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。     

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.     

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。     

初冬一次冷锋输送过程对中国东部霾天气的影响

利用常规地面气象资料、NCEP/NCAR再分析资料以及全国PM_2.5浓度数据,并结合后向轨迹、空气污染输送指数和传输通量分析,针对2019年12月10~11日一次冷锋输送造成我国中东部地区出现的大范围霾天气过程进行了分析.结果表明：（1）霾期间高空500hPa以经向环流为主,伴随着高空低压槽引导地面冷锋向东南方向移动,污染物浓度大值区也依次由华北地区移至黄淮、江淮地区.（2）冷锋过境前,华北至长江三角洲区域PM_2.5浓度均有明显增涨;北京以偏南方向的污染物输入为主,济南以西北和偏东方向输入为主,南京则主要是偏北和偏西方向的输入.（3）冷锋过境时,冷空气迅速将北京站的污染物清除;而济南站则受高压底部偏东风回流的影响,PM_2.5浓度维持在50μg/m³左右;冷锋推进至南京站时西北风已较小,对污染物的清除作用不明显.以江苏省为例,整个过程中,江苏本地污染物贡献占25.8%,江苏以外的污染物贡献占74.2%,以输送为主.（4）冷锋过境后,3站的边界层结构也略有不同,北京站的逆温层迅速被打破;济南站由于受海上暖湿平流影响,近地面由等温层变成逆温层;而南京站的近地面则由逆温层变为等温层.本研究揭示了在冷锋南下过程中,上游污染物对下游地区的影响,以及南北方站点表现出不同的污染物变化和清除特征.     

云南粳稻核心种质杂种后代孕穗期耐冷性研究

以236份云南地方粳稻核心种质和云南主栽梗稻Oryza satica品种合系35配制的杂种F5、BC1F4、BC2F3和BC3F2为材料,在昆明自然低温平均17.8℃(冷害)条件下,对亲本及其后代进行孕穗期耐冷性研究.结果表明:①亲本耐冷性状间的相关性明显高于其杂种后代,不同世代间总体趋势为随着回交世代增加其性状间相关性减弱.在亲本及其杂种后代间耐冷指标性状穗颈长、穗下节长、每穗实粒数、每穗秕粒数与结实率均呈较高的(≥0.370)极显著(n=236,R0.01=0.181)相关.②株高、穗颈长、穗下节长等耐冷性状在亲本强弱耐冷系统群间的差异明显,表现为亲本耐冷性强的材料秆和穗较长、穗粒数较多,同一性状变异程度减小.但随着回交代数的增加,这些性状的平均值逐渐趋同于轮回亲本,差异减小.③穗颈长、穗下节长、每穗实粒数、每穗秕粒数与结实率在5个稻作区间的变化规律呈现一致性,亲本和F5的差异较大,而BC2F4、BC2F3和BC3F2的差异较小,且趋同于轮回亲本.通过连续回交,在BC3F1即可获得耐冷性状表现良好的材料.     

冰中和水中四环素光降解动力学及其影响因素的比较

冰雪是一类重要且普遍的环境介质,而冰雪环境光化学是一门新兴的学科.在相同光照条件下比较冰中和水中有机污染物的光化学行为,有助于揭示冰雪光化学与水环境光化学之间的异同.本文以四环素（TC）为模型化合物,比较了模拟日光（λ>290 nm）照射下不同水体冰相和水相中TC的光降解动力学,研究了不同相中溶解性物质（腐殖酸（HA）、Cl^-、NO₃^-和Fe（III））对光降解的影响及作用机制,以揭示冰雪环境光化学和水环境光化学的异同.结果表明,冰中和水中TC光解遵循准一级反应动力学,纯水冰中表观光解量子产率为4.76×10^-3,高于纯水中表观光解量子产率（3.85×10^-3）.在不同水体中,冰相TC的光解快慢顺序为海水冰中 > 淡水冰中 > 纯水冰中,而在水相中光解快慢顺序与冰相不同,为淡水中 > 海水中 > 纯水中.通过考察主要溶解性物质对冰/水中TC光降解动力学的影响发现,无论是在冰相还是水相,Cl^-、HA、NO₃^-和Fe（III）均加快了TC的光降解,且促进作用随浓度的升高而增强.但在水相与冰相中每个因素促进的程度却存在差异,相对于水环境,冰中HA、NO₃^-、Fe（III）敏化作用较大,对TC光降解的促进作用较强;而冰中Cl^-对TC光解的促进作用较水相中弱.这些溶解性物质对TC光解的促进作用能够解释海水冰、淡水冰与海水、淡水中TC相对于纯水冰相/水相具有较强的光降解能力.进一步地,将实验数据外推到实际环境,在35°~50°N地区的仲冬季,冰雪表面和水体表层TC光化学降解的半减期分别为15.4~38.9 min和19.0~48.0 min,其不仅依赖于光解发生的纬度与季节,还受到反应基质（冰/水）的影响.以上结果揭示了冰中和水中TC光化学转化行为的异同,这对于准确评价寒冷环境中此类新型污染物的归趋具有重要意义.     

适冷微生物研究进展及应用现状

适冷微生物(包括嗜冷微生物、耐冷微生物)是在低温下仍具有生存和繁殖的能力的一类微生物,低温会对微生物产生如酶活性降低、膜流动性变差、蛋白质冷变性、不适当的蛋白质空间折叠和低温下细胞内部构造破坏等不利影响。适冷微生物能克服低温带来的消极影响,并能在极端环境下生长及代谢。随着宏基因组测序、蛋白质组学以及其它分析手段在环境微生物中的应用,作者对低温微生物的一些适应性改变有了新的认识。酶活性中心结构的改变、膜中脂质成分含量的增加,冷适应蛋白的快速表达等都被证明在对低温适应中起着重要作用。文章综述了适冷微生物的适冷机理及其在污染控制领域的应用,为适冷微生物的实际工程应用提供参考,为适冷微生物在环境工程中的进一步广泛应用奠定基础。     

介质阻挡放电降解苯乙烯的研究

研究了介质阻挡放电(DBD)常压下降解流动态苯乙烯时,不同电压、流速、初始浓度及湿度下苯乙烯的降解情况.结果表明,DBD降解苯乙烯15~20min即可达稳定,产物主要为CO、CO₂和H₂O;电压4800V时有少量带苯环的气态及固态物质产生,且随电压的升高而减少,到7500V时红外光谱已无法检测到;高电压下放电可以取得90%左右的降解率,产生带苯环的气态物质和结焦物质较少.流速在1.5cm/s,浓度为3000mg/m³,相对湿度为20%左右时,降解效果最好.