阳信县近10年热量变化对棉花生产的影响分析

利用阳信县气象站1971~2005年气象资料,分别计算阳信县近35年无霜期的长短以及10、15、20℃界限温度的初、终日期、持续日数、积温等热量指标。分析得出：近35年无霜期明显延长;10、15、20℃的界限温度的初日偏早,终日偏晚,持续日数增加;活动积温明显增多。指出近10年是阳信县热量最丰富的时期,并分析了近10年阳信县热量变化对当地棉花生产的可能影响,为科学评估阳信县气候资源、合理安排棉花生产提供参考。     

Satellite Evidence for an Arctic Sea Ice Cover in Transformation

Recent research using microwave satellite remote sensing data has established that there has been a reduction of about 3 percent per decade in the areal extent of the Arctic sea ice cover since 1978, although it is unknown whether the nature of the perennial ice pack has changed. These data were used to quantify changes in the ice cover's composition, revealing a substantial reduction of about 14 percent in the area of multiyear ice in winter during the period from 1978 to 1998. There also appears to be a strong correlation between the area of multiyear ice and the spatially averaged thickness of the perennial ice pack, which suggests that the satellite-derived areal decreases represent substantial rather than only peripheral changes. If this apparent transformation continues, it may lead to a markedly different ice regime in the Arctic, altering heat and mass exchanges as well as ocean stratification.     

近35年六安地区农业界限温度变化特征分析

利用安徽省六安地区6个县市气象观测站1981~2015年的逐日平均气温资料,采用线性趋势分析、M-K非参数突变分析等方法对稳定通过10、20℃初终日期、持续日数和积温的变化特征进行了分析。结果表明,近35年来六安地区稳定通过10和20℃的初日均呈提前趋势,初始日期在全市范围内提前幅度分别为2.2和3.1 d/10 a,气候突变点均出现在1997年;终止日期呈推迟趋势,推迟幅度分别为1.4和0.9 d/10 a,不存在显著的气候突变点。稳定通过10和20℃的持续日数均呈递增趋势,平均增幅分别为3.6和4.0 d/10 a,气候突变点分别出现在1997、1994年。稳定通过10和20℃的积温均呈递增趋势,平均增幅分别为126.7和116.0(℃·d)/10 a,气候突变点均出现在1994年。     

The isotopic composition of methane in polar ice cores

Air bubbles in polar ice cores indicate that about 300 years ago the atmospheric mixing ratio of methane began to increase rapidly. Today the mixing ratio is about 1.7 parts per million by volume, and, having doubled once in the past several hundred years, it will double again in the next 60 years if current rates continue. Carbon isotope ratios in methane up to 350 years in age have been measured with as little as 25 kilograms of polar ice recovered in 4-meter-long ice-core segments. The data show that (i) in situ microbiology or chemistry has not altered the ice-core methane concentrations, and (ii) that the carbon-13 to carbon-12 ratio of atmospheric CH(4) in ice from 100 years and 300 years ago was about 2 per mil lower than at present. Atmospheric methane has a rich spectrum of isotopic sources: the ice-core data indicate that anthropogenic burning of the earth's biomass is the principal cause of the recent (13)CH(4) enrichment, although other factors may also contribute.     

晚播对豫北冬小麦叶片生理及产量性状的影响

以冬小麦品种周麦18为材料,设置4个播期,同时对应不同播量,研究了晚播对豫北地区冬小麦叶片叶绿素含量、硝酸还原酶活性、植株干物质积累量及产量的影响.结果表明,晚播对叶片硝酸还原酶活性的影响主要表现在前期,对叶片叶绿素含量的影响主要表现在中期,至生长发育后期,播期对叶片生理性状的影响减小,各处理之间差异不显著.晚播加大播...     

不同干燥方式对青鱼片鲜度的影响

以青鱼片为试验材料,研究冰温真空干燥、热风干燥和真空冷冻干燥对其鲜度的影响.结果表明,热风干燥的鱼片鲜度明显低于冰温真空干燥和真空冷冻干燥;虽然冰温真空干燥和真空冷冻干燥的鱼片鲜度接近,但前者的鲜味成分IMP约为后者的2倍;此外,对3种干燥方式得到的鱼片的复水率进行比较,发现真空冷冻干燥的鱼片复水最快.     

设施杏扣棚升温后枝条内源激素的变化

以6￣7年生的设施杏(金太阳和凯特)为试材,研究了从扣棚升温至开花前枝条内源激素含量的变化。结果表明:ABA和ZR呈“升-降-升”的趋势;GA3变化较为复杂,IAA前期含量低且变化缓慢,后期含量急剧升高;四种内源激素中,ABA含量最高,IAA最少;ZR/ABA在升温后16d开始升高,而(IAA GA3 ZR)/ABA的升高,金太阳比凯特提前5d。     

Ice core evidence for extensive melting of the greenland ice sheet in the last interglacial

