MRTG日志文件的分析研究

对MRTG日志格式做了详细的分析,进一步说明了MRTG日志文件的形成,并且通过perl语言对日志文件进行了再分析.     

Self sensing carbon nanotube (CNT) and nanofiber (CNF) cementitious composites for real time damage assessment in smart structures

The self sensing properties of cementitious composites reinforced with well dispersed carbon nanotubes and carbon nanofibers were investigated. The electrical resistance of cementitious nanocomposites with w/c = 0.3 reinforced with well dispersed carbon nanotubes (CNTs) and nanofibers (CNFs) at an amount of 0.1 wt% and 0.3 wt% of cement was experimentally determined and compared with resistivity results of nanocomposites fabricated with “as received” nanoscale fibers at the same loading. Results indicate that conductivity measurements, besides being a valuable tool in evaluating the smart properties of the nanocomposites, may provide a good correlation between the resistivity values measured and the degree of dispersion of the material in the matrix. The addition of CNTs and CNFs at different loadings was proven to induce a decrease in electrical resistance, with the nanocomposites containing 0.1 wt% CNTs yielding better electrical properties. Furthermore, conductivity measurements under cyclic compressive loading provided an insight in the piezoresistive properties of selected nanocomposites. Results confirm that nanocomposites, reinforced with 0.1 wt% CNTs and CNFs, exhibited an increased change in resistivity, which is indicative of the amplified sensitivity of the material in strain sensing.     

Characterization of microstructural changes in an Al-6.8 wt.% Mg alloy by electrical resistivity measurements

Microstructural changes in an AlMg6.8 alloy after different thermo mechanical (TMT) and sensitization treatments were investigated by electrical resistivity measurements. The electrical resistivity was most affected by the content of Mg solute atoms in the α-Al matrix, due to β-phase precipitation, while contribution of the dislocation density to the resistivity of the AlMg6.8 alloy was less pronounced. The amount and distribution of the β-phase precipitated during sensitization were found to be strongly affected by the microstructure developed under the previously applied TMTs, i.e. by the dislocation density and the primary β-phase particles in the dual (α + β) phase structure. During sensitization of the specimens with a recovered/recrystallized dual (α + β) phase structure, precipitation of randomly distributed, globular β-phase particles occurred. Sensitization of cold deformed and recrystallized single α-Al structures induced β-phase precipitation in the form of a continuous layer along the shear bands/grain boundaries.     

Structural, photoluminescent and electrical properties of CdTe films with different compositions fabricated by CMBD

CdTe films with different compositions (Cd-rich, Te-rich and stoichiometric) were fabricated by a novel and low cost chemical molecular beam deposition method (CMBD) in atmospheric pressure hydrogen flow. Cd and Te granules were used as precursors. The films were deposited on ceramic (SiO₂:Al₂O₃) substrates at 580 °C and 600 °C. The growth rate was varied in the range of 9-30 Å/s. The composition (Cd/Te) of the samples was changed by controlling the molecular beam intensity (MBI) ratio. Three samples fabricated at MBI ratios Cd/Te = 0.5, 1.0 and 1.16 were investigated by XRD, AFM, EDX, SEM, photoluminescence (PL) and Hall methods.     

低电阻油层成因及其研究方法：以辽河油田为例

低电阻油层主要有两种储集层类型:一种是粉砂岩储集层;另一种是含粘土矿物的砂岩储集层.在这两种储集层中,由于强烈的毛细管作用和极大的内表面积形成的高含水饱和度使含烃储集层的电阻率与纯水层相似.在分析了辽河油田锦16块低电阻率油层的地质特点后,提出了识别低电阻油层的基本方法:从分析油藏的形成条件和储集层的岩性特征入手,利用测井信息结合岩心分析资料识别低电阻油层.     

Microstructure and electrical properties of high power laser thermal annealing on inkjet-printed Ag films

In this work, a high power continuous-wave (CW) Nd:YAG laser was used for thermal treatment of inkjet-printed Ag films - resulting in the elimination of organic additives (dispersant, binder, and organic solvent) in the Ag ink and annealing of Ag nano-particles. By optimizing laser parameters such as laser power and defocusing value, the laser energy can be totally converted into heat energy, which is used for thermal treatment of inkjet-printed Ag films. This results in the microstructure and the resistivity of the films to be controlled. We investigated the thermal diffusion mechanisms during laser annealing and the resulting microstructures. The impact of high power laser annealing on microstructures and electrical characteristics of inkjet-printed Ag films was compared to those of the films annealed by a conventional furnace annealing. Focused ion beam (FIB) channeling images show that the laser annealed Ag films have large columnar grains and a dense void-free structure, while furnace annealed films have much smaller grains and exhibit void formation. As a result, the laser annealed films have better electrical properties (low resistivity) compared to furnace annealed samples.     

Tectonics and architectonic quality in recently published Finnish log architecture: Corresponding architects’ perceptions

Due to the global increase in wood construction, it is crucial for architects to understand wood. In Finland, log building, a special subset of industrially manufactured massive timber construction materials is experiencing a renaissance. Cultural aspects combined with newer technical developments make log a complex material from the viewpoint of architectonic expression. To inform practicing architects, the aim of this study is to explore how the tectonics of logs contribute to the architectonic quality of log architecture. Semi-structured interviews among architects of twelve recently published log buildings are conducted. The results describe how architectonic quality is perceived among participants, and features of logs related to tectonics that they consider to be of importance in terms of architectonic quality. These features include the statics of log construction and log's nature as a simultaneously insulating, load-bearing and visual material. Differences between industrial and hand-hewn logs, as well as other architectural aspects of using logs in contemporary architecture are discussed. Especially the “non-settling” log was perceived to have manifold implications for the architectonic possibilities of log architecture. The results are of practical importance to designing architects and the log industry. Theoretical implications include tangible information on architectonic quality and tectonics of log building.     

混掺钢屑铁砂水泥砂浆压敏性研究

在砂浆中混掺钢屑和铁砂两种工业废弃料,制备得到环保低成本的水泥基复合材料,在测定其抗压强度的基础上采用交流两电极法研究其导电性能和压敏性能,并分析研究了混掺掺量、弹塑性荷载、不同加载速率以及冲击荷载等对其压敏性的影响。试验结果表明,随着导电材料掺量增加,试件压敏性更加明显。加载速率越大,试件电阻率变化越大;冲击荷载数值对瞬间电阻率与卸载后电阻率均有较大影响。     

Community response to environmental noise and the impact on cardiovascular risk score

Objective

The objective of our study was to investigate and evaluate the relationship between road traffic noise and cardiovascular risk.

Methods

The study sample (n = 659; 36.9% male, 63.1% female university students, mean age 22.83 ± 1.58 years) included a group exposed to road traffic noise (n = 280, L_eq,24 h = 67 ± 2 dB(A)) and a control group (n = 379, L_eq,24 h = 58.7 ± 6 dB(A)). Subjective response was determined by a validated noise annoyance questionnaire. The ten year risk of developing a coronary heart disease event was quantified as an evaluation of cardiovascular risk (SCORE60, Framingham 10-year risk estimation and projection to the age of 60, relative risk SCORE chart).

Results

Cardiovascular risk scores were significantly higher in the exposed group based on the Framingham scores projected to the age of 60, SCORE60 (AOR = 2.72 (95% CI = 1.21-6.15)) and the relative risk SCORE chart (AOR = 2.81 (1.46-5.41)).

Conclusions

These findings highlight the association between road traffic noise and cardiovascular risk.