Spatial-temporal characteristics and influencing factors of relative humidity in arid region of Northwest China during 1966–2017

Playing an important role in global warming and plant growth,relative humidity(RH)has profound impacts on production and living,and can be used as an integrated indicator for evaluating the wet-dry conditions in the arid and semi-arid area.However,information on the spatial-temporal variation and the influencing factors of RH in these regions is still limited.This study attempted to use daily meteorological data during 1966–2017 to reveal the spatial-temporal characteristics of RH in the arid region of Northwest China through rotated empirical orthogonal function and statistical analysis method,and the path analysis was used to clarify the impact of temperature(T),precipitation(P),actual evapotranspiration(ETa),wind speed(W)and sunshine duration(S)on RH.The results demonstrated that climatic conditions in North Xinjiang(NXJ)was more humid than those in Hexi Corridor(HXC)and South Xinjiang(SXJ).RH had a less significant downtrend in NXJ than that in HXC,but an increasingly rising trend was observed in SXJ during the last five decades,implying that HXC and NXJ were under the process of droughts,while SXJ was getting wetter.There was a turning point for the trend of RH in Xinjiang,which occurred in 2000.Path analysis indicated that RH was negatively correlated to T,ETa,W and S,but it increased with increase of P.S,T and W had the greatest direct effects on RH in HXC,NXJ and SXJ,respectively.ETa was the factor which had the greatest indirect effect on RH in HXC and NXJ,while T was the dominant factor in SXJ.

Analysis on the Temporal and Spatial Characteristics and Causes of Cold Wave in Qinhuangdao

[Objective] The aim was to study the temporal and spatial characteristics and causes of cold wave in Qinhuangdao.[Method] Based on temperature data from five surface meteorological stations in Qinhuangdao from 1970 to 2009 and the latest standards issuing cold wave early warning signal,statistical analysis on the temporal and spatial distribution of cold wave was carried out,and the causes were discussed preliminarily.[Result] From 1970 to 2009,the frequencies of blue and yellow cold wave in Qinhuangdao region were 2 334 and 105 times respectively,and cold wave occurred most frequently in Qinglong County and least frequently in Lulong County,which was related to the effects of underlying surface,latitude and altitude.Cold wave might happen from September to next May,and the earliest occurrence date was September 9,while the latest end date was May 26.In addition,the frequency of cold wave was the highest in January and lowest in May.From 1970 to 2009,blue cold wave occurred most frequently in 1972 and 1979 and least frequently in 1984,while the frequency of yellow cold wave was the highest in 1979 and lowest in 9 years.From decadal variation,cold wave appeared most frequently in the 1970s and least frequently in the 1990s.With the increase of temperature,the frequency of cold wave showed decrease trend,and the beginning date tended to postpone,while its end date advanced,and it showed that the changes of cold wave was mainly caused by climate warming.[Conclusion] The study could provide theoretical guidance for the meteorological disaster prevention and reduction and local agricultural service.

Spatio-temporal characteristics and influencing factors of urban floating population in China from 2011 to 2015

Although China’s urban floating population is mainly concentrated in developed cities,from the central and western cities to the eastern developed cities,but the characteristics of the floating population in different cities are significantly different.This paper systematically investigates the spatiotemporal characteristics and influencing factors of the floating population in different levels of cities.The results show that the regional imbalance to further strengthen,accumulation and dispersion trend has become increasingly obvious,liquidity is positively correlated and city level scale,and urban agglomeration and the core city is still polarization center of floating population.Flow range is closely related to urban hierarchy:the higher the intra-urban grade,the more tend to inter-provincial flow;the lower the city grade,the more tend to intra-urban mobility.Short-term(1-2 years)and long-term(more than 7 years)flow-time coexist.The short-term liquidity increases with the city grade,and the long-term liquidity decreases with the city level.Farmers are still the main body of the floating population.Younger age,lower education level,low-skilled,high gender ratio employees are the most basic demographic characteristics of the floating population,although there are differences between different cities.The main reason for affecting the floating population is seeking jobs and doing business.

