该根据工程项目的具体特点,综合考虑各种环境因素,实施有效的施工现场控制,为保证施工质量及安全创造良好的外部条件。 现阶段建筑工程管理越来越受到人们的重视,项目成本管理是工程管理不可或缺的内容。工程管理本质特征可以由项目成本管理体现出来。首先,建立项目成本管理责任制。项目管理人员的成本责任,不同于工作责任,工作责任完成不等于成本责任完成。在完成工作责任的同时,还应考虑成本责任的实施,进一步明确成本管理责任,使每个管理者都有成本管理意识,做到精打细算。其次,对施工队实行分包成本控制。项目部与施工队之间建立特定劳务合同关系,项目部有权对施工队的进度、质量、安全和现场管理标准进行监督管理,同时按合同支付劳务费用。再次,施工队成本的控制,由施工队自身管理,项目部不应该过多干预。 为了保证政府监督工作的有效性和权威性,应该提高监督队伍的整体素质。因此,加强建筑工程质量监督机构的质量管理的学习,从而使得监督队伍的业务素质得以提高。另外,质量监督手段也要不断进行完善,增加检测设备,使得监督工作具有较大科技的含量,实现监督工作的现代化。从建设市场的整体来看,市场运行的规则不够完善。执法不严,违法不究的现象常常会出现。工程质量受到危害在很大程度上都是由于建设市场的混乱所造成的。因此,政府必须建立健全的运行规则,保证这些规则能够真正落实处。

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。

本科毕业设计外文翻译

Section 3 Design philosophy, design method and earth pressures 3.1 Design philosophy 3.1.1 General The design of earth retaining structures requires consideration of the interaction between the ground and the structure. It requires the performance of two sets of calculations: 1)a set of equilibrium calculations to determine the overall proportions and the geometry of the structure necessary to achieve equilibrium under the relevant earth pressures and forces; 2)structural design calculations to determine the size and properties of thestructural sections necessary to resist the bending moments and shear forces determined from the equilibrium calculations. Both sets of calculations are carried out for specific design situations (see 3.2.2) in accordance with the principles of limit state design. The selected design situations should be sufficiently Severe and varied so as to encompass all reasonable conditions which can be foreseen during the period of construction and the life of the retaining wall. 3.1.2 Limit state design This code of practice adopts the philosophy of limit state design. This philosophy does not impose upon the designer any special requirements as to the manner in which the safety and stability of the retaining wall may be achieved, whether by overall factors of safety, or partial factors of safety, or by other measures. Limit states (see 1.3.13) are classified into: a) ultimate limit states (see 3.1.3); b) serviceability limit states (see 3.1.4). Typical ultimate limit states are depicted in figure 3. Rupture states which are reached before collapse occurs are, for simplicity, also classified and

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.sodocs.net/doc/522493730.html,,niuzhiguo@https://www.sodocs.net/doc/522493730.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.sodocs.net/doc/522493730.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-中文版

本科生毕业设计(论文)外文科技文献译文 译文题目(外文题目)学院(系)Socket网络编程的设计与实现A Design and Implementation of Active Network Socket Programming 机械与能源工程学院 专学业 号 机械设计制造及其自动化 071895 学生姓名李杰林 日期2012年5月27日指导教师签名日期

摘要:编程节点和活跃网络的概念将可编程性引入到通信网络中,并且代码和数据可以在发送过程中进行修改。最近,多个研究小组已经设计和实现了自己的设计平台。每个设计都有其自己的优点和缺点,但是在不同平台之间都存在着互操作性问题。因此,我们引入一个类似网络socket编程的概念。我们建立一组针对应用程序进行编程的简单接口,这组被称为活跃网络Socket编程(ANSP)的接口,将在所有执行环境下工作。因此,ANSP 提供一个类似于“一次性编写,无限制运行”的开放编程模型,它可以工作在所有的可执行环境下。它解决了活跃网络中的异构性,当应用程序需要访问异构网络内的所有地区,在临界点部署特殊服务或监视整个网络的性能时显得相当重要。我们的方案是在现有的环境中,所有应用程序可以很容易地安装上一个薄薄的透明层而不是引入一个新的平台。 关键词:活跃网络;应用程序编程接口;活跃网络socket编程

