ICP-AES法测定碳钢、低合金钢中13种元素

本文选择了硝酸、王水、逆王水,进行碳钢、低合金钢溶样条件试验,以谱线强度为指标,溶解酸种类、溶解酸浓度、溶解酸用量、定容酸用量等四因素为变化条件,各因素中有三水平,即按正交实验表L_9(3~4)进行试验,编制计算程序,快速、科学地优选出最佳溶样条件—30ml NHO_3(1+5v/v)和3ml HCl,ICP-AES法同时测定铝、砷、铬、钴、铜、磷、锰、钼、镍、硅、锡、钛和钒13种元素。为确定测试方法的重复性(r)和再现性(R)而进行精密度试验。精密度数据是由10个实验室对7个样品作试验确定的。方法的回收率为94％-105％。精密度在8％以内。     

土壤中铅铬铜铁锌锰钙的测定

报道使用全酸法消解土壤，并用同一消解液分剐测定土壤中的铅、铬、铜、铁、锌、锰、钙等金属元素。其中铅使用原子荧光光谱法测定，其他元素使用火焰原子吸收光谱法测定。方法准确、快速、简便，适用于环境土壤中多种元素的测定，结果满意。     

Determination of Calcium,Zinc, and Phosphorus in multigrade crankcase oils by XRF,DRES, and ICP-AES

The effect of viscosity index improvers such as styrene-isoprene copolymer (SICP), styrene-butadiene copolymer (SBCP), ethylene-propylene copolymer (OCP) and poly(alkyl) methacrylate (PMA), in multigrade oils on the determination of Ca, Zn and P in fresh and used lubricating oils was studied using XRF, DRES and ICP-AES techniques. Crankcase lubricating oil blends containing known amounts of Ca (2900 ppm), Zn (1700 ppm) and P (1600 ppm) were further formulated with different concentrations of these VI improvers and analysed for their Ca, Zn, and P contents by XRF, DRES and ICP-AES. Based on a comparison of the resulting analytical data, it was concluded that the VI improvers had no effect on the analysis results, and that the concentrations of Ca, Zn and P in the oil determined by these techniques correlate well with each other.     

A criterion base for assessment of strength, lifetime, reliability, survivability, and security of machines and man-machine systems

Stages and phases in the development of methods, criteria, and systems for the assessment of strength, lifetime, survivability, safety, risks, and security of machinery are described against the background of the history of the Institute of Science of Machines, Russian Academy of Sciences, its problems and its computational and experimental resources. A system of defining expressions for a differential and generalized assessment of required margins is reported and a cumulative curve is constructed that correlates external impacts and stress-and-strain and limiting states according to damage, failures, breakdowns, emergencies, and catastrophes.     

Microtribology of silicon,oxide, and carbide surfaces

This paper presents an overview of the microtribological properties of silicon oxide, sapphire, and titanium carbide surfaces as well as a self‐assembled monolayer with respect to their application in microsystems. Testing was performed with a reciprocating microtribometer with normal loads in the micronewton to millinewton range. Silicon and titanium carbide balls were used as counterbodies. For silicon oxide, sapphire and a perfluorodecyltrichlorosilane self‐assembled monolayer (FDTS), the microfriction corresponds to the water contact angle when the smoother titanium carbide ball or the relatively rougher silicon ball was used as a counterbody. Microfriction measurements performed on tribopairs of the same material, but having different roughnesses, showed that the friction of the rougher tribopairs is lower than that of the smoother ones. Interestingly, in the microforce regime, reduction in friction was significant and almost as much as when hydrophobic self‐assembled monolayers are applied on smooth surfaces. This investigation showed that comparative microtribological investigations between different material systems can be very challenging due to the fact that comparable roughness values on samples and countersamples are difficult to realize. Copyright © 2006 John Wiley & Sons, Ltd.     

The Wear of Copper,Aluminum, Mild Steel,and Zinc,and Their Wear Particle Shape Factors

Unlubricated, highly loaded sliding experiments were conducted for systems of mild steel, copper, aluminum, and zinc. Load is critical in determining the wear mode. A Cocks wedge mechanism is the primary method of wear for copper, and for aluminum until a critical temperature is reached. The wear of steel is characterized by the formation of small un-joined fragments.

The surfaces of wear particles were of two types; copper showed one type, and aluminum, mild steel, and zinc the other.

