用修正淬透性系数法对反应堆压力容器锻件RTNDT数值的预估

分析反应堆压力容器（RPV）锻件制造过程中关键化学元素含量及基准无塑性转变温度（RTNDT）数值，通过引入修正淬透性系数，建立了反映RTNDT变化规律的修正淬透性系数函数表达式，并给出了实例验证，结果表明，通过本文建立的修正淬透性系数函数式可以比较精确地预估RPV锻件的RTNDT值。      

Analysis of the impact of PCI planning on downlink throughput performance in LTE

The planning of Physical Cell Identities (PCI) has a strong impact on the performance of Long Term Evolution cellular networks. Although several PCI planning schemes have been proposed in the literature, no study has quantified the performance gains obtained by these schemes. In this paper, a comprehensive performance analysis is carried out to quantify the impact of PCI planning on user quality of service and network capacity in the downlink of LTE. First, an analytical model for the influence of PCI planning on reference signal collisions is developed. Based on this model, different PCI planning schemes are tested on a dynamic system-level simulator implementing a macrocellular scenario. During the analysis, both Voice-over-IP and full buffer services over time-synchronized and non-time synchronized networks are considered. Results show that call blocking and dropping for real-time services and user throughput for non-real time services can be significantly improved by a proper PCI plan.     

Accurate experimental (p, ρ, T) data of natural gas mixtures for the assessment of reference equations of state when dealing with hydrogen-enriched natural gas

The GERG-2008 equation of state is the approved ISO standard (ISO 20765-2) for the calculation of thermophysical properties of natural gas mixtures. The composition of natural gas can vary considerably due to the diversity of origin. Further diversification was generated by adding hydrogen, biogas, or other non-conventional energy gases. In this work, high-precision experimental (p, ρ, T) data for two gravimetrically prepared synthetic natural gas mixtures are reported. One mixture resembled a conventional natural gas of 11 components (11 M) with a nominal mixture composition (amount-of-substance fraction) of 0.8845 for methane as the matrix compound with the other compounds being 0.005 for oxygen, 0.04 for nitrogen, 0.015 for carbon dioxide, 0.04 for ethane, 0.01 for propane, 0.002 each for n- and isobutane, and ultimately 0.0005 each for isopentane, n-pentane, and n-hexane. The other mixture was a 13-component hydrogen-enriched natural gas with a low calorific value featuring a nominal composition of 0.7885 for methane, 0.03 for hydrogen, 0.005 for helium, 0.12 for nitrogen, 0.04 for carbon dioxide, 0.0075 for ethane, 0.003 for propane, 0.002 each for n- and isobutane, and 0.0005 each for neopentane, isopentane, n-pentane, and n-hexane. Density measurements were performed in an isothermal operational mode at temperatures between 260 and 350 K and at pressures up to 20 MPa by using a single-sinker densimeter with magnetic suspension coupling. The data were compared with the corresponding densities calculated from both GERG-2008 and AGA8-DC92 equations of state to test their performance on real mixtures. The average absolute deviation from GERG-2008 (AGA8-DC92) is 0.027% (0.078%) for 11 M and 0.095% (0.062%) for the 13-component H₂-enriched mixture, respectively. The corresponding maximum relative deviation from GERG-2008 (AGA8-DC92) amounts to 0.095% (0.127%) for 11 M and 0.291% (0.193%) for the H₂-enriched mixture.     

检测实验室中标准物质的质量控制及管理

标准物质是保证准确量值和量值溯源的重要工具，标准物质的有效控制和管理是确保实验室检测数据准确的关键步骤，关系着实验室质量控制水平。对标准物质进行有效的管理控制，充分发挥标准物质的功能，是当前检测实验室急需解决的关键问题。本文主要探究了从标准物质的购买、验收及验证、储存管理、配制、标识、使用、期间核查、失效后处理等全过程进行系统地控制，保证标准物质的质量，确保标准物质在质量控制、校准测量仪器、评价测量分析方法、赋予物质特性量值、考核评价检测人员的技术能力、产品检测过程等方面起到重要作用，从而达到提高检测实验室检测数据的准确性和检测技术能力水平的目的。     

