932 resultados para 66-2
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设计并制作了一种新型的SOI 2×2马赫-曾德(MZ)热光开关.这种光开关采用了深刻蚀结构的配对多模干涉耦合器,同时,为了保证单模传输和调制,在连接波导和调制臂区域采用了浅刻蚀结构.深刻蚀结构增强了多模干涉耦合器对光场的限制,有利于自映像质量的提高,从而减少了自映像损耗和不均衡度,同时也提高了制作容差.基于强限制配对干涉耦合器的新型热光开关,其插入损耗为-11.0 dB,其中包括光纤-波导耦合损耗-4.3 dB,上升和下降开关时间分别为3.5μs和8.8μs.
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The low-temperature heat capacities of 2-chloro-5-trichloromethylpyridine were measured with a high-precision automated adiabatic calorimeter in the temperature range from 80 K to 345 K. A solid-liquid phase transition was observed from 318.57 K to 327.44 K with peak temperature 324.67 K; the molar enthalpy and entropy of phase transition, DeltaH(m) and DeltaS(m), were determined to be 14.50 +/-0.02 kJ mol(-1) and 44.66 +/- 0.07 kJ K-1 mol(-1), respectively. The thermal stability was investigated through thermogravimetric analysis (TG). The TG and DTG results reveal that 2-chloro-5-trichloromethylpyridine starts to lose mass at 332 K due to evaporation and completely changes into vapour at 483 K under the present experimental conditions.
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建立了污染土壤预制床处理工程 ,对不同类型原油污染土壤分别进行堆腐处理 ,历时 2个阶段 ,共运行2 1 0d .当稀油、稠油、特稠油和高凝油污染土壤中石油烃总量 (TPH)为 2 5 8~ 77 2 g·kg- 1时 ,经过 5 3d(为第 1阶段 )的运行 ,TPH去除率 3 8 3 7%~ 5 6 74 % .第 2年 (为第 2阶段 )继续处理 1 5 6d ,TPH降解率达到 66 5 9%~80 96% .连续运行结果表明 ,污染土壤中易分解的石油烃污染物大部分在第 1阶段得到降解 ,第二阶段降解率明显降低
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一、蜜蜂嗅觉学习记忆应用基础研究特殊气味的探测在刑侦工作中意义重大,常用的警犬探测和仪器分析都有其局限之处。蜜蜂嗅觉灵敏,且学习记忆能力突出,具有为刑侦工作所用的潜力。基于此,我们希望通过训练蜜蜂将其对糖水奖励的伸喙反应与指定气味建立条件反射的原理,配合适当的训练方法,达到利用蜜蜂探测危险气味的目的。在实验中,我们首先比较了不同喂养方式的蜜蜂在气味学习中的差别。由于低浓度气味无法直接使蜜蜂建立条件化,我们采用了逐渐降低气味浓度的方法,成功训练蜜蜂对低浓度(3.6×10-7) 醋酸气味建立了条件反射。结果如下: 1)自然放养与人工孵化两种不同喂养方式的蜜蜂,各两组,分别学习醋酸CS+/薄荷CS-,或柠檬CS+/薄荷CS-的气味配对。以“获得(CS+),巩固(CS-/CS+ CS+/CS- CS-/CS+),检测,干净空气假阳性检测”的顺序操作。结果显示自然放养蜜蜂对醋酸气味没有偏好(第一次给醋酸气味伸喙率:6%),学习醋酸气味能力较低(24小时后检测正确率:66%, n=25),相对应,该类蜜蜂对柠檬气味显示出明显偏好(第一次给柠檬气味伸喙率:41%,P< 0.01),而学习效果(检测正确率:50%,n=20)与醋酸组相近(P>0.05)。人工孵化的蜜蜂对醋酸气味学习能力较自然放养蜜蜂大大提高(检测正确率:96%, n=32, P<0.01),同时对柠檬的学习结果(检测正确率:80%, n=32)也明显提高(0.01
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由Bi(Hcydta).5H2O和Nd(NO3).6H2O按1︰1的物质的量比,在水溶液中合成了含Bi(III)-Nd(III)的异核配位聚合物{[(NO3)Nd(H2O)4(μ3-cydta)Bi(μ-ONO2)].2.5H2O}n.用元素分析、红外光谱、热重-差热和X射线单晶衍射等手段对标题配合物的组成和结构进行了表征.该配合物属三斜晶系,空间群P1,晶胞参数:a=0.9235(3)nm,b=1.0902(4)nm,c=1.4253(5)nm,α=71.840(4)°,β=86.877(4)°,γ=76.991(4)°,Z=2,Mr=936.65,V=1.3284(8)nm3,Dc=2.342g.cm-3,μ=8.646mm-1,F(000)=900,最终偏离因子R1=0.0406,wR2=0.1124.在该配合物中,铋(III)与配体cydta4-的4O2N和1个硝酸根中1个O原子以及邻位分子的硝酸根形成8配位的畸变双帽三棱柱.钕(III)与4个水分子的O,1个硝酸根中2个O以及来自3个不同配体cydta4-的桥联羧基O结合,形成9配位的三帽三棱柱构型.羧酸根在Bi—Nd和硝酸根在Bi—Bi间的桥联作用...