Spatial-temporal Evolution Analysis on Land Use Multifunctionality in the China-Vietnam Border Area

Exploring the spatial and temporal evolution characteristics of the border land use multifunctionality(LUMF)provides insights for taking advantage of border land use and optimizing border land use policies.Based on the improved Technique for Order Preference by Similarity to an Ideal Solution(TOPSIS)mode,this study identifies and evaluates the LUMFs in the China-Vietnam border area between 2000 and 2018 from the perspectives of agricultural production,social security,ecological service,landscape recreation,and national security.The results show that:1)The comprehensive land use functions in most counties and cities continued to be improved.2)The comprehensive land use function exhibits remarkable spatial divergence and aggregation characteristics.The high-value area of the agricultural production function and social security function evolves from the east to the west.In addition,the spatial evolution of ecological service function is complicated,without an obvious spatial divergence and aggregation pattern.The landscape recreation function shows different spatial differentiation characteristics in the early and middle stage,and forms a large cluster in the later stage.Finally,the spatial evolution pattern of the national security function is significant.3)Designing differentiated border land policies,improving border land use security,and establishing a long-term mechanism for ecological protection and ecological compensation can aid in optimizing the LUMF level in the border area.

中国碳排放的时空非均衡特征与收敛机制

推动经济社会绿色低碳发展是实现高质量发展的关键环节,探究中国碳排放的时空非均衡特征与收敛机制对于建设人与自然和谐共生的美丽中国具有重要意义与时代价值。基于2001—2019年中国能源消费数据核算碳排放量,综合运用GIS技术、离散型Dagum基尼系数、核密度估计与收敛模型考察中国碳排放量的区域梯度性、地区差异来源、分布动态演进与收敛机制。研究结果表明:中国碳排放量呈现上升趋势,“十五”时期增速较快,“十一五”时期增速放缓,“十二五”时期增速大幅下降,“十三五”时期碳排放量进入低速增长阶段;中国碳排放量的空间非均衡特征明显,东、中、西部的地区间差异是总体差异的主要来源,西部地区碳排放量相对集中而中部地区碳排放量内部差距较大;中水平类型和低水平类型地区碳排放量增长趋势平缓且存在趋同现象,高水平类型地区碳排放量增长幅度较大且扩散趋势明显,人口密度、城镇化水平、产业结构和对外开放程度对碳排放量的作用效果存在时空异质性。

Forecasting Scenario Generation for Multiple Wind Farms Considering Time-series Characteristics and Spatial-temporal Correlation

Scenario forecasting methods have been widely studied in recent years to cope with the wind power uncertainty problem. The main difficulty of this problem is to accurately and comprehensively reflect the time-series characteristics and spatial-temporal correlation of wind power generation. In this paper, the marginal distribution model and the dependence structure are combined to describe these complex characteristics. On this basis, a scenario generation method for multiple wind farms is proposed. For the marginal distribution model, the autoregressive integrated moving average-generalized autoregressive conditional heteroskedasticity-t (ARIMA-GARCH-t) model is proposed to capture the time-series characteristics of wind power generation. For the dependence structure, a time-varying regular vine mixed Copula (TRVMC) model is established to capture the spatial-temporal correlation of multiple wind farms. Based on the data from 8 wind farms in Northwest China, sufficient scenarios are generated. The effectiveness of the scenarios is evaluated in 3 aspects. The results show that the generated scenarios have similar fluctuation characteristics, autocorrelation, and crosscorrelation with the actual wind power sequences.

一种快速挖掘鸡品种特征性SNP标记集合的方法

旨在建立一种快速挖掘鸡品种/品系特征性SNP标记集合的方法,实现通过少量SNP标记将目标品种/品系与其他品种/品系区分的目标。本研究以北京油鸡、京星黄鸡、7个山东地方鸡种、5个云南地方品种、藏鸡和白羽肉鸡专门化品系等19个品种/品系全基因组重测序数据为素材,通过群体分化指数分析后,提取MEAN_FAST≥0.65的SNP标记,进一步通过连锁不平衡分析提取独立SNP来缩减特征性SNP标记集合。随机选择6个品种/品系对该方法进行检验,结果表明,通过一次群体分化指数和连锁不平衡分析后进行位点筛选后,即可分别获得白羽肉鸡品系、京星黄鸡H系和京星黄鸡D2系的114、220和226个特征性SNPs位点,将目标品系与其它共18个代表性品种分开。对于在主成分和聚类分析中聚集在同一个分支的武定鸡和瓢鸡,通过该方法可分别获得204和178个特征性SNPs标记,将之与其它代表性品种分开。综上,通过本方法,可得到目标品种114~226个SNPs标记构成的集合,进一步利用主成分分析即可将目标品种/品系与其它代表性品种进行区分。该方法流程简便,获得的特征性SNP标记相对较少,有利于控制检测成本,可应用于地方品种或商业化品系的“分子身份证”构建,辅助种质资源保护和鉴定工作。

