排序方式： 共有8条查询结果，搜索用时 15 毫秒
1
1.
Leszek Krzemień Michał Łukomski Łukasz Bratasz Roman Kozłowski Marion F. Mecklenburg 《文物保护研究》2016,61(6):324-330
The drying shrinkage accumulation from exposure of freshly prepared gesso layers to relative humidity (RH) cycles was determined to elucidate the mechanism of craquelure pattern formation on panel paintings. The progresive drying shrinkage of the gesso is observed only under the cycles going to high RH levels which bring about transitions from brittle to ductile state of the material. The first incidence of fracture on the gesso layers occurred after a limited number of cycles ranging between a few and 100 for a range of layer thickness between 0.5 and 1?mm. The craquelure patterns stabilised also after a limited number of cycles (30 for the 1-mm thick layer). Upon increase in the gesso layer thickness, the strength of the layer is reduced and the spacing of shrinkage fractures increases. The study demonstrated that craquelure patterns, mimicking historical ones, can be realistically produced in laboratory conditions. Such studies would provide useful information for preparing specimens simulating historic panel paintings and would inform the current efforts on automatic, computer-aided classifications of crack formations on paintings. 相似文献
2.
Leszek Kuznicki 《Higher Education in Europe》1995,20(4):124-131
In 1951, the Polish Academy of Sciences was set up in Warsaw, more or less on a Soviet model, by the merging of two academies, one in Cracow and the other in Warsaw, that traced their origins to the late Eighteenth Century. The achievements of Polish science owe much to the excellent training and research facilities offered by the Academy, achievements that have won much recognition abroad, both West and East. Confronted with severe financial constraints since the period of transition began in 1989, the Academy has had to make painful adjustments and above all to face the fact that the salaries which it can afford to pay its researchers are abysmally low. Until such time as the economy improves, the continued high quality of the research undertaken by the Academy and its institutes and centres will depend upon their success in developing fruitful foreign partnerships. 相似文献
3.
Teresa Zwierko Wojciech Lubiński Piotr Lesiakowski Hanna Steciuk Leszek Piasecki Justyna Krzepota 《Journal of sports sciences》2013,31(16):1519-1528
AbstractThis longitudinal study investigated visual evoked potentials (VEPs) in 11 young female volleyball players who participated in extensive training for 2 years. The control group consisted of 7 age-matched female students who were not involved in any regular sports activity. Recordings of VEPs were performed twice: baseline recording (i.e., before training began) and after 2 years of systematic, volleyball-specific athletic training. The effect of athletic training on visual signal conductivity was assessed by recording the latency of N75, P100 and N135 components of the VEPs waveform. Extensive experience with volleyball training reduced signal conductivity time through visual pathway. Specifically, the latency of P100 was reduced on average by 2.2 ms during binocular viewing. Moreover, athletes had reduced N75 latency (difference of 3.3 ms) for visual stimuli that generated greater response from peripheral retina. These results indicate that sport training can affect very early sensory processing in athletes. 相似文献
4.
The on-site monitoring of acoustic emission (AE) has allowed the direct tracing of climate-induced crack propagation in an eighteenth-century wardrobe displayed in the Gallery of Decorative Art in the National Museum in Krakow, Poland. The anti-correlation measuring scheme and frequency filtering allowed very low levels of physical damage to the wardrobe to be detected in spite of the high background noise typical of the museum environment. The total AE energy recorded during two years of monitoring corresponded to a fractured area of 12 mm2 or a total crack propagation of 1.2 mm for two10-mm-thick panels. Although the total damage recorded was minute, correlation between the events of fracturing and falls in indoor relative humidity (RH) in winter due to insufficient humidification was evident. The risk of damage, expressed in terms of crack propagation, was quantified as a function of the magnitude of the RH falls of the duration compatible with the response time of the object. The data allow acceptable RH falls to be identified if a conservation professional or a curator selects a ‘tolerable’ yearly propagation of the fracture, in other words the progress of damage considered insignificant. 相似文献
5.
描述了一种微处理仪器.它可用于对船舶主推进轴的转矩、转速和功率的平均值的测量,以及进行基于轮机特性的标准化油耗的计算.测量结果和计算结果均可被转送至外接的计算机系统.在此微处理仪器中,有一套程序可用于监视在轮机特性区域的测量,并对轮机的负载进行记录.同时也提供了测量推进轴的转矩和转速的瞬时波动的方法.当测量数据产生严重失真时,则采用光谱分析和过滤的方法对真实信号进行估算. 相似文献
6.
Arkadiusz Kupczak Mariusz Jędrychowski Marcin Strojecki Leszek Krzemień Łukasz Bratasz Michał Łukomski 《文物保护研究》2018,63(5):151-155
ABSTRACTHERIe is a web-based decision-supporting software tool to facilitate the management of collection environments by precise assessment of climate-induced risk of physical damage to vulnerable objects. The software translates the relative humidity and temperature data recorded in the environment of the analysed object into a strain history experienced by it, and estimates the risk of physical damage using selected failure criteria. As all information is pre-calculated for the user, no engagement in complex and time-consuming numerical simulations is required. HERIe is available for testing at herie.mnk.pl. Detailed information on the methodologies used by the software is available at the above website which also contains tutorial climates. The current work aims at refining HERIe by selecting the damage criteria not only from laboratory studies but also from direct monitoring damage accumulation in objects, especially using the acoustic emission method. The software has been expanded to include moisture-induced response of parchment to support managing environments in libraries and archives. 相似文献
7.
Becky W. Packard Vincenza N. Marciano Jessica M. Payne Leszek A. Bledzki Craig T. Woodard 《Mentoring & Tutoring: Partnership in Learning》2013,21(5):433-445
Undergraduate research is viewed as an important catalyst for educational engagement and persistence, with an emphasis on the faculty mentoring relationship. Despite the common practice of having multi-tiered lab teams composed of newer undergraduates and more seasoned undergraduates serving as peer mentors, less is understood about the experience of peer mentors. Using the framework of legitimate peripheral participation, this study examined how peer mentors negotiated their roles in the lab. Nested case studies based on interviews with peer mentors, faculty members, and newer students illustrated how peer mentors establish credibility through prior lab experience and faculty-framed authority. Delegating supervision was an important component that helped newer students to accept the authority of the peer mentor. Implications for program development and future research involving peer mentoring are discussed. 相似文献
8.
This article researches higher education (HE) managers’ perception of graduate professional success and higher education institutions’ (HEI) activity aimed at enhancing graduate employability. The issue is worth examining not only because of growing relative unemployment rates among HE graduates but also because it is a part of a heated discussion on the contemporary evolution of HEIs. We analysed 36 semi-structured interviews with representatives of HEIs offering studies in the field of science in six countries (Austria, Germany, Italy, Poland, Slovenia and Turkey). Our analysis showed that there are three approaches observed, depending to a large extent on the balance between different HE stakeholders within subdomains (triple-helix theory). Our results support the hypothesis of diversification of HEIs’ models varying from the traditional ivory-tower-type university (with a dominating role of academic oligarchy) to the market-oriented educational enterprise (where the business sector is a key driver of change). 相似文献
1