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CLIMATE-CHANGE-INDUCED TEMPORAL VARIATION IN PRECIPITATION INCREASES NITROGEN LOSSES FROM INTENSIVE CROPPING

《农业科学与工程前沿（英文）》 2022年 第9卷 第3期   页码 457-464 doi: 10.15302/J-FASE-2022452

摘要：

● A simple model was used to evaluate how increasing temporal variability in precipitation influences crop yields and nitrogen losses.

关键词： crop yield     fertilizer timing     nitrogen loss     precipitation variability     toy model    

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Effect of land use and land cover change on soil erosion and the spatio-temporal variation in Liupan

Bin QUAN, M. J. M. R?MKENS, Rui LI, Fang WANG, Jie CHEN

《环境科学与工程前沿（英文）》 2011年 第5卷 第4期   页码 564-572 doi: 10.1007/s11783-011-0348-9

摘要： The Liupan Mountains are located in the southern Ningxia Hui Autonomous Region of China, that forms an important divide between landforms and bio-geographic regions. The populated part of the Liupan Mountain Region has suffered tremendous ecological damage over time due to population pressure, excessive demand and inappropriate use of agricultural land resources. To present the relationship between land use/cover change and spatio-temporal variation of soil erosion, data sets of land use between the late 1980s and 2000 were obtained from Landsat Thematic Mapper (TM) imagery, and spatial models were used to characterize landscape and soil erosion conditions. Also, soil erosion in response to land use and land cover change were quantified and analyzed using data from geographical information systems and remote sensing. Soil erosion by water was the dominant mode of soil loss, while soil erosion by wind was only present on a relatively small area. The degree of soil erosion was classified into five severity classes: slight, light, moderate, severe, and very severe. Soil erosion in the Liupan Mountain Region increased between the late 1980s and 2000, both in terms of acreage and severity. Moderate, severe, and very severe eroded areas accounted for 54.86% of the total land area. The lightly eroded area decreased, while the moderately eroded area increased by 368817 ha (22%) followed by severe erosion with 146552 ha (8.8%), and very severe erosion by 97067.6 ha (5.8%). Soil loss on sloping cropland increased with slope gradients. About 90% of the cropland was located on slopes less than 15°. Most of the increase in soil erosion on cropland was due to conversion of steep slopes to cropland and degradation of grassland and increased activities. Soil erosion was severe on grassland with a moderate or low grass cover and on dry land. Human activities, cultivation on steep slopes, and overgrazing of pastures were the main reasons for the increase in erosion severity.

关键词： land use/land cover change     soil erosion     geographical information system     remote sensing     Liupan Mountain Region    

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Temporal changes in the characteristics of algae in Dianchi Lake, Yunnan Province, China

Ruixia SHEN,Chunyan TIAN,Zhidan LIU,Yuanhui ZHANG,Baoming LI,Haifeng LU,Na DUAN

《农业科学与工程前沿（英文）》 2015年 第2卷 第3期   页码 266-275 doi: 10.15302/J-FASE-2015064

摘要： Algal blooms have become a worldwide environmental concern due to water eutrophication. Dianchi Lake in Yunnan Province, China is suffering from severe eutrophication and is listed in the Three Important Lakes Restoration Act of China. Hydrothermal liquefaction allows a promising and direct conversion of algal biomass into biocrude oil. In this study, algal samples were collected from Dianchi Lake after a separation procedure including dissolved air flotation with polyaluminum chloride and centrifugation during four months, April, June, August and October. The algal biochemical components varied over the period; lipids from 0.7% to 2.1% ash-free dry weight (afdw), protein from 20.9% to 33.4% afdw and ash from 36.6% to 45.2% dry weight. The algae in June had the highest lipid and protein concentrations, leading to a maximum biocrude oil yield of 24.3% afdw. Biodiversity analysis using pyrosequencing revealed different distributions of microbial communities, specifically in April (89.0%), June (63.7%) and August (84.0%), and in April (2.2%), June (12.0%) and August (1.0%). This study demonstrated remarkable temporal changes in the biochemical composition and biodiversity of algae harvested from Dianchi Lake and changes in biocrude oil production potential.

