Formal Scattering Approach to High-Order Harmonic Generation
卡博特炭黑技术资料
2Table of contents252000 561515Introduction Hig h jet masstone is a requirement of hig h-end performancecoating applications such as automotive OEM or automotiverefinish. The demand for increased jetness has heightened with theemerg ence of new resin technolog y. For this reason, raw materialand dispersion equipment suppliers have looked for ways to improvetheir products. In this respect, Cabot Corporation is no exceptionand continues to supply the market with innovative ideas for blackpigments that meet current market needs.This technical paper presents a summary of information reg ardingthe effect certain fundamental properties of carbon black may haveon coatings performance.It also outlines information on Cabot’s core line of hig h-colorcarbon black pig ments, including the well-established MONARCH1300 and MONARCH 1400 carbon blacks. Also covered aretwo new pigments, MONARCH 1500 carbon black and the revolu-tionary EMPEROR 2000 carbon black. While MONARCH 1300,MONARCH 1400, and MONARCH 1500 carbon blacks areoxidized pig ments, EMPEROR 2000 carbon black is based onCabot’s proprietary surface modification technology.This brochure demonstrates the ability of EMPEROR 2000 carbonblack to impart superior jetness in high performance coating applica-tions. The test criteria used to collect and to compare performancedata on these grades are highlighted in Section II of this brochure.3High-Color Carbon Blacks for High Performance Coating ApplicationsI. Carbon Black Properties and Coating PerformanceOne of the major reasons carbon black is used in coating applications isfor its color properties. Color development can be measured by conver-ting the color spectral reflectance data into three-dimensional colorspace, as provided by the Hunter Color formula measurements, asshown here.In automotive topcoat applications, extreme black (low L* values) anddeep blue undertones (low b* values) are the desired colors. The keyproperties of carbon black that can affect this color goal are:1. Primary particle size/surface area2. Primary aggregate shape/morphology3. Surface chemistry■ Effect of Primary Particle SizeMost pigments absorb and scatter portions of the visible light spectrum.The color of paint depends on how well the pigment is able to absorband scatter light. Carbon black can be used to help increase the amountof light absorbed by a coating because it can absorb and scatter lightmore effectively than many other pigments.As a carbon black’s primary particle size decreases, more surface areabecomes available to incident light.Also, primary aggregates tend to be smaller, assuming a constantstructure level, resulting in a finer carbon black. The overall effect of thefiner carbon black particle size is increased light absorption and moreefficient light scattering, giving a blacker or “jetter” color.Hunter Color Definition■ Effect of StructureA carbon black characterized by aggregates composed of many pri-mary particles with considerable branching or chaining is referred to asa “high structure” black. Conversely, an aggregate having relatively fewparticles forming a more compact unit is a “low structure” black.As structure increases, the absorption and scattering efficiencies aredecreased. Thus, in primary particles of the same size, a high structureblack will exhibit lower jetness than a black having low structure.■ Effect of Surface ChemistryIncreasing the volatiles content (that is, chemisorbed oxygen complex-es) on the surface of carbon black will generally increase dispersibilityand lower viscosity in liquid systems. The dispersibility of carbon blackcan also be enhanced through the adsorption of a limited amount ofmoisture on its surface.To some extent, both the volatiles content and adsorbed moisture canfunction as surfactants, whereby the surface is more readily “wetted” bythe vehicle. However, as the volatiles content of carbon black increases,its surface becomes more acidic. Thus, care should be taken whenformulating coatings systems.■ Physical formMost commercial high-color carbon blacks are available in either fluffyor pellet form. The pellet form handles more easily (reduced dusting) andnormally costs less than the fluffy form. However, the process of densi-fication, which is used to create the pellet form, tends to pack carbonblack agglomerates more closely, making dispersion more difficult thanwith the fluffy form.4II. High-Color Carbon Blacks: Cabot MONARCH/ BLACK PEARLS 1300 & 1400, MONARCH 1500, and EMPEROR 2000 Carbon Blacks■ Properties of an ideal high-color black for coatingsAn ideal high-color carbon black should provide superior “jetness” in high-color enamels or lacquer coatings. As explained above, key properties of such a carbon black would include sufficiently fine-sized primary particles for increased light absorption and lower structure for increased light scat-tering.The volatiles content and moisture level also can be adjusted to improve dispersibility. When these properties are obtained, superior “jetness” in high performance coating systems can be achieved.■ MONARCH/BLACK PEARLS 1300 & 1400,MONARCH 1500 and EMPEROR 2000 Carbon BlacksMONARCH/BLACK PEARLS 1300 & 1400, MONARCH 1500 and EMPEROR 2000 are commercially available Cabot highcolor carbon blacks. Because of their properties, Cabot believes that they are able to impart superior “jetness” for high performance coating applications. They exhibit a very fine primary particle size (9-13 nanometers) for increased light absorption combined with a low structure (90-100 DBP) for increased light scattering. Together, these properties help to achieve superior color “jetness” and improved gloss in high performance coating systems. Additionally, the specifications for volatiles content and moisture levels of these Cabot carbon blacks are optimized to help maintain dispersibility. MONARCH/BLACK PEARLS 1300 & 1400, MONARCH 1500 are Cabot oxidized high-color carbon blacks. These high-color carbon blacks are produced through the process of chemisorption of oxygen complexes onto the carbon black surface.EMPEROR 2000 carbon black is Cabot’s newest pigment black and is produced using an innovative chemical modification technology. This patented technology allows specific functional groups to be grafted onto the surface of the carbon black particle. F or EMPEROR 2000, the function of the attached groups is twofold: first, it helps to anchor adsorbed surfactants and dispersants that otherwise can float free of the carbon black surface and affect coating performance, and secondly, it improves the ease of dispersion and dispersion stability of the carbon black yielding the desired coating jetness with a strong blue undertone. The new technology is illustrated here.Conventional Commercial Carbon Black After-treatmentsCabot's New Surface Treatment (Chemical Modification)5■ Performance Comparison StudyCabot’s MONARCH 1300, 1400 & 1500, and EMPEROR 2000 carbonblacks were first tested in high-solids automotive topcoat acrylic formu-las for this comparison study. An in-house Cabot application develop-ment group developed the formulations based on high-solids acrylicpolyol resin suitable for one-component thermoset coatings. The formu-lation also contained a reactive melamine formaldehyde crosslinker. Thecarbon black dispersing agent used was a solution of high molecularweight blocked copolymer with cationic activity. A mixture of aromaticand ester solvents was used to help control the viscosity of the coatingformulation.The above carbon blacks were evaluated also in water-borne acryliclatex automotive base-coat formulas. This formulation also was devel-oped by our in-house applications development group. In addition tothe acrylic resin, the formulation consisted of a melamine formaldehyderesin as a crosslinker, a non-ionic low molecular weight dispersing agentand, for film formation, a mixture of propylene glycol n-butyl ether anddipropylene glycol n-butyl ether solvents.The formulations, performance properties and test results of both thehigh-solids acrylic and water-borne acrylic enamels are described in thesections A and B below. Additionally, accelerated weathering results aregiven for the water-borne acrylic enamel.High-Solids Acrylic EnamelMillbase Formulation:Butyl acetate, DisperBYK 161 and carbon black were premixed usinggood agitation to wet-out the pigment. Setalux 27.1597 was thenadded under good agitation. Once the resin was incorporated, the mill-base was premixed at 4,000 RPM for 20 minutes. The millbase wasthen charged to a horizontal mill along with 0.6-0.8 mm zirconium sili-cate media. The millbase was ground at 10m/sec. tip-speed to achieveparticle sizes of <5 microns on the Hegman Scale.6Letdown Masterbatch Formulation:The following materials were mixed together under good agitation.Finish masstone formulation:To prepare the finish formulation, 10 parts of the millbase and 50 parts ofthe letdown masterbatch were added together using good agitation forapproximately 20 minutes before application.Finish Masstone Formulation Constants:Carbon back loading in millbase (%) 10Dispersant/Carbon black solids ratio 0.975/1.00Pigment/Binder solids ratio 0.028/1.00Crosslinker %, solids 25Carbon black loading on total formulation (%) 1.67Performance Properties of High-Solids Acrylic EnamelPaint viscosities were adjusted with Aromatic 100 to 30 seconds with aNo.4 F ord cup. The paints were then sprayed out with a 665SX66SDnozzle using air assist applied at 35 psi. The final coating film thicknessand curing schedule were as follows:Monocoat Application:MasstoneAfter curing, the high-color pigment black panels were measured forcolor development and gloss. Color measurements were determinedusing a Hunter Labscan colorimeter using (45,0) geometry, CIELabequation, D-65 illuminant, and 10 degree observer. Gloss measurementswere determined using BYK Gardner Glossmeter. Similar gloss readingswere obtained for each of the carbon black formulations. The colordevelopment results are shown in the following table and in the chartsbelow. The results illustrate the increased jetness achieved when usingMONARCH 1500 and especially EMPEROR 2000 carbon blacks. Both L*values and Mc values are improved over those of MONARCH 1300 &1400 carbon blacks.781.41.210.80.60.40.2-0.2-0.4300275250225200Masstone9Finish masstone formulation:To prepare the finish formulation, 20 parts of the millbase and 182.9 partsof the letdown masterbatch were added together using good agitation forapproximately 20 minutes before application.Finish tinting formulation (10/90):To prepare the finish tinting formulation, 5 parts of the millbase concentrateformulation and 45 parts of the finish white base (TrueValue Weatherall100% Acrylic Latex GHP-9 White) were add together under goodagitation for approximately 20 minutes before application.Formulation Constants:Carbon back loading in millbase (%) 13.5Dispersant/Carbon black solids ratio 0.25/1.00Total solids by weight in final letdown (%) 35.0Pigment/Binder solids ratio 0.04/1.00Crosslinker %, solids 15Carbon black loading on total formulation (%) 1.33Performance Properties of Water-borne Acrylic LatexEnamelPaints were sprayed out using a 665SX66SD nozzle with air assistapplied at 35 psi. The final coating film thickness and curing schedulewas as follows:Monocoat Application:After curing, high-color pigment black panels were measured for colordevelopment and gloss. Color measurements were determined using aHunter Labscan colorimeter using (45,0) geometry, CIELab equation,D-65 illuminant, and 10 degree observer. Gloss measurements weredetermined using BYK Gardner Glossmeter. Similar gloss readings wereobtained for each of the carbon black formulations. The color develop-ment results are shown in the following table and in the charts below.The results illustrate the increased jetness achieved when usingMONARCH 1500 and especially EMPEROR 2000 carbon blacks. BothL* values and Mc values are improved over those of MONARCH 1300& 1400 carbon blacks. F urther, EMPEROR 2000 exhibits better bluetone than all other carbon blacks used in this formulation.1011Masstone21.510.50-0.5-130027525022520012TintingAccelerated weathering was performed with a QUV tester. The test wasbased on the ASTM 4587-91 method using UV-B fluorescent lamps. The tester was set at 4 light cycles followed by 4 condensation cycles. After 1000 hours of exposure, the panels were removed for evaluation. Weathering results are shown in the table below. Similar results are obtained for MONARCH 1300, 1400 and 1500, while EMPEROR 2000showed improved resistance to whitening and color retention.454035302520151050-5III. Formulation Guide■ The following modifiers were also used in our evaluationsof carbon black color performance:Dispersion AgentSince high-color blacks consist of small particle sizes, high surface areas,and high structures, dispersion and stability are much more difficult toachieve than with other carbon black grades. Dispersion agents arehighly recommended for dispersion and stability of high-color blacks incoating systems.The following dispersion agents and usage levels were used in ourevaluation:For Solvent-Borne Systems:Or a combination of Solsperse 32500 (0.50 - 0.60) and Solsperse 5000(0.10 - 0.20 parts per 1 part carbon black) may be used.For Water-Borne Systems:SurfactantSurfactant addition is also required in order to increase the dispersibilityand stability of water-borne formulations. The following surfactants wereused in our study of the water-borne acrylic latex system:13Leveling AgentSince substrates can be difficult to wet-out, especially withwater-borne coatings, wetting agents are required for waterborneformulations so that good, continuous film formation maybe achieved. Wetting (or leveling) agents can also eliminate filmdefects, such as orange peel, cratering or shrinkage. Thefollowing leveling agents were used in our comparison study:For Solvent-Borne Systems:For Water-Borne Systems:DefoamerF oaming in water-borne formulations is extremely difficult to control.Adding defoamer is a must to minimize the foaming effect in thesesystems. The following defoamers were used in our evaluation of water-borne acrylic latex systems:Dispersion ProcessOptimum dispersion of carbon black is necessary in order to achievesuperior color development in coatings formulations. All agglomeratesmust be broken down to primary aggregates to realize the full potentialof the optically functional units. Any degree of dispersion less than theoptimum will result in poorer jetness. The energy required for optimumdispersion must be supplied in the form of some type of media mill.14Definitions:DFT = Dry Film ThicknessL* is a measure of the lightness/darkness (lower numbers indicate darker color)b*is a measure of blue/yellow (lower numbers indicate bluer color)a* is a measure of red/green (lower numbers indicate a greener color) Mc: Mc is the Color Dependent Black Value and was developed by K. Lippok-Lohmer (Farbe + Lack, (1986), vol. 92, p. 1024). It is defined by the equation Mc = 100[log(Xn/X) - log (Zn/Z) + log (Yn/Y)], where X, Y, and Z are measured tristimulus values. The Mc value correlates well with the human perception of increased jetness. As the Mc value increases, the jetness of the masstone increases.Raw Material Suppliers*Setalux™ 27.1597 Akzo Nobel800.292.2308Solsperse® 5000 AveciaSolsperse® 32500 704.672.9920BYK® 024 BYK-ChemieBYK® 346 203.265.2086BYK® 348 BYK® 358DisperBYK® 161DisperBYK® 180DisperBYK® 2000Triton™ X-100 Dow ChemicalAMP-95™ 800.447.4369D-1441 Baker Petrolite781.335.6668Dehydran® 1293 CognisDehydran® 1620 215.628.1000Nopco® NS-1 Cymel® 202 Cytec Industries, Inc.Cymel® 373 847.652.6013EFKA® 3570 EFKA Additives440.943.4200Arcosolve™ PnB LyondellArcosolve™ DPnB 888-777-0232NeoCryl™ XK-100 NeoResins (Avecia)978.658.6600TEGO Dispers™ 760W TEGO Chemie800.446.1809* All raw materials used were North American versions.150908Europe +32 16 39 24 00+32 16 39 24 44North America )800 526 7591 Latin America+55 11 2144 6400(Middle East/Africa+971 4 8871 800Pacific/Asia+60 3 2096 3888China+86 21 5175 8800+86 21 6434 5532JapanA d d r e s s e s。
综述Representation learning a review and new perspectives
explanatory factors for the observed input. A good representation is also one that is useful as input to a supervised predictor. Among the various ways of learning representations, this paper focuses on deep learning methods: those that are formed by the composition of multiple non-linear transformations, with the goal of yielding more abstract – and ultimately more useful – representations. Here we survey this rapidly developing area with special emphasis on recent progress. We consider some of the fundamental questions that have been driving research in this area. Specifically, what makes one representation better than another? Given an example, how should we compute its representation, i.e. perform feature extraction? Also, what are appropriate objectives for learning good representations?