Evidence from ice at the bottom of ice cores from the Canadian Arctic Islands and Camp Century and Dye-3 in Greenland suggests that the Greenland ice sheet melted extensively or completely during the last interglacial period more than 100 ka (thousand years ago), in contrast to earlier interpretations. The presence of dirt particles in the basal ice has previously been thought to indicate that the base of the ice sheets had melted and that the evidence for the time of original growth of these ice masses had been destroyed. However, the particles most likely blew onto the ice when the dimensions of the ice caps and ice sheets were much smaller. Ice texture, gas content, and other evidence also suggest that the basal ice at each drill site is superimposed ice, a type of ice typical of the early growth stages of an ice cap or ice sheet. If the present-day ice masses began their growth during the last interglacial, the ice sheet from the earlier (Illinoian) glacial period must have competely or largely melted during the early part of the same interglacial period. If such melting did occur, the 6-meter higher-than-present sea level during the Sangamon cannot be attributed to disintegration of the West Antarctic ice sheet, as has been suggested.     

不同播期超甜玉米光合特性与产量的初步研究

通过不同播期超甜玉米生长发育中光合特性的测定,分析了光合速率（Ｐｎ）、蒸腾速率（Ｔｒ）、气孔导度（Ｇｓ）在不同生育期的变化．结果表明,甜玉米种植期中拔节期至大喇叭口期,光合速率较高,后期呈下降的趋势;甜玉米生长的前期蒸腾速率较低,后期蒸腾速率较高;气孔导度的变化呈单峰曲线状,以大喇叭口至抽穗期为最高峰时期．同时表明甜玉米适时早播有利于提高光合作用,增进同化物积累达到高产优质．揭示了甜玉米在生长发育时期一些主要光合特性的动态变化规律     

常温运输中加冰量对荔枝果实品质的影响

以荔枝果实为材料 ,设置多个加冰比例 [冰 / (冰 果 )× 10 0 % ]与急预冷 5℃等处理 ,7 5kg和 1 5kg包装 ,对果实温度、品质以及某些生理指标进行测定。结果表明 :室温下 72h后 ,对照与急降温预冷 5℃处理的果实温度相近 ,达 33℃左右 ,均高于室温 ,7 5kg和 1 5kg包装没有区别。加冰处理使果实温度先下降 ,后回升 ;加冰越多 ,果实品质保持越好 ,好果率越高 ,果实失重越少 ,细胞膜保持越完整。综合考虑经济效益及可行性后我们建议 :省际间荔枝的运输以小包装、加冰比例在 2 0 %～ 30 %较适宜     

特异高产株型大豆—沈豆4号生育规律的研究

采有特异高产株型大豆沈豆4号进行了3年的研究，探讨了沈豆4号在不同年份，不同播种期条件下的生育规律，结果表明，浓豆4号的株高增长，单株生物产量积累和籽粒鼓粒过程均可以用Logistic曲线方程来描述。不同播期对沈豆4号植株形态和生育进程有很大影响。在5月10日前后播种最适宜，此时植株生物产量积累轨迹更合乎高速积累出现早，积累速度不偏高的高产积累轨迹，沈豆4号开花后期和植株上部形成的籽粒其灌浆速率最大。     

湘西自治州雨季开始期的气候分析

[目的]分析湘西自治州雨季开始期的气候特征。[方法]利用湘西自治州1960～2011年全州8个县市的降水资料,分析了自治州雨季开始期的时空分布特征,并对自治州雨季开始期与厄尔尼诺和拉尼娜现象进行了相关分析。[结果]自治州雨季开始期从3月上旬到6月下旬,4月份最多,占35%,其次是3和5月,分别为22%和21%,雨季开始期不明显的占14%;自治州52年8个县市平均雨季开始期在4月16～20日。由于是山区,每年8个县市进入雨季的时间各不相同,其时间跨度从8 d到97 d,平均跨度为51 d;52年中雨季开始期正常年份占50%,偏早年份占23%,偏晚年份占27%。[结论]该研究为预测预报自治州雨季开始期提供了重要依据。     

Evolution of ocean temperature and ice volume through the mid-Pleistocene climate transition

Earth's climate underwent a fundamental change between 1250 and 700 thousand years ago, the mid-Pleistocene transition (MPT), when the dominant periodicity of climate cycles changed from 41 thousand to 100 thousand years in the absence of substantial change in orbital forcing. Over this time, an increase occurred in the amplitude of change of deep-ocean foraminiferal oxygen isotopic ratios, traditionally interpreted as defining the main rhythm of ice ages although containing large effects of changes in deep-ocean temperature. We have separated the effects of decreasing temperature and increasing global ice volume on oxygen isotope ratios. Our results suggest that the MPT was initiated by an abrupt increase in Antarctic ice volume 900 thousand years ago. We see no evidence of a pattern of gradual cooling, but near-freezing temperatures occur at every glacial maximum.     

Effect of sedimentation on ice-sheet grounding-line stability

Sedimentation filling space beneath ice shelves helps to stabilize ice sheets against grounding-line retreat in response to a rise in relative sea level of at least several meters. Recent Antarctic changes thus cannot be attributed to sea-level rise, strengthening earlier interpretations that warming has driven ice-sheet mass loss. Large sea-level rise, such as the approximately 100-meter rise at the end of the last ice age, may overwhelm the stabilizing feedback from sedimentation, but smaller sea-level changes are unlikely to have synchronized the behavior of ice sheets in the past.     

