持续高温的发生规律对农业生产的影响

1980年以来,晋南地区年平均气温开始快速上升,平均每年上升约0.1℃。进入90年代后,持续高温灾害天气的频繁出现,对农作物的生长发育和产量均造成了不同程度的影响。通过气象分析和跟踪研究证明,日最高气温在35℃以上的灾害天气持续8d以上时,大多数农作物的花粉开始败育,导致结实不良,产量降低。     

Atmospheric carbon dioxide and aerosols: effects of large increases on global climate

Effects on the global temperature of large increases in carbon dioxide and aerosol densities in the atmosphere of Earth have been computed. It is found that, although the addition of carbon dioxide in the atmosphere does increase the surface temperature, the rate of temperature increase diminishes with increasing carbon dioxide in the atmosphere. For aerosols, however, the net effect of increase in density is to reduce the surface temperature of Earth. Because of the exponential dependence of the backscattering, the rate of temperature decrease is augmented with increasing aerosol content. An increase by only a factor of 4 in global aerosol background concentration may be sufficient to reduce the surface temperature by as much as 3.5 degrees K. If sustained over a period of several years, such a temperature decrease over the whole globe is believed to be sufficient to trigger an ice age.     

Thermal Properties of Meteoritic Iron from -150{degrees} to 300{degrees} Celsius

Thermal diffusivity and specific heat have been measured by the flash method on a small specimen of meteoritic iron from the Canyon Diablo fall. Measurements have been made over the temperature range -150 degrees to 300 degrees C from which thermal conductivity values have been calculated.     

Temperature-dependence of resistance at an electrotonic synapse

The junctional resistance at septa of the crayfish lateral giant axon is inversely related to temperature with a Q(1l), of about 3 over the range from 5 degrees to 20 degrees C. Nonjunctional axonal membrane is much less affected. Resistance changes occur rapidly with temperature changes. No correlates in ultrastructure of the synapses have been found.     

不同防寒措施对南疆果树越冬温度指标的影响

[目的]研究不同防寒措施对南疆果树越冬期间温度指标的影响及不同防寒材料的保温性能,提出保温效果好、符合实际生产的果树越冬防寒措施.[方法]以稻草帘、短绒毛毡、塑料发泡材料三种包裹物防寒和培土防寒措施为研究内容,通过定点连续测定包裹物内外的温度,对不同包裹物防寒、培土防寒措施的保温效果进行分析.[结果]三种包裹物防寒措施中,稻草帘包裹措施的温度日较差小、夜间平均温度高、对低温及低温持续时间的干预最明显,能够提高最低温度4℃以上且低温出现天数明显减少.此外,树干基部培土20 cm能够提高最低温度9～12℃以上,是一种温度波动小、保温效果好、操作简便的防寒措施.[结论]培土措施和稻草帘包裹措施的保温效果更好,也符合实际生产.     

The reproducibility of observational estimates of surface and atmospheric temperature change

Although concerns have been expressed about the reliability of surface temperature data sets, findings of pronounced surface warming over the past 60 years have been independently reproduced by multiple groups. In contrast, an initial finding that the lower troposphere cooled since 1979 could not be reproduced. Attempts to confirm this apparent cooling trend led to the discovery of errors in the initial analyses of satellite-based tropospheric temperature measurements.     

Sea Surface Temperature, Surface Wind Divergence, and Convection over Tropical Oceans

Large-scale convection over the warm tropical oceans provides an important portion of the driving energy for the general circulation of the atmosphere. Analysis of regional associations between ocean temperature, surface wind divergence, and convection produced two important results. First, over broad regions of the Indian and Pacific oceans, sea surface temperatures (SSTs) in excess of 27.5 degrees C are required for large-scale deep convection to occur. However, SSTs above that temperature are not a sufficient condition for convection and further increases in SST appear to have little effect on the intensity of convection. Second, when SSTs are above 27.5 degrees C, surface wind divergence is closely associated with the presence or absence of deep convection. Although this result could have been expected, it was also found that areas of persistent divergent surface flow coincide with regions where convection appears to be consistently suppressed even when SSTs are above 27.5 degrees C. Thus changes in atmospheric stability caused by remotely forced changes in subsidence aloft may play a major role in regulating convection over warm tropical oceans.     

Life at high temperatures

Water environments with temperatures up to and above boiling are commonly found in association with geothermal activity. At temperatures above 60 degrees C, only bacteria are found. Bacteria with temperature optima over the range 65 degrees to 105 degrees C have been obtained in pure culture and are the object of many research projects. The upper temperature limit for life in liquid water has not yet been defined, but is likely to be somewhere between 110 degrees and 200 degrees C, since amino acids and nucleotides are destroyed at temperatures over 200 degrees C. Because bacteria capable of growth at high temperatures are found in many phylogenetic groups, it is likely that the ability to grow at high temperature had a polyphyletic origin. The macromolecules of these organisms are inherently more stable to heat than those of conventional organisms, but only small changes in sequence can lead to increases in thermostability. Because of their unique properties, thermophilic organisms and their enzymes have many potential biotechnological uses, and extensive research on industrial applications is under way.     

