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高三生物复习中应把握“三量三法”
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作者 李宏英 《教育实践与研究》 2007年第12B期48-48,55,共2页
高三生物复习过程是巩固所学知识和提高分析问题、解决问题能力的过程。在复习中,应把握三个“量”、三个“法”。
关键词 生物 复习 三“量” 三“法”
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三元正极材料清洗废水资源化回收零排放处理工艺 被引量:3
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作者 季宏飞 秦佩 吴晓伟 《当代化工》 CAS 2023年第10期2487-2491,2496,共6页
锂电三元正极材料在清洗过程中产生含有Li^(+)、Al^(3+)、SO_(4)^(2-)、镍钴锰氧化物及少量其他离子的废水,对该三元正极材料清洗废水的资源化回收零排放处理工艺进行了阐述。该废水处理系统涉及的成套工艺包括预处理单元、废水减量化... 锂电三元正极材料在清洗过程中产生含有Li^(+)、Al^(3+)、SO_(4)^(2-)、镍钴锰氧化物及少量其他离子的废水,对该三元正极材料清洗废水的资源化回收零排放处理工艺进行了阐述。该废水处理系统涉及的成套工艺包括预处理单元、废水减量化单元、沉锂单元和制纯水单元。重点对Al^(3+)的去除、膜浓缩、沉锂等关键工艺进行了重点描述,最后通过实际与理论对比分析,达到了预期的设计目标——锂资源得到有效回收、废水实现全部回用。通过对实际案例的相关数据的例举和分析,证明了本套废水处理工艺的可行性和可靠性,为锂电三元正极材料清洗废水的治理提供了典型的参考工艺路线。 展开更多
关键词 元正极材料 锂资源回收 废水零排放 膜浓缩 蒸发结晶
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Influence of sampling on three-dimensional surface shape measurement
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作者 QIAO Nao-sheng Shang Xue 《中国光学(中英文)》 EI CAS CSCD 北大核心 2024年第6期1512-1520,共9页
In order to accurately measure an object’s three-dimensional surface shape,the influence of sampling on it was studied.First,on the basis of deriving spectra expressions through the Fourier transform,the generation o... In order to accurately measure an object’s three-dimensional surface shape,the influence of sampling on it was studied.First,on the basis of deriving spectra expressions through the Fourier transform,the generation of CCD pixels was analyzed,and its expression was given.Then,based on the discrete expression of deformation fringes obtained after sampling,its Fourier spectrum expression was derived,resulting in an infinitely repeated"spectra island"in the frequency domain.Finally,on the basis of using a low-pass filter to remove high-order harmonic components and retaining only one fundamental frequency component,the inverse Fourier transform was used to reconstruct the signal strength.A method of reducing the sampling interval,i.e.,reducing the number of sampling points per fringe,was proposed to increase the ratio between the sampling frequency and the fundamental frequency of the grating.This was done to reconstruct the object’s surface shape more accurately under the condition of m>4.The basic principle was verified through simulation and experiment.In the simulation,the sampling intervals were 8 pixels,4 pixels,2 pixels,and 1 pixel,the maximum absolute error values obtained in the last three situations were 88.80%,38.38%,and 31.50%in the first situation,respectively,and the corresponding average absolute error values are 71.84%,43.27%,and 32.26%.It is demonstrated that the smaller the sampling interval,the better the recovery effect.Taking the same four sampling intervals in the experiment as in the simulation can also lead to the same conclusions.The simulated and experimental results show that reducing the sampling interval can improve the accuracy of object surface shape measurement and achieve better reconstruction results. 展开更多
关键词 three-dimensional surface shape measurement sampling interval spectra overlapping measurement accuracy
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Energy-Transfer in CsPbBr_(3)Nanocrystals:Sensitization of Porphyrin Triplets
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作者 Yinjie Lu Zongwei Chen 《Chinese Journal of Chemical Physics》 SCIE EI CAS CSCD 2024年第5期632-637,I0059-I0062,I0100,共11页
Sensitizing molecular triplets by colloidal nanocrystals via triplet energy transfer is important for applications such as upconversion or organic synthesis.Typically two step triplet energy transfer(TET)are included ... Sensitizing molecular triplets by colloidal nanocrystals via triplet energy transfer is important for applications such as upconversion or organic synthesis.Typically two step triplet energy transfer(TET)are included in these applications:firstly the triplet energy stored in nanocrystals are extracted into surface ligands,and then the ligands further transfer triplet energy into molecules in bulk solution.Here we report one-step TET application from CsPbBr_(3)perovskite nanocrystals(NCs)to surface-anchored metalloporphyrin derivative molecules(MP).Compared to conventional two-step TET,the one-step TET mechanism possess lower energy loss and higher TET efficiency which is more generally implementable.In this scheme,photoexcitation of CsPbBr_(3)NCs leads to the sensitization of MP ligands triplets which efficiently emit phosphorescence.The enhanced light absorption of MP ligands and down-shifted photon emission can be useful in devices such as luminescent solar concentrators. 展开更多
关键词 Triplet energy transfer CsPbBr_(3)nanocrystal Metalloporphyrin derivative Luminescent solar concentrators
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Experimental Study on Full-Surface Buckling of Variable Curvature Cylindrical Shell Using Multi-camera 3D-DIC System
