In Situ Northern Mid-Latitude Observations of ClO, O3, and BrO in the Wintertime Lower Stratosphere

In order to test photochemical theories linking chlorofluorocarbon derivatives to ozone(O(3)) depletion at high latitudes in the springtime, several related atmospheric species, including O(3), chlorine monoxide(ClO), and bromine monoxide (BrO) were measured in the lower stratosphere with instruments mounted on the NASA ER-2 aircraft on 13 February 1988. The flight path from Moffett Field, California (37 degrees N, 121 degrees W), to Great Slave Lake, Canada (61 degrees N, 115 degrees W), extended to the center of the polar jet associated with but outside of the Arctic vortex, in which the abundance of O(3) was twice its mid-latitude value, whereas BrO levels were 5 parts per trillion by volume (pptv) between 18 and 21 kilometers, and 2.4 pptv below that altitude. The ClO mixing ratio was as much as 65 pptv at 60 degrees N latitude at an altitude of 20 kilometers, and was enhanced over mid-latitude values by a factor of 3 to 5 at altitudes above 18 kilometers and by as much as a factor of 40 at altitudes below 17 kilometers. Levels of ClO and O(3) were highly correlated on all measured distance scales, and both showed an abrupt change in character at 54 degrees N latitude. The enhancement of ClO abundance north of 54 degrees N was most likely caused by low nitrogen dioxide levels in the flight path.     

Turbulent Vertical Transport due to Thin Intermittent Mixing Layers in the Stratosphere and Other Stable Fluids

Pollution effects in the stratosphere and the ocean are exacerbated by buoyant stability. Turbulence in such media is confined to thin layers. To estimate vertical transport by such turbulence, one can view the situation as nature's way of simulating the finite-difference diffusion equation. This analogy finally yields a diffusivity parameter which is valid for this extremely inhomogeneous case.     

热带海表面温度与对流关系分析

通过研究热带海表温度（SST）与地气对外辐射（OLR）关系探讨了热带海表温度与对流强度之间的相关性。结果显示,在温度小于约28℃时,OLR随SST的升高而增大,当SST大于28℃时,OLR随SST升高而减小,28℃左右为SST与OLR的相关关系拐点。OLR的异常反映了对流活动的异常,当对流活动的强弱和分布发生变化,必然会引起热源出现变异,因而影响环流的异常。通过对厄尔尼诺与拉尼娜事件的合成分析得到,OLR与SST之间的关系与厄尔尼诺和拉尼娜期间大气异常环流型的形成是非常密切的。由于OLR和SST之间存在相关性的拐点,使得厄尔尼诺和拉尼娜期间对流的上升或下沉区域位置有所不同,也进一步证实SST是决定对流的一个关键因子。     

NCEP/NCAR再分析温度·位势高度和风速场资料在上对流层/下平流层的适用性评估

利用全球169个探空站资料检验NCEP/NCAR再分析资料,分析全球（主要是陆地地区）上对流层互下平流层位势高度、温度以及风速场标准误差的分布特征。结果表明,再分析风速场资料标准误差分布主要受急流区的影响,在急流区与实际风场存在明显的差异;并且风速场标准误差的分布具有明显的冬夏季节差异,在海岸线附近平均偏差较大;再分析位势高度、温度场的标准误差高值区主要集中在东半球低纬地区（印度洋沿岸）,标准误差分布与其平均偏差分布基本一致,所以标准误差可以由平均偏差很好的解释;再分析温度、位势高度资料内陆地区标准误差偏低,高值区主要沿海岸线分布,风速场平均误差在海岸线附近比较大,这与探空站数据的质量地区差异及陆地观测站密集、海洋观测站较少密切相关。     

HCHs在海河干流沉积物／水间迁移行为研究

于2007年8月至2008年3月对海河干流表层水和沉积物中六六六(HCHs)污染状况进行了采样调查.结果表明,海河干流水体中HCHs含量为4.02～25.29 ng·L-1(平均值12.94 ng·L-1),表层沉积物中HCHs含量为2.77～5.96 ng·g-1(平均值4.25 ng·g-1),表层水和表层沉积物中HCHs的主要成分均为β-HCH.以γ-HCH为例,利用稳态非平衡逸度模型计算了γ-HCH在海河干流沉积物冰间的迁移和分布,模型结果用现场实测浓度进行验证,计算值与实测值吻合很好.模型参数灵敏度分析进一步表明,生物降解速率常数、污染物在悬浮颗粒物/水间分配系数以及水体颗粒物沉降通量是影响HCHs在沉积物/水间迁移过程的主要因素.     