Wear particle shape can be characterized by the ratios of dimensions (L/W) and (L/H). These factors are easily determined to good accuracy, and have distributions which are both far different in form and mean values for the various metals. The mean values of the shape factors are independent of particle size, and of each other.

Surface roughness is not related to wear particle size for highly loaded sliding.     

Latency, activation, and binding proteins of TGF-beta

The TGF-beta superfamily of growth factors consists of an increasing number of different polypeptide modulators of cell growth, differentiation, and morphogenesis. Three mammalian isoforms have been molecularly cloned. Numerous ways to regulate the expression of the TGF-beta genes have been identified. TGF-betas are, for example, subject to regulation by retinoids, steroid hormones, and vitamin D. A characteristic feature in the biology of TGF-betas is that they are usually secreted from cells in latent forms. The large latent complex consists of the small latent complex (TGF-beta and its propeptide) and a high molecular weight protease resistant binding protein, latent TGF-beta binding protein (LTBP). LTBPs are required for the proper folding and secretion of TGF-beta. TGF-beta is not just secreted from cultured cells but is deposited via LTBPs to the pericellular space, namely to the extracellular matrix. Release of these complexes and activation by proteases is under tight regulation and provides a means to rapidly increase local concentrations of TGF-beta. Biological events, where enhanced or focal proteolysis and activation of latent TGF-beta takes place, include cell invasion, tissue remodeling, and wound healing.     

少耕穴灌聚肥节水种植技术初探

介绍了少耕穴耕、开穴灌水、集中覆盖、合理密植、田间管理、收获等操作规程,指出了少耕穴灌聚肥节水种植技术具有抗旱保苗、增产增收、改善农田生态环境的效果,该项技术是大幅度提高干旱地区农业生产经济效益,使农民增产增收的实用新技术,值得大力推广.     

Assessing Nanotribological Performance and Surface Energies of Inconel-ZrN,Cr-ZrN,Nb-ZrN,and ZrN Thin Films

The nanotribological performance for three groups of metal-ZrN, including Inconel-ZrN, Cr-ZrN, Nb-ZrN, and polycrystalline ZrN thin films has been investigated and results were correlated with surface energy evaluations. Metal-ZrN and ZrN thin films were deposited using direct current (DC) unbalanced magnetron sputtering and their elemental composition was investigated using X-ray photoelectron spectroscopy (XPS). Both nanomechanical and nanotribological properties were evaluated using a triboscope interfaced with an atomic force microscope (AFM) and the surface energies were calculated from the contact angle measurements. The present research reports for the first time on the nanowear behavior, surface roughness, and friction coefficients correlated with surface energies of metal-ZrN and ZrN thin films.

All metal-ZrN thin films showed improved nanotribological performance compared to the polycrystalline ZrN. Results indicate that several of the Inconel-ZrN thin film compositions have both superior nanotribological behavior and good wettability and thus have high potential use for wear resistant applications.     

Fuel consumption,speed, and power of vehicles

The fuel consumption, speed, and power of vehicles are reviewed, as measures of competitiveness.     

Influence of viscosity index improver,molecular weight,and base oil on thickening,shear stability,and evaporation losses of multigrade oils

Some SAE 15W‐40 multigrade oils were formulated, using polymethacrylate (PMA) viscosity index improvers of different molecular weights, with a mixture of N 150 and N 500 as the base oil. Kinematic and dynamic viscosities, borderline pumping temperatures, pour points, shear stability, and evaporation losses were measured. The results confirm that viscometric properties as well as shear stability depend strongly on the polymer concentration and molecular weight of the VI improvers. However, evaporation losses are dominated by the volatility properties of the base oil.     

电感耦合等离子体质谱法测定大米中砷铅铜锌铬镉镍元素含量

建立电感耦合等离子体质谱法（ICP-MS）一次进样同时测定大米中重金属As、Pb、Cu、Zn、Cr、Cd、Ni元素含量的方法。实验表明,本方法的线性范围宽,线性相关系数在0.9994～0.9999范围内;元素检出限低,7种重金属元素检出限范围为1.52～51.3μg/kg;精密度良好,测定7种重金属元素含量的相对标准偏差均〈5%;采用国家标准物质大米（GBW10010）和玉米（GBW10012）测定对照,评价了方法的准确性,各元素的回收率在91.2%～110%范围内。结果表明,该方法简便、快速、灵敏、准确,适用于大米、玉米中7种重金属元素含量的同时测定。     