5071B主频标准说明书
5071BPrimary Frequency StandardFeatures• Easy to use with automatic startup and intuitive menu structure• Fast warm up ±5.0 x 10–13 accuracy in 30 minutes or less for high-per-formance tube• Integrated clock and message displays• Multiple timing and frequency inputs and outputs with easy access at front and rear• Automatic synchronization of 1PPS signal• Remote interface and controlincluding alarm output• Meets requirements in the new ITU-T G.811.1 ePRC standardBenefits• Maintains exceptional accuracy andstability even in unstable environ-ments—unsurpassed stability in thelab or field• Accuracy ±5.0 × 10–13 for highperformance• Stability ≤5.0 × 10–12 for highperformance (for 1 second averag-ing time)• Environmental stability ±8.0 × 10–14for high performance (frequencychange for any combination ofenvironmental conditions)• Long-term stability ≤1.0 × 10–14 forhigh performance (for 5-day averag-ing time)• Proven reliability with an averagemean time between failures (MTBF)of greater than 160,000 hours• Full traceability to NIST• AC and DC input and internal bat-tery back-upThe 5071B primary frequency standardhas the accuracy and stability you needfor both laboratory and field applica-tions. A stability specification for 30-day averaging time means the 5071Bwill keep extremely predictable timeand phase for long periods. Further,the 5071B can be used for long-termaveraging of noisy signals such as GPS.The 5071B is easy to use. No moremanual start-up steps or complicatedadjustments—everything is automatic.A logical menu structure simplifiesfront panel operations, selections,and status reporting. Remote controlfeatures tailor the 5071B for completeoperation and manageability in virtu-ally any location.Meeting the Needs of Leading- EdgeMetrology and Calibration LabsTimekeeping and National StandardsLaboratories verify the stability andaccuracy of their in-house cesiumstandards to Coordinated UniversalTime (UTC), provided by the BureauInternational des Poids et Mesures(BIPM) in Paris. A standard’s accuracyand reliability determine the qualityof service these timekeeping labsprovide. Of even greater concern is thestability of a standard. Stability directlyaffects a laboratory’s ability to delivertimekeeping and calibration services toits clients.The 5071B offers exceptional stabilityand is the first cesium standard tospecify its stability for averaging timeslonger than one day. The instrumenttakes into account environmentalconditions that can heavily influencea cesium standard’s long-term stabil-ity. Digital electronics continuouslymonitor and optimize the instrument’soperating parameters.Thus, the 5071B’s response to environ-mental conditions such as temperatureand humidity are virtually eliminated.The 5071B primary frequency standardmaintains its accuracy and stability,even in unstable environments.Satellite CommunicationsStable frequency generation is required to transmit and receive signals properly between ground terminals and com-munication satellites. Frequency flexibility is also needed to adjust for satellite-to-satellite carrier-frequency differences. The 5071B’s state-of-the-art technology produces offset and primary frequencies with the same guaranteed stability.For secure communications, precise timing synchroniza-tion ensures that encrypted data can be recovered quickly. Frequency-agile signals also require exact synchronization between transmitter and receiver during channel hops.The 5071B automates the synchronization to any external1PPS signal, greatly simplifying this aspect of satellite communications.The 5071B and GPSThe 5071B primary frequency standard can work very well with a GPS timing receiver to produce and maintain highly accurate time and frequency.The GPS system provides accurate time, frequency, and location information worldwide by means of microwave radio broadcasts from a system of satellites. Timing accuracy for the GPS system is based, in large part, on the accuracy and stability of a number of 5071B primary frequency standards. These standards are maintained by the GPS system, the US Naval Observatory, and various timing laboratories around the world that contribute to UTC, the world time scale. Because of their accurate time reference, GPS signals pro-cessed by a good GPS timing receiver can provide highly accurate time and frequency outputs. However, since GPS receivers rely on very low level microwave signals from the satellites, they sometimes lose accuracy because of interfer-ing signals, local antenna problems, or bad satellite data.In spite of these problems, a GPS timing receiver can be an excellent backup and reference to a local 5071B primary frequency standard. The GPS receiver provides an indepen-dent reference that can be used to verify the accuracy of a caesium standard, or it can be used as a temporary backup should the cesium standard need repair. The local 5071B standard has better stability, better output signal quality, and is not perturbed by interfering signals, intermittent signal loss, or bad satellite data.With these characteristics, the synergy created by combin-ing a good quality GPS timing receiver and a 5071B primary frequency standard can produce a highly robust, inexpensive, and redundant frequency and time system. Exceptional AccuracyThe intrinsic accuracy of the improved cesium beam tube (CBT) assures that any high performance 5071B will power up to within ±5.0 x 10–13 of the accepted standard for frequency. This is achieved under full environmental conditions in 30 minutes or less, and without the need for any adjustments or alignments.Unsurpassed StabilityThe 5071B high-performance cesium beam tube guarantees stability to be better than 1.0 x 10–14 for averaging times of five days or greater. The 5071B is the first cesium standard to specify stability for averaging times longer than 1.0 x 105 seconds (approximately one day).The 5071B is also the first cesium standard to specify and guarantee a flicker floor. Flicker floor is the point at which the standard’s stability (σy (2, τ)) does not change with longer averaging. The high performance 5071B flicker floor is guar-anteed to be 1.0 x 10–14 or better. Long-term measurements at the National Institute of Standards and Technology (NIST) show that the flicker floor is typically better than 5.0 x 10–15. Unstable environments are normal for many cesium stan-dard applications. The 5071B features a number of micropro-cessor controlled servo loops which allow it to virtually ignore changes in temperature, humidity, and magnetic fields.The 5071B delivers exceptional performance over very long periods of time, greatly increasing the availability of critical time and frequency services. Actual measurements made at NIST have demonstrated that a 5071B with the high-perfor-mance CBT will drift no more than 5.0 x 10–14 over the entire life of the CBT.Traditional ReliabilityThe 5071B design is based off its predecessor, the 5071A, which has demonstrated an average mean time between failures (MTBF) of greater than 160,000 hours since its introduction in 1992. This data is based on actual field repair data. Backing up this reliability is a 10-year warranty on the standard long-life cesium beam tube and a 5-year warranty for the high performance tube.Complete repair and maintenance services are available at our repair center in Beverly, Massachusetts.Full Traceability to NISTMicrochip provides NIST traceability to the accuracy mea-surements made on every 5071B. Traceability to NIST is maintained through the NIST-supplied Time Measurement and Analysis System (TMAS). This service exceeds the re-quirements of MIL-STD-45662A and can be a valuable tool in demonstrating traceability to your customers.High-Performance Cesium Beam TubeThe 5071A high performance cesium beam tube is optimal for the most demanding operations. The high-performance tube offers a full-environment accuracy specification of±5.0 x 10–13 —two times better than the specification for the standard tube. Stability is also significantly improved. The high-performance tube reaches a flicker floor of 1.0 x 10–14 or better, and long-term measurements at NIST show that the flicker floor is typically better than 5.0 x 10–15. Integrated Systems and Remote OperationToday, cesium standards are often integrated into telecom-munication, satellite communication, or navigation systems as master clocks. To accommodate these environments, the 5071A provides complete remote control and monitoring capabilities. Instrument functions and parameters can be interrogated programmatically.Communication is accomplished using the standard com-mands for programmable instruments (SCPI) language and a dedicated RS-232C port. Also, a rear panel logic output can be programmed to signal when user-defined abnormal condi-tions exist.For uninterruptible system service, an internal battery provides 45 minutes of backup in case of AC power failure. Thus, the 5071A can be managed easily even in the most remote locations.Straightforward OperationInternal microprocessor control makes start-up and opera-tion of the 5071A extremely simple. Once connected to an AC or DC power source, the 5071A automatically powers up to its full accuracy specifications. No adjustments or alignments are necessary during power-up or operation for the life of the cesium tube.An intuitive menu structure is accessible using the front panel LCD display and keypad. These menus—Instrument State, Clock Control, Instrument Configuration, Event Log, Frequen-cy Offset and Utilities—logically report status and facilitate control of the instrument. These functions are described as follows.Instrument StateOverall status is displayed, including any warnings in effect. Key instrument parameters such as C-field current, electron multiplier voltage, ion pump current, and cesium beam tube oven voltage are available. You can initiate a hard copy report of this data on your printer with the push of a button. Clock ControlSet the time and date, schedule leapseconds, adjust the epoch time (in 50 ns steps), and automatically synchronize the 1PPS signal to within 50 ns of an external pulse using this menu.Instrument ConfigurationSet the instrument mode (normal or standby) and assign frequencies (5 MHz or 10 MHz) to the two independently programmable output ports; configure the RS-232C data port. Event LogSignificant internal events (power source changes, hardware failures, warning conditions) are automatically recorded with the time and date of their occurrence. A single keystroke produces a hard copy on your printer for your records. Frequency Offset (Settability)Output frequencies may be offset by as much as 1.0 x 10–9 in steps of approximately 6.3 x 10–15. All product stability and output specifications apply to the offset frequency. UtilitiesThe firmware revision level and cesium beam tube identifica-tion information can be displayed.Accuracy and Long-term Stability11Lifetime accuracy (high performance CBT only) after a minimum two-month warm-up. Change no more than 5.0 × 10–14 for the life of the CBT.Specificationsfront panel or by remote control.The Microchip name and logo and the Microchip logo are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. All other trademarks mentioned herein are property of their respective companies. © 2023, Microchip Technology Incorporated and its subsidiaries. All Rights Reserved. 8/23DS00005002CRemote System Interface and Control RS-232-C (DTE configuration)Complete remote control and interrogation of all instrument。
Study_on_the_Pretreatment_Methods_for_the_Detectio
Creativity and Innovation2022,VOL.6,NO.5,75-80DOI:10.47297/wspciWSP2516-252712.20220605Study on the Pretreatment Methods for the Detection of Heavy Metal Stress in Shellfish by Hyperspectral TechnologyShuwen Wang2*,Jibin Zhang1,Hengjun Jiang1,Wenjun Xie1,Fengliang Chen11School of Electronic and Electrical Engineering,Lingnan Normal University,Zhanjiang,Guangdong2College of Computer and Intelligent Education,Lingnan Normal University,Zhanjiang,GuangdongABSTRACTIn this paper,hyperspectral technology was combined with differentoptimized pretreatment methods to construct a non-destructiveidentification method for cadmium contaminated and normal Ruditapesphilippinarum.Firstly,120samples of normal and heavy metal cadmiumpollution were collected,and their hyperspectral curves were compared,and then the optimization effects of different preprocessing methods onthe original spectra were explored,and finally the processing results wereused as the input of extreme learning machine classifier to screen out thebest preprocessing method.The results show that the use of SGsmoothing,multiplicative scatter correction(MSC),standard normalvariate transformation(SNVT),first derivative,second derivative and theircombination optimization methods is beneficial to the discrimination ofdifferent classes of spectral curves to a certain extent.Finally,theclassification accuracy of the extreme learning machine classifier is usedas the evaluation index to determine that the multiplicative scattercorrection preprocessing method is the optimal spectral preprocessingmethod.KEYWORDSHyperspectral image;Heavy metal cadmium;Pretreated Ruditapesphilippinensis1Research BackgroundRuditapes philippinarum is one of the main shellfish cultured along the coast.It is rich in various amino acids,vitamins and essential trace elements for human body.It has high nutritional value and delicious taste,so it is very popular[1].In recent years,with the rapid development of industry,a large number of pollutants are directly discharged into the sea,resulting in the aggravation of marine environmental pollution.Cadmium (Cd)is a typical harmful element which is easy to accumulate in organisms and difficult to metabolize,and widely exists in the natural environment[2].Ruditapes philippinarum is widely distributed in coastal areas with relatively serious heavy metal pollution.As a non-selective filter-feeding organism,Ruditapes philippinarum will accumulate heavy metal pollutants in sediments and water during feeding.Long-term consumption of heavy metal contaminated Ruditapes*Corresponding Author:Shuwen Wang(1975-04),male,Han,Zhaodong City,Heilongjiang Province,graduatestudent,associate professor,Interest:Application of intelligent measurement and controltechnology.Shuwen Wang et al. philippinarum will cause harm to human health[3].Therefore,it has become an urgent problem to improve the detection ability of heavy metal pollution in Ruditapes philippinarum and ensure the quality and food safety of Ruditapes philippinarum in food safety science.Aiming at the spectral interference and noise generated in the process of hyperspectral image acquisition of Ruditapes philippinarum,this paper studies the elimination of interference factors by different preprocessing methods,and explores the optimization effect of different single and combined preprocessing methods on the interference in the hyperspectral data of Ruditapes philippinarum[4].Finally,the extreme learning machine was used to realize the rapid non-destructive detection and analysis[5]of normal samples and heavy metal cadmium contaminated samples of Ruditapes philippinarum,and the optimal pretreatment method was determined according to the classification detection results.2Test Materials and Research Methods(1)Culture of test samplesThe samples of Ruditapes philippinarum were purchased from Cunjin Seafood Market,Zhanjiang City,Guangdong Province.The fine sand was disinfected to remove impurities and laid in a plastic culture box with a size of119cm×108cm×32cm and a volume of300L.Seawater was allowed to settle for24hours and then filtered for laboratory culture of Ruditapes philippinarum samples.The pH value of the sea water is8.0,the water temperature is28℃,the dissolved oxygen content is6.5mg/L,and the salinity is30‰.CdC12·2.5H2O solution with a concentration of0.8mg/L-1was addedinto the culture box to simulate the marine environment polluted by heavy metal cadmium.The control group was raised in seawater without any heavy metal elements.During the experiment,thefilter was closed for4hours every day,during which Chlorella was fed.Seawater containing CdC12·2.5H2O reagent and pure seawater were added to the two culture tanks every day to supplementthe loss of seawater in the culture tanks.The Ruditapes philippinarum samples were incubated in a culture box for10days to allow for the accumulation of the heavy metal cadmium.At the end of the culture,60cadmium contaminated samples and60uncontaminated samples of Ruditapes philippinarum were collected for hyperspectral image acquisition[6].(2)Hyperspectral image acquisitionIn this study,the hyperspectral imaging data of Ruditapes philippinarum samples were collected by SOC710-VP hyperspectral imager produced by Surface Optics Company in the United States.The system consists of a hyperspectral imager,a light source unit(halogen lamp),and a carrier plaorm unit(25),as shown in Figure1.The hyperspectral imager has an acquisition range of367.7-1051.9 nm with512bands.The spectrum at the front and end of the whole spectral range contains a lot of noise,so these two parts of the spectrum are removed,and450spectral bands from400.5nm to 1000.9nm are retained.The standard calibration of hyperspectral images,including spectral calibration,radiometric calibration,and reflectance normalization,is performed in SRAnal710 software.Fig.2is a hyperspectral image of Ruditapes philippinarum contaminated by heavy metal cadmium.76Creativity and Innovation 3Results and AnalysisFig.3shows the original spectrum of the Ruditapes philippinarum sample and the spectral curve pretreated by SG smoothing,multiplicative scatter correction (MSC),standard normal variate (SNV),first derivative (FD),second derivative (SD)and their various pretreatment combination optimizationmethods.(A)Rawspectrum (b)SGFig.1Hyperspectral image acquisitionsystemFig.2Hyperspectral image of Ruditapes philippinarum77Shuwen Wang etal.(c)MSC(e)FD(g)SG-FD (d)SNV (f)SD (h)SG-SD78Creativity andInnovation (i)MSC-FD (k)SNV-FD (j)MSC-SD(l)SNV-SDFig.3Spectral curves of Ruditapes philippinarum under various pretreatment methods and different combinations 60healthy samples and 60cadmium contaminated samples after spectral preprocessing are taken as experimental data sets,45samples of each class of samples are taken as training data sets,15samples are taken as test data sets,and the extreme learning machine classifier is used for classification.Because of the random selection,in order to reduce the random error,the modeling was repeated 500times each time,and the classification effect was evaluated by the average of the classification accuracy of the 500experimental results.The corresponding average classification accuracies of SG,MSC,SNV,FD,SD and their SG-FD,SG-SD,MSC-FD,MSC-SD,SNV-FD,SNV-SD preconditioning methods were 92.35%,95.25%,88.93%,91.89%,91.89%,83.99%、90.36%、93.93%、89.96%、88.94%、84.50%。
High Frequency Dynamics and Third Cumulant of Quantum Noise
