关于环保建筑材料的使用和可持续发展的探讨

随着环保型消费逐步占据主流,住宅建筑的生产商和消费者都对建材提出了安全、健康、环保的要求。采用清洁卫生技术生产,减少对天然资源和能源的使用,大量使用无公害、无污染、无放射性环保型建筑材料,有利于环境保护和人体健康,是住宅建筑发展的必然趋势。     

Alcohol consumption by young actively growing rats: a study of cortical bone histomorphometry and mechanical properties

Alcohol consumption by young actively growing rats has been previously demonstrated to decrease cortical and cancellous bone density, to reduce trabecular bone volume, and to inhibit bone growth at the epiphyseal growth plate. This study addresses the action of alcohol on cortical bone growth using histomorphometric techniques and on mechanical properties by three-point bending. Four-week-old, female Sprague-Dawley rats were divided into three groups. Alcohol-treated animals were fed a modified Lieber-DeCarli diet ad libitum containing 35% ethanol-derived calories, whereas the pair-fed animals (weight-matched to ethanol rats) received an isocaloric liquid diet in which maltose-dextrin-substituted calories were supplied by ethanol. Chow animals were fed a standard rat chow ad libitum. Femora were removed for analysis after 2, 4, 6, or 8 weeks on the diets. Cortical bone area, bone formation rates, and mineral apposition rates were reduced in the alcohol-fed animals. Bone stiffness, strength, and energy absorbed to fracture were significantly lower in the alcohol-fed animals. This distinctive alcohol effect was revealed to be caused by lower quality bone tissue as reflected by lower elastic moduli and yield strengths.     

控制辐照肉脂肪氧化技术的研究

通过对辐照剂量、贮藏温度、氧气含量和抗氧化剂等影响脂肪氧化因素的研究,揭示了辐照肉脂肪氧化的机理。结果表明:辐照处理可以明显诱导肉的脂肪氧化反应;降低贮藏温度、减少包装中的氧气含量和添加抗氧化剂,对抑制辐照肉的脂肪氧化效果明显。     

小变形下考虑摩擦效应的桩基水平承载分析方法

当前我国各类大型工程建设对桩基设计提出了更高的要求,桩基水平承载计算是一个突出问题。从传统水平受荷桩分析方法入手,推导考虑侧壁摩擦力的桩基水平承载挠曲微分方程,提出小变形下考虑摩擦效应的桩基水平承载计算方法(fm法)。编制相应的分析程序,通过算例验证方法的正确性和有效性。进一步比较传统m法与本文fm法的异同,并深入探讨尺寸效应对桩基水平承载的影响,可供工程参考。     

微米级银粉微观结构分析

通过使用XRD方法对热分解方法和碱体系还原得到的微米级银粉微观结构分析,结果表明微米级银粉都是纳米级的银晶体颗粒组成,且为面心立方结构;银粉晶粒表现为各向异性;制粉条件会影响银粉晶粒尺寸,升高热分解温度促使晶粒变小,机械整形和磨制促使晶粒变小;制备的银粉存在晶格畸变,均表现为晶格膨胀;制粉条件会影响晶面的布拉格衍射强度,且对不同晶面的影响程度存在差异。     

通信工程特色专业实践教学体系建设

本文主要介绍我校大学生科研训练计划SRTP、大学生电子科技竞赛、科研成果转化为优质教学资源和电子信息技术产业前沿论坛方面实践与思考。通过这些实践活动,学生能尽早地开展研究性学习,做到理论与实践密切结合,并激发其学习基础理论的热情,培养工程意识,提升实践能力与创新能力。     

富马海松酸环氧树脂的制备及漆膜性能

通过松香(RA)与富马酸(FA)高温下的Diels-Alder反应合成了富马海松酸(FPA),并利用碳谱(13CNMR)、电喷雾质谱(ESI-MS)、红外光谱(IR)对其进行了表征;通过FPA与丁二醇二缩水甘油醚(BDGE)、己二醇二缩水甘油醚(HDGE)的酯化反应合成了松香基环氧树脂预聚体(FB、FH),测试了预聚体与固化剂不同配比下固化物的漆膜性能;结果表明,当n(活性氢)/n(环氧基)在1.0、1.2时,漆膜的硬度大于HB,附着力小于2级,T-弯实验小于2 T,耐冲击强度大于9.8 J,耐化学性能良好。     

端到端网络服务健康度的人工免疫评价模型

从网络多维性能出发,建立了端到端网络服务健康度评价模型(ENHMM).该模型支持动态定制服务评价因子,同时给出基于评价因子的网络性能数据的主动测量方法.在评价算法上,利用了一种新的抗体促进与抑制机制的AiNet网络免疫算法.开发了原型系统对现实网络进行评价,得到了网络服务健康度等级.通过对评价结果的线性回归分析,发现该等级能够准确地反映用户感知的网络质量.     

宁南黄河灌区硫酸盐盐渍土盐胀规律及特性研究

对宁夏扶贫扬黄灌溉工程第四泵站硫酸盐盐渍土的盐胀规律及特性进行研究,通过室内进行单次降温膨胀试验,得出了硫酸盐盐渍土盐胀特性及影响因素。试验结果表明,含水量不变的条件下:(1)随温度的降低,试样的膨胀变形增加,膨胀变形的剧烈区间集中在15℃~-5℃之间;(2)随土的初始干密度的增大,试样的膨胀变形增大;(3)随土中硫酸盐的含量的增加,试样的膨胀变形增大。     

Concerted regulation of low density lipoprotein receptor gene expression by follicle-stimulating hormone and insulin-like growth factor I in porcine granulosa cells: promoter activation, messenger ribonucleic acid stability, and sterol feedback

The consequences of glucocorticoid receptor (GR) dysfunction for neuroimmunoendocrine responses to an inflammatory challenge were studied in transgenic mice expressing antisense RNA directed against the GR [GR-impaired (GR-i) mice]. Mice were implanted intraperitoneally with a biotelemetry transmitter to monitor body temperature and locomotion. GR-i mice showed decreased locomotion and body temperature during the dark phase of the diurnal cycle. Intraperitoneal administration of saline caused a rapid increase in body temperature in control mice, which was terminated within 90 min. In GR-i mice, however, body temperature remained elevated for about 6 h. Intraperitoneal injection of endotoxin (10 micrograms/mouse) produced a biphasic fever in control mice. However, in endotoxin-injected GR-i mice, body temperature was not significantly different from their saline-injected controls during the first 6 h. Body temperature then increased and remained elevated during the night period. Both strains showed hypolocomotion after endotoxin. In a second experiment, mice were injected intraperitoneally with saline or endotoxin and killed after 1, 3, 6 or 24 h. In GR-i mice, endotoxin caused an augmented rise in plasma ACTH, but not in corticosterone levels. The endotoxin-induced increase in serum levels of interleukin-1 beta and interleukin-6 was not different between the strains. However, whereas in control mice tumour necrosis factor-alpha levels were below detection at the time points studied, substantial levels of this cytokine were found in the serum of GR-i mice 1 h after endotoxin administration. It may be concluded that life-long impairment of GR evolves in aberrant physiological and humoral responses to an acute inflammatory challenge. These findings expand our understanding about the neuroendocrine and physiological disturbances associated with stress-related disorders.