Rapid fluctuations in sea level recorded at huon peninsula during the penultimate deglaciation

About 140,000 years ago, the breakup of large continental ice sheets initiated the Last Interglacial period. Sea level rose and peaked around 135,000 years ago about 14 meters below present levels. A record of Last Interglacial sea levels between 116,000 years to 136, 000 years ago is preserved at reef VII of the uplifted coral terraces of Huon Peninsula in Papua New Guinea. However, corals from a cave situated about 90 meters below the crest of reef VII are 130, 000 +/- 2000 years old and appear to have grown in conditions that were 6 degreesC cooler than those at present. These observations imply a drop in sea level of 60 to 80 meters. After 130,000 years, sea level began rising again in response to the major insolation maximum at 126,000 to 128,000 years ago. The early (about 140,000 years ago) start of the penultimate deglaciation, well before the peak in insolation, is consistent with the Devils Hole chronology.     

Synchronism of the siberian traps and the permian-triassic boundary

Uranium-lead ages from an ion probe were taken for zircons from the ore-bearing Noril'sk I intrusion that is comagmatic with, and intrusive to, the Siberian Traps. These values match, within an experimental error of +/-4 million years, the dates for zircons extracted from a tuff at the Permian-Triassic (P-Tr) boundary. The results are consistent with the hypothesis that the P-Tr extinction was caused by the Siberian basaltic flood volcanism. It is likely that the eruption of these magmas was accompanied by the injection of large amounts of sulfur dioxide into the upper atmosphere, which may have led to global cooling and to expansion of the polar ice cap. The P-Tr extinction event may have been caused by a combination of acid rain and global cooling as well as rapid and extreme changes in sea level resulting from expansion of the polar ice cap.     

Contribution of the Patagonia Icefields of South America to sea level rise

Digital elevation models of the Northern and Southern Patagonia Icefields of South America generated from the 2000 Shuttle Radar Topography Mission were compared with earlier cartography to estimate the volume change of the largest 63 glaciers. During the period 1968/1975-2000, these glaciers lost ice at a rate equivalent to a sea level rise of 0.042 +/- 0.002 millimeters per year. In the more recent years 1995-2000, average ice thinning rates have more than doubled to an equivalent sea level rise of 0.105 +/- 0.011 millimeters per year. The glaciers are thinning more quickly than can be explained by warmer air temperatures and decreased precipitation, and their contribution to sea level per unit area is larger than that of Alaska glaciers.     

北京市农业热量资源变化特征及对农业生产的影响

选取了北京市山区和平原两大农业种植生态区的9个代表气象观测站,基于1961～2008年的地面气象观测资料,采用统计回归分析方法分析了逐年山区和平原的≥0℃活动积温、≥10℃活动积温、≥10℃有效积温、稳定通过0、5、10、15和20℃的初、终日期及持续日数、年极端最高、最低气温、季节日较差平均值和年较差、初、终霜日期、无霜期日数和冬季负积温等热量资源指标的历史变化趋势特征,同时以突变理论中的Mann-Kendall方法检测分析热量资源指标的突变特征。结果表明,山区和平原区活动积温和有效积温在1961～2008年呈上升趋势,平原上升趋势比山区明显,平原在1996年存在突变点;山区和平原区日平均气温稳定通过0、5、10℃的初日突变后比突变前提前了4～10d,终日山区和平原没有突变点,但也分别推迟了0～3d和1～10d,初终日持续日数也呈增加趋势,但平原多于山区,高温区域低于低温区域;年极端最低气温呈明显的上升趋势,平原比山区增温速度快;年极端最高气温呈现不明显的上升趋势;除山区的夏季和秋季外,年较差和季平均气温日较差都呈现减小的趋势;初霜日期推迟,终霜日期提前,无霜期日数增加,山区比平原表现更为显著;平原区和山区冬季负积温均呈现明显的上升趋势,平原高于山区。     

冷冻浓缩过程冰晶生长的相场法模拟

以水为原料,利用相场模型从微观上对冰晶生长机制进行模拟,结果表明:随着过冷时间的延长,冰晶的分枝逐渐发达;随着过冷度的增高,冰晶的分枝也逐渐发达.表明控制过冷时间和过冷度是冷冻浓缩过程中降低冰晶夹带率的重要措施.     

近10年黑龙江省道路结冰的发展趋势及其与温度的关系

对近10年黑龙江省部分地区道路结冰进行了研究,并和6种不同的温度进行了相关性对比分析,利用二分法初步找出了预报道路结冰的温度指标。结果表明,春季第1个无道路结冰日和道路结冰终日大多是南早北晚的趋势,春季结冰天数增多,秋季则减少。在与温度的对比中,春季第1个无道路结冰日期的趋势分布与平均气温相吻合,春季道路结冰终日和秋季道路结冰初日则与最高地温有关。春季道路结冰的天数受最低气温影响明显,秋季则不同,受平均气温的影响更大。对预报最有利的温度为最低气温,其中0～2℃的温度范围是结冰的多发期。