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- 与 experimental method 相关的网络例句 [注:此内容来源于网络,仅供参考]
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In addition, some modifications on several computational methods are also presented. Using LMTO method the electronic structure of several systems are studied, and some results are obtained. They are: The ideal Nb (100) surface has three surface states, the multi-layer relaxed surface has two surface states. The surface energy of the ideal surface is higher than that of the relaxed surface, that means that the multi-layer relaxed surface is more stable than the former one, which supports the LEED results. The mono-layer relaxed Ag (111) surface is the most stable one among several" stable surface models"presented by several researchers. The surface energy of Ag (111) surface is higher than that of surface Ag (001), which supports some experimental results such as different reaction rate at different surface orientations for the same material. The surafce states of Si (111) surface not only locate near the Fermi level, but also in the valence band, which agrees well with Cohen's conclusion. Si (111)-H is an effective model for analysing the surface states and H adsorbed on the back surface is a good method for improving the convincingness of the results obtained on thinner slab models. The surface stability depends on three different kinds of MoSi〓(001) surfaces, the surface with mono-layer Si is the most stable one, and the surface with Mo at the first layer is the most unstable one among them. These are consistant with the Kemoda's experimental results. The valence bands of clean or K adsorbed CdTe (111) surface agrees well with the synchrotron radiation studies. The surface of CdTe (111) consists of four kinds of surface models which show different surface electronic structures and different surface structure stabilities. The conclusion agrees well with Wu's experimental work. The different absorbed alkali metals on the CdTe (111) surface give different adsorption characteristics which have relations not only with the valence electrons, but also with the core ones of the alkali metals. The electonic structures of Si-C alloys are different from that of Si-Ge alloys, and the energy band gaps of Si-C alloys do not increase linearly with Carbon concentration, our conclusion supports Alexander's results, but conflicts with Soref's one.
现分述如下: LMTO方法及其应用方面:1)通过对Nb(100)表面电子态分析发现清洁理想表面有三个表面态,多层弛豫表面有两个表面态;表面能大小说明多层弛豫表面更稳定,支持了LEED结果。2)通过对采用不同方法获得的几种不同Ag(111)表面稳定结构的表面能计算分析,给出了单层弛豫表面为Ag(111)表面的最稳定结构;从Ag(111)单层弛豫表面和Ag(001)表面的表面能比较,发现了Ag(001)表面表面能要比Ag(111)小的,表明了同种物质不同表面取向将表现出不同物理、化学性质,这是与实验中得出的结论是吻合的,3)通过对Si(111)表面态分析,不仅发现了Si(111)表面不仅具有居于费米能级附近的悬挂键所对应的表面态,而且还有很多表面态位于价带能量范围内,与Cohen等结果一致,H饱和slab模型背表面相当于增加了slab层的厚度,是一有效的变相增加slab层厚的方法,弛豫表面较清洁理想表面价带谱们低能端的少许移动,预示着总能降低,说明弛豫表面较清洁理想表面稳定。4)MoSi〓具有三种表面,从费米能级上态密度值大小得到单层Si表面最稳定,Mo原子为表层原子的表面最不稳定,双层Si原子表面居中的结论,这与Kemoda等人实验结果是一致的。5)通过对CdTe(111)表面表面电子态、表面结构稳定性及表面H、碱金属吸附的电子结构系列研究,不仅得出了CdTe(111)清洁及碱金属K吸附价带谱与同步辐射光电子谱相吻合的结果,而且发现了CdTe(111)表面具有四类不同原子近邻特征,表现出四类不同的表面结构及电子结构特征:不同表面态分布、不同的表面结构稳定性(表层原子与次层原子成三键有一悬挂键的表面要比表层原子与次层原子成一键有三悬挂键稳定(与Wu等人实验结果一致))、不同的H吸附特性。
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A series of theoretical and experimental studies on the microstrip patch antennas with dielectric superstrates is carried out systematically. Firstly, a comprehensive survey of the microstrip antenna technology and its theories are presented. Then, two analysis techniques, named as the spectral domain Green's function method and the spectral domain integral equation method are developed. The SDGF method is a simplified analysis technique, which takes advantage of the spectral domain immittance approach to find the dyadic Green's function for the stratified media, and obtains the complete closed-form formulas for radiation patterns, directivity, efficiency, gain etc. Some interesting calculated results are presented. The SDIE method is capable of determining resonant frequency, radiation characteristics, input impedance etc, for the covered microstrip patch antennas. Comparing with other full-wave analyses it reduced computation and mathematical labour remarkably. The singularities near the pole location of the surface-wave modes and the difficulty of the integral computation over infinite range of oscillating integrands are dealt with actively and documented well. Results predicted by the SDIE method agree extremely well with our experimental results for resonant frequencies of various superstrates. The superstrate effects on impedance and radiation characteristics also have been investigated experimentally so that the gap due to lack of measured data and computed results for multi-layered superstrate has been filled to some degrees and two useful observations have been achieved for weakening the resonant frequency shift and optimizing the microstrip antenna gain. As a meaningful application, the design and analysis of a 4×4 patch array are introduced.
