The effect of photodiode shape on charge transfer in CMOS image sensors
中考英语摄影艺术的审美价值与表现手法单选题40题
中考英语摄影艺术的审美价值与表现手法单选题40题1.Photography is the art of capturing images with a ______.A.penB.pencilC.cameraD.book答案：C。
摄影是用相机捕捉图像的艺术，A 选项pen 是钢笔，B 选项pencil 是铅笔，D 选项book 是书，都与摄影无关。
只有C 选项camera 是相机，符合题意。
2.In photography, a beautiful landscape is often a good ______.A.subjectB.objectC.projectD.topic答案：A。
在摄影中，美丽的风景通常是一个好的拍摄对象。
B 选项object 指物体，C 选项project 是项目，D 选项topic 是话题，都不符合摄影中对风景的描述。
A 选项subject 有对象、主题的意思，符合摄影语境。
3.A professional photographer always has a high-quality ______.A.lensB.mirrorC.windowD.door答案：A。
专业摄影师总是有一个高质量的镜头。
B 选项mirror 是镜子，C 选项window 是窗户，D 选项door 是门，都与摄影无关。
A 选项lens 是镜头，是摄影的重要工具。
4.The ______ of a photograph can make it more attractive.A.colorB.shapeC.sizeD.price答案：A。
照片的颜色可以使它更具吸引力。
B 选项shape 是形状，C 选项size 是尺寸，D 选项price 是价格，都不是使照片更具吸引力的主要因素。
A 选项color 颜色是影响照片美观的重要因素之一。
5.A good photograph needs a proper ______.A.lightB.darkC.cloudD.rain答案：A。
Photo-inducedcha...
Mater. Res. Soc. Symp. Proc. Vol. 1406 © 2012 Materials Research Society193DOI: 10.1557/opl.2012.Photo-induced changes in the Langmuir adsorption constants of metal oxide layers in self-cleaning cation sensors.Philip S. Foran1 and Colin Boxall11Engineering Department, Lancaster University, Lancaster, LA1 4YW, UK.ABSTRACTFor the first time, we have used a metal oxide-coated quartz crystal microbalance (QCM) to measure Cs+ adsorption onto illuminated and un-illuminated mesoporous TiO2 (m-TiO2) films by microgravimetric means in-situ. In the simplest case, such experiments yield two parameters of interest: K, the Langmuir adsorption coefficient and m max the maximum mass of adsorbate to form a complete monolayer at the m-TiO2-coated quartz crystal piezoelectric surface. Importantly, we have found that illumination of the m-TiO2 film with ultra bandgap light results in an increase in m max i.e. illumination allows for greater adsorption of substrate to occur than in the dark. Our studies also show that under illumination, K also increases indicating a higher affinity for surface adsorption. The photoinduced change in m max and K are thought to be due to an increase in surface bound titanol groups, thus increasing the number of available adsorption sites – and so providing evidence to support the notion of photoinduced adsorption processes in photocatalytic systems. These findings have implications for the development of a reversible adsorption based microgravimetric sensor for Cs+.INTRODUCTIONFunctional metal oxides such as TiO2 find use as, inter alia, anode materials in dye sensitised solar cells, photocatalysts for gas / liquid phase pollutant destruction and self-cleaning glass coatings [1]. In particular, the latter two applications rely upon the photo-generation of energetic charge carriers within the TiO2 matrix to drive the oxidation of organic contaminants or putative surface reconstruction resulting in an increase in surface bound titanol groups. The latter may increase both surface wettability and the number of surface sites at which pollutant substrate adsorption may occur prior to their destruction at that surface. Whether such photoinduced adsorption effects exist is one of the unsolved questions of photocatalysis. In 2003, Shultz et al. used sum frequency generation, a highly surface sensitive technique, to analyse TiO2 films under illumination and for the first time measured an increase in the surface hydroxyl count, which would increase the surface wettability. Their results also detected trace amounts of organics on the surface of as-prepared TiO2 coatings in ambient air. However, after UV irradiation, these trace organics were no longer present, therefore exposing more of the TiO2 surface and potentially further increasing the surface wettability [2].The Quartz Crystal Microbalance (QCM) is a stable, extremely sensitive device capable of detecting mass changes of a few nanograms (ng) per square centimetre [3], such as those that may accompany photo-induced changes in substrate adsorption at TiO2 surfaces. The quantitative relationship between the change in frequency, Δf (Hz), of a piezoelectric crystal and the mass change caused by mass loading, Δm (g) on the piezoelectric crystal surface was firstly derived by Sauerbrey, and is given by [ Eq. 1] where C f is a constant of linear proportionality whose value may be derived by calibration or by theoretical calculation:f f C m ∆=-∆[ Eq. 1]The QCM has been employed to determine Langmuir parameters K, the Langmuiradsorption coefficient and m max , the mass of a complete monolayer of adsorbate, for organic pesticides adsorbing at illuminated & un-illuminated TiO 2 coated quartz crystal surfaces [4]. However, in these experiments the organic adsorbent was destroyed at the illuminated TiO 2 surface via photo-oxidation and therefore gave lower than expected values for K. Thus, in order to deconvolute photoinduced changes in Langmuir behaviour on TiO 2 due to substratedecomposition and/or changes in the nature of the adsorbing surface (photoinduced adsorption), an adsorbate that is not degradable by photocatalysis must be used. This adsorbate must also couple with the resonator to have an effect on mass and therefore give measurable change in resonant frequency. Of interest here are the electrochemically inert alkali & alkaline earth metal cations, especially the heavier members of these groups, Cs & Sr. 137Cs and 90Sr are radionuclides resulting from nuclear fission. They are highly radiotoxic and have a half-life of about 30 years, making them a substantial hazard should they be released into the environment, from, for example, stored spent nuclear fuel pins in interim storage or in final geological repository. Current detection methods for 137Cs and 90Sr include ICP-MS (non-radiometric) and scintillation detectors (radiometric), neither of which are well suited to in-situ detection in aqueous streams. Cs + ions are not degraded via photocatalysis therefore providing a means to (i) study the Langmuir adsorption parameters K and m max on TiO 2 films in both the dark and under band-gap illumination, so investigating the photoinduced adsorption processes; (ii) explore the potential implications on this effect in the development of a reversible, in-situ, adsorption based microgravimetric sensor for Cs +.EXPERIMENTAL5MHz AT-cut QCM crystals (Inficon, UK) were coated with a mesoporous-TiO 2 (m-TiO 2) layer via sol –gel spin coating as follows. A reverse micellar sol –gel was prepared, as described by Yu et al. [5]. The resultant sol –gel was applied to quartz piezoelectrode substrates by spin coating for 10 s at 2900 rpm. Coated substrates were then fired in a furnace at 350 °C for 1 h to anneal the TiO 2 and produce a resilient coating. Annealing at this temperature has been shown to produce TiO 2 with predominantly the anatase structure by Raman analysis (not shown)[6]. QCM experiments were performed using a Maxtek research quartz crystal microbalance (RQCM) and data recorded on a desktop PC using the Maxtek RQCM logging software at a rate of 1200 data points per minute. Frequency responses are initially measured in Hz, to convert this to meaningful mass in ng a Sauerbrey sensitivity factor of C f = 6.217 ng/Hz was used [7], this allows for the calculation of adsorbed Cs + concentration.Illumination with 315nm monochromated light was provided by a 900W xenon lamp (Applied Photophysics) monochromation also served to reduce heating of the gold substrate. The semiconductor-coated quartz crystal oscillator was placed in a borosilicate beaker with adedicated flat quartz window to minimise any scattering of and absorption of the incident light. The beaker was submerged in a thermostatic water-bath set at 30˚C a close match for the crystal ’s turn-around point, minimising the effect of temperature fluctuations on the recorded frequency. This could not be completely eliminated, and noise with amplitude of about 0.5Hz is noticeable.All reagents, including CsNO 3 (>99%, purum p.a., Fluka, UK) were obtained from reputable suppliers at the highest available purity and used as received. Solutions of CsNO 3 were prepared immediately prior to the start of each experiment. The solutions were prepared using doubly deionized water (Millipore Milli-Q system) to a resistivity of 1.8 x 105 Ω·m . Solutions were deoxygenated by bubbling with nitrogen (Oxygen-Free, BOC, UK) prior to experiments at a higher relative flow rate and during experiments at a significantly lower flow rate through a filtered glass Pasteur pipette placed behind the crystal holder to minimize potential disturbance at the crystal face. This slow bubbling of N 2 also aided in solution mixing, during any one QCM run, experiments were calibrated in-situ until a stable baseline frequency was achieved. Allexperiments were performed in a dedicated dark room to eliminate the effects of ambient light on the system.DISCUSSIONUnder Dark ConditionsFrequency response of the m-TiO 2 coated crystal as a function of time in dark conditions at increasing Cs + concentrations is shown in Figure 1a. Concentration of Cs + at the start of the experiment was 0mM. The Cs + concentration in the test solution was increased to 0.25mM by addition of an aliquot from a caesium nitrate stock solution (0.01M) after 60 minutesequilibration and resulted in a rapid frequency decrease of 14 Hz. Increasing Cs + concentration in the solution induces a decrease in frequency at the QCM surface as a result of adsorption of Cs + onto the m-TiO2 matrix. Subsequent additions of Cs + at 60 mins intervals increased the concentration to 0.5mM, 0.75mM and 1mM with a measured frequency response of -18Hz, -19Hz and -19Hz, respectively.The Langmuir isotherm is defined by [ Eq. 2]:max 1m KC m KC=+ [ Eq. 2]where m is the concentration of mass adsorbed (mM), C is the concentration in solution (mM) and K is the Langmuir adsorption coefficient and m max is the maximum mass of adorbate (in this case Cs +) to form a complete monolayer at the m-TiO 2-coated quartz crystal surface. m isdetermined experimentally (directly from QCM experiments in this case) at different values of C and a plot of 1/m vs . 1/C, in accordance with the reciprocal form of the Langmuir isotherm [Eq. 3a], yields a straight line where the gradient and intercept can be used to evaluate K and m max. max max 1111m K m C m ⎛⎫=+ ⎪⎝⎭ max 111m m K C ⎛⎫=+ ⎪⎝⎭[ Eq. 3a, b]Thus, by using [Eq. 1] , the frequency changes of Figure 1a may be converted into mass changes and used in a plot of m max /m vs. 1/C, which yields values of K and m max of 6.7 and 22.5 respectively, Figure 1b.a) b)Figure 1. a) Frequency response of the m-TiO2 crystal at different concentrations of Cs+ under dark conditions. At t = 0mins C = 0mM. Concentration was increased by 250μM at 60minute intervals. b) Langmuir isotherm plot - response of the m-TiO2 crystal in dark conditions to Cs+ concentration. Gradient = 0.1486, intercept = 0.9967.Under UV IlluminationThe frequency response of the m-TiO2 coated QCM under illumination was investigated using a different experimental protocol to the dark response as follows. The coated crystals were mounted in its QCM holder and exposed to Cs+ containing solutions (0, 0.05, 0.1 and 0.2mM). The QCM’s signal was allowed to stabilise in the dark in the test solution for 24 hrs prior to illumination until no drift in frequency was observed. The recorded f vs. time data of Figure 2a shows the last hour of stabilisation of the QCM in the dark, with illumination at 315nm starting at time = 60 minutes.As reported by Lemon & Hupp [8], the rise in frequency, is due to local heating of the gold electrode on the crystal and not due to an apparent mass loss. This thermally induced frequency rise can be compensated for by performing the experiment in the absence of Cs+ and using the resultant f vs. time trace as a baseline reference. Therefore, the frequency responses for 0.05mM, 0.1mM and 0.2mM were -20Hz, -29Hz and -35Hz respectively.To exclude the possibility of the frequency rise/apparent mass loss being due to the photo-oxidation of surface contaminants, experiments were performed in a randomised order of 0mM, 0.1mM, 0.2mM and finally 0.05mM. Performing experiments from the lowest concentration incrementally would decrease the amount of surface organics available for photo-oxidation after each illumination period, resulting in a smaller frequency rise causing the incorrect interpretation of mass gain or Cs+ adsorption. However, performing the experiments in the aforementioned order overcomes this issue.a) b)Figure 2.a) Frequency response of the m-TiO2 crystal at different concentrations of Cs+ under illumination. C = 0mM, 0.05mM, 0.1mM and 0.2mM. b) Langmuir isotherm plot - response of the m-TiO2 crystal under illumination to Cs+ concentration. Gradient = 0.0694, intercept = 0.999.As in Figure 2a, mass change response for each added Cs+ concentration may be determined using [ Eq. 1] and used in a plot of m max/m vs. 1/C, which yields values of K and m max of 14.4 and 48 respectively, Figure 2b.It can be seen that under illumination the Langmuir adsorption coefficient, K, approximately doubles to the value of 14.4 from the value K = 6.7 obtained in the dark. Similarly,m approximately doubles to a value of 48 when the m-TiO2 coated crystal is maxilluminated compared to a value of 22.5 obtained in the dark, indicating that illumination allows for greater adsorption of Cs+ to occur on the TiO2 surface than in the dark. Two mechanisms can be envisaged: First, an intercalation of Cs+ cations with the TiO2 film to compensate a photolytically induced charge