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971.
972.
973.
Bo Li Bei-bei Kou Bin Li Jing Li Jing Zeng Qing-lei Niu Yu-tao Shao Ke-wei Zhang Hao-yu Yu Ying-sheng Wang 《China Geology》2022,5(2):293-299
Traditional suction anchor technology is mainly used in the fields of subsea structure bearing foundations,single-point mooring systems and offshore wind power. It is characterized by providing sufficient lateral and vertical bearing capacities and lateral bending moment. The anchor structure of a traditional suction anchor structure is improved with wellhead suction anchor technology, where a central pipe is added as a channel for drilling and completion operations. To solve the technical probl... 相似文献
974.
西部山区总辐射气候学计算及分布 总被引:11,自引:1,他引:11
根据西部山区太阳总辐射的实测资料分析,指出,西部山区总辐射的气候学计算必须考虑日照,水汽分布及海拔高度的影响。为此研制了适宜于西部山区的总辐射气候学计算公式Q=Q0(a+bs1+cs1^2),进而讨论了西部山区总辐射的时,空分布。 相似文献
975.
积云模式在人工增雨中的应用研究 总被引:5,自引:4,他引:5
采用胡志晋的一维时变双参数积云模式,利用福建省1985~1994年间的夏秋旱期可能出现的12种天气类型(台风除外)对测站(福州)为主的十年旱期出现的积云降水日(R≥0.1mm)进行分类,并按12种天气类型分别调试的结果(降水预报率达75%以上),经催化试验,确定福建省旱期积云降水的物理特征,人工增雨催化的方法、催化剂量和催化窗口,得到了一些有意义的结果,并根据催化试验的结果采用NDP-FORTRAN和BORLANDC++交互使用的方法,将云模式业务化成人工增雨指挥系统中的积云模式分系统,该系统可以进行旱期积云降水预报,人工增雨效果检验和作业方法的选择。 相似文献
976.
Zhou Xiaocheng Shi Hongyu Chen Chao Zeng Linghua Sun Fengxia Li Jing Chen Zhi Lü Chaojia Huang Dan Du Jianguo 《地球科学进展》2017,32(8):818-827
Degassing of Hydrogen (H2) from fault may be a good indicator of fault activity. The concentration of H2 in soil gas in the seismic surface rupture zone produced by the Wenchuan MS 8.0 earthquake was investigated in twenty three measuring regions in order to explore the relationship between the spatio-temporal variations of H2 concentration in soil gas along the seismic rupture zone and the vertical displacements and aftershocks activities. The results indicated: ① the sources of H2 were directly related to from the release of natural gas reservoirs; ②the average concentration of H2 in soil gas spatially decreased from Yingxiu to Nanba; ③the magnitudes of the H2 concentration anomalies declined significantly with time. It is very significant to study the variation tendency of atmospheric environment with further research of degassing of H2 from faults. 相似文献
977.
Iron is the fourth most abundant element in the earth's crust, and it often appears as a trace element in the ocean. Iron has a variable valence and diverse functions, and is an important force to regulate marine primary productivity and drive the geochemical cycle in the ocean. Previous studies have shown that iron plays an important role in maintaining primary productivity, coupling matter cycles, and regulating the transformation of biogenic factors. In recent years, with the development of microbial ecology, iron research has enter more in-depth levels, including microbial-driven iron oxidation-reduction behavior, metabolic processes, and interactions with other major elements(C/N/P). This paper attempts to review the latest progress of iron, focusing on the published literatures of the past fifteen years. Firstly, we explained the sources and occurrence states of iron in the ocean (such as dissolved, colloidal, granular and organic state); Secondly, we reviewed the types and process mechanisms of microbial-mediated iron redoxbehavior (for example nitrate oxidation, and biological reduction, etc.); Finally, we summarized the coupling relationship between iron and C/N/P cycle. Additionally, the ecological roles of iron in specific ecological event (for instance algal bloom) has also been described. Furthermore, the "chemical-biological-physical" theoretical framework for marine iron research is also discussed. The purpose of this paper is to provide more information for marine microecological research and their effects on iron cycle under changing environment, such as global change. 相似文献
978.
