计算机数字摄影检测结果的分析及思考

计算机摄影(CR)和数字摄影(DR)作为临床医学最重要的检查手段之一,其辐射计量和影像性能成为检测部门工作的重点.采用多功能质量检测仪和CR、DR性能检测设备,分别对78台CR、DR进行检测,并对检测结果进行统计分析和反思,期望为下一步制定规程、规范和科研开发提供参考,也为医院购置高性价比设备起到借鉴作用.     

Status and prospects of metrological support for laser medicine and laser medical technology

This article examines trends and prospective developments in the metrological support of laser medicine and the design of laser-based medical instruments. The main characteristics of the measurement procedures being developed to calibrate, test, and certify laser medical equipment are presented. Translated from Izmeritel'naya Tekhnika, No. 9, pp. 41–46, September, 1998.     

CR/DR图像性能检测方法研究

医用数字摄影(CR/DR)系统的广泛应用,每一个环节都可能对影像质量产生影响,使得其照片或者图像的质量控制显得尤为重要。该文研究CR/DR图像性能相关的技术规范或标准,对检测方法和手段进行讨论,对医学计量检定或医院开展质控工作具有一定的积极作用。     

Status and prospects for the development of high-precision dilatometry

Translated from Izmeritel'naya Tekhnika, No. 6, pp. 26–27, June, 1989.     

Neutron-activation measuring instrumentation. Status and prospects

An analysis is made of the present state of development and production in Russia of standardized neutron-activation measuring instruments. The coordinated approach to such development is indicated and the parameters of manufactured products are given. The basis for developing the problem further is established. Translated from Izmeritel'naya Tekhnika, No. 1, pp. 48–52, January, 1996.     

Dust explosion modeling: Status and prospects

Accidental dust explosions pose a threat to people and property in industries that produce, process, handle or transport combustible dusts. Over the last century, the international research community has made significant progress towards better understanding of the dust explosion phenomenon. These efforts have contributed to the development of improved standards and best practice guidelines for safe design and operation of process facilities. Results obtained with advanced consequence models demonstrate the potential for applying such tools to the design and optimization of process facilities and equipment for explosion protection. It is foreseen that further development of numerical methods will include improved representation of particle-laden flows and combustion. It is essential that safety engineers acknowledge the inherent limitations and uncertainties associated with the collection of dust samples from industrial facilities, parameters determined in standardized tests, and the extrapolation of results from laboratory experiments to accidental explosion scenarios in industry. This paper reviews some of the practical aspects associated with risk assessments and risk management for dust explosions in the process industries, with emphasis on consequence modeling. The discussion outlines prospects for further development of test methods and simulation tools for industrial dust explosions, and provides recommendations for safety engineers and researchers.     

四象限探测器的信号光捕获与跟踪技术研究

针对空间激光通信系统小型化设计的需求,提出了使用四象限探测器实现捕获与跟踪的方案。通过分析四象限探测器上光斑的位置分布,推导了三种光斑分布的4QD捕获牵引模型,通过对4QD光斑位置的解算以及与跟踪机构的精准标定,实现了4QD的高精度跟踪。在实验室基于一台激光终端与系统测试平台,对四象限探测器的捕获与跟踪方案及性能进行了实验验证,测试结果表明,在实验室动态条件下,用4QD作为捕获及跟踪探测器,捕获概率高达100%,跟踪精度优于3μrad,验证了该方案的可行性,为激光终端小型化设计奠定了基础。     

惯性传感技术发展与展望

利用GPS辅助INS的系统已在各种应用领域崭露头角，这些新的应用领域将驱动市场对极低成本惯性传感器的大量需求。在回顾惯性传感技术的发展历程、研究热点、应用领域的基础上，讨论和展望了光纤陀螺仪、微机械陀螺仪和加速度计，以及微型光学传感器技术近期和远期的发展趋势。     

Thin-film technology and dc-SQUID instrumentation for a superheated superconducting detector

We report on improvements of the dc-SQUID instrumentation developed to study superheating-supercooling transitions of thin-film indium dots. In previous measurements on ordered arrays of dots with diameters larger than 100µm the flip signal of an individual dot in perpendicular magnetic field has been detected. In order to use these dots as superheated superconducting detectors it is necessary to reduce the dot diameter to lower the energy threshold and to avoid intermediate states. For these reasons, our effort has been to develop small and thick dots with diameter down to10 µm and thickness up to3.5 µm. At the same time the coupling with the dc-SQUID readout was improved using a thin-film niobium pickup coil integrated on the same chip containing the dots. Phase transitions of individual dots were observed. The superheating phase transition spread in temperature of the samples was about 0.15 %.     