实用微带天线普遍加介质覆盖层来防护热,物理损伤和环境影响,也可能在飞行或严酷气候条件下自然形成覆盖层本论文对带介质覆盖层的微带贴片天线系统地作了一系列理论和实验研究首先,对微带天线技术和理论作了全面的综述然后,发展了两种分析方法,称为谱域格林函数法和谱域积分方程法SDGF法是一种简化的分析技术,它利用谱域导抗法来求得分层媒质的并矢格林函数,并得出方向图、方向性系数、增益等参数的完整的闭式公式,给出了一些令人感兴趣的计算结果SDIE法能确定介质覆盖微带天线的谐振频率、辐射特性和输入阻抗等与其它全波分析方法相比,它明显减小了计算量和数学工作量已有效地处理了表面波模极点附近的奇异性和对振荡的被积函数的无限区间积分计算的困难对于不同覆盖层情况下的谐振频率,由SDIE法所预示的结果与我们的实验结果吻合得很好对于覆盖层对阻抗和辐射特性的影响也已作了实验研究这在某种程度上填补了缺少实验数据和计算结果之间的间隙,并得出了缓解谐振频率偏移和优化天线增益的两点有用的结论作为有意义的应用,介绍了一个4×4元矩形贴片天线阵的设计和分析。
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Combining the experimental results and theoretical analysis, the following work has been accomplished.(1) Reasons of the decrease of interelectrode capacitance and the increase of discharge gap caused by the powder suspended in dielectric fluid are explained. And the mechanism that surface quality of workpiece improved by powder-mixed EDM is analyzed from this viewpoint.(2) The variation regularity of the percentage of silicon on the machined surface of workpiece has been summarized according to the experiment results when silicon powder was added into the working fluid. The entropy is introduced to explain the reasons for this variation regularity by thermodynamics.(3) The dimensional accuracy is greatly influenced by the overcut resulting from discharge gap and electrode wear in practice application. Empirical formulas for the overcut in EDM and powder-mixed EDM are established based on the experimental results using the ternary linear regressive method in this paper.(4) The influence of main factors on the machined surface characteristics has been evaluated based on the orthogonal experimental design method.
通过一系列普通电火花加工与混粉电火花加工的对比实验,运用工艺实验和理论分析相结合的方法,重点做了以下工作:(1)探讨了粉末颗粒导致极间电容减小、放电间隙增大的原因,并从这个角度解释了混粉电火花加工可以改善工件表面质量的机理;(2)以混合硅粉的电火花加工为例,实验得出峰值电流和脉冲宽度对加工表面层成分中硅元素含量的影响规律,并引入熵的概念从热力学的角度对硅元素含量变化的原因寻找了理论依据;(3)在实际加工中,由于粉末的加入使放电间隙变大,这使得混粉电火花加工的尺寸精度难以控制,本文利用三元线性回归的方法,在实验数据的基础上,建立了两种电火花加工过切量的计算公式;(4)将正交试验法应用于混粉电火花加工实验研究,并通过对实验指标极差的直观分析,得出各电参数对加工指标影响的敏感程度。
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Firstly, we used the Raman scattering method which can calibrate in real time to measure the O2 (a1 Δ) yield of SOG for the first time in China. The measurement relative error is less than 8%. Based on the data from the experiments, we report the results that the diluent category and ratios influence the O2 (a1 Δ) yield. The relationship of P-τ values and the O2 (a1 Δ) yield of this SOG were given. The effects of distance and bypass of gas transportation on the O2 (a1 Δ) yield are investigated. Secondly, the chlorine utilization was measured by using Raman spectroscopy simultaneously when the O2 (a1 Δ) yield was measured. This method originated with us. The result about the chlorine utilization is coincident with other theoretic and experimental conclusions. The relationship given in this paper between gas stay time in SOG and chlorine utilization offers reference to improve the reaction efficiency and chemical efficiency of COIL. Finally, the partial water vapor pressure at the exit of SOG was measured by absorption spectroscopy. The water vapor fraction and partial pressure have trends changed with the generator total pressure, the diluentratios, and the BHP temperature. These experimental results are very important to improve experimental conditions of SOG, reduce the water vapor fraction, and enhance the output power of COIL.