部分热带玉米种质穗部性状与单株产量之间的关系

试验运用灰色关联度分析方法,研究5个不同热带玉米种质穗部性状对单株产量的贡献大小。结果表明:种质T9904的百粒重与单株产量关联度大,对单株产量贡献大;种质T9907、T9925、T9945和T9963的穗行数与单株产量关联度大,对单株产量的提高起着重要的作用。种质T9904和T9945的百粒重和穗行数对单株产量的贡献作用相差较小。     

长江下游重金属在水相-悬浮物中的分布与输移

以长江下游的水体和悬浮物为研究对象,对干流和支流中重金属元素的分布与富集情况进行了研究。结果表明,重金属在水相与悬浮物中的含量表现出相反的季节性变化特征,枯水期悬浮物吸附重金属的能力较强,丰水期悬浮物解吸附重金属的能力较强;支流悬浮物中重金属的含量、变异系数和分配系数大于干流,不同江段重金属含量表现为：江苏段〉安徽段〉上海段。     

长江中下游夏季降水与土壤湿度关系的研究

利用1957年9月至2002年8月欧洲中心(ECMWF)ERA40土壤湿度再分析的月平均资料、1951—2011年中国气候中心753站逐日资料和NCEP/NCAR再分析的风场和位势高度场资料,采用EOF、相关、距平合成等方法研究分析了土壤湿度和长江中下游夏季降水的关系。结果表明,冬春季节土壤湿度对夏季降水有影响,前期华南土壤湿度增大(减小),导致夏季副高位置较平均东移减弱(西伸加强),东亚夏季风北上的阻力减小(增大),中国夏季雨带偏北(偏南),即华北华南多雨、长江中下游少雨(长江中下游多雨、华北华南少雨)。     

Atomic Chlorine and the Chlorine Monoxide Radical in the Stratosphere: Three in situ Observations

Three simultaneous observations of atomic chlorine (Cl) and the chlorine monoxide radical (ClO) are reported which encompass the altitude interval between 25 and 45 kilometers. Together, Cl and ClO form a gas-phase catalytic cycle potentially capable of depleting stratospheric ozone. Observed Cl and C1O densities, although variable, imply that chlorine compounds constitute an important part of the stratospheric ozone budget. The results are compared with recent models of stratospheric photochemistry which have been used as a basis for predicting ozone depletion resulting from fluorocarbon release.     

外来热带、亚热带玉米自交系与温带玉米自交系产量配合力分析及其遗传关系的研究

 以 4个分别代表我国北方温带玉米四大优势群的自交系 (黄早四、Mo17,B73和丹 340 )为测验种 ,采用NCⅡ设计 ,对来自 5个热带、亚热带玉米群体、地理族的 2 5个自交系进行产量配合力及杂种优势分析 ,根据配合力和杂种优势的表现 ,研究这些外来热带、亚热带玉米自交系与 4个测验种之间的遗传关系。研究结果表明 ,来自群体Suwan1、POP2 8的自交系的产量一般配合力 (GCA)效应值较高 ,5个自交系的平均产量GCA效应值分别为10 10 .6 4和 2 6 6 .5 7;来自群体POP32 (ETO)的自交系与B73及来自群体Suwan1的自交系与黄早四之间的平均产量特殊配合力 (SCA)效应值最高 ,分别为 879.2 9和 5 83.81;来自群体Suwan1的自交系与B73之间组合的杂种优势最大 ,平均产量对照优势值为 2 0 .36 % ,其次为来自群体POP32 (ETO)的自交系与B73的平均产量对照优势值(19.38% )。由此 ,Suwan1×瑞得、ETO×瑞得、POP2 8×瑞得、POP2 8×旅大红骨和Suwan1×兰卡斯特为 5大杂优模式     

