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991.
There has been increasing concern about the lack of involvement by social scientists and humanists in a global change program,
although many social scientists are already directly involved in various aspects of research on environmental change, and
their research interests are clearly central to a global change research agenda. Based on a historical review, the role of
social science disciplines as well as social science institutes in an emerging multidecadal global change program is discussed.
Both “plan of action” and “plan of inaction” are suggested to avoid potential pitfalls due to the rush development of a social
science program into the existing global climate change problem. 相似文献
992.
At present, researches on climate change of the Heihe River basin mainly focus on the relationship between basin climate change
and regional water resources, regional desertification and dynamic climatic seasons of sandstorm, but less on climate change
of oasis region, where there are more intense and frequent human activities. Based on data of precipitation, temperature,
strong wind and dust events frequencies obtained from the six meteorological stations of Zhangye region in Heihe River basin,
the features of climate change during 1968–2005 were carefully studied. Results show that the regional temperature rise rate
exceeded the average level of China. The annual precipitation changed a little, but the precipitation had a slowly increasing
trend in spring and winter. Frequencies of strong wind and sandstorm days show obviously descending trends, which had a close
correlation with the regional temperature rise and the precipitation increase in spring and winter. Meanwhile, further human
economic activities and exploitations to the oasis in the inland valley of arid regions also affected the climate change of
this region, which has a sensitive and fragile eco-environment.
__________
Translated from Journal of Desert Research, 2007, 27(6): 1048–1054 [译自: 中国沙漠] 相似文献
993.
Based on the determination of composition of volcanic volatiles and petrologic estimation of the total mass of volatiles erupted,
we showed important advances in the study of the impact of Mesozoic and Cenozoic volcanic activities on paleo-environmental
changes in China. The volcanic activities include western Liaoning and Zhangjiakou Mesozoic intermediate-acidic explosive
eruptions, southern Tibet and Shanwang Cenozoic volcanism, and Mt. Changbai volcanic eruption around one thousand years ago.
The paper predominantly discusses the earth’s surface temperature changes, ozone depletion, acidic rain formation and mass
mortalities of vertebrate induced by the Mesozoic and Cenozoic volcanism in China.
__________
Translated from Bulletin of Mineralogy, Petrology and Geochemistry, 2007, 26(4): 319–322 [译自: 矿物岩石地球化学通报] 相似文献
994.
Hualing Wei Nianqiao Fang Xuan Ding Lanshi Nie Xiuming Liu 《Frontiers of Earth Science》2008,2(2):162-169
This paper presents pelagic records of planktic foraminifera, as well as data of stable isotope stratigraphy and carbonate
stratigraphy since 3.5 Ma B.P. from site ODP758 in the Ninetyeast Ridge of the Indian Ocean. Based on these data, manifestations
and related mechanisms of major tectonic and environmental events such as the rapid uplift of the Himalaya Mountains, “middle
Pleistocene climatic transition” and “mid-Brunhes dissolution event” in the region are discussed. According to the analysis
and comparison of various indices and changes in terms of foraminifera assemblage, paleotemperature, paleosalinity and themocline
from site ODP758, the authors deduce that the paleoclimatic changes might correlate with the mid-Pleistocene transition at
1.4–1.7 Ma B.P. The changes of CaCO3, mass accumulation rates (MAR) of CaCO3 and non- CaCO3 MAR indicate that the loaded terrigenous sediments increased at 1.7 Ma, which is in agreement with the uplift history of
the Qinghai-Tibet plateau as shown by the available data. The last two changes coincide with the uplift of the Qinghai-Tibet
plateau, hence they are called “Qinghai-Tibet movement” (1.7 Ma), and the “Kunlun-Yellow River movement” (1.2–0.6 Ma). The
changes of the CaCO3 content, coarse fraction (> 150 μm) content and planktonic foraminifera biostratigraphy show that strong dissolution of abyssal
CaCO3 occurred in the study region during 0.5–0.4 Ma. The event was consistent with the “mid-Brunhes dissolution event” in the
sedimentary records of the Atlantic Ocean, Pacific Ocean, Indian Ocean and Nansha sea area of the South China Sea.
__________
Translated from Geological Bulletin of China, 2007, 26(12): 1627–1632 [译自: 地质通报] 相似文献
995.
