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61.
A novel microfluidic droplet generator is proposed, which can control the droplet size through turning an integrated micrometer head with ease, and the size of the produced micro-droplet can be automatically and real-time monitored by an open-sourced software and off-the-shelf hardware. 相似文献
62.
We develop conditions on a Sobolev function \(\psi \in W^{m,p}({\mathbb{R}}^d)\) such that if \(\widehat{\psi}(0) = 1\) and ψ satisfies the Strang–Fix conditions to order m ? 1, then a scale averaged approximation formula holds for all \(f \in W^{m,p}({\mathbb{R}}^d)\) :The dilations { a j } are lacunary, for example a j = 2 j , and the coefficients c j,k are explicit local averages of f, or even pointwise sampled values, when f has some smoothness. For convergence just in \({W^{m - 1,p}({\mathbb{R}}^d)}\) the scale averaging is unnecessary and one has the simpler formula \(f(x) = \lim_{j \to \infty} \sum_{k \in {\mathbb{Z}}^d} c_{j,k}\psi(a_j x - k)\) . The Strang–Fix rates of approximation are recovered. As a corollary of the scale averaged formula, we deduce new density or “spanning” criteria for the small scale affine system \(\{\psi(a_j x - k) : j > 0, k \in {\mathbb{Z}}^d \}\) in \(W^{m,p}({\mathbb{R}}^d)\) . We also span Sobolev space by derivatives and differences of affine systems, and we raise an open problem: does the Gaussian affine system span Sobolev space?
相似文献
$ f(x) = \lim_{J \to \infty} \frac{1}{J} \sum_{j=1}^{J} \sum_{k \in {{\mathbb{Z}}}^d} c_{j,k}\psi(a_j x - k) \quad {\rm in} W^{m, p}({{\mathbb{R}}}^d).$
63.
Stoffelbach F Griffete N Bui C Charleux B 《Chemical communications (Cambridge, England)》2008,(39):4807-4809
This communication describes the first example of the efficient use of a simple amphiphilic molecule as both a surfactant and an initiator in the miniemulsion polymerization of methyl methacrylate under AGET and ARGET ATRP conditions. 相似文献
64.
电感耦合等离子体-发射光谱法(ICP-AES)快速测定饮用水中8种微量元素 总被引:4,自引:0,他引:4
用电感耦合等离子体-发射光谱法(ICP-AES)同时快速测定饮用水中微量的铜、铅、锌、铁、锰、镉、铬、砷,具有快速、简便、灵敏度高等优点,精密度为1.2%~8.2%(RSD,n=5).回收率为90%~110%. 相似文献
65.
66.
The potential ability of atomic force microscopy (AFM) as a quantitative bioanalysis tool is demonstrated by using gold nanoparticles
as a size enhancer in a DNA hybridization reaction. Two sets of probe DNA were functionalized on gold nanoparticles and sandwich
hybridization occurred between two probe DNAs and target DNA, resulting in aggregation of the nanoparticles. At high concentrations
of target DNA in the range from 100 nM to 10 μM, the aggregation of gold nanoparticles was determined by monitoring the color
change with UV-vis spectroscopy. The absorption spectra broadened after the exposure of DNA–gold nanoparticles to target DNA
and a new absorption band at wavelengths >600 nm was observed. However, no differences were observed in the absorption spectra
of the gold nanoparticles at low concentrations of target DNA (10 pM to 10 nM) due to insufficient aggregation. AFM was used
as a biosensing tool over this range of target DNA concentrations in order to monitor the aggregation of gold nanoparticles
and to quantify the concentration of target DNA. Based on the AFM images, we successfully evaluated particle number and size
at low concentrations of target DNA. The calibration curve obtained when mean particle aggregate diameter was plotted against
concentration of target DNA showed good linearity over the range 10 pM to 10 nM, the working range for quantitative target
DNA analysis. This AFM-based DNA detection technique was three orders of magnitude more sensitive than a DNA detection method
based on UV-vis spectroscopy. 相似文献
67.
Sung Jae Na Nhat-Nguyen Bui Hye-Young Jang 《Journal of organometallic chemistry》2007,692(24):5523-5527
A new dirhodium tetraacetate II involving 1,3-bis(2,6-diisopropylphenyl)-imidazol-2-ylidene I was synthesized and characterized by general spectroscopic tools in the solution state as well as single X-ray crystallographic analysis in the solid state. The catalytic activity of dirhodium tetraacetate carbenoid II was tested for the allylic oxidation, and the improved reactivity to the allylic oxidation was observed compared to that of Rh2(OAc)4. The different electrochemical properties of dirhodium tetraacetate carbenoid II and Rh2(OAc)4 were compared via cyclic voltammetry. 相似文献
68.
乙酸铵离心交换法测定酸性和中性土壤阳离子交换量是经典方法,但此方法的蒸馏过程繁琐、时间长、效率低。本文引用纳氏试剂分光光度法测定土壤CEC值,并将结果与乙酸铵离心法常用的几种传统测定方法进行了实验对比和总结。通过对国家标准样品及实际土壤样品的CEC值测定,纳氏试剂比色法的精密度在2-4%之间,准确度与经典方法一致。与传统滴定法比较,取代了蒸馏的步骤,测定方法简单,干扰少,结果可靠,可操作性强。 相似文献
69.
70.
Bui Thi Giang Nguyen Van Mau Nguyen Minh Tuan 《Integral Equations and Operator Theory》2009,65(3):363-386
In this paper we present the operational properties of two integral transforms of Fourier type, provide the formulation of
convolutions, and obtain eight new convolutions for those transforms. Moreover, we consider applications such as the construction
of normed ring structures on
L1(\mathbbR)L_{1}({\mathbb{R}}), further applications to linear partial differential equations and an integral equation with a mixed Toeplitz-Hankel kernel. 相似文献