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Four single polymers with two kinds of attachment of orange chromophore to blue polymer host for white electroluminescence (EL) were designed. The effect of the side-chain attachment and main-chain attachment on the EL efficiencies of the resulting polymers was compared. The side-chain-type single polymers are found to exhibit more efficient white EL than that of the main-chain-type single polymers. Based on the side-chain-type white single polymer with 4-(4-alkyloxy-phenyl)-7-(4-diphenylamino-phenyl)-2,1,3-benzothiadiazoles as the orange-dopant unit and polyfluorene as the blue polymer host, white EL with simultaneous orange (lambda(max) = 545 nm) and blue emission (lambda(max) = 432 nm/460 nm) is realised. A single-layer device (indium tin oxide/poly(3,4-ethylenedioxythiophene)/polymer/Ca/Al) made of these polymers emits white light with the Commission Internationale de l'Eclairage coordinates of (0.30,0.40), possesses a turn-on voltage of 3.5 V, luminous efficiency of 10.66 cd A(-1), power efficiency of 6.68 lm W-1, and a maximum brightness of 21240 cd m(-2).
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The hydrothermal reactions of vanadium oxide starting materials with divalent transition metal cations in the presence of nitrogen donor chelating ligands yield the bimetallic cluster complexes with the formulae [{Cd(phen(2))(2)V4O12].5H(2)O (1) and [Ni(phen)(3)](2)[V4O12] . 17.5H(2)O (2). Crystal data: C48H52Cd2N8O22V4 (1), triclinic. P (1) over bar, a = 10.3366(10), b = 11.320(3), c = 13.268(3) Angstrom, alpha = 103.888(17)degrees, beta = 92.256(15)degrees, gamma = 107.444(14)degrees, Z = 1; C72H131N12Ni2O29.5V4 (2), triclinic. P (1) over bar, a = 12.305(3), b = 13.172(6), c = 15.133(4), alpha = 79.05(3)degrees, beta = 76.09(2)degrees, gamma = 74.66(3)degrees, Z = 1. Data were collected on a Siemens P4 four-circle diffractometer at 293 K in the range 1.59degrees < theta < 26.02degrees and 2.01degrees < 0 < 25.01degrees using the omega-scan technique, respectively. The structure of 1 consists of a [V4O12](4-) cluster covalently attached to two {Cd(phen)(2)}(2+) fragments, in which the [V4O12](4-) cluster adopts a chair-like configuration. In the structure of 2, the [V4O12](4-) cluster is isolated. And the complex formed a layer structure via hydrogen bonds between the V4O12](4-) unit and crystallization water molecules.
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The title two-dimensional coordination polymer was synthesised and characterised by X-ray diffraction analysis.
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Analysis of isothermal and nonisothermal crystallization kinetics of nylon 66 was carried out using differential scanning calorimetry (DSC). The commonly used Avrami equation and that modified by Jeziorny were used, respectively, to fit the primary stage of isothermal and nonisothermal crystallizations of nylon 66. In the isothermal crystallization process, mechanisms of spherulitic nucleation and growth were discussed. The lateral and folding surface free energies determined from the Lauritzen-Hoffman treatment are sigma = 9.77 erg/cm(2) and sigma (e) = 155.48 erg/cm(2), respectively; and the work of chain folding is q = 33.14 kJ/mol. The nonisothermal crystallization kinetics of nylon 66 was analyzed by using the Mo method combined with the Avrami and Ozawa equations. The average Avrami exponent (n) over bar was determined to be 3.45. The activation energies (DeltaE) were determined to be -485.45 kJ/mol and -331.27 kJ/mol, respectively, for the isothermal and nonisothermal crystallization processes by the Arrhenius and the Kissinger methods.
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用红外光谱法研究了Pa1010/66共聚物氢键含量、N-H键伸缩振动力常数分布与组成的关系,发现66盐重量含量为40%时氢键含量最低,N-H伸缩振动力常数分布最宽,解释了PA1010/66共聚物热力学、结晶、机械等性能随组成改变而变化的原因.
