燃气轮机叶片材料0Cr17Ni4Cu4Nb砂带磨削性能研究

理论分析了在切除过程中磨粒与材料表面的交互作用机理,进行了砂带磨削燃气轮机叶片材料0Cr17Ni4Cu4Nb的试验研究,系统分析了各磨削工艺参数对材料切除率的影响规律,该研究对生产实践具有理论指导意义.     

智能家居基于Cortex-M3/M0的感知与控制子网设计

在物联网智能家居系统中,将按功能分立的抄表网、环境网、电控网、安防网等分立子网,融合成按信息流向的感知网、控制网。本文介绍了采用NXP Cortex-M3/M0系列ARM微处理器设计开发物联网智能家居系统的技术要点。     

A changing society and problems of method: a politically committed research type

This essay examines a politically engaged research genre, which follows the biography of the author who founded two journals: one on mathematical models published in English (Quality and Quantity) and one on politically committed social and economic research published in Italian (Inchiesta). The research considered focuses on Italy in the 1950s, the research by Lazarsfeld in Vienna in the 1920s and in the United States in the 1950s and 1960s, and post-1968 politically committed research in Italy. The analysis of such politically committed types of research (all very different from one another in terms of the interpretative model of reality, the methods used and the relations with the tendering party and the people observed) allows one to understand how this kind of research can be performed with very different methods—all of which do, however, seek to modify reality on the grounds of the research results. The metaphor of the crystal and the flame presented by Italo Calvino in order to classify facts and ideas and styles and feelings can also be used to visualise the polarity (and the difficulty/impossibility of contact) that has always been present in sociology between two different tendencies: towards a discipline that offers the most abstract and objective interpretative model of reality possible with the use of mathematical models (the crystal), and, instead, towards a discipline in which an interpretative model of reality is central, one that produces a social change and in which the qualitative and quantitative methods utilised are at the service of this change (the flame). This polarity thus allows us to separate first and foremost all the politically committed research performed by others for different purposes (market research, research to verify some theoretical hypotheses, etc.) but the same polarity also lies within the politically committed research. We can, indeed, identify a type of politically committed research in an area that has, at one extreme, research tending towards the utmost objectivity and scientific quality of the results and where the co-ordinators try to have all the information on the subjects maintaining the greatest possible distance (the subjects must not know they are being observed); at the other extreme, there is a type of research in which the coordinator completely involves the subjects in the gathering of information that will serve to realise a piece of research whose political aims are explicitly shared. For the identification of a sufficiently articulated typology it has been important to consider five dimensions of politically committed research: (a) the characteristics of the research coordinator (his/her belonging to the type and the academic/non-academic professional status) and his/her interpretative model of reality (b) some general characteristics of the research (the tender and funding, the topic choice, the aims, the contributions to the sociological theory, the duration); (c) the research coordinators relations with the political actors (the intensity of the relations, the political use of the research); (d) the relations of the research co-ordinator with the research subjects; (e) the methodological choices (the basic strategies, the methods used, the use of mathematical procedures). The research that exemplifies this typology is all politically committed to the left and was realised in different times and contexts. I start by considering a kind of politically engaged research (co-research) that appeared in Italy in the 1950s; I then analyse two types of politically engaged research realised in Austria at the end of the 1920s and one in the United States in the 1950s; there then follow two kinds of research realised in the 1960s and 1970s in the United States and a further two kinds realised in Italy in the 1970s and early 1980s. In order to have other kinds of research please refer to the two Journals of which I am the editor: one is an English language journal of mathematical models (Quality and Quantity, International Journal of Methodology, founded in 1966 and published today by Kluwer of Amsterdam), and a politically engaged review (Inchiesta, founded in 1971 and still published today by Dedalo of Bari).     

Selective Recovery of Cadmium,Cobalt, and Nickel from Spent Ni–Cd Batteries Using Adogen® 464 and Mesoporous Silica Derivatives

Spent Ni–Cd batteries are now considered an important source for many valuable metals. The recovery of cadmium, cobalt, and nickel from spent Ni–Cd Batteries has been performed in this study. The optimum leaching process was achieved using 20% H₂SO₄, solid/liquid (S/L) 1/5 at 80 °C for 6 h. The leaching efficiency of Fe, Cd, and Co was nearly 100%, whereas the leaching efficiency of Ni was 95%. The recovery of the concerned elements was attained using successive different separation techniques. Cd(II) ions were extracted by a solvent, namely, Adogen^® 464, and precipitated as CdS with 0.5% Na₂S solution at pH of 1.25 and room temperature. The extraction process corresponded to pseudo-2nd-order. The prepared PTU-MS silica was applied for adsorption of Co(II) ions from aqueous solution, while the desorption process was performed using 0.3 M H₂SO₄. Cobalt was precipitated at pH 9.0 as Co(OH)₂ using NH₄OH. The kinetic and thermodynamic parameters were also investigated. Nickel was directly precipitated at pH 8.25 using a 10% NaOH solution at ambient temperature. FTIR, SEM, and EDX confirm the structure of the products.     