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作者 LI Xin SUN Wei 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2024年第5期589-598,共10页
To achieve full-surface strain measurement of variable curvature objects,a 360°3D digital image correlation(DIC)system is proposed.The measurement system consists of four double-camera systems,which capture the o... To achieve full-surface strain measurement of variable curvature objects,a 360°3D digital image correlation(DIC)system is proposed.The measurement system consists of four double-camera systems,which capture the object’s entire surface from multiple angles,enabling comprehensive full-surface measurement.To increase the stitching quality,a hierarchical coordinate matching method is proposed.Initially,a 3D rigid body calibration auxiliary block is employed to track motion trajectory,which enables preliminary matching of four 3D-DIC sub-systems.Subsequently,secondary precise matching is performed based on feature points on the test specimen’s surface.Through the hierarchical coordinate matching method,the local 3D coordinate systems of each double-camera system are unified into a global coordinate system,achieving 3D surface reconstruction of the variable curvature cylindrical shell,and error analysis is conducted on the results.Furthermore,axial compression buckling experiment is conducted to measure the displacement and strain fields on the cylindrical shell’s surface.The experimental results are compared with the finite element analysis,validating the accuracy and effectiveness of the proposed multi-camera 3D-DIC measuring system. 展开更多
关键词 360°3D digital image correlation(DIC) hierarchical coordinate matching method full-field 3D deformation measurement variable curvature cylindrical shell
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Robust adaptive polarization analysis method for eliminating ground roll in 3C land seismics 被引量:3
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作者 陈海峰 李向阳 +1 位作者 钱忠平 赵桂玲 《Applied Geophysics》 SCIE CSCD 2013年第3期295-304,358,共11页
To improve the data quality of converted waves, and better identify and suppress the strong ground-roll interference in three-component (3C) seismic recordings on land, we present an adaptive polarization filtering ... To improve the data quality of converted waves, and better identify and suppress the strong ground-roll interference in three-component (3C) seismic recordings on land, we present an adaptive polarization filtering method, which can effectively separate the ground- roll interference by combining complex polarization and instantaneous polarization analysis. The ground roll noise is characterized by elliptical plane polarization, strong energy, low apparent velocity, and low frequency. After low-pass filtering of the 3C data input within a given time-window of the ground roll, the complex covariance matrix is decomposed using the sliding time window with overlapping data and length that depends on the dominant ground-roll frequency. The ground-roll model is established using the main eigenvectors, and the ground roll is detected and identified using the instantaneous polarization area attributes and average energy constraints of the ground-roll zone. Finally, the ground roll is subtracted. The threshold of the method is stable and easy to select, and offers good ground- roll detection. The method is a robust polarization filtering method. Model calculations and actual data indicate that the method can effectively identify and attenuate ground roll while preserving the effective signals. 展开更多
关键词 three-component (3C) adaptive polarization filtering suppressing ground roll
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Dosimetric Evaluation of Three Dimensional Conformal and Conventional Treatment Plans of Early Untreated Carcinoma of Nasopharynx 被引量:1
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作者 罗伟 邓小武 卢泰祥 《The Chinese-German Journal of Clinical Oncology》 CAS 2005年第5期271-275,323-324,共7页
Objective: Conventional external beam irradiation techniques for nasopharyngeal carcinoma have limitations, and improving external beam irradiation techniques is needed to enhance the curative rate. This study was de... Objective: Conventional external beam irradiation techniques for nasopharyngeal carcinoma have limitations, and improving external beam irradiation techniques is needed to enhance the curative rate. This study was designed to cvaluate the difference in dose distribution of three dimensional conformal radiotherapy (3D CRT) and conventional treatment plan in early untreated nasopharyngeal carcinoma using a three dimensional treatment planning system. Methods: Twenty-two patients with early untreated nasopharyngeal carcinoma were selected. Conventional and 3D CRT plans were made for each of them and compared with respect to target volume coverage (V95),normal tissue sparing (D50, D33 and D5, etc), normal tissue complication probability (NTCP). Results: The average volumetric dose comparison indicated that the V95 of PTVnx70 were 98.22% and 99.99% (P=0.06), and PTVnd60, 