We have analyzed vertical seismic profile data acquired across a Marcellus Shale prospect and found that SV-P reflections could be extracted from far-offset VSP data generated by a vertical-vibrator source using time-variant receiver rotations. Optimal receiver rotation angles were determined by a dynamic steering of geophones to the time-varying approach directions of upgoing SV-P reflections. These SV-P reflections were then imaged using a VSP common-depth-point transformation based on ray tracing. Comparisons of our SV-P image with P-P and P-SV images derived (...) from the same offset VSP data found that for deep targets, SV-P data created an image that extended farther from the receiver well than P-P and P-SV images and that spanned a wider offset range than P-P and P-SV images do. A comparison of our VSP SV-P image with a surface-based P-SV profile that traversed the VSP well demonstrated that SV-P data were equivalent to P-SV data for characterizing geology and that a VSP-derived SV-P image could be used to calibrate surface-recorded SV-P data that were generated by P-wave sources. (shrink)
We have developed an example of hydrocarbon detection for an Ordovician cavern carbonate reservoir in western China with a burial depth exceeding 6600 m using amplitude variation with offset and spectral decomposition. We selected six production wells, three prolific oil wells, and three brine wells to test the hydrocarbon detection method. The three oil wells have been producing for more than three years, and the three water wells only produce brine. We performed spectral decomposition to the angle gathers and analyzed (...) amplitude variation patterns with incidence angles for different spectral components. Specifically, we compared the time corresponding to the peak spectral amplitude for different spectral components for the oil- and brine-saturated carbonate reservoirs. The main findings are as follows: Oil-saturated cavern carbonate reservoirs show decreasing peak time with increasing frequency; i.e., the high-frequency components travel faster than do the low-frequency components. The maximum time difference between the 10 and 50 Hz spectral components could reach 35 ms. In contrast, the brine-saturated carbonate reservoirs do not exhibit conspicuous variation in the peak time, AVO attributes extracted from the low-frequency spectral gathers are more robust than those extracted from the original seismic gathers, oil-saturated cavern carbonate reservoirs cause strong energies in the low-frequency spectral components and severe attenuation to the high-frequency spectral components at large incidence angles. In contrast, the brine-saturated carbonate reservoirs do not produce such phenomenon. Rock physics analysis for carbonate reservoirs under different saturation conditions was conducted. The synthetic gathers were generated for carbonate reservoirs under oil- and brine-saturated conditions. The spectrally decomposed synthetic gathers are in agreement with the real gathers. The results indicate that AVO analysis of spectrally decomposed prestack gathers could be used as an effective hydrocarbon detection method for carbonate reservoirs. (shrink)
A major controversy in the study of the "Analects" has been over the relation between two central concepts, ren (humanity, human excellence) and li (rites, rituals of propriety). Confucius seems to have said inconsistent things about this relation. Some passages appear to suggest that ren is more fundamental than li, while others seem to imply the contrary. It is therefore not surprising that there have been different interpretations and characterizations of this relation. Using the analogy of language grammar and mastery (...) of a language, it is proposed here that we should understand li as a cultural grammar and ren as the mastery of a culture. In this account, society cultivates its members through li toward the goal of ren, and persons of ren manifest their human excellence through their practice of li. (shrink)
Based on a national survey of Chinese scientific personnel in 2008, this paper sheds new light on the relationship between social networks and scientific performance. In this study, we used position generator to measure scientists’ ego-centered social networks. The scientists’ performance was measured by multiple indexes, including recognitions from the academic, governmental, and market sectors. The findings show that size and composition of scientists’ social networks have significant effect on their scientific performance. The notions of “information communication mechanism” and “resource (...) acquisition mechanism” are introduced to explain how network composition affects scientific performance along multiple dimensions. The policy implications of the study are also discussed. (shrink)
Physarum polycephalum, a unicellular and multiheaded slime mould, can form highly efficient networks connecting separated food sources during the process of foraging. These adaptive networks exhibit a unique characteristic in that they are optimized without the control of a central consciousness. Inspired by this phenomenon, we present an efficient exploration and navigation strategy for a swarm of robots, which exploits cooperation and self-organisation to overcome the limited abilities of the individual robots. The task faced by the robots consists in the (...) exploration of an unknown environment in order to find a path between two distant target areas. For the proposed algorithm, we experimentally present robustness tests and obstacle tests conducted to analyse the performance of our algorithm and compare the proposed algorithm with other swarm robot foraging algorithms that also focus on the path formation task. This work has certain significance for the research of swarm robots and Physarum polycephalum. For the research of swarm robotics, our algorithm not only can lead multirobot as a whole to overcome the limitations of very simple individual agents but also can offer better performance in terms of search efficiency and success rate. For the research of Physarum polycephalum, this work is the first one combining swarm robots and Physarum polycephalum. It also reveals the potential of the Physarum polycephalum foraging principle in multirobot systems. (shrink)
Li Zehou stands among the most influential Chinese philosophers in the post-Mao era. His notion of subjectality is of paramount importance for current developments in contemporary Chinese philosophy. It belongs to the central concepts in Li's theoretical framework, around which his entire philosophical system is constructed. With his elaboration of this concept, Li expanded the problem of the self in post-revolutionary modernism. The present article analyzes the theoretical bases of this concept, exposes its importance in the scope of contemporary Chinese (...) theory and shows why and how it represents a call for a new humanism. Through a multidimensional comparative perspective, the author also explains why the human subject, which is based upon Li's notion of subjectality, has the potential not only to transform modern alienation into a real “human condition,” that is, into spiritually fulfilled society of autonomous individuals but also to fill up the prevailing “vacuum of values.”. (shrink)
Available for the first time in English, Li Zehou's philosophical aesthetics interpret the historical origins and evolution of aesthetic experience and their significance to the intellectual, emotional, and spiritual growth of human beings. Although LI's ideas have been debated in China for more than two decades, his conversations with Jane Cauvel will now allow Western students and philosophers to re-encounter Chinese and Western conceptions of aesthetics, and the way art shapes indiciduals, societies, technology, and the future of humankind.