瑞典创世纪的6大品牌

瑞典虽然只有960万人口．却诞生了许多知名的跨国公司，人们熟悉的爱立信、沃尔沃、绅宝、山德维克、宜家和伊莱克斯等都诞生于北欧的这片土地上。而从小在工业设计环境熏陶中长大的瑞典人．则在总部牢牢地把握着设计工作。这是谁也抢不走．且源源不断从头脑中诞生的财富。连瑞典人自己也很难说清楚．瑞典到底有多少工业设计师．本文就带大家进入瑞典．看看你可能会惊讶很多非常熟悉的品牌．居然都出自只有中国黑龙江面积那么大的瑞典。     

Low cost microwave thick film structures

This paper examines the potential use of low cost materials and processes to produce thick film structures at low microwave frequencies. It examines empirically the upper frequency limits for the use of simple design techniques as a function of substrate thickness. It concludes that satisfactory results can be obtained using low cost methods up to about 12 GHz for 1 mm 96% alumina substrates and 16 GHz for 0.63 mm substrates. These are the most commonly available thick film substrate thicknesses. A low permittivity protective layer is desirable to maintain reliability.     

Capillarity Effect Controlled Precipitate Growth at the Grain Boundary of Long-Term Aging Al 5083 Alloy

A model was developed to predict thickness and continuity of β phase (Al₃Mg₂) formed at grain boundaries of long-term aged Al 5083 alloy. In this model, a variable collector plate mechanism was adopted at the early stage of aging, then, at about 1 month ( \( 2\sqrt {D_{\text{b}} t} \approx 100\;{\text{nm}} \) ), the model transitions to a constant collector plate mechanism. Two concentration profiles of Mg, one for a semi-infinite bulk at short diffusion distances and one for a finite slab at long diffusion distances ( \( 2\sqrt {D_{\text{m}} t} \approx 20\,{\text{pct}} \) of the grain size), were applied to this model for different aging times. Capillarity effects were used to determine the morphology of β phase at the grain boundary. Combining different collector plate mechanisms and Mg concentration profiles, the whole β phase growth process was divided into three stages (short-term Mg concentration profile-variable collector plate, short-term Mg concentration profile-constant collector plate, and long-term Mg concentration profile-constant collector plate). Finally, the model was solved numerically. Experimental results of β phase length and thickness were obtained using transmission electron microscopy (TEM) images of Al 5083 aged at 343 K (70 °C) for different thermal exposure times. Modeling results of β phase thickness and continuity agree well with experimental observations.     

Kinetics of the Benzylation of Potato Starch

The formation of benzyl ethers of potato starch by etherification with benzyl chloride is base catalyzed and is therefore carried out at high pH. In a suspension of starch granules the rate of starch ether formation is found not to be linearly related to the concentration of hydroxyl ions in the water phase of the suspension. At the same pH widely different rates of reaction can be observed, to be due to the tendency of the starch granules to “absorb” hydroxyl ions when electrolytes are added to the suspension. The rate of formation of the benzyl ether of starch is found to be linearly related to the amount of hydroxyl ions “absorbed” by the starch. The rate of the side reaction leading to benzyl alcohol turned out to be higher in the presence of starch than in water of the same pH.     

新兴的微乳技术（英）

从本世纪４０年代初舒尔曼及其助手发现微乳以来,微乳已被广泛地应用于许多领域。微乳具有很高的界面面积,稳定的热力学特性及对难溶液体的强溶解性,所以它被广泛地用在化妆品、制药、润滑剂、食品、农业喷洒、涂料、环境治理、清洗、燃料、化学合成、微孔介质的合成、提高反应的动力学特性、化学分析等诸多领域。讨论了微乳在新兴技术中的应用研究。     

The effects of duty cycles on pulsed current electrodeposition of ZnNiAl2O3 composite on steel substrate: Microstructures,hardness and corrosion resistance

