饲料中粗灰分的测量结果不确定度评定

本文介绍用重量法测定饲料样品的粗灰分含量。通过对影响样品测试结果的不确定度分量的分析和量化 ,求出被测量 (粗灰分含量 )的标准不确定度和扩展不确定度U =2uc(A) =0 0 7% ,给出各分量对测量结果不确定度的相对贡献 ,对测量结果进行了表述。     

蒸馏后滴定法测磷酸二氢铵中总氮含量测量结果不确定度的评定

用蒸馏后滴定法测定磷酸二氢铵中总氮含量的测量结果的不确定度进行了分析和评定。分析和评定结果表明 :磷酸二氢铵中总氮含量测量结果的合成标准不确定度uc=0 0 4 % ,当包含因子K =2时 ,扩展不确定度U为 0 0 8%。各分量中 ,以重复性测量和滴定管带来的不确定度分量贡献较大。     

亚甲蓝法测定天然气中硫化氢含量的不确定度评定

阐述了用亚甲蓝法测定天然气中硫化氢含量的分析方法,构建硫化氢含量分析数学模型,研究提出影响硫化氢分析结果的不确定度来源,对测量不确定度各个分量进行评定,结果表明测量重复性和从校准曲线计算硫化氢含量引入的标准不确定度是决定测量不确定度值大小的关键,取包含因子k=2,置信概率为95%,则测量结果的相对扩展不确定度为U_r=6%。     

HPLC法测定头孢拉定胶囊含量的不确定度评定

对高效液相色谱法测定头孢拉定含量的不确定度进行评定。量化了各分量的相对标准不确定度,并计算出合成标准不确定度,取k=2（近似置信概率95%）得出扩展不确定度1.46%。在现有条件下使测定结果受控,并可通过分析各分量的相对标准不确定度的大小来优化实验,使测定结果更加可靠。     

ICP-AES分析纯铝中硅含量的不确定度评定

讨论了采用电感耦合等离子体发射光谱法测定纯铝中硅量分析结果不确定度产生的原因。建立了数学模型,对测量重复性、标准溶液、标准曲线变动、试液体积及样品称量等引起的不确定分量进行评定,计算了合成标准不确定度和扩展不确定度,并给出纯铝中硅含量的不确定度报告。     

钨酸铵灼烧重量法测定钨精矿中三氧化钨的不确定度评定

讨论了钨酸铵灼烧重量法测定钨精矿中三氧化钨测量不确定度的影响因素,对测试过程中的测试不确定度分量进行了分析和计算,得出钨精矿中三氧化钨含量测量结果的合成扩展不确定度为0.21%,并对测量结果进行了表述。     

钨酸铵灼烧重量法测定钨精矿中三氧化钨的不确定度评定

讨论了钨酸铵灼烧重量法测定钨精矿中三氧化钨测量不确定度的影响因素,对测试过程中的测试不确定度分量进行了分析和计算,得出钨精矿中三氧化钨含量测量结果的合成扩展不确定度为0.21%,并对测量结果进行了表述。     

饲料中粗灰分的测量结果不确定度评定

本文介绍用重量法测定饲料样品的粗灰分含量。通过对影响样品测试结果的不确定度分量的分析和量化，求出被测量(粗灰分含量)的标准不确定度和扩展不确定度u=2uc(A↑-)=0．07％，给出各分量对测量结果不确定度的相对贡献，对测量结果进行了表述。     

红外分光光度法测定污泥中矿物油的不确定度评定

分析探讨了红外红外分光光度法测定污泥中矿物油含量不确定度的影响因素,并对其不确定度分量进行了评定,计算得到相对标准不确定度urel(X)为0. 0187,污泥样品中矿物油含量的标准不确定度u(X)为1. 0450mg/L,扩展不确定度U为2. 0899mg/L(k=2),所测污泥样品中的矿物油的含量为X=55. 83±2. 0899mg/L(k=2)。扩展不确定度贡献较大的主要分量是样品重复测定和配置三波长校准溶液引入的标准不确定度分量。     

