京津冀城市用地形态的双分形特征及其演化

区域城乡一体化的标志之一是城镇体系结构的一体化,这个过程可以从标度的角度进行描述和评价。分形是标度分析的重要方法,地理空间无尺度分布特征的典型参数是分维。论文以京津冀城镇体系为例,利用遥感图像的解译数据和人口普查数据开展分形分析、位序-规模分布分析和异速标度分析,用以解释1995—2013年间京津冀城镇体系演化的过程。结果表明,京津冀城镇体系及其演化的特征有：①京津冀空间结构和位序-规模分布都表现为自仿射双分形结构;②京津冀区域的城市人口-城区面积异速标度退化为假线性关系;③随着城镇体系的演化,自仿射的双分形结构逐步向自相似分形结构演化。由此得出结论：其一,京津冀城镇体系存在结构性的不协调因素。其空间结构和等级结构具有二元化特征,但演化方向却呈现内在结构一体化的显著趋势。其二,大城市用地不够集约。城市边缘区的无序扩张导致土地利用铺张浪费。地方政府和规划专家可以有意识地利用城镇体系演化的这种特征和趋势制定管理措施和优化规划方案。     

中国作物物候对气候变化的响应与适应研究进展

以气候变暖为主要特征的气候变化对作物物候产生了重要的影响,通常气温升高会导致作物生长速度加快,生育期缩短,从而造成作物产量下降,不利于农业发展。同时,作物物候变化可以直接或间接反映气候变化情况,对于气候变化具有重要的指示意义。作物物候的研究对于农业气象灾害的预防、农业生产管理水平的进步以及农业产量提高都极为关键。随着全球地表气温的持续升高,作物物候相关研究也越来越引起科学家的关注。论文结合作物物候的主要研究方法,综述了中国近几十年来小麦、玉米、水稻以及棉花、大豆等主要农作物的生育期变化特征以及主要的驱动因子,得到以下主要结论：①在研究方法上,统计分析方法应用最为普遍,其他几种方法都需要与统计分析方法相结合使用。另外,作物机理模型模拟方法易于操作、可行性强,在物候研究中应用也比较多。遥感反演方法对作物生育期的特征规律要求较高,一般主要关注作物返青期。②整体上,小麦全生育期主要呈缩短趋势,而玉米和水稻全生育期以延长趋势为主。③作物物候变化的驱动因子主要是气候变化和农业管理措施改变,其中,气候变化是主导驱动因子,对作物物候变化起决定作用,而调整农业管理措施,在一定程度上抵消气候变化对作物生育期的不利影响。作物物候对气候变化的响应和适应研究可以为农业生产适应气候变化提供重要的理论依据和对策。     

基于DEM的山地地理可照时数空间分布估算统计模型——以重庆为例

为了建立合理、准确且便于估算和应用的山地地理可照时数空间分布模型,本文以重庆为例,首先利用分布式模型估算了30 a平均年和各月可照时数,并利用基于气象行业标准得到的理论值进行了验证;其次,以栅格单元为统计样本,建立了基于地形尺度的可照时数估算的统计模型。结果表明:(1)基于分布式模型的模拟结果具有较高可信度,除10月外,其他各月和年的相对误差均小于10%,且东北和东南部的相对误差较中西部高。(2)西部方山丘陵区的可照时数高,中部平行岭谷区次之,东北和东南部低。冬季可照时数的空间异质性最大,夏季次之,春秋季接近,均较小。(3)各月和年可照时数与主要地理和地形因子之间的相关关系均表现为极显著性,各月复相关系数在0.7929~0.8277,年复相关系数为0.8522。(4)重庆可照时数估算统计模型在一定程度上简化了分布式模型的计算步骤和计算量,便于其应用,并可为其他地区估算可照时数提供方法参考。     

