有机纯度标准物质定值技术研究进展

有机标准物质作为参考标准广泛应用于色谱分析领域。有机标准物质化学纯度定值技术是赋予标准物质准确量值的关键。纯度定值技术包括直接测量主组分的方法和扣除杂质的方法。直接测量主组分的方法主要有气相色谱法(GC)、液相色谱法(LC)、定量核磁法(qNMR)、元素分析法和滴定法(重量滴定和容量滴定)。扣除杂质的方法要测量所有可以检测到的杂质组分,然后将其扣除来计算主成分的含量。典型的扣除杂质的方法是凝固点下降法和差示扫描量热法(DSC),并结合水分测量、残留溶剂测量和无机杂质测量进行分析。该文总结了有机标准物质化学纯度的多种定值技术(2000～2012),比较了多种定值技术的优缺点与局限性,并对有机标准物质化学纯度定值技术的发展进行了展望。

有机纯度标准物质定值技术研究进展

标准物质的定义是经过一系列的校准装置、进行评价测量所赋值的一种物质与材料,其中有一种是具有溯源新质的程序,来确定相关的测量,能够标准的测量出数据,作为准确的计量单位。有机标准物质是广泛的被色谱分析领域所研究,在这片领域里有一定的定值标准,它的化学纯度定值技术的计量标准是物质物质准确量值的重点。该文研究了多种的定值技术,然后对每种技术的效果进行比较,对有机标准物质化学纯度定值技术的发展有了更好的诠释和引导。

辛基二茂铁同分异构体纯度标准物质的定值技术研究

(2-辛基)-二茂铁、(3-辛基)-二茂铁和(4-辛基)-二茂铁是辛基二茂铁主要的3种同分异构体,由分离工业品辛基二茂铁制备而来。目前国内外金属有机化合物的标准物质有限,对这3种异构体进行高精度定值比较困难。该文首先考察标准物质候选物的均匀性和稳定性;再确定其中各杂质种类,用杂质扣除法对各候选物进行定值,重点研究了气相色谱法对各候选物中有机杂质及有机溶剂的定值技术,评定了标准物质的不确定度,为相关物质在高新技术领域的应用奠定了基础。

关于食品添加剂二氧化碳产品质量的监控与溯源传递体系的研究

本文介绍了二氧化碳作为添加剂在食品方面的主要应用;为了确保我国食品安全检测数据的有效性、可靠性和溯源性,应该在该领域对产品质量进行监管和建立该项国家最高计量标准,本文介绍了我国在这方面的基本情况。研究满足我国和国际互认要求的食品添加剂二氧化碳标准物质定值技术、分析方法,从而应对食品安全质量控制,并在国际贸易中提供该项食品安全检测所需的标准物质,是我们的责任和义务。

脂肪酸标准物质的研究进展

脂肪酸是一类具有重要功能的生物分子,广泛存在于动植物体内,是人体的重要组成成分,与人体很多疾病的发生都息息相关。脂肪酸标准物质是脂肪酸检测结果准确与否的依据,世界各国都在积极研制,目前我国脂肪酸标准物质研制单位主要有国家粮食局科学研究院和中国计量科学研究院等。综述了国内外脂肪酸标准物质的现状,对比分析了国内外脂肪酸标准物质的种类、特性量值组成和定值方法等。国外脂肪酸标准物质一般含有多种特性组分,特性量值较多,国内脂肪酸标准物质一般仅针对脂肪酸测量研制,基体比较单一,特性组分较少,量值较少。

维生素标准物质的研究进展

维生素是维持生命体健康活动必不可少的重要有机化合物,其最主要的功能是参与机体代谢调节,缺乏或过量均会引起相应的疾病,导致身体健康受损。准确测定维生素含量对监控营养食品质量、维护大众健康具有重要意义,维生素标准物质是保证维生素定量检测结果准确、可比和可溯源的重要物质基础。本文综述了国内外维生素标准物质的种类及技术水平现状,我国在维生素纯度标准物质方面的研究已经比较完善但在复杂基体方面的研究与发达国家仍存在一些差距,另外本文对维生素标准物质定值技术发展和需求进行了介绍。

Aerobic composting of paper mill sludge and the reuse of compost in agriculture

Paper mill sludge （PMS） is a kind of bio-solid waste. The technology of aerobic composting of PMS was investigated. The ratio of the material components was as follows, sludge：chicken dung：spill=6kg：2kg：4kg, which could attain 55% moisture content （MC） and 25 the ration of carbon to nitrogen （C/N）. The aeration rule of fan was controlled by single chip microcomputer （SCM）. During composting, the system temperature more than 55℃ lasted for 3 days, pH changed in the range of 6.5-8.5 and MC changed between 53% to 60%. PMS became mature on the 20th day. The germination index （GI） of compost attained 95% or so and coliform was 23/100 ml volatile solid （VS） and organic carbon （OC） were stable at the content of 60% and 30%, respectively. The result showed that this technology could make the sludge stable and innocuous. A pot experiment with latosolic red soil mixed with paper mill sludge compost （PMSC） was carried on. The result showed that PMSC could increase the crop biomass, the soil nutrients and the physical characteristics of the soil, such as OC, total nitrogen （TN）, total phosphorus （TP）. The total amount of heavy metals in the soil was measured to be lower than the Environmental standard for soil in China （GB15618-1995）. So PMSC was a good and safe soil amendment.

