Alternatives to standard hemodialysis

Survival of patients on hemodialysis remains poor, but the benefits of increasing urea clearance have probably been maximized within our current treatment schedules. Long dialysis sessions (8 hr) produce impressive outcomes, with mortality 53% to 55% lower than conventional schedules. Even increasing from 4 to 5 hr may improve survival. Increased frequency of dialysis (6 times weekly) produces impressive reductions in left ventricular mass and could conceivably be implemented in‐center. Preliminary data suggest a 61% reduction in mortality with increased frequency. Nightly dialysis combines longer sessions with increased frequency and has produced remarkable clinical gains in blood pressure, left ventricular mass, serum phosphate, and sleep apnea. However, the data are mainly from case series and impact on mortality remains unknown. Expansion of home hemodialysis would be necessary for this modality to grow. Convective therapies remove middle molecules more effectively, and observational data suggest hemodiafiltration has the potential to improve mortality by 35% to 36%. Hemodiafiltration has the advantage of being relatively easy to implement. The uremic milieu is complex and further investigation of the underlying pathophysiology is needed to inform future dialysis interventions. The survival data above are from observational studies, and hence benefits are likely to be exaggerated. Randomized trials of dialysis interventions are desperately needed. They remain difficult to perform, because of the complexity of both the patient population and the interventions, and because of limited available funding.     

新经济增长理论对我国人力资本发展的借鉴

新经济增长理论为人力资本理论注入了新的内容,为各国如何利用人力资本发展经济提供了理论指导。分析了新经济增长理论中有关人力资本的理论,以此对我国经济和人力资本的发展提出了一些借鉴;收益递增模型。     

数字移动电视的现状与发展前景

随着数字电视的普及推广,数字移动电视应运而生,并得到迅速发展。数字移动电视通常安装在交通工具上,兼具移动性和数字化的特点。它突破了传统电视固定收视的局限,带来了电视传播的新概念。同时,数字移动电视根据自身传播特性,不断探索新的运营模式,并带来一系列的产业链效应,蕴含着无限商机     

试论安定性不合格消石灰对柔性路面质量的影响

由于过烧石灰的存在和消解不当等原因，造成消石灰安定性不合格，当石灰稳定类路面结构成型或投入使用后，消石灰中的生石灰颗粒开始吸收周围水分，慢慢消解，消解过程中发生体积膨胀，对路面产生破坏。解决石灰安定性问题对防止公路前修后坏，延长路面使用寿命具有积极的现实意义。     

道路与匝道中线自动绘制的算法与实现

道路与立交匝道平面中线的计算机自动绘制是道路路线CAD软件的核心功能之一,在道路工程计算机动态交互式设计、计算机辅助成图方面具有基础性作用.依据道路中线线形的曲率变化特点,推导了道路中线坐标计算的通用数学模型,并根据一个工程实例在通用图形系统AutoCAD环境下实现了道路与匝道中线的自动绘制.     

Granular gases in mechanical engineering: on the origin of heterogeneous ultrasonic shot peening

The behavior of an ultrasonic shot peening process is observed and analyzed by using a model of inelastic hard spheres in a gravitational field that are fluidized by a vibrating bottom wall (sonotrode) in a cylindrical chamber. A marked heterogeneous distribution of impacts appears when the collision between the shot and the side wall becomes inelastic with constant dissipation. This effect is one order of magnitude larger than the simple heterogeneity arising from boundary collision on the cylinder. Variable restitution coefficients bring the simulation closer to the general observation and allow the investigation of peening regimes with changing shot density. We compute within this model other physical quantities (impact velocities, impact angle, temperature and density profile) that are influenced by the number N of spheres.     

SECANT-FUZZY LINEAR REGRESSION METHOD FOR HARMONIC COMPONENTS ESTIMATION IN A POWER SYSTEM

In order to avoid unnecessary damage of electrical equipments and installations,high quality power should be delivered to the end user and strict control on frequency should be made, Therefore, it is important to estimate the power system's harmonic components with higher accuracy. This paper presents a new approach for estimating harmonic component in a power system using secant - fuzzy linear regression method. In this approach the non - sinusoidal voltage or current waveform is written as I linear function. The coefficient of this function is assumed to be fuzzy number with a membership function that has center and spread value. The time dependent quantity is written as Taylor series with two different time dependent quantities. The objective is to use the sample obtained from the transmission line to find the power system harmonic components and frequencies. We used an experimental voltage signal from a sub power station as a numerical test.     

磨料高压水除鳞系统设计研究

磨料高压水除鳞系统取代酸洗线，原机械部分和磨料高压水部分都作了较大改进，才能保证除鳞彻底。     

铜密闭鼓风炉生产效益的回归分析

通过铜密闭鼓风炉生产过程中关键指标的回归分析,寻找降低消耗、增加产出、提高经济效益的有效途径     

不同氧化剂对Cu2S、Ni3S2矿浮选行为的影响

为了详细研究Cu2S、Ni2S2矿在氧化气氛中的浮选行为，分别就高锰酸钾、重铬酸钾作氧化剂时，对Ni3S2矿和Cu2S矿浮选行为的影响进行了研究，从而找出其变化规律。