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111.
112.
Weiping Lou Ke Sun Shanlei Sun Fenghua Ma Dongfang Wang 《Theoretical and Applied Climatology》2013,114(1-2):115-123
We analyze the pick beginning date and frost damage risk trends of Jiukeng, Longjing-43, and Wuniuzao tea trees with time, using meteorological data from 12 station pairs over the period 1971–2010 in the Longjing tea-producing area. The pick beginning date of Jiukeng, Longjing-43, and Wuniuzao varieties had no statistically significant trends before 1990. The pick beginning date of Jiukeng variety had statistically significant decreasing trends after 1990, and there were no statistically significant trends in the start date after 1990 for Longjing-43 and Wuniuzao varieties. The average pick beginning dates of Longjing-43 and Wuniuzao varieties before 1990 are later than those after 1990 by 3.8–4.8 and 2.0–3.1 days, respectively. We used the trend of difference between beginning date of tea plucking (BDTP) and 0 °C terminal date to analyze frost damage risk trends. Eleven counties had no statistically significant frost damage risk trends for Jiukeng, Longjing-43, and Wuniuzao varieties, leaving only one county with statistically significant trends. 相似文献
113.
114.
Kapil Bisht Yogesh Joshi Shashi Upadhyay Poonam Metha 《Journal of the Geological Society of India》2018,92(2):173-176
Glaciers being very sensitive to climate change have been identified as one of the best indicators of climate change and evidences have proved that most of the Himalayan glaciers have receded with an increased rate during the recent past under the influence of global warming. Lichenometric study was carried out on the moraines of Milam glacier (located in Pithoragarh district of Uttarakhand) with the help of lichen species Dimelaena oreina having an average annual growth rate of 1.31 mm. The study revealed that Milam glacier has receded 1450 m in last 69.37 years with an average recession rate of 20.90 m/year. Since lichenometric studies are cost effective and ecofriendly in comparison to carbon dating, satellite and remote sensing based studies and also reliable, hence, it should be promoted in Himalaya which is an abode of glaciers. 相似文献
115.
宁夏南部山区天然草场不同植被覆盖度的小气候特征比较 总被引:2,自引:0,他引:2
利用不同季节小气候加密观测和小气候常规观测资料,通过分析西吉月亮山禁牧草场和鸦儿湾荒地近地层气温、地温、风速、相对湿度等要素的差异和日变化特征,探讨了不同下垫面下小气候变化的趋势。结果表明:封山禁牧后,下垫面随之变化,会产生所谓的“绿岛效应”,尤其在植被生长旺盛的夏季,气温明显下降,空气湿度增大。说明封山禁牧这一措施对脆弱生态的恢复改造有明显的效果。 相似文献
116.
经济发展与能源消耗有着密切的关系,文章通过选取1994年至2009年欧盟27国的人口、经济和能源数据,利用碳排放动力学模型对欧盟关于2050年前削减温室气体排放80-95%的承诺进行预测,并对欧盟目标下的减排情景进行了分析。结果表明:(1)以当前的技术进步速率下,沿最优平稳经济增长路线,到2050年欧盟的碳排放量将为775.608MtC,达不到预定的减排要求;(2)在最优经济增长速度得出总能源消费量的基础上,采用调整能源结构与碳捕捉技术,预期可以达到设定减排80%的任务。其每一期的煤炭占比、石油占比、天然气占比应分别有4%、2.26%、1.23%转移至非碳能源占比,非碳能源的上升速率应达到2.21%/年;(3)若以历史的能源结构转移趋势预测未来的能源结构占比,即使考虑能源利用效率和碳捕捉技术的预期目标,欧盟仍然达不到在2050年的减排目标;(4)考虑欧盟提出的四种减排路径上下限组合,可预计出到2050年欧盟的减排范围在80.51%-87.16%;(5)若欧盟重振工业(特别是制造业),即使考虑欧盟制定的减排路径,仍存在着达不到减排预期的可能。 相似文献
117.
Y. M. Wang 《Journal of Geodesy》1990,64(3):231-246
The method of analytical downward continuation has been used for solving Molodensky’s problem. This method can also be used
to reduce the surface free air anomaly to the ellipsoid for the determination of the coefficients of the spherical harmonic
expansion of the geopotential. In the reduction of airborne or satellite gradiometry data, if the sea level is chosen as reference
surface, we will encounter the problem of the analytical downward continuation of the disturbing potential into the earth,
too. The goal of this paper is to find out the topographic effect of solving Stoke’sboundary value problem (determination
of the geoid) by using the method of analytical downward continuation.
It is shown that the disturbing potential obtained by using the analytical downward continuation is different from the true
disturbing potential on the sea level mostly by a −2πGρh 2/p. This correction is important and it is very easy to compute
and add to the final results. A terrain effect (effect of the topography from the Bouguer plate) is found to be much smaller
than the correction of the Bouguer plate and can be neglected in most cases.
It is also shown that the geoid determined by using the Helmert’s second condensation (including the indirect effect) and
using the analytical downward continuation procedure (including the topographic effect) are identical. They are different
procedures and may be used in different environments, e.g., the analytical downward continuation procedure is also more convenient
for processing the aerial gravity gradient data.
A numerical test was completed in a rough mountain area, 35°<ϕ<38°, 240°<λ<243°. A digital height model in 30″×30″ point value
was used. The test indicated that the terrain effect in the test area has theRMS value ±0.2−0.3 cm for geoid. The topographic effect on the deflections of the vertical is around1 arc second. 相似文献
118.
Tang Rongqing Wang Daoyan Zhang Xixian Egnineer Shanghai Jiao Tong University Shanghai Associate Professor Shanghai Jiao University Shanghai 《中国海洋工程》1993,(3)
- The authors have used a low-cost ROV of observation type for underice surveying of the Nen-Jiang Cross-river oil pipe line in the Da Qing oil field. The operation method, process and the safety measures for severe cold areas are presented. The fruitful tries and experience may be useful to ROV operators in severe cold areas. 相似文献
119.
Acta Geotechnica - This paper investigates the effect of a nodular segment, commonly found in nodular piles, on the dynamic response of a vertical vibrating tubular pile. A developed model of a... 相似文献
120.