机电产品聚氯乙烯中铅、镉、铬、汞含量测定——发射光谱法

采用高温压力罐，将机电产品中的聚氯乙烯样品用硝酸．氟硼酸．过氧化氢溶解后，用全谱直读双向视电感耦合等离子体原子发射光谱仪（DUO-ICP-AES）同时测定聚氯乙烯中的铅、镉、铬和汞，方法的检测限为0．0015～0．014μg／mL，方法的回收率和精密度分别为87．7％～100．0％和0．12％～4．60％，实际样品的检测结果较为满意。该方法快速简便，可应用于机电产品密封外壳部件聚氯乙烯中的铅、镉、铬和汞日常检验。     

微波消解-电感耦合等离子体质谱法测定电子烟雾化液中多种重金属元素

建立了微波消解-电感耦合等离子体质谱法同时测定电子烟雾化液中铅、砷、汞、镉、铬、镍等重金属元素的方法,并对市售40种电子烟雾化液进行测定。实验对微波消解条件和质谱检测条件进行优化,在优化条件下,6种元素线性相关系数均在0.999以上,检出限均可达μg/kg级别;在低、中、高3个加标水平下,铅、砷、镉、铬、镍加标回收率在94%至108%之间,汞加标回收率在78.1%至86.1%之间;方法精密度在5%以内。此方法前处理操作简便,检测时间短,精密度高,准确性好。     

电感耦合等离子体-质谱法测定番茄酱中多种重金属元素含量

将电感耦合等离子体-质谱(ICP-MS)技术应用于番茄酱中的无机元素分析,实现一次制样,同时测定番茄酱中13种食品安全相关元素含量。本文给出铅、镉、铬、汞、砷、锡、锌、铜、铁、锰、铝、镍、硒等13种元素的方法检出限为0.61～125.7μg/L,回收率为83.8%～112.5%,RSD值为0.3%～5.0%。该方法分析速度快、操作简单,方法检出限、精密度和线性范围均能满足出口番茄制品食品安全检测的相关要求。     

石墨炉原子吸收法测定海水中痕量铜铅镉镍

石墨炉原子吸收法测定海水中痕量铜、铅、镉、镍,方法的特征浓度（1%吸收）分别为铜：0.808μg/L、铅：1.20μg/L、镉：0.063 7μg/L、镍：1.12μg/L,最低检出限分别为铜：0.24μg/L、铅：0.36μg/L、镉：0.019μg/L、镍：0.34μg/L。室内控样测试结果的相对误差分别为铜：3.5%、铅：0.8%、镉：4.2%、镍：4.9%,相对标准偏差分别为铜：5.6%、铅：3.6%、镉：5.3%、镍：5.8%。     

电感耦合等离子体质谱法测定灌溉水中7种重金属及其定性分析

实验用ICP—MS同时测定农田灌溉水中铬、镍、铜、锌、砷、镉、铅等7种重金属元素,在优化的仪器条件下,各元素的标准曲线相关系数全部达到0.9999以上;样品测定精密度为1.52%～4.10%;各元素检出限在0.000246μg.L-1～0.260μg.L-1之间;样品加标回收率在91.6%～112.5%之间。测定国家标准物质铜铅锌镉镍铬和砷环境标准样品,各元素的准确度达到97.1%～106.4%,结果令人满意。实验证明采用该方法对灌溉水中多元素同时进行测定,具有线性范围宽、精密度高、灵敏度高、准确性好、简单快速的优点。同时采用半定量分析方法对灌溉水进行定性分析,对于含量在0.1mg.L-1数量级以上的元素其半定量结果准确度较高;若元素含量在0.01mg.L-1数量级以下,则半定量结果准确度较差。     

超声提取-ICP-MS法测定土壤中有效态铅和镉

本实验以DTPA为提取剂,建立了超声提取-电感耦合等离子体质谱（ICP-MS）测定土壤中有效态铅和镉的方法。实验考察了超声提取时间、溶液稀释倍数、测定条件等因素,并对基体干扰的消除进行了对比研究。在优化的ICP-MS 条件下,有效态铅和镉在1~200 μg/L浓度范围内线性关系良好,方法检出限分别为0.019 mg/kg、0.001 4 mg/kg,相对标准偏差小于6%（n=6）。用国家土壤标准物质进行方法精密度和准确度验证,相对误差小于5%（n=6）,该测定结果与国家标准方法（GB/T 23739-2009）一致,经t检验表明两者无显著性差异。该方法简便快捷、检出限低,具有良好的准确度和精密度,可满足大批量农业土壤污染调查样品中有效态铅和镉的分析要求。     

