A Statistical Procedure for Testing Nuclear Powered Cardiac Pacemakers

This article presents the results of a study of the functional case of the problem of parameter estimation when there is error in all the variables. There is consequently no distinction between independent and dependent variables. Posterior probability density functions are developed for the parameters with both linear and nonlinear, and possibly multiple, relations among the true values of the variables. There is no distinction between models that are linear or nonlinear in the parameters. The results are equivalent to generalizations of the work of some previous authors, but lead to new and efficient algorithms for finding point estimates and their precisions. For most of the results the error covariance matrix is assumed known, though a case is treated where it is known except for a scalar multiplier. The results are also shown to be valid if the covariance matrix is singular. Geometric interpretations are described.     

我公司污染治理经验浅谈

介绍了我公司在石灰工序粉尘污染治理的基础上,通过以点带面不断推进公司清洁生产的实践,取得了显著的环境效益、经济效益和社会效益。     

Numerical Determination of Secondary Dendrite Arm Spacing for IN738LC Investment Castings

A numerical model was developed to estimate the solidification conditions and the secondary dendrite arm spacing of equiaxed solidified IN738LC investment castings. The model, composed of geometric data, thermophysical properties, and boundary conditions, was verified by a comparison of calculated and measured process temperatures obtained from casting experiments. The computation of the secondary dendrite arm spacing was carried out from temperature gradient G, solidification rate v, and an alloy-specific parameter M, determined by means of an inverse approach. The calculated secondary dendrite arm spacing was found to be in very good agreement with metallographic measurements.     

Extraocular fast myosin heavy chain expression in the levator palpebrae and retractor bulbi muscles

PURPOSE: To determine whether the levator palpebrae superioris (LPS) and the retractor bulbi (RB) muscles, which share contractile characteristics with extraocular muscles (EOMs), express fast EOM-specific myosin heavy chain (MyHC) in the rabbit and other mammalian species. METHODS: Cryostat sections of rabbit eye and limb muscles were stained by indirect peroxidase immunohistochemical procedures using monoclonal antibodies (MAbs), including one (4A6) against EOM-specific fast MyHC. Myosin heavy chain isoforms from these muscles were separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), and the 4A6-reactive component was identified by immunoblotting. RESULTS: MAb 4A6 stained muscle fibers in rabbit LPS and RB. SDS-PAGE resolved a rabbit EOM-specific MyHC isoform (band 1) from two other components (bands 2 and 3) that comigrated with limb fast MyHCs. MAb 4A6 reacted only with band 1. Rabbit LPS and RB also displayed corresponding MyHC components with the same mobilities and immunoreactivities as bands 1 to 3 in the EOM. MAb 4A6 also stained muscle fibers in monkey and cat LPS, but it failed to stain muscle fibers in cat RB and rat LPS and RB. CONCLUSIONS: The expression of EOM-specific fast MyHC in EOM, LPS, and RB reflect their common developmental origin and similar contractile characteristics. These properties set them apart from other skeletal muscle groups. Eye muscles may constitute a distinct muscle group or allotype characterized by unique properties, including their propensity or resistance to disease.     

在泡沫碳化硅载体上自转化合成silicalite-1型沸石晶体

以泡沫碳化硅载体内的残余硅为硅源,在泡沫碳化硅载体上自转化合成silicalite-1型沸石晶体.用残余硅含量为16.7%的泡沫碳化硅作为载体,町制备出负载均匀、耐热性好,抗热冲击、比表面积为36 m2g-1的silicalite-1型沸石晶体/泡沫碳化硅复合材料.研究了泡沫碳化硅载体的残余硅含量和水热合成溶液的组成等因素对沸石晶体的自转化合成及其形貌的影响.结果表明,泡沫碳化硅载体中的残余硅含量是影响沸石晶体层结晶的关键因素.当载体中硅的含量过低时,溶液中的硅酸根浓度过低,不具备形成沸石晶体的条件;而当载体中硅的含量过高时,溶液中的硅酸根浓度过高,沸石晶体优先在残余硅的表面形核,随着这些硅的溶解,在其上形成的沸石晶体也随之脱落.增加模板剂的含量可促进沸石晶体形核,从而使沸石晶体的尺寸变小.     

A 3-V 340-mW 14-b 75-Msample/s CMOS ADC with 85-dB SFDR at Nyquistinput

This paper describes the design of a 14-b 75-Msample/s pipeline analog-to-digital converter (ADC) implemented in a 0.35-μm double-poly triple-metal CMOS process. The ADC uses a 4-b first stage to relax capacitor-matching requirements, buffered bootstrapping to reduce signal-dependent charge injection, and a flip-around track-and-hold amplifier with wide common-mode compliance to reduce noise and power consumption. It achieves 14-b accuracy without calibration or dithering. Typical differential nonlinearity is 0.6 LSB, and integral nonlinearity is 2 LSB. The ADC also achieves 73-dB signal-to-noise ratio, and 85-dB spurious-free dynamic range over the first Nyquist band. The 7.8-mm² ADC operates with a 2.7- to 3.6-V supply, and dissipates 340 mW at 3 V