锥栗种子萌发和贮藏特性的初步研究

该文采用常规方法对锥栗种子的形态特征、萌发和贮藏的生理生态特性进行初步研究.结果表明:锥栗种子千粒重和体积大,不易传播.种子在10～40℃均能萌发,萌发的适宜温度是20～35℃和室温（18～32℃）, 萌发时不需光.种子萌发无休眠,不耐脱水,属于顽拗性种子.在4℃时保湿贮藏半年,发芽率仍可达60%以上,采用室温湿沙贮藏半年,发芽率也可达40%以上,零上低温保湿贮藏是种子贮藏的理想方法.埋土种子的最终萌发率和成苗率均高于土壤表面的种子.种子在成熟、脱落和扩散过程中,由于遭受鼠、虫等动物危害,大部分已受损伤而丧失发芽率,在自然条件下种子很少萌发和成苗.      

Theoretical and experimental rate constants for two isotopic modifications of the reaction h + h2

Theoretical rate constants for two isotopic modifications of the simplest possible chemical reaction, namely, H + D(2) --> HD + D and D + H(2) --> HD + H, are presented. Experimental results, which have previously been obtained in the higher temperature regime by a shock tube technique, are combined with lower temperature results to give an experimental determination of the rate behavior over the large temperature range approximately 200 to 2000 K. It is now possible to assess the accuracy of ab initio potential energy surface calculations and to judge theoretical chemical kinetic methods.     

气候变化对农田生态系统碳氮过程的影响及其对生产的启示

从农田生态系统过程角度综合分析了气候变化([CO_2]增加、温度升高)对土壤碳库、氮供给生物化学过程的综合影响和长期效应。总结指出,[CO_2]增加、温度升高对农田生态系统过程的影响具有明显的时间效应,短时间尺度上加快农田土壤养分周转,改变碳氮组分,长时间尺度上导致土壤养分有效性降低;[CO_2]增加、温度升高和养分管理对农田生态系统过程的影响具有显著的交互作用,土壤养分有效性制约着气候变化对农田生态系统生产力和碳汇功能的影响。因此,气候变化([CO_2]增加、温度升高)情景下对农业生产管理包括施肥运筹及秸秆还田策略等的启示在于:根据气候变化背景下土壤养分的周转规律有效管理农田土壤养分、保持农田土壤肥力,从而保障农业高产的可持续性以及农田碳汇的生态服务功能。     

Thermoregulatory significance of thoracic lobes in the evolution of insect wings

The evolution of broadly attached thoracic lobes could have increased the body temperature excess of ancient wingless insects by 55 percent over that of lobeless forms. The subsequent expansion of these thoracic lobes for behavioral thermoregulation could have provided the morphological stage required for the evolution of functional wings.     

Twentieth-Century Sea Surface Temperature Trends

An analysis of historical sea surface temperatures provides evidence for global warming since 1900, in line with land-based analyses of global temperature trends, and also shows that over the same period, the eastern equatorial Pacific cooled and the zonal sea surface temperature gradient strengthened. Recent theoretical studies have predicted such a pattern as a response of the coupled ocean-atmosphere system to an exogenous heating of the tropical atmosphere. This pattern, however, is not reproduced by the complex ocean-atmosphere circulation models currently used to simulate the climatic response to increased greenhouse gases. Its presence is likely to lessen the mean 20th-century global temperature change in model simulations.     

脱水蔬菜等温吸湿规律研究

对预处理菜豆、青椒和茄子的脱水产品进行了静态吸湿试验，得出了反映其平衡含水率、温度和水分活度的等温吸湿曲线；分析讨论了温度、水分活度和物料结构对平衡含水率的影响；并得出３种物料各自最适宜的数学模型及其相应的模型系数。     

Superelastic effect in polycrystalline ferrous alloys

In superelastic alloys, large deformation can revert to a memorized shape after removing the stress. However, the stress increases with increasing temperature, which limits the practical use over a wide temperature range. Polycrystalline Fe-Mn-Al-Ni shape memory alloys show a small temperature dependence of the superelastic stress because of a small transformation entropy change brought about by a magnetic contribution to the Gibbs energies. For one alloy composition, the superelastic stress varies by 0.53 megapascal/°C over a temperature range from -196 to 240°C.     

