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1.
SIMOVSKI C.R VIITANEN A.J. TRETYAKOV S.A 《浙江大学学报(A卷英文版)》2006,7(1):29-33
INTRODUCTION The waveguide properties of linear arrays (chains) of silver nano-particles at optical frequencies are well known (Krenn et al., 1997; 1999; Tretyakov and Viitanen, 2000; Girard et al., 1994; Weber and Ford, 2004). Silver spheres and ellipsoids can support forward or backward waves along the chain depend- ing on their polarization state and the eigenfrequency (Krenn et al., 1999; Tretyakov and Viitanen, 2000; Girard et al., 1994; Weber and Ford, 2004). At com- paratively … 相似文献
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LEE Sang Hun LEE Kunwoo 《浙江大学学报(A卷英文版)》2006,7(9):1535-1543
INTRODUCTION 3D CAD systems for the feature-based B-rep solid models (Choi et al., 2002; Kim et al., 2003; 2005; Koo and Lee, 2002; Lee et al., 2004; Lee, 2005a) are becoming more suitable for CAD when compared with the conventional polygon-based mul- tiresolution modelling in computer graphics (Cignoni et al., 1998; Schr?der et al., 1992). As illustrated in Fig.1b, the object of the feature-based multiresolution modelling is a solid model where the suppressed ob- jects are form feat… 相似文献
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LIU Yun-kui XU Dan-qian XU Zhen-yuan ZHANG Yong-min 《Journal of Zhejiang University. Science. B》2006,(5)
INTRODUCTION Allyl selenides have drawn much attention as a class of important intermediates in organic synthesis. For example, they are useful synthetic precursors for the [1,3]- or [2,3]-sigmatropic rearrangements (Shar-pless and Lauer, 1972; Fujita et al., 1998; Carter and Bourland, 2000), allylic homocoupling reactions (Masugama et al., 1989), and various other chemical transformations (Shea et al., 1986; Back and Moussa, 2002; 2003). Generally, allyl selenides are synthe-sized fr… 相似文献
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ZHANG Xiu-yan RUAN Hui MU Lin HE Guo-qing TANG Xing-jun CHEN Qi-he 《浙江大学学报(A卷英文版)》2006,7(11):1948-1955
INTRODUCTION Enzymes are efficient and specific biocatalysts widely used in food industries, but their application in industrial process often involves special properties not found in natural source enzymes. In order to ob- tain desirable enzymes, in the past ten years, scientists have developed rational (Kurth et al., 1998; Mouratou et al., 1999; DeSantis et al., 1999) and irrational de- sign methods (Babbitt and Gerlt, 1997; O’Brien and Herschlag, 1999) to improve the enzyme propert… 相似文献
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An efficient method for tracing planar implicit curves 总被引：1，自引：0，他引：1
YU Zheng-sheng CAI Yao-zhi OH Min-jae KIM Tae-wan PENG Qun-sheng 《浙江大学学报(A卷英文版)》2006,7(7):1115-1123
INTRODUCTION Tracing a planar implicit curve f(x, y)=0 on a rectangular region [xl, xr]×[yb, yt] is of great interest in Computer-Aided Design and Computer Graphics. While parametric curves are easy to plot, plotting implicit curves is a challenging problem. Planar im- plicit curve plotting method can be classified into two categories (Shou et al., 2005; Martin et al., 2002; Lopes et al., 2002). In the first category are subdivi- sion methods (Shou et al., 2005; Martin et al., 2002) … 相似文献
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INTRODUCTION It is recognized that the transfer of soil moistureand heat occur simultaneously and are interrelated.Since the 1950s, many models have been developed,based on two nonisothermal water-heat coupledmodels by Philip and de Vries (1957) and Taylor andLary (1964), respectively. In China, some researcheson modeling coupled transfer of soil moisture andheat have also been conducted on the arid soils innorthern China (Kang et al., 1993; Guo and Li, 1997;Hu et al., 1992; … 相似文献
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INTRODUCTION Nitrogen oxides (NOx) are significant airborne contaminants resulting from fossil fuels combustion. The use of metal chelate additives for combined re- moval of NOx and SO2 in FGD (flue-gas desulfuriza- tion) systems was investigated by several groups (Harriott et al., 1993; Tsai et al., 1989; Shi et al., 1996a; 1997). Fe(II)EDTA (EDTA, ethylenediami- netetraacetate) as an additive for removing nitric oxide (NO) from flue gas had been extensively stud- ied, with the … 相似文献
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YANG Rui-jun XIA Qi PAN Qun-hua WANG Wei-nong LI Ming-lu 《浙江大学学报(A卷英文版)》2006,7(4):493-501
