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81.
Roland Gemperlein 《Mikrochimica acta》1988,94(1-6):353-356
A continuously scanning Michelson interferometer was developed to modulate an intensive light source spectrally. The interferogram is used as a stimulus to investigate spectral sensitivities in insects and man. The FIS-method is fast and precise and shows many advantages which are partly based on the advantages of Fourier spectroscopy. The existing applications are summarized. 相似文献
82.
原子转移自由基聚合原位合成温敏性微球 总被引:1,自引:0,他引:1
以过硫酸钾为引发剂、丙酮-水[V(丙酮)∶V(水)=4∶6]的混合溶剂为反应介质, 在少量二乙烯苯存在的条件下使苯乙烯(St)和对氯甲基苯乙烯(CMSt)进行无皂乳液共聚反应, 得到了粒径大小均匀的交联型聚苯乙烯(PSt)微球, 由X射线光电子能谱对表面组分测定发现: CMSt上的氯原子在聚合过程中富集于交联微球的表面. 以此交联型PSt微球为原子转移自由基聚合(ATRP)的引发剂, 在22 ℃下引发N-异丙基丙烯酰胺(NIPAAm)进行原位ATRP反应, 得到了表面原子转移自由基聚合接枝的交联聚苯乙烯(PNIPAAm-g-PSt)温敏性微球. 借助傅立叶变换红外光谱、差示扫描量热仪、扫描电子显微镜及激光光散射仪等对PNIPAAm-g-PSt的结构、相转变温度、形态及不同温度下的粒径变化进行了测定, 结果表明NIPAAm单体成功地原位ATRP接枝在交联PSt微球的表面, 接枝微球的球形更规整, 在水中的相转变温度约为32 ℃, 具有明显的温度敏感性. 相似文献
83.
本文以细支纱摩擦纺为研究对象,利用实验测试手段研究了尘笼胆结构对吸口轴向负压和尘笼胆安装角α对加捻区轴向负压和流速分布的影响。最后,基于类似于控制论中的“黑箱”原理,采用二次正交回归设计在实验室自制单头机上进行了32支纱的纺纱试验,建立了加捻辊加稔效率、纱线品质指标及CV值与尘笼胆几何尺寸、尘笼胆安装角α、摩擦辊转速及纺纱速度间的关系,并作了分析,由此得到选取α=0°、S=6毫米左右较好的结果。 相似文献
84.
Takayasu Yamauchi Hiroyuki Sazanami Yuuichi Sasaki Kimio Higashiyama 《Tetrahedron》2005,61(7):1731-1736
1,3-Oxazolidines were easily obtained by condensation of N-substituted (R)-phenylglycinol with aldehydes. Addition of organolithium reagents to 1,3-oxazolidines by complexation with the bulky Lewis acid aluminum tris(2,6-diphenylphenoxide) (ATPH) readily produced the corresponding chiral amines with good yield and high diastereoselectivity. The configuration of the new stereogenic center was shown to be opposite to that of adducts obtained for the same 1,3-oxazolidines using Grignard reagents. The best diastereoselectivity was achieved using N-isopropyl-1,3-oxazolidines. The mechanism of addition was deduced by determining the stereochemistry of the iminium-aluminum complex by NOE experiments. 相似文献
85.
A series of calixcrown ethers for which the cavity size of the crown ring is varied from crown-6 to crown-7 to crown-8 were examined for the transport abilities toward alkali metal ions. These ligands were incorporated into supported liquid membranes (SLMs) and into polymer inclusion membranes (PIMs) composed of cellulose triacetate (CTA) as a support and 2-nitrophenyl octyl ether (NPOE) and tris(2-butoxyethyl) phosphate (TBEP) as a plasticizer. In both membrane systems, calixcrown-6 showed the best selectivity toward a cesium ion over other alkali metal ions. The polymeric CTA membrane showed more rapid transport rate as well as higher durability than did the SLMs. 相似文献
86.
We present a unified approach for linear and nonlinear sensitivity analysis for models of reaction kinetics that are stated in terms of systems of ordinary differential equations (ODEs). The approach is based on the reformulation of the ODE problem as a density transport problem described by a Fokker-Planck equation. The resulting multidimensional partial differential equation is herein solved by extending the TRAIL algorithm originally introduced by Horenko and Weiser in the context of molecular dynamics (J. Comp. Chem. 2003, 24, 1921) and discussed it in comparison with Monte Carlo techniques. The extended TRAIL approach is fully adaptive and easily allows to study the influence of nonlinear dynamical effects. We illustrate the scheme in application to an enzyme-substrate model problem for sensitivity analysis w.r.t. to initial concentrations and parameter values. 相似文献
87.
88.
为研究老年人彩色视觉频率响应特性,获取彩度对比敏感度与空间频率之间的函数关系,本文在LCH均匀颜色空间基础上,固定明度和色调角值,以彩度作为变量,设计人眼彩度对比敏感度实验,进行人眼视觉观察实验。获得彩度对比敏感度与空间频率的关系,并构建指数型对比敏感度函数模型。经分析表明老年人眼彩度对比敏感度随着空间频率的增加,产生先升高再缓慢降低的变化,各色调角下彩度对比度存在差异。经分析人眼对比敏感度差异与人眼视觉辨色特性有很大的相关性。并且,将构建的对比敏感度函数模型用于实现基于人眼视觉系统的滤波处理。 相似文献
89.
E. Robens 《Journal of Thermal Analysis and Calorimetry》1996,47(2):619-622
A survey is given on important standardized definitions by which the capability of balances may be characterized. Some modifications are proposed with regard to the use of mass sensors for the continuous determination of mass variations. An important supplement is the relative resolution introduced by Jenemann. Optimum values are presented.I am indepted to H. R. Jenemann for his critical remarks. 相似文献
90.
Ming Guo Jue Wang Man Xiong Ronghui Wu Xuejuan Yang Jianzhong Zhou Minghui Li Jiajun Li 《大学化学》1986,35(12):237-246
In order to improve university laboratory teaching and practical education under the background of information technology, as well as overcome the difficulty for practical training, develop a virtual simulation experiment platform for rapid pyrolysis of natal materials and high-performance liquid chromatographic (HPLC) detection of its components. The experiment integrates the actual operation process of the plant to produce cleaved products by rapid pyrolysis of biomass with HPLC detection. The virtual experiment is divided into biomass sample pretreatment, rapid biomass pyrolysis, bio-oil extraction, and HPLC determination of complex components, making the biomass cleavage workshop "real" through simulation. This virtual simulation experiment fully integrates the utilization of biomass resources and basic chemistry courses (such as organic chemistry, instrumental analysis, chemical engineering principles, etc.), which are widely involved in agricultural and forestry majors with advantageous characteristics value. 相似文献