a r X i v :0807.0252v 1 [c o n d -m a t .m e s -h a l l ] 1 J u l 2008High Frequency Dynamics and Third Cumulant ofQuantum NoiseJ.Gabelli and B.ReuletLaboratoire de Physique des Solides,UMR8502bˆa timent 510,Universit´e Paris-Sud 91405ORSAY Cedex,FrancePhysics of current fluctuations has proven,during the last 15years,to be a very profound topic of electron transport in mesoscopic conductors (for a review,see ref.[1]).Usually,current fluctuations are characterized by their spectral density S 2(ω)measured at frequency ω:S 2(ω)= i (ω)i (−ω) ,(1)where i (ω)is the Fourier component of the classical fluctuating current at frequency ωand the brackets . denote time averaging.In the limit where the current can be considered as carried by individual,uncorrelated electrons of charge e crossing the sample (as in a tunnel junction),S 2(ω)is given by the Poisson value S 2(ω)=e I and is independent of the measurement frequency ω.At sufficiently high frequencies,however,this relation breaks down and should reveal information about energy scales of the system.In particular,in the quantum regime ω>eV (V is the voltage across the conductor),it turns out that the noise cannot be seen as a charge counting statistics problem anymore even for a conductor without intrinsic energy scale.In this regime,the noise spectral density reduces to its equilibrium value determined,at zero temperature,by the zero-point fluctuations (ZPF):S (eq )2(ω)=G ω,(2)with G the conductance of the system.Experimental investigations of the shot noise at finite frequency have clearly shown a constant (voltage independent)noise spectral density for ω>eV in several systems [2,3,4].Although these experiments were not able to give an absolute value of the equilibrium noise (because of intrinsic noise of linear amplifiers used for the measurement),one has good reasons be believe that ZPF can be observed with this kind of amplifiers.Indeed,it as been proven in other detection schemes,theoretically [5,6]and experimentally [7,8,9,10],that ZPF can be detected from deexcitation of an active detector whereas they cannot be detected by a passive detector which is itself effectively in the ground state.In view of recent interest in the theory of the full counting statistics (FCS)of charge transfer,attention has shifted from the conventional noise (the variance of the current fluctuations)to the study of the higher cumulants of current fluctuations.Whereas the discrimination between active and passive detector seems to be clear for noise spectral density measurement,the situation is more complex for the measurement of high order cumulants at finite frequency.Indeed,the issues of detection scheme are closely related to the problem of ordering quantum current operators and,if the problem can be solved in a general wayfor two operators [6,11],measurements of higher cumulants are pointing out the problem of appropriate symmetrization of the product of n current operators:S n (ω)= i (ω1)i (ω2)...i (ωn ) δ(ω1+ω2+...+ωn )(3)It is the goal of this paper to clearly present the problem of the third cumulant measurement on a well defined experimental setup using a linear amplifier as a detector.Until now,measurements of the third cumulant S 3of voltage fluctuations have been performed at low frequency,i.e.in the classical regime ω<eV,k B T where voltage fluctuations arise from charge transfer process [12,13,14].We report here the first measurement of S 3at high frequency,in the quantum regime ω>eV,k B T .It raises central questions of the statistics of quantum noise,in particular:1.The electromagnetic environment of the sample has been proven to strongly influence the measure-ment,through the possible modulation of the noise of the sample[12].What happens to this mechanism in the quantum regime?2.For eV< ω,the noise is due to ZPF and keeps its equilibrium value:S2=G ωwith G theconductance of the sample.Therefore,S2is independent of the bias voltage and no photon is emitted by the conductor.Is it possible,as suggested by some theories[15,16,17],that S3=0in this regime?In the spirit of these questions,we give theoretical and experimental answers to the environmental effects showing that they involve dynamics of the quantum noise.We study the case of a tunnel junction, the simplest coherent ing these results,we investigate the question of the third cumulant of quantum noise.1Environmental Effects and Dynamics of Quantum NoiseWe show in this section that the noise dynamics is a central concept in the understanding of environmen-tal effects on quantum transport.First,we present a simple approach(in the zero frequency limit)to calculate the effects of the environment on noise measurements in terms of the modification of probability distribution P(i)of currentfluctuations.We do not provide a rigorous calculation,but simple consider-ations that bear the essential ingredients of the phenomenon.This allows us to introduce the concept of noise dynamics and determine the correct current correlator which describes it at any frequency.Then, we report thefirst measurement of the dynamics of quantum noise in a tunnel junction.We observe that the noise of the tunnel junction responds in phase with the ac excitation,but its response is not adiabatic, as obtained in the limit of slow excitation.Our data are in quantitative agreement with a calculation we have performed.Figure1:Schematics of the experimental setup.Currentfluctuations i(t)=I(t)− I are measured by an ampmeter with a bandwidth∆f.1.1Effects of the environment on the probability distribution P(i)In the zero-frequency limit,high order moments are simply given by the probability distribution of the current P(i)calculated from the currentfluctuations measured in a certain bandwidth∆f(seefig.1):M n= i n P(i)di(4) The cumulant of order n,S n is then given by a linear combination of M k∆f k−1,with k≤n[18].In practice,it is very hard to perfectly voltage-bias a sample at any frequency and one has to deal with the non-zero impedance of the environment Z(see Fig.1).If Vfluctuates,the probability P(i)is modified.Let us call P(i;V)the probability distribution of the currentfluctuations around the dc current I when the sample is perfectly biased at voltage V,and P(i)the probability distribution in the presence of an environment.R is the resistance of the sample,taken to be independent of V.If the sample is biased by a voltage V0through an impedance Z,the dc voltage across the sample is V=R /Z V0with R =RZ/(R+Z).The currentfluctuations in the sampleflowing through the external impedance induce voltagefluctuations across the sample,given by:δV(t)=− +∞−∞Z(ω)i(ω)e iωt dω(5)Consequently,the probability distribution of thefluctuations is modified.This can be taken into account if thefluctuations are slow enough that the distribution P(i)follows the voltagefluctuations.Under this assumption one has:P(i)=P(i;V+δV)≃P(i,V)+δV∂P+ (7)∂VThis equation,derived in Ref.[19],shows that environmental correction to the moment of order n is related to the next moment of the sample perfectly voltage biased.For n=1we recover the link between noise and Dynamical Coulomb Blockade through the noise susceptibility(see below)that appears as ∂M2/∂V in the simple picture depicted here[20].Let us now apply the previous relation to the third cumulant(S n=M n∆f n−1for n=2,3):S3≃S3−3Z S4∂V(8)It is a simplified version of the relation derived in refs.[21].The way to understand this formula is the following:thefirst term on the right is the intrinsic cumulant;the second term comes from the sample currentfluctuations i(t)inducing voltagefluctuations across itself.These modulate the sample noise S2 by a quantity−Zi(t)dS2/dV.This modulation is in phase with thefluctuating current i(t),and gives rise to a contribution to the third order correlator i3(t) .This environmental contribution involves the impedance of the environment and the dynamical response of the noise which,in the adiabatic limit considered here,is given by dS2/dV.However,at high enough frequencies,and in particular in the quantum regime ω>eV,this relation should be modified to include photo-assisted processes.The notion of dynamical response of the noise is extended in the following section to the quantum regime in order to subtract properly the environmental terms in the measurement of the third cumulant.1.2Dynamics of Quantum Noise in a Tunnel Junction under ac Excitation In the same way as the complex ac conductance G(ω0)of a system measures the dynamical response of the average current to a small voltage excitation at frequencyω0,we investigate the dynamical response of (ω),that we name noise susceptibility.It measures the in-phase and out-of-phase currentfluctuationsχωoscillations at frequencyω0of the current noise spectral density S2(ω)measured at frequencyω.In order to introduce the correlator that describes the noise dynamics,we start with those which describe noise and photo-assisted noise.Beside the theoretical expressions,we present the corresponding measurements on a tunnel junction[22].It allows to calibrate the experimental setup and give quantitative comparisons between experiment and theory.Noise and photo-assisted noiseThe spectral density of the currentfluctuations at frequencyωof a tunnel junction(i.e.with no internal dynamics)biased at a dc voltage V is[1]:S02(ω+)+S02(ω−)S2(V,ω)=d S 2(ω)/d V ä (R 0/2e )-60-40-200204060eV/k B TS 2/(4k B G ) (K )Figure 2:Top:Measured noise temperature T N =S 2(ω)/(4k B G )of the sample plus the amplifier with no ac excitation.Bottom:measured differential noise spectral density dS 2(ω)/dV for various levels of excitation z =eδV/( ω0).z =0corresponds to photo-assisted noise.Solid lines are fits with Eq.(10).where ω±=ω±eV/ .S 02(ω)is the Johnson-Nyquist equilibrium noise,S 02(ω)=2G ωcoth ( ω/(2k B T ))and G is the conductance.At low temperature,the S 2vs.V curve (obtained at point C on Fig.3)has kinks at eV =± ω,as clearly demonstrated in our measurement,see Fig.2top.The temperature of the electrons is obtained by fitting the data with Eq.9.We obtain T =35mK,so that ω/k B T ∼8.5.Note that a huge,voltage independent,contribution T N ∼67K is added to the voltage dependent noise coming from the sample which masks the contribution from the ZPF.When an ac bias voltage δV cos ω0t is superimposed on the dc one,the electrons wavefunctions acquire an extra factor n J n (z )exp(inω0t )where J n is the Bessel function of the first kind and z =eδV/( ω0).The noise at frequency ωis modified by the ac bias,to give:S pa 2(V,ω)=+∞ n =−∞J 2n (z )S 2(V −n ω0/e,ω)(10)This effect,called photo-assisted noise,has been measured for ω=0[2].We show below the first measurement of photo-assisted noise at finite frequency ω.The multiple steps separated by eV = ω0are well pronounced and a fit with Eq.10provides the value of the rf coupling between the excitation line and the sample δV (see Fig.2bottom).Noise susceptibilityPhoto-assisted noise corresponds to the noise S 2(ω)in the presence of an excitation at frequency ω0,obtained by time averaging the square of the current filtered around ω,as in [2]for ω=0and in[4]for ω∼ω0.This is similar to the photo-voltaic effect for the dc current.The equivalent of the dynamical response of current at arbitrary frequencies ω0is the dynamical response of noise at frequency ω0.It involves the beating of two Fourier components of the current separated by ±ω0expressed by the correlator i (ω)i (ω0−ω) .Using the techniques described in [1],we have calculated the correlator that corresponds to our experimental setup,using the ”usual rules”of symmetrization for a two currentFigure3:Experimental setup for the measurement of the noise dynamics X(ω0,ω)and the third cumulant S3(ω,ω0−ω)forω∼ω0.The symbol⊕represents a combiner,which output is the sum of its two inputs. The symbol⊗represents a multiplier,which output is the product of its two inputs.The diode symbol represents a square law detector,which output is proportional to the low frequency part of the square of its input.correlator and a classical detector.Wefind the dynamical response of noise for a tunnel junction[20]:1X(ω0,ω)=(12)δVχω(ω)expresses the effect,tofirst order inδV,of a small excitation at frequencyω0to the noise measured 0at frequencyω.We show in Fig.4the data for X(ω0,ω)/δV at small injected powers as well as the (ω=ω0):theoretical curve forχωeχω(ω)=χω(0)=All the data fall on the same curve,as predicted,and are very well fitted by the theory.The cross-over occurs now for eV ∼ ω.χω(ω)is clearly different from the adiabatic response of noise dS 2(ω)/dV (solid line in Fig.4).However,in the limit δV →0and ω0→0(with z ≪1),Eq.(13)reduces to χω(0)∼(1/2)(dS 2/dV ).The factor 1/2comes from the fact that the sum of frequencies,±(ω+ω0)(here ∼12GHz),is not detected in our setup.This is the central result of our work:the quantum noise responds in phase but non-adiabatically.-1.0-0.50.00.51.0χω(ω) ä (R 0/e ) -30-20-100102030eV/k B TFigure 4:Normalized noise susceptibility χω(ω)vs.normalized dc bias.Symbols:data for various levels of excitation (z =0.85,0.6and 0.42).Dotted and dashed lines:fits of χω(ω)(Eq.(13)).Solid line:(1/2)dS 2/dV (experimental),as a comparison.Inset :Nyquist representation of X (ω0,ω)for z =1.7(in arbitrary units).The in-phase and out-of-phase responses are measured by shifting the phase ϕof the reference signal by 90◦.2Third Cumulant of Quantum Noise Fluctuations 2.1Operator oderingA theoretical framework to analyze FCS was developed in Ref.[23]to evaluate any cumulant of the current operator in the zero-frequency limit.In order to analyze frequency dispersion of current fluctuations it is necessary to go beyond the usual FCS theory [15,16,17].An essential problem in these approaches is to know what ordering of current operators ˆi corresponds to a given detection scheme.This problem is simpler for S 2:the correlator S +(ω)= ˆi (ω)ˆi (−ω) with ω>0represents what is measured by a detector that absorbs the photons emitted by the sample,like a photo-multiplier.The correlator S −(ω)= ˆi (−ω)ˆi (ω) =S +(−ω)represents what the sample absorbs,and can be detected by a detector in an excited state that decays by emitting photons into the sample.Finally a classical detector cannot separate emission from absorptions,and measures the symmetrized quantity:S sym.2(ω)= ˆi (ω)ˆi (−ω) + ˆi (−ω)ˆi (ω)2.2Measurement of S v 3(ω,0)Experimental setupWe have investigated the third cumulant S v 3(ω,0)of the voltage fluctuations of a tunnel junction in the quantum regime ω>eV .For technical reasons (the input impedance of the rf amplifier is fixed at Z =50Ω),we measured voltage fluctuations v (t )instead of current fluctuations i (t ).Thus,the impedance R =RZ/(R +Z )will act as the environment and will affect the measurement of the third cumulant S 3(ω,0)of the current fluctuations.We use the same experimental setup and sample as for the noisedynamics measurement,the only change is that the ac excitation is switched off:δV =V 0=0(see Fig.3.Thus only the noise of the amplifier can modulate the noise of the sample.A 5.7−6.7GHz band-pass filter followed by a square law detector allows to mix high-frequency components v (ω)v (−ω−δω)which are multiplied by low-frequency components selected by a 200MHz low pass filter,we end up with a dc signal proportional to S V 3∝ v (ω)v (−ω−δω)v (δω) .The fact that the same setup is used to detected S 3and χis quite remarkable:it clearly indicates that the environmental effects in S 3are indeed described by χand not by dS 2/dV .S v 3 (e 2R D 3 µΑ)eV/k B T S 3/e 2(µA )eV/k B T (a)(b)Figure 5:(a)Measurement of S v 3(ω,0)vs.bias voltage V (circles).The solid line corresponds to the best fit with Eq.(15).The dash dotted line corresponds to the perfect bias voltage contribution and the dotted lines to the effect of the environment.(b)Measurement of S 3(ω,0)vs.bias voltage V (squares).Experimental resultsS v3at T=35mK is shown in Fig.5(a),these data were averaged for4days.These results are clearly different from the voltage bias result because of the environmental contributions.As described before (see section1),the noise of the sample is modulated by its own noise and by the noise of the amplifier S2,N,to give rise to an extra contribution to S v3.By generalizing the expression(8),wefind,assuming real,frequency independent impedances to simplify the expression(but we used the full expression for thefits of the data):S v3(ω,0)=−R3S3(ω,0)+R4(S2,N(0)+S2(0))χ0(ω)++R4(S2,N(ω)+S2(ω))χω(0)+R4(S2,N(ω)+S2(ω))χω(ω)(15)To properly extract the environmental effects,wefit the data obtained at different temperatures(35mK, 250mK,500mK,1K,4.2K).The parameters R (0),R (ω),S2,N(0)and S2,N(0)that characterize the environment are independent of temperature,whereas S2(V)andχ(V)have temperature dependent shapes.This allows for a relatively reliable determination of the environmental contribution.We have performed independent measurements of these parameters and obtained a reasonable agreement with the values deduced from thefit.However more experiments are needed with another,more controlled environment,to confirm our result.The intrinsic S3in the quantum regime,obtained after subtraction of the environmental contributions,is shown in Fig.5(b).It seems to confirm the theoretical prediction by[16,17](solide line),i.e.S3(ω,0)=e2I even for ω>eV.Figure6:(a)Experimental detection scheme.The symbol represents a multiplier,which output is the product of its two inputs.The diode symbol represents a square law detector,which output is proportional to the low frequency part of the square of its input.S3(ω,δω→0)is given by the product of the square of high frequencyfluctuations with low frequencyfluctuations.(b)Equivalent detection scheme using a photodetector to measure square of high frequencyfluctuations.3ConclusionWe have shown thefirst measurement of the noise susceptibility,in a tunnel junction in the quantum regime ω∼ ω0≫k B T(ω/2π∼6GHz and T∼35mK)[4].We have observed that the noise responds in phase with the excitation,but not adiabatically.Our results are in very good,quantitative agreement with our prediction based on a new current-current correlatorχω(ω)∝ i(ω)i(ω0−ω) .Using the fact that the environmental contributions to S3are driven byχ,we have been able to extract the intrinsiccontribution from a measurement of v3 on a tunnel junction in the quantum regime.Our experimental setup is based on a”classical”detection scheme using linear amplifiers(see Fig.6(a))and the results are in agreement with theoretical predictions:S3(ω,0)remains proportional to the average current and is frequency independent[16,17].This result raises the intriguing question of the possibility to measure a non-zero third cumulant in the quantum regime ω>eV whereas the noise S2(ω)is the same as at equilibrium,and given by the zero-pointfluctuations.One can think of another way to measure S3(ω,0)with a photodetector(sensitive to photons emitted by the sample),as depicted infig.6(b).In this case S3is the result of correlations between the low frequency currentfluctuations and the low frequencyfluctuations of theflux of photons of frequency ωemitted by the sample.Since no photon of frequencyωis emitted for eV< ω,the output of the photo-detector is zero and S3(ω,0)=0.The expectation of such a measurement is sketched by a dashed line infig.5(b).Note that such a detection scheme has already been applied on laser diodes[24,25]. AcknowledgementsWe are very grateful to L.Spietz for providing us with the sample that he fabricated at Yale University. We thank M.Aprili,M.Devoret,P.Grangier,F.Hekking,J.