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61.
In this paper, we study some modified linear restriction estimates of the dynamics generated by Schrödinger operator on metric cone M, where the metric cone M is of the form M = (0, ∞) r  × Σ, with the cross section Σ being a compact (n ? 1)-dimensional Riemannian manifold (Σ, h) and the equipped metric being g = dr 2 + r 2 h. Assuming the initial data possesses additional regularity in angular variable θ ∈ Σ, we show some linear restriction estimates for the solutions. In terms of their applications, we obtain global-in-time Strichartz estimates for radial initial data and show small initial data scattering theory for the mass-critical nonlinear Schrödinger equation on two-dimensional metric cones.  相似文献   
62.
We generalize the notion of involutivity to systems of differential equations of different orders and show that the classical results relating involutivity, restrictions, characteristics and characteristicity, known for first order systems, extend to the general context. This involves, in particular, a new definition of strong characteristicity. The proof exploits a spectral sequence relating Spencer δ-cohomology of a symbolic system and its restriction to a non-characteristic subspace.   相似文献   
63.
A non-chiral, rigid 7-azabicyclo[2.2.1]heptane-1,4-dicarboxylic acid, an analogue of 2-aminoadipic acid, has been synthesized in six steps from dimethyl-meso-2,5-dibromohexanedioate in 28% total yield. A key step in the synthesis is double alkylation of a dimethyl pyrrolidine-2,5-dicarboxylate by 1-bromo-2-chloroethane.  相似文献   
64.
王荣  贾正平  阮金秀  谢华  陈巧云  贾海  张强  徐娟  敖燕 《分析化学》2007,35(8):1137-1141
采用线性聚丙烯酰胺修饰石英毛细管的高效毛细管电泳无胶筛分技术,对原核/真核质粒用不同限制性内切酶酶切,运用限制性内切酶指纹-高效毛细管电泳激光诱导荧光(REF-HPCE-LIF)检测法同时对内切酶酶切后多个和较长DNA片段进行了检测,电泳缓冲液为1×TBE(pH8.3),阴极电压进样(10kV,5s),分离电压13kV,25℃,激光诱导荧光检测器检测(λex=520nm)。结果表明,所建立的REF-HPCE-LIF方法可对原核/真核酶切后多个和较长DNA片段进行检测,获得了满意的限制性内切酶指纹图谱,能够检测片段大小相差不超过10bp。所建立的方法较琼脂糖电泳分辨率高,可应用在检测多个和较长DNA片段的突变,在诊断肿瘤方面有一定应用前景。  相似文献   
65.
从Bacillussphaericus78菌中将Bsp78I纯化到均一程度.测得该酶对pBR322DNA的Km值为2.67×10-8mol·L-1.用对氯汞苯甲酸、磷酸吡哆醛、2,3一丁二酮修饰该酶巯基、赖氨酸、精氨酸残基,结果表明这些基团均与该酶活性有关.  相似文献   
66.
采用固相亚磷酸三酯法和化学与酶促相结合的方法合成了9个PstI接头片段,并对它们进行了酶切反应研究.结果表明:PstI识别序列中尿苷的存在只降低其互补链的切割程度,对其本链没有影响;PstI切割底物是按两步单股切割机制进行,作用的最小底物是含有识别序列的8~12聚脱氧核糖核苷酸,且对底物中识别序列两边的碱基对数目有一定要求;PstI识别序列中的二个胞苷在酶反应中起的作用是不一样的  相似文献   
67.
The influence of the volume restriction effect on phase separation in colloidal dispersions consisting of a nonadsorbing polymer has been studied using statistical mechanical cell models and perturbation theories in combination with Monte Carlo experiments. The attractive interparticle potential proposed by Asakura and Oosawa is used to represent the effect of polymer depletion between the particles. The equilibrium properties are determined using the cell model for the solid-like phase (with Monte Carlo simulations for the structure of the solid phase) and a perturbation theory for the liquid-like phase. Both aqueous and nonaqueous dispersions are considered, and the phase separation behavior predicted is compared with available experimental and theoretical results.  相似文献   
68.
This work was aimed at identifying nucleotide polymorphic sites in a 359 bp region of the cytochrome b (cytb) mitochondrial gene of Iberian cattle (Bos taurus). This region is widely used as target in polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) species identification studies in foodstuffs destined for human and animal consumption. Two different coexisting restriction patterns were observed in four of the six animals studied when the 359 bp DNA fragment was cleaved with PalI, HinfI, MvaI, RsaI, or MboI. The amplification of both genotypes with the mitochondrial-specific primers L14735 and H15149 revealed the absence of nuclear pseudo-cytb genes, confirming the existence of mitochondrial heteroplasmy. The two coexisting mtDNA fragments were selectively sequenced in PCR extracts in which one genotype predominated over the other, both exhibiting a sequence variation of 10.4%. From the 37 nucleotide mismatches observed between genotypes, 32 were transitions and five were transversions. While 31 of the nucleotide mismatches between genotypes resulted to be conservative at the amino acid level, six changes implied amino acid substitutions, five of them being located in the variable transmembrane region. Genetic analysis suggests the presence of an Asian background in the mitochondria of Iberian cattle: while one of the genotypes matched the published sequence for Bos taurus, the other genotype clustered with a B. primigenius indicus animal and close to an Asian Bos taurus animal. These results also suggest that a number of current PCR-RFLP species identification methods based on cytb sequences may not be reliable for the accurate detection and identification of bovine material: an alternative battery of enzymes consisting of MmeI, NlaIV, and AluI is proposed.  相似文献   
69.
Our concern is with the problem of determining general reduced forms of constitutive equations of Cauchy elastic solids under all kinds of material symmetries, including well-known crystal classes and newly discovered quasicrystal classes. By means of Tschebysheff polynomials we present in unified forms simple irreducible representations for elastic constitutive equations under the infinitely many subgroup classes C 2m+1, C 2m+2, D 2m+1 and D 2m+2 for all m = 1, 2,... Moreover, we provide a simple representation for elastic constitutive equations under the most complicated point group, i.e. the icosahedral group. Each presented representation is expressed in terms of not more than nine polynomial tensor generators only. This revised version was published online in August 2006 with corrections to the Cover Date.  相似文献   
70.
For some general multivariate linear models, linear rank statistics are used in conjunction with Roy's Union-Intersection Principle to develop some tests for inference on the parameter (vector) when they are subject to certain linear constraints. More powerful tests are designed by incorporating the a priori information on these constraints. Profile analysis is an important application of this type of hypothesis testing problem; it consists of a set of hypothesis testing problem for the p responses q-sample model, where it is a priori assumed that the response-sample interactions are null.  相似文献   
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