关键词： algal blooms     temporal change     biochemical property     biodiversity     hydrothermal liquefaction    

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Changes in hourly precipitation may explain the sharp reduction of discharge in the middle reach of the Yellow River after 2000

Lin LUO, Zhongjing WANG

《环境科学与工程前沿（英文）》 2013年 第7卷 第5期   页码 756-768 doi: 10.1007/s11783-013-0563-7

摘要： The Hekou-Longmen reach, together with local floods, is the main source area for coarse sedimentations into the Yellow River. When total rainfall slightly increased in the area, discharge dramatically decreased by 40%–70% after the year of 2000, and attracting extensive attention in the context of global climate change. High temporal resolution precipitation (timescales between 1 and 4 h) data from the June to September period from 270 rain gauges over the past three decades was mined in order to help explain the phenomenon. Each rainfall event was classified as light/moderate rain, large rain, heavy rain or rainstorm by the event’s rainfall amount, and further classified as low intensity rain, medium intensity rain and high intensity rain by the event’s rainfall intensity. The Mann-Kendall trend test was applied to detect the presence and significance of monotonic trends, and to find the change points in the mean and variance of the precipitation characteristics series, including the amount, intensity, frequency and duration of each rainfall category. Results show that although the total amount of precipitation has slightly increased, the average rainfall intensity has significantly decreased. The larger change happened in light/moderate rain events and low/medium intensity rain events, and the intensity changes have a great extent occurred around the threshold of Non-Runoff Rainfall regime, which was proposed for the approximate calculation of initial losses. Changes in rainfall distribution between different classes of the Runoff Rainfall regime in the 2000s could lead to 0.9 mm less runoff depth (17.3% of the total reduction) than the 1980–1999 period. The study indicates that changes in hourly precipitation may be responsible for the sharp reduction of discharge.

关键词： precipitation intensity     Mann-Kendall rank statistic     spatial and temporal distribution     climatic change    

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中国耕地质量的提升战略研究

张红旗,谈明洪,孔祥斌,许咏梅,许尔琪,尚二萍

《中国工程科学》 2018年 第20卷 第5期   页码 16-22 doi: 10.15302/J-SSCAE-2018.05.003

摘要：

本文在系统分析我国耕地数量、质量变化态势的基础上，提出以统筹耕地数量、质量、生态三位一体为重点，实现耕地管理的三大战略转变的总体战略思路，以及提高国家耕地保有量、控制建设用地无序增长、提升耕地土壤肥力、防控土壤重金属污染和农膜污染五项重要措施，并建议尽快实施中低产田改造，农村土地综合整治，土壤重金属污染综合修复，水土保持、防沙与盐渍土改良四项重大工程。

关键词： 耕地质量     时空变化     战略     重大工程    

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Realtime prediction of hard rock TBM advance rate using temporal convolutional network (TCN) with tunnel

Zaobao LIU; Yongchen WANG; Long LI; Xingli FANG; Junze WANG

《结构与土木工程前沿（英文）》 2022年 第16卷 第4期   页码 401-413 doi: 10.1007/s11709-022-0823-3

摘要： Real-time dynamic adjustment of the tunnel bore machine (TBM) advance rate according to the rock-machine interaction parameters is of great significance to the adaptability of TBM and its efficiency in construction. This paper proposes a real-time predictive model of TBM advance rate using the temporal convolutional network (TCN), based on TBM construction big data. The prediction model was built using an experimental database, containing 235 data sets, established from the construction data from the Jilin Water-Diversion Tunnel Project in China. The TBM operating parameters, including total thrust, cutterhead rotation, cutterhead torque and penetration rate, are selected as the input parameters of the model. The TCN model is found outperforming the recurrent neural network (RNN) and long short-term memory (LSTM) model in predicting the TBM advance rate with much smaller values of mean absolute percentage error than the latter two. The penetration rate and cutterhead torque of the current moment have significant influence on the TBM advance rate of the next moment. On the contrary, the influence of the cutterhead rotation and total thrust is moderate. The work provides a new concept of real-time prediction of the TBM performance for highly efficient tunnel construction.