GIS支持下不同生态背景的土地利用空间特征分析 总被引:5,自引:3,他引:5
在遥感与地理信息系统技术支持下 ,分析了不同生态背景下的我国土地利用、土地覆盖特征的空间分布。具体表现为对不同温度带、不同降雨带、不同高程带上的土地利用的时空特征进行了研究分析 ,结果表明 :总体上我国的土地主要分布在寒温带以下、降雨<2 5 0 mm的干旱带、高程在 1 0 0 0~ 3 5 0 0 m的地区。其中耕地主要分布在中温带、降雨在 40 0~ 80 0 mm的半湿润带、高程在 1 0 0 m以下的低平原区 ;林地分布在中温带、降雨为 40 0~ 80 0 mm的半湿润带、高程在 1 0 0 0~ 3 5 0 0 m的中山区为最多 ;草地主要分布在寒温带以下、降雨 <2 5 0 mm的干旱区、高程 1 0 0 0~ 3 5 0 0 m的中山区 ;建设用地则主要分布在暖温带、降雨 40 0~ 80 0 mm的半湿润带、低平原区 ;未利用地主要分布在寒温带以下、降雨 <2 5 0 mm的干旱区、高程在 1 0 0 0~ 3 5 0 0 m的中山区。 相似文献
979.
Shuangwen Yi Jan‐Pieter Buylaert Andrew S. Murray Huayu Lu Christine Thiel Lin Zeng 《Boreas: An International Journal of Quaternary Research》2016,45(4):644-657
In this study, we report standard quartz SAR OSL and post‐IR infrared (IR) stimulated luminescence (post‐IR IRSL; pIRIR290) measurements made on sand‐sized quartz and K‐feldspar extracts from the loess‐palaeosol sequence at Niuyangzigou in northeastern China. The quartz OSL characteristics are satisfactory. Extensive pIRIR50,290 dose recovery tests were performed by adding doses on top of the natural dose. We found that dose recovery ratios improve significantly when the test dose ranges between ~15 and ~80% of the total dose, and good dose recovery (within ±5% of unity) can be obtained up to ~800 Gy. Otherwise, the dose recovery ratio deviates from unity. The De values also depend on the test dose size and so we conclude that the effect of test dose size should be routinely considered in pIRIR dating. First IR stimulation plateau pIRIR290 results are compared with multiple elevated temperature ‐pIRIR (MET‐pIRIR) data. It appears that the low temperature MET‐pIRIR data are strongly affected by poor dose recovery, but this is not the case for the pIRIR290 results. Natural signal measurements at the highest (first IR) stimulation temperature on a sample expected to be in field saturation suggest that ~10% signal loss occurs in pIRIR signals. Long‐term laboratory bleaching experiments (>80 days) show that a constant (or very difficult to bleach) residual pIRIR290 signal is reached after ~300 h, corresponding to a dose of 6.2±0.7 Gy. Quartz OSL and feldspar pIRIR50,290 ages are in good agreement at least back to c. 70 ka. Beyond this the quartz ages begin to underestimate but the feldspar ages are in agreement with the expected Last Interglacial age palaeosol. 相似文献
980.
通过对区内太古宙变质岩的岩石类型、产状特征、原岩类型讨论认为,喀喇沁-北票地区的太古宙变质岩石属于火山-沉积岩和花岗侵入岩变质建造。可以划分为两种不同系列的组成:(1)斜长角闪岩+磁铁石英岩+角闪石岩、辉石岩,代表了本区的“绿岩”组分;(2)斜长片麻岩,代表了太古宙中酸性侵入体(TTG岩套)。本区的太古宙花岗岩-绿岩地体经受了早期塑性变形和后期脆性变形、中生代的强烈花岗质岩浆侵入作用,金矿床受“绿 相似文献