青稞主要性状的差异性与遗传分析

为合理评价110份青稞品种(系)的农艺性状及遗传特性,对参试种质材料的株高、穗长、穗粒数、分蘖数和千粒重进行了调查统计,同时用分布于大麦全基因组的48对SSR标记进行了遗传多样性分析。结果表明,参试材料各农艺性状变异较大,变异系数为2.92%~42.33%,其中株高、穗长、分蘖数、穗粒数和千粒重变化范围分别为53~122cm、2.5~7cm、2~19个、20~90粒和25.46~60.34g。SSR标记共检测到168个等位变异,变化范围为2~6个。110份青稞种质材料分成三大类群。SSR标记的1 128个位点成对组合中,不论是共线性成对组合还是非共线性成对组合,都存在一定的连锁不平衡(linkage disequilibrium,LD)。D′统计概率(P<0.01)支持的LD成对位点438个,占全部位点的38.8%,D′的平均值为0.36,整体LD水平较高。较高水平的LD位点(D′>0.5)主要分布在2H、4H、6H和7H连锁群上。

电站锅炉一次风管道阻力动态调平方法的研究

电站锅炉制粉系统送粉管道中广泛采用冷态纯空气阻力调平方法，在纯空气条件下的阻力调平不能保证锅炉实际运行时各送粉管道间的阻力平衡。通过对煤粉空气混合气流造成送粉管道阻力特性改变的原因分析，提出了针对中间储仓式和直吹式制粉系统阻力调平的方法，给出相应的调整计算模型和计算机计算方法。

基于AFC系统的郑州市轨道交通客流特征分析

基于目前积累的AFC系统数据,分析郑州市线路开通近5年主要客流特征,从线网客运水平、增长趋势、高峰时段不均衡性、客流周期性变化规律、线路所经通道特点等方面论述分析。总结郑州轨道网络客流发展规律,探讨城市轨道交通与城市空间结构的关系以及郑州市轨道交通建设工作,为后期线路设计、建设、运营提供参考。

西部大开发20年人力资本时空演变及影响因素分析

本文采用基于劳动收入的人力资本测算法,对西部大开发以来西部89个城市的人力资本存量进行时空演变分析与影响因素探究,以期为更好的发挥人力资本在新时代推进西部大开发形成新格局中的作用提供参考。研究发现:从时序特征来看,各城市的人力资本存量呈现不同程度的增长趋势,但人力资本分布不平衡现象比较突出,人均人力资本绝对差异增大,相对差异减小;从空间特征来看,人均人力资本在空间变化上呈现出非均衡的分异特征,高值区多分布于西南地区与五大城市群城市;从影响因素来看,经济发展水平、产业结构、营商环境、创新水平、政府教育投入、基础教育质量、医疗卫生水平对西南与西北地区的人均人力资本均具有显著的正向促进作用。

基于不平衡响应的柔性转子系统动态参数识别研究

本文提出了一种利用柔性转子本身不平衡响应作为激励,利用小波变换理论去除嗓声,获取不平衡响应信号,识别油膜特性系数的新方法。实验结果评价表明,识别值具有较好的精度。

港口通过能力系统理论研究——港口交通流的分布与生产状态的分析方法

从分析港口生产不平衡这一特征出发,详细分析了传统意义的不平衡系数存在的问题,进而指出在应用中存在的一系列错误。文中通过大量资料对到、离港的船舶流、车流以及货流的特征与规律,运用统计学原理进行分析,并经过假设检验,提出描述方法,确定正确认识与描述港口交通流的分布特征及港口生产状态特征的方法。