accumulation layer on the TiO2 surface as described by Lemon and Hupp [8], However, no hole (h+) scavengers are present in this system to prevent recombination of photo-excited electrons, and therefore promote the build-up of such a charge layer, rendering this mechanism unlikely. Second, the increased adsorption is due to the result of an increase in surface titanol concentration in a manner analogous to that thought to give rise to photo-induced super-hydrophilic TiO2 surfaces, therefore increasing available surface sites for Cs+ adsorption.The detection of Cs+ ions in both dark conditions and under illumination on TiO2 films provides a means to micro gravimetrically measure Cs+ ions in solution. This may be adapted for use in ground water situations for the detection of 137Cs+ in-situ as a replacement for external analysis methods currently employed such as ICP-MS. However, aqueous sensors are prone to bio-fouling over time causing the sensors to eventually cease to function [9]. The photo-active properties of the metal-oxide m-TiO2 films used in this study may be exploited to enhance sensor performance two-fold. Firstly by photo-oxidation of surface organic contaminants therefore cleaning the sensor surface and preventing build-up of said bio-films and reducing the amount of maintenance required, which is especially desirable in a nuclear environment. Secondly, the sensitivity of the sensor may be improved by increasing the number of available adsorption sites for Cs+ ions via photo-condensation. Adsorption based sensors also suffer from a lack of an easy method of analyte desorption, this is typically achieved using a solvent wash. However, the photo-induced adsorption on metal-oxide films may be a switchable process. Whether Cs+ is expelled upon the removal of illumination is currently under investigation.CONCLUSIONSWe have deposited mesoporous-TiO2 films onto QCM crystals and successfully detected Cs+ in solution at various concentrations, with potential applications as a caesium sensor. Using this device we have shown that, compared to the dark, TiO2 films exhibit a change in Langmuir constants, K andm of Cs+ adsorption when illuminated. Specifically, we have found thatmaxillumination of the m-TiO2 film results in m max approximately doubling i.e. illumination allows for greater adsorption of Cs+ to occur than in the dark. Our studies also show that K approximately doubles, indicating a higher affinity for surface adsorption under illumination, providing support for the surface reconstruction based explanation (increase in surface titanol group concentration) of photo-induced super-hydrophilicicity mechanism on metal oxide films.ACKNOWLEDGMENTSThe authors wish to thank the Engineering and Physical Science Research Council UK for provision of a CASE award to support PSF, and Oxley Developments Ltd and The Lloyds Register Educational Trust for additional financial support. The Lloyds Register Educational Trust is an independent charity working to achieve advances in transportation, science, engineering and technology education, training and research worldwide for the benefit of all.REFERENCES[1] A. Fujishima, X. Zhang and D. A. Tryk, Surface Science Reports 63 (12), 515-582(2008).[2] C.-y. Wang, H. Groenzin and M. J. Shultz, Langmuir 19 (18), 7330-7334 (2003).[3] F. Pascal-Delannoy, B. Sorli and A. Boyer, Sensors and Actuators a-Physical 84 (3), 285-291 (2000).[4] C. Boxall and M. Muneer, presented at the Third International Conference onSemiconductor Photochemistry, University of Strathclyde, Glasgow, Scotland, 2010(unpublished).[5] J. C. Yu, J. G. Yu, W. K. Ho and J. C. Zhao, Journal of Photochemistry and Photobiologya-Chemistry 148 (1-3), 331-339 (2002).[6] X. D. Wang, J. Shen and Q. Pan, J. Raman Spectrosc. 42 (7), 1578-1582 (2011).[7] P. Foran and C. Boxall, Unpublished Work.[8] B. I. Lemon and J. T. Hupp, The Journal of Physical Chemistry 100 (35), 14578-14580(1996).[9] H. Ben-Yoav, T. Amzel, A. Biran, M. Sternheim, S. Belkin, A. Freeman and Y.Shacham-Diamand, Sensors and Actuators B: Chemical 158 (1), 366-371 (2011).。
电影特效材料中英文材料解析
大学英-中文翻译材料英文题目Film effects and compositing 中文题目电影特效合成学院：计算机科学与技术学院专业：学生姓名：指导教师：二O一六年六月Film EffectsIn the movie, artificially manufactured illusion and hallucinations, known as movie special effects (also known as special effects). In the movie birth, he has had to change electrical cover, said to be a spectacular revolution too. More and more computer-generated image is applied to the production of films in the works. Sometimes the charm of its visual effects has greatly exceeded the film story itself. "Another feature of the film is used as a visual media exists."We can say that the film was born in the beginning, we've got movie special effects initiation. Also like movie special effects movie of the same roots and long brothers in more than a century of years to witness this door thrive movie special art. And ushered in a new century, a new one more.Early years, by the use of special effects during the initial part of the films produced by the computer to the effects of all changes in the film, people have seen the impact and shock visually. It seems that in modern times, we have been hard to find ingredients without any special effects in a film. Visible, all shadow effects initiation. Also like movie special effects movie of the same roots and long brothers in more than a century of years to witness this door thrive movie special art. And ushered in a new century, a new one more.60s of last century, with the computer or that digital technology is mature and "seventh art" invasion led to the film as a visual art form has been earthshaking multiple categories of filmmakers with the majority of fans have also stepped special effects for the film on the assiduous no return.After the birth of the first climax: the first stage of movie special effectsMoving images eventually evolved into the final film in the hands of wise men Daumier brothers. And with the continuing integration of various technologies, as the seventh art films have their own unique charm. "Movie special effects," the term given to the film followed the birth can explore the place more. In the late nineteenth century to the early twentieth century, the film also ushered in the birth of the effects after the first surge of development. Wonders and amazing images of various monsters frequent leaps onto the big screen.The second phase of movie special effects: sustainable development, classic highlightsAfter the initial stages of exploration and summary, movie people have a more profound understanding of the term "movie special effects." More importantly, the development of filmmaking technology, special effects movie taste to a whole new level. Also, people on Earth from outer space fantasy also enriched this time special effects movie content, the "special effects people" who have a broader space to play. During this period there have been like <A Space Odyssey "and" Planet of the Apes> kind of classic. History of the development of special effects for the film adds permanent flash highlights.The third phase of movie special effects: the rapid take-off, masterpiece again and againAs a young man named George Lucas • few simple manuscripts gradually forming in his mind that the field of "Star Wars," then fired, and fired the special effects in movies revamped grand campaign. In the seventies and eighties of the twentieth century, this short period of two decades, movie special effects in the new creative ideas and technical course, including revamped computer imaging technology and has undergone enormous changes. Naturally, at this time, it is a "Star Wars" series, "Superman," "Indiana Jones," "Alien" and <abyss> so that sort of movie masterpiece. Not only rich people to the wonders of film gradually inflated demand, leaving the film itself has a wider space to play, shooting can not be done previously by means of a variety ofspecial effects to complete, perfect.The fourth stage of movie special effects: steady progress, excellenceBut the clock to turn of the century, film special effects has shown quite mature look. Effects depend on a variety of manufactured grand scenes, better films have emerged, though, and the seventies and eighties as a wide range, but also have their unmatched features. Among these, the "Lord of the Rings" series of unprecedented vast, simply become a milestone for the movie history. Even more amazing is that the "Lord of the Rings" also appeared in an unprecedented technology to produce full CG character "Gollum", the action vivid, lifelike facial expressions, the film seems to be all over the real role of acting, called the movie miracle. The same as the magical theme "• Harry Potter" series, tough hot <Terminator "series, puzzling Network World story," The Matrix "series, all reflect the effects of the great charm of the film, after mature. I believe that in the coming time, the special effects in movies based on constantly enhanced technologies and creative ideas on, will bring us more surprise.Special effects technologies includeMiniature model: people, monsters, buildings, and transportation models have been used to make the movie special effects. When the model must be moved, we can move through the following three ways in which any one of: hand, mechanical, electrical, or to make them move. Use hand takes a long time to move them, because the model activity on the screen within a second species, at least there are 24 action.The illusion of the film: at normal speed, motion picture film in every 24 seconds to shoot still pictures. Change the number of pictures taken within seconds of each can create some basic effects. Footage per second more than 24, will produce a slow-motion effect. Conversely, if the picture within less than 24 sec, then the movie will accelerate the action, this will become more intense, exciting.Computer generated image: people use computers, making the film special effects production speed and quality has made tremendous progress.Designers simply enter minimal information, the computer can automatically synthesize complex image and screen clips.List of movie special effects1 "Lord of the Rings" series, director Peter Jackson • In 2001 filming of "Lord of the Rings", the latest movie classic fantasy justifiably claim to special effects, the series trilogy swept the Oscar for best visual effects award three years, creating several one hundred million yuan at the box office astronomical.2 "Star Wars" series, "Star Wars" trilogy (1977-1982) was a "milestone in the history of cinema, one of the most important cultural events of the 20th century" and its influence is felt throughout the world. "Star Wars" movie focused on the use of the most advanced high-tech computers and digital production tools, creating an unprecedented space in the world.3 "Titanic" director James Cameron • Following the "Terminator," "True Lies" successful, well-built 1997 disaster love blockbuster "Titanic." Very powerful video effects, the highlight of the night wreck scenario, production staff increased keyframe animation in motion capture from the performers, the splashes when the collision between the falling debris from the ship, and the ship's sea spray, rope, smoke, fluctuations sails, iceberg, ice on the deck, crashing glass, and miserable people crashed into the sea during the phase, all looks very Era significance.4 "Terminator" series, James • Cameron produced in 1984 <Terminator>, about war 士卡尔雷斯voluntary return in 1984 toprotect Sarah, against the computer "Skynet" sent a robot through the passage of time. Great movie action scenes, T-800 machine skeleton human appearance, bullet beat to death scenes are very alarming. 5 "The Matrix" series, the Wachowski brothers in 1999 to build the <Matrix> Mourinho tells hackers successfully become a savior, and adventures in the virtual world wars the enemy, but unexpectedly became a blockbuster sci-fi special effects milestone. The film combines elements of Hong Kong action movies, kung fu, bullet everything, actor skip building the scene, there are professionals called "bullet time" effects processing, great pioneering spirit.Television synthesisSince the film, television appeared on our planet, synthesis technology to become an essential part, synthesis refers to the process a variety of source material mixed in a single composite picture of the process in animation production, it can be divided conventional synthetic techniques and digital synthesis. Traditional synthesis technology is mainly used in the film, filming the process of tape and film photofinishing process to achieve, although behind the process, but the result was very good, in the Disney animated film "Tom and Jerry", we can see Successful use of traditional synthesis techniques, and digital synthesis technology is compared to conventional synthesis technology is concerned, the main use of advanced computer graphics to learn the principles and methods to a variety of source material collected inside the computer, and the computer will be mixed into a single process complex images and then output to tape or film in this series complete the process.In the field of computer graphics into quite a long time, digital synthesis technology has been in the animation process, a more widely used, and its synthesis technology has reached a very high level, which we can from the "Rainbow Cat and Blue Rabbit Seven Xia Chuan "in those dazzling, incredible stunts but very realistic, fully demonstrated. With fat people improve theoretical computer and computer image processing speed, digital synthesis technology has been widely used. Animation artists in the use of computer-synthesized diversity strongly felt during the operation of digital synthesis technology brings great convenience and means. The effect of synthetic work more attractive than conventional synthesis techniques, more incredible, this synthesis technique for promoting the development of great power.Synthesis techniques using the lensShooting angle lens angle can be divided into objective and subjective perspective. Objectivity angle footage as if the audience time to participate in the process at the site to observe the activities of people and enjoy the scenery scenery in general, the picture is approachable, to life, it uses up to on television; subjective point of view due to the anthropomorphic viewpoint movement its way, often easier to mobilize the audience a sense of participation and attention, prone to intense psychological sense.