In this study, we examine the effect of duty cycles (33%, 50% and 67%) under square-wave galvanostatic pulses on the electrodeposition of zinc-nickel-alumina (ZnNiAl₂O₃) composites from a sulfate bath. XRD results showed that the dominant phases of the ZnNiAl₂O₃ electrodeposits were mixtures of Zn₂₁Ni₅ and Zn₂₂Ni₃ phases together with as Al₂O₃. The Ni content measured in the electrodeposits using EDS varied from 9.73 to 13.47 wt%. SEM results showed that finer and smoother surface electrodeposits were obtained by pulsed current electrodeposition at a low (33%) duty cycle. In addition, the corrosion properties of the electrodeposits were characterized by Tafel plots and electrochemical impedance spectroscopy (EIS), while the microhardness of the electrodeposits was measured by a Vickers hardness tester. In summary, this study revealed that pulsed current electrodeposition at a 33% duty cycle led to a finer and smoother surface morphology, an enhanced strength, a greater corrosion resistance, and a higher Ni content in the ZnNiAl₂O₃ composite coatings compared to plating at higher duty cycles or plating through DC electrodeposition.     

Preliminary observations on influence of dairy products on biofilm removal from silicone rubber voice prostheses in vitro

We determined oropharyngeal biofilm removal from silicone rubber voice prostheses in an artificial throat after perfusion with different commercially available dairy products, including buttermilk, Lactobacillus casei Shirota fermented milk (Yakult, Yakult Netherlands BV, Almere, The Netherlands), low-fat milk, and three types of yogurt. Buttermilk removed both yeasts and bacteria from biofilms on voice prostheses, but this was not observed with a pasteurized buttermilk product. Some of the other products, most notably Yakult fermented milk drink, reduced the number of bacteria, whereas growth of yeasts in the biofilms was not inhibited. This study demonstrates that there may be health benefits associated with the consumption of certain dairy products when applied to the upper digestive tract.     

An evaluation of depletion layer photoactivity in Cu2ZnSnS4 thin film

Cu₂ZnSnS₄ films were examined in Eu^3 +/Eu^2 + electrolyte to evaluate various analytical expressions for photocurrent response as a function of applied potential. A Gärtner model, which considers charge transfer (across the double layer) was evaluated. This model shows an adequate fit in the negative photocurrent region. The fit of the Gärtner model over a broader range of photocurrent is improved by modifying it to include the contributions due to space charge current and dark current as proposed and demonstrated in this study. Various other models and relevant fitting parameters are also evaluated and discussed in this article.     

The effects of dopant impurities on Cu<Subscript>2</Subscript>ZnSnS<Subscript>4</Subscript> system Raman properties

Impurities in Cu₂ZnSnS₄ (CZTS) can alter the electronic and optical properties, which may reduce photovoltaic device efficiency. Phonon dispersion susceptibility can be used to investigate the effects of foreign dopants on pairing between atoms within lattice. In order to investigate the effect of free holes on the optical phonons and asymmetry in the Raman peaks due to impurities, Sb-, Fe-, and Ag-doped CZTS thin films were prepared and systematically studied. Doping with impurities causes a shift in Raman peak frequency as well as linewidth. An investigation has been made based on the reduced mass of the vibrating CZTS lattice that changes due to dopant addition. For polycrystalline Sb-doped CZTS, the predicted wavenumber shift for Raman ‘A’ mode follows a similar trend as evidenced in experiments and can be explained by the square-root relationship between frequency and the vibrating mass. Raman lineshape for Sb-doped CZTS thin films and nanocrystals becomes wider, asymmetric, and moves toward lower vibrational frequency when laser power density increases. Atomic force microscopy was also performed to examine surface properties.     

Numerical Simulation of the Three-Phase Flow of a Bubble Interacting with the Steel–Slag Interface During the Secondary Refining Process

Metallurgical and Materials Transactions B - Gas stirring is an effective method for the secondary refining process of steel. The microphenomena among the phases of an argon bubble floating in...