-Y.Prieur,D.E.Prober and I.Safifor fruitful discussions.This work was supported by ANR-05-NANO-039-02.References[1]Y.M.Blanter and M.Bttiker,Shot Noise in Mesoscopic Conductors,Phys.Rep.3361(2000)[2]R.J.Schoelkopf,P.J.Burke,A.A.Kozhevnikov,and D.E.Prober and M.J.Rooks,Fre-quency Dependence of Shot Noise in a Diffusive Mesoscopic Conductor,Phys.Rev.Lett.783370(1997).R.J.Schoelkopf,A.A.Kozhevnikov,D.E.Prober and M.J.Rooks,Observa-tion of Photon-Assisted Shot Noise in a Phase-Coherent Conductor,Phys.Rev.Lett.802437(1998)[3]E.Zakka-Bajjani,J.Segala,F.Portier,P.Roche,C.Glattli,A.Cavanna,Y.Jin,Experi-mental Test of the High-Frequency Quantum Shot Noise Theory in a Quantum Point Contact,Phys.Rev.Lett.99236803(2007)[4]J.Gabelli and B.Reulet,Dynamics of Quantum Noise in a Tunnel Junction under ac Exci-tation,Phys.Rev.Lett.100026601(2008)[5]H.A.Haus and J.A.Mullen,Quantum Noise in Linear Amplifiers,Phys.Rev.1282407(1962)[6]Lesovik and Loosen,On the Detection of Finite-Frequency Current Fluctuations,PismaZhETF65269(1997)[7]R.H.Koch,D.J.Van Harlingen,and J.Clarke,Measurements of quantum noise in resistivelyshunted Josephson junctions,Phys.Rev.Lett.471216(1981)[8]R.Movshovich,B.Yurke,P.G.Kaminsky,A.D.Smith,A.H.Silver,R.W.Simon and M.V.Schneider,Observation of zero-point noise squeezing via a Josephson-parametric amplifier,Phys.Rev.Lett.65419(1990)[9]R.Deblock,E.Onac,L.Gurevich,and L.P.Kouwenhoven,Detection of Quantum Noisefrom an Electrically-Driven Two-Level System,Science301203(2003);P.-M.Billangeon,F.Pierre,H.Bouchiat,and R.Deblock,Phys.Rev.Lett.96136804(2006)[10]O.Astafiev,Yu.A.Pashkin,Y.Nakamura,T.Yamamoto and J.S.Tsai,Measurements ofquantum noise in resistively shunted Josephson junctions,Phys.Rev.Lett.93267007(2004)[11]U.Gavish,Y.Levinson and Y.Imry,Detection of quantum noise,Phys.Rev.B62R10637(2000)[12]B.Reulet,J.Senzier and D.E.Prober,Environmental Effects in the Third Moment of VoltageFluctuations in a Tunnel Junction,Phys.Rev.Lett.91196601(2003)[13]Yu.Bomze,G.Gershon,D.Shovkun,L.S.Levitov and M.Reznikov,Measurement of Count-ing Statistics of Electron Transport in a Tunnel Junction,Phys.Rev.Lett.95176601(2005) [14]S.Gustavsson,R.Leturcq,B.Simovic(,R.Schleser,T.Ihn,P.Studerus,K.Ensslin,D.C.Driscoll,and A.C.Gossard,Counting Statistics of Single Electron Transport in a Quantum Dot,Phys.Rev.Lett.96076605(2006).[15]A.Galaktionov,D.Golubev,and A.Zaikin,Statistics of currentfluctuations in mesoscopiccoherent conductors at nonzero frequencies,Phys.Rev.B68235333(2003)[16]D.S.Golubev,A.V.Galaktionov,and A.D.Zaikin,Electron transport and currentfluctua-tions in short coherent conductors,Phys.Rev.B72205417(2005)[17]J.Salo,F.W.J.Hekking,and J.P.Pekola,Frequency-dependent current correlation functionsfrom scattering theory,Phys.Rev.B74125427(2006)[18]N.G.van Kampen,Stochastic processes in Physics and Chemistry,Elsevier Third edition[19]B.Reulet,Higher Moments of Noise,Les Houches Summer School of Theoretical Physics,Session LXXXI,Nanophysics:Coherence and Transport.NATO ASI.H.Bouchiat,Y.Gefen, S.Gu´e ron,G.Montambaux and J.Dalibard editors.Elsevier(2005).(cond-mat/0502077).[20]J.Gabelli and B.Reulet,The Noise Susceptibility of a Photo-excited Coherent Conductor,(cond-mat/0801.1432(2008)[21]M.Kindermann,Yu.V.Nazarov and C.W.J.Beenakker,Distribution of Voltage Fluctuationsin a Current-Biased Conductor,Phys.Rev.Lett.90246805(2003)[22]Lafe Spietz,K.W.Lehnert,I.Siddiqi,R.J.Schoelkopf,Primary Electronic ThermometryUsing the Shot Noise of a Tunnel Junction,Science3001929(2003)[23]L.S.Levitov,H.W.Lee and G.B.Lesovik,Electron counting statistics and coherent states ofelectric current,J.Math.Phys.374845(1996)[24]W.H.Richardson and Y.Yamamoto,Quantum Correlation between the Junction-VoltageFluctuation and the Photon-Number Fluctuation in a Semiconductor Laser,Phys.Rev.Lett.661963(1991)[25]I.Maurin,I.Protsenko,J.-P.Hermier,A.Bramati,P.Grangier and E.Giacobino et al.,Lightintensity-voltage correlations and leakage-current excess noise in a single-mode semiconductor laser,Phys.Rev.A72033823(2005).。
srong coupling theory of superconductivity
I. INTRODUCTION
Traditionally, “strong-coupling superconductivity” is understood as superconductivity induced by a very strong phonon-mediated pairing interaction. The strong-coupling theory was developed by Eliashberg(21) on the basis of Migdal’s theory for the normal state (43). In strong-coupling superconductors the transition temperature Tc is comparable to the Debye temperature. Thus, typical energies of the superconducting electrons, e.g. kB T or the superconducting energy gap, are comparable to typical energies of the excitations mediating the attractive interaction. In this case the superconductivity is sensitive to the dynamic properties of these excitations, which leads to deviations from the universal laws of weak-coupling superconductivity (law of corresponding states) and, more importantly, opens the possibility of extracting information on the origin of the attractive interaction from superconducting measurements. The most prominent example is McMillan’s (41; 42) analysis of superconducting tunneling data which gives us the spectral function α2 F (ω ) of the phonon-mediated attractive interaction together with the instantaneous electronic interaction parameter µ∗ .(12; 45) The electronic part of the pairing interaction is found to be repulsive (positive µ∗ ) in all cases where it has been measured. However, attractive electronic interaction mechanisms, i.e. negative µ∗ ’s, are conceivable and have been suggested as a possible origin of high transition temperatures.(25; 26; 39) The material parameters of the strong-coupling theory, α2 F (ω ) and µ∗ , have been obtained from tunneling experiments for several superconductors. These material parameters can be used as input into the strongcoupling theory to calculate numerically strong-coupling corrections to the universal weak-coupling results. Such calculations were first performed by Scalapino, Wada, Swihart, Schrieffer, and Wilkins(54; 55) and have since been developed to some degree of perfection. Efficient computer codes have been designed for calculating Tc , the energy gap, the isotope effect, critical fields, magnetization curves, the vortex lattice, the electromagnetic response, and other measurable quantities of interest. The basic equations, numerical methods, and various results are documented in several textbooks (6; 26; 28; 58; 64) and review articles (3; 13; 16; 42; 51; 56). In table I we compare calculated and measured results for the ratio 2∆0 /kB Tc , which has the universal value 3.53 for isotropic weak-coupling superconductors. There is generally very good
AT9000高级传感器压力传感器进线型第二版说明书
AT9000 Advanced Transmitter Gauge Pressure TransmittersIn-line model2nd EditionNo. SS2-GTX00G-0600OVERVIEWAT9000 Advanced Transmitter is a micropro-cessor-based smart transmitter that features high performance and excellent stability. Capable of measuring gas, liquid, vapor, and liquid levels, it transmits 4 to 20 mA DC analog and digital sig-nals according to the measured pressure.It can also execute two-way communications between the Smart Communicator or HART ® 375 communicator, thus facilitating self-diagno-sis, range resetting, and automatic zero adjust-ment.FEATURESHigh performance and stability•Unique characterization and composite semi-conductor sensors realize high accuracy up to 0.04% F.S.•Our proven sensor technology enables Long-term stability up to 0.1% of URL per 10-year.Wide measuring range (range ability)•A wide measuring range is available from a single model. This feature is highly effective in taking measurement over a wide range and reducing the need for inventory.•Model GTX60G: 2.54 to 508 psig (17.5 to 3500 kPa) (range ability: 200 to 1)•Model GTX71G: 101 to 2030 psig (0.7 to 14 MPa) (range ability: 200 to 1)High durability•Max. range pressure test is cleared more than 100,000 times.•Anti-vibration specification is up to 3G .Remote communication•Two-way communication using digital output facilitates self-diagnosis, range resetting, auto-matic zero adjustment, and other operations.•HART ® protocol communication is available. (Option)China RoHSThis device is used in the Oil & Gas, Petrochem-ical, Chemical, Pulp & Paper, Food & Beverage, Machinery, Steel/Metal & Mining, and Automo-bile industries and therefore does not fall under the China RoHS Legislation.If this device is used in semiconductor manufac-turing equipment, labeling on the device and documents for the China RoHS may be required. If such documents are required, consult an Azbil Corp. representative.HART ® is a registered trademark of the HART Communication Foundation.No. SS2-GTX00G-0600Azbil Corporation- 2 -FUNCTIONAL SPECIFICATIONSFM Explosion-proof and Dust Approvals (Code F1)Explosion-proof for Class I, Division 1, Groups A, B, C and D; Class I, Zone 1, AEx d IICDust-Ignitionproof for Class II, III, Division 1, Groups E, F and GT5 -40 °C < T amb < +85 °C Hazardous locationsIndoor / Outdoor Type 4X, IP67Factory sealed, conduit seal not required for Division applicationsCaution - Use supply wires suitable for 5 °C above sur-rounding ambientFM Intrinsically safe Approval (Code F2)IS/I,II,III/1/ABCDEFG/T4; -40 °C < T amb < +60 °C; 80395278, 80395279,80395280; Entity; TYPE 4X; IP67 I/0/ AEx ia/IIC/T4; -40 °C < T amb < +60 °C; 80395278, 80395279, 80395280; Entity; TYPE 4X; IP67Entity Parameters: Vmax (Ui)=30 V olts, Imax (Ii)=100 mA, Pi=1 W, Ci=10 nF, Li=0.5 mHFM Nonincendive Approval (Code F5)NI/I/2/ABCD/T4; -40 °C < T amb < +60 °C; 80395494; NIFW; TYPE 4X; IP67NI/I/2/IIC/T4; -40 °C < T amb < +60 °C; 80395494; NIFW; TYPE 4X; IP67S/II, III/1/EFG/T4; -40 °C < T amb < +60 °C; 80395494;NIFW; TYPE 4X; P67Nonincendive Field Wiring Parameters: Vmax (Ui)=30 V olts, Ci=10 nF, Li=0.5 mHCombination of F1, F2 and F5(Code F6)ATEX Flameproof and Dust Certifications(Code A1)0344II 1/2 G Ex d IIC T6 Tprocess=85 °C-30 °C < T amb < +75 °C IP66/67II 1/2 G Ex d IIC T5 Tprocess=100 °C -30 °C < Tamb < +80 °C IP66/67II 1/2 G Ex d IIC T4 Tprocess=110 °C -30 °C < T amb< +80 °C IP66/67II 2 D Ex tD A21 IP66/67 T85 Tprocess=85 °C -30 °C < T amb < +75 °CII 2 D Ex tD A21 IP66/67 T100 Tprocess=100 °C -30 °C < T amb < +75 °CII 2 D Ex tD A21 IP66/67 T110 Tprocess=110 °C -30 °C < T amb < +75 °CCaution - Use supply wires suitable for 5 °C above sur-rounding ambientATEX Intrinsic safety and Dust Certifications (Code A2)0344II 1 G Ex ia IIC T4 TPROCESS = 105 °C-30 °C < T amb < +60 °C IP66 / 67ELECTRICAL PARAMETERS: Ui = 30 V , Ii = 93 mA, Pi = 1 W, Ci = 5 nF, Li = 0.5 mHII 1 D Ex iaD 20 IP66 / 67 T105 TPROCESS = 105 °C -30 °C < T amb < +60 °CATEX Type n and Dust Certifications (Code A5)0344II 3 G Ex nL IIC T4 TPROCESS = 105 °C -30 °C < T amb < +60 °C IP66 / 67ELECTRICAL PARAMETERS: Ui = 30 V , Ci = 5 nF, Li = 0.5 mHII 2 D Ex tD A21 IP66 / 67 T85 TPROCESS = 85 °C -30 °C < T amb < +75 °CII 2 D Ex tD A21 IP66 / 67 T100 TPROCESS = 100 °C -30 °C < T amb < +80 °CII 2 D Ex tD A21 IP66 / 67 T110 TPROCESS = 110 °C -30 °C < T amb < +80 °CNEPSI Flameproof and Dust Certifications (Code N1)Ex d IIC T6 DIP A21 T A 85 °C Tprocess=80 °C -40 °C < T amb < +75 °CEx d IIC T5 DIP A21 T A 100 °C Tprocess=95 °C -40 °C < T amb < +80 °CEx d IIC T4 DIP A21 T A 115 °C Tprocess=110 °C -40 °C < T amb < +80 °CENCLOSURE TYPE IP66/67NEPSI Intrinsic Safety Certification (Code N2)Ex ia IIC T4 Tprocess=105 °C -40 °C < T amb < +60 °C Enclosure IP66 / 67Electrical Parameters: Ui=30 V , Ii=100 mA, Pi=1 W, Ci=13 nF, Li=0.5 mHNEPSI Type n Certification (Code N5)Ex nL IIC T4 Tprocess=110 °C -40 °C < T amb < +60 °C Enclosure IP66 / 67Electrical Parameters: Ui=30 V , Ii=100 mA, Pi=1 W, Ci=13 nF, Li=0.5 mHIECEx Flameproof and Dust Certifications (Code E1)Certificate No. IECEx KEM 08.0001Ga/Gb Ex d IIC T6 Tprocess=85 °C -30 °C < T amb < +75 °C IP66/67Ga/Gb Ex d IIC T5 Tprocess=100 °C -30 °C < T amb < +80 °C IP66/67Ga/Gb Ex d IIC T4 Tprocess=110 °C -30 °C < T amb < +80 °C IP66/67Ex tD A21 IP66/67 T85 Tprocess=85 °C -30 °C < T amb < +75 °CEx tD A21 IP66/67 T100 Tprocess=100 °C -30 °C < T amb < +75 °CEx tD A21 IP66/67 T110 Tprocess=110 °C -30 °C < T amb < +75 °CCaution - Use supply wires suitable for 5 °C above sur-rounding ambientAzbil CorporationNo. SS2-GTX00G-0600- 3 -IECEx Intrinsic safety and Dust Certifications (Code E2)IECEx KEM 07.0058XZone 0 Ex ia IIC T4 TPROCESS = 105 °C -30 °C < T amb < +60 °C IP66 / 67ELECTRICAL PARAMETERS: Ui = 30 V , Ii = 93 mA, Pi = 1 W, Ci = 5 nF, Li = 0.5 mHEx iaD 20 IP66 / 67 T105 TPROCESS = 105 °C -30 °C < T amb < +60 °CIECEx Type n and Dust Certifications(Code E5)IECEx KEM 07.0058XEx nL IIC T4 TPROCESS = 105 °C -30 °C < T amb < +60 °C IP66 / 67ELECTRICAL PARAMETERS: Ui = 30 V , Ci = 5 nF, Li = 0.5 mHEx tD A21 IP66 / 67 T85 TPROCESS = 85 °C -30 °C < T amb < +75 °CEx tD A21 IP66 / 67 T100 TPROCESS = 100 °C -30 °C < T amb < +80 °CEx tD A21 IP66 / 67 T110 TPROCESS = 110 °C -30 °C < T amb < +80 °CKOSHA Flameproof (Code K1)Ex d II C T6 Tprocess = 85 °C -30 °C < T amb < +75 °CEx d II C T5 Tprocess = 100 °C -30 °C < T amb < +80 °C Ex d II C T4 Tprocess = 110 °C -30 °C < T amb < +80 °CEMC Conformity89/336/EEC, 92/31/EEC, 93/68/EEC Electromagnetic Compatibility (EMC) DirectiveMeasuring span / Setting range / Workingpressure rangeFigure 1Working pressure and temperature of wetted parts section (for general pur-pose models)Figure 2Working pressure and temperature ofwetted parts section (for oxygen and chlorine service)Supply voltage and load resistance17.9 to 42 V DC. Reverse polarity protection is standard. A load resistance of 250 : or more is necessary between loops. See Figure 3.Figure 3Supply voltage vs. load resistancecharacteristicsNote)For communication with HART communicator or Comm-Pad, a load resistance of 250 : or more is necessary.OutputAnalog output (4 to 20 mA DC) with DE protocol Analog output (4 to 20 mA DC) with HART protocol Digital output (DE protocol)Mo del Measuring Span Measuring range Overload Resistance valueGTX 60G 2.54 to 508 psi(17.5 to 3500 kPa)-14.5 to 508 psi(-100 to 3500 kPa)761 psi(5250 kPa)GTX 71G101 to 2030 psi(0.7 to 14 MPa)-14.5 to 2030 psi(-0.1 to 14 MPa)3045 psi(21 MPa)No. SS2-GTX00G-0600Azbil Corporation- 4 -Output signal3.6 to 21.6 mA3.8 to 20.5 mA (NAMUR NE43 compliant)Failure AlarmUpper: 21.6 mA or more Lower: 3.6 mA or lessAmbient temperature limitNormal operating range-31 to 158 °F (-25 to 70 °C) for general purpose models 14 to 158 °F (-10 to 70 °C) for oxygen and chlorine modelsOperative limits-40 to 185 °F (-40 to 85 °C) for general purpose models -40 to 176 °F (-40 to 80 °C) for oxygen and chlorine models-22 to 185 °F (-30 to 85 °C) for models with digital indi-catorsTransportation and storage conditions -40 to 158 °F (-40 to 70 °C)Temperature ranges of wetted partsNormal operating range-13 to 158 °F (-25 to 70 °C) for general purpose models 14 to 158 °F (-10 to 70 °C) for oxygen and chlorine modelsOperative limits-40 to 185 °F (-40 to 85 °C) for general purpose models -40 to 176 °F (-40 to 80 °C) for oxygen and chlorine modelsAmbient humidity limits5 to 100% RHStability against supply voltage change± 0.005% FS/VResponse timeBelow 100 msec. (when damping time is set to 0 sec.)Damping timeSelectable from 0 to 32 sec. in ten stagesAdjustable from 0 to 120 sec. (HART communication model)Zero Stability± 0.1% of URL per 10 year (model GTX60G)Lightning protectionApplicable Standards; IEC 61000-4-5Peak value of current surge (80/20 P sec. : 6000 AVibration effectPaint code X, H and DLess than ±0.1% of URL, field or pipeline with high vibra-tion level (10–60 Hz, 0–21 mm peak displacement/ 60–2000 Hz, 3g)Paint code ELess than ±0.1% of URL, field with general application or pipeline with low vibration level (10–60 Hz, 0–15 mm peak displacement/ 60–500 Hz, 2g)IndicatorThe digital LCD indicator (optional) indicates engineering units and can be set freely between -99999 and 99999 (5 digits). For meter calibration, specify the following items when placing your order •Meter calibration range •Meter calibration unit•Linear / Square-root for meter indication.Various kinds of data can be set using the Smart Com-municator or the HART ® 375 communicator.PaintStandardCorrosion-resistant paint (Baked acrylic paint)Corrosion-proof finishCorrosion-proof paint (Baked urethane paint), fungus-proof finishOPTIONAL SPECIFICATIONS Oil free finishThe transmitter is shipped with oil-free wetted parts.External zero/span adjustment functionThe transmitter can be easily zero/span adjusted in the field.ElbowThis is an adaptor for changing the electrical conduit con-nection port from the horizontal to the vertical direction, if required by wiring conditions in the field. One or two elbows may be used as needed.Conformance to Non SI unitsWe deliver transmitters set to any Non SI units as specified.Safety TransmitterSelect this option to be used as a component of Safety Instrumented System (SIS).AT9000 is complied with IEC 61508, certified according to Safety Integrity Level2 (SIL-2)Alarm Output (contact output)Contact output is prepared as alarm output when alarm (Output Alarm/Sensor Temp. Alarm) condition is detected. It can be set to Normally Open. (When alarm is detected, Contact ON).Custom calibrationCalibrate for the specified pressure range at the factory.Azbil CorporationNo. SS2-GTX00G-0600- 5 -PHYSICAL SPECIFICATIONS MaterialsFill fluidSilicone oil for general purpose models Fluorine oil for oxygen and chlorine models Center body 316 SSTTransmitter caseAluminum alloy, CF8M (Equivalent to 316 SST)For Wetted parts316 SST (Diaphragm 316L SST)WeightApprox. 1.3 kgINSTALLATIONElectrical connection1/2NPT internal thread, M20 internal thread.GroundingResistance 100 : max.MountingCan be installed on a 2-inch horizontal or vertical pipe (can be directly mounted on a process pipe)Process connectionMale: 1/2NPT, R1/2, G1/2, M20 × 1.5Female: 1/2NPT, Rc1/2TRANSMITTER HANDLING NOTESTo get the most from the performance this transmitter can offer, please use it properly noting the points mentioned below. Before using it, please read the Instruction Manual.Transmitter installation notesWiring notesHandling precautions for HART specifi-cation devices•If you need to operate with a secondary host (HART com-municator, etc.), set the communication interval of the pri-mary host (DCS, device management system) to 8 seconds or more, or suspend communication from the primary host. If the primary host repeats HART communication within 8 seconds, the request from the secondary host may not be received (communication may not be possible).•If electrical noise in the environment prevents HART-communications with the host, take countermeasures such as separating the signal cables from the source of the noise, improving the grounding, changing to shielded signal cables, etc. Even if noise interferes with HART communications, the 4–20 mA analog signal will be unaffected and can be used for control.•If this product is being operated in multidrop mode, there is a limit to the number of devices that can be used. If you are using multidrop mode, please consult with us.•When installing the transmitter, ensure that gaskets do not protrude from connecting points into the process (such as adapter flange connection points and connecting pipes and flanges). Failure to do so may cause a leak of process fluid,resulting in harm from burns, etc. In addition, if the process fluid contains toxic substances, take safety measures such as wearing goggles and a mask to prevent contact with the skin and eyes and to prevent inhalation.