98.41% and 99.63% (P=1.00), PTV,x60, 98.44% and 99.98% (P=0.03), PTVnx50, 98.85% and 99.63% (P=0.02) in conventional and 3DCRT treatment plans respectively. With respect to normal tissue sparing, the average D50 of unilateral parotid glands were 51.91 Gy and 64.30 Gy (P=0.00) respectively, and the unilateral temporomandibular joints, 49.98 Gy and 64.47 Gy (P=0.00), the Dlcc of spinal cords, 44.98 Gy and 48.09 Gy (P=0.00) in 3D CRT and conventional plans. Conclusion: Though only a little bit better dose coverage of target volume in subclinical lesion region was reached in 3D CRT plans, it spared more normal tissues e.g. parotid glands and temporomandibular joints etc and decreased their NTCP while it got the similar dose distribution in target volumes as conventional plans did for these early nasopharyngeal carcinoma cases. 展开更多
关键词 Nasopharyngeal carcinoma 3D TPS External beam irradiation plan DOSIMETRY
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ANALYSIS AND MEASUREMENT FOR THE DYNAMIC ERRORS OF COORDINATE MEASURING MACHINES 被引量:2
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作者 董晨松 张国雄 《Transactions of Tianjin University》 EI CAS 1998年第2期63-67,共5页
The analysis and calculating method of dynamic errors of CMMs during probing are discussed.To relate the dynamic displacement errors with the dynamic rotational errors a method for obtaining the displacement errors at... The analysis and calculating method of dynamic errors of CMMs during probing are discussed.To relate the dynamic displacement errors with the dynamic rotational errors a method for obtaining the displacement errors at the probing position from dynamic rotational errors is presented.It is pointed out that the finite element method might be used for modeling dynamic errors.However,dynamic errors are difficult to be modeled so a combined practical and theoretical approach is needed.In addition,the dynamic errors are measured with inductive position sensors. 展开更多
关键词 coordinate measuring machine (CMM) dynamic error finite element method(FEM)
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The 3D magnetic structure beneath the continental margin of the northeastern South China Sea 被引量:4
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作者 李淑玲 Yaoguo Li 孟小红 《Applied Geophysics》 SCIE CSCD 2012年第3期237-246,359,共11页
Understanding the continental margin of the Northeastern South China Sea is critical to the study of deep structures, tectonic evolution, and dynamics of the region. One set of important data for this endeavor is the ... Understanding the continental margin of the Northeastern South China Sea is critical to the study of deep structures, tectonic evolution, and dynamics of the region. One set of important data for this endeavor is the total-field magnetic data. Given the challenges associated with the magnetic data at low latitudes and with remanent magnetism in this area, we combine the equivalent-source technique and magnetic amplitude inversion to recover 3D subsurface magnetic structures. The inversion results show that this area is characterized by a north-south block division and east-west zonation. Magnetic regions strike in EW, NE and NW direction and are consistent with major tectonic trends in the region. The highly magnetic zone recovered from inversion in the continental margin differs visibly from that of the magnetically quiet zones to the south. The magnetic anomaly zone strikes in NE direction, covering an area of about 500 km × 60 km, and extending downward to a depth of 25 km or more. In combination with other geophysical data, we suggest that this strongly magnetic zone was produced by deep underplating of magma associated with plate subduction in Mesozoic period. The magnetically quiet zone in the south is an EW trending unit underlain by broad and gentle magnetic layers of lower crust. Its magnetic structure bears a clear resemblance to oceanic crust, assumed to be related to the presence of ancient oceanic crust there. 展开更多
关键词 Continental margin of the northeastern South China Sea magnetic anomalies amplitude inversion 3D magnetic structure
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Three-component seismic data in thin interbedded reservoir exploration
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作者 张丽艳 王彦春 裴江云 《Applied Geophysics》 SCIE CSCD 2015年第1期79-85,122,共8页
We present the first successful application of three-component seismic data to thin interbedded reservoir characterization in the Daqing placanticline of the LMD oilfield. The oilfield has reached the final high water... We present the first successful application of three-component seismic data to thin interbedded reservoir characterization in the Daqing placanticline of the LMD oilfield. The oilfield has reached the final high water cut stage and the principal problem is how to recognize the boundaries of sand layers that are thicker than 2 m. Conventional interpretation of single PP-wave seismic data results in multiple solutions, whereas the introduction of PS-wave enhances the reliability of interpretation. We analyze the gas reservoir characteristics by joint PP- and PS-waves, and use the amplitude and frequency decomposition attributes to delineate the gas reservoir boundaries because of the minimal effect of fl uids on S-wave. We perform joint inversion of PP- and PS-waves to obtain V P/V S, λρ, and μρ and map the lithology changes by using density, λρ, and μρ. The 3D–3C attribute λρ slices describe the sand layers distribution, while considering the well log data, and point to favorable region for tapping the remaining oil. 展开更多