统一监控、诊断、分析PROFIBUS、PROFINET和工业以太陬

一个安全、可靠的工业网络可保证工业系统正常无误运行,从而为工厂自动化不间断生产保驾护航。因此,能够实现工业网络的统一化监控和诊断是每一个用户的愿望。本文介绍了一个基于THSCOPE（软件）＋THLINK（硬件）的网络监控解决方案,让PROFIBUS、PROFINET和工业以太网的统一化监控、诊断和分析变为了现实。     

Microtribology,squeeze, and friction of the colloidal layer

Lubricant films containing colloidal overbased calcium salts have particular effects on detergency and on the wear process. The mechanical properties of such boundary films are very dependent on the process conditions, and are essentially a result of physico-chemical transformations of the colloid. Three types of films were compared: a film obtained by the drying of the base solvent, a film due to the compaction of the colloid between two steel surfaces, and a friction film obtained with this type of lubricant. Adsorption, compaction, and shear transformations induce a solid film. The pressure effect on the frictional behaviour of these colloidal films has been investigated using a surface force apparatus for low contact pressure (10⁴ to 10⁶ Pa), and using tribometers supporting heavy loads for the analysis of the high pressure domain. Above a critical pressure, evaluated at 10⁶ Pa, the colloidal film does not flow, but forms a compacted mattress sliding on the surface plane and squeezing a molecular layer of lubricant.     

HPLC Columns,Theory, Technology,and Practice

ABSTRACT

This paper presents some results of experimental research addressing the influence of different thermal insulation fillings on dynamic properties of industrial resistance temperature probes, based on a thin-film platinum resistance temperature detector. The experiments were carried out with four jacket thin-film resistance temperature probes, all having identical protection tube geometry, yet differing in the thermal insulation filling materials. Further, a comparison between transient response characteristics in water established experimentally and those based on simulations with electric–thermal analogy, is given. The results of these analyses can be applied to enhance the dynamic response of temperature measurement made by temperature probes in water.     

Membranes,minerals, and proteins of developing vertebrate enamel

Developing tooth enamel is formed as organized mineral in a specialized protein matrix. In order to analyze patterns of enamel mineralization and enamel protein expression in species representative of the main extant vertebrate lineages, we investigated developing teeth in a chondrichthyan, the horn shark, a teleost, the guppy, a urodele amphibian, the Mexican axolotl, an anuran amphibian, the leopard frog, two lepidosauria, a gecko and an iguana, and two mammals, a marsupial, the South American short-tailed gray opossum, and the house mouse. Electron microscopic analysis documented the presence of a distinct basal lamina in all species investigated. Subsequent stages of enamel biomineralization featured highly organized long and parallel enamel crystals in mammals, lepidosaurians, the frog, and the shark, while amorphous mineral deposits and/or randomly oriented crystals were observed in the guppy and the axolotl. In situ hybridization using a full-length mouse probe for amelogenin mRNA resulted in amelogenin specific signals in mouse, opossum, gecko, frog, axolotl, and shark. Using immunohistochemistry, amelogenin and tuftelin enamel proteins were detected in the enamel organ of many species investigated, but tuftelin epitopes were also found in other tissues. The anti-M179 antibody, however, did not react with the guppy and axolotl enameloid matrix. We conclude that basic features of vertebrate enamel/enameloid formation such as the presence of enamel proteins or the mineral deposition along the dentin-enamel junction were highly conserved in vertebrates. There were also differences in terms of enamel protein distribution and mineral organization between the vertebrates lineages. Our findings indicated a correlation between the presence of amelogenins and the presence of long and parallel hydroxyapatite crystals in tetrapods and shark.     

Formation,structure, and properties of lubricant-derived antiwear films

In recent years, surface analytical methods that determine structure have been combined with methods that measure elemental composition and oxidation states, to yield an improved understanding of lubricant-derived tribofilms. Methods assessing the mechanical properties of thin films have also been applied to tribofilms with thicknesses of the order of nanometres. These methods, in combination with chemical and physical studies of bulk lubricant systems and assessments of lubricant behaviour in tribological environments, have made it possible to describe comprehensively film forming mechanisms, structures and tribological properties. This paper outlines the initial results of such an attempt, focusing on zinc dialkyl dithiophosphates and overbased detergents in model systems and engine oils.