(A) Pull the lensA pull-up features (1) Pull the lens shift after the formation of the visual effects; (2) pull the lens to make the subject into small, surrounding environment from small to big. 2, pull the lens (1) the relationship between the performance of the main body and the environment in between; (2) through a variety of interrelated factors visual vertical and longitudinal orientation of the space, you can generate suspense, contrast, Lenovo's artistic effect ; (3) Pull the lens inside the tight rhythm pine, compared with the push-up, better able to exert emotional finish, resulting in many subtle emotions.(B) shift lens1, the shift lens features (1) shift the lens movement is not bound by the body (2) Lens shift in favor of the performance scenes. 2, the lens shift function (1) to develop a picture of the shape of the space, creating a unique artistic effect; (2) the performance scenes, with magnificent results when modeling complex scenes great depth, multi-level, multi-shadow matter ; (3) can be a strong subjective color shift lens effect to show a more realistic feel and live; sense of participation (4) caused immersive, marching figures used subjective lens.(C) with the lens 1, with the characteristics of the lens (1) screen always follow a moving subject; (2) the subject position of relative stability in the drawing board; (3) with the camera lens is different from the position of pushing forward the lens, also from the forward movement of the camera position before moving the camera. 2, with the function of the lens (1) Contact Lens and detailed performance can be continuously moving subject; it not only highlight the main, but also explain the main direction of motion, the relationship between speed, posture and its environment;(2) follow shot with the lens form a body of constant motion, stationary background change shape effect, help the environment by lead character; (3) follow shot with the lens from behind the characters, because the audience and the subject of the same viewpoint character can exhibit a kinds of subjective camera; (4) with the lens of the characters, things, scenes follow records are important in documentary programs.(D) pan1, panning features (1) people like panning or turning the head to look around a little while to realize another point by the visual effects; (2) a complete shake-up include: starting pieces, shaking off pieces of three mutually continuous process; (3) a motion panning from web sites to fall, forcing the audience to constantly adjust their visual attention. 2, panning function (1) of exhibition space, expanding horizons (2) in favor of more visual information through an inclusive Scene screen; (3) can be introduced to explain the intrinsic link the two subjects in the same scene;(4) to facilitate the performance of dynamic body movement momentum, direction of movement and trajectory; (5) can roll out to the accident, suspense, plus the formation of visual attention and downs in one shot.(E) Push the lens1, pushing the lens features (1) forming a visual effects forward; (2) have a clear objective body; (3) to make the subject from small to big, from big to small surrounding environment. 2, pushing the lens function (1) highlight the main character, highlighting key figures; (2) highlight detail, focused detail factors; (3) describes the relationship between global and local, with the main task of the objective environment in one shot; (4 ) can strengthen or weaken the sense of movement of the moving object; (5) can be used to adjust the screen rhythm generated outside of the emotional force.(Six) elevating the lens1, lift the lens features (1) Lift the lens down movement brought the expansion and contraction of the screen depending on the field; (2) continuously changing camera viewpoint movements formed a multi-angle, multi-faceted multi-patterned effect. 2, lifting the mirror function (1) is conducive to the performance of each local tall objects; (2) in favor of the relationship between the performance of deep space, the surface points; (3) can be used to display objects or scenes scale, momentum and atmosphere; (4 ) scheduling content conversion can be achieved within a shot; (5) can be expressed in changes in emotional state of the screen. (G) a comprehensive sports lens, the lens features a comprehensive sports (1) produce a morecomprehensive picture of the complex modeling results; (2) a comprehensive form of exercise each lens screen, its trajectory is multi-directional; multi-way movement One result after. 2, features comprehensive sports lens (1) record and performance in favor of a relatively complete a scene shot in one episode. (2) continuous dynamic integrated movement of the lens is conducive to the process of life; (3) in favor of pluralism formed by the direction of the screen ideographic structure ambiguity; (4) integrated in a longer continuous motion picture camera, you can with the rhythm of the music changes with each other "in tune" to form a sense of rhythm and music integrated screen image.(H) the empty lensEmpty lens is a kind of special lenses, used to introduce environmental background, explain time and space, to express the characters emotions in the film can be produced by physical metaphor for love, see King hygiene conditions, scenes, rendering mood, heighten the atmosphere, caused by Lenovo and other artistic effects. A good cartoon is the result of the integrated use of various lenses, of course, "Rainbow Cat and Blue Rabbit Seven Chivalrous Biography" is no exception, it is due to the combined use of various lenses, plus a unique combination of digital effects, making this film with magnificent momentum, shocking images, eye-popping.Screen lens design and synthesis technologyAnimation is a screen shot of the final design of the carrier appears, if the screen is viewed as the picture, then the footage this screen are designed around the screen, the design of the lens to the screen, the main terms from three directions.1, compositionComposition is the key essence of the picture, naturally footage design. "Rainbow Cat and Blue Rabbit Seven Chivalrous Biography" episode that the opening few shots, the composition is very reasonable, in order to show Zhangjiajie this particular content and visual sense, the various modeling objects in front of the lens is the performance and photography Factors organic organization, published in the screen, and the screen to form some form of psychological audience left a very deep impression, make people feel Zhangjiajie is a fascinating tourist destination, a paradise on earth, flowers, mountain springs, people initiation of a "He who has never been to the Great Wall is not a true man" feeling. Visible role in the composition in the cartoon is great.2, the colorCartoon color is the most abundant, because all the elements created by designers in the picture are by themselves to set the color, the color for the human mind has a fundamental effect, when the designer to set the story based on literary tone , rendering the atmosphere is warm and cold colors contrast, the best way to heighten the environment, such as "Rainbow Cat and Blue Rabbit Seven Chivalrous Biography" are used in the context of all realistic expression, its color is quite rich in rendering the atmosphere, the environment at the same contrast, Habitat also added the film can be ornamental. In addition, the effect of color uniform characters in the film, full of oriental flavor visual tone, has also become an important factor in the success of the film. In summary, the expression of emotional color cartoon style tone, rendering the atmosphere has an important role.3, lightLight has a very important role in the cinematography, the same picture is also quite a lot in the cartoon. In the cartoon is very particular about the use of light and shadow in the design, the designers have to assume that some of the light, when these different angles of incident lightpoints will produce different effects on the body. For example, in the "Rainbow Cat and Blue Rabbit Seven Chivalrous Biography" effect on the character set, it is a good proof of the great role light plays in the movie. Lens design is not just about the means to the story, it is a reflection of the style of the movie, the screen design and lens design both influence each other, mutual restraint as footage design is a combination of organic natural lens and screen.Synthesis of digital effectsTruth is the basic principle of artistic creation, both as unlike real life and life itself is the same, but also not true that science can and restore, cartoon people give full play to the imagination, it is a good cartoon hauntingly works of art, but no one wants to see those who are commonplace scene. Digital special effects make this more exciting, as one of the cartoon creation means the creation of digital effects also follow the basic rules of artistic creation - true. Specific operation, I believe that because of the attention to the following points:1, human scenery, sound and light color fidelityHuman scenery, sound and light colors are the most important element audiovisual language, they constitute a major component of picture information, principles of digital visual effects processing these elements is to recover the overall relationship among them, whether it is virtual generation, or synthetic keying , are the scenes which should be combined with an environment light conditions, uniform color, color, texture restoration, in order to achieve a realistic effect, which is done, which is to make the audience aware of the results of digital effects, resulting from the gradual sense, examples of this aspect, in front of the text has been talked about, there is no longer dwell on.2, a reasonable view of the lens movement, and the movement trajectory of the objectViewpoint is the audience's point of view of the lens, its location is still reasonable to follow the principles of true feelings, its rationality is built around people accustomed to a certain degree of visual development, such as aerial remote sensing camera that allows the audience to appreciate overlooking the earth, according to the head beings feeling. Lens movement also has its own rules, the traditional camera movement has to be very strict, mature specification, digital effects still can not be broken, if free to let the camera movement will cause the results form from content.Is a groundbreaking digital effects ax, the traditional view is that digital effects is to be repaired some undesirable pre-shoot camera, generate some interesting pictures. Some creators of digital effects in order to pursue fashion means to fill some of the special effects shots in the frame, so that the effects of formal, detached from the overall style and structure of the film, digital effects has become a manifestation of the way, it has changed the traditional way of making cartoons , a form of digital effects is an effect of animation is an animation production process will not be a lot of content, it is conceivable if there is no digital effects in the background, the development of what will be a cartoon look.In summary, the synthesis tool is not just post-processing of the material, but throughout an important part of every animation production process, and even planning, screenwriter can not forget the factor synthesis technology generates virtual characters than do some other functions of the work, but to create a realistic, but a vivid reality does not exist. Is a form of performance art, creators of audiovisual language tells a moving story, the characters express emotion, infection audience. With the development of computer technology will be a new face synthesis show in front of people, will create a new style of film language and style, providing unlimited imagination of the creators.电影特效在电影中，人工制造出来的假象和幻觉，被称为电影特效(也被称为特技效果)。
非放大高速光电探测器用户指南说明书