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LaC3n+ (n = 0, 1, 2) clusters have been studied using B3LYP (Becke 3-parameter-Lee-Yang-Parr) density functional method. The basis set is Dunning/ Huzinaga valence double zeta for carbon and [2s2p2d] for lanthanum, denoted LANL1DZ. Four isomers are presented for each cluster; two of them are edge binding isomers with C-2 upsilon symmetry, the other two are Linear chains with C-infinity upsilon symmetry. Meanwhile, two spin states for each isomer, that is, singlet and triplet for LaC3+, doublet and quartet for LaC3 and LaC32+, respectively, are also considered. Geometries, vibrational frequencies, infrared intensities, and other quantities are reported and discussed. The results indicate that at some spin states; the C-2 upsilon symmetry isomers are the dominant structures, while for the other spin states, linear isomers are energetically favored. (C) 1998 John Wiley & Sons, Inc.
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Chemorheology and corresponding models for an epoxy-terminated poly(phenylene ether ketone) (E-PEK) and 4,4'-diaminodiphenyl sulfone (DDS) system were investigated using a differential scanning calorimeter (DSC) and a cone-and-plate rheometer. For this system, the reported four-parameter chemorheological model and modified WLF chemorheological model can only be used in an isothermal or nonisothermal process, respectively. In order to predict the resin viscosity variation during a stepwise temperature cure cycle actually used, a new model based on the combination of the four-parameter model and the modified WLF model was developed. The combined model can predict the resin viscosity variation during a stepwise temperature cure cycle more accurately than the above two models. In order to simplify the establishment of this model, a new five-parameter chemorheological model was then developed. The parameters in this five-parameter model can be determined through very few rheology and DSC experiments. This model is practicable to describe the resin viscosity variation for isothermal, nonisothermal, or stepwise temperature cure cycles accurately. The five-parameter chemorheological model has also successfully been used in the E-PEK systems with two other curing agents, i.e., the diamine curing agent with the addition of a boron trifluride monoethylamine (BF3-MEA) accelerator and an anhydride curing agent (hexahydrophthalic acid anhydride). (C) 1997 John Wiley & Sons, Inc.
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The compounds O(CH2CH2C5H4)(2)Ln(THF)(2) [Ln = Sm(1), Yb(2)] were synthesized by the reduction of O(CH2CH2C5H4)(2)LnCl with sodium metal in tetrahydrofuran (THF) at room temperature. Recrystallization of 2 from dimethoxyethane (DME) produced the single-crystal O(CH2CH2C5H4)(2)Yb(DME) (3) whose structure has been determined by an X-ray diffraction study. The crystals are orthorhombic, space group Pcab, with a = 14.168(4), b = 13.541(6), c = 19.314(8) Angstrom, Z = 8, D-calc. = 1.66 g cm(-3).
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Blends of poly(N-vinyl-2-pyrrolidone) (PVP) with a copolyamide (CoPA) randomly composed of 1:1:1 (wt) nylon 6, nylon 66 and nylon 610 structural units were prepared by casting from a common solvent. They were found to be miscible and show a single, composition-dependent glass transition temperature (T(g)). The addition of PVP to CoPA significantly lowers the crystallinity owing to an increasing T(g) of the system. The observed miscibility is proposed to be the result of specific interactions between the proton acceptor groups of PVP and the amide groups of CoPA.
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The field observation of this study was carried out in the Changjiang Estuary from May 19 to 26,2003, just a few days before the Three Gorges Dam began to store water. A total of 29 stations, including 2 anchor stations, were distributed through almost the whole salinity gradient Based on the data gained from these stations, the biogeochemical characteristics of dissolved oxygen (DO) were examined. Spatial distribution of DO concentrations showed the pattern that it increased in a downriver direction. DO concentration generally varied within a narrow range of 733-8.10 mg l(-1) in the freshwater region and the west part of the mixed water region, and after that it increased rapidly. In vertical direction, the differences in DO concentrations between surface and 2 m above the bottom were big at the stations with water depths exceeding 20 m; DO concentration up to 14.88 mg l(-1) was recorded at the sea surface, while at 2 m above the bottom its concentration was only about 4 mg l(-1). The fluctuation in DO concentrations was small during a period of 48 h in the mixed water region and 2 m above the bottom of the seawater region; while it was large during the same period in the seawater region for surface and 5 m below the surface layer, and a maximum variation from 8.77 to 12.66 mg l(-1) in 4 h was recorded. Oxygen fluxes also showed a marked spatio-temporal variation. As a whole, the freshwater region and mixed water region were an oxygen sink while the seawater region was a source. Relationships between dissolved oxygen and some biogeochemical parameters which could markedly influence its spatio-temporal distribution were discussed in this paper. (C) 2008 Elsevier B.V. All rights reserved.