中国与欧美寒冷地带采暖耗能的比较

论文分别采用我国目前采暖标准和欧美国家的较高采暖标准,对我国严寒和寒冷地区8个城市的采暖耗能及相应的温室气体排放强度与欧美国家同纬度地区进行了对比。结果表明,中国季风气候的特点使严寒和寒冷地区冬季较世界同纬度地区更为寒冷而漫长,居民基本的生存采暖耗能需求高于世界同纬度地区。无论采用中国、德国、美国哪一种采暖标准,中国严寒和寒冷地区采暖强度远高于同纬度的欧美城市,有的城市要高于同纬度欧美城市1倍以上;目前中国严寒和寒冷地区的采暖标准属于维持基本生存必需的较低标准,中国要达到与欧美相同的热舒适水平必然比其他国家增加更多的采暖消耗;即使像目前这样,中国采取较低的采暖标准,而欧美国家采用较舒适的德国或美国标准,中国8个城市中有5~6个城市的采暖强度仍明显高于同纬度欧美城市。     

鞍山市倪家台地热田水化学特征及其演化机制

水化学分析结果表明,鞍山市倪家台地下热水属于HCO3.SO4-Na和SO4.HCO3-Na型水,且含有氟、锶和二氧化硅等多种矿物成分.由构建的硅-焓混合模型得出倪家台地区地下热水已有大量冷水混入,且混入比例介于67%—83%之间,水温下降的诱因是该区域过量开采地热水,在这种人为的长期干扰作用下,增大了上部含水层冷水对下部地热水的补给量,对今后可持续利用该区域地热资源构成了严重的威胁.     

氮磷钾对寒害腰果植株恢复生长结果的影响

通过观测不同施肥处理区寒害腰果植株重新开花坐果状况,分析施肥对寒害腰果植株恢复生长的影响,并分析腰果叶片养分含量与结果量之间的关系。结果表明：氮对寒害腰果植株重新开花的花枝数影响最大,钾次之,磷影响最小,随着氮施用量的增加,植株的花枝数逐渐增大;氮是影响寒害腰果植株结果量的主要因素,植株结果量随着氮施用量的增加而增加,磷、钾各处理间的结果量均未达到统计上显著差异;在施氮肥的基础上,配施磷钾肥,可以提高寒害腰果植株结果量,9个施肥处理中以N3P3K2处理的结果量最多。     

分岔隧道火灾火源位置对临界风速影响的数值模拟分析

为探究分岔隧道火灾火源位置对临界风速的影响规律,使用数值模拟方法对火源位于分岔隧道分岔口前和分岔口后的火灾场景下的临界风速进行研究.研究结果表明:火源位于分岔口后的主隧道时,临界风速明显大于火源位于分岔口前的临界风速;在一定范围热释放速率下,分岔隧道临界风速与热释放速率的1/3次方成正比;在分岔隧道模型中,相同热释放速...     

Effects of Neutral Posture on Muscle Tension During Computer Use

This study focused on developing a new approach to seated work positions as conducted on 67 office workers who use a Visual Display Terminal (VDT) as a major function of their working day. Muscle tension was measured by surface electromyography (sEMG) while participants were asked to adopt 4 selected working postures. Pain was measured before and after ergonomic intervention on the Nordic scale, which was modified for this study. Adjustable workstations were used to place participants in desired positions during the clinical testing sessions and the extended intervention period. Results indicate the effects of this ergonomic intervention may have positive effects on muscle tension and pain, significant enough to encourage employers to implement training and workstation modifications following these guidelines.     

Effect of Sweating on Insulation of Footwear

The study aimed to find out the influence of sweating on footwear insulation with a thermal foot model. Simultaneously, the influence of applied weight (35 kg), sock, and steel toe cap were studied. Water to 3 sweat glands was supplied with a pump at the rate of 10 g/hr in total. Four models of boots with steel toe caps were tested. The same models were manufactured also without steel toe. Sweating reduced footwear insulation 19–25% (30–37% in toes). During static conditions, only a minimal amount of sweat evaporated from boots. Weight affected sole insulation: Reduction depended on compressibility of sole material. The influence of steel toe varied with insulation. The method of thermal foot model appears to be a practical tool for footwear evaluation.     

