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Managed grassland alters soil N dynamics and N2O emissions in temperate steppe

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Journal of Environmental Sciences 2018年第4期30卷 20-30页

作者： Lijun Xu Xingliang Xu Xuejuan tang Xiaoping Xin Liming Ye Guixia Yang huajun tang Shijie Lv Dawei Xu Zhao Zhang Hulunber Grassland Ecosystem Observation and Research Station Institute of Agricultural Resources and Regional Planning of ChineseAcademy of Agricultural Sciences Beijing 100081 China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100081 China Department of Geology (WE13) Ghent University 9000 Gent Belgium Science College of Inner Mongolia Agricultural University Hohhot Inner Mongolia 010018 China

Reclamation of degraded grasslands as managed grasslands has been increasingly accelerated in recent years in China. Land use change affects soil nitrogen（N） dynamics and nitrous oxide（N2O） emissions. However, it remains unclear how large-scale grassland reclamation will impact the grassland ecosystem as a whole. Here, we investigated the effects of the conversion from native to managed grasslands on soil N dynamics and N2O emissions by field experiments in Hulunber in northern China. Soil（0-10 cm）, nitrate（NO3-）,ammonium（NH4＋）, and microbial N were measured in plots in a temperate steppe（Leymus chinensis grassland） and two managed grasslands（Medicago sativa and Bromus inermis grasslands） in 2011 and 2012. The results showed conversion of L. chinensis grassland to M.sativa or B. inermis grasslands decreased concentrations of NO3--N, but did not change NH4-N . Soil microbial N was slightly decreased by the conversion of L. chinensis grassland to M.sativa, but increased by the conversion to B. inermis. The conversion of L. chinensis grassland to M. sativa（i.e., a legume grass） increased N2O emissions by 26.2%, while the conversion to the B. inermis（i.e., a non-legume grass） reduced N2O emissions by 33.1%. The conversion from native to managed grasslands caused large created variations in soil NO3-＋-N and NH4-N concentrations. Net N mineralization rates did not change significantly in growing season or vegetation type, but to net nitrification rate. These results provide evidence on how reclamation may impact the grassland ecosystem in terms of N dynamics and N2O emissions.

关键词： Temperate steppe Managed grassland Land use Nitrogen mobility N2O emissions

MULTI-FACILITY ORDERED MEDIAN PROBLEMS IN DIRECTED NETWORKS

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Journal of Systems Science & Complexity 2011年第1期24卷 61-67页

作者： huajun tang T. C. Edwin CHENG C. T. NG Faculty of Management and Administration Macao University of Science and Technology Macao China Department of Logistics and Maritime Studies The Hong Kong Polytechnic University Hong Kong China

这份报纸使用一个有限统治集合(FDS ) 调查多设备在一个强烈连接的指导网络的订的中部的问题(OMP ) 。作者首先证明多设备 OMP 在节点集合有 FDS，它概括 Kalcsics 提供的 FDS 结果不仅，等。(2002 ) ，而且从单个设备的案例扩大 FDS ... 详细信息

这份报纸使用一个有限统治集合(FDS ) 调查多设备在一个强烈连接的指导网络的订的中部的问题(OMP ) 。作者首先证明多设备 OMP 在节点集合有 FDS，它概括 Kalcsics 提供的 FDS 结果不仅，等。(2002 ) ，而且从单个设备的案例扩大 FDS 结果到多重案例，充满重要差距。基于这 FDS 结果，然后，作者开发一个准确算法解决这个问题。如果设备的数字大，发现最佳的答案不管多么不是实际的，因为在指导网络的多设备 OMP 是 NP 难的。因此，我们在场为在指导网络的 p 中部的问题的一个经常近似的算法。最后，我们为未来研究提出一个开的问题。

关键词：有向网络设施逼近算法 FDS 公开问题 OMP 支配集中位数

Photostable lysosomal imaging of living cell with hyperspectral stimulated Raman scattering microscopy using a probe based on bisarylbutadiyne

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Chinese Chemical Letters 2019年第7期30卷 1393-1396页

作者： Cong Ding Yage Chen Haozheng Li Bingyao Wang Qi Wei huajun tang Shaokang Jia Zhiyong He Ping Wang Xiang Zhou College of Chemistry and Molecular Sciences Key Laboratory of Biomedical Polymers of the Ministry of Education WuhanUniversity Wuhan 430072 China Britton Chance Center for Biomedical Photonics Wuhan National Laboratory for Optoelectronics Huazhong University of Science and Technology Wuhan 430074 China MoE Key Laboratory for Biomedical Photonics Collaborative Innovation Center for Biomedical Engineering School of Engineering Sciences Huazhong University of Science and Technology Wuhan 430074 China

We designed a lysosome-selective Raman probe by conjugating bisphenylbutadiyne with morpholine, a well-known lysosome targeting moiety. This probe, named Lyso-BADY, has a Raman peak 28 times more intense than that of 5-ethynyl-2'-deoxyuridine. Lysosome in living cells was successfully visualized by hyperspectral stimulated Raman scattering (SRS) microscopy with this extracellular probe. Further study showed that the Raman signal of Lyso-BADY remained steady and strong even after a prolonged irradiation time. The photo-stability feature of Lyso-BADY rendered molecules of the similar structure as potentially versatile probe for continuous imaging in the future.

