陕西关中冬小麦气候适宜度分析

利用气候适宜度模型对陕西关中地区1986年以来的冬小麦不同生育期和全生育期的气候适宜度进行计算。结果表明：在冬小麦生长发育期间,温度适宜度和光照适宜度最高,降水适宜度最小;自1986年以来,随着气候变暖,多年温度、光照、气候适宜度变化呈逐年上升,降水适宜度则呈现逐年降低,从变化倾向来看,光照、温度和气候适宜度以每年0.004 4、0.000 2和0.001 3的速度升高,降水适宜度以每年0.002 1的速度减少。在气候变化背景下,对于关中地区冬小麦生产而言,光热资源较为充足,降水则是影响冬小麦生长发育主要气候因素,且随着气候进一步变暖,降水对冬小麦生产的影响将更加明显。     

Milankovitch radiation variations: a quantitative evaluation

A quantitative determination of changes in the surface temperature caused by variations in insolation calculated by Milankovitch has been made through the use of the thermodynamic model of Adem. Under extreme conditions, mean coolings of 3.1 degrees and 2.7 degrees C, respectively, at latitudes 25 degrees and 65 degrees N are obtained for Milankovitch radiation cycles. At the sensitive latitude 65 degrees N, a mean cooling below the present temperature for each of the times of radiation minimum is only 1.4 degrees C. This result indicates that the Milankovitch effect is rather small to have triggered glacial climates.     

Mariner 1969: preliminary results of the infrared radiometer experiment

The thermal energy emitted by Mars was measured in the 8- to 12- and 18- to 25-micrometer bands. The minimum temperature derived for the southern polar cap is 150 degrees K, an indication that the cap is formed by frozen carbon dioxide. No significant temperature fluctuations were detected with a 100-kilometer scale.     

Temperature Regulation in the Bumblebee Bombus vagans: A Field Study

Bombus vagans forages for nectar at 5 degrees C in shade and at 31 degrees C in sunshine. The production of heat while the bumblebee is on flowers, at ambient temperatures below 24 degrees C, helps to maintain a thoracic temperature that is near the minimum for flight between flowers. However, at ambient temperatures above 24 degrees C the thoracic temperature is no longer regulated at 32 degrees to 33 degrees C and rises.     

不同含水率速生杨木DMA图谱分析及应用

采用动态热机械分析仪对绝干、6％、12％、18％、30％、50％、100％和水饱和8种含水率速生杨木试件进行了动态黏弹性分析.动态力学分析参数为:温度扫描范围35～ 350℃,升温速度5℃·min-1,测量频率10Hz.储能模量的变化表明:各含水率试件在整个扫描温度范围内均出现2个明显的弹性转变过程,完成次级弹性转变的...     

宁津县气候变化规律分析

利用宁津县1971—2007年的气象资料,分析宁津县的气温变化与降水变化规律。结果表明:37年内的年平均气温、年平均最高气温、年平均最低气温自80年代后期以来呈上升趋势,到90年代后期增温幅度加快,尤其以冬、春季最为明显。年平均气温以0.44℃/10 a的速度上升,而年平均最低气温则以0.50/10 a的速度上升,明显高于年平均最高气温的上升趋势;年平均降水量总体上呈下降趋势,主要是夏季降水量减少明显。     

甘蓝—萝卜—白菜一年三收规模种植模式在咸阳北部的气候适宜性研究

利用咸阳各地1991—2020年日平均气温、日平均最低气温,结合2020年旬邑、渭城大田生产数据和甘蓝、萝卜、白菜营养生长所需气象条件,规划甘蓝—萝卜—白菜一年三收生产模式,为充分利用气候资源、提高土地利用率提供理论依据。结果表明,适宜甘蓝营养生长的日平均气温为15～24℃,且该时段内逐日平均最低气温≤12℃的天数不超过16天;适宜萝卜营养生长的日平均气温11～25℃,日相对湿度>47%;适宜白菜营养生长的日平均气温为5～25℃,日最低气温≥-2℃。咸阳北部县(市)甘蓝—萝卜—白菜一年三收可以实现。咸阳南部各县(市、区)由于夏季气温偏高不适宜冷凉蔬菜生长。     

Bacterial Sulfate Reduction Above 100{degrees}C in Deep-Sea Hydrothermal Vent Sediments

