论梁启超《清代学术概论》中的科学精神

在《清代学术概论》中,梁启超将清代思潮的变迁过程分成三个不同的阶段.而贯穿三个阶段他所予以重视的关键性精神即是“科学精神”.梁启超所关心的问题在于学问该如何得到发展,并且忧虑“致用”的主观动机容易介入研究过程,从而影响其客观性,因此,梁启超主张学者应避开去问所治的学问是否实用.“为学问而治学问”,这就是梁启超《清代学术概念》中所要表达的中心思想.梁启超深刻地体会到了政治权力主宰真理和正义的严酷现实,他所站到的非政治性立场本身就在政治社会环境中.《概论》在政治思想史学上具有深刻的意义.     

Kinematic analysis of the backstroke start: differences between backstroke specialists and non-specialists

Abstract

The purpose of this study was to clarify factors to perform the hole-entry technique in the backstroke start. A total of 16 well-trained Japanese competitive swimmers were divided into two groups (backstroke specialists and non-specialists) to compare their backstroke start motions. Their backstroke motions were videotaped, and two-dimensional co-ordinates for the swimmers were obtained from the video images using direct linear transformation methods. A non-paired t-test and Mann–Whitney U-test were used to analyse the statistical difference of the kinematic variables between the groups. Backstroke specialists showed a significantly shorter 5 m time (P = 0.009, effect size = –1.54), a significantly higher position of the toe (P = 0.010, effect size = 1.47) at signal and of the hip at toe-off (P = 0.002, effect size = 1.94), a significantly larger hip joint angle at toe-off (P = 0.007, effect size = 1.60) and a significantly higher angular velocities of the hip joints (45–85%; P < 0.05) for the normalised time as compared to that of non-specialists. An earlier initiation of the extension and the maintenance of a higher extension speed at the hip joints were important factors in achieving an arched-back posture, which facilitated and water entrance with a small entry range.     

Intra-plant diffusion of new technology: Role of productivity in the study of steel refining furnaces

This paper examines intra-plant diffusion of new technology in the Japanese steel industry. The introduction of the basic oxygen furnace (BOF) was the greatest breakthrough in steel refining in the last century. Using unique panel data, the paper estimates total factor productivity by technology type, and associates the estimates with intra-plant diffusion. The paper finds that intra-plant diffusion accounts for about a half of the industry productivity growth. Large plants are likely to adopt the new technology earlier, but retain the old technology longer, than their smaller counterparts.     

Partial reinforcement delayed extinction effect after regularly alternating reward training

When extinction is delayed very long, the superior resistance to extinction of the random schedule group relative to the alternating schedule group disappears (partial reinforcement delayed extinction effect, PRDE). Two experiments assessed the effects of reinforcement/nonreinforcement on Trial 1 on the PRDE. Following extended partial reinforcement acquisition training in a runway, rats received extinction training after a short (1-day) or long (23-day) retention interval. The schedules used in Experiment 1 were: a single-alternation (SA) schedule beginning each day with a rewarded (r) trial, for Group r-SA; an SA schedule beginning with a nonrewarded (n) trial, for Group n-SA; and a random (Rd) schedule, for Group Rd. The schedules and group names used in Experiment 2 were r-SA, Rd, and r-Rd. The results were that (1) rats given r-SA schedules yielded considerable resistance under delayed extinction, (2) those given Rd and r-Rd schedules showed a decline in resistance to extinction over a long retention interval, (3) those given the n-SA schedule showed relatively low resistance at both retention intervals, although retention deficit was not greater than in the case of the Rd schedule, and thus, (4) the PRDE was found in both experiments, although only weakly in Experiment 1. The results indicated that a regularly alternating reward pattern was a more important determinant than was type of reward on Trial 1 for the PRDE. The PRDE due to differential retention deficits among schedules is discussed on the basis of dual-process associative sequential mechanisms and cognitive rule-encoding mechanisms.     