氢化物发生-原子荧光光谱法同时测定煤炭中砷、汞含量的不确定度评估

本文对煤炭中砷、汞含量测定的不确定度进行了评估。用氢化物发生-原子荧光光谱法同时测定了煤炭中的砷、汞含量,通过对影响样品测量结果的不确定度分量的分析和量化,计算出被测量(砷、汞含量)的标准不确定度和扩展不确定度,从而给出各分量对总测量不确定度的相对贡献,并对测量结果进行了表述。     

6.5 wt% Si high silicon steel sheets prepared by composite electrodeposition in magnetic field

A new preparation method of near-net-shape 6.5?wt% Si high silicon steel sheets was proposed by combining composite electrodeposition (CED) and diffusion annealing under magnetic field. The obtained sheets were characterized by scanning electron microscopy, energy dispersive spectrometry, analytical balance and a silicon steel material measurement system. The results show that the surface morphology, the elemental distribution, the cathode current efficiency and the silicon content of coatings were obviously influenced by the micro and macro magnetohydrodynamics (MHD) flows under magnetic field. With the effect of magnetic field, the silicon particles content of coatings showed an increasing trend and the diffusion process showed that an approximately uniform 6.5?wt% silicon steel sheet has been successfully obtained. The magnetism measurement showed that the high silicon steel sheet has the lower iron loss, and the iron loss further decreased under magnetic field. The new method proposed in this article, which is more environmentally friendly and low energy consumption, is feasible to prepare high silicon steel sheets.     

PCVD涂硅的动力学研究

采用等离子体化学气相沉积（PCVD）法,在0．1－0．3mm厚的普通硅钢片表面涂硅,再进行短时间高温扩散,使硅钢片的含Si量增加到6．5％,铁损P10／50比原来钢片降低50％,其他磁性能也大有改善。试验结果表明,在460－600℃涂硅,其他条件不变,涂硅速度随温度升高而降低,并对等离子体反应的动力学和热力学进行了研究。     

Use of silane for the deposition of hard and oxidation resistant Ti–Si–N coatings by a hybrid cathodic arc and chemical vapour process

Ti–Si–N coatings were deposited on M2 steel substrates using a hybrid cathodic arc and chemical vapour deposition process. Silane was used as the silicon precursor. Whatever the films silicon content, only TiN grains were detected by X-ray diffraction. The mean grain size was estimated to be lower than 10 nm. The silicon content strongly influenced the TiN preferred orientation. Depth sensing indentation showed that films with Si/Ti = 0.08 exhibited a hardness close to 43 GPa. Silicon addition into TiN-based coatings induced an improvement of their oxidation resistance. The film properties were comparable to those obtained for Ti–Si–N coatings deposited using a Ti–Si target, indicating that the hybrid process was suitable for the deposition of hard and oxidation resistant Ti–Si–N coatings.     

硅含量与氧化温度对含Nb高强钢氧化行为的影响

为了更真实地反映工业生产实际工况中硅含量与氧化温度对Nb高强钢氧化行为的影响,设计了4种不同的氧化温度,采用与工业现场类似的加热制度对不同Si含量的含Nb高强钢进行氧化.采用扫描电子显微镜及能谱仪分析了氧化铁皮形貌及确定氧化铁皮各层结构.研究了硅含量及氧化温度对含Nb高强钢氧化行为的综合影响.结果表明:在相同氧气含量及氧化时间下,含Nb高强钢的氧化增重取决于氧化温度及硅含量的综合作用;当加热温度低于1 173℃(硅酸亚铁熔点)时,硅含量增加,氧化铁皮总量减少;当加热温度高于1 173℃时,硅含量增加,氧化铁皮总量增加;当硅含量较高时(1.21％,质量分数),试样的氧化增重曲线主要遵循线性规律.     