The currently known upper temperature limit for growth of organisms, shared by a number of archaebacteria, is 110 degrees C. However, among the sulfate-reducing bacteria, growth temperatures of greater than 100 degrees C have not been found. A search for high-temperature activity of sulfate-reducing bacteria was done in hot deep-sea sediments at the hydrothermal vents of the Guaymas Basin tectonic spreading center in the Gulf of California. Radiotracer studies revealed that sulfate reduction can occur at temperatures up to 110 degrees C, with an optimum rate at 103 degrees to 106 degrees C. This observation expands the upper temperature limit of this process in deep-ocean sediments by 20 degrees C and indicates the existence of an unknown group of hyperthermophilic bacteria with a potential importance for the biogeochemistry of sulfur above 100 degrees C.     

气候变化对盘锦水稻生育期的影响分析

[目的]研究气候变化对盘锦水稻生育期变化的影响。[方法]选取盘锦大洼气象站1980~2009年水稻生育期观测资料及生育期气象资料,通过统计分析方法研究生育期变化及其与气象条件的关系。[结果]水稻全生育期平均气温、平均最高气温、平均最低气温均呈现升高的趋势,降水量呈减少的趋势,日照时数变化平缓;营养生长期与生殖生长期内平均气温、平均最高气温、平均最低气温的变化与全生育期的变化相似;平均气温与平均最高气温的升高导致全生育期和营养生长期缩短,却使生殖生长期延长。[结论]气候变化致使水稻生育期缩短,但营养生长期与生殖生长期变化不同。     

气候变化对黄淮海地区夏玉米-冬小麦种植模式和产量的影响

【目的】全球气候正以变暖为主要特征发生显著变化,探究气候变化对黄淮海地区夏玉米-冬小麦种植制度的影响,为制定合理的应对措施提供理论依据。【方法】通过气象站点观测值的加权平均和一元线性回归分析黄淮海各省市地区1992—2013年来的气候变化特征。利用农业气象站点多年长期观察的夏玉米-冬小麦物候数据,通过加权求平均,分析气候变暖背景下夏玉米-冬小麦的生育期和茬口推移情况。采用一元线性回归分析1992—2013年来黄淮海地区夏玉米-冬小麦周年产量变化。同时利用非线性回归分析法和面板数据敏感性分析法分析气候变化对黄淮海地区夏玉米-冬小麦周年产量的影响。【结果】1992—2013年来,黄淮海地区温度整体呈现波动上升趋势,降水总量变化趋势不明显,但区域差异显著。在气候变化的背景下,黄淮海地区夏玉米-冬小麦种植模式发生明显改变:冬小麦播种时间推迟,生育期存在缩短趋势,不同地区缩短2—5 d不等;夏玉米播种时间南部推迟而北部提前,收获时间总体呈现推迟趋势,整个黄淮海地区生育时长未发生明显变化。茬口时间因夏玉米-冬小麦生育期的推移呈现不同程度延长,造成了气候和土地资源的浪费。1992—2013年间黄淮海地区夏玉米-冬小麦单产呈显著上升趋势,多数省份达到显著水平。非线性敏感性分析表明,最低温度、最高温度和平均温度对夏玉米-冬小麦产量的影响基本表现为同时增产或同时减产的一致性。冬小麦产量受最低温度的影响最为显著,东南部的江苏省和山东省减产明显,而北部河北省和西部河南省表现为增产。温度升高除对河南省夏玉米有增产作用外,其他省份夏玉米产量均出现不同程度的降低,这可能与温度升高的幅度不同和降水的区域性差异有关。降水量对夏玉米-冬小麦产量影响存在地区差异。总体上气候变暖对周年单产影响表现为北部增产,而南部减产,因而选择适宜早播且生育期长的夏玉米品种对保障周年产量具有重要意义。【结论】气候变暖背景下,黄淮海地区冬小麦播种时间推迟,生育期缩短,夏玉米生育期北部延长而南部缩短,生育期的推移导致茬口时间延长,造成了气候资源和土地资源的浪费。1992—2013年间夏玉米-冬小麦周年产量显著提高。温度升高和降水增加对产量的影响存在区域差异,整个区域平均来看升温使夏玉米减产,冬小麦增产;降水增加有利于黄淮海北部地区夏玉米的产量形成,对南部地区夏玉米产量则存在不利影响,而对黄淮海大部分地区冬小麦的产量形成不利。     