NON-AMPLIFIED HIGH SPEED PHOTODETECTOR USER’S GUIDEThank you for purchasing your Non-amplified High Speed Photodetector. This user’s guide will help answer any questions you may have regarding the safe use and optimal operation of your Photodetector.TABLE OF CONTENTSI. Non-amplified High Speed Photodetector Overview ...................................................................................... 1 II. Operation of your Non-amplified High Speed Photodetector ......................................................................... 1 III. Troubleshooting ............................................................................................................................................... 2 IV. Drawings: Non-amplified High Speed Photodetectors ................................................................................... 3 V. Specifications: Non-amplified High Speed Photodetectors ............................................................................ 3 VI. Schematics: Non-amplified High Speed Photodetectors ................................................................................. 4 VII. Glossary of Terms . (4)I.Non-amplified High Speed Photodetector OverviewThe Non-amplified High Speed Photodetectors contain PIN photodiodes that utilize the photovoltaiceffect to convert optical power into an electrical current. Figure 1 below identifies the main elements of your Photodetector.Figure 1: Non-amplified High Speed PhotodetectorWhen terminated into 50Ω into an oscilloscope, the pulsewidth of a laser can be measured. When terminated into a spectrum analyzer, the frequency response of a laser can be measured.II.Operation of your Non-amplified High Speed PhotodetectorA. Caution: Eye safety precautions must be followed when utilizing any equipment used in the vicinityof laser beams. Laser beams may reflect from the surface of the detector or the optical mount and caution must be exercised.B. Mount the detector to an optical stand by the mounting holes on the bottom of the detector housing.C. Adjust the voltage of the oscilloscope to 20mV/division before connecting the detector.D.Connect the detector to the oscilloscope using a coaxial cable designed for 10GHz operation.Sensor AperturePower SwitchSMA Connectore the 50Ω termination input of the oscilloscope.F.After being certain that the damage threshold of the detector is not exceeded, place the detector inthe center of the laser beam.G.There is an internal 50Ωresistor at the output of the photodiode. This will cause the output current toyour test equipment to be half that of the photodiode output. For example, the output to yourequipment will be 450µA for a 1mW optical input at 0.9A/W.III.TroubleshootingA.No signal is seen the first time the detector is used.1.Is the power switch on?2.Be certain that the signal is not high off scale on the oscilloscope.3.Is the wavelength of the laser within the spectral range of the detector?4.Has a 50Ω termination input been used?5.Try moving the detector within the laser beam.6.Is there enough light (see sensitivity spec on the data sheet) incident on the detector to generate asignal? The detector’s small active area makes alignment somewhat difficult.B. A signal has been previously obtained, but not currently.1.Try steps listed under A.2.Inspect the active area of the photodiode for any signs of damage.3.Test the power supply:a.Units with internal batteries will typically operate for several years, but operation with CWor high rep rate lasers can drain the batteries much faster. If a load is present at the output,current will be drawn from the batteries, so disconnect the BNC when not in use.Remove top cover to replace the 3V lithium cells with Duracell Model DL2430, positive sidedown.b.Units with an external power supply should at least receive the voltage that is printed on theplug.C.Increasing the power incident on the detector does not result in a higher voltage signal on theoscilloscope:1.The detector is probably saturated. You should lower the power incident on the detector to alevel below the saturation point.IV.Drawings: Non-amplified High Speed PhotodetectorsA.818-BB-35, 818-BB-45, 818-BB-51 Dimensions:V.Specifications: Non-amplified High Speed PhotodetectorsPart No. (Model)818-BB-35 818-BB-45 818-BB-51 Rise Time/Fall Time (ps)<25/<25 <30/<30 28 Responsivity (A/W)>0.90 at 1300nm 0.53 at 830nm 1.3 at 2000nm Power Supply6V battery/5V external 3V battery/5V external 3V battery/5V external Spectral Range (nm) 830-1650 500-890 830-2150 Bandwidth>15GHz >12.5GHz >12.5GHz Active Area Diameter (µm)32 60 40Dark Current<3nA <0.5nA <1µA Acceptance Angle (1/2 angle)15° 15° 20⁰Noise Equivalent Power (pW/√Hz)<0.03 at 1300nm <0.02 at 830nm <0.44 at 2000nm Mounting (Tapped Hole)8-32 or M4 8-32 or M4 8-32 or M4 Output Connector SMA SMA SMAVI.Schematics: Non-amplified High Speed PhotodetectorsBandwidth: The range of frequencies from 0Hz (DC) to the frequency at which the amplitude decreases by 3dB. Bandwidth and rise time can be approximately related by the equation:Bandwidth ≈ 0.35/rise time for a Gaussian pulse input.Bias Voltage: The photodiode’s junction capacitance can be modified by applying a reverse voltage.The bias voltage reduces the junction capacitance, which causes the photodiode to have a fasterresponse.Dark Current: When a termination is present, a dark current (nA range) will flow if the photodiode is biased. Disconnecting the coaxial cable will prevent this current from flowing.Decoupling Capacitor: Maintains bias voltage when fast pulses cause the battery voltage to reduce (this would slow the response time of the photodiode); the capacitor allows the battery to recover to its initial voltage. It also acts as a filter for external power supplies.Noise Equivalent Power (NEP): A function of responsivity and dark current and is the minimumoptical power needed for an output signal to noise ratio of 1. Dark current is the current that flowsthrough a reverse biased photodiode even when light is not present, and is typically on the order of nA.Shot noise (Ishot) is a source of noise generated in part by dark current; in the case of reversed biaseddiodes it is the dominant contributor. NEP is calculated from shot noise and responsivity. For example, for a responsivity @ 830nm = 0.5 A/W:q = charge on an electronPhotodiode: Converts photons into a photocurrent.Resistor: Protects the photodiode from excessive current. This could occur if an external power supply was too high in voltage, or if its polarity were reversed; this happens when a customer uses their own power supply.Responsivity: In amps per watt (A/W), responsivity is the current output of the photodiode for a given input power, and is determined by the diode structure. Responsivity varies with wavelength and diode material.Rise Time/Fall Time: Rise Time is the time taken by a signal to change from a specified low value to a specified high value. Fall Time is the time taken for the amplitude of a pulse to decrease from a specified value to another specified value. A larger junction capacitance will slow the detector’s response time.SMA Connector: Used to connect the customer’s coaxial cable for high frequencies.Termination Resistor (50Ω): Reduces signal reflections and balances the 50Ω microstrip/coaxial cable lines. As a result, half the photodiode current is lost to the internal resistor.Hz 0.08pA/s 0.08pA )1020)(2(1.6x10=2_9-19===−A x As qI Noise Shot d Hz 0.16pW/0.5AW *08.0/R 830nm ===Hz pA I NEP shot。
德罗斯特
德罗斯特效应照片制作教程先说一下什么是德罗斯特效应，德罗斯特效应（Droste effect）是递归的一种视觉形式，是指一张图片的某个部分与整张图片相同，如此产生无限循环。
就好像是说，你拿着一面镜子，然后再站在一面镜子前面，让两面镜子相对。
你看到镜子里面的情景，是相同的，无限循环的。
德罗斯特效应是一组非常有意思的照片，非常神奇，有的需要你花时间去辨别，如果你在这些图像上盯着太久，你可能会觉得自己越来越走到框架里面，甚至造成头晕、胸闷、脑子混乱…这种神奇的效果就被称为“德罗斯特效应”。
开始之前我们需要3个软件，分别是photoshop，GIMP（类似于PS），还有一个名为Mathmap 的数学软件，作为插件性质嵌入到GIMP里面，就像PS里面的滤镜一样。
可以自己到网上搜索。
下载好之后就可以进行安装了1 解压2 将 mathmap.exe, libgsl.dll, libgslcblas.dll 复制到 GIMP 插件(plugin)目录，默认是C:\Program Files\GIMP 2\lib\gimp\2.0\plug-ins3 复制 mathmaprc 、new_template.c 到C:\Users\你的用户名\.gimp-2.8\mathmap如果没有mathmap这个文件夹的话请新建一个。
1 你需要一张事先准备好做效果的图片，并在photoshop里面将需要的框架部分抠出来，背景透明，并保存为PSD或PNG文件。
抠图，换背景，加投影，加灯光调色我就不一一介绍了2.把刚才做好的PSD文件拖到GIMP里面，选择菜单的 Filters/Generic/Mathmap/Mathmap 打开Mathmap 插件,如图3.在设置面板里（Settings）去掉自动预览项（Auto Preview）4.进入Expression界面，将原有的默认代码删除，粘贴上我给你们的代码（文章最后会补上），然后就可以点预览（Preview）按钮了5.切换到 User Variables 面板，勾选 Tile Based on Transparency 和 Transparency Points In 项，然后点左边的预览(Preview)按钮感谢代码for Mathmap的原作者Breic 和改进者Pisco Bandito附代码########################################## Droste Effect code for Mathmap #### Original Code by Breic (Ben) #### Adapted by Pisco Bandito (Josh) #### Version 4.0 #### This version for Windows and Linux ###########################################You may need to alter the values of the following 9 variables to suit your image. r1=.4; # r1 is the inner radius. r1 is greater than zero and less than r2r2=1; # r2 is the outer radius. r2 is greater than r1 and less than 1p1=1; # periodicity - the number of times the image will repeat per cyclep2=1; # number of strands - the number of "arms" the spiral will have# procedural scaling and rotationzoom=.1; #Between .1 and 10rotate=-30; #Between -360 and 360# Procedural ShiftingxShift=.2; #Between -1 and 1yShift=0; #Between -1 and 1### To avoid framing problems on the largest annulus when tiling based on transparency, look# outside (levelsToLookOut) levels to see if something farther out should cover up this pixel# Try setting to 0 to see framing errors; 1 should be sufficient unless you have three or more# image layers contributing to some pixel (in which case set it to 2 or more). Larger values# slow the code down, and may lead to floating point errors.##levelsToLookOut=3;########################################################################################################################## You should not have to change anything below this line ##########################################################################################################################imageX=W; # image size, in pixelsimageY=H;minDimension=min(imageX, imageY);## User Variables, set these on the User Settings Tab ##retwist=user_bool("Do Not Retwist (Leave Unchecked for Droste Effect)");retwist=!retwist;### Tiling can be based on transparency (if the input image is a tiff), or simply based on the# radius. Using transparency, there can be protrusions between different annular layers.# Tiling based on transparency, you can decide whether you want to look inward or # outward from a transparent pixel. For example, with a frame you'll want to look inward,# while for a flower you'll want to look outward.##tileBasedOnTransparency=user_bool("Tile Based on Transparency?"); transparentPointsIn=user_bool("Transparency Points In?");# Miscellaneous variablestrue=1;false=0;epsilon=.01;##Correct the Rotation Variablerotate=pi/180*rotate;### Droste-effect code starts here# Set Droste effect parameters##alpha=atan(p2/p1*log(r2/r1)/(2*pi));f=cos(alpha);beta=f*exp(I*alpha);# the angle of rotation between adjacent annular levelsif (p2 > 0)then angle = 2*pi*p1;elseangle =-2*pi*p1;end;### Code to set up the viewport properly##if (retwist) thenxbounds=[-r2,r2];ybounds=[-r2,r2];elseybounds=[0,2.1*pi];xbounds=[-log(r2/r1), log(r2/r1)];end;xymiddle=ri:[0.5*(xbounds[0]+xbounds[1]),0.5*(ybounds[0]+ybounds[1])];xyrange=xy:[xbounds[1]-xbounds[0], ybounds[1]-ybounds[0]];aspectRatio=W/H;xyrange[0]=xyrange[1]*aspectRatio;xbounds=[xymiddle[0]-0.5*xyrange[0],xymiddle[0]+0.5*xyrange[0]];z=ri:[(xbounds[0]+(xbounds[1]-xbounds[0])*(x+W/2)/W)+xShift,(ybounds[0]+(ybound s[1]-ybounds[0])*(y+H/2)/H)+yShift];if (retwist) then # only allow for procedural zooming/scaling in the standard coordinateszinitial=z;z=xymiddle+(z-xymiddle)/zoom*exp(-I*rotate);elsezinitial=r1*exp(z); # save these coordinates for drawing a frame laterzinitial=zinitial*zoom*exp(I*rotate);end;### The Droste effect math all takes place over the next six lines.# All the rest of the code is for niceties.##if (retwist) thenz2=log(z/r1);elsez2 = z;end;logz=z2; # save these coordinates for drawing a grid laterz=p1*z2/beta;rotatedscaledlogz=z; # save these coordinates for drawing a grid laterz=r1*exp(z);## End Droste effect math## Tilingif (tileBasedOnTransparency && levelsToLookOut > 0) thenif ( transparentPointsIn) then ratio=r1/r2*exp(-I*angle); end;if (!transparentPointsIn) then ratio=r2/r1*exp( I*angle); end;z=z*exp(levelsToLookOut*log(ratio));end;### When tiling based on transparency, color is accumulated into the colorSoFar variable,# while alphaRemaining tells how much remains for lower layers to contribute (initially 1,# finally 0).##colorSoFar=rgba:[0,0,0,0];alphaRemaining=1;ix=minDimension/2*z[0];iy=minDimension/2*z[1];color=origValXY(ix,iy);colorSoFar = colorSoFar + (color*(alpha(color)*alphaRemaining)); alphaRemaining=alphaRemaining*(1-alpha(color));# do we need to look inward from the current point, or outward?sign=0;if (tileBasedOnTransparency) thenif ( transparentPointsIn && alphaRemaining > epsilon) then sign=-1; end;if (!transparentPointsIn && alphaRemaining > epsilon) then sign= 1; end;elseradius=sqrt(z[0]*z[0]+z[1]*z[1]);if (radius < r1) then sign=-1; end;if (radius > r2) then sign= 1; end;end;if (sign < 0) then ratio=r2/r1*exp( I*angle); end;if (sign > 0) then ratio=r1/r2*exp(-I*angle); end;### Iteratively move inward or outward, until# the point has radius r in [r1, r2), if tileBasedOnTransparency=false# or until alphaRemaining=0, if tileBasedOnTransparency=true# In the latter case, we accumulate color at each step##iteration=0; maxiteration=10;while (sign != 0 && iteration < maxiteration) doz2=z*ratio;z=z2;rotatedscaledlogz=rotatedscaledlogz+ri:[0,-sign*angle];ix=minDimension/2*(z[0]);iy=minDimension/2*(z[1]);color=origValXY(ix,iy);colorSoFar = colorSoFar + (color*(alpha(color)*alphaRemaining));alphaRemaining=alphaRemaining*(1-alpha(color));radius=sqrt(z[0]*z[0]+z[1]*z[1]);sign=0;if (tileBasedOnTransparency) thenif ( transparentPointsIn && alphaRemaining > epsilon) then sign=-1; end;if (!transparentPointsIn && alphaRemaining > epsilon) then sign= 1; end;elseradius=sqrt(z[0]*z[0]+z[1]*z[1]);if (radius < r1) then sign=-1; end;if (radius > r2) then sign= 1; end;end;iteration=iteration+1;end;color=colorSoFar;color=rgba:[color[0], color[1], color[2], 1]; # set the alpha value to 1 (it could be <1 if the loop terminated at iteration maxiteration)#This last line is important, it returns the pixel value for the current pixel color。
