宰后放置时间对牛肉食用品质的影响

以牛后腿肉为原料,钡0定pH值、剪切力、蒸煮损失等指标随贮藏时间的变化状况,以确定宰后放置不同时间对牛肉品质指标的影响规律．结果表明：宰后放置时间对牛肉各品质指标均有显著影响．牛肉的pH值随着宰后放置时间的延长呈先降低后上升的趋势,于宰后4d达到极限pH;而蒸煮损失的变化趋势则相反．肌肉的剪切力在宰后1d内显著增加,24h时达到最大值,当放置较长时间时,剪切力随着宰后时间整体呈现降低趋势．     

Fostering metacognitive awareness among teachers: Implications for the Nigerian school system

Abstract

This article focused on the concept of metacognition. Some theoretical models of metacognition were discussed to provide a general framework to understand the relationship between the different aspects or components of this phenomenon. The study also looked at five metacognitive strategies that enhance learning in schools, namely: (1) graphic organizers; (2) metacognitive scaffolding; (3) reciprocal teaching; (4) explicit instruction; and (5) collaborative learning. The work also briefly highlighted the problems of metacognitive strategies used in Nigerian schools. We noted that all learners do not engage spontaneously in metacognitive thinking unless they are explicitly encouraged to do so through carefully designed instructional activities. The study therefore recommended effective practice of scaffolded instruction on metacognitive strategies use in Nigerian schools and other countries in the world.     

GPS在高层建筑变形监测中的应用

GPS技术以其连续、实时、高精度、全天候测量和自动化程度高等优点,在变形监测的应用越来越发挥着传统测量无法比拟的作用.对GPS技术在高层建筑变形监测应用中的监测模式、测量方法、数据处理及其待解决的一些问题做了介绍和分析,最后指出了GPS技术在变形监测中应用的发展前景将更加广阔.     

南天山西段前陆褶皱冲断带平衡剖面分析

平衡剖面技术是一种基于几何守恒原理的应用于造山带和盆地结构恢复的方法.本文以挤压环境下形成的南天山西段前陆褶皱冲断带为例,对其典型二维地震剖面进行变形分析和平衡剖面恢复.结果表明,从平面上可将该冲断带划分为多排近似平行、东西走向的背斜带,由南往北依次为喀什、阿图什、托帕一康西维尔和喀拉伯克托尔一温古尔背斜带:从剖面上可以将该冲断带划分为两个不同层次的推覆构造系统:浅层为大规模叠瓦式冲断系统;深层为原地隐伏双重冲断构造系统.对重点剖面进行平衡剖面分析,得出自上新世以来研究区南北构造缩短量为49.1 km,缩短率为50.51%.地壳平均缩短速率为13.72 mm/a.     

南海北部陆缘有限变形分析——以西沙海槽为例

依据有限变形理论,计算了不同壳幔密度结构条件下西沙海槽构造应力场及其有限变形.结果表明:现今海槽中部处于隆升状态,最大隆升速率可达7×10^-3cma,上、下地壳分界面上有限变形水平应变分量exx在海槽中部为压性,南北两侧为张性;垂向应变分量ezz在中部为张性,两侧为压性.     

高钼奥氏体不锈钢高温软化行为与流变应力模型

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超薄铁电膜的居里温度及其表面效应

采用平均场理论下的横场 Ｉｓｉｎｇ模型,得到同时考虑Ωｓ≠Ω,Ｊｓ≠Ｊ情况下超薄铁电膜的居里温度表达式,进一步研究除发现存在临界表面层隧穿频率．Ωｓｃ外还发现由Ｊｓ／Ｊ＝ Ｃ所反映的临界值Ｃｓc     

电解沉积纳米晶体Cu的热稳定性及机械性能研究(英文)

采用电解沉积技术制备出无孔隙、无污染、微观应变很小的 理想 "纳米晶体单质Cu样品.对电解沉积纳米晶体Cu进行冷轧处理,首次发现纳米晶体材料具有室温下的超塑延展性,在冷轧过程初始阶段样品有少量的加工硬化,当变形量达到一定程度时(ε >80 0 % ),加工硬化效应消失。恒定的晶粒尺寸,恒定的位错密度,以及恒定的硬度值,说明纳米晶体Cu的塑性变形机制由晶界行为所控制,并非位错运动机制。系统的研究了纳米晶体中微观应变对其热稳定性的影响,发现随纳米晶Cu样品中微观应变的增加,晶粒长大的起始温度升高,而微观应变释放的起始温度下降.     

Characteristics and evolution of mesozoic foreland fold and thrust belt in western Kunlun Shan, China

The authors’ analysis of the chemical components and sedimentary characteristics of the well developed Triassic strata in the southeastern part of western Kunlun Shan led them to conclude that the sediments comprise a set of typical deep-water to semi-deep-water flysch that formed in the passive continental margin of the Qiangtang Block. This suit of strata had undergone strong deformation giving rise to a SW-thrusting duplex, imbricate fans, high-angle thrust fault, recumbent fold, SW-inverted fold, etc.. The deformational intensity weakens gradually southeastward. This is a foreland fold and thrust belt caused by the collision between the Qiangtang Block and the island are on the southern margin of the the Tarim Plate at the end of late Triassic. The sedimentary and deformational characteristics of the Triassic strata were used to reconstruct the evolution of this foreland fold and thrust belt as proposed below. Before the end of Triassic, this region was a passive continental margin in the north of the Qiangtang Block. The end of Triassic to Jurassic was a stage of thrusting, folding, uplifting and development of the foreland basin. The evolution of the fold and thrust was completed in Cretaceous. Project supported by NSFC (49872073) and Key Project of NSFC.     

浅谈材料力学中简易法快速画梁的剪力图和弯矩图

文章以作用于梁上的横向分布力集度与剪力、弯矩的微分关系为基础,归纳总结了几种荷载作用下剪力图、弯矩图的特征.掌握这些特征就能不写内力方程而根据外力直接画出相应的剪力图和弯矩图.