黑河流域土地利用变化对土壤有机碳和全氮储量的影响——元分析（英文）

Land use and cover change(LUCC) is an important indicator of the human-earth system under climate/environmental change,which also serves as a key impact factor of carbon balance,and a major source/sink of soil carbon cycles.The Heihe River Basin(HRB) is known as a typical ecologically fragile area in the arid/semi-arid regions of northwestern China,which makes it more sensitive to the LUCC.However,its sensitivity varies in a broad range of controlling factors,such as soil layers,LUCCs and calculation methods(e.g.the fixed depth method,FD,and the equivalent mass method,ESM).In this study,we performed a meta-analysis to assess the response of soil organic carbon(SOC) and total nitrogen(TN) storage to the LUCC as well as method bias based on 383 sets of SOC data and 148 sets of TN data from the HRB.We first evaluated the calculation methods and found that based on the FD method,the LUCC caused SOC and TN storage to decrease by 17.39% and 14.27%,respectively;while the losses estimated using the ESM method were 19.31% and 18.52%,respectively.The deviations between two methods were mainly due to the fact that the FD method ignores the heterogeneity of soil bulk density(BD),which may underestimate the results subsequently.We then analyzed the response of SOC and TN storage to various types of the LUCC.In particular,when woodland and grassland were converted into cultivated land or other land types,SOC and TN suffered from heavy losses,while other LUCCs had minor influences.Finally,we showed that increasing the depth of the soil layers would reduce the losses of SOC and TN storage.In summary,we identified a series of controlling factors(e.g.soil layer,the LUCC and calculation method) to evaluate the impact of the LUCC on SOC and TN storage in the HRB,which should be considered in future research.     

黄河下游沿岸农业景观中蜘蛛对非农生境的响应（英文）

Non-crop habitats have been suggested to impact local biodiversity significantly in agricultural landscapes. However, there have been few studies of the effects of less-focused non-crop habitats(orchard, wetland, pit and ditch) on variation of spider abundance. In this study, spiders in 30 woodlands were captured using pitfall traps in Fengqiu County, China, and the effects of local and landscape variations at different scales(50 m, 100 m, 200 m, 350 m and 500 m) on spider abundance were analysed. The most important variation that influenced spider abundance at the 500 m scale was the less-focused non-crop habitat(LNH) cover, and 10% was an appropriate proportion of LNH cover to sustain high level of spider diversity in the investigated landscape. Non-metric multidimensional scaling analyses revealed that there were significant differences in the spider composition among the high, medium and low LNH coverage. Based on indicator species analysis, different spider species were associated with landscapes with different levels of LNH cover. Lycosidae, which accounted for 48% of the total specimens, preferred woodland habitats neighbouring areas with high LNH cover. Compared with woodland habitats, LNH provided more diverse food sources and habitat to sustain more spider species in the study area. Furthermore, linear elements composed of vegetation, such as pits and ditches, may prevent agricultural intensification by enhancing landscape connectivity and providing habitats for different spiders. Our findings may provide a theoretical basis for biodiversity conservation in agro-ecosystems and top-down control of pests.     

环渤海区域及邻区现今地壳构造运动形变特征分析

将环渤海区域划分为5个次级块体,利用整体旋转与线性应变模型分析2009~2014年中国大陆构造环境监测网络的GPS对地观测速度场数据,得到相对于欧亚板块0.5°×0.5°的水平运动速度场和应变场。分析形变速度场和应变场的空间变化发现,环渤海区域整体上呈现0.25×10^-9/a的NW-SE 111.3°的双向趋势性扩张运动,太行块体、山西块体分别呈NW-SE 116.3°、NW-SE 130°的微弱扩张运动,胶辽块体、冀鲁块体和阴山-燕山块体分别存在NW-SE 144.3°、NE-SW 39.5°和NW-SE 155.6°的微弱压缩运动,其中太行块体的扩张运动量级相对于其他次级块体较大。尽管环渤海区域内部各次级块体的形变在空间上存在以上差异,但整体上环渤海区域主压应变轴方向基本为NEE-SWW,主张应变轴方向为NNW-SSE,且主压应变轴走向为NE 47.70°～89.74°,与利用地球物理方法得到的主压应变轴优势方向大体一致,表明环渤海区域现今地壳运动相对稳定。     