关键词： Raman probe SRS Cell imaging Photo-stability feature

A NOTE ON THE NESTEDNESS PROPERTY FOR ORDERED MEDIAN PROBLEMS IN TREE NETWORKS

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Journal of Systems Science & Complexity 2013年第3期26卷 335-340页

作者： tang huajun Faculty of Management and Administration Macao University of Science and Technology

The nestedness property has become an increasingly important means for devising efficient algorithms for network location problems.There have been attempts to explore the nestedness property of network location problems with some special cases of the convex ordered median objectives.However,there is little research on the nestedness property for those problems with the concave ordered median objectives.This paper constructs a tree network T and shows that the nestedness property cannot hold for the concave ordered median problem,which fills a gap in the research on the nestedness property.Finally,the authors pose an open problem on identifying the nestedness property for the continuous strategic ordered median problem.

关键词：网络问题属性表中位数嵌套有序注记树型位置

泸州市居民对中西医结合现场急救认知现状与学习意愿的调查研究

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现代医药卫生 2024年第6期40卷 989-993页

作者：吴悠阳谢明江何芮先陈艺鑫汤华军西南医科大学中西医结合学院四川泸州646000 西南医科大学药学院四川泸州646000 西南医科大学基础医学院人体解剖学教研室四川泸州646000

目的了解泸州市居民对中西医结合现场急救的认知现状、民众对中西医结合进行现场急救的态度及对学习急救知识的意愿,探讨提高全民现场急救能力的方法和途径。方法自行设计调查问卷,以网络推送及线下调查等方式,对居民的基本信息、居民... 详细信息

目的了解泸州市居民对中西医结合现场急救的认知现状、民众对中西医结合进行现场急救的态度及对学习急救知识的意愿,探讨提高全民现场急救能力的方法和途径。方法自行设计调查问卷,以网络推送及线下调查等方式,对居民的基本信息、居民对急救知识的了解程度、对中西医结合急救的接受程度、突发情况的急救能力、接受急救知识的态度、对急救知识偏好及获取途径等进行一系列调查,对调查收集的数据整理并进行统计学分析。结果回收有效问卷1028份,25.8%的居民对现场急救知识了解较少,31.4%的居民对中医方面的现场急救知识了解较少,45.9%的居民未主动获取过急救知识,居民对中暑患者及心脏病患者的急救知识正确率较低(35.9%、57.6%),88.2%的居民认为中西医结合进行现场急救值得研究,62.5%的居民愿意每天花费10 min学习急救知识,居民更愿意学习户外突发状况类急救知识(78.9%)及居家突发状况类急救知识(81.4%),77.4%的居民愿意以网络推文、小视频等方式学习急救知识。结论泸州市居民对急救知识的了解情况不容乐观,但态度相对积极,有关部门应出台更多的奖励制度及法律保障,以提高居民积极性,同时应加大对中西医结合现场急救研究的投入,并以多种形式宣传、培训,将其融入居民生活中。

关键词：现场急救认知学习意愿问卷调查中西医结合居民泸州

AN AGENT-BASED POPULATION MODEL FOR CHINA

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AN AGENT-BASED POPULATION MODEL FOR CHINA

Time-Series Modeling and Prediction of Global Monthly Absolute Temperature for Environmental Decision Making

Computer and Computing Technologies in Agriculture——First IFIP TC 12 International Conference(CCTA2007) Volume I

作者： Zhongxin Chen Einar Holm huajun tang Kalle Mkil Wenjuan Li Shenghe Liu Key Laboratory of Resource Remote Sensing and Digital Agriculture Ministry of Agriculture Institute of Agriculture Resources®ional Planning Chinese Academy of Agricultural Sciences Kiruna Spatial Modelling Centre Umea University Institute of Geographical Science&Natural Resources Research

Human is a crucial factor responsible for local and large scale environmental change and is a key factor in rural management.Accurate simulating and predicting population change and its spatial distribution is of great interests to environmental scientists as well as social scientists.In this paper,we introduced the development of a spatial-explicit agent-based population model for China based on a prototype from SVERIGE model.The model was used to predict the population in China.The validation result shows that agent-based model performances well in population prediction in China.