照片美学分析英语作文
照片美学分析英语作文Photography is an art form that has evolved significantly over the years, and it has become an integral part of our everyday lives. The art of photography is not just about capturing a moment in time, but also about understanding the aesthetic principles that govern the creation of a visually compelling image. In this essay, we will explore the concept of photographic aesthetics and how it can be used to create stunning and impactful images.One of the fundamental elements of photographic aesthetics is composition. The way in which the various elements within the frame are arranged can have a significant impact on the overall impact of the image. The rule of thirds is a widely recognized compositional technique that involves dividing the frame into a grid of nine equal parts and placing the subject or focal point at the intersection of these lines. This creates a sense of balance and harmony within the image, drawing the viewer's eye to the most important elements.Another important aspect of photographic aesthetics is the use of light. The way in which light interacts with the subject and the environment can create a range of visual effects, from dramatic shadows to soft and ethereal lighting. Photographers who are skilledin the use of light can create images that evoke a particular mood or emotion, whether it's the warm glow of a sunset or the stark contrast of a high-contrast black and white image.Color is also an important consideration in photographic aesthetics. The choice of color palette can have a significant impact on the overall tone and mood of an image. Some photographers may opt for a more vibrant and saturated color scheme, while others may prefer a more muted and subdued palette. The use of color can also be used to create a sense of balance and harmony within the frame, as well as to draw the viewer's attention to specific elements.Another important aspect of photographic aesthetics is the use of negative space. Negative space refers to the areas within the frame that are not occupied by the subject or main elements of the image. Skillful use of negative space can create a sense of balance and visual interest, as well as draw the viewer's attention to the most important elements of the image.Perspective is also an important consideration in photographic aesthetics. The way in which the photographer chooses to position the camera can have a significant impact on the way in which the subject is perceived. For example, shooting from a low angle can create a sense of power and dominance, while shooting from a high angle can create a sense of vulnerability or smallness.Finally, the choice of lens and camera settings can also play a role in the overall aesthetic of an image. Different lenses can create different effects, such as a wide-angle lens that creates a sense of depth and drama, or a telephoto lens that compresses the image and creates a more intimate and isolated feel.In conclusion, photographic aesthetics is a complex and multifaceted field that requires a deep understanding of the various elements that contribute to the creation of a visually compelling image. Whetherit's the use of composition, light, color, negative space, perspective, or camera settings, the skilled photographer can create images that not only capture a moment in time, but also convey a sense of emotion and beauty. By mastering the principles of photographic aesthetics, photographers can create images that truly stand out and leave a lasting impression on the viewer.。
ps里的通道是什么概念（WhatistheconceptofthechannelinPS）
ps里的通道是什么概念（What is the concept of the channel inPS）What is the concept of the channel in PS?In order to record the selection area, you can save it as a separate image in the form of black and white, and then make a variety of effects. The black and white images which are independent and attached to the original image and used to preserve the selection area are called "passages"Channel). In other words, the channel is the most important part of image processing.However, there are not many people who really know the Photoshop channel. A little knowledge of basic concepts results in technical faults, and some difficulties can not be broken. This is caused by putting the cart before the horse in learning. This paper tries to discuss the essence, operation and special form of Photoshop channel by using the common image processing methods to help readers get the inspiration, understand the nature and master the application.Origin of channel -- traditional photographic synthesis technology and its digitalizationApplication of 1. shutterWe know that the full digitalization of the Phototypesetting industry is only a matter of recent years. Before that, the workload of image compositing workers was so large that thecontent was boring. They will have to shut myself in the darkroom, as the shutters in the enlarger below, to choose the film exposure. The shutter is actually coated with black dye in different parts of a transparent film so that the light cannot pass through it. At the time of exposure, shutter and film overlapped, so that the cover plate on the image below the black area because of opaque black cover and not be exposed, leaving only the image corresponding to the transparent part, is said to complete the choice of the photo exposure. In the repeated several times the same boy with Mou Xi Mo - Huang angry turbulent appearance the Bu Bu sieve centre news magpie get control milling will flash?The concept of the channel is evolved from the shield. In the channel, white is used instead of transparency to represent the part to be processed (selection area); black is used to represent the non processed part (the non selection region). Therefore, the channel has the same meaning as the mask, and has no independent meaning, but only when it is attached to other images (or models), can it reflect its function. And the biggest difference between the channel and the mask is also the biggest advantage of the channel, that is, the channel can be completely processed by the computer, that is, it is completely digital.2. channels -- digitization of traditional technologyThe computer can work tirelessly for 24 hours, and it's extremely efficient. Therefore, people have spared no effort to put all possible information to the computer processing, the wave of digital sweeping across the world, the image processingindustry is no exception.How to change a vivid photograph into "0" and "1" on our hard diskWhat about it? Before that, let's take a look at the features of digital information. First of all, as the name suggests, the biggest feature of digital information is that any form of information can be expressed in complete and accurate numbers, whether it is a record, a phone call, or a video. This feature of digitization is easy to understand, and we call it "parsing."".Secondly, limited by storage and computation, the capacity of digital information must be limited. That is to say, in order to analyze the rapidly changing and nuanced analog signals, we must choose something to replace the original information flow with a small enough and resolvable "information element"". We see that such a "sampling" process inevitably loses some raw data between the elements and the elements. So we must take a close degree of indicators to judge the digital information and analog information. Obviously, in the limited length of the "information flow", the "information" of the more, this transformation is more accurate, on the other hand, the "information" is less, the close degree is more rough. Therefore, we use the number of "information elements" in the unit information flow to measure the fidelity of digital information. In digital audio, this index is called "sampling rate" and "quantization accuracy"; in digital video, it is called "frame rate"";In digital images, it is called "resolution"". As long as this index is large enough to confuse people's senses and make our ears and eyes mistakenly think that this is a coherent picture, or a piece of music, without any perceptible pause or particles. Compared with the "continuous" nature of analog information, the characteristic of digital information is called "discontinuity", or "discontinuous"".Now, an image is separated from a vertical line with many equidistant horizontal lines, each of which is a pixel (pixelThat is, an independent information element, and the digital work is half done. Next, what we need to do is to record the color information of each pixel.Because we are going to discuss the color image, so only black and white and grey information (in black and white images, and "Brightness", "gray" concept is equivalent), regardless of its hue. But don't forget, but also have different levels of gray, like "","Light gray "or" gray".But it's not enough to describe the brightness of objects only in words. As mentioned above, digital information has the characteristics of "discontinuity", so it was proposed that the integer between 0 and 100 should be used to represent the gray level: for example, 0Pure black, 100 in pure white, and 50 in black and white.As is known to all, in computers, data is stored in bits (bit). Each bit can only store the information of "0" or "1" to correspond to the binary bit. Let's see to represent a 0 to 100How many binary bits are needed for any integer between them: log 2 101=6.6582That is to say, we used 7 bit storage space to store data only with 6.6 bits. Isn't that a waste? And the root of this waste is that we divide the gray scale between black and white into man-made onesThe 101 paragraph, not the other number.So, in order to make the best use of everything, people usually divide the gray level with an integer power of 2. Usually, gray scale is divided into 256 levels (represented by 0~255), and this will take up 8The space of one storage bit (one byte). And the origin of the number 8, is to make the naked eye in any adjacent two levels of change, without a trace of awareness.Through the above two steps, the gray information of each pixel is written into the hard disk according to the divided grid, from top to bottom, from left to right, and the digital work is finally completed. And when we experience the feeling that computers are processing the speed of the constituency, we will understand that this series of complicated transformations and operations is not futile.Two, several special channel typesAs you can see from the previous section, the earliest channel concept is a special image that is evolved from the mask in traditional photographic technology to represent the range of selection. After that, the rapid development of computer image processing technology, the concept of channels and expand greatly, which covers the vector drawing, 3D modeling, material, rendering and other fields, and is no longer confined to the graphic design of the original meaning of "boundary". The "channel" of every hue has a different name, use and calculation methods, but with the original concept of channel are essentially similar: they are attached to other image exists, single color grayscale image.1. primary color channel, Alpha channel and spot color channelIn the previous description, we have carefully understood the channel, that is, the digital process of monochrome images. So, how do computers use these numbers to represent color images? First of all, let's understand the concept of primary colors and the mixing principle of addition and subtraction.In primary school art class, we understand the concept of red, yellow, blue tricolor.Here the red, yellow and blue accurately should be magenta (Magenta), yellow (Yellow) and green (Cyan). The three colors are mixed in different proportions, can obtain any other colors; and mixing the three colors to themaximum extent, will make all the wavelength range of visible light and show black all absorbed. We call these three elements the "light source tricolor", and the hybrid method that reduces the brightness of the color in the mixing process is called subtraction mixing.Usually, in printing, this subtraction mixing principle is applied: in white paper, through the mixture of light source, tricolor ink, to obtain a variety of colors and their combination of images. But in practice, the black cost is high and the quality is poor by mixing, so it is usually artificially added a low cost black inkBlacK) printed together with product, Huang and qing. Therefore, this printing process is also known as "four color printing", and its color system is called "CMYK color system"".The principle of additive mixing in accordance with the principle of subtractive mixing in printing is that the display element follows. Red (Red), green (Green), blue (Blue)Three colors are called "tricolor". Three colors of light can be mixed to obtain any other colors, and the maximum mixing will get the highest brightness color - white. We know the vast majority of display devices around usAdditive mixing principle is applied to CRT cathode ray tube and LCD liquid crystal panel. Therefore, when the equipment is not started, the darker the background color and the lower the brightness, the better the imaging effect. The display color system is also called RGBColor system.The laws of nature are so simple and graceful that theever-changing colors are merely the organic combination of three simple primary colors. Therefore, any color image can be regarded as the superposition of three images of different primary colors. Since any monochromatic grayscale map can be considered as a channel, then we can use it completely3~4 