•Use the transmitter within the operating ranges stated in the specifications (for explosion-proofing, pressure rating, temperature, humidity, voltage, vibration, shock, mounting direction, atmosphere, etc.). Using the transmitter outside the operating conditions may cause device failure or fire, resulting in a harmful physical risk of burning or the like.•When performing wiring work in explosion-proof areas, follow the work method specified in the explosion-proof guidelines.•After installation, do not use the transmitter as a foothold or put your weight on it. Doing so may cause damage.•Be careful not to hit the glass indicator with tools etc. This could break the glass and cause injury.•The transmitter is heavy. Wear safety shoes and take care when installing it.•Impact to transmitter can damage sensor module .•To avoid shocks, do not perform electrical wiring work with wet hands or with live wires.•Do wiring work properly in conformance with the specifications. Wiring mistakes may result inmalfunction or irreparable damage to the instrument .•Use a power supply that conforms to the specifications. Use of an improper power supply may result in malfunction or irreparable damage to the instrument.•Use a power supply with overcurrent protection for this instrument.No. SS2-GTX00G-0600Azbil Corporation- 6 -PERFORMANCE SPECIFICATIONS Reference accuracyShown for each item are the percentage ratio for F (psi), which is the greatest value of either the upper range value (URV)*1, the lower range value (LRV)*2 or the span.Model GTX60G (for regular type)(Material of wetted parts: Diaphragm; 316L SST, Others; 316 SST)Model GTX60G (for oxygen)(Material of wetted parts: Diaphragm; 316L SST, Others; 316 SST)Model GTX71G (for regular type / oxygen)(Material of wetted parts: Diaphragm; 316L SST, Others; 316 SST)Note)*1) URV denotes the process value for 100% (20 mA DC) output.*2) LRV denotes the process value for 0% (4 mA DC) output.*3) Within a range of URV > 0 and LRV > 0.*4) Reference accuracy at calibrated condition.*5) In case code D “Digital output (DE communication)” is selected, reference accuracy becomes the same as one of “for oxygen /chlorine service”.Reference accuracy (*3)(*4)(*5)± 0.04% (For F > 50.8 psi (350 kPa))%(For F < 50.8 psi (350 kPa))Ambient Temperature effect (Shift from the set range)Change of 86°F (30°C) (*3)Combined shift:(including zero and span shifts)± 0.15%(For F > 50.8 psi (350 kPa))%(For F < 50.8 psi (350 kPa) )Reference accuracy (*3)(*4)± 0.075% (For F > 254 psi (1750 kPa))± 0.1%(254 psi (1750 kPa) > F > 20.3 psi (140 kPa) )%(For F < 20.3 psi (140 kPa))Temperature charac-teristics (Shift from the set range)Change of 86°F (30°C) (*3)(Range from 23 to 131ºF (-5 to 55ºC))Combined shift:(including zero and span shifts)± 0.44%(For F > 50.8 psi (350 kPa))%(For F < 50.8 psi (350 kPa))Reference accuracy (*3)(*4)± 0.15%(For F > 304 psi (2.1 MPa))%(For F < 304 psi (2.1 MPa))Ambient Temperatureeffect(Shift from the set range)Change of 30°C (*3)Combined shift:(including zero and span shifts)± 0.41%(For F > 508 psi (3.5 MPa))%(For F < 508 psi (3.5 MPa))0.0080.03250.8F ---------u +©¹§·r 0.0750.07550.8F ---------u +©¹§·r 0.0250.07520.3F ---------u +©¹§·r 0.190.2550.8F ---------u +©¹§·r 0.050.1+304F --------u ©¹§·r 0.180.23508F --------u +©¹§·rAzbil CorporationNo. SS2-GTX00G-0600- 7 -MODEL SELECTIONModel GTX60G(Standard gauge pressure, In-line model)Model No.:GTX__G-Selection I (I II III IV V VI VII)-Selection II (I II III IV V VI) - OptionNote)*1Not applicable for the combination with code F1 and F6 of Explosion-proof.*2Not applicable for the combination with code Q1 “Safety Transmitter” of Option.*3Not applicable for combination with code E of paint.Basic Model No.Measuring span2.54 to 508 psig (17.5 to 3500 kPa)GTX60GSelection I I Output4 to 20mA (SFN Communication)A 4 to 20mA (HART Communication)B 4 to 20 mA (SFN/HART Biringual Communication) *2E II Fill fluidRegular type (Silicone oil)A For oxygen service (Fluorine oil)H III Material (Meter-body cover, Vent/Drain plugs)Meterbody cover Vent / Drain plugs None (Direct mount)None (Direct mount)XIV Material (centerbody)316 SST (Diaphragm:316L SST)AV Process connections Rc 1/2 internal thread11/2NPT internal thread 21/2NPT external thread 3R1/2 external thread 4G1/2 external thread5M20 × 1.5 external thread7VI Process installation Direct mounting FVII Bolt/nut NoneXSelection II-I Electrical connection 1/2 NPT, Watertight A M20, Watertight *1B IIExplosion-proofNoneXX FM Explosion-proof F1FM Intrinsically safe F2FM NonincendiveF5Combined of FM Explosion-proof, Intrinsically safe and Nonincendive F6ATEX Explosion-proof A1ATEX Intrinsically safe A2ATEX Type nA5IECEx Explosion-proof E1IECEx Intrinsically safe E2IECEx Type nE5NEPSI Explosion-proof *3N1NEPSI Intrinsically safe *3N2NEPSI Type n *3N5KOSHA Explosion-proof *3K1Taiwan Explosion-proof T1III Indicator NoneX With indicator AIV Paint *13StandardX None (316 stainless steel housing) *This option will be available in the future.E Corrosion-proof (Urethane)HV Failure alarmUP Scale A DOWN scale BVI Mounting bracket NoneX CF8 (L form)1No. SS2-GTX00G-0600Azbil Corporation- 8 -Model GTX71G (High gauge pressure In-line model)Model No.:GTX_ _G - Selection I (I II III IV V VI VII) - Selection II (I II III IV V VI) - OptionNote)*1Not applicable for the combination with code F1 and F6 of Explosion-proof.*2Not applicable for the combination with code Q1 “Safety Transmitter” of Option.*3Not applicable for combination with code E of paint.Basic Model No.Measuring span 101 to 2030 psig (0.7 to 14 MPa)GTX71GSelection I I Output4 to 20 mA (SFN Communication)A 4 to 20 mA (HART Communication)B 4 to 20 mA (SFN/HART Biringual Communication) *2E II Fill fluidRegular type (Silicone oil)A For oxygen service (Fluorine oil)H III Material (Meter-body cover, Vent/Drain plugs)Meterbody cover Vent / Drain plugs None (Direct mount)None (Direct mount)XIV Material (centerbody)316 SST (Diaphragm: 316L SST)AVProcess connections Rc 1/2 internal thread11/2NPT internal thread 21/2NPT external thread 3R1/2 external thread 4G1/2 external thread5M20 × 1.5 external thread7VI Process installation Direct mounting FVII Bolt/nut NoneXSelection II-I Electrical connection 1/2 NPT, Watertight A M20, Watertight *1B IIExplosion-proofNoneXX FM Explosion-proof F1FM Intrinsically safe F2FM NonincendiveF5Combined of FM Explosion-proof, Intrinsically safe and Nonincendive F6ATEX Explosion-proof A1ATEX Intrinsically safe A2ATEX Type nA5IECEx Explosion-proof E1IECEx Intrinsically safe E2IECEx Type nE5NEPSI Explosion-proof *3N1NEPSI Intrinsically safe *3N2NEPSI Type n *3N5KOSHA Exposion-proof *3K1Taiwan Explosion-proof T1III Indicator NoneX With indicator AIV Paint *12StandardX None (316 stainless steel housing) *This option will be available in the future.E Corrosion-proof (Urethane)HV Failure alarmUP scale A DOWN scale BVI Mounting bracket NoneX CF8 (L form)1Azbil Corporation No. SS2-GTX00G-0600- 9 -Model No.:GTX_ _G -Selection I ( I II III IV V VI VII) - Selection II (I II III IV V VI ) - OptionNote)*1No need to select when Fill Fluid code H, or J is selected.*2Not applicable for the combination with code A2, or Q7 of Option*3Not applicable for the combination with code A, or B of Process installation.*4Not applicable for the combination with code F1, F6 of Explosion-proof.*5Not applicable for any Explosion-proof. Please select code XX “None” of Explosion-proof.*6Not applicable for the combination with code B “M20 watertight” of Electrical connection.*7Not applicable for the combination with code X “None” of Indicator. Please select “With indicator”.*8Not applicable for the combination with code D “Digital output(DE communication)” of output*9Not applicable for the combination with code F2, F5, F6, N2, N5, E2, E5, A2 and A5 of Explosion-proof.*10In case code P8 is selected, code E of Paint should be selected.*11In case code P8 is selected, code X of Mounting bracket shoult be selected.Option-No optionsXX With external Zero/Span adjustment *7*8A2One elbow (left) *3*4*6G1One elbow (right) *3*4*6G22 elbows *3*5*6G3Oil and water free finish K1Oil free finish *1K3316 SST (Parts in contact with atmosphere) *10*11P8Safety Transmitter *2*8Q1NAMUR NE43 Compliant Output signal limits:3.8 to 20.5 mA (Output 21.6 mA/selected upper limit, 3.6 mA/selected lower limit) *8Q2Alarm Output (contact output) *9Q7Custom calibration R1Test report T1Mill certificateT2Traceability certificate T4Non SI UnitW1No. SS2-GTX00G-0600Azbil Corporation DIMENSIONS- 10 -Azbil Corporation No. SS2-GTX00G-0600- 11 -。
integral equation methods in scattering theory
Integral equation methods in scattering theory are a set of mathematical techniques used to analyze the interaction of waves with obstacles. These methods are essential in understanding the behavior of waves in complex media and in particular, in determining the scattering properties of objects.In scattering theory, the interaction of a wave with an obstacle is typically described using integral equations. These equations express the relationship between the scattered field and the incident field, as well as the properties of the obstacle itself. The most common integral equation method in scattering theory is the Lippmann-Schwinger equation.The Lippmann-Schwinger equation is a Fredholm integral equation that relates the scattered field to the incident field and the obstacle's scattering operator. It is derived from the conservation of energy and momentum in the scattering process. The equation provides a means to calculate the scattered field efficiently, given a known incident field and obstacle's scattering operator.Another important integral equation method in scattering theory is the Born approximation. The Born approximation is a perturbative method that approximates the exact solution of the Lippmann-Schwinger equation using a series expansion. It is useful when the obstacle's scattering operator is small compared to the incident field, allowing for an analytical solution of the scattering problem.In addition to these two methods, there are other integral equation techniques that can be used in scattering theory, such as the Rayleigh-Sommerfeld diffraction formula and the Kirchhoff integral formula. These methods are derived from different physical assumptions and are suitable for different types of scattering problems.Integral equation methods in scattering theory have found applications in various fields, including acoustics, electromagnetics, and quantum mechanics. Inacoustics, for example, these methods are used to study the scattering of sound waves by obstacles such as buildings or mountains. In electromagnetics, they are used to analyze the interaction of electromagnetic waves with conducting objects or dielectrics. In quantum mechanics, integral equation methods are used to study the scattering of particles by potentials or potentials.Integral equation methods in scattering theory provide a powerful tool for understanding wave interactions with obstacles. They allow for efficient calculations of scattered fields and provide insights into the physical properties of scattering systems. As such, these methods continue to play a crucial role in various fields of applied mathematics and physics.。
环糊精
26CyclodextrinsKatia Martina and Giancarlo CravottoCONTENTS26.1 Introduction (593)26.2 Inclusion Complex Formation (595)26.3 Applications of CD in Food (596)26.4 Analysis of CD (597)26.4.1 Characterization of CD-Inclusion Complex (597)26.4.2 Determination of CD Content (598)26.4.2.1 The Colorimetric Method (598)26.4.2.2 Chromatography (599)26.4.2.3 Affinity Capillary Electrophoresis (600)26.5 Conclusion (600)References (601)26.1 I ntroductionCyclodextrins (CDs) are unique molecular complexation agents. They possess a cage-like supramolecular structure, which involves intra- and intermolecular interactions where no covalent bonds are formed between interacting molecules, ions, or radicals. It is mainly a “host–guest” type phenomenon. CDs are definitively the most important supramolecular hosts found in the literature. As a result of molecular complexation, CDs are widely used in many industrial fields (cosmetics, pharmaceutics, bioremediation, etc.) and in analytical chemistry. Their high biocompatibility and negligible cytotoxicity have opened the doors to their uses such as drug excipients and agents for drug-controlled release (Stella and Rajewski 1997, Matsuda and Arima 1999), in food and flavors (Mabuchi and Ngoa 2001), cosmetics (Buschmann and Schollmeyer 2002), textiles (Buschmann et al. 2001), environment protection (Baudin et al. 2000), and fermentation and catalysis (Koukiekolo et al. 2001, Kumar et al. 2001).CDs are cyclic oligosaccharides consisting of at least six glucopyranose units which are joined together by a (1 → 4) linkage. CDs are known as cycloamyloses, cyclomaltoses, and historically as Schardinger dextrins. They are produced as a result of an intramolecular transglycosylation reaction from the degra-dation of starch which is performed by the CD glucanotransferase enzyme (CGTase) (Szetjli 1998). The first reference to the molecule, which later proved to be CD, was published by Villiers in 1891. Digesting starch with Bacillus amylobacter, he isolated two crystalline products, probably α- and β-CDs. In 1903, Schardinger reported the isolation of two crystalline products that he called α- and β-dextrin, in which the helix of amylose was conserved in fixed-ring structures.From the x-ray structures, it appears that the secondary hydroxyl groups (C2 and C3) are located on the wider edge of the ring and the primary hydroxyl groups (C6) on the other edge. The apolar –CH (C3 and C5) and ether-like oxygens are on the inside of the truncated cone-shaped molecules (Figure 26.1). This results in a hydrophilic structure with an apolar cavity, which provides a hydrophobic matrix, often described as a “microheterogeneous environment.” As a result of this cavity, CDs are able to form inclu-sion complexes with a wide variety of hydrophobic guest molecules. One or two guest molecules can be entrapped by one, two, or three CDs.593594 Handbook of Analysis of Active Compounds in Functional FoodsAlthough CDs with up to 12 glucose units are known, only the first three homologues (α-, β-, and γ-CD) have been extensively studied and used. β-CD is the most accessible due to its low price and high versatility. The main properties of the aforementioned CDs are given in Table 26.1.The safety profiles of the three most common natural CDs and some of their derivatives have recently been reviewed (Irie and Uekama 1997, Thompson 1997). All toxicity studies have demonstrated that orally administered CDs are practically nontoxic due to the fact that they are not absorbed by the gastro-intestinal tract.Pioneer country in the industrial applications of CDs was Japan, since 1990 it become the largest con-sumer in the world. Eighty percent of the annual consumption was used in the food industry and over 10% in cosmetics, <5% was used in the pharmaceutical and the agrochemical industries. The industrial usage of CDs progresses somewhat slower in Europe and America. The constant annual growth of the number of scientific papers and patents indicates the scale of research and industrial interest in this field. From a regulatory standpoint, a monograph for β-CD is available in both the US Pharmacopoeia/National Formulary (USP 23/NF 18, 1995) and the European Pharmacopoeia (3rd ed., 1997). All native CDs are listed in the generally regarded and/or recognized as safe (GRAS) list of the US-FDA for use as a food additive. β-CD was recently approved in Europe as a food additive (up to 1 g/kg food). In Japan, the native CDs were declared to be enzymatically modified starch and, therefore, their use in food prod-ucts has been permitted since 1978.FIGURE 26.1 Chemical structure of α, β, and γ-CD.Cyclodextrins 595Apart from these naturally occurring CDs, many derivatives have been synthesized so as to improve solubility, stability to light or oxygen and control over the chemical activity of guest molecules (Eastburnand and Tao 1994, Szente and Szejtli 1999). Through partial functionalization, the applications of CDs are expanded. CDs are modified through substituting various functional compounds on the pri-mary and/or secondary face of the molecule.26.2 I nclusion Complex FormationThe most notable feature of CDs is their ability to form solid inclusion complexes (host–guest complexes) with a very wide range of solid, liquid, and gaseous compounds by molecular complexation (Szejtli 1982).Since the exterior of the CDs is hydrophilic, they can include guest molecules in water solution. As depicted in Figure 26.2, the guest can be either completely or partially surrounded by the host molecule. The driving force in complex formation is the substitution of the high enthalpy water molecules by an appropriate guest (Muñoz-Botella et al. 1995). One, two, or more CDs can entrap one or more guest molecules. More frequently the host–guest ratio is 1:1; however, 2:1, 1:2, 2:2 or even more complicated associations and higher-order equilibria have been described. The packing of the CD adducts is related to the dimensions of the guest and cavity. Several factors play a role in inclusion complex formation and several interactions have been found:a. Hydrophobic effects, which cause the apolar group of a molecule to fit into the cavity.b. Van der Waals interactions between permanent and induced dipoles.c. Hydrogen bonds between guest molecules and secondary hydroxyl groups at the rim of the cavity.d. Solvent effects.TABLE 26.1Physical Properties of α-, β-, and γ-CDsPropertyα-CD β-CD γ-CD Number of glucose units678Mol wt. (anhydrous)97211351297V olume of cavity (Å3 in 1 mol CD)174262427Solubility in water (g 100 mL −1 r.t.)14.5 1.8523.2Outer diameter (Å)14.615.417.5Cavity diameter (Å) 4.7–5.3 6.0–6.57.5–8.3′R ″CD derivatives R R ′ R ″Native CD R R ′ R ″ = H1:1 and 1:2 inclusion complexes with a naphthalene derivativeFIGURE 26.2 1:1 and 1:2 host–guest CD complexes.596Handbook of Analysis of Active Compounds in Functional Foods Regardless of what kind of stabilizing forces are involved, the geometric characteristics and the polar-ity of guest molecules, the medium and temperature are the most important factors for determining the stability of the inclusion complex. Geometric rather than the chemical factors are decisive in determin-ing the kind of guest molecules which can penetrate the cavity. If the guest is too small, it will easily pass in and out of the cavity with little or no bonding at all. Complex formation with guest molecules signifi-cantly larger than the cavity may also be possible, but the complex is formed in such a way that only certain groups or side chains penetrate the CD cavity.Complexes can be formed either in solution or in the crystalline state and water is typically the solvent of choice. Inclusion complexation can be accomplished in cosolvent systems, also in the presence of any nonaqueous solvent. Inclusion in CDs exerts a strong effect on the physicochemical properties of guest molecules as they are temporarily locked or caged within the host cavity giving rise to beneficial modi-fications which are not achievable otherwise (Dodziuk 2006).Molecular encapsulation can be responsible for the solubility enhancement of highly insoluble guests, the stabilization of labile guests against degradation and greater control over volatility and sublimation. It can also modify taste through the masking of flavors, unpleasant odors, and the controlled release of drugs and flavors. Therefore, CDs are widely used in food industry (Shaw 1990), in food packaging (Fenyvesi et al. 2007), in pharmaceuticals (Loftsson and Duchene 2007, Laze-Knoerr et al. 2010), and above all in cosmetics and toiletries (Szejtli 2006).26.3 A pplications of CD in FoodToday the nontoxicity of β-CD is well proven, the same tenet is generally accepted for the other CDs. The regulatory statuses of CDs differ in Europe, the United States, and Japan, because official processes for food approval are different. In the United States α-, β-, and γ-CD have obtained the GRAS status and can be commercialized as such. In Europe, the approval process for α-CD as Novel Food has just started and is expected to legalize the widespread application of α-CD to dietary products, including soluble fiber. In Japan, α-, β-, and γ-CDs are recognized as natural products and their commercialization in the food sector is restricted only by purity considerations. In Australia and New Zealand, α- and γ-CD have been classified as Novel Foods since 2004 and 2003, respectively.Nowadays the application of CD-assisted molecular encapsulation in foods offers many advantages (Cravotto et al. 2006):• Improvement in the solubility of substances.