由侧得的数据得到了加入稀释气体、稀释气体种类以及稀释比例对单重态氧产率的影响,给出了该发生器P一:值与仇产率的关系,还考察了传输距离对仇产率的影响;在国际上首创利用喇曼散射光谱法在侧量产率的同时进行了氯气利用率的检侧,侧试结果与其他理论及实验结果十分相近;给出了气体在发生器中的滞留时间与氯气利用率之间的关系,该结果为提高氧碘化学激光器的反应效率和化学效率提供了参考依据;另外采用了吸收光谱法对发生器出口处的水汽含量进行了测量、得到了水汽分压和百分含量随着发生器压力、稀释气体比例以及BHP温度等的变化情况,该实验结果对于改进发生器工作条件、减少水汽含量、提高氧碘化学激光器的出光功率具有十分重要的指导意义。
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A prediction model has been proposed to deal with threshold voltage shift as a function of 1MeV neutron flux and gate oxide thickness, and to deal with room-temperature annealing of threshold voltage shift induced-by 〓Coγ as a function of electric field and gate oxide thickness. The commonness and individuality of MOS device degradation between hot-carrier effect and ionizing radiation were investigated. The dependence of substrate current, gate current and threshold voltage shift due to hot-carrier on gate oxide thickness were simulated with MEDICI-2D simulator. The photocurrents of PN junction and bipolar transistor were studied. Their transient responses on varied bias voltages, pulse durations and absorbed doses were simulated. The influences of NPN base width on base and collector photocurrents were investigated. We also studied 1MeV neutron displacement damage in PN junction, and calculated reverse current leakage under the neutron flux of 2. 67×10〓 per square centimeter. 3 The study of nondestructive screening method for MOS radiation tolerance A theoretical and experimental study of nondestructive screening methods for radiation tolerance of nMOS and pMOS were firstly fulfilled. We determined the informative parameters pertinent to the method and proposed how to deal with experimental data and verify obtained results statistically, as well as make the required steps for nondestructive screening. Based on the experimental data of 180 samples of discrete pMOS devices, the relation between sample quantity and correlation coefficient, screening equation, and other significant results were obtained from the threshold voltage shifts of pre-and post-irradiation samples.
二、分立器件电离和位移辐射损伤响应研究在国内首次开展了电离辐射引起的氧化层阈值电压漂移和退火理论研究,编程计算了1MeV中子引起的MOS器件阈值电压漂移与中子通量及栅氧厚度的关系,计算了〓Coγ光子引起的阈值电压漂移及退火的时效曲线与纵向电场和栅氧厚度的关系等,对评估MOS型集成电路电离损伤和加固方法研究,以及论文中开展的MOSFETs无损筛选方法研究奠定了基础;分析了MOS器件热载流子损伤效应与辐射电离损伤效应之间的异同性,利用二维模拟软件MEDICI-2D模拟了衬底电流和栅电流,在不同栅氧厚度下随栅压的变化曲线,计算了热载流子效应造成的阈值电压漂移,研究结果对当前存在的以热载流子效应研究取代电离辐射损伤实验研究的设想,具有重要的参考价值;开展了PN结和双极晶体管电离光电流研究,计算了不同偏压、不同辐射脉宽和不同吸收剂量下PN结光电流的瞬时响应,计算了不同辐射脉宽下NPN晶体管基极电流和收集极电流的瞬时响应,以及基区宽度对NPN晶体管光电流的影响,研究结果对双极器件抗电离辐射损伤响应及加固方法研究具有重要意义;在国内首次开展了器件位移损伤的理论研究,分析了辐射产生的缺陷对电性能的影响,计算了注量为2.67×10〓cm〓的1MeV中子产生的缺陷对PN结反向电流的影响。
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In this thesis,the AM1,MNDO,MINDO/3(mainly AM1)and INDO/S-CI semiempirical MO methods were used toinvestigate the excited-state intramolecular protontransfer reactions of salicylic acid derivatives—salicylic acid,methyl salicylate,salicylaldehyde,o-hydroxyaceto-phenone,salicylamide and 3-hydroxy-picolinamide (6 conformers and 2-3 anion species);2-(2'-hydroxy-5' methylphenyl) benzotriazole(4 conformers),2-(2' hydroxyphenyl) benzimidazole (3 conformers and 3anion species),Bis-2,5-(2-benzoxazolyl)hydroquinone(3 conformers),2-(2'-hydroxyphenyl)benzothiazole(2conformers) and 7-azaindole dimer (2 conformers).Theinvestigations were described as follows.Geometry optimization,relative stability andhydrogen