Banded corals: changes in oceanic carbon-14 during the little ice age

Radiocarbon analyses and stable isotope measurements are presented foro recent cores of banded corals from the Florida Straits. These values provide a record of variations in the ratio of carbon-14 to carbon-12 in the dissolved inorganic carbon in the surface waters of the Gulf Stream from A.D. 1642 to 1800. An increase in the carbon-14/carbon-12 ratio of 7 per mil for coral growth during the early 1700's was most likely induced by an increase in the carbon-14/carbon-12 ratio of 20 per mil in the atmospheric carbon dioxide that occurred at about 1700. The ratios of oxygen 18 to oxygen-16 in these coral bands show a small decrease of a water temperature ( approximately 1 degrees C) during the latter part of the Little Ice Age (1700 to 1725). These results support the hypothesis that the increase in atmospheric carbon-14 at about 1700, and possibly the temperature change as well, was caused by a decrease in solar activity (Maunder sunspot minimum).     

Preliminary infrared radiometry of the night side of mercury from mariner 10

The infrared radiometer on Mariner 10 measured the thermal emission from the planet with a spatial resolution element as small as 40 kilometers in a broad wavelength band centered at 45 micrometers. The minimum brightness temperature (near local midnight) in these near-equatorial scans was 100 degrees K. Along the track observed, the temperature declined steadily from local sunset to near midnight, behaving as would be expected for a homogeneous, porous material with a thermal inertia of 0.0017 cal cm(-2) sec(-(1/2)) degrees K(-1), a value only slightly larger than that of the moon. From near midnight to dawn, however, the temperature fluctuated over a range of about 10 degrees K, implying the presence of regions having thermal inertia as high as 0.003 cal cm(-2) sec-(1/2) degrees K(-1).     

青海省海东市1961-2015年气温变化趋势和演变特征

为了研究近55年来青海省海东市气温变化的特点及其规律,利用海东市5气象站1961-2015年的气温资料,使用线性趋势、Mann-Kendall突变检验和累积距平法等方法进行分析研究。结果表明：55年来海东市年平均气温、最高气温和最低气温呈极显著的增温趋势,年际增长率分别为0.33℃/10a、0.33℃/10a和0.43℃/10a,从年代际变化来看,平均气温和最低气温(最高气温)在20世纪90年代到21世纪00年代(80年代到90年代)增暖趋势明显;四季平均气温、最高气温和最低气温均呈显著的增温趋势,存在着非对称性变化的特点,以最低气温增温更明显,冬季增温对年平均气温增高贡献最大,三者增温的强弱在时间和空间上均表现出不一致性;海东市年平均气温20世纪90年代中后期的增暖是一突变现象,突变开始的具体时间是1996-1997年,最高气温于1993年发生了突变。     

Supercooling of Water to -92{degrees}C Under Pressure

The temperature at which "clean" supercooled water freezes has been determined as a function of pressure up to 3 kilobars, using a differential thermal analysis technique on subdivided water samples. The supercooling limit of such samples, -38 degrees C at normal pressure, is lowered by initial increase of pressure, reaching a minimum value of -92 degrees C at 2.00 kilobars.     

塔城市近47年气候变化特征

利用塔城市1961～2007年地面气象资料,分析了47年来温度、降水、日照和风速的变化特征,结果显示,气温呈明显上升趋势,气温变化速率达0.50℃/10a,47年平均气温上升了约2.4℃。四季季平均气温整体上都呈上升趋势,冬季气温最为明显,线性增长率达0.85℃/10a;秋季次之,线性增温速率为0.58℃/10a;夏季线性增长速率为0.39℃/10a;春季线性增温速率最小为0.34℃/10a,年平均最高气温的年代际变化呈波动式上升特征,增温率为0.37℃/10a。春、夏、秋、冬的线性增温率分别为0.217、0.266、0.488和0.540℃/10a。平均最低气温年代际变化与平均最高气温年代际变化比较相似。近47年来,年降水量呈增加趋势,降水量倾向率3.49 mm/10a,年降水量变化的波动较为明显,春、夏季降水量变化不太明显,秋季降水量有明显的减少趋势,冬季降水量上升趋势最明显,对全年降水量上升趋势贡献最大,其次为春季。近47年来,平均日照时数有明显的下降趋势,其变化速率为-21.1 h/10a。年平均风速呈较小的减弱趋势,减少速率仅为-0.08 m/s.10a。     

TEMPERATURE-DEPENDENT HISTOTYPIC CHANGES IN WALKER CARCINOSARCOMA IN THE CHORIOALLANTOIS

Solid tumors grew in the chorioallantois of chick embryos after the topical inoculation of ascites tumor cells. The microscopic character of the growth varied depending on the temperature of incubation. At 32.5 degrees C a sarcomatous appearance was prominent; at 37.5 degrees C carcinomatous structure in several alveolar patterns predominated; at 42.5 degrees C growth was that of a "giant cell" carcinoma.     