1 导言 1990年,为了在互联网上引入新的网络协议,克拉克和藤农豪斯[1]提出了一种新的设 计框架。自公布这一标志性文件,活跃网络设计框架[2,3,10]已经慢慢在20世纪90 年代末成形。活跃网络允许程序代码和数据可以同时在互联网上提供积极的网络范式,此外,他们可以在传送到目的地的过程中得到执行和修改。ABone作为一个全球性的骨干网络,开 始进行活跃网络实验。除执行平台的不成熟,商业上活跃网络在互联网上的部署也成为主要障碍。例如,一个供应商可能不乐意让网络路由器运行一些可能影响其预期路由性能的未知程序,。因此,作为替代提出了允许活跃网络在互联网上运作的概念,如欧洲研究课题组提出的应用层活跃网络(ALAN)项目[4]。 在ALAN项目中,活跃服务器系统位于网络的不同地址,并且这些应用程序都可以运行在活跃系统的网络应用层上。另一个潜在的方法是网络服务提供商提供更优质的活跃网络服务类。这个服务类应该提供最优质的服务质量(QOS),并允许路由器对计算机的访问。通过这种方法,网络服务提供商可以创建一个新的收入来源。 对活跃网络的研究已取得稳步进展。由于活跃网络在互联网上推出了可编程性,相应 地应建立供应用程序工作的可执行平台。这些操作系统平台执行环境(EES),其中一些已 被创建,例如,活跃信号协议(ASP)[12]和活跃网络传输系统(ANTS)[11]。因此,不 同的应用程序可以实现对活跃网络概念的测试。 在这些EES 环境下,已经开展了一系列验证活跃网络概念的实验,例如,移动网络[5],网页代理[6],多播路由器[7]。活跃网络引进了很多在网络上兼有灵活性和可扩展性的方案。几个研究小组已经提出了各种可通过路由器进行网络计算的可执行环境。他们的成果和现有基础设施的潜在好处正在被评估[8,9]。不幸的是,他们很少关心互操作性问题,活跃网络由多个执行环境组成,例如,在ABone 中存在三个EES,专为一个EES编写的应用程序不能在其他平台上运行。这就出现了一种资源划分为不同运行环境的问题。此外,总是有一些关键的网络应用需要跨环境运行,如信息收集和关键点部署监测网络的服务。 在本文中,被称为活跃网络Socket编程(ANSP)的框架模型,可以在所有EES下运行。它提供了以下主要目标: ??通过单一编程接口编写应用程序。 由于ANSP提供的编程接口,使得EES的设计与ANSP 独立。这使得未来执行环境的发展和提高更加透明。