bonding energy First,for sylicylic acid derivative molecules,the AM1,MNDO and MINDO/3 methods were used toinvestigate ground-state geometry optimization,energies,relative stabilities and hydrogen-bondingenergies on the five kinds of the molecules(designing 6 conformers and 2-3 anion species).Comparing with experimental data,the optimizedgeometry,the order of stability,the hydrogen-bonding energies and the distances between O-O in O-H..O hydrogen bonds by AM1 method were in agreementwith the experimental data,however,the C-C bondlengths optimized by MNDO and MINDO/3 were longer,C-O and O-H bond lengths were shorter;for C-N bondlengths,the results opitimized by MNDO method werethe same as those by AM1 method,nevertheless the C-Nbond lengths given by MINDO/3 method were muchshorter.For some sylicylic acid derivatives(e.g.methyl salicylate,salicylamide),the order ofstabilities on the conformers given by MNDO andMINDO/3 methods were not in agreement with theexisting conformers deduced by experimental methods,and the hydrogen bonding energies calculated by MNDO.and MINDO/3 methods were smaller.Second,the studyon the other systems found that the optimizedgeometry of the proton-transfered product with INDOmethod could not be obtained,only could theoptimized geometry of reactant be obtained,and thecalculated hydrogen bonding energies were greater.Many results of calculation indicated that the studyon the excited-state intramolecular proton transferreaction system using AM1 method was suitable andreliable.
本论文用AM1、MNDO、MINDO/3(主要是AM1)和INDO/S-CI半经验分子轨道方法对水杨酸衍生物系列——水杨酸、水杨酸甲酯、水杨醛、O-羟基乙酰苯酮、水杨酰胺和3-羟基吡啶酰胺(6种异构体和2-3种阴离子);2-(2'-羟基-5'-甲基苯基)苯并三〓唑(4种异构体);2-(2'-羟基苯基)苯并咪唑(3种异构体和3种阴离子);2,5-二间氮杂氧茚氢醌(3种异构体);2-(2'-羟基苯基)间〓杂硫茚(2种异构体)和7-〓吲哚二体(2种异构体)的激发态分子内质子转移反应在以下几个方面进行了较系统的理论研究:几何构型优化和相对稳定性及氢键能首先以水杨酸衍生物系列分子为例,用AM1、MNDO和MINDO/3方法考察了5种分子(每种分子设计6种异构体和2-3种阴离子)的基态几何构型优化,能量、相对稳定性和氢键能计算,通过和实验数据进行比较,AM1方法给出的优化几何构型、稳定性次序、氢键能和O—H。。。O氢键的0—0距离与实验数据吻合最好,MNDO和MINDO/3方法优化的C-C键长偏长,C-O键和O-H键长偏短;对于C-N键长,MNDO和AM1优化结果差别不大,而MINDO/3给出了过短的C-N键长,MNDO和MINDO/3方法给出的有些水杨酸衍生物分子(如水杨酸甲酯和水杨酰胺)异构体的稳定性次序和实验上推测的可存在异构体结果不一致,MNDO和MINDO/3方法给出的氢键能偏低,对其他体系的研究发现INDO方法常常不能得到质子转移产物的优化几何构型,只能得到反应物的优化构型,并且估算的氢键能偏高,大量的计算结果表明AM1方法对本论文研究的激发态分子内质子转移反应体系是适宜和可靠的。
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The photoelastic coating method used to carry out experimental research of stress distribution is the relatively suitable method in experimental mechanics at present. But it is necessary to improve the measurement accuracy and the degree of automation.
光弹性贴片法是现有的实验力学方法中比较适用于对锻压设备应力分布进行研究的一种方法,提高其测量精度和自动化程度有利于扩大其应用领域。
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Qualitative results are obtained by using this method in fluid fielddesign and structure optimization of disturbing elements.5 Experimental models are made efficiently and accurately by RPM method. Allthe models satisfy the precision and strength requirements.6 CFD is employed to simulate the application of tube with static mixer in anindustrial furnace, in which a tube model library containing the geometricalmodel and physical model in common use is build.7 Disturbed flow in tube with static mixer is demonstrated in an experimentsystem designed and manufactured by the author. Fluid field is measured byuse of seven-hole probe method. An experimental system are designed and builtfor this purpose.