关键词 3D–3C thin interbedded reservoirs gas reservoir characterization joint inversion tapping remaining oil
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An Analysis of the Hoarse Speech Signals by the Three Mass Model of Vocal Cords *
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作者 程启明 陈雪丽 万德钧 《Journal of Southeast University(English Edition)》 EI CAS 1998年第1期81-85,共5页
A three mass model of vocal cords as well as mathematical expression of the model are discussed. Different kinds of typical hoarse speech due to laryngeal diseases are simulated on microcomputer and the effects of di... A three mass model of vocal cords as well as mathematical expression of the model are discussed. Different kinds of typical hoarse speech due to laryngeal diseases are simulated on microcomputer and the effects of different pathological factors of vocal cords on model parameters are studied. Some typical spectrum distribution of the simulated speech signals are given. Moreover, hoarse speech signals of some typical cases are analyzed by the methods of digital signal processing, including FFT, LPC, Cepstrum technique, Pseudocolor encoding, etc. The experiment results show that the three mass model analysis of vocal cords is an efficient method for analysis of hoarse speech signals. 展开更多
关键词 hoarse speech signal three mass model of vocal cords laryngeal diseases
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Determination of energy coupling to material in laser welding by a novel “sandwich” method 被引量:1
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作者 张屹 史如坤 李力钧 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2012年第7期1701-1710,共10页
A mathematical energy coupling model was developed to analyze the light transmission in the keyhole and energy distribution on the keyhole wall.The main characteristics of the model include:1) a prototype of the key... A mathematical energy coupling model was developed to analyze the light transmission in the keyhole and energy distribution on the keyhole wall.The main characteristics of the model include:1) a prototype of the keyhole and the inverse Bremsstrahlung absorption coefficient in the keyhole plasma are obtained from the experiments;2) instead of using a parallel incident beam,a focused laser beam with real Gaussian intensity distribution is implemented;3) both Fresnel absorption and inverse Bremsstrahlung absorption during multiple reflections are considered.The calculation results show that the distribution of absorbed laser intensity by the keyhole wall is not uniform.The maximum laser energy is absorbed by the bottom of the keyhole,although no rays irradiate directly onto the bottom.According to analysis of beam focusing characteristics,the location of the focal plane plays a more important role in the laser energy absorption by the front wall than by the rear wall. 展开更多
关键词 laser welding mathematical energy coupling model "sandwich" method KEYHOLE
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APPLICATION OF THE MULTI-SLIT METHOD IN THE RESEARCH ON THE MECHANICAL PROPERTIES OF RABBIT AORTAS
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作者 虞启琏 王小泉 +1 位作者 齐力 谢小锐 《Transactions of Tianjin University》 EI CAS 1995年第1期92+84-89,共7页
n the research on the mechanical properties of the blood vessel, it is necessary to measure three-dimensional deformation of the blood vessel. This paper presents a non-contact optical method for measuring these defor... n the research on the mechanical properties of the blood vessel, it is necessary to measure three-dimensional deformation of the blood vessel. This paper presents a non-contact optical method for measuring these deformation in vitro or in vivo, and the data-processing procedure for the three-dimensional coordinate reconstruction of the aorta surface. The accuracy of this method is tested with a known cylinder. This method has been used in the study of the rabbit aorta and the result shows that it is valuable in the research on the mechanical properties of the blood vessel. 展开更多
关键词 blood vessel 3--D deformation MEASUREMENT multi-slit
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Gauge dependence of chiral condensate and fermion mass by an unquenched model
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作者 周雨青 杨永宏 《Journal of Southeast University(English Edition)》 EI CAS 2011年第1期111-114,共4页
