Spatiotemporal distribution and decadal change of the monthly temperature predictability limit in China

Based on the nonlinear Lyapunov exponent and nonlinear error growth dynamics, the spatiotemporal distribution and decadal change of the monthly temperature predictability limit （MTPL） in China is quantitatively analyzed. Data used are daily temperature of 518 stations from 1960 to 2011 in China. The results are summarized as follows： （1） The spatial distribution of MTPL varies regionally. MTPL is higher in most areas of Northeast China, southwest Yunnan Province, and the eastern part of Northwest China. MTPL is lower in the middle and lower reaches of the Yangtze River and Huang-huai Basin. （2） The spatial distribution of MTPL varies distinctly with seasons. MTPL is higher in boreal summer than in boreal winter. （3） MTPL has had distinct decadal changes in China, with increase since the 1970s and decrease since 2000. Especially in the northeast part of the country, MTPL has significantly increased since 1986. Decadal change of MTPL in Northwest China, Northeast China and the Huang-huai Basin may have a close relationship with the persistence of temperature anomaly. Since the beginning of the 21st century, MTPL has decreased slowly in most of the country, except for the south. The research provides a scientific foundation to understand the mechanism of monthly temperature anomalies and an important reference for improvement of monthly temperature prediction.     

北太平洋海气系统主要模态的年代际变化

结合北太平洋各种指数、海表温度和高度场,分析了北太平洋海气系统的突变特征及其与时间尺度分量的联系.研究结果表明:各种指数、海表温度和高度场在20世纪60年代、70年代和90年代末期均存在显著突变;海表温度60年代的突变主要分布于北太平洋北部,70年代的突变主要分布于北太平洋北部、中部和东南部,90年代突变则主要分布于北太平洋东南部和西南部;高度场突变主要分布于北太平洋北部、西北部和东南部,且突变范围从高层向低层递减.各种指数中60年代突变1～8a尺度分量的贡献较大,70年代突变是20～30a尺度分量的贡献较大,90年代的突变则是1～8a尺度和20～30a尺度分量作用相当.在3个突变时期中,海表温度和高度场的空间分布及相关性分析验证了这种联系的可能性.     

Fire and flood management of coastal swamp enabled first rice paddy cultivation in east China

The adoption of cereal cultivation was one of the most important cultural processes in history, marking the transition from hunting and gathering by Mesolithic foragers to the food-producing economy of Neolithic farmers. In the Lower Yangtze region of China, a centre of rice domestication, the timing and system of initial rice cultivation remain unclear. Here we report detailed evidence from Kuahuqiao that reveals the precise cultural and environmental context of rice cultivation at this earliest known Neolithic site in eastern China, 7,700 calibrated years before present (cal. yr bp). Pollen, algal, fungal spore and micro-charcoal data from sediments demonstrate that these Neolithic communities selected lowland swamps for their rice cultivation and settlement, using fire to clear alder-dominated wetland scrub and prepare the site for occupation, then to maintain wet grassland vegetation of paddy type. Regular flooding by slightly brackish water was probably controlled by 'bunding' to maintain crop yields. The site's exploitation ceased when it was overwhelmed by marine inundation 7,550 cal. yr bp. Our results establish that rice cultivation began in coastal wetlands of eastern China, an ecosystem vulnerable to coastal change but of high fertility and productivity, attractions maximized for about two centuries by sustained high levels of cultural management of the environment.     

蘑菇室外稻田栽培的研究

蘑菇室外稻田栽培,方法是在水稻收割后,利用冬春季节闲置的稻田进行蘑菇堆料和栽培,这是蘑菇种植的一种新模式.操作为就地收集栽培原料(稻草)、就地进行原料堆制发酵、就地进行做畦栽培.蘑菇的这一新的栽培模式具有投资少,操作方法简便,适宜贫困山区推广应用,对贫困地区农民的脱贫致富将起到重要的推动作用.     

The temporal and spatial distribution of ancient rice in China and its implications

The relics of ancient rice have been regarded as the most important objective evidence of the origina- tion and spread of rice cultivation.Based on the records of 280 rice relics sites and the rice cropping regionalization as well as the distribution map of paddy soils,the current study compiled the temporal and spatial distribution map of ancient rice distribution in China.The map shows that the distribution of ancient rice is spatially extensive and meantime comparatively concentrated,temporarily covering a long and relatively continuous time-span.The rice relics in the Central China double and single rice cropping regions are among the earliest and the most abundant ones,possessing continuity in time sequence.Combined with the discovery of ancient rice and paddy filed relics,soil micromorphology, pollen combination and element geochemistry,it is suggested that Central China was the origin center of rice cultivation in China.Rice had been spread to the rest part of China in three major waves,also to the East Asian part like Korea and Japan.The temporal and spatial distribution of ancient rice reflects the past environmental change,which is also meaningful to the current rice regionalization and plan- ning as well as food security in China.     