建立了一个由模型的几何、物理参数组定义的常用模型的模型库,提高计算效率,缩短放大研究周期。6、提出了基于速度的流场扰流效果的评价方法,将之应用于流场设计和扰流元件结构优化的评价中,获得了量化的评价结果。7、设计、制造流动显示实验系统,验证静态混合式炉管对流体的扰动效果:采用七孔探针流体力学实验方法,在流体力学实验测量系统中,对静态混合式炉管模拟流场的三维速度分布和流体、压力降等进行测量。
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The resolution index of electron diffraction in TEM is analyzed. The exactly experimental method is given for demarcating electron diffraction camera length by Gold-monocrystal in TEM.
同时对TEM中的电子衍射分辨率指数进行了分析和讨论,并给出了实际应用金单晶标样精确标定TEM电子衍射相机长度的实验方法。
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In chapter 2 and 3, experimentally, using the Angular-Resolved high-resolution fast Electron Energy Loss Spectrometer , at the condition of 2. 5 keV incident energy and 50-60 meV energy resolution, we measured the Optical Oscillator Strength Density Spectra for the excitations of 4p, 4s or 3d electron. The oscillator strengths for excitations of the valent shell 4p electron were obtained, and comparisons were done between presently experimental and previously experimental and theoretical results. The experimental results of different groups agree with each other approximately, but the semi-experientially theoretical results do not match with the experimental results. The delayed maximum in the photoabsorption spectra was discussed. It should arise from the transition of 4p→∈d. For the excitation of the inner-valent 4s electron, the discrepancies for the resonant structures in previous electron-impact results and photoionization results were clarified in present work, which confirms again that the fast electron impact method is suitable to measure the optical oscillator strengths. The autoionization Rydberg series 4s〓ns (n=5, 6, 7) and 4s〓nd (n=4, 5, 6, 7) were identified without ambiguity by the measurement at 0°, 2° and 4°scattering angles. The energy levels and natural widths of the excitations of Kr3d and Ar2p inner shell, including optically allowed and forbidden transitions, were determined. The widths of these inner shell excitations are nearly the same, which was interpreted by the Resonant Auger effect .
在第二章和第三章,实验上,使用角分辨的高能量分辨快电子能量损失谱仪,在2.5keV电子入射能量和50-60meV能量分辨下,测量了Kr原子由价壳层4p到内价壳层4s,再到内壳层3d电子激发的光学振子强度密度谱;得到了价壳层4p电子激发束缚态的光学振子强度,与前人实验和半经验理论结果作了细致的比较,说明几家实验是比较符合的,但半经验的理论计算存在问题;分析了光吸收谱中的延迟极大现象,说明在第一电离阈值以上几个eV范围内的极大值源于4p→εd跃迁产生的延迟极大;对于内价壳层4s激发的自电离区,澄清了前人实验中电子碰撞方法和光学方法在共振结构上存在差异的问题,再一次肯定了快电子碰撞方法是获得绝对光学振子强度的一种好方法;通过在非0°散射角的测量(如2°和4°),清楚地标识了4s电子激发的光学禁戒跃迁自电离里德堡系列4s〓ns(n=5,6,7)和4s〓nd(n=4,5,6,7);通过在0°和4°散射角的测量,观测并标识了几个新的内壳层光学禁戒跃迁能级,得到了Kr原子3d和Ar原子2p内壳层激发态(包括光学允许和禁戒跃迁形成的)的能级位置和自然宽度,用共振俄歇效应解释了这些内壳层激发态(不管是光学允许还是禁戒跃迁产生的)的自然宽度彼此比较接近的原因。
- 推荐网络例句
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This one mode pays close attention to network credence foundation of the businessman very much.
这一模式非常关注商人的网络信用基础。
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Cell morphology of bacterial ghost of Pasteurella multocida was observed by scanning electron microscopy and inactivation ratio was estimated by CFU analysi.
扫描电镜观察多杀性巴氏杆菌细菌幽灵和菌落形成单位评价遗传灭活率。
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There is no differences of cell proliferation vitality between labeled and unlabeled NSCs.
双标记神经干细胞的增殖、分化活力与未标记神经干细胞相比无改变。