On the Generation Algorithm of VRS Virtual Observations

In the past few years, network RTK positioning technology, especially the VRS technology, has been widely used in some parts of China and in many countries around the world. The principle of the VRS technology is discussed with corresponding formula deduction, and detailed descriptions and applications of VRS corrections and virtual observations generation algorithm are given.

LTAG Technology Passed Appraisal

Recently the LTAG technology combining selective hydro-saturation of LCO with selective catalytic cracking technology for producing high-octane gasoline or light aromatic hydrocarbons has passed technical appraisal.

Metocean Design Parameter Estimation for Fixed Platform Based on Copula Functions

Considering the dependent relationship among wave height,wind speed,and current velocity,we construct novel trivariate joint probability distributions via Archimedean copula functions.Total 30-year data of wave height,wind speed,and current velocity in the Bohai Sea are hindcast and sampled for case study.Four kinds of distributions,namely,Gumbel distribution,lognormal distribution,Weibull distribution,and Pearson Type III distribution,are candidate models for marginal distributions of wave height,wind speed,and current velocity.The Pearson Type III distribution is selected as the optimal model.Bivariate and trivariate probability distributions of these environmental conditions are established based on four bivariate and trivariate Archimedean copulas,namely,Clayton,Frank,Gumbel-Hougaard,and Ali-Mikhail-Haq copulas.These joint probability models can maximize marginal information and the dependence among the three variables.The design return values of these three variables can be obtained by three methods:univariate probability,conditional probability,and joint probability.The joint return periods of different load combinations are estimated by the proposed models.Platform responses(including base shear,overturning moment,and deck displacement) are further calculated.For the same return period,the design values of wave height,wind speed,and current velocity obtained by the conditional and joint probability models are much smaller than those by univariate probability.Considering the dependence among variables,the multivariate probability distributions provide close design parameters to actual sea state for ocean platform design.

Remote Sensing of Ecosystem Services:An Opportunity for Spatially Explicit Assessment

Ecosystem service is an emerging concept that grows to be a hot research area in ecology.Spatially explicit ecosystem service values are important for ecosystem service management.However,it is difficult to quantify ecosystem services.Remote sensing provides images covering Earth surface,which by nature are spatially explicit.Thus,remote sensing can be useful for quantitative assessment of ecosystem services.This paper reviews spatially explicit ecosystem service studies conducted in ecology and remote sensing in order to find out how remote sensing can be used for ecosystem service assessment.Several important areas considered include land cover,biodiversity,and carbon,water and soil related ecosystem services.We found that remote sensing can be used for ecosystem service assessment in three different ways:direct monitoring,indirect monitoring,and combined use with ecosystem models.Some plant and water related ecosystem services can be directly monitored by remote sensing.Most commonly,remote sensing can provide surrogate information on plant and soil characteristics in an ecosystem.For ecosystem process related ecosystem services,remote sensing can help measure spatially explicit parameters.We conclude that acquiring good in-situ measurements and selecting appropriate remote sensor data in terms of resolution are critical for accurate assessment of ecosystem services.

怎样提高果树定植苗的成活率

新建果园时，苗木定植质量的好坏，不仅关系到土地，光能的利用及果园今后管理，更重要的是直接影响苗木的成活，生长和结果，而在果树的实际生产担任中，常见到一些果农花了一笔数目步．不小的钱去购了一批果苗回来，却由于定植的质量不高，导致部分果苗没有成活面需重新补种，浪费了时间及人力，物力，同时也增加了成本，为了避免这种不必要的损作，现将果树定植技术介绍如下。

Research on stability of a slope due to underground mining

This paper will present a detailed analysis of the deformation mechanism and stability assessment of the slope through field investigations, numerical modeling and measurements. Field investigation indicated that three thin coal seams encountered large mined-out area at one side and free surface of hill slope at the other side, which lead to the caving of roof strata movement, ground movement and crown crack along the preferred orientations of joints. The three-dimensional numeri- cal modeling study on the case demonstrated that the plasticity failure occurred gradually along with the extension of mined-out area in depth. When the depth of mining reached the verge defined by the seismic prospecting method, a large mount of tension failure occurred on the crown of the slope. The factor of safety was 1.36 calculated by the shear strength reduction technique, which indicated the slope was in stable state. The measurement showed that the residual deformation occurred before 1998 and became stable subsequently, which indicated that the residual deformation almost finished and the slope is in stable state.

新烟碱类农药有证标准物质研究进展

新烟碱类农药已成为世界上使用最广泛的杀虫剂,具有高效、广谱、低毒和高选择性的特点。但该类农药可通过饮水、食物和呼吸等方式对人的神经系统、生殖系统等造成潜在的危害。新烟碱类农药有证标准物质是确保新烟碱类农药定量检测结果准确、可比、可溯源的化学砝码。对国内外新烟碱类农药有证标准物质的种类、样品制备和定值技术进行了全面的总结。国内新烟碱类农药有证标准物质以纯度和溶液为主,成份量基本都是啶虫脒和吡虫啉,基体标准物质非常缺乏;纯度标准物质通常采用提纯市售原料的方法制备,并使用质量平衡法、差示扫描量热法等进行定值。国际上新烟碱类农药有证标准物质以基体为主,含有多种特性量;采用向空白样本或者阳性样本添加预期浓度目标分析物的方式制备基体样品,并使用液相色谱同位素稀释质谱法等进行定值。我国新烟碱类农药有证标准物质在种类和结构上发展不平衡。因此,我国应加速开发多组分、多量值的新烟碱类农药基体标准物质,完善量值溯源体系,满足海量检测的需求。