辉光放电发射光谱法测定纯净钢中磷含量的不确定度评定

磷元素的激发波长短,纯净钢中磷元素的百分含量低,准确测量存在一定难度。通过辉光放电发射光谱法对纯净钢中磷元素含量进行测定。对测定过程中分析不确定因子进行相应不确定度的评定和计算,找出影响结果最大的不确定因素。评定结果表明,辉光放电发射光谱法测定纯净钢中磷元素含量能满足分析准确度的要求,可应用于中低合金钢中低含量磷元素的快速定量分析。     

Effect of silicon and aluminium in ferrite on tensile and impact properties

Two ferritic interstitial-free steels with approximately the same amount of solid solution strengthening by addition of 2?wt-% silicon and 4?wt-% aluminium are investigated using quasi-static tensile and dynamic impact tests. The addition of 2?wt-% silicon (2Si) results in brittle fracture in V-notched Charpy impact tests at ambient temperature, whilst the 4?wt-% aluminium-containing (4Al) steel has high absorbed energy of 320?±?12?J?cm^?2. In addition, the 4Al steel has a ductile-to-brittle-transition temperature (DBTT) ～60°C lower than the 2Si steel. It is proposed that the addition of silicon suppresses dislocation cross-slip at high strain rate and is responsible for the observed cleavage fracture and high DBTT in the 2Si steel. The ease of dislocation slip in the 4Al steel increases the impact toughness.     

Mathematical model for cutting effect on magnetic flux distribution near the cut edge of non-oriented electrical steels

Basic magnetic properties of non-oriented electrical steel sheets with different grain size and silicon content have different behaviour before and after cutting into strips. Cutting process causes a significant drop in flux density and deterioration of magnetic properties occurs over a region up to 10 mm from close to the cut edge. Therefore some degraded regions are formed at each side of the cut. A new mathematical model was formed for the degree of deterioration on flux distribution near the cut edge. The variation of magnetic induction in the cutting region was given as a function of four different parameters depending on the material. The model also included the variation of these parameters with the grain size and silicon content. It is observed that the change in the parameters until 2.5% Si content is not significant, while it has a remarkable variation for them after 2.5% Si content and similar effect was found to be for grain size. The mathematical model gives the degree to which the magnetic properties of the region around the edge degrade after the cutting process. The calculated results of the model showed good agreements with the experimental results.     

Effect of Zn addition on primary silicon morphology and B distribution in Si–Al alloy

Si–Al–Zn alloy melts were used for silicon purification by the solvent refining process. The effect of metal Zn addition on alloy macrostructure, primary Si morphology, as well as B distribution in Si–Al alloy during solvent refining process was studied in this work. The three main results were as follows. First, with the increasing of Zn content in Si–Al alloy, the primary silicon changed from slender plate-like to irregular and short, meanwhile the distribution of primary silicon changed from bottom to central and top. Second, the more Zn content in Si–Al alloy, the more inclusions of eutectic melts will be in primary silicon, which results in diffusion difficulty of impurity B in inclusions. Third and last, with increasing Zn content, the refining ratio of B increased gradually and removal fraction of B decreased accordingly.     

Influence of silicon content on the microstructure and hardness of CrN coatings deposited by reactive magnetron sputtering

CrN and CrSiN films were deposited on the stainless steel and silicon substrates by DC magnetron sputtering and their microstructural features were investigated by X-ray diffraction (XRD), scanning electron microscope (FE-SEM/EDS), and atomic force microscopy (AFM). The influence of Si content along with process parameters such as power on the microstructural characteristics of Cr–Si–N and CrN films were investigated and compared between each other. The power and increasing Si contents strongly influence the microstructural and hardness of the deposited films. XRD analysis of the coatings indicates a grain refinement with increase in Si content during deposition of coatings, which is tandem with AFM and SEM results. Also, the surface roughness and particle size are decreasing with addition of Si in the films. The hardness of CrN and CrSiN was measured by microhardness tester and found that introduction of Si content in the CrN system increases its hardness from 1839 Hv to 2570 Hv.     

辉光放电质谱仪测定不锈钢中微量元素的不确定度分析

本文以不锈钢中铁(Fe)元素作为内标,采用辉光放电质谱仪测定不锈钢中锰(Mn),硅(Si),硫(S),磷(P),镍(Ni),铬(Cr),钨(W),钒(V),钼(Mo),铝(Al),钛(Ti),铜(Cu)等12种元素。讨论了测试过程中由测量重复性、样品不均匀性和标准样品本身不确定度等因素所带来的不确定度分量,计算出测定不锈钢中的12种元素百分含量的合成不确定度及扩展不确定度。研究结果表明,采用辉光放电质谱仪测定不锈钢中的12种元素含量的扩展不确定度均小于0.01%。