channels to record a color photograph. Each channel records the distribution information of a corresponding primary color on the color image, so we call it the "primary color channel"". For display purposes the pictures (such as web page) can be decomposed intoR, G, B three primary color channels, and the output of the picture (such as posters, magazine covers, packaging paper, etc.) is decomposed into C, M, Y three primary color channel and a K channel.Since each single pixel of the channel requires 8 binary bits of storage space, then each pixel in the tri color channel is composed of three monochromatic pixels, which requires 8 x 3=24Two binary bits for storage. So, in the amount of data is three times the original, the number of colors can be expressed into 224 ~ 1.6 * 107. We usually have these 1600The gamut of tens of millions of colors is called "24bit true color."".2.Alpha channelThe Alpha channel is a specially designed channel for saving the selection area. When you generate an image file, you don't have to generate AlphaPassage. Usually, it is generated by people in the process of image processing, and the region information is read from it. Therefore, in the output plate, AlphaThe channel will be deleted because it has nothing to do with the final generated image. But sometimes, for example, when a 3D software is rendered at last, a Alpha channel is generated to make a later synthesis in the plane processing software.In addition to the file format PSD of Photoshop, GIF and TIFF format files can store Alpha channels. And the GIF file can also use AlphaChannel as background removal for image processing. Therefore, we can make use of this feature of GIF file to make arbitrary shape graphics.3. spot color channelIn order to make their printed works different, they often have to do some special treatment. Such as the increase of fluorescent ink or luminous ink,Registering system (such as colorless printed bronzing), thesespecial color ink (we call it the "spot") are not made by three color printing ink can be used mixed, spot color channel and spot color printing at.In the image processing software, there is a list of complete spot color ink. We only need to choose the spot color ink, will produce its corresponding spot color channel. But in the processing, the spot color channel is opposite to the primary color channel, and the black represents the selection (that is, inkjet ink), and the white represents not selecting (not printing ink). This is something that needs special attention.Spot color printing can make the work more visual and shocking in the visual effect, but because most of the spot color can not show the effect on the display, so its production process also has a considerable empirical component.4. mask and texture mixing channelThe mask is also known as the "Mask", can be said to be the best embodies the "shield" meaning channel application.In an image (or a layer) add a black-and-white grayscale image, the black part of the image will be hidden (and not deleted), become transparent; white will be fully revealed; and part of the gray scale in a semi transparent state. No matter in the mask image synthesis or in special effects, have irreplaceable function. The mask can also be applied to the 3D model of the mapping above. The metal rust, the glass decals, these irregular graphics, tend to be processed by way of mapping with rectangular mask. This type of mask because of the need toadjust their position in 3D surface, so often seen as a special form of the map, called "opacity map".The mask can be used not only in the simple map, can be used in more complex multidimensional material. When the two materials are mixed together on the same surface, people also need to use the channel to handle their distribution. But unlike ordinary mask is such a "mixed channel" is directly used in the two images: the black part of the showA image; white part displaysB image; gray scale part is both. Therefore, the mixing channel is derived from the concept of mask, used two images overlap between a simplified application control.5. displacement mapping and bump mappingIn 3D software, the channel is not only limited to the processing of planar maps, but it is also used to represent more complex materials, and even to model.Imagine, we want to model a coin: its surface complex patterns and patterns will certainly bring a lot of trouble to our work, using the usual modeling means, almost impossible to complete. Some people may ask: can we use a flat image to represent the bump of the surface of an object (like an elevation map), and allow the computer to do the tedious modeling work automatically? The answer is: Yes, and the key plan is the channel.A channel is attached to the surface of an object with theso-called "displacement map", and then the computer will operate like this:The map on the surface of the node, according to the brightness information of the pixels on the map channel, along the surface in the normal direction of the point of traction in different degrees, or concave, convex, or like a color picture than the front elevation map, in the mud Niechu high mountain and canyon. Now, if we use the plane drawing tools to draw a two-dimensional image, and then transformed into the displacement map and give an object, the very texture of the coin on the.Although displacement mapping can greatly reduce the workload of modeling, but because the resulting model is not optimized enough, the number of polygons is too large, will cause a dramatic rise in rendering time. For this reason, people came up with a good compromise. Without increasing the complexity of the model, the bump effect on the object surface is similar to the real model generated in the displacement map, which is called bump mapping algorithm. Bump mapping also uses the channel as a source of information, through special surface mapping and light and shadow processing,Showing the high light and shadow of objects, so that the effect of light and shade in most cases can reach a convincing degree.Now, we're going to use the bump map to create a coin model and compare it with the previous replacement model. We will find that in the flat face "processing (sight perpendicular plane), which has the same excellent performance with the former, but the rendering time is much better than the former; in the" side"(normal to the plane perpendicular to the line of sight) contrast, displacement mapping still shows the surface topography true, the plane is smooth as bumpmap treatment. This also exposes the drawbacks of bump mapping. The above two algorithms have their own advantages and disadvantages, and in the final decision which algorithm to use to make the channel and model to combine to achieve the desired effect, the visual angle has become a decisive factor.6. vector channelIn order to reduce the amount of data, people will point painted again using digital image analysis, calculation method of the complex will be on the point, line, surface and color information into a simple mathematical formula; the formula graph is called the "vector graphics"; and the formula of the channel, is called vector channel". Although vector graphics can compress image information hundreds of times, its calculation method is too complex, and the conversion effect is often unsatisfactory. As a result, he can only play a role in showing concise and colorful geometric figures, but rarely when dealing with real effects (such as photos).Photoshop in the "path", several preset in the 3DS map, illustrator, flash and other drawing software in vector mask, belong to this type of channel.The ancients said: "do not build high platform in the sand."". If you want to have excellent skills, you must try hard to learn basic knowledge. The application of channel is engaged in the art industry personnel from entry to the master of the cadenzais the only way which must be passed, this course. I hope we can learn from every little bit here in the near future, let his works exude art shine.。
45钢的J_C损伤失效参量研究
2
动力学有限元程序的失效准则
材料的失效是一种具有复杂物理力学机制的现象。在动力学有限元中, 对失效的模拟引进了侵蚀
的概念, 当某一单元的特征参量( 应力、 应变或其他参量) 达到指定的临界数值时 , 便认为该单元完全破 坏, 丧失承载能力, 将单元进行删除。各商用有限元程序提供了较多的失效判据 , 主要包括最大塑性应 变、 最大主应变、 最大主应力、 最大等效应力、 应力阈值、 应力冲量、 最小时间步长、 最大压力等 , 以及其他 专用失效准则。 - C 材料模型中的损伤失效模型是应用较广的专用失效准则。基于 J. R. Rice 等[ 4] 提出的空洞增 J 长方程, G. R. Johnso n 等[ 5] 提出了考虑应力三轴性、 应变率和温度效应的 J - C 失效模型。 J - C 模型定义 单元的损伤 D=
在同一应力状态同一应变率下材料的失效应变与温度呈线性关系则通过对实验数据的线性拟合其斜率即为d5在参考温度下同一应力状态材料的失效应变与应变率的对数成线性关系在参考温度下在确定d4采用最小二乘非线性拟合即可得到d1d2失效模型考虑了应力状态应变率和温度等影响因素具有更大范围的适应性
第 27 卷 第 2 期 2007 年 3 月
表 1 45 钢 Taylor 撞击结果 Table 1 Taylor impact results v 0 / ( m/ s) 154 164 205 217 227 290 319 L / mm 91. 2 90. 9 87. 0 85. 7 84. 3 77. 9 76. 3 d max / mm 32. 1 32. 1 35. 5 38. 1 38. 2 47. 5 50. 6
第2期
陈
刚等 : 45 钢的 J - C 损伤失效参量研究
The power of the sun Artificial photosynthesis
The power of the sun ArtificialphotosynthesisArtificial photosynthesis, also known as solar fuel generation, is a groundbreaking technology that mimics the natural process of photosynthesis in plants to convert sunlight into energy. This innovative approach holds immense potential in addressing the global energy crisis and reducing our dependence on fossil fuels. By harnessing the power of the sun, artificial photosynthesis has the ability to produce clean and renewable energy sources, such as hydrogen fuel, that can help combat climate change and create a more sustainable future for generations to come. One of the key advantages of artificial photosynthesis isits ability to capture and store solar energy in the form of chemical bonds, which can then be used to generate electricity or produce fuel for various applications. This process involves splitting water molecules into hydrogen and oxygen using sunlight as the driving force, a concept that has the potential to revolutionize the way we power our world. Unlike traditional solar panels, which can only generate electricity when the sun is shining, artificial photosynthesis offers a way to store solar energy for use during periods of low sunlight or high energy demand. Furthermore, artificial photosynthesis has the potential to address the intermittency and storage challenges associated with renewable energy sources, such as solar and wind power. By converting sunlight into storable fuels like hydrogen, artificial photosynthesis offers a way to store excess energy generated during peak sunlight hours for use when the sun is not shining. This could help overcome the limitations of current energy storage technologies and provide a reliable and sustainable source of power for homes, businesses, and industries. In addition to its environmental benefits, artificial photosynthesis also has the potential to drive economic growth and create new opportunities for innovation and job creation. As the demand for clean energy solutions continues to grow, investments in artificial photosynthesis research and development are expected to increase, leading to the creation of new industries and job opportunities in the renewable energy sector. This could help stimulate economic growth, reduce greenhouse gas emissions, and create a more sustainable and resilient energysystem for future generations. Despite its many advantages, artificial photosynthesis still faces several challenges that must be overcome before it can be widely adopted as a mainstream energy technology. One of the key challenges is the high cost of production and implementation, which currently limits the scalability and commercial viability of artificial photosynthesis systems. Research and development efforts are ongoing to improve the efficiency and reduce the cost of artificial photosynthesis technologies, but more investment and collaboration are needed to accelerate progress and bring this technology to market. Another challenge facing artificial photosynthesis is the need for robust and reliable infrastructure to support the widespread adoption of this technology. This includes the development of new materials, catalysts, and systems for capturing, storing, and converting solar energy into usable fuels. Additionally, policy and regulatory frameworks must be put in place to incentivize investment in artificial photosynthesis and ensure a smooth transition to a more sustainable energy system. Collaboration between governments, industry, and research institutions will be key to overcoming these challenges and unlocking the full potential of artificial photosynthesis. In conclusion, artificial photosynthesis holds great promise as a clean and renewable energy technology that can help address the global energy crisis and reduce our reliance on fossil fuels. By harnessing the power of the sun to produce clean fuels like hydrogen, artificial photosynthesis offers a sustainable and scalable solution to our energy needs. While there are challenges to overcome, the potential benefits of artificial photosynthesis are immense, and with continued investment and innovation, this technology has the power to transform the way we generate and use energy for a more sustainable future.。
PHOTODIODE
