冷原子吸收法测定尿中汞的不确定度评定

目的冷原子吸收法测定尿中汞的不确定度进行评定,保证检测工作的准确性。方法结合日常检测,根据测量不确定度的评定理论和检测方法进行评定,确定和计算测量过程中各不确定度分量,并对测定结果进行完整描述。结果合成标准不确定度为0.0410,对于尿汞含量为0.139μg的样品,其扩展不确定度为0.0112μg。结论该法的不确定度主要来源于样品处理、标准溶液配制和曲线线性等方面。     

多菌灵中DAP和HAP含量测量不确定度评定

对多菌灵中DAP和HAP含量测量进行不确定度评定,建立不确定度评定程序和方法。依据《测量不确定度评定与表示指南》建立数学模型,进行不确定度的计算并合成不确定度。找出影响多菌灵中DAP和HAP含量测量的主要因素,分析归纳了不确定度分量的主要来源,并对结果予以讨论。评定程序和方法符合规范要求,适用于同类型试验不确定度评定。     

GCMS测定电子电气产品中BDE-209含量的不确定度评定

分析了用气相色谱-质谱联用法(GCMS)测定电子电气产品中十溴二苯醚(BDE-209)含量的检测过程,运用测量不确定度评定的理论,对测定的结果的不确定度进行了评定,分析了不确定度的来源,对各分量进行了计算,合成不确定度。最终结果的不确定度主要由工作曲线、样品前处理以及测量重复性等不确定度引起。本文建立的不确定度评定方法可用于GCMS法测定电子电气产品中其他的多溴联苯和多溴二苯醚含量的不确定度评定。     

原子荧光法测定化妆品中砷的不确定度评定

采用微波消解法处理样品、氢化物原子荧光光度法测定化妆品中砷的含量,并根据《JJF1059.1-2012测量不确定度评定与表示》建立数学模型,对上述方法的不确定度进行分析评定.经计算,其测量不确定度主要来源于标准曲线拟合及测量重复性,而称样及稀释过程引入的不确定度则较小;因此,为降低不确定度,提高结果准确性,需定期对仪器...     

连续流动法测定烟草及烟草制品中氯的不确定度评定

依据《JJF 1059.1-2012测量不确定度评定与表示》对连续流动法测定烟草样品中氯含量的不确定度进行评定,通过分析得出,测量重复性、样品前处理、标准溶液制备、标准曲线拟合、连续流动分析仪测量重复性是不确定度的主要来源。分析结果表明,当烟草样品中氯为0.80%时,扩展不确定度为0.12%,k=2。     

连续流动法测定烟草及烟草制品中总植物碱的不确定度评定

依据《JJF 1059.1-2012测量不确定度评定与表示》对连续流动法测定烟草样品中总植物碱含量的不确定度进行评定,通过分析得出,测量重复性、样品前处理、标准溶液制备、标准曲线拟合、连续流动分析仪测量重复性是不确定度的主要来源。分析结果表明,当烟草样品中总植物碱为1.89%时,扩展不确定度为0.10%,k=2。     

HPLC 法测定淀粉中马来酸的不确定度评定

建立了HPLC测定淀粉中马来酸的分析方法,并进行了不确定度评定。根据CNAS-GL06-2006《化学分析中不确定度的评估指南》和JJF1059.1-2012《测量不确定度评定与表示》规定的原理与方法,对HPLC测定淀粉中马来酸含量测量不确定性的来源进行分析,建立了测量不确定度评定的数学模型,计算并评定了测量结果的合成不确定度。结果表明：以HPLC测定淀粉中马来酸含量,其不确定度主要来源于校准曲线拟合和马来酸标准溶液,其次为测量重复性和高效液相色谱仪。     

气相色谱法测定鸡蛋中七氯的不确定度评定

采用气相色谱法测定鸡蛋中七氯残留量,对测量结果的不确定度进行评定。分析了测量程序中不确定度的各项来源,包括标准品溶液配制、仪器测量重复性、样品处理和回收率等引入的不确定及其计算方法。七氯的测定结果的合成不确定度为0.014,其检测结果可表示为(3.98±0.11)μg/kg。实验结果表明,测量不确定度评定方法的确立对鸡蛋中七氯检测和结果判定有重要意义。     