关键词： hard rock tunnel     tunnel bore machine advance rate prediction     temporal convolutional networks     soft computing     construction big data    

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Temporal trend of mortality from major cancers in Xuanwei, China

null

《医学前沿（英文）》 2015年 第9卷 第4期   页码 487-495 doi: 10.1007/s11684-015-0413-z

摘要：

Although a number of studies have examined the etiology of lung cancer in Xuanwei County, China, other types of cancer in this county have not been reported systematically. This study aimed to investigate the temporal trend of eight major cancers in Xuanwei County using data from three mortality surveys (1973–1975, 1990–1992, and 2004–2005). The Chinese population in 1990 was used as a standard population to calculate age-standardized mortality rates. Cancers of lung, liver, breast, brain, esophagus, leukemia, rectum, and stomach were identified as the leading cancers in this county in terms of mortality rate. During the three time periods, lung cancer remained as the most common type of cancer. The mortality rates for all other types of cancer were lower than those of the national average, but an increasing trend was observed for all the cancers, particularly from 1990–1992 to 2004–2005. The temporal trend could be partly explained by changes in risk factors, but it also may be due to the improvement in cancer diagnosis and screening. Further epidemiological studies are warranted to systematically examine the underlying reasons for the temporal trend of the major cancers in Xuanwei County.

关键词： cancer     mortality     Xuanwei     temporal trend    

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The temporal changes of the concentration level of typical toxic organics in the river sediments around

Qiang Li, Xiong Xu, Yaoyao Fang, Ruiyang Xiao, Donghong Wang, Wenjue Zhong

《环境科学与工程前沿（英文）》 2018年 第12卷 第6期 doi: 10.1007/s11783-018-1054-7

摘要：

The current situation of typical organics in the sediments around Beijing was unclear.

56 kinds of typical toxic organics were detected in this article.

Historical data was compared with the data in this study.

The change of different organics in the sediments around Beijing was concluded.

关键词： Organic compounds     Endocrine disrupters     Sediments     Concentration     Temporal changes    

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Spatio-temporal variations of water quality in Yuqiao Reservoir Basin, North China

Yuan XU,Ruqin XIE,Yuqiu WANG,Jian SHA

《环境科学与工程前沿（英文）》 2015年 第9卷 第4期   页码 649-664 doi: 10.1007/s11783-014-0702-9

摘要： Fuzzy comprehensive assessment and multivariate statistical techniques including cluster analysis, discriminant analysis, principal component analysis, and factor analysis were applied to analyze the water quality status of Yuqiao Reservoir Basin, North China, for assessing its spatio-temporal variations and identifying potential pollution sources. In this paper, we considered data for 14 water quality parameters collected during 1990–2004 at 7 water quality monitoring sites. The results of fuzzy comprehensive assessment revealed that water quality in Yuqiao Reservoir Basin showed a downtrend from 1990 to 2001 with fluctuation, and a slowly upward trend after 2001. The major water quality belonged to Class III and IV. Besides, hierarchical cluster analysis divided 7 monitoring sites into two groups (Group A and B), and 12 months into three periods (low-flow (LF), normal-flow (NF), and high-flow (HF) period). Temp, pH, SS, T-har, DO, NO -N and TP were identified as significant variables affecting spatial variations, and Temp, pH and NO -N were identified as significant variables affecting temporal variations by discriminant analysis. Factor analysis identified four latent pollution sources for water quality variations: nutrient pollution, organic pollution, inorganic pollution, and natural pollution. Moreover, for Group A regions, pollution inputs mainly came from domestic wastewater and industrial sewage. For Group B regions, it is more likely that water pollution resulted from the combined effects of domestic wastewater, hospital wastewater, agriculture runoff, and fishpond discharge, as well as the incoming water from upstream.

关键词： Fuzzy comprehensive assessment     multivariate statistical analysis     water quality    

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The effect of texture and irrigation on the soil moisture vertical-temporal variability in an urban artificial

Xiaofeng ZHANG,Xu ZHANG,Guanghe LI

《环境科学与工程前沿（英文）》 2015年 第9卷 第2期   页码 269-278 doi: 10.1007/s11783-014-0672-y

摘要： Soil moisture variability in natural landscapes has been widely studied; however, less attention has been paid to its variability in the urban landscapes with respect to the possible influence of texture stratification and irrigation management. Therefore, a case study was carried out in the Beijing Olympic Forest Park to continuously monitor the soil in three typical profiles from 26 April to 11 November 2010. The texture stratification significantly affected the vertical distribution of moisture in the non-irrigated profile where moisture was mostly below field capacity. In the profile where irrigation was sufficient to maintain moisture above field capacity, gravity flow led to increased moisture with depth and thus eliminated the influence of texture. In the non-irrigated sites, the upper layer (above 80 cm) exhibited long-term moisture persistence with the time scale approximating the average rainfall interval. However, a coarse-textured layer weakened the influence of rainfall, and a fine-textured layer weakened the influence of evapotranspiration, both of which resulted in random noise-like moisture series in the deeper layers. At the irrigated site, frequent irrigation neutralized the influence of evapotranspiration in the upper layer (above 60 cm) and overshadowed the influence of rainfall in the deeper layer. As a result, the moisture level in the upper layer also behaved as a random noise-like series; whereas due to deep transpiration, the moisture of the deep layer had a persistence time-scale longer than a month, consistent with characteristic time-scales found for deep transpiration.