10年见证中国空间科学发展进入新时代

 空间科学与空间技术、空间应用构成航天活动的3大领域。回顾了党的十八大以来中国空间科学的重要进展,突出表现为中国科学院空间科学战略性先导科技专项率先建立了中国的专用科学卫星系列,并产出了一批有国际影响的原创科学成果,载人航天与深空探测重大航天工程日益重视科学、技术和应用的融合;分析了以美、欧等航天强国为代表的国际空间科学发展态势,以及中国空间科学发展进入新时代的新历史方位,阐述了空间科学和空间技术与应用的联系和相互促进,指出重大科学目标引领、重大科学成果导向已成为中国空间科学任务的主要原则。面向建设科技强国、航天强国的时代需求,建议中国在有基础有优势的极端宇宙、时空涟漪、日地全景和宜居行星等科学主题上,加快部署系列科学卫星和相关任务,实现“0”到“1”的突破,让发达的空间科学成为高水平科技自立自强的重要抓手,成为航天强国建成的重要标志。     

Response of rice cultivation to fluctuating sea level during the Mid-Holocene

Archaeological analysis of a section of ancient rice fields at Tianluoshan for diatoms, seeds and phytoliths has shown that the highest local sea level in eastern China during the Holocene appeared before 7.0 ka BP. Entering the Mid-Holocene, as seawater regressed, a vast wetland plain appeared in the coastal area, where farmers of the Neolithic Hemudu culture cultivated rice. However, there were still several sea-level fluctuations in the Mid-Holocene, of which the biggest were from 6.4 to 6.3 ka BP and from 4.6 to 2.1 ka BP. In addition, in the period dominated by wetland grass vegetation, 6.3 to 4.6 ka BP, smaller fluctuations appar- ently pushed the coastline back on to the land. Even though the sea-level rises associated with these shoreline transgressions did not have the intensity of the highest sea level period, there still would have been profound impacts on the lives and production activities of people living in the region. Archaeological evidence from ancient rice fields at Tianluoshan shows that larger sea-level rise events pushed seawater onto the land and inundated large areas of rice fields, whereas weaker sea-level rise events resulted in the intrusion of seawater along rivers, causing an increase in soil salinity and a decrease in rice yields. The impact of sea-level rise on rice cultivation caused changes in local diet. In regions where rice production fell, the prevalence of gathering and hunting rose. High sea levels in the early Holocene imply that the origin of rice cultivation in the eastern coastal plain is likely to have been in small nearby mountain basins.     

Distribution, fluxes and decadal changes of nutrients in the Jiulong River Estuary, Southwest Taiwan Strait

The Jiulong River Estuary (JRE) is a typical subtropical macro-tide estuary on the southwest coast of the Taiwan Strait (TWS),which has been greatly impacted by human activities over the past 30 years.To understand nutrient dynamics and fluxes under such a heavy background of anthropogenic perturbation,eight cruises were conducted from April 2008 to April 2011,covering both wet (May to September) and dry (October to April next year) seasons.Nutrient concentrations were very high for the freshwater end-member in the upper reach of the JRE (nitrate (NO 3-N):120-230 mol L-1 ;nitrite (NO 2-N):5-15 mol L-1 ;ammonium (NH 4-N):15-170 mol L-1 ;soluble reactive phosphorus (SRP):1.2-3.5 mol L-1 ;dissolved silicate (DSi):200-340 mol L-1).In dry seasons,concentrations of these nutrients were higher than in wet seasons.Nitrate was the dominant chemical species of dissolved inorganic nitrogen (DIN),with percentages of 67%-96% in wet seasons and 55%-72% in dry seasons.Distributions of NO 3-N and DSi against salinity were nearly constant during all cruises,and showed generally conservative mixing behaviors in the estuary (1相似文献   

建三江垦区水稻高产栽培技术体系研究

建三江垦区是黑龙江省重要的水稻生产基地,地处高寒地区,具有独特的地理气候特点。通过水稻育苗基质、覆膜方式、插秧方式和收获时期的研究,系统地针对建三江地区寒地水稻栽培方式进行了初步探讨,为垦区水稻高产稳产提供依据。     

The climatic suitability for maize cultivation in China

To provide scientific support for planning maize production and designing countermeasures against the effects of climate change on the national maize crop, we analyzed the climatic suitability for cultivating maize across China. These analyses were based on annual climate indices at the Chinese national level; these indices influence the geographical distribution of maize cultivation. The annual climate indices, together with geographical information on the current cultivation sites of maize, the maximum entropy (MaxEnt) model, and the ArcGIS spatial analysis technique were used to analyze and predict maize distribution. The results show that the MaxEnt model can be used to study the climatic suitability for maize cultivation. The eight key climatic factors affecting maize cultivation areas were the frost-free period, annual average temperature, ≥0°C accumulated temperature, ≥10°C accumulated temperature continuous days, ≥10°C accumulated temperature, annual precipitation, warmest month average temperature, and humidity index. We classified climatic zones in terms of their suitability for maize cultivation, based on the existence probability determined using the MaxEnt model. Furthermore, climatic thresholds for a potential maize cultivation zone were determined based on the relationship between the dominant climatic factors and the potential maize cultivation area. The results indicated that the importance and thresholds of main climate controls differ for different maize species and maturities, and their specific climatic suitability should be studied further to identify the best cultivation zones. The MaxEnt model is a useful tool to study climatic suitability for maize cultivation.     

