检索结果-南通市图书馆

Long-term trend and abrupt events of the Holocene Asian monsoon inferred from a stalagmiteδ^(18)O record from Shennongjia in Central China

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2006年第2期51卷 221-228页

作者： SHAO Xiaohua WANG Yongjin CHENG Hai kONG Xinggong WU Jiangying edwards r. Lawrence College of Geography Science Nanjing Normal University Nanjing 210097 China Department of Geology and Geophysics Minnesota University MN 55455 USA

A high-resolution oxygen-isotope record from a thorium-uranium-dated stalagmite from Shanbao Cave at Shennongjia reflects variations in the amount of monsoon precipitation for the period from 11.5 to 2.1 ka (1 ka = 1000 cal aBP). Between 11.5 and 9.3 ka, a sharp decrease in δ18O indicates a rapid increase in monsoon precipitation. An interval of generally high monsoon precipitation is observed between 9.3 and 4.4 ka. An arid period has prevailed between 4.4 and 2.1 ka. The long-term trend of Shanbao record appears to follow summer insolation at 33°N latitude. An abrupt decrease in monsoon precipitation around 4.3 ka is synchronous with the collapse of Neolithic culture in central China. This abrupt change could have resulted from the amplifi- cation of the gradually decreased summer insolation by the positive vegetation-atmosphere-aerosol feed- back. The weakened Asian monsoon events were in concert with decreased Greenland temperature dur- ing the early Holocene, centered at 8.2, 8.6, 9.3, 10.2 and 11.0 ka. This correlation suggests that changes in low-latitude monsoon are connected with climate change in high-latitude polar region.

关键词：全新世亚洲季风长期趋势突发事件古气候氧同位素中国神龙架石笋

Great flood in the middle-lower Yellow river reaches at 4000 a BP inferred from accurately-dated stalagmite records

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2018年第4期63卷 206-208页

作者： Liangcheng Tan Chuan-Chou Shen Yanjun Cai Hai Cheng r.Lawrence edwards State key Laboratory of Loess and Quaternary Geology Institute of Earth Environment Chinese Academy of Sciences Open Studio for Oceanic-Continental Climate and Environment Changes Qingdao National Laboratory for Marine Science and Technology Institute of Global Environmental Change Xi’an Jiaotong University High-Precision Mass Spectrometry and Environment Change Laboratory (HISPEC) Department of Geosciences Taiwan University Department of Earth Sciences University of Minnesota

recently,Wu et al.[1]suggested an earthquake-induced landslide dam outburst flood on the eastern Tibetan Plateau at 1920BCE(3870 a BP,BP denotes year before 1950 CE)caused the Great Flood in the middle-lower Yellow river reaches,and resulted in the founding of Xia Dynasty at 3850 a *** age is$150–300younger than the previously estimated age of the Xia Dynasty[2].While the geological evidence of the outburst flood。

关键词：石笋记录活动范围大洪水 BP 黄河黄土高原 BCE 幻灯片

Joint Contact Forces with Changes in running Stride Length and Midsole Stiffness

在线全文

学校读者我要写书评

暂无评论

Journal of Science in Sport and Exercise 2020年第1期2卷 69-76页

作者： Joshua M.Thomas WBrent edwards Timothy r.Derrick Department of Health Wellnessand SportUniversity of DubuqueDubuqueIA 52001USA Human Performance Laboratory Faculty of KinesiologyUniversity of CalgaryCalgaryAB T2N 1N4Canada Department of kinesiology Iowa State University111L Forker BuildingAmesIA 50011USA

The purpose of this study was to determine if lower extremity joint loading was influenced by stride length or shoe midsole *** subjects completed 10 trials of overground running at an average speed of 4.43 m/s in each of three condi-tions:normal running,running with a stride length(SL)reduced by 10%of normal,and running with a cushioned midsole stiffness(i.e.,mechanical impact reduction of 13.7-10.9 g).reaction forces calculated from inverse dynamics were summed with muscle forces estimated from a musculoskeletal model using static optimization to obtain joint contact forces at the hip,knee and ankle *** components of the contact forces[axial,anterior-posterior,and medial-lateral(ML)]were examined using parametric statistics(α=0.05).reducing stride length resulted in significant decreases in absolute peak ankle contact forces in the axial direction(normal:-14.5±1.5 BW;reduced SL:-14.0±1.6 BW)and the ML direction(normal:0.67±0.23 BW;reduced SL:0.61±0.21 BW).reducing stride length also reduced the peak absolute axial forces at the knee(normal:-10.6±1.3 BW;reduced SL:-9.8±1.2 BW)and the hip(normal:-7.26±2.24 BW;reduced SL:-6.75±2.10 BW).The cushioned shoe did not statistically reduce the peak absolute contact forces from the normal stride condition at any of the *** hoc stress analysis suggested that the observed changes in anterior hip force would increase stress more than any of the other statistically significant *** in stride length appear to decrease some joint contact variables but cushioning in the heel region of the shoe does not.