Based on three-dimensional quantum electrodynamics theory,a set of truncated Dyson-Schwinger(D-S) equations are solved to study photon and fermion propagators with the effect of vacuum polarization.Numerical studies... Based on three-dimensional quantum electrodynamics theory,a set of truncated Dyson-Schwinger(D-S) equations are solved to study photon and fermion propagators with the effect of vacuum polarization.Numerical studies show that condensation and the value of fermion mass depends heavily on how the D-S equations are truncated.By solving a set of coupled D-S equations,it is also found that the fermion propagator shows a clear dependence on the order parameter.The truncated D-S equations under unquenched approximation are used to study the mass-function and chiral condensation of the fermions.The results under the unquenched approximation are clearly different from the ones under quenched approximation.With the increase in the order parameter,the fermion condensation in the unquenched approximation decreases when 0≤ξ5,while it increases when ξ5.However,nothing like this is observed in the quenched approximation,which indicates that there may be flaws in the quenched approximations. 展开更多
关键词 quantum electrodynamics(QED3) unquenched fermion-boson vertex fermion chiral condensate quenched drawback
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Energy Transfer Probability Between Host and Guest in Doped Organic Electrophosphorescent Devices 被引量:1
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作者 李宏建 欧阳俊 +3 位作者 代国章 戴小玉 潘艳芝 谢强 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2006年第4期674-678,共5页
An expression for energy transfer probability (η) between host (TPD) and guest (Ir(ppy)3) phosphorescent systems is proposed,and the energy transfer process in doped organic electrophosphorescent (EP) devic... An expression for energy transfer probability (η) between host (TPD) and guest (Ir(ppy)3) phosphorescent systems is proposed,and the energy transfer process in doped organic electrophosphorescent (EP) devices is discussed. The results show that (1) The rate of the triplet energy transfer (KHG and KGH) exponentially increases with the host-guest molecular distance (R), and KHG decreases quickly as the intermolecular distance of the guest (RGG) increases. In addition,the KHG/KGH ratio of the dopant system increases when R or RGG is reduced; (2) The energy transfer probability approximately linearly decreases as R increases from 0.8 to 1.2nm,and the variation of RGG can be neglected when R〈1.1nm. For 1. 1nm〈R〈l. 2nm, RGG (〈1.6nm) plays an increasingly important role when 71 drops with the latter' (3) η increases when the Forster energy transfer rate increases or Gibb's energy declines. 展开更多
关键词 ELECTROPHOSPHORESCENCE energy transfer probability TRIPLET
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3D-QSAR Analysis of DDPH Derivatives for α_1-Adrenoceptor Antagonist Activity
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作者 方浩 卢景芬 夏霖 《Journal of Chinese Pharmaceutical Sciences》 CAS 2005年第3期149-153,共5页
Aim and methods The study of three-dimensional quantitative structure-activity relationship (3D-QSAR) of DDPH and its derivatives has been performed using Apex-3D programme. Results The result indicates that substit... Aim and methods The study of three-dimensional quantitative structure-activity relationship (3D-QSAR) of DDPH and its derivatives has been performed using Apex-3D programme. Results The result indicates that substituents of para- and ortho-positions in phenyl ring of aryloxyalkylamine greatly influence the bioactivity. Conclusion The biophore model and 3D-QSAR equation help us not only further understand receptor-ligand interactions, but also design new compounds with better bioactivity. 展开更多
关键词 Apex-3D α^1-adrenoceptor ANTAGONIST 3D-QSAR
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Improving Efficiency by Doping PtOEP into Spiro Light-Emitting Devices
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作者 赵俊卿 乔士柱 +3 位作者 许福运 张宁玉 庞岩涛 陈莹 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2008年第3期418-422,共5页
To investigate effective means of improving the efficiency of organic light-emitting devices (OLEDs) by making full use of ,triplet emission, a phosphorescent material Pt (II) Octaethylporphine (PtOEP) is doped ... To investigate effective means of improving the efficiency of organic light-emitting devices (OLEDs) by making full use of ,triplet emission, a phosphorescent material Pt (II) Octaethylporphine (PtOEP) is doped into polymer host polyspirobifluorene (Spiro) to allow radiative recombination of triplet excitons. The current and brightness characteristics of the devices are tested and the electroluminescent spectra are described. Both fluorescence and phosphorescence are ob- served,and an obvious increase in external quantum efficiency is realized compared to undoped devices when different phosphorescent dopant concentrations are tried. Thus,the phosphorescent emission from triplet excited states might be an effective way to increase the efficiency of OLEDs when the concentration of the phosphorescent dopant is properiy controlled. 展开更多