杂交水稻盘育抛秧栽培技术研究

杂交水稻盘育抛秧栽培方式可以提高秧苗素质.大田抛秧在600盘/hm2密度下有较好的生物学性状和最高产量.与传统育秧移栽方式比,产量提高11.35%.“汕优63”的6年平均产量达7 499.25 kg/hm2.     

我国纸浆林树种选择与培育技术研究进展

通过对我国主要纸浆林树种选择和经营管理研究进行系统地总结和回顾,指出适地适树、制浆性能优良、速生性和抗逆性原则在纸浆林树种选择中的必要性,同时综述了经 营纸浆林中科学整地种植、合理密度调控等关键技术措施的研究进展,为纸浆林培育的产业化和工业化提供技术支撑。     

稻草、茭白鞘叶栽培凤尾菇试验研究

传统的凤尾菇栽培料主要成分是木屑,试验采用稻草、茭白鞘叶代替部分木屑栽培凤尾菇,用不同的栽培料配方栽培凤尾菇,共设置7个试验组,以传统培养料配方为对照组(CK)。通过对菌丝生长、子实体生长和产量等指标的考察,分析不同配方对凤尾菇生长的影响。结果表明:试验组中配料以木屑、稻草、茭白鞘叶以合适比例混合为基料时,凤尾菇产量最好,生物学效率最高为32.24%。     

湖南省水稻气象灾害多致灾因子时空特征研究

本文依据水稻气象灾害标准,提取了湖南省1981—2013年双季稻生育期内干旱、洪涝、高温热害和低温冷害,分别探讨致灾因子类型和灾次的时空分布与组合特征.结果表明,湖南省水稻灾害呈现鲜明的多致灾因子特征.单一生育期内,水稻致灾因子类型以2~3种为主,多致灾因子类型组合以干旱高温热害组合比例最高,达到22.87%.水稻致灾因子灾次以4~6次为主,湖南东部地区高于中西部地区.各站多致灾因子灾次的频率分布呈现出明显的泊松分布特征,泊松参数值自西向东逐渐增大,最大值为5.5次.根据多致灾因子类型和灾次的组合特征,最终将湖南省划分为8个多致灾因子区.洞庭湖区及湘中地区为双季稻主产区,水稻种植过程中应注意防范高温热害和干旱灾害.     

东南亚稻米生产时空变化格局分析

 稻米是重要的基础战略物资,其生产关乎国计民生。基于FAO数据库,从区域及国家两个层次定量分析了1961-2014年东南亚稻米生产的时空格局及其演变特征,并借助LMDI模型探讨了稻米增产的贡献因素。研究表明,1961年以来东南亚稻米生产取得了长足发展,占世界稻米生产的近30%且呈上升趋势,东南亚稻米种植向中南半岛的泰国、越南推进;东南亚国家稻米增产受单产水平提升的影响较为显著。     

发展我国现代物流教育的探讨

要实现我国乃至我省物流的现代化，物流人才的培养是关键．在分析我国物流教育现状和发展趋势的基础上，探讨了现阶段我国发展物流教育应注重物流规划、电子商务、信息技术和物流技术等问题，并对物流教育的学科建设提出了建议、     

中国雉科鸟类特有种分布的研究

我国现有雉科鸟类特有种20种,约占我国现有雉科鸟类总种数56种的35．7％．通过对我国雉科鸟类特有种的地理分布情况及有关分布资料的收集、整理,研究了中国雉科鸟类特有种的多样性及其分布．我国雉科鸟类特有种在水平分布上具有不均匀的特点,西南山地亚区、青海藏南亚区、西部山地高原亚区的雉科鸟类特有种丰富度明显高于其他亚区,其雉科鸟类特有种数量分别为9、6和6种,同时还有不少种类是局限性分布和间断性分布,     

中国雉科鸟类特有种分布的研究

我国现有雉科鸟类特有种20种,约占我国现有雉科鸟类总种数56种的35．7％．通过对我国雉科鸟类特有种的地理分布情况及有关分布资料的收集、整理,研究了中国雉科鸟类特有种的多样性及其分布．我国雉科鸟类特有种在水平分布上具有不均匀的特点,西南山地亚区、青海藏南亚区、西部山地高原亚区的雉科鸟类特有种丰富度明显高于其他亚区,其雉科鸟类特有种数量分别为9、6和6种,同时还有不少种类是局限性分布和间断性分布．