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91.
VA Belitser TV Varetskaia SN Tsynkalovskaia LA Tsariuk LI Shevchenko 《Canadian Metallurgical Quarterly》1976,48(4):521-532
A new diagnostic method to determine fibrinogen and fibrin splitting products is based on the fact that high-molecular fragments acting as specific inhibitors of fibrin self-assembly compose these products. Fibrinogen and fibrin splitting products are detected and determined quantitatively by prolongation of coagulation time in the test with the standard monomeric fibrin. The number of units of anticoagulating activity in the studied urine are the results of the determinations. Sensitivity of the method if necessary may be increased by adding of a certain amount of the fibrinogen and fibrin splitting products to the test that makes a favourable background for the action of the products. The method is rather sensitive, reliable and simple. It may be used in ordinary clinical laboratories. The method proved to be quite satisfactory when testing renal diseases at the clinic. It is of great significance for early detection of the transplanted kidney rejection. The new method is compared with the known immunological method which consist in determination of the inhibitory effect of the fibrinogen and fibrin splitting products on agglutination of erythrocytes of specific antibodies; the erythrocytes being subjected to "tanning" and "loading" with fibrinogen. A satisfactory correlation is found between the results of two methods. 相似文献
92.
Stability analysis is of great significance in those feedback control systems in which the power amplifier is operated as a pulse-modulator device, since under these circumstances the whole control system is highly non-linear. Stability in PWM feedback control systems with a proportional type regulator has been amply described in the literature. Only recently, however, have such studies been extended to include systems with a proportional-plus-integral regulator. In this paper the problem is considered for the case involving a PWM control system, where the regulator is a proportional-plus-integral-plus-derivative, the PWM modulator is of a very general type and the controlled process is of arbitrary order. The stability of the system is analysed by means of a discrete version of the second Lyapunov method ; this method in turn leads to an investigation of the positivity region of a quadratic form defined in the parameter space of the regulator. To improve the stability region obtained, a procedure is investigated whereby only a few parameters of the quadratic Lyapunov function need to be varied. The method proposed has proved extremely simple and flexible to apply, even in cases where the system is of arbitrary order. 相似文献
93.
M. DE LA SEN 《控制论与系统》2013,44(2-3):125-150
Abstract A perturbation theory for evaluation algorithms of arithmetic expressions is applied to the generalized least-squares identification of the continuous parameters by using nonperiodic discrete data. The sampling instants are distributed in such a way that a sequence of the elemental arithmetic expressions of the identification algorithm are suboptimized according to bang-bang rules on the extrema of appropriate variation intervals. The weighting scalars in the generalized least-squares method are updated with the same purpose. 相似文献
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Progress towards a methodology for high throughput 3D reconstruction of soot nanoparticles via electron tomography
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The aim of this work is to make progress towards the development of 3D reconstruction as a legitimate alternative to traditional 2D characterization of soot. Time constraints are the greatest opposition to its implementation, as currently reconstruction of a single soot particle takes around 5–6 h to complete. As such, the accuracy and detail gains are currently insufficient to challenge 2D characterization of a representative sample (e.g. 200 particles). This work is a consideration of the optimization of the steps included within the computational reconstruction and manual segmentation of soot particles. Our optimal process reduced the time required by over 70% in comparison to a typical procedure, whilst producing models with no appreciable decrease in quality. 相似文献
97.
针对机器人关节柔性引起的轨迹跟踪误差问题和末端执行器残余振动现象,在PD反馈控制律基础上,提出一种基于柔体动力学模型的前馈力矩补偿控制算法和后置多模态自适应输入整形算法前馈力/位混合控制策略。建立六轴工业机器人柔体动力学简化模型,在不附加关节编码器和外设的情况下进行柔体动力学参数辨识,再将动力学模型改写为力矩计算方程,经计算得到前馈力矩并加入控制律中进行补偿;计算前馈力矩所用的期望轨迹需经过输入整形器处理,考虑机器人系统的时变性问题,采用后置多模态自适应输入整形算法对期望输入位移信号进行命令整形,从而抑制末端的残余振动现象。结果表明:所提出的前馈力/位混合控制策略能有效减少轨迹跟踪误差,抑制机器人末端的残余振动现象。 相似文献
98.
M. DE LA SEN 《International journal of control》2013,86(6):1769-1775
In this note, it is proved that stability of composite systems including parallel subsystems can be achieved for certain sets of initial conditions and additional stability assumptions for the non-hyperstable subsystems. It is required that at least one subsystem be asymptotically hyperstable. 相似文献
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100.
HI McFarland AA Lobito MM Johnson JT Nyswaner JA Frank GR Palardy N Tresser CP Genain JP Mueller LA Matis MJ Lenardo 《Canadian Metallurgical Quarterly》1999,162(4):2384-2390
Definition of the immune process that causes demyelination in multiple sclerosis is essential to determine the feasibility of Ag-directed immunotherapy. Using the nonhuman primate, Callithrix jacchus jacchus (common marmoset), we show that immunization with myelin basic protein and proteolipid protein determinants results in clinical disease with significant demyelination. Demyelination was associated with spreading to myelin oligodendrocyte glycoprotein (MOG) determinants that generated anti-MOG serum Abs and Ig deposition in central nervous system white matter lesions. These data associate intermolecular "determinant spreading" with clinical autoimmune disease in primates and raise important issues for the pathogenesis and treatment of multiple sclerosis. 相似文献