冷热循环对粉末冶金SiCp/Al复合材料力学性能的影响

采用粉末冶金制备了15％（体积分数）SiCp/Al复合材料，研究了不同冷热循环工艺对复合材料力学性能的影响。结果表明，上限温度在175℃以下的冷热循环对复合材料的屈服强度和抗拉强度影响不大，当上限温度达到200℃后复合材料的屈服强度提高了80MPa，抗拉强度则基本不变。复合材料的屈服强度的提高主要是由于材料在冷热循环的高温过程中基体中的G．P区转变成了过渡相口”。断口观察表明，经过不同冷热循环工艺处理后，复合材料的断裂形式大致相同，即除了基体断裂外，还存在SiC颗粒开裂的情况。冷热循环对复合材料的延伸率影响不明显。     

The ukrainian state standard for the liquid flow rate unit

Design and metrological characteristics are given for the Ukrainian state primary standard for the units of volume and mass liquid flow. __________ Translated from Izmeritel’naya Tekhnika, No. 6, pp. 39–45, June, 2007.     

Quality of Deployment in Surveillance Wireless Sensor Networks

When wireless sensors are used to keep an area under surveillance, a critical issue is the quality of the deployment from the sensing coverage viewpoint. In this paper, we propose several quality measures, which indicate if the deployment provides sufficient coverage, or whether redeployment is required or not. The terrain is modeled as a grid and the placement of the sensors is uniformly distributed. Neyman–Pearson detection is utilized to determine the effects of false-alarm and signal characteristics on the measures.     

Label-free THz sensing of genetic sequences: towards 'THz biochips'

THz-wave-based approaches for the label-free characterization of genetic material are described. Time-resolved THz spectroscopic analysis of genetic sequences (polynucleotides) demonstrate a distinct complex refractive index in the THz frequency range as a function of the binding state of the analysed DNA sequences. By monitoring THz signals, one can thus infer the binding state of oligo- and polynucleotides, enabling the label-free determination of the genetic composition of target polynucleotides by sensing their binding to known probe molecules. Here we review integrated THz sensing array developments exhibiting high sensitivity and single-base mutation detection capabilities. Recent achievements using functionalized biosensing arrays of high-Q resonators are illustrated.     

Complete salvaging of decommissioned objects of the nuclear-powered fleet in the northwest and methodological approaches

The basic problems of complete salvaging of the decommissioned Russian nuclear-powered fleet in the northwest are examined: salvaging of nuclear-powered submarines, nuclear-powered surface ships, nuclear tenders, and ecological remediation of the objects of the shored infrastructure supporting the operation of the ships in the nuclear-powered nanval fleet of Russia. The basic methodological aproaches whose implementation will make it possible to determine rational ways to decrease the ecological threat and to increase national safety are formulated on the basis of an analysis of the scales and complexity of the problems which have accumulated concerning the complete salvaging and remediation of the objects of the nuclear-powered fleet. __________ Translated from Atomnaya énergiya, Vol. 101, No. 1, pp. 4–11, July, 2006.     

From global <Superscript>137</Superscript>Cs to determinations of the sedimentation rate in deep lakes and sea estuaries

Sedimentation rate in deep lakes and estiaries of the Baltic, Pechora, and Laptev Seas was determined using global ¹³⁷Cs as a sedimentogenesis marker. The sedimentation rate in Lake Ladoga and Levinson- Lessing Lake was 0.3–3 mm year^?1, and that in estuaries of the Baltic, Pechora, and Laptev Seas was 0.74–1.76, 1.0, and 3.3–5.0 mm year^?1, respectively. At a sedimentation rate of >1–2 mm year–1, the concentration peaks of global and “Chernobyl” ¹³⁷Cs in the bulk of the bottom sediments do not overlap, and the sedimentation rate is estimated for each kind of nuclides separately. At a sedimentation rate of <1 mm year^?1, “Chernobyl” ¹³⁷Cs + ¹³⁷Cs from dumping into sea mask in the bottom sediments the subsurface maximum of the global ¹³⁷Cs concentration and prevent the sedimentation rate determination. The use of ¹³⁷Cs for sedimentation rate determinations is appropriate for the poorly studied shelf zone of Russian Arctic seas.     

Determination of the Principal Volatile Compounds of Turkish Raki

Turkish Raki is a type of traditional aniseed spirit produced in different areas of Turkey. The amounts and the repartition of the alcoholic fermentation products (fusel alcohols, esters, and aldehydes) are mainly responsible for the flavours and quality of the spirit. Previous studies have been carried out on the quantification of the volatiles of the different aniseed spirits using GC and GC‐MS. In this study of 20 different commercial brands of bottled Raki and 5 homemade Turkish Raki products, the major volatiles and methanol were determined using direct injection with GC‐MS. SPME extraction was also used as a confirmation method for the separation of Raki volatiles. Eight different substances were successfully identified using SPME extraction. The results indicated that some homemade Turkish Raki products from the different regions contained slightly higher concentrations of the most studied compounds. The toxic compound methanol was detected only at a level far below the acceptable legal limit.     

Hard carbon coatings and boundary lubrication of steel parts

It is shown that the composition and structure of diamond-like carbon coatings deposited on friction surfaces of steel parts of lubricated friction units have a substantial effect on the degree of the orientation of molecules of a lubricant in a boundary film and, therefore, on the antifriction behavior of the lubricant under boundary lubrication conditions. We present the results of research carried out in recent years at the Department of Friction, Wear, and Lubrication of the Blagonravov Institute of Machine Science of the Russian Academy of Sciences in collaboration with the Chemical Faculty of the Lomonosov Moscow State University and the 25th State Research Institute of the Ministry of Defense of the Russian Federation in order to enhance the lubricity of oils, as well as to simplify and cheapen their compositions, which is of great importance from the viewpoint of ecology.     

Antioxidant phenolic compounds of pomegranate wines produced by different maceration methods

Various methods were evaluated in the production of ‘Hicaz’ pomegranate wine by microvinification. The chemical, phenolic and antioxidant characteristics of the wines were assessed by measurement of water‐soluble dry matter, acidity, density, alcohol content, volatile acidity, total monomeric anthocyanins, polarized colour intensity and individual phenolic compounds. Three different methods – classical maceration (N), seed‐supplemented maceration (S) and seed + enzyme supplemented maceration (E) – were applied. Total phenolic compounds of pomegranate must and wines (after 18 months of storage) were 1897 mg/L (must), 1663 mg/L (N), 1339 mg/L (E) and 1414 mg/L (S). Phenolic compounds in pomegranate must and wines included gallic acid, vanillic acid, caffeic acid, ferulic acid, p‐coumaric acid, hydroxycinnamic acid, epicatechin and catechin. Total antioxidant capacities (Trolox equivalents) of pomegranate must and wines (N, E and S) were 9.9 mm /L (must), 9.8 mm /L (N), 9.7 mm /L (E) and 9.5 mm /L (S). Copyright © 2017 The Institute of Brewing & Distilling