关键词： Gait Injury Compressive force Shear force Cushioning Strain

Measuring Natural Hazard-related Disasters through Self-reports

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Disaster risk Science 2021年第4期12卷 540-552页

作者： Ben edwards Matthew Gray Judith B.Borja Centre for Social research and Methods Australian National UniversityCanberra2601Australia University of San Carlos–Office of Population Studies Foundation Inc.(USC-OPS)6000Cebu CityPhilippines

Exposure to multiple natural hazard-related disasters will become more common due to climate *** article reports on the development and validation of a cumulative measure of exposure to natural hazard-related disasters(2013–2017)at the area level,and an individual-level measure of disaster impact using data from the Longitudinal Cohort Study on the Filipino Child and linked data from the International Disaster Database(EM-DAT).Caregiver reports of cumulative exposure to disasters had statistically significant associations with disasters reported by neighborhood officials and with disasters in *** ecometric techniques we generated a reliable community average measure of exposure to natural hazard-related *** on neighbor but not individual self-reports this exogenous measure of disaster exposure in the local area was more strongly related to EM-DAT and official neighborhood reports than individual *** capture household variation we developed an individual-level measure of disaster *** impact was associated with measures of exposure(individual and community average),community ratings by officials,and EM-DAT but only moderately associated with the community average *** the community average and disaster impacts measures were associated with household income and the adequacy of income in households.

关键词： Disaster exposure Measuring disasters Philippines Socioeconomic impacts Social surveys Subjective indicators

An annually laminated stalagmite from the eastern Qinghai-Tibetan Plateau provides evidence of climate instability during the early MIS5e in the Asian summer monsoon

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2023年第5期66卷 1147-1164页

作者： Tao GAO Pingzhong ZHANG Hai CHENG Leilei ZHANG Xinhu LI Hongyu SHI Wei JIA Youfeng NING Hanying LI r.Lawrence edwards key Laboratory of Mineral resources in Western China(Gansu Province)and School of Earth Sciences Lanzhou UniversityLanzhou730000China Institute of Global Environmental Change Xi’an Jiaotong UniversityXi’an710054China Department of Earth Sciences University of MinnesotaMinneapolis55455USA

The Marine Isotope Stage(MIS5e)is characterized by a warmer climate than that of the pre-industrial period,and serves as an analog for the Current Warm Period(CWP).However,uncertainties persist regarding its climatic ***,we retrieved a stalagmite(WXB075)from Wanxiang Cave in the eastern Qinghai-Tibetan Plateau,and employed abs-olute^(230)Th dating and relative annual layer data to establish a high-precision chronological framework for reconstructing the history of the Asian summer monsoon(ASM)and environmental evolution during early MIS5e with multiple *** findings indicate that the annually laminated stalagmite was formed during Cooling Event 27(C27).The deposition of WXB075 experienced a hiatus(~125.58 ka BP)due to a significant cooling event in the North Atlantic,which may be linked to the unstable climate in the Northern ***,the impact of meltwater discharge in high northern latitudes results in a two-phase evolution of the ASM,i.e.,an initial weaker stage followed by a gradual increase(with exception of deposition hiatus).The climatic instability of ASM is generally characterized by a quasi-60 year cycle that affects vegetation conditions,biological productivity,and karst hydroclimate ***,the increase in meltwater and decrease in temperature in the Northern Hemisphere have led to a weakened ASM and subsequent reduction in ***,vegetation degradation above the cave has occurred along with a slowdown of karst *** vegetation conditions,organic matter content,and wet/drought of the karst hydroclimate were affected by both the large-scale monsoon circulation and local environment during extreme weakening(strengthening)of the monsoon when high-frequency climatic events of ASM occurred.A comparison ofδ^(18)O records between early MIS5e and the past 2000 years reveals that the climate during early MIS5e differed significantly from that of CWP,Medieval Warm Period(MWP),and Dark Age Co

关键词： Eastern Qinghai-Tibetan Plateau Climate instability Wanxiang Cave stalagmite Asian summer monsoon Environmental response Deposition hiatus

research on encoding and decoding of non-binary polar codes over GF(2m)

在线全文

学校读者我要写书评

暂无评论

Digital Communications and Networks 2022年第3期8卷 359-372页

作者： Shufeng Li Mingyu Cai robert edwards Yao Sun Libiao Jin The State key Laboratory of Media Convergence and Communication School of Information and EngineeringCommunication University of ChinaBeijing100024China The Wolfson School of Mechanical Electrical and Manufacturing Engineering Loughborough UniversityLeicestershireLE113TEUK James Watt School of Engineering University of GlasgowG128QQScotlandUK