• Protection of the active ingredients against oxidation, light-induced reactions, heat-promoted decomposition, loss by volatility, and sublimation.• Elimination (or reduction) of undesired tastes/odors, microbiological contamination, hygro-scopicity, and so on.Typical technological advantages include, for example, stability, standardized compositions, simple dosing and handling of dry powders, reduced packing and storage costs, more economical, and man-power savings. CDs are mainly used, in food processing, as carriers for the molecular encapsulation of flavors and other sensitive ingredients. As CDs are not altered by moderate heat, they protect flavors throughout many rigorous food-processing methods such as freezing, thawing, and microwaving. β-CD preserves flavor quality and quantity to a greater extent and for a longer time compared to other encap-sulants (Hirayama and Uekama 1987).CDs can improve the chemical stability of foods by complete or partial inclusion of oxygen-sensitive components. They can be used to stabilize flavors against heat that can induce degradation and they can also be employed to prolong shelf-life by acting as stabilizers.CDs are used for the removal or masking of undesirable components; for example, trimethylamine can be deodorized by the inclusion of a mixture of α-, β-, and γ-CDs. CDs are also used to free soybean products from their fatty smell and astringent taste. Even the debittering of citrus juices with β-CD is a long pursued goal.Cyclodextrins 597 CDs have an important use in the removal of cholesterol from animal products such as milk, butter, and egg yolks and have recently been studied as neutraceutics carriers to disperse and protect natural lipophylic molecules such as polyunsaturated fatty acids, Coenzyme Q10 (ubiquinone) and Vitamin K3.26.4 A nalysis of CD26.4.1 C haracterization of CD-Inclusion ComplexWhen molecules are inserted within the hydrophobic interior of the CDs, several weak forces between the host and guest are involved, that is, dipole–dipole interaction, electrostatic interactions, van der Waals forces, and hydrophobic and hydrogen bonding interactions. An equilibrium exists between the free and complexed guest molecules. The equilibrium constant depends on the nature of the CD and guest molecule, as well as temperature, moisture level, and so on. The inclusion complexes formed in this way can be isolated as stable crystalline substances, and precise information on their topology can be obtained from the structural x-ray analysis of single crystals (Song et al. 2009). The topology of the inclusion complex can also be determined in solution. The interactions between host and guest may lead to characteristic shifts in the 1H and 13C NMR spectra (Dodziuk et al. 2004, Chierotti and Gobetto 2008). Nuclear Overhauser effects (NOE) provide more precise information since their magnitudes are a mea-sure of the distance between host and guest protons. Circular dichroism spectra give information on the topology of the adduct, when achiral guests are inserted into the chiral cavity (Silva et al. 2007). Potentiometry, calorimetry, and spectroscopic methods including fluorescence, infrared, Raman, and mass spectrometry have also been used to study inclusion complexes (Daniel et al. 2002).The molecular encapsulation of natural essential oils, spices, and flavors such as cheese, cocoa, meat, and coffee aromas with β-CD has been known since several years. The literature has dealt with the improved physical and chemical stability of these air-, light-, and heat-sensitive flavors (Szente et al. 1988; Qi and Hedges 1995) and investigated the interaction of these compounds with CDs.UV absorbance spectroscopy was applied to investigate hyperchromic effects induced by the addition of β-CD to a water solution of caffeine (Mejri et al. 2009). The spectroscopic and photochemical behav-ior of β-CD inclusion complexes with l-tyrosine were investigated by Shanmugam et al. (2008). UV–vis, fluorimetry, FT-IR, scanning electron microscope techniques, and thermodynamic parameters have been used to examine β-CD/l-tyrosine complexation.Nishijo and Tsuchitani (2001) studied the formation of an inclusion complex between α-CD and l-tryp-tophan using nuclear magnetic resonance (NMR). Linde et al. (2010) investigated the complexation of amino acids by β-CD using different NMR experiments such as diffusion-ordered spectroscopy (DOSY) and rotating frame Overhauser effect spectroscopy (ROESY). This study provided molecular level infor-mation on complex structure and association-binding constants and advanced the sensorial knowledge and the development of new technologies for masking the bitter taste of peptides in functional food products. The preparation of stable, host–guest complexes of β-CD with thymol, carvacrol, and oil of origanum has been described by LeBlanc et al. (2008). The complex was characterized by NMR and the inclusion constant was measured by fluorescence spectroscopy where 6-p-toluidinylnaphthalene-2-sulfonate was in competitive binding and acted as a fluorescent probe.Caccia et al. (1998) provide the evidence of the inclusion complex between neohesperidin dihydrochalcone/β-CD by x-ray, high resolution NMR and MS spectroscopy. The association constant was determined by NMR via an iterative nonlinear fitting of the chemical shift variation of H3 in β-CD. The geometry of the binding was studied by nuclear NOEs between the proton directly involved in the host/guest interaction as well as by ROESY. The use of fast atom bombardment (FAB) gave comple-mentary information on specific host–guest interaction, while x-ray diffractometry patterns could define the complex in solid state.Differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), or nuclear magnetic resonance (1H-NMR) were employed by Marcolino et al. (2011) to study the stability of the β-CD com-plexes with bixin and curcumin. Owing to the huge industrial applications of natural colorants, this study aimed to compare different methods of complexes formation and evaluate their stability.598Handbook of Analysis of Active Compounds in Functional Foods Natural and synthetic coffee flavors were included in β-CD and the complexes were analyzed by x-ray diffraction by Szente and Szejtli (1986). By thermofractometry and the loss of a volatile constitu-ent, it was demonstrated that the volatility of these complexed flavors diminished in such a way that they could be stored for longer periods. Various spectroscopic methods have been compared, by Goubet et al. (1998, 2000), to study the competition for specific binding to β-CD. The substrates were a group of flavors which show different physicochemical properties, such as vapor pressure, water solubility, and log P.Inverse gas chromatography was recently used for the direct assessment of the retention of several aroma compounds of varying chemical functionalities by high amylose corn starch, wheat starch, and β-CD (Delarue and Giampaoli 2000). The inclusion selectivity of several monoterpene alcohols with β-CD in water/alcohol mixtures was studied by Chatjigakis et al. (1999) using reverse-phase HPLC. Flavor r etention in α-, β-, and γ-CDs was compared, by Reineccius et al. (2002), by the GC analysis of the released flavor compounds; quantification was accomplished using standard internal protocols.GC-MS was used for the identification of the volatile constituents of cinnamon leaf and garlic oils before and after the microencapsulation process with β-CD (Ayala-Zavala et al. 2008). The profile of volatile substances in the β-CD microcapsules was used to evaluate the competitive equilibrium between β-CD and all volatile substances. The eugenol and allyl disulfide content of cinnamon leaf and garlic oils were used as a pattern to evaluate the efficiency in the microencapsulation process. The IR spectra of the microcapsules was employed to demonstrate the formation of intramolecular hydrogen bonds between the guest and host molecules.Samperio et al. (2010) investigated the solubility in water and in apple juice of 23 different essential oils and 4 parabens. The study was focused on the β-CD complexes of few essential oil components (o-methoxycinnamaldehyde,trans, trans-2,4-decadienal, and citronellol), evaluating the increase of solubility in water and the storage stability. UV absorption spectrophotometry was performed to quan-tify the compound in solution. Linear regression analysis was used to calculate the concentration of test compounds in solution from day 0 to day 7.26.4.2 D etermination of CD ContentTraditionally, a variety of techniques have been developed to analyze CDs and their derivatives.Few analytical methods for the quantification of β-CD are described in the literature. Among them are colorimetric methods, LC methods based on the use of indirect photometric detection, pulse ampero-metry, or refractive index experiments, affinity capillary electrophoresis, and mass spectrometry are able to provide qualitative and quantitative data when analyzing the complex CD mixtures.26.4.2.1 T he Colorimetric MethodThe colorimetric method may be used as an alternative to chromatography especially at low CD concen-trations, this also works in the presence of linear oligosaccharides. The colorimetric method, based on the complexation of phenolphthalein, was employed by Higuti et al. (2004) to carry out sensitive and relatively specific quantification of β-CD. A decrease in absorbance at 550 nm, due to phenolphthalein–CD complex formation, was exploited to study the optimization of the CGTase production in Bacillus firmus. A highly reproducible and selective α-CD determination method had already been described by Lejeune et al. (1989). This involves the formation of an inclusion complex between the α-CD and methyl orange under conditions of low pH and low temperature. The metal indicator calmagite (1-(1-hydrohy-4-methyl-phenylazo)-2-naphthol-4-sulfonic acid) interacts selectively with γ-CD and was described by Hokse (1983) to quantify a standard solution of γ-CD.Kobayashi et al. (2008) observed that various kinds of hydrophobic food polyphenols and fatty acids could be dispersed in water containing starch by the action of GTAse (CD-producing enzyme). NMR and spectrophotometric methods were used to confirm the presence of CDs as solubilizing agents. The for-mation of inclusion complexes was demonstrated by using Congo Red as a model molecule in the pres-ence of GTAse or α-, β-, and γ-CD, respectively. Major changes in the 1H NMR profile of Congo Red were observed in the presence of γ- and β-CD.Cyclodextrins 599On the other hand, a spectrophotometric and infrared spectroscopic study of the interaction between Orange G, a valuable clastogenic and genotoxic acid dye used as a food colorant, and β-CD has been described by Wang et al. (2007) as a method for the quantitative determination of this dye. Based on the enhancement of the absorbance of Orange G when complexed by β-CD, the authors proposed a ratiomet-ric method, carried out spectrophotometrically, for the quantitative determination of Orange G in bulk aqueous solution. The absorbance ratio of the complex at 479 and 329 nm in a buffer solution at pH 7.0 showed a linear relationship in the range of 1.0 × 10−5 to 4.0 × 10−5 mol L−1. IR spectroscopy of the com-plex was described to confirm the inclusion complex formation.26.4.2.2 C hromatography26.4.2.2.1 T hin-Layer ChromatographyOne reference in the literature refers to the use of thin-layer chromatography (TLC) technique as an inexpensive, simple, and very informative method for the analysis and separation of CD inclusion com-plex food components. Prosek et al. (2004) isolated the inclusion complex between coenzyme Q10 (CoQ10) and β-CD and described its analysis and separation by one-dimensional, two-dimensional, and multidimensional TLC. The article described different TLC supports, mobile phases, and visualization methods in detail and the authors evaluated that 70% of the complex remained unchanged during the first semipreparative chromatography run and only a small amount of CoQ10 was lost from the complex dur-ing the TLC procedure. The results were confirmed by the use of other separation techniques such as HPLC, HPLC-MS, and NMR.26.4.2.2.2 L iquid Chromatography, LC-MS, HPLC-MSLiquid chromatography (LC) methods are employed for the analysis and separation of CDs and their derivatives. The separation of the complex samples containing CDs in mixture with linear oligosaccha-ride residual starch as well as protein salts and other substances may suffer from poor sensitivity, resolu-tion, and long separation times. Good results can be achieved where differences in mass or polarity are found or, otherwise, will require extensive sample preparation.Several stationary phases have been described, for example, resins modified with specific adsorbents and reverse-phase media used in combination with either refractive index detection (Berthod et al. 1998), evaporative light scattering (Caron et al. 1997, Agüeros et al. 2005), indirect photometric detection (Takeuchi et al. 1990), postcolumn complexation with phenolphthalein (Frijlink et al. 1987, Bassappa et al. 1998), polarimetric detection (Goodall 1993), or pulsed amperometric detection (Kubota et al. 1992).López et al. (2009) described the application of LC and refractive index detection to estimate the amount of residual β-CD (>20 mg per 100 g of product) present in milk, cream, and butter after treat-ment with β-CD. The analyses were performed with a C18 reversed-phase silica-based LC column, α-CD was defined as an internal standard. The repeatability of the analytical method for β-CD was tested on commercial milk, cream, and butter spiked with known amounts of β-CD.The detection limit in milk was determined to be >0.03 mg mL−1 of β-CD which is similar to that found by LC using amperometric detection (Kubota et al. 1992) and its reproducibility was comparable to that found in a colorimetric method for the estimation of β-CD using phenolphthalein (Basappa et al. 1998, Frijlink et al. 1987).LC-MS coupling has led to the development of new interfaces, extending the automation of various procedures and increasing the sensitivity for high-polar and high-molecular mass compounds. New ion-ization techniques such as electron spray (ESI) and matrix-assisted laser desorption ionization (MALDI) (Bartsch et al. 1996, Sporn and Wang 1998) on quadrupole, magnetic sector, or time-of-flight (TOF) instruments or coupled with instruments with tandem MS (MS-MS) capabilities have also been funda-mental in food applications. By coupling HPLC to isotope-ratio, MS has been proven valuable in provid-ing precise isotopic measurements for nonvolatile species such as carbohydrates. For these reasons, the number of reported applications of LC-MS in the analysis of CD in food is rapidly increasing.HPLC/MS analyses for the detection of minute amounts of CDs in enzyme and heat-treated, s tarch-containing food products were proposed by Szente et al. (2006). A suitable sensitive and selective600Handbook of Analysis of Active Compounds in Functional Foods analytical method was studied with the aim of verifying the presence of parent β- and γ-CDs and all the three, α-, β-, and γ-branched CDs with different degrees of glycosylation in appropriately preconcen-trated and purified food samples (beer samples, corn syrups, and bread). Both the HPLC-retention times and mass-spectral data were used for the identification of CDs. As the expected concentrations of CDs were very low, selected ion monitoring (SIM) was preferred to the routinely used refractive index and evaporative light scattering detection techniques as the only reliable detection method. The malto-oli-gomer mixture was analyzed with a detection window opened at the masses of CD sodium salts in order to enable the detection of any malto-oligomer side products.Wang et al. (1999) proposed the efficient qualitative and quantitative analysis of food oligosaccharides by MALDI-TOF-MS. In order to optimize the method, matrices, alkali–metal adducts, response inten-sity, and sample preparation were all examined individually. A series of experiments were carried out by the authors to study analyte incorporation in the matrix. In a first phase of experiments, maltohexanose and γ-CD were used as reference samples to verify the suitability of 2,5-dihydroxybenzoic acid (DHB), 3-aminoquinoline (3-AQ), 4-hydroxy-a-cyanocinnamic acid (HCCA), and 2,5-dihydroxybenzoic acid (DHB), 1-hydroxy-isoquinoline (HIC), (1:1) as the matrix material. Spot-to-spot or sample-to-sample repeatability tests and the ability to achieve a good quality spectrum with a reasonable signal-to-noise ratio and the best resolution were compared. Good quality spectra and acceptable repeatability were achieved with DHB but many interfering matrix peaks were observed in the low mass region. The best results were achieved using a 2,4,6-trihydroxy-acetophenone monohydrate (THAP) matrix. The authors exploited the high solubility of THAP in acetone, its fast evaporation to fine crystals, and the homo-geneous incorporation of the sample to avoid low-quality results which may be due to irregular crystal-lization when the substance is used directly in water.26.4.2.3 A ffinity Capillary ElectrophoresisAffinity capillary electrophoresis (ACE) techniques have been introduced more recently and are currently in rapid development. CDs have played a central role in the development of a wide variety of analytical methods based on ACE in the separation of chiral molecules. ACE also provides a powerful analytical tool for the analysis of CDs and their derivatives.The electrophoretic separation and analysis of α-, β-, and γ-CDs have been carried out recently without modification. CDs that are charged at very high pH can be separated by the formation of inclu-sion complexes. Their complexes, with a large range of aromatic ions, facilitate detection by indirect UV absorbance (Larsen and Zimmermann 1998, 1999). In addition, fluorescent molecules such as 2-anilinonaphthalene-6-sulfonic have been used for the separation and detection of CDs in a ACE system (Penn et al. 1994).Furthermore, the indirect electrophoretic determination of CD content has recently been described using periodate oxidation. The amount of produced iodate was monitored by ACE and reproducible quantitative results were obtained for α-, β-, and γ-CDs (Pumera et al. 2000). Nevertheless, ACE has not been yet exploited for the analysis of CDs in food. The major advantages of ACE compared to other analysis methods are their short analysis times and high versatility. An exhaustive review of this topic was published in 1999 (Larsen and Zimmermann 1998, 1999).26.5 C onclusionThe use of native CDs for human consumption is growing dramatically due to their well-established safety. CDs are effective in protecting lipophilic food components from degradation during cooking and storage. In this context, several methodologies have been developed to detect, identify, and quantify CDs in food extracts and to study molecular inclusion complexes. X-ray and NMR spectroscopy afford valuable and detailed insight into the structure and the dynamics of a wide range of complexes which are not amenable to study by other analytical techniques. HPLC coupled with refractive index and evaporative light scattering detection technique is routinely used in CD food analysis and LC-MS data in this respect are particularly useful in detecting minute amounts of CDs in complex food samples.。