INTRODUCTION Mobile ad hoc networks are under active research focused on issues such as routing, security (Venkatra- man and Agrawal, 2003) and data management (Fan and Zhang, 2004). People have proposes many kinds of security mechanisms such as SAR (Yi et al., 2002), SRP (Papadimitratos and Haas, 2002), ARAN (San- zgiri et al., 2002), ARIADNE (Hu et al., 2005) and SEAD (Hu et al., 2002) for networks. The resource consumptions of security mechanisms are always large in mobile … 相似文献
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CHEN Jie GAO Dao-ming 《浙江大学学报(A卷英文版)》2006,7(8):1416-1421
INTRODUCTION The technology of using waterjet for cleaning is an important problem in engineering. There are many researches on using waterjets for cleaning. Most of them are focused on the relationship between clean-ing parameters and cleaning effectiveness (Louis and Schikorr, 1982; Summers, 1982; Liu et al., 1999; Taggart et al., 2002). However, few researches are related to the optimization of cleaning parameters to improve cleaning performance even if it is very cru-cial for fully… 相似文献
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INTRODUCTION π-conjugated polymers have received a great deal of attention because of their unique chemical and physical properties, including electrochromism, electrically conducting properties, chemical sensing ability, and electroluminescent properties. Their structures, synthetic methodologies, and physical and chemical properties were intensely studied in the past two decades (Friend et al., 1999; Heeger, 2001; Ya-mamoto, 2002). Especially, processable derivatives of polythiophene … 相似文献
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通过钯催化的Heck耦合反应,合成了一种含噁二唑基团与MEHPV单元的交替共聚物（oxa-MEHPV）,并利用UV-vis,FT-IR,^1H-NMR对其单体和聚合物的结构进行了表征,研究了目标聚合物的荧光性能、由于在MEH-PPV的主链骨架上引入噁二唑基团,oxa-MEHPV分子链的刚性得到增强,表现出更好的热稳定性能,在常规有机溶液如氯仿、二氯甲烷、甲苯等中也有更好的溶解性．同时,由于噁二唑具有很好的电子亲和能力,聚合物紫外吸收波长发生了较大的蓝移,较MEH-PPV拥有了更好的电子迁移率和更高的荧光量子效率,因而在聚合物电致发光（PLED）领域有潜在的应用前景. 相似文献
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Imprinted polymers were prepared for selective removal of Cu（Ⅱ） ions from metal solutions. Three ion-imprinted polymers were synthesized with methacrylic acid （MAA）, acrylamide （AA） and N,N＇-methylenebisacrylamide （MBAA） respectively as the functional monomers, ethleneglycoldimethacrylate （EGDMA） as the cross-linking agent, 2,2＇- azobisisobutyronitrile （AIBN） as the initiator and Cu （Ⅱ） ion as the imprint ion. The template Cu （Ⅱ） ion was removed from the polymer by leaching with a liquid of a 1：1 volumetric ratio of HCl to ethylenediaminetetraacetic acid （EDTA）. The capacity and selectivity of Cu（Ⅱ） ion adsorption were investigated with the three imprinted polymers and their non-imprinted counterparts. The polymers have a maximum adsorption capacity at pH 7.0. The isotherm of their batch adsorption of Cu（Ⅱ） ions shows a Langmuir adsorption pattern. Imprinted polymers all have a much higher capacity and higher selectivity of Cu（Ⅱ） adsorption than nonimprinted ones. MAA polymer benefits the most from imprinting. Imprinted MAA polymer has the highest selectivity when used to rebind Cu （Ⅱ） ion from an aqueous solution in the presence of other metal ions. Ion imprinting can be a promising technique of preparing selective adsorbents to separate and preconcentrate metal in a medium of multiple competitive metal ions through solid phase extraction （SPE）. 相似文献
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Imprinted polymers were prepared for selective removal of Cu(II) ions from metal solutions. Three ion-imprinted polymers were synthesized with methacrylic acid (MAA), acrylamide (AA) and N,N'-methylenebisacrylamide (MBAA) respectively as the functional monomers, ethleneglycoldimethacrylate (EGDMA) as the cross-linking agent, 2,2'-azobisisobutyronitrile (AIBN) as the initiator and Cu (II) ion as the imprint ion. The template Cu (II) ion was removed from the polymer by leaching with a liquid of a 1:1 volumetric ratio of HCl to ethylenediaminetetraacetic acid (EDTA). The capacity and selectivity of Cu(II) ion adsorption were investigated with the three imprinted polymers and their non-imprinted counterparts. The polymers have a maximum adsorption capacity at pH 7.0. The isotherm of their batch adsorption of Cu(II) ions shows a Langmuir adsorption pattern. Imprinted polymers all have a much higher capacity and higher selectivity of Cu(II) adsorption than non-imprinted ones. MAA polymer benefits the most from imprinting. Imprinted MAA polymer has the highest selectivity when used to rebind Cu (II) ion from an aqueous solution in the presence of other metal ions. Ion imprinting can be a promising technique of preparing selective adsorbents to separate and preconcentrate metal in a medium of multiple competitive metal ions through solid phase extraction (SPE). 相似文献