石墨消解连续光源原子吸收法测定废气中重金属

采用DEENA石墨消解仪对采集的废气样品进行前处理,利用contrAA700连续光源原子吸收光谱仪测定样品中重金属铜、锌、镍、铅、镉、锰。本试验优化了消解液的组合,使样品消解更完全,且克服了传统火焰原子吸收法需要更换空心阴极灯的缺陷,提高了分析速度。各元素的检出限分别为铜0.0025mg/m~3,锌0.0012mg/m~3,镍0.0038mg/m~3,锰0.0025mg/m~3,铅0.0075mg/m~3,镉0.0025mg/m~3。各元素的回收率分别为铜94.2%,锌102.5%,镍95.6%,锰104.1%,铅97.3%,镉95.3%。本方法具有较高的准确度,相比传统的火焰原子吸收法有更高的工作效率,适用于废气中多种重金属的同时测定。     

二氧化铀中十五个杂质元素的化学光谱测定

本文介绍采用反相柱上色层技术使铀和铀中杂质分离。用光谱法测定杂质元素,可测定硼、镉、银、铅、铜、铁、铬、锡、镁、钙、镍、钼、锰、钒、铝等15个杂质元素。取样50毫克时,各杂质元素的测定范围分别为0.2～320ppm,方法的回收率在86～125%之间,在95%置信范围内,方法的精密度小于±23%。     

氢化物发生原子荧光光度法同时测定膨化食品中的铅和锡

本文介绍在优化好的实验参数和测量条件下用氢化物发生原子荧光光度法对膨化食品中的铅、锡进行同时测定的方法,该方法的精密度Pb(1.56%～2.24%)、Sn(2.04%～3.58%),检出限Pb(0.063mg/L)、Sn(0.158mg/L),结果令人满意。     

不锈钢螺母的钻孔、攻螺孔

在石油、化工行业机械设备及管道的紧固联接中，为了确保联接的牢固，严防腐蚀失效，不锈钢紧固件被广泛应用，其材质一般为铬不锈钢或铬镍不锈钢。铬不锈钢分为wc1=12％、wc1=17％和wc1=27％等种类；铬镍不锈钢中wc1=17％～20％，wni=8％～11％。铬镍不锈钢的抗腐蚀性能及力学性能比铬不锈钢高，     

Innervation of cerebral blood vessels: morphology, plasticity, age-related, and Alzheimer's disease-related neurodegeneration

The light microscopical and ultrastructural morphology of the innervation of the major cerebral arteries and pial vessels is described, including the origins of the different groups of nerve fibres and their characteristic neurotransmitter phenotype. Species and region specific variations are described and novel data regarding the parasympathetic innervation of cerebral vessels are presented. The dynamic nature, or plasticity, of cerebrovascular innervation is emphasized in describing changes affecting particular subpopulations of neurons during normal ageing and in Alzheimer's disease. The molecular controls on plasticity are discussed with particular reference to target-associated factors such as the neurotrophins and their neuronal receptors, as well as extracellular matrix related factors such as laminin. Hypotheses are presented regarding the principal extrinsic and intrinsic influences on plasticity of the cerebrovascular innervation.     

Synthetics versus vegetable oils: Applications,options, and performance

Environmental concerns have brought forward vegetable oils as alternatives to more expensive synthetic lubricant base stocks, in moderate operating conditions. The contents of various acids, such as oleic and linoleum, can be changed by selective breeding to produce more desirable lubricating properties and less oxidation vulnerability. Different tests are needed for such lubricants, and the Baader test has been modified to show the ageing stability of rapeseed oil raffinate, TMP trioleate, dioctyl adipate, and HOSO. Such oils can also be modified with additive packages.     

电火花沉积重熔碾轧修整试验

针对电火花沉积层存在的孔隙、微裂纹、表面组织疏松、连续性差及表面质量差等缺陷,提出了电火花沉积重熔碾轧修整加工方法。进行了所提方法与电火花沉积的对比试验,并对制备的沉积层进行了分析。结果表明：重熔碾轧修整时电极对沉积表面有较大的挤压碾轧作用,能有效消除沉积层内部孔隙、微裂纹、组织疏松等缺陷,细化沉积层晶粒结构,提高沉积层的连续性、完整性。电极对沉积层表面有显著的磨削涂覆作用,重熔碾轧修整表面粗糙度为电火花沉积表面粗糙度的76.3%,基本消除了表面孔洞、裂纹等缺陷,提高了沉积层表面质量。     

通用低噪喷油螺杆空压机的噪声控制

封闭、空冷、螺杆压缩机机组的噪声源分为:气载噪声(如冷却风扇噪声)及源于压缩机排气压力脉动的结构衍生型噪声。在一个声学实验室内,对经过多种试验性改进的隔声机组上,进行了系统噪声试验和冷却空气吸入和排出系统等的试验,从此机组测得了70dB(A)的噪声值。     