全量化工艺处理垃圾填埋场后期及封场渗滤液实例
DOI ：10.19965/ki.iwt.2023-0072第 44 卷第 1 期2024年 1 月Vol.44 No.1Jan.，2024工业水处理Industrial Water Treatment 全量化工艺处理垃圾填埋场后期及封场渗滤液实例陈俊（武汉森泰环保股份有限公司，湖北武汉 430000）[ 摘要 ] 针对国内垃圾填埋场后期及封场渗滤液可生化性低、无法采用生化进行有效处理、膜浓缩液长期回灌、渗滤液累积盐分越来越高得不到解决等问题，提出一种全量化处理组合工艺，即“软化预处理+高压碟管式反渗透（DTRO ）+特种分离膜+低温负压蒸发技术+三相固化技术”，适合盐分高、氨氮高、生化性低的终端渗滤液处理。
运行结果表明，清水回收率可达到90%~95%，固化后填埋物仅为5%~10%。
液相和固相处理系统优势互补，系统运行稳定，能耗较低，脱盐率达到99.5%以上；出水COD≤60 mg/L ，BOD 5≤20 mg/L ，氨氮≤8 mg/L ，总氮≤20 mg/L ，SS≤6 mg/L ，产水符合《生活垃圾填埋场污染控制标准》（GB 16889—2008）表3规定的限值要求。
［关键词］ 后期及封场渗滤液；全量化工艺；特种分离膜；低温负压蒸发技术；三相固化技术［中图分类号］ X703 ［文献标识码］B ［文章编号］ 1005-829X （2024）01-0198-09A case of treatment of landfill leachate in late stage andclosure stage by full quantification processCHEN Jun（Wuhan Sentai Environmental Protection Co.， L td.， W uhan 430000，China ）Abstract ：In view of the low biodegradability of the leachate in the late stage of domestic landfills and closures ，it cannot be effectively treated by biochemistry. Furthermore ， the membrane concentrate is recharged for a long time ，and the increasingly accumulated salinity of the leachate cannot be solved. Aiming to these problems ，they proposed a combined process of full quantitative treatment ，namely “softening pretreatment ， DTRO ， special separation mem ⁃brane ， low temperature negative pressure evaporation technology and three -phase curing technology ”，which is suit⁃able for terminal leachate with high salinity ，high ammonia nitrogen and low biochemical properties. The operation results showed that the recovery rate of clean water can reach 90%-95%，and the landfill after solidification was only 5%-10%. The advantages of liquid and solid phase treatment systems complemented each other ，and the sys⁃tem run stably ，with low energy consumption. The desalination rate reached more than 99.5%，effluent COD≤60 mg/L ，BOD 5≤20 mg/L ，ammonia nitrogen≤8 mg/L ，total nitrogen≤20 mg/L ，SS≤6 mg/L. And the produced water met the limit requirements specified in Table 3 of the Standards for Pollution Control of Domestic Waste Landfills （GB 16889—2008）.Key words ：late stage and closure leachate ；full quantification process ；special separation membrane ；low tempera⁃ture negative pressure evaporation technology ；three -phase curing technology近年来，随着我国城市化程度的加快和居民生活消费水平的提高，我国城市生活垃圾的产生量增长迅速〔1〕。
EUROGRAPHICS 2006 D. W. Fellner and C. Hansen Short Papers Real-time Reflection using Ray
EUROGRAPHICS2006/D.W.Fellner and C.Hansen Short Papers Real-time Reflection using Ray Tracing with Geometry FieldShengying Li,Zhe Fan,Xiaotian Yin,Klaus Mueller,Arie E.Kaufman,Xianfeng GuDepartment of Computer Science,Center for Visual Computing,Stony Brook University,U.S.A.1.IntroductionInter-reflection among mirror objects has always been of great interest in computer graphics.Handling reflections with high accuracy in real time remains a challenge,due to the expensive global computational process,especially for the intersection testing,which is not suitable for graphics hardware.Ray tracing is the most well known algorithm for achiev-ing accurate renderings.Great efforts have been spent to ac-celerate ray-tracing by designing special hardware[WSS05] [PBMH02,CHH02,WSE04].Environment mapping[BN76, Gre86]is an alternative approach that provides fast reflec-tion of the surroundings assuming the scene elements are infinitely far away from the reflector.Localized environment maps[SKALP05]offer better approximations forflat sur-faces.Inspired by the work of lightfields and geometry im-ages,we have developed a novel method,geometryfield, which converts intersection testing to table lookup.Hence, the computational power of graphics hardware can be fully utilized.Without sophisticated data structures and optimiza-tions,our simple algorithm has demonstrated the capability of real time rendering of inter-reflections.Our method re-sponds to the trend of fast increases in memory capacities. In our experiments,we obtain convincing results using cur-rent graphics hardware.The lightfield[LH96,GGSC96]is one of the central con-cepts in image based rendering,which maps a ray to the color of the intersection point.Surface reflections have been rendered using lightfields[YYM05],layered lightfields and layered depth images[LR98],and surface lightfields [WAA00].Ray classification[AK87]records potentially intersecting primitives in each cell of the5D ray space dis-cretization,and the virtual lightfield[SMKY04]extends the idea and uses a lightfield data structure to propagate radi-ance for globally illuminated scenes.The geometry image[GGH02]represents a surface as an image.The color at a pixel represents the position vector of the surface.Similarly,a normal map represents the normals of a surface by an image.Geometry images are generalized to multi-chart geometry images[SWG03],and smooth ge-ometry images[LHSW03].The geometryfield of a surface S is a map,where the input is an incident ray,and the output is the texture coordinates of thefirst intersection point.Suppose S is represented as a geometry image r u v,γis a ray in3intersecting S.The first intersection point p is r u p v p.Then the map G:γu p v p is the geometryfield of surface S.From u p v p,the position and the normal of p can be obtained from the geometry image and the normal map.Conventional expensive intersection testings are replaced by simple table lookups in a precomputed geometryfield.c The Eurographics Association2006.BF89][SKSU05],animation in [BS96]and displacement map in [WWT 04].The geometry field representation has several advantages.First,it effectively reduces the memory cost.In general,a geometry field is 4dimensional.If the position,normal and color material information are stored for each entry,the stor-age requirement will be extremely high.Instead,only the texture coordinates are stored,such that the size of a geome-try field is within the memory capacity of current hardware.Second,due to the regular structure of a geometry field,it can be represented as a generalized texture.The whole ren-dering algorithm can be implemented in common graphics hardware.The time cost is independent of the geometric complexity of the scene,and only dependent on the size of the geometry field.Figure 1illustrates the concept of the ge-ometry field.Most real-time reflection methods make assumptions of the geometries of the reflectors or their geometric relations to the scene.In contrast,the geometry field handles arbi-trary surfaces and scenes without making any assumptions.In experiments,we constructed geometry fields for compli-cated surfaces,such as Michelangelo’s David head model with 100K faces.The inter reflections are computed using the GPU at 60FPS .The method can be generalized for self-reflection and refraction as well.2.Geometry FieldThe geometry field for a surface is a map which records all ray/surface intersection information.It reduces the cost of intersection testing by table lookup in run time.An im-plementation on graphics hardware can achieve high paral-lelism.The efficiency can be further improved by the regu-larity of geometry images,which leads to large spatial co-herence.In our framework,all surfaces are represented as geome-try images.General triangular meshes are converted to ge-ometry images by conformal parameterizations,which help to reduce the distortions.Figure 1demonstrates the geom-etry image of the David head surface.A ray is represented by its two intersection points (in,out)with the bounding box of the surface.Hence,the geometry field is a 4dimensional function.To construct the geometry field,we first construct a bounding box of the geometry image,then compute the in-tersection points of rays with the box.We only consider rays with two intersection points,the entrance s and the exit t and parameterize them using the point pair s t .Next,we compute the intersection point of each ray with the geometry image and record the texture coordinates of the one closest to s .In order to speed up the intersection calculation,we use an octree structure to subdivide the cube.All the computa-tions are carried out in the local coordinates of the geometry image.The result is a 4D lookup table and the internal rep-resentation on the GPU is described in the next implementa-tion section.3.Rendering with Inter-reflectionGeometry fields and geometry images are generated offline in software.The run time rendering algorithms have been implemented on a NVidia’s GeForce 7800graphics card.3.1.Data StructuresEach geometric object O i is represented as a geometry field GF i and a geometry image GI i ,which incorporates the posi-tion,normal,material and texture information.Furthermore,each geometric object is normalized in the unit cube of the bounding box.Points on the 6faces of the unit cube are sampled uniformly and enumerated.So,the 4D geometry field is stored as a 2D texture,with i j represent-ing the indices for the in and out points on the unit cube.Each geometric object has a geometry field,which isc The Eurographics Association 2006.stored as a single2D texture.Each object may have mul-tiple instantiations sharing the geometryfield with different local frames.3.2.Algorithm PipelineNon-reflective surfaces are simply rendered using conven-tional OpenGLfixed pipeline functionalities.Reflective sur-faces are rasterized with our geometryfield-based vertex shader and fragment shader.The vertex shader is conven-tional but the fragment shader is capable of computing the inter-reflection.We adapt simple convolution kernels(cur-rently linear)for interpolation when looking up in a geom-etryfield.The algorithm pipeline composes the following steps:1.Calculate the eye ray in world coordinates.2.Calculate the reflection rayγin world coordinates.3.Calculate the local shading c of the reflector surface.4.Trace rayγto get reflected color c r,blend it with the localshading c.The algorithm for tracing a ray is as follows:Color TraceRay(Rayγ,ObjectId i,int depth)1.For each object O j i j in the scene,a.Transform the incoming ray starting point and the raydirection from the world coordinate to the local frameof O j.b.Check if the ray hits the bounding box of O j(the unitcube).c.If the ray hits the box at points s and t,convert s and tto the indices of the geometryfield GF j.d.Lookup the geometryfield GF j to obtain the texturecoordinates u j v j of the intersection point.e.If u j v j is valid,lookup the position from the geom-etry image GF j,compute the depth d j.Otherwise,setd j.2.Choose the nearest u k v k k min j d j.If u k v k isvalid,look for the position,color,and normal of the in-tersection point from the geometry image GI k,compute the shading and blend it to the local color c,and compute the next level reflected rayγr.3.If the recursion depth exceeds the limit,return c.Other-wise,call TraceRay(γr,k,depth+1)to get the reflected color c r.4.Blend c and c r.Return the blended color.4.Experimental ResultsThis section demonstrates the experimental results for our real time inter-reflection algorithm based on geometryfields. The experiments are applied on the windows platform with a36GHz CPU,3G RAM and NVidia’s GeForce7800GPU.4.1.PreprocessingWe have tested our algorithms on triangular meshes,whose complexities are up to tens of thousands of faces.The com-plexity information and the performance of our algorithms are detailed in Table1.All geometryfields are of size of 242462.4.2.Real Time RenderingIn our real-time rendering system,the camera position,the relative positions of reflected objects and mirror objects can be monitored interactively by users.Figure2shows the ren-dering snapshots for inter-reflection among different geome-tries.The frame rates are all around60FPS,which are inde-pendent of the geometric complexities.In thefirst row,thefirst twofigures show multiple David heads reflecting on a mirror torus.Because the mirror distor-tion is directly calculated without approximation,all multi-ple reflection images are changing continuously on the torus in our experiments.The secondfigure also illustrates that ge-ometric features of David head’s hair in the mirror are ren-dered with highfidelity.The next twofigures of thefirst row present that multiple instances of David head reflect on a mirror ball.Inter-surface reflections between two mirrored balls are illustrated in thefirst twofigures of the second row in Figure 2.From the snapshots,the mirror image of the red sphere is shown on the blue sphere.In the center area of the mirror image,the mirror image of the blue ball on the red ball is also recognizable.This demonstrates the second level inter-reflection.The last twofigures show inter-reflection between sphere-David head and male-female faces.5.Conclusions and Future WorkThis paper has proposed a novel algorithm for real-time inter-reflection by ray tracing based on a new object repre-sentation,geometryfield.A geometryfield is a combination of a lightfield with a geometry image,and it represents the intersection point of a surface with an arbitrary ray as a4D lookup table.Conventional intersection testing in ray tracing is replaced by indexing a geometryfield,such that real time inter-surface reflection is achieved on current graphics hardware. The method is efficient,accurate and simple.Experiments have shown the high quality of the reflection results and the fast rendering speed in several examples.Table1:Performance(in sec)of our preprocess algorithm. Surface Parame-Geom.terization Field192208Torus344205000095Male Face20050410114420Figure2:Real time rendering ers can interactively manipulate the camera position and the relative spacial relations among the geometric objects in the scene.The inter-reflections are rendered in real time at60FPS.Applications of geometryfields are not limited to reflec-tion.It can be easily generalized for computing refractionand self reflection.In the future,we will do research on full-featured ray-tracing based on geometryfields in real time.References[AK87]A RVO J.,K IRK D.:Fast ray tracing by ray classifica-tion.In SIGGRAPH’87:Proceedings of the14th annual con-ference on Computer graphics and interactive techniques(NewYork,NY,USA,1987),ACM Press,pp.55–64.1[BF89]B UCKALEW C.,F USSELL D.:Illumination networks:Fast realistic rendering with general reflectance functions.SIG-GRAPH’89Proceedings23,3(1989),89–98.2[BN76]B LINN J.F.,N EWELL M.E.:Texture and reflection incomputer generated mun.ACM19,10(1976),542–547.1[BS96]B ESUIEVSKY G.,S BERT M.:The multi-frame lightingmethod-a Monte-Carlo based solution for radiosity in dynamicenvironments.In Rendering Techniques’96(1996),pp.pp185–194.2[CHH02]C ARR N.A.,H ALL J.D.,H ART J.C.:The ray engine.In ACM SIGGRAPH/EUROGRAPHICS conference on Graphicshardware(2002),pp.37–46.1[GGH02]G U X.,G ORTLER S.J.,H OPPE H.:Geometry images.In SIGGRAPH(2002),pp.355–361.1[GGSC96]G ORTLER S.J.,G RZESZCZUK R.,S ZELISKI R.,C O-HEN M.F.:The lumigraph.In SIGGRAPH(1996),pp.43–54.1[Gre86]G REENE N.:Environment mapping and other applica-tions of world projections.IEEE Computer Graphics and Appli-cations6,11(1986),21–29.1[LH96]L EVOY M.,H ANRAHAN P.:Lightfield rendering.InSIGGRAPH(1996),pp.31–42.1[LHSW03]L OSASSO F.,H OPPE H.,S CHAEFER S.,W ARRENJ.D.:Smooth geometry images.In Symposium on GeometryProcessing(2003),pp.138–145.1[LR98]L ISCHINSKI D.,R APPOPORT A.:Image-based render-ing for non-diffuse synthetic scenes.In Rendering Techniques(1998),pp.301–314.1[PBMH02]P URCELL T.J.,B UCK I.,M ARK W.R.,H ANRA-HAN P.:Ray tracing on programmable graphics hardware.InSIGGRAPH(2002),pp.703–712.1[SKALP05]S ZIRMAY-K ALOS L.,A SZÓDI B.,L AZÁNYI I.,P REMECZ M.:Approximate ray-tracing on the gpu with distanceimpostors.In Eurographics(2005).1[SKSU05]S ZIRMAY-K ALOS L.,S BERT M.,U MMENHOFFERT.:Real-time multiple scattering in participating media with illu-mination networks.In Proceedings of Eurographics Symposiumon Rendering2005(June2005),Eurographics.2[SMKY04]S LATER M.,M ORTENSEN J.,K HANNA P.,Y U I.:Avirtual lightfield approach to global illumination.cgi00(2004),102–109.1[SWG03]S ANDER P.V.,W OOD Z.J.,G ORTLER S.J.,S NY-DER J.,H OPPE H.:Multi-chart geometry images.In Symposiumon Geometry Processing(2003),pp.146–155.1[WAA00]W OOD D.N.,A ZUMA D.I.,A LDINGER K.,C UR-LESS B.,D UCHAMP T.,S ALESIN D.,S TUETZLE W.:Surfacelightfields for3d photography.In SIGGRAPH(2000),pp.287–296.1[WSE04]W EISKOPF D.,S CHAFHITZEL T.,E RTL T.:Gpu basednonlinear ray tracing.625–634.1[WSS05]W OOP S.,S CHMITTLER J.,S LUSALLEK P.:Rpu:aprogrammable ray processing unit for realtime ray tracing.ACMTrans.Graph.24,3(2005),434–444.1[WWT04]W ANG L.,W ANG X.,T ONG X.,L IN S.,H U S.,G UO B.:View-dependent displacement mapping.ACM Trans-actions on Graphics22,3(2004),334–339.2[YYM05]Y U J.,Y ANG J.,M C M ILLAN L.:Real-time reflectionmapping with parallax.In ACM SIGGRAPH2005SymposiumonInteractive3D Graphics and Games(2005).1c The Eurographics Association2006.。
Generation of higher order gauss-laguerre modes in single-pass 2nd harmonic generation
Preben Buchhave and Peter Tidemand-Lichtenberg
DTU Physics, Department of Physics, Technical University of Denmark, DK-2800 Kgs. Lyngby, Denmark *Corresponding author: pbu@fysik.dtu.dk
©2008 Optical Society of America
OCIS codes: (190.2620) Harmonic generation and mixing; (190.4410) Nonlinear optics, parametric; (190.4420) Nonlinear optics, transverse effects.