关键词： moisture vertical distribution     moisture temporal variation     texture stratification     irrigation     meteorological forcing     urban landscape    

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Spatial and Temporal Distribution of PM

Xiao-hong Chen,Xiang-bo Tang

《工程管理前沿（英文）》 2016年 第3卷 第2期   页码 171-181 doi: 10.15302/J-FEM-2016017

摘要： Utilizing the initial hourly monitoring data of PM concentrations at 23 monitoring sites across the Chang-Zhu-Tan city cluster between January 2013 and February 2014 that released in Real-time Air Quality Reporting System in Hunan Province, this paper draws diagrams and analyzes the change rule of the pollutants concentration over time. In addition, this paper studies the regional distribution of PM seasonal pollution in the vicinity of the monitoring sites using ArcGIS geographic information system with the Kriging interpolation method. On this basis, this paper puts forward some effective control strategies to cope with regional PM pollution combined with the information of industry distribution and development status in the Chang-Zhu-Tan city cluster.

关键词： PM2.5     spatial and temporal distribution     ArcGIS     the chang-Zhu-Tan city cluster    

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Climate change and China’s mega urban regions

Chaolin GU, Sunsheng HAN

《结构与土木工程前沿（英文）》 2010年 第4卷 第4期   页码 418-430 doi: 10.1007/s11709-010-0075-5

摘要： China’s mega urban regions are focal points of economic development and environmental concerns. This paper positions four mega urban regions (i.e., the Yangtze River Delta, the Pearl River Delta, the Bohai Bay Area, and the South-eastern Fujian Province) along China’s coast into the national economy and elaborates their development challenges and planning innovations. Mega urban regions in China are spatial consequences of rapid economic transition. They deserve close scrutiny and demands for innovative planning responses in order to maintain their key role in driving economic growth but limiting their greenhouse gas emission.

关键词： climate change     mega urban region     urban planning    

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Tackling climate change and promoting the energy revolution

Xiangwan DU

《能源前沿（英文）》 2018年 第12卷 第3期   页码 338-343 doi: 10.1007/s11708-018-0535-5

摘要：

Following the Paris Agreement, green and low-carbon development has entered into a new stage. China’s international responsibility to combat climate change is consistent with the inherent sustainable development needs of the country. In this paper, the reasonability of China’s Intended Nationally Determined Contributions (INDC) is examined and the fact that low-carbon development can lead to modernization is demonstrated based on data analysis of energy economics from developed countries. Considering the fact that such an energy revolution forms the basis for China’s low-carbon transition, a roadmap of the China’s energy utilization is presented. Based on research results from the Chinese Academy of Engineering, the three historical stages of China’s energy structure reform are analyzed. Promoting a low-carbon transition through an energy revolution is a long-term and arduous process that requires a genuine transformation of development outlook and patterns. By empirically analyzing situations at home and abroad, a conclusion is made that economic development and a low-carbon transition can be achieved simultaneously; specifically, low-carbon development fosters new points of economic growth and gives rise to different development paths.

关键词： climate change     Paris Agreement     low-carbon transition     energy revolution    

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Large Scale Infrastructure Projects: The Art of Project or Change Management?

Geert Letens,Kurt Verweire,Peter De Prins

《工程管理前沿（英文）》 2016年 第3卷 第3期   页码 197-202 doi: 10.15302/J-FEM-2016033

摘要： Although it is generally understood that change is a fundamental component of managing projects in the construction industry in general and an inevitable challenge for large scale infrastructure project in particular, there has been little to no attention in the literature to understand change in this context from a more holistic perspective. For this purpose, this work looks at change through the eyes of a framework of six batteries of change that seem essential to charge an organization’s capabilities for change. The framework brings together the expertise of four specialists that all have developed their insights over many years of study and practice, and has been validated through an extensive review of the management literature on organization development and change. Reflections on the application of this model in the construction industry and in large scale infrastructure projects demonstrate that energizing organizations to successfully deal with change goes beyond the traditional techniques of managing change from a program or project management perspective. Assessing the six batteries of change in this context can help organizations to develop capabilities for change that build change energy by balancing formal/rational methods with informal/emotional interventions at both a local (department/subproject) and global (business) level.