社会分层视域下的思想政治教育对象层次性研究

社会分层是思想政治教育不可回避的视域,为思想政治教育客体层次性研究提供了崭新的视角,体现出二者良好的耦合性。在社会分层视域下审视思想政治教育对象层次性生成原因及其表现,探寻不同层次教育对象的施教路径,是提高思想政治教育实效性的重要基础。     

Absence of postzygotic isolating mechanisms: evidence from experimental hybridization between two species of tropical sea urchins

Two reef margin species of tropical sea urchins, Echinometra sp. C (Ec) and Echinometra oblonga (Eo), occur sympatrically on Okinawa intertidal reefs in southern Japan. Hybridization between these species was examined through a series of cross-fertilization experiments. At limited sperm concentrations, where conspecific crosses reached near 100% fertilization, both heterospecific crosses showed high fertilization rates (81%–85%). The compatibility of the gametes demonstrated that if gamete recognition molecules are involved in fertilization of these species, they are not strongly species-specific. We found that conspecific crosses reached peak fertilization levels much faster than did heterospecific crosses, indicating the presence of a prezygotic barrier to hybridization in the gametes. Larval survival, metamorphosis, and juvenile and adult survival of hybrid groups were nearly identical to those of their parent species. Hybrids from crosses in both directions developed normally through larval stages to sexually mature adults, indicating that neither gametic incompatibility nor hybrid inviability appeared to maintain reproductive isolation between these species. In adults, Ec×Ec crosses gave the highest live weight, followed by Eo (ova)×Ec (sperm), Ec (ova)×Eo (sperm), and Eo×Eo. Other growth performance measures (viz., test size, Aristotle’s lantern length, and gonad index) of hybrid groups and their parental siblings showed the same trends. The phenotypic color patterns of the hybrids were closer to the maternal coloration, whereas spine length, tube-foot and gonad spicule characteristics, pedicellaria valve length, and gamete sizes showed intermediate features. Adult F₁ hybrids were completely fertile and displayed high fertilization success in F₁ backcrosses, eliminating the likelihood that hybrid sterility is a postzygotic mechanism of reproductive isolation. Conversely, intensive surveys failed to find hybrid individuals in the field, suggesting the lack or rarity of natural hybridization. This strongly suggests that reproductive isolation is achieved by prezygotic isolating mechanism(s). Of these mechanisms, habitat segregation, gamete competition, differences in spawning times, gametic incompatibility or other genetic and non-genetic factors appear to be important in maintaining the integrity of these species.     

Peers’ perceptions of Japanese returnees

Many studies have examined the reentry process of Japanese children raised abroad. Results suggest that “feeling different” is a key factor in describing their experiences. These studies, however, were based only on self-reports of returnees. The current study examined returnees’ peers’ perceptions and the factors that affected them. Results indicated that the returnees’ peers’ perceptions could be summarized by two factors: “advantage” and “difference/disadvantage.” Those who had studied abroad and who had known many returnees had a balanced perspective of the returnee experience. Women were more likely to perceive advantages while those who were older were more likely to perceive differences/disadvantages.     

Contribution of hand and foot force to take-off velocity for the kick-start in competitive swimming

This study examines the hand and foot reaction force recorded independently while performing the kick-start technique. Eleven male competitive swimmers performed three trials for the kick-start with maximum effort. Three force platforms (main block, backplate and handgrip) were used to measure reaction forces during starting motion. Force impulses from the hands, front foot and rearfoot were calculated via time integration. During the kick-start, the vertical impulse from the front foot was significantly higher than that from the rearfoot and the horizontal impulse from the rearfoot was significantly higher than that from the front foot. The force impulse from the front foot was dominant for generating vertical take-off velocity and the force impulse from the rearfoot was dominant for horizontal take-off velocity. The kick-start’s shorter block time in comparison to prior measurements of the grab start was explained by the development of horizontal reaction force from the hands and the rearfoot at the beginning of the starting motion.     

Comparing US and Japanese Elementary School Teachers' Facility for Linking Rational Number Representations

Using cognitive ethnography as a guiding framework, we investigated US and Japanese fourth-grade teachers' domain knowledge of key fraction representations in individual interviews. The framework focused on revealing cultural trends in participants' organization of knowledge and their interpretations of that organization. Our analyses of the interviews, which included a representation sorting task, indicated three major differences that defined US and Japanese teachers' approaches to rational number representation: (1) Japanese teachers interpreted all rational number representations as conveying primarily mathematical information, whereas US teachers interpreted only some representations as conveying primarily mathematical information; (2) the US teachers focused more intently on part-whole relations than Japanese in their interpretations; and (3) Japanese teachers more easily linked rational number representations to more advanced upcoming content in the curriculum. A review of US textbooks used by the teachers reflected their consistency with US teachers' interpretations of the representations. These findings imply that strong cultural differences underlay the approaches that teachers in both nations take to rational number representation and that these differences may help explain established cross-national differences in student reasoning.