Additive manufacturing technology: the status,applications, and prospects

Additive manufacturing (AM) has first emerged in 1987 with the invention of stereolithography. The AM is an important, rapidly emerging, manufacturing technology that takes the information from a computer-aided design (CAD) and builds parts in a layer-by-layer style. As this technology offers many advantages such as manufacturing of complex geometries, reducing manufacturing cost and energy consumption, it has transformed manufacturing from the mass production to the mass customization. Also, it has found wide applications in several fields although some drawbacks. This paper presents the state of the art of the different AM processes, the material processing issues, and the post-processing operations. A comparison between AM and conventional processes is presented as well. We finish by presenting some prospects of this technology such as hybrid manufacturing and 4D printing.     

Fluorescence microscopy: established and emerging methods, experimental strategies, and applications in immunology

Cutting-edge biophysical technologies including total internal reflection fluorescence microscopy, single molecule fluorescence, single channel opening events, fluorescence resonance energy transfer, high-speed exposures, two-photon imaging, fluorescence lifetime imaging, and other tools are becoming increasingly important in immunology as they link molecular events to cellular physiology, a key goal of modern immunology. The primary concern in all forms of microscopy is the generation of contrast; for fluorescence microscopy contrast can be thought of as the difference in intensity between the cell and background, the signal-to-noise ratio. High information-content images can be formed by enhancing the signal, suppressing the noise, or both. As improved tools, such as ICCD and EMCCD cameras, become available for fluorescence imaging in molecular and cellular immunology, it is important to optimize other aspects of the imaging system. Numerous practical strategies to enhance fluorescence microscopy experiments are reviewed. The use of instrumentation such as light traps, cameras, objectives, improved fluorescent labels, and image filtration routines applicable to low light level experiments are discussed. New methodologies providing resolution well beyond that given by the Rayleigh criterion are outlined. Ongoing and future developments in fluorescence microscopy instrumentation and technique are reviewed. This review is intended to address situations where the signal is weak, which is important for emerging techniques stressing super-resolution or live cell dynamics, but is less important for conventional applications such as indirect immunofluorescence. This review provides a broad integrative discussion of fluorescence microscopy with selected applications in immunology.     

In situ, noninvasive characterization of superhydrophobic coatings

Light scattering was used to measure the time-dependent loss of air entrapped within a submerged microporous hydrophobic surface subjected to different environmental conditions. The loss of trapped air resulted in a measurable decrease in surface reflectivity and the kinetics of the process was determined in real time and compared to surface properties, such as porosity and morphology. The light-scattering results were compared with measurements of skin-friction drag, static contact angle, and contact-angle hysteresis. The in situ, noninvasive optical technique was shown to correlate well with the more conventional methods for quantifying surface hydrophobicity, such as flow slip and contact angle.     

Measurement of gas flow in short ducts,also rectangular

This paper presents a discussion of the system of the measurement of the gas flow (of air or flue gases) dedicated particularly for use in rectangular ducts with short straight sections and with considerable cross-section dimensions (above 1 m). The measurement is conducted at a necking – the duct inset – with a single-point sensor such as the Prandtl tube. The measuring method may be used in newly designed air and flue gas ducts, as well as in those already in service, such as air conditioning or ventilation systems and power boilers.     

Curie point, susceptibility, and temperature measurements of rapidly heated ferromagnetic wires

This article describes a technique to measure the temperature of a resistively heated ferromagnetic wire. The wire's temperature rapidly increases, a scenario in which a thermocouple or thermistor's thermal inertia prevents it from keeping up with the rapid temperature variation. The temperature is derived from electrical measurands (voltage and current) and time, as well as thermophysical data such as heat losses and emissivity, and is based on a dynamical thermal-electrical energy conservation principle. We go on to use our technique for the quantitative determination of the Curie point as well as the magnetic susceptibility at elevated temperatures. The results are in good agreement with accepted values.     

益智仁中Mg、Al、Fe、Zn、Cd、Pb含量及精油成分分析

文章以ICP-MS法测定益智仁中Mg、Al、Fe、Zn、Cd、Pb六种元素含量,并用水蒸汽法提取精油,通过气相-质谱（GC-MS）联用手段对精油的主要化学成分进行分析,以峰面积归一化法确定各组分的相对含量;结果从益智仁精油中分离出28个色谱峰,并鉴定了其中的25种成分,占精油总含量的94.08%,其主要成分依次为圆柚酮（15.51%）、γ-榄香烯（10.71%）、朱栾倍半萜（瓦伦烯）（8.69%）、α-芹子烯（6.71%）等,从元素测定来看Mg含量很高达6550μg/g,Pb含量很低,仅1.59μg/g。