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991.
992.
一元线性回归试验数据的优化 总被引:1,自引:1,他引:0
运用统计学处理平行试验数据中可疑值的原理,建立了一元线性回归试验数据的优化方法。其中Grubbs法适用于精密度要求较低的试验,4d法则适用于精密度要求较高的试验和确定两变量的线性范围。 相似文献
993.
994.
A novel reactive polyorganosiloxane containing nitro groups was first prepared by acid-catalyzed equilibration polymerization. The monomer, 3-(4-nitrophenoxy)propylmethyldichlorosilane (NPPMS), was synthesized by hydrosilylation reaction with dicyclopentadienylplatinum(II) chloride (Cp2PtC12) catalyst in high yield. The synthesized polynitroorganosiloxane, which has potential application as a precursor for synthesizing advanced functional polymers, was characterized by FTIR, 1H-NMR, 13C-NMR, 29Si-NMR, vapor pressure osmometry (VPO) and gel permeation chromatography (GPC). 相似文献
995.
对于带约束条件和多余参数的两个线性模型e1=L(X1β+Z1γ,V1,L1)和d2=L(X2β+Z2δ,V2,L2),其中V1和V2是已知对称的正定矩阵,γ和δ是多余参数,L1和L2是已知的约束矩阵,文中给出了一种新的比较准则,并得到了几个充要条件。 相似文献
996.
Peptide dendrimers are attractive synthetic polymers and have been widely used as a new generation of biomaterials in recent years. Peptide dendrimers, as well as general dendrimers, may be synthesized to reach nano sizes, and display well-defined architectures, highly-branched structures, high density of functional terminal groups, and controllable molecular weights. On the other hand, peptide dendrimers have properties similar to proteins and some special characteristics, such as good biocompatibility, water solubility and resistance to proteolytic digestion. Due to these advantages, peptide dendrimers have received considerable attention in biomedicine. This review focuses on the development of peptide dendrimers with emphasis on their applications both in diagnostics and in therapy. 相似文献
997.
Shape reconstruction of an inverse boundary value problem of two‐dimensional Navier–Stokes equations
This paper is concerned with the problem of the shape reconstruction of two‐dimensional flows governed by the Navier–Stokes equations. Our objective is to derive a regularized Gauss–Newton method using the corresponding operator equation in which the unknown is the geometric domain. The theoretical foundation for the Gauss–Newton method is given by establishing the differentiability of the initial boundary value problem with respect to the boundary curve in the sense of a domain derivative. The numerical examples show that our theory is useful for practical purpose and the proposed algorithm is feasible. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
998.
Li‐Ying Li Wei‐Dong He Wen‐Tao Li Ke‐Ren Zhang Ting‐Ting Pan Zong‐Lei Ding Bo‐Yu Zhang 《Journal of polymer science. Part A, Polymer chemistry》2010,48(22):5018-5029
Well‐defined H‐shaped pentablock copolymers composed of poly(N‐isopropylacrylamide) (PNIPAM), poly(N,N‐dimethylaminoethylacrylamide) (PDMAEMA), and poly(ethylene glycol) (PEG) with the chain architecture of (A/B)‐b‐C‐b‐(A/B) were synthesized by the combination of single‐electron‐transfer living radical polymerization, atom‐transfer radical polymerization, and click chemistry. Single‐electron‐transfer living radical polymerization of NIPAM using α,ω azide‐capped PEG macroinitiator resulted in PNIPAM‐b‐PEG‐b‐PNIPAM with azide groups at the block joints. Atom‐transfer radical polymerization of DMAEMA initiated by propargyl 2‐chloropropionate gave out α‐capped alkyne‐PDMAEMA. The H‐shaped copolymers were finally obtained by the click reaction between PNIPAM‐b‐PEG‐b‐PNIPAM and alkyne‐PDMAEMA. These copolymers were used to prepare stable colloidal gold nanoparticles (GNPs) in aqueous solution without any external reducing agent. The formation of GNPs was affected by the length of PDMAEMA block, the feed ratio of the copolymer to HAuCl4, and the pH value. The surface plasmon absorbance of these obtained GNPs also exhibited pH and thermal dependence because of the existence of PNIAPM and PDAMEMA blocks. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010 相似文献
999.
A sub-micron hydrophilic microchannel was fabricated on poly(dimethylsiloxane) (PDMS) in one step using vacuum ultraviolet light (VUV) lithography in vacuum. The topographies and properties of the irradiated PDMS surface were characterized and analyzed by atomic force microscopy (AFM), and the chemical composition changes on VUV-treated PDMS analyzed by X-ray photoelectron spectroscopy (XPS). The hydrophilic stability of irradiated PDMS surface was studied by static water contact angle. As demonstrated, the hydrophilicity on surface of PDMS microchannel can be kept for a longer term even three months after the treatment. 相似文献
1000.
Guo-min He 《Surface science》2009,603(13):2021-18
We have systematically investigated the adsorption of Si on the Ag(0 0 1) surface employing density-functional theory. Various adsorption geometries have been considered for Si coverages up to 2.0 monolayers. Our results show that the behaviors of Si at the early stages of growth on the Ag(0 0 1) surface are governed by a competition between the Si-Si and Si-Ag interactions. From the calculated results, we presented alternative models for the observed 3 × 3 and 4 × 7 structures. Our results provide a reasonable explanation for the experimental findings in a previous work. 相似文献