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以对羟基苯甲酸丁酯为模板,α-甲基丙烯酸（MAA）为功能单体,乙二醇二甲基丙烯酸酯（EGDMA）为交联剂,聚乙烯醇为分散剂,采用悬浮聚合法在氯仿溶剂中制备了分子印迹聚合物（MIP）。通过考察该聚合物对模板分子的间歇式吸附实验表明,所制备的分子印迹聚合物对模板分子的吸附较快,最大表观结合量近270μg／g。Scatchard方程研究表明在研究的浓度范围内在聚合物中形成了两类不同的结合位点。 相似文献
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MA Hai-zhu YE Gao-xiang 《浙江大学学报(A卷英文版)》2007,8(7):991-998
The unperturbed dimension and temperature character of poly(dibenzyl itaconate)s (PDBzI) are studied by a revised rotational isomeric state (RIS) method. The improved formulas of the mean-square radius of gyration, deduced by the pseudo-stereochemical equilibrium approach, may be used to investigate the configurational-conformational properties of atactic polymers with large side groups [poly(itaconates) for instance]. The calculated results showed that poly(itaconates) have larger dimension of the molecule than other vinyl polymers. Comparison of the dimension between considering and without considering side groups showed that the effect of large side groups on the unperturbed dimension for short-chain polymers is more obvious than that of long-chain polymers and, if the dimension of side groups increases, the effect also increases. The dimension differences of PDBzI between short-chain and long-chain polymers are investigated by the relation of characteristic ratios and temperature coefficients with temperature. Moreover, the dependence between the temperature coefficients and the tacticity of chains shows that the temperature characters of the isotactic, syndiotactic and atactic PDBzI chains have remarkable difference. 相似文献
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The effects of the concentration of dissolved total organic carbon(TOC),the TOC/Br-ratio,bromide ion levels,the chlorine to ammonia-N ratio(Cl:N),the monochloramine dose and the chlorine dose on the formation of trihalomethanes(THMs)(including chloroform,bromodichloromethane,chlorodibromomethane,and bromoform)from chlorination were investigated using aqueous humic acid(HA)solutions.The profile of the chloramine decay was also studied under various bromide ion concentrations.Monochloramine decayed in the presence of organic material and bromide ions.The percentage of chloroform and brominated THMs varied according to the TOC/Br-ratio.Total THMs(TTHMs)formation increased from 112 to 190 μg/L with the increase concentrations of bromide ions from 0.67 to 6.72 mg/L,but the chlorine-substituted THMs were replaced by bromine-substituted THMs.A strong linear correlation was obtained between the monochloramine dose and the formation of THMs for Cl:N ratios of 3:1 and 5:1.These ratios had a distinct effect on the formation of chloroform but had little impact on the formation of bromodichloromethane or chlorodibromomethane.The presence of bromide ions increased the rate of monochloramine decay. 相似文献
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详细探讨了在碱催化下,采用环氧丙烷对罗望子多糖的羟丙基化改性工艺条件,并利用核磁共振氢谱和红外光谱对结构进行确认,结果表明：改性后的罗望子多糖胶粘度大幅下降,且具有良好的室温水溶解性。 相似文献
20.
The effects of the concentration of dissolved total organic carbon (TOC), the TOC/Br- ratio, bromide ion levels, the chlorine to ammonia-N ratio (Cl:N), the monochloramine dose and the chlorine dose on the formation of trihalomethanes (THMs) (including chloroform, bromodichloromethane, chlorodibromomethane, and bromoform) from chlorination were investigated using aqueous humic acid (HA) solutions. The profile of the chloramine decay was also studied under various bromide ion concentrations. Monochloramine decayed in the presence of organic material and bromide ions. The percentage of chloroform and brominated THMs varied according to the TOC/Br- ratio. Total THMs (TTHMs) formation increased from 112 to 190 μg/L with the increase concentrations of bromide ions from 0.67 to 6.72 mg/L, but the chlorine-substituted THMs were replaced by bromine-substituted THMs. A strong linear correlation was obtained between the monochloramine dose and the formation of THMs for Cl:N ratios of 3:1 and 5:1. These ratios had a distinct effect on the formation of chloroform but had little impact on the formation of bromodichloromethane or chlorodibromomethane. The presence of bromide ions increased the rate of monochloramine decay. 相似文献