The Effect of Protective Gloves on Manual Dexterity in the Cold Environments

This article presents a study on the effect of different protective gloves (which are commercially available and commonly used in the cold) on manual dexterity in cold environments. The experiments compared statistically four different types of gloves and two different types of gloving (outer or double) at +19 °C and -10 °C. Performance was determined both objectively and subjectively using two manual dexterity tasks: bolt-nut and pick-up tasks. The response measured was the time of performing each task. Statistical analysis showed that all independent factors such as glove type, participant, object size, and temperature had significant effects on the hand cooling reaction. A significant difference in the performance between the gloves was found in the bolt-nut task. It was also found that outer-inner combination gloving may be an approach to use for precision tasks.     

Anomalous Ba/Ca signals associated with low temperature stresses in Porites corals from Daya Bay, northern South China Sea

Barium to calcium (Ba/Ca) ratio in corals has been considered as a useful geochemical proxy for upwelling, river flood and other oceanic processes. However, recent studies indicated that additional environmental or biological factors can influence the incorporation of Ba into coral skeletons. In this study, Ba/Ca ratios of two Porites corals collected from Daya Bay, northern South China Sea were analyzed. Ba/Ca signals in the two corals were ‘anomalous’ in comparison with Ba behaviors seen in other near-shore corals influenced by upwelling or riverine runoff. Our Ba/Ca profiles displayed similar and remarkable patterns characterized by low and randomly fluctuating background signals periodically interrupted by sharp and large synchronous peaks, clearly indicating an environmental forcing. Further analysis indicated that the Ba/Ca profiles were not correlated with previously claimed environmental factors such as precipitation, coastal upwelling, anthropogenic activities or phytoplankton blooms in other areas. The maxima of Ba/Ca appeared to occur in the period of Sr/Ca maxima, coinciding with the winter minimum temperatures, which suggests that the anomalous high Ba/Ca signals were related to winter-time low sea surface temperature. We speculated that the Ba/Ca peaks in corals of the Daya Bay were most likely the results of enrichment of Ba-rich particles in their skeletons when coral polyps retracted under the stresses of anomalous winter low temperatures. In this case, Ba/Ca ratio in relatively high-latitude corals can be a potential proxy for tracing the low temperature stress.     

Estimating influence of stocking regimes on livestock grazing distributions

Livestock often concentrate grazing in particular regions of landscapes while partly or wholly avoiding other regions. Dispersing livestock from the heavily grazed regions is a central challenge in grazing land management. Position data gathered from GPS-collared livestock hold potential for increasing knowledge of factors driving livestock aggregation patterns, but advances in gathering the data have outpaced advancements in analyzing and learning from it. We fit a hierarchical seemingly unrelated regression (SUR) model to explore how season of stocking and the location where cattle entered a pasture influenced grazing distributions. Stocking alternated between summer on one side of the pasture one year and fall on another side of the pasture the next year for 18 years. Waypoints were recorded on cattle for 50 d each year. We focused our analysis on the pasture's 10 most heavily grazed 4-ha units, because these units were the most prone to negative grazing impacts. Though grazing of the study units was always disproportionately heavy, it was much heavier with the summer than fall stocking regime: Bayesian confidence intervals indicate summer grazing of study units was approximately double the average fall grazing value. This is our core result, and it illustrates the strong effect stocking season or date or both can have on grazing distributions. We fit three additional models to explore the relative importance of stocking season versus location. According to this analysis, stocking season played a role, but stocking location was the main driver. Ostensibly minor factors (e.g. stocking location) can greatly influence livestock distributions.     

国外舰载导弹发射装置发展综述

介绍了国外舰载导弹发射装置的基本概况及发展历程,分析了固定式发射装置、回转式发射装置、臂式发射装置、垂直发射装置的优缺点及适装范围。根据冷热发射方式的特点,分析了4种发射装置安装方式、贮弹量、射界、发射效率、反应速度、可靠性、安全性等基本性能,阐明了倾斜发射、垂直发射、冷热共架发射的基本原理。垂直发射装置以射界大、效率高、反应快、贮弹量多等优点成为舰载发射装置主流,倾斜发射在近程末端区域防空方面,可提前指向目标,减少导弹近距离大幅机动时间,提升末端拦截概率,是垂直发射的有效补充。舰载导弹发射装置正在朝垂直化、通用化发展,模块化发射和电磁垂直发射是下一代舰载发射的发展方向。