微波消解-ICP-AES法对电镀金层杂质元素含量测定的不确定度评价

采用微波消解-ICP-AES法测定了电镀金层中杂质元素的含量,并按照JJF1059—1999《测量不确定度评定与表示》对测量过程中对各种因素导致的不确定度进行评定。分析了测量不确定度分量的主要来源,对各不确定度分量进行了评定和计算。结果表明以微波消解-ICP-AES法测定电镀金层中杂质元素的含量时,测量不确定度主要由标准溶液的浓度、标准曲线非线性、测量重复性、仪器稳定性引入。通过对不确定度的评定,可以保证分析结果的准确性。     

气相色谱法测定醋酸纤维滤棒中三乙酸甘油酯的不确定度评定

为提高测量结果的准确性,依据JJF 1059.1-2012《测量不确定度评定与表示》对气相色谱法测定醋酸纤维滤棒中三乙酸甘油酯的不确定度进行评定,通过分析得出,测量重复性、样品前处理、标准溶液制备、标准曲线拟合、气相色谱仪测量重复性是不确定度的主要来源。分析结果表明,当醋酸纤维滤棒中三乙酸甘油酯的含量为7.32%,扩展不确定度为0.42%,k=2。     

Studies regarding simulation process to static loading of the structures obtained from polylactic acid, 3D printed

Being a relatively new process, additive manufacturing needs many studies to be able to produce parts with the required properties. The aim of the paper is to establish whether, based on the physical and mechanical properties determined by tensile testing and by applying finite element analysis (FEA), viable results can be obtained regarding the behavior of the 3D printed structures at the different, static loading. The application of FEA for the tensile testing of 3D specimens led to the results close to those obtained by the tests. The values of the results obtained by simulation are higher by up to 7.2% compared with those recorded by tests. The simulation was applied both for the printed specimens from a single material and from two materials (multi-material). Regardless of the materials used in printing and the simulation method, the results of applying FEA are close to those recorded by testing.     

2014年1-8月我国硫酸磷肥行业运行态势分析

介绍了2014年1-8月我国硫酸磷肥生产运行情况.2014年1-8月我国硫酸总产量57.63 Mt,同比增长5.6％.据中国磷肥工业协会核实数据显示,2014年1-8月我国磷肥产量（以P2O5计）11.35 Mt,同比增长3.5％;其中DAP累计实物产量9.69 Mt,同比下降3.3％;MAP累计实物产量7.4Mt,同比增长21.1％;NPK累计实物产量24.24 Mt,同比增长9.7％.2014年1-8月我国累计进口硫磺6.8 Mt,同比下降4.7％.累计进口硫酸0.96 Mt,同比上升20.9％;累计进口硫酸平均价格为32.6美元/t,同比下降18.5％.我国磷复肥生产装置不能满负荷生产,必然降低了硫酸生产装置的开工率.预计至2018年,我国硫酸产能将达到140 Mt/a,硫酸装置总开工率应在80％以下.     

使用红外光谱法和热重法分析硫化橡胶的成分

使用红外光谱法鉴定牌号为N402和C606两种硫化橡胶的主成分,并通过比较溶剂抽提前后和裂解前后的红外光谱和热重分析结果,得到了其中添加剂的信息.比较了裂解液透射分析法、裂解液衰减全反射(ATR)法和衰减全反射(ATR)直接法得到的红外光谱,结果表明:裂解液透射分析法和裂解液ATR法可以得到相似的红外谱图;裂解液透射分...     

Performance correlations for basin type solar stills

Many experimental and numerical studies have been done on different configurations of solar stills to reach the optimum design by examining the effect of climatic, operational and design parameters on its performance. Some of the most important parameters investigated were solar radiation, cover tilt angle, brine depth, and using dyes with the brine. The majority of the investigators presented their results in scatter diagrams rather than correlations. Four correlations are derived in this work to illustrate the effect of solar radiation, dyes, cover slope and brine depth on the productivity of the basin type solar still using the available data given by the different investigators. The correlations developed illustrate that the still productivity could be influenced by the brine depth alone by up to 33% and by the tilt angle alone by up to 63%. A cover tilt angle of about 30° gives the highest productivity. The still productivity could be enhanced by adding dark soluble dye to the brine by up to 20%. The still productivity increases with the increase of insulation thickness of the still and the solar radiation received.     