交流采样及A／D转换在35kV变电所微机监控系统中的应用

本文详细论述了变电所微机监控系统中的测量前端—交流采样及Ａ／Ｄ转换装置的原理、结构和应用，对于变电所自动控制和自动保护有一定的参考价值。该系统具有快速、准确、可靠、维护简单及成本低等优点，是变电所自动控制和安全运行必不可少的前提，更是电力自动化发展的方向。     

新疆尉犁蛭石矿中金云母/蛭石混层结构研究

蛭石矿中常伴生有金/黑云母结构,云母层的存在严重影响了蛭石矿的性能,现有方法不能充分揭示混层的晶体结构特征和蛭石晶层及金云母晶层含量。本文以新疆尉犁蛭石矿为研究对象,利用X-射线衍射(XRD)和X射线荧光光谱(XRF)研究尉犁蛭石结构和相含量。以XRD强度理论和分子量为基础,建立新型水金云母(金云母-蛭石的1∶1规则间层矿物)的参比强度近似计算方法,研究水金云母分子量变化对于定量相分析结果的影响,并与已有的分晶层方法计算得到的各晶层含量进行系统比较。结果表明新疆尉犁蛭石由24.56%的蛭石和75.44%的水金云母组成;以参比强度为基础的XRD定量分析方法具有结果可靠、分析简单,同时可以获得层状硅酸盐多层次结构信息的优点。     

现代大地测量参考系统的定义

说明了现代大地测量参考系统的定义及建立在大地测量系统的基础。给出在目前全球尺度已达到几个cm量级精度的基础上，现代大地测量参考系统确立的4个步骤。     

比利时鲁汶格鲁特别根霍夫的保护与更新策略及其启示

本文在简要介绍格鲁特别根霍夫发展历史和保护更新历程的基础上，归纳出该区域的保护与更新策略，对于我国历史文化建筑的保护与更新具有启示和借鉴意义。     

JSCORS的基准站分布设计与试验

具有实时定位服务功能的连续运行卫星定位服务系统(CORS)是当代GPS发展的热点之一,江苏省连续运行参考站网络是我国首批省级的连续运行的参考站网络系统.基准站分布设计是JSCORS整体设计与建设的一项重要内容,科学、合理地选择基准站址,有利于高质量、高稳定的发挥JSCORS的作用.     

Nanomaterials for environmental studies: Classification, reference material issues, and strategies for physico-chemical characterisation

NanoImpactNet is a European Commission Framework Programme 7 (FP7) funded project that provides a forum for the discussion of current opinions on nanomaterials in relation to human and environmental issues. In September 2008, in Zurich, a NanoImpactNet environmental workshop focused on three key questions:

1.

What properties should be characterised for nanomaterials used in environmental and ecotoxicology studies?

2.

What reference materials should be developed for use in environmental and ecotoxicological studies?

3.

Is it possible to group different nanomaterials into categories for consideration in environmental studies?

Such questions have been, at least partially, addressed by other projects/workshops especially in relation to human health effects. Such projects provide a useful basis on which this workshop was based, but in this particular case these questions were reformulated in order to focus specifically on environmental studies. The workshop participants, through a series of discussion and reflection sessions, generated the conclusions listed below.The physicochemical characterisation information identified as important for environmental studies included measures of aggregation/agglomeration/dispersability, size, dissolution (solubility), surface area, surface charge, surface chemistry/composition, with the assumption that chemical composition would already be known.There is a need to have test materials for ecotoxicology, and several substances are potentially useful, including TiO₂ nanoparticles, polystyrene beads labelled with fluorescent dyes, and silver nanoparticles. Some of these test materials could then be developed into certified reference materials over time.No clear consensus was reached regarding the classification of nanomaterials into categories to aid environmental studies, except that a chemistry-based classification system was a reasonable starting point, with some modifications. It was suggested, that additional work may be required to derive criteria that can be used to generate such categories, that would also include aspects of the material structure and physical behaviour.