东秦岭松树沟─洋淇沟超基性岩体稀土元素地球化学与岩体成因

松树沟─洋淇沟超基性岩稀土分配模式为轻稀土富集右倾型，与典型阿尔卑斯型超基性岩轻稀土亏损左倾型不同。通过定量稀土元素模拟计算，提出两期不平衡部分熔融模型，认为：（１）松树沟─洋淇沟岩体是地幔原岩经不平衡部分熔融而成的残余体，而富水杂岩及榴闪岩，变质玄武岩则为熔体结晶产物；（２）阿尔卑斯型超基性岩的稀土元素特征取决于地幔原岩稀土元素初始含量和部分熔融过程是否平衡两个因素。松树沟─洋淇沟岩体轻稀土富集特征，主要是不平衡部分熔融的结果。

中国2010-2015年土地利用变化的时空格局与新特征（英文）

Land use/cover change is an important theme on the impacts of human activities on the earth systems and global environmental change. National land-use changes of China during 2010–2015 were acquired by the digital interpretation method using the high-resolution remotely sensed images, e.g. the Landsat 8 OLI, GF-2 remote sensing images. The spatiotemporal characteristics of land-use changes across China during 2010–2015 were revealed by the indexes of dynamic degree model, annual land-use changes ratio etc. The results indicated that the built-up land increased by 24.6×10~3 km^2 while the cropland decreased by 4.9×10~3 km^2, and the total area of woodland and grassland decreased by 16.4×10~3 km^2. The spatial pattern of land-use changes in China during 2010–2015 was concordant with that of the period 2000–2010. Specially, new characteristics of land-use changes emerged in different regions of China in 2010–2015. The built-up land in eastern China expanded continually, and the total area of cropland decreased, both at decreasing rates. The rates of built-up land expansion and cropland shrinkage were accelerated in central China. The rates of built-up land expansion and cropland growth increased in western China, while the decreasing rate of woodland and grassland accelerated. In northeastern China, built-up land expansion slowed continually, and cropland area increased slightly accompanied by the conversions between paddy land and dry land. Besides, woodland and grassland area decreased in northeastern China. The characteristics of land-use changes in eastern China were essentially consistent with the spatial govern and control requirements of the optimal development zones and key development zones according to the Major Function-oriented Zones Planning implemented during the 12 th Five-Year Plan(2011–2015). It was a serious challenge for the central government of China to effectively protect the reasonable layout of land use types dominated with the key ecological function zones and agricultural production zones in centraland western China. Furthermore, the local governments should take effective measures to strengthen the management of territorial development in future.

中国能源碳足迹时空格局演化及脱钩效应

In 2007,China surpassed the USA to become the largest carbon emitter in the world.China has promised a 60%–65%reduction in carbon emissions per unit GDP by 2030,compared to the baseline of 2005.Therefore,it is important to obtain accurate dynamic information on the spatial and temporal patterns of carbon emissions and carbon footprints to support formulating effective national carbon emission reduction policies.This study attempts to build a carbon emission panel data model that simulates carbon emissions in China from 2000–2013 using nighttime lighting data and carbon emission statistics data.By applying the Exploratory Spatial-Temporal Data Analysis(ESTDA)framework,this study conducted an analysis on the spatial patterns and dynamic spatial-temporal interactions of carbon footprints from 2001–2013.The improved Tapio decoupling model was adopted to investigate the levels of coupling or decoupling between the carbon emission load and economic growth in 336 prefecture-level units.The results show that,firstly,high accuracy was achieved by the model in simulating carbon emissions.Secondly,the total carbon footprints and carbon deficits across China increased with average annual growth rates of 4.82%and 5.72%,respectively.The overall carbon footprints and carbon deficits were larger in the North than that in the South.There were extremely significant spatial autocorrelation features in the carbon footprints of prefecture-level units.Thirdly,the relative lengths of the Local Indicators of Spatial Association(LISA)time paths were longer in the North than that in the South,and they increased from the coastal to the central and western regions.Lastly,the overall decoupling index was mainly a weak decoupling type,but the number of cities with this weak decoupling continued to decrease.The unsustainable development trend of China’s economic growth and carbon emission load will continue for some time.