函数模型与随机模型双约束的GPS-InSAR数据融合方法建立三维形变场

针对InSAR技术研究地表三维形变时监测信息不足的问题,以GPS监测信息为先验信息,建立附有随机模型约束的地表三维形变模型。考虑到SAR卫星极轨方式运行导致LOS向观测量对南北向形变不敏感的问题,以GPS南北向形变观测值作为强约束,构建三维形变解算的函数约束条件。模拟数据与西安地区实测数据的计算结果表明,基于随机模型与函数模型共同约束的地表三维形变参数最小二乘解的精度优于仅有函数模型约束或仅有随机模型约束及无任何约束的参数解精度。     

On the Study of Wave Propagation and Distribution in the Global Ocean

Based on the simulation with SWAN wave model and data of ERA-Interim from 1979 to 2016, how the waves propagate globally and why swell pools distribute in the eastern ocean were investigated in this study. The simulation results show that waves from North Pacific and North Atlantic mainly propagate southeastward or southward and swells generated in Southern Ocean spread northeastward. The waves from high latitude regions spread along the east coast and encounter in the tropical Pacific and Atlantic to form swell fronts around equator and then turn eastward. As the weak wind field with numerous swell inflows, swell pools are generally located on the eastern side of the ocean basin, where the swell index S are greater than 0.9 calculated using ERA-20 C data for the period of 1981–2010. Another remarkable feature is that swell pools move southward and split into two parts in winter, while they move northward and merge together in summer.     

Transition Periods Between Sea Ice Concentration and Sea Surface Air Temperature in the Arctic Revealed by an Abnormal Running Correlation

This study used the synthetic running correlation coefficient calculation method to calculate the running correlation coefficients between the daily sea ice concentration(SIC) and sea surface air temperature(SSAT) in the Beaufort-Chukchi-East Siberian-Laptev Sea(BCEL Sea), Kara Sea and southern Chukchi Sea, with an aim to understand and measure the seasonally occurring changes in the Arctic climate system. The similarities and differences among these three regions were also discussed. There are periods in spring and autumn when the changes in SIC and SSAT are not synchronized, which is a result of the seasonally occurring variation in the climate system. These periods are referred to as transition periods. Spring transition periods can be found in all three regions, and the start and end dates of these periods have advancing trends. The multiyear average duration of the spring transition periods in the BCEL Sea, Kara Sea and southern Chukchi Sea is 74 days, 57 days and 34 days, respectively. In autumn, transition periods exist in only the southern Chukchi Sea, with a multiyear average duration of only 16 days. Moreover, in the Kara Sea, positive correlation events can be found in some years, which are caused by weather time scale processes.     

Characterization of Turbot(Scophthalmus maximus) Skin and the Extracted Acid-Soluble Collagen

The biochemical composition of the turbot skin was investigated. The moisture level of the skin was found to be 51.4%. Based on dry matter content, there were relatively high protein(82.1%) and lipid(13.1%) concentrations in the turbot skin. Mineral element analysis revealed that the turbot skin had high Ca content(2069.0 mg kg^-1), and the concentrations of toxic heavy metals Hg and Pb were less than 0.005 mg kg^-1, which indicates that the turbot skin is a safe resource for collagen production. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis(SDS-PAGE) analysis showed that acid-soluble collagen(ASC) extracted from the turbot skin was type-I collagen. The imino acid content of the ASC was 241.6 per 1000 amino acids, which suggests a relatively high denaturation temperature. The Fourier transform infrared(FTIR) spectra of ASC reflected a highly stable structure, and the measured denaturation temperature of ASC was 29.5℃, which is higher than those from many temperate fishes. ASC was the most soluble at pH 4.0, and when the pH values were below or above 4.0, the solubility decreased rapidly. The ASC exhibited a relatively high solubility when NaCl concentration was lower than 2%. These results show that turbo skin can be employed as a source for producing collagen with high quality.