专利名称：PHOTODIODE 发明人：SENBA SHINJI 申请号：JP25246690申请日：19900921公开号：JPH04130781A 公开日：19920501专利内容由知识产权出版社提供摘要：PURPOSE:To reduce a depletion layer capacity as a high photocurrent is held and to contrive the improvement of the high-frequency characteristics of a photodiode by a method wherein an electrode region having an area smaller than that of a P-N junction is formed on the side of the conductivity type, where a depletion layer spreads, of the photodiode and an end part of the depletion layer is brought into contact to the electrode region. CONSTITUTION:A semi-insulative InP layer 7 is grown on an N<+>-InP substrate 1 and a part only, which corresponds to the diameter (e) of an N side electrode, of this layer 7 is removed by etching. Subsequently, an N<->-InGaAs photo absorption layer 2 and an N<->-InP window layer 3 are grown and a P<+> diffused region 4 is formed. Lastly, electrodes 5 and 6 are formed and a photodiode is completed. In this photodiode, as an end 8 of a depletion layer comes into contact to the electrode region 7 having an area smaller than the area (b<2>) of a P-N junction, a depletion layer capacity is mainly decided by the area (e<2>) of the latter electrode region 7. As a result, a capacity smaller than the depletion layer capacity, which is decided by the area of the P-N junction, is obtained. Accordingly, the high-frequency characteristics of the photodiode can be improved without deteriorating a photocurrent.申请人：MITSUBISHI ELECTRIC CORP更多信息请下载全文后查看。
The Effect of Nuclear Shape
Russia
1
I. INTRODUCTION
In a previous paper [1] in reactions of 12C and 11 Li projectiles on a 12C target, it has been shown that the total reaction cross section, inclusive fragment cross sections and fragment momentum distributions are sensitive to the assumed proton and neutron radial density distributions of the projectile. These results stimulated us to further investigate effects of nuclear shape of neutron rich isotopes in the heavy ions reactions. A special attention in our investigations will be given to the neutron halo nuclei for the following reason. Recent developments of radioactive nuclear beams enabled one to study a detailed structure of nuclei far from the stability line [2]. The neutron halos have been observed in nuclei near the neutron drip line by reaction measurements with intermediate and high energy radioactive nuclear beams. These nuclei are of a special interest in relation to shell structures near the drip line and to new excitation modes associated with the excess neutron on the nuclear surface. In this paper we use the method of hyperspherical functions (HSF) [3] to construct the densities of the light drip line nuclei. Such nuclei typically have small binding energies and extended radial densities, and for them a suitable treatment of the tails of nuclear radial wave functions is essential. Physically such wave functions should have exponential tails. A main advantage of the HSF is that it provides a realistic radial wave functions at large distances. In addition, the spurious center-of-mass motion is removed from the onset and the symmetries are properly taken into account. In [4], an attempt was made to provide a unified description of
全息照相的原理英语作文
全息照相的原理英语作文The principle of holographic photography is based on the interference pattern created by the interaction oflight waves. This pattern captures the three-dimensional information of an object, allowing us to reproduce a realistic and detailed image.Holographic photography uses a laser beam to illuminate the object and a photosensitive material to record the interference pattern. The laser light is coherent, meaning that all the light waves have the same frequency and phase, which is essential for creating a clear and sharp hologram.When the laser light reflects off the object, it combines with the reference beam to create an interference pattern on the photosensitive material. This pattern contains information about the object's shape, size, and texture, allowing us to reconstruct a lifelike image when the hologram is illuminated with laser light.Unlike traditional photography, holographic photography captures the complete wavefront of light, preserving both the intensity and phase information. This allows us to reproduce not only the appearance of the object but alsoits depth and spatial relationships, creating a truly realistic representation.One of the key advantages of holographic photography is its ability to capture and display three-dimensional images without the need for special glasses or viewing devices. This makes holograms an ideal tool for scientific research, medical imaging, and artistic expression, opening up new possibilities for visual communication and storytelling.In conclusion, holographic photography offers a unique and powerful way to capture and reproduce three-dimensional images with unparalleled realism and detail. By harnessing the principles of interference and wavefront reconstruction, holograms enable us to experience the world in a new and immersive way, pushing the boundaries of visual representation and storytelling.。
The photoelectric effect
Interpretation
Slope is same for all targets y intercept is different for different target materials. e∆V=hf - φmetal φ is the “work function” of the metal…the mininum amount of energy required to remove an electron. h=6.63 x 10-34 is Planck’s Constant!
Current vs. Bias voltage
High intensity (bright) Stopping potential
Low intensity (dim) Reverse bias Forward bias
Stopping voltage vs. Frequency (c/λ)
frequency
ห้องสมุดไป่ตู้
Concluding statements
Einstein figured out the photoelectric effect in 1905 (the same year he developed the theory of special relativity and explained Brownian Motion). This is what he got the Nobel prize for. I like to think of the the photoelectric equation in terms of conservation of energy light energy ejecting electron & KE KE e∆V hf = φ + KE = φ + e∆V
Effects of the Surface Roughness on Sliding Angles of
Received December 20, 1999. In Final Form: March 22, 2000
Introduction
Wettability is one of the important properties of solid surfaces from both fundamental and practical aspects. Among various factors, surface energy and surface roughness are the dominant factors for the wettability. When the surface energy is lowered, the hydrophobicity is enhanced. However, even a material with the lowest surface energy (6.7 mJ/m2 for a surface with regularly aligned closest-hexagonal-packed -CF3 groups) gives a water contact angle of only around 120°.1 For higher hydrophobicity, providing a proper surface roughness is required.2 In fact, surfaces with a water contact angle of more than 150° were developed by introducing proper roughness on materials having low surface energies.3-23
The Photoelectric Effect
The Photoelectric EffectIn the 1890's, it was discovered that metal surfaces in vacuum which are exposed to ultraviolet light emit electrons. This was convincing evidence that atoms contain electrons. In 1902, the German physicist Philipp Lenard started to investigate this photoemission phenomenon in detail, using an apparatus involving two electrodes in a vacuum tube, as shown schematically in Fig. 2.14. By adjusting the potentiometer setting so as to vary the voltage V applied to the "collector" electrode, the photocurrent A could be plotted against applied voltage, as in Fig. 2.15a.For a given intensity I of the ultraviolet light, the photocurrent increased with increasing positive voltage. This is easily explainable in terms of the positive collector electrode attracting a larger fraction of emitted negatively-charged electrons. When the light intensity was increased, the photocurrent also increased, indicating that more photoelectrons were being produced. When the battery leads were reversed so that the applied bias V was negative, the photocurrent decreased and became zero if the magnitude of the negative bias exceeded a certain value Vs. This behaviour can be explained in terms of the negative collector repelling the photoelectrons, reducing the photocurrent or suppressing the photocurrent entirely (by stopping the electrons reaching the collector) when V reaches the stopping voltage Vs. At that point, even the most energetic photoelectrons (those released with a kinetic energy Kmax, assuming there is some spread in kinetic energy K) will exchange all of their kinetic energy for potential energy eVs by the time they reach the collector, in other words Kmax = Vs. What cannot be explained on the basis of classical physics is the fact that the value of Vs is independent of the light intensity I . According to classical theory, larger I implies a stronger electric (and magnetic) field E in the incident electromagnetic wave. It is this electric field which is presumed responsible for attracting electrons out of the metal into the vacuum and larger E should result in electrons with higher kinetic energies, requiring a larger negative Vs to stop them reaching the collector.Also at odds with classical theory is the fact that Vs (or Kmax) varies with frequency f of the incident light; in fact the experimental data lie on a straight line with intercept f0; see Fig. 2.15b. For a given light intensity, we would expect the electric field E to be independent of frequency or wavelength, on the basis of classical physics.In one of his papers published in 1905, Einstein came up with an explanation for these discrepancies. In fact, his explanation of the photoelectric effect (not the more controversial theory of relativity) was cited as his greatest contribution to physics when he was awarded the Nobel Prize in 1922.Einstein had recognized an inconsistency between Planck's idea of quantization of oscillators (in the walls of a cavity) and the usual assumption that cavity radiation consists of continuous electromagnetic waves. Using ideas derived from thermodynamics, he showed that cavity radiation could be treated as a system of particles, which we now refer to as photons, each carrying a quantum of energy of magnitude hf .Extending this idea to all cases of electromagnetic waves, the energy of the radiation is present in "bundles" ; see Fig.2.16b. In the photoelectric effect, each photon donates all of its energy hf to an electron in the metal. If this process occurs at the metal surface, the electron is released into the vacuum with a kinetic energy given by:Kmax = hf - phiwhere phi is the work function of the metal; it represents the minimum energy which must be supplied to release an electron from the metal. For convenience, this work function is normally measured in units of electronvolts (eV): 1 eV = 1.6 10^-19 J . V alues range from 2.2 eV (for the alkali metal lithium) to 6.35 eV (for the noble metal platinum).Einstein's concept explains the two puzzling features of the photoelectric effect. Increasing the light intensity increases the number of photons per second arriving at the metal electrode but does not change the energy of each photon, so the photoelectron energy Kmax and the stopping voltage Vs remain the same (Fig. 2.15a). However, increasing the light frequency will increase the photon energy, resulting in more energetic photoelectrons (Fig.2.15b). Conversely, if the light frequency is decreased below the threshold value f0 , the photons will not have enough energy to overcome the work function; at the threshold frequency f0 photons would be released but with zero kinetic energy, so thathf0 = phiThis last equation provides a means of measuring work functions of different materials.The fact that some electrons are emitted with lower kinetic energies K is partly due to the fact that the conduction electrons in a metal have a spread of energies (they occur in an energy band rather than all having the same energy). The other reason is that, if the energy exchange takes place below the surface, the ejected electrons interact with surrounding atoms and lose some of their energy in escaping,.The photoelectric effect has been utilized in devices called photocells, consisting of two electrodes in a sealed vacuum tube. By coating one electrode (the photocathode) with a alkali metal of low work function, a photocurrent could be generated even from visible light (photon energyroughly 2 eV to 4 eV) so the photocell was used for measuring light intensity or for converting the "optical" sound track of early movie film into an electrical current which could be fed to loudspeakers. Nowadays, solid-state devices (photodiodes) are used in such applications but a related vacuum-tube device, the photomultiplier tube (PMT), is still used in scientific applications (Fig. 14.20) because it provides high internal amplification without adding much electronic noise.Generally speaking, the quantum picture of electromagnetic radiation (Fig.2.16b) is needed to explain momentary interactions of light and matter, processes which usually occur on an atomic scale. On the other hand, the wave picture (Fig. 2.16a) remains successful in describing the propagation of light over long time intervals. Further evidence for the quantum nature of electromagnetic radiation comes from considering the generation and scattering of x-rays.。
然后看待修图图英语作文
然后看待修图图英语作文English:Editing photos has become a common practice in today's digital age. While some argue that it distorts reality and promotes unrealistic beauty standards, others see it as a creative form of expression and a way to enhance images. It is important to consider the ethical implications of photo editing, especially in the context of media and advertising where the portrayal of unattainable beauty ideals can have negative effects on individuals' self-esteem. However, there are also positive aspects to photo editing, such as the ability to correct imperfections, enhance colors, and create visually striking images. Ultimately, the key is to use photo editing responsibly and consciously, considering the impact it may have on society's perception of beauty and reality.中文翻译:图片修图在当今数字时代已经成为一种常见做法。
PhotodiodeAmplifers
+
Biasing the Amplifier:
• The output is stable but there is a big DC offset. Why? Light + -10 Volts Output never goes below here even with no light.