Tropical forests and the global carbon cycle

New data on the three major determinants of the carbon release from tropical forest clearing are used in a computer model that simulates land use change and its effects on the carbon content of vegetation and soil in order to calculate the net flux of carbon dioxide between tropical ecosystems and the atmosphere. The model also permits testing the sensitivity of the calculated flux to uncertainties in these data. The tropics were a net source of at least 0.4 x 10(15) grams but not more than 1.6 x 10(15) grams of carbon in 1980, considerably less than previous estimates. Decreases in soil organic matter were responsible for 0.1 x 10(15) to 0.3 x 10(15) grams of the release, while the burning and decay of cleared vegetation accounted for 0.3 x 10(15) to 1.3 x 10(15) grams. These estimates are lower than many previous ones because lower biomass estimates and slightly lower land clearing rates were used and because ecosystem recovery processes were included. These new estimates of the biotic release allow for the possibility of a balanced global budget given the large remaining uncertainties in the marine, terrestrial, and fossil fuel components of the carbon cycle.     

Relation Between Endodormancy Induction and Changes in Two Main Electron Transport Pathways of Nectarine Buds

Operation regulations of two main electron transport pathways in nectarine （Prunus persica var. nectariana cv. Shuguang） buds during endodormancy induction were studied to understand possible roles which two main electron transport pathways played in the buds of deciduous fruit trees during endodormancy induction. Respiratory inhibitors （KCN and SHAM） were used to investigate total respiration rate （Vt）, the development and operation of the alternative pathway and partitioning of electrons between the cytochrome and alternative pathways in nectarine buds during endodormancy induction. Results indicated that changes of Vt in flower and leaf buds showed single and double hump-shaped curves, respectively. In endodormancy induction, the capacity （Valt,） and activity （ρValt） of the alternative pathway rapidly increased, but changes of them had different patterns during the entire measuration. At the same time, changes of engagements of the alternative （ρValt/Vt） and cytochrome pathway （ρ′Vcyt/Vt） were opposite, and ρ′Vcyt/Vt was always further higher than ρValt/Vt during the entire measuration. All these results indicated that the development and operation of the alternative pathway played important roles in endodormancy induction, but the cytochrome pathway was the main pathway for mitochondrial electron transport in buds during endodormancy induction.     

油桃芽体自然休眠诱导与两条主要电子传递途径的关系

 【目的】研究油桃芽体自然休眠诱导期两条主要电子传递途径的运行规律,以期了解主要电子传递途径在落叶果树芽体自然休眠诱导中的可能生理作用。【方法】以油桃品种‘曙光’（Prunus persica var. nectariana cv.Shuguang）为试材,采用呼吸抑制剂法测定休眠诱导期芽体总呼吸速率（Vt）、交替途径发生与实际运行、细胞色素途径与交替途径之间电子配比的动态变化。【结果】花芽和叶芽总呼吸速率变化趋势不一致,花芽呈双峰曲线,叶芽呈单峰曲线。进入休眠诱导期后,芽体交替途径容量（Valt）和交替途径实际运行活性（ρValt）快速上升,但整个测定过程中芽体Valt和ρValt的变化不同步;芽体交替途径实际运行活性对总呼吸的贡献 (ρValt/Vt) 和细胞色素途径活性对总呼吸的贡献（ρ′Vcyt/Vt）的变化趋势相反,在整个测定过程中,ρ′Vcyt/Vt始终远远高于ρValt/Vt。【结论】交替途径的发生及运行在芽体自然休眠诱导过程中起着极为重要的作用,但细胞色素途径仍是自然休眠诱导期芽体线粒体电子传递的主要途径。     

Observations of the Nighttime Abundance of OClO in the Winter Stratosphere Above Thule, Greenland

Observations at Thule, Greenland, that made use of direct light from the moon on 2,3, 4,5, and 7 February 1988 revealed nighttime chlorine dioxide (OClO) abundances that were less than those obtained in Antarctica by about a factor of 5, but that exceeded model predictions based on homogeneous (gas-phase) photochemistry by about a factor of 10. The observed time scale for the formation of OClO after sunset strongly supports the current understanding of the diurnal chemistry of OClO. These data suggest that heterogeneous (surface) reactions due to polar stratospheric clouds can occur in the Arctic, providing a mechanism for possible Arctic ozone depletion.