Model for parallel surface and pore diffusion of an adsorbate in a spherical adsorbent particle

A model is presented to describe the rate of uptake of a species by a spherical adsorbent particle when intraparticle transport can occur by parallel diffusion through the pore space and along the surfaces of pore walls. Although the conventional shrinking core model (SCM) has been applied to such systems previously, its use is valid only when adsorption onto the pore walls is described by a rectangular isotherm. As with the SCM, the new model differs from homogeneous models by envisaging the advance of the adsorbate to be marked by a distinct inward-moving interface, but it generalizes the SCM to allow for an incompletely saturated adsorbed shell behind the front governed by any Langmuir isotherm. The model has been applied to previously published experimental data for the uptake of bovine serum albumin by chitosan beads and compared to the results obtained when the same data are analysed using the corresponding homogeneous model. The fit of the two models to the convension-time data yields comparable results, but significant differences in the predicted absorbate concentration profiles within adsorbent particles are observed, particularly at high conversions.     

丙烷脱氢制丙烯经济及技术分析

丙烯是重要的有机化工原料，除用于生产聚丙烯外，还是生产丙烯腈，丁醇、辛醇、环氧丙烷、异丙醇、丙苯、丙烯酸、羧基醇及壬基酚等产品的主要原料，丙烯的齐聚物是提高汽油辛烷值的主要成分，丙烷催化脱氢制丙烯比烃类蒸气裂解能产生更多的丙烯。当用蒸气裂解生产丙烯时，丙烯收率最多只有33％、而用催化脱氢法生产丙烯，总收率可达74％－86％，用唯一原料生产唯一产品，催化脱氢的设备投资比烃类蒸气裂解低33％。并且采用催化脱氢的方法，能有效地得用液化石油气资源使之转变为有用的烯烃。     

复合纳米TiO2薄膜银钛协同抗菌与净化研究

通过水热法制备了Mo、N共掺杂的TiO2纳米管,再将其分散制备成溶胶,用电泳沉积在氧化铝基材上成膜,再将薄膜经AgCl溶胶浸泡后紫外光照制备Ag／Agcl／TiO2薄膜。考查在银钛协同效应下复合材料的光催化活性与抗菌性能。结果表明,复合后的Ag／Agcl／TiO2薄膜通过银钛协同作用极大地提高了其抗菌和净化性能。     

Two-stage model of nanocones formation on a surface of elementary semiconductors by laser radiation

ABSTRACT: In this work we study mechanism of nanocone formation on a surface of elementary semiconductors by Nd:YAG laser radiation. Our previous investigations of SiGe and CdZnTe solid solutions have shown that nanocone formation mechanism is characterised by two stages. The first stage is characterized by formation of heterostructure. For example, Ge/Si heterostructure from SiGe solid solutions, and the second stage is characterized by formation of nanocones by mechanical plastic deformation of the compressed Ge layer on Si due to mismatch of Si and Ge crystalline lattice. The mechanism of nanocone formation for elementary semiconductors is not clear until now. Therefore, the main goal of our investigations is to study the stages of nanocone formation in elementary semiconductors. A new mechanism of p-n junction formation by laser radiation in the elementary semiconductor as a first stage of nanocones formation is proposed. We explain this effect by following way: p-n junction is formed by generation and redistribution of intrinsic point defects in temperature gradient field - the Thermogradient effect, which is caused by strongly absorbed laser radiation. According to the Thermogradient effect, interstitial atoms drift towards the irradiated surface, but vacancies drift to the opposite direction - in the bulk of semiconductor. Since interstitials in Ge crystal are of n-type and vacancies are known to be of p-type, a n-p junction is formed. The mechanism is confirmed by appearance of diode-like current-voltage characteristics after i-Ge irradiation crystal by laser radiation. In Si mechanism is confirmed by conductivity type inversion and increase microhardness of Si crystal. The second stage of nanocone formation is laser heating up of top layer enriched by interstitial atoms with its further plastic deformation due to compressive stress caused by interstitials in the top layer and vacancies in the buried layer.     

Synthesis and optical studies of conjugated polyfluorenyl cations

Polyfluorene based precursor polymers were synthesized either by Yamamoto type or Suzuki polycondensation. These polymers were then converted to the corresponding conjugated polycations by treatment with trifluoroacetic acid. The formation of the conjugated polycations were followed by UV-vis and characterized by ¹H NMR. The absorption maxima of the polycations fall in the range of 580-690 nm. The formation of the polycations is evidenced by a red shift in absorption maxima compared to the parent polymers due to the generation of stable cations with more extended conjugation and planarity. The cationic polymers show low solubility in common organic solvents, however the solubility of the cationic salt can be greatly enhanced by controlling the cation density along the polymer chain by copolymerization.