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排序方式: 共有393条查询结果,搜索用时 140 毫秒
31.
低钠盐及其化验研究   总被引:1,自引:0,他引:1  
介绍了低钠盐对人体的作用,对低钠盐的定性和定量分析方法进行了研究,包括:低钠盐中镁离子和钾离子的鉴定,用EDTA滴定法测定低钠盐中镁含量和用间接滴定法测定低钠盐中钾含量。  相似文献   
32.
本文用胶子结构函数的遮蔽效应和末态作用分析了在p-A碰撞中粲偶素和b夸克偶素产额压低的实验数据,较好地描述了粲偶素和b夸克偶素产额的压低与A和X2的关系.  相似文献   
33.
许秀芳 《大学化学》2017,32(2):23-28
将"讲一练二考三"的新型教学理念应用于大学化学的教学是一种有意义的尝试。本文结合计算化学课程的特点和本人的教学实践,从课程建设思路、教学内容、教学方式、练习方式和考试方式等几个方面阐述了采用"讲一练二考三"模式建设面向实际应用的计算化学课程的一些经验和方法,探讨了计算化学课程授课内容和教学方法的改革。  相似文献   
34.
Crespo  L. G.  Sun  J. Q. 《Nonlinear dynamics》2003,31(2):119-131
A cell mapping strategy based on Bellman'sPrinciple of optimality (BP) is proposed to solve the fixed final time optimalcontrol of strongly nonlinear systems with state and control bounds. Thefixed final time problem is transformed into a fixed final time-fixed finalstate optimal control problem by reversing the time. This transformationallows to solve the problem in the framework of the BP. Backward searchingalgorithms within the cell mapping context are used to obtain the solution ofthe new problem. This approach reduces considerably the computational effortrequired for the original problem when it is solved by a forward searchingapproach. The vibration control problem of damped and undamped variablestiffness oscillators with bounded stiffness tuning range is studied todemonstrate the effectiveness of the approach. A numerical study on theconvergence of the method is also presented.  相似文献   
35.
In this paper, we deal with the backward problem of determining initial condition for Rayleigh‐Stokes where the data are given at a fixed time. The problem has many applications in some non‐Newtonian fluids. We give some regularity properties of the solution to backward problem.  相似文献   
36.
The Parkinson larynx: Tremor and videostroboscopic findings   总被引:3,自引:0,他引:3  
Patients with Parkinson's disease have a high incidence of speech, voice, and laryngeal abnormalities. To characterize laryngeal abnormalities, visual-perceptual ratings of endoscopic and stroboscopic examinations of 22 patients diagnosed with idiopathic Parkinson's disease and 7 patients with Parkinson's-plus syndromes were carried out by four trained viewers. Incidence of tremor, tremor location, phase closure, phase symmetry, amplitude, and mucosal waveform were scored. Tremor was observed in one or more of these conditions—rest, normal pitch and loudness, or loud phonation—for most of the 29 patients. Fifty-five percent of the idiopathic Parkinson's disease patients had tremor, with the primary location being vertical laryngeal tremor. Sixty-four percent of the Parkinson's-plus patients had tremor, with the arytenoid cartilages being the primary location. Laryngeal tremor was observed early in the disease in these Parkinson's disease patients. The most striking stroboscopic findings for the idiopathic Parkinson's disease patients were abnormal phase closure and phase asymmetry. Amplitude and mucosal wave-form were essentially within normal limits in the majority of the idiopathic Parkinson patients.  相似文献   
37.
We study the inverse problem of finding the coefficient of thermal conductivity of the heat equation (along with the solution). As the overdetermination condition we take the values of the solution at the final time. Existence of a regular solution is proven.  相似文献   
38.
U N L Mathur  Y R Waghmare 《Pramana》1984,22(3-4):257-274
Matrix element of the Galilean invariant non-relativistic reduction of the pseudoscalar-pseudovector interaction has been calculated assuming the reaction to be a direct process with boundπ being absorbed by a correlated pair of nucleons. The Hartree-Fock wavefunctions obtained with the unitary-model-operator approach starting with the realistic nucleon-nucleon interaction have been used forπ-capturing nucleon pair in the initial state. The calculations have been done with and without antisymmetrising the initial state wavefunction of the pion absorbing pair. For the final state nucleon-nucleon interaction has been taken into account. The strongπ-nucleus interaction together with the Coulomb interaction with the finite nuclear size on the bound pion wavefunction are taken into account. Angular distributions of the emitted nucleon-pair, the branching ratios and the total absorption rates are calculated for16O with and without antisymmetrisation effect. The calculated results are compared with the experimental and other theoretical work.  相似文献   
39.
The flexible fiberoptic laryngoscope is a valuable tool in the examination of laryngeal and supraglottic structure and function. Nevertheless, persistent questions remain about the validity of the perceived image, and a variety of concerns arise relative to the equipment used, the difficult to examine patient, and the difficulty in obtaining measurable objective data. All of these areas are discussed. Distortions of the video image that result from the wideangle lens effect are described. Given an awareness of the distortions that may be present in the fiberoptic video image, it is clear that it is necessary to exercise caution in making judgments of anatomic or physiologic integrity based on fiberoptic information alone.  相似文献   
40.
The η meson can be bound to atomic nuclei.Experimental search is discussed in the form of final state interaction for the reactions dp → 3 Heη and dd → 4 Heη.For the latter case tensor polarized deuterons were used in order to extract the s-wave strength.For both reactions complex scattering lengths are deduced: a 3 Heη = ± 10.7±0.8 +0.1 -0.5 +i· 1.5±2.6 +1.0-0.9 fm and a 4 Heη = [±(3.1±0.5)+i·(0±0.5)] fm.In a two-nucleon transfer reaction under quasi-free conditions,p 27 Al → 3 HeX,was investigated.The system X can be the bound 25 Mg  η at rest.When a possible decay of an intermediate N  (1535) is required,a highly significant bump shows up in the missing mass spectrum.The data give for a bound state a binding energy of 13.3±1.6 MeV and a width of σ=4.4±1.3 MeV.  相似文献   
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