25 © 2004 National Semiconductor Corporation
19 © 2004 National Semiconductor Corporation
Mechanical Analogy:
• A gear and rack mechanical servo. This gear is the amp output stage. You are the amplifier front-end trying to keep the pointers the same. This gear is the feedback.
+
Amplifier Stability:
• Oscillations caused by capacitive diode on input. Photodiode looks like cap to amp -10 Volts
18 © 2004 National Semiconductor Corporation
10 millivolts is not very useful.
4 © 2004 National Semiconductor Corporation
The Photodiode:
Worse yet: Light Diodes are capacitors too, so fast signals are difficult. 2 Volts High impedance point difficult to interface with.
光电词汇
photonic bandgap 光子能隙
photonic crystal 光子晶体
photonic crystal fiber 光子晶体光纤
photonic crystals 光子晶体
Photonics 光电
photonoise limit 光子噪声限
photometric calibration 光度校正
photometric calibration data files 光度校准数据文件
photometric computer 测光计算机
photometric head 光度头
photometric integrating sphere 光度积分球
photon bunching 光子聚束
photon capture 光子俘获
photon counter 光子计数器
photon counting spectrophotometer 光子计数分度计
photon density 光子密度
photon detector 光子探测器
photon drag detector 光子牵引探测器
photontransition 光子跃迁
photonuclear disintegration 光致核蜕变
photonuclear excitation 光核激发
photooxidation 感光氧化用，光致氧化作用
photooxygenation 光致氧化
photooxygenation actinometer 光致氧化感光计
photohole 光穴
光电传感器
In 1905， Albert Einstein, physicist of Germany, used quantum theory of light（光 量子学说） to explain photoelectric emission effect, as a result of which he won the Nobel prize in physics in 1921.
Photoelectric characteristic
IΦ
请判断灵敏度的高低
4mA
photocurrent
(光电流)
Photosensiti ve Triode(光
敏三极管)
Photosensit ive diode(光
0.3mA
敏二极管)
Light
0
3000lx
E
请计算当E=100lx时，光敏二极管的光电流IΦ
different external forms of Photosensitive Diodes
光敏二极管阵列
Backward bias connection of photosensitive diode (光敏二极管的反向偏置接法)
在没有光照时，由于二 极管反向偏置，所以反向电 流很小，这时的电流称为暗 电流，相当于普通二极管的 反向饱和漏电流。 当光照射在二极管的PN 结（又称耗尽层）上时，在 PN结附近产生的电子-空穴对 数量也随之增加，光电流也 相应增大，光电流与照度成 正比。
当光照增加 时，光电流IΦ 与光照度成正 比关系。
3. Photosensitive Triode(光敏三极管)
光敏三极管有两个PN结。与普通三极管
相似，有电流增益，灵敏度比光敏二极管高。 多数光敏三极管的基极没有引出线，只有正 负（c、e）两个引脚，所以其外型与光敏二 极管相似，从外观上很难区别。)
中考英语摄影艺术的表现力提升单选题40题
中考英语摄影艺术的表现力提升单选题40题1.Photography is an art that uses light and ____ to create images.A.colorB.shapeC.sizeD.weight答案：A。
摄影是一门利用光和颜色来创造图像的艺术。
选项B“shape”形状、选项C“size”大小、选项D“weight”重量都与摄影创造图像的主要元素不太相关，而颜色是摄影中非常重要的元素之一。
2.A good photograph often has strong ____.A.contentB.meaningC.contrastD.value答案：C。
一幅好的照片通常有强烈的对比度。
选项A“content”内容、选项B“meaning”意义、选项D“value”价值，虽然对于照片也很重要，但不如对比度更能直接体现照片的视觉效果。
3.The ____ of a photograph can make it more attractive.positionB.backgroundC.subjectD.lightning答案：A。
照片的构图可以使它更具吸引力。
选项B“background”背景、选项C“subject”主题、选项D“lightning”闪电，都不是直接决定照片吸引力的主要因素，而构图是影响照片整体美感的重要方面。
4.In photography, focus is achieved by adjusting the ____.A.lensB.shutterC.flashD.memory card答案：A。
在摄影中，焦点是通过调整镜头来实现的。
选项B“shutter”快门、选项C“flash”闪光灯、选项D“memory card”存储卡都与调整焦点无关。
5.A beautiful landscape photograph often shows the ____ of nature.A.beautyB.powerC.mysteryD.weakness答案：A。
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The effect of photodiode shape on charge transfer in CMOS image sensorsBhumjae Shin a ,Sangsik Park a ,*,Hyuntaek Shin ba Department of Electronics Engineering,Sejong University,Seoul 143-747,Republic of Korea bClairPixel Co.,Ltd.,Republic of Koreaa r t i c l e i n f o Article history:Received 24February 2010Received in revised form 31May 2010Accepted 9June 2010Available online 3July 2010The review of this paper was arranged by Prof.A.Zaslavsky Keywords:Image sensor CMOSPhotodiode Charge transfer Depletiona b s t r a c tThe output signal of a CMOS image sensor is derived from the electrons generated by light incident on the pinned photodiode in each pixel.The output voltage depends on the transfer of the signal electrons from the pinned photodiode to the readout node.In large photodiodes it becomes difficult to fully extract the generated electrons because of the reduction in lateral electric field that pushes the electrons to the transfer transistor.To enhance the transfer,a triangular shaped photodiode was proposed which increases the lateral electric field applied to the photo generated pared with a conven-tional rectangular shaped pixel,the electrons are extracted more easily in a triangular shape since the narrow tail end forms an increased potential gradient.A VGA type image sensor chip showed that the tri-angular photodiode had 50%higher output voltage than a conventional rectangular photodiode.It was verified that the output voltage is enhanced more by the electric force than the light receiving area.The noise due to the residual electrons was not seen in the image acquired from image sensor having tri-angular photodiode.Ó2010Elsevier Ltd.All rights reserved.1.IntroductionThe CMOS image sensor (CIS)market is now larger than the market of the CCD image sensor,principally because CISs have var-ious advantages over CCDs.The advantages of CISs are lower power consumption,increased integration,lower cost and versatile ran-dom access.The inferiority of the picture quality of the CIS com-pared to CCD is overcome by the CDS (Correlated Double Sampling)operation in the 4-transistor pixel [1,2].It is expected that the market share of the CISs will increase commensurate with the rapid growth of the mobile phone industry.Fig.1shows the operation of the pinned photodiode in a 4-tran-sistor CIS pixel [3].The pinned photodiode is composed of an n-layer within a p-well,and a p-layer covering the n-layer [4–6].The pinned photodiode has no contacts,and the signal electrons are transferred to the read out node by the operation of the transfer gate (TG)[7].Fig.1a is the equilibrium state of the pn junction,where the neutral n-region is formed.After the integration time,a pulse u TG is applied on the gate of TG to read out the signal elec-trons.The electrons in the n-neutral region are fully extracted out to the n-type floating diffusion.At this point the neutral region of the n-type has disappeared and the n-type region becomes com-pletely depleted state as shown in Fig.1b.The complete transfer of the signal electrons from the photodi-ode to the readout node is very important.The voltage signal is formed by the electrons from the photodiode charging the readout node and forming a signal exactly proportional to the number of electrons present.Any divergence from this introduces error.Recently a large photodiode and a small photodiode are used to-gether to achieve the wide dynamic range,where the former is for high sensitivity in low illumination and the later is for high satura-tion characteristics in high illumination [8–11].In large photodiodes it becomes difficult to fully deplete the n-region because of the reduction in the lateral electric field pushing the electrons to the transfer transistor as shown in Fig.1c.In low voltage operation,the lateral electric field forcing the electrons is very weak since the distance to the transfer transistor is longer in larger photodiodes.Finally,the electrons can be left behind if there is a potential barrier or pocket in the photodiode.Any of these effects can cause electrons to stay in the photodiode,these remaining electrons create image lag [12].An incomplete depletion creates random noise since the num-ber of the remaining electrons varies with each transfer operation.These remnant electrons are equivalent to charging a capacitor (n-layer of the photodiode)and therefore behave like kTC noise of an equivalent smaller capacitance [13,14].This kTC noise appears as irregular sparkling dots which change from picture to picture.In Section 2,the electron transfer in the large photodiode is ana-lyzed with regards to output voltage.The improvement of electron transfer with the proposed triangular photodiode is discussed in Section 3.0038-1101/$-see front matter Ó2010Elsevier Ltd.All rights reserved.doi:10.1016/j.sse.2010.06.006*Corresponding author.Tel.:+82234083733;fax:+82234084329.E-mail address:sspark@sejong.ac.kr (S.Park).2.Electron transfer in large photodiodesThe performance of each photodiode was verified using a VGA format(640(H)Â480(V)pixels)image sensor which is composed of4-transistor pixels,timing generation circuits,A/D converters and data buffer registers.The image sensor was manufactured using 0.18l m design rules in a CMOS process.The doping concentration of the p-well is5Â1016/cm3on the surface and3Â1016/cm3within thefirst1l m from the silicon surface.The n and p-layer of the pho-todiode was formed by implantation with a dose of3Â1012/cm2and 5Â1013/cm2,respectively.Fig.2shows the output voltage of image sensors having differ-ent photodiode areas.The measured output voltage is normalized Fig.4.Dependence of the output voltage on the length of photodiode.Fig.8.Simulated potential distribution of rectangular photodiode(a)and trapezoidal photodiode(b).Fig.6shows the increase in output voltage as the angle h in-creases.The trapezoid becomes triangle when the angle reaches 26.1°.The output voltage of the triangle-shaped photodiode shows the highest output voltage,which also has the narrowest tail end. This narrow tail also decreases the capture area for light.This re-sult shows that the output voltage is more enhanced by the electric force than the light receiving area.The potential profile of a rectangular photodiode is shown in Fig.7a.There is no potential gradient forcing electrons since there is no narrow channel effect.A potential gradient is formed in the trapezoidal photodiode as shown in Fig.7b.The potential distribution dependence caused by the shape of the photodiode was predicted using the simulation program SPEC-TRA.The predicted potential distributions of the rectangular and triangular photodiode are compared in Fig.8.The larger central well where electrons remain in the rectangular photodiode is shown in Fig.8a.The correspondingly decreased area in the trian-gular photodiode is shown in Fig.8b.This means more electrons were pulled out of photodiode,and contributed to signal charge. The potential barrier should be lower than0.3V to suppress the image lag below1%[1].The digital output codes of the image sensor which have rectan-gular and triangular photodiode are compared in Fig.9.The output code was acquired under the illumination of1.0lux,and the signal charge was modulated by controlling the light integration time.The offset voltage is removed by subtracting the level of OB(opti-cal black)pixel from the data.The smaller triangular photodiode shows50%higher output voltage than the wider rectangular pho-todiode by virtue of potential gradient.The images taken by the image sensors having rectangular and triangular photodiodes are compared in Fig.10.The noise gener-ated by remnant electrons appears in the image acquired from im-age sensor having rectangular photodiode.That noise disappears in the image acquired from the image sensor having triangular photo-diodes.The image acquired from the image sensor having triangu-lar photodiode also shows higher output voltage.4.ConclusionA new shape of photodiode was proposed to enhance the trans-fer of the electrons in a photodiode of CMOS image sensor.The shape of the proposed photodiode is triangular which generates a lateral electric force to the electrons that assists in reducing the remnant electrons that cause image lag and pared with a conventional rectangular shaped photodiode,the electrons are pulled out more easily in a triangular shaped photodiode because the narrow tail end forms a potential gradient.The measurement showed that the smaller triangular photodiode had50%higher out-put voltage than the wider rectangular photodiode by virtue of theincreased potential gradient.It was verified that the output voltage is more enhanced by the electric force than the light receiving area. 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