土木工程毕业设计范文,图纸计算书、建筑说明书外文翻译、开题报告书

- - -. 毕业设计(论文) 开题报告 题目XX雅筑地产中天锦庭6号住宅楼设计 专业土木工程 班级 学生 指导教师教授 讲师

一、毕业设计(论文)课题来源、类型 本论文课题来源于XX雅筑地产中天锦庭6号住宅楼设计,本设计来自工程实际,结构类型为钢筋混凝土剪力墙结构。该建筑分十三层,耐火等级为一级,主体结构为二级耐久年限,抗震设防为八级。二、选题的目的及意义 随着我国经济发展和城市化进程,人们对住宅的需求量逐渐增多,住宅物业管理日益为人们所关注。住宅小区已经成为人们安家置业的首选,几十万到几百万的小区住宅比比皆是。尤其近几年,高层小高层已然成为现代开发商与消费者选择的主流。这是由高层和小高层的特点所决定的,高层建筑可节约城市用地,缩短公用设施和市政管网的开发周期。人们花的钱越多,不但对住宅的本身的美观质量要求越来越高,同时对物业小区的服务和管理也要求越来越高,比如对小区的绿化,保安,停车场,维修甚至对各项投诉的要求小区管理者做的好。信息时代的今天,住宅小区的硬件设施也必须跟得上时代的步伐,对现代化住宅小区建设的要求越来越高。小区楼的艺术美更要符合现代人的需求,此外还必须有较高的实用性、经济性。住宅小区的居住环境安全与否,是小区居民极其关心的问题,要创建一个安全的居住环境不仅要有科学的小区管理制度,而且在很大程度上也依赖于小区规划的安全性,这其中涉及到居民的生理、心理安全和社会安全等因素。在住宅小区的规划设计中应充分考虑居民的有效防X行为,通过控制小区和组团入口、明确划分空间领域等措施来提高小区的安全防卫能力。一是在小区和组团的入口处设置明显标志,使住宅小区具有较强的领域性和归属性。二是注重院落空间的强化,使居民之间既有充分了解和相互熟悉的机会,又可以使住户视线能够触及到住宅入口,便于对陌生人进行观察、监视。三是注重小区交通网络的合理组织。在小区主干道的规划设计上要做到“顺而不穿,通而不畅”,减少交通环境的混乱交杂,提高安全系数,在小区级道路的规划上尽量作曲形设计,限制车辆穿行的速度,达到安全与降低噪音的目的。同时,规划时应尽量减少组团的出入口,一般设置两个即可,以便有效控制外来行人任意穿行,从而起到安全防卫的作用。我这次选择的是高层住宅楼的设计,目的就是为了设计一栋满足居住需求和美观要求的住宅楼。并且也可以通过这次的毕业设计,把以前学习的专业课的知识运用到实践中,以及对它们更加深入的学习和系统化的总结。在这个过程中需要查阅、搜集许多的资料,将提高我运用图书馆的资料文献和互联网上大量信息的能力。office办公软件的综合运用使我的电脑基本功有了很大的提高。从建筑设计到结构的计算设计都是由自己单独完成,这就培养了我们独立解决设计中的问题以及娴熟使用auto CAD和PKPM系列软件的能力。综合性地运用几年内所学知识去分析、解决一个问题,在作毕业设计的过程中,所学知识得到疏理和运用,它既是一次检阅,又是一次锻炼。

毕业设计外文资料翻译译文

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毕业设计外文翻译

毕业设计(论文) 外文文献翻译 题目:A new constructing auxiliary function method for global optimization 学院: 专业名称: 学号: 学生姓名: 指导教师: 2014年2月14日

一个新的辅助函数的构造方法的全局优化 Jiang-She Zhang,Yong-Jun Wang https://www.sodocs.net/doc/522493730.html,/10.1016/j.mcm.2007.08.007 非线性函数优化问题中具有许多局部极小,在他们的搜索空间中的应用,如工程设计,分子生物学是广泛的,和神经网络训练.虽然现有的传统的方法,如最速下降方法,牛顿法,拟牛顿方法,信赖域方法,共轭梯度法,收敛迅速,可以找到解决方案,为高精度的连续可微函数,这在很大程度上依赖于初始点和最终的全局解的质量很难保证.在全局优化中存在的困难阻碍了许多学科的进一步发展.因此,全局优化通常成为一个具有挑战性的计算任务的研究. 一般来说,设计一个全局优化算法是由两个原因造成的困难:一是如何确定所得到的最小是全球性的(当时全球最小的是事先不知道),和其他的是,如何从中获得一个更好的最小跳.对第一个问题,一个停止规则称为贝叶斯终止条件已被报道.许多最近提出的算法的目标是在处理第二个问题.一般来说,这些方法可以被类?主要分两大类,即:(一)确定的方法,及(ii)的随机方法.随机的方法是基于生物或统计物理学,它跳到当地的最低使用基于概率的方法.这些方法包括遗传算法(GA),模拟退火法(SA)和粒子群优化算法(PSO).虽然这些方法有其用途,它们往往收敛速度慢和寻找更高精度的解决方案是耗费时间.他们更容易实现和解决组合优化问题.然而,确定性方法如填充函数法,盾构法,等,收敛迅速,具有较高的精度,通常可以找到一个解决方案.这些方法往往依赖于修改目标函数的函数“少”或“低”局部极小,比原来的目标函数,并设计算法来减少该?ED功能逃离局部极小更好的发现. 引用确定性算法中,扩散方程法,有效能量的方法,和积分变换方法近似的原始目标函数的粗结构由一组平滑函数的极小的“少”.这些方法通过修改目标函数的原始目标函数的积分.这样的集成是实现太贵,和辅助功能的最终解决必须追溯到

