205 resultados para 232


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检测代表性的5个水质指标:氨氮(NH3-N)、总磷(T-P)、化学需氧量(COD)、生化需氧量(BOD5)、固体悬浮物(SS)的去除率,确定沈阳市满堂河污水处理厂最佳的污泥回流比与最佳曝气量.结果表明:回流比为75%,曝气量为34 kg/h时,各指标的去除率达到最大,即污水处理的效果最佳.

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运用河口湿地来削减氮磷入海通量 ,防止近海水体富营养化。首先对辽河三角洲湿地净化系统进行了理论分析 ,并建立了相应的概念模型 ,然后依靠野外实验数据 ,为湿地的营养物去除功能建立了一个空间模型。该模型包括两大部分 :一是灌渠子系统 ,二是苇田子系统。前者使用的是一个非线性回归模型 ,后者则是以百分率为基础的简单模型。该模型在个别灌区试运行后 ,推广到整个苇田研究区

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对污水的生态处理原理进行扼要论述 ,对污水的生态处理技术体系进行较为全面地概括 ,并就目前的应用条件与适用范围进行了阐述 ,在简要回顾污水的生态处理技术发展历史的基础上对该领域今后的发展趋势进行了展望 ,以推进污水生态处理系统的技术创新和在我国各地区的广泛应用 ,为全面实施污水处理与水资源综合利用相结合的污水无害化与资源化战略提供科学依据与技术支撑

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采用熔融共混的方法制备了聚碳酸1,2-丙二酯(PPC)/聚琥珀酸丁二酯(PBS)共混物和PPC/PBS/DAOP(邻苯二甲酸二烯丙酯)增塑共混物,对共混物的相容性、热性能、结晶性和物理机械性能进行了初步研究.研究结果表明PPC/PBS共混物为不相容体系,PPC对PBS的结晶度影响很小;PBS的加入提高了共混物的起始热分解温度(Td-5%),当共混物中PBS含量从10%增加到90%时,共混物的Td-5%可分别增加15℃到59℃.DAOP对PPC/PBS共混物有增塑作用,当PPC/PBS/DAOP的比例从30/70/0变化到30/70/30时,共混物玻璃化转变温度(Tg)下降了36.9℃.与PPC/PBS共混物相比,组成优化的DAOP增塑共混物PPC/PBS/DAOP(PPC/PBS/DAOP=30/70/5)的断裂伸长率和断裂能最大可提高31倍和34倍,分别达到655.1%和3.4 J/...

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研究聚酰亚胺胶粘剂的结构与性能,蜂窝复合材料的高低温压缩性能。结果表明:聚酰亚胺胶粘剂具有较高的高低温拉伸搭接剪切强度,室温和200℃的搭接剪切强度分别为24.64MPa和18.36MPa,满足蜂窝芯材的粘接性能;石英纤维增强的聚酰亚胺蜂窝复合材料400℃压缩强度和压缩模量分别为1.72MPa和27.22MPa。

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Dodecenly succinic anhydride (DDSA) starches were prepared commercially by the base catalyzed reaction of DDSA in pre-emulsion with starch granular in aqueous slurry. The results indicated that the degree of substitution and reaction efficiency were 0.0256% and 42.7%, respectively, at the parameters for the preparation of DDSA starches in starch slurry 30%, DDSA/starch radio 10% (wt/wt), pH 8.5-9.0, reaction temperature 313 K. After modification, product surface chemical composite had been changed which was prone to migrate into less polar solution. The chemical structural characteristics were investigated by methods of FTIR and H-1 NMR. The results of X-ray diffraction showed the native A-type crystalline pattern, indicating that reaction of corn starch with DDSA caused no change in the crystalline structure. Compared to native starch, the hydrophobic performance of esters was greatly increased. With the DS increasing, contact angles were gradually increased, however, the adhesion works were decreased. The maximum contact angle of DDSA starch could attend to 123 degrees, and the corresponding adhesion work was 33.2 mJ m(-2).

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采用铸造或压铸的方法制备了系列Mg-RE 基合金,研究了合金的组织、时效过程和力学性能.结果表明,各种Mg-RE合金的微观组织、相组成以及力学性能既有相似之处也有明显差别,合金的相组成由a-Mg 以及Mg-Gd 基合金中加入其它稀土元素,可有效改善合金的时效硬化特性和提高合金的力学性能.合金性能的提高主要与时效过程中生成的镁稀土化合物强化相有关.

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The self-assembly processes of the rod-coil diblock oligomer thin film of tetra-aniline (TANI)-block-poly(L-lactide) (PLLA) with different film thicknesses induced in the coil-selective solvent of acetone vapor at room temperature were studied. The morphologies of the oligomer films were determined by the film thickness. For the thicker film (232 nm), the nonextinct concentric ring-banded textures could form. While for the thinner and appropriate film (about 6 nm), multistacked diamond-shaped appearances with the periodic thickness being about 8.5 nm(6-nm-thick extended PLLA chain and 2.5-nm-thick p-pi conjugating TANI bimolecular layer) formed. The possible formation models of those two regular morphologies were presented in detail.