北五味子物候的观测及气象要素影响

采用物候与气象因子相结合的同步观测方法,对长春地区北五味子的生长特性和影响其生长率的气象因子进行研究.结果表明:北五味子返青前候平均气温在-5℃时可视为返青期即将开始的温度指标.日平均气温在-2℃时枝条开始返青.候平均气温≥5℃或≥5℃的有效积温高于20℃可作为进入树液流动期的温度指标.≥5℃的有效积温100℃是进入展叶期的温度指标.北五味子果实发育到成熟要求平均气温20℃以上,≥10℃有效积温1500℃以上.幼果膨大期是北五味子的水分临界期,此间降水量在70～80mm就可以满足植株生长的需要.日平均温度24℃为北五味子生长的最适温度.     

Early meteorological results from the viking 2 lander

Early results from the meteorological instruments on the Viking 2 lander are presented. As on lander 1, the daily patterns of temperature, wind, and pressure have been highly repetitive during the early summer period. The average daily maximum temperature was 241 degrees K and the diurnal minimum was 191 degrees K. The wind has a vector mean of 0.7 meter per second from the southeast with a diurnal amplitude of 3 meters per second. Pressure exhibits both diurnal and semidiurnal oscillations, although of substantially smaller amplitude than those of lander 1. Departures from the repetitive diurnal patterns begin to appear on sol 37.     

Empirical models of the electron temperature and density in the nightside venus ionosphere

Empirical models of the electron temperature and electron density of the late afternoon and nightside Venus ionosphere have been derived from Pioneer Venus measurements acquired between 10 December 1978 and 23 March 1979. The models describe the average ionosphere conditions near 18 degrees N latitude between 150 and 700 kilometers altitude for solar zenith angles of 80 degrees to 180 degrees . The average index of solar flux was 200. A major feature of the density model is the factor of 10 decrease beyond 90 degrees followed by a very gradual decrease between 120 degrees and 180 degrees . The density at 150 degrees is about five times greater than observed by Venera 9 and 10 at solar minimum (solar flux approximately 80), a difference that is probably related to the effects of increased solar activity on the processes that maintain the nightside ionosphere. The nightside electron density profile from the model (above 150 kilometers) can be reproduced theoretically either by transport of 0(+) ions from the dayside or by precipitation of low-energy electrons. The ion transport process would require a horizontal flow velocity of about 300 meters per second, a value that is consistent with other Pioneer Venus observations. Although currently available energetic electron data do not yet permit the role of precipitation to be evaluated quantitatively, this process is clearly involved to some extent in the formation of the nightside ionosphere. Perhaps the most surprising feature of the temperature model is that the electron temperature remains high throughout the nightside ionosphere. These high nocturnal temperatures and the existence of a well-defined nightside ionopause suggest that energetic processes occur across the top of the entire nightside ionosphere, maintaining elevated temperatures. A heat flux of 2 x 10(10) electron volts per square centimeter per second, introduced at the ionopause, is consistent with the average electron temperature profile on the nightside at a solar zenith angle of 140 degrees .     

Atomic hydrogen on Mars: measurements at solar minimum

The Copernicus Orbiting Astronomical Observatory was used to obtain measurements of Mars Lyman-alpha (1215.671-angstrom) emission at the solar minimum, which has resulted in the first information on atomic hydrogen concentrations in the upper atmosphere of Mars at the solar minimum. The Copernicus measurements, coupled with the Viking in situ measurements of the temperature (170 degrees +/- 30 degrees K) of the upper atmosphere of Mars, indicate that the atomic hydrogen number density at the exobase of Mars (250 kilometers) is about 60 times greater than that deduced from Mariner 6 and 7 Lyman-alpha measurements obtained during a period of high solar activity. The Copernicus results are consistent with Hunten's hypothesis of the diffusion-limited escape of atomic hydrogen from Mars.