关键词： large scale project management     organization development and change     batteries of change model    

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Machine learning for detecting mesial temporal lobe epilepsy by structural and functional neuroimaging

Baiwan Zhou, Dongmei An, Fenglai Xiao, Running Niu, Wenbin Li, Wei Li, Xin Tong, Graham J Kemp, Dong Zhou, Qiyong Gong, Du Lei

《医学前沿（英文）》 2020年 第14卷 第5期   页码 630-641 doi: 10.1007/s11684-019-0718-4

摘要： Mesial temporal lobe epilepsy (mTLE), the most common type of focal epilepsy, is associated with functional and structural brain alterations. Machine learning (ML) techniques have been successfully used in discriminating mTLE from healthy controls. However, either functional or structural neuroimaging data are mostly used separately as input, and the opportunity to combine both has not been exploited yet. We conducted a multimodal ML study based on functional and structural neuroimaging measures. We enrolled 37 patients with left mTLE, 37 patients with right mTLE, and 74 healthy controls and trained a support vector ML model to distinguish them by using each measure and the combinations of the measures. For each single measure, we obtained a mean accuracy of 74% and 69% for discriminating left mTLE and right mTLE from controls, respectively, and 64% when all patients were combined. We achieved an accuracy of 78% by integrating functional data and 79% by integrating structural data for left mTLE, and the highest accuracy of 84% was obtained when all functional and structural measures were combined. These findings suggest that combining multimodal measures within a single model is a promising direction for improving the classification of individual patients with mTLE.

关键词： mesial temporal lobe epilepsy     functional magnetic resonance imaging     structural magnetic resonance imaging     machine learning     support vector machine    

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标题 作者 时间 类型 操作

CLIMATE-CHANGE-INDUCED TEMPORAL VARIATION IN PRECIPITATION INCREASES NITROGEN LOSSES FROM INTENSIVE CROPPING

期刊论文

Effect of land use and land cover change on soil erosion and the spatio-temporal variation in Liupan

Bin QUAN, M. J. M. R?MKENS, Rui LI, Fang WANG, Jie CHEN

期刊论文

Temporal changes in the characteristics of algae in Dianchi Lake, Yunnan Province, China

Ruixia SHEN,Chunyan TIAN,Zhidan LIU,Yuanhui ZHANG,Baoming LI,Haifeng LU,Na DUAN

期刊论文

Changes in hourly precipitation may explain the sharp reduction of discharge in the middle reach of the Yellow River after 2000

Lin LUO, Zhongjing WANG

期刊论文

中国耕地质量的提升战略研究

张红旗,谈明洪,孔祥斌,许咏梅,许尔琪,尚二萍

期刊论文

Realtime prediction of hard rock TBM advance rate using temporal convolutional network (TCN) with tunnel

Zaobao LIU; Yongchen WANG; Long LI; Xingli FANG; Junze WANG

期刊论文

Temporal trend of mortality from major cancers in Xuanwei, China

null

期刊论文

The temporal changes of the concentration level of typical toxic organics in the river sediments around

Qiang Li, Xiong Xu, Yaoyao Fang, Ruiyang Xiao, Donghong Wang, Wenjue Zhong

期刊论文

Spatio-temporal variations of water quality in Yuqiao Reservoir Basin, North China

Yuan XU,Ruqin XIE,Yuqiu WANG,Jian SHA

期刊论文

The effect of texture and irrigation on the soil moisture vertical-temporal variability in an urban artificial

Xiaofeng ZHANG,Xu ZHANG,Guanghe LI

期刊论文

Spatial and Temporal Distribution of PM

Xiao-hong Chen,Xiang-bo Tang

期刊论文

Climate change and China’s mega urban regions

Chaolin GU, Sunsheng HAN

期刊论文

Tackling climate change and promoting the energy revolution

Xiangwan DU

期刊论文

Large Scale Infrastructure Projects: The Art of Project or Change Management?

Geert Letens,Kurt Verweire,Peter De Prins

期刊论文

Machine learning for detecting mesial temporal lobe epilepsy by structural and functional neuroimaging

Baiwan Zhou, Dongmei An, Fenglai Xiao, Running Niu, Wenbin Li, Wei Li, Xin Tong, Graham J Kemp, Dong Zhou, Qiyong Gong, Du Lei

期刊论文