关键词： Agent-Based Model SVERIGE Population Prediction China

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Advances in Atmospheric Sciences 2013年第2期30卷 382-396页

作者： YE Liming YANG Guixia Eric VAN RANST tang huajun Key Laboratory of Agri-Informatics Ministry of Agriculture/Institute ofAgricultural Resources and Regional PlanningChinese Academy of Agricultural Sciences Beijing 100081 Department of Geology and Soil Science (WE13) Ghent University Krijgslaan 281 9000 Gent Belgium Chinese Academy of Agricultural Sciences Beijing 100081

A generalized, structural, time series modeling framework was developed to analyze the monthly records of absolute surface temperature, one of the most important environmental parameters, using a deterministicstochastic combined （DSC） approach. Although the development of the framework was based on the characterization of the variation patterns of a global dataset, the methodology could be applied to any monthly absolute temperature record. Deterministic processes were used to characterize the variation patterns of the global trend and the cyclic oscillations of the temperature signal, involving polynomial functions and the Fourier method, respectively, while stochastic processes were employed to account for any remaining patterns in the temperature signal, involving seasonal autoregressive integrated moving average （SARIMA） models. A prediction of the monthly global surface temperature during the second decade of the 21st century using the DSC model shows that the global temperature will likely continue to rise at twice the average rate of the past 150 years. The evaluation of prediction accuracy shows that DSC models perform systematically well against selected models of other authors, suggesting that DSC models, when coupled with other ecoenvironmental models, can be used as a supplemental tool for short-term （10-year） environmental planning and decision making.

关键词： time series analysis statistical model polynomial trend Fourier method ARIMA climatechange

A comparative analysis of five global cropland datasets in China

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Science China Earth Sciences 2016年第12期59卷 2307-2317页

作者： LU Miao WU WenBin ZHANG Li LIAO AnPing PENG Shu tang huajun Key Laboratory of Agri-informatics Ministry of Agriculture/Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural Sciences National Geomatics Centre of China

Accurate information of cropland area and spatial location is critical for studies of national food security, global environmental change, terrestrial ecosystem geophysics and the geochemical cycle. In this paper, we compared five global cropland datasets in circa 2010 of China from in terms of cropland area and spatial location, including Global Land30, FROM-GLC, Glob Cover, MODIS Collection 5, and MODIS Cropland. The results showed that the accuracies of cropland area and spatial location of Globe Land30 were higher than the other four products. The cropland areas of the five products varied in most of the provinces. Compared with the statistical data, the best goodness of fit was obtained using Globe Land30, followed by MODIS Collection 5 and FROM-GLC, with MODIS Cropland and Glob Cover having the poorer accuracies. Regarding the spatial location of cropland, Globe Land30 achieved the best accuracy, followed by FROM-GLC and MODIS Collection 5, with Glob Cover and MODIS Cropland having the poorer accuracies. In addition, the spatial agreement of the five datasets was reduced from agricultural production area to pastoral area and significantly affected by elevation and slope factors. Although the spatial resolution of MODIS Collection 5 was the lowest, accuracies of the cropland area and spatial location were better than those of Glob Cover and MODIS Cropland. Therefore, high spatial resolution remote sensing images can help to improve the accuracy of the dataset during land cover mapping, while it is also important to select a suitable classification method. Furthermore, in northwestern and southeastern China, spectral mixing pixels are universal because of the complicated landscape and fragmentized topography and result in uncertainty and poor consistency when using the five products. Therefore, these regions require additional attention in future cropland mapping studies.

关键词： Land cover Cropland area Spatial location Accuracy Spatial agreement

Change analysis of rice area and production in China during the past three decades

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Journal of Geographical Sciences 2013年第6期23卷 1005-1018页

作者： LIU Zhenhuan LI Zhengguo tang Pengqin LI Zhipeng WU Wenbin YANG Peng YOU Liangzhi tang huajun Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences / Key Laboratory of Agri-informatics Ministry ofAgriculture Beijing 100081 China Environment and Production Technology Division International Food Policy Research Institute 2033KStreet NW Washington DC 20006 USA

Rice＇s spatial-temporal distributions, which are critical for agricultural, environ- mental and food security research, are affected by natural conditions as well as socio-eco- nomic developments. Based on multi-source data, an effective model named the Spatial Production Allocation Model （SPAM） which integrates arable land distribution, administrative unit statistics of crop data, agricultural irrigation data and crop suitability data, was used to get a series of spatial distributions of rice area and production with 10-km pixels at a national scale -it was applied from the early 1980s onwards and used to analyze the pattern of spatial and temporal changes. The results show that significant changes occurred in rice in China during 1980-2010. Overall, more than 50% of the rice area decreased, while nearly 70% of rice production increased in the change region during 1980-2010. Spatially, most of the increased area and production were in Northeast China, especially, in Jilin and Heilongjiang; most of the decreased area and production were located in Southeast China, especially, in regions of rapidly urbanization in Guangdong, Fujian and Zhejiang. Thus, the centroid of rice area was moved northeast approximately 230 km since 1980, and rice production about 320 km, which means rice production moved northeastward faster than rice area because of the significant rice yield increase in Northeast China. The results also show that rice area change had a decisive impact on rice production change. About 54.5% of the increase in rice pro- duction is due to the expansion of sown area, while around 83.2% of the decrease in rice production is due to contraction of rice area. This implies that rice production increase may be due to area expansion and other non-area factors, but reduced rice production could largely be attributed to rice area decrease.

关键词： rice distribution spatial production allocation model spatial-temporal changes China