difference frequency generation. However, nonlinear effects such as depletion and phase shift were not included, and the method only applies to very low power beams. In this paper an alternative formulation is used, where the beams are expanded in higher order Gauss-Hermite (G-H) or Gauss-Laguerre (G-L) modes after passage of each thin slab. The choice of mode expansion depends on the symmetry of the problem. Since both G-H and G-L modes form complete orthogonal sets of functions, an expansion of the beams in these modes fully describes the result of the interaction, and diffraction due to the distortion of the wave front is included by the mix of the higher order modes. Besides forming an alternative way of performing a wave propagation calculation, this method has the advantage that it allows to follow the generation of higher order modes both spatially and temporally through the crystal. Furthermore it is possible to calculate the power generated in each of these modes. It is also possible to input higher order pump modes or superposition of modes and calculate the power conversion efficiency into the generated modes, a method that has recently been used in generation of squeezed light in higher order G-H modes [6]. In the calculations the phase matching may be adjusted at will; it is for example possible to adjust the phase matching to compensate at least partially for the Gouy phase shift in a particular mode and thus selectively generate light in one mode by pumping in another mode [7]. In the following, single pass second harmonic generation (SHG) in an efficient nonlinear crystal pumped by a pump beam of known mode composition is considered. As an example we shall look at a single mode Q-switched Nd:YAG laser pulse frequency doubled through a PPKTP crystal and investigate the formation of higher order G-L modes as the fields propagate through the crystal, as well as illustrate the temporal development of the pulse shape as a function of time. 2. Wave propagation with G-L expansion The calculations are performed in the following way: 1. The crystal is divided into thin slabs normal to the optical axis. 2. The three interacting beams that make up the total field incident on a slab interact on their way through the slab. The slab is assumed so thin that the nonlinear differential equations governing the interaction (the coupled wave equations) can be approximated by difference equations, and diffraction effects on the way through the slab are unimportant (plane wave approximation within a slab). Losses can be included in each slab. The beams may be focused anywhere inside or outside the crystal. Collinear beams are assumed, although the simulations can easily be expanded to include non-collinear beams and walk-off. 3. After passage of a slab, the field incident on the slab has been distorted due to the nonlinear interaction. The fields leaving the slab are expanded in G-L modes. 4. The beam waist radius and phase of the individual modes of the expansion are recalculated for the position of the next slab. The different phase shifts of the different order G-L modes implicitly take care of diffraction. 5. The G-L modes with the new phases and beam waists are added for each beam, and these new beams are used as input for the next slab; the calculation is repeated from 2. 6. The output beams are found by summing the G-L modes leaving the last slab. 2.1. Nonlinear interaction The coupled wave equations (CWE) for the 2nd order nonlinear interaction between three beams, described by the normalized electric fields a j ( x, y, z ) , where j identifies the field, are in the difference equation form given by [8]
Lattice approach to high-energy hadron-hadron scattering
a r X i v :0809.2524v 1 [h e p -l a t ] 15 S e p 2008Lattice approach to high–energy hadron–hadron scatteringM.Giordano a ∗and E.Meggiolaro aaDipartimento di Fisica,Universit`a di Pisa,and INFN,Sezione di Pisa Largo Pontecorvo 3,I–56127Pisa,Italy.We discuss the non perturbative approach to the problem of high–energy hadron–hadron (dipole–dipole)scat-tering at low momentum transfer by means of numerical simulations in Lattice Gauge Theory.1.IntroductionThe prediction from first principles of total cross sections at high energy is one of the old-est open problems of hadronic physics.Present–day experimental data are well described by a universal pomeron –like power–law behaviour (see,for example,Ref.[1]and references therein),σ(hh )tot (s )∼s →∞(s/s 0)ǫP ,where the so–called softpomeron intercept is ǫP ≃0.08,but this is forbid-den as a true asymptotic behaviour by the well–known Froissart–Lukaszuk–Martin theorem [2].As we believe QCD to be the fundamental the-ory of strong interactions,it should predict the correct asymptotic behaviour;nevertheless,a sat-isfactory explanation is still lacking.The problem of total cross sections is part of the more general problem of high–energy scatter-ing at low transferred momentum,the so–called soft high–energy scattering .As soft high–energy processes possess two different energy scales,the total center–of–mass energy squared s and the transferred momentum squared t ,smaller than the typical energy scale of strong interactions (|t | 1GeV 2≪s ),we cannot fully rely on perturbation theory.A genuine non perturba-tive approach in the framework of QCD has been proposed by Nachtmann in [3],and further devel-oped in [4,5,6,7,8]:using a functional integral ap-proach,high–energy hadron–hadron elastic scat-tering amplitudes are shown to be governed by the correlation function of certain Wilson loops defined in Minkowski space.Moreover,as it has been shown in [9,10],such a correlation func-2classical trajectories and closed at proper times ±T by straight–line paths in the transverse plane. In[9,10](see also[12,13])it has been shown that,under certain analyticity hypotheses,this correlation function can be reconstructed fromthe Euclidean correlation function of two Eu-clidean Wilson loops, W1and W2,G E(θ;T; z⊥;1,2)≡W(T)1 W(T)2m τ+f q[¯q]1R1E,C2:X2q[¯q]E(τ)=p2E2, 0⊥,cosθWL( l1 ; r1⊥;d) W L( l2 ; r2⊥;0) −1,(4)where d=(0, d⊥,0), d⊥=(d2,d3),and moreoverC L(ˆl1 ,ˆl2 ; d⊥; r1⊥, r2⊥)≡limL1,L2→∞G L( l1 , l2 ; d⊥; r1⊥, r2⊥),(5)where L i≡| l i |are defined to be the lengths ofthe longitudinal sides of the loops in lattice units,and l i ≡L iˆl i .In the continuum limit,whereO(4)invariance is restored,we expectC L(ˆl1 ,ˆl2 ; d⊥; r1⊥, r2⊥)≃a→0C E(θ;a d⊥;a r1⊥,1/2,a r2⊥,1/2),(6)whereˆl1 ·ˆl2 ≡cosθdefines the relative angleθ,and a is the lattice spacing.30.20.40.60.8130507090110130150G E (θ)θ[◦]Figure ttice data plotted against θfor vari-ous lengths of the loops.4.Numerical resultsAs already pointed out in the Introduction,nu-merical simulations cannot provide the analytic expression for the relevant correlation function,but nevertheless,as these simulations are first–principles calculations,they provide the “correct”(inside the errors)prediction of QCD.Approxi-mate analytic calculations have then to be com-pared with the lattice data,in order to test the goodness of the approximations involved.In par-ticular,we are interested in the dependence on the relative angle θ,as it encodes the energy de-pendence of the scattering amplitudes,which is recovered after the proper analytic continuation.In Fig.1we show,as an example,the lattice data for G L in the case of parallel transverse sides with | r 1⊥|=| r 2⊥|=1at d =0,plotted against the angle θfor various lengths of the loops.These data are obtained using Wilson action for SU (3)pure–gauge (quenched )theory,on a 164lattice at β=6.0.The data are quite stable against variations of the lengths,so that we can take the largest–length data as a reasonable approxima-tion of C L .In Figs.2and 3we compare C L with the pre-diction of various models (the loop configuration is the same as in Fig.1).While the Stochas-tic Vacuum Model (SVM)[16]provides a fully quantitative prediction,that can be directly com-pared with the data,the Instanton Liquid Model (ILM)[17]and the AdS/CFT correspondence [18]give only the qualitative dependence on the an-0.20.40.60.811.230507090110130150C E (θ)θ[◦]Figure parison of lattice data with the SVM prediction (solid)and with a best–fit with the SVM functional form (dotted).0.20.40.60.811.230507090110130150C E (θ)θ[◦]Figure parison of lattice data with best–fits with the lowest–order perturbative (solid),the ILM (dotted)and the AdS/CFT (dashed)ex-pressions.gle θ,so that a comparison can be made by trying to fit the data with the given functional form.In Fig.2we show the SVM prediction,to-gether with a best–fit with the SVM functional form;in Fig.3we show the best–fits with the ex-pressions obtained in perturbation theory to low-est order [19,16,10],in the ILM and using the AdS/CFT correspondence.A detailed discussion of the results is given in [11];here we simply note that the agreement of the numerical data with the various models is not fully satisfactory,and fur-ther investigations have to be made,both on the numerical and on the analytical side.We want also to remark that while perturbative effects40.00010.0010.010.1112C E (d )d45◦90◦Figure 4.Dependence of C E on the distance for θ=45◦and θ=90◦in the case r 1⊥= r 2⊥,| r 1⊥|=1, r 1⊥ d ⊥(logarithmic scale).-0.3-0.2-0.100.10.20.330507090110130150C −E (θ)θ[◦]Figure 5.“Antisymmetric”part of lattice data,and corresponding SVM prediction.seem to be dominant at short distances between the loops,non perturbative effects are already rel-evant at distances of about 0.2fm;however,as the correlation function is rapidly decreasing with thedistance d =| d⊥|between the centers of the loops (see Fig.4),a detailed study at large distances is difficult,and requires the use of noise reduction techniques.Lattice data show also the presence of odd-eron contributions to dipole–dipole scattering.Indeed,as explained in [13,11],making use of the crossing–symmetry relations for loops [12]one can show that the crossing–odd component of the dipole–dipole scattering amplitudes is related via the usual analytic continuation to the antisym-metric (with respect to π/2)component C −E of C E :this quantity is shown in Fig.5,togetherwith the coresponding SVM prediction (the loop configuration is the same as in Fig.1).REFERENCES1.S.Donnachie,G.Dosch,ndshoff andO.Nachtmann,Pomeron Physics and QCD (Cambridge University Press,Cambridge,2002).2.M.Froissart,Phys.Rev.123(1961)1053;A.Martin,Il Nuovo Cimento 42A (1966)930;L.Lukaszuk and A.Martin,Il Nuovo Cimento 47A (1967)265.3.O.Nachtmann,Ann.Phys.209(1991)436.4.H.G.Dosch,E.Ferreira and A.Kr¨a mer,Phys.Rev.D 50(1994)1992.5.O.Nachtmann,in Perturbative and Non-perturbative aspects of Quantum Field The-ory ,edited by tal and W.Schweiger (Springer–Verlag,Berlin,Heidelberg,1997).6. E.R.Berger and O.Nachtmann,Eur.Phys.J.C 7(1999)459.7.H.G.Dosch,in At the frontier of ParticlePhysics –Handbook of QCD (Boris Ioffe Festschrift),edited by M.Shifman (World Scientific,Singapore,2001),vol.2,1195–1236.8. A.I.Shoshi, F.D.Steffen and H.J.Pirner,Nucl.Phys.A 709(2002)131.9. E.Meggiolaro,Nucl.Phys.B 625(2002)312.10.E.Meggiolaro,Nucl.Phys.B 707(2005)199.11.M.Giordano,E.Meggiolaro,arXiv:0808.102212.M.Giordano and E.Meggiolaro,Phys.Rev.D 74(2006)016003.13.E.Meggiolaro,Phys.Lett.B 651(2007)177.14.I.I.Balitsky and L.N.Lipatov,Sov.J.Nucl.Phys.28(1978)822;I.I.Balitsky and L.N.Lipatov,JETP Letters 30(1979)355.15.J.E.Bresenham,IBM Sys.Jour.4(1965)25.16.A.I.Shoshi, F.D.Steffen,H.G.Dosch andH.J.Pirner,Phys.Rev.D 68(2003)074004.17.E.Shuryak and I.Zahed,Phys.Rev.D 62(2000)085014.18.R.A.Janik and R.Peschanski,Nucl.Phys.B565(2000)193.19.A.Babansky and I.Balitsky,Phys.Rev.D67(2003)054026.。
the Imaging of the Brain
AMS
systematic investigation of this equation, which we have called the global relation, reduces the problem of determining the unknown boundary values (the construction of the generalized Dirichlet to Neumann map), to the problem of inverting certain integrals. Such integrals can be analytically inverted using generalized FTs. The relevant spectral analysis is based on two fundamental mathematical techniques of complex analysis, namely the Riemann-Hilbert [1] and the ∂-bar [2] problems. A schematic summary of the above discussion is given below: I. Fourier transforms can be
人类蛋白质组图谱
人类蛋白质组图谱A draft map of the human proteome.|核心内容：在过去的十年里，人类基因组序列的可获得性改变了生物医学研究。
然而，目前还不存在直接测量蛋白质和多肽的人类蛋白质组的等值图谱。
在这里，我们提出了一份利用高分辨率傅立叶变换质谱法绘制的人类蛋白质组草图。
对30个组织学正常的人类样本(包括17个成人组织、7个胎儿组织和6个纯化的原代造血细胞)进行了深入的蛋白质组学分析，结果鉴定出由17,294个基因编码的蛋白质，约占人类注释蛋白编码基因总数的84%。
一种独特而全面的蛋白质基因组分析策略使我们能够发现许多新的蛋白质编码区，包括翻译的假基因、非编码RNA和上游开放阅读框架。
这份大型的人类蛋白质组目录(在)上以交互式网络资源的形式提供)将补充现有的人类基因组和转录组数据，以加速健康和疾病方面的生物医学研究。
原文摘要：The availability of human genome sequence has transformed biomedical research over the past decade.However, an equivalent map for the human proteome with direct measurements of proteins and peptides does not exist yet. Here we present a draft map of the human proteome using high-resolution Fourier-transform mass spectrometry.In-depth proteomic profiling of 30 histologically normal human samples, including 17 adult tissues, 7 fetal tissues and 6 purified primary haematopoietic cells, resulted in identification of proteins encoded by 17,294 genes accounting for approximately 84% of the total annotated protein-coding genes in humans.A unique and comprehensive strategy for proteogenomic analysis enabled us to discover a number of novel protein-coding regions, which includes translated pseudogenes, non-codingRNAs and upstream open reading frames.This large human proteome catalogue (available as an interactive web-based resource at ) will complement available human genome and transcriptome data to accelerate biomedical research in health and disease.该网站相关问答：1What is the human proteome map portal?.The human proteome map portal is the web-based resource that reorganizes mass spectrometry-based proteomics data to explore expressed proteins in fetal tissues/adult tissues/hematopoietic cells obtained from human.网站链接/入口：2Are these data from individuals with any known diseases?.All samples used to generate these data were obtained from histologically normal samples.每个样品，也就是不同来源的各个组织或细胞（肯定是不同来源，从一个人身上取到所有健康的样品，这是不可能的），都是组织结构上正常的，可以认为是健康的。