变电站不锈钢金属膨胀节泄漏原因分析

从化学成分、断口电镜扫描、X射线能谱和金相试验等方面,分析了沧州供电公司某变电站电流互感器不锈钢膨胀节泄漏的原因,认为泄漏是不锈钢膨胀节外表面点状电化学腐蚀所致,而该膨胀节表面状态的不连续性,周围潮湿的空气介质及空气介质中富含S、Cl等元素,是造成膨胀节外表面点状电化学腐蚀的主要原因。     

GFAAS法测定LiMn2O4中的Pb和Cd

采用石墨炉原子吸收光谱法(GFAAs)测定锂离子电池正极材料LiMn2O4中杂质Pb和Cd的含量.探讨了HNO2浓度、Pb和Cd的灰化温度和原子化温度、基体改进剂对测定结果的影响.该方法的操作简单,准确度高,Pb的回收率为91.22%～93.75%,Cd的回收率为96.5%～108.6%;精密度好,两种元素测定的相对标准偏差RSD(n=lO)<5%.     

Sogatella furcifera Saliva Mucin-like Protein Is Required for Feeding and Induces Rice Defences

The white-backed planthopper (WBPH), Sogatella furcifera, is one of the most important piercing-sucking pests of rice (Oryza sativa) in Asia. Mucin-like salivary protein (SFMLP) is highly expressed in the salivary glands of WBPH, which plays an important role in WBPH feeding. In this study, WBPH injected with dsSFMLP had difficulty in sucking phloem sap from rice plants, which significantly reduced their food intake, weight, and survival. In contrast, the knockdown of the SFMLP gene had only a marginal effect on the survival of WBPH fed an artificial diet. Further studies showed that silencing SFMLP resulted in the short and single-branched salivary sheaths secretion and less formation of salivary flanges in rice. These data suggest that SFMLP is involved in the formation of the salivary sheath and is essential for feeding in WBPH. Overexpression of the SFMLP gene in rice plants promoted the feeding of WBPH, whereas silencing the gene in rice plants significantly decreased WBPH performance. Additionally, it was found that overexpression of SFMLP in rice plants elicited the signalling pathway of SA (salicylic acid) while suppressing JA (jasmonic acid); in contrast, silencing of the SFMLP gene in rice plants showed the opposite results. This study clarified the function of SFMLP in WBPH feeding as well as mediating rice defences.     

Improving Lipid Production of Yarrowia lipolytica by the Aldehyde Dehydrogenase-Mediated Furfural Detoxification

Yarrowia lipolytica, the non-conventional yeast capable of high lipogenesis, is a microbial chassis for producing lipid-based biofuels and chemicals from renewable resources such as lignocellulosic biomass. However, the low tolerance of Y. lipolytica against furfural, a major inhibitory furan aldehyde derived from the pretreatment processes of lignocellulosic biomass, has restricted the efficient conversion of lignocellulosic hydrolysates. In this study, the furfural tolerance of Y. lipolytica has been improved by supporting its endogenous detoxification mechanism. Specifically, the endogenous genes encoding the aldehyde dehydrogenase family proteins were overexpressed in Y. lipolytica to support the conversion of furfural to furoic acid. Among them, YALI0E15400p (FALDH2) has shown the highest conversion rate of furfural to furoic acid and resulted in two-fold increased cell growth and lipid production in the presence of 0.4 g/L of furfural. To our knowledge, this is the first report to identify the native furfural detoxification mechanism and increase furfural resistance through rational engineering in Y. lipolytica. Overall, these results will improve the potential of Y. lipolytica to produce lipids and other value-added chemicals from a carbon-neutral feedstock of lignocellulosic biomass.     

四川盆西平原区裸土扬尘中Pb、Cd化学形态的生物有效性

为探究四川盆西平原区裸土扬尘中Pb、Cd总质量分数与其生物有效性的规律,在构建的"阳离子型污染物土壤表层运移行为研究系统"内进行模拟起尘试验,对土壤样品进行Pb、Cd模拟污染试验,结果表明:试验条件下,四川盆西平原区裸土扬尘颗粒物中Pb、Cd的总质量分数随着粒径的减小而增大,其中Pb的化学形态以碳酸盐结合态为主(44....     

Strain-softening behavior of an Fe-6.5 wt%Si alloy during warm deformation and its applications

An Fe-6.5 wt%Si alloy with columnar grains was compressed at a temperature below its recrystallization temperature. The Vickers hardness and structure of the alloy before and after deformation were investigated. The results showed that with an increase in the degree of deformation, Vickers hardness of the alloy initially increased rapidly and then decreased slowly, indicating that the alloy had a strain-softening behavior after a large deformation. Meanwhile, the work-hardening exponent of the alloy decreased significantly. Transmission electron microscopy confirmed that the decrease of the order degree was responsible for the strain-softening behavior of the deformed alloy. Applying its softening behavior, the Fe-6.5 wt%Si alloy with columnar grains was rolled at 400 °C and then at room temperature. An Fe-6.5 wt%Si thin strip with thickness of 0.20 mm was fabricated. The surface of the strip was bright and had no obvious edge cracks.