气温变化背景下中国黄淮旱地冬小麦农艺性状的变化特征 ——以山西临汾为例

【目的】作物品种选育是在气候变化背景下的自然选择和人工选择的结果。黄淮麦区是中国最大的麦区,在保障中国小麦生产和粮食安全中有重要作用。研究过去30年黄淮旱地冬小麦品种农艺性状和气温要素变化规律,为旱地小麦育种适应未来气候变化提供理论依据和技术支撑。【方法】利用近30年来国家黄淮旱地冬小麦区域试验典型代表临汾点的对照品种农艺性状及该市的气温资料,研究对照品种农艺性状、生育期平均气温和≥0℃积温的变化规律,并进行农艺性状和气象要素的相关、多元回归和通径分析。【结果】小麦生育期的平均气温、≥0℃积温、最低和最高温度在逐年呈缓慢增加。小麦生育期平均气温平均每年上升0.05℃,≥0℃积温平均每年上升21.9℃,且二者呈正相关关系。≥0℃积温变化更能深入反映小麦生育期的温度变化情况。小麦生育期最高气温平均每年上升0.02℃、最低气温平均每年上升0.16℃。播种至越冬前的平均气温和≥0℃积温增加最多,营养生长阶段平均气温和≥0℃积温增加明显,生殖生长阶段平均气温增加较少且≥0℃积温有下降趋势。随着气候变暖,分蘖多的强冬性品种逐渐被分蘖适中的冬性和弱冬性品种替代。1986-1996年对照品种农艺性状变化幅度不大,1997-2007年期间变化较大,2007-2014年变化幅度最大;这和小麦生育期平均气温变化趋势基本相同。黄淮旱地对照品种千粒重和穗粒数逐年缓慢上升,分别每年平均增加1.57%和3.39%。有效穗数和产量及株高缓慢下降,分别每年平均下降0.16%和1.29%。产量与株高（0.684^**）、有效穗（0.531^**）和千粒重（0.541^**）均极显著正相关。株高、起身至拔节期≥0℃积温和平均气温是决定小麦产量的3个主要因子,分别决定了小麦产量的46.73%、26.17和3.26%的变异。在黄淮旱地小麦适应气候变化中,起身至拔节期≥0℃积温和株高对产量贡献较大且为正效应;起身至拔节期平均气温为负效应。【结论】气候变暖对黄淮旱地冬小麦农艺性状变化趋势有较强的影响,选育株高和有效穗数适中、穗粒数较多、千粒重较大的中高产抗旱品种是黄淮旱地小麦适应未来气候变化的育种改良方向。     

天水市近63年极端温度变化特征分析

为了研究气候变暖对天水极端温度的影响,利用天水观测站1951年至2013年逐年的极端温度资料,运用气候倾向率、趋势系数、百分位法、滑动T检验等统计方法,分析极端温度对气候变暖的响应特征。结果表明：天水年极端最高（低）温度均呈显著性升高趋势,极端最高气温上升0.2℃/10a,极端最低气温上升0.3℃/10a,都通过了α=0.01的显著性检验;通过百分位法定义了极端温度的阈值,分析发现：极端最高气温与阈值的差值随时间序列的增加逐步增大,极端最低气温与阈值的差值随时间序列的增加逐步减少,对极端最高温度和极端最低温度利用滑动T检验法进行突变检验,在α=0.01显著性水平下,极端最低温度没有发生突变,而极端最高温度在1983年和1993年发生了两次十分明显的突变。     

水稻生育期预测的非线性发育模型

在水稻模拟研究中发育期预测是基础环节。因为它为模拟作物生产力提供时间上的框架。目前对水稻发育过程尚未完全研究清楚,难以用解释性模型来描述。生产上普遍使用的积温法有一定问题,因为它隐含着发育速度与温度呈线性关系。本研究发现:对于调节IR8(籼稻)和藤坂5号(粳稻)播种到开花期间的发育速度,夜温比昼温有更大的效应。这一现象假设是由于发育速度与温度呈非线性关系引起的,因为夜温通常比昼温低。基于这一假设,本研究提出一个解释性能较好的非线性模型来量化水稻发育对温度的反应,并用相乘法则来综合温度和光周期的效应。该模型比线性加性模型和CERES-Rice中的发育模型有更好的预测性能,尽管由于数据观察值本身的异质性,模拟值与观察值还有一定差异。这种异质性来源之一是移栽效应,它在基因型(品种)间的差异似乎较小。为改善模型的预测性能,移栽效应可以作为一个乘子引入模型中以修饰光温效应。     

1901 - 2012 年福州市气温变化趋势

采用现代气候统计分析方法并结合Mann-Kendall检验和小波分析法,对1901—2012年福州市年平均气温、年极端最高气温、年极端最低气温等序列数据进行分析研究．结果表明：（1）1901—2012年福州市气温变化呈三峰二谷起伏形态,1981—2010年年平均气温比1901—1930年年平均气温高1．2℃;（2）年极端最高气温演变趋势总体上与年平均气温相似,小波分析结果表明,≥35℃年高温日数和年平均气温均存在较稳定的准50a和准25a的振荡周期;（3）福州市1901—2012年冬季极端最低温度年际分布呈两头高中间低的态势;（4）采用Mann-Kendall检验法分析,结果表明福州地区年平均气温在1990年发生突变,1990年后福州地区显著升温．     

温度对棉籽发育的影响

1988～1989年研究结果表明,20℃以上的日均温有利于棉籽体积增大,干物质积累,可溶性糖和淀粉的产生和转化,以及油分和蛋白质的累积。20℃以下特别是17℃以下对上述方面均有不利影响。初步认为龄期15℃的日均温是棉籽干物质和油分累积趋于停止的临界温度。