Two-dimensional noble transition-metal dichalcogenides for nanophotonics and optoelectronics:Status and prospects

An emerging subclass of transition-metal dichalcogenides(TMDs),noble-transition-metal dichalcogenides(NMDs),has led to an increase in nanoscientific research in...     

Status of and prospects for the development of a transmission system for standard signals

The status of the upgraded system for transmission of frequency and time standard signals is described. The signals are transmitted by different means: the global satellite navigation system (GLONASS), ultralong, long, and short wave radio stations for special and other purposes, and the global internet. The areas in which this system is being developed are examined and its structure is described.     

我国微孔滤膜研究现状与发展

介绍了我国微孔滤膜的研发和当前应用的概况，简要分析了我国微孔滤膜的国内市场及其应用前景．     

Physical image quality comparison of four types of digital detector for chest radiology

Image quality for similar exposure conditions has been compared for two computed radiography (CR) systems (needle-based and conventional storage phosphor) and two flat-panel (DR) systems from different manufacturers mainly devoted to chest radiology. Image quality was assessed with a contrast-detail object and acrylic material to simulate clinical conditions. Specific image evaluation software was used to measure the contrast and obtain an image quality figure. Phantom and detector incident air kerma were measured for all images. Image quality differences were significant, and in the range of 100-300 microGy (phantom incident air kerma) the needle-based CR system and one of the DR systems show similar image quality and they are quite superior when compared with the conventional CR system.     

生物质固化成型技术研究进展与展望

生物质固化成型技术是规模化利用生物质能源的一种有效途径,综述了生物质固化成型技术在国内外的研究现状,提出了目前生物质固化成型技术存在的主要问题,并围绕山东大学在生物质固化成型技术研究与设备开发方面所取得的研究进展,分析了生物质固化成型技术机理和主要装备系统,提出了生物质固化成型技术的发展方向。     

生物性包装材料的现状与发展前景

随着包装工业的迅速壮大,包装材料获得了长足的发展,各式各样的包装材料层出不穷。然而,基于可持续发展战略的考虑,人们对产品包装的要求越来越高,不仅要求包装外表新颖美观,还要求包装材料无污染,易分解。因此,生物性包装材料受到了越来越多业界人士的广泛关注。本文从生物性包装材料发展趋势出发,分析了生物性包装材料产生的必然性,明确了生物性包装材料的基本定义与分类,介绍了几种生物性包装材料的制作流程及在现实生活中的应用。     

Determinants of information and digital technology implementation for smart manufacturing

This study aims to identify and analyse factors that determine the implementation of Information and Digital Technologies (IDT) of smart manufacturing. By performing a state-of-the-art and content-driven review of literature, consulting a group of experts from academia and industry, and implementing interpretive structural modelling methodology, the study identified eleven enabling factors and mapped the contextual interrelationships among them. The study further explained the complex precedence relationships that exist among determinants of smart manufacturing IDT adoption. Results showed that perceived benefits and management support are the two driver determinants that act as stepping-stones in the implementation of smart manufacturing IDT. Operations technology maturity and cybersecurity maturity were found to be the dependent determinants of smart manufacturing IDT implementation and highly driven by the linkage and driver determinates. The findings are expected to assist academicians, industrialists, and the policymakers with achieving a detailed understanding of smart manufacturing transformation processes, and conditions that facilitate the manufacturing digitalisation in the Industry 4.0 era.     

Uncertainty in radon measurements with CR39 detector due to unknown deposition of Po

Uncertainty in radon measurements using the CR39 solid-state nuclear track detector in chambers is introduced by the unknown fraction f₁ of ²¹⁸Po that deposited onto the inner chamber walls. This uncertainty was estimated for cylindrical chambers with different size in the present study. It was found that the uncertainty increased with the chamber height and radius. For short chambers with a height H=2 cm the uncertainty was less than 5%, while in tall chambers with H=7 cm it could be up to 17%. The radial track density on the CR39 detector inside the diffusion chamber was also found to be dependent on the fraction f₁. In this work, some examples of this dependence are shown.