Binary Polar Codes (BPCs) have advantages of high-efficiency and capacity-achieving but suffer from large latency due to the Successive-Cancellation List (SCL) decoding. Non-Binary Polar Codes (NBPCs) have been investigated to obtain the performance gains and reduce latency under the implementation of parallel architectures for multi-bit decoding. However, most of the existing works only focus on the reed-Solomon matrix-based NBPCs and the probability domain-based non-binary polar decoding, which lack flexible structure and have a large computation amount in the decoding process, while little attention has been paid to general non-binary kernel-based NBPCs and Log-Likelihood ratio (LLr) based decoding methods. In this paper, we consider a scheme of NBPCs with a general structure over GF(2m). Specifically, we pursue a detailed Monte-Carlo simulation implementation to determine the construction for proposed NBPCs. For non-binary polar decoding, an SCL decoding based on LLrs is proposed for NBPCs, which can be implemented with non-binary kernels of arbitrary size. Moreover, we propose a Perfect Polarization-Based SCL (PPB-SCL) algorithm based on LLrs to reduce decoding complexity by deriving a new update function of path metric for NBPCs and eliminating the path splitting process at perfect polarized (i.e., highly reliable) positions. Simulation results show that the bit error rate of the proposed NBPCs significantly outperforms that of BPCs. In addition, the proposed PPB-SCL decoding obtains about a 40% complexity reduction of SCL decoding for NBPCs.

关键词： Non-binary polar code Log-likelihood ratio Successive-cancellation list Perfect polarization based-SCL Decoding complexity

The transport of chemical components in homogeneous snowpacks on Urumqi Glacier No.1, eastern Tianshan Mountains, Central Asia

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Arid Land 2015年第5期7卷 612-622页

作者： YOU Xiaoni LI Zhongqin ross edwards WANG Lixia key Laboratory of Cryosphere and Environment/Tianshan Glaciological Station/Laboratory of Ice Core and Cold regions Environment Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Tianshui Normal University Imaging and Applied Physics Curtin University of Technology

Chemical records from alpine ice cores provide an invaluable source of paleoclimatic and environ- mental information. Not only the atmospheric chemical composition but also depositional and post-depositional processes are recorded within snow/tim strata. To interpret the environmental and climatic significance of ice core records, we studied the variability of glacier snowpack chemistry by investigating homogeneous snowpacks from October 2003 to September 2006 on Urumqi Glacier No. 1 in eastern Tianshan Mountains, Central Asia. Principle Component Analysis of ionic species in dry and wet seasons revealed the impact of meltwater in redistributing ions in the snowpacks. The 1st, 2nd and 3rd principle components for dry seasons differ significantly, reflecting complex associations between depositional or/and post-depositional processes. The variability trend of ionic concentrations during the wet seasons was found to fit a Gauss Function with significant parameters. The elution factor revealed that more than half of ions are leached out during the wet seasons. Differences with respect to ion snowpack mo- bility were found. Of the ions studied SO42- was the most mobile and Mg2＋ the least mobile. A threshold relationship between air temperatures and the elution process was investigated over the study period. The results indicate that the strong melt/ablation processes and iconic redistribution occur at a threshold air temperature of 0℃. The study found that surface melt on the snowpacks is the main factor causing the alteration of the snowpack chemistry. rainfall also has an impact on the chemistry but plays a less significant role than the surface melt.

关键词： Urumqi Glacier No. 1 snowpack meltwater air temperature precipitation

Allowing Ourselves to reimagine Ecologically responsible Futures for Education research and Practice Globally: Critiquing the Limitations Imposed by Christian Hegemony

在线全文

学校读者我要写书评

暂无评论

ECNU review of Education 2020年第1期3卷 164-168页

作者： Sachi edwards University of Tokyo

The field of comparative and international education,from its inception,has centered on Western epistemologies and ontologies,often with the(inaccurate)assumption(implicit or explicit)that this knowledge,history,and set of values are universally applicable(Silova et al.,2017;Sobe,2017;Takayama,2018).Even critical perspectives from the field that position Western frameworks as hegemonic and colonialist still feature Western knowledge systems as the primary target of critique,and are often forced to adopt those very(Western)systems as the means by which to leverage that critique(i.e.,through Western style academic writing,scholarly journals and conferences,and research and/or other higher education institutions).Indeed,we struggle,as a field,to push beyond the boundaries that Western systems—systems that have been imposed around the world through globalization and Western expansionism—allow us to imagine.

关键词： education Ecological knowledge

The nature and variety of innovation

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Innovation Studies 2018年第2期2卷 65-79页

作者： Monica edwards-Schachter Collaborator at Polytechnic University of Valencia Camino de vera s/n.46022ValenciaSpain

What is our current understanding of innovation and how many types of innovation do we know?Broadly,innovation landscapes are characterized by well-established categories,such as product,process,organizational,and marketing innovation,explained and theorized in terms of their links with technological *** global challenges and changes in the structure of knowledge production,have led to diverse innovations,and recognizing and classifying such innovations is more complex,fragmented,and geographically dispersed than ever *** progressive incorporation of hidden and non-technological innovations,together with the emergence of the fourth industrial revolution,is contributing to change our understanding of innovation and its *** paper provides an overview of the most salient types of innovation in recent decades,enabling both researchers and practitioners to navigate the complex web of innovation definitions and *** studies face the challenge of finding a comprehensive and inclusive definition that captures the significance of innovation,and overcoming the terminological‘Babel'ization and increased fragmentation of the field of innovation research.

关键词： Innovation Nature of innovation Innovation types knowledge society Technological innovation Social innovation