关键词 external quantum efficiency TRIPLET organic light-emitting device
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A 3D-QSAR Study on C-3 Substituted 4,6-Dichloroindole-2- Carboxylic Acids with Comparative Molecular Field Analysis
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作者 宋怀恩 沈建华 +1 位作者 闻韧 蒋华良 《Journal of Chinese Pharmaceutical Sciences》 CAS 2004年第2期119-123,共5页
Aim and Method Comparative molecular field analysis (CoMFA), a threedimensional quantitative structure-activity relationship (3D-QSAR) method was applied to a novelseries of C-3 substituted 4, 6-dichloioindole-2-carbo... Aim and Method Comparative molecular field analysis (CoMFA), a threedimensional quantitative structure-activity relationship (3D-QSAR) method was applied to a novelseries of C-3 substituted 4, 6-dichloioindole-2-carboxylic acids to study the relationship betweentheir structure and the affinity for the glycine site of the NMDA receptor. Result Hie coefficientsof cross-validation q^2 and non cross-validation r^2 for the model established by the study are0.744 and 0.993, respectively, the value of variance ratio F is 261.343, and standard error estimate(SE) is 0.039. Conclusion These values indicate that the CoMFA model may have a good prediction forthe activity of C-3 substituted 4, 6-dichloroin-dole-2-carboxylic acids. As a consequence, thepredicted activity values of new designed compounds supports our conclusion from the model. 展开更多
关键词 3D-QSAR COMFA C-3 substituted 4 6-dichloroindole-2-caiboxylic acids NMDAreceptor
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Biomass Allocation of Scirpus mariqueter Along an Elevational Gradient in a Salt Marsh of the Yangtse River Estuary 被引量:11
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作者 孙书存 蔡永立 刘红 《Acta Botanica Sinica》 CSCD 2001年第2期178-185,共8页
Scirpus mariqueter Tang et Zhang is a typical pioneer plant colonizing the bare beaches of the Yangtse River estuary. To explore the life history strategy of the species with reference to environmental physical stre... Scirpus mariqueter Tang et Zhang is a typical pioneer plant colonizing the bare beaches of the Yangtse River estuary. To explore the life history strategy of the species with reference to environmental physical stress, the biomass allocations to different plant components and some related morphological parameters were examined along an elevational gradient within a salt marsh. Authors found that S. mariqueter performed best at medium elevation within the marsh, with relatively high density of shoot and individual ramet dry mass. Biomass allocation to corm was the highest at low elevations, and the least at high elevations, suggesting that a conservative strategy was adopted by the species to cope with the harsh physical conditions at the low elevation. The investment in rhizome decreased from low to high elevations, while the proportion of inflorescence mass increased, indicating that during the life history, the species shifts from predominant asexual reproduction to predominant sexual reproduction. This may be favourable for the species to colonize larger area, and to spread and persist at a meta_population level. Correlation analyses showed that sexual reproduction was inversely related to growth and asexual reproduction. However, it is difficult to determine the relationship between asexual reproduction and growth possibly because of the varied function of the corms of the species in different life history stages. 展开更多
关键词 asexual reproduction CORM salt marsh sexual reproduction life history strategy trade_off
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METHODS OF VISUAL RECOGNITION,POSITIONING AND ORIENTATING OF 3 D SIMPLE GEOMETRIC WORKPIECE
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作者 王向军 王以忠 叶声华 《Transactions of Tianjin University》 EI CAS 1998年第2期36-40,共5页
The methods of visual recognition,positioning and orienting with simple 3 D geometric workpieces are presented in this paper.The principle and operating process of multiple orientation run le... The methods of visual recognition,positioning and orienting with simple 3 D geometric workpieces are presented in this paper.The principle and operating process of multiple orientation run length coding based on general orientation run length coding and visual recognition method are described elaborately.The method of positioning and orientating based on the moment of inertia of the workpiece binary image is stated also.It has been applied in a research on flexible automatic coordinate measuring system formed by integrating computer aided design,computer vision and computer aided inspection planning,with a coordinate measuring machine.The results show that integrating computer vision with measurement system is a feasible and effective approach to improve their flexibility and automation. 展开更多
关键词 automatic measurement visual recognition visual positioning visual orientating coordinate measuring machine
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