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We reported, for the first time to the best of our knowledge, the Sm3+ -doped yttriurn oxysulfide phosphors has reddish orange long-lasting phosphorescence. The phosphor show prominent luminescence in reddish orange due to the electronic transitions of (4)G(5/2) --> H-6(J) (J = 5/2, 7/2, 9/2), the afterglow color of this type of phosphors is a mixture of the three above mentioned electronic transition emissions and have a little different when the concentration of the Sm3+ dopant changes. Synthesis procedure of the Sm3+-yttrium oxysulfide reddish orange phosphor through the flux fusion method with binary flux compositions was presented. The synthesized phosphors were analyzed using X-ray diffraction (XRD) to interpret the structural characterization. The XRD analysis result reveal that the Y2O2S:Sm3+ phosphor synthesized with a binary flux composition containing (S and Na2CO3 at a ratio of 1: 1 at 30 wt.% of total raw material) at 1050degreesC for 3 h was in single-phase. Luminescence properties of the Y2O2S:Sm3+ long-lasting phosphor was analyzed by measuring the excitation spectra, emission spectra and afterglow decay curve. The mechanism of the strong afterglow from Y2O2S:Sm3+ was also discussed in this paper.

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研究虎眼万年青多糖对机体非特异性免疫和体液免疫功能的影响.方法:采用小鼠碳廓清单核巨噬细胞吞噬功能测定法筛选出虎眼万年青多糖中的有效组分,即60%醇浓度的虎眼万年青中性多糖(OCAPS3);采用溶血素测定方法研究不同剂量OCAPS3对小鼠抗体形成的影响.结果:OCAPS3能显著提高巨噬细胞的吞噬功能以及抗体生成的能力.结论:证明虎眼万年青多糖能有效地增强小鼠的非特异性免疫和体液免疫功能.

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用SiO2 为无机组份和以与SiO2 具有相似折射率和优良力学性能的丙烯酸类如甲基丙烯酸甲酯(MMA)和甲基丙烯酸羟乙酯 (HEMA) ,在交联剂 3 (三甲氧基硅 )丙基甲基丙烯酸酯 (MSMA)存在下 ,快速制备了两种杂化基质材料SiO2 /P(MMA MSMA)和SiO2 /P(HEMA MSMA)。分别以盐酸和六次甲基四胺作为酸性催化剂和碱性催化剂 ,建立了快速制备透明凝胶的两步溶胶 凝胶法 ,大大缩短了溶胶的成胶时间 ,所得杂化材料具有良好的光学透明性 ,利用此方法制备了掺杂稀土配合物的多种发光杂化材料。采用组装的方法 ,得到了稀土配合物与层状化合物α 磷酸氢锆 (α ZrP)及中孔分子筛材料MCM 4 1的组装体 ,并对所制备的杂化材料进行了表征。另外 ,将稀土配合物通过共价键嫁接于无机SiO2 基质中 ,得到了含有稀土配合物的分子杂化材料

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The rational synthesis and the structural and magnetic characterization of a nickel cluster are presented. The compound comprises a rhomblike Ni4O16 group encapsulated between two-heptadentate tungstoarsenate ligands [AsW9O34](9-). The crystal structure of K-10[Ni-4(H2O)(2)(AsW9O34)(2)](.)4H(2)O was solved in monoclinic, P2(1)/n symmetry, with a = 12.258(3) Angstrom, b = 21.232(4) Angstrom, c = 15.837(3) Angstrom, beta = 92.05(3)degrees, V = 4119.1(14) Angstrom(3), Z = 2, and R = 0.0862. The crystal structure of the Ni(II) derivative was compared with that of the Cu(II), Zn(II), Co(II) and Mn(II) derivatives. The Ni4O14(H2O)(2) unit in the compound shows no Jahn-Teller distortion. On the other hand, the Ni(II) derivative shows ferromagnetic exchange interactions within the Ni4O16 group (J = 7.8 cm(-1), J' = 13.7 cm(-1)) and an S = 4 ground state, the highest spin state reported in a heteropoly complex. Its redox electrochemistry has been studied in acid buffer solutions using cyclic voltammetry. It exhibited two steps of one-electron redox waves attributed to redox processes of the tungsten-oxo framework. The new catalyst showed an electrocatalytic effect on the reduction of NO2-.

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A functionalized high-density polyethylene (HDPE) with maleic anhydride (MAH) was prepared using a reactive extruding method. This copolymer was used as a compatibilizer of blends of polyamide 6 (PA6) and ultrahigh molecular weight polyethylene (UHMWPE). Morphologies were examined by a scanning electron microscope. It was found that the dimension of UHMWPE and HDPE domains in the PA6 matrix decreased dramatically, compared with that of the uncompatibilized blending system. The size of the UHMWPE domains was reduced from 35 mu m (PA6/UHMWPE, 80/20) to less than 4 mu m (PA6/UHMWPE/HDPE-g-MAH, 80/20/20). The tensile strength and Izod impact strength of PA6/UHMWPE/HDPE-g-MAH (80/20/20) were 1.5 and 1.6 times as high as those of PA6/UHMWPE: (80/20), respectively. This behavior could be attributed to chemical reactions between the anhydride groups of HDPE-g-MAH and the terminal amino groups of PA6 in PA6/UHMWPE/HDPE-g-MAH blends. Thermal analysis was performed to confirm that the above chemical reactions took place during the blending process. (C) 2000 John Wiley & Sons, Inc.