Comparison of dietary intakes of Canadian Armed Forces personnel consuming field rations in acute hot, cold, and temperate conditions with standardized infantry

Background:Dietary Reference Intakes are used to guide the energy intake of the Canadian Armed Forces(CAF)field rations provided to military personnel deployed for training or operations.However,the high energy expenditures likely to occur under harsh environmental/metabolically challenging deployment conditions may not be adequately considered.This study examined the Ad libitum energy and nutrient intakes of CAF personnel(n=18)consuming field rations in a resting thermoneutral environment and during a day of standardized strenuous infantry activities at varying environmental temperatures.Methods:Dietary intake was assessed using a measured food intake/food waste method during the experimental treatment and for 6 h after treatment.Four treatments were administered in a randomized counterbalanced design:exercise(as standardized infantry activities)in the heat(30℃),exercise in the cold(–10℃),exercise in temperate thermoneutral(21℃)air temperatures and a resting(sedentary)trial(21℃).Results:The average Ad libitum consumption of field rations was 70%of the provided total energy(2776±99 kcal/8 h)during all treatments.Even with an acute challenge of increased energy expenditure and temperature stress in the simulated field conditions,participants’energy intakes(1985±747 kcal/8 h)under hot,cold and temperate treatments did not differ from energy intake during the sedentary condition(1920±640 kcal/8 h).Participants’energy intakes(1009±527 kcal/6 h)did not increase during the 6 h posttreatment period when the stresses of the strenuous physical activities and the harsh environmental temperatures had subsided.Conclusions:These results should be considered when planning the provision of field rations for CAF personnel expected to be engaged in strenuous physical activities with prolonged exposure to temperature extremes.

低场核磁共振在食用油质量评价中的应用

低场核磁共振一般是指恒定磁场强度低于0.5 T的核磁共振现象,操作方法简单快速、测量精确并且对样品无破坏性,在食用油研究中得到了广泛应用。文章简述了低场核磁共振的基本原理、仪器参数及其在食用油质量评价中的应用现状。

重建中国学术话语:经验论证与价值探索——外语学科建设学理基础刍议

本文认为,作为中国学术话语的一部分,中国的外语学科自应将践证精神作为自己的学理基础,因为愈能返本求源的经验也就愈具普遍性,故此真正意义上的学术研究即必须深深地扎根于中西学术各自的初始经验,并在其中构拟具有人类共享文化价值的共同学术"据点",这样中西学术各自的初始经验便可以通过某些操作规则转换成为基于共同的学术据点提炼而成的学术话语,并对人类文明的层累叠加作出应有的贡献.

ε-arithmetics for real vectors and linear processing of real vector-valued signals

In this paper,we introduce a new concept,namelyε-arithmetics,for real vectors of any fixed dimension.The basic idea is to use vectors of rational values(called rational vectors)to approximate vectors of real values of the same dimension withinεrange.For rational vectors of a fixed dimension m,they can form a field that is an mth order extension Q(α)of the rational field Q whereαhas its minimal polynomial of degree m over Q.Then,the arithmetics,such as addition,subtraction,multiplication,and division,of real vectors can be defined by using that of their approximated rational vectors withinεrange.We also define complex conjugate of a real vector and then inner product and convolutions of two real vectors and two real vector sequences(signals)of finite length.With these newly defined concepts for real vectors,linear processing,such as linear filtering,ARMA modeling,and least squares fitting,can be implemented to real vectorvalued signals with real vector-valued coefficients,which will broaden the existing linear processing to scalar-valued signals.

理性教育:香港大学景观设计学硕士设计论文教学体系

中国面临着巨大的环境和社会挑战,景观设计在帮助中国社会战胜这些挑战方面发挥着重要的作用。景观设计师需要能够在有关环境、文化和社会问题的讨论中发挥参与、理解和分析的权威作用,并且能够提出合理的论据,从而制定有意义的行动。随着景观设计师在中国的影响力的不断扩大,我们的教学不应再局限于景观的专业知识,以及构成、材料、技术方面的操作技能,而应转向引导学生解决问题的理性教育。应该在教学中向学生传授严谨的知识和理论框架,以利于他们未来的职业实践,进一步说,即扩展学科领域。香港大学的景观设计教育经历了20年的发展,我们在有关设计论文的过程和价值方面也积累了一些思考。设计论文要求学生在景观设计学科领域内提出具有批判性的观点,并通过设计过程检验其假设是否成立。论文的最终目标在于促进景观设计领域中的知识、方法和实践的运用,为学生进入实践领域做准备,以及让他们——学科未来的领导者——积极参与这一过程,并培养其批判性的自我反思能力、创新能力,以及对社会、经济、环境可持续性发展的坚定信念。本文结合景观设计硕士设计论文课程,提出了相应的方法,并对部分学生成果进行了展示。