In this paper, the data on the paleoclimatic and paleoenvironmental changes during the Holocene are presented and a discussion
is made on a 225-cm-long sediment core from Ulungur Lake, located in Northwest China. The chronology is constructed from six
AMS radiocarbon dates on the bulk organic matter. On the basis of the analysis of ostracod assemblages and the shell stable
isotopes, the core is divided into three paleoclimatic and paleoenvironmental evolution stages: 9 985–5 250 cal.aB.P. stage
is the wettest phase of the core section. The climate changed from moderate-dry to cool-wet, and then to warm-wet in turn,
and the lake level rose accordingly, showing the characteristic of a high lake level. 5 250–1 255 cal.aB.P. stage was the
driest phase of the core sediment. The climate turned from the early warm-dry to the late warm-wet and the lake level fell
and rose again. Finally, the 1 255 cal.aB.P. stage was the medium stage of the section. The temperature was low and then increased
after the 1920s and the climate was dry. The whole climatic and environmental evolution records of Lake Ulungur were not only
in agreement with the sporopollen record of the same core but also in agreement with the record of environmental changes of
adjacent areas. It responded to regional environmental changes and global abrupt climate events, following the westerly climate
change mode on 100-year-scale, primarily with cold-wet and warmdry characteristics.
__________
Translated from Quaternary Sciences, 2007, 27(3):382–391 [译自:第四纪研究] 相似文献
996.
通过对井田内泉和暗河流量的调查研究,认为永宁镇组一、三段碳酸盐岩裂隙溶洞水为井田的主要含水层,含水层主要接受大气降水及河流的渗透补给;煤层上覆地层飞仙关组为相对隔水层,厚度大于500m,下覆无强含水层,其地下水对煤层的开采影响不大,井田水文地质条件较简单。采用比拟法对井田的涌水量进行了预算,推算该矿井开采设计涌水量为13 238m^3/d。 相似文献
997.
998.
湘西北渔塘地区寒武系清虚洞组风暴岩及其地质意义 总被引:3,自引:0,他引:3
在湘西北渔塘地区,下寒武统的清虚洞组下部发育一套地质特征典型、沉积序列特殊的风暴岩。其底面侵蚀构造清楚,覆盖于底面上的各层段厚度变化较大,在各层段内由下向上碎屑粒度依次变细,并相继出现叠加式丘状交错层理、平行层理和浪成沙纹层理等沉积构造,是典型的浅海风暴岩。该风暴沉积的发现,对建立湘西北地层的沉积学剖面、探讨该区风暴沉积模式的空间变化、明确成矿环境和成矿地质特征等具有重要意义。 相似文献
999.
山东玲珑金矿床成矿流体地球化学特征 总被引:3,自引:0,他引:3
玲珑金矿床第一成矿阶段与含金黄铁矿共生的石英中主要发育4种类型的原生流体包裹体:Ⅰ气液两相,Ⅱ含CO2三相,ⅢCO2,Ⅳ单液相包裹体。流体包裹体成分激光拉曼光谱分析及测温结果显示:①Ⅰa型包体,气液比10%~15%,均一温度为162.7~235.6℃,w(NaCl)(盐度)为4.65%~7.59%,气相平均摩尔分数为:H2O 96.48%,CO22.4%;②Ⅰb型包体,气液比30%~45%,均一温度266.9~349.2℃,w(NaCl)为10.8%~13.4%,气相平均摩尔分数为H2O 69.75%,CO224.74%;③Ⅱ型含CO2包体,CO2相所占比例为20%~90%,其均一温度为193.5~321.6℃,w(NaCl)2.9%~5.3%,CO2相中,H2O的摩尔分数为27.72%,CO2为70.6%。包裹体成分分析及测温结果综合研究认为,玲珑金矿成矿过程中存在大气降水热液与地幔来源流体的混合作用,前者与从流体中分离出的富CO2流体混合,以不同比例被捕获形成Ⅱ型包体;而与分异出CO2后的CO2不饱和地幔流体混合,被捕获形成Ⅰb型包体。两种流体混合导致的含矿热液物化条件变化对金的沉淀成矿具有重要意义。 相似文献
1000.
封闭体系有机质与有机碳氢氮恢复动力学研究 总被引:3,自引:0,他引:3
在封闭体系的条件下,对典型的Ⅰ、Ⅱ、Ⅲ型干酪根在热演化过程中的损失进行生烃动力学研究,获得了Ⅰ、Ⅱ、Ⅲ型干酪根的总量、有机碳、氢以及氮质量损失动力学参数。用Kinetics软件计算了封闭体系干酪根有机碳丰度、氢碳原子比和氮碳原子比的恢复系数。认为在对高成熟—过成熟干酪根进行生烃评价时,Ⅰ、Ⅲ型干酪根残余有机碳丰度需要进行恢复,而Ⅱ型干酪根残余有机碳丰度不需要恢复。三种类型干酪根的氢碳原子比均需要进行恢复。 相似文献