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291.
Authors Index
Author Index Volume 65 相似文献292.
月内冷暖起伏大强对流天气频繁——2009年3月—— 总被引:1,自引:0,他引:1
3月我国主要气候特点:气温偏高,降水略偏多.全国平均气温为4.5℃,较常年同期(3.2℃)偏高1.3℃.全国平均降水量为29.1mm,较常年同期(28.1mm)偏多1.0mm.海南3月区域平均降水量为1951年以来历史同期最大值. 相似文献
293.
294.
根据松花江流域1961-2000年观测气温、降水量资料和ECHAM5/MPI-OM模式对该流域21世纪前50 a气候变化的预估结果,分析了松花江流域1961-2000年年平均气温和年降水量变化,并对21世纪前50 a气温和降水量变化趋势进行了预估。结果表明,在全球变暖的背景下,作为中国气候变暖区域响应的先锋,松花江流域年平均气温自1980年代初持续升高,升温幅度比较显著;年降水量在1961-2000年无明显增加或减少趋势,年代际差异也不大。相对于1961-1990年的气候场,21世纪前半叶,年平均气温仍将呈明显增加趋势,到2040年代升温幅度达1℃以上,年降水量变化趋势不显著,可能微弱增加,但冬季平均气温和冬季降水量都呈增加趋势,春季降水量也为增加趋势。 相似文献
295.
蚕豆生长发育的温度指标分析 总被引:1,自引:0,他引:1
利用1971-2006年蚕豆单产统计资料,采用滑动平均的方法,计算每年蚕豆气象产量,并以此划分丰、平、歉气候年景.以2001-2006年田间观测数据和生产实际为基础,确定蚕豆平均生长发育期,分析蚕豆生长与日平均温度、日最高温度、日最低温度之间的关系.通过研究得出蚕豆从播种到成熟的最适温度上限、最适温度下限、最适温度上限极值、最适温度下限极值、受害温度、死亡温度,并以此为基础结合蚕豆生长期的其它气象因子,制定蚕豆生长季气象服务决策表,为规范化、数字化的气象服务业务流程奠定基础. 相似文献
296.
Here we present a multi-proxy paleolimnological record from a closed-basin lake (Ebinur Lake) in northwestern China to investigate
climate change in this arid region during the last 1,500 years. The 120-cm long sediment core was dated by AMS radiocarbon
and 210Pb methods. The fine-grained clay sediments contain 3–17% organic matter (OM) and 9–31% carbonate, and are interrupted by
multiple sand and silt layers. These sand/silt layers, having consistently low OM, were found at 700–800, 1000–1100, 1300–1400,
and 1700–1750 a.d., with a time spacing of 300–400 years. We interpret that the low OM sand/silt layers were deposited during higher lake levels
caused by increased river inflow from the surrounding mountains during wet climate intervals. This interpretation is supported
by concurrent decreases in δ
18O and δ
13C of bulk carbonate and in carbonate content. Wet climate intervals at 700–800 a.d. and at 1700–1750 a.d. also correlate with elevated snow accumulation and low δ
18O from Guliya ice core on the NW Tibetan Plateau, both regions strongly influenced by the westerlies. This approximate 400-year
periodicity of wet–dry climate oscillations appear to correlate with solar activity as shown by atmosphere 14C concentration and with paleo-moisture records in interior North America. Our results suggest that solar activities might
have played a significant role in driving wet–dry climate oscillations at centennial scales in the interior of Eurasian continent. 相似文献
297.
从规划类清洁发展机制(P-CDM)项目提出的背景出发,介绍了P-CDM项目开发的基本框架,对现阶段开发此类项目在指定国家主管机构审批、开发过程中的技术问题,指定的经营实体审定和减排量销售等方面所面临的困境进行了详细分析。针对上述问题,从政策选择角度,建议进一步完善国家主管机构的管理办法,发挥行业组织和科研机构的优势,解决P-CDM项目开发中存在的技术问题,通过规模效应促进P-CDM项目的市场建设,进一步简化相关的国际规则,以真正降低P-CDM项目开发的交易成本。 相似文献
298.
299.
Metamorphic garnet pyroxenite from the 540-600 m main borehole of the Chinese Continental Scientific Drilling (CCSD) project 总被引:1,自引:0,他引:1
Compared to other mafic and ultramafic rocks from the CCSD main borehole as well as from the outcrops, rocks from the 540-600 m section is extraordinary in terms of its geophysical as well as geochemical properties. It consists of > 70% hematite-ilmenite garnet pyroxenite (HI-GPX) and < 30% intercalated rutile garnet pyroxenite (R-GPX). Whole-rock geochemical data show that HI-GPXs have: (1) relatively high V with an average of 606 ppm, but lower Nb and Ta; (2) highest TFeO, Fe2O3/FeO ratio, and highly variable but strong positive Eu anomalies with Eu/Eu? up to 2.9; (3) anomalously high V/Sc ratios ranging from 8.39 to 43.23, average 15.03; and (4) high amounts of hematite-ilmenite solid solutions with a very fine intergrowth structure down to nanometer scale. V/Sc ratios in the CCSD garnet pyroxenites are correlated negatively with MgO, but positively with Fe2O3/FeO ratios. Both suites of pyroxenites have similar rare earth elements and high field strength elements geochemistry. These features demonstrate that these pyroxenites were formed from metamorphism of high-Fe and/or -Ti gabbroic cumulates. This can account not only for low high field strength elements (HFSE) and rare earth elements (REE) but also low Nb/Ta and Zr/Hf ratios in these rocks. Seemingly negative correlation between Nb/Ta and Zr/Hf in the CCSD metabasites, not significantly affected by UHP metamorphism, is also consistent with the silicate differentiation trend in a basaltic magma chamber. 相似文献
300.
Ping Zeng Huiquan Chen Baichuan Ao Ping Ji Xiaojian Wang Zhiliang Ou 《Coastal Engineering》2002,44(4)
A numerical and experimental modeling is presented for studying the transport of waste heat from a nuclear power plant into coastal water by using a full-field physical model with scale distortion, a local physical model with normal scale and a depth-averaged k− turbulence model with a modified second-order upwind scheme. Field investigations are also used to provide the calibration and validation of the modeling. A case study simulating the turbulent tidal flow and waste heat transport in the coastal water near Daya Bay Nuclear Power Plant in Southern China was conducted. The experimental result of the case study shows that the water temperature in coastal water was a little oversimulated near the surface and was a little undersimulated near the bottom of heated-water layer by the full-field physical model. The numerical study shows that the depth-averaged k− turbulence model presented a satisfied prediction of turbulent tidal flow and far-field temperature distribution in coastal water, although the near-field stratification due to the heated water effluent was not accounted for. The result of the effect of scale distortion on physical model shows that a full-field physical model with a scale distortion of 10 produced a satisfied result of temperature distribution in the present case study. 相似文献