山东建筑大学本科毕业设计说明书外文文献及翻译格式模版

附件3: (本科毕业论文)文献、资料题目: 院(部) 专 班 姓名:张三 学号: 指导教师:张九光 翻译日期:2005.6.30

,the National Institute of Standards and Technology (NIST) has been working to develop a new encryption standard to keep government information secure .The organization is in the final stages of an open process of selecting one or more algorithms ,or data-scrambling formulas ,for the new Advanced Encryption Standard (AES) and plans to make adecision by late summer or early fall .The standard is slated to go into effect next year . AES is intended to be a stronger ,more efficient successor to Triple Data Encryption Standard (3DES),which replaced the aging DES ,which was cracked in less than three days in July 1998. “Until we have the AES ,3DES will still offer protection for years to come .So there is no need to immediately switch over ,”says Edward Roback , acting chief of the computer security division at NIST and chairman of the AES selection committee .“What AES will offer is a more efficient algorithm .It will be a federal standard ,but it will be widely implemented in the IT community .” According to Roback ,efficiency of the proposed algorithms is measured by how fast they can encrypt and decrypt information ,how fast they can present an encryption key and how much information they can encrypt . The AES review committee is also looking at how much space the algorithm takes up on a chip and how much memory it requires .Roback says the selection of a more efficient AES will also result in cost savings and better use of resources . “DES w as designed for hardware implementations ,and we are now living in a world of much more efficient software ,and we have learned an awful lot about the design of algorithms ,”says Roback .“When you start multiplying this with the billions of implementations done daily ,the saving on overhead on the networks will be enormous .” ……

室内设计中英文翻译【适用于毕业论文外文翻译】

毕业设计英文资料翻译Translation of the English Documents for Graduation Design 课题名称 院(系) 专业 姓名 学号 起讫日期 指导教师 2011 年 02 月 20 日

译文: 室内设计 室内设计不仅包括装修及家具的空间,而且还考虑到空间规划,灯光,与用户行为有关的程序化问题,包括从具体问题的可及性到在空间中的活动的性质。在商业和公共空间显著的变化后,室内设计如今的标志是一个新的弹性类型学。 室内设计不仅包括方案规划也包括室内空间的物理治疗:预测其使用的性质以及它的家具和表面,包括墙,地面,天花板。在职权范围上,室内设计有别于室内装修工程。装修关心的是家具的选择,然而设计者要把离散的装饰元素整合成方案关注的空间和使用。室内设计师在从底层向上的内部的空间时间方面与与建筑师合作,但是他们仍然独立的工作,尤其在翻修的情况下。历史上,植根于总体艺术作品的概念,曾经都是建筑师设计的。总体艺术作品的概念源于十九世纪末和二十世纪初的工艺美术运动。其支持者(从弗兰克·劳埃德·赖特到凡德罗)在室内设计专业的起源期间延长其做法以包括内饰领域行为并不是偶然的。事实上,这是一个建筑师采取的防御措施,建筑师们把室内装修或设计师的形式上的干预看作是对他们完整的艺术性的一种威胁。 如今,除了像理查德·迈耶那样的非常重视均匀性的现代主义者,扮演室内设计师角色的建筑师(数量在增长)更有倾向于理论与实践的折衷,并联21世纪的定价多元化。尽管如此,对室内设计师以及室内设计领域的偏见持续存在。由于室内被视为一个集装箱的蜉蝣,从而阻碍了对室内的批评性的讨论。此外,对室内的传统观点充满了偏见:阶级偏见与百年历史的协会商人有关,性别偏见与把装饰行业描述成主要是妇女和男性同性恋的领域。因此,室内设计作为文化价值的表达的信誉已被严重损坏。 然而,对文化大系统的理解在全球化的影响下一直在变化。在一个更宽容的环境中,鼓励不同文化间的融合,高文化和低文化的区别被消除。同样,有更频繁的生产性借贷的事例发生在建筑,设计,装修等曾经被看作是专有领地的领域。并且建筑,室内设计,室内装修领域仍然有不同的教育协议以及不同的关注重点,他们表现出更大的互相的兴趣。 另一种考虑这种新兴的合成的方法是用现代,技术和历史替代建筑,室内设计和装修的三合一。后现代时代的特征之一是提高了对过去影响现在的角色的认识。在室内,这表现在一个新的兴趣饰品,工艺和重要性以及空间复杂性,所有平行于正在运行的现代化的项目。

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

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